#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
+#include <linux/syscalls.h>
#include <linux/time.h>
+#include <linux/posix-timers.h>
+#include <linux/hrtimer.h>
#include <asm/uaccess.h>
+/**
+ * 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)
+{
+ ktime_t rem = hrtimer_get_remaining(timer);
+
+ /*
+ * 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)
{
- register unsigned long val, interval;
+ struct task_struct *tsk = current;
+ cputime_t cinterval, cval;
switch (which) {
case ITIMER_REAL:
- interval = current->it_real_incr;
- val = 0;
- /*
- * FIXME! This needs to be atomic, in case the kernel timer happens!
- */
- if (timer_pending(¤t->real_timer)) {
- val = current->real_timer.expires - jiffies;
-
- /* look out for negative/zero itimer.. */
- if ((long) val <= 0)
- val = 1;
- }
+ spin_lock_irq(&tsk->sighand->siglock);
+ 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);
break;
case ITIMER_VIRTUAL:
- val = current->it_virt_value;
- interval = current->it_virt_incr;
+ read_lock(&tasklist_lock);
+ spin_lock_irq(&tsk->sighand->siglock);
+ cval = tsk->signal->it_virt_expires;
+ cinterval = tsk->signal->it_virt_incr;
+ if (!cputime_eq(cval, cputime_zero)) {
+ struct task_struct *t = tsk;
+ cputime_t utime = tsk->signal->utime;
+ do {
+ utime = cputime_add(utime, t->utime);
+ t = next_thread(t);
+ } while (t != tsk);
+ if (cputime_le(cval, utime)) { /* about to fire */
+ cval = jiffies_to_cputime(1);
+ } else {
+ cval = cputime_sub(cval, utime);
+ }
+ }
+ spin_unlock_irq(&tsk->sighand->siglock);
+ read_unlock(&tasklist_lock);
+ cputime_to_timeval(cval, &value->it_value);
+ cputime_to_timeval(cinterval, &value->it_interval);
break;
case ITIMER_PROF:
- val = current->it_prof_value;
- interval = current->it_prof_incr;
+ read_lock(&tasklist_lock);
+ spin_lock_irq(&tsk->sighand->siglock);
+ cval = tsk->signal->it_prof_expires;
+ cinterval = tsk->signal->it_prof_incr;
+ if (!cputime_eq(cval, cputime_zero)) {
+ struct task_struct *t = tsk;
+ cputime_t ptime = cputime_add(tsk->signal->utime,
+ tsk->signal->stime);
+ do {
+ ptime = cputime_add(ptime,
+ cputime_add(t->utime,
+ t->stime));
+ t = next_thread(t);
+ } while (t != tsk);
+ if (cputime_le(cval, ptime)) { /* about to fire */
+ cval = jiffies_to_cputime(1);
+ } else {
+ cval = cputime_sub(cval, ptime);
+ }
+ }
+ spin_unlock_irq(&tsk->sighand->siglock);
+ read_unlock(&tasklist_lock);
+ cputime_to_timeval(cval, &value->it_value);
+ cputime_to_timeval(cinterval, &value->it_interval);
break;
default:
return(-EINVAL);
}
- jiffies_to_timeval(val, &value->it_value);
- jiffies_to_timeval(interval, &value->it_interval);
return 0;
}
-/* SMP: Only we modify our itimer values. */
asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
{
int error = -EFAULT;
return error;
}
-void it_real_fn(unsigned long __data)
+
+/*
+ * The timer is automagically restarted, when interval != 0
+ */
+int it_real_fn(struct hrtimer *timer)
{
- struct task_struct * p = (struct task_struct *) __data;
- unsigned long interval;
-
- send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p);
- interval = p->it_real_incr;
- if (interval) {
- if (interval > (unsigned long) LONG_MAX)
- interval = LONG_MAX;
- p->real_timer.expires = jiffies + interval;
- add_timer(&p->real_timer);
+ struct signal_struct *sig =
+ container_of(timer, struct signal_struct, real_timer);
+
+ send_group_sig_info(SIGALRM, SEND_SIG_PRIV, sig->tsk);
+
+ if (sig->it_real_incr.tv64 != 0) {
+ hrtimer_forward(timer, timer->base->softirq_time,
+ sig->it_real_incr);
+ return HRTIMER_RESTART;
}
+ return HRTIMER_NORESTART;
+}
+
+/*
+ * We do not care about correctness. We just sanitize the values so
+ * the ktime_t operations which expect normalized values do not
+ * break. This converts negative values to long timeouts similar to
+ * the code in kernel versions < 2.6.16
+ *
+ * Print a limited number of warning messages when an invalid timeval
+ * is detected.
+ */
+static void fixup_timeval(struct timeval *tv, int interval)
+{
+ static int warnlimit = 10;
+ unsigned long tmp;
+
+ if (warnlimit > 0) {
+ warnlimit--;
+ printk(KERN_WARNING
+ "setitimer: %s (pid = %d) provided "
+ "invalid timeval %s: tv_sec = %ld tv_usec = %ld\n",
+ current->comm, current->pid,
+ interval ? "it_interval" : "it_value",
+ tv->tv_sec, (long) tv->tv_usec);
+ }
+
+ tmp = tv->tv_usec;
+ if (tmp >= USEC_PER_SEC) {
+ tv->tv_usec = tmp % USEC_PER_SEC;
+ tv->tv_sec += tmp / USEC_PER_SEC;
+ }
+
+ tmp = tv->tv_sec;
+ if (tmp > LONG_MAX)
+ tv->tv_sec = LONG_MAX;
+}
+
+/*
+ * Returns true if the timeval is in canonical form
+ */
+#define timeval_valid(t) \
+ (((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))
+
+/*
+ * Check for invalid timevals, sanitize them and print a limited
+ * number of warnings.
+ */
+static void check_itimerval(struct itimerval *value) {
+
+ if (unlikely(!timeval_valid(&value->it_value)))
+ fixup_timeval(&value->it_value, 0);
+
+ if (unlikely(!timeval_valid(&value->it_interval)))
+ fixup_timeval(&value->it_interval, 1);
}
int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
{
- register unsigned long i, j;
- int k;
+ struct task_struct *tsk = current;
+ struct hrtimer *timer;
+ ktime_t expires;
+ cputime_t cval, cinterval, nval, ninterval;
+
+ /*
+ * Validate the timevals in value.
+ *
+ * Note: Although the spec requires that invalid values shall
+ * return -EINVAL, we just fixup the value and print a limited
+ * number of warnings in order not to break users of this
+ * historical misfeature.
+ *
+ * Scheduled for replacement in March 2007
+ */
+ check_itimerval(value);
- i = timeval_to_jiffies(&value->it_interval);
- j = timeval_to_jiffies(&value->it_value);
- if (ovalue && (k = do_getitimer(which, ovalue)) < 0)
- return k;
switch (which) {
- case ITIMER_REAL:
- del_timer_sync(¤t->real_timer);
- current->it_real_value = j;
- current->it_real_incr = i;
- if (!j)
- break;
- if (j > (unsigned long) LONG_MAX)
- j = LONG_MAX;
- i = j + jiffies;
- current->real_timer.expires = i;
- add_timer(¤t->real_timer);
- break;
- case ITIMER_VIRTUAL:
- if (j)
- j++;
- current->it_virt_value = j;
- current->it_virt_incr = i;
- break;
- case ITIMER_PROF:
- if (j)
- j++;
- current->it_prof_value = j;
- current->it_prof_incr = i;
- break;
- default:
- return -EINVAL;
+ case ITIMER_REAL:
+again:
+ spin_lock_irq(&tsk->sighand->siglock);
+ 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 (hrtimer_try_to_cancel(timer) < 0) {
+ spin_unlock_irq(&tsk->sighand->siglock);
+ goto again;
+ }
+ tsk->signal->it_real_incr =
+ 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);
+ break;
+ case ITIMER_VIRTUAL:
+ nval = timeval_to_cputime(&value->it_value);
+ ninterval = timeval_to_cputime(&value->it_interval);
+ read_lock(&tasklist_lock);
+ spin_lock_irq(&tsk->sighand->siglock);
+ cval = tsk->signal->it_virt_expires;
+ cinterval = tsk->signal->it_virt_incr;
+ if (!cputime_eq(cval, cputime_zero) ||
+ !cputime_eq(nval, cputime_zero)) {
+ if (cputime_gt(nval, cputime_zero))
+ nval = cputime_add(nval,
+ jiffies_to_cputime(1));
+ set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
+ &nval, &cval);
+ }
+ tsk->signal->it_virt_expires = nval;
+ tsk->signal->it_virt_incr = ninterval;
+ spin_unlock_irq(&tsk->sighand->siglock);
+ read_unlock(&tasklist_lock);
+ if (ovalue) {
+ cputime_to_timeval(cval, &ovalue->it_value);
+ cputime_to_timeval(cinterval, &ovalue->it_interval);
+ }
+ break;
+ case ITIMER_PROF:
+ nval = timeval_to_cputime(&value->it_value);
+ ninterval = timeval_to_cputime(&value->it_interval);
+ read_lock(&tasklist_lock);
+ spin_lock_irq(&tsk->sighand->siglock);
+ cval = tsk->signal->it_prof_expires;
+ cinterval = tsk->signal->it_prof_incr;
+ if (!cputime_eq(cval, cputime_zero) ||
+ !cputime_eq(nval, cputime_zero)) {
+ if (cputime_gt(nval, cputime_zero))
+ nval = cputime_add(nval,
+ jiffies_to_cputime(1));
+ set_process_cpu_timer(tsk, CPUCLOCK_PROF,
+ &nval, &cval);
+ }
+ tsk->signal->it_prof_expires = nval;
+ tsk->signal->it_prof_incr = ninterval;
+ spin_unlock_irq(&tsk->sighand->siglock);
+ read_unlock(&tasklist_lock);
+ if (ovalue) {
+ cputime_to_timeval(cval, &ovalue->it_value);
+ cputime_to_timeval(cinterval, &ovalue->it_interval);
+ }
+ break;
+ default:
+ return -EINVAL;
}
return 0;
}
-/* SMP: Again, only we play with our itimers, and signals are SMP safe
- * now so that is not an issue at all anymore.
+/**
+ * alarm_setitimer - set alarm in seconds
+ *
+ * @seconds: number of seconds until alarm
+ * 0 disables the alarm
+ *
+ * Returns the remaining time in seconds of a pending timer or 0 when
+ * the timer is not active.
+ *
+ * On 32 bit machines the seconds value is limited to (INT_MAX/2) to avoid
+ * negative timeval settings which would cause immediate expiry.
*/
+unsigned int alarm_setitimer(unsigned int seconds)
+{
+ struct itimerval it_new, it_old;
+
+#if BITS_PER_LONG < 64
+ if (seconds > INT_MAX)
+ seconds = INT_MAX;
+#endif
+ it_new.it_value.tv_sec = seconds;
+ it_new.it_value.tv_usec = 0;
+ it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;
+
+ do_setitimer(ITIMER_REAL, &it_new, &it_old);
+
+ /*
+ * We can't return 0 if we have an alarm pending ... And we'd
+ * better return too much than too little anyway
+ */
+ if ((!it_old.it_value.tv_sec && it_old.it_value.tv_usec) ||
+ it_old.it_value.tv_usec >= 500000)
+ it_old.it_value.tv_sec++;
+
+ return it_old.it_value.tv_sec;
+}
+
asmlinkage long sys_setitimer(int which,
struct itimerval __user *value,
struct itimerval __user *ovalue)
git://git.onelab.eu / linux-2.6.git / blobdiff