[PATCH 2/2] timer: use local_bh_enable_force_wake() in del_timer_sync()

[Yong Zhang <yong.zhang0@gmail.com>]

From: Yong Zhang <yong.zhang0@gmail.com>
Subject: [PATCH 2/2] timer: use local_bh_enable_force_wake() in del_timer_sync()

raw_local_irq_save()/raw_local_irq_restore() is also not suitable
here because lockdep will report "possible reason: unannotated irqs-off"

To cure this issue, use local_bh_enable_force_wake() here in case of
we have pending softirq left during this time.

Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 kernel/timer.c |    6 +-----
 1 files changed, 1 insertions(+), 5 deletions(-)

diff --git a/kernel/timer.c b/kernel/timer.c
index d53ce66..1654dc1 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -969,14 +969,10 @@ 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();
-	raw_local_irq_restore(flags);
+	local_bh_enable_force_wake();
 #endif
 	/*
 	 * don't use it in hardirq context, because it
-- 
1.7.1