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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Lai Jiangshan <laijs@cn.fujitsu.com>,
	Darren Hart <dvhart@linux.intel.com>,
	Richard Weinberger <richard@nod.at>
Subject: [PATCH 2/2] futex: Fix WARN_ON() test for UP
Date: Thu, 17 Mar 2011 15:21:07 -0400	[thread overview]
Message-ID: <20110317192208.682654502@goodmis.org> (raw)
In-Reply-To: 20110317192105.308382309@goodmis.org

[-- Attachment #1: 0002-futex-Fix-WARN_ON-test-for-UP.patch --]
[-- Type: text/plain, Size: 1077 bytes --]

From: Steven Rostedt <srostedt@redhat.com>

An update of the futex code had a

	WARN_ON(!spin_is_locked(q->lock_ptr))

But on UP, spin_is_locked() is always false, and will
trigger this warning, and even worse, it will exit the function
without doing the necessary work.

Converting this to a WARN_ON_SMP() fixes the problem.

Reported-by: Richard Weinberger <richard@nod.at>
Tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/futex.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index 9fe9131..850d00b 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -785,8 +785,8 @@ static void __unqueue_futex(struct futex_q *q)
 {
 	struct futex_hash_bucket *hb;
 
-	if (WARN_ON(!q->lock_ptr || !spin_is_locked(q->lock_ptr)
-			|| plist_node_empty(&q->list)))
+	if (WARN_ON_SMP(!q->lock_ptr || !spin_is_locked(q->lock_ptr))
+	    || WARN_ON(plist_node_empty(&q->list)))
 		return;
 
 	hb = container_of(q->lock_ptr, struct futex_hash_bucket, lock);
-- 
1.7.2.3



  parent reply	other threads:[~2011-03-17 19:22 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-17 19:21 [PATCH 0/2] [GIT PULL] futex: Fix WARN_ON triggering on UP Steven Rostedt
2011-03-17 19:21 ` [PATCH 1/2] WARN_ON_SMP(): Allow use in if statements " Steven Rostedt
2011-03-17 20:46   ` Darren Hart
2011-03-25  9:35   ` Peter Zijlstra
2011-03-25 10:48   ` [tip:core/urgent] WARN_ON_SMP(): Allow use in if() " tip-bot for Steven Rostedt
2011-03-25 16:45     ` Linus Torvalds
2011-03-25 18:16       ` Steven Rostedt
2011-03-25 18:19         ` Steven Rostedt
2011-03-25 19:31           ` Alexey Dobriyan
2011-03-25 19:36             ` Steven Rostedt
2011-03-25 19:40             ` Steven Rostedt
2011-03-25 19:47               ` Alexey Dobriyan
2011-03-25 19:53                 ` Steven Rostedt
2011-03-25 19:56                 ` Ingo Molnar
2011-03-17 19:21 ` Steven Rostedt [this message]
2011-03-17 20:00   ` [PATCH 2/2] futex: Fix WARN_ON() test for UP Darren Hart
2011-03-25  9:35   ` Peter Zijlstra
2011-03-25 10:49   ` [tip:core/urgent] " tip-bot for Steven Rostedt
2011-03-17 19:27 ` [PATCH 0/2] [GIT PULL] futex: Fix WARN_ON triggering on UP Steven Rostedt

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