1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
4 * Copyright (C) 2015 Richard Weinberger (richard@nod.at)
5 */
6
7#ifndef __UM_UACCESS_H
8#define __UM_UACCESS_H
9
10#include <asm/elf.h>
11#include <asm/unaligned.h>
12
13#define __under_task_size(addr, size) \
14	(((unsigned long) (addr) < TASK_SIZE) && \
15	 (((unsigned long) (addr) + (size)) < TASK_SIZE))
16
17#define __access_ok_vsyscall(addr, size) \
18	  (((unsigned long) (addr) >= FIXADDR_USER_START) && \
19	  ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
20	  ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
21
22#define __addr_range_nowrap(addr, size) \
23	((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
24
25extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n);
26extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n);
27extern unsigned long __clear_user(void __user *mem, unsigned long len);
28static inline int __access_ok(const void __user *ptr, unsigned long size);
29
30/* Teach asm-generic/uaccess.h that we have C functions for these. */
31#define __access_ok __access_ok
32#define __clear_user __clear_user
33
34#define INLINE_COPY_FROM_USER
35#define INLINE_COPY_TO_USER
36
37#include <asm-generic/uaccess.h>
38
39static inline int __access_ok(const void __user *ptr, unsigned long size)
40{
41	unsigned long addr = (unsigned long)ptr;
42	return __addr_range_nowrap(addr, size) &&
43		(__under_task_size(addr, size) ||
44		 __access_ok_vsyscall(addr, size));
45}
46
47/* no pagefaults for kernel addresses in um */
48#define __get_kernel_nofault(dst, src, type, err_label)			\
49do {									\
50	*((type *)dst) = get_unaligned((type *)(src));			\
51	if (0) /* make sure the label looks used to the compiler */	\
52		goto err_label;						\
53} while (0)
54
55#define __put_kernel_nofault(dst, src, type, err_label)			\
56do {									\
57	put_unaligned(*((type *)src), (type *)(dst));			\
58	if (0) /* make sure the label looks used to the compiler */	\
59		goto err_label;						\
60} while (0)
61
62#endif
63