This prepares sys_futex for y2038 safe calling: the native
syscall is changed to receive a __kernel_timespec argument, which
will be switched to 64-bit time_t in the future. All the internal
time handling gets changed to timespec64, and the compat_sys_futex
entry point is moved under the CONFIG_COMPAT_32BIT_TIME check
to provide compatibility for existing 32-bit architectures.

Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
 include/linux/syscalls.h |  2 +-
 kernel/futex.c           | 22 ++++++++++++----------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index d2b19e814218..c3d504dbba9c 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -528,7 +528,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags);
 
 /* kernel/futex.c */
 asmlinkage long sys_futex(u32 __user *uaddr, int op, u32 val,
-                       struct timespec __user *utime, u32 __user *uaddr2,
+                       struct __kernel_timespec __user *utime, u32 __user 
*uaddr2,
                        u32 val3);
 asmlinkage long sys_get_robust_list(int pid,
                                    struct robust_list_head __user * __user 
*head_ptr,
diff --git a/kernel/futex.c b/kernel/futex.c
index e9013d1e65a1..129555a3b64d 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3556,10 +3556,10 @@ long do_futex(u32 __user *uaddr, int op, u32 val, 
ktime_t *timeout,
 
 
 SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
-               struct timespec __user *, utime, u32 __user *, uaddr2,
+               struct __kernel_timespec __user *, utime, u32 __user *, uaddr2,
                u32, val3)
 {
-       struct timespec ts;
+       struct timespec64 ts;
        ktime_t t, *tp = NULL;
        u32 val2 = 0;
        int cmd = op & FUTEX_CMD_MASK;
@@ -3569,12 +3569,12 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, 
u32, val,
                      cmd == FUTEX_WAIT_REQUEUE_PI)) {
                if (unlikely(should_fail_futex(!(op & FUTEX_PRIVATE_FLAG))))
                        return -EFAULT;
-               if (copy_from_user(&ts, utime, sizeof(ts)) != 0)
+               if (get_timespec64(&ts, utime))
                        return -EFAULT;
-               if (!timespec_valid(&ts))
+               if (!timespec64_valid(&ts))
                        return -EINVAL;
 
-               t = timespec_to_ktime(ts);
+               t = timespec64_to_ktime(ts);
                if (cmd == FUTEX_WAIT)
                        t = ktime_add_safe(ktime_get(), t);
                tp = &t;
@@ -3745,12 +3745,14 @@ COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid,
 
        return ret;
 }
+#endif /* CONFIG_COMPAT */
 
+#ifdef CONFIG_COMPAT_32BIT_TIME
 COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
                struct compat_timespec __user *, utime, u32 __user *, uaddr2,
                u32, val3)
 {
-       struct timespec ts;
+       struct timespec64 ts;
        ktime_t t, *tp = NULL;
        int val2 = 0;
        int cmd = op & FUTEX_CMD_MASK;
@@ -3758,12 +3760,12 @@ COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, 
op, u32, val,
        if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
                      cmd == FUTEX_WAIT_BITSET ||
                      cmd == FUTEX_WAIT_REQUEUE_PI)) {
-               if (compat_get_timespec(&ts, utime))
+               if (compat_get_timespec64(&ts, utime))
                        return -EFAULT;
-               if (!timespec_valid(&ts))
+               if (!timespec64_valid(&ts))
                        return -EINVAL;
 
-               t = timespec_to_ktime(ts);
+               t = timespec64_to_ktime(ts);
                if (cmd == FUTEX_WAIT)
                        t = ktime_add_safe(ktime_get(), t);
                tp = &t;
@@ -3774,7 +3776,7 @@ COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, 
op, u32, val,
 
        return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
 }
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_COMPAT_32BIT_TIME */
 
 static void __init futex_detect_cmpxchg(void)
 {
-- 
2.9.0

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