sched_rr_get_interval(): move compat to native, get rid of set_fs()

switch to using timespec64 internally, while we are at it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 30 insertions, 22 deletions

diff --git a/kernel/compat.c b/kernel/compat.c
index a46a4a40bb8b..d1cee656a7ed 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -562,22 +562,6 @@ COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
 }
 #endif
 
-COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
-                       compat_pid_t, pid,
-                       struct compat_timespec __user *, interval)
-{
-        struct timespec t;
-        int ret;
-        mm_segment_t old_fs = get_fs();
-
-        set_fs(KERNEL_DS);
-        ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t);
-        set_fs(old_fs);
-        if (compat_put_timespec(&t, interval))
-                return -EFAULT;
-        return ret;
-}
-
 /*
  * Allocate user-space memory for the duration of a single system call,
  * in order to marshall parameters inside a compat thunk.
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 18a6966567da..e74f0a5a8647 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -16,6 +16,7 @@
 #include <linux/init_task.h>
 #include <linux/context_tracking.h>
 #include <linux/rcupdate_wait.h>
+#include <linux/compat.h>
 
 #include <linux/blkdev.h>
 #include <linux/kprobes.h>
@@ -5098,13 +5099,11 @@ SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
  * Return: On success, 0 and the timeslice is in @interval. Otherwise,
  * an error code.
  */
-SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
-                struct timespec __user *, interval)
+static int sched_rr_get_interval(pid_t pid, struct timespec64 *t)
 {
         struct task_struct *p;
         unsigned int time_slice;
         struct rq_flags rf;
-        struct timespec t;
         struct rq *rq;
         int retval;
 
@@ -5128,15 +5127,40 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
         task_rq_unlock(rq, p, &rf);
 
         rcu_read_unlock();
-        jiffies_to_timespec(time_slice, &t);
-        retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
-        return retval;
+        jiffies_to_timespec64(time_slice, t);
+        return 0;
 
 out_unlock:
         rcu_read_unlock();
         return retval;
 }
 
+SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
+                struct timespec __user *, interval)
+{
+        struct timespec64 t;
+        int retval = sched_rr_get_interval(pid, &t);
+
+        if (retval == 0)
+                retval = put_timespec64(&t, interval);
+
+        return retval;
+}
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
+                       compat_pid_t, pid,
+                       struct compat_timespec __user *, interval)
+{
+        struct timespec64 t;
+        int retval = sched_rr_get_interval(pid, &t);
+
+        if (retval == 0)
+                retval = compat_put_timespec64(&t, interval);
+        return retval;
+}
+#endif
+
 void sched_show_task(struct task_struct *p)
 {
         unsigned long free = 0;