From: Bradley Morgan <include@grrlz.net>
To: "Rafael J . Wysocki" <rafael@kernel.org>
Cc: Thierry Reding <treding@nvidia.com>,
Daniel Leznan <daniel.lezcano@kernel.org>,
Thomas Gleixner <tglx@kernel.org>,
Valentin Schneider <vschneid@redhat.com>,
Rosen Penev <rosenp@gmail.com>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 0/2] PM: cpu: Restore the RCU grace period to cpu_pm_unregister_notifier()
Date: Thu, 13 Aug 2026 07:43:41 +0000 [thread overview]
Message-ID: <20260813074343.26460-1-include@grrlz.net> (raw)
Since commit b2f6662ac08d ("PM: cpu: Make notifier chain use a
raw_spinlock_t") cpu_pm_unregister_notifier() no longer waits for an
RCU grace period, but cpu_pm_notify() still walks the chain with only
rcu_read_lock() held. A driver that frees its notifier block right
after unregistering can race with a concurrent walker.
Patch 1 moves the one caller that unregisters from atomic context out
from under its spinlock, patch 2 restores the grace period.
Bradley Morgan (2):
clocksource/drivers/timer-ti-dm: Unregister CPU PM notifier outside of
the timer lock
PM: cpu: Restore synchronize_rcu() to cpu_pm_unregister_notifier()
drivers/clocksource/timer-ti-dm.c | 9 ++++++---
kernel/cpu_pm.c | 9 ++++++++-
2 files changed, 14 insertions(+), 4 deletions(-)
--
2.47.3
next reply other threads:[~2026-08-13 7:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-13 7:43 Bradley Morgan [this message]
2026-08-13 7:43 ` [PATCH 1/2] clocksource/drivers/timer-ti-dm: Unregister CPU PM notifier outside of the timer lock Bradley Morgan
2026-08-13 7:43 ` [PATCH 2/2] PM: cpu: Restore synchronize_rcu() to cpu_pm_unregister_notifier() Bradley Morgan
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