[PATCH] hrtimer: create and use timespec_valid macro

add timespec_valid(ts) [returns false if the timespec is denorm]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/time.h

@@ -44,6 +44,12 @@ extern unsigned long mktime(const unsigned int year, const unsigned int mon,
 
 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
 
+/*
+ * Returns true if the timespec is norm, false if denorm:
+ */
+#define timespec_valid(ts) \
+	(((ts)->tv_sec >= 0) && (((unsigned) (ts)->tv_nsec) < NSEC_PER_SEC))
+
 extern struct timespec xtime;
 extern struct timespec wall_to_monotonic;
 extern seqlock_t xtime_lock;

kernel/posix-timers.c

@@ -712,8 +712,7 @@ sys_timer_create(const clockid_t which_clock,
  */
 static int good_timespec(const struct timespec *ts)
 {
-	if ((!ts) || (ts->tv_sec < 0) ||
-			((unsigned) ts->tv_nsec >= NSEC_PER_SEC))
+	if ((!ts) || !timespec_valid(ts))
 		return 0;
 	return 1;
 }
@@ -1406,7 +1405,7 @@ sys_clock_nanosleep(const clockid_t which_clock, int flags,
 	if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
 		return -EFAULT;
 
-	if ((unsigned) t.tv_nsec >= NSEC_PER_SEC || t.tv_sec < 0)
+	if (!timespec_valid(&t))
 		return -EINVAL;
 
 	/*