PM: sleep: Fix possible overflow in pm_system_cancel_wakeup()

[ Upstream commit 2933954b71f10d392764f95eec0f0aa2d103054b ]

It is not actually guaranteed that pm_abort_suspend will be
nonzero when pm_system_cancel_wakeup() is called which may lead to
subtle issues, so make it use atomic_dec_if_positive() instead of
atomic_dec() for the safety sake.

Fixes: 33e4f80ee69b ("ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Rafael J. Wysocki 2019-07-15 13:03:48 +02:00 committed by Greg Kroah-Hartman
parent ed45a2de36
commit 07f604c868

View File

@ -877,7 +877,7 @@ EXPORT_SYMBOL_GPL(pm_system_wakeup);
void pm_system_cancel_wakeup(void)
{
atomic_dec(&pm_abort_suspend);
atomic_dec_if_positive(&pm_abort_suspend);
}
void pm_wakeup_clear(bool reset)