Commit bec2f7cb authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

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: default avatarArnd Bergmann <arnd@arndb.de>
parent 04e7712f

include/linux/syscalls.h

+1 −1
Original line number Diff line number Diff line
@@ -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,

kernel/futex.c

+12 −10
Original line number Diff line number Diff line
@@ -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)

{

CRA Git | Maintained and supported by SUSTech CRA and CCSE