Commit-ID: 51218298a25e6942957c5595f2abf130d47d5df9 Gitweb: http://git.kernel.org/tip/51218298a25e6942957c5595f2abf130d47d5df9 Author: Alexandre Belloni <alexandre.bell...@free-electrons.com> AuthorDate: Mon, 21 Aug 2017 00:01:46 +0200 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Thu, 31 Aug 2017 21:36:45 +0200
alarmtimer: Ensure RTC module is not unloaded When registering the rtc device to be used to handle alarm timers, get_device is used to ensure the device doesn't go away but the module can still be unloaded. Call try_module_get to ensure the rtc driver will not go away. Reported-and-tested-by: Michal Simek <mon...@monstr.eu> Signed-off-by: Alexandre Belloni <alexandre.bell...@free-electrons.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Acked-by: John Stultz <john.stu...@linaro.org> Cc: Stephen Boyd <sb...@codeaurora.org> Link: http://lkml.kernel.org/r/20170820220146.30969-1-alexandre.bell...@free-electrons.com --- kernel/time/alarmtimer.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 73a2b47..ec09ce9 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -28,6 +28,7 @@ #include <linux/workqueue.h> #include <linux/freezer.h> #include <linux/compat.h> +#include <linux/module.h> #include "posix-timers.h" @@ -103,6 +104,11 @@ static int alarmtimer_rtc_add_device(struct device *dev, spin_lock_irqsave(&rtcdev_lock, flags); if (!rtcdev) { + if (!try_module_get(rtc->owner)) { + spin_unlock_irqrestore(&rtcdev_lock, flags); + return -1; + } + rtcdev = rtc; /* hold a reference so it doesn't go away */ get_device(dev);
