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Diffstat (limited to 'kernel/itimer.c')
-rw-r--r--kernel/itimer.c117
1 files changed, 110 insertions, 7 deletions
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 379be2f8c84..204ed7939e7 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -128,21 +128,75 @@ asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
/*
* The timer is automagically restarted, when interval != 0
*/
-int it_real_fn(void *data)
+int it_real_fn(struct hrtimer *timer)
{
- struct task_struct *tsk = (struct task_struct *) data;
+ struct signal_struct *sig =
+ container_of(timer, struct signal_struct, real_timer);
- send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);
-
- if (tsk->signal->it_real_incr.tv64 != 0) {
- hrtimer_forward(&tsk->signal->real_timer,
- tsk->signal->it_real_incr);
+ 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)
{
struct task_struct *tsk = current;
@@ -150,6 +204,18 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
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);
+
switch (which) {
case ITIMER_REAL:
again:
@@ -226,6 +292,43 @@ again:
return 0;
}
+/**
+ * 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)