hrtimer: Store time as ktime_t in restart block

The hrtimer core uses ktime_t to represent times, use that also for the
restart block. CPU timers internally use nanoseconds instead of ktime_t
but use the same restart block, so use the correct accessors for those.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251110-restart-block-expiration-v1-3-5d39cc93df4f@linutronix.de

Author: t-8ch

include/linux/restart_block.h

@@ -43,7 +43,7 @@ struct restart_block {
 				struct __kernel_timespec __user *rmtp;
 				struct old_timespec32 __user *compat_rmtp;
 			};
-			u64 expires;
+			ktime_t expires;
 		} nanosleep;
 		/* For poll */
 		struct {

kernel/time/hrtimer.c

@@ -2145,7 +2145,7 @@ static long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
 	int ret;
 
 	hrtimer_setup_sleeper_on_stack(&t, restart->nanosleep.clockid, HRTIMER_MODE_ABS);
-	hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
+	hrtimer_set_expires(&t.timer, restart->nanosleep.expires);
 	ret = do_nanosleep(&t, HRTIMER_MODE_ABS);
 	destroy_hrtimer_on_stack(&t.timer);
 	return ret;
@@ -2172,7 +2172,7 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode,
 
 	restart = &current->restart_block;
 	restart->nanosleep.clockid = t.timer.base->clockid;
-	restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
+	restart->nanosleep.expires = hrtimer_get_expires(&t.timer);
 	set_restart_fn(restart, hrtimer_nanosleep_restart);
 out:
 	destroy_hrtimer_on_stack(&t.timer);

kernel/time/posix-cpu-timers.c

@@ -1557,7 +1557,7 @@ 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 = expires;
+		restart->nanosleep.expires = ns_to_ktime(expires);
 		if (restart->nanosleep.type != TT_NONE)
 			error = nanosleep_copyout(restart, &it.it_value);
 	}
@@ -1599,7 +1599,7 @@ static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
 	clockid_t which_clock = restart_block->nanosleep.clockid;
 	struct timespec64 t;
 
-	t = ns_to_timespec64(restart_block->nanosleep.expires);
+	t = ktime_to_timespec64(restart_block->nanosleep.expires);
 
 	return do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t);
 }