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| author | Lukas Wunner <lukas@wunner.de> | 2023-09-15 09:55:39 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-09-23 11:14:33 +0200 |
| commit | 57e0917c5ded2376f00338e885314838df2a17a9 (patch) | |
| tree | a342f405722c2da0ba2acb77b040253b4e7f2a54 /kernel | |
| parent | 03c02f826f736b473fc13eac6baf5ffc8c7379bc (diff) | |
| download | linux-57e0917c5ded2376f00338e885314838df2a17a9.tar.gz linux-57e0917c5ded2376f00338e885314838df2a17a9.tar.bz2 linux-57e0917c5ded2376f00338e885314838df2a17a9.zip | |
panic: Reenable preemption in WARN slowpath
[ Upstream commit cccd32816506cbac3a4c65d9dff51b3125ef1a03 ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -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 10effe40a3fa..ea1c5fcb2d19 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; } |