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| author | Jiri Olsa <jolsa@kernel.org> | 2022-09-26 17:33:39 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-09-26 20:30:40 -0700 |
| commit | 0e253f7e558a3e250902ba2034091e0185448836 (patch) | |
| tree | 060afdb7e12dbcbff8912660496c5bf85d7ff656 /kernel | |
| parent | c09eb2e578eb1668bbc84dc07e8d8bd6f04b9a02 (diff) | |
| download | linux-0e253f7e558a3e250902ba2034091e0185448836.tar.gz | |
bpf: Return value in kprobe get_func_ip only for entry address
Changing return value of kprobe's version of bpf_get_func_ip to return zero if the attach address is not on the function's entry point. For kprobes attached in the middle of the function we can't easily get to the function address especially now with the CONFIG_X86_KERNEL_IBT support. If user cares about current IP for kprobes attached within the function body, they can get it with PT_REGS_IP(ctx). Suggested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Martynas Pumputis <m@lambda.lt> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20220926153340.1621984-6-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index ebd1b348beb3..688552df95ca 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1048,7 +1048,10 @@ BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) { struct kprobe *kp = kprobe_running(); - return kp ? (uintptr_t)kp->addr : 0; + if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) + return 0; + + return get_entry_ip((uintptr_t)kp->addr); } static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { |