diff options
| author | Jiri Olsa <jolsa@redhat.com> | 2021-07-14 12:43:56 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-07-16 03:59:09 +0300 |
| commit | 9ffd9f3ff7193933dae171740ab70a103d460065 (patch) | |
| tree | a274a2d5bad87bc289efe4c3da0da20bf2e8eed8 | |
| parent | 9b99edcae5c80c8fb9f8e7149bae528c9e610a72 (diff) | |
| download | linux-9ffd9f3ff7193933dae171740ab70a103d460065.tar.xz | |
bpf: Add bpf_get_func_ip helper for kprobe programs
Adding bpf_get_func_ip helper for BPF_PROG_TYPE_KPROBE programs,
so it's now possible to call bpf_get_func_ip from both kprobe and
kretprobe programs.
Taking the caller's address from 'struct kprobe::addr', which is
defined for both kprobe and kretprobe.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/20210714094400.396467-5-jolsa@kernel.org
| -rw-r--r-- | include/uapi/linux/bpf.h | 2 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 2 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 16 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 2 |
4 files changed, 20 insertions, 2 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 89688f16ad60..2db6925e04f4 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4844,7 +4844,7 @@ union bpf_attr { * * u64 bpf_get_func_ip(void *ctx) * Description - * Get address of the traced function (for tracing programs). + * Get address of the traced function (for tracing and kprobe programs). * Return * Address of the traced function. */ diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ceef190514e4..97216f799ba8 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6175,6 +6175,8 @@ static int check_get_func_ip(struct bpf_verifier_env *env) return -ENOTSUPP; } return 0; + } else if (type == BPF_PROG_TYPE_KPROBE) { + return 0; } verbose(env, "func %s#%d not supported for program type %d\n", diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 3e71503eeb23..0b113716bc7a 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -961,6 +961,20 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { .arg1_type = ARG_PTR_TO_CTX, }; +BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) +{ + struct kprobe *kp = kprobe_running(); + + return kp ? (u64) kp->addr : 0; +} + +static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { + .func = bpf_get_func_ip_kprobe, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -1092,6 +1106,8 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_override_return: return &bpf_override_return_proto; #endif + case BPF_FUNC_get_func_ip: + return &bpf_get_func_ip_proto_kprobe; default: return bpf_tracing_func_proto(func_id, prog); } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 89688f16ad60..2db6925e04f4 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4844,7 +4844,7 @@ union bpf_attr { * * u64 bpf_get_func_ip(void *ctx) * Description - * Get address of the traced function (for tracing programs). + * Get address of the traced function (for tracing and kprobe programs). * Return * Address of the traced function. */ |