[PATCH v2 4/7] Change k_clock clock_getres() to use timespec64

[Deepa Dinamani <deepa.kernel@gmail.com>]

struct timespec is not y2038 safe on 32 bit machines.
Replace uses of struct timespec with struct timespec64
in the kernel.

The syscall interfaces themselves will be changed
in a separate series.

Note that the clock_getres() interface has also been changed
to use timespec64 even though this particular interface is
not affected by the y2038 problem. This helps verification for
internal kernel code for y2038 readiness by getting rid of
time_t/ timeval/ timespec.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
---
 drivers/char/mmtimer.c         |  2 +-
 include/linux/posix-timers.h   |  2 +-
 kernel/time/alarmtimer.c       |  2 +-
 kernel/time/posix-clock.c      |  9 +++------
 kernel/time/posix-cpu-timers.c |  6 +++---
 kernel/time/posix-timers.c     | 10 ++++++----
 6 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c
index 40d880b..79d8ada 100644
--- a/drivers/char/mmtimer.c
+++ b/drivers/char/mmtimer.c
@@ -765,7 +765,7 @@ static int sgi_timer_set(struct k_itimer *timr, int flags,
 	return err;
 }
 
-static int sgi_clock_getres(const clockid_t which_clock, struct timespec *tp)
+static int sgi_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
 {
 	tp->tv_sec = 0;
 	tp->tv_nsec = sgi_clock_period;
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 0688f39..dd05b49 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -87,7 +87,7 @@ struct k_itimer {
 };
 
 struct k_clock {
-	int (*clock_getres) (const clockid_t which_clock, struct timespec *tp);
+	int (*clock_getres) (const clockid_t which_clock, struct timespec64 *tp);
 	int (*clock_set) (const clockid_t which_clock,
 			  const struct timespec *tp);
 	int (*clock_get) (const clockid_t which_clock, struct timespec64 *tp);
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 944ca6e..e8a45e2 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -541,7 +541,7 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
  *
  * Returns the granularity of underlying alarm base clock
  */
-static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp)
+static int alarm_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
 {
 	if (!alarmtimer_get_rtcdev())
 		return -EINVAL;
diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c
index fab6bd3..af91031 100644
--- a/kernel/time/posix-clock.c
+++ b/kernel/time/posix-clock.c
@@ -316,20 +316,17 @@ static int pc_clock_gettime(clockid_t id, struct timespec64 *ts)
 	return err;
 }
 
-static int pc_clock_getres(clockid_t id, struct timespec *ts)
+static int pc_clock_getres(clockid_t id, struct timespec64 *ts)
 {
 	struct posix_clock_desc cd;
-	struct timespec64 ts64;
 	int err;
 
 	err = get_clock_desc(id, &cd);
 	if (err)
 		return err;
 
-	if (cd.clk->ops.clock_getres) {
-		err = cd.clk->ops.clock_getres(cd.clk, &ts64);
-		*ts = timespec64_to_timespec(ts64);
-	}
+	if (cd.clk->ops.clock_getres)
+		err = cd.clk->ops.clock_getres(cd.clk, ts);
 	else
 		err = -EOPNOTSUPP;
 
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 082231c..37ce9ed 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -116,7 +116,7 @@ static inline u64 virt_ticks(struct task_struct *p)
 }
 
 static int
-posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
+posix_cpu_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
 {
 	int error = check_clock(which_clock);
 	if (!error) {
@@ -1369,7 +1369,7 @@ static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
 #define THREAD_CLOCK	MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED)
 
 static int process_cpu_clock_getres(const clockid_t which_clock,
-				    struct timespec *tp)
+				    struct timespec64 *tp)
 {
 	return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
 }
@@ -1394,7 +1394,7 @@ static long process_cpu_nsleep_restart(struct restart_block *restart_block)
 	return -EINVAL;
 }
 static int thread_cpu_clock_getres(const clockid_t which_clock,
-				   struct timespec *tp)
+				   struct timespec64 *tp)
 {
 	return posix_cpu_clock_getres(THREAD_CLOCK, tp);
 }
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 6817064..f67dae9 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -258,9 +258,9 @@ static int posix_get_monotonic_coarse(clockid_t which_clock,
 	return 0;
 }
 
-static int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
+static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *tp)
 {
-	*tp = ktime_to_timespec(KTIME_LOW_RES);
+	*tp = ktime_to_timespec64(KTIME_LOW_RES);
 	return 0;
 }
 
@@ -276,7 +276,7 @@ static int posix_get_tai(clockid_t which_clock, struct timespec64 *tp)
 	return 0;
 }
 
-static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec *tp)
+static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
 {
 	tp->tv_sec = 0;
 	tp->tv_nsec = hrtimer_resolution;
@@ -1075,13 +1075,15 @@ SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
 		struct timespec __user *, tp)
 {
 	struct k_clock *kc = clockid_to_kclock(which_clock);
+	struct timespec64 rtn_tp64;
 	struct timespec rtn_tp;
 	int error;
 
 	if (!kc)
 		return -EINVAL;
 
-	error = kc->clock_getres(which_clock, &rtn_tp);
+	error = kc->clock_getres(which_clock, &rtn_tp64);
+	rtn_tp = timespec64_to_timespec(rtn_tp64);
 
 	if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp)))
 		error = -EFAULT;
-- 
2.7.4