diff options
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 1 | ||||
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | kernel/bpf/core.c | 33 |
3 files changed, 34 insertions, 1 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 15672cb926fc..40e1b3b9634f 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -3845,7 +3845,6 @@ void arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp } return; #endif - WARN(1, "verification of programs using bpf_throw should have failed\n"); } void bpf_arch_poke_desc_update(struct bpf_jit_poke_descriptor *poke, diff --git a/include/linux/bpf.h b/include/linux/bpf.h index c3802af11bac..b267c378d884 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -3663,5 +3663,6 @@ static inline bool bpf_is_subprog(const struct bpf_prog *prog) int bpf_prog_get_file_line(struct bpf_prog *prog, unsigned long ip, const char **filep, const char **linep, int *nump); +struct bpf_prog *bpf_prog_find_from_stack(void); #endif /* _LINUX_BPF_H */ diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 833442661742..037d67cf5fb1 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -3262,4 +3262,37 @@ int bpf_prog_get_file_line(struct bpf_prog *prog, unsigned long ip, const char * return 0; } +struct walk_stack_ctx { + struct bpf_prog *prog; +}; + +static bool find_from_stack_cb(void *cookie, u64 ip, u64 sp, u64 bp) +{ + struct walk_stack_ctx *ctxp = cookie; + struct bpf_prog *prog; + + /* + * The RCU read lock is held to safely traverse the latch tree, but we + * don't need its protection when accessing the prog, since it has an + * active stack frame on the current stack trace, and won't disappear. + */ + rcu_read_lock(); + prog = bpf_prog_ksym_find(ip); + rcu_read_unlock(); + if (!prog) + return true; + if (bpf_is_subprog(prog)) + return true; + ctxp->prog = prog; + return false; +} + +struct bpf_prog *bpf_prog_find_from_stack(void) +{ + struct walk_stack_ctx ctx = {}; + + arch_bpf_stack_walk(find_from_stack_cb, &ctx); + return ctx.prog; +} + #endif |