* POSIX clocks & timers
*/
#include <linux/mm.h>
-#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
-#include <asm/semaphore.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/compiler.h>
* must supply functions here, even if the function just returns
* ENOSYS. The standard POSIX timer management code assumes the
* following: 1.) The k_itimer struct (sched.h) is used for the
- * timer. 2.) The list, it_lock, it_clock, it_id and it_process
+ * timer. 2.) The list, it_lock, it_clock, it_id and it_pid
* fields are not modified by timer code.
*
* At this time all functions EXCEPT clock_nanosleep can be
struct itimerspec *, struct itimerspec *);
static int common_timer_del(struct k_itimer *timer);
-static int posix_timer_fn(struct hrtimer *data);
+static enum hrtimer_restart posix_timer_fn(struct hrtimer *data);
static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags);
return 0;
}
+static int no_timer_create(struct k_itimer *new_timer)
+{
+ return -EOPNOTSUPP;
+}
+
+static int no_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *tsave, struct timespec __user *rmtp)
+{
+ return -EOPNOTSUPP;
+}
+
/*
* Return nonzero if we know a priori this clockid_t value is bogus.
*/
return 0;
}
+/*
+ * Get monotonic time for posix timers
+ */
+static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
+{
+ getrawmonotonic(tp);
+ return 0;
+}
+
+
+static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp)
+{
+ *tp = current_kernel_time();
+ return 0;
+}
+
+static int posix_get_monotonic_coarse(clockid_t which_clock,
+ struct timespec *tp)
+{
+ *tp = get_monotonic_coarse();
+ return 0;
+}
+
+static int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
+{
+ *tp = ktime_to_timespec(KTIME_LOW_RES);
+ return 0;
+}
/*
* Initialize everything, well, just everything in Posix clocks/timers ;)
*/
.clock_get = posix_ktime_get_ts,
.clock_set = do_posix_clock_nosettime,
};
+ struct k_clock clock_monotonic_raw = {
+ .clock_getres = hrtimer_get_res,
+ .clock_get = posix_get_monotonic_raw,
+ .clock_set = do_posix_clock_nosettime,
+ .timer_create = no_timer_create,
+ .nsleep = no_nsleep,
+ };
+ struct k_clock clock_realtime_coarse = {
+ .clock_getres = posix_get_coarse_res,
+ .clock_get = posix_get_realtime_coarse,
+ .clock_set = do_posix_clock_nosettime,
+ .timer_create = no_timer_create,
+ .nsleep = no_nsleep,
+ };
+ struct k_clock clock_monotonic_coarse = {
+ .clock_getres = posix_get_coarse_res,
+ .clock_get = posix_get_monotonic_coarse,
+ .clock_set = do_posix_clock_nosettime,
+ .timer_create = no_timer_create,
+ .nsleep = no_nsleep,
+ };
register_posix_clock(CLOCK_REALTIME, &clock_realtime);
register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic);
+ register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
+ register_posix_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
+ register_posix_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
posix_timers_cache = kmem_cache_create("posix_timers_cache",
- sizeof (struct k_itimer), 0, 0, NULL, NULL);
+ sizeof (struct k_itimer), 0, SLAB_PANIC,
+ NULL);
idr_init(&posix_timers_id);
return 0;
}
if (timr->it.real.interval.tv64 == 0)
return;
- timr->it_overrun += hrtimer_forward(timer, timer->base->get_time(),
- timr->it.real.interval);
+ timr->it_overrun += (unsigned int) hrtimer_forward(timer,
+ timer->base->get_time(),
+ timr->it.real.interval);
timr->it_overrun_last = timr->it_overrun;
timr->it_overrun = -1;
else
schedule_next_timer(timr);
- info->si_overrun = timr->it_overrun_last;
+ info->si_overrun += timr->it_overrun_last;
}
if (timr)
unlock_timer(timr, flags);
}
-int posix_timer_event(struct k_itimer *timr,int si_private)
+int posix_timer_event(struct k_itimer *timr, int si_private)
{
- memset(&timr->sigq->info, 0, sizeof(siginfo_t));
+ struct task_struct *task;
+ int shared, ret = -1;
+ /*
+ * FIXME: if ->sigq is queued we can race with
+ * dequeue_signal()->do_schedule_next_timer().
+ *
+ * If dequeue_signal() sees the "right" value of
+ * si_sys_private it calls do_schedule_next_timer().
+ * We re-queue ->sigq and drop ->it_lock().
+ * do_schedule_next_timer() locks the timer
+ * and re-schedules it while ->sigq is pending.
+ * Not really bad, but not that we want.
+ */
timr->sigq->info.si_sys_private = si_private;
- /* Send signal to the process that owns this timer.*/
-
- timr->sigq->info.si_signo = timr->it_sigev_signo;
- timr->sigq->info.si_errno = 0;
- timr->sigq->info.si_code = SI_TIMER;
- timr->sigq->info.si_tid = timr->it_id;
- timr->sigq->info.si_value = timr->it_sigev_value;
-
- if (timr->it_sigev_notify & SIGEV_THREAD_ID) {
- struct task_struct *leader;
- int ret = send_sigqueue(timr->it_sigev_signo, timr->sigq,
- timr->it_process);
-
- if (likely(ret >= 0))
- return ret;
-
- timr->it_sigev_notify = SIGEV_SIGNAL;
- leader = timr->it_process->group_leader;
- put_task_struct(timr->it_process);
- timr->it_process = leader;
- }
- return send_group_sigqueue(timr->it_sigev_signo, timr->sigq,
- timr->it_process);
+ rcu_read_lock();
+ task = pid_task(timr->it_pid, PIDTYPE_PID);
+ if (task) {
+ shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
+ ret = send_sigqueue(timr->sigq, task, shared);
+ }
+ rcu_read_unlock();
+ /* If we failed to send the signal the timer stops. */
+ return ret > 0;
}
EXPORT_SYMBOL_GPL(posix_timer_event);
* This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
*/
-static int posix_timer_fn(struct hrtimer *timer)
+static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
{
struct k_itimer *timr;
unsigned long flags;
int si_private = 0;
- int ret = HRTIMER_NORESTART;
+ enum hrtimer_restart ret = HRTIMER_NORESTART;
timr = container_of(timer, struct k_itimer, it.real.timer);
spin_lock_irqsave(&timr->it_lock, flags);
* it should be restarted.
*/
if (timr->it.real.interval.tv64 != 0) {
- timr->it_overrun +=
- hrtimer_forward(timer,
- timer->base->softirq_time,
+ 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;
return ret;
}
-static struct task_struct * good_sigevent(sigevent_t * event)
+static struct pid *good_sigevent(sigevent_t * event)
{
struct task_struct *rtn = current->group_leader;
if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
- (!(rtn = find_task_by_pid(event->sigev_notify_thread_id)) ||
- rtn->tgid != current->tgid ||
+ (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
+ !same_thread_group(rtn, current) ||
(event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
return NULL;
((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
return NULL;
- return rtn;
+ return task_pid(rtn);
}
void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock)
static struct k_itimer * alloc_posix_timer(void)
{
struct k_itimer *tmr;
- tmr = kmem_cache_alloc(posix_timers_cache, GFP_KERNEL);
+ tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
if (!tmr)
return tmr;
- memset(tmr, 0, sizeof (struct k_itimer));
if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
kmem_cache_free(posix_timers_cache, tmr);
- tmr = NULL;
+ return NULL;
}
+ memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
return tmr;
}
idr_remove(&posix_timers_id, tmr->it_id);
spin_unlock_irqrestore(&idr_lock, flags);
}
+ put_pid(tmr->it_pid);
sigqueue_free(tmr->sigq);
- if (unlikely(tmr->it_process) &&
- tmr->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
- put_task_struct(tmr->it_process);
kmem_cache_free(posix_timers_cache, tmr);
}
/* Create a POSIX.1b interval timer. */
-asmlinkage long
-sys_timer_create(const clockid_t which_clock,
- struct sigevent __user *timer_event_spec,
- timer_t __user * created_timer_id)
+SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
+ struct sigevent __user *, timer_event_spec,
+ timer_t __user *, created_timer_id)
{
- int error = 0;
- struct k_itimer *new_timer = NULL;
- int new_timer_id;
- struct task_struct *process = NULL;
- unsigned long flags;
+ struct k_itimer *new_timer;
+ int error, new_timer_id;
sigevent_t event;
int it_id_set = IT_ID_NOT_SET;
goto out;
}
spin_lock_irq(&idr_lock);
- error = idr_get_new(&posix_timers_id, (void *) new_timer,
- &new_timer_id);
+ error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id);
spin_unlock_irq(&idr_lock);
- if (error == -EAGAIN)
- goto retry;
- else if (error) {
+ if (error) {
+ if (error == -EAGAIN)
+ goto retry;
/*
- * Wierd looking, but we return EAGAIN if the IDR is
+ * Weird looking, but we return EAGAIN if the IDR is
* full (proper POSIX return value for this)
*/
error = -EAGAIN;
error = -EFAULT;
goto out;
}
- new_timer->it_sigev_notify = event.sigev_notify;
- new_timer->it_sigev_signo = event.sigev_signo;
- new_timer->it_sigev_value = event.sigev_value;
-
- read_lock(&tasklist_lock);
- if ((process = good_sigevent(&event))) {
- /*
- * We may be setting up this process for another
- * thread. It may be exiting. To catch this
- * case the we check the PF_EXITING flag. If
- * the flag is not set, the siglock will catch
- * him before it is too late (in exit_itimers).
- *
- * The exec case is a bit more invloved but easy
- * to code. If the process is in our thread
- * group (and it must be or we would not allow
- * it here) and is doing an exec, it will cause
- * us to be killed. In this case it will wait
- * for us to die which means we can finish this
- * linkage with our last gasp. I.e. no code :)
- */
- spin_lock_irqsave(&process->sighand->siglock, flags);
- if (!(process->flags & PF_EXITING)) {
- new_timer->it_process = process;
- list_add(&new_timer->list,
- &process->signal->posix_timers);
- spin_unlock_irqrestore(&process->sighand->siglock, flags);
- if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID))
- get_task_struct(process);
- } else {
- spin_unlock_irqrestore(&process->sighand->siglock, flags);
- process = NULL;
- }
- }
- read_unlock(&tasklist_lock);
- if (!process) {
+ rcu_read_lock();
+ new_timer->it_pid = get_pid(good_sigevent(&event));
+ rcu_read_unlock();
+ if (!new_timer->it_pid) {
error = -EINVAL;
goto out;
}
} else {
- new_timer->it_sigev_notify = SIGEV_SIGNAL;
- new_timer->it_sigev_signo = SIGALRM;
- new_timer->it_sigev_value.sival_int = new_timer->it_id;
- process = current->group_leader;
- spin_lock_irqsave(&process->sighand->siglock, flags);
- new_timer->it_process = process;
- list_add(&new_timer->list, &process->signal->posix_timers);
- spin_unlock_irqrestore(&process->sighand->siglock, flags);
+ event.sigev_notify = SIGEV_SIGNAL;
+ event.sigev_signo = SIGALRM;
+ event.sigev_value.sival_int = new_timer->it_id;
+ new_timer->it_pid = get_pid(task_tgid(current));
}
+ new_timer->it_sigev_notify = event.sigev_notify;
+ new_timer->sigq->info.si_signo = event.sigev_signo;
+ new_timer->sigq->info.si_value = event.sigev_value;
+ new_timer->sigq->info.si_tid = new_timer->it_id;
+ new_timer->sigq->info.si_code = SI_TIMER;
+
+ spin_lock_irq(¤t->sighand->siglock);
+ new_timer->it_signal = current->signal;
+ list_add(&new_timer->list, ¤t->signal->posix_timers);
+ spin_unlock_irq(¤t->sighand->siglock);
+
+ return 0;
/*
* In the case of the timer belonging to another task, after
* the task is unlocked, the timer is owned by the other task
* and may cease to exist at any time. Don't use or modify
* new_timer after the unlock call.
*/
-
out:
- if (error)
- release_posix_timer(new_timer, it_id_set);
-
+ release_posix_timer(new_timer, it_id_set);
return error;
}
* 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)
+static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags)
{
struct k_itimer *timr;
/*
* 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);
+ timr = 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;
+ if (timr->it_signal == current->signal) {
+ spin_unlock(&idr_lock);
+ return timr;
}
- } else
- spin_unlock_irqrestore(&idr_lock, *flags);
+ spin_unlock(&timr->it_lock);
+ }
+ spin_unlock_irqrestore(&idr_lock, *flags);
- return timr;
+ return NULL;
}
/*
*/
if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING ||
(timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
- timr->it_overrun += hrtimer_forward(timer, now, iv);
+ timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
- remaining = ktime_sub(timer->expires, now);
+ remaining = ktime_sub(hrtimer_get_expires(timer), now);
/* Return 0 only, when the timer is expired and not pending */
if (remaining.tv64 <= 0) {
/*
}
/* Get the time remaining on a POSIX.1b interval timer. */
-asmlinkage long
-sys_timer_gettime(timer_t timer_id, struct itimerspec __user *setting)
+SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
+ struct itimerspec __user *, setting)
{
struct k_itimer *timr;
struct itimerspec cur_setting;
* 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)
+SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
{
struct k_itimer *timr;
int overrun;
- long flags;
+ unsigned long flags;
timr = lock_timer(timer_id, &flags);
if (!timr)
if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
return 0;
- mode = flags & TIMER_ABSTIME ? HRTIMER_ABS : HRTIMER_REL;
+ mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
timr->it.real.timer.function = posix_timer_fn;
- timer->expires = timespec_to_ktime(new_setting->it_value);
+ hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
/* Convert interval */
timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
/* SIGEV_NONE timers are not queued ! See common_timer_get */
if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
/* Setup correct expiry time for relative timers */
- if (mode == HRTIMER_REL)
- timer->expires = ktime_add(timer->expires,
- timer->base->get_time());
+ if (mode == HRTIMER_MODE_REL) {
+ hrtimer_add_expires(timer, timer->base->get_time());
+ }
return 0;
}
- hrtimer_start(timer, timer->expires, mode);
+ hrtimer_start_expires(timer, mode);
return 0;
}
/* Set a POSIX.1b interval timer */
-asmlinkage long
-sys_timer_settime(timer_t timer_id, int flags,
- const struct itimerspec __user *new_setting,
- struct itimerspec __user *old_setting)
+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;
- long flag;
+ unsigned long flag;
struct itimerspec *rtn = old_setting ? &old_spec : NULL;
if (!new_setting)
}
/* Delete a POSIX.1b interval timer. */
-asmlinkage long
-sys_timer_delete(timer_t timer_id)
+SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
{
struct k_itimer *timer;
- long flags;
+ unsigned long flags;
retry_delete:
timer = lock_timer(timer_id, &flags);
* 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;
- }
+ timer->it_signal = NULL;
+
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
return 0;
* 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;
- }
+ timer->it_signal = NULL;
+
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
}
}
EXPORT_SYMBOL_GPL(do_posix_clock_nonanosleep);
-asmlinkage long sys_clock_settime(const clockid_t which_clock,
- const struct timespec __user *tp)
+SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
+ const struct timespec __user *, tp)
{
struct timespec new_tp;
return CLOCK_DISPATCH(which_clock, clock_set, (which_clock, &new_tp));
}
-asmlinkage long
-sys_clock_gettime(const clockid_t which_clock, struct timespec __user *tp)
+SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
+ struct timespec __user *,tp)
{
struct timespec kernel_tp;
int error;
}
-asmlinkage long
-sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp)
+SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
+ struct timespec __user *, tp)
{
struct timespec rtn_tp;
int error;
struct timespec *tsave, struct timespec __user *rmtp)
{
return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
- HRTIMER_ABS : HRTIMER_REL, which_clock);
+ HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
+ which_clock);
}
-asmlinkage long
-sys_clock_nanosleep(const clockid_t which_clock, int flags,
- const struct timespec __user *rqtp,
- struct timespec __user *rmtp)
+SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
+ const struct timespec __user *, rqtp,
+ struct timespec __user *, rmtp)
{
struct timespec t;
Code Review / linux-2.6.git / blobdiff