From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Wed, 23 Feb 2011 17:56:00 +0000 (-0800)
Subject: rcu: Use WARN_ON_ONCE for DEBUG_OBJECTS_RCU_HEAD warnings
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=108aae22339f445c134aeb48eca25df1014ab08d;p=deliverable%2Flinux.git

rcu: Use WARN_ON_ONCE for DEBUG_OBJECTS_RCU_HEAD warnings

Avoid additional multiple-warning confusion in memory-corruption scenarios.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
---

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index b54d6d18258c..7784bd216b6a 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -147,12 +147,12 @@ static int rcuhead_fixup_init(void *addr, enum debug_obj_state state)
 		 * attempt any fixup and just print a warning.
 		 */
 #ifndef CONFIG_PREEMPT
-		WARN_ON(1);
+		WARN_ON_ONCE(1);
 		return 0;
 #endif
 		if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
 		    irqs_disabled()) {
-			WARN_ON(1);
+			WARN_ON_ONCE(1);
 			return 0;
 		}
 		rcu_barrier();
@@ -196,12 +196,12 @@ static int rcuhead_fixup_activate(void *addr, enum debug_obj_state state)
 		 * attempt any fixup and just print a warning.
 		 */
 #ifndef CONFIG_PREEMPT
-		WARN_ON(1);
+		WARN_ON_ONCE(1);
 		return 0;
 #endif
 		if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
 		    irqs_disabled()) {
-			WARN_ON(1);
+			WARN_ON_ONCE(1);
 			return 0;
 		}
 		rcu_barrier();
@@ -233,12 +233,12 @@ static int rcuhead_fixup_free(void *addr, enum debug_obj_state state)
 		 * attempt any fixup and just print a warning.
 		 */
 #ifndef CONFIG_PREEMPT
-		WARN_ON(1);
+		WARN_ON_ONCE(1);
 		return 0;
 #endif
 		if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
 		    irqs_disabled()) {
-			WARN_ON(1);
+			WARN_ON_ONCE(1);
 			return 0;
 		}
 		rcu_barrier();