Re: [PATCH] Hook compat_sys_nanosleep up to high res timer code

Thomas Gleixner
2007-10-15T06:12:05Z

On Sun, 14 Oct 2007, Anton Blanchard wrote:
> Hi Arnd,
>
> > The code looks correct, but I think it would be nicer to change
> > hrtimer_nanosleep to take a kernel pointer and have all three
> > callers (common_nsleep, sys_nanosleep and compat_sys_nanosleep)
> > do the copy_to_user/put_compat_timespec in the caller.
>
> Good idea, I had considered that but thought a larger cleanup might run
> afoul of the merge rules :)

Looks good, except ....

> --- a/kernel/compat.c
> +++ b/kernel/compat.c
> @@ -40,62 +40,26 @@ int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user
> __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
> }

Can you put this into a separate patch please ?

> --- a/kernel/hrtimer.c
> +++ b/kernel/hrtimer.c
> restart = &current_thread_info()->restart_block;
> @@ -1353,7 +1347,8 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
> asmlinkage long
> sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
> {
> - struct timespec tu;
> + struct timespec tu, rmt;
> + int ret;
>
> if (copy_from_user(&tu, rqtp, sizeof(tu)))
> return -EFAULT;
> @@ -1361,7 +1356,14 @@ sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
> if (!timespec_valid(&tu))
> return -EINVAL;
>
> - return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
> + ret = hrtimer_nanosleep(&tu, &rmt, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
> +
> + if (ret) {

Can you check for rmtp as well ? rmtp is optional and can be NULL

> + if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
> + return -EFAULT;
> + }
> +
> + return ret;
> }
>
> /*
> diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
> index 7a15afb..fc7dac2 100644
> --- a/kernel/posix-timers.c
> +++ b/kernel/posix-timers.c
> @@ -980,9 +980,19 @@ sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp)
> static int common_nsleep(const clockid_t which_clock, int flags,
> struct timespec *tsave, struct timespec __user *rmtp)
> {
> - return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
> + struct timespec rmt;
> + int ret;
> +
> + ret = hrtimer_nanosleep(tsave, &rmt, flags & TIMER_ABSTIME ?
> HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
> which_clock);
> +
> + if (ret) {

Ditto.

> + if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
> + return -EFAULT;
> + }
> +
> + return ret;
> }

Thanks,

tglx