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-rw-r--r--kernel/bpf/Makefile2
-rw-r--r--kernel/bpf/arraymap.c29
-rw-r--r--kernel/bpf/bpf_cgrp_storage.c246
-rw-r--r--kernel/bpf/bpf_inode_storage.c42
-rw-r--r--kernel/bpf/bpf_local_storage.c206
-rw-r--r--kernel/bpf/bpf_lsm.c22
-rw-r--r--kernel/bpf/bpf_task_storage.c161
-rw-r--r--kernel/bpf/btf.c1308
-rw-r--r--kernel/bpf/cgroup_iter.c16
-rw-r--r--kernel/bpf/core.c24
-rw-r--r--kernel/bpf/cpumap.c33
-rw-r--r--kernel/bpf/devmap.c4
-rw-r--r--kernel/bpf/hashtab.c37
-rw-r--r--kernel/bpf/helpers.c439
-rw-r--r--kernel/bpf/local_storage.c2
-rw-r--r--kernel/bpf/map_in_map.c61
-rw-r--r--kernel/bpf/memalloc.c46
-rw-r--r--kernel/bpf/ringbuf.c6
-rw-r--r--kernel/bpf/syscall.c469
-rw-r--r--kernel/bpf/trampoline.c80
-rw-r--r--kernel/bpf/verifier.c2659
-rw-r--r--kernel/cgroup/cgroup.c1
-rw-r--r--kernel/jump_label.c56
-rw-r--r--kernel/module/kallsyms.c2
-rw-r--r--kernel/rcu/tasks.h2
-rw-r--r--kernel/trace/bpf_trace.c113
-rw-r--r--kernel/trace/ftrace.c16
27 files changed, 4459 insertions, 1623 deletions
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index 341c94f208f4..3a12e6b400a2 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -25,7 +25,7 @@ ifeq ($(CONFIG_PERF_EVENTS),y)
obj-$(CONFIG_BPF_SYSCALL) += stackmap.o
endif
ifeq ($(CONFIG_CGROUPS),y)
-obj-$(CONFIG_BPF_SYSCALL) += cgroup_iter.o
+obj-$(CONFIG_BPF_SYSCALL) += cgroup_iter.o bpf_cgrp_storage.o
endif
obj-$(CONFIG_CGROUP_BPF) += cgroup.o
ifeq ($(CONFIG_INET),y)
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 832b2659e96e..484706959556 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -306,14 +306,6 @@ static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key
return 0;
}
-static void check_and_free_fields(struct bpf_array *arr, void *val)
-{
- if (map_value_has_timer(&arr->map))
- bpf_timer_cancel_and_free(val + arr->map.timer_off);
- if (map_value_has_kptrs(&arr->map))
- bpf_map_free_kptrs(&arr->map, val);
-}
-
/* Called from syscall or from eBPF program */
static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
u64 map_flags)
@@ -335,13 +327,13 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
return -EEXIST;
if (unlikely((map_flags & BPF_F_LOCK) &&
- !map_value_has_spin_lock(map)))
+ !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
return -EINVAL;
if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
val = this_cpu_ptr(array->pptrs[index & array->index_mask]);
copy_map_value(map, val, value);
- check_and_free_fields(array, val);
+ bpf_obj_free_fields(array->map.record, val);
} else {
val = array->value +
(u64)array->elem_size * (index & array->index_mask);
@@ -349,7 +341,7 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
copy_map_value_locked(map, val, value, false);
else
copy_map_value(map, val, value);
- check_and_free_fields(array, val);
+ bpf_obj_free_fields(array->map.record, val);
}
return 0;
}
@@ -386,7 +378,7 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
pptr = array->pptrs[index & array->index_mask];
for_each_possible_cpu(cpu) {
copy_map_value_long(map, per_cpu_ptr(pptr, cpu), value + off);
- check_and_free_fields(array, per_cpu_ptr(pptr, cpu));
+ bpf_obj_free_fields(array->map.record, per_cpu_ptr(pptr, cpu));
off += size;
}
rcu_read_unlock();
@@ -409,12 +401,12 @@ static void array_map_free_timers(struct bpf_map *map)
struct bpf_array *array = container_of(map, struct bpf_array, map);
int i;
- /* We don't reset or free kptr on uref dropping to zero. */
- if (!map_value_has_timer(map))
+ /* We don't reset or free fields other than timer on uref dropping to zero. */
+ if (!btf_record_has_field(map->record, BPF_TIMER))
return;
for (i = 0; i < array->map.max_entries; i++)
- bpf_timer_cancel_and_free(array_map_elem_ptr(array, i) + map->timer_off);
+ bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i));
}
/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
@@ -423,22 +415,21 @@ static void array_map_free(struct bpf_map *map)
struct bpf_array *array = container_of(map, struct bpf_array, map);
int i;
- if (map_value_has_kptrs(map)) {
+ if (!IS_ERR_OR_NULL(map->record)) {
if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
for (i = 0; i < array->map.max_entries; i++) {
void __percpu *pptr = array->pptrs[i & array->index_mask];
int cpu;
for_each_possible_cpu(cpu) {
- bpf_map_free_kptrs(map, per_cpu_ptr(pptr, cpu));
+ bpf_obj_free_fields(map->record, per_cpu_ptr(pptr, cpu));
cond_resched();
}
}
} else {
for (i = 0; i < array->map.max_entries; i++)
- bpf_map_free_kptrs(map, array_map_elem_ptr(array, i));
+ bpf_obj_free_fields(map->record, array_map_elem_ptr(array, i));
}
- bpf_map_free_kptr_off_tab(map);
}
if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
diff --git a/kernel/bpf/bpf_cgrp_storage.c b/kernel/bpf/bpf_cgrp_storage.c
new file mode 100644
index 000000000000..6cdf6d9ed91d
--- /dev/null
+++ b/kernel/bpf/bpf_cgrp_storage.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+ */
+
+#include <linux/types.h>
+#include <linux/bpf.h>
+#include <linux/bpf_local_storage.h>
+#include <uapi/linux/btf.h>
+#include <linux/btf_ids.h>
+
+DEFINE_BPF_STORAGE_CACHE(cgroup_cache);
+
+static DEFINE_PER_CPU(int, bpf_cgrp_storage_busy);
+
+static void bpf_cgrp_storage_lock(void)
+{
+ migrate_disable();
+ this_cpu_inc(bpf_cgrp_storage_busy);
+}
+
+static void bpf_cgrp_storage_unlock(void)
+{
+ this_cpu_dec(bpf_cgrp_storage_busy);
+ migrate_enable();
+}
+
+static bool bpf_cgrp_storage_trylock(void)
+{
+ migrate_disable();
+ if (unlikely(this_cpu_inc_return(bpf_cgrp_storage_busy) != 1)) {
+ this_cpu_dec(bpf_cgrp_storage_busy);
+ migrate_enable();
+ return false;
+ }
+ return true;
+}
+
+static struct bpf_local_storage __rcu **cgroup_storage_ptr(void *owner)
+{
+ struct cgroup *cg = owner;
+
+ return &cg->bpf_cgrp_storage;
+}
+
+void bpf_cgrp_storage_free(struct cgroup *cgroup)
+{
+ struct bpf_local_storage *local_storage;
+ bool free_cgroup_storage = false;
+ unsigned long flags;
+
+ rcu_read_lock();
+ local_storage = rcu_dereference(cgroup->bpf_cgrp_storage);
+ if (!local_storage) {
+ rcu_read_unlock();
+ return;
+ }
+
+ bpf_cgrp_storage_lock();
+ raw_spin_lock_irqsave(&local_storage->lock, flags);
+ free_cgroup_storage = bpf_local_storage_unlink_nolock(local_storage);
+ raw_spin_unlock_irqrestore(&local_storage->lock, flags);
+ bpf_cgrp_storage_unlock();
+ rcu_read_unlock();
+
+ if (free_cgroup_storage)
+ kfree_rcu(local_storage, rcu);
+}
+
+static struct bpf_local_storage_data *
+cgroup_storage_lookup(struct cgroup *cgroup, struct bpf_map *map, bool cacheit_lockit)
+{
+ struct bpf_local_storage *cgroup_storage;
+ struct bpf_local_storage_map *smap;
+
+ cgroup_storage = rcu_dereference_check(cgroup->bpf_cgrp_storage,
+ bpf_rcu_lock_held());
+ if (!cgroup_storage)
+ return NULL;
+
+ smap = (struct bpf_local_storage_map *)map;
+ return bpf_local_storage_lookup(cgroup_storage, smap, cacheit_lockit);
+}
+
+static void *bpf_cgrp_storage_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_local_storage_data *sdata;
+ struct cgroup *cgroup;
+ int fd;
+
+ fd = *(int *)key;
+ cgroup = cgroup_get_from_fd(fd);
+ if (IS_ERR(cgroup))
+ return ERR_CAST(cgroup);
+
+ bpf_cgrp_storage_lock();
+ sdata = cgroup_storage_lookup(cgroup, map, true);
+ bpf_cgrp_storage_unlock();
+ cgroup_put(cgroup);
+ return sdata ? sdata->data : NULL;
+}
+
+static int bpf_cgrp_storage_update_elem(struct bpf_map *map, void *key,
+ void *value, u64 map_flags)
+{
+ struct bpf_local_storage_data *sdata;
+ struct cgroup *cgroup;
+ int fd;
+
+ fd = *(int *)key;
+ cgroup = cgroup_get_from_fd(fd);
+ if (IS_ERR(cgroup))
+ return PTR_ERR(cgroup);
+
+ bpf_cgrp_storage_lock();
+ sdata = bpf_local_storage_update(cgroup, (struct bpf_local_storage_map *)map,
+ value, map_flags, GFP_ATOMIC);
+ bpf_cgrp_storage_unlock();
+ cgroup_put(cgroup);
+ return PTR_ERR_OR_ZERO(sdata);
+}
+
+static int cgroup_storage_delete(struct cgroup *cgroup, struct bpf_map *map)
+{
+ struct bpf_local_storage_data *sdata;
+
+ sdata = cgroup_storage_lookup(cgroup, map, false);
+ if (!sdata)
+ return -ENOENT;
+
+ bpf_selem_unlink(SELEM(sdata), true);
+ return 0;
+}
+
+static int bpf_cgrp_storage_delete_elem(struct bpf_map *map, void *key)
+{
+ struct cgroup *cgroup;
+ int err, fd;
+
+ fd = *(int *)key;
+ cgroup = cgroup_get_from_fd(fd);
+ if (IS_ERR(cgroup))
+ return PTR_ERR(cgroup);
+
+ bpf_cgrp_storage_lock();
+ err = cgroup_storage_delete(cgroup, map);
+ bpf_cgrp_storage_unlock();
+ cgroup_put(cgroup);
+ return err;
+}
+
+static int notsupp_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+ return -ENOTSUPP;
+}
+
+static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
+{
+ return bpf_local_storage_map_alloc(attr, &cgroup_cache);
+}
+
+static void cgroup_storage_map_free(struct bpf_map *map)
+{
+ bpf_local_storage_map_free(map, &cgroup_cache, NULL);
+}
+
+/* *gfp_flags* is a hidden argument provided by the verifier */
+BPF_CALL_5(bpf_cgrp_storage_get, struct bpf_map *, map, struct cgroup *, cgroup,
+ void *, value, u64, flags, gfp_t, gfp_flags)
+{
+ struct bpf_local_storage_data *sdata;
+
+ WARN_ON_ONCE(!bpf_rcu_lock_held());
+ if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE))
+ return (unsigned long)NULL;
+
+ if (!cgroup)
+ return (unsigned long)NULL;
+
+ if (!bpf_cgrp_storage_trylock())
+ return (unsigned long)NULL;
+
+ sdata = cgroup_storage_lookup(cgroup, map, true);
+ if (sdata)
+ goto unlock;
+
+ /* only allocate new storage, when the cgroup is refcounted */
+ if (!percpu_ref_is_dying(&cgroup->self.refcnt) &&
+ (flags & BPF_LOCAL_STORAGE_GET_F_CREATE))
+ sdata = bpf_local_storage_update(cgroup, (struct bpf_local_storage_map *)map,
+ value, BPF_NOEXIST, gfp_flags);
+
+unlock:
+ bpf_cgrp_storage_unlock();
+ return IS_ERR_OR_NULL(sdata) ? (unsigned long)NULL : (unsigned long)sdata->data;
+}
+
+BPF_CALL_2(bpf_cgrp_storage_delete, struct bpf_map *, map, struct cgroup *, cgroup)
+{
+ int ret;
+
+ WARN_ON_ONCE(!bpf_rcu_lock_held());
+ if (!cgroup)
+ return -EINVAL;
+
+ if (!bpf_cgrp_storage_trylock())
+ return -EBUSY;
+
+ ret = cgroup_storage_delete(cgroup, map);
+ bpf_cgrp_storage_unlock();
+ return ret;
+}
+
+const struct bpf_map_ops cgrp_storage_map_ops = {
+ .map_meta_equal = bpf_map_meta_equal,
+ .map_alloc_check = bpf_local_storage_map_alloc_check,
+ .map_alloc = cgroup_storage_map_alloc,
+ .map_free = cgroup_storage_map_free,
+ .map_get_next_key = notsupp_get_next_key,
+ .map_lookup_elem = bpf_cgrp_storage_lookup_elem,
+ .map_update_elem = bpf_cgrp_storage_update_elem,
+ .map_delete_elem = bpf_cgrp_storage_delete_elem,
+ .map_check_btf = bpf_local_storage_map_check_btf,
+ .map_btf_id = &bpf_local_storage_map_btf_id[0],
+ .map_owner_storage_ptr = cgroup_storage_ptr,
+};
+
+const struct bpf_func_proto bpf_cgrp_storage_get_proto = {
+ .func = bpf_cgrp_storage_get,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
+ .arg1_type = ARG_CONST_MAP_PTR,
+ .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_btf_id = &bpf_cgroup_btf_id[0],
+ .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
+ .arg4_type = ARG_ANYTHING,
+};
+
+const struct bpf_func_proto bpf_cgrp_storage_delete_proto = {
+ .func = bpf_cgrp_storage_delete,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_CONST_MAP_PTR,
+ .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_btf_id = &bpf_cgroup_btf_id[0],
+};
diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c
index 5f7683b19199..05f4c66c9089 100644
--- a/kernel/bpf/bpf_inode_storage.c
+++ b/kernel/bpf/bpf_inode_storage.c
@@ -56,11 +56,9 @@ static struct bpf_local_storage_data *inode_storage_lookup(struct inode *inode,
void bpf_inode_storage_free(struct inode *inode)
{
- struct bpf_local_storage_elem *selem;
struct bpf_local_storage *local_storage;
bool free_inode_storage = false;
struct bpf_storage_blob *bsb;
- struct hlist_node *n;
bsb = bpf_inode(inode);
if (!bsb)
@@ -74,30 +72,11 @@ void bpf_inode_storage_free(struct inode *inode)
return;
}
- /* Neither the bpf_prog nor the bpf-map's syscall
- * could be modifying the local_storage->list now.
- * Thus, no elem can be added-to or deleted-from the
- * local_storage->list by the bpf_prog or by the bpf-map's syscall.
- *
- * It is racing with bpf_local_storage_map_free() alone
- * when unlinking elem from the local_storage->list and
- * the map's bucket->list.
- */
raw_spin_lock_bh(&local_storage->lock);
- hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) {
- /* Always unlink from map before unlinking from
- * local_storage.
- */
- bpf_selem_unlink_map(selem);
- free_inode_storage = bpf_selem_unlink_storage_nolock(
- local_storage, selem, false, false);
- }
+ free_inode_storage = bpf_local_storage_unlink_nolock(local_storage);
raw_spin_unlock_bh(&local_storage->lock);
rcu_read_unlock();
- /* free_inoode_storage should always be true as long as
- * local_storage->list was non-empty.
- */
if (free_inode_storage)
kfree_rcu(local_storage, rcu);
}
@@ -226,27 +205,14 @@ static int notsupp_get_next_key(struct bpf_map *map, void *key,
static struct bpf_map *inode_storage_map_alloc(union bpf_attr *attr)
{
- struct bpf_local_storage_map *smap;
-
- smap = bpf_local_storage_map_alloc(attr);
- if (IS_ERR(smap))
- return ERR_CAST(smap);
-
- smap->cache_idx = bpf_local_storage_cache_idx_get(&inode_cache);
- return &smap->map;
+ return bpf_local_storage_map_alloc(attr, &inode_cache);
}
static void inode_storage_map_free(struct bpf_map *map)
{
- struct bpf_local_storage_map *smap;
-
- smap = (struct bpf_local_storage_map *)map;
- bpf_local_storage_cache_idx_free(&inode_cache, smap->cache_idx);
- bpf_local_storage_map_free(smap, NULL);
+ bpf_local_storage_map_free(map, &inode_cache, NULL);
}
-BTF_ID_LIST_SINGLE(inode_storage_map_btf_ids, struct,
- bpf_local_storage_map)
const struct bpf_map_ops inode_storage_map_ops = {
.map_meta_equal = bpf_map_meta_equal,
.map_alloc_check = bpf_local_storage_map_alloc_check,
@@ -257,7 +223,7 @@ const struct bpf_map_ops inode_storage_map_ops = {
.map_update_elem = bpf_fd_inode_storage_update_elem,
.map_delete_elem = bpf_fd_inode_storage_delete_elem,
.map_check_btf = bpf_local_storage_map_check_btf,
- .map_btf_id = &inode_storage_map_btf_ids[0],
+ .map_btf_id = &bpf_local_storage_map_btf_id[0],
.map_owner_storage_ptr = inode_storage_ptr,
};
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index f27fa5ba7d72..b39a46e8fb08 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c
@@ -88,8 +88,14 @@ void bpf_local_storage_free_rcu(struct rcu_head *rcu)
{
struct bpf_local_storage *local_storage;
+ /* If RCU Tasks Trace grace period implies RCU grace period, do
+ * kfree(), else do kfree_rcu().
+ */
local_storage = container_of(rcu, struct bpf_local_storage, rcu);
- kfree_rcu(local_storage, rcu);
+ if (rcu_trace_implies_rcu_gp())
+ kfree(local_storage);
+ else
+ kfree_rcu(local_storage, rcu);
}
static void bpf_selem_free_rcu(struct rcu_head *rcu)
@@ -97,16 +103,19 @@ static void bpf_selem_free_rcu(struct rcu_head *rcu)
struct bpf_local_storage_elem *selem;
selem = container_of(rcu, struct bpf_local_storage_elem, rcu);
- kfree_rcu(selem, rcu);
+ if (rcu_trace_implies_rcu_gp())
+ kfree(selem);
+ else
+ kfree_rcu(selem, rcu);
}
/* local_storage->lock must be held and selem->local_storage == local_storage.
* The caller must ensure selem->smap is still valid to be
* dereferenced for its smap->elem_size and smap->cache_idx.
*/
-bool bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_storage,
- struct bpf_local_storage_elem *selem,
- bool uncharge_mem, bool use_trace_rcu)
+static bool bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_storage,
+ struct bpf_local_storage_elem *selem,
+ bool uncharge_mem, bool use_trace_rcu)
{
struct bpf_local_storage_map *smap;
bool free_local_storage;
@@ -233,6 +242,7 @@ void bpf_selem_unlink(struct bpf_local_storage_elem *selem, bool use_trace_rcu)
__bpf_selem_unlink_storage(selem, use_trace_rcu);
}
+/* If cacheit_lockit is false, this lookup function is lockless */
struct bpf_local_storage_data *
bpf_local_storage_lookup(struct bpf_local_storage *local_storage,
struct bpf_local_storage_map *smap,
@@ -372,7 +382,7 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap,
if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST) ||
/* BPF_F_LOCK can only be used in a value with spin_lock */
unlikely((map_flags & BPF_F_LOCK) &&
- !map_value_has_spin_lock(&smap->map)))
+ !btf_record_has_field(smap->map.record, BPF_SPIN_LOCK)))
return ERR_PTR(-EINVAL);
if (gfp_flags == GFP_KERNEL && (map_flags & ~BPF_F_LOCK) != BPF_NOEXIST)
@@ -491,7 +501,7 @@ unlock_err:
return ERR_PTR(err);
}
-u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache)
+static u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache)
{
u64 min_usage = U64_MAX;
u16 i, res = 0;
@@ -515,76 +525,14 @@ u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache)
return res;
}
-void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache,
- u16 idx)
+static void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache,
+ u16 idx)
{
spin_lock(&cache->idx_lock);
cache->idx_usage_counts[idx]--;
spin_unlock(&cache->idx_lock);
}
-void bpf_local_storage_map_free(struct bpf_local_storage_map *smap,
- int __percpu *busy_counter)
-{
- struct bpf_local_storage_elem *selem;
- struct bpf_local_storage_map_bucket *b;
- unsigned int i;
-
- /* Note that this map might be concurrently cloned from
- * bpf_sk_storage_clone. Wait for any existing bpf_sk_storage_clone
- * RCU read section to finish before proceeding. New RCU
- * read sections should be prevented via bpf_map_inc_not_zero.
- */
- synchronize_rcu();
-
- /* bpf prog and the userspace can no longer access this map
- * now. No new selem (of this map) can be added
- * to the owner->storage or to the map bucket's list.
- *
- * The elem of this map can be cleaned up here
- * or when the storage is freed e.g.
- * by bpf_sk_storage_free() during __sk_destruct().
- */
- for (i = 0; i < (1U << smap->bucket_log); i++) {
- b = &smap->buckets[i];
-
- rcu_read_lock();
- /* No one is adding to b->list now */
- while ((selem = hlist_entry_safe(
- rcu_dereference_raw(hlist_first_rcu(&b->list)),
- struct bpf_local_storage_elem, map_node))) {
- if (busy_counter) {
- migrate_disable();
- this_cpu_inc(*busy_counter);
- }
- bpf_selem_unlink(selem, false);
- if (busy_counter) {
- this_cpu_dec(*busy_counter);
- migrate_enable();
- }
- cond_resched_rcu();
- }
- rcu_read_unlock();
- }
-
- /* While freeing the storage we may still need to access the map.
- *
- * e.g. when bpf_sk_storage_free() has unlinked selem from the map
- * which then made the above while((selem = ...)) loop
- * exit immediately.
- *
- * However, while freeing the storage one still needs to access the
- * smap->elem_size to do the uncharging in
- * bpf_selem_unlink_storage_nolock().
- *
- * Hence, wait another rcu grace period for the storage to be freed.
- */
- synchronize_rcu();
-
- kvfree(smap->buckets);
- bpf_map_area_free(smap);
-}
-
int bpf_local_storage_map_alloc_check(union bpf_attr *attr)
{
if (attr->map_flags & ~BPF_LOCAL_STORAGE_CREATE_FLAG_MASK ||
@@ -604,7 +552,7 @@ int bpf_local_storage_map_alloc_check(union bpf_attr *attr)
return 0;
}
-struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
+static struct bpf_local_storage_map *__bpf_local_storage_map_alloc(union bpf_attr *attr)
{
struct bpf_local_storage_map *smap;
unsigned int i;
@@ -654,3 +602,117 @@ int bpf_local_storage_map_check_btf(const struct bpf_map *map,
return 0;
}
+
+bool bpf_local_storage_unlink_nolock(struct bpf_local_storage *local_storage)
+{
+ struct bpf_local_storage_elem *selem;
+ bool free_storage = false;
+ struct hlist_node *n;
+
+ /* Neither the bpf_prog nor the bpf_map's syscall
+ * could be modifying the local_storage->list now.
+ * Thus, no elem can be added to or deleted from the
+ * local_storage->list by the bpf_prog or by the bpf_map's syscall.
+ *
+ * It is racing with bpf_local_storage_map_free() alone
+ * when unlinking elem from the local_storage->list and
+ * the map's bucket->list.
+ */
+ hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) {
+ /* Always unlink from map before unlinking from
+ * local_storage.
+ */
+ bpf_selem_unlink_map(selem);
+ /* If local_storage list has only one element, the
+ * bpf_selem_unlink_storage_nolock() will return true.
+ * Otherwise, it will return false. The current loop iteration
+ * intends to remove all local storage. So the last iteration
+ * of the loop will set the free_cgroup_storage to true.
+ */
+ free_storage = bpf_selem_unlink_storage_nolock(
+ local_storage, selem, false, false);
+ }
+
+ return free_storage;
+}
+
+struct bpf_map *
+bpf_local_storage_map_alloc(union bpf_attr *attr,
+ struct bpf_local_storage_cache *cache)
+{
+ struct bpf_local_storage_map *smap;
+
+ smap = __bpf_local_storage_map_alloc(attr);
+ if (IS_ERR(smap))
+ return ERR_CAST(smap);
+
+ smap->cache_idx = bpf_local_storage_cache_idx_get(cache);
+ return &smap->map;
+}
+
+void bpf_local_storage_map_free(struct bpf_map *map,
+ struct bpf_local_storage_cache *cache,
+ int __percpu *busy_counter)
+{
+ struct bpf_local_storage_map_bucket *b;
+ struct bpf_local_storage_elem *selem;
+ struct bpf_local_storage_map *smap;
+ unsigned int i;
+
+ smap = (struct bpf_local_storage_map *)map;
+ bpf_local_storage_cache_idx_free(cache, smap->cache_idx);
+
+ /* Note that this map might be concurrently cloned from
+ * bpf_sk_storage_clone. Wait for any existing bpf_sk_storage_clone
+ * RCU read section to finish before proceeding. New RCU
+ * read sections should be prevented via bpf_map_inc_not_zero.
+ */
+ synchronize_rcu();
+
+ /* bpf prog and the userspace can no longer access this map
+ * now. No new selem (of this map) can be added
+ * to the owner->storage or to the map bucket's list.
+ *
+ * The elem of this map can be cleaned up here
+ * or when the storage is freed e.g.
+ * by bpf_sk_storage_free() during __sk_destruct().
+ */
+ for (i = 0; i < (1U << smap->bucket_log); i++) {
+ b = &smap->buckets[i];
+
+ rcu_read_lock();
+ /* No one is adding to b->list now */
+ while ((selem = hlist_entry_safe(
+ rcu_dereference_raw(hlist_first_rcu(&b->list)),
+ struct bpf_local_storage_elem, map_node))) {
+ if (busy_counter) {
+ migrate_disable();
+ this_cpu_inc(*busy_counter);
+ }
+ bpf_selem_unlink(selem, false);
+ if (busy_counter) {
+ this_cpu_dec(*busy_counter);
+ migrate_enable();
+ }
+ cond_resched_rcu();
+ }
+ rcu_read_unlock();
+ }
+
+ /* While freeing the storage we may still need to access the map.
+ *
+ * e.g. when bpf_sk_storage_free() has unlinked selem from the map
+ * which then made the above while((selem = ...)) loop
+ * exit immediately.
+ *
+ * However, while freeing the storage one still needs to access the
+ * smap->elem_size to do the uncharging in
+ * bpf_selem_unlink_storage_nolock().
+ *
+ * Hence, wait another rcu grace period for the storage to be freed.
+ */
+ synchronize_rcu();
+
+ kvfree(smap->buckets);
+ bpf_map_area_free(smap);
+}
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index d6c9b3705f24..9ea42a45da47 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -151,6 +151,7 @@ BTF_ID_LIST_SINGLE(bpf_ima_inode_hash_btf_ids, struct, inode)
static const struct bpf_func_proto bpf_ima_inode_hash_proto = {
.func = bpf_ima_inode_hash,
.gpl_only = false,
+ .might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &bpf_ima_inode_hash_btf_ids[0],
@@ -169,6 +170,7 @@ BTF_ID_LIST_SINGLE(bpf_ima_file_hash_btf_ids, struct, file)
static const struct bpf_func_proto bpf_ima_file_hash_proto = {
.func = bpf_ima_file_hash,
.gpl_only = false,
+ .might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &bpf_ima_file_hash_btf_ids[0],
@@ -221,9 +223,9 @@ bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_bprm_opts_set:
return &bpf_bprm_opts_set_proto;
case BPF_FUNC_ima_inode_hash:
- return prog->aux->sleepable ? &bpf_ima_inode_hash_proto : NULL;
+ return &bpf_ima_inode_hash_proto;
case BPF_FUNC_ima_file_hash:
- return prog->aux->sleepable ? &bpf_ima_file_hash_proto : NULL;
+ return &bpf_ima_file_hash_proto;
case BPF_FUNC_get_attach_cookie:
return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto : NULL;
#ifdef CONFIG_NET
@@ -343,11 +345,27 @@ BTF_ID(func, bpf_lsm_task_to_inode)
BTF_ID(func, bpf_lsm_userns_create)
BTF_SET_END(sleepable_lsm_hooks)
+BTF_SET_START(untrusted_lsm_hooks)
+BTF_ID(func, bpf_lsm_bpf_map_free_security)
+BTF_ID(func, bpf_lsm_bpf_prog_alloc_security)
+BTF_ID(func, bpf_lsm_bpf_prog_free_security)
+BTF_ID(func, bpf_lsm_file_alloc_security)
+BTF_ID(func, bpf_lsm_file_free_security)
+BTF_ID(func, bpf_lsm_sk_alloc_security)
+BTF_ID(func, bpf_lsm_sk_free_security)
+BTF_ID(func, bpf_lsm_task_free)
+BTF_SET_END(untrusted_lsm_hooks)
+
bool bpf_lsm_is_sleepable_hook(u32 btf_id)
{
return btf_id_set_contains(&sleepable_lsm_hooks, btf_id);
}
+bool bpf_lsm_is_trusted(const struct bpf_prog *prog)
+{
+ return !btf_id_set_contains(&untrusted_lsm_hooks, prog->aux->attach_btf_id);
+}
+
const struct bpf_prog_ops lsm_prog_ops = {
};
diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c
index 6f290623347e..1e486055a523 100644
--- a/kernel/bpf/bpf_task_storage.c
+++ b/kernel/bpf/bpf_task_storage.c
@@ -71,10 +71,8 @@ task_storage_lookup(struct task_struct *task, struct bpf_map *map,
void bpf_task_storage_free(struct task_struct *task)
{
- struct bpf_local_storage_elem *selem;
struct bpf_local_storage *local_storage;
bool free_task_storage = false;
- struct hlist_node *n;
unsigned long flags;
rcu_read_lock();
@@ -85,32 +83,13 @@ void bpf_task_storage_free(struct task_struct *task)
return;
}
- /* Neither the bpf_prog nor the bpf-map's syscall
- * could be modifying the local_storage->list now.
- * Thus, no elem can be added-to or deleted-from the
- * local_storage->list by the bpf_prog or by the bpf-map's syscall.
- *
- * It is racing with bpf_local_storage_map_free() alone
- * when unlinking elem from the local_storage->list and
- * the map's bucket->list.
- */
bpf_task_storage_lock();
raw_spin_lock_irqsave(&local_storage->lock, flags);
- hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) {
- /* Always unlink from map before unlinking from
- * local_storage.
- */
- bpf_selem_unlink_map(selem);
- free_task_storage = bpf_selem_unlink_storage_nolock(
- local_storage, selem, false, false);
- }
+ free_task_storage = bpf_local_storage_unlink_nolock(local_storage);
raw_spin_unlock_irqrestore(&local_storage->lock, flags);
bpf_task_storage_unlock();
rcu_read_unlock();
- /* free_task_storage should always be true as long as
- * local_storage->list was non-empty.
- */
if (free_task_storage)
kfree_rcu(local_storage, rcu);
}
@@ -184,7 +163,8 @@ out:
return err;
}
-static int task_storage_delete(struct task_struct *task, struct bpf_map *map)
+static int task_storage_delete(struct task_struct *task, struct bpf_map *map,
+ bool nobusy)
{
struct bpf_local_storage_data *sdata;
@@ -192,6 +172,9 @@ static int task_storage_delete(struct task_struct *task, struct bpf_map *map)
if (!sdata)
return -ENOENT;
+ if (!nobusy)
+ return -EBUSY;
+
bpf_selem_unlink(SELEM(sdata), true);
return 0;
@@ -220,63 +203,108 @@ static int bpf_pid_task_storage_delete_elem(struct bpf_map *map, void *key)
}
bpf_task_storage_lock();
- err = task_storage_delete(task, map);
+ err = task_storage_delete(task, map, true);
bpf_task_storage_unlock();
out:
put_pid(pid);
return err;
}
-/* *gfp_flags* is a hidden argument provided by the verifier */
-BPF_CALL_5(bpf_task_storage_get, struct bpf_map *, map, struct task_struct *,
- task, void *, value, u64, flags, gfp_t, gfp_flags)
+/* Called by bpf_task_storage_get*() helpers */
+static void *__bpf_task_storage_get(struct bpf_map *map,
+ struct task_struct *task, void *value,
+ u64 flags, gfp_t gfp_flags, bool nobusy)
{
struct bpf_local_storage_data *sdata;
- WARN_ON_ONCE(!bpf_rcu_lock_held());
- if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE))
- return (unsigned long)NULL;
-
- if (!task)
- return (unsigned long)NULL;
-
- if (!bpf_task_storage_trylock())
- return (unsigned long)NULL;
-
- sdata = task_storage_lookup(task, map, true);
+ sdata = task_storage_lookup(task, map, nobusy);
if (sdata)
- goto unlock;
+ return sdata->data;
/* only allocate new storage, when the task is refcounted */
if (refcount_read(&task->usage) &&
- (flags & BPF_LOCAL_STORAGE_GET_F_CREATE))
+ (flags & BPF_LOCAL_STORAGE_GET_F_CREATE) && nobusy) {
sdata = bpf_local_storage_update(
task, (struct bpf_local_storage_map *)map, value,
BPF_NOEXIST, gfp_flags);
+ return IS_ERR(sdata) ? NULL : sdata->data;
+ }
+
+ return NULL;
+}
-unlock:
+/* *gfp_flags* is a hidden argument provided by the verifier */
+BPF_CALL_5(bpf_task_storage_get_recur, struct bpf_map *, map, struct task_struct *,
+ task, void *, value, u64, flags, gfp_t, gfp_flags)
+{
+ bool nobusy;
+ void *data;
+
+ WARN_ON_ONCE(!bpf_rcu_lock_held());
+ if (flags & ~BPF_LOCAL_STORAGE_GET_F_CREATE || !task)
+ return (unsigned long)NULL;
+
+ nobusy = bpf_task_storage_trylock();
+ data = __bpf_task_storage_get(map, task, value, flags,
+ gfp_flags, nobusy);
+ if (nobusy)
+ bpf_task_storage_unlock();
+ return (unsigned long)data;
+}
+
+/* *gfp_flags* is a hidden argument provided by the verifier */
+BPF_CALL_5(bpf_task_storage_get, struct bpf_map *, map, struct task_struct *,
+ task, void *, value, u64, flags, gfp_t, gfp_flags)
+{
+ void *data;
+
+ WARN_ON_ONCE(!bpf_rcu_lock_held());
+ if (flags & ~BPF_LOCAL_STORAGE_GET_F_CREATE || !task)
+ return (unsigned long)NULL;
+
+ bpf_task_storage_lock();
+ data = __bpf_task_storage_get(map, task, value, flags,
+ gfp_flags, true);
bpf_task_storage_unlock();
- return IS_ERR_OR_NULL(sdata) ? (unsigned long)NULL :
- (unsigned long)sdata->data;
+ return (unsigned long)data;
}
-BPF_CALL_2(bpf_task_storage_delete, struct bpf_map *, map, struct task_struct *,
+BPF_CALL_2(bpf_task_storage_delete_recur, struct bpf_map *, map, struct task_struct *,
task)
{
+ bool nobusy;
int ret;
WARN_ON_ONCE(!bpf_rcu_lock_held());
if (!task)
return -EINVAL;
- if (!bpf_task_storage_trylock())
- return -EBUSY;
+ nobusy = bpf_task_storage_trylock();
+ /* This helper must only be called from places where the lifetime of the task
+ * is guaranteed. Either by being refcounted or by being protected
+ * by an RCU read-side critical section.
+ */
+ ret = task_storage_delete(task, map, nobusy);
+ if (nobusy)
+ bpf_task_storage_unlock();
+ return ret;
+}
+
+BPF_CALL_2(bpf_task_storage_delete, struct bpf_map *, map, struct task_struct *,
+ task)
+{
+ int ret;
+
+ WARN_ON_ONCE(!bpf_rcu_lock_held());
+ if (!task)
+ return -EINVAL;
+ bpf_task_storage_lock();
/* This helper must only be called from places where the lifetime of the task
* is guaranteed. Either by being refcounted or by being protected
* by an RCU read-side critical section.
*/
- ret = task_storage_delete(task, map);
+ ret = task_storage_delete(task, map, true);
bpf_task_storage_unlock();
return ret;
}
@@ -288,26 +316,15 @@ static int notsupp_get_next_key(struct bpf_map *map, void *key, void *next_key)
static struct bpf_map *task_storage_map_alloc(union bpf_attr *attr)
{
- struct bpf_local_storage_map *smap;
-
- smap = bpf_local_storage_map_alloc(attr);
- if (IS_ERR(smap))
- return ERR_CAST(smap);
-
- smap->cache_idx = bpf_local_storage_cache_idx_get(&task_cache);
- return &smap->map;
+ return bpf_local_storage_map_alloc(attr, &task_cache);
}
static void task_storage_map_free(struct bpf_map *map)
{
- struct bpf_local_storage_map *smap;
-
- smap = (struct bpf_local_storage_map *)map;
- bpf_local_storage_cache_idx_free(&task_cache, smap->cache_idx);
- bpf_local_storage_map_free(smap, &bpf_task_storage_busy);
+ bpf_local_storage_map_free(map, &task_cache, &bpf_task_storage_busy);
}
-BTF_ID_LIST_SINGLE(task_storage_map_btf_ids, struct, bpf_local_storage_map)
+BTF_ID_LIST_GLOBAL_SINGLE(bpf_local_storage_map_btf_id, struct, bpf_local_storage_map)
const struct bpf_map_ops task_storage_map_ops = {
.map_meta_equal = bpf_map_meta_equal,
.map_alloc_check = bpf_local_storage_map_alloc_check,
@@ -318,10 +335,21 @@ const struct bpf_map_ops task_storage_map_ops = {
.map_update_elem = bpf_pid_task_storage_update_elem,
.map_delete_elem = bpf_pid_task_storage_delete_elem,
.map_check_btf = bpf_local_storage_map_check_btf,
- .map_btf_id = &task_storage_map_btf_ids[0],
+ .map_btf_id = &bpf_local_storage_map_btf_id[0],
.map_owner_storage_ptr = task_storage_ptr,
};
+const struct bpf_func_proto bpf_task_storage_get_recur_proto = {
+ .func = bpf_task_storage_get_recur,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
+ .arg1_type = ARG_CONST_MAP_PTR,
+ .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
+ .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
+ .arg4_type = ARG_ANYTHING,
+};
+
const struct bpf_func_proto bpf_task_storage_get_proto = {
.func = bpf_task_storage_get,
.gpl_only = false,
@@ -333,6 +361,15 @@ const struct bpf_func_proto bpf_task_storage_get_proto = {
.arg4_type = ARG_ANYTHING,
};
+const struct bpf_func_proto bpf_task_storage_delete_recur_proto = {
+ .func = bpf_task_storage_delete_recur,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_CONST_MAP_PTR,
+ .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
+};
+
const struct bpf_func_proto bpf_task_storage_delete_proto = {
.func = bpf_task_storage_delete,
.gpl_only = false,
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 35c07afac924..f7dd8af06413 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -19,6 +19,7 @@
#include <linux/bpf_verifier.h>
#include <linux/btf.h>
#include <linux/btf_ids.h>
+#include <linux/bpf_lsm.h>
#include <linux/skmsg.h>
#include <linux/perf_event.h>
#include <linux/bsearch.h>
@@ -199,11 +200,13 @@ DEFINE_IDR(btf_idr);
DEFINE_SPINLOCK(btf_idr_lock);
enum btf_kfunc_hook {
+ BTF_KFUNC_HOOK_COMMON,
BTF_KFUNC_HOOK_XDP,
BTF_KFUNC_HOOK_TC,
BTF_KFUNC_HOOK_STRUCT_OPS,
BTF_KFUNC_HOOK_TRACING,
BTF_KFUNC_HOOK_SYSCALL,
+ BTF_KFUNC_HOOK_FMODRET,
BTF_KFUNC_HOOK_MAX,
};
@@ -237,6 +240,7 @@ struct btf {
struct rcu_head rcu;
struct btf_kfunc_set_tab *kfunc_set_tab;
struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab;
+ struct btf_struct_metas *struct_meta_tab;
/* split BTF support */
struct btf *base_btf;
@@ -477,16 +481,6 @@ static bool btf_type_nosize_or_null(const struct btf_type *t)
return !t || btf_type_nosize(t);
}
-static bool __btf_type_is_struct(const struct btf_type *t)
-{
- return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
-}
-
-static bool btf_type_is_array(const struct btf_type *t)
-{
- return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
-}
-
static bool btf_type_is_datasec(const struct btf_type *t)
{
return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
@@ -1642,8 +1636,30 @@ static void btf_free_dtor_kfunc_tab(struct btf *btf)
btf->dtor_kfunc_tab = NULL;
}
+static void btf_struct_metas_free(struct btf_struct_metas *tab)
+{
+ int i;
+
+ if (!tab)
+ return;
+ for (i = 0; i < tab->cnt; i++) {
+ btf_record_free(tab->types[i].record);
+ kfree(tab->types[i].field_offs);
+ }
+ kfree(tab);
+}
+
+static void btf_free_struct_meta_tab(struct btf *btf)
+{
+ struct btf_struct_metas *tab = btf->struct_meta_tab;
+
+ btf_struct_metas_free(tab);
+ btf->struct_meta_tab = NULL;
+}
+
static void btf_free(struct btf *btf)
{
+ btf_free_struct_meta_tab(btf);
btf_free_dtor_kfunc_tab(btf);
btf_free_kfunc_set_tab(btf);
kvfree(btf->types);
@@ -3191,7 +3207,7 @@ static void btf_struct_log(struct btf_verifier_env *env,
btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
}
-enum btf_field_type {
+enum btf_field_info_type {
BTF_FIELD_SPIN_LOCK,
BTF_FIELD_TIMER,
BTF_FIELD_KPTR,
@@ -3203,18 +3219,28 @@ enum {
};
struct btf_field_info {
- u32 type_id;
+ enum btf_field_type type;
u32 off;
- enum bpf_kptr_type type;
+ union {
+ struct {
+ u32 type_id;
+ } kptr;
+ struct {
+ const char *node_name;
+ u32 value_btf_id;
+ } list_head;
+ };
};
static int btf_find_struct(const struct btf *btf, const struct btf_type *t,
- u32 off, int sz, struct btf_field_info *info)
+ u32 off, int sz, enum btf_field_type field_type,
+ struct btf_field_info *info)
{
if (!__btf_type_is_struct(t))
return BTF_FIELD_IGNORE;
if (t->size != sz)
return BTF_FIELD_IGNORE;
+ info->type = field_type;
info->off = off;
return BTF_FIELD_FOUND;
}
@@ -3222,9 +3248,12 @@ static int btf_find_struct(const struct btf *btf, const struct btf_type *t,
static int btf_find_kptr(const struct btf *btf, const struct btf_type *t,
u32 off, int sz, struct btf_field_info *info)
{
- enum bpf_kptr_type type;
+ enum btf_field_type type;
u32 res_id;
+ /* Permit modifiers on the pointer itself */
+ if (btf_type_is_volatile(t))
+ t = btf_type_by_id(btf, t->type);
/* For PTR, sz is always == 8 */
if (!btf_type_is_ptr(t))
return BTF_FIELD_IGNORE;
@@ -3248,28 +3277,135 @@ static int btf_find_kptr(const struct btf *btf, const struct btf_type *t,
if (!__btf_type_is_struct(t))
return -EINVAL;
- info->type_id = res_id;
- info->off = off;
info->type = type;
+ info->off = off;
+ info->kptr.type_id = res_id;
return BTF_FIELD_FOUND;
}
-static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t,
- const char *name, int sz, int align,
- enum btf_field_type field_type,
+static const char *btf_find_decl_tag_value(const struct btf *btf,
+ const struct btf_type *pt,
+ int comp_idx, const char *tag_key)
+{
+ int i;
+
+ for (i = 1; i < btf_nr_types(btf); i++) {
+ const struct btf_type *t = btf_type_by_id(btf, i);
+ int len = strlen(tag_key);
+
+ if (!btf_type_is_decl_tag(t))
+ continue;
+ if (pt != btf_type_by_id(btf, t->type) ||
+ btf_type_decl_tag(t)->component_idx != comp_idx)
+ continue;
+ if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len))
+ continue;
+ return __btf_name_by_offset(btf, t->name_off) + len;
+ }
+ return NULL;
+}
+
+static int btf_find_list_head(const struct btf *btf, const struct btf_type *pt,
+ const struct btf_type *t, int comp_idx,
+ u32 off, int sz, struct btf_field_info *info)
+{
+ const char *value_type;
+ const char *list_node;
+ s32 id;
+
+ if (!__btf_type_is_struct(t))
+ return BTF_FIELD_IGNORE;
+ if (t->size != sz)
+ return BTF_FIELD_IGNORE;
+ value_type = btf_find_decl_tag_value(btf, pt, comp_idx, "contains:");
+ if (!value_type)
+ return -EINVAL;
+ list_node = strstr(value_type, ":");
+ if (!list_node)
+ return -EINVAL;
+ value_type = kstrndup(value_type, list_node - value_type, GFP_KERNEL | __GFP_NOWARN);
+ if (!value_type)
+ return -ENOMEM;
+ id = btf_find_by_name_kind(btf, value_type, BTF_KIND_STRUCT);
+ kfree(value_type);
+ if (id < 0)
+ return id;
+ list_node++;
+ if (str_is_empty(list_node))
+ return -EINVAL;
+ info->type = BPF_LIST_HEAD;
+ info->off = off;
+ info->list_head.value_btf_id = id;
+ info->list_head.node_name = list_node;
+ return BTF_FIELD_FOUND;
+}
+
+static int btf_get_field_type(const char *name, u32 field_mask, u32 *seen_mask,
+ int *align, int *sz)
+{
+ int type = 0;
+
+ if (field_mask & BPF_SPIN_LOCK) {
+ if (!strcmp(name, "bpf_spin_lock")) {
+ if (*seen_mask & BPF_SPIN_LOCK)
+ return -E2BIG;
+ *seen_mask |= BPF_SPIN_LOCK;
+ type = BPF_SPIN_LOCK;
+ goto end;
+ }
+ }
+ if (field_mask & BPF_TIMER) {
+ if (!strcmp(name, "bpf_timer")) {
+ if (*seen_mask & BPF_TIMER)
+ return -E2BIG;
+ *seen_mask |= BPF_TIMER;
+ type = BPF_TIMER;
+ goto end;
+ }
+ }
+ if (field_mask & BPF_LIST_HEAD) {
+ if (!strcmp(name, "bpf_list_head")) {
+ type = BPF_LIST_HEAD;
+ goto end;
+ }
+ }
+ if (field_mask & BPF_LIST_NODE) {
+ if (!strcmp(name, "bpf_list_node")) {
+ type = BPF_LIST_NODE;
+ goto end;
+ }
+ }
+ /* Only return BPF_KPTR when all other types with matchable names fail */
+ if (field_mask & BPF_KPTR) {
+ type = BPF_KPTR_REF;
+ goto end;
+ }
+ return 0;
+end:
+ *sz = btf_field_type_size(type);
+ *align = btf_field_type_align(type);
+ return type;
+}
+
+static int btf_find_struct_field(const struct btf *btf,
+ const struct btf_type *t, u32 field_mask,
struct btf_field_info *info, int info_cnt)
{
+ int ret, idx = 0, align, sz, field_type;
const struct btf_member *member;
struct btf_field_info tmp;
- int ret, idx = 0;
- u32 i, off;
+ u32 i, off, seen_mask = 0;
for_each_member(i, t, member) {
const struct btf_type *member_type = btf_type_by_id(btf,
member->type);
- if (name && strcmp(__btf_name_by_offset(btf, member_type->name_off), name))
+ field_type = btf_get_field_type(__btf_name_by_offset(btf, member_type->name_off),
+ field_mask, &seen_mask, &align, &sz);
+ if (field_type == 0)
continue;
+ if (field_type < 0)
+ return field_type;
off = __btf_member_bit_offset(t, member);
if (off % 8)
@@ -3277,22 +3413,30 @@ static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t
return -EINVAL;
off /= 8;
if (off % align)
- return -EINVAL;
+ continue;
switch (field_type) {
- case BTF_FIELD_SPIN_LOCK:
- case BTF_FIELD_TIMER:
- ret = btf_find_struct(btf, member_type, off, sz,
+ case BPF_SPIN_LOCK:
+ case BPF_TIMER:
+ case BPF_LIST_NODE:
+ ret = btf_find_struct(btf, member_type, off, sz, field_type,
idx < info_cnt ? &info[idx] : &tmp);
if (ret < 0)
return ret;
break;
- case BTF_FIELD_KPTR:
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
ret = btf_find_kptr(btf, member_type, off, sz,
idx < info_cnt ? &info[idx] : &tmp);
if (ret < 0)
return ret;
break;
+ case BPF_LIST_HEAD:
+ ret = btf_find_list_head(btf, t, member_type, i, off, sz,
+ idx < info_cnt ? &info[idx] : &tmp);
+ if (ret < 0)
+ return ret;
+ break;
default:
return -EFAULT;
}
@@ -3307,42 +3451,53 @@ static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t
}
static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
- const char *name, int sz, int align,
- enum btf_field_type field_type,
- struct btf_field_info *info, int info_cnt)
+ u32 field_mask, struct btf_field_info *info,
+ int info_cnt)
{
+ int ret, idx = 0, align, sz, field_type;
const struct btf_var_secinfo *vsi;
struct btf_field_info tmp;
- int ret, idx = 0;
- u32 i, off;
+ u32 i, off, seen_mask = 0;
for_each_vsi(i, t, vsi) {
const struct btf_type *var = btf_type_by_id(btf, vsi->type);
const struct btf_type *var_type = btf_type_by_id(btf, var->type);
- off = vsi->offset;
-
- if (name && strcmp(__btf_name_by_offset(btf, var_type->name_off), name))
+ field_type = btf_get_field_type(__btf_name_by_offset(btf, var_type->name_off),
+ field_mask, &seen_mask, &align, &sz);
+ if (field_type == 0)
continue;
+ if (field_type < 0)
+ return field_type;
+
+ off = vsi->offset;
if (vsi->size != sz)
continue;
if (off % align)
- return -EINVAL;
+ continue;
switch (field_type) {
- case BTF_FIELD_SPIN_LOCK:
- case BTF_FIELD_TIMER:
- ret = btf_find_struct(btf, var_type, off, sz,
+ case BPF_SPIN_LOCK:
+ case BPF_TIMER:
+ case BPF_LIST_NODE:
+ ret = btf_find_struct(btf, var_type, off, sz, field_type,
idx < info_cnt ? &info[idx] : &tmp);
if (ret < 0)
return ret;
break;
- case BTF_FIELD_KPTR:
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
ret = btf_find_kptr(btf, var_type, off, sz,
idx < info_cnt ? &info[idx] : &tmp);
if (ret < 0)
return ret;
break;
+ case BPF_LIST_HEAD:
+ ret = btf_find_list_head(btf, var, var_type, -1, off, sz,
+ idx < info_cnt ? &info[idx] : &tmp);
+ if (ret < 0)
+ return ret;
+ break;
default:
return -EFAULT;
}
@@ -3357,169 +3512,327 @@ static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
}
static int btf_find_field(const struct btf *btf, const struct btf_type *t,
- enum btf_field_type field_type,
- struct btf_field_info *info, int info_cnt)
+ u32 field_mask, struct btf_field_info *info,
+ int info_cnt)
{
- const char *name;
- int sz, align;
-
- switch (field_type) {
- case BTF_FIELD_SPIN_LOCK:
- name = "bpf_spin_lock";
- sz = sizeof(struct bpf_spin_lock);
- align = __alignof__(struct bpf_spin_lock);
- break;
- case BTF_FIELD_TIMER:
- name = "bpf_timer";
- sz = sizeof(struct bpf_timer);
- align = __alignof__(struct bpf_timer);
- break;
- case BTF_FIELD_KPTR:
- name = NULL;
- sz = sizeof(u64);
- align = 8;
- break;
- default:
- return -EFAULT;
- }
-
if (__btf_type_is_struct(t))
- return btf_find_struct_field(btf, t, name, sz, align, field_type, info, info_cnt);
+ return btf_find_struct_field(btf, t, field_mask, info, info_cnt);
else if (btf_type_is_datasec(t))
- return btf_find_datasec_var(btf, t, name, sz, align, field_type, info, info_cnt);
+ return btf_find_datasec_var(btf, t, field_mask, info, info_cnt);
return -EINVAL;
}
-/* find 'struct bpf_spin_lock' in map value.
- * return >= 0 offset if found
- * and < 0 in case of error
- */
-int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t)
+static int btf_parse_kptr(const struct btf *btf, struct btf_field *field,
+ struct btf_field_info *info)
{
- struct btf_field_info info;
+ struct module *mod = NULL;
+ const struct btf_type *t;
+ struct btf *kernel_btf;
int ret;
+ s32 id;
- ret = btf_find_field(btf, t, BTF_FIELD_SPIN_LOCK, &info, 1);
- if (ret < 0)
- return ret;
- if (!ret)
- return -ENOENT;
- return info.off;
+ /* Find type in map BTF, and use it to look up the matching type
+ * in vmlinux or module BTFs, by name and kind.
+ */
+ t = btf_type_by_id(btf, info->kptr.type_id);
+ id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info),
+ &kernel_btf);
+ if (id < 0)
+ return id;
+
+ /* Find and stash the function pointer for the destruction function that
+ * needs to be eventually invoked from the map free path.
+ */
+ if (info->type == BPF_KPTR_REF) {
+ const struct btf_type *dtor_func;
+ const char *dtor_func_name;
+ unsigned long addr;
+ s32 dtor_btf_id;
+
+ /* This call also serves as a whitelist of allowed objects that
+ * can be used as a referenced pointer and be stored in a map at
+ * the same time.
+ */
+ dtor_btf_id = btf_find_dtor_kfunc(kernel_btf, id);
+ if (dtor_btf_id < 0) {
+ ret = dtor_btf_id;
+ goto end_btf;
+ }
+
+ dtor_func = btf_type_by_id(kernel_btf, dtor_btf_id);
+ if (!dtor_func) {
+ ret = -ENOENT;
+ goto end_btf;
+ }
+
+ if (btf_is_module(kernel_btf)) {
+ mod = btf_try_get_module(kernel_btf);
+ if (!mod) {
+ ret = -ENXIO;
+ goto end_btf;
+ }
+ }
+
+ /* We already verified dtor_func to be btf_type_is_func
+ * in register_btf_id_dtor_kfuncs.
+ */
+ dtor_func_name = __btf_name_by_offset(kernel_btf, dtor_func->name_off);
+ addr = kallsyms_lookup_name(dtor_func_name);
+ if (!addr) {
+ ret = -EINVAL;
+ goto end_mod;
+ }
+ field->kptr.dtor = (void *)addr;
+ }
+
+ field->kptr.btf_id = id;
+ field->kptr.btf = kernel_btf;
+ field->kptr.module = mod;
+ return 0;
+end_mod:
+ module_put(mod);
+end_btf:
+ btf_put(kernel_btf);
+ return ret;
}
-int btf_find_timer(const struct btf *btf, const struct btf_type *t)
+static int btf_parse_list_head(const struct btf *btf, struct btf_field *field,
+ struct btf_field_info *info)
{
- struct btf_field_info info;
- int ret;
+ const struct btf_type *t, *n = NULL;
+ const struct btf_member *member;
+ u32 offset;
+ int i;
- ret = btf_find_field(btf, t, BTF_FIELD_TIMER, &info, 1);
- if (ret < 0)
- return ret;
- if (!ret)
+ t = btf_type_by_id(btf, info->list_head.value_btf_id);
+ /* We've already checked that value_btf_id is a struct type. We
+ * just need to figure out the offset of the list_node, and
+ * verify its type.
+ */
+ for_each_member(i, t, member) {
+ if (strcmp(info->list_head.node_name, __btf_name_by_offset(btf, member->name_off)))
+ continue;
+ /* Invalid BTF, two members with same name */
+ if (n)
+ return -EINVAL;
+ n = btf_type_by_id(btf, member->type);
+ if (!__btf_type_is_struct(n))
+ return -EINVAL;
+ if (strcmp("bpf_list_node", __btf_name_by_offset(btf, n->name_off)))
+ return -EINVAL;
+ offset = __btf_member_bit_offset(n, member);
+ if (offset % 8)
+ return -EINVAL;
+ offset /= 8;
+ if (offset % __alignof__(struct bpf_list_node))
+ return -EINVAL;
+
+ field->list_head.btf = (struct btf *)btf;
+ field->list_head.value_btf_id = info->list_head.value_btf_id;
+ field->list_head.node_offset = offset;
+ }
+ if (!n)
return -ENOENT;
- return info.off;
+ return 0;
}
-struct bpf_map_value_off *btf_parse_kptrs(const struct btf *btf,
- const struct btf_type *t)
+struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
+ u32 field_mask, u32 value_size)
{
- struct btf_field_info info_arr[BPF_MAP_VALUE_OFF_MAX];
- struct bpf_map_value_off *tab;
- struct btf *kernel_btf = NULL;
- struct module *mod = NULL;
- int ret, i, nr_off;
+ struct btf_field_info info_arr[BTF_FIELDS_MAX];
+ struct btf_record *rec;
+ u32 next_off = 0;
+ int ret, i, cnt;
- ret = btf_find_field(btf, t, BTF_FIELD_KPTR, info_arr, ARRAY_SIZE(info_arr));
+ ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr));
if (ret < 0)
return ERR_PTR(ret);
if (!ret)
return NULL;
- nr_off = ret;
- tab = kzalloc(offsetof(struct bpf_map_value_off, off[nr_off]), GFP_KERNEL | __GFP_NOWARN);
- if (!tab)
+ cnt = ret;
+ /* This needs to be kzalloc to zero out padding and unused fields, see
+ * comment in btf_record_equal.
+ */
+ rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN);
+ if (!rec)
return ERR_PTR(-ENOMEM);
- for (i = 0; i < nr_off; i++) {
- const struct btf_type *t;
- s32 id;
+ rec->spin_lock_off = -EINVAL;
+ rec->timer_off = -EINVAL;
+ for (i = 0; i < cnt; i++) {
+ if (info_arr[i].off + btf_field_type_size(info_arr[i].type) > value_size) {
+ WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size);
+ ret = -EFAULT;
+ goto end;
+ }
+ if (info_arr[i].off < next_off) {
+ ret = -EEXIST;
+ goto end;
+ }
+ next_off = info_arr[i].off + btf_field_type_size(info_arr[i].type);
- /* Find type in map BTF, and use it to look up the matching type
- * in vmlinux or module BTFs, by name and kind.
- */
- t = btf_type_by_id(btf, info_arr[i].type_id);
- id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info),
- &kernel_btf);
- if (id < 0) {
- ret = id;
+ rec->field_mask |= info_arr[i].type;
+ rec->fields[i].offset = info_arr[i].off;
+ rec->fields[i].type = info_arr[i].type;
+
+ switch (info_arr[i].type) {
+ case BPF_SPIN_LOCK:
+ WARN_ON_ONCE(rec->spin_lock_off >= 0);
+ /* Cache offset for faster lookup at runtime */
+ rec->spin_lock_off = rec->fields[i].offset;
+ break;
+ case BPF_TIMER:
+ WARN_ON_ONCE(rec->timer_off >= 0);
+ /* Cache offset for faster lookup at runtime */
+ rec->timer_off = rec->fields[i].offset;
+ break;
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
+ ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]);
+ if (ret < 0)
+ goto end;
+ break;
+ case BPF_LIST_HEAD:
+ ret = btf_parse_list_head(btf, &rec->fields[i], &info_arr[i]);
+ if (ret < 0)
+ goto end;
+ break;
+ case BPF_LIST_NODE:
+ break;
+ default:
+ ret = -EFAULT;
goto end;
}
+ rec->cnt++;
+ }
- /* Find and stash the function pointer for the destruction function that
- * needs to be eventually invoked from the map free path.
- */
- if (info_arr[i].type == BPF_KPTR_REF) {
- const struct btf_type *dtor_func;
- const char *dtor_func_name;
- unsigned long addr;
- s32 dtor_btf_id;
-
- /* This call also serves as a whitelist of allowed objects that
- * can be used as a referenced pointer and be stored in a map at
- * the same time.
- */
- dtor_btf_id = btf_find_dtor_kfunc(kernel_btf, id);
- if (dtor_btf_id < 0) {
- ret = dtor_btf_id;
- goto end_btf;
- }
+ /* bpf_list_head requires bpf_spin_lock */
+ if (btf_record_has_field(rec, BPF_LIST_HEAD) && rec->spin_lock_off < 0) {
+ ret = -EINVAL;
+ goto end;
+ }
- dtor_func = btf_type_by_id(kernel_btf, dtor_btf_id);
- if (!dtor_func) {
- ret = -ENOENT;
- goto end_btf;
- }
+ return rec;
+end:
+ btf_record_free(rec);
+ return ERR_PTR(ret);
+}
- if (btf_is_module(kernel_btf)) {
- mod = btf_try_get_module(kernel_btf);
- if (!mod) {
- ret = -ENXIO;
- goto end_btf;
- }
- }
+int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec)
+{
+ int i;
- /* We already verified dtor_func to be btf_type_is_func
- * in register_btf_id_dtor_kfuncs.
- */
- dtor_func_name = __btf_name_by_offset(kernel_btf, dtor_func->name_off);
- addr = kallsyms_lookup_name(dtor_func_name);
- if (!addr) {
- ret = -EINVAL;
- goto end_mod;
- }
- tab->off[i].kptr.dtor = (void *)addr;
- }
+ /* There are two owning types, kptr_ref and bpf_list_head. The former
+ * only supports storing kernel types, which can never store references
+ * to program allocated local types, atleast not yet. Hence we only need
+ * to ensure that bpf_list_head ownership does not form cycles.
+ */
+ if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & BPF_LIST_HEAD))
+ return 0;
+ for (i = 0; i < rec->cnt; i++) {
+ struct btf_struct_meta *meta;
+ u32 btf_id;
+
+ if (!(rec->fields[i].type & BPF_LIST_HEAD))
+ continue;
+ btf_id = rec->fields[i].list_head.value_btf_id;
+ meta = btf_find_struct_meta(btf, btf_id);
+ if (!meta)
+ return -EFAULT;
+ rec->fields[i].list_head.value_rec = meta->record;
+
+ if (!(rec->field_mask & BPF_LIST_NODE))
+ continue;
- tab->off[i].offset = info_arr[i].off;
- tab->off[i].type = info_arr[i].type;
- tab->off[i].kptr.btf_id = id;
- tab->off[i].kptr.btf = kernel_btf;
- tab->off[i].kptr.module = mod;
+ /* We need to ensure ownership acyclicity among all types. The
+ * proper way to do it would be to topologically sort all BTF
+ * IDs based on the ownership edges, since there can be multiple
+ * bpf_list_head in a type. Instead, we use the following
+ * reasoning:
+ *
+ * - A type can only be owned by another type in user BTF if it
+ * has a bpf_list_node.
+ * - A type can only _own_ another type in user BTF if it has a
+ * bpf_list_head.
+ *
+ * We ensure that if a type has both bpf_list_head and
+ * bpf_list_node, its element types cannot be owning types.
+ *
+ * To ensure acyclicity:
+ *
+ * When A only has bpf_list_head, ownership chain can be:
+ * A -> B -> C
+ * Where:
+ * - B has both bpf_list_head and bpf_list_node.
+ * - C only has bpf_list_node.
+ *
+ * When A has both bpf_list_head and bpf_list_node, some other
+ * type already owns it in the BTF domain, hence it can not own
+ * another owning type through any of the bpf_list_head edges.
+ * A -> B
+ * Where:
+ * - B only has bpf_list_node.
+ */
+ if (meta->record->field_mask & BPF_LIST_HEAD)
+ return -ELOOP;
}
- tab->nr_off = nr_off;
- return tab;
-end_mod:
- module_put(mod);
-end_btf:
- btf_put(kernel_btf);
-end:
- while (i--) {
- btf_put(tab->off[i].kptr.btf);
- if (tab->off[i].kptr.module)
- module_put(tab->off[i].kptr.module);
+ return 0;
+}
+
+static int btf_field_offs_cmp(const void *_a, const void *_b, const void *priv)
+{
+ const u32 a = *(const u32 *)_a;
+ const u32 b = *(const u32 *)_b;
+
+ if (a < b)
+ return -1;
+ else if (a > b)
+ return 1;
+ return 0;
+}
+
+static void btf_field_offs_swap(void *_a, void *_b, int size, const void *priv)
+{
+ struct btf_field_offs *foffs = (void *)priv;
+ u32 *off_base = foffs->field_off;
+ u32 *a = _a, *b = _b;
+ u8 *sz_a, *sz_b;
+
+ sz_a = foffs->field_sz + (a - off_base);
+ sz_b = foffs->field_sz + (b - off_base);
+
+ swap(*a, *b);
+ swap(*sz_a, *sz_b);
+}
+
+struct btf_field_offs *btf_parse_field_offs(struct btf_record *rec)
+{
+ struct btf_field_offs *foffs;
+ u32 i, *off;
+ u8 *sz;
+
+ BUILD_BUG_ON(ARRAY_SIZE(foffs->field_off) != ARRAY_SIZE(foffs->field_sz));
+ if (IS_ERR_OR_NULL(rec))
+ return NULL;
+
+ foffs = kzalloc(sizeof(*foffs), GFP_KERNEL | __GFP_NOWARN);
+ if (!foffs)
+ return ERR_PTR(-ENOMEM);
+
+ off = foffs->field_off;
+ sz = foffs->field_sz;
+ for (i = 0; i < rec->cnt; i++) {
+ off[i] = rec->fields[i].offset;
+ sz[i] = btf_field_type_size(rec->fields[i].type);
}
- kfree(tab);
- return ERR_PTR(ret);
+ foffs->cnt = rec->cnt;
+
+ if (foffs->cnt == 1)
+ return foffs;
+ sort_r(foffs->field_off, foffs->cnt, sizeof(foffs->field_off[0]),
+ btf_field_offs_cmp, btf_field_offs_swap, foffs);
+ return foffs;
}
static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
@@ -4468,7 +4781,6 @@ static int btf_func_proto_check(struct btf_verifier_env *env,
nr_args--;
}
- err = 0;
for (i = 0; i < nr_args; i++) {
const struct btf_type *arg_type;
u32 arg_type_id;
@@ -4477,8 +4789,12 @@ static int btf_func_proto_check(struct btf_verifier_env *env,
arg_type = btf_type_by_id(btf, arg_type_id);
if (!arg_type) {
btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
- err = -EINVAL;
- break;
+ return -EINVAL;
+ }
+
+ if (btf_type_is_resolve_source_only(arg_type)) {
+ btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+ return -EINVAL;
}
if (args[i].name_off &&
@@ -4486,25 +4802,23 @@ static int btf_func_proto_check(struct btf_verifier_env *env,
!btf_name_valid_identifier(btf, args[i].name_off))) {
btf_verifier_log_type(env, t,
"Invalid arg#%u", i + 1);
- err = -EINVAL;
- break;
+ return -EINVAL;
}
if (btf_type_needs_resolve(arg_type) &&
!env_type_is_resolved(env, arg_type_id)) {
err = btf_resolve(env, arg_type, arg_type_id);
if (err)
- break;
+ return err;
}
if (!btf_type_id_size(btf, &arg_type_id, NULL)) {
btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
- err = -EINVAL;
- break;
+ return -EINVAL;
}
}
- return err;
+ return 0;
}
static int btf_func_check(struct btf_verifier_env *env,
@@ -4918,6 +5232,119 @@ static int btf_parse_hdr(struct btf_verifier_env *env)
return btf_check_sec_info(env, btf_data_size);
}
+static const char *alloc_obj_fields[] = {
+ "bpf_spin_lock",
+ "bpf_list_head",
+ "bpf_list_node",
+};
+
+static struct btf_struct_metas *
+btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf)
+{
+ union {
+ struct btf_id_set set;
+ struct {
+ u32 _cnt;
+ u32 _ids[ARRAY_SIZE(alloc_obj_fields)];
+ } _arr;
+ } aof;
+ struct btf_struct_metas *tab = NULL;
+ int i, n, id, ret;
+
+ BUILD_BUG_ON(offsetof(struct btf_id_set, cnt) != 0);
+ BUILD_BUG_ON(sizeof(struct btf_id_set) != sizeof(u32));
+
+ memset(&aof, 0, sizeof(aof));
+ for (i = 0; i < ARRAY_SIZE(alloc_obj_fields); i++) {
+ /* Try to find whether this special type exists in user BTF, and
+ * if so remember its ID so we can easily find it among members
+ * of structs that we iterate in the next loop.
+ */
+ id = btf_find_by_name_kind(btf, alloc_obj_fields[i], BTF_KIND_STRUCT);
+ if (id < 0)
+ continue;
+ aof.set.ids[aof.set.cnt++] = id;
+ }
+
+ if (!aof.set.cnt)
+ return NULL;
+ sort(&aof.set.ids, aof.set.cnt, sizeof(aof.set.ids[0]), btf_id_cmp_func, NULL);
+
+ n = btf_nr_types(btf);
+ for (i = 1; i < n; i++) {
+ struct btf_struct_metas *new_tab;
+ const struct btf_member *member;
+ struct btf_field_offs *foffs;
+ struct btf_struct_meta *type;
+ struct btf_record *record;
+ const struct btf_type *t;
+ int j, tab_cnt;
+
+ t = btf_type_by_id(btf, i);
+ if (!t) {
+ ret = -EINVAL;
+ goto free;
+ }
+ if (!__btf_type_is_struct(t))
+ continue;
+
+ cond_resched();
+
+ for_each_member(j, t, member) {
+ if (btf_id_set_contains(&aof.set, member->type))
+ goto parse;
+ }
+ continue;
+ parse:
+ tab_cnt = tab ? tab->cnt : 0;
+ new_tab = krealloc(tab, offsetof(struct btf_struct_metas, types[tab_cnt + 1]),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!new_tab) {
+ ret = -ENOMEM;
+ goto free;
+ }
+ if (!tab)
+ new_tab->cnt = 0;
+ tab = new_tab;
+
+ type = &tab->types[tab->cnt];
+ type->btf_id = i;
+ record = btf_parse_fields(btf, t, BPF_SPIN_LOCK | BPF_LIST_HEAD | BPF_LIST_NODE, t->size);
+ /* The record cannot be unset, treat it as an error if so */
+ if (IS_ERR_OR_NULL(record)) {
+ ret = PTR_ERR_OR_ZERO(record) ?: -EFAULT;
+ goto free;
+ }
+ foffs = btf_parse_field_offs(record);
+ /* We need the field_offs to be valid for a valid record,
+ * either both should be set or both should be unset.
+ */
+ if (IS_ERR_OR_NULL(foffs)) {
+ btf_record_free(record);
+ ret = -EFAULT;
+ goto free;
+ }
+ type->record = record;
+ type->field_offs = foffs;
+ tab->cnt++;
+ }
+ return tab;
+free:
+ btf_struct_metas_free(tab);
+ return ERR_PTR(ret);
+}
+
+struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id)
+{
+ struct btf_struct_metas *tab;
+
+ BUILD_BUG_ON(offsetof(struct btf_struct_meta, btf_id) != 0);
+ tab = btf->struct_meta_tab;
+ if (!tab)
+ return NULL;
+ return bsearch(&btf_id, tab->types, tab->cnt, sizeof(tab->types[0]), btf_id_cmp_func);
+}
+
static int btf_check_type_tags(struct btf_verifier_env *env,
struct btf *btf, int start_id)
{
@@ -4968,6 +5395,7 @@ static int btf_check_type_tags(struct btf_verifier_env *env,
static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size,
u32 log_level, char __user *log_ubuf, u32 log_size)
{
+ struct btf_struct_metas *struct_meta_tab;
struct btf_verifier_env *env = NULL;
struct bpf_verifier_log *log;
struct btf *btf = NULL;
@@ -5036,15 +5464,34 @@ static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size,
if (err)
goto errout;
+ struct_meta_tab = btf_parse_struct_metas(log, btf);
+ if (IS_ERR(struct_meta_tab)) {
+ err = PTR_ERR(struct_meta_tab);
+ goto errout;
+ }
+ btf->struct_meta_tab = struct_meta_tab;
+
+ if (struct_meta_tab) {
+ int i;
+
+ for (i = 0; i < struct_meta_tab->cnt; i++) {
+ err = btf_check_and_fixup_fields(btf, struct_meta_tab->types[i].record);
+ if (err < 0)
+ goto errout_meta;
+ }
+ }
+
if (log->level && bpf_verifier_log_full(log)) {
err = -ENOSPC;
- goto errout;
+ goto errout_meta;
}
btf_verifier_env_free(env);
refcount_set(&btf->refcnt, 1);
return btf;
+errout_meta:
+ btf_free_struct_meta_tab(btf);
errout:
btf_verifier_env_free(env);
if (btf)
@@ -5086,7 +5533,7 @@ static u8 bpf_ctx_convert_map[] = {
#undef BPF_MAP_TYPE
#undef BPF_LINK_TYPE
-static const struct btf_member *
+const struct btf_member *
btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
const struct btf_type *t, enum bpf_prog_type prog_type,
int arg)
@@ -5159,6 +5606,26 @@ static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
return kern_ctx_type->type;
}
+int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type)
+{
+ const struct btf_member *kctx_member;
+ const struct btf_type *conv_struct;
+ const struct btf_type *kctx_type;
+ u32 kctx_type_id;
+
+ conv_struct = bpf_ctx_convert.t;
+ /* get member for kernel ctx type */
+ kctx_member = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1;
+ kctx_type_id = kctx_member->type;
+ kctx_type = btf_type_by_id(btf_vmlinux, kctx_type_id);
+ if (!btf_type_is_struct(kctx_type)) {
+ bpf_log(log, "kern ctx type id %u is not a struct\n", kctx_type_id);
+ return -EINVAL;
+ }
+
+ return kctx_type_id;
+}
+
BTF_ID_LIST(bpf_ctx_convert_btf_id)
BTF_ID(struct, bpf_ctx_convert)
@@ -5356,6 +5823,22 @@ static u32 get_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto,
return nr_args + 1;
}
+static bool prog_args_trusted(const struct bpf_prog *prog)
+{
+ enum bpf_attach_type atype = prog->expected_attach_type;
+
+ switch (prog->type) {
+ case BPF_PROG_TYPE_TRACING:
+ return atype == BPF_TRACE_RAW_TP || atype == BPF_TRACE_ITER;
+ case BPF_PROG_TYPE_LSM:
+ return bpf_lsm_is_trusted(prog);
+ case BPF_PROG_TYPE_STRUCT_OPS:
+ return true;
+ default:
+ return false;
+ }
+}
+
bool btf_ctx_access(int off, int size, enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
@@ -5499,6 +5982,9 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
}
info->reg_type = PTR_TO_BTF_ID;
+ if (prog_args_trusted(prog))
+ info->reg_type |= PTR_TRUSTED;
+
if (tgt_prog) {
enum bpf_prog_type tgt_type;
@@ -5765,6 +6251,9 @@ error:
/* check __percpu tag */
if (strcmp(tag_value, "percpu") == 0)
tmp_flag = MEM_PERCPU;
+ /* check __rcu tag */
+ if (strcmp(tag_value, "rcu") == 0)
+ tmp_flag = MEM_RCU;
}
stype = btf_type_skip_modifiers(btf, mtype->type, &id);
@@ -5794,20 +6283,50 @@ error:
return -EINVAL;
}
-int btf_struct_access(struct bpf_verifier_log *log, const struct btf *btf,
- const struct btf_type *t, int off, int size,
- enum bpf_access_type atype __maybe_unused,
+int btf_struct_access(struct bpf_verifier_log *log,
+ const struct bpf_reg_state *reg,
+ int off, int size, enum bpf_access_type atype __maybe_unused,
u32 *next_btf_id, enum bpf_type_flag *flag)
{
+ const struct btf *btf = reg->btf;
enum bpf_type_flag tmp_flag = 0;
+ const struct btf_type *t;
+ u32 id = reg->btf_id;
int err;
- u32 id;
+ while (type_is_alloc(reg->type)) {
+ struct btf_struct_meta *meta;
+ struct btf_record *rec;
+ int i;
+
+ meta = btf_find_struct_meta(btf, id);
+ if (!meta)
+ break;
+ rec = meta->record;
+ for (i = 0; i < rec->cnt; i++) {
+ struct btf_field *field = &rec->fields[i];
+ u32 offset = field->offset;
+ if (off < offset + btf_field_type_size(field->type) && offset < off + size) {
+ bpf_log(log,
+ "direct access to %s is disallowed\n",
+ btf_field_type_name(field->type));
+ return -EACCES;
+ }
+ }
+ break;
+ }
+
+ t = btf_type_by_id(btf, id);
do {
err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag);
switch (err) {
case WALK_PTR:
+ /* For local types, the destination register cannot
+ * become a pointer again.
+ */
+ if (type_is_alloc(reg->type))
+ return SCALAR_VALUE;
/* If we found the pointer or scalar on t+off,
* we're done.
*/
@@ -5842,8 +6361,8 @@ int btf_struct_access(struct bpf_verifier_log *log, const struct btf *btf,
* end up with two different module BTFs, but IDs point to the common type in
* vmlinux BTF.
*/
-static bool btf_types_are_same(const struct btf *btf1, u32 id1,
- const struct btf *btf2, u32 id2)
+bool btf_types_are_same(const struct btf *btf1, u32 id1,
+ const struct btf *btf2, u32 id2)
{
if (id1 != id2)
return false;
@@ -6125,122 +6644,19 @@ int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *pr
return btf_check_func_type_match(log, btf1, t1, btf2, t2);
}
-static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = {
-#ifdef CONFIG_NET
- [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK],
- [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
- [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP],
-#endif
-};
-
-/* Returns true if struct is composed of scalars, 4 levels of nesting allowed */
-static bool __btf_type_is_scalar_struct(struct bpf_verifier_log *log,
- const struct btf *btf,
- const struct btf_type *t, int rec)
-{
- const struct btf_type *member_type;
- const struct btf_member *member;
- u32 i;
-
- if (!btf_type_is_struct(t))
- return false;
-
- for_each_member(i, t, member) {
- const struct btf_array *array;
-
- member_type = btf_type_skip_modifiers(btf, member->type, NULL);
- if (btf_type_is_struct(member_type)) {
- if (rec >= 3) {
- bpf_log(log, "max struct nesting depth exceeded\n");
- return false;
- }
- if (!__btf_type_is_scalar_struct(log, btf, member_type, rec + 1))
- return false;
- continue;
- }
- if (btf_type_is_array(member_type)) {
- array = btf_type_array(member_type);
- if (!array->nelems)
- return false;
- member_type = btf_type_skip_modifiers(btf, array->type, NULL);
- if (!btf_type_is_scalar(member_type))
- return false;
- continue;
- }
- if (!btf_type_is_scalar(member_type))
- return false;
- }
- return true;
-}
-
-static bool is_kfunc_arg_mem_size(const struct btf *btf,
- const struct btf_param *arg,
- const struct bpf_reg_state *reg)
-{
- int len, sfx_len = sizeof("__sz") - 1;
- const struct btf_type *t;
- const char *param_name;
-
- t = btf_type_skip_modifiers(btf, arg->type, NULL);
- if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE)
- return false;
-
- /* In the future, this can be ported to use BTF tagging */
- param_name = btf_name_by_offset(btf, arg->name_off);
- if (str_is_empty(param_name))
- return false;
- len = strlen(param_name);
- if (len < sfx_len)
- return false;
- param_name += len - sfx_len;
- if (strncmp(param_name, "__sz", sfx_len))
- return false;
-
- return true;
-}
-
-static bool btf_is_kfunc_arg_mem_size(const struct btf *btf,
- const struct btf_param *arg,
- const struct bpf_reg_state *reg,
- const char *name)
-{
- int len, target_len = strlen(name);
- const struct btf_type *t;
- const char *param_name;
-
- t = btf_type_skip_modifiers(btf, arg->type, NULL);
- if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE)
- return false;
-
- param_name = btf_name_by_offset(btf, arg->name_off);
- if (str_is_empty(param_name))
- return false;
- len = strlen(param_name);
- if (len != target_len)
- return false;
- if (strcmp(param_name, name))
- return false;
-
- return true;
-}
-
static int btf_check_func_arg_match(struct bpf_verifier_env *env,
const struct btf *btf, u32 func_id,
struct bpf_reg_state *regs,
bool ptr_to_mem_ok,
- struct bpf_kfunc_arg_meta *kfunc_meta,
bool processing_call)
{
enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
- bool rel = false, kptr_get = false, trusted_args = false;
- bool sleepable = false;
struct bpf_verifier_log *log = &env->log;
- u32 i, nargs, ref_id, ref_obj_id = 0;
- bool is_kfunc = btf_is_kernel(btf);
const char *func_name, *ref_tname;
const struct btf_type *t, *ref_t;
const struct btf_param *args;
- int ref_regno = 0, ret;
+ u32 i, nargs, ref_id;
+ int ret;
t = btf_type_by_id(btf, func_id);
if (!t || !btf_type_is_func(t)) {
@@ -6266,14 +6682,6 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
return -EINVAL;
}
- if (is_kfunc && kfunc_meta) {
- /* Only kfunc can be release func */
- rel = kfunc_meta->flags & KF_RELEASE;
- kptr_get = kfunc_meta->flags & KF_KPTR_GET;
- trusted_args = kfunc_meta->flags & KF_TRUSTED_ARGS;
- sleepable = kfunc_meta->flags & KF_SLEEPABLE;
- }
-
/* check that BTF function arguments match actual types that the
* verifier sees.
*/
@@ -6281,42 +6689,9 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
enum bpf_arg_type arg_type = ARG_DONTCARE;
u32 regno = i + 1;
struct bpf_reg_state *reg = &regs[regno];
- bool obj_ptr = false;
t = btf_type_skip_modifiers(btf, args[i].type, NULL);
if (btf_type_is_scalar(t)) {
- if (is_kfunc && kfunc_meta) {
- bool is_buf_size = false;
-
- /* check for any const scalar parameter of name "rdonly_buf_size"
- * or "rdwr_buf_size"
- */
- if (btf_is_kfunc_arg_mem_size(btf, &args[i], reg,
- "rdonly_buf_size")) {
- kfunc_meta->r0_rdonly = true;
- is_buf_size = true;
- } else if (btf_is_kfunc_arg_mem_size(btf, &args[i], reg,
- "rdwr_buf_size"))
- is_buf_size = true;
-
- if (is_buf_size) {
- if (kfunc_meta->r0_size) {
- bpf_log(log, "2 or more rdonly/rdwr_buf_size parameters for kfunc");
- return -EINVAL;
- }
-
- if (!tnum_is_const(reg->var_off)) {
- bpf_log(log, "R%d is not a const\n", regno);
- return -EINVAL;
- }
-
- kfunc_meta->r0_size = reg->var_off.value;
- ret = mark_chain_precision(env, regno);
- if (ret)
- return ret;
- }
- }
-
if (reg->type == SCALAR_VALUE)
continue;
bpf_log(log, "R%d is not a scalar\n", regno);
@@ -6329,88 +6704,14 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
return -EINVAL;
}
- /* These register types have special constraints wrt ref_obj_id
- * and offset checks. The rest of trusted args don't.
- */
- obj_ptr = reg->type == PTR_TO_CTX || reg->type == PTR_TO_BTF_ID ||
- reg2btf_ids[base_type(reg->type)];
-
- /* Check if argument must be a referenced pointer, args + i has
- * been verified to be a pointer (after skipping modifiers).
- * PTR_TO_CTX is ok without having non-zero ref_obj_id.
- */
- if (is_kfunc && trusted_args && (obj_ptr && reg->type != PTR_TO_CTX) && !reg->ref_obj_id) {
- bpf_log(log, "R%d must be referenced\n", regno);
- return -EINVAL;
- }
-
ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id);
ref_tname = btf_name_by_offset(btf, ref_t->name_off);
- /* Trusted args have the same offset checks as release arguments */
- if ((trusted_args && obj_ptr) || (rel && reg->ref_obj_id))
- arg_type |= OBJ_RELEASE;
ret = check_func_arg_reg_off(env, reg, regno, arg_type);
if (ret < 0)
return ret;
- if (is_kfunc && reg->ref_obj_id) {
- /* Ensure only one argument is referenced PTR_TO_BTF_ID */
- if (ref_obj_id) {
- bpf_log(log, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n",
- regno, reg->ref_obj_id, ref_obj_id);
- return -EFAULT;
- }
- ref_regno = regno;
- ref_obj_id = reg->ref_obj_id;
- }
-
- /* kptr_get is only true for kfunc */
- if (i == 0 && kptr_get) {
- struct bpf_map_value_off_desc *off_desc;
-
- if (reg->type != PTR_TO_MAP_VALUE) {
- bpf_log(log, "arg#0 expected pointer to map value\n");
- return -EINVAL;
- }
-
- /* check_func_arg_reg_off allows var_off for
- * PTR_TO_MAP_VALUE, but we need fixed offset to find
- * off_desc.
- */
- if (!tnum_is_const(reg->var_off)) {
- bpf_log(log, "arg#0 must have constant offset\n");
- return -EINVAL;
- }
-
- off_desc = bpf_map_kptr_off_contains(reg->map_ptr, reg->off + reg->var_off.value);
- if (!off_desc || off_desc->type != BPF_KPTR_REF) {
- bpf_log(log, "arg#0 no referenced kptr at map value offset=%llu\n",
- reg->off + reg->var_off.value);
- return -EINVAL;
- }
-
- if (!btf_type_is_ptr(ref_t)) {
- bpf_log(log, "arg#0 BTF type must be a double pointer\n");
- return -EINVAL;
- }
-
- ref_t = btf_type_skip_modifiers(btf, ref_t->type, &ref_id);
- ref_tname = btf_name_by_offset(btf, ref_t->name_off);
-
- if (!btf_type_is_struct(ref_t)) {
- bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n",
- func_name, i, btf_type_str(ref_t), ref_tname);
- return -EINVAL;
- }
- if (!btf_struct_ids_match(log, btf, ref_id, 0, off_desc->kptr.btf,
- off_desc->kptr.btf_id, true)) {
- bpf_log(log, "kernel function %s args#%d expected pointer to %s %s\n",
- func_name, i, btf_type_str(ref_t), ref_tname);
- return -EINVAL;
- }
- /* rest of the arguments can be anything, like normal kfunc */
- } else if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
+ if (btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
/* If function expects ctx type in BTF check that caller
* is passing PTR_TO_CTX.
*/
@@ -6420,109 +6721,10 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
i, btf_type_str(t));
return -EINVAL;
}
- } else if (is_kfunc && (reg->type == PTR_TO_BTF_ID ||
- (reg2btf_ids[base_type(reg->type)] && !type_flag(reg->type)))) {
- const struct btf_type *reg_ref_t;
- const struct btf *reg_btf;
- const char *reg_ref_tname;
- u32 reg_ref_id;
-
- if (!btf_type_is_struct(ref_t)) {
- bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n",
- func_name, i, btf_type_str(ref_t),
- ref_tname);
- return -EINVAL;
- }
-
- if (reg->type == PTR_TO_BTF_ID) {
- reg_btf = reg->btf;
- reg_ref_id = reg->btf_id;
- } else {
- reg_btf = btf_vmlinux;
- reg_ref_id = *reg2btf_ids[base_type(reg->type)];
- }
-
- reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id,
- &reg_ref_id);
- reg_ref_tname = btf_name_by_offset(reg_btf,
- reg_ref_t->name_off);
- if (!btf_struct_ids_match(log, reg_btf, reg_ref_id,
- reg->off, btf, ref_id,
- trusted_args || (rel && reg->ref_obj_id))) {
- bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n",
- func_name, i,
- btf_type_str(ref_t), ref_tname,
- regno, btf_type_str(reg_ref_t),
- reg_ref_tname);
- return -EINVAL;
- }
} else if (ptr_to_mem_ok && processing_call) {
const struct btf_type *resolve_ret;
u32 type_size;
- if (is_kfunc) {
- bool arg_mem_size = i + 1 < nargs && is_kfunc_arg_mem_size(btf, &args[i + 1], &regs[regno + 1]);
- bool arg_dynptr = btf_type_is_struct(ref_t) &&
- !strcmp(ref_tname,
- stringify_struct(bpf_dynptr_kern));
-
- /* Permit pointer to mem, but only when argument
- * type is pointer to scalar, or struct composed
- * (recursively) of scalars.
- * When arg_mem_size is true, the pointer can be
- * void *.
- * Also permit initialized local dynamic pointers.
- */
- if (!btf_type_is_scalar(ref_t) &&
- !__btf_type_is_scalar_struct(log, btf, ref_t, 0) &&
- !arg_dynptr &&
- (arg_mem_size ? !btf_type_is_void(ref_t) : 1)) {
- bpf_log(log,
- "arg#%d pointer type %s %s must point to %sscalar, or struct with scalar\n",
- i, btf_type_str(ref_t), ref_tname, arg_mem_size ? "void, " : "");
- return -EINVAL;
- }
-
- if (arg_dynptr) {
- if (reg->type != PTR_TO_STACK) {
- bpf_log(log, "arg#%d pointer type %s %s not to stack\n",
- i, btf_type_str(ref_t),
- ref_tname);
- return -EINVAL;
- }
-
- if (!is_dynptr_reg_valid_init(env, reg)) {
- bpf_log(log,
- "arg#%d pointer type %s %s must be valid and initialized\n",
- i, btf_type_str(ref_t),
- ref_tname);
- return -EINVAL;
- }
-
- if (!is_dynptr_type_expected(env, reg,
- ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL)) {
- bpf_log(log,
- "arg#%d pointer type %s %s points to unsupported dynamic pointer type\n",
- i, btf_type_str(ref_t),
- ref_tname);
- return -EINVAL;
- }
-
- continue;
- }
-
- /* Check for mem, len pair */
- if (arg_mem_size) {
- if (check_kfunc_mem_size_reg(env, &regs[regno + 1], regno + 1)) {
- bpf_log(log, "arg#%d arg#%d memory, len pair leads to invalid memory access\n",
- i, i + 1);
- return -EINVAL;
- }
- i++;
- continue;
- }
- }
-
resolve_ret = btf_resolve_size(btf, ref_t, &type_size);
if (IS_ERR(resolve_ret)) {
bpf_log(log,
@@ -6535,36 +6737,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
if (check_mem_reg(env, reg, regno, type_size))
return -EINVAL;
} else {
- bpf_log(log, "reg type unsupported for arg#%d %sfunction %s#%d\n", i,
- is_kfunc ? "kernel " : "", func_name, func_id);
+ bpf_log(log, "reg type unsupported for arg#%d function %s#%d\n", i,
+ func_name, func_id);
return -EINVAL;
}
}
- /* Either both are set, or neither */
- WARN_ON_ONCE((ref_obj_id && !ref_regno) || (!ref_obj_id && ref_regno));
- /* We already made sure ref_obj_id is set only for one argument. We do
- * allow (!rel && ref_obj_id), so that passing such referenced
- * PTR_TO_BTF_ID to other kfuncs works. Note that rel is only true when
- * is_kfunc is true.
- */
- if (rel && !ref_obj_id) {
- bpf_log(log, "release kernel function %s expects refcounted PTR_TO_BTF_ID\n",
- func_name);
- return -EINVAL;
- }
-
- if (sleepable && !env->prog->aux->sleepable) {
- bpf_log(log, "kernel function %s is sleepable but the program is not\n",
- func_name);
- return -EINVAL;
- }
-
- if (kfunc_meta && ref_obj_id)
- kfunc_meta->ref_obj_id = ref_obj_id;
-
- /* returns argument register number > 0 in case of reference release kfunc */
- return rel ? ref_regno : 0;
+ return 0;
}
/* Compare BTF of a function declaration with given bpf_reg_state.
@@ -6594,7 +6773,7 @@ int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog,
return -EINVAL;
is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
- err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, NULL, false);
+ err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, false);
/* Compiler optimizations can remove arguments from static functions
* or mismatched type can be passed into a global function.
@@ -6637,7 +6816,7 @@ int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog,
return -EINVAL;
is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
- err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, NULL, true);
+ err = btf_check_func_arg_match(env, btf, btf_id, regs, is_global, true);
/* Compiler optimizations can remove arguments from static functions
* or mismatched type can be passed into a global function.
@@ -6648,14 +6827,6 @@ int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog,
return err;
}
-int btf_check_kfunc_arg_match(struct bpf_verifier_env *env,
- const struct btf *btf, u32 func_id,
- struct bpf_reg_state *regs,
- struct bpf_kfunc_arg_meta *meta)
-{
- return btf_check_func_arg_match(env, btf, func_id, regs, true, meta, true);
-}
-
/* Convert BTF of a function into bpf_reg_state if possible
* Returns:
* EFAULT - there is a verifier bug. Abort verification.
@@ -7038,23 +7209,6 @@ bool btf_is_module(const struct btf *btf)
return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0;
}
-static int btf_id_cmp_func(const void *a, const void *b)
-{
- const int *pa = a, *pb = b;
-
- return *pa - *pb;
-}
-
-bool btf_id_set_contains(const struct btf_id_set *set, u32 id)
-{
- return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL;
-}
-
-static void *btf_id_set8_contains(const struct btf_id_set8 *set, u32 id)
-{
- return bsearch(&id, set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func);
-}
-
enum {
BTF_MODULE_F_LIVE = (1 << 0),
};
@@ -7415,6 +7569,8 @@ static u32 *__btf_kfunc_id_set_contains(const struct btf *btf,
static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type)
{
switch (prog_type) {
+ case BPF_PROG_TYPE_UNSPEC:
+ return BTF_KFUNC_HOOK_COMMON;
case BPF_PROG_TYPE_XDP:
return BTF_KFUNC_HOOK_XDP;
case BPF_PROG_TYPE_SCHED_CLS:
@@ -7443,16 +7599,24 @@ u32 *btf_kfunc_id_set_contains(const struct btf *btf,
u32 kfunc_btf_id)
{
enum btf_kfunc_hook hook;
+ u32 *kfunc_flags;
+
+ kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id);
+ if (kfunc_flags)
+ return kfunc_flags;
hook = bpf_prog_type_to_kfunc_hook(prog_type);
return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id);
}
-/* This function must be invoked only from initcalls/module init functions */
-int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
- const struct btf_kfunc_id_set *kset)
+u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id)
+{
+ return __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_FMODRET, kfunc_btf_id);
+}
+
+static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook,
+ const struct btf_kfunc_id_set *kset)
{
- enum btf_kfunc_hook hook;
struct btf *btf;
int ret;
@@ -7471,13 +7635,29 @@ int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
if (IS_ERR(btf))
return PTR_ERR(btf);
- hook = bpf_prog_type_to_kfunc_hook(prog_type);
ret = btf_populate_kfunc_set(btf, hook, kset->set);
btf_put(btf);
return ret;
}
+
+/* This function must be invoked only from initcalls/module init functions */
+int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
+ const struct btf_kfunc_id_set *kset)
+{
+ enum btf_kfunc_hook hook;
+
+ hook = bpf_prog_type_to_kfunc_hook(prog_type);
+ return __register_btf_kfunc_id_set(hook, kset);
+}
EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set);
+/* This function must be invoked only from initcalls/module init functions */
+int register_btf_fmodret_id_set(const struct btf_kfunc_id_set *kset)
+{
+ return __register_btf_kfunc_id_set(BTF_KFUNC_HOOK_FMODRET, kset);
+}
+EXPORT_SYMBOL_GPL(register_btf_fmodret_id_set);
+
s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id)
{
struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab;
diff --git a/kernel/bpf/cgroup_iter.c b/kernel/bpf/cgroup_iter.c
index 9fcf09f2ef00..06989d278846 100644
--- a/kernel/bpf/cgroup_iter.c
+++ b/kernel/bpf/cgroup_iter.c
@@ -157,23 +157,37 @@ static const struct seq_operations cgroup_iter_seq_ops = {
.show = cgroup_iter_seq_show,
};
-BTF_ID_LIST_SINGLE(bpf_cgroup_btf_id, struct, cgroup)
+BTF_ID_LIST_GLOBAL_SINGLE(bpf_cgroup_btf_id, struct, cgroup)
static int cgroup_iter_seq_init(void *priv, struct bpf_iter_aux_info *aux)
{
struct cgroup_iter_priv *p = (struct cgroup_iter_priv *)priv;
struct cgroup *cgrp = aux->cgroup.start;
+ /* bpf_iter_attach_cgroup() has already acquired an extra reference
+ * for the start cgroup, but the reference may be released after
+ * cgroup_iter_seq_init(), so acquire another reference for the
+ * start cgroup.
+ */
p->start_css = &cgrp->self;
+ css_get(p->start_css);
p->terminate = false;
p->visited_all = false;
p->order = aux->cgroup.order;
return 0;
}
+static void cgroup_iter_seq_fini(void *priv)
+{
+ struct cgroup_iter_priv *p = (struct cgroup_iter_priv *)priv;
+
+ css_put(p->start_css);
+}
+
static const struct bpf_iter_seq_info cgroup_iter_seq_info = {
.seq_ops = &cgroup_iter_seq_ops,
.init_seq_private = cgroup_iter_seq_init,
+ .fini_seq_private = cgroup_iter_seq_fini,
.seq_priv_size = sizeof(struct cgroup_iter_priv),
};
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 38159f39e2af..7f98dec6e90f 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -34,6 +34,7 @@
#include <linux/log2.h>
#include <linux/bpf_verifier.h>
#include <linux/nodemask.h>
+#include <linux/bpf_mem_alloc.h>
#include <asm/barrier.h>
#include <asm/unaligned.h>
@@ -60,6 +61,9 @@
#define CTX regs[BPF_REG_CTX]
#define IMM insn->imm
+struct bpf_mem_alloc bpf_global_ma;
+bool bpf_global_ma_set;
+
/* No hurry in this branch
*
* Exported for the bpf jit load helper.
@@ -2251,8 +2255,14 @@ static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
{
struct bpf_prog_array *progs;
+ /* If RCU Tasks Trace grace period implies RCU grace period, there is
+ * no need to call kfree_rcu(), just call kfree() directly.
+ */
progs = container_of(rcu, struct bpf_prog_array, rcu);
- kfree_rcu(progs, rcu);
+ if (rcu_trace_implies_rcu_gp())
+ kfree(progs);
+ else
+ kfree_rcu(progs, rcu);
}
void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
@@ -2740,6 +2750,18 @@ int __weak bpf_arch_text_invalidate(void *dst, size_t len)
return -ENOTSUPP;
}
+#ifdef CONFIG_BPF_SYSCALL
+static int __init bpf_global_ma_init(void)
+{
+ int ret;
+
+ ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
+ bpf_global_ma_set = !ret;
+ return ret;
+}
+late_initcall(bpf_global_ma_init);
+#endif
+
DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
EXPORT_SYMBOL(bpf_stats_enabled_key);
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index b5ba34ddd4b6..e0b2d016f0bf 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -4,13 +4,16 @@
* Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
*/
-/* The 'cpumap' is primarily used as a backend map for XDP BPF helper
+/**
+ * DOC: cpu map
+ * The 'cpumap' is primarily used as a backend map for XDP BPF helper
* call bpf_redirect_map() and XDP_REDIRECT action, like 'devmap'.
*
- * Unlike devmap which redirects XDP frames out another NIC device,
+ * Unlike devmap which redirects XDP frames out to another NIC device,
* this map type redirects raw XDP frames to another CPU. The remote
* CPU will do SKB-allocation and call the normal network stack.
- *
+ */
+/*
* This is a scalability and isolation mechanism, that allow
* separating the early driver network XDP layer, from the rest of the
* netstack, and assigning dedicated CPUs for this stage. This
@@ -85,7 +88,6 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
{
u32 value_size = attr->value_size;
struct bpf_cpu_map *cmap;
- int err = -ENOMEM;
if (!bpf_capable())
return ERR_PTR(-EPERM);
@@ -97,29 +99,26 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
attr->map_flags & ~BPF_F_NUMA_NODE)
return ERR_PTR(-EINVAL);
+ /* Pre-limit array size based on NR_CPUS, not final CPU check */
+ if (attr->max_entries > NR_CPUS)
+ return ERR_PTR(-E2BIG);
+
cmap = bpf_map_area_alloc(sizeof(*cmap), NUMA_NO_NODE);
if (!cmap)
return ERR_PTR(-ENOMEM);
bpf_map_init_from_attr(&cmap->map, attr);
- /* Pre-limit array size based on NR_CPUS, not final CPU check */
- if (cmap->map.max_entries > NR_CPUS) {
- err = -E2BIG;
- goto free_cmap;
- }
-
/* Alloc array for possible remote "destination" CPUs */
cmap->cpu_map = bpf_map_area_alloc(cmap->map.max_entries *
sizeof(struct bpf_cpu_map_entry *),
cmap->map.numa_node);
- if (!cmap->cpu_map)
- goto free_cmap;
+ if (!cmap->cpu_map) {
+ bpf_map_area_free(cmap);
+ return ERR_PTR(-ENOMEM);
+ }
return &cmap->map;
-free_cmap:
- bpf_map_area_free(cmap);
- return ERR_PTR(err);
}
static void get_cpu_map_entry(struct bpf_cpu_map_entry *rcpu)
@@ -668,9 +667,9 @@ static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
return 0;
}
-static int cpu_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+static int cpu_map_redirect(struct bpf_map *map, u64 index, u64 flags)
{
- return __bpf_xdp_redirect_map(map, ifindex, flags, 0,
+ return __bpf_xdp_redirect_map(map, index, flags, 0,
__cpu_map_lookup_elem);
}
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index f9a87dcc5535..d01e4c55b376 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -992,14 +992,14 @@ static int dev_map_hash_update_elem(struct bpf_map *map, void *key, void *value,
map, key, value, map_flags);
}
-static int dev_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+static int dev_map_redirect(struct bpf_map *map, u64 ifindex, u64 flags)
{
return __bpf_xdp_redirect_map(map, ifindex, flags,
BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS,
__dev_map_lookup_elem);
}
-static int dev_hash_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+static int dev_hash_map_redirect(struct bpf_map *map, u64 ifindex, u64 flags)
{
return __bpf_xdp_redirect_map(map, ifindex, flags,
BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS,
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index f39ee3e05589..5aa2b5525f79 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -222,7 +222,7 @@ static void htab_free_prealloced_timers(struct bpf_htab *htab)
u32 num_entries = htab->map.max_entries;
int i;
- if (!map_value_has_timer(&htab->map))
+ if (!btf_record_has_field(htab->map.record, BPF_TIMER))
return;
if (htab_has_extra_elems(htab))
num_entries += num_possible_cpus();
@@ -231,28 +231,25 @@ static void htab_free_prealloced_timers(struct bpf_htab *htab)
struct htab_elem *elem;
elem = get_htab_elem(htab, i);
- bpf_timer_cancel_and_free(elem->key +
- round_up(htab->map.key_size, 8) +
- htab->map.timer_off);
+ bpf_obj_free_timer(htab->map.record, elem->key + round_up(htab->map.key_size, 8));
cond_resched();
}
}
-static void htab_free_prealloced_kptrs(struct bpf_htab *htab)
+static void htab_free_prealloced_fields(struct bpf_htab *htab)
{
u32 num_entries = htab->map.max_entries;
int i;
- if (!map_value_has_kptrs(&htab->map))
+ if (IS_ERR_OR_NULL(htab->map.record))
return;
if (htab_has_extra_elems(htab))
num_entries += num_possible_cpus();
-
for (i = 0; i < num_entries; i++) {
struct htab_elem *elem;
elem = get_htab_elem(htab, i);
- bpf_map_free_kptrs(&htab->map, elem->key + round_up(htab->map.key_size, 8));
+ bpf_obj_free_fields(htab->map.record, elem->key + round_up(htab->map.key_size, 8));
cond_resched();
}
}
@@ -764,10 +761,7 @@ static void check_and_free_fields(struct bpf_htab *htab,
{
void *map_value = elem->key + round_up(htab->map.key_size, 8);
- if (map_value_has_timer(&htab->map))
- bpf_timer_cancel_and_free(map_value + htab->map.timer_off);
- if (map_value_has_kptrs(&htab->map))
- bpf_map_free_kptrs(&htab->map, map_value);
+ bpf_obj_free_fields(htab->map.record, map_value);
}
/* It is called from the bpf_lru_list when the LRU needs to delete
@@ -1091,7 +1085,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
head = &b->head;
if (unlikely(map_flags & BPF_F_LOCK)) {
- if (unlikely(!map_value_has_spin_lock(map)))
+ if (unlikely(!btf_record_has_field(map->record, BPF_SPIN_LOCK)))
return -EINVAL;
/* find an element without taking the bucket lock */
l_old = lookup_nulls_elem_raw(head, hash, key, key_size,
@@ -1474,12 +1468,8 @@ static void htab_free_malloced_timers(struct bpf_htab *htab)
struct htab_elem *l;
hlist_nulls_for_each_entry(l, n, head, hash_node) {
- /* We don't reset or free kptr on uref dropping to zero,
- * hence just free timer.
- */
- bpf_timer_cancel_and_free(l->key +
- round_up(htab->map.key_size, 8) +
- htab->map.timer_off);
+ /* We only free timer on uref dropping to zero */
+ bpf_obj_free_timer(htab->map.record, l->key + round_up(htab->map.key_size, 8));
}
cond_resched_rcu();
}
@@ -1490,8 +1480,8 @@ static void htab_map_free_timers(struct bpf_map *map)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
- /* We don't reset or free kptr on uref dropping to zero. */
- if (!map_value_has_timer(&htab->map))
+ /* We only free timer on uref dropping to zero */
+ if (!btf_record_has_field(htab->map.record, BPF_TIMER))
return;
if (!htab_is_prealloc(htab))
htab_free_malloced_timers(htab);
@@ -1517,11 +1507,10 @@ static void htab_map_free(struct bpf_map *map)
if (!htab_is_prealloc(htab)) {
delete_all_elements(htab);
} else {
- htab_free_prealloced_kptrs(htab);
+ htab_free_prealloced_fields(htab);
prealloc_destroy(htab);
}
- bpf_map_free_kptr_off_tab(map);
free_percpu(htab->extra_elems);
bpf_map_area_free(htab->buckets);
bpf_mem_alloc_destroy(&htab->pcpu_ma);
@@ -1675,7 +1664,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map,
elem_map_flags = attr->batch.elem_flags;
if ((elem_map_flags & ~BPF_F_LOCK) ||
- ((elem_map_flags & BPF_F_LOCK) && !map_value_has_spin_lock(map)))
+ ((elem_map_flags & BPF_F_LOCK) && !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
return -EINVAL;
map_flags = attr->batch.flags;
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index a6b04faed282..af30c6cbd65d 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -4,6 +4,7 @@
#include <linux/bpf.h>
#include <linux/btf.h>
#include <linux/bpf-cgroup.h>
+#include <linux/cgroup.h>
#include <linux/rcupdate.h>
#include <linux/random.h>
#include <linux/smp.h>
@@ -19,6 +20,7 @@
#include <linux/proc_ns.h>
#include <linux/security.h>
#include <linux/btf_ids.h>
+#include <linux/bpf_mem_alloc.h>
#include "../../lib/kstrtox.h"
@@ -336,6 +338,7 @@ const struct bpf_func_proto bpf_spin_lock_proto = {
.gpl_only = false,
.ret_type = RET_VOID,
.arg1_type = ARG_PTR_TO_SPIN_LOCK,
+ .arg1_btf_id = BPF_PTR_POISON,
};
static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock)
@@ -358,6 +361,7 @@ const struct bpf_func_proto bpf_spin_unlock_proto = {
.gpl_only = false,
.ret_type = RET_VOID,
.arg1_type = ARG_PTR_TO_SPIN_LOCK,
+ .arg1_btf_id = BPF_PTR_POISON,
};
void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
@@ -366,9 +370,9 @@ void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
struct bpf_spin_lock *lock;
if (lock_src)
- lock = src + map->spin_lock_off;
+ lock = src + map->record->spin_lock_off;
else
- lock = dst + map->spin_lock_off;
+ lock = dst + map->record->spin_lock_off;
preempt_disable();
__bpf_spin_lock_irqsave(lock);
copy_map_value(map, dst, src);
@@ -657,6 +661,7 @@ BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size,
const struct bpf_func_proto bpf_copy_from_user_proto = {
.func = bpf_copy_from_user,
.gpl_only = false,
+ .might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
@@ -687,6 +692,7 @@ BPF_CALL_5(bpf_copy_from_user_task, void *, dst, u32, size,
const struct bpf_func_proto bpf_copy_from_user_task_proto = {
.func = bpf_copy_from_user_task,
.gpl_only = true,
+ .might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
@@ -1169,7 +1175,7 @@ BPF_CALL_3(bpf_timer_init, struct bpf_timer_kern *, timer, struct bpf_map *, map
ret = -ENOMEM;
goto out;
}
- t->value = (void *)timer - map->timer_off;
+ t->value = (void *)timer - map->record->timer_off;
t->map = map;
t->prog = NULL;
rcu_assign_pointer(t->callback_fn, NULL);
@@ -1398,7 +1404,7 @@ static const struct bpf_func_proto bpf_kptr_xchg_proto = {
#define DYNPTR_SIZE_MASK 0xFFFFFF
#define DYNPTR_RDONLY_BIT BIT(31)
-static bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr)
+static bool bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr)
{
return ptr->size & DYNPTR_RDONLY_BIT;
}
@@ -1408,7 +1414,7 @@ static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_typ
ptr->size |= type << DYNPTR_TYPE_SHIFT;
}
-u32 bpf_dynptr_get_size(struct bpf_dynptr_kern *ptr)
+u32 bpf_dynptr_get_size(const struct bpf_dynptr_kern *ptr)
{
return ptr->size & DYNPTR_SIZE_MASK;
}
@@ -1432,7 +1438,7 @@ void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr)
memset(ptr, 0, sizeof(*ptr));
}
-static int bpf_dynptr_check_off_len(struct bpf_dynptr_kern *ptr, u32 offset, u32 len)
+static int bpf_dynptr_check_off_len(const struct bpf_dynptr_kern *ptr, u32 offset, u32 len)
{
u32 size = bpf_dynptr_get_size(ptr);
@@ -1477,7 +1483,7 @@ static const struct bpf_func_proto bpf_dynptr_from_mem_proto = {
.arg4_type = ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL | MEM_UNINIT,
};
-BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, struct bpf_dynptr_kern *, src,
+BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, const struct bpf_dynptr_kern *, src,
u32, offset, u64, flags)
{
int err;
@@ -1489,7 +1495,11 @@ BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, struct bpf_dynptr_kern *, src
if (err)
return err;
- memcpy(dst, src->data + src->offset + offset, len);
+ /* Source and destination may possibly overlap, hence use memmove to
+ * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
+ * pointing to overlapping PTR_TO_MAP_VALUE regions.
+ */
+ memmove(dst, src->data + src->offset + offset, len);
return 0;
}
@@ -1500,12 +1510,12 @@ static const struct bpf_func_proto bpf_dynptr_read_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
- .arg3_type = ARG_PTR_TO_DYNPTR,
+ .arg3_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
};
-BPF_CALL_5(bpf_dynptr_write, struct bpf_dynptr_kern *, dst, u32, offset, void *, src,
+BPF_CALL_5(bpf_dynptr_write, const struct bpf_dynptr_kern *, dst, u32, offset, void *, src,
u32, len, u64, flags)
{
int err;
@@ -1517,7 +1527,11 @@ BPF_CALL_5(bpf_dynptr_write, struct bpf_dynptr_kern *, dst, u32, offset, void *,
if (err)
return err;
- memcpy(dst->data + dst->offset + offset, src, len);
+ /* Source and destination may possibly overlap, hence use memmove to
+ * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
+ * pointing to overlapping PTR_TO_MAP_VALUE regions.
+ */
+ memmove(dst->data + dst->offset + offset, src, len);
return 0;
}
@@ -1526,14 +1540,14 @@ static const struct bpf_func_proto bpf_dynptr_write_proto = {
.func = bpf_dynptr_write,
.gpl_only = false,
.ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_DYNPTR,
+ .arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE_OR_ZERO,
.arg5_type = ARG_ANYTHING,
};
-BPF_CALL_3(bpf_dynptr_data, struct bpf_dynptr_kern *, ptr, u32, offset, u32, len)
+BPF_CALL_3(bpf_dynptr_data, const struct bpf_dynptr_kern *, ptr, u32, offset, u32, len)
{
int err;
@@ -1554,7 +1568,7 @@ static const struct bpf_func_proto bpf_dynptr_data_proto = {
.func = bpf_dynptr_data,
.gpl_only = false,
.ret_type = RET_PTR_TO_DYNPTR_MEM_OR_NULL,
- .arg1_type = ARG_PTR_TO_DYNPTR,
+ .arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_CONST_ALLOC_SIZE_OR_ZERO,
};
@@ -1663,6 +1677,12 @@ bpf_base_func_proto(enum bpf_func_id func_id)
return &bpf_dynptr_write_proto;
case BPF_FUNC_dynptr_data:
return &bpf_dynptr_data_proto;
+#ifdef CONFIG_CGROUPS
+ case BPF_FUNC_cgrp_storage_get:
+ return &bpf_cgrp_storage_get_proto;
+ case BPF_FUNC_cgrp_storage_delete:
+ return &bpf_cgrp_storage_delete_proto;
+#endif
default:
break;
}
@@ -1700,20 +1720,401 @@ bpf_base_func_proto(enum bpf_func_id func_id)
}
}
-BTF_SET8_START(tracing_btf_ids)
+void bpf_list_head_free(const struct btf_field *field, void *list_head,
+ struct bpf_spin_lock *spin_lock)
+{
+ struct list_head *head = list_head, *orig_head = list_head;
+
+ BUILD_BUG_ON(sizeof(struct list_head) > sizeof(struct bpf_list_head));
+ BUILD_BUG_ON(__alignof__(struct list_head) > __alignof__(struct bpf_list_head));
+
+ /* Do the actual list draining outside the lock to not hold the lock for
+ * too long, and also prevent deadlocks if tracing programs end up
+ * executing on entry/exit of functions called inside the critical
+ * section, and end up doing map ops that call bpf_list_head_free for
+ * the same map value again.
+ */
+ __bpf_spin_lock_irqsave(spin_lock);
+ if (!head->next || list_empty(head))
+ goto unlock;
+ head = head->next;
+unlock:
+ INIT_LIST_HEAD(orig_head);
+ __bpf_spin_unlock_irqrestore(spin_lock);
+
+ while (head != orig_head) {
+ void *obj = head;
+
+ obj -= field->list_head.node_offset;
+ head = head->next;
+ /* The contained type can also have resources, including a
+ * bpf_list_head which needs to be freed.
+ */
+ bpf_obj_free_fields(field->list_head.value_rec, obj);
+ /* bpf_mem_free requires migrate_disable(), since we can be
+ * called from map free path as well apart from BPF program (as
+ * part of map ops doing bpf_obj_free_fields).
+ */
+ migrate_disable();
+ bpf_mem_free(&bpf_global_ma, obj);
+ migrate_enable();
+ }
+}
+
+__diag_push();
+__diag_ignore_all("-Wmissing-prototypes",
+ "Global functions as their definitions will be in vmlinux BTF");
+
+void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign)
+{
+ struct btf_struct_meta *meta = meta__ign;
+ u64 size = local_type_id__k;
+ void *p;
+
+ p = bpf_mem_alloc(&bpf_global_ma, size);
+ if (!p)
+ return NULL;
+ if (meta)
+ bpf_obj_init(meta->field_offs, p);
+ return p;
+}
+
+void bpf_obj_drop_impl(void *p__alloc, void *meta__ign)
+{
+ struct btf_struct_meta *meta = meta__ign;
+ void *p = p__alloc;
+
+ if (meta)
+ bpf_obj_free_fields(meta->record, p);
+ bpf_mem_free(&bpf_global_ma, p);
+}
+
+static void __bpf_list_add(struct bpf_list_node *node, struct bpf_list_head *head, bool tail)
+{
+ struct list_head *n = (void *)node, *h = (void *)head;
+
+ if (unlikely(!h->next))
+ INIT_LIST_HEAD(h);
+ if (unlikely(!n->next))
+ INIT_LIST_HEAD(n);
+ tail ? list_add_tail(n, h) : list_add(n, h);
+}
+
+void bpf_list_push_front(struct bpf_list_head *head, struct bpf_list_node *node)
+{
+ return __bpf_list_add(node, head, false);
+}
+
+void bpf_list_push_back(struct bpf_list_head *head, struct bpf_list_node *node)
+{
+ return __bpf_list_add(node, head, true);
+}
+
+static struct bpf_list_node *__bpf_list_del(struct bpf_list_head *head, bool tail)
+{
+ struct list_head *n, *h = (void *)head;
+
+ if (unlikely(!h->next))
+ INIT_LIST_HEAD(h);
+ if (list_empty(h))
+ return NULL;
+ n = tail ? h->prev : h->next;
+ list_del_init(n);
+ return (struct bpf_list_node *)n;
+}
+
+struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head)
+{
+ return __bpf_list_del(head, false);
+}
+
+struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head)
+{
+ return __bpf_list_del(head, true);
+}
+
+/**
+ * bpf_task_acquire - Acquire a reference to a task. A task acquired by this
+ * kfunc which is not stored in a map as a kptr, must be released by calling
+ * bpf_task_release().
+ * @p: The task on which a reference is being acquired.
+ */
+struct task_struct *bpf_task_acquire(struct task_struct *p)
+{
+ return get_task_struct(p);
+}
+
+/**
+ * bpf_task_acquire_not_zero - Acquire a reference to a rcu task object. A task
+ * acquired by this kfunc which is not stored in a map as a kptr, must be
+ * released by calling bpf_task_release().
+ * @p: The task on which a reference is being acquired.
+ */
+struct task_struct *bpf_task_acquire_not_zero(struct task_struct *p)
+{
+ /* For the time being this function returns NULL, as it's not currently
+ * possible to safely acquire a reference to a task with RCU protection
+ * using get_task_struct() and put_task_struct(). This is due to the
+ * slightly odd mechanics of p->rcu_users, and how task RCU protection
+ * works.
+ *
+ * A struct task_struct is refcounted by two different refcount_t
+ * fields:
+ *
+ * 1. p->usage: The "true" refcount field which tracks a task's
+ * lifetime. The task is freed as soon as this
+ * refcount drops to 0.
+ *
+ * 2. p->rcu_users: An "RCU users" refcount field which is statically
+ * initialized to 2, and is co-located in a union with
+ * a struct rcu_head field (p->rcu). p->rcu_users
+ * essentially encapsulates a single p->usage
+ * refcount, and when p->rcu_users goes to 0, an RCU
+ * callback is scheduled on the struct rcu_head which
+ * decrements the p->usage refcount.
+ *
+ * There are two important implications to this task refcounting logic
+ * described above. The first is that
+ * refcount_inc_not_zero(&p->rcu_users) cannot be used anywhere, as
+ * after the refcount goes to 0, the RCU callback being scheduled will
+ * cause the memory backing the refcount to again be nonzero due to the
+ * fields sharing a union. The other is that we can't rely on RCU to
+ * guarantee that a task is valid in a BPF program. This is because a
+ * task could have already transitioned to being in the TASK_DEAD
+ * state, had its rcu_users refcount go to 0, and its rcu callback
+ * invoked in which it drops its single p->usage reference. At this
+ * point the task will be freed as soon as the last p->usage reference
+ * goes to 0, without waiting for another RCU gp to elapse. The only
+ * way that a BPF program can guarantee that a task is valid is in this
+ * scenario is to hold a p->usage refcount itself.
+ *
+ * Until we're able to resolve this issue, either by pulling
+ * p->rcu_users and p->rcu out of the union, or by getting rid of
+ * p->usage and just using p->rcu_users for refcounting, we'll just
+ * return NULL here.
+ */
+ return NULL;
+}
+
+/**
+ * bpf_task_kptr_get - Acquire a reference on a struct task_struct kptr. A task
+ * kptr acquired by this kfunc which is not subsequently stored in a map, must
+ * be released by calling bpf_task_release().
+ * @pp: A pointer to a task kptr on which a reference is being acquired.
+ */
+struct task_struct *bpf_task_kptr_get(struct task_struct **pp)
+{
+ /* We must return NULL here until we have clarity on how to properly
+ * leverage RCU for ensuring a task's lifetime. See the comment above
+ * in bpf_task_acquire_not_zero() for more details.
+ */
+ return NULL;
+}
+
+/**
+ * bpf_task_release - Release the reference acquired on a task.
+ * @p: The task on which a reference is being released.
+ */
+void bpf_task_release(struct task_struct *p)
+{
+ if (!p)
+ return;
+
+ put_task_struct(p);
+}
+
+#ifdef CONFIG_CGROUPS
+/**
+ * bpf_cgroup_acquire - Acquire a reference to a cgroup. A cgroup acquired by
+ * this kfunc which is not stored in a map as a kptr, must be released by
+ * calling bpf_cgroup_release().
+ * @cgrp: The cgroup on which a reference is being acquired.
+ */
+struct cgroup *bpf_cgroup_acquire(struct cgroup *cgrp)
+{
+ cgroup_get(cgrp);
+ return cgrp;
+}
+
+/**
+ * bpf_cgroup_kptr_get - Acquire a reference on a struct cgroup kptr. A cgroup
+ * kptr acquired by this kfunc which is not subsequently stored in a map, must
+ * be released by calling bpf_cgroup_release().
+ * @cgrpp: A pointer to a cgroup kptr on which a reference is being acquired.
+ */
+struct cgroup *bpf_cgroup_kptr_get(struct cgroup **cgrpp)
+{
+ struct cgroup *cgrp;
+
+ rcu_read_lock();
+ /* Another context could remove the cgroup from the map and release it
+ * at any time, including after we've done the lookup above. This is
+ * safe because we're in an RCU read region, so the cgroup is
+ * guaranteed to remain valid until at least the rcu_read_unlock()
+ * below.
+ */
+ cgrp = READ_ONCE(*cgrpp);
+
+ if (cgrp && !cgroup_tryget(cgrp))
+ /* If the cgroup had been removed from the map and freed as
+ * described above, cgroup_tryget() will return false. The
+ * cgroup will be freed at some point after the current RCU gp
+ * has ended, so just return NULL to the user.
+ */
+ cgrp = NULL;
+ rcu_read_unlock();
+
+ return cgrp;
+}
+
+/**
+ * bpf_cgroup_release - Release the reference acquired on a cgroup.
+ * If this kfunc is invoked in an RCU read region, the cgroup is guaranteed to
+ * not be freed until the current grace period has ended, even if its refcount
+ * drops to 0.
+ * @cgrp: The cgroup on which a reference is being released.
+ */
+void bpf_cgroup_release(struct cgroup *cgrp)
+{
+ if (!cgrp)
+ return;
+
+ cgroup_put(cgrp);
+}
+
+/**
+ * bpf_cgroup_ancestor - Perform a lookup on an entry in a cgroup's ancestor
+ * array. A cgroup returned by this kfunc which is not subsequently stored in a
+ * map, must be released by calling bpf_cgroup_release().
+ * @cgrp: The cgroup for which we're performing a lookup.
+ * @level: The level of ancestor to look up.
+ */
+struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level)
+{
+ struct cgroup *ancestor;
+
+ if (level > cgrp->level || level < 0)
+ return NULL;
+
+ ancestor = cgrp->ancestors[level];
+ cgroup_get(ancestor);
+ return ancestor;
+}
+#endif /* CONFIG_CGROUPS */
+
+/**
+ * bpf_task_from_pid - Find a struct task_struct from its pid by looking it up
+ * in the root pid namespace idr. If a task is returned, it must either be
+ * stored in a map, or released with bpf_task_release().
+ * @pid: The pid of the task being looked up.
+ */
+struct task_struct *bpf_task_from_pid(s32 pid)
+{
+ struct task_struct *p;
+
+ rcu_read_lock();
+ p = find_task_by_pid_ns(pid, &init_pid_ns);
+ if (p)
+ bpf_task_acquire(p);
+ rcu_read_unlock();
+
+ return p;
+}
+
+void *bpf_cast_to_kern_ctx(void *obj)
+{
+ return obj;
+}
+
+void *bpf_rdonly_cast(void *obj__ign, u32 btf_id__k)
+{
+ return obj__ign;
+}
+
+void bpf_rcu_read_lock(void)
+{
+ rcu_read_lock();
+}
+
+void bpf_rcu_read_unlock(void)
+{
+ rcu_read_unlock();
+}
+
+__diag_pop();
+
+BTF_SET8_START(generic_btf_ids)
#ifdef CONFIG_KEXEC_CORE
BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE)
#endif
-BTF_SET8_END(tracing_btf_ids)
+BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_list_push_front)
+BTF_ID_FLAGS(func, bpf_list_push_back)
+BTF_ID_FLAGS(func, bpf_list_pop_front, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_list_pop_back, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_task_acquire_not_zero, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_task_kptr_get, KF_ACQUIRE | KF_KPTR_GET | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_task_release, KF_RELEASE)
+#ifdef CONFIG_CGROUPS
+BTF_ID_FLAGS(func, bpf_cgroup_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_cgroup_kptr_get, KF_ACQUIRE | KF_KPTR_GET | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_TRUSTED_ARGS | KF_RET_NULL)
+#endif
+BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
+BTF_SET8_END(generic_btf_ids)
-static const struct btf_kfunc_id_set tracing_kfunc_set = {
+static const struct btf_kfunc_id_set generic_kfunc_set = {
.owner = THIS_MODULE,
- .set = &tracing_btf_ids,
+ .set = &generic_btf_ids,
+};
+
+
+BTF_ID_LIST(generic_dtor_ids)
+BTF_ID(struct, task_struct)
+BTF_ID(func, bpf_task_release)
+#ifdef CONFIG_CGROUPS
+BTF_ID(struct, cgroup)
+BTF_ID(func, bpf_cgroup_release)
+#endif
+
+BTF_SET8_START(common_btf_ids)
+BTF_ID_FLAGS(func, bpf_cast_to_kern_ctx)
+BTF_ID_FLAGS(func, bpf_rdonly_cast)
+BTF_ID_FLAGS(func, bpf_rcu_read_lock)
+BTF_ID_FLAGS(func, bpf_rcu_read_unlock)
+BTF_SET8_END(common_btf_ids)
+
+static const struct btf_kfunc_id_set common_kfunc_set = {
+ .owner = THIS_MODULE,
+ .set = &common_btf_ids,
};
static int __init kfunc_init(void)
{
- return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &tracing_kfunc_set);
+ int ret;
+ const struct btf_id_dtor_kfunc generic_dtors[] = {
+ {
+ .btf_id = generic_dtor_ids[0],
+ .kfunc_btf_id = generic_dtor_ids[1]
+ },
+#ifdef CONFIG_CGROUPS
+ {
+ .btf_id = generic_dtor_ids[2],
+ .kfunc_btf_id = generic_dtor_ids[3]
+ },
+#endif
+ };
+
+ ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set);
+ ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &generic_kfunc_set);
+ ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);
+ ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,
+ ARRAY_SIZE(generic_dtors),
+ THIS_MODULE);
+ return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &common_kfunc_set);
}
late_initcall(kfunc_init);
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index 098cf336fae6..e90d9f63edc5 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -151,7 +151,7 @@ static int cgroup_storage_update_elem(struct bpf_map *map, void *key,
return -EINVAL;
if (unlikely((flags & BPF_F_LOCK) &&
- !map_value_has_spin_lock(map)))
+ !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
return -EINVAL;
storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c
index 135205d0d560..38136ec4e095 100644
--- a/kernel/bpf/map_in_map.c
+++ b/kernel/bpf/map_in_map.c
@@ -12,6 +12,7 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
struct bpf_map *inner_map, *inner_map_meta;
u32 inner_map_meta_size;
struct fd f;
+ int ret;
f = fdget(inner_map_ufd);
inner_map = __bpf_map_get(f);
@@ -20,18 +21,13 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
/* Does not support >1 level map-in-map */
if (inner_map->inner_map_meta) {
- fdput(f);
- return ERR_PTR(-EINVAL);
+ ret = -EINVAL;
+ goto put;
}
if (!inner_map->ops->map_meta_equal) {
- fdput(f);
- return ERR_PTR(-ENOTSUPP);
- }
-
- if (map_value_has_spin_lock(inner_map)) {
- fdput(f);
- return ERR_PTR(-ENOTSUPP);
+ ret = -ENOTSUPP;
+ goto put;
}
inner_map_meta_size = sizeof(*inner_map_meta);
@@ -41,8 +37,8 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
inner_map_meta = kzalloc(inner_map_meta_size, GFP_USER);
if (!inner_map_meta) {
- fdput(f);
- return ERR_PTR(-ENOMEM);
+ ret = -ENOMEM;
+ goto put;
}
inner_map_meta->map_type = inner_map->map_type;
@@ -50,9 +46,33 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
inner_map_meta->value_size = inner_map->value_size;
inner_map_meta->map_flags = inner_map->map_flags;
inner_map_meta->max_entries = inner_map->max_entries;
- inner_map_meta->spin_lock_off = inner_map->spin_lock_off;
- inner_map_meta->timer_off = inner_map->timer_off;
- inner_map_meta->kptr_off_tab = bpf_map_copy_kptr_off_tab(inner_map);
+
+ inner_map_meta->record = btf_record_dup(inner_map->record);
+ if (IS_ERR(inner_map_meta->record)) {
+ /* btf_record_dup returns NULL or valid pointer in case of
+ * invalid/empty/valid, but ERR_PTR in case of errors. During
+ * equality NULL or IS_ERR is equivalent.
+ */
+ ret = PTR_ERR(inner_map_meta->record);
+ goto free;
+ }
+ if (inner_map_meta->record) {
+ struct btf_field_offs *field_offs;
+ /* If btf_record is !IS_ERR_OR_NULL, then field_offs is always
+ * valid.
+ */
+ field_offs = kmemdup(inner_map->field_offs, sizeof(*inner_map->field_offs), GFP_KERNEL | __GFP_NOWARN);
+ if (!field_offs) {
+ ret = -ENOMEM;
+ goto free_rec;
+ }
+ inner_map_meta->field_offs = field_offs;
+ }
+ /* Note: We must use the same BTF, as we also used btf_record_dup above
+ * which relies on BTF being same for both maps, as some members like
+ * record->fields.list_head have pointers like value_rec pointing into
+ * inner_map->btf.
+ */
if (inner_map->btf) {
btf_get(inner_map->btf);
inner_map_meta->btf = inner_map->btf;
@@ -68,11 +88,19 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
fdput(f);
return inner_map_meta;
+free_rec:
+ btf_record_free(inner_map_meta->record);
+free:
+ kfree(inner_map_meta);
+put:
+ fdput(f);
+ return ERR_PTR(ret);
}
void bpf_map_meta_free(struct bpf_map *map_meta)
{
- bpf_map_free_kptr_off_tab(map_meta);
+ kfree(map_meta->field_offs);
+ bpf_map_free_record(map_meta);
btf_put(map_meta->btf);
kfree(map_meta);
}
@@ -84,9 +112,8 @@ bool bpf_map_meta_equal(const struct bpf_map *meta0,
return meta0->map_type == meta1->map_type &&
meta0->key_size == meta1->key_size &&
meta0->value_size == meta1->value_size &&
- meta0->timer_off == meta1->timer_off &&
meta0->map_flags == meta1->map_flags &&
- bpf_map_equal_kptr_off_tab(meta0, meta1);
+ btf_record_equal(meta0->record, meta1->record);
}
void *bpf_map_fd_get_ptr(struct bpf_map *map,
diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index 4901fa1048cd..ebcc3dd0fa19 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -171,9 +171,24 @@ static void alloc_bulk(struct bpf_mem_cache *c, int cnt, int node)
memcg = get_memcg(c);
old_memcg = set_active_memcg(memcg);
for (i = 0; i < cnt; i++) {
- obj = __alloc(c, node);
- if (!obj)
- break;
+ /*
+ * free_by_rcu is only manipulated by irq work refill_work().
+ * IRQ works on the same CPU are called sequentially, so it is
+ * safe to use __llist_del_first() here. If alloc_bulk() is
+ * invoked by the initial prefill, there will be no running
+ * refill_work(), so __llist_del_first() is fine as well.
+ *
+ * In most cases, objects on free_by_rcu are from the same CPU.
+ * If some objects come from other CPUs, it doesn't incur any
+ * harm because NUMA_NO_NODE means the preference for current
+ * numa node and it is not a guarantee.
+ */
+ obj = __llist_del_first(&c->free_by_rcu);
+ if (!obj) {
+ obj = __alloc(c, node);
+ if (!obj)
+ break;
+ }
if (IS_ENABLED(CONFIG_PREEMPT_RT))
/* In RT irq_work runs in per-cpu kthread, so disable
* interrupts to avoid preemption and interrupts and
@@ -222,9 +237,13 @@ static void __free_rcu(struct rcu_head *head)
static void __free_rcu_tasks_trace(struct rcu_head *head)
{
- struct bpf_mem_cache *c = container_of(head, struct bpf_mem_cache, rcu);
-
- call_rcu(&c->rcu, __free_rcu);
+ /* If RCU Tasks Trace grace period implies RCU grace period,
+ * there is no need to invoke call_rcu().
+ */
+ if (rcu_trace_implies_rcu_gp())
+ __free_rcu(head);
+ else
+ call_rcu(head, __free_rcu);
}
static void enque_to_free(struct bpf_mem_cache *c, void *obj)
@@ -253,8 +272,9 @@ static void do_call_rcu(struct bpf_mem_cache *c)
*/
__llist_add(llnode, &c->waiting_for_gp);
/* Use call_rcu_tasks_trace() to wait for sleepable progs to finish.
- * Then use call_rcu() to wait for normal progs to finish
- * and finally do free_one() on each element.
+ * If RCU Tasks Trace grace period implies RCU grace period, free
+ * these elements directly, else use call_rcu() to wait for normal
+ * progs to finish and finally do free_one() on each element.
*/
call_rcu_tasks_trace(&c->rcu, __free_rcu_tasks_trace);
}
@@ -444,9 +464,17 @@ static void free_mem_alloc(struct bpf_mem_alloc *ma)
{
/* waiting_for_gp lists was drained, but __free_rcu might
* still execute. Wait for it now before we freeing percpu caches.
+ *
+ * rcu_barrier_tasks_trace() doesn't imply synchronize_rcu_tasks_trace(),
+ * but rcu_barrier_tasks_trace() and rcu_barrier() below are only used
+ * to wait for the pending __free_rcu_tasks_trace() and __free_rcu(),
+ * so if call_rcu(head, __free_rcu) is skipped due to
+ * rcu_trace_implies_rcu_gp(), it will be OK to skip rcu_barrier() by
+ * using rcu_trace_implies_rcu_gp() as well.
*/
rcu_barrier_tasks_trace();
- rcu_barrier();
+ if (!rcu_trace_implies_rcu_gp())
+ rcu_barrier();
free_mem_alloc_no_barrier(ma);
}
diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c
index 9e832acf4692..80f4b4d88aaf 100644
--- a/kernel/bpf/ringbuf.c
+++ b/kernel/bpf/ringbuf.c
@@ -447,7 +447,7 @@ BPF_CALL_3(bpf_ringbuf_reserve, struct bpf_map *, map, u64, size, u64, flags)
const struct bpf_func_proto bpf_ringbuf_reserve_proto = {
.func = bpf_ringbuf_reserve,
- .ret_type = RET_PTR_TO_ALLOC_MEM_OR_NULL,
+ .ret_type = RET_PTR_TO_RINGBUF_MEM_OR_NULL,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_CONST_ALLOC_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
@@ -490,7 +490,7 @@ BPF_CALL_2(bpf_ringbuf_submit, void *, sample, u64, flags)
const struct bpf_func_proto bpf_ringbuf_submit_proto = {
.func = bpf_ringbuf_submit,
.ret_type = RET_VOID,
- .arg1_type = ARG_PTR_TO_ALLOC_MEM | OBJ_RELEASE,
+ .arg1_type = ARG_PTR_TO_RINGBUF_MEM | OBJ_RELEASE,
.arg2_type = ARG_ANYTHING,
};
@@ -503,7 +503,7 @@ BPF_CALL_2(bpf_ringbuf_discard, void *, sample, u64, flags)
const struct bpf_func_proto bpf_ringbuf_discard_proto = {
.func = bpf_ringbuf_discard,
.ret_type = RET_VOID,
- .arg1_type = ARG_PTR_TO_ALLOC_MEM | OBJ_RELEASE,
+ .arg1_type = ARG_PTR_TO_RINGBUF_MEM | OBJ_RELEASE,
.arg2_type = ARG_ANYTHING,
};
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7b373a5e861f..35972afb6850 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -175,8 +175,8 @@ static void maybe_wait_bpf_programs(struct bpf_map *map)
synchronize_rcu();
}
-static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
- void *value, __u64 flags)
+static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
+ void *key, void *value, __u64 flags)
{
int err;
@@ -190,7 +190,7 @@ static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
map->map_type == BPF_MAP_TYPE_SOCKMAP) {
return sock_map_update_elem_sys(map, key, value, flags);
} else if (IS_FD_PROG_ARRAY(map)) {
- return bpf_fd_array_map_update_elem(map, f.file, key, value,
+ return bpf_fd_array_map_update_elem(map, map_file, key, value,
flags);
}
@@ -205,12 +205,12 @@ static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
flags);
} else if (IS_FD_ARRAY(map)) {
rcu_read_lock();
- err = bpf_fd_array_map_update_elem(map, f.file, key, value,
+ err = bpf_fd_array_map_update_elem(map, map_file, key, value,
flags);
rcu_read_unlock();
} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
rcu_read_lock();
- err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
+ err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
flags);
rcu_read_unlock();
} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
@@ -495,114 +495,181 @@ static void bpf_map_release_memcg(struct bpf_map *map)
}
#endif
-static int bpf_map_kptr_off_cmp(const void *a, const void *b)
+static int btf_field_cmp(const void *a, const void *b)
{
- const struct bpf_map_value_off_desc *off_desc1 = a, *off_desc2 = b;
+ const struct btf_field *f1 = a, *f2 = b;
- if (off_desc1->offset < off_desc2->offset)
+ if (f1->offset < f2->offset)
return -1;
- else if (off_desc1->offset > off_desc2->offset)
+ else if (f1->offset > f2->offset)
return 1;
return 0;
}
-struct bpf_map_value_off_desc *bpf_map_kptr_off_contains(struct bpf_map *map, u32 offset)
+struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
+ enum btf_field_type type)
{
- /* Since members are iterated in btf_find_field in increasing order,
- * offsets appended to kptr_off_tab are in increasing order, so we can
- * do bsearch to find exact match.
- */
- struct bpf_map_value_off *tab;
+ struct btf_field *field;
- if (!map_value_has_kptrs(map))
+ if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & type))
+ return NULL;
+ field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
+ if (!field || !(field->type & type))
return NULL;
- tab = map->kptr_off_tab;
- return bsearch(&offset, tab->off, tab->nr_off, sizeof(tab->off[0]), bpf_map_kptr_off_cmp);
+ return field;
}
-void bpf_map_free_kptr_off_tab(struct bpf_map *map)
+void btf_record_free(struct btf_record *rec)
{
- struct bpf_map_value_off *tab = map->kptr_off_tab;
int i;
- if (!map_value_has_kptrs(map))
+ if (IS_ERR_OR_NULL(rec))
return;
- for (i = 0; i < tab->nr_off; i++) {
- if (tab->off[i].kptr.module)
- module_put(tab->off[i].kptr.module);
- btf_put(tab->off[i].kptr.btf);
+ for (i = 0; i < rec->cnt; i++) {
+ switch (rec->fields[i].type) {
+ case BPF_SPIN_LOCK:
+ case BPF_TIMER:
+ break;
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
+ if (rec->fields[i].kptr.module)
+ module_put(rec->fields[i].kptr.module);
+ btf_put(rec->fields[i].kptr.btf);
+ break;
+ case BPF_LIST_HEAD:
+ case BPF_LIST_NODE:
+ /* Nothing to release for bpf_list_head */
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ continue;
+ }
}
- kfree(tab);
- map->kptr_off_tab = NULL;
+ kfree(rec);
}
-struct bpf_map_value_off *bpf_map_copy_kptr_off_tab(const struct bpf_map *map)
+void bpf_map_free_record(struct bpf_map *map)
{
- struct bpf_map_value_off *tab = map->kptr_off_tab, *new_tab;
- int size, i;
+ btf_record_free(map->record);
+ map->record = NULL;
+}
- if (!map_value_has_kptrs(map))
- return ERR_PTR(-ENOENT);
- size = offsetof(struct bpf_map_value_off, off[tab->nr_off]);
- new_tab = kmemdup(tab, size, GFP_KERNEL | __GFP_NOWARN);
- if (!new_tab)
+struct btf_record *btf_record_dup(const struct btf_record *rec)
+{
+ const struct btf_field *fields;
+ struct btf_record *new_rec;
+ int ret, size, i;
+
+ if (IS_ERR_OR_NULL(rec))
+ return NULL;
+ size = offsetof(struct btf_record, fields[rec->cnt]);
+ new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
+ if (!new_rec)
return ERR_PTR(-ENOMEM);
- /* Do a deep copy of the kptr_off_tab */
- for (i = 0; i < tab->nr_off; i++) {
- btf_get(tab->off[i].kptr.btf);
- if (tab->off[i].kptr.module && !try_module_get(tab->off[i].kptr.module)) {
- while (i--) {
- if (tab->off[i].kptr.module)
- module_put(tab->off[i].kptr.module);
- btf_put(tab->off[i].kptr.btf);
+ /* Do a deep copy of the btf_record */
+ fields = rec->fields;
+ new_rec->cnt = 0;
+ for (i = 0; i < rec->cnt; i++) {
+ switch (fields[i].type) {
+ case BPF_SPIN_LOCK:
+ case BPF_TIMER:
+ break;
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
+ btf_get(fields[i].kptr.btf);
+ if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
+ ret = -ENXIO;
+ goto free;
}
- kfree(new_tab);
- return ERR_PTR(-ENXIO);
+ break;
+ case BPF_LIST_HEAD:
+ case BPF_LIST_NODE:
+ /* Nothing to acquire for bpf_list_head */
+ break;
+ default:
+ ret = -EFAULT;
+ WARN_ON_ONCE(1);
+ goto free;
}
+ new_rec->cnt++;
}
- return new_tab;
+ return new_rec;
+free:
+ btf_record_free(new_rec);
+ return ERR_PTR(ret);
}
-bool bpf_map_equal_kptr_off_tab(const struct bpf_map *map_a, const struct bpf_map *map_b)
+bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
{
- struct bpf_map_value_off *tab_a = map_a->kptr_off_tab, *tab_b = map_b->kptr_off_tab;
- bool a_has_kptr = map_value_has_kptrs(map_a), b_has_kptr = map_value_has_kptrs(map_b);
+ bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
int size;
- if (!a_has_kptr && !b_has_kptr)
+ if (!a_has_fields && !b_has_fields)
return true;
- if (a_has_kptr != b_has_kptr)
+ if (a_has_fields != b_has_fields)
return false;
- if (tab_a->nr_off != tab_b->nr_off)
+ if (rec_a->cnt != rec_b->cnt)
return false;
- size = offsetof(struct bpf_map_value_off, off[tab_a->nr_off]);
- return !memcmp(tab_a, tab_b, size);
+ size = offsetof(struct btf_record, fields[rec_a->cnt]);
+ /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
+ * members are zeroed out. So memcmp is safe to do without worrying
+ * about padding/unused fields.
+ *
+ * While spin_lock, timer, and kptr have no relation to map BTF,
+ * list_head metadata is specific to map BTF, the btf and value_rec
+ * members in particular. btf is the map BTF, while value_rec points to
+ * btf_record in that map BTF.
+ *
+ * So while by default, we don't rely on the map BTF (which the records
+ * were parsed from) matching for both records, which is not backwards
+ * compatible, in case list_head is part of it, we implicitly rely on
+ * that by way of depending on memcmp succeeding for it.
+ */
+ return !memcmp(rec_a, rec_b, size);
}
-/* Caller must ensure map_value_has_kptrs is true. Note that this function can
- * be called on a map value while the map_value is visible to BPF programs, as
- * it ensures the correct synchronization, and we already enforce the same using
- * the bpf_kptr_xchg helper on the BPF program side for referenced kptrs.
- */
-void bpf_map_free_kptrs(struct bpf_map *map, void *map_value)
+void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
{
- struct bpf_map_value_off *tab = map->kptr_off_tab;
- unsigned long *btf_id_ptr;
- int i;
+ if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
+ return;
+ bpf_timer_cancel_and_free(obj + rec->timer_off);
+}
- for (i = 0; i < tab->nr_off; i++) {
- struct bpf_map_value_off_desc *off_desc = &tab->off[i];
- unsigned long old_ptr;
+void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
+{
+ const struct btf_field *fields;
+ int i;
- btf_id_ptr = map_value + off_desc->offset;
- if (off_desc->type == BPF_KPTR_UNREF) {
- u64 *p = (u64 *)btf_id_ptr;
+ if (IS_ERR_OR_NULL(rec))
+ return;
+ fields = rec->fields;
+ for (i = 0; i < rec->cnt; i++) {
+ const struct btf_field *field = &fields[i];
+ void *field_ptr = obj + field->offset;
- WRITE_ONCE(*p, 0);
+ switch (fields[i].type) {
+ case BPF_SPIN_LOCK:
+ break;
+ case BPF_TIMER:
+ bpf_timer_cancel_and_free(field_ptr);
+ break;
+ case BPF_KPTR_UNREF:
+ WRITE_ONCE(*(u64 *)field_ptr, 0);
+ break;
+ case BPF_KPTR_REF:
+ field->kptr.dtor((void *)xchg((unsigned long *)field_ptr, 0));
+ break;
+ case BPF_LIST_HEAD:
+ if (WARN_ON_ONCE(rec->spin_lock_off < 0))
+ continue;
+ bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
+ break;
+ case BPF_LIST_NODE:
+ break;
+ default:
+ WARN_ON_ONCE(1);
continue;
}
- old_ptr = xchg(btf_id_ptr, 0);
- off_desc->kptr.dtor((void *)old_ptr);
}
}
@@ -610,14 +677,24 @@ void bpf_map_free_kptrs(struct bpf_map *map, void *map_value)
static void bpf_map_free_deferred(struct work_struct *work)
{
struct bpf_map *map = container_of(work, struct bpf_map, work);
+ struct btf_field_offs *foffs = map->field_offs;
+ struct btf_record *rec = map->record;
security_bpf_map_free(map);
- kfree(map->off_arr);
bpf_map_release_memcg(map);
- /* implementation dependent freeing, map_free callback also does
- * bpf_map_free_kptr_off_tab, if needed.
- */
+ /* implementation dependent freeing */
map->ops->map_free(map);
+ /* Delay freeing of field_offs and btf_record for maps, as map_free
+ * callback usually needs access to them. It is better to do it here
+ * than require each callback to do the free itself manually.
+ *
+ * Note that the btf_record stashed in map->inner_map_meta->record was
+ * already freed using the map_free callback for map in map case which
+ * eventually calls bpf_map_free_meta, since inner_map_meta is only a
+ * template bpf_map struct used during verification.
+ */
+ kfree(foffs);
+ btf_record_free(rec);
}
static void bpf_map_put_uref(struct bpf_map *map)
@@ -778,8 +855,7 @@ static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
struct bpf_map *map = filp->private_data;
int err;
- if (!map->ops->map_mmap || map_value_has_spin_lock(map) ||
- map_value_has_timer(map) || map_value_has_kptrs(map))
+ if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
return -ENOTSUPP;
if (!(vma->vm_flags & VM_SHARED))
@@ -906,84 +982,6 @@ int map_check_no_btf(const struct bpf_map *map,
return -ENOTSUPP;
}
-static int map_off_arr_cmp(const void *_a, const void *_b, const void *priv)
-{
- const u32 a = *(const u32 *)_a;
- const u32 b = *(const u32 *)_b;
-
- if (a < b)
- return -1;
- else if (a > b)
- return 1;
- return 0;
-}
-
-static void map_off_arr_swap(void *_a, void *_b, int size, const void *priv)
-{
- struct bpf_map *map = (struct bpf_map *)priv;
- u32 *off_base = map->off_arr->field_off;
- u32 *a = _a, *b = _b;
- u8 *sz_a, *sz_b;
-
- sz_a = map->off_arr->field_sz + (a - off_base);
- sz_b = map->off_arr->field_sz + (b - off_base);
-
- swap(*a, *b);
- swap(*sz_a, *sz_b);
-}
-
-static int bpf_map_alloc_off_arr(struct bpf_map *map)
-{
- bool has_spin_lock = map_value_has_spin_lock(map);
- bool has_timer = map_value_has_timer(map);
- bool has_kptrs = map_value_has_kptrs(map);
- struct bpf_map_off_arr *off_arr;
- u32 i;
-
- if (!has_spin_lock && !has_timer && !has_kptrs) {
- map->off_arr = NULL;
- return 0;
- }
-
- off_arr = kmalloc(sizeof(*map->off_arr), GFP_KERNEL | __GFP_NOWARN);
- if (!off_arr)
- return -ENOMEM;
- map->off_arr = off_arr;
-
- off_arr->cnt = 0;
- if (has_spin_lock) {
- i = off_arr->cnt;
-
- off_arr->field_off[i] = map->spin_lock_off;
- off_arr->field_sz[i] = sizeof(struct bpf_spin_lock);
- off_arr->cnt++;
- }
- if (has_timer) {
- i = off_arr->cnt;
-
- off_arr->field_off[i] = map->timer_off;
- off_arr->field_sz[i] = sizeof(struct bpf_timer);
- off_arr->cnt++;
- }
- if (has_kptrs) {
- struct bpf_map_value_off *tab = map->kptr_off_tab;
- u32 *off = &off_arr->field_off[off_arr->cnt];
- u8 *sz = &off_arr->field_sz[off_arr->cnt];
-
- for (i = 0; i < tab->nr_off; i++) {
- *off++ = tab->off[i].offset;
- *sz++ = sizeof(u64);
- }
- off_arr->cnt += tab->nr_off;
- }
-
- if (off_arr->cnt == 1)
- return 0;
- sort_r(off_arr->field_off, off_arr->cnt, sizeof(off_arr->field_off[0]),
- map_off_arr_cmp, map_off_arr_swap, map);
- return 0;
-}
-
static int map_check_btf(struct bpf_map *map, const struct btf *btf,
u32 btf_key_id, u32 btf_value_id)
{
@@ -1006,39 +1004,12 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
if (!value_type || value_size != map->value_size)
return -EINVAL;
- map->spin_lock_off = btf_find_spin_lock(btf, value_type);
-
- if (map_value_has_spin_lock(map)) {
- if (map->map_flags & BPF_F_RDONLY_PROG)
- return -EACCES;
- if (map->map_type != BPF_MAP_TYPE_HASH &&
- map->map_type != BPF_MAP_TYPE_ARRAY &&
- map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
- map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
- map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
- map->map_type != BPF_MAP_TYPE_TASK_STORAGE)
- return -ENOTSUPP;
- if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
- map->value_size) {
- WARN_ONCE(1,
- "verifier bug spin_lock_off %d value_size %d\n",
- map->spin_lock_off, map->value_size);
- return -EFAULT;
- }
- }
+ map->record = btf_parse_fields(btf, value_type,
+ BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD,
+ map->value_size);
+ if (!IS_ERR_OR_NULL(map->record)) {
+ int i;
- map->timer_off = btf_find_timer(btf, value_type);
- if (map_value_has_timer(map)) {
- if (map->map_flags & BPF_F_RDONLY_PROG)
- return -EACCES;
- if (map->map_type != BPF_MAP_TYPE_HASH &&
- map->map_type != BPF_MAP_TYPE_LRU_HASH &&
- map->map_type != BPF_MAP_TYPE_ARRAY)
- return -EOPNOTSUPP;
- }
-
- map->kptr_off_tab = btf_parse_kptrs(btf, value_type);
- if (map_value_has_kptrs(map)) {
if (!bpf_capable()) {
ret = -EPERM;
goto free_map_tab;
@@ -1047,15 +1018,60 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
ret = -EACCES;
goto free_map_tab;
}
- if (map->map_type != BPF_MAP_TYPE_HASH &&
- map->map_type != BPF_MAP_TYPE_LRU_HASH &&
- map->map_type != BPF_MAP_TYPE_ARRAY &&
- map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY) {
- ret = -EOPNOTSUPP;
- goto free_map_tab;
+ for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
+ switch (map->record->field_mask & (1 << i)) {
+ case 0:
+ continue;
+ case BPF_SPIN_LOCK:
+ if (map->map_type != BPF_MAP_TYPE_HASH &&
+ map->map_type != BPF_MAP_TYPE_ARRAY &&
+ map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
+ map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
+ map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
+ map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
+ map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
+ ret = -EOPNOTSUPP;
+ goto free_map_tab;
+ }
+ break;
+ case BPF_TIMER:
+ if (map->map_type != BPF_MAP_TYPE_HASH &&
+ map->map_type != BPF_MAP_TYPE_LRU_HASH &&
+ map->map_type != BPF_MAP_TYPE_ARRAY) {
+ ret = -EOPNOTSUPP;
+ goto free_map_tab;
+ }
+ break;
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
+ if (map->map_type != BPF_MAP_TYPE_HASH &&
+ map->map_type != BPF_MAP_TYPE_LRU_HASH &&
+ map->map_type != BPF_MAP_TYPE_ARRAY &&
+ map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY) {
+ ret = -EOPNOTSUPP;
+ goto free_map_tab;
+ }
+ break;
+ case BPF_LIST_HEAD:
+ if (map->map_type != BPF_MAP_TYPE_HASH &&
+ map->map_type != BPF_MAP_TYPE_LRU_HASH &&
+ map->map_type != BPF_MAP_TYPE_ARRAY) {
+ ret = -EOPNOTSUPP;
+ goto free_map_tab;
+ }
+ break;
+ default:
+ /* Fail if map_type checks are missing for a field type */
+ ret = -EOPNOTSUPP;
+ goto free_map_tab;
+ }
}
}
+ ret = btf_check_and_fixup_fields(btf, map->record);
+ if (ret < 0)
+ goto free_map_tab;
+
if (map->ops->map_check_btf) {
ret = map->ops->map_check_btf(map, btf, key_type, value_type);
if (ret < 0)
@@ -1064,7 +1080,7 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
return ret;
free_map_tab:
- bpf_map_free_kptr_off_tab(map);
+ bpf_map_free_record(map);
return ret;
}
@@ -1073,6 +1089,7 @@ free_map_tab:
static int map_create(union bpf_attr *attr)
{
int numa_node = bpf_map_attr_numa_node(attr);
+ struct btf_field_offs *foffs;
struct bpf_map *map;
int f_flags;
int err;
@@ -1117,8 +1134,6 @@ static int map_create(union bpf_attr *attr)
mutex_init(&map->freeze_mutex);
spin_lock_init(&map->owner.lock);
- map->spin_lock_off = -EINVAL;
- map->timer_off = -EINVAL;
if (attr->btf_key_type_id || attr->btf_value_type_id ||
/* Even the map's value is a kernel's struct,
* the bpf_prog.o must have BTF to begin with
@@ -1154,13 +1169,17 @@ static int map_create(union bpf_attr *attr)
attr->btf_vmlinux_value_type_id;
}
- err = bpf_map_alloc_off_arr(map);
- if (err)
+
+ foffs = btf_parse_field_offs(map->record);
+ if (IS_ERR(foffs)) {
+ err = PTR_ERR(foffs);
goto free_map;
+ }
+ map->field_offs = foffs;
err = security_bpf_map_alloc(map);
if (err)
- goto free_map_off_arr;
+ goto free_map_field_offs;
err = bpf_map_alloc_id(map);
if (err)
@@ -1184,8 +1203,8 @@ static int map_create(union bpf_attr *attr)
free_map_sec:
security_bpf_map_free(map);
-free_map_off_arr:
- kfree(map->off_arr);
+free_map_field_offs:
+ kfree(map->field_offs);
free_map:
btf_put(map->btf);
map->ops->map_free(map);
@@ -1332,7 +1351,7 @@ static int map_lookup_elem(union bpf_attr *attr)
}
if ((attr->flags & BPF_F_LOCK) &&
- !map_value_has_spin_lock(map)) {
+ !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
err = -EINVAL;
goto err_put;
}
@@ -1405,7 +1424,7 @@ static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
}
if ((attr->flags & BPF_F_LOCK) &&
- !map_value_has_spin_lock(map)) {
+ !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
err = -EINVAL;
goto err_put;
}
@@ -1423,7 +1442,7 @@ static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
goto free_key;
}
- err = bpf_map_update_value(map, f, key, value, attr->flags);
+ err = bpf_map_update_value(map, f.file, key, value, attr->flags);
kvfree(value);
free_key:
@@ -1568,7 +1587,7 @@ int generic_map_delete_batch(struct bpf_map *map,
return -EINVAL;
if ((attr->batch.elem_flags & BPF_F_LOCK) &&
- !map_value_has_spin_lock(map)) {
+ !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
return -EINVAL;
}
@@ -1609,23 +1628,21 @@ int generic_map_delete_batch(struct bpf_map *map,
return err;
}
-int generic_map_update_batch(struct bpf_map *map,
+int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
void __user *values = u64_to_user_ptr(attr->batch.values);
void __user *keys = u64_to_user_ptr(attr->batch.keys);
u32 value_size, cp, max_count;
- int ufd = attr->batch.map_fd;
void *key, *value;
- struct fd f;
int err = 0;
if (attr->batch.elem_flags & ~BPF_F_LOCK)
return -EINVAL;
if ((attr->batch.elem_flags & BPF_F_LOCK) &&
- !map_value_has_spin_lock(map)) {
+ !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
return -EINVAL;
}
@@ -1645,7 +1662,6 @@ int generic_map_update_batch(struct bpf_map *map,
return -ENOMEM;
}
- f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */
for (cp = 0; cp < max_count; cp++) {
err = -EFAULT;
if (copy_from_user(key, keys + cp * map->key_size,
@@ -1653,7 +1669,7 @@ int generic_map_update_batch(struct bpf_map *map,
copy_from_user(value, values + cp * value_size, value_size))
break;
- err = bpf_map_update_value(map, f, key, value,
+ err = bpf_map_update_value(map, map_file, key, value,
attr->batch.elem_flags);
if (err)
@@ -1666,7 +1682,6 @@ int generic_map_update_batch(struct bpf_map *map,
kvfree(value);
kvfree(key);
- fdput(f);
return err;
}
@@ -1688,7 +1703,7 @@ int generic_map_lookup_batch(struct bpf_map *map,
return -EINVAL;
if ((attr->batch.elem_flags & BPF_F_LOCK) &&
- !map_value_has_spin_lock(map))
+ !btf_record_has_field(map->record, BPF_SPIN_LOCK))
return -EINVAL;
value_size = bpf_map_value_size(map);
@@ -1810,7 +1825,7 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
}
if ((attr->flags & BPF_F_LOCK) &&
- !map_value_has_spin_lock(map)) {
+ !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
err = -EINVAL;
goto err_put;
}
@@ -1881,8 +1896,7 @@ static int map_freeze(const union bpf_attr *attr)
if (IS_ERR(map))
return PTR_ERR(map);
- if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS ||
- map_value_has_timer(map) || map_value_has_kptrs(map)) {
+ if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) {
fdput(f);
return -ENOTSUPP;
}
@@ -2117,11 +2131,11 @@ static void bpf_prog_get_stats(const struct bpf_prog *prog,
st = per_cpu_ptr(prog->stats, cpu);
do {
- start = u64_stats_fetch_begin_irq(&st->syncp);
+ start = u64_stats_fetch_begin(&st->syncp);
tnsecs = u64_stats_read(&st->nsecs);
tcnt = u64_stats_read(&st->cnt);
tmisses = u64_stats_read(&st->misses);
- } while (u64_stats_fetch_retry_irq(&st->syncp, start));
+ } while (u64_stats_fetch_retry(&st->syncp, start));
nsecs += tnsecs;
cnt += tcnt;
misses += tmisses;
@@ -4460,13 +4474,13 @@ put_file:
#define BPF_MAP_BATCH_LAST_FIELD batch.flags
-#define BPF_DO_BATCH(fn) \
+#define BPF_DO_BATCH(fn, ...) \
do { \
if (!fn) { \
err = -ENOTSUPP; \
goto err_put; \
} \
- err = fn(map, attr, uattr); \
+ err = fn(__VA_ARGS__); \
} while (0)
static int bpf_map_do_batch(const union bpf_attr *attr,
@@ -4500,13 +4514,13 @@ static int bpf_map_do_batch(const union bpf_attr *attr,
}
if (cmd == BPF_MAP_LOOKUP_BATCH)
- BPF_DO_BATCH(map->ops->map_lookup_batch);
+ BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
- BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch);
+ BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
else if (cmd == BPF_MAP_UPDATE_BATCH)
- BPF_DO_BATCH(map->ops->map_update_batch);
+ BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr);
else
- BPF_DO_BATCH(map->ops->map_delete_batch);
+ BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
err_put:
if (has_write)
bpf_map_write_active_dec(map);
@@ -5133,13 +5147,14 @@ int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
run_ctx.bpf_cookie = 0;
run_ctx.saved_run_ctx = NULL;
- if (!__bpf_prog_enter_sleepable(prog, &run_ctx)) {
+ if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
/* recursion detected */
bpf_prog_put(prog);
return -EBUSY;
}
attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
- __bpf_prog_exit_sleepable(prog, 0 /* bpf_prog_run does runtime stats */, &run_ctx);
+ __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
+ &run_ctx);
bpf_prog_put(prog);
return 0;
#endif
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index bf0906e1e2b9..d6395215b849 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -864,7 +864,7 @@ static __always_inline u64 notrace bpf_prog_start_time(void)
* [2..MAX_U64] - execute bpf prog and record execution time.
* This is start time.
*/
-u64 notrace __bpf_prog_enter(struct bpf_prog *prog, struct bpf_tramp_run_ctx *run_ctx)
+static u64 notrace __bpf_prog_enter_recur(struct bpf_prog *prog, struct bpf_tramp_run_ctx *run_ctx)
__acquires(RCU)
{
rcu_read_lock();
@@ -901,7 +901,8 @@ static void notrace update_prog_stats(struct bpf_prog *prog,
}
}
-void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start, struct bpf_tramp_run_ctx *run_ctx)
+static void notrace __bpf_prog_exit_recur(struct bpf_prog *prog, u64 start,
+ struct bpf_tramp_run_ctx *run_ctx)
__releases(RCU)
{
bpf_reset_run_ctx(run_ctx->saved_run_ctx);
@@ -912,8 +913,8 @@ void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start, struct bpf_tramp_
rcu_read_unlock();
}
-u64 notrace __bpf_prog_enter_lsm_cgroup(struct bpf_prog *prog,
- struct bpf_tramp_run_ctx *run_ctx)
+static u64 notrace __bpf_prog_enter_lsm_cgroup(struct bpf_prog *prog,
+ struct bpf_tramp_run_ctx *run_ctx)
__acquires(RCU)
{
/* Runtime stats are exported via actual BPF_LSM_CGROUP
@@ -927,8 +928,8 @@ u64 notrace __bpf_prog_enter_lsm_cgroup(struct bpf_prog *prog,
return NO_START_TIME;
}
-void notrace __bpf_prog_exit_lsm_cgroup(struct bpf_prog *prog, u64 start,
- struct bpf_tramp_run_ctx *run_ctx)
+static void notrace __bpf_prog_exit_lsm_cgroup(struct bpf_prog *prog, u64 start,
+ struct bpf_tramp_run_ctx *run_ctx)
__releases(RCU)
{
bpf_reset_run_ctx(run_ctx->saved_run_ctx);
@@ -937,7 +938,8 @@ void notrace __bpf_prog_exit_lsm_cgroup(struct bpf_prog *prog, u64 start,
rcu_read_unlock();
}
-u64 notrace __bpf_prog_enter_sleepable(struct bpf_prog *prog, struct bpf_tramp_run_ctx *run_ctx)
+u64 notrace __bpf_prog_enter_sleepable_recur(struct bpf_prog *prog,
+ struct bpf_tramp_run_ctx *run_ctx)
{
rcu_read_lock_trace();
migrate_disable();
@@ -953,8 +955,8 @@ u64 notrace __bpf_prog_enter_sleepable(struct bpf_prog *prog, struct bpf_tramp_r
return bpf_prog_start_time();
}
-void notrace __bpf_prog_exit_sleepable(struct bpf_prog *prog, u64 start,
- struct bpf_tramp_run_ctx *run_ctx)
+void notrace __bpf_prog_exit_sleepable_recur(struct bpf_prog *prog, u64 start,
+ struct bpf_tramp_run_ctx *run_ctx)
{
bpf_reset_run_ctx(run_ctx->saved_run_ctx);
@@ -964,8 +966,30 @@ void notrace __bpf_prog_exit_sleepable(struct bpf_prog *prog, u64 start,
rcu_read_unlock_trace();
}
-u64 notrace __bpf_prog_enter_struct_ops(struct bpf_prog *prog,
- struct bpf_tramp_run_ctx *run_ctx)
+static u64 notrace __bpf_prog_enter_sleepable(struct bpf_prog *prog,
+ struct bpf_tramp_run_ctx *run_ctx)
+{
+ rcu_read_lock_trace();
+ migrate_disable();
+ might_fault();
+
+ run_ctx->saved_run_ctx = bpf_set_run_ctx(&run_ctx->run_ctx);
+
+ return bpf_prog_start_time();
+}
+
+static void notrace __bpf_prog_exit_sleepable(struct bpf_prog *prog, u64 start,
+ struct bpf_tramp_run_ctx *run_ctx)
+{
+ bpf_reset_run_ctx(run_ctx->saved_run_ctx);
+
+ update_prog_stats(prog, start);
+ migrate_enable();
+ rcu_read_unlock_trace();
+}
+
+static u64 notrace __bpf_prog_enter(struct bpf_prog *prog,
+ struct bpf_tramp_run_ctx *run_ctx)
__acquires(RCU)
{
rcu_read_lock();
@@ -976,8 +1000,8 @@ u64 notrace __bpf_prog_enter_struct_ops(struct bpf_prog *prog,
return bpf_prog_start_time();
}
-void notrace __bpf_prog_exit_struct_ops(struct bpf_prog *prog, u64 start,
- struct bpf_tramp_run_ctx *run_ctx)
+static void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start,
+ struct bpf_tramp_run_ctx *run_ctx)
__releases(RCU)
{
bpf_reset_run_ctx(run_ctx->saved_run_ctx);
@@ -997,6 +1021,36 @@ void notrace __bpf_tramp_exit(struct bpf_tramp_image *tr)
percpu_ref_put(&tr->pcref);
}
+bpf_trampoline_enter_t bpf_trampoline_enter(const struct bpf_prog *prog)
+{
+ bool sleepable = prog->aux->sleepable;
+
+ if (bpf_prog_check_recur(prog))
+ return sleepable ? __bpf_prog_enter_sleepable_recur :
+ __bpf_prog_enter_recur;
+
+ if (resolve_prog_type(prog) == BPF_PROG_TYPE_LSM &&
+ prog->expected_attach_type == BPF_LSM_CGROUP)
+ return __bpf_prog_enter_lsm_cgroup;
+
+ return sleepable ? __bpf_prog_enter_sleepable : __bpf_prog_enter;
+}
+
+bpf_trampoline_exit_t bpf_trampoline_exit(const struct bpf_prog *prog)
+{
+ bool sleepable = prog->aux->sleepable;
+
+ if (bpf_prog_check_recur(prog))
+ return sleepable ? __bpf_prog_exit_sleepable_recur :
+ __bpf_prog_exit_recur;
+
+ if (resolve_prog_type(prog) == BPF_PROG_TYPE_LSM &&
+ prog->expected_attach_type == BPF_LSM_CGROUP)
+ return __bpf_prog_exit_lsm_cgroup;
+
+ return sleepable ? __bpf_prog_exit_sleepable : __bpf_prog_exit;
+}
+
int __weak
arch_prepare_bpf_trampoline(struct bpf_tramp_image *tr, void *image, void *image_end,
const struct btf_func_model *m, u32 flags,
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 264b3dc714cc..a5255a0dcbb6 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -262,7 +262,7 @@ struct bpf_call_arg_meta {
struct btf *ret_btf;
u32 ret_btf_id;
u32 subprogno;
- struct bpf_map_value_off_desc *kptr_off_desc;
+ struct btf_field *kptr_field;
u8 uninit_dynptr_regno;
};
@@ -451,17 +451,29 @@ static bool reg_type_not_null(enum bpf_reg_type type)
type == PTR_TO_SOCK_COMMON;
}
-static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
+static bool type_is_ptr_alloc_obj(u32 type)
{
- return reg->type == PTR_TO_MAP_VALUE &&
- map_value_has_spin_lock(reg->map_ptr);
+ return base_type(type) == PTR_TO_BTF_ID && type_flag(type) & MEM_ALLOC;
}
-static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type)
+static struct btf_record *reg_btf_record(const struct bpf_reg_state *reg)
{
- type = base_type(type);
- return type == PTR_TO_SOCKET || type == PTR_TO_TCP_SOCK ||
- type == PTR_TO_MEM || type == PTR_TO_BTF_ID;
+ struct btf_record *rec = NULL;
+ struct btf_struct_meta *meta;
+
+ if (reg->type == PTR_TO_MAP_VALUE) {
+ rec = reg->map_ptr->record;
+ } else if (type_is_ptr_alloc_obj(reg->type)) {
+ meta = btf_find_struct_meta(reg->btf, reg->btf_id);
+ if (meta)
+ rec = meta->record;
+ }
+ return rec;
+}
+
+static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
+{
+ return btf_record_has_field(reg_btf_record(reg), BPF_SPIN_LOCK);
}
static bool type_is_rdonly_mem(u32 type)
@@ -511,6 +523,23 @@ static bool is_dynptr_ref_function(enum bpf_func_id func_id)
return func_id == BPF_FUNC_dynptr_data;
}
+static bool is_callback_calling_function(enum bpf_func_id func_id)
+{
+ return func_id == BPF_FUNC_for_each_map_elem ||
+ func_id == BPF_FUNC_timer_set_callback ||
+ func_id == BPF_FUNC_find_vma ||
+ func_id == BPF_FUNC_loop ||
+ func_id == BPF_FUNC_user_ringbuf_drain;
+}
+
+static bool is_storage_get_function(enum bpf_func_id func_id)
+{
+ return func_id == BPF_FUNC_sk_storage_get ||
+ func_id == BPF_FUNC_inode_storage_get ||
+ func_id == BPF_FUNC_task_storage_get ||
+ func_id == BPF_FUNC_cgrp_storage_get;
+}
+
static bool helper_multiple_ref_obj_use(enum bpf_func_id func_id,
const struct bpf_map *map)
{
@@ -541,7 +570,7 @@ static bool is_cmpxchg_insn(const struct bpf_insn *insn)
static const char *reg_type_str(struct bpf_verifier_env *env,
enum bpf_reg_type type)
{
- char postfix[16] = {0}, prefix[32] = {0};
+ char postfix[16] = {0}, prefix[64] = {0};
static const char * const str[] = {
[NOT_INIT] = "?",
[SCALAR_VALUE] = "scalar",
@@ -563,7 +592,7 @@ static const char *reg_type_str(struct bpf_verifier_env *env,
[PTR_TO_BUF] = "buf",
[PTR_TO_FUNC] = "func",
[PTR_TO_MAP_KEY] = "map_key",
- [PTR_TO_DYNPTR] = "dynptr_ptr",
+ [CONST_PTR_TO_DYNPTR] = "dynptr_ptr",
};
if (type & PTR_MAYBE_NULL) {
@@ -573,16 +602,15 @@ static const char *reg_type_str(struct bpf_verifier_env *env,
strncpy(postfix, "_or_null", 16);
}
- if (type & MEM_RDONLY)
- strncpy(prefix, "rdonly_", 32);
- if (type & MEM_ALLOC)
- strncpy(prefix, "alloc_", 32);
- if (type & MEM_USER)
- strncpy(prefix, "user_", 32);
- if (type & MEM_PERCPU)
- strncpy(prefix, "percpu_", 32);
- if (type & PTR_UNTRUSTED)
- strncpy(prefix, "untrusted_", 32);
+ snprintf(prefix, sizeof(prefix), "%s%s%s%s%s%s%s",
+ type & MEM_RDONLY ? "rdonly_" : "",
+ type & MEM_RINGBUF ? "ringbuf_" : "",
+ type & MEM_USER ? "user_" : "",
+ type & MEM_PERCPU ? "percpu_" : "",
+ type & MEM_RCU ? "rcu_" : "",
+ type & PTR_UNTRUSTED ? "untrusted_" : "",
+ type & PTR_TRUSTED ? "trusted_" : ""
+ );
snprintf(env->type_str_buf, TYPE_STR_BUF_LEN, "%s%s%s",
prefix, str[base_type(type)], postfix);
@@ -697,6 +725,28 @@ static bool dynptr_type_refcounted(enum bpf_dynptr_type type)
return type == BPF_DYNPTR_TYPE_RINGBUF;
}
+static void __mark_dynptr_reg(struct bpf_reg_state *reg,
+ enum bpf_dynptr_type type,
+ bool first_slot);
+
+static void __mark_reg_not_init(const struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg);
+
+static void mark_dynptr_stack_regs(struct bpf_reg_state *sreg1,
+ struct bpf_reg_state *sreg2,
+ enum bpf_dynptr_type type)
+{
+ __mark_dynptr_reg(sreg1, type, true);
+ __mark_dynptr_reg(sreg2, type, false);
+}
+
+static void mark_dynptr_cb_reg(struct bpf_reg_state *reg,
+ enum bpf_dynptr_type type)
+{
+ __mark_dynptr_reg(reg, type, true);
+}
+
+
static int mark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
enum bpf_arg_type arg_type, int insn_idx)
{
@@ -718,9 +768,8 @@ static int mark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_
if (type == BPF_DYNPTR_TYPE_INVALID)
return -EINVAL;
- state->stack[spi].spilled_ptr.dynptr.first_slot = true;
- state->stack[spi].spilled_ptr.dynptr.type = type;
- state->stack[spi - 1].spilled_ptr.dynptr.type = type;
+ mark_dynptr_stack_regs(&state->stack[spi].spilled_ptr,
+ &state->stack[spi - 1].spilled_ptr, type);
if (dynptr_type_refcounted(type)) {
/* The id is used to track proper releasing */
@@ -728,8 +777,8 @@ static int mark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_
if (id < 0)
return id;
- state->stack[spi].spilled_ptr.id = id;
- state->stack[spi - 1].spilled_ptr.id = id;
+ state->stack[spi].spilled_ptr.ref_obj_id = id;
+ state->stack[spi - 1].spilled_ptr.ref_obj_id = id;
}
return 0;
@@ -751,25 +800,23 @@ static int unmark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_re
}
/* Invalidate any slices associated with this dynptr */
- if (dynptr_type_refcounted(state->stack[spi].spilled_ptr.dynptr.type)) {
- release_reference(env, state->stack[spi].spilled_ptr.id);
- state->stack[spi].spilled_ptr.id = 0;
- state->stack[spi - 1].spilled_ptr.id = 0;
- }
-
- state->stack[spi].spilled_ptr.dynptr.first_slot = false;
- state->stack[spi].spilled_ptr.dynptr.type = 0;
- state->stack[spi - 1].spilled_ptr.dynptr.type = 0;
+ if (dynptr_type_refcounted(state->stack[spi].spilled_ptr.dynptr.type))
+ WARN_ON_ONCE(release_reference(env, state->stack[spi].spilled_ptr.ref_obj_id));
+ __mark_reg_not_init(env, &state->stack[spi].spilled_ptr);
+ __mark_reg_not_init(env, &state->stack[spi - 1].spilled_ptr);
return 0;
}
static bool is_dynptr_reg_valid_uninit(struct bpf_verifier_env *env, struct bpf_reg_state *reg)
{
struct bpf_func_state *state = func(env, reg);
- int spi = get_spi(reg->off);
- int i;
+ int spi, i;
+ if (reg->type == CONST_PTR_TO_DYNPTR)
+ return false;
+
+ spi = get_spi(reg->off);
if (!is_spi_bounds_valid(state, spi, BPF_DYNPTR_NR_SLOTS))
return true;
@@ -782,13 +829,17 @@ static bool is_dynptr_reg_valid_uninit(struct bpf_verifier_env *env, struct bpf_
return true;
}
-bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env,
- struct bpf_reg_state *reg)
+static bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env, struct bpf_reg_state *reg)
{
struct bpf_func_state *state = func(env, reg);
- int spi = get_spi(reg->off);
+ int spi;
int i;
+ /* This already represents first slot of initialized bpf_dynptr */
+ if (reg->type == CONST_PTR_TO_DYNPTR)
+ return true;
+
+ spi = get_spi(reg->off);
if (!is_spi_bounds_valid(state, spi, BPF_DYNPTR_NR_SLOTS) ||
!state->stack[spi].spilled_ptr.dynptr.first_slot)
return false;
@@ -802,21 +853,24 @@ bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env,
return true;
}
-bool is_dynptr_type_expected(struct bpf_verifier_env *env,
- struct bpf_reg_state *reg,
- enum bpf_arg_type arg_type)
+static bool is_dynptr_type_expected(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
+ enum bpf_arg_type arg_type)
{
struct bpf_func_state *state = func(env, reg);
enum bpf_dynptr_type dynptr_type;
- int spi = get_spi(reg->off);
+ int spi;
/* ARG_PTR_TO_DYNPTR takes any type of dynptr */
if (arg_type == ARG_PTR_TO_DYNPTR)
return true;
dynptr_type = arg_to_dynptr_type(arg_type);
-
- return state->stack[spi].spilled_ptr.dynptr.type == dynptr_type;
+ if (reg->type == CONST_PTR_TO_DYNPTR) {
+ return reg->dynptr.type == dynptr_type;
+ } else {
+ spi = get_spi(reg->off);
+ return state->stack[spi].spilled_ptr.dynptr.type == dynptr_type;
+ }
}
/* The reg state of a pointer or a bounded scalar was saved when
@@ -875,7 +929,7 @@ static void print_verifier_state(struct bpf_verifier_env *env,
if (reg->id)
verbose_a("id=%d", reg->id);
- if (reg_type_may_be_refcounted_or_null(t) && reg->ref_obj_id)
+ if (reg->ref_obj_id)
verbose_a("ref_obj_id=%d", reg->ref_obj_id);
if (t != SCALAR_VALUE)
verbose_a("off=%d", reg->off);
@@ -1008,9 +1062,9 @@ static void *copy_array(void *dst, const void *src, size_t n, size_t size, gfp_t
if (unlikely(check_mul_overflow(n, size, &bytes)))
return NULL;
- if (ksize(dst) < bytes) {
+ if (ksize(dst) < ksize(src)) {
kfree(dst);
- dst = kmalloc_track_caller(bytes, flags);
+ dst = kmalloc_track_caller(kmalloc_size_roundup(bytes), flags);
if (!dst)
return NULL;
}
@@ -1027,12 +1081,14 @@ out:
*/
static void *realloc_array(void *arr, size_t old_n, size_t new_n, size_t size)
{
+ size_t alloc_size;
void *new_arr;
if (!new_n || old_n == new_n)
goto out;
- new_arr = krealloc_array(arr, new_n, size, GFP_KERNEL);
+ alloc_size = kmalloc_size_roundup(size_mul(new_n, size));
+ new_arr = krealloc(arr, alloc_size, GFP_KERNEL);
if (!new_arr) {
kfree(arr);
return NULL;
@@ -1204,8 +1260,10 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
dst_state->frame[i] = NULL;
}
dst_state->speculative = src->speculative;
+ dst_state->active_rcu_lock = src->active_rcu_lock;
dst_state->curframe = src->curframe;
- dst_state->active_spin_lock = src->active_spin_lock;
+ dst_state->active_lock.ptr = src->active_lock.ptr;
+ dst_state->active_lock.id = src->active_lock.id;
dst_state->branches = src->branches;
dst_state->parent = src->parent;
dst_state->first_insn_idx = src->first_insn_idx;
@@ -1324,9 +1382,6 @@ static const int caller_saved[CALLER_SAVED_REGS] = {
BPF_REG_0, BPF_REG_1, BPF_REG_2, BPF_REG_3, BPF_REG_4, BPF_REG_5
};
-static void __mark_reg_not_init(const struct bpf_verifier_env *env,
- struct bpf_reg_state *reg);
-
/* This helper doesn't clear reg->id */
static void ___mark_reg_known(struct bpf_reg_state *reg, u64 imm)
{
@@ -1389,6 +1444,19 @@ static void mark_reg_known_zero(struct bpf_verifier_env *env,
__mark_reg_known_zero(regs + regno);
}
+static void __mark_dynptr_reg(struct bpf_reg_state *reg, enum bpf_dynptr_type type,
+ bool first_slot)
+{
+ /* reg->type has no meaning for STACK_DYNPTR, but when we set reg for
+ * callback arguments, it does need to be CONST_PTR_TO_DYNPTR, so simply
+ * set it unconditionally as it is ignored for STACK_DYNPTR anyway.
+ */
+ __mark_reg_known_zero(reg);
+ reg->type = CONST_PTR_TO_DYNPTR;
+ reg->dynptr.type = type;
+ reg->dynptr.first_slot = first_slot;
+}
+
static void mark_ptr_not_null_reg(struct bpf_reg_state *reg)
{
if (base_type(reg->type) == PTR_TO_MAP_VALUE) {
@@ -1400,7 +1468,7 @@ static void mark_ptr_not_null_reg(struct bpf_reg_state *reg)
/* transfer reg's id which is unique for every map_lookup_elem
* as UID of the inner map.
*/
- if (map_value_has_timer(map->inner_map_meta))
+ if (btf_record_has_field(map->inner_map_meta->record, BPF_TIMER))
reg->map_uid = reg->id;
} else if (map->map_type == BPF_MAP_TYPE_XSKMAP) {
reg->type = PTR_TO_XDP_SOCK;
@@ -1689,7 +1757,7 @@ static void __mark_reg_unknown(const struct bpf_verifier_env *env,
reg->type = SCALAR_VALUE;
reg->var_off = tnum_unknown;
reg->frameno = 0;
- reg->precise = env->subprog_cnt > 1 || !env->bpf_capable;
+ reg->precise = !env->bpf_capable;
__mark_reg_unbounded(reg);
}
@@ -2498,15 +2566,30 @@ static int check_reg_arg(struct bpf_verifier_env *env, u32 regno,
return 0;
}
+static void mark_jmp_point(struct bpf_verifier_env *env, int idx)
+{
+ env->insn_aux_data[idx].jmp_point = true;
+}
+
+static bool is_jmp_point(struct bpf_verifier_env *env, int insn_idx)
+{
+ return env->insn_aux_data[insn_idx].jmp_point;
+}
+
/* for any branch, call, exit record the history of jmps in the given state */
static int push_jmp_history(struct bpf_verifier_env *env,
struct bpf_verifier_state *cur)
{
u32 cnt = cur->jmp_history_cnt;
struct bpf_idx_pair *p;
+ size_t alloc_size;
+
+ if (!is_jmp_point(env, env->insn_idx))
+ return 0;
cnt++;
- p = krealloc(cur->jmp_history, cnt * sizeof(*p), GFP_USER);
+ alloc_size = kmalloc_size_roundup(size_mul(cnt, sizeof(*p)));
+ p = krealloc(cur->jmp_history, alloc_size, GFP_USER);
if (!p)
return -ENOMEM;
p[cnt - 1].idx = env->insn_idx;
@@ -2658,6 +2741,11 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx,
if (opcode == BPF_CALL) {
if (insn->src_reg == BPF_PSEUDO_CALL)
return -ENOTSUPP;
+ /* BPF helpers that invoke callback subprogs are
+ * equivalent to BPF_PSEUDO_CALL above
+ */
+ if (insn->src_reg == 0 && is_callback_calling_function(insn->imm))
+ return -ENOTSUPP;
/* regular helper call sets R0 */
*reg_mask &= ~1;
if (*reg_mask & 0x3f) {
@@ -2747,8 +2835,11 @@ static void mark_all_scalars_precise(struct bpf_verifier_env *env,
/* big hammer: mark all scalars precise in this path.
* pop_stack may still get !precise scalars.
+ * We also skip current state and go straight to first parent state,
+ * because precision markings in current non-checkpointed state are
+ * not needed. See why in the comment in __mark_chain_precision below.
*/
- for (; st; st = st->parent)
+ for (st = st->parent; st; st = st->parent) {
for (i = 0; i <= st->curframe; i++) {
func = st->frame[i];
for (j = 0; j < BPF_REG_FP; j++) {
@@ -2766,9 +2857,122 @@ static void mark_all_scalars_precise(struct bpf_verifier_env *env,
reg->precise = true;
}
}
+ }
+}
+
+static void mark_all_scalars_imprecise(struct bpf_verifier_env *env, struct bpf_verifier_state *st)
+{
+ struct bpf_func_state *func;
+ struct bpf_reg_state *reg;
+ int i, j;
+
+ for (i = 0; i <= st->curframe; i++) {
+ func = st->frame[i];
+ for (j = 0; j < BPF_REG_FP; j++) {
+ reg = &func->regs[j];
+ if (reg->type != SCALAR_VALUE)
+ continue;
+ reg->precise = false;
+ }
+ for (j = 0; j < func->allocated_stack / BPF_REG_SIZE; j++) {
+ if (!is_spilled_reg(&func->stack[j]))
+ continue;
+ reg = &func->stack[j].spilled_ptr;
+ if (reg->type != SCALAR_VALUE)
+ continue;
+ reg->precise = false;
+ }
+ }
}
-static int __mark_chain_precision(struct bpf_verifier_env *env, int regno,
+/*
+ * __mark_chain_precision() backtracks BPF program instruction sequence and
+ * chain of verifier states making sure that register *regno* (if regno >= 0)
+ * and/or stack slot *spi* (if spi >= 0) are marked as precisely tracked
+ * SCALARS, as well as any other registers and slots that contribute to
+ * a tracked state of given registers/stack slots, depending on specific BPF
+ * assembly instructions (see backtrack_insns() for exact instruction handling
+ * logic). This backtracking relies on recorded jmp_history and is able to
+ * traverse entire chain of parent states. This process ends only when all the
+ * necessary registers/slots and their transitive dependencies are marked as
+ * precise.
+ *
+ * One important and subtle aspect is that precise marks *do not matter* in
+ * the currently verified state (current state). It is important to understand
+ * why this is the case.
+ *
+ * First, note that current state is the state that is not yet "checkpointed",
+ * i.e., it is not yet put into env->explored_states, and it has no children
+ * states as well. It's ephemeral, and can end up either a) being discarded if
+ * compatible explored state is found at some point or BPF_EXIT instruction is
+ * reached or b) checkpointed and put into env->explored_states, branching out
+ * into one or more children states.
+ *
+ * In the former case, precise markings in current state are completely
+ * ignored by state comparison code (see regsafe() for details). Only
+ * checkpointed ("old") state precise markings are important, and if old
+ * state's register/slot is precise, regsafe() assumes current state's
+ * register/slot as precise and checks value ranges exactly and precisely. If
+ * states turn out to be compatible, current state's necessary precise
+ * markings and any required parent states' precise markings are enforced
+ * after the fact with propagate_precision() logic, after the fact. But it's
+ * important to realize that in this case, even after marking current state
+ * registers/slots as precise, we immediately discard current state. So what
+ * actually matters is any of the precise markings propagated into current
+ * state's parent states, which are always checkpointed (due to b) case above).
+ * As such, for scenario a) it doesn't matter if current state has precise
+ * markings set or not.
+ *
+ * Now, for the scenario b), checkpointing and forking into child(ren)
+ * state(s). Note that before current state gets to checkpointing step, any
+ * processed instruction always assumes precise SCALAR register/slot
+ * knowledge: if precise value or range is useful to prune jump branch, BPF
+ * verifier takes this opportunity enthusiastically. Similarly, when
+ * register's value is used to calculate offset or memory address, exact
+ * knowledge of SCALAR range is assumed, checked, and enforced. So, similar to
+ * what we mentioned above about state comparison ignoring precise markings
+ * during state comparison, BPF verifier ignores and also assumes precise
+ * markings *at will* during instruction verification process. But as verifier
+ * assumes precision, it also propagates any precision dependencies across
+ * parent states, which are not yet finalized, so can be further restricted
+ * based on new knowledge gained from restrictions enforced by their children
+ * states. This is so that once those parent states are finalized, i.e., when
+ * they have no more active children state, state comparison logic in
+ * is_state_visited() would enforce strict and precise SCALAR ranges, if
+ * required for correctness.
+ *
+ * To build a bit more intuition, note also that once a state is checkpointed,
+ * the path we took to get to that state is not important. This is crucial
+ * property for state pruning. When state is checkpointed and finalized at
+ * some instruction index, it can be correctly and safely used to "short
+ * circuit" any *compatible* state that reaches exactly the same instruction
+ * index. I.e., if we jumped to that instruction from a completely different
+ * code path than original finalized state was derived from, it doesn't
+ * matter, current state can be discarded because from that instruction
+ * forward having a compatible state will ensure we will safely reach the
+ * exit. States describe preconditions for further exploration, but completely
+ * forget the history of how we got here.
+ *
+ * This also means that even if we needed precise SCALAR range to get to
+ * finalized state, but from that point forward *that same* SCALAR register is
+ * never used in a precise context (i.e., it's precise value is not needed for
+ * correctness), it's correct and safe to mark such register as "imprecise"
+ * (i.e., precise marking set to false). This is what we rely on when we do
+ * not set precise marking in current state. If no child state requires
+ * precision for any given SCALAR register, it's safe to dictate that it can
+ * be imprecise. If any child state does require this register to be precise,
+ * we'll mark it precise later retroactively during precise markings
+ * propagation from child state to parent states.
+ *
+ * Skipping precise marking setting in current state is a mild version of
+ * relying on the above observation. But we can utilize this property even
+ * more aggressively by proactively forgetting any precise marking in the
+ * current state (which we inherited from the parent state), right before we
+ * checkpoint it and branch off into new child state. This is done by
+ * mark_all_scalars_imprecise() to hopefully get more permissive and generic
+ * finalized states which help in short circuiting more future states.
+ */
+static int __mark_chain_precision(struct bpf_verifier_env *env, int frame, int regno,
int spi)
{
struct bpf_verifier_state *st = env->cur_state;
@@ -2785,18 +2989,18 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno,
if (!env->bpf_capable)
return 0;
- func = st->frame[st->curframe];
+ /* Do sanity checks against current state of register and/or stack
+ * slot, but don't set precise flag in current state, as precision
+ * tracking in the current state is unnecessary.
+ */
+ func = st->frame[frame];
if (regno >= 0) {
reg = &func->regs[regno];
if (reg->type != SCALAR_VALUE) {
WARN_ONCE(1, "backtracing misuse");
return -EFAULT;
}
- if (!reg->precise)
- new_marks = true;
- else
- reg_mask = 0;
- reg->precise = true;
+ new_marks = true;
}
while (spi >= 0) {
@@ -2809,11 +3013,7 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno,
stack_mask = 0;
break;
}
- if (!reg->precise)
- new_marks = true;
- else
- stack_mask = 0;
- reg->precise = true;
+ new_marks = true;
break;
}
@@ -2821,12 +3021,42 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno,
return 0;
if (!reg_mask && !stack_mask)
return 0;
+
for (;;) {
DECLARE_BITMAP(mask, 64);
u32 history = st->jmp_history_cnt;
if (env->log.level & BPF_LOG_LEVEL2)
verbose(env, "last_idx %d first_idx %d\n", last_idx, first_idx);
+
+ if (last_idx < 0) {
+ /* we are at the entry into subprog, which
+ * is expected for global funcs, but only if
+ * requested precise registers are R1-R5
+ * (which are global func's input arguments)
+ */
+ if (st->curframe == 0 &&
+ st->frame[0]->subprogno > 0 &&
+ st->frame[0]->callsite == BPF_MAIN_FUNC &&
+ stack_mask == 0 && (reg_mask & ~0x3e) == 0) {
+ bitmap_from_u64(mask, reg_mask);
+ for_each_set_bit(i, mask, 32) {
+ reg = &st->frame[0]->regs[i];
+ if (reg->type != SCALAR_VALUE) {
+ reg_mask &= ~(1u << i);
+ continue;
+ }
+ reg->precise = true;
+ }
+ return 0;
+ }
+
+ verbose(env, "BUG backtracing func entry subprog %d reg_mask %x stack_mask %llx\n",
+ st->frame[0]->subprogno, reg_mask, stack_mask);
+ WARN_ONCE(1, "verifier backtracking bug");
+ return -EFAULT;
+ }
+
for (i = last_idx;;) {
if (skip_first) {
err = 0;
@@ -2866,7 +3096,7 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno,
break;
new_marks = false;
- func = st->frame[st->curframe];
+ func = st->frame[frame];
bitmap_from_u64(mask, reg_mask);
for_each_set_bit(i, mask, 32) {
reg = &func->regs[i];
@@ -2932,12 +3162,17 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno,
int mark_chain_precision(struct bpf_verifier_env *env, int regno)
{
- return __mark_chain_precision(env, regno, -1);
+ return __mark_chain_precision(env, env->cur_state->curframe, regno, -1);
}
-static int mark_chain_precision_stack(struct bpf_verifier_env *env, int spi)
+static int mark_chain_precision_frame(struct bpf_verifier_env *env, int frame, int regno)
{
- return __mark_chain_precision(env, -1, spi);
+ return __mark_chain_precision(env, frame, regno, -1);
+}
+
+static int mark_chain_precision_stack_frame(struct bpf_verifier_env *env, int frame, int spi)
+{
+ return __mark_chain_precision(env, frame, -1, spi);
}
static bool is_spillable_regtype(enum bpf_reg_type type)
@@ -3186,14 +3421,17 @@ static int check_stack_write_var_off(struct bpf_verifier_env *env,
stype = &state->stack[spi].slot_type[slot % BPF_REG_SIZE];
mark_stack_slot_scratched(env, spi);
- if (!env->allow_ptr_leaks
- && *stype != NOT_INIT
- && *stype != SCALAR_VALUE) {
- /* Reject the write if there's are spilled pointers in
- * range. If we didn't reject here, the ptr status
- * would be erased below (even though not all slots are
- * actually overwritten), possibly opening the door to
- * leaks.
+ if (!env->allow_ptr_leaks && *stype != STACK_MISC && *stype != STACK_ZERO) {
+ /* Reject the write if range we may write to has not
+ * been initialized beforehand. If we didn't reject
+ * here, the ptr status would be erased below (even
+ * though not all slots are actually overwritten),
+ * possibly opening the door to leaks.
+ *
+ * We do however catch STACK_INVALID case below, and
+ * only allow reading possibly uninitialized memory
+ * later for CAP_PERFMON, as the write may not happen to
+ * that slot.
*/
verbose(env, "spilled ptr in range of var-offset stack write; insn %d, ptr off: %d",
insn_idx, i);
@@ -3683,15 +3921,15 @@ int check_ptr_off_reg(struct bpf_verifier_env *env,
}
static int map_kptr_match_type(struct bpf_verifier_env *env,
- struct bpf_map_value_off_desc *off_desc,
+ struct btf_field *kptr_field,
struct bpf_reg_state *reg, u32 regno)
{
- const char *targ_name = kernel_type_name(off_desc->kptr.btf, off_desc->kptr.btf_id);
- int perm_flags = PTR_MAYBE_NULL;
+ const char *targ_name = kernel_type_name(kptr_field->kptr.btf, kptr_field->kptr.btf_id);
+ int perm_flags = PTR_MAYBE_NULL | PTR_TRUSTED;
const char *reg_name = "";
/* Only unreferenced case accepts untrusted pointers */
- if (off_desc->type == BPF_KPTR_UNREF)
+ if (kptr_field->type == BPF_KPTR_UNREF)
perm_flags |= PTR_UNTRUSTED;
if (base_type(reg->type) != PTR_TO_BTF_ID || (type_flag(reg->type) & ~perm_flags))
@@ -3738,15 +3976,15 @@ static int map_kptr_match_type(struct bpf_verifier_env *env,
* strict mode to true for type match.
*/
if (!btf_struct_ids_match(&env->log, reg->btf, reg->btf_id, reg->off,
- off_desc->kptr.btf, off_desc->kptr.btf_id,
- off_desc->type == BPF_KPTR_REF))
+ kptr_field->kptr.btf, kptr_field->kptr.btf_id,
+ kptr_field->type == BPF_KPTR_REF))
goto bad_type;
return 0;
bad_type:
verbose(env, "invalid kptr access, R%d type=%s%s ", regno,
reg_type_str(env, reg->type), reg_name);
verbose(env, "expected=%s%s", reg_type_str(env, PTR_TO_BTF_ID), targ_name);
- if (off_desc->type == BPF_KPTR_UNREF)
+ if (kptr_field->type == BPF_KPTR_UNREF)
verbose(env, " or %s%s\n", reg_type_str(env, PTR_TO_BTF_ID | PTR_UNTRUSTED),
targ_name);
else
@@ -3756,7 +3994,7 @@ bad_type:
static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
int value_regno, int insn_idx,
- struct bpf_map_value_off_desc *off_desc)
+ struct btf_field *kptr_field)
{
struct bpf_insn *insn = &env->prog->insnsi[insn_idx];
int class = BPF_CLASS(insn->code);
@@ -3766,7 +4004,7 @@ static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
* - Reject cases where variable offset may touch kptr
* - size of access (must be BPF_DW)
* - tnum_is_const(reg->var_off)
- * - off_desc->offset == off + reg->var_off.value
+ * - kptr_field->offset == off + reg->var_off.value
*/
/* Only BPF_[LDX,STX,ST] | BPF_MEM | BPF_DW is supported */
if (BPF_MODE(insn->code) != BPF_MEM) {
@@ -3777,7 +4015,7 @@ static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
/* We only allow loading referenced kptr, since it will be marked as
* untrusted, similar to unreferenced kptr.
*/
- if (class != BPF_LDX && off_desc->type == BPF_KPTR_REF) {
+ if (class != BPF_LDX && kptr_field->type == BPF_KPTR_REF) {
verbose(env, "store to referenced kptr disallowed\n");
return -EACCES;
}
@@ -3787,19 +4025,19 @@ static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
/* We can simply mark the value_regno receiving the pointer
* value from map as PTR_TO_BTF_ID, with the correct type.
*/
- mark_btf_ld_reg(env, cur_regs(env), value_regno, PTR_TO_BTF_ID, off_desc->kptr.btf,
- off_desc->kptr.btf_id, PTR_MAYBE_NULL | PTR_UNTRUSTED);
+ mark_btf_ld_reg(env, cur_regs(env), value_regno, PTR_TO_BTF_ID, kptr_field->kptr.btf,
+ kptr_field->kptr.btf_id, PTR_MAYBE_NULL | PTR_UNTRUSTED);
/* For mark_ptr_or_null_reg */
val_reg->id = ++env->id_gen;
} else if (class == BPF_STX) {
val_reg = reg_state(env, value_regno);
if (!register_is_null(val_reg) &&
- map_kptr_match_type(env, off_desc, val_reg, value_regno))
+ map_kptr_match_type(env, kptr_field, val_reg, value_regno))
return -EACCES;
} else if (class == BPF_ST) {
if (insn->imm) {
verbose(env, "BPF_ST imm must be 0 when storing to kptr at off=%u\n",
- off_desc->offset);
+ kptr_field->offset);
return -EACCES;
}
} else {
@@ -3818,45 +4056,30 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
struct bpf_func_state *state = vstate->frame[vstate->curframe];
struct bpf_reg_state *reg = &state->regs[regno];
struct bpf_map *map = reg->map_ptr;
- int err;
+ struct btf_record *rec;
+ int err, i;
err = check_mem_region_access(env, regno, off, size, map->value_size,
zero_size_allowed);
if (err)
return err;
- if (map_value_has_spin_lock(map)) {
- u32 lock = map->spin_lock_off;
+ if (IS_ERR_OR_NULL(map->record))
+ return 0;
+ rec = map->record;
+ for (i = 0; i < rec->cnt; i++) {
+ struct btf_field *field = &rec->fields[i];
+ u32 p = field->offset;
- /* if any part of struct bpf_spin_lock can be touched by
- * load/store reject this program.
- * To check that [x1, x2) overlaps with [y1, y2)
+ /* If any part of a field can be touched by load/store, reject
+ * this program. To check that [x1, x2) overlaps with [y1, y2),
* it is sufficient to check x1 < y2 && y1 < x2.
*/
- if (reg->smin_value + off < lock + sizeof(struct bpf_spin_lock) &&
- lock < reg->umax_value + off + size) {
- verbose(env, "bpf_spin_lock cannot be accessed directly by load/store\n");
- return -EACCES;
- }
- }
- if (map_value_has_timer(map)) {
- u32 t = map->timer_off;
-
- if (reg->smin_value + off < t + sizeof(struct bpf_timer) &&
- t < reg->umax_value + off + size) {
- verbose(env, "bpf_timer cannot be accessed directly by load/store\n");
- return -EACCES;
- }
- }
- if (map_value_has_kptrs(map)) {
- struct bpf_map_value_off *tab = map->kptr_off_tab;
- int i;
-
- for (i = 0; i < tab->nr_off; i++) {
- u32 p = tab->off[i].offset;
-
- if (reg->smin_value + off < p + sizeof(u64) &&
- p < reg->umax_value + off + size) {
+ if (reg->smin_value + off < p + btf_field_type_size(field->type) &&
+ p < reg->umax_value + off + size) {
+ switch (field->type) {
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
if (src != ACCESS_DIRECT) {
verbose(env, "kptr cannot be accessed indirectly by helper\n");
return -EACCES;
@@ -3875,10 +4098,14 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
return -EACCES;
}
break;
+ default:
+ verbose(env, "%s cannot be accessed directly by load/store\n",
+ btf_field_type_name(field->type));
+ return -EACCES;
}
}
}
- return err;
+ return 0;
}
#define MAX_PACKET_OFF 0xffff
@@ -4095,6 +4322,30 @@ static bool is_flow_key_reg(struct bpf_verifier_env *env, int regno)
return reg->type == PTR_TO_FLOW_KEYS;
}
+static bool is_trusted_reg(const struct bpf_reg_state *reg)
+{
+ /* A referenced register is always trusted. */
+ if (reg->ref_obj_id)
+ return true;
+
+ /* If a register is not referenced, it is trusted if it has the
+ * MEM_ALLOC or PTR_TRUSTED type modifiers, and no others. Some of the
+ * other type modifiers may be safe, but we elect to take an opt-in
+ * approach here as some (e.g. PTR_UNTRUSTED and PTR_MAYBE_NULL) are
+ * not.
+ *
+ * Eventually, we should make PTR_TRUSTED the single source of truth
+ * for whether a register is trusted.
+ */
+ return type_flag(reg->type) & BPF_REG_TRUSTED_MODIFIERS &&
+ !bpf_type_has_unsafe_modifiers(reg->type);
+}
+
+static bool is_rcu_reg(const struct bpf_reg_state *reg)
+{
+ return reg->type & MEM_RCU;
+}
+
static int check_pkt_ptr_alignment(struct bpf_verifier_env *env,
const struct bpf_reg_state *reg,
int off, int size, bool strict)
@@ -4511,6 +4762,18 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
u32 btf_id;
int ret;
+ if (!env->allow_ptr_leaks) {
+ verbose(env,
+ "'struct %s' access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN\n",
+ tname);
+ return -EPERM;
+ }
+ if (!env->prog->gpl_compatible && btf_is_kernel(reg->btf)) {
+ verbose(env,
+ "Cannot access kernel 'struct %s' from non-GPL compatible program\n",
+ tname);
+ return -EINVAL;
+ }
if (off < 0) {
verbose(env,
"R%d is ptr_%s invalid negative access: off=%d\n",
@@ -4541,17 +4804,28 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
return -EACCES;
}
- if (env->ops->btf_struct_access) {
- ret = env->ops->btf_struct_access(&env->log, reg->btf, t,
- off, size, atype, &btf_id, &flag);
+ if (env->ops->btf_struct_access && !type_is_alloc(reg->type)) {
+ if (!btf_is_kernel(reg->btf)) {
+ verbose(env, "verifier internal error: reg->btf must be kernel btf\n");
+ return -EFAULT;
+ }
+ ret = env->ops->btf_struct_access(&env->log, reg, off, size, atype, &btf_id, &flag);
} else {
- if (atype != BPF_READ) {
+ /* Writes are permitted with default btf_struct_access for
+ * program allocated objects (which always have ref_obj_id > 0),
+ * but not for untrusted PTR_TO_BTF_ID | MEM_ALLOC.
+ */
+ if (atype != BPF_READ && reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) {
verbose(env, "only read is supported\n");
return -EACCES;
}
- ret = btf_struct_access(&env->log, reg->btf, t, off, size,
- atype, &btf_id, &flag);
+ if (type_is_alloc(reg->type) && !reg->ref_obj_id) {
+ verbose(env, "verifier internal error: ref_obj_id for allocated object must be non-zero\n");
+ return -EFAULT;
+ }
+
+ ret = btf_struct_access(&env->log, reg, off, size, atype, &btf_id, &flag);
}
if (ret < 0)
@@ -4563,6 +4837,30 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
if (type_flag(reg->type) & PTR_UNTRUSTED)
flag |= PTR_UNTRUSTED;
+ /* By default any pointer obtained from walking a trusted pointer is
+ * no longer trusted except the rcu case below.
+ */
+ flag &= ~PTR_TRUSTED;
+
+ if (flag & MEM_RCU) {
+ /* Mark value register as MEM_RCU only if it is protected by
+ * bpf_rcu_read_lock() and the ptr reg is rcu or trusted. MEM_RCU
+ * itself can already indicate trustedness inside the rcu
+ * read lock region. Also mark rcu pointer as PTR_MAYBE_NULL since
+ * it could be null in some cases.
+ */
+ if (!env->cur_state->active_rcu_lock ||
+ !(is_trusted_reg(reg) || is_rcu_reg(reg)))
+ flag &= ~MEM_RCU;
+ else
+ flag |= PTR_MAYBE_NULL;
+ } else if (reg->type & MEM_RCU) {
+ /* ptr (reg) is marked as MEM_RCU, but the struct field is not tagged
+ * with __rcu. Mark the flag as PTR_UNTRUSTED conservatively.
+ */
+ flag |= PTR_UNTRUSTED;
+ }
+
if (atype == BPF_READ && value_regno >= 0)
mark_btf_ld_reg(env, regs, value_regno, ret, reg->btf, btf_id, flag);
@@ -4577,6 +4875,7 @@ static int check_ptr_to_map_access(struct bpf_verifier_env *env,
{
struct bpf_reg_state *reg = regs + regno;
struct bpf_map *map = reg->map_ptr;
+ struct bpf_reg_state map_reg;
enum bpf_type_flag flag = 0;
const struct btf_type *t;
const char *tname;
@@ -4597,9 +4896,9 @@ static int check_ptr_to_map_access(struct bpf_verifier_env *env,
t = btf_type_by_id(btf_vmlinux, *map->ops->map_btf_id);
tname = btf_name_by_offset(btf_vmlinux, t->name_off);
- if (!env->allow_ptr_to_map_access) {
+ if (!env->allow_ptr_leaks) {
verbose(env,
- "%s access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN\n",
+ "'struct %s' access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN\n",
tname);
return -EPERM;
}
@@ -4615,7 +4914,10 @@ static int check_ptr_to_map_access(struct bpf_verifier_env *env,
return -EACCES;
}
- ret = btf_struct_access(&env->log, btf_vmlinux, t, off, size, atype, &btf_id, &flag);
+ /* Simulate access to a PTR_TO_BTF_ID */
+ memset(&map_reg, 0, sizeof(map_reg));
+ mark_btf_ld_reg(env, &map_reg, 0, PTR_TO_BTF_ID, btf_vmlinux, *map->ops->map_btf_id, 0);
+ ret = btf_struct_access(&env->log, &map_reg, off, size, atype, &btf_id, &flag);
if (ret < 0)
return ret;
@@ -4751,7 +5053,7 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
if (value_regno >= 0)
mark_reg_unknown(env, regs, value_regno);
} else if (reg->type == PTR_TO_MAP_VALUE) {
- struct bpf_map_value_off_desc *kptr_off_desc = NULL;
+ struct btf_field *kptr_field = NULL;
if (t == BPF_WRITE && value_regno >= 0 &&
is_pointer_value(env, value_regno)) {
@@ -4765,11 +5067,10 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
if (err)
return err;
if (tnum_is_const(reg->var_off))
- kptr_off_desc = bpf_map_kptr_off_contains(reg->map_ptr,
- off + reg->var_off.value);
- if (kptr_off_desc) {
- err = check_map_kptr_access(env, regno, value_regno, insn_idx,
- kptr_off_desc);
+ kptr_field = btf_record_find(reg->map_ptr->record,
+ off + reg->var_off.value, BPF_KPTR);
+ if (kptr_field) {
+ err = check_map_kptr_access(env, regno, value_regno, insn_idx, kptr_field);
} else if (t == BPF_READ && value_regno >= 0) {
struct bpf_map *map = reg->map_ptr;
@@ -5160,10 +5461,6 @@ static int check_stack_range_initialized(
}
if (is_spilled_reg(&state->stack[spi]) &&
- base_type(state->stack[spi].spilled_ptr.type) == PTR_TO_BTF_ID)
- goto mark;
-
- if (is_spilled_reg(&state->stack[spi]) &&
(state->stack[spi].spilled_ptr.type == SCALAR_VALUE ||
env->allow_ptr_leaks)) {
if (clobber) {
@@ -5193,6 +5490,11 @@ mark:
mark_reg_read(env, &state->stack[spi].spilled_ptr,
state->stack[spi].spilled_ptr.parent,
REG_LIVE_READ64);
+ /* We do not set REG_LIVE_WRITTEN for stack slot, as we can not
+ * be sure that whether stack slot is written to or not. Hence,
+ * we must still conservatively propagate reads upwards even if
+ * helper may write to the entire memory range.
+ */
}
return update_stack_depth(env, state, min_off);
}
@@ -5374,8 +5676,8 @@ int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
return err;
}
-int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
- u32 regno)
+static int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
+ u32 regno)
{
struct bpf_reg_state *mem_reg = &cur_regs(env)[regno - 1];
bool may_be_null = type_may_be_null(mem_reg->type);
@@ -5403,23 +5705,26 @@ int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state
}
/* Implementation details:
- * bpf_map_lookup returns PTR_TO_MAP_VALUE_OR_NULL
+ * bpf_map_lookup returns PTR_TO_MAP_VALUE_OR_NULL.
+ * bpf_obj_new returns PTR_TO_BTF_ID | MEM_ALLOC | PTR_MAYBE_NULL.
* Two bpf_map_lookups (even with the same key) will have different reg->id.
- * For traditional PTR_TO_MAP_VALUE the verifier clears reg->id after
- * value_or_null->value transition, since the verifier only cares about
- * the range of access to valid map value pointer and doesn't care about actual
- * address of the map element.
+ * Two separate bpf_obj_new will also have different reg->id.
+ * For traditional PTR_TO_MAP_VALUE or PTR_TO_BTF_ID | MEM_ALLOC, the verifier
+ * clears reg->id after value_or_null->value transition, since the verifier only
+ * cares about the range of access to valid map value pointer and doesn't care
+ * about actual address of the map element.
* For maps with 'struct bpf_spin_lock' inside map value the verifier keeps
* reg->id > 0 after value_or_null->value transition. By doing so
* two bpf_map_lookups will be considered two different pointers that
- * point to different bpf_spin_locks.
+ * point to different bpf_spin_locks. Likewise for pointers to allocated objects
+ * returned from bpf_obj_new.
* The verifier allows taking only one bpf_spin_lock at a time to avoid
* dead-locks.
* Since only one bpf_spin_lock is allowed the checks are simpler than
* reg_is_refcounted() logic. The verifier needs to remember only
* one spin_lock instead of array of acquired_refs.
- * cur_state->active_spin_lock remembers which map value element got locked
- * and clears it after bpf_spin_unlock.
+ * cur_state->active_lock remembers which map value element or allocated
+ * object got locked and clears it after bpf_spin_unlock.
*/
static int process_spin_lock(struct bpf_verifier_env *env, int regno,
bool is_lock)
@@ -5427,8 +5732,10 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno,
struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
struct bpf_verifier_state *cur = env->cur_state;
bool is_const = tnum_is_const(reg->var_off);
- struct bpf_map *map = reg->map_ptr;
u64 val = reg->var_off.value;
+ struct bpf_map *map = NULL;
+ struct btf *btf = NULL;
+ struct btf_record *rec;
if (!is_const) {
verbose(env,
@@ -5436,49 +5743,78 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno,
regno);
return -EINVAL;
}
- if (!map->btf) {
- verbose(env,
- "map '%s' has to have BTF in order to use bpf_spin_lock\n",
- map->name);
- return -EINVAL;
- }
- if (!map_value_has_spin_lock(map)) {
- if (map->spin_lock_off == -E2BIG)
+ if (reg->type == PTR_TO_MAP_VALUE) {
+ map = reg->map_ptr;
+ if (!map->btf) {
verbose(env,
- "map '%s' has more than one 'struct bpf_spin_lock'\n",
- map->name);
- else if (map->spin_lock_off == -ENOENT)
- verbose(env,
- "map '%s' doesn't have 'struct bpf_spin_lock'\n",
- map->name);
- else
- verbose(env,
- "map '%s' is not a struct type or bpf_spin_lock is mangled\n",
+ "map '%s' has to have BTF in order to use bpf_spin_lock\n",
map->name);
+ return -EINVAL;
+ }
+ } else {
+ btf = reg->btf;
+ }
+
+ rec = reg_btf_record(reg);
+ if (!btf_record_has_field(rec, BPF_SPIN_LOCK)) {
+ verbose(env, "%s '%s' has no valid bpf_spin_lock\n", map ? "map" : "local",
+ map ? map->name : "kptr");
return -EINVAL;
}
- if (map->spin_lock_off != val + reg->off) {
- verbose(env, "off %lld doesn't point to 'struct bpf_spin_lock'\n",
- val + reg->off);
+ if (rec->spin_lock_off != val + reg->off) {
+ verbose(env, "off %lld doesn't point to 'struct bpf_spin_lock' that is at %d\n",
+ val + reg->off, rec->spin_lock_off);
return -EINVAL;
}
if (is_lock) {
- if (cur->active_spin_lock) {
+ if (cur->active_lock.ptr) {
verbose(env,
"Locking two bpf_spin_locks are not allowed\n");
return -EINVAL;
}
- cur->active_spin_lock = reg->id;
+ if (map)
+ cur->active_lock.ptr = map;
+ else
+ cur->active_lock.ptr = btf;
+ cur->active_lock.id = reg->id;
} else {
- if (!cur->active_spin_lock) {
+ struct bpf_func_state *fstate = cur_func(env);
+ void *ptr;
+ int i;
+
+ if (map)
+ ptr = map;
+ else
+ ptr = btf;
+
+ if (!cur->active_lock.ptr) {
verbose(env, "bpf_spin_unlock without taking a lock\n");
return -EINVAL;
}
- if (cur->active_spin_lock != reg->id) {
+ if (cur->active_lock.ptr != ptr ||
+ cur->active_lock.id != reg->id) {
verbose(env, "bpf_spin_unlock of different lock\n");
return -EINVAL;
}
- cur->active_spin_lock = 0;
+ cur->active_lock.ptr = NULL;
+ cur->active_lock.id = 0;
+
+ for (i = fstate->acquired_refs - 1; i >= 0; i--) {
+ int err;
+
+ /* Complain on error because this reference state cannot
+ * be freed before this point, as bpf_spin_lock critical
+ * section does not allow functions that release the
+ * allocated object immediately.
+ */
+ if (!fstate->refs[i].release_on_unlock)
+ continue;
+ err = release_reference(env, fstate->refs[i].id);
+ if (err) {
+ verbose(env, "failed to release release_on_unlock reference");
+ return err;
+ }
+ }
}
return 0;
}
@@ -5502,24 +5838,13 @@ static int process_timer_func(struct bpf_verifier_env *env, int regno,
map->name);
return -EINVAL;
}
- if (!map_value_has_timer(map)) {
- if (map->timer_off == -E2BIG)
- verbose(env,
- "map '%s' has more than one 'struct bpf_timer'\n",
- map->name);
- else if (map->timer_off == -ENOENT)
- verbose(env,
- "map '%s' doesn't have 'struct bpf_timer'\n",
- map->name);
- else
- verbose(env,
- "map '%s' is not a struct type or bpf_timer is mangled\n",
- map->name);
+ if (!btf_record_has_field(map->record, BPF_TIMER)) {
+ verbose(env, "map '%s' has no valid bpf_timer\n", map->name);
return -EINVAL;
}
- if (map->timer_off != val + reg->off) {
+ if (map->record->timer_off != val + reg->off) {
verbose(env, "off %lld doesn't point to 'struct bpf_timer' that is at %d\n",
- val + reg->off, map->timer_off);
+ val + reg->off, map->record->timer_off);
return -EINVAL;
}
if (meta->map_ptr) {
@@ -5535,10 +5860,9 @@ static int process_kptr_func(struct bpf_verifier_env *env, int regno,
struct bpf_call_arg_meta *meta)
{
struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
- struct bpf_map_value_off_desc *off_desc;
struct bpf_map *map_ptr = reg->map_ptr;
+ struct btf_field *kptr_field;
u32 kptr_off;
- int ret;
if (!tnum_is_const(reg->var_off)) {
verbose(env,
@@ -5551,30 +5875,136 @@ static int process_kptr_func(struct bpf_verifier_env *env, int regno,
map_ptr->name);
return -EINVAL;
}
- if (!map_value_has_kptrs(map_ptr)) {
- ret = PTR_ERR_OR_ZERO(map_ptr->kptr_off_tab);
- if (ret == -E2BIG)
- verbose(env, "map '%s' has more than %d kptr\n", map_ptr->name,
- BPF_MAP_VALUE_OFF_MAX);
- else if (ret == -EEXIST)
- verbose(env, "map '%s' has repeating kptr BTF tags\n", map_ptr->name);
- else
- verbose(env, "map '%s' has no valid kptr\n", map_ptr->name);
+ if (!btf_record_has_field(map_ptr->record, BPF_KPTR)) {
+ verbose(env, "map '%s' has no valid kptr\n", map_ptr->name);
return -EINVAL;
}
meta->map_ptr = map_ptr;
kptr_off = reg->off + reg->var_off.value;
- off_desc = bpf_map_kptr_off_contains(map_ptr, kptr_off);
- if (!off_desc) {
+ kptr_field = btf_record_find(map_ptr->record, kptr_off, BPF_KPTR);
+ if (!kptr_field) {
verbose(env, "off=%d doesn't point to kptr\n", kptr_off);
return -EACCES;
}
- if (off_desc->type != BPF_KPTR_REF) {
+ if (kptr_field->type != BPF_KPTR_REF) {
verbose(env, "off=%d kptr isn't referenced kptr\n", kptr_off);
return -EACCES;
}
- meta->kptr_off_desc = off_desc;
+ meta->kptr_field = kptr_field;
+ return 0;
+}
+
+/* There are two register types representing a bpf_dynptr, one is PTR_TO_STACK
+ * which points to a stack slot, and the other is CONST_PTR_TO_DYNPTR.
+ *
+ * In both cases we deal with the first 8 bytes, but need to mark the next 8
+ * bytes as STACK_DYNPTR in case of PTR_TO_STACK. In case of
+ * CONST_PTR_TO_DYNPTR, we are guaranteed to get the beginning of the object.
+ *
+ * Mutability of bpf_dynptr is at two levels, one is at the level of struct
+ * bpf_dynptr itself, i.e. whether the helper is receiving a pointer to struct
+ * bpf_dynptr or pointer to const struct bpf_dynptr. In the former case, it can
+ * mutate the view of the dynptr and also possibly destroy it. In the latter
+ * case, it cannot mutate the bpf_dynptr itself but it can still mutate the
+ * memory that dynptr points to.
+ *
+ * The verifier will keep track both levels of mutation (bpf_dynptr's in
+ * reg->type and the memory's in reg->dynptr.type), but there is no support for
+ * readonly dynptr view yet, hence only the first case is tracked and checked.
+ *
+ * This is consistent with how C applies the const modifier to a struct object,
+ * where the pointer itself inside bpf_dynptr becomes const but not what it
+ * points to.
+ *
+ * Helpers which do not mutate the bpf_dynptr set MEM_RDONLY in their argument
+ * type, and declare it as 'const struct bpf_dynptr *' in their prototype.
+ */
+int process_dynptr_func(struct bpf_verifier_env *env, int regno,
+ enum bpf_arg_type arg_type, struct bpf_call_arg_meta *meta)
+{
+ struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+
+ /* MEM_UNINIT and MEM_RDONLY are exclusive, when applied to an
+ * ARG_PTR_TO_DYNPTR (or ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_*):
+ */
+ if ((arg_type & (MEM_UNINIT | MEM_RDONLY)) == (MEM_UNINIT | MEM_RDONLY)) {
+ verbose(env, "verifier internal error: misconfigured dynptr helper type flags\n");
+ return -EFAULT;
+ }
+ /* CONST_PTR_TO_DYNPTR already has fixed and var_off as 0 due to
+ * check_func_arg_reg_off's logic. We only need to check offset
+ * alignment for PTR_TO_STACK.
+ */
+ if (reg->type == PTR_TO_STACK && (reg->off % BPF_REG_SIZE)) {
+ verbose(env, "cannot pass in dynptr at an offset=%d\n", reg->off);
+ return -EINVAL;
+ }
+ /* MEM_UNINIT - Points to memory that is an appropriate candidate for
+ * constructing a mutable bpf_dynptr object.
+ *
+ * Currently, this is only possible with PTR_TO_STACK
+ * pointing to a region of at least 16 bytes which doesn't
+ * contain an existing bpf_dynptr.
+ *
+ * MEM_RDONLY - Points to a initialized bpf_dynptr that will not be
+ * mutated or destroyed. However, the memory it points to
+ * may be mutated.
+ *
+ * None - Points to a initialized dynptr that can be mutated and
+ * destroyed, including mutation of the memory it points
+ * to.
+ */
+ if (arg_type & MEM_UNINIT) {
+ if (!is_dynptr_reg_valid_uninit(env, reg)) {
+ verbose(env, "Dynptr has to be an uninitialized dynptr\n");
+ return -EINVAL;
+ }
+
+ /* We only support one dynptr being uninitialized at the moment,
+ * which is sufficient for the helper functions we have right now.
+ */
+ if (meta->uninit_dynptr_regno) {
+ verbose(env, "verifier internal error: multiple uninitialized dynptr args\n");
+ return -EFAULT;
+ }
+
+ meta->uninit_dynptr_regno = regno;
+ } else /* MEM_RDONLY and None case from above */ {
+ /* For the reg->type == PTR_TO_STACK case, bpf_dynptr is never const */
+ if (reg->type == CONST_PTR_TO_DYNPTR && !(arg_type & MEM_RDONLY)) {
+ verbose(env, "cannot pass pointer to const bpf_dynptr, the helper mutates it\n");
+ return -EINVAL;
+ }
+
+ if (!is_dynptr_reg_valid_init(env, reg)) {
+ verbose(env,
+ "Expected an initialized dynptr as arg #%d\n",
+ regno);
+ return -EINVAL;
+ }
+
+ /* Fold modifiers (in this case, MEM_RDONLY) when checking expected type */
+ if (!is_dynptr_type_expected(env, reg, arg_type & ~MEM_RDONLY)) {
+ const char *err_extra = "";
+
+ switch (arg_type & DYNPTR_TYPE_FLAG_MASK) {
+ case DYNPTR_TYPE_LOCAL:
+ err_extra = "local";
+ break;
+ case DYNPTR_TYPE_RINGBUF:
+ err_extra = "ringbuf";
+ break;
+ default:
+ err_extra = "<unknown>";
+ break;
+ }
+ verbose(env,
+ "Expected a dynptr of type %s as arg #%d\n",
+ err_extra, regno);
+ return -EINVAL;
+ }
+ }
return 0;
}
@@ -5639,16 +6069,6 @@ struct bpf_reg_types {
u32 *btf_id;
};
-static const struct bpf_reg_types map_key_value_types = {
- .types = {
- PTR_TO_STACK,
- PTR_TO_PACKET,
- PTR_TO_PACKET_META,
- PTR_TO_MAP_KEY,
- PTR_TO_MAP_VALUE,
- },
-};
-
static const struct bpf_reg_types sock_types = {
.types = {
PTR_TO_SOCK_COMMON,
@@ -5666,6 +6086,7 @@ static const struct bpf_reg_types btf_id_sock_common_types = {
PTR_TO_TCP_SOCK,
PTR_TO_XDP_SOCK,
PTR_TO_BTF_ID,
+ PTR_TO_BTF_ID | PTR_TRUSTED,
},
.btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
};
@@ -5679,7 +6100,7 @@ static const struct bpf_reg_types mem_types = {
PTR_TO_MAP_KEY,
PTR_TO_MAP_VALUE,
PTR_TO_MEM,
- PTR_TO_MEM | MEM_ALLOC,
+ PTR_TO_MEM | MEM_RINGBUF,
PTR_TO_BUF,
},
};
@@ -5694,14 +6115,31 @@ static const struct bpf_reg_types int_ptr_types = {
},
};
+static const struct bpf_reg_types spin_lock_types = {
+ .types = {
+ PTR_TO_MAP_VALUE,
+ PTR_TO_BTF_ID | MEM_ALLOC,
+ }
+};
+
static const struct bpf_reg_types fullsock_types = { .types = { PTR_TO_SOCKET } };
static const struct bpf_reg_types scalar_types = { .types = { SCALAR_VALUE } };
static const struct bpf_reg_types context_types = { .types = { PTR_TO_CTX } };
-static const struct bpf_reg_types alloc_mem_types = { .types = { PTR_TO_MEM | MEM_ALLOC } };
+static const struct bpf_reg_types ringbuf_mem_types = { .types = { PTR_TO_MEM | MEM_RINGBUF } };
static const struct bpf_reg_types const_map_ptr_types = { .types = { CONST_PTR_TO_MAP } };
-static const struct bpf_reg_types btf_ptr_types = { .types = { PTR_TO_BTF_ID } };
-static const struct bpf_reg_types spin_lock_types = { .types = { PTR_TO_MAP_VALUE } };
-static const struct bpf_reg_types percpu_btf_ptr_types = { .types = { PTR_TO_BTF_ID | MEM_PERCPU } };
+static const struct bpf_reg_types btf_ptr_types = {
+ .types = {
+ PTR_TO_BTF_ID,
+ PTR_TO_BTF_ID | PTR_TRUSTED,
+ PTR_TO_BTF_ID | MEM_RCU,
+ },
+};
+static const struct bpf_reg_types percpu_btf_ptr_types = {
+ .types = {
+ PTR_TO_BTF_ID | MEM_PERCPU,
+ PTR_TO_BTF_ID | MEM_PERCPU | PTR_TRUSTED,
+ }
+};
static const struct bpf_reg_types func_ptr_types = { .types = { PTR_TO_FUNC } };
static const struct bpf_reg_types stack_ptr_types = { .types = { PTR_TO_STACK } };
static const struct bpf_reg_types const_str_ptr_types = { .types = { PTR_TO_MAP_VALUE } };
@@ -5710,13 +6148,13 @@ static const struct bpf_reg_types kptr_types = { .types = { PTR_TO_MAP_VALUE } }
static const struct bpf_reg_types dynptr_types = {
.types = {
PTR_TO_STACK,
- PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL,
+ CONST_PTR_TO_DYNPTR,
}
};
static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = {
- [ARG_PTR_TO_MAP_KEY] = &map_key_value_types,
- [ARG_PTR_TO_MAP_VALUE] = &map_key_value_types,
+ [ARG_PTR_TO_MAP_KEY] = &mem_types,
+ [ARG_PTR_TO_MAP_VALUE] = &mem_types,
[ARG_CONST_SIZE] = &scalar_types,
[ARG_CONST_SIZE_OR_ZERO] = &scalar_types,
[ARG_CONST_ALLOC_SIZE_OR_ZERO] = &scalar_types,
@@ -5730,7 +6168,7 @@ static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = {
[ARG_PTR_TO_BTF_ID] = &btf_ptr_types,
[ARG_PTR_TO_SPIN_LOCK] = &spin_lock_types,
[ARG_PTR_TO_MEM] = &mem_types,
- [ARG_PTR_TO_ALLOC_MEM] = &alloc_mem_types,
+ [ARG_PTR_TO_RINGBUF_MEM] = &ringbuf_mem_types,
[ARG_PTR_TO_INT] = &int_ptr_types,
[ARG_PTR_TO_LONG] = &int_ptr_types,
[ARG_PTR_TO_PERCPU_BTF_ID] = &percpu_btf_ptr_types,
@@ -5789,7 +6227,7 @@ static int check_reg_type(struct bpf_verifier_env *env, u32 regno,
return -EACCES;
found:
- if (reg->type == PTR_TO_BTF_ID) {
+ if (reg->type == PTR_TO_BTF_ID || reg->type & PTR_TRUSTED) {
/* For bpf_sk_release, it needs to match against first member
* 'struct sock_common', hence make an exception for it. This
* allows bpf_sk_release to work for multiple socket types.
@@ -5806,7 +6244,7 @@ found:
}
if (meta->func_id == BPF_FUNC_kptr_xchg) {
- if (map_kptr_match_type(env, meta->kptr_off_desc, reg, regno))
+ if (map_kptr_match_type(env, meta->kptr_field, reg, regno))
return -EACCES;
} else {
if (arg_btf_id == BPF_PTR_POISON) {
@@ -5825,6 +6263,11 @@ found:
return -EACCES;
}
}
+ } else if (type_is_alloc(reg->type)) {
+ if (meta->func_id != BPF_FUNC_spin_lock && meta->func_id != BPF_FUNC_spin_unlock) {
+ verbose(env, "verifier internal error: unimplemented handling of MEM_ALLOC\n");
+ return -EFAULT;
+ }
}
return 0;
@@ -5834,64 +6277,80 @@ int check_func_arg_reg_off(struct bpf_verifier_env *env,
const struct bpf_reg_state *reg, int regno,
enum bpf_arg_type arg_type)
{
- enum bpf_reg_type type = reg->type;
- bool fixed_off_ok = false;
+ u32 type = reg->type;
- switch ((u32)type) {
- /* Pointer types where reg offset is explicitly allowed: */
- case PTR_TO_STACK:
- if (arg_type_is_dynptr(arg_type) && reg->off % BPF_REG_SIZE) {
- verbose(env, "cannot pass in dynptr at an offset\n");
+ /* When referenced register is passed to release function, its fixed
+ * offset must be 0.
+ *
+ * We will check arg_type_is_release reg has ref_obj_id when storing
+ * meta->release_regno.
+ */
+ if (arg_type_is_release(arg_type)) {
+ /* ARG_PTR_TO_DYNPTR with OBJ_RELEASE is a bit special, as it
+ * may not directly point to the object being released, but to
+ * dynptr pointing to such object, which might be at some offset
+ * on the stack. In that case, we simply to fallback to the
+ * default handling.
+ */
+ if (arg_type_is_dynptr(arg_type) && type == PTR_TO_STACK)
+ return 0;
+ /* Doing check_ptr_off_reg check for the offset will catch this
+ * because fixed_off_ok is false, but checking here allows us
+ * to give the user a better error message.
+ */
+ if (reg->off) {
+ verbose(env, "R%d must have zero offset when passed to release func or trusted arg to kfunc\n",
+ regno);
return -EINVAL;
}
- fallthrough;
+ return __check_ptr_off_reg(env, reg, regno, false);
+ }
+
+ switch (type) {
+ /* Pointer types where both fixed and variable offset is explicitly allowed: */
+ case PTR_TO_STACK:
case PTR_TO_PACKET:
case PTR_TO_PACKET_META:
case PTR_TO_MAP_KEY:
case PTR_TO_MAP_VALUE:
case PTR_TO_MEM:
case PTR_TO_MEM | MEM_RDONLY:
- case PTR_TO_MEM | MEM_ALLOC:
+ case PTR_TO_MEM | MEM_RINGBUF:
case PTR_TO_BUF:
case PTR_TO_BUF | MEM_RDONLY:
case SCALAR_VALUE:
- /* Some of the argument types nevertheless require a
- * zero register offset.
- */
- if (base_type(arg_type) != ARG_PTR_TO_ALLOC_MEM)
- return 0;
- break;
+ return 0;
/* All the rest must be rejected, except PTR_TO_BTF_ID which allows
* fixed offset.
*/
case PTR_TO_BTF_ID:
+ case PTR_TO_BTF_ID | MEM_ALLOC:
+ case PTR_TO_BTF_ID | PTR_TRUSTED:
+ case PTR_TO_BTF_ID | MEM_RCU:
+ case PTR_TO_BTF_ID | MEM_ALLOC | PTR_TRUSTED:
/* When referenced PTR_TO_BTF_ID is passed to release function,
- * it's fixed offset must be 0. In the other cases, fixed offset
- * can be non-zero.
- */
- if (arg_type_is_release(arg_type) && reg->off) {
- verbose(env, "R%d must have zero offset when passed to release func\n",
- regno);
- return -EINVAL;
- }
- /* For arg is release pointer, fixed_off_ok must be false, but
- * we already checked and rejected reg->off != 0 above, so set
- * to true to allow fixed offset for all other cases.
+ * its fixed offset must be 0. In the other cases, fixed offset
+ * can be non-zero. This was already checked above. So pass
+ * fixed_off_ok as true to allow fixed offset for all other
+ * cases. var_off always must be 0 for PTR_TO_BTF_ID, hence we
+ * still need to do checks instead of returning.
*/
- fixed_off_ok = true;
- break;
+ return __check_ptr_off_reg(env, reg, regno, true);
default:
- break;
+ return __check_ptr_off_reg(env, reg, regno, false);
}
- return __check_ptr_off_reg(env, reg, regno, fixed_off_ok);
}
-static u32 stack_slot_get_id(struct bpf_verifier_env *env, struct bpf_reg_state *reg)
+static u32 dynptr_ref_obj_id(struct bpf_verifier_env *env, struct bpf_reg_state *reg)
{
struct bpf_func_state *state = func(env, reg);
- int spi = get_spi(reg->off);
+ int spi;
+
+ if (reg->type == CONST_PTR_TO_DYNPTR)
+ return reg->ref_obj_id;
- return state->stack[spi].spilled_ptr.id;
+ spi = get_spi(reg->off);
+ return state->stack[spi].spilled_ptr.ref_obj_id;
}
static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
@@ -5940,7 +6399,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
goto skip_type_check;
/* arg_btf_id and arg_size are in a union. */
- if (base_type(arg_type) == ARG_PTR_TO_BTF_ID)
+ if (base_type(arg_type) == ARG_PTR_TO_BTF_ID ||
+ base_type(arg_type) == ARG_PTR_TO_SPIN_LOCK)
arg_btf_id = fn->arg_btf_id[arg];
err = check_reg_type(env, regno, arg_type, arg_btf_id, meta);
@@ -5955,11 +6415,22 @@ skip_type_check:
if (arg_type_is_release(arg_type)) {
if (arg_type_is_dynptr(arg_type)) {
struct bpf_func_state *state = func(env, reg);
- int spi = get_spi(reg->off);
+ int spi;
- if (!is_spi_bounds_valid(state, spi, BPF_DYNPTR_NR_SLOTS) ||
- !state->stack[spi].spilled_ptr.id) {
- verbose(env, "arg %d is an unacquired reference\n", regno);
+ /* Only dynptr created on stack can be released, thus
+ * the get_spi and stack state checks for spilled_ptr
+ * should only be done before process_dynptr_func for
+ * PTR_TO_STACK.
+ */
+ if (reg->type == PTR_TO_STACK) {
+ spi = get_spi(reg->off);
+ if (!is_spi_bounds_valid(state, spi, BPF_DYNPTR_NR_SLOTS) ||
+ !state->stack[spi].spilled_ptr.ref_obj_id) {
+ verbose(env, "arg %d is an unacquired reference\n", regno);
+ return -EINVAL;
+ }
+ } else {
+ verbose(env, "cannot release unowned const bpf_dynptr\n");
return -EINVAL;
}
} else if (!reg->ref_obj_id && !register_is_null(reg)) {
@@ -6056,19 +6527,22 @@ skip_type_check:
break;
case ARG_PTR_TO_SPIN_LOCK:
if (meta->func_id == BPF_FUNC_spin_lock) {
- if (process_spin_lock(env, regno, true))
- return -EACCES;
+ err = process_spin_lock(env, regno, true);
+ if (err)
+ return err;
} else if (meta->func_id == BPF_FUNC_spin_unlock) {
- if (process_spin_lock(env, regno, false))
- return -EACCES;
+ err = process_spin_lock(env, regno, false);
+ if (err)
+ return err;
} else {
verbose(env, "verifier internal error\n");
return -EFAULT;
}
break;
case ARG_PTR_TO_TIMER:
- if (process_timer_func(env, regno, meta))
- return -EACCES;
+ err = process_timer_func(env, regno, meta);
+ if (err)
+ return err;
break;
case ARG_PTR_TO_FUNC:
meta->subprogno = reg->subprogno;
@@ -6091,52 +6565,9 @@ skip_type_check:
err = check_mem_size_reg(env, reg, regno, true, meta);
break;
case ARG_PTR_TO_DYNPTR:
- /* We only need to check for initialized / uninitialized helper
- * dynptr args if the dynptr is not PTR_TO_DYNPTR, as the
- * assumption is that if it is, that a helper function
- * initialized the dynptr on behalf of the BPF program.
- */
- if (base_type(reg->type) == PTR_TO_DYNPTR)
- break;
- if (arg_type & MEM_UNINIT) {
- if (!is_dynptr_reg_valid_uninit(env, reg)) {
- verbose(env, "Dynptr has to be an uninitialized dynptr\n");
- return -EINVAL;
- }
-
- /* We only support one dynptr being uninitialized at the moment,
- * which is sufficient for the helper functions we have right now.
- */
- if (meta->uninit_dynptr_regno) {
- verbose(env, "verifier internal error: multiple uninitialized dynptr args\n");
- return -EFAULT;
- }
-
- meta->uninit_dynptr_regno = regno;
- } else if (!is_dynptr_reg_valid_init(env, reg)) {
- verbose(env,
- "Expected an initialized dynptr as arg #%d\n",
- arg + 1);
- return -EINVAL;
- } else if (!is_dynptr_type_expected(env, reg, arg_type)) {
- const char *err_extra = "";
-
- switch (arg_type & DYNPTR_TYPE_FLAG_MASK) {
- case DYNPTR_TYPE_LOCAL:
- err_extra = "local";
- break;
- case DYNPTR_TYPE_RINGBUF:
- err_extra = "ringbuf";
- break;
- default:
- err_extra = "<unknown>";
- break;
- }
- verbose(env,
- "Expected a dynptr of type %s as arg #%d\n",
- err_extra, arg + 1);
- return -EINVAL;
- }
+ err = process_dynptr_func(env, regno, arg_type, meta);
+ if (err)
+ return err;
break;
case ARG_CONST_ALLOC_SIZE_OR_ZERO:
if (!tnum_is_const(reg->var_off)) {
@@ -6203,8 +6634,9 @@ skip_type_check:
break;
}
case ARG_PTR_TO_KPTR:
- if (process_kptr_func(env, regno, meta))
- return -EACCES;
+ err = process_kptr_func(env, regno, meta);
+ if (err)
+ return err;
break;
}
@@ -6365,6 +6797,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
func_id != BPF_FUNC_task_storage_delete)
goto error;
break;
+ case BPF_MAP_TYPE_CGRP_STORAGE:
+ if (func_id != BPF_FUNC_cgrp_storage_get &&
+ func_id != BPF_FUNC_cgrp_storage_delete)
+ goto error;
+ break;
case BPF_MAP_TYPE_BLOOM_FILTER:
if (func_id != BPF_FUNC_map_peek_elem &&
func_id != BPF_FUNC_map_push_elem)
@@ -6477,6 +6914,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE)
goto error;
break;
+ case BPF_FUNC_cgrp_storage_get:
+ case BPF_FUNC_cgrp_storage_delete:
+ if (map->map_type != BPF_MAP_TYPE_CGRP_STORAGE)
+ goto error;
+ break;
default:
break;
}
@@ -6548,9 +6990,10 @@ static bool check_btf_id_ok(const struct bpf_func_proto *fn)
int i;
for (i = 0; i < ARRAY_SIZE(fn->arg_type); i++) {
- if (base_type(fn->arg_type[i]) == ARG_PTR_TO_BTF_ID && !fn->arg_btf_id[i])
- return false;
-
+ if (base_type(fn->arg_type[i]) == ARG_PTR_TO_BTF_ID)
+ return !!fn->arg_btf_id[i];
+ if (base_type(fn->arg_type[i]) == ARG_PTR_TO_SPIN_LOCK)
+ return fn->arg_btf_id[i] == BPF_PTR_POISON;
if (base_type(fn->arg_type[i]) != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i] &&
/* arg_btf_id and arg_size are in a union. */
(base_type(fn->arg_type[i]) != ARG_PTR_TO_MEM ||
@@ -6651,6 +7094,10 @@ typedef int (*set_callee_state_fn)(struct bpf_verifier_env *env,
struct bpf_func_state *callee,
int insn_idx);
+static int set_callee_state(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee, int insn_idx);
+
static int __check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
int *insn_idx, int subprog,
set_callee_state_fn set_callee_state_cb)
@@ -6701,6 +7148,16 @@ static int __check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn
}
}
+ /* set_callee_state is used for direct subprog calls, but we are
+ * interested in validating only BPF helpers that can call subprogs as
+ * callbacks
+ */
+ if (set_callee_state_cb != set_callee_state && !is_callback_calling_function(insn->imm)) {
+ verbose(env, "verifier bug: helper %s#%d is not marked as callback-calling\n",
+ func_id_name(insn->imm), insn->imm);
+ return -EFAULT;
+ }
+
if (insn->code == (BPF_JMP | BPF_CALL) &&
insn->src_reg == 0 &&
insn->imm == BPF_FUNC_timer_set_callback) {
@@ -6947,11 +7404,10 @@ static int set_user_ringbuf_callback_state(struct bpf_verifier_env *env,
{
/* bpf_user_ringbuf_drain(struct bpf_map *map, void *callback_fn, void
* callback_ctx, u64 flags);
- * callback_fn(struct bpf_dynptr_t* dynptr, void *callback_ctx);
+ * callback_fn(const struct bpf_dynptr_t* dynptr, void *callback_ctx);
*/
__mark_reg_not_init(env, &callee->regs[BPF_REG_0]);
- callee->regs[BPF_REG_1].type = PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL;
- __mark_reg_known_zero(&callee->regs[BPF_REG_1]);
+ mark_dynptr_cb_reg(&callee->regs[BPF_REG_1], BPF_DYNPTR_TYPE_LOCAL);
callee->regs[BPF_REG_2] = caller->regs[BPF_REG_3];
/* unused */
@@ -7283,6 +7739,11 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
return -EINVAL;
}
+ if (!env->prog->aux->sleepable && fn->might_sleep) {
+ verbose(env, "helper call might sleep in a non-sleepable prog\n");
+ return -EINVAL;
+ }
+
/* With LD_ABS/IND some JITs save/restore skb from r1. */
changes_data = bpf_helper_changes_pkt_data(fn->func);
if (changes_data && fn->arg1_type != ARG_PTR_TO_CTX) {
@@ -7301,6 +7762,17 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
return err;
}
+ if (env->cur_state->active_rcu_lock) {
+ if (fn->might_sleep) {
+ verbose(env, "sleepable helper %s#%d in rcu_read_lock region\n",
+ func_id_name(func_id), func_id);
+ return -EINVAL;
+ }
+
+ if (env->prog->aux->sleepable && is_storage_get_function(func_id))
+ env->insn_aux_data[insn_idx].storage_get_func_atomic = true;
+ }
+
meta.func_id = func_id;
/* check args */
for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) {
@@ -7329,7 +7801,15 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
regs = cur_regs(env);
+ /* This can only be set for PTR_TO_STACK, as CONST_PTR_TO_DYNPTR cannot
+ * be reinitialized by any dynptr helper. Hence, mark_stack_slots_dynptr
+ * is safe to do directly.
+ */
if (meta.uninit_dynptr_regno) {
+ if (regs[meta.uninit_dynptr_regno].type == CONST_PTR_TO_DYNPTR) {
+ verbose(env, "verifier internal error: CONST_PTR_TO_DYNPTR cannot be initialized\n");
+ return -EFAULT;
+ }
/* we write BPF_DW bits (8 bytes) at a time */
for (i = 0; i < BPF_DYNPTR_SIZE; i += 8) {
err = check_mem_access(env, insn_idx, meta.uninit_dynptr_regno,
@@ -7347,15 +7827,24 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
if (meta.release_regno) {
err = -EINVAL;
- if (arg_type_is_dynptr(fn->arg_type[meta.release_regno - BPF_REG_1]))
+ /* This can only be set for PTR_TO_STACK, as CONST_PTR_TO_DYNPTR cannot
+ * be released by any dynptr helper. Hence, unmark_stack_slots_dynptr
+ * is safe to do directly.
+ */
+ if (arg_type_is_dynptr(fn->arg_type[meta.release_regno - BPF_REG_1])) {
+ if (regs[meta.release_regno].type == CONST_PTR_TO_DYNPTR) {
+ verbose(env, "verifier internal error: CONST_PTR_TO_DYNPTR cannot be released\n");
+ return -EFAULT;
+ }
err = unmark_stack_slots_dynptr(env, &regs[meta.release_regno]);
- else if (meta.ref_obj_id)
+ } else if (meta.ref_obj_id) {
err = release_reference(env, meta.ref_obj_id);
- /* meta.ref_obj_id can only be 0 if register that is meant to be
- * released is NULL, which must be > R0.
- */
- else if (register_is_null(&regs[meta.release_regno]))
+ } else if (register_is_null(&regs[meta.release_regno])) {
+ /* meta.ref_obj_id can only be 0 if register that is meant to be
+ * released is NULL, which must be > R0.
+ */
err = 0;
+ }
if (err) {
verbose(env, "func %s#%d reference has not been acquired before\n",
func_id_name(func_id), func_id);
@@ -7429,11 +7918,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
return -EFAULT;
}
- if (base_type(reg->type) != PTR_TO_DYNPTR)
- /* Find the id of the dynptr we're
- * tracking the reference of
- */
- meta.ref_obj_id = stack_slot_get_id(env, reg);
+ meta.ref_obj_id = dynptr_ref_obj_id(env, reg);
break;
}
}
@@ -7488,7 +7973,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
regs[BPF_REG_0].map_uid = meta.map_uid;
regs[BPF_REG_0].type = PTR_TO_MAP_VALUE | ret_flag;
if (!type_may_be_null(ret_type) &&
- map_value_has_spin_lock(meta.map_ptr)) {
+ btf_record_has_field(meta.map_ptr->record, BPF_SPIN_LOCK)) {
regs[BPF_REG_0].id = ++env->id_gen;
}
break;
@@ -7504,7 +7989,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
mark_reg_known_zero(env, regs, BPF_REG_0);
regs[BPF_REG_0].type = PTR_TO_TCP_SOCK | ret_flag;
break;
- case RET_PTR_TO_ALLOC_MEM:
+ case RET_PTR_TO_MEM:
mark_reg_known_zero(env, regs, BPF_REG_0);
regs[BPF_REG_0].type = PTR_TO_MEM | ret_flag;
regs[BPF_REG_0].mem_size = meta.mem_size;
@@ -7552,8 +8037,8 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
mark_reg_known_zero(env, regs, BPF_REG_0);
regs[BPF_REG_0].type = PTR_TO_BTF_ID | ret_flag;
if (func_id == BPF_FUNC_kptr_xchg) {
- ret_btf = meta.kptr_off_desc->kptr.btf;
- ret_btf_id = meta.kptr_off_desc->kptr.btf_id;
+ ret_btf = meta.kptr_field->kptr.btf;
+ ret_btf_id = meta.kptr_field->kptr.btf_id;
} else {
if (fn->ret_btf_id == BPF_PTR_POISON) {
verbose(env, "verifier internal error:");
@@ -7667,19 +8152,926 @@ static void mark_btf_func_reg_size(struct bpf_verifier_env *env, u32 regno,
}
}
+struct bpf_kfunc_call_arg_meta {
+ /* In parameters */
+ struct btf *btf;
+ u32 func_id;
+ u32 kfunc_flags;
+ const struct btf_type *func_proto;
+ const char *func_name;
+ /* Out parameters */
+ u32 ref_obj_id;
+ u8 release_regno;
+ bool r0_rdonly;
+ u32 ret_btf_id;
+ u64 r0_size;
+ struct {
+ u64 value;
+ bool found;
+ } arg_constant;
+ struct {
+ struct btf *btf;
+ u32 btf_id;
+ } arg_obj_drop;
+ struct {
+ struct btf_field *field;
+ } arg_list_head;
+};
+
+static bool is_kfunc_acquire(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta->kfunc_flags & KF_ACQUIRE;
+}
+
+static bool is_kfunc_ret_null(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta->kfunc_flags & KF_RET_NULL;
+}
+
+static bool is_kfunc_release(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta->kfunc_flags & KF_RELEASE;
+}
+
+static bool is_kfunc_trusted_args(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta->kfunc_flags & KF_TRUSTED_ARGS;
+}
+
+static bool is_kfunc_sleepable(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta->kfunc_flags & KF_SLEEPABLE;
+}
+
+static bool is_kfunc_destructive(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta->kfunc_flags & KF_DESTRUCTIVE;
+}
+
+static bool is_kfunc_rcu(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta->kfunc_flags & KF_RCU;
+}
+
+static bool is_kfunc_arg_kptr_get(struct bpf_kfunc_call_arg_meta *meta, int arg)
+{
+ return arg == 0 && (meta->kfunc_flags & KF_KPTR_GET);
+}
+
+static bool __kfunc_param_match_suffix(const struct btf *btf,
+ const struct btf_param *arg,
+ const char *suffix)
+{
+ int suffix_len = strlen(suffix), len;
+ const char *param_name;
+
+ /* In the future, this can be ported to use BTF tagging */
+ param_name = btf_name_by_offset(btf, arg->name_off);
+ if (str_is_empty(param_name))
+ return false;
+ len = strlen(param_name);
+ if (len < suffix_len)
+ return false;
+ param_name += len - suffix_len;
+ return !strncmp(param_name, suffix, suffix_len);
+}
+
+static bool is_kfunc_arg_mem_size(const struct btf *btf,
+ const struct btf_param *arg,
+ const struct bpf_reg_state *reg)
+{
+ const struct btf_type *t;
+
+ t = btf_type_skip_modifiers(btf, arg->type, NULL);
+ if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE)
+ return false;
+
+ return __kfunc_param_match_suffix(btf, arg, "__sz");
+}
+
+static bool is_kfunc_arg_constant(const struct btf *btf, const struct btf_param *arg)
+{
+ return __kfunc_param_match_suffix(btf, arg, "__k");
+}
+
+static bool is_kfunc_arg_ignore(const struct btf *btf, const struct btf_param *arg)
+{
+ return __kfunc_param_match_suffix(btf, arg, "__ign");
+}
+
+static bool is_kfunc_arg_alloc_obj(const struct btf *btf, const struct btf_param *arg)
+{
+ return __kfunc_param_match_suffix(btf, arg, "__alloc");
+}
+
+static bool is_kfunc_arg_scalar_with_name(const struct btf *btf,
+ const struct btf_param *arg,
+ const char *name)
+{
+ int len, target_len = strlen(name);
+ const char *param_name;
+
+ param_name = btf_name_by_offset(btf, arg->name_off);
+ if (str_is_empty(param_name))
+ return false;
+ len = strlen(param_name);
+ if (len != target_len)
+ return false;
+ if (strcmp(param_name, name))
+ return false;
+
+ return true;
+}
+
+enum {
+ KF_ARG_DYNPTR_ID,
+ KF_ARG_LIST_HEAD_ID,
+ KF_ARG_LIST_NODE_ID,
+};
+
+BTF_ID_LIST(kf_arg_btf_ids)
+BTF_ID(struct, bpf_dynptr_kern)
+BTF_ID(struct, bpf_list_head)
+BTF_ID(struct, bpf_list_node)
+
+static bool __is_kfunc_ptr_arg_type(const struct btf *btf,
+ const struct btf_param *arg, int type)
+{
+ const struct btf_type *t;
+ u32 res_id;
+
+ t = btf_type_skip_modifiers(btf, arg->type, NULL);
+ if (!t)
+ return false;
+ if (!btf_type_is_ptr(t))
+ return false;
+ t = btf_type_skip_modifiers(btf, t->type, &res_id);
+ if (!t)
+ return false;
+ return btf_types_are_same(btf, res_id, btf_vmlinux, kf_arg_btf_ids[type]);
+}
+
+static bool is_kfunc_arg_dynptr(const struct btf *btf, const struct btf_param *arg)
+{
+ return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_DYNPTR_ID);
+}
+
+static bool is_kfunc_arg_list_head(const struct btf *btf, const struct btf_param *arg)
+{
+ return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_LIST_HEAD_ID);
+}
+
+static bool is_kfunc_arg_list_node(const struct btf *btf, const struct btf_param *arg)
+{
+ return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_LIST_NODE_ID);
+}
+
+/* Returns true if struct is composed of scalars, 4 levels of nesting allowed */
+static bool __btf_type_is_scalar_struct(struct bpf_verifier_env *env,
+ const struct btf *btf,
+ const struct btf_type *t, int rec)
+{
+ const struct btf_type *member_type;
+ const struct btf_member *member;
+ u32 i;
+
+ if (!btf_type_is_struct(t))
+ return false;
+
+ for_each_member(i, t, member) {
+ const struct btf_array *array;
+
+ member_type = btf_type_skip_modifiers(btf, member->type, NULL);
+ if (btf_type_is_struct(member_type)) {
+ if (rec >= 3) {
+ verbose(env, "max struct nesting depth exceeded\n");
+ return false;
+ }
+ if (!__btf_type_is_scalar_struct(env, btf, member_type, rec + 1))
+ return false;
+ continue;
+ }
+ if (btf_type_is_array(member_type)) {
+ array = btf_array(member_type);
+ if (!array->nelems)
+ return false;
+ member_type = btf_type_skip_modifiers(btf, array->type, NULL);
+ if (!btf_type_is_scalar(member_type))
+ return false;
+ continue;
+ }
+ if (!btf_type_is_scalar(member_type))
+ return false;
+ }
+ return true;
+}
+
+
+static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = {
+#ifdef CONFIG_NET
+ [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK],
+ [PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
+ [PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP],
+#endif
+};
+
+enum kfunc_ptr_arg_type {
+ KF_ARG_PTR_TO_CTX,
+ KF_ARG_PTR_TO_ALLOC_BTF_ID, /* Allocated object */
+ KF_ARG_PTR_TO_KPTR, /* PTR_TO_KPTR but type specific */
+ KF_ARG_PTR_TO_DYNPTR,
+ KF_ARG_PTR_TO_LIST_HEAD,
+ KF_ARG_PTR_TO_LIST_NODE,
+ KF_ARG_PTR_TO_BTF_ID, /* Also covers reg2btf_ids conversions */
+ KF_ARG_PTR_TO_MEM,
+ KF_ARG_PTR_TO_MEM_SIZE, /* Size derived from next argument, skip it */
+};
+
+enum special_kfunc_type {
+ KF_bpf_obj_new_impl,
+ KF_bpf_obj_drop_impl,
+ KF_bpf_list_push_front,
+ KF_bpf_list_push_back,
+ KF_bpf_list_pop_front,
+ KF_bpf_list_pop_back,
+ KF_bpf_cast_to_kern_ctx,
+ KF_bpf_rdonly_cast,
+ KF_bpf_rcu_read_lock,
+ KF_bpf_rcu_read_unlock,
+};
+
+BTF_SET_START(special_kfunc_set)
+BTF_ID(func, bpf_obj_new_impl)
+BTF_ID(func, bpf_obj_drop_impl)
+BTF_ID(func, bpf_list_push_front)
+BTF_ID(func, bpf_list_push_back)
+BTF_ID(func, bpf_list_pop_front)
+BTF_ID(func, bpf_list_pop_back)
+BTF_ID(func, bpf_cast_to_kern_ctx)
+BTF_ID(func, bpf_rdonly_cast)
+BTF_SET_END(special_kfunc_set)
+
+BTF_ID_LIST(special_kfunc_list)
+BTF_ID(func, bpf_obj_new_impl)
+BTF_ID(func, bpf_obj_drop_impl)
+BTF_ID(func, bpf_list_push_front)
+BTF_ID(func, bpf_list_push_back)
+BTF_ID(func, bpf_list_pop_front)
+BTF_ID(func, bpf_list_pop_back)
+BTF_ID(func, bpf_cast_to_kern_ctx)
+BTF_ID(func, bpf_rdonly_cast)
+BTF_ID(func, bpf_rcu_read_lock)
+BTF_ID(func, bpf_rcu_read_unlock)
+
+static bool is_kfunc_bpf_rcu_read_lock(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta->func_id == special_kfunc_list[KF_bpf_rcu_read_lock];
+}
+
+static bool is_kfunc_bpf_rcu_read_unlock(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta->func_id == special_kfunc_list[KF_bpf_rcu_read_unlock];
+}
+
+static enum kfunc_ptr_arg_type
+get_kfunc_ptr_arg_type(struct bpf_verifier_env *env,
+ struct bpf_kfunc_call_arg_meta *meta,
+ const struct btf_type *t, const struct btf_type *ref_t,
+ const char *ref_tname, const struct btf_param *args,
+ int argno, int nargs)
+{
+ u32 regno = argno + 1;
+ struct bpf_reg_state *regs = cur_regs(env);
+ struct bpf_reg_state *reg = &regs[regno];
+ bool arg_mem_size = false;
+
+ if (meta->func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx])
+ return KF_ARG_PTR_TO_CTX;
+
+ /* In this function, we verify the kfunc's BTF as per the argument type,
+ * leaving the rest of the verification with respect to the register
+ * type to our caller. When a set of conditions hold in the BTF type of
+ * arguments, we resolve it to a known kfunc_ptr_arg_type.
+ */
+ if (btf_get_prog_ctx_type(&env->log, meta->btf, t, resolve_prog_type(env->prog), argno))
+ return KF_ARG_PTR_TO_CTX;
+
+ if (is_kfunc_arg_alloc_obj(meta->btf, &args[argno]))
+ return KF_ARG_PTR_TO_ALLOC_BTF_ID;
+
+ if (is_kfunc_arg_kptr_get(meta, argno)) {
+ if (!btf_type_is_ptr(ref_t)) {
+ verbose(env, "arg#0 BTF type must be a double pointer for kptr_get kfunc\n");
+ return -EINVAL;
+ }
+ ref_t = btf_type_by_id(meta->btf, ref_t->type);
+ ref_tname = btf_name_by_offset(meta->btf, ref_t->name_off);
+ if (!btf_type_is_struct(ref_t)) {
+ verbose(env, "kernel function %s args#0 pointer type %s %s is not supported\n",
+ meta->func_name, btf_type_str(ref_t), ref_tname);
+ return -EINVAL;
+ }
+ return KF_ARG_PTR_TO_KPTR;
+ }
+
+ if (is_kfunc_arg_dynptr(meta->btf, &args[argno]))
+ return KF_ARG_PTR_TO_DYNPTR;
+
+ if (is_kfunc_arg_list_head(meta->btf, &args[argno]))
+ return KF_ARG_PTR_TO_LIST_HEAD;
+
+ if (is_kfunc_arg_list_node(meta->btf, &args[argno]))
+ return KF_ARG_PTR_TO_LIST_NODE;
+
+ if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) {
+ if (!btf_type_is_struct(ref_t)) {
+ verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n",
+ meta->func_name, argno, btf_type_str(ref_t), ref_tname);
+ return -EINVAL;
+ }
+ return KF_ARG_PTR_TO_BTF_ID;
+ }
+
+ if (argno + 1 < nargs && is_kfunc_arg_mem_size(meta->btf, &args[argno + 1], &regs[regno + 1]))
+ arg_mem_size = true;
+
+ /* This is the catch all argument type of register types supported by
+ * check_helper_mem_access. However, we only allow when argument type is
+ * pointer to scalar, or struct composed (recursively) of scalars. When
+ * arg_mem_size is true, the pointer can be void *.
+ */
+ if (!btf_type_is_scalar(ref_t) && !__btf_type_is_scalar_struct(env, meta->btf, ref_t, 0) &&
+ (arg_mem_size ? !btf_type_is_void(ref_t) : 1)) {
+ verbose(env, "arg#%d pointer type %s %s must point to %sscalar, or struct with scalar\n",
+ argno, btf_type_str(ref_t), ref_tname, arg_mem_size ? "void, " : "");
+ return -EINVAL;
+ }
+ return arg_mem_size ? KF_ARG_PTR_TO_MEM_SIZE : KF_ARG_PTR_TO_MEM;
+}
+
+static int process_kf_arg_ptr_to_btf_id(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg,
+ const struct btf_type *ref_t,
+ const char *ref_tname, u32 ref_id,
+ struct bpf_kfunc_call_arg_meta *meta,
+ int argno)
+{
+ const struct btf_type *reg_ref_t;
+ bool strict_type_match = false;
+ const struct btf *reg_btf;
+ const char *reg_ref_tname;
+ u32 reg_ref_id;
+
+ if (base_type(reg->type) == PTR_TO_BTF_ID) {
+ reg_btf = reg->btf;
+ reg_ref_id = reg->btf_id;
+ } else {
+ reg_btf = btf_vmlinux;
+ reg_ref_id = *reg2btf_ids[base_type(reg->type)];
+ }
+
+ if (is_kfunc_trusted_args(meta) || (is_kfunc_release(meta) && reg->ref_obj_id))
+ strict_type_match = true;
+
+ reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id, &reg_ref_id);
+ reg_ref_tname = btf_name_by_offset(reg_btf, reg_ref_t->name_off);
+ if (!btf_struct_ids_match(&env->log, reg_btf, reg_ref_id, reg->off, meta->btf, ref_id, strict_type_match)) {
+ verbose(env, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n",
+ meta->func_name, argno, btf_type_str(ref_t), ref_tname, argno + 1,
+ btf_type_str(reg_ref_t), reg_ref_tname);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int process_kf_arg_ptr_to_kptr(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg,
+ const struct btf_type *ref_t,
+ const char *ref_tname,
+ struct bpf_kfunc_call_arg_meta *meta,
+ int argno)
+{
+ struct btf_field *kptr_field;
+
+ /* check_func_arg_reg_off allows var_off for
+ * PTR_TO_MAP_VALUE, but we need fixed offset to find
+ * off_desc.
+ */
+ if (!tnum_is_const(reg->var_off)) {
+ verbose(env, "arg#0 must have constant offset\n");
+ return -EINVAL;
+ }
+
+ kptr_field = btf_record_find(reg->map_ptr->record, reg->off + reg->var_off.value, BPF_KPTR);
+ if (!kptr_field || kptr_field->type != BPF_KPTR_REF) {
+ verbose(env, "arg#0 no referenced kptr at map value offset=%llu\n",
+ reg->off + reg->var_off.value);
+ return -EINVAL;
+ }
+
+ if (!btf_struct_ids_match(&env->log, meta->btf, ref_t->type, 0, kptr_field->kptr.btf,
+ kptr_field->kptr.btf_id, true)) {
+ verbose(env, "kernel function %s args#%d expected pointer to %s %s\n",
+ meta->func_name, argno, btf_type_str(ref_t), ref_tname);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int ref_set_release_on_unlock(struct bpf_verifier_env *env, u32 ref_obj_id)
+{
+ struct bpf_func_state *state = cur_func(env);
+ struct bpf_reg_state *reg;
+ int i;
+
+ /* bpf_spin_lock only allows calling list_push and list_pop, no BPF
+ * subprogs, no global functions. This means that the references would
+ * not be released inside the critical section but they may be added to
+ * the reference state, and the acquired_refs are never copied out for a
+ * different frame as BPF to BPF calls don't work in bpf_spin_lock
+ * critical sections.
+ */
+ if (!ref_obj_id) {
+ verbose(env, "verifier internal error: ref_obj_id is zero for release_on_unlock\n");
+ return -EFAULT;
+ }
+ for (i = 0; i < state->acquired_refs; i++) {
+ if (state->refs[i].id == ref_obj_id) {
+ if (state->refs[i].release_on_unlock) {
+ verbose(env, "verifier internal error: expected false release_on_unlock");
+ return -EFAULT;
+ }
+ state->refs[i].release_on_unlock = true;
+ /* Now mark everyone sharing same ref_obj_id as untrusted */
+ bpf_for_each_reg_in_vstate(env->cur_state, state, reg, ({
+ if (reg->ref_obj_id == ref_obj_id)
+ reg->type |= PTR_UNTRUSTED;
+ }));
+ return 0;
+ }
+ }
+ verbose(env, "verifier internal error: ref state missing for ref_obj_id\n");
+ return -EFAULT;
+}
+
+/* Implementation details:
+ *
+ * Each register points to some region of memory, which we define as an
+ * allocation. Each allocation may embed a bpf_spin_lock which protects any
+ * special BPF objects (bpf_list_head, bpf_rb_root, etc.) part of the same
+ * allocation. The lock and the data it protects are colocated in the same
+ * memory region.
+ *
+ * Hence, everytime a register holds a pointer value pointing to such
+ * allocation, the verifier preserves a unique reg->id for it.
+ *
+ * The verifier remembers the lock 'ptr' and the lock 'id' whenever
+ * bpf_spin_lock is called.
+ *
+ * To enable this, lock state in the verifier captures two values:
+ * active_lock.ptr = Register's type specific pointer
+ * active_lock.id = A unique ID for each register pointer value
+ *
+ * Currently, PTR_TO_MAP_VALUE and PTR_TO_BTF_ID | MEM_ALLOC are the two
+ * supported register types.
+ *
+ * The active_lock.ptr in case of map values is the reg->map_ptr, and in case of
+ * allocated objects is the reg->btf pointer.
+ *
+ * The active_lock.id is non-unique for maps supporting direct_value_addr, as we
+ * can establish the provenance of the map value statically for each distinct
+ * lookup into such maps. They always contain a single map value hence unique
+ * IDs for each pseudo load pessimizes the algorithm and rejects valid programs.
+ *
+ * So, in case of global variables, they use array maps with max_entries = 1,
+ * hence their active_lock.ptr becomes map_ptr and id = 0 (since they all point
+ * into the same map value as max_entries is 1, as described above).
+ *
+ * In case of inner map lookups, the inner map pointer has same map_ptr as the
+ * outer map pointer (in verifier context), but each lookup into an inner map
+ * assigns a fresh reg->id to the lookup, so while lookups into distinct inner
+ * maps from the same outer map share the same map_ptr as active_lock.ptr, they
+ * will get different reg->id assigned to each lookup, hence different
+ * active_lock.id.
+ *
+ * In case of allocated objects, active_lock.ptr is the reg->btf, and the
+ * reg->id is a unique ID preserved after the NULL pointer check on the pointer
+ * returned from bpf_obj_new. Each allocation receives a new reg->id.
+ */
+static int check_reg_allocation_locked(struct bpf_verifier_env *env, struct bpf_reg_state *reg)
+{
+ void *ptr;
+ u32 id;
+
+ switch ((int)reg->type) {
+ case PTR_TO_MAP_VALUE:
+ ptr = reg->map_ptr;
+ break;
+ case PTR_TO_BTF_ID | MEM_ALLOC:
+ case PTR_TO_BTF_ID | MEM_ALLOC | PTR_TRUSTED:
+ ptr = reg->btf;
+ break;
+ default:
+ verbose(env, "verifier internal error: unknown reg type for lock check\n");
+ return -EFAULT;
+ }
+ id = reg->id;
+
+ if (!env->cur_state->active_lock.ptr)
+ return -EINVAL;
+ if (env->cur_state->active_lock.ptr != ptr ||
+ env->cur_state->active_lock.id != id) {
+ verbose(env, "held lock and object are not in the same allocation\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static bool is_bpf_list_api_kfunc(u32 btf_id)
+{
+ return btf_id == special_kfunc_list[KF_bpf_list_push_front] ||
+ btf_id == special_kfunc_list[KF_bpf_list_push_back] ||
+ btf_id == special_kfunc_list[KF_bpf_list_pop_front] ||
+ btf_id == special_kfunc_list[KF_bpf_list_pop_back];
+}
+
+static int process_kf_arg_ptr_to_list_head(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg, u32 regno,
+ struct bpf_kfunc_call_arg_meta *meta)
+{
+ struct btf_field *field;
+ struct btf_record *rec;
+ u32 list_head_off;
+
+ if (meta->btf != btf_vmlinux || !is_bpf_list_api_kfunc(meta->func_id)) {
+ verbose(env, "verifier internal error: bpf_list_head argument for unknown kfunc\n");
+ return -EFAULT;
+ }
+
+ if (!tnum_is_const(reg->var_off)) {
+ verbose(env,
+ "R%d doesn't have constant offset. bpf_list_head has to be at the constant offset\n",
+ regno);
+ return -EINVAL;
+ }
+
+ rec = reg_btf_record(reg);
+ list_head_off = reg->off + reg->var_off.value;
+ field = btf_record_find(rec, list_head_off, BPF_LIST_HEAD);
+ if (!field) {
+ verbose(env, "bpf_list_head not found at offset=%u\n", list_head_off);
+ return -EINVAL;
+ }
+
+ /* All functions require bpf_list_head to be protected using a bpf_spin_lock */
+ if (check_reg_allocation_locked(env, reg)) {
+ verbose(env, "bpf_spin_lock at off=%d must be held for bpf_list_head\n",
+ rec->spin_lock_off);
+ return -EINVAL;
+ }
+
+ if (meta->arg_list_head.field) {
+ verbose(env, "verifier internal error: repeating bpf_list_head arg\n");
+ return -EFAULT;
+ }
+ meta->arg_list_head.field = field;
+ return 0;
+}
+
+static int process_kf_arg_ptr_to_list_node(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg, u32 regno,
+ struct bpf_kfunc_call_arg_meta *meta)
+{
+ const struct btf_type *et, *t;
+ struct btf_field *field;
+ struct btf_record *rec;
+ u32 list_node_off;
+
+ if (meta->btf != btf_vmlinux ||
+ (meta->func_id != special_kfunc_list[KF_bpf_list_push_front] &&
+ meta->func_id != special_kfunc_list[KF_bpf_list_push_back])) {
+ verbose(env, "verifier internal error: bpf_list_node argument for unknown kfunc\n");
+ return -EFAULT;
+ }
+
+ if (!tnum_is_const(reg->var_off)) {
+ verbose(env,
+ "R%d doesn't have constant offset. bpf_list_node has to be at the constant offset\n",
+ regno);
+ return -EINVAL;
+ }
+
+ rec = reg_btf_record(reg);
+ list_node_off = reg->off + reg->var_off.value;
+ field = btf_record_find(rec, list_node_off, BPF_LIST_NODE);
+ if (!field || field->offset != list_node_off) {
+ verbose(env, "bpf_list_node not found at offset=%u\n", list_node_off);
+ return -EINVAL;
+ }
+
+ field = meta->arg_list_head.field;
+
+ et = btf_type_by_id(field->list_head.btf, field->list_head.value_btf_id);
+ t = btf_type_by_id(reg->btf, reg->btf_id);
+ if (!btf_struct_ids_match(&env->log, reg->btf, reg->btf_id, 0, field->list_head.btf,
+ field->list_head.value_btf_id, true)) {
+ verbose(env, "operation on bpf_list_head expects arg#1 bpf_list_node at offset=%d "
+ "in struct %s, but arg is at offset=%d in struct %s\n",
+ field->list_head.node_offset, btf_name_by_offset(field->list_head.btf, et->name_off),
+ list_node_off, btf_name_by_offset(reg->btf, t->name_off));
+ return -EINVAL;
+ }
+
+ if (list_node_off != field->list_head.node_offset) {
+ verbose(env, "arg#1 offset=%d, but expected bpf_list_node at offset=%d in struct %s\n",
+ list_node_off, field->list_head.node_offset,
+ btf_name_by_offset(field->list_head.btf, et->name_off));
+ return -EINVAL;
+ }
+ /* Set arg#1 for expiration after unlock */
+ return ref_set_release_on_unlock(env, reg->ref_obj_id);
+}
+
+static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_arg_meta *meta)
+{
+ const char *func_name = meta->func_name, *ref_tname;
+ const struct btf *btf = meta->btf;
+ const struct btf_param *args;
+ u32 i, nargs;
+ int ret;
+
+ args = (const struct btf_param *)(meta->func_proto + 1);
+ nargs = btf_type_vlen(meta->func_proto);
+ if (nargs > MAX_BPF_FUNC_REG_ARGS) {
+ verbose(env, "Function %s has %d > %d args\n", func_name, nargs,
+ MAX_BPF_FUNC_REG_ARGS);
+ return -EINVAL;
+ }
+
+ /* Check that BTF function arguments match actual types that the
+ * verifier sees.
+ */
+ for (i = 0; i < nargs; i++) {
+ struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[i + 1];
+ const struct btf_type *t, *ref_t, *resolve_ret;
+ enum bpf_arg_type arg_type = ARG_DONTCARE;
+ u32 regno = i + 1, ref_id, type_size;
+ bool is_ret_buf_sz = false;
+ int kf_arg_type;
+
+ t = btf_type_skip_modifiers(btf, args[i].type, NULL);
+
+ if (is_kfunc_arg_ignore(btf, &args[i]))
+ continue;
+
+ if (btf_type_is_scalar(t)) {
+ if (reg->type != SCALAR_VALUE) {
+ verbose(env, "R%d is not a scalar\n", regno);
+ return -EINVAL;
+ }
+
+ if (is_kfunc_arg_constant(meta->btf, &args[i])) {
+ if (meta->arg_constant.found) {
+ verbose(env, "verifier internal error: only one constant argument permitted\n");
+ return -EFAULT;
+ }
+ if (!tnum_is_const(reg->var_off)) {
+ verbose(env, "R%d must be a known constant\n", regno);
+ return -EINVAL;
+ }
+ ret = mark_chain_precision(env, regno);
+ if (ret < 0)
+ return ret;
+ meta->arg_constant.found = true;
+ meta->arg_constant.value = reg->var_off.value;
+ } else if (is_kfunc_arg_scalar_with_name(btf, &args[i], "rdonly_buf_size")) {
+ meta->r0_rdonly = true;
+ is_ret_buf_sz = true;
+ } else if (is_kfunc_arg_scalar_with_name(btf, &args[i], "rdwr_buf_size")) {
+ is_ret_buf_sz = true;
+ }
+
+ if (is_ret_buf_sz) {
+ if (meta->r0_size) {
+ verbose(env, "2 or more rdonly/rdwr_buf_size parameters for kfunc");
+ return -EINVAL;
+ }
+
+ if (!tnum_is_const(reg->var_off)) {
+ verbose(env, "R%d is not a const\n", regno);
+ return -EINVAL;
+ }
+
+ meta->r0_size = reg->var_off.value;
+ ret = mark_chain_precision(env, regno);
+ if (ret)
+ return ret;
+ }
+ continue;
+ }
+
+ if (!btf_type_is_ptr(t)) {
+ verbose(env, "Unrecognized arg#%d type %s\n", i, btf_type_str(t));
+ return -EINVAL;
+ }
+
+ if (reg->ref_obj_id) {
+ if (is_kfunc_release(meta) && meta->ref_obj_id) {
+ verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n",
+ regno, reg->ref_obj_id,
+ meta->ref_obj_id);
+ return -EFAULT;
+ }
+ meta->ref_obj_id = reg->ref_obj_id;
+ if (is_kfunc_release(meta))
+ meta->release_regno = regno;
+ }
+
+ ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id);
+ ref_tname = btf_name_by_offset(btf, ref_t->name_off);
+
+ kf_arg_type = get_kfunc_ptr_arg_type(env, meta, t, ref_t, ref_tname, args, i, nargs);
+ if (kf_arg_type < 0)
+ return kf_arg_type;
+
+ switch (kf_arg_type) {
+ case KF_ARG_PTR_TO_ALLOC_BTF_ID:
+ case KF_ARG_PTR_TO_BTF_ID:
+ if (!is_kfunc_trusted_args(meta) && !is_kfunc_rcu(meta))
+ break;
+
+ if (!is_trusted_reg(reg)) {
+ if (!is_kfunc_rcu(meta)) {
+ verbose(env, "R%d must be referenced or trusted\n", regno);
+ return -EINVAL;
+ }
+ if (!is_rcu_reg(reg)) {
+ verbose(env, "R%d must be a rcu pointer\n", regno);
+ return -EINVAL;
+ }
+ }
+
+ fallthrough;
+ case KF_ARG_PTR_TO_CTX:
+ /* Trusted arguments have the same offset checks as release arguments */
+ arg_type |= OBJ_RELEASE;
+ break;
+ case KF_ARG_PTR_TO_KPTR:
+ case KF_ARG_PTR_TO_DYNPTR:
+ case KF_ARG_PTR_TO_LIST_HEAD:
+ case KF_ARG_PTR_TO_LIST_NODE:
+ case KF_ARG_PTR_TO_MEM:
+ case KF_ARG_PTR_TO_MEM_SIZE:
+ /* Trusted by default */
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -EFAULT;
+ }
+
+ if (is_kfunc_release(meta) && reg->ref_obj_id)
+ arg_type |= OBJ_RELEASE;
+ ret = check_func_arg_reg_off(env, reg, regno, arg_type);
+ if (ret < 0)
+ return ret;
+
+ switch (kf_arg_type) {
+ case KF_ARG_PTR_TO_CTX:
+ if (reg->type != PTR_TO_CTX) {
+ verbose(env, "arg#%d expected pointer to ctx, but got %s\n", i, btf_type_str(t));
+ return -EINVAL;
+ }
+
+ if (meta->func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx]) {
+ ret = get_kern_ctx_btf_id(&env->log, resolve_prog_type(env->prog));
+ if (ret < 0)
+ return -EINVAL;
+ meta->ret_btf_id = ret;
+ }
+ break;
+ case KF_ARG_PTR_TO_ALLOC_BTF_ID:
+ if (reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) {
+ verbose(env, "arg#%d expected pointer to allocated object\n", i);
+ return -EINVAL;
+ }
+ if (!reg->ref_obj_id) {
+ verbose(env, "allocated object must be referenced\n");
+ return -EINVAL;
+ }
+ if (meta->btf == btf_vmlinux &&
+ meta->func_id == special_kfunc_list[KF_bpf_obj_drop_impl]) {
+ meta->arg_obj_drop.btf = reg->btf;
+ meta->arg_obj_drop.btf_id = reg->btf_id;
+ }
+ break;
+ case KF_ARG_PTR_TO_KPTR:
+ if (reg->type != PTR_TO_MAP_VALUE) {
+ verbose(env, "arg#0 expected pointer to map value\n");
+ return -EINVAL;
+ }
+ ret = process_kf_arg_ptr_to_kptr(env, reg, ref_t, ref_tname, meta, i);
+ if (ret < 0)
+ return ret;
+ break;
+ case KF_ARG_PTR_TO_DYNPTR:
+ if (reg->type != PTR_TO_STACK &&
+ reg->type != CONST_PTR_TO_DYNPTR) {
+ verbose(env, "arg#%d expected pointer to stack or dynptr_ptr\n", i);
+ return -EINVAL;
+ }
+
+ ret = process_dynptr_func(env, regno, ARG_PTR_TO_DYNPTR | MEM_RDONLY, NULL);
+ if (ret < 0)
+ return ret;
+ break;
+ case KF_ARG_PTR_TO_LIST_HEAD:
+ if (reg->type != PTR_TO_MAP_VALUE &&
+ reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) {
+ verbose(env, "arg#%d expected pointer to map value or allocated object\n", i);
+ return -EINVAL;
+ }
+ if (reg->type == (PTR_TO_BTF_ID | MEM_ALLOC) && !reg->ref_obj_id) {
+ verbose(env, "allocated object must be referenced\n");
+ return -EINVAL;
+ }
+ ret = process_kf_arg_ptr_to_list_head(env, reg, regno, meta);
+ if (ret < 0)
+ return ret;
+ break;
+ case KF_ARG_PTR_TO_LIST_NODE:
+ if (reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) {
+ verbose(env, "arg#%d expected pointer to allocated object\n", i);
+ return -EINVAL;
+ }
+ if (!reg->ref_obj_id) {
+ verbose(env, "allocated object must be referenced\n");
+ return -EINVAL;
+ }
+ ret = process_kf_arg_ptr_to_list_node(env, reg, regno, meta);
+ if (ret < 0)
+ return ret;
+ break;
+ case KF_ARG_PTR_TO_BTF_ID:
+ /* Only base_type is checked, further checks are done here */
+ if ((base_type(reg->type) != PTR_TO_BTF_ID ||
+ (bpf_type_has_unsafe_modifiers(reg->type) && !is_rcu_reg(reg))) &&
+ !reg2btf_ids[base_type(reg->type)]) {
+ verbose(env, "arg#%d is %s ", i, reg_type_str(env, reg->type));
+ verbose(env, "expected %s or socket\n",
+ reg_type_str(env, base_type(reg->type) |
+ (type_flag(reg->type) & BPF_REG_TRUSTED_MODIFIERS)));
+ return -EINVAL;
+ }
+ ret = process_kf_arg_ptr_to_btf_id(env, reg, ref_t, ref_tname, ref_id, meta, i);
+ if (ret < 0)
+ return ret;
+ break;
+ case KF_ARG_PTR_TO_MEM:
+ resolve_ret = btf_resolve_size(btf, ref_t, &type_size);
+ if (IS_ERR(resolve_ret)) {
+ verbose(env, "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
+ i, btf_type_str(ref_t), ref_tname, PTR_ERR(resolve_ret));
+ return -EINVAL;
+ }
+ ret = check_mem_reg(env, reg, regno, type_size);
+ if (ret < 0)
+ return ret;
+ break;
+ case KF_ARG_PTR_TO_MEM_SIZE:
+ ret = check_kfunc_mem_size_reg(env, &regs[regno + 1], regno + 1);
+ if (ret < 0) {
+ verbose(env, "arg#%d arg#%d memory, len pair leads to invalid memory access\n", i, i + 1);
+ return ret;
+ }
+ /* Skip next '__sz' argument */
+ i++;
+ break;
+ }
+ }
+
+ if (is_kfunc_release(meta) && !meta->release_regno) {
+ verbose(env, "release kernel function %s expects refcounted PTR_TO_BTF_ID\n",
+ func_name);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
int *insn_idx_p)
{
const struct btf_type *t, *func, *func_proto, *ptr_type;
struct bpf_reg_state *regs = cur_regs(env);
- struct bpf_kfunc_arg_meta meta = { 0 };
const char *func_name, *ptr_type_name;
+ bool sleepable, rcu_lock, rcu_unlock;
+ struct bpf_kfunc_call_arg_meta meta;
u32 i, nargs, func_id, ptr_type_id;
int err, insn_idx = *insn_idx_p;
const struct btf_param *args;
+ const struct btf_type *ret_t;
struct btf *desc_btf;
u32 *kfunc_flags;
- bool acq;
/* skip for now, but return error when we find this in fixup_kfunc_call */
if (!insn->imm)
@@ -7700,24 +9092,68 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
func_name);
return -EACCES;
}
- if (*kfunc_flags & KF_DESTRUCTIVE && !capable(CAP_SYS_BOOT)) {
- verbose(env, "destructive kfunc calls require CAP_SYS_BOOT capabilities\n");
+
+ /* Prepare kfunc call metadata */
+ memset(&meta, 0, sizeof(meta));
+ meta.btf = desc_btf;
+ meta.func_id = func_id;
+ meta.kfunc_flags = *kfunc_flags;
+ meta.func_proto = func_proto;
+ meta.func_name = func_name;
+
+ if (is_kfunc_destructive(&meta) && !capable(CAP_SYS_BOOT)) {
+ verbose(env, "destructive kfunc calls require CAP_SYS_BOOT capability\n");
return -EACCES;
}
- acq = *kfunc_flags & KF_ACQUIRE;
+ sleepable = is_kfunc_sleepable(&meta);
+ if (sleepable && !env->prog->aux->sleepable) {
+ verbose(env, "program must be sleepable to call sleepable kfunc %s\n", func_name);
+ return -EACCES;
+ }
+
+ rcu_lock = is_kfunc_bpf_rcu_read_lock(&meta);
+ rcu_unlock = is_kfunc_bpf_rcu_read_unlock(&meta);
+ if ((rcu_lock || rcu_unlock) && !env->rcu_tag_supported) {
+ verbose(env, "no vmlinux btf rcu tag support for kfunc %s\n", func_name);
+ return -EACCES;
+ }
- meta.flags = *kfunc_flags;
+ if (env->cur_state->active_rcu_lock) {
+ struct bpf_func_state *state;
+ struct bpf_reg_state *reg;
+
+ if (rcu_lock) {
+ verbose(env, "nested rcu read lock (kernel function %s)\n", func_name);
+ return -EINVAL;
+ } else if (rcu_unlock) {
+ bpf_for_each_reg_in_vstate(env->cur_state, state, reg, ({
+ if (reg->type & MEM_RCU) {
+ reg->type &= ~(MEM_RCU | PTR_MAYBE_NULL);
+ reg->type |= PTR_UNTRUSTED;
+ }
+ }));
+ env->cur_state->active_rcu_lock = false;
+ } else if (sleepable) {
+ verbose(env, "kernel func %s is sleepable within rcu_read_lock region\n", func_name);
+ return -EACCES;
+ }
+ } else if (rcu_lock) {
+ env->cur_state->active_rcu_lock = true;
+ } else if (rcu_unlock) {
+ verbose(env, "unmatched rcu read unlock (kernel function %s)\n", func_name);
+ return -EINVAL;
+ }
/* Check the arguments */
- err = btf_check_kfunc_arg_match(env, desc_btf, func_id, regs, &meta);
+ err = check_kfunc_args(env, &meta);
if (err < 0)
return err;
/* In case of release function, we get register number of refcounted
- * PTR_TO_BTF_ID back from btf_check_kfunc_arg_match, do the release now
+ * PTR_TO_BTF_ID in bpf_kfunc_arg_meta, do the release now.
*/
- if (err) {
- err = release_reference(env, regs[err].ref_obj_id);
+ if (meta.release_regno) {
+ err = release_reference(env, regs[meta.release_regno].ref_obj_id);
if (err) {
verbose(env, "kfunc %s#%d reference has not been acquired before\n",
func_name, func_id);
@@ -7731,18 +9167,92 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
/* Check return type */
t = btf_type_skip_modifiers(desc_btf, func_proto->type, NULL);
- if (acq && !btf_type_is_struct_ptr(desc_btf, t)) {
- verbose(env, "acquire kernel function does not return PTR_TO_BTF_ID\n");
- return -EINVAL;
+ if (is_kfunc_acquire(&meta) && !btf_type_is_struct_ptr(meta.btf, t)) {
+ /* Only exception is bpf_obj_new_impl */
+ if (meta.btf != btf_vmlinux || meta.func_id != special_kfunc_list[KF_bpf_obj_new_impl]) {
+ verbose(env, "acquire kernel function does not return PTR_TO_BTF_ID\n");
+ return -EINVAL;
+ }
}
if (btf_type_is_scalar(t)) {
mark_reg_unknown(env, regs, BPF_REG_0);
mark_btf_func_reg_size(env, BPF_REG_0, t->size);
} else if (btf_type_is_ptr(t)) {
- ptr_type = btf_type_skip_modifiers(desc_btf, t->type,
- &ptr_type_id);
- if (!btf_type_is_struct(ptr_type)) {
+ ptr_type = btf_type_skip_modifiers(desc_btf, t->type, &ptr_type_id);
+
+ if (meta.btf == btf_vmlinux && btf_id_set_contains(&special_kfunc_set, meta.func_id)) {
+ if (meta.func_id == special_kfunc_list[KF_bpf_obj_new_impl]) {
+ struct btf *ret_btf;
+ u32 ret_btf_id;
+
+ if (unlikely(!bpf_global_ma_set))
+ return -ENOMEM;
+
+ if (((u64)(u32)meta.arg_constant.value) != meta.arg_constant.value) {
+ verbose(env, "local type ID argument must be in range [0, U32_MAX]\n");
+ return -EINVAL;
+ }
+
+ ret_btf = env->prog->aux->btf;
+ ret_btf_id = meta.arg_constant.value;
+
+ /* This may be NULL due to user not supplying a BTF */
+ if (!ret_btf) {
+ verbose(env, "bpf_obj_new requires prog BTF\n");
+ return -EINVAL;
+ }
+
+ ret_t = btf_type_by_id(ret_btf, ret_btf_id);
+ if (!ret_t || !__btf_type_is_struct(ret_t)) {
+ verbose(env, "bpf_obj_new type ID argument must be of a struct\n");
+ return -EINVAL;
+ }
+
+ mark_reg_known_zero(env, regs, BPF_REG_0);
+ regs[BPF_REG_0].type = PTR_TO_BTF_ID | MEM_ALLOC;
+ regs[BPF_REG_0].btf = ret_btf;
+ regs[BPF_REG_0].btf_id = ret_btf_id;
+
+ env->insn_aux_data[insn_idx].obj_new_size = ret_t->size;
+ env->insn_aux_data[insn_idx].kptr_struct_meta =
+ btf_find_struct_meta(ret_btf, ret_btf_id);
+ } else if (meta.func_id == special_kfunc_list[KF_bpf_obj_drop_impl]) {
+ env->insn_aux_data[insn_idx].kptr_struct_meta =
+ btf_find_struct_meta(meta.arg_obj_drop.btf,
+ meta.arg_obj_drop.btf_id);
+ } else if (meta.func_id == special_kfunc_list[KF_bpf_list_pop_front] ||
+ meta.func_id == special_kfunc_list[KF_bpf_list_pop_back]) {
+ struct btf_field *field = meta.arg_list_head.field;
+
+ mark_reg_known_zero(env, regs, BPF_REG_0);
+ regs[BPF_REG_0].type = PTR_TO_BTF_ID | MEM_ALLOC;
+ regs[BPF_REG_0].btf = field->list_head.btf;
+ regs[BPF_REG_0].btf_id = field->list_head.value_btf_id;
+ regs[BPF_REG_0].off = field->list_head.node_offset;
+ } else if (meta.func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx]) {
+ mark_reg_known_zero(env, regs, BPF_REG_0);
+ regs[BPF_REG_0].type = PTR_TO_BTF_ID | PTR_TRUSTED;
+ regs[BPF_REG_0].btf = desc_btf;
+ regs[BPF_REG_0].btf_id = meta.ret_btf_id;
+ } else if (meta.func_id == special_kfunc_list[KF_bpf_rdonly_cast]) {
+ ret_t = btf_type_by_id(desc_btf, meta.arg_constant.value);
+ if (!ret_t || !btf_type_is_struct(ret_t)) {
+ verbose(env,
+ "kfunc bpf_rdonly_cast type ID argument must be of a struct\n");
+ return -EINVAL;
+ }
+
+ mark_reg_known_zero(env, regs, BPF_REG_0);
+ regs[BPF_REG_0].type = PTR_TO_BTF_ID | PTR_UNTRUSTED;
+ regs[BPF_REG_0].btf = desc_btf;
+ regs[BPF_REG_0].btf_id = meta.arg_constant.value;
+ } else {
+ verbose(env, "kernel function %s unhandled dynamic return type\n",
+ meta.func_name);
+ return -EFAULT;
+ }
+ } else if (!__btf_type_is_struct(ptr_type)) {
if (!meta.r0_size) {
ptr_type_name = btf_name_by_offset(desc_btf,
ptr_type->name_off);
@@ -7770,20 +9280,24 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
regs[BPF_REG_0].type = PTR_TO_BTF_ID;
regs[BPF_REG_0].btf_id = ptr_type_id;
}
- if (*kfunc_flags & KF_RET_NULL) {
+
+ if (is_kfunc_ret_null(&meta)) {
regs[BPF_REG_0].type |= PTR_MAYBE_NULL;
/* For mark_ptr_or_null_reg, see 93c230e3f5bd6 */
regs[BPF_REG_0].id = ++env->id_gen;
}
mark_btf_func_reg_size(env, BPF_REG_0, sizeof(void *));
- if (acq) {
+ if (is_kfunc_acquire(&meta)) {
int id = acquire_reference_state(env, insn_idx);
if (id < 0)
return id;
- regs[BPF_REG_0].id = id;
+ if (is_kfunc_ret_null(&meta))
+ regs[BPF_REG_0].id = id;
regs[BPF_REG_0].ref_obj_id = id;
}
+ if (reg_may_point_to_spin_lock(&regs[BPF_REG_0]) && !regs[BPF_REG_0].id)
+ regs[BPF_REG_0].id = ++env->id_gen;
} /* else { add_kfunc_call() ensures it is btf_type_is_void(t) } */
nargs = btf_type_vlen(func_proto);
@@ -9211,6 +10725,11 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
return err;
return adjust_ptr_min_max_vals(env, insn,
dst_reg, src_reg);
+ } else if (dst_reg->precise) {
+ /* if dst_reg is precise, src_reg should be precise as well */
+ err = mark_chain_precision(env, insn->src_reg);
+ if (err)
+ return err;
}
} else {
/* Pretend the src is a reg with a known value, since we only
@@ -9950,17 +11469,20 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state,
bool is_null)
{
if (type_may_be_null(reg->type) && reg->id == id &&
- !WARN_ON_ONCE(!reg->id)) {
- if (WARN_ON_ONCE(reg->smin_value || reg->smax_value ||
- !tnum_equals_const(reg->var_off, 0) ||
- reg->off)) {
- /* Old offset (both fixed and variable parts) should
- * have been known-zero, because we don't allow pointer
- * arithmetic on pointers that might be NULL. If we
- * see this happening, don't convert the register.
- */
+ (is_rcu_reg(reg) || !WARN_ON_ONCE(!reg->id))) {
+ /* Old offset (both fixed and variable parts) should have been
+ * known-zero, because we don't allow pointer arithmetic on
+ * pointers that might be NULL. If we see this happening, don't
+ * convert the register.
+ *
+ * But in some cases, some helpers that return local kptrs
+ * advance offset for the returned pointer. In those cases, it
+ * is fine to expect to see reg->off.
+ */
+ if (WARN_ON_ONCE(reg->smin_value || reg->smax_value || !tnum_equals_const(reg->var_off, 0)))
+ return;
+ if (reg->type != (PTR_TO_BTF_ID | MEM_ALLOC | PTR_MAYBE_NULL) && WARN_ON_ONCE(reg->off))
return;
- }
if (is_null) {
reg->type = SCALAR_VALUE;
/* We don't need id and ref_obj_id from this point
@@ -10134,6 +11656,7 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
struct bpf_verifier_state *other_branch;
struct bpf_reg_state *regs = this_branch->frame[this_branch->curframe]->regs;
struct bpf_reg_state *dst_reg, *other_branch_regs, *src_reg = NULL;
+ struct bpf_reg_state *eq_branch_regs;
u8 opcode = BPF_OP(insn->code);
bool is_jmp32;
int pred = -1;
@@ -10243,8 +11766,8 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
/* detect if we are comparing against a constant value so we can adjust
* our min/max values for our dst register.
* this is only legit if both are scalars (or pointers to the same
- * object, I suppose, but we don't support that right now), because
- * otherwise the different base pointers mean the offsets aren't
+ * object, I suppose, see the PTR_MAYBE_NULL related if block below),
+ * because otherwise the different base pointers mean the offsets aren't
* comparable.
*/
if (BPF_SRC(insn->code) == BPF_X) {
@@ -10293,6 +11816,36 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
find_equal_scalars(other_branch, &other_branch_regs[insn->dst_reg]);
}
+ /* if one pointer register is compared to another pointer
+ * register check if PTR_MAYBE_NULL could be lifted.
+ * E.g. register A - maybe null
+ * register B - not null
+ * for JNE A, B, ... - A is not null in the false branch;
+ * for JEQ A, B, ... - A is not null in the true branch.
+ */
+ if (!is_jmp32 && BPF_SRC(insn->code) == BPF_X &&
+ __is_pointer_value(false, src_reg) && __is_pointer_value(false, dst_reg) &&
+ type_may_be_null(src_reg->type) != type_may_be_null(dst_reg->type)) {
+ eq_branch_regs = NULL;
+ switch (opcode) {
+ case BPF_JEQ:
+ eq_branch_regs = other_branch_regs;
+ break;
+ case BPF_JNE:
+ eq_branch_regs = regs;
+ break;
+ default:
+ /* do nothing */
+ break;
+ }
+ if (eq_branch_regs) {
+ if (type_may_be_null(src_reg->type))
+ mark_ptr_not_null_reg(&eq_branch_regs[insn->src_reg]);
+ else
+ mark_ptr_not_null_reg(&eq_branch_regs[insn->dst_reg]);
+ }
+ }
+
/* detect if R == 0 where R is returned from bpf_map_lookup_elem().
* NOTE: these optimizations below are related with pointer comparison
* which will never be JMP32.
@@ -10399,8 +11952,8 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
insn->src_reg == BPF_PSEUDO_MAP_IDX_VALUE) {
dst_reg->type = PTR_TO_MAP_VALUE;
dst_reg->off = aux->map_off;
- if (map_value_has_spin_lock(map))
- dst_reg->id = ++env->id_gen;
+ WARN_ON_ONCE(map->max_entries != 1);
+ /* We want reg->id to be same (0) as map_value is not distinct */
} else if (insn->src_reg == BPF_PSEUDO_MAP_FD ||
insn->src_reg == BPF_PSEUDO_MAP_IDX) {
dst_reg->type = CONST_PTR_TO_MAP;
@@ -10478,11 +12031,16 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
return err;
}
- if (env->cur_state->active_spin_lock) {
+ if (env->cur_state->active_lock.ptr) {
verbose(env, "BPF_LD_[ABS|IND] cannot be used inside bpf_spin_lock-ed region\n");
return -EINVAL;
}
+ if (env->cur_state->active_rcu_lock) {
+ verbose(env, "BPF_LD_[ABS|IND] cannot be used inside bpf_rcu_read_lock-ed region\n");
+ return -EINVAL;
+ }
+
if (regs[ctx_reg].type != PTR_TO_CTX) {
verbose(env,
"at the time of BPF_LD_ABS|IND R6 != pointer to skb\n");
@@ -10684,7 +12242,7 @@ static int check_return_code(struct bpf_verifier_env *env)
* 3 let S be a stack
* 4 S.push(v)
* 5 while S is not empty
- * 6 t <- S.pop()
+ * 6 t <- S.peek()
* 7 if t is what we're looking for:
* 8 return t
* 9 for all edges e in G.adjacentEdges(t) do
@@ -10733,11 +12291,16 @@ static struct bpf_verifier_state_list **explored_state(
return &env->explored_states[(idx ^ state->callsite) % state_htab_size(env)];
}
-static void init_explored_state(struct bpf_verifier_env *env, int idx)
+static void mark_prune_point(struct bpf_verifier_env *env, int idx)
{
env->insn_aux_data[idx].prune_point = true;
}
+static bool is_prune_point(struct bpf_verifier_env *env, int insn_idx)
+{
+ return env->insn_aux_data[insn_idx].prune_point;
+}
+
enum {
DONE_EXPLORING = 0,
KEEP_EXPLORING = 1,
@@ -10766,9 +12329,11 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env,
return -EINVAL;
}
- if (e == BRANCH)
+ if (e == BRANCH) {
/* mark branch target for state pruning */
- init_explored_state(env, w);
+ mark_prune_point(env, w);
+ mark_jmp_point(env, w);
+ }
if (insn_state[w] == 0) {
/* tree-edge */
@@ -10795,8 +12360,7 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env,
return DONE_EXPLORING;
}
-static int visit_func_call_insn(int t, int insn_cnt,
- struct bpf_insn *insns,
+static int visit_func_call_insn(int t, struct bpf_insn *insns,
struct bpf_verifier_env *env,
bool visit_callee)
{
@@ -10806,10 +12370,12 @@ static int visit_func_call_insn(int t, int insn_cnt,
if (ret)
return ret;
- if (t + 1 < insn_cnt)
- init_explored_state(env, t + 1);
+ mark_prune_point(env, t + 1);
+ /* when we exit from subprog, we need to record non-linear history */
+ mark_jmp_point(env, t + 1);
+
if (visit_callee) {
- init_explored_state(env, t);
+ mark_prune_point(env, t);
ret = push_insn(t, t + insns[t].imm + 1, BRANCH, env,
/* It's ok to allow recursion from CFG point of
* view. __check_func_call() will do the actual
@@ -10825,13 +12391,13 @@ static int visit_func_call_insn(int t, int insn_cnt,
* DONE_EXPLORING - the instruction was fully explored
* KEEP_EXPLORING - there is still work to be done before it is fully explored
*/
-static int visit_insn(int t, int insn_cnt, struct bpf_verifier_env *env)
+static int visit_insn(int t, struct bpf_verifier_env *env)
{
struct bpf_insn *insns = env->prog->insnsi;
int ret;
if (bpf_pseudo_func(insns + t))
- return visit_func_call_insn(t, insn_cnt, insns, env, true);
+ return visit_func_call_insn(t, insns, env, true);
/* All non-branch instructions have a single fall-through edge. */
if (BPF_CLASS(insns[t].code) != BPF_JMP &&
@@ -10844,13 +12410,13 @@ static int visit_insn(int t, int insn_cnt, struct bpf_verifier_env *env)
case BPF_CALL:
if (insns[t].imm == BPF_FUNC_timer_set_callback)
- /* Mark this call insn to trigger is_state_visited() check
- * before call itself is processed by __check_func_call().
- * Otherwise new async state will be pushed for further
- * exploration.
+ /* Mark this call insn as a prune point to trigger
+ * is_state_visited() check before call itself is
+ * processed by __check_func_call(). Otherwise new
+ * async state will be pushed for further exploration.
*/
- init_explored_state(env, t);
- return visit_func_call_insn(t, insn_cnt, insns, env,
+ mark_prune_point(env, t);
+ return visit_func_call_insn(t, insns, env,
insns[t].src_reg == BPF_PSEUDO_CALL);
case BPF_JA:
@@ -10863,22 +12429,15 @@ static int visit_insn(int t, int insn_cnt, struct bpf_verifier_env *env)
if (ret)
return ret;
- /* unconditional jmp is not a good pruning point,
- * but it's marked, since backtracking needs
- * to record jmp history in is_state_visited().
- */
- init_explored_state(env, t + insns[t].off + 1);
- /* tell verifier to check for equivalent states
- * after every call and jump
- */
- if (t + 1 < insn_cnt)
- init_explored_state(env, t + 1);
+ mark_prune_point(env, t + insns[t].off + 1);
+ mark_jmp_point(env, t + insns[t].off + 1);
return ret;
default:
/* conditional jump with two edges */
- init_explored_state(env, t);
+ mark_prune_point(env, t);
+
ret = push_insn(t, t + 1, FALLTHROUGH, env, true);
if (ret)
return ret;
@@ -10914,7 +12473,7 @@ static int check_cfg(struct bpf_verifier_env *env)
while (env->cfg.cur_stack > 0) {
int t = insn_stack[env->cfg.cur_stack - 1];
- ret = visit_insn(t, insn_cnt, env);
+ ret = visit_insn(t, env);
switch (ret) {
case DONE_EXPLORING:
insn_state[t] = EXPLORED;
@@ -11505,15 +13064,6 @@ static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold,
equal = memcmp(rold, rcur, offsetof(struct bpf_reg_state, parent)) == 0;
- if (rold->type == PTR_TO_STACK)
- /* two stack pointers are equal only if they're pointing to
- * the same stack frame, since fp-8 in foo != fp-8 in bar
- */
- return equal && rold->frameno == rcur->frameno;
-
- if (equal)
- return true;
-
if (rold->type == NOT_INIT)
/* explored state can't have used this */
return true;
@@ -11521,10 +13071,12 @@ static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold,
return false;
switch (base_type(rold->type)) {
case SCALAR_VALUE:
+ if (equal)
+ return true;
if (env->explore_alu_limits)
return false;
if (rcur->type == SCALAR_VALUE) {
- if (!rold->precise && !rcur->precise)
+ if (!rold->precise)
return true;
/* new val must satisfy old val knowledge */
return range_within(rold, rcur) &&
@@ -11567,7 +13119,8 @@ static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold,
*/
return memcmp(rold, rcur, offsetof(struct bpf_reg_state, id)) == 0 &&
range_within(rold, rcur) &&
- tnum_in(rold->var_off, rcur->var_off);
+ tnum_in(rold->var_off, rcur->var_off) &&
+ check_ids(rold->id, rcur->id, idmap);
case PTR_TO_PACKET_META:
case PTR_TO_PACKET:
if (rcur->type != rold->type)
@@ -11591,20 +13144,14 @@ static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold,
/* new val must satisfy old val knowledge */
return range_within(rold, rcur) &&
tnum_in(rold->var_off, rcur->var_off);
- case PTR_TO_CTX:
- case CONST_PTR_TO_MAP:
- case PTR_TO_PACKET_END:
- case PTR_TO_FLOW_KEYS:
- case PTR_TO_SOCKET:
- case PTR_TO_SOCK_COMMON:
- case PTR_TO_TCP_SOCK:
- case PTR_TO_XDP_SOCK:
- /* Only valid matches are exact, which memcmp() above
- * would have accepted
+ case PTR_TO_STACK:
+ /* two stack pointers are equal only if they're pointing to
+ * the same stack frame, since fp-8 in foo != fp-8 in bar
*/
+ return equal && rold->frameno == rcur->frameno;
default:
- /* Don't know what's going on, just say it's not safe */
- return false;
+ /* Only valid matches are exact, which memcmp() */
+ return equal;
}
/* Shouldn't get here; if we do, say it's not safe */
@@ -11714,7 +13261,6 @@ static bool func_states_equal(struct bpf_verifier_env *env, struct bpf_func_stat
{
int i;
- memset(env->idmap_scratch, 0, sizeof(env->idmap_scratch));
for (i = 0; i < MAX_BPF_REG; i++)
if (!regsafe(env, &old->regs[i], &cur->regs[i],
env->idmap_scratch))
@@ -11738,13 +13284,28 @@ static bool states_equal(struct bpf_verifier_env *env,
if (old->curframe != cur->curframe)
return false;
+ memset(env->idmap_scratch, 0, sizeof(env->idmap_scratch));
+
/* Verification state from speculative execution simulation
* must never prune a non-speculative execution one.
*/
if (old->speculative && !cur->speculative)
return false;
- if (old->active_spin_lock != cur->active_spin_lock)
+ if (old->active_lock.ptr != cur->active_lock.ptr)
+ return false;
+
+ /* Old and cur active_lock's have to be either both present
+ * or both absent.
+ */
+ if (!!old->active_lock.id != !!cur->active_lock.id)
+ return false;
+
+ if (old->active_lock.id &&
+ !check_ids(old->active_lock.id, cur->active_lock.id, env->idmap_scratch))
+ return false;
+
+ if (old->active_rcu_lock != cur->active_rcu_lock)
return false;
/* for states to be equal callsites have to be the same
@@ -11847,34 +13408,36 @@ static int propagate_precision(struct bpf_verifier_env *env,
{
struct bpf_reg_state *state_reg;
struct bpf_func_state *state;
- int i, err = 0;
+ int i, err = 0, fr;
- state = old->frame[old->curframe];
- state_reg = state->regs;
- for (i = 0; i < BPF_REG_FP; i++, state_reg++) {
- if (state_reg->type != SCALAR_VALUE ||
- !state_reg->precise)
- continue;
- if (env->log.level & BPF_LOG_LEVEL2)
- verbose(env, "propagating r%d\n", i);
- err = mark_chain_precision(env, i);
- if (err < 0)
- return err;
- }
+ for (fr = old->curframe; fr >= 0; fr--) {
+ state = old->frame[fr];
+ state_reg = state->regs;
+ for (i = 0; i < BPF_REG_FP; i++, state_reg++) {
+ if (state_reg->type != SCALAR_VALUE ||
+ !state_reg->precise)
+ continue;
+ if (env->log.level & BPF_LOG_LEVEL2)
+ verbose(env, "frame %d: propagating r%d\n", i, fr);
+ err = mark_chain_precision_frame(env, fr, i);
+ if (err < 0)
+ return err;
+ }
- for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
- if (!is_spilled_reg(&state->stack[i]))
- continue;
- state_reg = &state->stack[i].spilled_ptr;
- if (state_reg->type != SCALAR_VALUE ||
- !state_reg->precise)
- continue;
- if (env->log.level & BPF_LOG_LEVEL2)
- verbose(env, "propagating fp%d\n",
- (-i - 1) * BPF_REG_SIZE);
- err = mark_chain_precision_stack(env, i);
- if (err < 0)
- return err;
+ for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
+ if (!is_spilled_reg(&state->stack[i]))
+ continue;
+ state_reg = &state->stack[i].spilled_ptr;
+ if (state_reg->type != SCALAR_VALUE ||
+ !state_reg->precise)
+ continue;
+ if (env->log.level & BPF_LOG_LEVEL2)
+ verbose(env, "frame %d: propagating fp%d\n",
+ (-i - 1) * BPF_REG_SIZE, fr);
+ err = mark_chain_precision_stack_frame(env, fr, i);
+ if (err < 0)
+ return err;
+ }
}
return 0;
}
@@ -11906,13 +13469,6 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
int i, j, err, states_cnt = 0;
bool add_new_state = env->test_state_freq ? true : false;
- cur->last_insn_idx = env->prev_insn_idx;
- if (!env->insn_aux_data[insn_idx].prune_point)
- /* this 'insn_idx' instruction wasn't marked, so we will not
- * be doing state search here
- */
- return 0;
-
/* bpf progs typically have pruning point every 4 instructions
* http://vger.kernel.org/bpfconf2019.html#session-1
* Do not add new state for future pruning if the verifier hasn't seen
@@ -12047,10 +13603,10 @@ next:
env->max_states_per_insn = states_cnt;
if (!env->bpf_capable && states_cnt > BPF_COMPLEXITY_LIMIT_STATES)
- return push_jmp_history(env, cur);
+ return 0;
if (!add_new_state)
- return push_jmp_history(env, cur);
+ return 0;
/* There were no equivalent states, remember the current one.
* Technically the current state is not proven to be safe yet,
@@ -12069,6 +13625,10 @@ next:
env->prev_jmps_processed = env->jmps_processed;
env->prev_insn_processed = env->insn_processed;
+ /* forget precise markings we inherited, see __mark_chain_precision */
+ if (env->bpf_capable)
+ mark_all_scalars_imprecise(env, cur);
+
/* add new state to the head of linked list */
new = &new_sl->state;
err = copy_verifier_state(new, cur);
@@ -12186,21 +13746,31 @@ static int do_check(struct bpf_verifier_env *env)
return -E2BIG;
}
- err = is_state_visited(env, env->insn_idx);
- if (err < 0)
- return err;
- if (err == 1) {
- /* found equivalent state, can prune the search */
- if (env->log.level & BPF_LOG_LEVEL) {
- if (do_print_state)
- verbose(env, "\nfrom %d to %d%s: safe\n",
- env->prev_insn_idx, env->insn_idx,
- env->cur_state->speculative ?
- " (speculative execution)" : "");
- else
- verbose(env, "%d: safe\n", env->insn_idx);
+ state->last_insn_idx = env->prev_insn_idx;
+
+ if (is_prune_point(env, env->insn_idx)) {
+ err = is_state_visited(env, env->insn_idx);
+ if (err < 0)
+ return err;
+ if (err == 1) {
+ /* found equivalent state, can prune the search */
+ if (env->log.level & BPF_LOG_LEVEL) {
+ if (do_print_state)
+ verbose(env, "\nfrom %d to %d%s: safe\n",
+ env->prev_insn_idx, env->insn_idx,
+ env->cur_state->speculative ?
+ " (speculative execution)" : "");
+ else
+ verbose(env, "%d: safe\n", env->insn_idx);
+ }
+ goto process_bpf_exit;
}
- goto process_bpf_exit;
+ }
+
+ if (is_jmp_point(env, env->insn_idx)) {
+ err = push_jmp_history(env, state);
+ if (err)
+ return err;
}
if (signal_pending(current))
@@ -12383,11 +13953,14 @@ static int do_check(struct bpf_verifier_env *env)
return -EINVAL;
}
- if (env->cur_state->active_spin_lock &&
- (insn->src_reg == BPF_PSEUDO_CALL ||
- insn->imm != BPF_FUNC_spin_unlock)) {
- verbose(env, "function calls are not allowed while holding a lock\n");
- return -EINVAL;
+ if (env->cur_state->active_lock.ptr) {
+ if ((insn->src_reg == BPF_REG_0 && insn->imm != BPF_FUNC_spin_unlock) ||
+ (insn->src_reg == BPF_PSEUDO_CALL) ||
+ (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
+ (insn->off != 0 || !is_bpf_list_api_kfunc(insn->imm)))) {
+ verbose(env, "function calls are not allowed while holding a lock\n");
+ return -EINVAL;
+ }
}
if (insn->src_reg == BPF_PSEUDO_CALL)
err = check_func_call(env, insn, &env->insn_idx);
@@ -12420,11 +13993,16 @@ static int do_check(struct bpf_verifier_env *env)
return -EINVAL;
}
- if (env->cur_state->active_spin_lock) {
+ if (env->cur_state->active_lock.ptr) {
verbose(env, "bpf_spin_unlock is missing\n");
return -EINVAL;
}
+ if (env->cur_state->active_rcu_lock) {
+ verbose(env, "bpf_rcu_read_unlock is missing\n");
+ return -EINVAL;
+ }
+
/* We must do check_reference_leak here before
* prepare_func_exit to handle the case when
* state->curframe > 0, it may be a callback
@@ -12677,7 +14255,14 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
{
enum bpf_prog_type prog_type = resolve_prog_type(prog);
- if (map_value_has_spin_lock(map)) {
+ if (btf_record_has_field(map->record, BPF_LIST_HEAD)) {
+ if (is_tracing_prog_type(prog_type)) {
+ verbose(env, "tracing progs cannot use bpf_list_head yet\n");
+ return -EINVAL;
+ }
+ }
+
+ if (btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
if (prog_type == BPF_PROG_TYPE_SOCKET_FILTER) {
verbose(env, "socket filter progs cannot use bpf_spin_lock yet\n");
return -EINVAL;
@@ -12694,7 +14279,7 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
}
}
- if (map_value_has_timer(map)) {
+ if (btf_record_has_field(map->record, BPF_TIMER)) {
if (is_tracing_prog_type(prog_type)) {
verbose(env, "tracing progs cannot use bpf_timer yet\n");
return -EINVAL;
@@ -12727,10 +14312,11 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
case BPF_MAP_TYPE_INODE_STORAGE:
case BPF_MAP_TYPE_SK_STORAGE:
case BPF_MAP_TYPE_TASK_STORAGE:
+ case BPF_MAP_TYPE_CGRP_STORAGE:
break;
default:
verbose(env,
- "Sleepable programs can only use array, hash, and ringbuf maps\n");
+ "Sleepable programs can only use array, hash, ringbuf and local storage maps\n");
return -EINVAL;
}
@@ -13386,6 +14972,10 @@ static int opt_subreg_zext_lo32_rnd_hi32(struct bpf_verifier_env *env,
if (!bpf_jit_needs_zext() && !is_cmpxchg_insn(&insn))
continue;
+ /* Zero-extension is done by the caller. */
+ if (bpf_pseudo_kfunc_call(&insn))
+ continue;
+
if (WARN_ON(load_reg == -1)) {
verbose(env, "verifier bug. zext_dst is set, but no reg is defined\n");
return -EFAULT;
@@ -13513,6 +15103,13 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
break;
case PTR_TO_BTF_ID:
case PTR_TO_BTF_ID | PTR_UNTRUSTED:
+ /* PTR_TO_BTF_ID | MEM_ALLOC always has a valid lifetime, unlike
+ * PTR_TO_BTF_ID, and an active ref_obj_id, but the same cannot
+ * be said once it is marked PTR_UNTRUSTED, hence we must handle
+ * any faults for loads into such types. BPF_WRITE is disallowed
+ * for this case.
+ */
+ case PTR_TO_BTF_ID | MEM_ALLOC | PTR_UNTRUSTED:
if (type == BPF_READ) {
insn->code = BPF_LDX | BPF_PROBE_MEM |
BPF_SIZE((insn)->code);
@@ -13878,8 +15475,8 @@ static int fixup_call_args(struct bpf_verifier_env *env)
return err;
}
-static int fixup_kfunc_call(struct bpf_verifier_env *env,
- struct bpf_insn *insn)
+static int fixup_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
+ struct bpf_insn *insn_buf, int insn_idx, int *cnt)
{
const struct bpf_kfunc_desc *desc;
@@ -13889,7 +15486,7 @@ static int fixup_kfunc_call(struct bpf_verifier_env *env,
}
/* insn->imm has the btf func_id. Replace it with
- * an address (relative to __bpf_base_call).
+ * an address (relative to __bpf_call_base).
*/
desc = find_kfunc_desc(env->prog, insn->imm, insn->off);
if (!desc) {
@@ -13898,8 +15495,33 @@ static int fixup_kfunc_call(struct bpf_verifier_env *env,
return -EFAULT;
}
+ *cnt = 0;
insn->imm = desc->imm;
-
+ if (insn->off)
+ return 0;
+ if (desc->func_id == special_kfunc_list[KF_bpf_obj_new_impl]) {
+ struct btf_struct_meta *kptr_struct_meta = env->insn_aux_data[insn_idx].kptr_struct_meta;
+ struct bpf_insn addr[2] = { BPF_LD_IMM64(BPF_REG_2, (long)kptr_struct_meta) };
+ u64 obj_new_size = env->insn_aux_data[insn_idx].obj_new_size;
+
+ insn_buf[0] = BPF_MOV64_IMM(BPF_REG_1, obj_new_size);
+ insn_buf[1] = addr[0];
+ insn_buf[2] = addr[1];
+ insn_buf[3] = *insn;
+ *cnt = 4;
+ } else if (desc->func_id == special_kfunc_list[KF_bpf_obj_drop_impl]) {
+ struct btf_struct_meta *kptr_struct_meta = env->insn_aux_data[insn_idx].kptr_struct_meta;
+ struct bpf_insn addr[2] = { BPF_LD_IMM64(BPF_REG_2, (long)kptr_struct_meta) };
+
+ insn_buf[0] = addr[0];
+ insn_buf[1] = addr[1];
+ insn_buf[2] = *insn;
+ *cnt = 3;
+ } else if (desc->func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx] ||
+ desc->func_id == special_kfunc_list[KF_bpf_rdonly_cast]) {
+ insn_buf[0] = BPF_MOV64_REG(BPF_REG_0, BPF_REG_1);
+ *cnt = 1;
+ }
return 0;
}
@@ -14041,9 +15663,19 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
if (insn->src_reg == BPF_PSEUDO_CALL)
continue;
if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) {
- ret = fixup_kfunc_call(env, insn);
+ ret = fixup_kfunc_call(env, insn, insn_buf, i + delta, &cnt);
if (ret)
return ret;
+ if (cnt == 0)
+ continue;
+
+ new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt);
+ if (!new_prog)
+ return -ENOMEM;
+
+ delta += cnt - 1;
+ env->prog = prog = new_prog;
+ insn = new_prog->insnsi + i + delta;
continue;
}
@@ -14161,13 +15793,12 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
goto patch_call_imm;
}
- if (insn->imm == BPF_FUNC_task_storage_get ||
- insn->imm == BPF_FUNC_sk_storage_get ||
- insn->imm == BPF_FUNC_inode_storage_get) {
- if (env->prog->aux->sleepable)
- insn_buf[0] = BPF_MOV64_IMM(BPF_REG_5, (__force __s32)GFP_KERNEL);
- else
+ if (is_storage_get_function(insn->imm)) {
+ if (!env->prog->aux->sleepable ||
+ env->insn_aux_data[i + delta].storage_get_func_atomic)
insn_buf[0] = BPF_MOV64_IMM(BPF_REG_5, (__force __s32)GFP_ATOMIC);
+ else
+ insn_buf[0] = BPF_MOV64_IMM(BPF_REG_5, (__force __s32)GFP_KERNEL);
insn_buf[1] = *insn;
cnt = 2;
@@ -14237,7 +15868,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
BUILD_BUG_ON(!__same_type(ops->map_peek_elem,
(int (*)(struct bpf_map *map, void *value))NULL));
BUILD_BUG_ON(!__same_type(ops->map_redirect,
- (int (*)(struct bpf_map *map, u32 ifindex, u64 flags))NULL));
+ (int (*)(struct bpf_map *map, u64 index, u64 flags))NULL));
BUILD_BUG_ON(!__same_type(ops->map_for_each_callback,
(int (*)(struct bpf_map *map,
bpf_callback_t callback_fn,
@@ -14616,6 +16247,8 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog)
BPF_MAIN_FUNC /* callsite */,
0 /* frameno */,
subprog);
+ state->first_insn_idx = env->subprog_info[subprog].start;
+ state->last_insn_idx = -1;
regs = state->frame[state->curframe]->regs;
if (subprog || env->prog->type == BPF_PROG_TYPE_EXT) {
@@ -15025,12 +16658,22 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
ret = -EINVAL;
switch (prog->type) {
case BPF_PROG_TYPE_TRACING:
- /* fentry/fexit/fmod_ret progs can be sleepable only if they are
+
+ /* fentry/fexit/fmod_ret progs can be sleepable if they are
* attached to ALLOW_ERROR_INJECTION and are not in denylist.
*/
if (!check_non_sleepable_error_inject(btf_id) &&
within_error_injection_list(addr))
ret = 0;
+ /* fentry/fexit/fmod_ret progs can also be sleepable if they are
+ * in the fmodret id set with the KF_SLEEPABLE flag.
+ */
+ else {
+ u32 *flags = btf_kfunc_is_modify_return(btf, btf_id);
+
+ if (flags && (*flags & KF_SLEEPABLE))
+ ret = 0;
+ }
break;
case BPF_PROG_TYPE_LSM:
/* LSM progs check that they are attached to bpf_lsm_*() funcs.
@@ -15051,7 +16694,10 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
bpf_log(log, "can't modify return codes of BPF programs\n");
return -EINVAL;
}
- ret = check_attach_modify_return(addr, tname);
+ ret = -EINVAL;
+ if (btf_kfunc_is_modify_return(btf, btf_id) ||
+ !check_attach_modify_return(addr, tname))
+ ret = 0;
if (ret) {
bpf_log(log, "%s() is not modifiable\n", tname);
return ret;
@@ -15240,10 +16886,11 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr)
env->allow_ptr_leaks = bpf_allow_ptr_leaks();
env->allow_uninit_stack = bpf_allow_uninit_stack();
- env->allow_ptr_to_map_access = bpf_allow_ptr_to_map_access();
env->bypass_spec_v1 = bpf_bypass_spec_v1();
env->bypass_spec_v4 = bpf_bypass_spec_v4();
env->bpf_capable = bpf_capable();
+ env->rcu_tag_supported = btf_vmlinux &&
+ btf_find_by_name_kind(btf_vmlinux, "rcu", BTF_KIND_TYPE_TAG) > 0;
if (is_priv)
env->test_state_freq = attr->prog_flags & BPF_F_TEST_STATE_FREQ;
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 15cc26513596..c099cf3fa02d 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -5353,6 +5353,7 @@ static void css_free_rwork_fn(struct work_struct *work)
atomic_dec(&cgrp->root->nr_cgrps);
cgroup1_pidlist_destroy_all(cgrp);
cancel_work_sync(&cgrp->release_agent_work);
+ bpf_cgrp_storage_free(cgrp);
if (cgroup_parent(cgrp)) {
/*
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 4d6c6f5f60db..d9c822bbffb8 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -113,9 +113,40 @@ int static_key_count(struct static_key *key)
}
EXPORT_SYMBOL_GPL(static_key_count);
-void static_key_slow_inc_cpuslocked(struct static_key *key)
+/*
+ * static_key_fast_inc_not_disabled - adds a user for a static key
+ * @key: static key that must be already enabled
+ *
+ * The caller must make sure that the static key can't get disabled while
+ * in this function. It doesn't patch jump labels, only adds a user to
+ * an already enabled static key.
+ *
+ * Returns true if the increment was done. Unlike refcount_t the ref counter
+ * is not saturated, but will fail to increment on overflow.
+ */
+bool static_key_fast_inc_not_disabled(struct static_key *key)
{
+ int v;
+
STATIC_KEY_CHECK_USE(key);
+ /*
+ * Negative key->enabled has a special meaning: it sends
+ * static_key_slow_inc() down the slow path, and it is non-zero
+ * so it counts as "enabled" in jump_label_update(). Note that
+ * atomic_inc_unless_negative() checks >= 0, so roll our own.
+ */
+ v = atomic_read(&key->enabled);
+ do {
+ if (v <= 0 || (v + 1) < 0)
+ return false;
+ } while (!likely(atomic_try_cmpxchg(&key->enabled, &v, v + 1)));
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(static_key_fast_inc_not_disabled);
+
+bool static_key_slow_inc_cpuslocked(struct static_key *key)
+{
lockdep_assert_cpus_held();
/*
@@ -124,15 +155,9 @@ void static_key_slow_inc_cpuslocked(struct static_key *key)
* jump_label_update() process. At the same time, however,
* the jump_label_update() call below wants to see
* static_key_enabled(&key) for jumps to be updated properly.
- *
- * So give a special meaning to negative key->enabled: it sends
- * static_key_slow_inc() down the slow path, and it is non-zero
- * so it counts as "enabled" in jump_label_update(). Note that
- * atomic_inc_unless_negative() checks >= 0, so roll our own.
*/
- for (int v = atomic_read(&key->enabled); v > 0; )
- if (likely(atomic_try_cmpxchg(&key->enabled, &v, v + 1)))
- return;
+ if (static_key_fast_inc_not_disabled(key))
+ return true;
jump_label_lock();
if (atomic_read(&key->enabled) == 0) {
@@ -144,16 +169,23 @@ void static_key_slow_inc_cpuslocked(struct static_key *key)
*/
atomic_set_release(&key->enabled, 1);
} else {
- atomic_inc(&key->enabled);
+ if (WARN_ON_ONCE(!static_key_fast_inc_not_disabled(key))) {
+ jump_label_unlock();
+ return false;
+ }
}
jump_label_unlock();
+ return true;
}
-void static_key_slow_inc(struct static_key *key)
+bool static_key_slow_inc(struct static_key *key)
{
+ bool ret;
+
cpus_read_lock();
- static_key_slow_inc_cpuslocked(key);
+ ret = static_key_slow_inc_cpuslocked(key);
cpus_read_unlock();
+ return ret;
}
EXPORT_SYMBOL_GPL(static_key_slow_inc);
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index f5c5c9175333..4523f99b0358 100644
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c
@@ -494,7 +494,6 @@ unsigned long module_kallsyms_lookup_name(const char *name)
return ret;
}
-#ifdef CONFIG_LIVEPATCH
int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
struct module *, unsigned long),
void *data)
@@ -531,4 +530,3 @@ out:
mutex_unlock(&module_mutex);
return ret;
}
-#endif /* CONFIG_LIVEPATCH */
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index b0b885e071fa..fe9840d90e96 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -1535,6 +1535,8 @@ static void rcu_tasks_trace_postscan(struct list_head *hop)
{
// Wait for late-stage exiting tasks to finish exiting.
// These might have passed the call to exit_tasks_rcu_finish().
+
+ // If you remove the following line, update rcu_trace_implies_rcu_gp()!!!
synchronize_rcu();
// Any tasks that exit after this point will set
// TRC_NEED_QS_CHECKED in ->trc_reader_special.b.need_qs.
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 1ed08967fb97..3bbd3f0c810c 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -6,6 +6,7 @@
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
#include <linux/bpf_perf_event.h>
#include <linux/btf.h>
#include <linux/filter.h>
@@ -773,7 +774,7 @@ BPF_CALL_0(bpf_get_current_task_btf)
const struct bpf_func_proto bpf_get_current_task_btf_proto = {
.func = bpf_get_current_task_btf,
.gpl_only = true,
- .ret_type = RET_PTR_TO_BTF_ID,
+ .ret_type = RET_PTR_TO_BTF_ID_TRUSTED,
.ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
};
@@ -1456,6 +1457,10 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_get_current_cgroup_id_proto;
case BPF_FUNC_get_current_ancestor_cgroup_id:
return &bpf_get_current_ancestor_cgroup_id_proto;
+ case BPF_FUNC_cgrp_storage_get:
+ return &bpf_cgrp_storage_get_proto;
+ case BPF_FUNC_cgrp_storage_delete:
+ return &bpf_cgrp_storage_delete_proto;
#endif
case BPF_FUNC_send_signal:
return &bpf_send_signal_proto;
@@ -1480,9 +1485,9 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_get_task_stack:
return &bpf_get_task_stack_proto;
case BPF_FUNC_copy_from_user:
- return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
+ return &bpf_copy_from_user_proto;
case BPF_FUNC_copy_from_user_task:
- return prog->aux->sleepable ? &bpf_copy_from_user_task_proto : NULL;
+ return &bpf_copy_from_user_task_proto;
case BPF_FUNC_snprintf_btf:
return &bpf_snprintf_btf_proto;
case BPF_FUNC_per_cpu_ptr:
@@ -1490,8 +1495,12 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_this_cpu_ptr:
return &bpf_this_cpu_ptr_proto;
case BPF_FUNC_task_storage_get:
+ if (bpf_prog_check_recur(prog))
+ return &bpf_task_storage_get_recur_proto;
return &bpf_task_storage_get_proto;
case BPF_FUNC_task_storage_delete:
+ if (bpf_prog_check_recur(prog))
+ return &bpf_task_storage_delete_recur_proto;
return &bpf_task_storage_delete_proto;
case BPF_FUNC_for_each_map_elem:
return &bpf_for_each_map_elem_proto;
@@ -2452,6 +2461,8 @@ struct bpf_kprobe_multi_link {
unsigned long *addrs;
u64 *cookies;
u32 cnt;
+ u32 mods_cnt;
+ struct module **mods;
};
struct bpf_kprobe_multi_run_ctx {
@@ -2507,6 +2518,14 @@ error:
return err;
}
+static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
+{
+ u32 i;
+
+ for (i = 0; i < cnt; i++)
+ module_put(mods[i]);
+}
+
static void free_user_syms(struct user_syms *us)
{
kvfree(us->syms);
@@ -2519,6 +2538,7 @@ static void bpf_kprobe_multi_link_release(struct bpf_link *link)
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
unregister_fprobe(&kmulti_link->fp);
+ kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
}
static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
@@ -2528,6 +2548,7 @@ static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
kvfree(kmulti_link->addrs);
kvfree(kmulti_link->cookies);
+ kfree(kmulti_link->mods);
kfree(kmulti_link);
}
@@ -2550,7 +2571,7 @@ static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void
swap(*cookie_a, *cookie_b);
}
-static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b)
+static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
{
const unsigned long *addr_a = a, *addr_b = b;
@@ -2561,7 +2582,7 @@ static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b)
static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
{
- return __bpf_kprobe_multi_cookie_cmp(a, b);
+ return bpf_kprobe_multi_addrs_cmp(a, b);
}
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
@@ -2579,7 +2600,7 @@ static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
return 0;
entry_ip = run_ctx->entry_ip;
addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
- __bpf_kprobe_multi_cookie_cmp);
+ bpf_kprobe_multi_addrs_cmp);
if (!addr)
return 0;
cookie = link->cookies + (addr - link->addrs);
@@ -2663,6 +2684,71 @@ static void symbols_swap_r(void *a, void *b, int size, const void *priv)
}
}
+struct module_addr_args {
+ unsigned long *addrs;
+ u32 addrs_cnt;
+ struct module **mods;
+ int mods_cnt;
+ int mods_cap;
+};
+
+static int module_callback(void *data, const char *name,
+ struct module *mod, unsigned long addr)
+{
+ struct module_addr_args *args = data;
+ struct module **mods;
+
+ /* We iterate all modules symbols and for each we:
+ * - search for it in provided addresses array
+ * - if found we check if we already have the module pointer stored
+ * (we iterate modules sequentially, so we can check just the last
+ * module pointer)
+ * - take module reference and store it
+ */
+ if (!bsearch(&addr, args->addrs, args->addrs_cnt, sizeof(addr),
+ bpf_kprobe_multi_addrs_cmp))
+ return 0;
+
+ if (args->mods && args->mods[args->mods_cnt - 1] == mod)
+ return 0;
+
+ if (args->mods_cnt == args->mods_cap) {
+ args->mods_cap = max(16, args->mods_cap * 3 / 2);
+ mods = krealloc_array(args->mods, args->mods_cap, sizeof(*mods), GFP_KERNEL);
+ if (!mods)
+ return -ENOMEM;
+ args->mods = mods;
+ }
+
+ if (!try_module_get(mod))
+ return -EINVAL;
+
+ args->mods[args->mods_cnt] = mod;
+ args->mods_cnt++;
+ return 0;
+}
+
+static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
+{
+ struct module_addr_args args = {
+ .addrs = addrs,
+ .addrs_cnt = addrs_cnt,
+ };
+ int err;
+
+ /* We return either err < 0 in case of error, ... */
+ err = module_kallsyms_on_each_symbol(module_callback, &args);
+ if (err) {
+ kprobe_multi_put_modules(args.mods, args.mods_cnt);
+ kfree(args.mods);
+ return err;
+ }
+
+ /* or number of modules found if everything is ok. */
+ *mods = args.mods;
+ return args.mods_cnt;
+}
+
int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
struct bpf_kprobe_multi_link *link = NULL;
@@ -2773,10 +2859,25 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
bpf_kprobe_multi_cookie_cmp,
bpf_kprobe_multi_cookie_swap,
link);
+ } else {
+ /*
+ * We need to sort addrs array even if there are no cookies
+ * provided, to allow bsearch in get_modules_for_addrs.
+ */
+ sort(addrs, cnt, sizeof(*addrs),
+ bpf_kprobe_multi_addrs_cmp, NULL);
+ }
+
+ err = get_modules_for_addrs(&link->mods, addrs, cnt);
+ if (err < 0) {
+ bpf_link_cleanup(&link_primer);
+ return err;
}
+ link->mods_cnt = err;
err = register_fprobe_ips(&link->fp, addrs, cnt);
if (err) {
+ kprobe_multi_put_modules(link->mods, link->mods_cnt);
bpf_link_cleanup(&link_primer);
return err;
}
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index acfa4e029bcc..8e842f68b9a5 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -8257,6 +8257,10 @@ struct kallsyms_data {
size_t found;
};
+/* This function gets called for all kernel and module symbols
+ * and returns 1 in case we resolved all the requested symbols,
+ * 0 otherwise.
+ */
static int kallsyms_callback(void *data, const char *name,
struct module *mod, unsigned long addr)
{
@@ -8299,17 +8303,19 @@ static int kallsyms_callback(void *data, const char *name,
int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
{
struct kallsyms_data args;
- int err;
+ int found_all;
memset(addrs, 0, sizeof(*addrs) * cnt);
args.addrs = addrs;
args.syms = sorted_syms;
args.cnt = cnt;
args.found = 0;
- err = kallsyms_on_each_symbol(kallsyms_callback, &args);
- if (err < 0)
- return err;
- return args.found == args.cnt ? 0 : -ESRCH;
+
+ found_all = kallsyms_on_each_symbol(kallsyms_callback, &args);
+ if (found_all)
+ return 0;
+ found_all = module_kallsyms_on_each_symbol(kallsyms_callback, &args);
+ return found_all ? 0 : -ESRCH;
}
#ifdef CONFIG_SYSCTL
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-01 09:26:02 +0000