From: "Steven Rostedt (VMware)" rostedt@goodmis.org

Add a function to remove all dynamic events from the tracing directory. It requires a loop as some of the dynamic events may depend on others being removed first. Also add a safety that prevents it from looping infinitely due to a bug where an event never gets removed.

Link: https://lkml.kernel.org/r/20210819152825.348941368@goodmis.org

Cc: Shuah Khan shuah@kernel.org Cc: Shuah Khan skhan@linuxfoundation.org Cc: linux-kselftest@vger.kernel.org Acked-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org --- .../testing/selftests/ftrace/test.d/functions | 22 +++++++++++++++++++ 1 file changed, 22 insertions(+)

diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions index a6fac927ee82..f68d336b961b 100644 --- a/tools/testing/selftests/ftrace/test.d/functions +++ b/tools/testing/selftests/ftrace/test.d/functions @@ -83,6 +83,27 @@ clear_synthetic_events() { # reset all current synthetic events done }

+clear_dynamic_events() { # reset all current dynamic events + again=1 + stop=1 + # loop mulitple times as some events require other to be removed first + while [ $again -eq 1 ]; do + stop=$((stop+1)) + # Prevent infinite loops + if [ $stop -gt 10 ]; then + break; + fi + again=2 + grep -v '^#' dynamic_events| + while read line; do + del=`echo $line | sed -e 's/^.([^ ]*).*/-\1/'` + if ! echo "$del" >> dynamic_events; then + again=1 + fi + done + done +} + initialize_ftrace() { # Reset ftrace to initial-state # As the initial state, ftrace will be set to nop tracer, # no events, no triggers, no filters, no function filters, @@ -93,6 +114,7 @@ initialize_ftrace() { # Reset ftrace to initial-state reset_events_filter reset_ftrace_filter disable_events + clear_dynamic_events [ -f set_event_pid ] && echo > set_event_pid [ -f set_ftrace_pid ] && echo > set_ftrace_pid [ -f set_ftrace_notrace ] && echo > set_ftrace_notrace