hrtimer: hook compat_sys_nanosleep up to high res timer code

Now we have high res timers on ppc64 I thought Id test them. It turns
out compat_sys_nanosleep hasnt been converted to the hrtimer code and so
is limited to HZ resolution.

The follow patch converts compat_sys_nanosleep to use high res timers.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 11 insertions, 46 deletions

diff --git a/kernel/compat.c b/kernel/compat.c
index 3bae3742c2aa..252a446fb0d0 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -40,62 +40,27 @@ 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)
-{
-        unsigned long expire = restart->arg0, now = jiffies;
-        struct compat_timespec __user *rmtp;
-
-        /* Did it expire while we handled signals? */
-        if (!time_after(expire, now))
-                return 0;
-
-        expire = schedule_timeout_interruptible(expire - now);
-        if (expire == 0)
-                return 0;
-
-        rmtp = (struct compat_timespec __user *)restart->arg1;
-        if (rmtp) {
-                struct compat_timespec ct;
-                struct timespec t;
-
-                jiffies_to_timespec(expire, &t);
-                ct.tv_sec = t.tv_sec;
-                ct.tv_nsec = t.tv_nsec;
-                if (copy_to_user(rmtp, &ct, sizeof(ct)))
-                        return -EFAULT;
-        }
-        /* The 'restart' block is already filled in */
-        return -ERESTART_RESTARTBLOCK;
-}
-
 asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
-                struct compat_timespec __user *rmtp)
+                                     struct compat_timespec __user *rmtp)
 {
-        struct timespec t;
-        struct restart_block *restart;
-        unsigned long expire;
+        struct timespec tu, rmt;
+        long ret;
 
-        if (get_compat_timespec(&t, rqtp))
+        if (get_compat_timespec(&tu, rqtp))
                 return -EFAULT;
 
-        if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0))
+        if (!timespec_valid(&tu))
                 return -EINVAL;
 
-        expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
-        expire = schedule_timeout_interruptible(expire);
-        if (expire == 0)
-                return 0;
+        ret = hrtimer_nanosleep(&tu, rmtp ? &rmt : NULL, HRTIMER_MODE_REL,
+                                CLOCK_MONOTONIC);
 
-        if (rmtp) {
-                jiffies_to_timespec(expire, &t);
-                if (put_compat_timespec(&t, rmtp))
+        if (ret && rmtp) {
+                if (put_compat_timespec(&rmt, rmtp))
                         return -EFAULT;
         }
-        restart = &current_thread_info()->restart_block;
-        restart->fn = compat_nanosleep_restart;
-        restart->arg0 = jiffies + expire;
-        restart->arg1 = (unsigned long) rmtp;
-        return -ERESTART_RESTARTBLOCK;
+
+        return ret;
 }
 
 static inline long get_compat_itimerval(struct itimerval *o,