time/posix-timers: Move the compat copyouts to the nanosleep implementations

Turn restart_block.nanosleep.{rmtp,compat_rmtp} into a tagged union (kind =
1 -> native, kind = 2 -> compat, kind = 0 -> nothing) and make the places
doing actual copyout handle compat as well as native (that will become a
helper in the next commit).  Result: compat wrappers, messing with
reassignments, etc. are gone.

[ tglx: Folded in a variant of Peter Zijlstras enum patch ]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170607084241.28657-6-viro@ZenIV.linux.org.uk

1 files changed, 0 insertions, 131 deletions

diff --git a/kernel/compat.c b/kernel/compat.c
index cc9ba9d29b47..23afa26f574b 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -213,82 +213,6 @@ int compat_convert_timespec(struct timespec __user **kts,
         return 0;
 }
 
-static long compat_nanosleep_restart(struct restart_block *restart)
-{
-        struct compat_timespec __user *rmtp;
-        struct timespec rmt;
-        mm_segment_t oldfs;
-        long ret;
-
-        restart->nanosleep.rmtp = (struct timespec __user *) &rmt;
-        oldfs = get_fs();
-        set_fs(KERNEL_DS);
-        ret = hrtimer_nanosleep_restart(restart);
-        set_fs(oldfs);
-
-        if (ret == -ERESTART_RESTARTBLOCK) {
-                rmtp = restart->nanosleep.compat_rmtp;
-
-                if (rmtp && compat_put_timespec(&rmt, rmtp))
-                        return -EFAULT;
-        }
-
-        return ret;
-}
-
-COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
-                       struct compat_timespec __user *, rmtp)
-{
-        struct timespec tu, rmt;
-        struct timespec64 tu64;
-        mm_segment_t oldfs;
-        long ret;
-
-        if (compat_get_timespec(&tu, rqtp))
-                return -EFAULT;
-
-        tu64 = timespec_to_timespec64(tu);
-        if (!timespec64_valid(&tu64))
-                return -EINVAL;
-
-        oldfs = get_fs();
-        set_fs(KERNEL_DS);
-        current->restart_block.nanosleep.rmtp =
-                                rmtp ? (struct timespec __user *)&rmt : NULL;
-        ret = hrtimer_nanosleep(&tu64, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
-        set_fs(oldfs);
-
-        /*
-         * hrtimer_nanosleep() can only return 0 or
-         * -ERESTART_RESTARTBLOCK here because:
-         *
-         * - we call it with HRTIMER_MODE_REL and therefor exclude the
-         *   -ERESTARTNOHAND return path.
-         *
-         * - we supply the rmtp argument from the task stack (due to
-         *   the necessary compat conversion. So the update cannot
-         *   fail, which excludes the -EFAULT return path as well. If
-         *   it fails nevertheless we have a bigger problem and wont
-         *   reach this place anymore.
-         *
-         * - if the return value is 0, we do not have to update rmtp
-         *    because there is no remaining time.
-         *
-         * We check for -ERESTART_RESTARTBLOCK nevertheless if the
-         * core implementation decides to return random nonsense.
-         */
-        if (ret == -ERESTART_RESTARTBLOCK) {
-                struct restart_block *restart = &current->restart_block;
-
-                restart->fn = compat_nanosleep_restart;
-                restart->nanosleep.compat_rmtp = rmtp;
-
-                if (rmtp && compat_put_timespec(&rmt, rmtp))
-                        return -EFAULT;
-        }
-        return ret;
-}
-
 static inline long get_compat_itimerval(struct itimerval *o,
                 struct compat_itimerval __user *i)
 {
@@ -821,61 +745,6 @@ COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
         return err;
 }
 
-static long compat_clock_nanosleep_restart(struct restart_block *restart)
-{
-        long err;
-        mm_segment_t oldfs;
-        struct timespec tu;
-        struct compat_timespec __user *rmtp = restart->nanosleep.compat_rmtp;
-
-        restart->nanosleep.rmtp = (struct timespec __user *) &tu;
-        oldfs = get_fs();
-        set_fs(KERNEL_DS);
-        err = clock_nanosleep_restart(restart);
-        set_fs(oldfs);
-
-        if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
-            compat_put_timespec(&tu, rmtp))
-                return -EFAULT;
-
-        if (err == -ERESTART_RESTARTBLOCK) {
-                restart->fn = compat_clock_nanosleep_restart;
-                restart->nanosleep.compat_rmtp = rmtp;
-        }
-        return err;
-}
-
-COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
-                       struct compat_timespec __user *, rqtp,
-                       struct compat_timespec __user *, rmtp)
-{
-        long err;
-        mm_segment_t oldfs;
-        struct timespec in, out;
-        struct restart_block *restart;
-
-        if (compat_get_timespec(&in, rqtp))
-                return -EFAULT;
-
-        oldfs = get_fs();
-        set_fs(KERNEL_DS);
-        err = sys_clock_nanosleep(which_clock, flags,
-                                  (struct timespec __user *) &in,
-                                  (struct timespec __user *) &out);
-        set_fs(oldfs);
-
-        if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
-            compat_put_timespec(&out, rmtp))
-                return -EFAULT;
-
-        if (err == -ERESTART_RESTARTBLOCK) {
-                restart = &current->restart_block;
-                restart->fn = compat_clock_nanosleep_restart;
-                restart->nanosleep.compat_rmtp = rmtp;
-        }
-        return err;
-}
-
 /*
  * We currently only need the following fields from the sigevent
  * structure: sigev_value, sigev_signo, sig_notify and (sometimes