On Mon, 20 May 2024 20:57:37 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
>
> The kprobe_eventname.tc test checks if a function with .isra. can have a
> kprobe attached to it. It loops through the kallsyms file for all the
> functions that have the .isra. name, and checks if it exists in the
> available_filter_functions file, and if it does, it uses it to attach a
> kprobe to it.
>
> The issue is that kprobes can not attach to functions that are listed more
> than once in available_filter_functions. With the latest kernel, the
> function that is found is: rapl_event_update.isra.0
>
> # grep rapl_event_update.isra.0 /sys/kernel/tracing/available_filter_functions
> rapl_event_update.isra.0
> rapl_event_update.isra.0
>
> It is listed twice. This causes the attached kprobe to it to fail which in
> turn fails the test. Instead of just picking the function function that is
> found in available_filter_functions, pick the first one that is listed
> only once in available_filter_functions.
>
Looks good to me.
Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Thanks!
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 604e3548236de ("selftests/ftrace: Select an existing function in kprobe_eventname test")
> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
> ---
> .../testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> index 1f6981ef7afa..ba19b81cef39 100644
> --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> @@ -30,7 +30,8 @@ find_dot_func() {
> fi
>
> grep " [tT] .*\.isra\..*" /proc/kallsyms | cut -f 3 -d " " | while read f; do
> - if grep -s $f available_filter_functions; then
> + cnt=`grep -s $f available_filter_functions | wc -l`;
> + if [ $cnt -eq 1 ]; then
> echo $f
> break
> fi
> --
> 2.43.0
>
--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
