Commit 9ffd9f3f authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov

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: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Reviewed-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/20210714094400.396467-5-jolsa@kernel.org
parent 9b99edca
......@@ -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.
*/
......
......@@ -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",
......
......@@ -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);
}
......
......@@ -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.
*/
......
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