From 08f003891b84f52e49a5bdbc8a589fb052ac9a4e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 8 May 2024 05:22:37 +0200 Subject: Merging debian version 4.19.260-1. Signed-off-by: Daniel Baumann --- ...-READ_ONCE-to-access-timer-base-in-hrimer.patch | 38 ++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 debian/patches-rt/0292-hrtimer-Use-READ_ONCE-to-access-timer-base-in-hrimer.patch (limited to 'debian/patches-rt/0292-hrtimer-Use-READ_ONCE-to-access-timer-base-in-hrimer.patch') diff --git a/debian/patches-rt/0292-hrtimer-Use-READ_ONCE-to-access-timer-base-in-hrimer.patch b/debian/patches-rt/0292-hrtimer-Use-READ_ONCE-to-access-timer-base-in-hrimer.patch new file mode 100644 index 000000000..96b0c6320 --- /dev/null +++ b/debian/patches-rt/0292-hrtimer-Use-READ_ONCE-to-access-timer-base-in-hrimer.patch @@ -0,0 +1,38 @@ +From: Julien Grall +Date: Wed, 21 Aug 2019 10:24:07 +0100 +Subject: [PATCH 292/342] hrtimer: Use READ_ONCE to access timer->base in + hrimer_grab_expiry_lock() +Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=651af665014e442103551831276cb17778ec5ffa + +[ Upstream commit 2c8fdbe7ef0ad06c1a326886c5954e117b5657d6 ] + +The update to timer->base is protected by the base->cpu_base->lock(). +However, hrtimer_grab_expirty_lock() does not access it with the lock. + +So it would theorically be possible to have timer->base changed under +our feet. We need to prevent the compiler to refetch timer->base so the +check and the access is performed on the same base. + +Other access of timer->base are either done with a lock or protected +with READ_ONCE(). So use READ_ONCE() in hrtimer_grab_expirty_lock(). + +Signed-off-by: Julien Grall +Signed-off-by: Sebastian Andrzej Siewior +Signed-off-by: Steven Rostedt (VMware) +--- + kernel/time/hrtimer.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c +index eb2db7e6a241..dff440fd968b 100644 +--- a/kernel/time/hrtimer.c ++++ b/kernel/time/hrtimer.c +@@ -959,7 +959,7 @@ EXPORT_SYMBOL_GPL(hrtimer_forward); + + void hrtimer_grab_expiry_lock(const struct hrtimer *timer) + { +- struct hrtimer_clock_base *base = timer->base; ++ struct hrtimer_clock_base *base = READ_ONCE(timer->base); + + if (base && base->cpu_base) { + spin_lock(&base->cpu_base->softirq_expiry_lock); -- cgit v1.2.3