[PATCH v9 2/6] selftests/ftrace: Add clear_dynamic_events() to test cases

Steven Rostedt
2021-08-20T20:47:47Z

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
--
2.30.2