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, Frederic Weisbecker <frederic@kernel.org>,
"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 1/8] rcu: Report callbacks enqueued on offline CPU blind spot
Date: Thu, 12 Dec 2024 10:39:29 -0800 [thread overview]
Message-ID: <20241212183936.1936196-1-paulmck@kernel.org> (raw)
In-Reply-To: <928b8031-2bfe-4c90-9952-7d331e027ae3@paulmck-laptop>
From: Frederic Weisbecker <frederic@kernel.org>
Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier
blind spot. Report any potential misuse.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/tree.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index ff98233d4aa59..24f1cb292a92d 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in)
head->func = func;
head->next = NULL;
kasan_record_aux_stack_noalloc(head);
+
local_irq_save(flags);
rdp = this_cpu_ptr(&rcu_data);
+ RCU_LOCKDEP_WARN(!rcu_rdp_cpu_online(rdp), "Callback enqueued on offline CPU!");
+
lazy = lazy_in && !rcu_async_should_hurry();
/* Add the callback to our list. */
--
2.40.1
next prev parent reply other threads:[~2024-12-12 18:39 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-12 18:39 [PATCH rcu 0/8] Miscellaneous fixes for v6.14 Paul E. McKenney
2024-12-12 18:39 ` Paul E. McKenney [this message]
2024-12-12 18:39 ` [PATCH rcu 2/8] rcu: Make rcu_report_exp_cpu_mult() caller acquire lock Paul E. McKenney
2024-12-12 18:39 ` [PATCH rcu 3/8] rcu: Move rcu_report_exp_rdp() setting of ->cpu_no_qs.b.exp under lock Paul E. McKenney
2024-12-12 18:39 ` [PATCH rcu 4/8] rcu: Replace open-coded rcu_exp_need_qs() from rcu_exp_handler() with call Paul E. McKenney
2024-12-12 18:39 ` [PATCH rcu 5/8] rcu: Make preemptible rcu_exp_handler() check idempotency Paul E. McKenney
2024-12-12 18:39 ` [PATCH rcu 6/8] rcu: Add KCSAN exclusive-writer assertions for rdp->cpu_no_qs.b.exp Paul E. McKenney
2024-12-12 18:39 ` [PATCH rcu 7/8] rcu: Add lockdep_assert_irqs_disabled() to rcu_exp_need_qs() Paul E. McKenney
2024-12-12 18:39 ` [PATCH rcu 8/8] MAINTAINERS: Update RCU git tree Paul E. McKenney
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