#include <linux/syscalls.h>
#include <linux/time.h>
#include <linux/posix-timers.h>
+#include <linux/hrtimer.h>
#include <asm/uaccess.h>
-static unsigned long it_real_value(struct signal_struct *sig)
+/**
+ * itimer_get_remtime - get remaining time for the timer
+ *
+ * @timer: the timer to read
+ *
+ * Returns the delta between the expiry time and now, which can be
+ * less than zero or 1usec for an pending expired timer
+ */
+static struct timeval itimer_get_remtime(struct hrtimer *timer)
{
- unsigned long val = 0;
- if (timer_pending(&sig->real_timer)) {
- val = sig->real_timer.expires - jiffies;
+ ktime_t rem = hrtimer_get_remaining(timer);
- /* look out for negative/zero itimer.. */
- if ((long) val <= 0)
- val = 1;
- }
- return val;
+ /*
+ * Racy but safe: if the itimer expires after the above
+ * hrtimer_get_remtime() call but before this condition
+ * then we return 0 - which is correct.
+ */
+ if (hrtimer_active(timer)) {
+ if (rem.tv64 <= 0)
+ rem.tv64 = NSEC_PER_USEC;
+ } else
+ rem.tv64 = 0;
+
+ return ktime_to_timeval(rem);
}
int do_getitimer(int which, struct itimerval *value)
{
struct task_struct *tsk = current;
- unsigned long interval, val;
cputime_t cinterval, cval;
switch (which) {
case ITIMER_REAL:
spin_lock_irq(&tsk->sighand->siglock);
- interval = tsk->signal->it_real_incr;
- val = it_real_value(tsk->signal);
+ value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
+ value->it_interval =
+ ktime_to_timeval(tsk->signal->it_real_incr);
spin_unlock_irq(&tsk->sighand->siglock);
- jiffies_to_timeval(val, &value->it_value);
- jiffies_to_timeval(interval, &value->it_interval);
break;
case ITIMER_VIRTUAL:
read_lock(&tasklist_lock);
return error;
}
+
/*
- * Called with P->sighand->siglock held and P->signal->real_timer inactive.
- * If interval is nonzero, arm the timer for interval ticks from now.
+ * The timer is automagically restarted, when interval != 0
*/
-static inline void it_real_arm(struct task_struct *p, unsigned long interval)
+int it_real_fn(void *data)
{
- p->signal->it_real_value = interval; /* XXX unnecessary field?? */
- if (interval == 0)
- return;
- if (interval > (unsigned long) LONG_MAX)
- interval = LONG_MAX;
- /* the "+ 1" below makes sure that the timer doesn't go off before
- * the interval requested. This could happen if
- * time requested % (usecs per jiffy) is more than the usecs left
- * in the current jiffy */
- p->signal->real_timer.expires = jiffies + interval + 1;
- add_timer(&p->signal->real_timer);
-}
+ struct task_struct *tsk = (struct task_struct *) data;
-void it_real_fn(unsigned long __data)
-{
- struct task_struct * p = (struct task_struct *) __data;
+ send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);
- send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p);
+ if (tsk->signal->it_real_incr.tv64 != 0) {
+ hrtimer_forward(&tsk->signal->real_timer,
+ tsk->signal->it_real_incr);
- /*
- * Now restart the timer if necessary. We don't need any locking
- * here because do_setitimer makes sure we have finished running
- * before it touches anything.
- */
- it_real_arm(p, p->signal->it_real_incr);
+ return HRTIMER_RESTART;
+ }
+ return HRTIMER_NORESTART;
}
int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
{
struct task_struct *tsk = current;
- unsigned long val, interval;
+ struct hrtimer *timer;
+ ktime_t expires;
cputime_t cval, cinterval, nval, ninterval;
switch (which) {
case ITIMER_REAL:
again:
spin_lock_irq(&tsk->sighand->siglock);
- interval = tsk->signal->it_real_incr;
- val = it_real_value(tsk->signal);
+ timer = &tsk->signal->real_timer;
+ if (ovalue) {
+ ovalue->it_value = itimer_get_remtime(timer);
+ ovalue->it_interval
+ = ktime_to_timeval(tsk->signal->it_real_incr);
+ }
/* We are sharing ->siglock with it_real_fn() */
- if (try_to_del_timer_sync(&tsk->signal->real_timer) < 0) {
+ if (hrtimer_try_to_cancel(timer) < 0) {
spin_unlock_irq(&tsk->sighand->siglock);
goto again;
}
tsk->signal->it_real_incr =
- timeval_to_jiffies(&value->it_interval);
- it_real_arm(tsk, timeval_to_jiffies(&value->it_value));
+ timeval_to_ktime(value->it_interval);
+ expires = timeval_to_ktime(value->it_value);
+ if (expires.tv64 != 0)
+ hrtimer_start(timer, expires, HRTIMER_REL);
spin_unlock_irq(&tsk->sighand->siglock);
- if (ovalue) {
- jiffies_to_timeval(val, &ovalue->it_value);
- jiffies_to_timeval(interval,
- &ovalue->it_interval);
- }
break;
case ITIMER_VIRTUAL:
nval = timeval_to_cputime(&value->it_value);