From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Thu, 29 Nov 2012 08:46:03 +0000 (+0800)
Subject: srcu: Add might_sleep() annotation to synchronize_srcu()
X-Git-Tag: v3.12-rc1~1454^2^2~6
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6e6f1b307e23201fb3e7aaf16322e80355d2a3d5;p=kernel%2Fkernel-generic.git

srcu: Add might_sleep() annotation to synchronize_srcu()

Although synchronize_srcu() can sleep, it will not sleep if the fast
path succeeds, which means that illegal use of synchronize_rcu()
might go unnoticed.  This commit therefore adds might_sleep(), which
unconditionally catches illegal use of synchronize_rcu() from atomic
context.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---

diff --git a/kernel/srcu.c b/kernel/srcu.c
index c9d003b..3e43a21 100644
--- a/kernel/srcu.c
+++ b/kernel/srcu.c
@@ -421,6 +421,7 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount)
 			   !lock_is_held(&rcu_sched_lock_map),
 			   "Illegal synchronize_srcu() in same-type SRCU (or RCU) read-side critical section");
 
+	might_sleep();
 	init_completion(&rcu.completion);
 
 	head->next = NULL;