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>

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a27cf40..247ad9e 100644 (file)
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -553,7 +553,7 @@ 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 5cc7c3b..b305bea 100644 (file)
--- 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)
 {