Re: [PATCH 5/5] selftests/ftrace: Update fprobe test to check enabled_functions file

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

On Tue, 18 Feb 2025 14:30:38 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> From: Steven Rostedt <rostedt@goodmis.org>
> 
> A few bugs were found in the fprobe accounting logic along with it using
> the function graph infrastructure. Update the fprobe selftest to catch
> those bugs in case they or something similar shows up in the future.
> 
> The test now checks the enabled_functions file which shows all the
> functions attached to ftrace or fgraph. When enabling a fprobe, make sure
> that its corresponding function is also added to that file. Also add two
> more fprobes to enable to make sure that the fprobe logic works properly
> with multiple probes.

This looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

BTW, would I pick the last 3 patches via probes/fixes branch?

Thanks,

> 
> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> ---
>  .../test.d/dynevent/add_remove_fprobe.tc      | 54 +++++++++++++++++++
>  1 file changed, 54 insertions(+)
> 
> diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc
> index dc25bcf4f9e2..449f9d8be746 100644
> --- a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc
> +++ b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc
> @@ -7,12 +7,38 @@ echo 0 > events/enable
>  echo > dynamic_events
>  
>  PLACE=$FUNCTION_FORK
> +PLACE2="kmem_cache_free"
> +PLACE3="schedule_timeout"
>  
>  echo "f:myevent1 $PLACE" >> dynamic_events
> +
> +# Make sure the event is attached and is the only one
> +grep -q $PLACE enabled_functions
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne 1 ]; then
> +	exit_fail
> +fi
> +
>  echo "f:myevent2 $PLACE%return" >> dynamic_events
>  
> +# It should till be the only attached function
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne 1 ]; then
> +	exit_fail
> +fi
> +
> +# add another event
> +echo "f:myevent3 $PLACE2" >> dynamic_events
> +
> +grep -q $PLACE2 enabled_functions
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne 2 ]; then
> +	exit_fail
> +fi
> +
>  grep -q myevent1 dynamic_events
>  grep -q myevent2 dynamic_events
> +grep -q myevent3 dynamic_events
>  test -d events/fprobes/myevent1
>  test -d events/fprobes/myevent2
>  
> @@ -21,6 +47,34 @@ echo "-:myevent2" >> dynamic_events
>  grep -q myevent1 dynamic_events
>  ! grep -q myevent2 dynamic_events
>  
> +# should still have 2 left
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne 2 ]; then
> +	exit_fail
> +fi
> +
>  echo > dynamic_events
>  
> +# Should have none left
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne 0 ]; then
> +	exit_fail
> +fi
> +
> +echo "f:myevent4 $PLACE" >> dynamic_events
> +
> +# Should only have one enabled
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne 1 ]; then
> +	exit_fail
> +fi
> +
> +echo > dynamic_events
> +
> +# Should have none left
> +cnt=`cat enabled_functions | wc -l`
> +if [ $cnt -ne 0 ]; then
> +	exit_fail
> +fi
> +
>  clear_trace
> -- 
> 2.47.2
> 
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>