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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Anna-Maria Gleixner <anna-maria@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH 6/6] userns: Use irqsave variant of refcount_dec_and_lock()
Date: Tue,  3 Jul 2018 22:01:41 +0200
Message-ID: <20180703200141.28415-7-bigeasy@linutronix.de> (raw)
In-Reply-To: <20180703200141.28415-1-bigeasy@linutronix.de>

From: Anna-Maria Gleixner <anna-maria@linutronix.de>

The irqsave variant of refcount_dec_and_lock handles irqsave/restore when
taking/releasing the spin lock. With this variant the call of
local_irq_save/restore is no longer required.

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
[bigeasy: s@atomic_dec_and_lock@refcount_dec_and_lock@g ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 kernel/user.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/user.c b/kernel/user.c
index 5f65ef195259..0df9b1640b2a 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -169,11 +169,8 @@ void free_uid(struct user_struct *up)
 	if (!up)
 		return;
 
-	local_irq_save(flags);
-	if (refcount_dec_and_lock(&up->__count, &uidhash_lock))
+	if (refcount_dec_and_lock_irqsave(&up->__count, &uidhash_lock, &flags))
 		free_user(up, flags);
-	else
-		local_irq_restore(flags);
 }
 
 struct user_struct *alloc_uid(kuid_t uid)
-- 
2.18.0


      parent reply index

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-03 20:01 [PATCH 0/6] use irqsafe variant of refcount_dec_and_lock() / atomic_dec_and_lock() Sebastian Andrzej Siewior
2018-07-03 20:01 ` [PATCH 1/6] drivers/md/raid5: Use irqsave variant of atomic_dec_and_lock() Sebastian Andrzej Siewior
2018-07-16 12:27   ` Sebastian Andrzej Siewior
2018-07-17  0:37     ` Shaohua Li
2018-07-18 10:57       ` Sebastian Andrzej Siewior
2018-07-19  2:44         ` Shaohua Li
2018-07-19  7:35           ` Sebastian Andrzej Siewior
2018-07-03 20:01 ` [PATCH 2/6] drivers/md/raid5: Do not disable irq on release_inactive_stripe_list() call Sebastian Andrzej Siewior
2018-07-20  8:29   ` Sebastian Andrzej Siewior
2018-07-03 20:01 ` [PATCH 3/6] bdi: Use refcount_t for reference counting instead atomic_t Sebastian Andrzej Siewior
2018-07-16 12:30   ` Sebastian Andrzej Siewior
2018-07-16 22:57   ` Andrew Morton
2018-07-17 15:56     ` Sebastian Andrzej Siewior
2018-07-03 20:01 ` [PATCH 4/6] bdi: Use irqsave variant of refcount_dec_and_lock() Sebastian Andrzej Siewior
2018-07-03 20:01 ` [PATCH 5/6] userns: Use refcount_t for reference counting instead atomic_t Sebastian Andrzej Siewior
2018-07-16 12:39   ` Sebastian Andrzej Siewior
2018-07-03 20:01 ` Sebastian Andrzej Siewior [this message]

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