nanosleep: Use get_timespec64() and put_timespec64()

Usage of these apis and their compat versions makes
the syscalls: clock_nanosleep and nanosleep and
their compat implementations simpler.

This is a preparatory patch to isolate data conversions to
struct timespec64 at userspace boundaries. This helps contain
the changes needed to transition to new y2038 safe types.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/linux/hrtimer.h

@@ -453,7 +453,7 @@ static inline u64 hrtimer_forward_now(struct hrtimer *timer,
 
 /* Precise sleep: */
 
-extern int nanosleep_copyout(struct restart_block *, struct timespec *);
+extern int nanosleep_copyout(struct restart_block *, struct timespec64 *);
 extern long hrtimer_nanosleep(const struct timespec64 *rqtp,
 			      const enum hrtimer_mode mode,
 			      const clockid_t clockid);

kernel/time/alarmtimer.c

@@ -712,14 +712,14 @@ static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp,
 		alarmtimer_freezerset(absexp, type);
 	restart = &current->restart_block;
 	if (restart->nanosleep.type != TT_NONE) {
-		struct timespec rmt;
+		struct timespec64 rmt;
 		ktime_t rem;
 
 		rem = ktime_sub(absexp, alarm_bases[type].gettime());
 
 		if (rem <= 0)
 			return 0;
-		rmt = ktime_to_timespec(rem);
+		rmt = ktime_to_timespec64(rem);
 
 		return nanosleep_copyout(restart, &rmt);
 	}

kernel/time/hrtimer.c

@@ -1440,17 +1440,17 @@ 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)
+int nanosleep_copyout(struct restart_block *restart, struct timespec64 *ts)
 {
 	switch(restart->nanosleep.type) {
 #ifdef CONFIG_COMPAT
 	case TT_COMPAT:
-		if (compat_put_timespec(ts, restart->nanosleep.compat_rmtp))
+		if (compat_put_timespec64(ts, restart->nanosleep.compat_rmtp))
 			return -EFAULT;
 		break;
 #endif
 	case TT_NATIVE:
-		if (copy_to_user(restart->nanosleep.rmtp, ts, sizeof(struct timespec)))
+		if (put_timespec64(ts, restart->nanosleep.rmtp))
 			return -EFAULT;
 		break;
 	default:
@@ -1485,11 +1485,11 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
 	restart = &current->restart_block;
 	if (restart->nanosleep.type != TT_NONE) {
 		ktime_t rem = hrtimer_expires_remaining(&t->timer);
-		struct timespec rmt;
+		struct timespec64 rmt;
 
 		if (rem <= 0)
 			return 0;
-		rmt = ktime_to_timespec(rem);
+		rmt = ktime_to_timespec64(rem);
 
 		return nanosleep_copyout(restart, &rmt);
 	}
@@ -1546,19 +1546,17 @@ out:
 SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
 		struct timespec __user *, rmtp)
 {
-	struct timespec64 tu64;
-	struct timespec tu;
+	struct timespec64 tu;
 
-	if (copy_from_user(&tu, rqtp, sizeof(tu)))
+	if (get_timespec64(&tu, rqtp))
 		return -EFAULT;
 
-	tu64 = timespec_to_timespec64(tu);
-	if (!timespec64_valid(&tu64))
+	if (!timespec64_valid(&tu))
 		return -EINVAL;
 
 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 	current->restart_block.nanosleep.rmtp = rmtp;
-	return hrtimer_nanosleep(&tu64, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+	return hrtimer_nanosleep(&tu, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
 }
 
 #ifdef CONFIG_COMPAT
@@ -1566,19 +1564,17 @@ SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
 COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
 		       struct compat_timespec __user *, rmtp)
 {
-	struct timespec64 tu64;
-	struct timespec tu;
+	struct timespec64 tu;
 
-	if (compat_get_timespec(&tu, rqtp))
+	if (compat_get_timespec64(&tu, rqtp))
 		return -EFAULT;
 
-	tu64 = timespec_to_timespec64(tu);
-	if (!timespec64_valid(&tu64))
+	if (!timespec64_valid(&tu))
 		return -EINVAL;
 
 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
-	return hrtimer_nanosleep(&tu64, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+	return hrtimer_nanosleep(&tu, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
 }
 #endif
 

kernel/time/posix-cpu-timers.c

@@ -1314,12 +1314,8 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
 		 */
 		restart = &current->restart_block;
 		restart->nanosleep.expires = expires;
-		if (restart->nanosleep.type != TT_NONE) {
-			struct timespec ts;
-
-			ts = timespec64_to_timespec(it.it_value);
-			error = nanosleep_copyout(restart, &ts);
-		}
+		if (restart->nanosleep.type != TT_NONE)
+			error = nanosleep_copyout(restart, &it.it_value);
 	}
 
 	return error;

kernel/time/posix-timers.c

@@ -1213,26 +1213,24 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 		struct timespec __user *, rmtp)
 {
 	const struct k_clock *kc = clockid_to_kclock(which_clock);
-	struct timespec64 t64;
-	struct timespec t;
+	struct timespec64 t;
 
 	if (!kc)
 		return -EINVAL;
 	if (!kc->nsleep)
 		return -ENANOSLEEP_NOTSUP;
 
-	if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
+	if (get_timespec64(&t, rqtp))
 		return -EFAULT;
 
-	t64 = timespec_to_timespec64(t);
-	if (!timespec64_valid(&t64))
+	if (!timespec64_valid(&t))
 		return -EINVAL;
 	if (flags & TIMER_ABSTIME)
 		rmtp = NULL;
 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 	current->restart_block.nanosleep.rmtp = rmtp;
 
-	return kc->nsleep(which_clock, flags, &t64);
+	return kc->nsleep(which_clock, flags, &t);
 }
 
 #ifdef CONFIG_COMPAT
@@ -1241,26 +1239,24 @@ COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
 		       struct compat_timespec __user *, rmtp)
 {
 	const struct k_clock *kc = clockid_to_kclock(which_clock);
-	struct timespec64 t64;
-	struct timespec t;
+	struct timespec64 t;
 
 	if (!kc)
 		return -EINVAL;
 	if (!kc->nsleep)
 		return -ENANOSLEEP_NOTSUP;
 
-	if (compat_get_timespec(&t, rqtp))
+	if (compat_get_timespec64(&t, rqtp))
 		return -EFAULT;
 
-	t64 = timespec_to_timespec64(t);
-	if (!timespec64_valid(&t64))
+	if (!timespec64_valid(&t))
 		return -EINVAL;
 	if (flags & TIMER_ABSTIME)
 		rmtp = NULL;
 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
 
-	return kc->nsleep(which_clock, flags, &t64);
+	return kc->nsleep(which_clock, flags, &t);
 }
 #endif