Convert to the 64bit methods with timespec64/itimerspec64 type for the timer_gettime
syscall function, and change the timer_gettime syscall implementation according to
the CONFIG_64BIT macro.
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..f7cf00b 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 int 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);
+ return 0;
+}
+
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
On Monday 11 May 2015 19:15:14 Baolin Wang wrote:
> +static int 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);
> + return 0;
> +}
This function is unfortunately incorrect, because you never copy
the cur_setting value into cur_setting64.
Arnd
On Tuesday 12 May 2015 10:05:45 Baolin Wang wrote:
> On 12 May 2015 at 00:30, Arnd Bergmann <[email protected]> wrote:
>
> > On Monday 11 May 2015 19:15:14 Baolin Wang wrote:
> > > +static int 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);
> > > + return 0;
> > > +}
> >
> > This function is unfortunately incorrect, because you never copy
> > the cur_setting value into cur_setting64.
> >
>
> Thanks for your comments. But i think this is just a temporary default
> function,
> and will be removed after all the drivers' conversion, so just ensure it
> won't
> cause the kernel crash.
>
No, that function has to do the right thing. The purpose of the function
is to keep the kernel working when only half the series is applied, this
is a fundamental part of how we do kernel development: Each patch in
you series needs to bring the kernel closer to what we want to have in
the end but not introduce bugs. Your current function stops the
timer_gettime() system call from working and makes it return uninitialized
kernel data.
Arnd
On Tue, 12 May 2015, Baolin Wang wrote:
> On 12 May 2015 at 00:30, Arnd Bergmann <[email protected]> wrote:
>
> > On Monday 11 May 2015 19:15:14 Baolin Wang wrote:
> > > +static int 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);
> > > + return 0;
> > > +}
> >
> > This function is unfortunately incorrect, because you never copy
> > the cur_setting value into cur_setting64.
>
> Thanks for your comments. But i think this is just a temporary
> default function, and will be removed after all the drivers'
> conversion, so just ensure it won't cause the kernel crash.
The function is crap no matter whether its removed later or not. And
it breaks bisectability.
Thanks,
tglx