From 6b898c07cb1d5bd8344a8044288bb4ae3873da74 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 17 Sep 2012 23:03:31 +0000 Subject: [PATCH] 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 Cc: Thomas Gleixner Cc: Alan Cox Cc: Peter Zijlstra Signed-off-by: Daniel Vetter Signed-off-by: Greg Kroah-Hartman --- kernel/printk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) 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; -- 2.30.2