y2038: futex: Add support for __kernel_timespec

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 <arnd@arndb.de>

1 files changed, 12 insertions, 10 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 5cc7c3b098e9..b305beaab739 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3558,10 +3558,10 @@ 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;
@@ -3571,12 +3571,12 @@ 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;
@@ -3747,12 +3747,14 @@ err_unlock:
 
         return ret;
 }
+#endif /* CONFIG_COMPAT */
 
+#ifdef CONFIG_COMPAT_32BIT_TIME
 COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
                 struct old_timespec32 __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;
@@ -3760,12 +3762,12 @@ 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 (get_old_timespec32(&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;
@@ -3776,7 +3778,7 @@ 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)
 {