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From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com,
	rostedt@goodmis.org, Xuanqiang Luo <luoxuanqiang@kylinos.cn>,
	"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH v2 2/5] rcu: use WRITE_ONCE() for ->next and ->pprev of hlist_nulls
Date: Wed,  5 Nov 2025 12:19:57 -0800	[thread overview]
Message-ID: <20251105202000.2700370-2-paulmck@kernel.org> (raw)
In-Reply-To: <cf8b57e0-1803-45e9-a217-9c9aeb64a2f9@paulmck-laptop>

From: Xuanqiang Luo <luoxuanqiang@kylinos.cn>

In rculist_nulls.h we can still see ordinary assignments to ->pprev and
->next of hlist_nulls.

As noted in the two patches below:
commit efd04f8a8b45 ("rcu: Use WRITE_ONCE() for assignments to ->next for
rculist_nulls")
commit 860c8802ace1 ("rcu: Use WRITE_ONCE() for assignments to ->pprev for
hlist_nulls")

We should use WRITE_ONCE().

Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 include/linux/rculist_nulls.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/rculist_nulls.h b/include/linux/rculist_nulls.h
index 89186c499dd4..d5a656cc4c6a 100644
--- a/include/linux/rculist_nulls.h
+++ b/include/linux/rculist_nulls.h
@@ -138,7 +138,7 @@ static inline void hlist_nulls_add_tail_rcu(struct hlist_nulls_node *n,
 
 	if (last) {
 		WRITE_ONCE(n->next, last->next);
-		n->pprev = &last->next;
+		WRITE_ONCE(n->pprev, &last->next);
 		rcu_assign_pointer(hlist_nulls_next_rcu(last), n);
 	} else {
 		hlist_nulls_add_head_rcu(n, h);
@@ -148,8 +148,8 @@ static inline void hlist_nulls_add_tail_rcu(struct hlist_nulls_node *n,
 /* after that hlist_nulls_del will work */
 static inline void hlist_nulls_add_fake(struct hlist_nulls_node *n)
 {
-	n->pprev = &n->next;
-	n->next = (struct hlist_nulls_node *)NULLS_MARKER(NULL);
+	WRITE_ONCE(n->pprev, &n->next);
+	WRITE_ONCE(n->next, (struct hlist_nulls_node *)NULLS_MARKER(NULL));
 }
 
 /**
-- 
2.40.1


  parent reply	other threads:[~2025-11-05 20:20 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-05 20:19 [PATCH v2 0/5] Miscellaneous RCU updates for v6.19 Paul E. McKenney
2025-11-05 20:19 ` [PATCH v2 1/5] locktorture: Fix memory leak in param_set_cpumask() Paul E. McKenney
2025-11-05 20:19 ` Paul E. McKenney [this message]
2025-11-05 20:19 ` [PATCH v2 3/5] torture: Add kvm-series.sh to test commit/scenario combination Paul E. McKenney
2025-11-05 20:19 ` [PATCH v2 4/5] rcutorture: Permit kvm-again.sh to re-use the build directory Paul E. McKenney
2025-11-05 20:20 ` [PATCH v2 5/5] rcutorture: Remove redundant rcutorture_one_extend() from rcu_torture_one_read() Paul E. McKenney
2025-11-05 23:06 ` [PATCH v2 0/5] Miscellaneous RCU updates for v6.19 Frederic Weisbecker

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