diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-15 11:56:19 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-15 11:56:19 -0800 |
commit | 5bbcc0f595fadb4cac0eddc4401035ec0bd95b09 (patch) | |
tree | 3b65e490cc36a6c6fecac1fa24d9e0ac9ced4455 /kernel/bpf | |
parent | 892204e06cb9e89fbc4b299a678f9ca358e97cac (diff) | |
parent | 50895b9de1d3e0258e015e8e55128d835d9a9f19 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
"Highlights:
1) Maintain the TCP retransmit queue using an rbtree, with 1GB
windows at 100Gb this really has become necessary. From Eric
Dumazet.
2) Multi-program support for cgroup+bpf, from Alexei Starovoitov.
3) Perform broadcast flooding in hardware in mv88e6xxx, from Andrew
Lunn.
4) Add meter action support to openvswitch, from Andy Zhou.
5) Add a data meta pointer for BPF accessible packets, from Daniel
Borkmann.
6) Namespace-ify almost all TCP sysctl knobs, from Eric Dumazet.
7) Turn on Broadcom Tags in b53 driver, from Florian Fainelli.
8) More work to move the RTNL mutex down, from Florian Westphal.
9) Add 'bpftool' utility, to help with bpf program introspection.
From Jakub Kicinski.
10) Add new 'cpumap' type for XDP_REDIRECT action, from Jesper
Dangaard Brouer.
11) Support 'blocks' of transformations in the packet scheduler which
can span multiple network devices, from Jiri Pirko.
12) TC flower offload support in cxgb4, from Kumar Sanghvi.
13) Priority based stream scheduler for SCTP, from Marcelo Ricardo
Leitner.
14) Thunderbolt networking driver, from Amir Levy and Mika Westerberg.
15) Add RED qdisc offloadability, and use it in mlxsw driver. From
Nogah Frankel.
16) eBPF based device controller for cgroup v2, from Roman Gushchin.
17) Add some fundamental tracepoints for TCP, from Song Liu.
18) Remove garbage collection from ipv6 route layer, this is a
significant accomplishment. From Wei Wang.
19) Add multicast route offload support to mlxsw, from Yotam Gigi"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2177 commits)
tcp: highest_sack fix
geneve: fix fill_info when link down
bpf: fix lockdep splat
net: cdc_ncm: GetNtbFormat endian fix
openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start
netem: remove unnecessary 64 bit modulus
netem: use 64 bit divide by rate
tcp: Namespace-ify sysctl_tcp_default_congestion_control
net: Protect iterations over net::fib_notifier_ops in fib_seq_sum()
ipv6: set all.accept_dad to 0 by default
uapi: fix linux/tls.h userspace compilation error
usbnet: ipheth: prevent TX queue timeouts when device not ready
vhost_net: conditionally enable tx polling
uapi: fix linux/rxrpc.h userspace compilation errors
net: stmmac: fix LPI transitioning for dwmac4
atm: horizon: Fix irq release error
net-sysfs: trigger netlink notification on ifalias change via sysfs
openvswitch: Using kfree_rcu() to simplify the code
openvswitch: Make local function ovs_nsh_key_attr_size() static
openvswitch: Fix return value check in ovs_meter_cmd_features()
...
Diffstat (limited to 'kernel/bpf')
-rw-r--r-- | kernel/bpf/Makefile | 3 | ||||
-rw-r--r-- | kernel/bpf/arraymap.c | 6 | ||||
-rw-r--r-- | kernel/bpf/cgroup.c | 570 | ||||
-rw-r--r-- | kernel/bpf/core.c | 180 | ||||
-rw-r--r-- | kernel/bpf/cpumap.c | 706 | ||||
-rw-r--r-- | kernel/bpf/devmap.c | 5 | ||||
-rw-r--r-- | kernel/bpf/disasm.c | 214 | ||||
-rw-r--r-- | kernel/bpf/disasm.h | 32 | ||||
-rw-r--r-- | kernel/bpf/hashtab.c | 5 | ||||
-rw-r--r-- | kernel/bpf/inode.c | 15 | ||||
-rw-r--r-- | kernel/bpf/lpm_trie.c | 98 | ||||
-rw-r--r-- | kernel/bpf/offload.c | 194 | ||||
-rw-r--r-- | kernel/bpf/percpu_freelist.c | 8 | ||||
-rw-r--r-- | kernel/bpf/sockmap.c | 9 | ||||
-rw-r--r-- | kernel/bpf/stackmap.c | 5 | ||||
-rw-r--r-- | kernel/bpf/syscall.c | 325 | ||||
-rw-r--r-- | kernel/bpf/verifier.c | 1480 |
17 files changed, 2987 insertions, 868 deletions
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index af3ab6164ff5..e691da0b3bab 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -3,8 +3,11 @@ obj-y := core.o obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o +obj-$(CONFIG_BPF_SYSCALL) += disasm.o ifeq ($(CONFIG_NET),y) obj-$(CONFIG_BPF_SYSCALL) += devmap.o +obj-$(CONFIG_BPF_SYSCALL) += cpumap.o +obj-$(CONFIG_BPF_SYSCALL) += offload.o ifeq ($(CONFIG_STREAM_PARSER),y) obj-$(CONFIG_BPF_SYSCALL) += sockmap.o endif diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index c4b9ab01bba5..7c25426d3cf5 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -19,6 +19,9 @@ #include "map_in_map.h" +#define ARRAY_CREATE_FLAG_MASK \ + (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) + static void bpf_array_free_percpu(struct bpf_array *array) { int i; @@ -56,7 +59,8 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr) /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || - attr->value_size == 0 || attr->map_flags & ~BPF_F_NUMA_NODE || + attr->value_size == 0 || + attr->map_flags & ~ARRAY_CREATE_FLAG_MASK || (percpu && numa_node != NUMA_NO_NODE)) return ERR_PTR(-EINVAL); diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 546113430049..b789ab78d28f 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -27,129 +27,405 @@ void cgroup_bpf_put(struct cgroup *cgrp) { unsigned int type; - for (type = 0; type < ARRAY_SIZE(cgrp->bpf.prog); type++) { - struct bpf_prog *prog = cgrp->bpf.prog[type]; - - if (prog) { - bpf_prog_put(prog); + for (type = 0; type < ARRAY_SIZE(cgrp->bpf.progs); type++) { + struct list_head *progs = &cgrp->bpf.progs[type]; + struct bpf_prog_list *pl, *tmp; + + list_for_each_entry_safe(pl, tmp, progs, node) { + list_del(&pl->node); + bpf_prog_put(pl->prog); + kfree(pl); static_branch_dec(&cgroup_bpf_enabled_key); } + bpf_prog_array_free(cgrp->bpf.effective[type]); + } +} + +/* count number of elements in the list. + * it's slow but the list cannot be long + */ +static u32 prog_list_length(struct list_head *head) +{ + struct bpf_prog_list *pl; + u32 cnt = 0; + + list_for_each_entry(pl, head, node) { + if (!pl->prog) + continue; + cnt++; } + return cnt; +} + +/* if parent has non-overridable prog attached, + * disallow attaching new programs to the descendent cgroup. + * if parent has overridable or multi-prog, allow attaching + */ +static bool hierarchy_allows_attach(struct cgroup *cgrp, + enum bpf_attach_type type, + u32 new_flags) +{ + struct cgroup *p; + + p = cgroup_parent(cgrp); + if (!p) + return true; + do { + u32 flags = p->bpf.flags[type]; + u32 cnt; + + if (flags & BPF_F_ALLOW_MULTI) + return true; + cnt = prog_list_length(&p->bpf.progs[type]); + WARN_ON_ONCE(cnt > 1); + if (cnt == 1) + return !!(flags & BPF_F_ALLOW_OVERRIDE); + p = cgroup_parent(p); + } while (p); + return true; +} + +/* compute a chain of effective programs for a given cgroup: + * start from the list of programs in this cgroup and add + * all parent programs. + * Note that parent's F_ALLOW_OVERRIDE-type program is yielding + * to programs in this cgroup + */ +static int compute_effective_progs(struct cgroup *cgrp, + enum bpf_attach_type type, + struct bpf_prog_array __rcu **array) +{ + struct bpf_prog_array __rcu *progs; + struct bpf_prog_list *pl; + struct cgroup *p = cgrp; + int cnt = 0; + + /* count number of effective programs by walking parents */ + do { + if (cnt == 0 || (p->bpf.flags[type] & BPF_F_ALLOW_MULTI)) + cnt += prog_list_length(&p->bpf.progs[type]); + p = cgroup_parent(p); + } while (p); + + progs = bpf_prog_array_alloc(cnt, GFP_KERNEL); + if (!progs) + return -ENOMEM; + + /* populate the array with effective progs */ + cnt = 0; + p = cgrp; + do { + if (cnt == 0 || (p->bpf.flags[type] & BPF_F_ALLOW_MULTI)) + list_for_each_entry(pl, + &p->bpf.progs[type], node) { + if (!pl->prog) + continue; + rcu_dereference_protected(progs, 1)-> + progs[cnt++] = pl->prog; + } + p = cgroup_parent(p); + } while (p); + + *array = progs; + return 0; +} + +static void activate_effective_progs(struct cgroup *cgrp, + enum bpf_attach_type type, + struct bpf_prog_array __rcu *array) +{ + struct bpf_prog_array __rcu *old_array; + + old_array = xchg(&cgrp->bpf.effective[type], array); + /* free prog array after grace period, since __cgroup_bpf_run_*() + * might be still walking the array + */ + bpf_prog_array_free(old_array); } /** * cgroup_bpf_inherit() - inherit effective programs from parent * @cgrp: the cgroup to modify - * @parent: the parent to inherit from */ -void cgroup_bpf_inherit(struct cgroup *cgrp, struct cgroup *parent) +int cgroup_bpf_inherit(struct cgroup *cgrp) { - unsigned int type; +/* has to use marco instead of const int, since compiler thinks + * that array below is variable length + */ +#define NR ARRAY_SIZE(cgrp->bpf.effective) + struct bpf_prog_array __rcu *arrays[NR] = {}; + int i; - for (type = 0; type < ARRAY_SIZE(cgrp->bpf.effective); type++) { - struct bpf_prog *e; + for (i = 0; i < NR; i++) + INIT_LIST_HEAD(&cgrp->bpf.progs[i]); - e = rcu_dereference_protected(parent->bpf.effective[type], - lockdep_is_held(&cgroup_mutex)); - rcu_assign_pointer(cgrp->bpf.effective[type], e); - cgrp->bpf.disallow_override[type] = parent->bpf.disallow_override[type]; - } + for (i = 0; i < NR; i++) + if (compute_effective_progs(cgrp, i, &arrays[i])) + goto cleanup; + + for (i = 0; i < NR; i++) + activate_effective_progs(cgrp, i, arrays[i]); + + return 0; +cleanup: + for (i = 0; i < NR; i++) + bpf_prog_array_free(arrays[i]); + return -ENOMEM; } +#define BPF_CGROUP_MAX_PROGS 64 + /** - * __cgroup_bpf_update() - Update the pinned program of a cgroup, and + * __cgroup_bpf_attach() - Attach the program to a cgroup, and * propagate the change to descendants * @cgrp: The cgroup which descendants to traverse - * @parent: The parent of @cgrp, or %NULL if @cgrp is the root - * @prog: A new program to pin - * @type: Type of pinning operation (ingress/egress) - * - * Each cgroup has a set of two pointers for bpf programs; one for eBPF - * programs it owns, and which is effective for execution. - * - * If @prog is not %NULL, this function attaches a new program to the cgroup - * and releases the one that is currently attached, if any. @prog is then made - * the effective program of type @type in that cgroup. - * - * If @prog is %NULL, the currently attached program of type @type is released, - * and the effective program of the parent cgroup (if any) is inherited to - * @cgrp. - * - * Then, the descendants of @cgrp are walked and the effective program for - * each of them is set to the effective program of @cgrp unless the - * descendant has its own program attached, in which case the subbranch is - * skipped. This ensures that delegated subcgroups with own programs are left - * untouched. + * @prog: A program to attach + * @type: Type of attach operation * * Must be called with cgroup_mutex held. */ -int __cgroup_bpf_update(struct cgroup *cgrp, struct cgroup *parent, - struct bpf_prog *prog, enum bpf_attach_type type, - bool new_overridable) +int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog, + enum bpf_attach_type type, u32 flags) { - struct bpf_prog *old_prog, *effective = NULL; - struct cgroup_subsys_state *pos; - bool overridable = true; - - if (parent) { - overridable = !parent->bpf.disallow_override[type]; - effective = rcu_dereference_protected(parent->bpf.effective[type], - lockdep_is_held(&cgroup_mutex)); - } - - if (prog && effective && !overridable) - /* if parent has non-overridable prog attached, disallow - * attaching new programs to descendent cgroup - */ + struct list_head *progs = &cgrp->bpf.progs[type]; + struct bpf_prog *old_prog = NULL; + struct cgroup_subsys_state *css; + struct bpf_prog_list *pl; + bool pl_was_allocated; + int err; + + if ((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI)) + /* invalid combination */ + return -EINVAL; + + if (!hierarchy_allows_attach(cgrp, type, flags)) return -EPERM; - if (prog && effective && overridable != new_overridable) - /* if parent has overridable prog attached, only - * allow overridable programs in descendent cgroup + if (!list_empty(progs) && cgrp->bpf.flags[type] != flags) + /* Disallow attaching non-overridable on top + * of existing overridable in this cgroup. + * Disallow attaching multi-prog if overridable or none */ return -EPERM; - old_prog = cgrp->bpf.prog[type]; - - if (prog) { - overridable = new_overridable; - effective = prog; - if (old_prog && - cgrp->bpf.disallow_override[type] == new_overridable) - /* disallow attaching non-overridable on top - * of existing overridable in this cgroup - * and vice versa - */ - return -EPERM; + if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS) + return -E2BIG; + + if (flags & BPF_F_ALLOW_MULTI) { + list_for_each_entry(pl, progs, node) + if (pl->prog == prog) + /* disallow attaching the same prog twice */ + return -EINVAL; + + pl = kmalloc(sizeof(*pl), GFP_KERNEL); + if (!pl) + return -ENOMEM; + pl_was_allocated = true; + pl->prog = prog; + list_add_tail(&pl->node, progs); + } else { + if (list_empty(progs)) { + pl = kmalloc(sizeof(*pl), GFP_KERNEL); + if (!pl) + return -ENOMEM; + pl_was_allocated = true; + list_add_tail(&pl->node, progs); + } else { + pl = list_first_entry(progs, typeof(*pl), node); + old_prog = pl->prog; + pl_was_allocated = false; + } + pl->prog = prog; } - if (!prog && !old_prog) - /* report error when trying to detach and nothing is attached */ - return -ENOENT; + cgrp->bpf.flags[type] = flags; - cgrp->bpf.prog[type] = prog; + /* allocate and recompute effective prog arrays */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); - css_for_each_descendant_pre(pos, &cgrp->self) { - struct cgroup *desc = container_of(pos, struct cgroup, self); - - /* skip the subtree if the descendant has its own program */ - if (desc->bpf.prog[type] && desc != cgrp) { - pos = css_rightmost_descendant(pos); - } else { - rcu_assign_pointer(desc->bpf.effective[type], - effective); - desc->bpf.disallow_override[type] = !overridable; - } + err = compute_effective_progs(desc, type, &desc->bpf.inactive); + if (err) + goto cleanup; } - if (prog) - static_branch_inc(&cgroup_bpf_enabled_key); + /* all allocations were successful. Activate all prog arrays */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); + activate_effective_progs(desc, type, desc->bpf.inactive); + desc->bpf.inactive = NULL; + } + + static_branch_inc(&cgroup_bpf_enabled_key); if (old_prog) { bpf_prog_put(old_prog); static_branch_dec(&cgroup_bpf_enabled_key); } return 0; + +cleanup: + /* oom while computing effective. Free all computed effective arrays + * since they were not activated + */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); + + bpf_prog_array_free(desc->bpf.inactive); + desc->bpf.inactive = NULL; + } + + /* and cleanup the prog list */ + pl->prog = old_prog; + if (pl_was_allocated) { + list_del(&pl->node); + kfree(pl); + } + return err; +} + +/** + * __cgroup_bpf_detach() - Detach the program from a cgroup, and + * propagate the change to descendants + * @cgrp: The cgroup which descendants to traverse + * @prog: A program to detach or NULL + * @type: Type of detach operation + * + * Must be called with cgroup_mutex held. + */ +int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, + enum bpf_attach_type type, u32 unused_flags) +{ + struct list_head *progs = &cgrp->bpf.progs[type]; + u32 flags = cgrp->bpf.flags[type]; + struct bpf_prog *old_prog = NULL; + struct cgroup_subsys_state *css; + struct bpf_prog_list *pl; + int err; + + if (flags & BPF_F_ALLOW_MULTI) { + if (!prog) + /* to detach MULTI prog the user has to specify valid FD + * of the program to be detached + */ + return -EINVAL; + } else { + if (list_empty(progs)) + /* report error when trying to detach and nothing is attached */ + return -ENOENT; + } + + if (flags & BPF_F_ALLOW_MULTI) { + /* find the prog and detach it */ + list_for_each_entry(pl, progs, node) { + if (pl->prog != prog) + continue; + old_prog = prog; + /* mark it deleted, so it's ignored while + * recomputing effective + */ + pl->prog = NULL; + break; + } + if (!old_prog) + return -ENOENT; + } else { + /* to maintain backward compatibility NONE and OVERRIDE cgroups + * allow detaching with invalid FD (prog==NULL) + */ + pl = list_first_entry(progs, typeof(*pl), node); + old_prog = pl->prog; + pl->prog = NULL; + } + + /* allocate and recompute effective prog arrays */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); + + err = compute_effective_progs(desc, type, &desc->bpf.inactive); + if (err) + goto cleanup; + } + + /* all allocations were successful. Activate all prog arrays */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); + + activate_effective_progs(desc, type, desc->bpf.inactive); + desc->bpf.inactive = NULL; + } + + /* now can actually delete it from this cgroup list */ + list_del(&pl->node); + kfree(pl); + if (list_empty(progs)) + /* last program was detached, reset flags to zero */ + cgrp->bpf.flags[type] = 0; + + bpf_prog_put(old_prog); + static_branch_dec(&cgroup_bpf_enabled_key); + return 0; + +cleanup: + /* oom while computing effective. Free all computed effective arrays + * since they were not activated + */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); + + bpf_prog_array_free(desc->bpf.inactive); + desc->bpf.inactive = NULL; + } + + /* and restore back old_prog */ + pl->prog = old_prog; + return err; +} + +/* Must be called with cgroup_mutex held to avoid races. */ +int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); + enum bpf_attach_type type = attr->query.attach_type; + struct list_head *progs = &cgrp->bpf.progs[type]; + u32 flags = cgrp->bpf.flags[type]; + int cnt, ret = 0, i; + + if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) + cnt = bpf_prog_array_length(cgrp->bpf.effective[type]); + else + cnt = prog_list_length(progs); + + if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags))) + return -EFAULT; + if (copy_to_user(&uattr->query.prog_cnt, &cnt, sizeof(cnt))) + return -EFAULT; + if (attr->query.prog_cnt == 0 || !prog_ids || !cnt) + /* return early if user requested only program count + flags */ + return 0; + if (attr->query.prog_cnt < cnt) { + cnt = attr->query.prog_cnt; + ret = -ENOSPC; + } + + if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) { + return bpf_prog_array_copy_to_user(cgrp->bpf.effective[type], + prog_ids, cnt); + } else { + struct bpf_prog_list *pl; + u32 id; + + i = 0; + list_for_each_entry(pl, progs, node) { + id = pl->prog->aux->id; + if (copy_to_user(prog_ids + i, &id, sizeof(id))) + return -EFAULT; + if (++i == cnt) + break; + } + } + return ret; } /** @@ -171,36 +447,26 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk, struct sk_buff *skb, enum bpf_attach_type type) { - struct bpf_prog *prog; + unsigned int offset = skb->data - skb_network_header(skb); + struct sock *save_sk; struct cgroup *cgrp; - int ret = 0; + int ret; if (!sk || !sk_fullsock(sk)) return 0; - if (sk->sk_family != AF_INET && - sk->sk_family != AF_INET6) + if (sk->sk_family != AF_INET && sk->sk_family != AF_INET6) return 0; cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - - rcu_read_lock(); - - prog = rcu_dereference(cgrp->bpf.effective[type]); - if (prog) { - unsigned int offset = skb->data - skb_network_header(skb); - struct sock *save_sk = skb->sk; - - skb->sk = sk; - __skb_push(skb, offset); - ret = bpf_prog_run_save_cb(prog, skb) == 1 ? 0 : -EPERM; - __skb_pull(skb, offset); - skb->sk = save_sk; - } - - rcu_read_unlock(); - - return ret; + save_sk = skb->sk; + skb->sk = sk; + __skb_push(skb, offset); + ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb, + bpf_prog_run_save_cb); + __skb_pull(skb, offset); + skb->sk = save_sk; + return ret == 1 ? 0 : -EPERM; } EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb); @@ -221,19 +487,10 @@ int __cgroup_bpf_run_filter_sk(struct sock *sk, enum bpf_attach_type type) { struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - struct bpf_prog *prog; - int ret = 0; + int ret; - - rcu_read_lock(); - - prog = rcu_dereference(cgrp->bpf.effective[type]); - if (prog) - ret = BPF_PROG_RUN(prog, sk) == 1 ? 0 : -EPERM; - - rcu_read_unlock(); - - return ret; + ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sk, BPF_PROG_RUN); + return ret == 1 ? 0 : -EPERM; } EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk); @@ -258,18 +515,77 @@ int __cgroup_bpf_run_filter_sock_ops(struct sock *sk, enum bpf_attach_type type) { struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - struct bpf_prog *prog; - int ret = 0; + int ret; + ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sock_ops, + BPF_PROG_RUN); + return ret == 1 ? 0 : -EPERM; +} +EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops); + +int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor, + short access, enum bpf_attach_type type) +{ + struct cgroup *cgrp; + struct bpf_cgroup_dev_ctx ctx = { + .access_type = (access << 16) | dev_type, + .major = major, + .minor = minor, + }; + int allow = 1; rcu_read_lock(); + cgrp = task_dfl_cgroup(current); + allow = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, + BPF_PROG_RUN); + rcu_read_unlock(); - prog = rcu_dereference(cgrp->bpf.effective[type]); - if (prog) - ret = BPF_PROG_RUN(prog, sock_ops) == 1 ? 0 : -EPERM; + return !allow; +} +EXPORT_SYMBOL(__cgroup_bpf_check_dev_permission); - rcu_read_unlock(); +static const struct bpf_func_proto * +cgroup_dev_func_proto(enum bpf_func_id func_id) +{ + switch (func_id) { + case BPF_FUNC_map_lookup_elem: + return &bpf_map_lookup_elem_proto; + case BPF_FUNC_map_update_elem: + return &bpf_map_update_elem_proto; + case BPF_FUNC_map_delete_elem: + return &bpf_map_delete_elem_proto; + case BPF_FUNC_get_current_uid_gid: + return &bpf_get_current_uid_gid_proto; + case BPF_FUNC_trace_printk: + if (capable(CAP_SYS_ADMIN)) + return bpf_get_trace_printk_proto(); + default: + return NULL; + } +} - return ret; +static bool cgroup_dev_is_valid_access(int off, int size, + enum bpf_access_type type, + struct bpf_insn_access_aux *info) +{ + if (type == BPF_WRITE) + return false; + + if (off < 0 || off + size > sizeof(struct bpf_cgroup_dev_ctx)) + return false; + /* The verifier guarantees that size > 0. */ + if (off % size != 0) + return false; + if (size != sizeof(__u32)) + return false; + + return true; } -EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops); + +const struct bpf_prog_ops cg_dev_prog_ops = { +}; + +const struct bpf_verifier_ops cg_dev_verifier_ops = { + .get_func_proto = cgroup_dev_func_proto, + .is_valid_access = cgroup_dev_is_valid_access, +}; diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 7b62df86be1d..8a6c37762330 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -309,12 +309,25 @@ bpf_get_prog_addr_region(const struct bpf_prog *prog, static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) { + const char *end = sym + KSYM_NAME_LEN; + BUILD_BUG_ON(sizeof("bpf_prog_") + - sizeof(prog->tag) * 2 + 1 > KSYM_NAME_LEN); + sizeof(prog->tag) * 2 + + /* name has been null terminated. + * We should need +1 for the '_' preceding + * the name. However, the null character + * is double counted between the name and the + * sizeof("bpf_prog_") above, so we omit + * the +1 here. + */ + sizeof(prog->aux->name) > KSYM_NAME_LEN); sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); - *sym = 0; + if (prog->aux->name[0]) + snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); + else + *sym = 0; } static __always_inline unsigned long @@ -1367,7 +1380,13 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) * valid program, which in this case would simply not * be JITed, but falls back to the interpreter. */ - fp = bpf_int_jit_compile(fp); + if (!bpf_prog_is_dev_bound(fp->aux)) { + fp = bpf_int_jit_compile(fp); + } else { + *err = bpf_prog_offload_compile(fp); + if (*err) + return fp; + } bpf_prog_lock_ro(fp); /* The tail call compatibility check can only be done at @@ -1381,11 +1400,163 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) } EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); +static unsigned int __bpf_prog_ret1(const void *ctx, + const struct bpf_insn *insn) +{ + return 1; +} + +static struct bpf_prog_dummy { + struct bpf_prog prog; +} dummy_bpf_prog = { + .prog = { + .bpf_func = __bpf_prog_ret1, + }, +}; + +/* to avoid allocating empty bpf_prog_array for cgroups that + * don't have bpf program attached use one global 'empty_prog_array' + * It will not be modified the caller of bpf_prog_array_alloc() + * (since caller requested prog_cnt == 0) + * that pointer should be 'freed' by bpf_prog_array_free() + */ +static struct { + struct bpf_prog_array hdr; + struct bpf_prog *null_prog; +} empty_prog_array = { + .null_prog = NULL, +}; + +struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) +{ + if (prog_cnt) + return kzalloc(sizeof(struct bpf_prog_array) + + sizeof(struct bpf_prog *) * (prog_cnt + 1), + flags); + + return &empty_prog_array.hdr; +} + +void bpf_prog_array_free(struct bpf_prog_array __rcu *progs) +{ + if (!progs || + progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr) + return; + kfree_rcu(progs, rcu); +} + +int bpf_prog_array_length(struct bpf_prog_array __rcu *progs) +{ + struct bpf_prog **prog; + u32 cnt = 0; + + rcu_read_lock(); + prog = rcu_dereference(progs)->progs; + for (; *prog; prog++) + cnt++; + rcu_read_unlock(); + return cnt; +} + +int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs, + __u32 __user *prog_ids, u32 cnt) +{ + struct bpf_prog **prog; + u32 i = 0, id; + + rcu_read_lock(); + prog = rcu_dereference(progs)->progs; + for (; *prog; prog++) { + id = (*prog)->aux->id; + if (copy_to_user(prog_ids + i, &id, sizeof(id))) { + rcu_read_unlock(); + return -EFAULT; + } + if (++i == cnt) { + prog++; + break; + } + } + rcu_read_unlock(); + if (*prog) + return -ENOSPC; + return 0; +} + +void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs, + struct bpf_prog *old_prog) +{ + struct bpf_prog **prog = progs->progs; + + for (; *prog; prog++) + if (*prog == old_prog) { + WRITE_ONCE(*prog, &dummy_bpf_prog.prog); + break; + } +} + +int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, + struct bpf_prog *exclude_prog, + struct bpf_prog *include_prog, + struct bpf_prog_array **new_array) +{ + int new_prog_cnt, carry_prog_cnt = 0; + struct bpf_prog **existing_prog; + struct bpf_prog_array *array; + int new_prog_idx = 0; + + /* Figure out how many existing progs we need to carry over to + * the new array. + */ + if (old_array) { + existing_prog = old_array->progs; + for (; *existing_prog; existing_prog++) { + if (*existing_prog != exclude_prog && + *existing_prog != &dummy_bpf_prog.prog) + carry_prog_cnt++; + if (*existing_prog == include_prog) + return -EEXIST; + } + } + + /* How many progs (not NULL) will be in the new array? */ + new_prog_cnt = carry_prog_cnt; + if (include_prog) + new_prog_cnt += 1; + + /* Do we have any prog (not NULL) in the new array? */ + if (!new_prog_cnt) { + *new_array = NULL; + return 0; + } + + /* +1 as the end of prog_array is marked with NULL */ + array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); + if (!array) + return -ENOMEM; + + /* Fill in the new prog array */ + if (carry_prog_cnt) { + existing_prog = old_array->progs; + for (; *existing_prog; existing_prog++) + if (*existing_prog != exclude_prog && + *existing_prog != &dummy_bpf_prog.prog) + array->progs[new_prog_idx++] = *existing_prog; + } + if (include_prog) + array->progs[new_prog_idx++] = include_prog; + array->progs[new_prog_idx] = NULL; + *new_array = array; + return 0; +} + static void bpf_prog_free_deferred(struct work_struct *work) { struct bpf_prog_aux *aux; aux = container_of(work, struct bpf_prog_aux, work); + if (bpf_prog_is_dev_bound(aux)) + bpf_prog_offload_destroy(aux->prog); bpf_jit_free(aux->prog); } @@ -1498,5 +1669,8 @@ int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); +/* These are only used within the BPF_SYSCALL code */ +#ifdef CONFIG_BPF_SYSCALL EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type); EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu); +#endif diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c new file mode 100644 index 000000000000..ce5b669003b2 --- /dev/null +++ b/kernel/bpf/cpumap.c @@ -0,0 +1,706 @@ +/* bpf/cpumap.c + * + * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc. + * Released under terms in GPL version 2. See COPYING. + */ + +/* 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, + * 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 + * basically allows for 10G wirespeed pre-filtering via bpf. + */ +#include <linux/bpf.h> +#include <linux/filter.h> +#include <linux/ptr_ring.h> + +#include <linux/sched.h> +#include <linux/workqueue.h> +#include <linux/kthread.h> +#include <linux/capability.h> +#include <trace/events/xdp.h> + +#include <linux/netdevice.h> /* netif_receive_skb_core */ +#include <linux/etherdevice.h> /* eth_type_trans */ + +/* General idea: XDP packets getting XDP redirected to another CPU, + * will maximum be stored/queued for one driver ->poll() call. It is + * guaranteed that setting flush bit and flush operation happen on + * same CPU. Thus, cpu_map_flush operation can deduct via this_cpu_ptr() + * which queue in bpf_cpu_map_entry contains packets. + */ + +#define CPU_MAP_BULK_SIZE 8 /* 8 == one cacheline on 64-bit archs */ +struct xdp_bulk_queue { + void *q[CPU_MAP_BULK_SIZE]; + unsigned int count; +}; + +/* Struct for every remote "destination" CPU in map */ +struct bpf_cpu_map_entry { + u32 cpu; /* kthread CPU and map index */ + int map_id; /* Back reference to map */ + u32 qsize; /* Queue size placeholder for map lookup */ + + /* XDP can run multiple RX-ring queues, need __percpu enqueue store */ + struct xdp_bulk_queue __percpu *bulkq; + + /* Queue with potential multi-producers, and single-consumer kthread */ + struct ptr_ring *queue; + struct task_struct *kthread; + struct work_struct kthread_stop_wq; + + atomic_t refcnt; /* Control when this struct can be free'ed */ + struct rcu_head rcu; +}; + +struct bpf_cpu_map { + struct bpf_map map; + /* Below members specific for map type */ + struct bpf_cpu_map_entry **cpu_map; + unsigned long __percpu *flush_needed; +}; + +static int bq_flush_to_queue(struct bpf_cpu_map_entry *rcpu, + struct xdp_bulk_queue *bq); + +static u64 cpu_map_bitmap_size(const union bpf_attr *attr) +{ + return BITS_TO_LONGS(attr->max_entries) * sizeof(unsigned long); +} + +static struct bpf_map *cpu_map_alloc(union bpf_attr *attr) +{ + struct bpf_cpu_map *cmap; + int err = -ENOMEM; + u64 cost; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return ERR_PTR(-EPERM); + + /* check sanity of attributes */ + if (attr->max_entries == 0 || attr->key_size != 4 || + attr->value_size != 4 || attr->map_flags & ~BPF_F_NUMA_NODE) + return ERR_PTR(-EINVAL); + + cmap = kzalloc(sizeof(*cmap), GFP_USER); + if (!cmap) + return ERR_PTR(-ENOMEM); + + /* mandatory map attributes */ + cmap->map.map_type = attr->map_type; + cmap->map.key_size = attr->key_size; + cmap->map.value_size = attr->value_size; + cmap->map.max_entries = attr->max_entries; + cmap->map.map_flags = attr->map_flags; + cmap->map.numa_node = bpf_map_attr_numa_node(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; + } + + /* make sure page count doesn't overflow */ + cost = (u64) cmap->map.max_entries * sizeof(struct bpf_cpu_map_entry *); + cost += cpu_map_bitmap_size(attr) * num_possible_cpus(); + if (cost >= U32_MAX - PAGE_SIZE) + goto free_cmap; + cmap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; + + /* Notice returns -EPERM on if map size is larger than memlock limit */ + ret = bpf_map_precharge_memlock(cmap->map.pages); + if (ret) { + err = ret; + goto free_cmap; + } + + /* A per cpu bitfield with a bit per possible CPU in map */ + cmap->flush_needed = __alloc_percpu(cpu_map_bitmap_size(attr), + __alignof__(unsigned long)); + if (!cmap->flush_needed) + 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_percpu; + + return &cmap->map; +free_percpu: + free_percpu(cmap->flush_needed); +free_cmap: + kfree(cmap); + return ERR_PTR(err); +} + +void __cpu_map_queue_destructor(void *ptr) +{ + /* The tear-down procedure should have made sure that queue is + * empty. See __cpu_map_entry_replace() and work-queue + * invoked cpu_map_kthread_stop(). Catch any broken behaviour + * gracefully and warn once. + */ + if (WARN_ON_ONCE(ptr)) + page_frag_free(ptr); +} + +static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu) +{ + if (atomic_dec_and_test(&rcpu->refcnt)) { + /* The queue should be empty at this point */ + ptr_ring_cleanup(rcpu->queue, __cpu_map_queue_destructor); + kfree(rcpu->queue); + kfree(rcpu); + } +} + +static void get_cpu_map_entry(struct bpf_cpu_map_entry *rcpu) +{ + atomic_inc(&rcpu->refcnt); +} + +/* called from workqueue, to workaround syscall using preempt_disable */ +static void cpu_map_kthread_stop(struct work_struct *work) +{ + struct bpf_cpu_map_entry *rcpu; + + rcpu = container_of(work, struct bpf_cpu_map_entry, kthread_stop_wq); + + /* Wait for flush in __cpu_map_entry_free(), via full RCU barrier, + * as it waits until all in-flight call_rcu() callbacks complete. + */ + rcu_barrier(); + + /* kthread_stop will wake_up_process and wait for it to complete */ + kthread_stop(rcpu->kthread); +} + +/* For now, xdp_pkt is a cpumap internal data structure, with info + * carried between enqueue to dequeue. It is mapped into the top + * headroom of the packet, to avoid allocating separate mem. + */ +struct xdp_pkt { + void *data; + u16 len; + u16 headroom; + u16 metasize; + struct net_device *dev_rx; +}; + +/* Convert xdp_buff to xdp_pkt */ +static struct xdp_pkt *convert_to_xdp_pkt(struct xdp_buff *xdp) +{ + struct xdp_pkt *xdp_pkt; + int metasize; + int headroom; + + /* Assure headroom is available for storing info */ + headroom = xdp->data - xdp->data_hard_start; + metasize = xdp->data - xdp->data_meta; + metasize = metasize > 0 ? metasize : 0; + if (unlikely((headroom - metasize) < sizeof(*xdp_pkt))) + return NULL; + + /* Store info in top of packet */ + xdp_pkt = xdp->data_hard_start; + + xdp_pkt->data = xdp->data; + xdp_pkt->len = xdp->data_end - xdp->data; + xdp_pkt->headroom = headroom - sizeof(*xdp_pkt); + xdp_pkt->metasize = metasize; + + return xdp_pkt; +} + +struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu, + struct xdp_pkt *xdp_pkt) +{ + unsigned int frame_size; + void *pkt_data_start; + struct sk_buff *skb; + + /* build_skb need to place skb_shared_info after SKB end, and + * also want to know the memory "truesize". Thus, need to + * know the memory frame size backing xdp_buff. + * + * XDP was designed to have PAGE_SIZE frames, but this + * assumption is not longer true with ixgbe and i40e. It + * would be preferred to set frame_size to 2048 or 4096 + * depending on the driver. + * frame_size = 2048; + * frame_len = frame_size - sizeof(*xdp_pkt); + * + * Instead, with info avail, skb_shared_info in placed after + * packet len. This, unfortunately fakes the truesize. + * Another disadvantage of this approach, the skb_shared_info + * is not at a fixed memory location, with mixed length + * packets, which is bad for cache-line hotness. + */ + frame_size = SKB_DATA_ALIGN(xdp_pkt->len) + xdp_pkt->headroom + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + + pkt_data_start = xdp_pkt->data - xdp_pkt->headroom; + skb = build_skb(pkt_data_start, frame_size); + if (!skb) + return NULL; + + skb_reserve(skb, xdp_pkt->headroom); + __skb_put(skb, xdp_pkt->len); + if (xdp_pkt->metasize) + skb_metadata_set(skb, xdp_pkt->metasize); + + /* Essential SKB info: protocol and skb->dev */ + skb->protocol = eth_type_trans(skb, xdp_pkt->dev_rx); + + /* Optional SKB info, currently missing: + * - HW checksum info (skb->ip_summed) + * - HW RX hash (skb_set_hash) + * - RX ring dev queue index (skb_record_rx_queue) + */ + + return skb; +} + +static int cpu_map_kthread_run(void *data) +{ + struct bpf_cpu_map_entry *rcpu = data; + + set_current_state(TASK_INTERRUPTIBLE); + + /* When kthread gives stop order, then rcpu have been disconnected + * from map, thus no new packets can enter. Remaining in-flight + * per CPU stored packets are flushed to this queue. Wait honoring + * kthread_stop signal until queue is empty. + */ + while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) { + unsigned int processed = 0, drops = 0, sched = 0; + struct xdp_pkt *xdp_pkt; + + /* Release CPU reschedule checks */ + if (__ptr_ring_empty(rcpu->queue)) { + set_current_state(TASK_INTERRUPTIBLE); + /* Recheck to avoid lost wake-up */ + if (__ptr_ring_empty(rcpu->queue)) { + schedule(); + sched = 1; + } else { + __set_current_state(TASK_RUNNING); + } + } else { + sched = cond_resched(); + } + + /* Process packets in rcpu->queue */ + local_bh_disable(); + /* + * The bpf_cpu_map_entry is single consumer, with this + * kthread CPU pinned. Lockless access to ptr_ring + * consume side valid as no-resize allowed of queue. + */ + while ((xdp_pkt = __ptr_ring_consume(rcpu->queue))) { + struct sk_buff *skb; + int ret; + + skb = cpu_map_build_skb(rcpu, xdp_pkt); + if (!skb) { + page_frag_free(xdp_pkt); + continue; + } + + /* Inject into network stack */ + ret = netif_receive_skb_core(skb); + if (ret == NET_RX_DROP) + drops++; + + /* Limit BH-disable period */ + if (++processed == 8) + break; + } + /* Feedback loop via tracepoint */ + trace_xdp_cpumap_kthread(rcpu->map_id, processed, drops, sched); + + local_bh_enable(); /* resched point, may call do_softirq() */ + } + __set_current_state(TASK_RUNNING); + + put_cpu_map_entry(rcpu); + return 0; +} + +struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu, int map_id) +{ + gfp_t gfp = GFP_ATOMIC|__GFP_NOWARN; + struct bpf_cpu_map_entry *rcpu; + int numa, err; + + /* Have map->numa_node, but choose node of redirect target CPU */ + numa = cpu_to_node(cpu); + + rcpu = kzalloc_node(sizeof(*rcpu), gfp, numa); + if (!rcpu) + return NULL; + + /* Alloc percpu bulkq */ + rcpu->bulkq = __alloc_percpu_gfp(sizeof(*rcpu->bulkq), + sizeof(void *), gfp); + if (!rcpu->bulkq) + goto free_rcu; + + /* Alloc queue */ + rcpu->queue = kzalloc_node(sizeof(*rcpu->queue), gfp, numa); + if (!rcpu->queue) + goto free_bulkq; + + err = ptr_ring_init(rcpu->queue, qsize, gfp); + if (err) + goto free_queue; + + rcpu->cpu = cpu; + rcpu->map_id = map_id; + rcpu->qsize = qsize; + + /* Setup kthread */ + rcpu->kthread = kthread_create_on_node(cpu_map_kthread_run, rcpu, numa, + "cpumap/%d/map:%d", cpu, map_id); + if (IS_ERR(rcpu->kthread)) + goto free_ptr_ring; + + get_cpu_map_entry(rcpu); /* 1-refcnt for being in cmap->cpu_map[] */ + get_cpu_map_entry(rcpu); /* 1-refcnt for kthread */ + + /* Make sure kthread runs on a single CPU */ + kthread_bind(rcpu->kthread, cpu); + wake_up_process(rcpu->kthread); + + return rcpu; + +free_ptr_ring: + ptr_ring_cleanup(rcpu->queue, NULL); +free_queue: + kfree(rcpu->queue); +free_bulkq: + free_percpu(rcpu->bulkq); +free_rcu: + kfree(rcpu); + return NULL; +} + +void __cpu_map_entry_free(struct rcu_head *rcu) +{ + struct bpf_cpu_map_entry *rcpu; + int cpu; + + /* This cpu_map_entry have been disconnected from map and one + * RCU graze-period have elapsed. Thus, XDP cannot queue any + * new packets and cannot change/set flush_needed that can + * find this entry. + */ + rcpu = container_of(rcu, struct bpf_cpu_map_entry, rcu); + + /* Flush remaining packets in percpu bulkq */ + for_each_online_cpu(cpu) { + struct xdp_bulk_queue *bq = per_cpu_ptr(rcpu->bulkq, cpu); + + /* No concurrent bq_enqueue can run at this point */ + bq_flush_to_queue(rcpu, bq); + } + free_percpu(rcpu->bulkq); + /* Cannot kthread_stop() here, last put free rcpu resources */ + put_cpu_map_entry(rcpu); +} + +/* After xchg pointer to bpf_cpu_map_entry, use the call_rcu() to + * ensure any driver rcu critical sections have completed, but this + * does not guarantee a flush has happened yet. Because driver side + * rcu_read_lock/unlock only protects the running XDP program. The + * atomic xchg and NULL-ptr check in __cpu_map_flush() makes sure a + * pending flush op doesn't fail. + * + * The bpf_cpu_map_entry is still used by the kthread, and there can + * still be pending packets (in queue and percpu bulkq). A refcnt + * makes sure to last user (kthread_stop vs. call_rcu) free memory + * resources. + * + * The rcu callback __cpu_map_entry_free flush remaining packets in + * percpu bulkq to queue. Due to caller map_delete_elem() disable + * preemption, cannot call kthread_stop() to make sure queue is empty. + * Instead a work_queue is started for stopping kthread, + * cpu_map_kthread_stop, which waits for an RCU graze period before + * stopping kthread, emptying the queue. + */ +void __cpu_map_entry_replace(struct bpf_cpu_map *cmap, + u32 key_cpu, struct bpf_cpu_map_entry *rcpu) +{ + struct bpf_cpu_map_entry *old_rcpu; + + old_rcpu = xchg(&cmap->cpu_map[key_cpu], rcpu); + if (old_rcpu) { + call_rcu(&old_rcpu->rcu, __cpu_map_entry_free); + INIT_WORK(&old_rcpu->kthread_stop_wq, cpu_map_kthread_stop); + schedule_work(&old_rcpu->kthread_stop_wq); + } +} + +int cpu_map_delete_elem(struct bpf_map *map, void *key) +{ + struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); + u32 key_cpu = *(u32 *)key; + + if (key_cpu >= map->max_entries) + return -EINVAL; + + /* notice caller map_delete_elem() use preempt_disable() */ + __cpu_map_entry_replace(cmap, key_cpu, NULL); + return 0; +} + +int cpu_map_update_elem(struct bpf_map *map, void *key, void *value, + u64 map_flags) +{ + struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); + struct bpf_cpu_map_entry *rcpu; + + /* Array index key correspond to CPU number */ + u32 key_cpu = *(u32 *)key; + /* Value is the queue size */ + u32 qsize = *(u32 *)value; + + if (unlikely(map_flags > BPF_EXIST)) + return -EINVAL; + if (unlikely(key_cpu >= cmap->map.max_entries)) + return -E2BIG; + if (unlikely(map_flags == BPF_NOEXIST)) + return -EEXIST; + if (unlikely(qsize > 16384)) /* sanity limit on qsize */ + return -EOVERFLOW; + + /* Make sure CPU is a valid possible cpu */ + if (!cpu_possible(key_cpu)) + return -ENODEV; + + if (qsize == 0) { + rcpu = NULL; /* Same as deleting */ + } else { + /* Updating qsize cause re-allocation of bpf_cpu_map_entry */ + rcpu = __cpu_map_entry_alloc(qsize, key_cpu, map->id); + if (!rcpu) + return -ENOMEM; + } + rcu_read_lock(); + __cpu_map_entry_replace(cmap, key_cpu, rcpu); + rcu_read_unlock(); + return 0; +} + +void cpu_map_free(struct bpf_map *map) +{ + struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); + int cpu; + u32 i; + + /* At this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, + * so the bpf programs (can be more than one that used this map) were + * disconnected from events. Wait for outstanding critical sections in + * these programs to complete. The rcu critical section only guarantees + * no further "XDP/bpf-side" reads against bpf_cpu_map->cpu_map. + * It does __not__ ensure pending flush operations (if any) are + * complete. + */ + synchronize_rcu(); + + /* To ensure all pending flush operations have completed wait for flush + * bitmap to indicate all flush_needed bits to be zero on _all_ cpus. + * Because the above synchronize_rcu() ensures the map is disconnected + * from the program we can assume no new bits will be set. + */ + for_each_online_cpu(cpu) { + unsigned long *bitmap = per_cpu_ptr(cmap->flush_needed, cpu); + + while (!bitmap_empty(bitmap, cmap->map.max_entries)) + cond_resched(); + } + + /* For cpu_map the remote CPUs can still be using the entries + * (struct bpf_cpu_map_entry). + */ + for (i = 0; i < cmap->map.max_entries; i++) { + struct bpf_cpu_map_entry *rcpu; + + rcpu = READ_ONCE(cmap->cpu_map[i]); + if (!rcpu) + continue; + + /* bq flush and cleanup happens after RCU graze-period */ + __cpu_map_entry_replace(cmap, i, NULL); /* call_rcu */ + } + free_percpu(cmap->flush_needed); + bpf_map_area_free(cmap->cpu_map); + kfree(cmap); +} + +struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key) +{ + struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); + struct bpf_cpu_map_entry *rcpu; + + if (key >= map->max_entries) + return NULL; + + rcpu = READ_ONCE(cmap->cpu_map[key]); + return rcpu; +} + +static void *cpu_map_lookup_elem(struct bpf_map *map, void *key) +{ + struct bpf_cpu_map_entry *rcpu = + __cpu_map_lookup_elem(map, *(u32 *)key); + + return rcpu ? &rcpu->qsize : NULL; +} + +static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key) +{ + struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); + u32 index = key ? *(u32 *)key : U32_MAX; + u32 *next = next_key; + + if (index >= cmap->map.max_entries) { + *next = 0; + return 0; + } + + if (index == cmap->map.max_entries - 1) + return -ENOENT; + *next = index + 1; + return 0; +} + +const struct bpf_map_ops cpu_map_ops = { + .map_alloc = cpu_map_alloc, + .map_free = cpu_map_free, + .map_delete_elem = cpu_map_delete_elem, + .map_update_elem = cpu_map_update_elem, + .map_lookup_elem = cpu_map_lookup_elem, + .map_get_next_key = cpu_map_get_next_key, +}; + +static int bq_flush_to_queue(struct bpf_cpu_map_entry *rcpu, + struct xdp_bulk_queue *bq) +{ + unsigned int processed = 0, drops = 0; + const int to_cpu = rcpu->cpu; + struct ptr_ring *q; + int i; + + if (unlikely(!bq->count)) + return 0; + + q = rcpu->queue; + spin_lock(&q->producer_lock); + + for (i = 0; i < bq->count; i++) { + void *xdp_pkt = bq->q[i]; + int err; + + err = __ptr_ring_produce(q, xdp_pkt); + if (err) { + drops++; + page_frag_free(xdp_pkt); /* Free xdp_pkt */ + } + processed++; + } + bq->count = 0; + spin_unlock(&q->producer_lock); + + /* Feedback loop via tracepoints */ + trace_xdp_cpumap_enqueue(rcpu->map_id, processed, drops, to_cpu); + return 0; +} + +/* Runs under RCU-read-side, plus in softirq under NAPI protection. + * Thus, safe percpu variable access. + */ +static int bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_pkt *xdp_pkt) +{ + struct xdp_bulk_queue *bq = this_cpu_ptr(rcpu->bulkq); + + if (unlikely(bq->count == CPU_MAP_BULK_SIZE)) + bq_flush_to_queue(rcpu, bq); + + /* Notice, xdp_buff/page MUST be queued here, long enough for + * driver to code invoking us to finished, due to driver + * (e.g. ixgbe) recycle tricks based on page-refcnt. + * + * Thus, incoming xdp_pkt is always queued here (else we race + * with another CPU on page-refcnt and remaining driver code). + * Queue time is very short, as driver will invoke flush + * operation, when completing napi->poll call. + */ + bq->q[bq->count++] = xdp_pkt; + return 0; +} + +int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp, + struct net_device *dev_rx) +{ + struct xdp_pkt *xdp_pkt; + + xdp_pkt = convert_to_xdp_pkt(xdp); + if (unlikely(!xdp_pkt)) + return -EOVERFLOW; + + /* Info needed when constructing SKB on remote CPU */ + xdp_pkt->dev_rx = dev_rx; + + bq_enqueue(rcpu, xdp_pkt); + return 0; +} + +void __cpu_map_insert_ctx(struct bpf_map *map, u32 bit) +{ + struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); + unsigned long *bitmap = this_cpu_ptr(cmap->flush_needed); + + __set_bit(bit, bitmap); +} + +void __cpu_map_flush(struct bpf_map *map) +{ + struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); + unsigned long *bitmap = this_cpu_ptr(cmap->flush_needed); + u32 bit; + + /* The napi->poll softirq makes sure __cpu_map_insert_ctx() + * and __cpu_map_flush() happen on same CPU. Thus, the percpu + * bitmap indicate which percpu bulkq have packets. + */ + for_each_set_bit(bit, bitmap, map->max_entries) { + struct bpf_cpu_map_entry *rcpu = READ_ONCE(cmap->cpu_map[bit]); + struct xdp_bulk_queue *bq; + + /* This is possible if entry is removed by user space + * between xdp redirect and flush op. + */ + if (unlikely(!rcpu)) + continue; + + __clear_bit(bit, bitmap); + + /* Flush all frames in bulkq to real queue */ + bq = this_cpu_ptr(rcpu->bulkq); + bq_flush_to_queue(rcpu, bq); + + /* If already running, costs spin_lock_irqsave + smb_mb */ + wake_up_process(rcpu->kthread); + } +} diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index e745d6a88224..ebdef54bf7df 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -50,6 +50,9 @@ #include <linux/bpf.h> #include <linux/filter.h> +#define DEV_CREATE_FLAG_MASK \ + (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) + struct bpf_dtab_netdev { struct net_device *dev; struct bpf_dtab *dtab; @@ -83,7 +86,7 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr) /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || - attr->value_size != 4 || attr->map_flags & ~BPF_F_NUMA_NODE) + attr->value_size != 4 || attr->map_flags & ~DEV_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL); dtab = kzalloc(sizeof(*dtab), GFP_USER); diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c new file mode 100644 index 000000000000..e682850c9715 --- /dev/null +++ b/kernel/bpf/disasm.c @@ -0,0 +1,214 @@ +/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com + * Copyright (c) 2016 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include <linux/bpf.h> + +#include "disasm.h" + +#define __BPF_FUNC_STR_FN(x) [BPF_FUNC_ ## x] = __stringify(bpf_ ## x) +static const char * const func_id_str[] = { + __BPF_FUNC_MAPPER(__BPF_FUNC_STR_FN) +}; +#undef __BPF_FUNC_STR_FN + +const char *func_id_name(int id) +{ + BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID); + + if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id]) + return func_id_str[id]; + else + return "unknown"; +} + +const char *const bpf_class_string[8] = { + [BPF_LD] = "ld", + [BPF_LDX] = "ldx", + [BPF_ST] = "st", + [BPF_STX] = "stx", + [BPF_ALU] = "alu", + [BPF_JMP] = "jmp", + [BPF_RET] = "BUG", + [BPF_ALU64] = "alu64", +}; + +const char *const bpf_alu_string[16] = { + [BPF_ADD >> 4] = "+=", + [BPF_SUB >> 4] = "-=", + [BPF_MUL >> 4] = "*=", + [BPF_DIV >> 4] = "/=", + [BPF_OR >> 4] = "|=", + [BPF_AND >> 4] = "&=", + [BPF_LSH >> 4] = "<<=", + [BPF_RSH >> 4] = ">>=", + [BPF_NEG >> 4] = "neg", + [BPF_MOD >> 4] = "%=", + [BPF_XOR >> 4] = "^=", + [BPF_MOV >> 4] = "=", + [BPF_ARSH >> 4] = "s>>=", + [BPF_END >> 4] = "endian", +}; + +static const char *const bpf_ldst_string[] = { + [BPF_W >> 3] = "u32", + [BPF_H >> 3] = "u16", + [BPF_B >> 3] = "u8", + [BPF_DW >> 3] = "u64", +}; + +static const char *const bpf_jmp_string[16] = { + [BPF_JA >> 4] = "jmp", + [BPF_JEQ >> 4] = "==", + [BPF_JGT >> 4] = ">", + [BPF_JLT >> 4] = "<", + [BPF_JGE >> 4] = ">=", + [BPF_JLE >> 4] = "<=", + [BPF_JSET >> 4] = "&", + [BPF_JNE >> 4] = "!=", + [BPF_JSGT >> 4] = "s>", + [BPF_JSLT >> 4] = "s<", + [BPF_JSGE >> 4] = "s>=", + [BPF_JSLE >> 4] = "s<=", + [BPF_CALL >> 4] = "call", + [BPF_EXIT >> 4] = "exit", +}; + +static void print_bpf_end_insn(bpf_insn_print_cb verbose, + struct bpf_verifier_env *env, + const struct bpf_insn *insn) +{ + verbose(env, "(%02x) r%d = %s%d r%d\n", insn->code, insn->dst_reg, + BPF_SRC(insn->code) == BPF_TO_BE ? "be" : "le", + insn->imm, insn->dst_reg); +} + +void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env, + const struct bpf_insn *insn, bool allow_ptr_leaks) +{ + u8 class = BPF_CLASS(insn->code); + + if (class == BPF_ALU || class == BPF_ALU64) { + if (BPF_OP(insn->code) == BPF_END) { + if (class == BPF_ALU64) + verbose(env, "BUG_alu64_%02x\n", insn->code); + else + print_bpf_end_insn(verbose, env, insn); + } else if (BPF_OP(insn->code) == BPF_NEG) { + verbose(env, "(%02x) r%d = %s-r%d\n", + insn->code, insn->dst_reg, + class == BPF_ALU ? "(u32) " : "", + insn->dst_reg); + } else if (BPF_SRC(insn->code) == BPF_X) { + verbose(env, "(%02x) %sr%d %s %sr%d\n", + insn->code, class == BPF_ALU ? "(u32) " : "", + insn->dst_reg, + bpf_alu_string[BPF_OP(insn->code) >> 4], + class == BPF_ALU ? "(u32) " : "", + insn->src_reg); + } else { + verbose(env, "(%02x) %sr%d %s %s%d\n", + insn->code, class == BPF_ALU ? "(u32) " : "", + insn->dst_reg, + bpf_alu_string[BPF_OP(insn->code) >> 4], + class == BPF_ALU ? "(u32) " : "", + insn->imm); + } + } else if (class == BPF_STX) { + if (BPF_MODE(insn->code) == BPF_MEM) + verbose(env, "(%02x) *(%s *)(r%d %+d) = r%d\n", + insn->code, + bpf_ldst_string[BPF_SIZE(insn->code) >> 3], + insn->dst_reg, + insn->off, insn->src_reg); + else if (BPF_MODE(insn->code) == BPF_XADD) + verbose(env, "(%02x) lock *(%s *)(r%d %+d) += r%d\n", + insn->code, + bpf_ldst_string[BPF_SIZE(insn->code) >> 3], + insn->dst_reg, insn->off, + insn->src_reg); + else + verbose(env, "BUG_%02x\n", insn->code); + } else if (class == BPF_ST) { + if (BPF_MODE(insn->code) != BPF_MEM) { + verbose(env, "BUG_st_%02x\n", insn->code); + return; + } + verbose(env, "(%02x) *(%s *)(r%d %+d) = %d\n", + insn->code, + bpf_ldst_string[BPF_SIZE(insn->code) >> 3], + insn->dst_reg, + insn->off, insn->imm); + } else if (class == BPF_LDX) { + if (BPF_MODE(insn->code) != BPF_MEM) { + verbose(env, "BUG_ldx_%02x\n", insn->code); + return; + } + verbose(env, "(%02x) r%d = *(%s *)(r%d %+d)\n", + insn->code, insn->dst_reg, + bpf_ldst_string[BPF_SIZE(insn->code) >> 3], + insn->src_reg, insn->off); + } else if (class == BPF_LD) { + if (BPF_MODE(insn->code) == BPF_ABS) { + verbose(env, "(%02x) r0 = *(%s *)skb[%d]\n", + insn->code, + bpf_ldst_string[BPF_SIZE(insn->code) >> 3], + insn->imm); + } else if (BPF_MODE(insn->code) == BPF_IND) { + verbose(env, "(%02x) r0 = *(%s *)skb[r%d + %d]\n", + insn->code, + bpf_ldst_string[BPF_SIZE(insn->code) >> 3], + insn->src_reg, insn->imm); + } else if (BPF_MODE(insn->code) == BPF_IMM && + BPF_SIZE(insn->code) == BPF_DW) { + /* At this point, we already made sure that the second + * part of the ldimm64 insn is accessible. + */ + u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm; + bool map_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD; + + if (map_ptr && !allow_ptr_leaks) + imm = 0; + + verbose(env, "(%02x) r%d = 0x%llx\n", insn->code, + insn->dst_reg, (unsigned long long)imm); + } else { + verbose(env, "BUG_ld_%02x\n", insn->code); + return; + } + } else if (class == BPF_JMP) { + u8 opcode = BPF_OP(insn->code); + + if (opcode == BPF_CALL) { + verbose(env, "(%02x) call %s#%d\n", insn->code, + func_id_name(insn->imm), insn->imm); + } else if (insn->code == (BPF_JMP | BPF_JA)) { + verbose(env, "(%02x) goto pc%+d\n", + insn->code, insn->off); + } else if (insn->code == (BPF_JMP | BPF_EXIT)) { + verbose(env, "(%02x) exit\n", insn->code); + } else if (BPF_SRC(insn->code) == BPF_X) { + verbose(env, "(%02x) if r%d %s r%d goto pc%+d\n", + insn->code, insn->dst_reg, + bpf_jmp_string[BPF_OP(insn->code) >> 4], + insn->src_reg, insn->off); + } else { + verbose(env, "(%02x) if r%d %s 0x%x goto pc%+d\n", + insn->code, insn->dst_reg, + bpf_jmp_string[BPF_OP(insn->code) >> 4], + insn->imm, insn->off); + } + } else { + verbose(env, "(%02x) %s\n", + insn->code, bpf_class_string[class]); + } +} diff --git a/kernel/bpf/disasm.h b/kernel/bpf/disasm.h new file mode 100644 index 000000000000..8de977e420b6 --- /dev/null +++ b/kernel/bpf/disasm.h @@ -0,0 +1,32 @@ +/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com + * Copyright (c) 2016 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#ifndef __BPF_DISASM_H__ +#define __BPF_DISASM_H__ + +#include <linux/bpf.h> +#include <linux/kernel.h> +#include <linux/stringify.h> + +extern const char *const bpf_alu_string[16]; +extern const char *const bpf_class_string[8]; + +const char *func_id_name(int id); + +struct bpf_verifier_env; +typedef void (*bpf_insn_print_cb)(struct bpf_verifier_env *env, + const char *, ...); +void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env, + const struct bpf_insn *insn, bool allow_ptr_leaks); + +#endif diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 6533f08d1238..e469e05c8e83 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -18,8 +18,9 @@ #include "bpf_lru_list.h" #include "map_in_map.h" -#define HTAB_CREATE_FLAG_MASK \ - (BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE) +#define HTAB_CREATE_FLAG_MASK \ + (BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE | \ + BPF_F_RDONLY | BPF_F_WRONLY) struct bucket { struct hlist_nulls_head head; diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index be1dde967208..01aaef1a77c5 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -295,7 +295,7 @@ out: } static void *bpf_obj_do_get(const struct filename *pathname, - enum bpf_type *type) + enum bpf_type *type, int flags) { struct inode *inode; struct path path; @@ -307,7 +307,7 @@ static void *bpf_obj_do_get(const struct filename *pathname, return ERR_PTR(ret); inode = d_backing_inode(path.dentry); - ret = inode_permission(inode, MAY_WRITE); + ret = inode_permission(inode, ACC_MODE(flags)); if (ret) goto out; @@ -326,18 +326,23 @@ out: return ERR_PTR(ret); } -int bpf_obj_get_user(const char __user *pathname) +int bpf_obj_get_user(const char __user *pathname, int flags) { enum bpf_type type = BPF_TYPE_UNSPEC; struct filename *pname; int ret = -ENOENT; + int f_flags; void *raw; + f_flags = bpf_get_file_flag(flags); + if (f_flags < 0) + return f_flags; + pname = getname(pathname); if (IS_ERR(pname)) return PTR_ERR(pname); - raw = bpf_obj_do_get(pname, &type); + raw = bpf_obj_do_get(pname, &type, f_flags); if (IS_ERR(raw)) { ret = PTR_ERR(raw); goto out; @@ -346,7 +351,7 @@ int bpf_obj_get_user(const char __user *pathname) if (type == BPF_TYPE_PROG) ret = bpf_prog_new_fd(raw); else if (type == BPF_TYPE_MAP) - ret = bpf_map_new_fd(raw); + ret = bpf_map_new_fd(raw, f_flags); else goto out; diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index 1b767844a76f..885e45479680 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -389,10 +389,99 @@ out: return ret; } -static int trie_delete_elem(struct bpf_map *map, void *key) +/* Called from syscall or from eBPF program */ +static int trie_delete_elem(struct bpf_map *map, void *_key) { - /* TODO */ - return -ENOSYS; + struct lpm_trie *trie = container_of(map, struct lpm_trie, map); + struct bpf_lpm_trie_key *key = _key; + struct lpm_trie_node __rcu **trim, **trim2; + struct lpm_trie_node *node, *parent; + unsigned long irq_flags; + unsigned int next_bit; + size_t matchlen = 0; + int ret = 0; + + if (key->prefixlen > trie->max_prefixlen) + return -EINVAL; + + raw_spin_lock_irqsave(&trie->lock, irq_flags); + + /* Walk the tree looking for an exact key/length match and keeping + * track of the path we traverse. We will need to know the node + * we wish to delete, and the slot that points to the node we want + * to delete. We may also need to know the nodes parent and the + * slot that contains it. + */ + trim = &trie->root; + trim2 = trim; + parent = NULL; + while ((node = rcu_dereference_protected( + *trim, lockdep_is_held(&trie->lock)))) { + matchlen = longest_prefix_match(trie, node, key); + + if (node->prefixlen != matchlen || + node->prefixlen == key->prefixlen) + break; + + parent = node; + trim2 = trim; + next_bit = extract_bit(key->data, node->prefixlen); + trim = &node->child[next_bit]; + } + + if (!node || node->prefixlen != key->prefixlen || + (node->flags & LPM_TREE_NODE_FLAG_IM)) { + ret = -ENOENT; + goto out; + } + + trie->n_entries--; + + /* If the node we are removing has two children, simply mark it + * as intermediate and we are done. + */ + if (rcu_access_pointer(node->child[0]) && + rcu_access_pointer(node->child[1])) { + node->flags |= LPM_TREE_NODE_FLAG_IM; + goto out; + } + + /* If the parent of the node we are about to delete is an intermediate + * node, and the deleted node doesn't have any children, we can delete + * the intermediate parent as well and promote its other child + * up the tree. Doing this maintains the invariant that all + * intermediate nodes have exactly 2 children and that there are no + * unnecessary intermediate nodes in the tree. + */ + if (parent && (parent->flags & LPM_TREE_NODE_FLAG_IM) && + !node->child[0] && !node->child[1]) { + if (node == rcu_access_pointer(parent->child[0])) + rcu_assign_pointer( + *trim2, rcu_access_pointer(parent->child[1])); + else + rcu_assign_pointer( + *trim2, rcu_access_pointer(parent->child[0])); + kfree_rcu(parent, rcu); + kfree_rcu(node, rcu); + goto out; + } + + /* The node we are removing has either zero or one child. If there + * is a child, move it into the removed node's slot then delete + * the node. Otherwise just clear the slot and delete the node. + */ + if (node->child[0]) + rcu_assign_pointer(*trim, rcu_access_pointer(node->child[0])); + else if (node->child[1]) + rcu_assign_pointer(*trim, rcu_access_pointer(node->child[1])); + else + RCU_INIT_POINTER(*trim, NULL); + kfree_rcu(node, rcu); + +out: + raw_spin_unlock_irqrestore(&trie->lock, irq_flags); + + return ret; } #define LPM_DATA_SIZE_MAX 256 @@ -406,7 +495,8 @@ static int trie_delete_elem(struct bpf_map *map, void *key) #define LPM_KEY_SIZE_MAX LPM_KEY_SIZE(LPM_DATA_SIZE_MAX) #define LPM_KEY_SIZE_MIN LPM_KEY_SIZE(LPM_DATA_SIZE_MIN) -#define LPM_CREATE_FLAG_MASK (BPF_F_NO_PREALLOC | BPF_F_NUMA_NODE) +#define LPM_CREATE_FLAG_MASK (BPF_F_NO_PREALLOC | BPF_F_NUMA_NODE | \ + BPF_F_RDONLY | BPF_F_WRONLY) static struct bpf_map *trie_alloc(union bpf_attr *attr) { diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c new file mode 100644 index 000000000000..2816feb38be1 --- /dev/null +++ b/kernel/bpf/offload.c @@ -0,0 +1,194 @@ +#include <linux/bpf.h> +#include <linux/bpf_verifier.h> +#include <linux/bug.h> +#include <linux/list.h> +#include <linux/netdevice.h> +#include <linux/printk.h> +#include <linux/rtnetlink.h> + +/* protected by RTNL */ +static LIST_HEAD(bpf_prog_offload_devs); + +int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr) +{ + struct net *net = current->nsproxy->net_ns; + struct bpf_dev_offload *offload; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (attr->prog_flags) + return -EINVAL; + + offload = kzalloc(sizeof(*offload), GFP_USER); + if (!offload) + return -ENOMEM; + + offload->prog = prog; + init_waitqueue_head(&offload->verifier_done); + + rtnl_lock(); + offload->netdev = __dev_get_by_index(net, attr->prog_target_ifindex); + if (!offload->netdev) { + rtnl_unlock(); + kfree(offload); + return -EINVAL; + } + + prog->aux->offload = offload; + list_add_tail(&offload->offloads, &bpf_prog_offload_devs); + rtnl_unlock(); + + return 0; +} + +static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd, + struct netdev_bpf *data) +{ + struct net_device *netdev = prog->aux->offload->netdev; + + ASSERT_RTNL(); + + if (!netdev) + return -ENODEV; + if (!netdev->netdev_ops->ndo_bpf) + return -EOPNOTSUPP; + + data->command = cmd; + + return netdev->netdev_ops->ndo_bpf(netdev, data); +} + +int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env) +{ + struct netdev_bpf data = {}; + int err; + + data.verifier.prog = env->prog; + + rtnl_lock(); + err = __bpf_offload_ndo(env->prog, BPF_OFFLOAD_VERIFIER_PREP, &data); + if (err) + goto exit_unlock; + + env->dev_ops = data.verifier.ops; + + env->prog->aux->offload->dev_state = true; + env->prog->aux->offload->verifier_running = true; +exit_unlock: + rtnl_unlock(); + return err; +} + +static void __bpf_prog_offload_destroy(struct bpf_prog *prog) +{ + struct bpf_dev_offload *offload = prog->aux->offload; + struct netdev_bpf data = {}; + + data.offload.prog = prog; + + if (offload->verifier_running) + wait_event(offload->verifier_done, !offload->verifier_running); + + if (offload->dev_state) + WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data)); + + offload->dev_state = false; + list_del_init(&offload->offloads); + offload->netdev = NULL; +} + +void bpf_prog_offload_destroy(struct bpf_prog *prog) +{ + struct bpf_dev_offload *offload = prog->aux->offload; + + offload->verifier_running = false; + wake_up(&offload->verifier_done); + + rtnl_lock(); + __bpf_prog_offload_destroy(prog); + rtnl_unlock(); + + kfree(offload); +} + +static int bpf_prog_offload_translate(struct bpf_prog *prog) +{ + struct bpf_dev_offload *offload = prog->aux->offload; + struct netdev_bpf data = {}; + int ret; + + data.offload.prog = prog; + + offload->verifier_running = false; + wake_up(&offload->verifier_done); + + rtnl_lock(); + ret = __bpf_offload_ndo(prog, BPF_OFFLOAD_TRANSLATE, &data); + rtnl_unlock(); + + return ret; +} + +static unsigned int bpf_prog_warn_on_exec(const void *ctx, + const struct bpf_insn *insn) +{ + WARN(1, "attempt to execute device eBPF program on the host!"); + return 0; +} + +int bpf_prog_offload_compile(struct bpf_prog *prog) +{ + prog->bpf_func = bpf_prog_warn_on_exec; + + return bpf_prog_offload_translate(prog); +} + +u32 bpf_prog_offload_ifindex(struct bpf_prog *prog) +{ + struct bpf_dev_offload *offload = prog->aux->offload; + u32 ifindex; + + rtnl_lock(); + ifindex = offload->netdev ? offload->netdev->ifindex : 0; + rtnl_unlock(); + + return ifindex; +} + +const struct bpf_prog_ops bpf_offload_prog_ops = { +}; + +static int bpf_offload_notification(struct notifier_block *notifier, + ulong event, void *ptr) +{ + struct net_device *netdev = netdev_notifier_info_to_dev(ptr); + struct bpf_dev_offload *offload, *tmp; + + ASSERT_RTNL(); + + switch (event) { + case NETDEV_UNREGISTER: + list_for_each_entry_safe(offload, tmp, &bpf_prog_offload_devs, + offloads) { + if (offload->netdev == netdev) + __bpf_prog_offload_destroy(offload->prog); + } + break; + default: + break; + } + return NOTIFY_OK; +} + +static struct notifier_block bpf_offload_notifier = { + .notifier_call = bpf_offload_notification, +}; + +static int __init bpf_offload_init(void) +{ + register_netdevice_notifier(&bpf_offload_notifier); + return 0; +} + +subsys_initcall(bpf_offload_init); diff --git a/kernel/bpf/percpu_freelist.c b/kernel/bpf/percpu_freelist.c index 5c51d1985b51..673fa6fe2d73 100644 --- a/kernel/bpf/percpu_freelist.c +++ b/kernel/bpf/percpu_freelist.c @@ -78,8 +78,10 @@ struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *s) { struct pcpu_freelist_head *head; struct pcpu_freelist_node *node; + unsigned long flags; int orig_cpu, cpu; + local_irq_save(flags); orig_cpu = cpu = raw_smp_processor_id(); while (1) { head = per_cpu_ptr(s->freelist, cpu); @@ -87,14 +89,16 @@ struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *s) node = head->first; if (node) { head->first = node->next; - raw_spin_unlock(&head->lock); + raw_spin_unlock_irqrestore(&head->lock, flags); return node; } raw_spin_unlock(&head->lock); cpu = cpumask_next(cpu, cpu_possible_mask); if (cpu >= nr_cpu_ids) cpu = 0; - if (cpu == orig_cpu) + if (cpu == orig_cpu) { + local_irq_restore(flags); return NULL; + } } } diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index dbd7b322a86b..5ee2e41893d9 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -41,6 +41,9 @@ #include <net/strparser.h> #include <net/tcp.h> +#define SOCK_CREATE_FLAG_MASK \ + (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) + struct bpf_stab { struct bpf_map map; struct sock **sock_map; @@ -122,7 +125,7 @@ static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb) */ TCP_SKB_CB(skb)->bpf.map = NULL; skb->sk = psock->sock; - bpf_compute_data_end_sk_skb(skb); + bpf_compute_data_pointers(skb); preempt_disable(); rc = (*prog->bpf_func)(skb, prog->insnsi); preempt_enable(); @@ -385,7 +388,7 @@ static int smap_parse_func_strparser(struct strparser *strp, * any socket yet. */ skb->sk = psock->sock; - bpf_compute_data_end_sk_skb(skb); + bpf_compute_data_pointers(skb); rc = (*prog->bpf_func)(skb, prog->insnsi); skb->sk = NULL; rcu_read_unlock(); @@ -508,7 +511,7 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr) /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || - attr->value_size != 4 || attr->map_flags & ~BPF_F_NUMA_NODE) + attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL); if (attr->value_size > KMALLOC_MAX_SIZE) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 135be433e9a0..a15bc636cc98 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -11,6 +11,9 @@ #include <linux/perf_event.h> #include "percpu_freelist.h" +#define STACK_CREATE_FLAG_MASK \ + (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) + struct stack_map_bucket { struct pcpu_freelist_node fnode; u32 hash; @@ -60,7 +63,7 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr) if (!capable(CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); - if (attr->map_flags & ~BPF_F_NUMA_NODE) + if (attr->map_flags & ~STACK_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL); /* check sanity of attributes */ diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 25d074920a00..09badc37e864 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -23,6 +23,9 @@ #include <linux/version.h> #include <linux/kernel.h> #include <linux/idr.h> +#include <linux/cred.h> +#include <linux/timekeeping.h> +#include <linux/ctype.h> #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \ (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ @@ -31,6 +34,8 @@ #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map)) +#define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) + DEFINE_PER_CPU(int, bpf_prog_active); static DEFINE_IDR(prog_idr); static DEFINE_SPINLOCK(prog_idr_lock); @@ -207,6 +212,7 @@ static void bpf_map_free_deferred(struct work_struct *work) struct bpf_map *map = container_of(work, struct bpf_map, work); bpf_map_uncharge_memlock(map); + security_bpf_map_free(map); /* implementation dependent freeing */ map->ops->map_free(map); } @@ -291,17 +297,54 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) } #endif -static const struct file_operations bpf_map_fops = { +static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, + loff_t *ppos) +{ + /* We need this handler such that alloc_file() enables + * f_mode with FMODE_CAN_READ. + */ + return -EINVAL; +} + +static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, + size_t siz, loff_t *ppos) +{ + /* We need this handler such that alloc_file() enables + * f_mode with FMODE_CAN_WRITE. + */ + return -EINVAL; +} + +const struct file_operations bpf_map_fops = { #ifdef CONFIG_PROC_FS .show_fdinfo = bpf_map_show_fdinfo, #endif .release = bpf_map_release, + .read = bpf_dummy_read, + .write = bpf_dummy_write, }; -int bpf_map_new_fd(struct bpf_map *map) +int bpf_map_new_fd(struct bpf_map *map, int flags) { + int ret; + + ret = security_bpf_map(map, OPEN_FMODE(flags)); + if (ret < 0) + return ret; + return anon_inode_getfd("bpf-map", &bpf_map_fops, map, - O_RDWR | O_CLOEXEC); + flags | O_CLOEXEC); +} + +int bpf_get_file_flag(int flags) +{ + if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) + return -EINVAL; + if (flags & BPF_F_RDONLY) + return O_RDONLY; + if (flags & BPF_F_WRONLY) + return O_WRONLY; + return O_RDWR; } /* helper macro to check that unused fields 'union bpf_attr' are zero */ @@ -312,18 +355,46 @@ int bpf_map_new_fd(struct bpf_map *map) offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ sizeof(attr->CMD##_LAST_FIELD)) != NULL -#define BPF_MAP_CREATE_LAST_FIELD numa_node +/* dst and src must have at least BPF_OBJ_NAME_LEN number of bytes. + * Return 0 on success and < 0 on error. + */ +static int bpf_obj_name_cpy(char *dst, const char *src) +{ + const char *end = src + BPF_OBJ_NAME_LEN; + + memset(dst, 0, BPF_OBJ_NAME_LEN); + + /* Copy all isalnum() and '_' char */ + while (src < end && *src) { + if (!isalnum(*src) && *src != '_') + return -EINVAL; + *dst++ = *src++; + } + + /* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */ + if (src == end) + return -EINVAL; + + return 0; +} + +#define BPF_MAP_CREATE_LAST_FIELD map_name /* called via syscall */ static int map_create(union bpf_attr *attr) { int numa_node = bpf_map_attr_numa_node(attr); struct bpf_map *map; + int f_flags; int err; err = CHECK_ATTR(BPF_MAP_CREATE); if (err) return -EINVAL; + f_flags = bpf_get_file_flag(attr->map_flags); + if (f_flags < 0) + return f_flags; + if (numa_node != NUMA_NO_NODE && ((unsigned int)numa_node >= nr_node_ids || !node_online(numa_node))) @@ -334,18 +405,26 @@ static int map_create(union bpf_attr *attr) if (IS_ERR(map)) return PTR_ERR(map); + err = bpf_obj_name_cpy(map->name, attr->map_name); + if (err) + goto free_map_nouncharge; + atomic_set(&map->refcnt, 1); atomic_set(&map->usercnt, 1); - err = bpf_map_charge_memlock(map); + err = security_bpf_map_alloc(map); if (err) goto free_map_nouncharge; + err = bpf_map_charge_memlock(map); + if (err) + goto free_map_sec; + err = bpf_map_alloc_id(map); if (err) goto free_map; - err = bpf_map_new_fd(map); + err = bpf_map_new_fd(map, f_flags); if (err < 0) { /* failed to allocate fd. * bpf_map_put() is needed because the above @@ -362,6 +441,8 @@ static int map_create(union bpf_attr *attr) free_map: bpf_map_uncharge_memlock(map); +free_map_sec: + security_bpf_map_free(map); free_map_nouncharge: map->ops->map_free(map); return err; @@ -460,6 +541,11 @@ static int map_lookup_elem(union bpf_attr *attr) if (IS_ERR(map)) return PTR_ERR(map); + if (!(f.file->f_mode & FMODE_CAN_READ)) { + err = -EPERM; + goto err_put; + } + key = memdup_user(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); @@ -540,6 +626,11 @@ static int map_update_elem(union bpf_attr *attr) if (IS_ERR(map)) return PTR_ERR(map); + if (!(f.file->f_mode & FMODE_CAN_WRITE)) { + err = -EPERM; + goto err_put; + } + key = memdup_user(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); @@ -562,6 +653,12 @@ static int map_update_elem(union bpf_attr *attr) if (copy_from_user(value, uvalue, value_size) != 0) goto free_value; + /* Need to create a kthread, thus must support schedule */ + if (map->map_type == BPF_MAP_TYPE_CPUMAP) { + err = map->ops->map_update_elem(map, key, value, attr->flags); + goto out; + } + /* must increment bpf_prog_active to avoid kprobe+bpf triggering from * inside bpf map update or delete otherwise deadlocks are possible */ @@ -592,7 +689,7 @@ static int map_update_elem(union bpf_attr *attr) } __this_cpu_dec(bpf_prog_active); preempt_enable(); - +out: if (!err) trace_bpf_map_update_elem(map, ufd, key, value); free_value: @@ -623,6 +720,11 @@ static int map_delete_elem(union bpf_attr *attr) if (IS_ERR(map)) return PTR_ERR(map); + if (!(f.file->f_mode & FMODE_CAN_WRITE)) { + err = -EPERM; + goto err_put; + } + key = memdup_user(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); @@ -666,6 +768,11 @@ static int map_get_next_key(union bpf_attr *attr) if (IS_ERR(map)) return PTR_ERR(map); + if (!(f.file->f_mode & FMODE_CAN_READ)) { + err = -EPERM; + goto err_put; + } + if (ukey) { key = memdup_user(ukey, map->key_size); if (IS_ERR(key)) { @@ -703,9 +810,9 @@ err_put: return err; } -static const struct bpf_verifier_ops * const bpf_prog_types[] = { -#define BPF_PROG_TYPE(_id, _ops) \ - [_id] = &_ops, +static const struct bpf_prog_ops * const bpf_prog_types[] = { +#define BPF_PROG_TYPE(_id, _name) \ + [_id] = & _name ## _prog_ops, #define BPF_MAP_TYPE(_id, _ops) #include <linux/bpf_types.h> #undef BPF_PROG_TYPE @@ -717,7 +824,10 @@ static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type]) return -EINVAL; - prog->aux->ops = bpf_prog_types[type]; + if (!bpf_prog_is_dev_bound(prog->aux)) + prog->aux->ops = bpf_prog_types[type]; + else + prog->aux->ops = &bpf_offload_prog_ops; prog->type = type; return 0; } @@ -820,6 +930,7 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu) free_used_maps(aux); bpf_prog_uncharge_memlock(aux->prog); + security_bpf_prog_free(aux); bpf_prog_free(aux->prog); } @@ -867,15 +978,23 @@ static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) } #endif -static const struct file_operations bpf_prog_fops = { +const struct file_operations bpf_prog_fops = { #ifdef CONFIG_PROC_FS .show_fdinfo = bpf_prog_show_fdinfo, #endif .release = bpf_prog_release, + .read = bpf_dummy_read, + .write = bpf_dummy_write, }; int bpf_prog_new_fd(struct bpf_prog *prog) { + int ret; + + ret = security_bpf_prog(prog); + if (ret < 0) + return ret; + return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, O_RDWR | O_CLOEXEC); } @@ -938,7 +1057,22 @@ struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) } EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); -static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type) +static bool bpf_prog_can_attach(struct bpf_prog *prog, + enum bpf_prog_type *attach_type, + struct net_device *netdev) +{ + struct bpf_dev_offload *offload = prog->aux->offload; + + if (prog->type != *attach_type) + return false; + if (offload && offload->netdev != netdev) + return false; + + return true; +} + +static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, + struct net_device *netdev) { struct fd f = fdget(ufd); struct bpf_prog *prog; @@ -946,7 +1080,7 @@ static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type) prog = ____bpf_prog_get(f); if (IS_ERR(prog)) return prog; - if (type && prog->type != *type) { + if (attach_type && !bpf_prog_can_attach(prog, attach_type, netdev)) { prog = ERR_PTR(-EINVAL); goto out; } @@ -959,12 +1093,12 @@ out: struct bpf_prog *bpf_prog_get(u32 ufd) { - return __bpf_prog_get(ufd, NULL); + return __bpf_prog_get(ufd, NULL, NULL); } struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type) { - struct bpf_prog *prog = __bpf_prog_get(ufd, &type); + struct bpf_prog *prog = __bpf_prog_get(ufd, &type, NULL); if (!IS_ERR(prog)) trace_bpf_prog_get_type(prog); @@ -972,8 +1106,19 @@ struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type) } EXPORT_SYMBOL_GPL(bpf_prog_get_type); +struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, + struct net_device *netdev) +{ + struct bpf_prog *prog = __bpf_prog_get(ufd, &type, netdev); + + if (!IS_ERR(prog)) + trace_bpf_prog_get_type(prog); + return prog; +} +EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); + /* last field in 'union bpf_attr' used by this command */ -#define BPF_PROG_LOAD_LAST_FIELD prog_flags +#define BPF_PROG_LOAD_LAST_FIELD prog_target_ifindex static int bpf_prog_load(union bpf_attr *attr) { @@ -1015,10 +1160,14 @@ static int bpf_prog_load(union bpf_attr *attr) if (!prog) return -ENOMEM; - err = bpf_prog_charge_memlock(prog); + err = security_bpf_prog_alloc(prog->aux); if (err) goto free_prog_nouncharge; + err = bpf_prog_charge_memlock(prog); + if (err) + goto free_prog_sec; + prog->len = attr->insn_cnt; err = -EFAULT; @@ -1032,11 +1181,22 @@ static int bpf_prog_load(union bpf_attr *attr) atomic_set(&prog->aux->refcnt, 1); prog->gpl_compatible = is_gpl ? 1 : 0; + if (attr->prog_target_ifindex) { + err = bpf_prog_offload_init(prog, attr); + if (err) + goto free_prog; + } + /* find program type: socket_filter vs tracing_filter */ err = find_prog_type(type, prog); if (err < 0) goto free_prog; + prog->aux->load_time = ktime_get_boot_ns(); + err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name); + if (err) + goto free_prog; + /* run eBPF verifier */ err = bpf_check(&prog, attr); if (err < 0) @@ -1071,16 +1231,18 @@ free_used_maps: free_used_maps(prog->aux); free_prog: bpf_prog_uncharge_memlock(prog); +free_prog_sec: + security_bpf_prog_free(prog->aux); free_prog_nouncharge: bpf_prog_free(prog); return err; } -#define BPF_OBJ_LAST_FIELD bpf_fd +#define BPF_OBJ_LAST_FIELD file_flags static int bpf_obj_pin(const union bpf_attr *attr) { - if (CHECK_ATTR(BPF_OBJ)) + if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0) return -EINVAL; return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname)); @@ -1088,10 +1250,12 @@ static int bpf_obj_pin(const union bpf_attr *attr) static int bpf_obj_get(const union bpf_attr *attr) { - if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0) + if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || + attr->file_flags & ~BPF_OBJ_FLAG_MASK) return -EINVAL; - return bpf_obj_get_user(u64_to_user_ptr(attr->pathname)); + return bpf_obj_get_user(u64_to_user_ptr(attr->pathname), + attr->file_flags); } #ifdef CONFIG_CGROUP_BPF @@ -1132,6 +1296,9 @@ static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach) return 0; } +#define BPF_F_ATTACH_MASK \ + (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI) + static int bpf_prog_attach(const union bpf_attr *attr) { enum bpf_prog_type ptype; @@ -1145,7 +1312,7 @@ static int bpf_prog_attach(const union bpf_attr *attr) if (CHECK_ATTR(BPF_PROG_ATTACH)) return -EINVAL; - if (attr->attach_flags & ~BPF_F_ALLOW_OVERRIDE) + if (attr->attach_flags & ~BPF_F_ATTACH_MASK) return -EINVAL; switch (attr->attach_type) { @@ -1159,6 +1326,9 @@ static int bpf_prog_attach(const union bpf_attr *attr) case BPF_CGROUP_SOCK_OPS: ptype = BPF_PROG_TYPE_SOCK_OPS; break; + case BPF_CGROUP_DEVICE: + ptype = BPF_PROG_TYPE_CGROUP_DEVICE; + break; case BPF_SK_SKB_STREAM_PARSER: case BPF_SK_SKB_STREAM_VERDICT: return sockmap_get_from_fd(attr, true); @@ -1176,8 +1346,8 @@ static int bpf_prog_attach(const union bpf_attr *attr) return PTR_ERR(cgrp); } - ret = cgroup_bpf_update(cgrp, prog, attr->attach_type, - attr->attach_flags & BPF_F_ALLOW_OVERRIDE); + ret = cgroup_bpf_attach(cgrp, prog, attr->attach_type, + attr->attach_flags); if (ret) bpf_prog_put(prog); cgroup_put(cgrp); @@ -1189,6 +1359,8 @@ static int bpf_prog_attach(const union bpf_attr *attr) static int bpf_prog_detach(const union bpf_attr *attr) { + enum bpf_prog_type ptype; + struct bpf_prog *prog; struct cgroup *cgrp; int ret; @@ -1201,26 +1373,71 @@ static int bpf_prog_detach(const union bpf_attr *attr) switch (attr->attach_type) { case BPF_CGROUP_INET_INGRESS: case BPF_CGROUP_INET_EGRESS: + ptype = BPF_PROG_TYPE_CGROUP_SKB; + break; case BPF_CGROUP_INET_SOCK_CREATE: + ptype = BPF_PROG_TYPE_CGROUP_SOCK; + break; case BPF_CGROUP_SOCK_OPS: - cgrp = cgroup_get_from_fd(attr->target_fd); - if (IS_ERR(cgrp)) - return PTR_ERR(cgrp); - - ret = cgroup_bpf_update(cgrp, NULL, attr->attach_type, false); - cgroup_put(cgrp); + ptype = BPF_PROG_TYPE_SOCK_OPS; + break; + case BPF_CGROUP_DEVICE: + ptype = BPF_PROG_TYPE_CGROUP_DEVICE; break; case BPF_SK_SKB_STREAM_PARSER: case BPF_SK_SKB_STREAM_VERDICT: - ret = sockmap_get_from_fd(attr, false); - break; + return sockmap_get_from_fd(attr, false); default: return -EINVAL; } + cgrp = cgroup_get_from_fd(attr->target_fd); + if (IS_ERR(cgrp)) + return PTR_ERR(cgrp); + + prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); + if (IS_ERR(prog)) + prog = NULL; + + ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, 0); + if (prog) + bpf_prog_put(prog); + cgroup_put(cgrp); return ret; } +#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt + +static int bpf_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + struct cgroup *cgrp; + int ret; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + if (CHECK_ATTR(BPF_PROG_QUERY)) + return -EINVAL; + if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) + return -EINVAL; + + switch (attr->query.attach_type) { + case BPF_CGROUP_INET_INGRESS: + case BPF_CGROUP_INET_EGRESS: + case BPF_CGROUP_INET_SOCK_CREATE: + case BPF_CGROUP_SOCK_OPS: + case BPF_CGROUP_DEVICE: + break; + default: + return -EINVAL; + } + cgrp = cgroup_get_from_fd(attr->query.target_fd); + if (IS_ERR(cgrp)) + return PTR_ERR(cgrp); + ret = cgroup_bpf_query(cgrp, attr, uattr); + cgroup_put(cgrp); + return ret; +} #endif /* CONFIG_CGROUP_BPF */ #define BPF_PROG_TEST_RUN_LAST_FIELD test.duration @@ -1305,20 +1522,26 @@ static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) return fd; } -#define BPF_MAP_GET_FD_BY_ID_LAST_FIELD map_id +#define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags static int bpf_map_get_fd_by_id(const union bpf_attr *attr) { struct bpf_map *map; u32 id = attr->map_id; + int f_flags; int fd; - if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID)) + if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || + attr->open_flags & ~BPF_OBJ_FLAG_MASK) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EPERM; + f_flags = bpf_get_file_flag(attr->open_flags); + if (f_flags < 0) + return f_flags; + spin_lock_bh(&map_idr_lock); map = idr_find(&map_idr, id); if (map) @@ -1330,7 +1553,7 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr) if (IS_ERR(map)) return PTR_ERR(map); - fd = bpf_map_new_fd(map); + fd = bpf_map_new_fd(map, f_flags); if (fd < 0) bpf_map_put(map); @@ -1358,8 +1581,25 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, info.type = prog->type; info.id = prog->aux->id; + info.load_time = prog->aux->load_time; + info.created_by_uid = from_kuid_munged(current_user_ns(), + prog->aux->user->uid); memcpy(info.tag, prog->tag, sizeof(prog->tag)); + memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); + + ulen = info.nr_map_ids; + info.nr_map_ids = prog->aux->used_map_cnt; + ulen = min_t(u32, info.nr_map_ids, ulen); + if (ulen) { + u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); + u32 i; + + for (i = 0; i < ulen; i++) + if (put_user(prog->aux->used_maps[i]->id, + &user_map_ids[i])) + return -EFAULT; + } if (!capable(CAP_SYS_ADMIN)) { info.jited_prog_len = 0; @@ -1385,6 +1625,11 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, return -EFAULT; } + if (bpf_prog_is_dev_bound(prog->aux)) { + info.status |= BPF_PROG_STATUS_DEV_BOUND; + info.ifindex = bpf_prog_offload_ifindex(prog); + } + done: if (copy_to_user(uinfo, &info, info_len) || put_user(info_len, &uattr->info.info_len)) @@ -1413,6 +1658,7 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map, info.value_size = map->value_size; info.max_entries = map->max_entries; info.map_flags = map->map_flags; + memcpy(info.name, map->name, sizeof(map->name)); if (copy_to_user(uinfo, &info, info_len) || put_user(info_len, &uattr->info.info_len)) @@ -1467,6 +1713,10 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz if (copy_from_user(&attr, uattr, size) != 0) return -EFAULT; + err = security_bpf(cmd, &attr, size); + if (err < 0) + return err; + switch (cmd) { case BPF_MAP_CREATE: err = map_create(&attr); @@ -1499,6 +1749,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz case BPF_PROG_DETACH: err = bpf_prog_detach(&attr); break; + case BPF_PROG_QUERY: + err = bpf_prog_query(&attr, uattr); + break; #endif case BPF_PROG_TEST_RUN: err = bpf_prog_test_run(&attr, uattr); diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index c48ca2a34b5e..dd54d20ace2f 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -21,6 +21,17 @@ #include <linux/vmalloc.h> #include <linux/stringify.h> +#include "disasm.h" + +static const struct bpf_verifier_ops * const bpf_verifier_ops[] = { +#define BPF_PROG_TYPE(_id, _name) \ + [_id] = & _name ## _verifier_ops, +#define BPF_MAP_TYPE(_id, _ops) +#include <linux/bpf_types.h> +#undef BPF_PROG_TYPE +#undef BPF_MAP_TYPE +}; + /* bpf_check() is a static code analyzer that walks eBPF program * instruction by instruction and updates register/stack state. * All paths of conditional branches are analyzed until 'bpf_exit' insn. @@ -153,28 +164,42 @@ struct bpf_call_arg_meta { int access_size; }; -/* verbose verifier prints what it's seeing - * bpf_check() is called under lock, so no race to access these global vars - */ -static u32 log_level, log_size, log_len; -static char *log_buf; - static DEFINE_MUTEX(bpf_verifier_lock); /* log_level controls verbosity level of eBPF verifier. * verbose() is used to dump the verification trace to the log, so the user * can figure out what's wrong with the program */ -static __printf(1, 2) void verbose(const char *fmt, ...) +static __printf(2, 3) void verbose(struct bpf_verifier_env *env, + const char *fmt, ...) { + struct bpf_verifer_log *log = &env->log; + unsigned int n; va_list args; - if (log_level == 0 || log_len >= log_size - 1) + if (!log->level || !log->ubuf || bpf_verifier_log_full(log)) return; va_start(args, fmt); - log_len += vscnprintf(log_buf + log_len, log_size - log_len, fmt, args); + n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args); va_end(args); + + WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1, + "verifier log line truncated - local buffer too short\n"); + + n = min(log->len_total - log->len_used - 1, n); + log->kbuf[n] = '\0'; + + if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1)) + log->len_used += n; + else + log->ubuf = NULL; +} + +static bool type_is_pkt_pointer(enum bpf_reg_type type) +{ + return type == PTR_TO_PACKET || + type == PTR_TO_PACKET_META; } /* string representation of 'enum bpf_reg_type' */ @@ -187,26 +212,12 @@ static const char * const reg_type_str[] = { [PTR_TO_MAP_VALUE_OR_NULL] = "map_value_or_null", [PTR_TO_STACK] = "fp", [PTR_TO_PACKET] = "pkt", + [PTR_TO_PACKET_META] = "pkt_meta", [PTR_TO_PACKET_END] = "pkt_end", }; -#define __BPF_FUNC_STR_FN(x) [BPF_FUNC_ ## x] = __stringify(bpf_ ## x) -static const char * const func_id_str[] = { - __BPF_FUNC_MAPPER(__BPF_FUNC_STR_FN) -}; -#undef __BPF_FUNC_STR_FN - -static const char *func_id_name(int id) -{ - BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID); - - if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id]) - return func_id_str[id]; - else - return "unknown"; -} - -static void print_verifier_state(struct bpf_verifier_state *state) +static void print_verifier_state(struct bpf_verifier_env *env, + struct bpf_verifier_state *state) { struct bpf_reg_state *reg; enum bpf_reg_type t; @@ -217,21 +228,21 @@ static void print_verifier_state(struct bpf_verifier_state *state) t = reg->type; if (t == NOT_INIT) continue; - verbose(" R%d=%s", i, reg_type_str[t]); + verbose(env, " R%d=%s", i, reg_type_str[t]); if ((t == SCALAR_VALUE || t == PTR_TO_STACK) && tnum_is_const(reg->var_off)) { /* reg->off should be 0 for SCALAR_VALUE */ - verbose("%lld", reg->var_off.value + reg->off); + verbose(env, "%lld", reg->var_off.value + reg->off); } else { - verbose("(id=%d", reg->id); + verbose(env, "(id=%d", reg->id); if (t != SCALAR_VALUE) - verbose(",off=%d", reg->off); - if (t == PTR_TO_PACKET) - verbose(",r=%d", reg->range); + verbose(env, ",off=%d", reg->off); + if (type_is_pkt_pointer(t)) + verbose(env, ",r=%d", reg->range); else if (t == CONST_PTR_TO_MAP || t == PTR_TO_MAP_VALUE || t == PTR_TO_MAP_VALUE_OR_NULL) - verbose(",ks=%d,vs=%d", + verbose(env, ",ks=%d,vs=%d", reg->map_ptr->key_size, reg->map_ptr->value_size); if (tnum_is_const(reg->var_off)) { @@ -239,243 +250,174 @@ static void print_verifier_state(struct bpf_verifier_state *state) * could be a pointer whose offset is too big * for reg->off */ - verbose(",imm=%llx", reg->var_off.value); + verbose(env, ",imm=%llx", reg->var_off.value); } else { if (reg->smin_value != reg->umin_value && reg->smin_value != S64_MIN) - verbose(",smin_value=%lld", + verbose(env, ",smin_value=%lld", (long long)reg->smin_value); if (reg->smax_value != reg->umax_value && reg->smax_value != S64_MAX) - verbose(",smax_value=%lld", + verbose(env, ",smax_value=%lld", (long long)reg->smax_value); if (reg->umin_value != 0) - verbose(",umin_value=%llu", + verbose(env, ",umin_value=%llu", (unsigned long long)reg->umin_value); if (reg->umax_value != U64_MAX) - verbose(",umax_value=%llu", + verbose(env, ",umax_value=%llu", (unsigned long long)reg->umax_value); if (!tnum_is_unknown(reg->var_off)) { char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); - verbose(",var_off=%s", tn_buf); + verbose(env, ",var_off=%s", tn_buf); } } - verbose(")"); + verbose(env, ")"); } } - for (i = 0; i < MAX_BPF_STACK; i += BPF_REG_SIZE) { - if (state->stack_slot_type[i] == STACK_SPILL) - verbose(" fp%d=%s", -MAX_BPF_STACK + i, - reg_type_str[state->spilled_regs[i / BPF_REG_SIZE].type]); + for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) { + if (state->stack[i].slot_type[0] == STACK_SPILL) + verbose(env, " fp%d=%s", + -MAX_BPF_STACK + i * BPF_REG_SIZE, + reg_type_str[state->stack[i].spilled_ptr.type]); } - verbose("\n"); + verbose(env, "\n"); } -static const char *const bpf_class_string[] = { - [BPF_LD] = "ld", - [BPF_LDX] = "ldx", - [BPF_ST] = "st", - [BPF_STX] = "stx", - [BPF_ALU] = "alu", - [BPF_JMP] = "jmp", - [BPF_RET] = "BUG", - [BPF_ALU64] = "alu64", -}; - -static const char *const bpf_alu_string[16] = { - [BPF_ADD >> 4] = "+=", - [BPF_SUB >> 4] = "-=", - [BPF_MUL >> 4] = "*=", - [BPF_DIV >> 4] = "/=", - [BPF_OR >> 4] = "|=", - [BPF_AND >> 4] = "&=", - [BPF_LSH >> 4] = "<<=", - [BPF_RSH >> 4] = ">>=", - [BPF_NEG >> 4] = "neg", - [BPF_MOD >> 4] = "%=", - [BPF_XOR >> 4] = "^=", - [BPF_MOV >> 4] = "=", - [BPF_ARSH >> 4] = "s>>=", - [BPF_END >> 4] = "endian", -}; - -static const char *const bpf_ldst_string[] = { - [BPF_W >> 3] = "u32", - [BPF_H >> 3] = "u16", - [BPF_B >> 3] = "u8", - [BPF_DW >> 3] = "u64", -}; - -static const char *const bpf_jmp_string[16] = { - [BPF_JA >> 4] = "jmp", - [BPF_JEQ >> 4] = "==", - [BPF_JGT >> 4] = ">", - [BPF_JLT >> 4] = "<", - [BPF_JGE >> 4] = ">=", - [BPF_JLE >> 4] = "<=", - [BPF_JSET >> 4] = "&", - [BPF_JNE >> 4] = "!=", - [BPF_JSGT >> 4] = "s>", - [BPF_JSLT >> 4] = "s<", - [BPF_JSGE >> 4] = "s>=", - [BPF_JSLE >> 4] = "s<=", - [BPF_CALL >> 4] = "call", - [BPF_EXIT >> 4] = "exit", -}; +static int copy_stack_state(struct bpf_verifier_state *dst, + const struct bpf_verifier_state *src) +{ + if (!src->stack) + return 0; + if (WARN_ON_ONCE(dst->allocated_stack < src->allocated_stack)) { + /* internal bug, make state invalid to reject the program */ + memset(dst, 0, sizeof(*dst)); + return -EFAULT; + } + memcpy(dst->stack, src->stack, + sizeof(*src->stack) * (src->allocated_stack / BPF_REG_SIZE)); + return 0; +} -static void print_bpf_insn(const struct bpf_verifier_env *env, - const struct bpf_insn *insn) +/* do_check() starts with zero-sized stack in struct bpf_verifier_state to + * make it consume minimal amount of memory. check_stack_write() access from + * the program calls into realloc_verifier_state() to grow the stack size. + * Note there is a non-zero 'parent' pointer inside bpf_verifier_state + * which this function copies over. It points to previous bpf_verifier_state + * which is never reallocated + */ +static int realloc_verifier_state(struct bpf_verifier_state *state, int size, + bool copy_old) { - u8 class = BPF_CLASS(insn->code); - - if (class == BPF_ALU || class == BPF_ALU64) { - if (BPF_SRC(insn->code) == BPF_X) - verbose("(%02x) %sr%d %s %sr%d\n", - insn->code, class == BPF_ALU ? "(u32) " : "", - insn->dst_reg, - bpf_alu_string[BPF_OP(insn->code) >> 4], - class == BPF_ALU ? "(u32) " : "", - insn->src_reg); - else - verbose("(%02x) %sr%d %s %s%d\n", - insn->code, class == BPF_ALU ? "(u32) " : "", - insn->dst_reg, - bpf_alu_string[BPF_OP(insn->code) >> 4], - class == BPF_ALU ? "(u32) " : "", - insn->imm); - } else if (class == BPF_STX) { - if (BPF_MODE(insn->code) == BPF_MEM) - verbose("(%02x) *(%s *)(r%d %+d) = r%d\n", - insn->code, - bpf_ldst_string[BPF_SIZE(insn->code) >> 3], - insn->dst_reg, - insn->off, insn->src_reg); - else if (BPF_MODE(insn->code) == BPF_XADD) - verbose("(%02x) lock *(%s *)(r%d %+d) += r%d\n", - insn->code, - bpf_ldst_string[BPF_SIZE(insn->code) >> 3], - insn->dst_reg, insn->off, - insn->src_reg); - else - verbose("BUG_%02x\n", insn->code); - } else if (class == BPF_ST) { - if (BPF_MODE(insn->code) != BPF_MEM) { - verbose("BUG_st_%02x\n", insn->code); - return; - } - verbose("(%02x) *(%s *)(r%d %+d) = %d\n", - insn->code, - bpf_ldst_string[BPF_SIZE(insn->code) >> 3], - insn->dst_reg, - insn->off, insn->imm); - } else if (class == BPF_LDX) { - if (BPF_MODE(insn->code) != BPF_MEM) { - verbose("BUG_ldx_%02x\n", insn->code); - return; + u32 old_size = state->allocated_stack; + struct bpf_stack_state *new_stack; + int slot = size / BPF_REG_SIZE; + + if (size <= old_size || !size) { + if (copy_old) + return 0; + state->allocated_stack = slot * BPF_REG_SIZE; + if (!size && old_size) { + kfree(state->stack); + state->stack = NULL; } - verbose("(%02x) r%d = *(%s *)(r%d %+d)\n", - insn->code, insn->dst_reg, - bpf_ldst_string[BPF_SIZE(insn->code) >> 3], - insn->src_reg, insn->off); - } else if (class == BPF_LD) { - if (BPF_MODE(insn->code) == BPF_ABS) { - verbose("(%02x) r0 = *(%s *)skb[%d]\n", - insn->code, - bpf_ldst_string[BPF_SIZE(insn->code) >> 3], - insn->imm); - } else if (BPF_MODE(insn->code) == BPF_IND) { - verbose("(%02x) r0 = *(%s *)skb[r%d + %d]\n", - insn->code, - bpf_ldst_string[BPF_SIZE(insn->code) >> 3], - insn->src_reg, insn->imm); - } else if (BPF_MODE(insn->code) == BPF_IMM && - BPF_SIZE(insn->code) == BPF_DW) { - /* At this point, we already made sure that the second - * part of the ldimm64 insn is accessible. - */ - u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm; - bool map_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD; + return 0; + } + new_stack = kmalloc_array(slot, sizeof(struct bpf_stack_state), + GFP_KERNEL); + if (!new_stack) + return -ENOMEM; + if (copy_old) { + if (state->stack) + memcpy(new_stack, state->stack, + sizeof(*new_stack) * (old_size / BPF_REG_SIZE)); + memset(new_stack + old_size / BPF_REG_SIZE, 0, + sizeof(*new_stack) * (size - old_size) / BPF_REG_SIZE); + } + state->allocated_stack = slot * BPF_REG_SIZE; + kfree(state->stack); + state->stack = new_stack; + return 0; +} - if (map_ptr && !env->allow_ptr_leaks) - imm = 0; +static void free_verifier_state(struct bpf_verifier_state *state, + bool free_self) +{ + kfree(state->stack); + if (free_self) + kfree(state); +} - verbose("(%02x) r%d = 0x%llx\n", insn->code, - insn->dst_reg, (unsigned long long)imm); - } else { - verbose("BUG_ld_%02x\n", insn->code); - return; - } - } else if (class == BPF_JMP) { - u8 opcode = BPF_OP(insn->code); +/* copy verifier state from src to dst growing dst stack space + * when necessary to accommodate larger src stack + */ +static int copy_verifier_state(struct bpf_verifier_state *dst, + const struct bpf_verifier_state *src) +{ + int err; - if (opcode == BPF_CALL) { - verbose("(%02x) call %s#%d\n", insn->code, - func_id_name(insn->imm), insn->imm); - } else if (insn->code == (BPF_JMP | BPF_JA)) { - verbose("(%02x) goto pc%+d\n", - insn->code, insn->off); - } else if (insn->code == (BPF_JMP | BPF_EXIT)) { - verbose("(%02x) exit\n", insn->code); - } else if (BPF_SRC(insn->code) == BPF_X) { - verbose("(%02x) if r%d %s r%d goto pc%+d\n", - insn->code, insn->dst_reg, - bpf_jmp_string[BPF_OP(insn->code) >> 4], - insn->src_reg, insn->off); - } else { - verbose("(%02x) if r%d %s 0x%x goto pc%+d\n", - insn->code, insn->dst_reg, - bpf_jmp_string[BPF_OP(insn->code) >> 4], - insn->imm, insn->off); - } - } else { - verbose("(%02x) %s\n", insn->code, bpf_class_string[class]); - } + err = realloc_verifier_state(dst, src->allocated_stack, false); + if (err) + return err; + memcpy(dst, src, offsetof(struct bpf_verifier_state, allocated_stack)); + return copy_stack_state(dst, src); } -static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx) +static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx, + int *insn_idx) { - struct bpf_verifier_stack_elem *elem; - int insn_idx; + struct bpf_verifier_state *cur = env->cur_state; + struct bpf_verifier_stack_elem *elem, *head = env->head; + int err; if (env->head == NULL) - return -1; + return -ENOENT; - memcpy(&env->cur_state, &env->head->st, sizeof(env->cur_state)); - insn_idx = env->head->insn_idx; + if (cur) { + err = copy_verifier_state(cur, &head->st); + if (err) + return err; + } + if (insn_idx) + *insn_idx = head->insn_idx; if (prev_insn_idx) - *prev_insn_idx = env->head->prev_insn_idx; - elem = env->head->next; - kfree(env->head); + *prev_insn_idx = head->prev_insn_idx; + elem = head->next; + free_verifier_state(&head->st, false); + kfree(head); env->head = elem; env->stack_size--; - return insn_idx; + return 0; } static struct bpf_verifier_state *push_stack(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx) { + struct bpf_verifier_state *cur = env->cur_state; struct bpf_verifier_stack_elem *elem; + int err; - elem = kmalloc(sizeof(struct bpf_verifier_stack_elem), GFP_KERNEL); + elem = kzalloc(sizeof(struct bpf_verifier_stack_elem), GFP_KERNEL); if (!elem) goto err; - memcpy(&elem->st, &env->cur_state, sizeof(env->cur_state)); elem->insn_idx = insn_idx; elem->prev_insn_idx = prev_insn_idx; elem->next = env->head; env->head = elem; env->stack_size++; + err = copy_verifier_state(&elem->st, cur); + if (err) + goto err; if (env->stack_size > BPF_COMPLEXITY_LIMIT_STACK) { - verbose("BPF program is too complex\n"); + verbose(env, "BPF program is too complex\n"); goto err; } return &elem->st; err: /* pop all elements and return */ - while (pop_stack(env, NULL) >= 0); + while (!pop_stack(env, NULL, NULL)); return NULL; } @@ -507,10 +449,11 @@ static void __mark_reg_known_zero(struct bpf_reg_state *reg) __mark_reg_known(reg, 0); } -static void mark_reg_known_zero(struct bpf_reg_state *regs, u32 regno) +static void mark_reg_known_zero(struct bpf_verifier_env *env, + struct bpf_reg_state *regs, u32 regno) { if (WARN_ON(regno >= MAX_BPF_REG)) { - verbose("mark_reg_known_zero(regs, %u)\n", regno); + verbose(env, "mark_reg_known_zero(regs, %u)\n", regno); /* Something bad happened, let's kill all regs */ for (regno = 0; regno < MAX_BPF_REG; regno++) __mark_reg_not_init(regs + regno); @@ -519,6 +462,31 @@ static void mark_reg_known_zero(struct bpf_reg_state *regs, u32 regno) __mark_reg_known_zero(regs + regno); } +static bool reg_is_pkt_pointer(const struct bpf_reg_state *reg) +{ + return type_is_pkt_pointer(reg->type); +} + +static bool reg_is_pkt_pointer_any(const struct bpf_reg_state *reg) +{ + return reg_is_pkt_pointer(reg) || + reg->type == PTR_TO_PACKET_END; +} + +/* Unmodified PTR_TO_PACKET[_META,_END] register from ctx access. */ +static bool reg_is_init_pkt_pointer(const struct bpf_reg_state *reg, + enum bpf_reg_type which) +{ + /* The register can already have a range from prior markings. + * This is fine as long as it hasn't been advanced from its + * origin. + */ + return reg->type == which && + reg->id == 0 && + reg->off == 0 && + tnum_equals_const(reg->var_off, 0); +} + /* Attempts to improve min/max values based on var_off information */ static void __update_reg_bounds(struct bpf_reg_state *reg) { @@ -595,10 +563,11 @@ static void __mark_reg_unknown(struct bpf_reg_state *reg) __mark_reg_unbounded(reg); } -static void mark_reg_unknown(struct bpf_reg_state *regs, u32 regno) +static void mark_reg_unknown(struct bpf_verifier_env *env, + struct bpf_reg_state *regs, u32 regno) { if (WARN_ON(regno >= MAX_BPF_REG)) { - verbose("mark_reg_unknown(regs, %u)\n", regno); + verbose(env, "mark_reg_unknown(regs, %u)\n", regno); /* Something bad happened, let's kill all regs */ for (regno = 0; regno < MAX_BPF_REG; regno++) __mark_reg_not_init(regs + regno); @@ -613,10 +582,11 @@ static void __mark_reg_not_init(struct bpf_reg_state *reg) reg->type = NOT_INIT; } -static void mark_reg_not_init(struct bpf_reg_state *regs, u32 regno) +static void mark_reg_not_init(struct bpf_verifier_env *env, + struct bpf_reg_state *regs, u32 regno) { if (WARN_ON(regno >= MAX_BPF_REG)) { - verbose("mark_reg_not_init(regs, %u)\n", regno); + verbose(env, "mark_reg_not_init(regs, %u)\n", regno); /* Something bad happened, let's kill all regs */ for (regno = 0; regno < MAX_BPF_REG; regno++) __mark_reg_not_init(regs + regno); @@ -625,22 +595,23 @@ static void mark_reg_not_init(struct bpf_reg_state *regs, u32 regno) __mark_reg_not_init(regs + regno); } -static void init_reg_state(struct bpf_reg_state *regs) +static void init_reg_state(struct bpf_verifier_env *env, + struct bpf_reg_state *regs) { int i; for (i = 0; i < MAX_BPF_REG; i++) { - mark_reg_not_init(regs, i); + mark_reg_not_init(env, regs, i); regs[i].live = REG_LIVE_NONE; } /* frame pointer */ regs[BPF_REG_FP].type = PTR_TO_STACK; - mark_reg_known_zero(regs, BPF_REG_FP); + mark_reg_known_zero(env, regs, BPF_REG_FP); /* 1st arg to a function */ regs[BPF_REG_1].type = PTR_TO_CTX; - mark_reg_known_zero(regs, BPF_REG_1); + mark_reg_known_zero(env, regs, BPF_REG_1); } enum reg_arg_type { @@ -671,29 +642,29 @@ static void mark_reg_read(const struct bpf_verifier_state *state, u32 regno) static int check_reg_arg(struct bpf_verifier_env *env, u32 regno, enum reg_arg_type t) { - struct bpf_reg_state *regs = env->cur_state.regs; + struct bpf_reg_state *regs = env->cur_state->regs; if (regno >= MAX_BPF_REG) { - verbose("R%d is invalid\n", regno); + verbose(env, "R%d is invalid\n", regno); return -EINVAL; } if (t == SRC_OP) { /* check whether register used as source operand can be read */ if (regs[regno].type == NOT_INIT) { - verbose("R%d !read_ok\n", regno); + verbose(env, "R%d !read_ok\n", regno); return -EACCES; } - mark_reg_read(&env->cur_state, regno); + mark_reg_read(env->cur_state, regno); } else { /* check whether register used as dest operand can be written to */ if (regno == BPF_REG_FP) { - verbose("frame pointer is read only\n"); + verbose(env, "frame pointer is read only\n"); return -EACCES; } regs[regno].live |= REG_LIVE_WRITTEN; if (t == DST_OP) - mark_reg_unknown(regs, regno); + mark_reg_unknown(env, regs, regno); } return 0; } @@ -706,6 +677,7 @@ static bool is_spillable_regtype(enum bpf_reg_type type) case PTR_TO_STACK: case PTR_TO_CTX: case PTR_TO_PACKET: + case PTR_TO_PACKET_META: case PTR_TO_PACKET_END: case CONST_PTR_TO_MAP: return true; @@ -717,35 +689,48 @@ static bool is_spillable_regtype(enum bpf_reg_type type) /* check_stack_read/write functions track spill/fill of registers, * stack boundary and alignment are checked in check_mem_access() */ -static int check_stack_write(struct bpf_verifier_state *state, int off, +static int check_stack_write(struct bpf_verifier_env *env, + struct bpf_verifier_state *state, int off, int size, int value_regno) { - int i, spi = (MAX_BPF_STACK + off) / BPF_REG_SIZE; + int i, slot = -off - 1, spi = slot / BPF_REG_SIZE, err; + + err = realloc_verifier_state(state, round_up(slot + 1, BPF_REG_SIZE), + true); + if (err) + return err; /* caller checked that off % size == 0 and -MAX_BPF_STACK <= off < 0, * so it's aligned access and [off, off + size) are within stack limits */ + if (!env->allow_ptr_leaks && + state->stack[spi].slot_type[0] == STACK_SPILL && + size != BPF_REG_SIZE) { + verbose(env, "attempt to corrupt spilled pointer on stack\n"); + return -EACCES; + } if (value_regno >= 0 && is_spillable_regtype(state->regs[value_regno].type)) { /* register containing pointer is being spilled into stack */ if (size != BPF_REG_SIZE) { - verbose("invalid size of register spill\n"); + verbose(env, "invalid size of register spill\n"); return -EACCES; } /* save register state */ - state->spilled_regs[spi] = state->regs[value_regno]; - state->spilled_regs[spi].live |= REG_LIVE_WRITTEN; + state->stack[spi].spilled_ptr = state->regs[value_regno]; + state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN; for (i = 0; i < BPF_REG_SIZE; i++) - state->stack_slot_type[MAX_BPF_STACK + off + i] = STACK_SPILL; + state->stack[spi].slot_type[i] = STACK_SPILL; } else { /* regular write of data into stack */ - state->spilled_regs[spi] = (struct bpf_reg_state) {}; + state->stack[spi].spilled_ptr = (struct bpf_reg_state) {}; for (i = 0; i < size; i++) - state->stack_slot_type[MAX_BPF_STACK + off + i] = STACK_MISC; + state->stack[spi].slot_type[(slot - i) % BPF_REG_SIZE] = + STACK_MISC; } return 0; } @@ -756,66 +741,72 @@ static void mark_stack_slot_read(const struct bpf_verifier_state *state, int slo while (parent) { /* if read wasn't screened by an earlier write ... */ - if (state->spilled_regs[slot].live & REG_LIVE_WRITTEN) + if (state->stack[slot].spilled_ptr.live & REG_LIVE_WRITTEN) break; /* ... then we depend on parent's value */ - parent->spilled_regs[slot].live |= REG_LIVE_READ; + parent->stack[slot].spilled_ptr.live |= REG_LIVE_READ; state = parent; parent = state->parent; } } -static int check_stack_read(struct bpf_verifier_state *state, int off, int size, +static int check_stack_read(struct bpf_verifier_env *env, + struct bpf_verifier_state *state, int off, int size, int value_regno) { - u8 *slot_type; - int i, spi; + int i, slot = -off - 1, spi = slot / BPF_REG_SIZE; + u8 *stype; - slot_type = &state->stack_slot_type[MAX_BPF_STACK + off]; + if (state->allocated_stack <= slot) { + verbose(env, "invalid read from stack off %d+0 size %d\n", + off, size); + return -EACCES; + } + stype = state->stack[spi].slot_type; - if (slot_type[0] == STACK_SPILL) { + if (stype[0] == STACK_SPILL) { if (size != BPF_REG_SIZE) { - verbose("invalid size of register spill\n"); + verbose(env, "invalid size of register spill\n"); return -EACCES; } for (i = 1; i < BPF_REG_SIZE; i++) { - if (slot_type[i] != STACK_SPILL) { - verbose("corrupted spill memory\n"); + if (stype[(slot - i) % BPF_REG_SIZE] != STACK_SPILL) { + verbose(env, "corrupted spill memory\n"); return -EACCES; } } - spi = (MAX_BPF_STACK + off) / BPF_REG_SIZE; - if (value_regno >= 0) { /* restore register state from stack */ - state->regs[value_regno] = state->spilled_regs[spi]; + state->regs[value_regno] = state->stack[spi].spilled_ptr; mark_stack_slot_read(state, spi); } return 0; } else { for (i = 0; i < size; i++) { - if (slot_type[i] != STACK_MISC) { - verbose("invalid read from stack off %d+%d size %d\n", + if (stype[(slot - i) % BPF_REG_SIZE] != STACK_MISC) { + verbose(env, "invalid read from stack off %d+%d size %d\n", off, i, size); return -EACCES; } } if (value_regno >= 0) /* have read misc data from the stack */ - mark_reg_unknown(state->regs, value_regno); + mark_reg_unknown(env, state->regs, value_regno); return 0; } } /* check read/write into map element returned by bpf_map_lookup_elem() */ static int __check_map_access(struct bpf_verifier_env *env, u32 regno, int off, - int size) + int size, bool zero_size_allowed) { - struct bpf_map *map = env->cur_state.regs[regno].map_ptr; + struct bpf_reg_state *regs = cur_regs(env); + struct bpf_map *map = regs[regno].map_ptr; - if (off < 0 || size <= 0 || off + size > map->value_size) { - verbose("invalid access to map value, value_size=%d off=%d size=%d\n", + if (off < 0 || size < 0 || (size == 0 && !zero_size_allowed) || + off + size > map->value_size) { + verbose(env, "invalid access to map value, value_size=%d off=%d size=%d\n", map->value_size, off, size); return -EACCES; } @@ -824,9 +815,9 @@ static int __check_map_access(struct bpf_verifier_env *env, u32 regno, int off, /* check read/write into a map element with possible variable offset */ static int check_map_access(struct bpf_verifier_env *env, u32 regno, - int off, int size) + int off, int size, bool zero_size_allowed) { - struct bpf_verifier_state *state = &env->cur_state; + struct bpf_verifier_state *state = env->cur_state; struct bpf_reg_state *reg = &state->regs[regno]; int err; @@ -834,8 +825,8 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno, * need to try adding each of min_value and max_value to off * to make sure our theoretical access will be safe. */ - if (log_level) - print_verifier_state(state); + if (env->log.level) + print_verifier_state(env, state); /* The minimum value is only important with signed * comparisons where we can't assume the floor of a * value is 0. If we are using signed variables for our @@ -843,13 +834,15 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno, * will have a set floor within our range. */ if (reg->smin_value < 0) { - verbose("R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n", + verbose(env, "R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n", regno); return -EACCES; } - err = __check_map_access(env, regno, reg->smin_value + off, size); + err = __check_map_access(env, regno, reg->smin_value + off, size, + zero_size_allowed); if (err) { - verbose("R%d min value is outside of the array range\n", regno); + verbose(env, "R%d min value is outside of the array range\n", + regno); return err; } @@ -858,13 +851,15 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno, * If reg->umax_value + off could overflow, treat that as unbounded too. */ if (reg->umax_value >= BPF_MAX_VAR_OFF) { - verbose("R%d unbounded memory access, make sure to bounds check any array access into a map\n", + verbose(env, "R%d unbounded memory access, make sure to bounds check any array access into a map\n", regno); return -EACCES; } - err = __check_map_access(env, regno, reg->umax_value + off, size); + err = __check_map_access(env, regno, reg->umax_value + off, size, + zero_size_allowed); if (err) - verbose("R%d max value is outside of the array range\n", regno); + verbose(env, "R%d max value is outside of the array range\n", + regno); return err; } @@ -897,13 +892,14 @@ static bool may_access_direct_pkt_data(struct bpf_verifier_env *env, } static int __check_packet_access(struct bpf_verifier_env *env, u32 regno, - int off, int size) + int off, int size, bool zero_size_allowed) { - struct bpf_reg_state *regs = env->cur_state.regs; + struct bpf_reg_state *regs = cur_regs(env); struct bpf_reg_state *reg = ®s[regno]; - if (off < 0 || size <= 0 || (u64)off + size > reg->range) { - verbose("invalid access to packet, off=%d size=%d, R%d(id=%d,off=%d,r=%d)\n", + if (off < 0 || size < 0 || (size == 0 && !zero_size_allowed) || + (u64)off + size > reg->range) { + verbose(env, "invalid access to packet, off=%d size=%d, R%d(id=%d,off=%d,r=%d)\n", off, size, regno, reg->id, reg->off, reg->range); return -EACCES; } @@ -911,9 +907,9 @@ static int __check_packet_access(struct bpf_verifier_env *env, u32 regno, } static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off, - int size) + int size, bool zero_size_allowed) { - struct bpf_reg_state *regs = env->cur_state.regs; + struct bpf_reg_state *regs = cur_regs(env); struct bpf_reg_state *reg = ®s[regno]; int err; @@ -926,13 +922,13 @@ static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off, * detail to prove they're safe. */ if (reg->smin_value < 0) { - verbose("R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n", + verbose(env, "R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n", regno); return -EACCES; } - err = __check_packet_access(env, regno, off, size); + err = __check_packet_access(env, regno, off, size, zero_size_allowed); if (err) { - verbose("R%d offset is outside of the packet\n", regno); + verbose(env, "R%d offset is outside of the packet\n", regno); return err; } return err; @@ -946,12 +942,8 @@ static int check_ctx_access(struct bpf_verifier_env *env, int insn_idx, int off, .reg_type = *reg_type, }; - /* for analyzer ctx accesses are already validated and converted */ - if (env->analyzer_ops) - return 0; - - if (env->prog->aux->ops->is_valid_access && - env->prog->aux->ops->is_valid_access(off, size, t, &info)) { + if (env->ops->is_valid_access && + env->ops->is_valid_access(off, size, t, &info)) { /* A non zero info.ctx_field_size indicates that this field is a * candidate for later verifier transformation to load the whole * field and then apply a mask when accessed with a narrower @@ -959,16 +951,16 @@ static int check_ctx_access(struct bpf_verifier_env *env, int insn_idx, int off, * will only allow for whole field access and rejects any other * type of narrower access. */ - env->insn_aux_data[insn_idx].ctx_field_size = info.ctx_field_size; *reg_type = info.reg_type; + env->insn_aux_data[insn_idx].ctx_field_size = info.ctx_field_size; /* remember the offset of last byte accessed in ctx */ if (env->prog->aux->max_ctx_offset < off + size) env->prog->aux->max_ctx_offset = off + size; return 0; } - verbose("invalid bpf_context access off=%d size=%d\n", off, size); + verbose(env, "invalid bpf_context access off=%d size=%d\n", off, size); return -EACCES; } @@ -983,10 +975,11 @@ static bool __is_pointer_value(bool allow_ptr_leaks, static bool is_pointer_value(struct bpf_verifier_env *env, int regno) { - return __is_pointer_value(env->allow_ptr_leaks, &env->cur_state.regs[regno]); + return __is_pointer_value(env->allow_ptr_leaks, cur_regs(env) + regno); } -static int check_pkt_ptr_alignment(const struct bpf_reg_state *reg, +static int check_pkt_ptr_alignment(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, int off, int size, bool strict) { struct tnum reg_off; @@ -1011,7 +1004,8 @@ static int check_pkt_ptr_alignment(const struct bpf_reg_state *reg, char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); - verbose("misaligned packet access off %d+%s+%d+%d size %d\n", + verbose(env, + "misaligned packet access off %d+%s+%d+%d size %d\n", ip_align, tn_buf, reg->off, off, size); return -EACCES; } @@ -1019,7 +1013,8 @@ static int check_pkt_ptr_alignment(const struct bpf_reg_state *reg, return 0; } -static int check_generic_ptr_alignment(const struct bpf_reg_state *reg, +static int check_generic_ptr_alignment(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, const char *pointer_desc, int off, int size, bool strict) { @@ -1034,7 +1029,7 @@ static int check_generic_ptr_alignment(const struct bpf_reg_state *reg, char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); - verbose("misaligned %saccess off %s+%d+%d size %d\n", + verbose(env, "misaligned %saccess off %s+%d+%d size %d\n", pointer_desc, tn_buf, reg->off, off, size); return -EACCES; } @@ -1051,8 +1046,11 @@ static int check_ptr_alignment(struct bpf_verifier_env *env, switch (reg->type) { case PTR_TO_PACKET: - /* special case, because of NET_IP_ALIGN */ - return check_pkt_ptr_alignment(reg, off, size, strict); + case PTR_TO_PACKET_META: + /* Special case, because of NET_IP_ALIGN. Given metadata sits + * right in front, treat it the very same way. + */ + return check_pkt_ptr_alignment(env, reg, off, size, strict); case PTR_TO_MAP_VALUE: pointer_desc = "value "; break; @@ -1065,7 +1063,8 @@ static int check_ptr_alignment(struct bpf_verifier_env *env, default: break; } - return check_generic_ptr_alignment(reg, pointer_desc, off, size, strict); + return check_generic_ptr_alignment(env, reg, pointer_desc, off, size, + strict); } /* check whether memory at (regno + off) is accessible for t = (read | write) @@ -1078,8 +1077,9 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn int bpf_size, enum bpf_access_type t, int value_regno) { - struct bpf_verifier_state *state = &env->cur_state; - struct bpf_reg_state *reg = &state->regs[regno]; + struct bpf_verifier_state *state = env->cur_state; + struct bpf_reg_state *regs = cur_regs(env); + struct bpf_reg_state *reg = regs + regno; int size, err = 0; size = bpf_size_to_bytes(bpf_size); @@ -1097,27 +1097,28 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn if (reg->type == PTR_TO_MAP_VALUE) { if (t == BPF_WRITE && value_regno >= 0 && is_pointer_value(env, value_regno)) { - verbose("R%d leaks addr into map\n", value_regno); + verbose(env, "R%d leaks addr into map\n", value_regno); return -EACCES; } - err = check_map_access(env, regno, off, size); + err = check_map_access(env, regno, off, size, false); if (!err && t == BPF_READ && value_regno >= 0) - mark_reg_unknown(state->regs, value_regno); + mark_reg_unknown(env, regs, value_regno); } else if (reg->type == PTR_TO_CTX) { enum bpf_reg_type reg_type = SCALAR_VALUE; if (t == BPF_WRITE && value_regno >= 0 && is_pointer_value(env, value_regno)) { - verbose("R%d leaks addr into ctx\n", value_regno); + verbose(env, "R%d leaks addr into ctx\n", value_regno); return -EACCES; } /* ctx accesses must be at a fixed offset, so that we can * determine what type of data were returned. */ if (reg->off) { - verbose("dereference of modified ctx ptr R%d off=%d+%d, ctx+const is allowed, ctx+const+const is not\n", + verbose(env, + "dereference of modified ctx ptr R%d off=%d+%d, ctx+const is allowed, ctx+const+const is not\n", regno, reg->off, off - reg->off); return -EACCES; } @@ -1125,24 +1126,26 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); - verbose("variable ctx access var_off=%s off=%d size=%d", + verbose(env, + "variable ctx access var_off=%s off=%d size=%d", tn_buf, off, size); return -EACCES; } err = check_ctx_access(env, insn_idx, off, size, t, ®_type); if (!err && t == BPF_READ && value_regno >= 0) { /* ctx access returns either a scalar, or a - * PTR_TO_PACKET[_END]. In the latter case, we know - * the offset is zero. + * PTR_TO_PACKET[_META,_END]. In the latter + * case, we know the offset is zero. */ if (reg_type == SCALAR_VALUE) - mark_reg_unknown(state->regs, value_regno); + mark_reg_unknown(env, regs, value_regno); else - mark_reg_known_zero(state->regs, value_regno); - state->regs[value_regno].id = 0; - state->regs[value_regno].off = 0; - state->regs[value_regno].range = 0; - state->regs[value_regno].type = reg_type; + mark_reg_known_zero(env, regs, + value_regno); + regs[value_regno].id = 0; + regs[value_regno].off = 0; + regs[value_regno].range = 0; + regs[value_regno].type = reg_type; } } else if (reg->type == PTR_TO_STACK) { @@ -1154,55 +1157,52 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); - verbose("variable stack access var_off=%s off=%d size=%d", + verbose(env, "variable stack access var_off=%s off=%d size=%d", tn_buf, off, size); return -EACCES; } off += reg->var_off.value; if (off >= 0 || off < -MAX_BPF_STACK) { - verbose("invalid stack off=%d size=%d\n", off, size); + verbose(env, "invalid stack off=%d size=%d\n", off, + size); return -EACCES; } if (env->prog->aux->stack_depth < -off) env->prog->aux->stack_depth = -off; - if (t == BPF_WRITE) { - if (!env->allow_ptr_leaks && - state->stack_slot_type[MAX_BPF_STACK + off] == STACK_SPILL && - size != BPF_REG_SIZE) { - verbose("attempt to corrupt spilled pointer on stack\n"); - return -EACCES; - } - err = check_stack_write(state, off, size, value_regno); - } else { - err = check_stack_read(state, off, size, value_regno); - } - } else if (reg->type == PTR_TO_PACKET) { + if (t == BPF_WRITE) + err = check_stack_write(env, state, off, size, + value_regno); + else + err = check_stack_read(env, state, off, size, + value_regno); + } else if (reg_is_pkt_pointer(reg)) { if (t == BPF_WRITE && !may_access_direct_pkt_data(env, NULL, t)) { - verbose("cannot write into packet\n"); + verbose(env, "cannot write into packet\n"); return -EACCES; } if (t == BPF_WRITE && value_regno >= 0 && is_pointer_value(env, value_regno)) { - verbose("R%d leaks addr into packet\n", value_regno); + verbose(env, "R%d leaks addr into packet\n", + value_regno); return -EACCES; } - err = check_packet_access(env, regno, off, size); + err = check_packet_access(env, regno, off, size, false); if (!err && t == BPF_READ && value_regno >= 0) - mark_reg_unknown(state->regs, value_regno); + mark_reg_unknown(env, regs, value_regno); } else { - verbose("R%d invalid mem access '%s'\n", - regno, reg_type_str[reg->type]); + verbose(env, "R%d invalid mem access '%s'\n", regno, + reg_type_str[reg->type]); return -EACCES; } if (!err && size < BPF_REG_SIZE && value_regno >= 0 && t == BPF_READ && - state->regs[value_regno].type == SCALAR_VALUE) { + regs[value_regno].type == SCALAR_VALUE) { /* b/h/w load zero-extends, mark upper bits as known 0 */ - state->regs[value_regno].var_off = tnum_cast( - state->regs[value_regno].var_off, size); - __update_reg_bounds(&state->regs[value_regno]); + regs[value_regno].var_off = + tnum_cast(regs[value_regno].var_off, size); + __update_reg_bounds(®s[value_regno]); } return err; } @@ -1213,7 +1213,7 @@ static int check_xadd(struct bpf_verifier_env *env, int insn_idx, struct bpf_ins if ((BPF_SIZE(insn->code) != BPF_W && BPF_SIZE(insn->code) != BPF_DW) || insn->imm != 0) { - verbose("BPF_XADD uses reserved fields\n"); + verbose(env, "BPF_XADD uses reserved fields\n"); return -EINVAL; } @@ -1228,7 +1228,7 @@ static int check_xadd(struct bpf_verifier_env *env, int insn_idx, struct bpf_ins return err; if (is_pointer_value(env, insn->src_reg)) { - verbose("R%d leaks addr into mem\n", insn->src_reg); + verbose(env, "R%d leaks addr into mem\n", insn->src_reg); return -EACCES; } @@ -1259,9 +1259,9 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno, int access_size, bool zero_size_allowed, struct bpf_call_arg_meta *meta) { - struct bpf_verifier_state *state = &env->cur_state; + struct bpf_verifier_state *state = env->cur_state; struct bpf_reg_state *regs = state->regs; - int off, i; + int off, i, slot, spi; if (regs[regno].type != PTR_TO_STACK) { /* Allow zero-byte read from NULL, regardless of pointer type */ @@ -1269,7 +1269,7 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno, register_is_null(regs[regno])) return 0; - verbose("R%d type=%s expected=%s\n", regno, + verbose(env, "R%d type=%s expected=%s\n", regno, reg_type_str[regs[regno].type], reg_type_str[PTR_TO_STACK]); return -EACCES; @@ -1280,13 +1280,13 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno, char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), regs[regno].var_off); - verbose("invalid variable stack read R%d var_off=%s\n", + verbose(env, "invalid variable stack read R%d var_off=%s\n", regno, tn_buf); } off = regs[regno].off + regs[regno].var_off.value; if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 || - access_size <= 0) { - verbose("invalid stack type R%d off=%d access_size=%d\n", + access_size < 0 || (access_size == 0 && !zero_size_allowed)) { + verbose(env, "invalid stack type R%d off=%d access_size=%d\n", regno, off, access_size); return -EACCES; } @@ -1301,8 +1301,12 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno, } for (i = 0; i < access_size; i++) { - if (state->stack_slot_type[MAX_BPF_STACK + off + i] != STACK_MISC) { - verbose("invalid indirect read from stack off %d+%d size %d\n", + slot = -(off + i) - 1; + spi = slot / BPF_REG_SIZE; + if (state->allocated_stack <= slot || + state->stack[spi].slot_type[slot % BPF_REG_SIZE] != + STACK_MISC) { + verbose(env, "invalid indirect read from stack off %d+%d size %d\n", off, i, access_size); return -EACCES; } @@ -1314,13 +1318,16 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, int access_size, bool zero_size_allowed, struct bpf_call_arg_meta *meta) { - struct bpf_reg_state *regs = env->cur_state.regs, *reg = ®s[regno]; + struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; switch (reg->type) { case PTR_TO_PACKET: - return check_packet_access(env, regno, reg->off, access_size); + case PTR_TO_PACKET_META: + return check_packet_access(env, regno, reg->off, access_size, + zero_size_allowed); case PTR_TO_MAP_VALUE: - return check_map_access(env, regno, reg->off, access_size); + return check_map_access(env, regno, reg->off, access_size, + zero_size_allowed); default: /* scalar_value|ptr_to_stack or invalid ptr */ return check_stack_boundary(env, regno, access_size, zero_size_allowed, meta); @@ -1331,7 +1338,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, enum bpf_arg_type arg_type, struct bpf_call_arg_meta *meta) { - struct bpf_reg_state *regs = env->cur_state.regs, *reg = ®s[regno]; + struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; enum bpf_reg_type expected_type, type = reg->type; int err = 0; @@ -1344,22 +1351,24 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, if (arg_type == ARG_ANYTHING) { if (is_pointer_value(env, regno)) { - verbose("R%d leaks addr into helper function\n", regno); + verbose(env, "R%d leaks addr into helper function\n", + regno); return -EACCES; } return 0; } - if (type == PTR_TO_PACKET && + if (type_is_pkt_pointer(type) && !may_access_direct_pkt_data(env, meta, BPF_READ)) { - verbose("helper access to the packet is not allowed\n"); + verbose(env, "helper access to the packet is not allowed\n"); return -EACCES; } if (arg_type == ARG_PTR_TO_MAP_KEY || arg_type == ARG_PTR_TO_MAP_VALUE) { expected_type = PTR_TO_STACK; - if (type != PTR_TO_PACKET && type != expected_type) + if (!type_is_pkt_pointer(type) && + type != expected_type) goto err_type; } else if (arg_type == ARG_CONST_SIZE || arg_type == ARG_CONST_SIZE_OR_ZERO) { @@ -1383,12 +1392,13 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, */ if (register_is_null(*reg)) /* final test in check_stack_boundary() */; - else if (type != PTR_TO_PACKET && type != PTR_TO_MAP_VALUE && + else if (!type_is_pkt_pointer(type) && + type != PTR_TO_MAP_VALUE && type != expected_type) goto err_type; meta->raw_mode = arg_type == ARG_PTR_TO_UNINIT_MEM; } else { - verbose("unsupported arg_type %d\n", arg_type); + verbose(env, "unsupported arg_type %d\n", arg_type); return -EFAULT; } @@ -1406,12 +1416,13 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, * we have to check map_key here. Otherwise it means * that kernel subsystem misconfigured verifier */ - verbose("invalid map_ptr to access map->key\n"); + verbose(env, "invalid map_ptr to access map->key\n"); return -EACCES; } - if (type == PTR_TO_PACKET) + if (type_is_pkt_pointer(type)) err = check_packet_access(env, regno, reg->off, - meta->map_ptr->key_size); + meta->map_ptr->key_size, + false); else err = check_stack_boundary(env, regno, meta->map_ptr->key_size, @@ -1422,12 +1433,13 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, */ if (!meta->map_ptr) { /* kernel subsystem misconfigured verifier */ - verbose("invalid map_ptr to access map->value\n"); + verbose(env, "invalid map_ptr to access map->value\n"); return -EACCES; } - if (type == PTR_TO_PACKET) + if (type_is_pkt_pointer(type)) err = check_packet_access(env, regno, reg->off, - meta->map_ptr->value_size); + meta->map_ptr->value_size, + false); else err = check_stack_boundary(env, regno, meta->map_ptr->value_size, @@ -1442,7 +1454,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, */ if (regno == 0) { /* kernel subsystem misconfigured verifier */ - verbose("ARG_CONST_SIZE cannot be first argument\n"); + verbose(env, + "ARG_CONST_SIZE cannot be first argument\n"); return -EACCES; } @@ -1459,7 +1472,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, meta = NULL; if (reg->smin_value < 0) { - verbose("R%d min value is negative, either use unsigned or 'var &= const'\n", + verbose(env, "R%d min value is negative, either use unsigned or 'var &= const'\n", regno); return -EACCES; } @@ -1473,7 +1486,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, } if (reg->umax_value >= BPF_MAX_VAR_SIZ) { - verbose("R%d unbounded memory access, use 'var &= const' or 'if (var < const)'\n", + verbose(env, "R%d unbounded memory access, use 'var &= const' or 'if (var < const)'\n", regno); return -EACCES; } @@ -1484,12 +1497,13 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, return err; err_type: - verbose("R%d type=%s expected=%s\n", regno, + verbose(env, "R%d type=%s expected=%s\n", regno, reg_type_str[type], reg_type_str[expected_type]); return -EACCES; } -static int check_map_func_compatibility(struct bpf_map *map, int func_id) +static int check_map_func_compatibility(struct bpf_verifier_env *env, + struct bpf_map *map, int func_id) { if (!map) return 0; @@ -1502,7 +1516,8 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id) break; case BPF_MAP_TYPE_PERF_EVENT_ARRAY: if (func_id != BPF_FUNC_perf_event_read && - func_id != BPF_FUNC_perf_event_output) + func_id != BPF_FUNC_perf_event_output && + func_id != BPF_FUNC_perf_event_read_value) goto error; break; case BPF_MAP_TYPE_STACK_TRACE: @@ -1522,6 +1537,11 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id) if (func_id != BPF_FUNC_redirect_map) goto error; break; + /* Restrict bpf side of cpumap, open when use-cases appear */ + case BPF_MAP_TYPE_CPUMAP: + if (func_id != BPF_FUNC_redirect_map) + goto error; + break; case BPF_MAP_TYPE_ARRAY_OF_MAPS: case BPF_MAP_TYPE_HASH_OF_MAPS: if (func_id != BPF_FUNC_map_lookup_elem) @@ -1545,6 +1565,7 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id) break; case BPF_FUNC_perf_event_read: case BPF_FUNC_perf_event_output: + case BPF_FUNC_perf_event_read_value: if (map->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) goto error; break; @@ -1558,7 +1579,8 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id) goto error; break; case BPF_FUNC_redirect_map: - if (map->map_type != BPF_MAP_TYPE_DEVMAP) + if (map->map_type != BPF_MAP_TYPE_DEVMAP && + map->map_type != BPF_MAP_TYPE_CPUMAP) goto error; break; case BPF_FUNC_sk_redirect_map: @@ -1575,7 +1597,7 @@ static int check_map_func_compatibility(struct bpf_map *map, int func_id) return 0; error: - verbose("cannot pass map_type %d into func %s#%d\n", + verbose(env, "cannot pass map_type %d into func %s#%d\n", map->map_type, func_id_name(func_id), func_id); return -EINVAL; } @@ -1598,57 +1620,55 @@ static int check_raw_mode(const struct bpf_func_proto *fn) return count > 1 ? -EINVAL : 0; } -/* Packet data might have moved, any old PTR_TO_PACKET[_END] are now invalid, - * so turn them into unknown SCALAR_VALUE. +/* Packet data might have moved, any old PTR_TO_PACKET[_META,_END] + * are now invalid, so turn them into unknown SCALAR_VALUE. */ static void clear_all_pkt_pointers(struct bpf_verifier_env *env) { - struct bpf_verifier_state *state = &env->cur_state; + struct bpf_verifier_state *state = env->cur_state; struct bpf_reg_state *regs = state->regs, *reg; int i; for (i = 0; i < MAX_BPF_REG; i++) - if (regs[i].type == PTR_TO_PACKET || - regs[i].type == PTR_TO_PACKET_END) - mark_reg_unknown(regs, i); + if (reg_is_pkt_pointer_any(®s[i])) + mark_reg_unknown(env, regs, i); - for (i = 0; i < MAX_BPF_STACK; i += BPF_REG_SIZE) { - if (state->stack_slot_type[i] != STACK_SPILL) + for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) { + if (state->stack[i].slot_type[0] != STACK_SPILL) continue; - reg = &state->spilled_regs[i / BPF_REG_SIZE]; - if (reg->type != PTR_TO_PACKET && - reg->type != PTR_TO_PACKET_END) - continue; - __mark_reg_unknown(reg); + reg = &state->stack[i].spilled_ptr; + if (reg_is_pkt_pointer_any(reg)) + __mark_reg_unknown(reg); } } static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx) { - struct bpf_verifier_state *state = &env->cur_state; const struct bpf_func_proto *fn = NULL; - struct bpf_reg_state *regs = state->regs; + struct bpf_reg_state *regs; struct bpf_call_arg_meta meta; bool changes_data; int i, err; /* find function prototype */ if (func_id < 0 || func_id >= __BPF_FUNC_MAX_ID) { - verbose("invalid func %s#%d\n", func_id_name(func_id), func_id); + verbose(env, "invalid func %s#%d\n", func_id_name(func_id), + func_id); return -EINVAL; } - if (env->prog->aux->ops->get_func_proto) - fn = env->prog->aux->ops->get_func_proto(func_id); + if (env->ops->get_func_proto) + fn = env->ops->get_func_proto(func_id); if (!fn) { - verbose("unknown func %s#%d\n", func_id_name(func_id), func_id); + verbose(env, "unknown func %s#%d\n", func_id_name(func_id), + func_id); return -EINVAL; } /* eBPF programs must be GPL compatible to use GPL-ed functions */ if (!env->prog->gpl_compatible && fn->gpl_only) { - verbose("cannot call GPL only function from proprietary program\n"); + verbose(env, "cannot call GPL only function from proprietary program\n"); return -EINVAL; } @@ -1662,7 +1682,7 @@ static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx) */ err = check_raw_mode(fn); if (err) { - verbose("kernel subsystem misconfigured func %s#%d\n", + verbose(env, "kernel subsystem misconfigured func %s#%d\n", func_id_name(func_id), func_id); return err; } @@ -1693,16 +1713,17 @@ static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx) return err; } + regs = cur_regs(env); /* reset caller saved regs */ for (i = 0; i < CALLER_SAVED_REGS; i++) { - mark_reg_not_init(regs, caller_saved[i]); + mark_reg_not_init(env, regs, caller_saved[i]); check_reg_arg(env, caller_saved[i], DST_OP_NO_MARK); } /* update return register (already marked as written above) */ if (fn->ret_type == RET_INTEGER) { /* sets type to SCALAR_VALUE */ - mark_reg_unknown(regs, BPF_REG_0); + mark_reg_unknown(env, regs, BPF_REG_0); } else if (fn->ret_type == RET_VOID) { regs[BPF_REG_0].type = NOT_INIT; } else if (fn->ret_type == RET_PTR_TO_MAP_VALUE_OR_NULL) { @@ -1710,14 +1731,15 @@ static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx) regs[BPF_REG_0].type = PTR_TO_MAP_VALUE_OR_NULL; /* There is no offset yet applied, variable or fixed */ - mark_reg_known_zero(regs, BPF_REG_0); + mark_reg_known_zero(env, regs, BPF_REG_0); regs[BPF_REG_0].off = 0; /* remember map_ptr, so that check_map_access() * can check 'value_size' boundary of memory access * to map element returned from bpf_map_lookup_elem() */ if (meta.map_ptr == NULL) { - verbose("kernel subsystem misconfigured verifier\n"); + verbose(env, + "kernel subsystem misconfigured verifier\n"); return -EINVAL; } regs[BPF_REG_0].map_ptr = meta.map_ptr; @@ -1728,12 +1750,12 @@ static int check_call(struct bpf_verifier_env *env, int func_id, int insn_idx) else if (insn_aux->map_ptr != meta.map_ptr) insn_aux->map_ptr = BPF_MAP_PTR_POISON; } else { - verbose("unknown return type %d of func %s#%d\n", + verbose(env, "unknown return type %d of func %s#%d\n", fn->ret_type, func_id_name(func_id), func_id); return -EINVAL; } - err = check_map_func_compatibility(meta.map_ptr, func_id); + err = check_map_func_compatibility(env, meta.map_ptr, func_id); if (err) return err; @@ -1780,7 +1802,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, const struct bpf_reg_state *ptr_reg, const struct bpf_reg_state *off_reg) { - struct bpf_reg_state *regs = env->cur_state.regs, *dst_reg; + struct bpf_reg_state *regs = cur_regs(env), *dst_reg; bool known = tnum_is_const(off_reg->var_off); s64 smin_val = off_reg->smin_value, smax_val = off_reg->smax_value, smin_ptr = ptr_reg->smin_value, smax_ptr = ptr_reg->smax_value; @@ -1792,39 +1814,42 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, dst_reg = ®s[dst]; if (WARN_ON_ONCE(known && (smin_val != smax_val))) { - print_verifier_state(&env->cur_state); - verbose("verifier internal error: known but bad sbounds\n"); + print_verifier_state(env, env->cur_state); + verbose(env, + "verifier internal error: known but bad sbounds\n"); return -EINVAL; } if (WARN_ON_ONCE(known && (umin_val != umax_val))) { - print_verifier_state(&env->cur_state); - verbose("verifier internal error: known but bad ubounds\n"); + print_verifier_state(env, env->cur_state); + verbose(env, + "verifier internal error: known but bad ubounds\n"); return -EINVAL; } if (BPF_CLASS(insn->code) != BPF_ALU64) { /* 32-bit ALU ops on pointers produce (meaningless) scalars */ if (!env->allow_ptr_leaks) - verbose("R%d 32-bit pointer arithmetic prohibited\n", + verbose(env, + "R%d 32-bit pointer arithmetic prohibited\n", dst); return -EACCES; } if (ptr_reg->type == PTR_TO_MAP_VALUE_OR_NULL) { if (!env->allow_ptr_leaks) - verbose("R%d pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL prohibited, null-check it first\n", + verbose(env, "R%d pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL prohibited, null-check it first\n", dst); return -EACCES; } if (ptr_reg->type == CONST_PTR_TO_MAP) { if (!env->allow_ptr_leaks) - verbose("R%d pointer arithmetic on CONST_PTR_TO_MAP prohibited\n", + verbose(env, "R%d pointer arithmetic on CONST_PTR_TO_MAP prohibited\n", dst); return -EACCES; } if (ptr_reg->type == PTR_TO_PACKET_END) { if (!env->allow_ptr_leaks) - verbose("R%d pointer arithmetic on PTR_TO_PACKET_END prohibited\n", + verbose(env, "R%d pointer arithmetic on PTR_TO_PACKET_END prohibited\n", dst); return -EACCES; } @@ -1879,7 +1904,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, } dst_reg->var_off = tnum_add(ptr_reg->var_off, off_reg->var_off); dst_reg->off = ptr_reg->off; - if (ptr_reg->type == PTR_TO_PACKET) { + if (reg_is_pkt_pointer(ptr_reg)) { dst_reg->id = ++env->id_gen; /* something was added to pkt_ptr, set range to zero */ dst_reg->range = 0; @@ -1889,7 +1914,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, if (dst_reg == off_reg) { /* scalar -= pointer. Creates an unknown scalar */ if (!env->allow_ptr_leaks) - verbose("R%d tried to subtract pointer from scalar\n", + verbose(env, "R%d tried to subtract pointer from scalar\n", dst); return -EACCES; } @@ -1899,7 +1924,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, */ if (ptr_reg->type == PTR_TO_STACK) { if (!env->allow_ptr_leaks) - verbose("R%d subtraction from stack pointer prohibited\n", + verbose(env, "R%d subtraction from stack pointer prohibited\n", dst); return -EACCES; } @@ -1939,7 +1964,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, } dst_reg->var_off = tnum_sub(ptr_reg->var_off, off_reg->var_off); dst_reg->off = ptr_reg->off; - if (ptr_reg->type == PTR_TO_PACKET) { + if (reg_is_pkt_pointer(ptr_reg)) { dst_reg->id = ++env->id_gen; /* something was added to pkt_ptr, set range to zero */ if (smin_val < 0) @@ -1954,13 +1979,13 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, * ptr &= ~3 which would reduce min_value by 3.) */ if (!env->allow_ptr_leaks) - verbose("R%d bitwise operator %s on pointer prohibited\n", + verbose(env, "R%d bitwise operator %s on pointer prohibited\n", dst, bpf_alu_string[opcode >> 4]); return -EACCES; default: /* other operators (e.g. MUL,LSH) produce non-pointer results */ if (!env->allow_ptr_leaks) - verbose("R%d pointer arithmetic with %s operator prohibited\n", + verbose(env, "R%d pointer arithmetic with %s operator prohibited\n", dst, bpf_alu_string[opcode >> 4]); return -EACCES; } @@ -1976,7 +2001,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env, struct bpf_reg_state *dst_reg, struct bpf_reg_state src_reg) { - struct bpf_reg_state *regs = env->cur_state.regs; + struct bpf_reg_state *regs = cur_regs(env); u8 opcode = BPF_OP(insn->code); bool src_known, dst_known; s64 smin_val, smax_val; @@ -2126,7 +2151,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env, /* Shifts greater than 63 are undefined. This includes * shifts by a negative number. */ - mark_reg_unknown(regs, insn->dst_reg); + mark_reg_unknown(env, regs, insn->dst_reg); break; } /* We lose all sign bit information (except what we can pick @@ -2154,7 +2179,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env, /* Shifts greater than 63 are undefined. This includes * shifts by a negative number. */ - mark_reg_unknown(regs, insn->dst_reg); + mark_reg_unknown(env, regs, insn->dst_reg); break; } /* BPF_RSH is an unsigned shift, so make the appropriate casts */ @@ -2182,7 +2207,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env, __update_reg_bounds(dst_reg); break; default: - mark_reg_unknown(regs, insn->dst_reg); + mark_reg_unknown(env, regs, insn->dst_reg); break; } @@ -2197,7 +2222,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env, static int adjust_reg_min_max_vals(struct bpf_verifier_env *env, struct bpf_insn *insn) { - struct bpf_reg_state *regs = env->cur_state.regs, *dst_reg, *src_reg; + struct bpf_reg_state *regs = cur_regs(env), *dst_reg, *src_reg; struct bpf_reg_state *ptr_reg = NULL, off_reg = {0}; u8 opcode = BPF_OP(insn->code); int rc; @@ -2214,12 +2239,12 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env, * an arbitrary scalar. */ if (!env->allow_ptr_leaks) { - verbose("R%d pointer %s pointer prohibited\n", + verbose(env, "R%d pointer %s pointer prohibited\n", insn->dst_reg, bpf_alu_string[opcode >> 4]); return -EACCES; } - mark_reg_unknown(regs, insn->dst_reg); + mark_reg_unknown(env, regs, insn->dst_reg); return 0; } else { /* scalar += pointer @@ -2271,13 +2296,13 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env, /* Got here implies adding two SCALAR_VALUEs */ if (WARN_ON_ONCE(ptr_reg)) { - print_verifier_state(&env->cur_state); - verbose("verifier internal error: unexpected ptr_reg\n"); + print_verifier_state(env, env->cur_state); + verbose(env, "verifier internal error: unexpected ptr_reg\n"); return -EINVAL; } if (WARN_ON(!src_reg)) { - print_verifier_state(&env->cur_state); - verbose("verifier internal error: no src_reg\n"); + print_verifier_state(env, env->cur_state); + verbose(env, "verifier internal error: no src_reg\n"); return -EINVAL; } return adjust_scalar_min_max_vals(env, insn, dst_reg, *src_reg); @@ -2286,7 +2311,7 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env, /* check validity of 32-bit and 64-bit arithmetic operations */ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) { - struct bpf_reg_state *regs = env->cur_state.regs; + struct bpf_reg_state *regs = cur_regs(env); u8 opcode = BPF_OP(insn->code); int err; @@ -2295,14 +2320,14 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) if (BPF_SRC(insn->code) != 0 || insn->src_reg != BPF_REG_0 || insn->off != 0 || insn->imm != 0) { - verbose("BPF_NEG uses reserved fields\n"); + verbose(env, "BPF_NEG uses reserved fields\n"); return -EINVAL; } } else { if (insn->src_reg != BPF_REG_0 || insn->off != 0 || (insn->imm != 16 && insn->imm != 32 && insn->imm != 64) || BPF_CLASS(insn->code) == BPF_ALU64) { - verbose("BPF_END uses reserved fields\n"); + verbose(env, "BPF_END uses reserved fields\n"); return -EINVAL; } } @@ -2313,7 +2338,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) return err; if (is_pointer_value(env, insn->dst_reg)) { - verbose("R%d pointer arithmetic prohibited\n", + verbose(env, "R%d pointer arithmetic prohibited\n", insn->dst_reg); return -EACCES; } @@ -2327,7 +2352,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) if (BPF_SRC(insn->code) == BPF_X) { if (insn->imm != 0 || insn->off != 0) { - verbose("BPF_MOV uses reserved fields\n"); + verbose(env, "BPF_MOV uses reserved fields\n"); return -EINVAL; } @@ -2337,7 +2362,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) return err; } else { if (insn->src_reg != BPF_REG_0 || insn->off != 0) { - verbose("BPF_MOV uses reserved fields\n"); + verbose(env, "BPF_MOV uses reserved fields\n"); return -EINVAL; } } @@ -2357,11 +2382,12 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) } else { /* R1 = (u32) R2 */ if (is_pointer_value(env, insn->src_reg)) { - verbose("R%d partial copy of pointer\n", + verbose(env, + "R%d partial copy of pointer\n", insn->src_reg); return -EACCES; } - mark_reg_unknown(regs, insn->dst_reg); + mark_reg_unknown(env, regs, insn->dst_reg); /* high 32 bits are known zero. */ regs[insn->dst_reg].var_off = tnum_cast( regs[insn->dst_reg].var_off, 4); @@ -2376,14 +2402,14 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) } } else if (opcode > BPF_END) { - verbose("invalid BPF_ALU opcode %x\n", opcode); + verbose(env, "invalid BPF_ALU opcode %x\n", opcode); return -EINVAL; } else { /* all other ALU ops: and, sub, xor, add, ... */ if (BPF_SRC(insn->code) == BPF_X) { if (insn->imm != 0 || insn->off != 0) { - verbose("BPF_ALU uses reserved fields\n"); + verbose(env, "BPF_ALU uses reserved fields\n"); return -EINVAL; } /* check src1 operand */ @@ -2392,7 +2418,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) return err; } else { if (insn->src_reg != BPF_REG_0 || insn->off != 0) { - verbose("BPF_ALU uses reserved fields\n"); + verbose(env, "BPF_ALU uses reserved fields\n"); return -EINVAL; } } @@ -2404,7 +2430,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) if ((opcode == BPF_MOD || opcode == BPF_DIV) && BPF_SRC(insn->code) == BPF_K && insn->imm == 0) { - verbose("div by zero\n"); + verbose(env, "div by zero\n"); return -EINVAL; } @@ -2413,7 +2439,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) int size = BPF_CLASS(insn->code) == BPF_ALU64 ? 64 : 32; if (insn->imm < 0 || insn->imm >= size) { - verbose("invalid shift %d\n", insn->imm); + verbose(env, "invalid shift %d\n", insn->imm); return -EINVAL; } } @@ -2431,6 +2457,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) static void find_good_pkt_pointers(struct bpf_verifier_state *state, struct bpf_reg_state *dst_reg, + enum bpf_reg_type type, bool range_right_open) { struct bpf_reg_state *regs = state->regs, *reg; @@ -2501,15 +2528,15 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *state, * dst_reg->off is known < MAX_PACKET_OFF, therefore it fits in a u16. */ for (i = 0; i < MAX_BPF_REG; i++) - if (regs[i].type == PTR_TO_PACKET && regs[i].id == dst_reg->id) + if (regs[i].type == type && regs[i].id == dst_reg->id) /* keep the maximum range already checked */ regs[i].range = max(regs[i].range, new_range); - for (i = 0; i < MAX_BPF_STACK; i += BPF_REG_SIZE) { - if (state->stack_slot_type[i] != STACK_SPILL) + for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) { + if (state->stack[i].slot_type[0] != STACK_SPILL) continue; - reg = &state->spilled_regs[i / BPF_REG_SIZE]; - if (reg->type == PTR_TO_PACKET && reg->id == dst_reg->id) + reg = &state->stack[i].spilled_ptr; + if (reg->type == type && reg->id == dst_reg->id) reg->range = max(reg->range, new_range); } } @@ -2758,29 +2785,122 @@ static void mark_map_regs(struct bpf_verifier_state *state, u32 regno, for (i = 0; i < MAX_BPF_REG; i++) mark_map_reg(regs, i, id, is_null); - for (i = 0; i < MAX_BPF_STACK; i += BPF_REG_SIZE) { - if (state->stack_slot_type[i] != STACK_SPILL) + for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) { + if (state->stack[i].slot_type[0] != STACK_SPILL) continue; - mark_map_reg(state->spilled_regs, i / BPF_REG_SIZE, id, is_null); + mark_map_reg(&state->stack[i].spilled_ptr, 0, id, is_null); } } +static bool try_match_pkt_pointers(const struct bpf_insn *insn, + struct bpf_reg_state *dst_reg, + struct bpf_reg_state *src_reg, + struct bpf_verifier_state *this_branch, + struct bpf_verifier_state *other_branch) +{ + if (BPF_SRC(insn->code) != BPF_X) + return false; + + switch (BPF_OP(insn->code)) { + case BPF_JGT: + if ((dst_reg->type == PTR_TO_PACKET && + src_reg->type == PTR_TO_PACKET_END) || + (dst_reg->type == PTR_TO_PACKET_META && + reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) { + /* pkt_data' > pkt_end, pkt_meta' > pkt_data */ + find_good_pkt_pointers(this_branch, dst_reg, + dst_reg->type, false); + } else if ((dst_reg->type == PTR_TO_PACKET_END && + src_reg->type == PTR_TO_PACKET) || + (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) && + src_reg->type == PTR_TO_PACKET_META)) { + /* pkt_end > pkt_data', pkt_data > pkt_meta' */ + find_good_pkt_pointers(other_branch, src_reg, + src_reg->type, true); + } else { + return false; + } + break; + case BPF_JLT: + if ((dst_reg->type == PTR_TO_PACKET && + src_reg->type == PTR_TO_PACKET_END) || + (dst_reg->type == PTR_TO_PACKET_META && + reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) { + /* pkt_data' < pkt_end, pkt_meta' < pkt_data */ + find_good_pkt_pointers(other_branch, dst_reg, + dst_reg->type, true); + } else if ((dst_reg->type == PTR_TO_PACKET_END && + src_reg->type == PTR_TO_PACKET) || + (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) && + src_reg->type == PTR_TO_PACKET_META)) { + /* pkt_end < pkt_data', pkt_data > pkt_meta' */ + find_good_pkt_pointers(this_branch, src_reg, + src_reg->type, false); + } else { + return false; + } + break; + case BPF_JGE: + if ((dst_reg->type == PTR_TO_PACKET && + src_reg->type == PTR_TO_PACKET_END) || + (dst_reg->type == PTR_TO_PACKET_META && + reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) { + /* pkt_data' >= pkt_end, pkt_meta' >= pkt_data */ + find_good_pkt_pointers(this_branch, dst_reg, + dst_reg->type, true); + } else if ((dst_reg->type == PTR_TO_PACKET_END && + src_reg->type == PTR_TO_PACKET) || + (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) && + src_reg->type == PTR_TO_PACKET_META)) { + /* pkt_end >= pkt_data', pkt_data >= pkt_meta' */ + find_good_pkt_pointers(other_branch, src_reg, + src_reg->type, false); + } else { + return false; + } + break; + case BPF_JLE: + if ((dst_reg->type == PTR_TO_PACKET && + src_reg->type == PTR_TO_PACKET_END) || + (dst_reg->type == PTR_TO_PACKET_META && + reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) { + /* pkt_data' <= pkt_end, pkt_meta' <= pkt_data */ + find_good_pkt_pointers(other_branch, dst_reg, + dst_reg->type, false); + } else if ((dst_reg->type == PTR_TO_PACKET_END && + src_reg->type == PTR_TO_PACKET) || + (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) && + src_reg->type == PTR_TO_PACKET_META)) { + /* pkt_end <= pkt_data', pkt_data <= pkt_meta' */ + find_good_pkt_pointers(this_branch, src_reg, + src_reg->type, true); + } else { + return false; + } + break; + default: + return false; + } + + return true; +} + static int check_cond_jmp_op(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx) { - struct bpf_verifier_state *other_branch, *this_branch = &env->cur_state; + struct bpf_verifier_state *other_branch, *this_branch = env->cur_state; struct bpf_reg_state *regs = this_branch->regs, *dst_reg; u8 opcode = BPF_OP(insn->code); int err; if (opcode > BPF_JSLE) { - verbose("invalid BPF_JMP opcode %x\n", opcode); + verbose(env, "invalid BPF_JMP opcode %x\n", opcode); return -EINVAL; } if (BPF_SRC(insn->code) == BPF_X) { if (insn->imm != 0) { - verbose("BPF_JMP uses reserved fields\n"); + verbose(env, "BPF_JMP uses reserved fields\n"); return -EINVAL; } @@ -2790,13 +2910,13 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env, return err; if (is_pointer_value(env, insn->src_reg)) { - verbose("R%d pointer comparison prohibited\n", + verbose(env, "R%d pointer comparison prohibited\n", insn->src_reg); return -EACCES; } } else { if (insn->src_reg != BPF_REG_0) { - verbose("BPF_JMP uses reserved fields\n"); + verbose(env, "BPF_JMP uses reserved fields\n"); return -EINVAL; } } @@ -2871,52 +2991,15 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env, */ mark_map_regs(this_branch, insn->dst_reg, opcode == BPF_JNE); mark_map_regs(other_branch, insn->dst_reg, opcode == BPF_JEQ); - } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGT && - dst_reg->type == PTR_TO_PACKET && - regs[insn->src_reg].type == PTR_TO_PACKET_END) { - /* pkt_data' > pkt_end */ - find_good_pkt_pointers(this_branch, dst_reg, false); - } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGT && - dst_reg->type == PTR_TO_PACKET_END && - regs[insn->src_reg].type == PTR_TO_PACKET) { - /* pkt_end > pkt_data' */ - find_good_pkt_pointers(other_branch, ®s[insn->src_reg], true); - } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLT && - dst_reg->type == PTR_TO_PACKET && - regs[insn->src_reg].type == PTR_TO_PACKET_END) { - /* pkt_data' < pkt_end */ - find_good_pkt_pointers(other_branch, dst_reg, true); - } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLT && - dst_reg->type == PTR_TO_PACKET_END && - regs[insn->src_reg].type == PTR_TO_PACKET) { - /* pkt_end < pkt_data' */ - find_good_pkt_pointers(this_branch, ®s[insn->src_reg], false); - } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGE && - dst_reg->type == PTR_TO_PACKET && - regs[insn->src_reg].type == PTR_TO_PACKET_END) { - /* pkt_data' >= pkt_end */ - find_good_pkt_pointers(this_branch, dst_reg, true); - } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGE && - dst_reg->type == PTR_TO_PACKET_END && - regs[insn->src_reg].type == PTR_TO_PACKET) { - /* pkt_end >= pkt_data' */ - find_good_pkt_pointers(other_branch, ®s[insn->src_reg], false); - } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLE && - dst_reg->type == PTR_TO_PACKET && - regs[insn->src_reg].type == PTR_TO_PACKET_END) { - /* pkt_data' <= pkt_end */ - find_good_pkt_pointers(other_branch, dst_reg, false); - } else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLE && - dst_reg->type == PTR_TO_PACKET_END && - regs[insn->src_reg].type == PTR_TO_PACKET) { - /* pkt_end <= pkt_data' */ - find_good_pkt_pointers(this_branch, ®s[insn->src_reg], true); - } else if (is_pointer_value(env, insn->dst_reg)) { - verbose("R%d pointer comparison prohibited\n", insn->dst_reg); + } else if (!try_match_pkt_pointers(insn, dst_reg, ®s[insn->src_reg], + this_branch, other_branch) && + is_pointer_value(env, insn->dst_reg)) { + verbose(env, "R%d pointer comparison prohibited\n", + insn->dst_reg); return -EACCES; } - if (log_level) - print_verifier_state(this_branch); + if (env->log.level) + print_verifier_state(env, this_branch); return 0; } @@ -2931,15 +3014,15 @@ static struct bpf_map *ld_imm64_to_map_ptr(struct bpf_insn *insn) /* verify BPF_LD_IMM64 instruction */ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn) { - struct bpf_reg_state *regs = env->cur_state.regs; + struct bpf_reg_state *regs = cur_regs(env); int err; if (BPF_SIZE(insn->code) != BPF_DW) { - verbose("invalid BPF_LD_IMM insn\n"); + verbose(env, "invalid BPF_LD_IMM insn\n"); return -EINVAL; } if (insn->off != 0) { - verbose("BPF_LD_IMM64 uses reserved fields\n"); + verbose(env, "BPF_LD_IMM64 uses reserved fields\n"); return -EINVAL; } @@ -2992,19 +3075,19 @@ static bool may_access_skb(enum bpf_prog_type type) */ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn) { - struct bpf_reg_state *regs = env->cur_state.regs; + struct bpf_reg_state *regs = cur_regs(env); u8 mode = BPF_MODE(insn->code); int i, err; if (!may_access_skb(env->prog->type)) { - verbose("BPF_LD_[ABS|IND] instructions not allowed for this program type\n"); + verbose(env, "BPF_LD_[ABS|IND] instructions not allowed for this program type\n"); return -EINVAL; } if (insn->dst_reg != BPF_REG_0 || insn->off != 0 || BPF_SIZE(insn->code) == BPF_DW || (mode == BPF_ABS && insn->src_reg != BPF_REG_0)) { - verbose("BPF_LD_[ABS|IND] uses reserved fields\n"); + verbose(env, "BPF_LD_[ABS|IND] uses reserved fields\n"); return -EINVAL; } @@ -3014,7 +3097,8 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn) return err; if (regs[BPF_REG_6].type != PTR_TO_CTX) { - verbose("at the time of BPF_LD_ABS|IND R6 != pointer to skb\n"); + verbose(env, + "at the time of BPF_LD_ABS|IND R6 != pointer to skb\n"); return -EINVAL; } @@ -3027,7 +3111,7 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn) /* reset caller saved regs to unreadable */ for (i = 0; i < CALLER_SAVED_REGS; i++) { - mark_reg_not_init(regs, caller_saved[i]); + mark_reg_not_init(env, regs, caller_saved[i]); check_reg_arg(env, caller_saved[i], DST_OP_NO_MARK); } @@ -3035,7 +3119,45 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn) * the value fetched from the packet. * Already marked as written above. */ - mark_reg_unknown(regs, BPF_REG_0); + mark_reg_unknown(env, regs, BPF_REG_0); + return 0; +} + +static int check_return_code(struct bpf_verifier_env *env) +{ + struct bpf_reg_state *reg; + struct tnum range = tnum_range(0, 1); + + switch (env->prog->type) { + case BPF_PROG_TYPE_CGROUP_SKB: + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_CGROUP_DEVICE: + break; + default: + return 0; + } + + reg = cur_regs(env) + BPF_REG_0; + if (reg->type != SCALAR_VALUE) { + verbose(env, "At program exit the register R0 is not a known value (%s)\n", + reg_type_str[reg->type]); + return -EINVAL; + } + + if (!tnum_in(range, reg->var_off)) { + verbose(env, "At program exit the register R0 "); + if (!tnum_is_unknown(reg->var_off)) { + char tn_buf[48]; + + tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); + verbose(env, "has value %s", tn_buf); + } else { + verbose(env, "has unknown scalar value"); + } + verbose(env, " should have been 0 or 1\n"); + return -EINVAL; + } return 0; } @@ -3099,7 +3221,7 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env) return 0; if (w < 0 || w >= env->prog->len) { - verbose("jump out of range from insn %d to %d\n", t, w); + verbose(env, "jump out of range from insn %d to %d\n", t, w); return -EINVAL; } @@ -3116,13 +3238,13 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env) insn_stack[cur_stack++] = w; return 1; } else if ((insn_state[w] & 0xF0) == DISCOVERED) { - verbose("back-edge from insn %d to %d\n", t, w); + verbose(env, "back-edge from insn %d to %d\n", t, w); return -EINVAL; } else if (insn_state[w] == EXPLORED) { /* forward- or cross-edge */ insn_state[t] = DISCOVERED | e; } else { - verbose("insn state internal bug\n"); + verbose(env, "insn state internal bug\n"); return -EFAULT; } return 0; @@ -3216,7 +3338,7 @@ peek_stack: mark_explored: insn_state[t] = EXPLORED; if (cur_stack-- <= 0) { - verbose("pop stack internal bug\n"); + verbose(env, "pop stack internal bug\n"); ret = -EFAULT; goto err_free; } @@ -3225,7 +3347,7 @@ mark_explored: check_state: for (i = 0; i < insn_cnt; i++) { if (insn_state[i] != EXPLORED) { - verbose("unreachable insn %d\n", i); + verbose(env, "unreachable insn %d\n", i); ret = -EINVAL; goto err_free; } @@ -3340,8 +3462,9 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur, return false; /* Check our ids match any regs they're supposed to */ return check_ids(rold->id, rcur->id, idmap); + case PTR_TO_PACKET_META: case PTR_TO_PACKET: - if (rcur->type != PTR_TO_PACKET) + if (rcur->type != rold->type) return false; /* We must have at least as much range as the old ptr * did, so that any accesses which were safe before are @@ -3379,6 +3502,57 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur, return false; } +static bool stacksafe(struct bpf_verifier_state *old, + struct bpf_verifier_state *cur, + struct idpair *idmap) +{ + int i, spi; + + /* if explored stack has more populated slots than current stack + * such stacks are not equivalent + */ + if (old->allocated_stack > cur->allocated_stack) + return false; + + /* walk slots of the explored stack and ignore any additional + * slots in the current stack, since explored(safe) state + * didn't use them + */ + for (i = 0; i < old->allocated_stack; i++) { + spi = i / BPF_REG_SIZE; + + if (old->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_INVALID) + continue; + if (old->stack[spi].slot_type[i % BPF_REG_SIZE] != + cur->stack[spi].slot_type[i % BPF_REG_SIZE]) + /* Ex: old explored (safe) state has STACK_SPILL in + * this stack slot, but current has has STACK_MISC -> + * this verifier states are not equivalent, + * return false to continue verification of this path + */ + return false; + if (i % BPF_REG_SIZE) + continue; + if (old->stack[spi].slot_type[0] != STACK_SPILL) + continue; + if (!regsafe(&old->stack[spi].spilled_ptr, + &cur->stack[spi].spilled_ptr, + idmap)) + /* when explored and current stack slot are both storing + * spilled registers, check that stored pointers types + * are the same as well. + * Ex: explored safe path could have stored + * (bpf_reg_state) {.type = PTR_TO_STACK, .off = -8} + * but current path has stored: + * (bpf_reg_state) {.type = PTR_TO_STACK, .off = -16} + * such verifier states are not equivalent. + * return false to continue verification of this path + */ + return false; + } + return true; +} + /* compare two verifier states * * all states stored in state_list are known to be valid, since @@ -3423,37 +3597,8 @@ static bool states_equal(struct bpf_verifier_env *env, goto out_free; } - for (i = 0; i < MAX_BPF_STACK; i++) { - if (old->stack_slot_type[i] == STACK_INVALID) - continue; - if (old->stack_slot_type[i] != cur->stack_slot_type[i]) - /* Ex: old explored (safe) state has STACK_SPILL in - * this stack slot, but current has has STACK_MISC -> - * this verifier states are not equivalent, - * return false to continue verification of this path - */ - goto out_free; - if (i % BPF_REG_SIZE) - continue; - if (old->stack_slot_type[i] != STACK_SPILL) - continue; - if (!regsafe(&old->spilled_regs[i / BPF_REG_SIZE], - &cur->spilled_regs[i / BPF_REG_SIZE], - idmap)) - /* when explored and current stack slot are both storing - * spilled registers, check that stored pointers types - * are the same as well. - * Ex: explored safe path could have stored - * (bpf_reg_state) {.type = PTR_TO_STACK, .off = -8} - * but current path has stored: - * (bpf_reg_state) {.type = PTR_TO_STACK, .off = -16} - * such verifier states are not equivalent. - * return false to continue verification of this path - */ - goto out_free; - else - continue; - } + if (!stacksafe(old, cur, idmap)) + goto out_free; ret = true; out_free: kfree(idmap); @@ -3489,17 +3634,19 @@ static bool do_propagate_liveness(const struct bpf_verifier_state *state, } } /* ... and stack slots */ - for (i = 0; i < MAX_BPF_STACK / BPF_REG_SIZE; i++) { - if (parent->stack_slot_type[i * BPF_REG_SIZE] != STACK_SPILL) + for (i = 0; i < state->allocated_stack / BPF_REG_SIZE && + i < parent->allocated_stack / BPF_REG_SIZE; i++) { + if (parent->stack[i].slot_type[0] != STACK_SPILL) continue; - if (state->stack_slot_type[i * BPF_REG_SIZE] != STACK_SPILL) + if (state->stack[i].slot_type[0] != STACK_SPILL) continue; - if (parent->spilled_regs[i].live & REG_LIVE_READ) + if (parent->stack[i].spilled_ptr.live & REG_LIVE_READ) continue; - if (writes && (state->spilled_regs[i].live & REG_LIVE_WRITTEN)) + if (writes && + (state->stack[i].spilled_ptr.live & REG_LIVE_WRITTEN)) continue; - if (state->spilled_regs[i].live & REG_LIVE_READ) { - parent->spilled_regs[i].live |= REG_LIVE_READ; + if (state->stack[i].spilled_ptr.live & REG_LIVE_READ) { + parent->stack[i].spilled_ptr.live |= REG_LIVE_READ; touched = true; } } @@ -3529,7 +3676,8 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) { struct bpf_verifier_state_list *new_sl; struct bpf_verifier_state_list *sl; - int i; + struct bpf_verifier_state *cur = env->cur_state; + int i, err; sl = env->explored_states[insn_idx]; if (!sl) @@ -3539,7 +3687,7 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) return 0; while (sl != STATE_LIST_MARK) { - if (states_equal(env, &sl->state, &env->cur_state)) { + if (states_equal(env, &sl->state, cur)) { /* reached equivalent register/stack state, * prune the search. * Registers read by the continuation are read by us. @@ -3550,7 +3698,7 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) * they'll be immediately forgotten as we're pruning * this state and will pop a new one. */ - propagate_liveness(&sl->state, &env->cur_state); + propagate_liveness(&sl->state, cur); return 1; } sl = sl->next; @@ -3562,16 +3710,21 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) * it will be rejected. Since there are no loops, we won't be * seeing this 'insn_idx' instruction again on the way to bpf_exit */ - new_sl = kmalloc(sizeof(struct bpf_verifier_state_list), GFP_USER); + new_sl = kzalloc(sizeof(struct bpf_verifier_state_list), GFP_KERNEL); if (!new_sl) return -ENOMEM; /* add new state to the head of linked list */ - memcpy(&new_sl->state, &env->cur_state, sizeof(env->cur_state)); + err = copy_verifier_state(&new_sl->state, cur); + if (err) { + free_verifier_state(&new_sl->state, false); + kfree(new_sl); + return err; + } new_sl->next = env->explored_states[insn_idx]; env->explored_states[insn_idx] = new_sl; /* connect new state to parentage chain */ - env->cur_state.parent = &new_sl->state; + cur->parent = &new_sl->state; /* clear write marks in current state: the writes we did are not writes * our child did, so they don't screen off its reads from us. * (There are no read marks in current state, because reads always mark @@ -3579,33 +3732,37 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) * explored_states can get read marks.) */ for (i = 0; i < BPF_REG_FP; i++) - env->cur_state.regs[i].live = REG_LIVE_NONE; - for (i = 0; i < MAX_BPF_STACK / BPF_REG_SIZE; i++) - if (env->cur_state.stack_slot_type[i * BPF_REG_SIZE] == STACK_SPILL) - env->cur_state.spilled_regs[i].live = REG_LIVE_NONE; + cur->regs[i].live = REG_LIVE_NONE; + for (i = 0; i < cur->allocated_stack / BPF_REG_SIZE; i++) + if (cur->stack[i].slot_type[0] == STACK_SPILL) + cur->stack[i].spilled_ptr.live = REG_LIVE_NONE; return 0; } static int ext_analyzer_insn_hook(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx) { - if (!env->analyzer_ops || !env->analyzer_ops->insn_hook) - return 0; + if (env->dev_ops && env->dev_ops->insn_hook) + return env->dev_ops->insn_hook(env, insn_idx, prev_insn_idx); - return env->analyzer_ops->insn_hook(env, insn_idx, prev_insn_idx); + return 0; } static int do_check(struct bpf_verifier_env *env) { - struct bpf_verifier_state *state = &env->cur_state; + struct bpf_verifier_state *state; struct bpf_insn *insns = env->prog->insnsi; - struct bpf_reg_state *regs = state->regs; + struct bpf_reg_state *regs; int insn_cnt = env->prog->len; int insn_idx, prev_insn_idx = 0; int insn_processed = 0; bool do_print_state = false; - init_reg_state(regs); + state = kzalloc(sizeof(struct bpf_verifier_state), GFP_KERNEL); + if (!state) + return -ENOMEM; + env->cur_state = state; + init_reg_state(env, state->regs); state->parent = NULL; insn_idx = 0; for (;;) { @@ -3614,7 +3771,7 @@ static int do_check(struct bpf_verifier_env *env) int err; if (insn_idx >= insn_cnt) { - verbose("invalid insn idx %d insn_cnt %d\n", + verbose(env, "invalid insn idx %d insn_cnt %d\n", insn_idx, insn_cnt); return -EFAULT; } @@ -3623,7 +3780,8 @@ static int do_check(struct bpf_verifier_env *env) class = BPF_CLASS(insn->code); if (++insn_processed > BPF_COMPLEXITY_LIMIT_INSNS) { - verbose("BPF program is too large. Processed %d insn\n", + verbose(env, + "BPF program is too large. Processed %d insn\n", insn_processed); return -E2BIG; } @@ -3633,12 +3791,12 @@ static int do_check(struct bpf_verifier_env *env) return err; if (err == 1) { /* found equivalent state, can prune the search */ - if (log_level) { + if (env->log.level) { if (do_print_state) - verbose("\nfrom %d to %d: safe\n", + verbose(env, "\nfrom %d to %d: safe\n", prev_insn_idx, insn_idx); else - verbose("%d: safe\n", insn_idx); + verbose(env, "%d: safe\n", insn_idx); } goto process_bpf_exit; } @@ -3646,25 +3804,27 @@ static int do_check(struct bpf_verifier_env *env) if (need_resched()) cond_resched(); - if (log_level > 1 || (log_level && do_print_state)) { - if (log_level > 1) - verbose("%d:", insn_idx); + if (env->log.level > 1 || (env->log.level && do_print_state)) { + if (env->log.level > 1) + verbose(env, "%d:", insn_idx); else - verbose("\nfrom %d to %d:", + verbose(env, "\nfrom %d to %d:", prev_insn_idx, insn_idx); - print_verifier_state(&env->cur_state); + print_verifier_state(env, state); do_print_state = false; } - if (log_level) { - verbose("%d: ", insn_idx); - print_bpf_insn(env, insn); + if (env->log.level) { + verbose(env, "%d: ", insn_idx); + print_bpf_insn(verbose, env, insn, + env->allow_ptr_leaks); } err = ext_analyzer_insn_hook(env, insn_idx, prev_insn_idx); if (err) return err; + regs = cur_regs(env); if (class == BPF_ALU || class == BPF_ALU64) { err = check_alu_op(env, insn); if (err) @@ -3714,7 +3874,7 @@ static int do_check(struct bpf_verifier_env *env) * src_reg == stack|map in some other branch. * Reject it. */ - verbose("same insn cannot be used with different pointers\n"); + verbose(env, "same insn cannot be used with different pointers\n"); return -EINVAL; } @@ -3754,14 +3914,14 @@ static int do_check(struct bpf_verifier_env *env) } else if (dst_reg_type != *prev_dst_type && (dst_reg_type == PTR_TO_CTX || *prev_dst_type == PTR_TO_CTX)) { - verbose("same insn cannot be used with different pointers\n"); + verbose(env, "same insn cannot be used with different pointers\n"); return -EINVAL; } } else if (class == BPF_ST) { if (BPF_MODE(insn->code) != BPF_MEM || insn->src_reg != BPF_REG_0) { - verbose("BPF_ST uses reserved fields\n"); + verbose(env, "BPF_ST uses reserved fields\n"); return -EINVAL; } /* check src operand */ @@ -3784,7 +3944,7 @@ static int do_check(struct bpf_verifier_env *env) insn->off != 0 || insn->src_reg != BPF_REG_0 || insn->dst_reg != BPF_REG_0) { - verbose("BPF_CALL uses reserved fields\n"); + verbose(env, "BPF_CALL uses reserved fields\n"); return -EINVAL; } @@ -3797,7 +3957,7 @@ static int do_check(struct bpf_verifier_env *env) insn->imm != 0 || insn->src_reg != BPF_REG_0 || insn->dst_reg != BPF_REG_0) { - verbose("BPF_JA uses reserved fields\n"); + verbose(env, "BPF_JA uses reserved fields\n"); return -EINVAL; } @@ -3809,7 +3969,7 @@ static int do_check(struct bpf_verifier_env *env) insn->imm != 0 || insn->src_reg != BPF_REG_0 || insn->dst_reg != BPF_REG_0) { - verbose("BPF_EXIT uses reserved fields\n"); + verbose(env, "BPF_EXIT uses reserved fields\n"); return -EINVAL; } @@ -3824,13 +3984,18 @@ static int do_check(struct bpf_verifier_env *env) return err; if (is_pointer_value(env, BPF_REG_0)) { - verbose("R0 leaks addr as return value\n"); + verbose(env, "R0 leaks addr as return value\n"); return -EACCES; } + err = check_return_code(env); + if (err) + return err; process_bpf_exit: - insn_idx = pop_stack(env, &prev_insn_idx); - if (insn_idx < 0) { + err = pop_stack(env, &prev_insn_idx, &insn_idx); + if (err < 0) { + if (err != -ENOENT) + return err; break; } else { do_print_state = true; @@ -3856,19 +4021,19 @@ process_bpf_exit: insn_idx++; } else { - verbose("invalid BPF_LD mode\n"); + verbose(env, "invalid BPF_LD mode\n"); return -EINVAL; } } else { - verbose("unknown insn class %d\n", class); + verbose(env, "unknown insn class %d\n", class); return -EINVAL; } insn_idx++; } - verbose("processed %d insns, stack depth %d\n", - insn_processed, env->prog->aux->stack_depth); + verbose(env, "processed %d insns, stack depth %d\n", insn_processed, + env->prog->aux->stack_depth); return 0; } @@ -3880,7 +4045,8 @@ static int check_map_prealloc(struct bpf_map *map) !(map->map_flags & BPF_F_NO_PREALLOC); } -static int check_map_prog_compatibility(struct bpf_map *map, +static int check_map_prog_compatibility(struct bpf_verifier_env *env, + struct bpf_map *map, struct bpf_prog *prog) { @@ -3891,12 +4057,12 @@ static int check_map_prog_compatibility(struct bpf_map *map, */ if (prog->type == BPF_PROG_TYPE_PERF_EVENT) { if (!check_map_prealloc(map)) { - verbose("perf_event programs can only use preallocated hash map\n"); + verbose(env, "perf_event programs can only use preallocated hash map\n"); return -EINVAL; } if (map->inner_map_meta && !check_map_prealloc(map->inner_map_meta)) { - verbose("perf_event programs can only use preallocated inner hash map\n"); + verbose(env, "perf_event programs can only use preallocated inner hash map\n"); return -EINVAL; } } @@ -3919,14 +4085,14 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env) for (i = 0; i < insn_cnt; i++, insn++) { if (BPF_CLASS(insn->code) == BPF_LDX && (BPF_MODE(insn->code) != BPF_MEM || insn->imm != 0)) { - verbose("BPF_LDX uses reserved fields\n"); + verbose(env, "BPF_LDX uses reserved fields\n"); return -EINVAL; } if (BPF_CLASS(insn->code) == BPF_STX && ((BPF_MODE(insn->code) != BPF_MEM && BPF_MODE(insn->code) != BPF_XADD) || insn->imm != 0)) { - verbose("BPF_STX uses reserved fields\n"); + verbose(env, "BPF_STX uses reserved fields\n"); return -EINVAL; } @@ -3937,7 +4103,7 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env) if (i == insn_cnt - 1 || insn[1].code != 0 || insn[1].dst_reg != 0 || insn[1].src_reg != 0 || insn[1].off != 0) { - verbose("invalid bpf_ld_imm64 insn\n"); + verbose(env, "invalid bpf_ld_imm64 insn\n"); return -EINVAL; } @@ -3946,19 +4112,20 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env) goto next_insn; if (insn->src_reg != BPF_PSEUDO_MAP_FD) { - verbose("unrecognized bpf_ld_imm64 insn\n"); + verbose(env, + "unrecognized bpf_ld_imm64 insn\n"); return -EINVAL; } f = fdget(insn->imm); map = __bpf_map_get(f); if (IS_ERR(map)) { - verbose("fd %d is not pointing to valid bpf_map\n", + verbose(env, "fd %d is not pointing to valid bpf_map\n", insn->imm); return PTR_ERR(map); } - err = check_map_prog_compatibility(map, env->prog); + err = check_map_prog_compatibility(env, map, env->prog); if (err) { fdput(f); return err; @@ -4067,7 +4234,7 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of */ static int convert_ctx_accesses(struct bpf_verifier_env *env) { - const struct bpf_verifier_ops *ops = env->prog->aux->ops; + const struct bpf_verifier_ops *ops = env->ops; int i, cnt, size, ctx_field_size, delta = 0; const int insn_cnt = env->prog->len; struct bpf_insn insn_buf[16], *insn; @@ -4080,7 +4247,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) cnt = ops->gen_prologue(insn_buf, env->seen_direct_write, env->prog); if (cnt >= ARRAY_SIZE(insn_buf)) { - verbose("bpf verifier is misconfigured\n"); + verbose(env, "bpf verifier is misconfigured\n"); return -EINVAL; } else if (cnt) { new_prog = bpf_patch_insn_data(env, 0, insn_buf, cnt); @@ -4128,7 +4295,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) u8 size_code; if (type == BPF_WRITE) { - verbose("bpf verifier narrow ctx access misconfigured\n"); + verbose(env, "bpf verifier narrow ctx access misconfigured\n"); return -EINVAL; } @@ -4147,7 +4314,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) &target_size); if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf) || (ctx_field_size && !target_size)) { - verbose("bpf verifier is misconfigured\n"); + verbose(env, "bpf verifier is misconfigured\n"); return -EINVAL; } @@ -4229,7 +4396,7 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) cnt = map_ptr->ops->map_gen_lookup(map_ptr, insn_buf); if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf)) { - verbose("bpf verifier is misconfigured\n"); + verbose(env, "bpf verifier is misconfigured\n"); return -EINVAL; } @@ -4268,12 +4435,13 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) insn = new_prog->insnsi + i + delta; } patch_call_imm: - fn = prog->aux->ops->get_func_proto(insn->imm); + fn = env->ops->get_func_proto(insn->imm); /* all functions that have prototype and verifier allowed * programs to call them, must be real in-kernel functions */ if (!fn->func) { - verbose("kernel subsystem misconfigured func %s#%d\n", + verbose(env, + "kernel subsystem misconfigured func %s#%d\n", func_id_name(insn->imm), insn->imm); return -EFAULT; } @@ -4297,6 +4465,7 @@ static void free_states(struct bpf_verifier_env *env) if (sl) while (sl != STATE_LIST_MARK) { sln = sl->next; + free_verifier_state(&sl->state, false); kfree(sl); sl = sln; } @@ -4307,16 +4476,21 @@ static void free_states(struct bpf_verifier_env *env) int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) { - char __user *log_ubuf = NULL; struct bpf_verifier_env *env; + struct bpf_verifer_log *log; int ret = -EINVAL; + /* no program is valid */ + if (ARRAY_SIZE(bpf_verifier_ops) == 0) + return -EINVAL; + /* 'struct bpf_verifier_env' can be global, but since it's not small, * allocate/free it every time bpf_check() is called */ env = kzalloc(sizeof(struct bpf_verifier_env), GFP_KERNEL); if (!env) return -ENOMEM; + log = &env->log; env->insn_aux_data = vzalloc(sizeof(struct bpf_insn_aux_data) * (*prog)->len); @@ -4324,6 +4498,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) if (!env->insn_aux_data) goto err_free_env; env->prog = *prog; + env->ops = bpf_verifier_ops[env->prog->type]; /* grab the mutex to protect few globals used by verifier */ mutex_lock(&bpf_verifier_lock); @@ -4332,29 +4507,27 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) /* user requested verbose verifier output * and supplied buffer to store the verification trace */ - log_level = attr->log_level; - log_ubuf = (char __user *) (unsigned long) attr->log_buf; - log_size = attr->log_size; - log_len = 0; + log->level = attr->log_level; + log->ubuf = (char __user *) (unsigned long) attr->log_buf; + log->len_total = attr->log_size; ret = -EINVAL; - /* log_* values have to be sane */ - if (log_size < 128 || log_size > UINT_MAX >> 8 || - log_level == 0 || log_ubuf == NULL) - goto err_unlock; - - ret = -ENOMEM; - log_buf = vmalloc(log_size); - if (!log_buf) + /* log attributes have to be sane */ + if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 || + !log->level || !log->ubuf) goto err_unlock; - } else { - log_level = 0; } env->strict_alignment = !!(attr->prog_flags & BPF_F_STRICT_ALIGNMENT); if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) env->strict_alignment = true; + if (env->prog->aux->offload) { + ret = bpf_prog_offload_verifier_prep(env); + if (ret) + goto err_unlock; + } + ret = replace_map_fd_with_map_ptr(env); if (ret < 0) goto skip_full_check; @@ -4373,9 +4546,13 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) env->allow_ptr_leaks = capable(CAP_SYS_ADMIN); ret = do_check(env); + if (env->cur_state) { + free_verifier_state(env->cur_state, true); + env->cur_state = NULL; + } skip_full_check: - while (pop_stack(env, NULL) >= 0); + while (!pop_stack(env, NULL, NULL)); free_states(env); if (ret == 0) @@ -4385,17 +4562,11 @@ skip_full_check: if (ret == 0) ret = fixup_bpf_calls(env); - if (log_level && log_len >= log_size - 1) { - BUG_ON(log_len >= log_size); - /* verifier log exceeded user supplied buffer */ + if (log->level && bpf_verifier_log_full(log)) ret = -ENOSPC; - /* fall through to return what was recorded */ - } - - /* copy verifier log back to user space including trailing zero */ - if (log_level && copy_to_user(log_ubuf, log_buf, log_len + 1) != 0) { + if (log->level && !log->ubuf) { ret = -EFAULT; - goto free_log_buf; + goto err_release_maps; } if (ret == 0 && env->used_map_cnt) { @@ -4406,7 +4577,7 @@ skip_full_check: if (!env->prog->aux->used_maps) { ret = -ENOMEM; - goto free_log_buf; + goto err_release_maps; } memcpy(env->prog->aux->used_maps, env->used_maps, @@ -4419,9 +4590,7 @@ skip_full_check: convert_pseudo_ld_imm64(env); } -free_log_buf: - if (log_level) - vfree(log_buf); +err_release_maps: if (!env->prog->aux->used_maps) /* if we didn't copy map pointers into bpf_prog_info, release * them now. Otherwise free_bpf_prog_info() will release them. @@ -4435,58 +4604,3 @@ err_free_env: kfree(env); return ret; } - -int bpf_analyzer(struct bpf_prog *prog, const struct bpf_ext_analyzer_ops *ops, - void *priv) -{ - struct bpf_verifier_env *env; - int ret; - - env = kzalloc(sizeof(struct bpf_verifier_env), GFP_KERNEL); - if (!env) - return -ENOMEM; - - env->insn_aux_data = vzalloc(sizeof(struct bpf_insn_aux_data) * - prog->len); - ret = -ENOMEM; - if (!env->insn_aux_data) - goto err_free_env; - env->prog = prog; - env->analyzer_ops = ops; - env->analyzer_priv = priv; - - /* grab the mutex to protect few globals used by verifier */ - mutex_lock(&bpf_verifier_lock); - - log_level = 0; - - env->strict_alignment = false; - if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) - env->strict_alignment = true; - - env->explored_states = kcalloc(env->prog->len, - sizeof(struct bpf_verifier_state_list *), - GFP_KERNEL); - ret = -ENOMEM; - if (!env->explored_states) - goto skip_full_check; - - ret = check_cfg(env); - if (ret < 0) - goto skip_full_check; - - env->allow_ptr_leaks = capable(CAP_SYS_ADMIN); - - ret = do_check(env); - -skip_full_check: - while (pop_stack(env, NULL) >= 0); - free_states(env); - - mutex_unlock(&bpf_verifier_lock); - vfree(env->insn_aux_data); -err_free_env: - kfree(env); - return ret; -} -EXPORT_SYMBOL_GPL(bpf_analyzer); |