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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Darren Hart <darren@dvhart.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Bhuvanesh_Surachari@mentor.com, Andy Lowe <Andy_Lowe@mentor.com>
Subject: [patch 4/5] futex: Remove pointless put_pi_state calls in requeue()
Date: Sat, 19 Dec 2015 20:07:40 -0000	[thread overview]
Message-ID: <20151219200607.432780944@linutronix.de> (raw)
In-Reply-To: 20151219200501.563704646@linutronix.de

[-- Attachment #1: futex--Remove-pointless-free_pi_state-calls-in-requeue --]
[-- Type: text/plain, Size: 889 bytes --]

In the error handling cases we neither have pi_state nor a reference
to it. Remove the pointless code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/futex.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1737,9 +1737,9 @@ static int futex_requeue(u32 __user *uad
 		case 0:
 			/* We hold a reference on the pi state. */
 			break;
+
+			/* If the above failed, then pi_state is NULL */
 		case -EFAULT:
-			put_pi_state(pi_state);
-			pi_state = NULL;
 			double_unlock_hb(hb1, hb2);
 			hb_waiters_dec(hb2);
 			put_futex_key(&key2);
@@ -1755,8 +1755,6 @@ static int futex_requeue(u32 __user *uad
 			 *   exit to complete.
 			 * - The user space value changed.
 			 */
-			put_pi_state(pi_state);
-			pi_state = NULL;
 			double_unlock_hb(hb1, hb2);
 			hb_waiters_dec(hb2);
 			put_futex_key(&key2);



  parent reply	other threads:[~2015-12-19 20:09 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-19 20:07 [patch 0/5] futex: Plug a pi_state leak and clarify the refcounting Thomas Gleixner
2015-12-19 20:07 ` [patch 1/5] futex: Drop refcount if requeue_pi() acquired the rtmutex Thomas Gleixner
2015-12-20 13:18   ` [tip:locking/core] " tip-bot for Thomas Gleixner
2015-12-19 20:07 ` [patch 2/5] futex: Rename free_pi_state() to put_pi_state() Thomas Gleixner
2015-12-20 13:19   ` [tip:locking/core] futex: Rename free_pi_state() to put_pi_state( ) tip-bot for Thomas Gleixner
2015-12-19 20:07 ` [patch 3/5] futex: Document pi_state refcounting in requeue code Thomas Gleixner
2015-12-20  7:41   ` Darren Hart
2015-12-20 13:19   ` [tip:locking/core] " tip-bot for Thomas Gleixner
2015-12-19 20:07 ` Thomas Gleixner [this message]
2015-12-20 13:19   ` [tip:locking/core] futex: Remove pointless put_pi_state calls in requeue() tip-bot for Thomas Gleixner
2015-12-19 20:07 ` [patch 5/5] futex: Cleanup the goto confusion in requeue_pi() Thomas Gleixner
2015-12-20  5:15   ` Darren Hart
2015-12-20  5:40     ` Mike Galbraith
2015-12-20  7:37       ` Darren Hart
2015-12-20  5:46     ` Darren Hart
2015-12-20 13:20   ` [tip:locking/core] " tip-bot for Thomas Gleixner

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