diff mbox series

[v2,01/11] powerpc: qspinlock: Mark accesses to qnode lock checks

Message ID 20230510033117.1395895-2-rmclure@linux.ibm.com (mailing list archive)
State Accepted
Commit 03d44ee80eac980a869ed3d5637ed85de6fb957f
Headers show
Series powerpc: KCSAN fix warnings and mark accesses | expand

Commit Message

Rohan McLure May 10, 2023, 3:31 a.m. UTC 
The powerpc implemenation of qspinlocks will both poll and spin on the
bitlock guarding a qnode. Mark these accesses with READ_ONCE to convey
to KCSAN that polling is intentional here.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/lib/qspinlock.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/lib/qspinlock.c b/arch/powerpc/lib/qspinlock.c
index e4bd145255d0..b76c1f6acce5 100644
--- a/arch/powerpc/lib/qspinlock.c
+++ b/arch/powerpc/lib/qspinlock.c
@@ -435,7 +435,7 @@  static __always_inline bool yield_to_prev(struct qspinlock *lock, struct qnode *
 
 	smp_rmb(); /* See __yield_to_locked_owner comment */
 
-	if (!node->locked) {
+	if (!READ_ONCE(node->locked)) {
 		yield_to_preempted(prev_cpu, yield_count);
 		spin_begin();
 		return preempted;
@@ -584,7 +584,7 @@  static __always_inline void queued_spin_lock_mcs_queue(struct qspinlock *lock, b
 
 		/* Wait for mcs node lock to be released */
 		spin_begin();
-		while (!node->locked) {
+		while (!READ_ONCE(node->locked)) {
 			spec_barrier();
 
 			if (yield_to_prev(lock, node, old, paravirt))