Re: [PATCH PATCH 2/2] selftests: livepatch: test if ftrace can trace a livepatched function

From: Miroslav Benes
Date: Fri Mar 14 2025 - 09:17:03 EST


Hi,

> +start_test "trace livepatched function and check that the live patch remains in effect"
> +
> +FUNCTION_NAME="livepatch_cmdline_proc_show"
> +
> +load_lp $MOD_LIVEPATCH
> +trace_function "$FUNCTION_NAME"

trace_funtion() calls cleanup_ftrace() to prepare the test. Ok.

> +if [[ "$(cat /proc/cmdline)" == "$MOD_LIVEPATCH: this has been live patched" ]] ; then
> + log "livepatch: ok"
> +fi
> +
> +check_traced_function "$FUNCTION_NAME"
> +
> +cleanup_tracing

Here, I suppose, cleanup_tracing() is called to clean up after the check
above so that nothing stays and more tests can be added later. Right?
Would it make sense then to call cleanup_tracing() in
check_traced_function()? I think it would less error prone.
If needed, check_traced_function() can always be upgraded so that it
checks for more traced functions.

Miroslav