posix-timers: Take compat timer_settime(2) to native one

... and get rid of set_fs() in there

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/20170607084241.28657-10-viro@ZenIV.linux.org.uk

diff --git a/kernel/compat.c b/kernel/compat.c
index 97087b3..df39e2e 100644 (file)
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -635,29 +635,6 @@ COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock,
        return sys_timer_create(which_clock, event, created_timer_id);
 }
 
-COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
-                      struct compat_itimerspec __user *, new,
-                      struct compat_itimerspec __user *, old)
-{
-       long err;
-       mm_segment_t oldfs;
-       struct itimerspec newts, oldts;
-
-       if (!new)
-               return -EINVAL;
-       if (get_compat_itimerspec(&newts, new))
-               return -EFAULT;
-       oldfs = get_fs();
-       set_fs(KERNEL_DS);
-       err = sys_timer_settime(timer_id, flags,
-                               (struct itimerspec __user *) &newts,
-                               (struct itimerspec __user *) &oldts);
-       set_fs(oldfs);
-       if (!err && old && put_compat_itimerspec(old, &oldts))
-               return -EFAULT;
-       return err;
-}
-
 COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
                       struct compat_itimerspec __user *, setting)
 {

diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index 954d1d8..ad263df 100644 (file)
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -42,6 +42,7 @@ SYS_NI(setitimer);
 SYS_NI(alarm);
 #endif
 COMPAT_SYS_NI(clock_adjtime);
+COMPAT_SYS_NI(timer_settime);
 
 /*
  * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index b1b6d52..a73feac 100644 (file)
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -819,31 +819,21 @@ int common_timer_set(struct k_itimer *timr, int flags,
        return 0;
 }
 
-/* Set a POSIX.1b interval timer */
-SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
-               const struct itimerspec __user *, new_setting,
-               struct itimerspec __user *, old_setting)
+static int do_timer_settime(timer_t timer_id, int flags,
+                           struct itimerspec64 *new_spec64,
+                           struct itimerspec64 *old_spec64)
 {
-       struct itimerspec64 new_spec64, old_spec64;
-       struct itimerspec64 *rtn = old_setting ? &old_spec64 : NULL;
-       struct itimerspec new_spec, old_spec;
+       const struct k_clock *kc;
        struct k_itimer *timr;
        unsigned long flag;
-       const struct k_clock *kc;
        int error = 0;
 
-       if (!new_setting)
+       if (!timespec64_valid(&new_spec64->it_interval) ||
+           !timespec64_valid(&new_spec64->it_value))
                return -EINVAL;
 
-       if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
-               return -EFAULT;
-       new_spec64 = itimerspec_to_itimerspec64(&new_spec);
-
-       if (!timespec64_valid(&new_spec64.it_interval) ||
-           !timespec64_valid(&new_spec64.it_value))
-               return -EINVAL;
-       if (rtn)
-               memset(rtn, 0, sizeof(*rtn));
+       if (old_spec64)
+               memset(old_spec64, 0, sizeof(*old_spec64));
 retry:
        timr = lock_timer(timer_id, &flag);
        if (!timr)
@@ -853,22 +843,71 @@ retry:
        if (WARN_ON_ONCE(!kc || !kc->timer_set))
                error = -EINVAL;
        else
-               error = kc->timer_set(timr, flags, &new_spec64, rtn);
+               error = kc->timer_set(timr, flags, new_spec64, old_spec64);
 
        unlock_timer(timr, flag);
        if (error == TIMER_RETRY) {
-               rtn = NULL;     // We already got the old time...
+               old_spec64 = NULL;      // We already got the old time...
                goto retry;
        }
 
-       old_spec = itimerspec64_to_itimerspec(&old_spec64);
-       if (old_setting && !error &&
-           copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
-               error = -EFAULT;
+       return error;
+}
+
+/* Set a POSIX.1b interval timer */
+SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
+               const struct itimerspec __user *, new_setting,
+               struct itimerspec __user *, old_setting)
+{
+       struct itimerspec64 new_spec64, old_spec64;
+       struct itimerspec64 *rtn = old_setting ? &old_spec64 : NULL;
+       struct itimerspec new_spec;
+       int error = 0;
+
+       if (!new_setting)
+               return -EINVAL;
 
+       if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
+               return -EFAULT;
+       new_spec64 = itimerspec_to_itimerspec64(&new_spec);
+
+       error = do_timer_settime(timer_id, flags, &new_spec64, rtn);
+       if (!error && old_setting) {
+               struct itimerspec old_spec;
+               old_spec = itimerspec64_to_itimerspec(&old_spec64);
+               if (copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
+                       error = -EFAULT;
+       }
        return error;
 }
 
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
+                      struct compat_itimerspec __user *, new,
+                      struct compat_itimerspec __user *, old)
+{
+       struct itimerspec64 new_spec64, old_spec64;
+       struct itimerspec64 *rtn = old ? &old_spec64 : NULL;
+       struct itimerspec new_spec;
+       int error = 0;
+
+       if (!new)
+               return -EINVAL;
+       if (get_compat_itimerspec(&new_spec, new))
+               return -EFAULT;
+
+       new_spec64 = itimerspec_to_itimerspec64(&new_spec);
+       error = do_timer_settime(timer_id, flags, &new_spec64, rtn);
+       if (!error && old) {
+               struct itimerspec old_spec;
+               old_spec = itimerspec64_to_itimerspec(&old_spec64);
+               if (put_compat_itimerspec(old, &old_spec))
+                       error = -EFAULT;
+       }
+       return error;
+}
+#endif
+
 int common_timer_del(struct k_itimer *timer)
 {
        const struct k_clock *kc = timer->kclock;