Commit ce0a568d authored Aug 21, 2018 by Anna-Maria Gleixner Committed by Linus Torvalds Aug 22, 2018

userns: use irqsave variant of refcount_dec_and_lock()

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.

[bigeasy@linutronix.de: s@atomic_dec_and_lock@refcount_dec_and_lock@g]
Link: http://lkml.kernel.org/r/20180703200141.28415-7-bigeasy@linutronix.de


Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent fc371912

kernel/user.c

+1 −4

Original line number	Original line	Diff line number	Diff line
	@@ -169,11 +169,8 @@ void free_uid(struct user_struct *up)
	if (!up)		if (!up)
	return;		return;

	local_irq_save(flags);		if (refcount_dec_and_lock_irqsave(&up->__count, &uidhash_lock, &flags))
	if (refcount_dec_and_lock(&up->__count, &uidhash_lock))
	free_user(up, flags);		free_user(up, flags);
	else
	local_irq_restore(flags);
	}		}

	struct user_struct *alloc_uid(kuid_t uid)		struct user_struct *alloc_uid(kuid_t uid)