2015-05-12 14:08:10

by Baolin Wang

Subject: [PATCH v3 06/23] posix-timers:Convert to the 64bit methods for the timer_gettime syscall function

This patch introduces the timer_get64 method with itimerspec64 type for k_clock
structure, that makes it ready for the 2038 year.

Convert to the 64bit method with itimerspec64 type for the timer_gettime
syscall function, and change the timer_gettime syscall implementation according to
the CONFIG_64BIT macro.

Also add a default 64bit method for the timer_get64 pointer of k_clock structure,
and it will be removed after all the drivers are converted to 64bit methods.

Signed-off-by: Baolin Wang <[email protected]>
---
include/linux/posix-timers.h | 2 ++
kernel/time/posix-timers.c | 31 +++++++++++++++++++++++++++----
2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 907f3fd..e84436b 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -113,6 +113,8 @@ struct k_clock {
#define TIMER_RETRY 1
void (*timer_get) (struct k_itimer * timr,
struct itimerspec * cur_setting);
+ void (*timer_get64) (struct k_itimer *timr,
+ struct itimerspec64 *cur_setting);
};

extern struct k_clock clock_posix_cpu;
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 9df664a..91036b1 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -140,6 +140,7 @@ static int common_timer_del(struct k_itimer *timer);
static enum hrtimer_restart posix_timer_fn(struct hrtimer *data);

static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
+static struct k_clock *clockid_to_kclock(const clockid_t id);

#define lock_timer(tid, flags) \
({ struct k_itimer *__timr; \
@@ -513,6 +514,16 @@ static struct pid *good_sigevent(sigevent_t * event)
return task_pid(rtn);
}

+static void default_timer_get64(struct k_itimer *timr,
+ struct itimerspec64 *cur_setting64)
+{
+ struct itimerspec cur_setting;
+ struct k_clock *kc = clockid_to_kclock(timr->it_clock);
+
+ kc->timer_get(timr, &cur_setting);
+ *cur_setting64 = itimerspec_to_itimerspec64(&cur_setting);
+}
+
void posix_timers_register_clock(const clockid_t clock_id,
struct k_clock *new_clock)
{
@@ -533,6 +544,9 @@ void posix_timers_register_clock(const clockid_t clock_id,
return;
}

+ if (new_clock->timer_get && !new_clock->timer_get64)
+ new_clock->timer_get64 = default_timer_get64;
+
posix_clocks[clock_id] = *new_clock;
}
EXPORT_SYMBOL_GPL(posix_timers_register_clock);
@@ -766,7 +780,7 @@ common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
cur_setting->it_value = ktime_to_timespec(remaining);
}

-static int __timer_gettime(timer_t timer_id, struct itimerspec *cur_setting)
+static int __timer_gettime(timer_t timer_id, struct itimerspec64 *cur_setting)
{
struct k_itimer *timr;
struct k_clock *kc;
@@ -778,10 +792,10 @@ static int __timer_gettime(timer_t timer_id, struct itimerspec *cur_setting)
return -EINVAL;

kc = clockid_to_kclock(timr->it_clock);
- if (WARN_ON_ONCE(!kc || !kc->timer_get))
+ if (WARN_ON_ONCE(!kc || !kc->timer_get64))
ret = -EINVAL;
else
- kc->timer_get(timr, cur_setting);
+ kc->timer_get64(timr, cur_setting);

unlock_timer(timr, flags);
return ret;
@@ -791,8 +805,17 @@ static int __timer_gettime(timer_t timer_id, struct itimerspec *cur_setting)
SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
struct itimerspec __user *, setting)
{
- struct itimerspec cur_setting;
+#ifdef CONFIG_64BIT
+ struct itimerspec64 cur_setting;
int ret = __timer_gettime(timer_id, &cur_setting);
+#else
+ struct itimerspec64 cur_setting64;
+ struct itimerspec cur_setting;
+
+ int ret = __timer_gettime(timer_id, &cur_setting64);
+ if (!ret)
+ cur_setting = itimerspec64_to_itimerspec(&cur_setting64);
+#endif

if (!ret && copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
return -EFAULT;
--
1.7.9.5

2015-05-12 15:34:13

by Arnd Bergmann

Subject: Re: [PATCH v3 06/23] posix-timers:Convert to the 64bit methods for the timer_gettime syscall function

On Tuesday 12 May 2015 22:07:53 Baolin Wang wrote:
> }
>
> +static void default_timer_get64(struct k_itimer *timr,
> + struct itimerspec64 *cur_setting64)
> +{
> + struct itimerspec cur_setting;
> + struct k_clock *kc = clockid_to_kclock(timr->it_clock);
> +
> + kc->timer_get(timr, &cur_setting);
> + *cur_setting64 = itimerspec_to_itimerspec64(&cur_setting);
> +}
> +
>

The new version is correct, but when I asked you in private to send the update,
what I meant was a reply to my email, and only the updated function for the
sake of discussion. You have now sent the patch as a new thread, which means
we have two email conversations with the same subject line and different
contents, which is rather confusing and should be avoided.

Arnd