commit 01f36a554e upstream.
trace_printk schedules work via irq_work_queue(), but doesn't
wait until it was processed. The kprobe_module.tc testcase does:
:;: "Load module again, which means the event1 should be recorded";:
modprobe trace-printk
grep "event1:" trace
so the grep which checks the trace file might run before the irq work
was processed. Fix this by adding a irq_work_sync().
Link: http://lore.kernel.org/linux-trace-devel/20191218074427.96184-3-svens@linux.ibm.com
Cc: stable@vger.kernel.org
Fixes: af2a0750f3 ("selftests/ftrace: Improve kprobe on module testcase to load/unload module")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>