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 <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Reviewed-by: Yong Zhang <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]>
kishon · Feb 4, 2011 · f266a51 · f266a51
1 parent 831d52b
commit f266a51
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/kernel/timer.c b/kernel/timer.c
@@ -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