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Diffstat (limited to 'kernel/bpf/arraymap.c')
-rw-r--r--kernel/bpf/arraymap.c102
1 files changed, 84 insertions, 18 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 8ff419b632a6..c6c81eceb68f 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -10,11 +10,13 @@
#include <linux/filter.h>
#include <linux/perf_event.h>
#include <uapi/linux/btf.h>
+#include <linux/rcupdate_trace.h>
#include "map_in_map.h"
#define ARRAY_CREATE_FLAG_MASK \
- (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK)
+ (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \
+ BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP)
static void bpf_array_free_percpu(struct bpf_array *array)
{
@@ -60,7 +62,11 @@ int array_map_alloc_check(union bpf_attr *attr)
return -EINVAL;
if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
- attr->map_flags & BPF_F_MMAPABLE)
+ attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP))
+ return -EINVAL;
+
+ if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY &&
+ attr->map_flags & BPF_F_PRESERVE_ELEMS)
return -EINVAL;
if (attr->value_size > KMALLOC_MAX_SIZE)
@@ -208,7 +214,7 @@ static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm,
}
/* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
-static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
+static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
struct bpf_insn *insn = insn_buf;
@@ -217,6 +223,9 @@ static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
const int map_ptr = BPF_REG_1;
const int index = BPF_REG_2;
+ if (map->map_flags & BPF_F_INNER_MAP)
+ return -EOPNOTSUPP;
+
*insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
*insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
if (!map->bypass_spec_v1) {
@@ -487,6 +496,15 @@ static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
vma->vm_pgoff + pgoff);
}
+static bool array_map_meta_equal(const struct bpf_map *meta0,
+ const struct bpf_map *meta1)
+{
+ if (!bpf_map_meta_equal(meta0, meta1))
+ return false;
+ return meta0->map_flags & BPF_F_INNER_MAP ? true :
+ meta0->max_entries == meta1->max_entries;
+}
+
struct bpf_iter_seq_array_map_info {
struct bpf_map *map;
void *percpu_value_buf;
@@ -625,6 +643,7 @@ static const struct bpf_iter_seq_info iter_seq_info = {
static int array_map_btf_id;
const struct bpf_map_ops array_map_ops = {
+ .map_meta_equal = array_map_meta_equal,
.map_alloc_check = array_map_alloc_check,
.map_alloc = array_map_alloc,
.map_free = array_map_free,
@@ -647,6 +666,7 @@ const struct bpf_map_ops array_map_ops = {
static int percpu_array_map_btf_id;
const struct bpf_map_ops percpu_array_map_ops = {
+ .map_meta_equal = bpf_map_meta_equal,
.map_alloc_check = array_map_alloc_check,
.map_alloc = array_map_alloc,
.map_free = array_map_free,
@@ -888,6 +908,7 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
struct bpf_prog *old,
struct bpf_prog *new)
{
+ u8 *old_addr, *new_addr, *old_bypass_addr;
struct prog_poke_elem *elem;
struct bpf_array_aux *aux;
@@ -908,12 +929,13 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
* there could be danger of use after free otherwise.
* 2) Initially when we start tracking aux, the program
* is not JITed yet and also does not have a kallsyms
- * entry. We skip these as poke->ip_stable is not
- * active yet. The JIT will do the final fixup before
- * setting it stable. The various poke->ip_stable are
- * successively activated, so tail call updates can
- * arrive from here while JIT is still finishing its
- * final fixup for non-activated poke entries.
+ * entry. We skip these as poke->tailcall_target_stable
+ * is not active yet. The JIT will do the final fixup
+ * before setting it stable. The various
+ * poke->tailcall_target_stable are successively
+ * activated, so tail call updates can arrive from here
+ * while JIT is still finishing its final fixup for
+ * non-activated poke entries.
* 3) On program teardown, the program's kallsym entry gets
* removed out of RCU callback, but we can only untrack
* from sleepable context, therefore bpf_arch_text_poke()
@@ -930,7 +952,7 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
* 5) Any other error happening below from bpf_arch_text_poke()
* is a unexpected bug.
*/
- if (!READ_ONCE(poke->ip_stable))
+ if (!READ_ONCE(poke->tailcall_target_stable))
continue;
if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
continue;
@@ -938,12 +960,39 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
poke->tail_call.key != key)
continue;
- ret = bpf_arch_text_poke(poke->ip, BPF_MOD_JUMP,
- old ? (u8 *)old->bpf_func +
- poke->adj_off : NULL,
- new ? (u8 *)new->bpf_func +
- poke->adj_off : NULL);
- BUG_ON(ret < 0 && ret != -EINVAL);
+ old_bypass_addr = old ? NULL : poke->bypass_addr;
+ old_addr = old ? (u8 *)old->bpf_func + poke->adj_off : NULL;
+ new_addr = new ? (u8 *)new->bpf_func + poke->adj_off : NULL;
+
+ if (new) {
+ ret = bpf_arch_text_poke(poke->tailcall_target,
+ BPF_MOD_JUMP,
+ old_addr, new_addr);
+ BUG_ON(ret < 0 && ret != -EINVAL);
+ if (!old) {
+ ret = bpf_arch_text_poke(poke->tailcall_bypass,
+ BPF_MOD_JUMP,
+ poke->bypass_addr,
+ NULL);
+ BUG_ON(ret < 0 && ret != -EINVAL);
+ }
+ } else {
+ ret = bpf_arch_text_poke(poke->tailcall_bypass,
+ BPF_MOD_JUMP,
+ old_bypass_addr,
+ poke->bypass_addr);
+ BUG_ON(ret < 0 && ret != -EINVAL);
+ /* let other CPUs finish the execution of program
+ * so that it will not possible to expose them
+ * to invalid nop, stack unwind, nop state
+ */
+ if (!ret)
+ synchronize_rcu();
+ ret = bpf_arch_text_poke(poke->tailcall_target,
+ BPF_MOD_JUMP,
+ old_addr, NULL);
+ BUG_ON(ret < 0 && ret != -EINVAL);
+ }
}
}
}
@@ -1003,6 +1052,11 @@ static void prog_array_map_free(struct bpf_map *map)
fd_array_map_free(map);
}
+/* prog_array->aux->{type,jited} is a runtime binding.
+ * Doing static check alone in the verifier is not enough.
+ * Thus, prog_array_map cannot be used as an inner_map
+ * and map_meta_equal is not implemented.
+ */
static int prog_array_map_btf_id;
const struct bpf_map_ops prog_array_map_ops = {
.map_alloc_check = fd_array_map_alloc_check,
@@ -1090,6 +1144,9 @@ static void perf_event_fd_array_release(struct bpf_map *map,
struct bpf_event_entry *ee;
int i;
+ if (map->map_flags & BPF_F_PRESERVE_ELEMS)
+ return;
+
rcu_read_lock();
for (i = 0; i < array->map.max_entries; i++) {
ee = READ_ONCE(array->ptrs[i]);
@@ -1099,11 +1156,19 @@ static void perf_event_fd_array_release(struct bpf_map *map,
rcu_read_unlock();
}
+static void perf_event_fd_array_map_free(struct bpf_map *map)
+{
+ if (map->map_flags & BPF_F_PRESERVE_ELEMS)
+ bpf_fd_array_map_clear(map);
+ fd_array_map_free(map);
+}
+
static int perf_event_array_map_btf_id;
const struct bpf_map_ops perf_event_array_map_ops = {
+ .map_meta_equal = bpf_map_meta_equal,
.map_alloc_check = fd_array_map_alloc_check,
.map_alloc = array_map_alloc,
- .map_free = fd_array_map_free,
+ .map_free = perf_event_fd_array_map_free,
.map_get_next_key = array_map_get_next_key,
.map_lookup_elem = fd_array_map_lookup_elem,
.map_delete_elem = fd_array_map_delete_elem,
@@ -1137,6 +1202,7 @@ static void cgroup_fd_array_free(struct bpf_map *map)
static int cgroup_array_map_btf_id;
const struct bpf_map_ops cgroup_array_map_ops = {
+ .map_meta_equal = bpf_map_meta_equal,
.map_alloc_check = fd_array_map_alloc_check,
.map_alloc = array_map_alloc,
.map_free = cgroup_fd_array_free,
@@ -1190,7 +1256,7 @@ static void *array_of_map_lookup_elem(struct bpf_map *map, void *key)
return READ_ONCE(*inner_map);
}
-static u32 array_of_map_gen_lookup(struct bpf_map *map,
+static int array_of_map_gen_lookup(struct bpf_map *map,
struct bpf_insn *insn_buf)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-25 04:07:33 +0000