Commit f266a511 authored Feb 03, 2011 by Peter Zijlstra Committed by Thomas Gleixner Feb 04, 2011

lockdep, timer: Fix del_timer_sync() annotation



Calling local_bh_enable() will want to actually start processing
softirqs, which isn't a good idea since this can get called with IRQs
disabled.

Cure this by using _local_bh_enable() which doesn't start processing
softirqs, and use raw_local_irq_save() to avoid any softirqs from
happening without letting lockdep think IRQs are in fact disabled.

Reported-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
LKML-Reference: <20110203141548.039540914@chello.nl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent 831d52bc

kernel/timer.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -969,10 +969,14 @@ EXPORT_SYMBOL(try_to_del_timer_sync);
		int del_timer_sync(struct timer_list *timer)
		{
		#ifdef CONFIG_LOCKDEP
		unsigned long flags;

		raw_local_irq_save(flags);
		local_bh_disable();
		lock_map_acquire(&timer->lockdep_map);
		lock_map_release(&timer->lockdep_map);
		local_bh_enable();
		_local_bh_enable();
		raw_local_irq_restore(flags);
		#endif
		/*
		* don't use it in hardirq context, because it

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