Commit 5ab4bb7b authored Dec 31, 2019 by Kaitao Cheng Committed by Greg Kroah-Hartman Jan 14, 2020

kernel/trace: Fix do not unregister tracepoints when register sched_migrate_task fail

commit 50f9ad607ea891a9308e67b81f774c71736d1098 upstream.

In the function, if register_trace_sched_migrate_task() returns error,
sched_switch/sched_wakeup_new/sched_wakeup won't unregister. That is
why fail_deprobe_sched_switch was added.

Link: http://lkml.kernel.org/r/20191231133530.2794-1-pilgrimtao@gmail.com



Cc: stable@vger.kernel.org
Fixes: 478142c3 ("tracing: do not grab lock in wakeup latency function tracing")
Signed-off-by: Kaitao Cheng <pilgrimtao@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 53a13c56

kernel/trace/trace_sched_wakeup.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -640,7 +640,7 @@ static void start_wakeup_tracer(struct trace_array *tr)
		if (ret) {
		pr_info("wakeup trace: Couldn't activate tracepoint"
		" probe to kernel_sched_migrate_task\n");
		return;
		goto fail_deprobe_sched_switch;
		}

		wakeup_reset(tr);
		@@ -658,6 +658,8 @@ static void start_wakeup_tracer(struct trace_array *tr)
		printk(KERN_ERR "failed to start wakeup tracer\n");

		return;
		fail_deprobe_sched_switch:
		unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL);
		fail_deprobe_wake_new:
		unregister_trace_sched_wakeup_new(probe_wakeup, NULL);
		fail_deprobe: