Re: [PATCH 2/3] selftests/ftrace: Pick only the first kprobe event to test

[Steven Rostedt]

On Fri,  1 May 2020 22:37:51 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> Since the kprobe/kprobe_args_type.tc reads out all event logs
> from the trace buffer, the test can fail if there is another
> fork event happens.
> Use head command to pick only the first kprobe event from
> the trace buffer to test the argument types.
> 
> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> ---
>  .../ftrace/test.d/kprobe/kprobe_args_type.tc       |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_type.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_type.tc
> index 1bcb67dcae26..81490ecaaa92 100644
> --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_type.tc
> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_type.tc
> @@ -38,7 +38,7 @@ for width in 64 32 16 8; do
>    echo 0 > events/kprobes/testprobe/enable
>  
>    : "Confirm the arguments is recorded in given types correctly"
> -  ARGS=`grep "testprobe" trace | sed -e 's/.* arg1=\(.*\) arg2=\(.*\) arg3=\(.*\) arg4=\(.*\)/\1 \2 \3 \4/'`
> +  ARGS=`grep "testprobe" trace | head -n 1 | sed -e 's/.* arg1=\(.*\) arg2=\(.*\) arg3=\(.*\) arg4=\(.*\)/\1 \2 \3 \4/'`
>    check_types $ARGS $width
>  
>    : "Clear event for next loop"

I think I've manually added this exact change to my tests to keep it from
failing.

Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

-- Steve