Re: [PATCH v3] tracing/kprobes: Skip symbol counting logic for module symbols in create_local_trace_kprobe()

From: Google
Date: Wed Dec 18 2024 - 20:17:53 EST


On Mon, 16 Dec 2024 19:11:45 +0300
Nikolay Kuratov <kniv@xxxxxxxxxxxxxx> wrote:

> commit b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols")
> avoids checking number_of_same_symbols() for module symbol in
> __trace_kprobe_create(), but create_local_trace_kprobe() should avoid this
> check too. Doing this check leads to ENOENT for module_name:symbol_name
> constructions passed over perf_event_open.
>
> No bug in mainline and 6.12 as those contain more general fix
> commit 9d8616034f16 ("tracing/kprobes: Add symbol counting check when module loads")

Thanks! It seems Greg already queued v2 for stable kernels, and
it seems no theoletical change in this version.

Thank you,

>
> Link: https://lore.kernel.org/linux-trace-kernel/20240705161030.b3ddb33a8167013b9b1da202@xxxxxxxxxx
> Fixes: b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols")
> Signed-off-by: Nikolay Kuratov <kniv@xxxxxxxxxxxxxx>
> ---
> v1 -> v2:
> * Reword commit title and message
> * Send for stable instead of mainline
> v2 -> v3:
> * Specify first good LTS version in commit message
> * Remove explicit versions from the subject since 6.1 and 5.10 need fix too
>
> kernel/trace/trace_kprobe.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 12d997bb3e78..94cb09d44115 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -1814,7 +1814,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
> int ret;
> char *event;
>
> - if (func) {
> + if (func && !strchr(func, ':')) {
> unsigned int count;
>
> count = number_of_same_symbols(func);
> --
> 2.34.1
>


--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>