From: Steven Rostedt rostedt@goodmis.org

Running the following commands was broken:

# cd /sys/kernel/tracing # echo "filename.ustring ~ "/proc*"" > events/syscalls/sys_enter_openat/filter # echo 1 > events/syscalls/sys_enter_openat/enable # ls /proc/$$/maps # cat trace

And would produce nothing when it should have produced something like:

ls-1192 [007] ..... 8169.828333: sys_openat(dfd: ffffffffffffff9c, filename: 7efc18359904, flags: 80000, mode: 0)

Add a test to check this case so that it will be caught if it breaks again.

Link: https://lore.kernel.org/linux-trace-kernel/20250417183003.505835fb@gandalf.l...

Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org --- Changes since v1: https://lore.kernel.org/20250417223323.3edb4f6c@batman.local.home

- Use $TMPDIR instead of $TESTDIR as test file (Masami Hiramatsu)

.../test.d/filter/event-filter-function.tc | 20 +++++++++++++++++++ 1 file changed, 20 insertions(+)

diff --git a/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc b/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc index 118247b8dd84..c62165fabd0c 100644 --- a/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc +++ b/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc @@ -80,6 +80,26 @@ if [ $misscnt -gt 0 ]; then exit_fail fi

+# Check strings too +if [ -f events/syscalls/sys_enter_openat/filter ]; then + DIRNAME=`basename $TMPDIR` + echo "filename.ustring ~ "*$DIRNAME*"" > events/syscalls/sys_enter_openat/filter + echo 1 > events/syscalls/sys_enter_openat/enable + echo 1 > tracing_on + ls /bin/sh + nocnt=`grep openat trace | wc -l` + ls $TMPDIR + echo 0 > tracing_on + hitcnt=`grep openat trace | wc -l`; + echo 0 > events/syscalls/sys_enter_openat/enable + if [ $nocnt -gt 0 ]; then + exit_fail + fi + if [ $hitcnt -eq 0 ]; then + exit_fail + fi +fi + reset_events_filter

exit 0