[PATCH 2/2] selftests/ftrace: Reset triggers at top level before instance loop

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

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

When running instance tests, 'ftracetest' creates a new ftrace instance
and runs the tests inside it. Before starting each test, it executes
'initialize_system()' to reset the ftrace state to initial-state.

However, since 'initialize_system()' is executed in the context of the
instance directory, it only cleans up triggers and filters of that
instance.
Any triggers or dynamic events left behind in the top-level instance by
previous failed top-level tests, are left completely untouched. These
top-level leftovers can cause subsequent instance-based tests to fail
or even crash the kernel.

Fix this by executing 'initialize_system()' in the top-level tracing
directory once before entering the instance loop.

Fixes: b5b77be812de ("selftests: ftrace: Allow some tests to be run in a tracing instance")
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 tools/testing/selftests/ftrace/ftracetest |    1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/ftrace/ftracetest b/tools/testing/selftests/ftrace/ftracetest
index 0a56bf209f6c..8ad2c385407e 100755
--- a/tools/testing/selftests/ftrace/ftracetest
+++ b/tools/testing/selftests/ftrace/ftracetest
@@ -503,6 +503,7 @@ for t in $TEST_CASES; do
 done
 
 # Test on instance loop
+(cd $TRACING_DIR; initialize_system)
 INSTANCE=" (instance) "
 for t in $TEST_CASES; do
   test_on_instance $t || continue