[PATCH] posix-timers: Declare function parameter as const and constify k_clock structures

From: Bhumika Goyal
Date: Thu Feb 16 2017 - 16:00:42 EST


The second parameter struct k_clock *new_clock of function
posix_timers_register_clock is only dereferenced and copied into another
structure. Therefore it can be made const. Update the function
prototype accordingly.
Update the structures passed to posix_timers_register_clock, as this is
their only use.

Signed-off-by: Bhumika Goyal <bhumirks@xxxxxxxxx>
---
include/linux/posix-timers.h | 3 ++-
kernel/time/posix-timers.c | 16 ++++++++--------
2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 62d44c1..bf57135 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -118,7 +118,8 @@ struct k_clock {
extern struct k_clock clock_posix_cpu;
extern struct k_clock clock_posix_dynamic;

-void posix_timers_register_clock(const clockid_t clock_id, struct k_clock *new_clock);
+void posix_timers_register_clock(const clockid_t clock_id,
+ const struct k_clock *new_clock);

/* function to call to trigger timer event */
int posix_timer_event(struct k_itimer *timr, int si_private);
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 1e6623d..d92eadf 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -284,7 +284,7 @@ static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec *tp)
*/
static __init int init_posix_timers(void)
{
- struct k_clock clock_realtime = {
+ const struct k_clock clock_realtime = {
.clock_getres = posix_get_hrtimer_res,
.clock_get = posix_clock_realtime_get,
.clock_set = posix_clock_realtime_set,
@@ -296,7 +296,7 @@ static __init int init_posix_timers(void)
.timer_get = common_timer_get,
.timer_del = common_timer_del,
};
- struct k_clock clock_monotonic = {
+ const struct k_clock clock_monotonic = {
.clock_getres = posix_get_hrtimer_res,
.clock_get = posix_ktime_get_ts,
.nsleep = common_nsleep,
@@ -306,19 +306,19 @@ static __init int init_posix_timers(void)
.timer_get = common_timer_get,
.timer_del = common_timer_del,
};
- struct k_clock clock_monotonic_raw = {
+ const struct k_clock clock_monotonic_raw = {
.clock_getres = posix_get_hrtimer_res,
.clock_get = posix_get_monotonic_raw,
};
- struct k_clock clock_realtime_coarse = {
+ const struct k_clock clock_realtime_coarse = {
.clock_getres = posix_get_coarse_res,
.clock_get = posix_get_realtime_coarse,
};
- struct k_clock clock_monotonic_coarse = {
+ const struct k_clock clock_monotonic_coarse = {
.clock_getres = posix_get_coarse_res,
.clock_get = posix_get_monotonic_coarse,
};
- struct k_clock clock_tai = {
+ const struct k_clock clock_tai = {
.clock_getres = posix_get_hrtimer_res,
.clock_get = posix_get_tai,
.nsleep = common_nsleep,
@@ -328,7 +328,7 @@ static __init int init_posix_timers(void)
.timer_get = common_timer_get,
.timer_del = common_timer_del,
};
- struct k_clock clock_boottime = {
+ const struct k_clock clock_boottime = {
.clock_getres = posix_get_hrtimer_res,
.clock_get = posix_get_boottime,
.nsleep = common_nsleep,
@@ -521,7 +521,7 @@ static struct pid *good_sigevent(sigevent_t * event)
}

void posix_timers_register_clock(const clockid_t clock_id,
- struct k_clock *new_clock)
+ const struct k_clock *new_clock)
{
if ((unsigned) clock_id >= MAX_CLOCKS) {
printk(KERN_WARNING "POSIX clock register failed for clock_id %d\n",
--
1.9.1