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| author | Lukas Wunner <lukas@wunner.de> | 2023-09-15 09:55:39 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-09-15 11:28:08 +0200 |
| commit | cccd32816506cbac3a4c65d9dff51b3125ef1a03 (patch) | |
| tree | 84b555d90d1c8e45aac145cd27fa95643184d532 | |
| parent | 9fdfb15a3dbf818e06be514f4abbfc071004cbe7 (diff) | |
| download | lwn-cccd32816506cbac3a4c65d9dff51b3125ef1a03.tar.gz lwn-cccd32816506cbac3a4c65d9dff51b3125ef1a03.zip | |
panic: Reenable preemption in WARN slowpath
Commit:
5a5d7e9badd2 ("cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG")
amended warn_slowpath_fmt() to disable preemption until the WARN splat
has been emitted.
However the commit neglected to reenable preemption in the !fmt codepath,
i.e. when a WARN splat is emitted without additional format string.
One consequence is that users may see more splats than intended. E.g. a
WARN splat emitted in a work item results in at least two extra splats:
BUG: workqueue leaked lock or atomic
(emitted by process_one_work())
BUG: scheduling while atomic
(emitted by worker_thread() -> schedule())
Ironically the point of the commit was to *avoid* extra splats. ;)
Fix it.
Fixes: 5a5d7e9badd2 ("cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/3ec48fde01e4ee6505f77908ba351bad200ae3d1.1694763684.git.lukas@wunner.de
| -rw-r--r-- | kernel/panic.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/panic.c b/kernel/panic.c index 07239d4ad81e..ffa037fa777d 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -697,6 +697,7 @@ void warn_slowpath_fmt(const char *file, int line, unsigned taint, if (!fmt) { __warn(file, line, __builtin_return_address(0), taint, NULL, NULL); + warn_rcu_exit(rcu); return; } |