[PATCH 3.2 049/102] alarmtimer: Lock k_itimer during timer callback
3.2.64-rc1 review patch. If anyone has any objections, please let me know.
--
From: Richard Larocque
commit 474e941bed9262f5fa2394f9a4a67e24499e5926 upstream.
Locks the k_itimer's it_lock member when handling the alarm timer's
expiry callback.
The regular posix timers defined in posix-timers.c have this lock held
during timout processing because their callbacks are routed through
posix_timer_fn(). The alarm timers follow a different path, so they
ought to grab the lock somewhere else.
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: Richard Cochran
Cc: Prarit Bhargava
Cc: Sharvil Nanavati
Signed-off-by: Richard Larocque
Signed-off-by: John Stultz
Signed-off-by: Ben Hutchings
---
kernel/time/alarmtimer.c | 10 --
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -448,8 +448,12 @@ static enum alarmtimer_type clock2alarm(
static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
ktime_t now)
{
+ unsigned long flags;
struct k_itimer *ptr = container_of(alarm, struct k_itimer,
it.alarm.alarmtimer);
+ enum alarmtimer_restart result = ALARMTIMER_NORESTART;
+
+ spin_lock_irqsave(>it_lock, flags);
if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) {
if (posix_timer_event(ptr, 0) != 0)
ptr->it_overrun++;
@@ -459,9 +463,11 @@ static enum alarmtimer_restart alarm_han
if (ptr->it.alarm.interval.tv64) {
ptr->it_overrun += alarm_forward(alarm, now,
ptr->it.alarm.interval);
- return ALARMTIMER_RESTART;
+ result = ALARMTIMER_RESTART;
}
- return ALARMTIMER_NORESTART;
+ spin_unlock_irqrestore(>it_lock, flags);
+
+ return result;
}
/**
--
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[PATCH 3.2 049/102] alarmtimer: Lock k_itimer during timer callback
3.2.64-rc1 review patch. If anyone has any objections, please let me know.
--
From: Richard Larocque rlaroc...@google.com
commit 474e941bed9262f5fa2394f9a4a67e24499e5926 upstream.
Locks the k_itimer's it_lock member when handling the alarm timer's
expiry callback.
The regular posix timers defined in posix-timers.c have this lock held
during timout processing because their callbacks are routed through
posix_timer_fn(). The alarm timers follow a different path, so they
ought to grab the lock somewhere else.
Cc: Thomas Gleixner t...@linutronix.de
Cc: Ingo Molnar mi...@kernel.org
Cc: Richard Cochran richardcoch...@gmail.com
Cc: Prarit Bhargava pra...@redhat.com
Cc: Sharvil Nanavati shar...@google.com
Signed-off-by: Richard Larocque rlaroc...@google.com
Signed-off-by: John Stultz john.stu...@linaro.org
Signed-off-by: Ben Hutchings b...@decadent.org.uk
---
kernel/time/alarmtimer.c | 10 --
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -448,8 +448,12 @@ static enum alarmtimer_type clock2alarm(
static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
ktime_t now)
{
+ unsigned long flags;
struct k_itimer *ptr = container_of(alarm, struct k_itimer,
it.alarm.alarmtimer);
+ enum alarmtimer_restart result = ALARMTIMER_NORESTART;
+
+ spin_lock_irqsave(ptr-it_lock, flags);
if ((ptr-it_sigev_notify ~SIGEV_THREAD_ID) != SIGEV_NONE) {
if (posix_timer_event(ptr, 0) != 0)
ptr-it_overrun++;
@@ -459,9 +463,11 @@ static enum alarmtimer_restart alarm_han
if (ptr-it.alarm.interval.tv64) {
ptr-it_overrun += alarm_forward(alarm, now,
ptr-it.alarm.interval);
- return ALARMTIMER_RESTART;
+ result = ALARMTIMER_RESTART;
}
- return ALARMTIMER_NORESTART;
+ spin_unlock_irqrestore(ptr-it_lock, flags);
+
+ return result;
}
/**
--
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