Unverified Commit 5816fc7b authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!11820 powerpc/qspinlock: Fix deadlock in MCS queue 

Merge Pull Request from: @ci-robot 
 
PR sync from: Yongqiang Liu <liuyongqiang13@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/NMDAZZLMD7JVU6KIDLCBJ4CEUCNSFJZK/ 
 
https://gitee.com/src-openeuler/kernel/issues/IARYD6 
 
Link:https://gitee.com/openeuler/kernel/pulls/11820

 

Reviewed-by: default avatarWeilong Chen <chenweilong@huawei.com>
Signed-off-by: default avatarZhang Peng <zhangpeng362@huawei.com>
parents 6d1d24f5 e0d98a97

arch/powerpc/lib/qspinlock.c

+9 −1
Original line number Diff line number Diff line
@@ -715,7 +715,15 @@ static __always_inline void queued_spin_lock_mcs_queue(struct qspinlock *lock, b 
	}



release:

	qnodesp->count--; /* release the node */

	/*

	 * Clear the lock before releasing the node, as another CPU might see stale

	 * values if an interrupt occurs after we increment qnodesp->count

	 * but before node->lock is initialized. The barrier ensures that

	 * there are no further stores to the node after it has been released.

	 */

	node->lock = NULL;

	barrier();

	qnodesp->count--;

}



void queued_spin_lock_slowpath(struct qspinlock *lock)