hrtimer: fix *rmtp/restarts handling in compat_sys_nanosleep()

Spotted by Pavel Emelyanov and Alexey Dobriyan.

compat_sys_nanosleep() implicitly uses hrtimer_nanosleep_restart(), this can't
work. Make a suitable compat_nanosleep_restart() helper.

Introduced by commit c70878b4e0
hrtimer: hook compat_sys_nanosleep up to high res timer code

Also, set ->addr_limit = KERNEL_DS before doing hrtimer_nanosleep(), this func
was changed by the previous patch and now takes the "__user *" parameter.

Thanks to Ingo Molnar for fixing the bug in this patch.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Pavel Emelyanov <xemul@sw.ru>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Toyo Abe <toyoa@mvista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Oleg Nesterov 2008-02-01 20:35:31 +03:00 committed by Thomas Gleixner
parent 080344b988
commit 416529374b

View File

@ -40,10 +40,36 @@ int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user
__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}
static long compat_nanosleep_restart(struct restart_block *restart)
{
struct compat_timespec __user *rmtp;
struct timespec rmt;
mm_segment_t oldfs;
long ret;
rmtp = (struct compat_timespec __user *)(restart->arg1);
restart->arg1 = (unsigned long)&rmt;
oldfs = get_fs();
set_fs(KERNEL_DS);
ret = hrtimer_nanosleep_restart(restart);
set_fs(oldfs);
if (ret) {
restart->fn = compat_nanosleep_restart;
restart->arg1 = (unsigned long)rmtp;
if (rmtp && put_compat_timespec(&rmt, rmtp))
return -EFAULT;
}
return ret;
}
asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
struct compat_timespec __user *rmtp)
{
struct timespec tu, rmt;
mm_segment_t oldfs;
long ret;
if (get_compat_timespec(&tu, rqtp))
@ -52,11 +78,21 @@ asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
if (!timespec_valid(&tu))
return -EINVAL;
ret = hrtimer_nanosleep(&tu, rmtp ? &rmt : NULL, HRTIMER_MODE_REL,
CLOCK_MONOTONIC);
oldfs = get_fs();
set_fs(KERNEL_DS);
ret = hrtimer_nanosleep(&tu,
rmtp ? (struct timespec __user *)&rmt : NULL,
HRTIMER_MODE_REL, CLOCK_MONOTONIC);
set_fs(oldfs);
if (ret && rmtp) {
if (put_compat_timespec(&rmt, rmtp))
if (ret) {
struct restart_block *restart
= &current_thread_info()->restart_block;
restart->fn = compat_nanosleep_restart;
restart->arg1 = (unsigned long)rmtp;
if (rmtp && put_compat_timespec(&rmt, rmtp))
return -EFAULT;
}