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| author | Ye Weihua <yeweihua4@huawei.com> | 2025-08-18 07:33:32 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-04 15:31:42 +0200 |
| commit | 2a2deb9f8df70480050351ac27041f19bb9e718b (patch) | |
| tree | c9d4dbd09b052e17446314c8779fb6dc7d46ed4a | |
| parent | f471b3e24d1ec7c79f51e671b8cf5ff8d52d40ff (diff) | |
trace/fgraph: Fix the warning caused by missing unregister notifier
[ Upstream commit edede7a6dcd7435395cf757d053974aaab6ab1c2 ]
This warning was triggered during testing on v6.16:
notifier callback ftrace_suspend_notifier_call already registered
WARNING: CPU: 2 PID: 86 at kernel/notifier.c:23 notifier_chain_register+0x44/0xb0
...
Call Trace:
<TASK>
blocking_notifier_chain_register+0x34/0x60
register_ftrace_graph+0x330/0x410
ftrace_profile_write+0x1e9/0x340
vfs_write+0xf8/0x420
? filp_flush+0x8a/0xa0
? filp_close+0x1f/0x30
? do_dup2+0xaf/0x160
ksys_write+0x65/0xe0
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x77/0x7f
When writing to the function_profile_enabled interface, the notifier was
not unregistered after start_graph_tracing failed, causing a warning the
next time function_profile_enabled was written.
Fixed by adding unregister_pm_notifier in the exception path.
Link: https://lore.kernel.org/20250818073332.3890629-1-yeweihua4@huawei.com
Fixes: 4a2b8dda3f870 ("tracing/function-graph-tracer: fix a regression while suspend to disk")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Ye Weihua <yeweihua4@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/trace/fgraph.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index c12335499ec9..2eed8bc672f9 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -1316,6 +1316,7 @@ error: ftrace_graph_active--; gops->saved_func = NULL; fgraph_lru_release_index(i); + unregister_pm_notifier(&ftrace_suspend_notifier); } return ret; } |