/* Delete a POSIX.1b interval timer. */
asmlinkage long
sys_timer_delete(timer_t timer_id)
{
struct k_itimer *timer;
long flags;
retry_delete:
timer = lock_timer(timer_id, &flags);
if (!timer)
return -EINVAL;
if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
goto retry_delete;
}
spin_lock(¤t->sighand->siglock);
list_del(&timer->list);
spin_unlock(¤t->sighand->siglock);
/*
* This keeps any tasks waiting on the spin lock from thinking
* they got something (see the lock code above).
*/
if (timer->it_process) {
if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
put_task_struct(timer->it_process);
timer->it_process = NULL;
}
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
return 0;
}
/*
* return timer owned by the process, used by exit_itimers
*/
static void itimer_delete(struct k_itimer *timer)
{
unsigned long flags;
retry_delete:
spin_lock_irqsave(&timer->it_lock, flags);
/* On RT we can race with a deletion */
if (!timer->it_signal) {
unlock_timer(timer, flags);
return;
}
if (timer_delete_hook(timer) == TIMER_RETRY) {
rcu_read_lock();
unlock_timer(timer, flags);
timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
timer);
rcu_read_unlock();
goto retry_delete;
}
list_del(&timer->list);
/*
* This keeps any tasks waiting on the spin lock from thinking
* they got something (see the lock code above).
*/
timer->it_signal = NULL;
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
}
/* Delete a POSIX.1b interval timer. */
SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
{
struct k_itimer *timer;
unsigned long flags;
retry_delete:
timer = lock_timer(timer_id, &flags);
if (!timer)
return -EINVAL;
rcu_read_lock();
if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
timer);
rcu_read_unlock();
goto retry_delete;
}
rcu_read_unlock();
spin_lock(¤t->sighand->siglock);
list_del(&timer->list);
spin_unlock(¤t->sighand->siglock);
/*
* This keeps any tasks waiting on the spin lock from thinking
* they got something (see the lock code above).
*/
timer->it_signal = NULL;
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
return 0;
}
/*
* Locking issues: We need to protect the result of the id look up until
* we get the timer locked down so it is not deleted under us. The
* removal is done under the idr spinlock so we use that here to bridge
* the find to the timer lock. To avoid a dead lock, the timer id MUST
* be release with out holding the timer lock.
*/
static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags)
{
struct k_itimer *timr;
/*
* Watch out here. We do a irqsave on the idr_lock and pass the
* flags part over to the timer lock. Must not let interrupts in
* while we are moving the lock.
*/
spin_lock_irqsave(&idr_lock, *flags);
timr = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id);
if (timr) {
spin_lock(&timr->it_lock);
spin_unlock(&idr_lock);
if ((timr->it_id != timer_id) || !(timr->it_process) ||
timr->it_process->tgid != current->tgid) {
unlock_timer(timr, *flags);
timr = NULL;
}
} else
spin_unlock_irqrestore(&idr_lock, *flags);
return timr;
}
/*
* This function gets called when a POSIX.1b interval timer expires. It
* is used as a callback from the kernel internal timer. The
* run_timer_list code ALWAYS calls with interrupts on.
* This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
*/
static int posix_timer_fn(void *data)
{
struct k_itimer *timr = data;
unsigned long flags;
int si_private = 0;
int ret = HRTIMER_NORESTART;
spin_lock_irqsave(&timr->it_lock, flags);
if (timr->it.real.interval.tv64 != 0)
si_private = ++timr->it_requeue_pending;
if (posix_timer_event(timr, si_private)) {
/*
* signal was not sent because of sig_ignor
* we will not get a call back to restart it AND
* it should be restarted.
*/
if (timr->it.real.interval.tv64 != 0) {
timr->it_overrun +=
hrtimer_forward(&timr->it.real.timer,
timr->it.real.interval);
ret = HRTIMER_RESTART;
}
}
unlock_timer(timr, flags);
return ret;
}
/*****************************************************************************
* remove_timer *
****************************************************************************/
static void remove_timer(int id)
{
/* removes a timer from the timer list */
struct ddekit_timer_s *l,*m;
lock_timer();
for (l = &list; l && l->next && l->next->id!=id; l = l->next )
;
if (l && l->next) {
m = l->next;
DDEBUG_MSG_VERBOSE(
"deleting timer at for tick: %d fn: %p, (now: %d)\n",
m->exp, m->fn, jiffies);
l->next = m->next;
DDEBUG_MSG_TIMER(m);
ddekit_simple_free(m);
}
unlock_timer();
}
/*****************************************************************************
* _ddekit_timer_update *
****************************************************************************/
void _ddekit_timer_update()
{
lock_timer();
static myclock_t next_timout;
if(list.next)
{
if(!_ddekit_timer_pending || list.next->exp < next_timout) {
unsigned to = list.next->exp - jiffies;
_ddekit_timer_pending = 1;
if (list.next->exp <= jiffies) {
DDEBUG_MSG_WARN("Timeout lies in past to %d, now: %d",
list.next->exp, jiffies);
to = 1;
}
sys_setalarm(to, 0 /* REL */);
DDEBUG_MSG_VERBOSE("requesting alarm for clock tick %d , now %d",
list.next->exp, jiffies);
}
next_timout = list.next->exp;
}
unlock_timer();
}
/* Get the time remaining on a POSIX.1b interval timer. */
SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
struct itimerspec __user *, setting)
{
struct itimerspec cur_setting;
struct k_itimer *timr;
struct k_clock *kc;
unsigned long flags;
int ret = 0;
timr = lock_timer(timer_id, &flags);
if (!timr)
return -EINVAL;
kc = clockid_to_kclock(timr->it_clock);
if (WARN_ON_ONCE(!kc || !kc->timer_get))
ret = -EINVAL;
else
kc->timer_get(timr, &cur_setting);
unlock_timer(timr, flags);
if (!ret && copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
return -EFAULT;
return ret;
}
/*****************************************************************************
* insert_timer *
****************************************************************************/
static int insert_timer(struct ddekit_timer_s *t)
{
/* inserts a timer to the timer list */
int ret;
lock_timer();
struct ddekit_timer_s *l;
for (l = &list; l->next && l->next->exp <= t->exp; l = l->next) {
}
t->next = l->next;
l->next = t;
t->id = ret = _id;
_id++;
if (_id==0) {
DDEBUG_MSG_WARN("Timer ID overflow...");
}
DDEBUG_MSG_TIMER(t);
unlock_timer();
return ret;
}
static void itimer_delete(struct k_itimer *timer)
{
unsigned long flags;
retry_delete:
spin_lock_irqsave(&timer->it_lock, flags);
if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
goto retry_delete;
}
list_del(&timer->list);
timer->it_signal = NULL;
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
}
/*
* return timer owned by the process, used by exit_itimers
*/
static void itimer_delete(struct k_itimer *timer)
{
unsigned long flags;
retry_delete:
spin_lock_irqsave(&timer->it_lock, flags);
if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
goto retry_delete;
}
list_del(&timer->list);
/*
* This keeps any tasks waiting on the spin lock from thinking
* they got something (see the lock code above).
*/
timer->it_signal = NULL;
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
}
/*****************************************************************************
* ddekit_timer_pending *
****************************************************************************/
int ddekit_timer_pending(int timer)
{
int ret=0;
struct ddekit_timer_s *t;
lock_timer();
for (t=list.next; t; t = t->next) {
if (t->id==timer) {
ret = 1;
}
}
unlock_timer();
return ret;
}
/*
* Get the number of overruns of a POSIX.1b interval timer. This is to
* be the overrun of the timer last delivered. At the same time we are
* accumulating overruns on the next timer. The overrun is frozen when
* the signal is delivered, either at the notify time (if the info block
* is not queued) or at the actual delivery time (as we are informed by
* the call back to do_schedule_next_timer(). So all we need to do is
* to pick up the frozen overrun.
*/
SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
{
struct k_itimer *timr;
int overrun;
unsigned long flags;
timr = lock_timer(timer_id, &flags);
if (!timr)
return -EINVAL;
overrun = timr->it_overrun_last;
unlock_timer(timr, flags);
return overrun;
}
/*
* return timer owned by the process, used by exit_itimers
*/
static inline void itimer_delete(struct k_itimer *timer)
{
unsigned long flags;
retry_delete:
spin_lock_irqsave(&timer->it_lock, flags);
if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
goto retry_delete;
}
list_del(&timer->list);
/*
* This keeps any tasks waiting on the spin lock from thinking
* they got something (see the lock code above).
*/
if (timer->it_process) {
if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
put_task_struct(timer->it_process);
timer->it_process = NULL;
}
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
}
SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
{
struct k_itimer *timer;
unsigned long flags;
retry_delete:
timer = lock_timer(timer_id, &flags);
if (!timer)
return -EINVAL;
if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
goto retry_delete;
}
spin_lock(¤t->sighand->siglock);
list_del(&timer->list);
spin_unlock(¤t->sighand->siglock);
timer->it_signal = NULL;
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
return 0;
}
/*
* Get the number of overruns of a POSIX.1b interval timer. This is to
* be the overrun of the timer last delivered. At the same time we are
* accumulating overruns on the next timer. The overrun is frozen when
* the signal is delivered, either at the notify time (if the info block
* is not queued) or at the actual delivery time (as we are informed by
* the call back to do_schedule_next_timer(). So all we need to do is
* to pick up the frozen overrun.
*/
asmlinkage long
sys_timer_getoverrun(timer_t timer_id)
{
struct k_itimer *timr;
int overrun;
long flags;
timr = lock_timer(timer_id, &flags);
if (!timr)
return -EINVAL;
overrun = timr->it_overrun_last;
unlock_timer(timr, flags);
return overrun;
}
/* Set a POSIX.1b interval timer */
SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
const struct itimerspec __user *, new_setting,
struct itimerspec __user *, old_setting)
{
struct k_itimer *timr;
struct itimerspec new_spec, old_spec;
int error = 0;
unsigned long flag;
struct itimerspec *rtn = old_setting ? &old_spec : NULL;
struct k_clock *kc;
if (!new_setting)
return -EINVAL;
if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
return -EFAULT;
if (!timespec_valid(&new_spec.it_interval) ||
!timespec_valid(&new_spec.it_value))
return -EINVAL;
retry:
timr = lock_timer(timer_id, &flag);
if (!timr)
return -EINVAL;
rcu_read_lock();
kc = clockid_to_kclock(timr->it_clock);
if (WARN_ON_ONCE(!kc || !kc->timer_set))
error = -EINVAL;
else
error = kc->timer_set(timr, flags, &new_spec, rtn);
unlock_timer(timr, flag);
if (error == TIMER_RETRY) {
timer_wait_for_callback(kc, timr);
rtn = NULL; // We already got the old time...
rcu_read_unlock();
goto retry;
}
rcu_read_unlock();
if (old_setting && !error &&
copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
error = -EFAULT;
return error;
}
/*
* This function is exported for use by the signal deliver code. It is
* called just prior to the info block being released and passes that
* block to us. It's function is to update the overrun entry AND to
* restart the timer. It should only be called if the timer is to be
* restarted (i.e. we have flagged this in the sys_private entry of the
* info block).
*
* To protect aginst the timer going away while the interrupt is queued,
* we require that the it_requeue_pending flag be set.
*/
void do_schedule_next_timer(struct siginfo *info)
{
struct k_itimer *timr;
unsigned long flags;
timr = lock_timer(info->si_tid, &flags);
if (timr && timr->it_requeue_pending == info->si_sys_private) {
if (timr->it_clock < 0)
posix_cpu_timer_schedule(timr);
else
schedule_next_timer(timr);
info->si_overrun = timr->it_overrun_last;
}
unlock_timer(timr, flags);
}
/*****************************************************************************
* get_next *
****************************************************************************/
static struct ddekit_timer_s * get_next( myclock_t exp )
{
/*
* this one get the next timer, which's timeout expired,
* returns NULL if no timer is pending
*/
struct ddekit_timer_s * ret = 0;
lock_timer();
if (list.next)
{
if (list.next->exp <= exp)
{
ret = list.next;
list.next = ret->next;
}
}
unlock_timer();
return ret;
}
/* Get the time remaining on a POSIX.1b interval timer. */
SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
struct itimerspec __user *, setting)
{
struct k_itimer *timr;
struct itimerspec cur_setting;
unsigned long flags;
timr = lock_timer(timer_id, &flags);
if (!timr)
return -EINVAL;
CLOCK_DISPATCH(timr->it_clock, timer_get, (timr, &cur_setting));
unlock_timer(timr, flags);
if (copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
return -EFAULT;
return 0;
}
/* Set a POSIX.1b interval timer */
SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
const struct itimerspec __user *, new_setting,
struct itimerspec __user *, old_setting)
{
struct k_itimer *timr;
struct itimerspec new_spec, old_spec;
int error = 0;
unsigned long flag;
struct itimerspec *rtn = old_setting ? &old_spec : NULL;
if (!new_setting)
return -EINVAL;
if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
return -EFAULT;
if (!timespec_valid(&new_spec.it_interval) ||
!timespec_valid(&new_spec.it_value))
return -EINVAL;
retry:
timr = lock_timer(timer_id, &flag);
if (!timr)
return -EINVAL;
error = CLOCK_DISPATCH(timr->it_clock, timer_set,
(timr, flags, &new_spec, rtn));
unlock_timer(timr, flag);
if (error == TIMER_RETRY) {
hrtimer_wait_for_timer(&timr->it.real.timer);
rtn = NULL; // We already got the old time...
goto retry;
}
if (old_setting && !error &&
copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
error = -EFAULT;
return error;
}
static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
{
struct k_itimer *timr;
unsigned long flags;
int si_private = 0;
enum hrtimer_restart ret = HRTIMER_NORESTART;
timr = container_of(timer, struct k_itimer, it.real.timer);
spin_lock_irqsave(&timr->it_lock, flags);
if (timr->it.real.interval.tv64 != 0)
si_private = ++timr->it_requeue_pending;
if (posix_timer_event(timr, si_private)) {
if (timr->it.real.interval.tv64 != 0) {
ktime_t now = hrtimer_cb_get_time(timer);
#ifdef CONFIG_HIGH_RES_TIMERS
{
ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
if (timr->it.real.interval.tv64 < kj.tv64)
now = ktime_add(now, kj);
}
#endif
timr->it_overrun += (unsigned int)
hrtimer_forward(timer, now,
timr->it.real.interval);
ret = HRTIMER_RESTART;
++timr->it_requeue_pending;
}
}
unlock_timer(timr, flags);
return ret;
}
/*
* This function gets called when a POSIX.1b interval timer expires. It
* is used as a callback from the kernel internal timer. The
* run_timer_list code ALWAYS calls with interrupts on.
* This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
*/
static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
{
struct k_itimer *timr;
unsigned long flags;
int si_private = 0;
enum hrtimer_restart ret = HRTIMER_NORESTART;
timr = container_of(timer, struct k_itimer, it.real.timer);
spin_lock_irqsave(&timr->it_lock, flags);
if (timr->it.real.interval.tv64 != 0)
si_private = ++timr->it_requeue_pending;
if (posix_timer_event(timr, si_private)) {
/*
* signal was not sent because of sig_ignor
* we will not get a call back to restart it AND
* it should be restarted.
*/
if (timr->it.real.interval.tv64 != 0) {
ktime_t now = hrtimer_cb_get_time(timer);
/*
* FIXME: What we really want, is to stop this
* timer completely and restart it in case the
* SIG_IGN is removed. This is a non trivial
* change which involves sighand locking
* (sigh !), which we don't want to do late in
* the release cycle.
*
* For now we just let timers with an interval
* less than a jiffie expire every jiffie to
* avoid softirq starvation in case of SIG_IGN
* and a very small interval, which would put
* the timer right back on the softirq pending
* list. By moving now ahead of time we trick
* hrtimer_forward() to expire the timer
* later, while we still maintain the overrun
* accuracy, but have some inconsistency in
* the timer_gettime() case. This is at least
* better than a starved softirq. A more
* complex fix which solves also another related
* inconsistency is already in the pipeline.
*/
#ifdef CONFIG_HIGH_RES_TIMERS
{
ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ);
if (timr->it.real.interval.tv64 < kj.tv64)
now = ktime_add(now, kj);
}
#endif
timr->it_overrun += (unsigned int)
hrtimer_forward(timer, now,
timr->it.real.interval);
ret = HRTIMER_RESTART;
++timr->it_requeue_pending;
}
}
unlock_timer(timr, flags);
return ret;
}
