Commit da7446d3 authored by Kaitao Cheng's avatar Kaitao Cheng Committed by Wenyu Huang
Browse files

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

stable inclusion
from stable-v4.19.297
commit 50f9ad60
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8BAW8

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=50f9ad607ea891a9308e67b81f774c71736d109

--------------------------------

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: default avatarKaitao Cheng <pilgrimtao@gmail.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: default avatarWenyu Huang <huangwenyu4@huawei.com>
parent 713c5508

kernel/trace/trace_sched_wakeup.c

+3 −1
Original line number Diff line number Diff line
@@ -642,7 +642,7 @@ 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);
@@ -660,6 +660,8 @@ 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: