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-rw-r--r--kernel/locking/osq_lock.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index a3167941093b..a74ee6abd039 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -109,6 +109,19 @@ bool osq_lock(struct optimistic_spin_queue *lock)
prev = decode_cpu(old);
node->prev = prev;
+
+ /*
+ * osq_lock() unqueue
+ *
+ * node->prev = prev osq_wait_next()
+ * WMB MB
+ * prev->next = node next->prev = prev // unqueue-C
+ *
+ * Here 'node->prev' and 'next->prev' are the same variable and we need
+ * to ensure these stores happen in-order to avoid corrupting the list.
+ */
+ smp_wmb();
+
WRITE_ONCE(prev->next, node);
/*