diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-09-17 23:03:31 +0000 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-23 20:14:55 -0700 |
commit | 6b898c07cb1d5bd8344a8044288bb4ae3873da74 (patch) | |
tree | 746c283ebf35c7e038b28fee4f7a094f1b885db2 /kernel | |
parent | ecbbfd44a08fa80e0d664814efd4c187721b85f6 (diff) | |
download | linux-6b898c07cb1d5bd8344a8044288bb4ae3873da74.tar.bz2 |
console: use might_sleep in console_lock
Instead of BUG_ON(in_interrupt()), since that doesn't check for all
the newfangled stuff like preempt.
Note that this is valid since the console_sem is essentially used like
a real mutex with only two twists:
- we allow trylock from hardirq context
- across suspend/resume we lock the logical console_lock, but drop the
semaphore protecting the locking state.
Now that doesn't guarantee that no one is playing tricks in
single-thread atomic contexts at suspend/resume/boot time, but
- I couldn't find anything suspicious with some grepping,
- might_sleep shouldn't die,
- and I think the upside of catching more potential issues is worth
the risk of getting a might_sleep backtrace that would have been
save (and then dealing with that fallout).
Cc: Dave Airlie <airlied@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/printk.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/printk.c b/kernel/printk.c index ee79f14db358..22e070f3470a 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1914,7 +1914,8 @@ static int __cpuinit console_cpu_notify(struct notifier_block *self, */ void console_lock(void) { - BUG_ON(in_interrupt()); + might_sleep(); + down(&console_sem); if (console_suspended) return; |