diff options
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 56 |
1 files changed, 44 insertions, 12 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 3bc2ed2e171b..e6a0a948e30c 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2154,14 +2154,14 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) prog->expected_attach_type = attr->expected_attach_type; prog->aux->attach_btf_id = attr->attach_btf_id; if (attr->attach_prog_fd) { - struct bpf_prog *tgt_prog; + struct bpf_prog *dst_prog; - tgt_prog = bpf_prog_get(attr->attach_prog_fd); - if (IS_ERR(tgt_prog)) { - err = PTR_ERR(tgt_prog); + dst_prog = bpf_prog_get(attr->attach_prog_fd); + if (IS_ERR(dst_prog)) { + err = PTR_ERR(dst_prog); goto free_prog_nouncharge; } - prog->aux->linked_prog = tgt_prog; + prog->aux->dst_prog = dst_prog; } prog->aux->offload_requested = !!attr->prog_ifindex; @@ -2498,11 +2498,23 @@ struct bpf_link *bpf_link_get_from_fd(u32 ufd) struct bpf_tracing_link { struct bpf_link link; enum bpf_attach_type attach_type; + struct bpf_trampoline *trampoline; + struct bpf_prog *tgt_prog; }; static void bpf_tracing_link_release(struct bpf_link *link) { - WARN_ON_ONCE(bpf_trampoline_unlink_prog(link->prog)); + struct bpf_tracing_link *tr_link = + container_of(link, struct bpf_tracing_link, link); + + WARN_ON_ONCE(bpf_trampoline_unlink_prog(link->prog, + tr_link->trampoline)); + + bpf_trampoline_put(tr_link->trampoline); + + /* tgt_prog is NULL if target is a kernel function */ + if (tr_link->tgt_prog) + bpf_prog_put(tr_link->tgt_prog); } static void bpf_tracing_link_dealloc(struct bpf_link *link) @@ -2545,7 +2557,9 @@ static const struct bpf_link_ops bpf_tracing_link_lops = { static int bpf_tracing_prog_attach(struct bpf_prog *prog) { struct bpf_link_primer link_primer; + struct bpf_prog *tgt_prog = NULL; struct bpf_tracing_link *link; + struct bpf_trampoline *tr; int err; switch (prog->type) { @@ -2583,19 +2597,37 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog) &bpf_tracing_link_lops, prog); link->attach_type = prog->expected_attach_type; - err = bpf_link_prime(&link->link, &link_primer); - if (err) { - kfree(link); - goto out_put_prog; + mutex_lock(&prog->aux->dst_mutex); + + if (!prog->aux->dst_trampoline) { + err = -ENOENT; + goto out_unlock; } + tr = prog->aux->dst_trampoline; + tgt_prog = prog->aux->dst_prog; + + err = bpf_link_prime(&link->link, &link_primer); + if (err) + goto out_unlock; - err = bpf_trampoline_link_prog(prog); + err = bpf_trampoline_link_prog(prog, tr); if (err) { bpf_link_cleanup(&link_primer); - goto out_put_prog; + link = NULL; + goto out_unlock; } + link->tgt_prog = tgt_prog; + link->trampoline = tr; + + prog->aux->dst_prog = NULL; + prog->aux->dst_trampoline = NULL; + mutex_unlock(&prog->aux->dst_mutex); + return bpf_link_settle(&link_primer); +out_unlock: + mutex_unlock(&prog->aux->dst_mutex); + kfree(link); out_put_prog: bpf_prog_put(prog); return err; |