1 files changed, 110 insertions, 7 deletions

diff --git a/kernel/itimer.c b/kernel/itimer.c
index 379be2f8c84c..204ed7939e75 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)