hrtimers/posix-timers: Merge nanosleep timespec copyout logics into a new helper

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170607084241.28657-7-viro@ZenIV.linux.org.uk

include/linux/hrtimer.h

@@ -452,6 +452,8 @@ static inline u64 hrtimer_forward_now(struct hrtimer *timer,
 }
 
 /* Precise sleep: */
+
+extern int nanosleep_copyout(struct restart_block *, struct timespec *);
 extern long hrtimer_nanosleep(struct timespec64 *rqtp,
 			      const enum hrtimer_mode mode,
 			      const clockid_t clockid);

kernel/time/alarmtimer.c

@@ -721,15 +721,7 @@ static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp,
 			return 0;
 		rmt = ktime_to_timespec(rem);
 
-#ifdef CONFIG_COMPAT
-		if (restart->nanosleep.type == TT_COMPAT) {
-			if (compat_put_timespec(&rmt,
-						restart->nanosleep.compat_rmtp))
-				return -EFAULT;
-		} else
-#endif
-		if (copy_to_user(restart->nanosleep.rmtp, &rmt, sizeof(rmt)))
-			return -EFAULT;
+		return nanosleep_copyout(restart, &rmt);
 	}
 	return -ERESTART_RESTARTBLOCK;
 }

kernel/time/hrtimer.c

@@ -1440,6 +1440,25 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
 }
 EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
 
+int nanosleep_copyout(struct restart_block *restart, struct timespec *ts)
+{
+	switch(restart->nanosleep.type) {
+#ifdef CONFIG_COMPAT
+	case TT_COMPAT:
+		if (compat_put_timespec(ts, restart->nanosleep.compat_rmtp))
+			return -EFAULT;
+		break;
+#endif
+	case TT_NATIVE:
+		if (copy_to_user(restart->nanosleep.rmtp, ts, sizeof(struct timespec)))
+			return -EFAULT;
+		break;
+	default:
+		BUG();
+	}
+	return -ERESTART_RESTARTBLOCK;
+}
+
 static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
 {
 	struct restart_block *restart;
@@ -1472,15 +1491,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
 			return 0;
 		rmt = ktime_to_timespec(rem);
 
-#ifdef CONFIG_COMPAT
-		if (restart->nanosleep.type == TT_COMPAT) {
-			if (compat_put_timespec(&rmt,
-						restart->nanosleep.compat_rmtp))
-				return -EFAULT;
-		} else
-#endif
-		if (copy_to_user(restart->nanosleep.rmtp, &rmt, sizeof(rmt)))
-			return -EFAULT;
+		return nanosleep_copyout(restart, &rmt);
 	}
 	return -ERESTART_RESTARTBLOCK;
 }

kernel/time/posix-cpu-timers.c

@@ -1312,22 +1312,13 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
 		 * Report back to the user the time still remaining.
 		 */
 		restart = &current->restart_block;
+		restart->nanosleep.expires = timespec64_to_ns(rqtp);
 		if (restart->nanosleep.type != TT_NONE) {
 			struct timespec ts;
 
 			ts = timespec64_to_timespec(it.it_value);
-#ifdef CONFIG_COMPAT
-			if (restart->nanosleep.type == TT_COMPAT) {
-				if (compat_put_timespec(&ts,
-						restart->nanosleep.compat_rmtp))
-					return -EFAULT;
-			} else
-#endif
-			if (copy_to_user(restart->nanosleep.rmtp, &ts,
-					sizeof(ts)))
-				return -EFAULT;
+			error = nanosleep_copyout(restart, &ts);
 		}
-		restart->nanosleep.expires = timespec64_to_ns(rqtp);
 	}
 
 	return error;