[PATCH v5 11/24] posix-timers: Implement y2038 safe clock_set64() callback

[Baolin Wang]

The clock_set() callback in struct k_clock is not year 2038 safe on
32bit systems.

To address this implement a new callback clock_set64() which uses
struct timespec64 along with a default implementation which is a
wrapper for the existing clock_set() callback. The default callback
is installed at registration time for all posix clocks which are not
yet converted to clock_set64() and will be removed once this is
completed.

Use the new callback in __clock_settime().

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
 include/linux/posix-timers.h |    2 ++
 kernel/time/posix-timers.c   |   24 +++++++++++++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 16c3364..2b19ec8 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -100,6 +100,8 @@ struct k_clock {
 	int (*clock_getres) (const clockid_t which_clock, struct timespec *tp);
 	int (*clock_set) (const clockid_t which_clock,
 			  const struct timespec *tp);
+	int (*clock_set64) (const clockid_t which_clock,
+			    const struct timespec64 *tp);
 	int (*clock_get) (const clockid_t which_clock, struct timespec * tp);
 	int (*clock_adj) (const clockid_t which_clock, struct timex *tx);
 	int (*timer_create) (struct k_itimer *timer);
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 65610ac..dcc632c 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -577,6 +577,18 @@ static int default_timer_set64(struct k_itimer *timr, int flags,
 	return ret;
 }
 
+static int default_clock_set64(const clockid_t which_clock,
+			       const struct timespec64 *tp64)
+{
+	struct k_clock *kc = clockid_to_kclock(which_clock);
+	struct timespec tp;
+	int ret;
+
+	tp = timespec64_to_timespec(*tp64);
+	ret = kc->clock_set(which_clock, &tp);
+	return ret;
+}
+
 void posix_timers_register_clock(const clockid_t clock_id,
 				 struct k_clock *new_clock)
 {
@@ -601,6 +613,8 @@ void posix_timers_register_clock(const clockid_t clock_id,
 		new_clock->timer_get64 = default_timer_get64;
 	if (new_clock->timer_set && !new_clock->timer_set64)
 		new_clock->timer_set64 = default_timer_set64;
+	if (new_clock->clock_set && !new_clock->clock_set64)
+		new_clock->clock_set64 = default_clock_set64;
 
 	posix_clocks[clock_id] = *new_clock;
 }
@@ -1089,22 +1103,22 @@ void exit_itimers(struct signal_struct *sig)
 	}
 }
 
-static int __clock_settime(clockid_t which_clock, struct timespec *ts)
+static int __clock_settime(clockid_t which_clock, struct timespec64 *ts)
 {
 	struct k_clock *kc = clockid_to_kclock(which_clock);
 
-	if (!kc || !kc->clock_set)
+	if (!kc || !kc->clock_set64)
 		return -EINVAL;
 
-	return kc->clock_set(which_clock, ts);
+	return kc->clock_set64(which_clock, ts);
 }
 
 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
 		const struct timespec __user *, tp)
 {
-	struct timespec new_tp;
+	struct timespec64 new_tp;
 
-	if (copy_from_user(&new_tp, tp, sizeof (*tp)))
+	if (get_timespec(&new_tp, tp))
 		return -EFAULT;
 
 	return __clock_settime(which_clock, &new_tp);
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/