uaccess.h

 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 <linux/unaligned.h>
12#include <sysdep/faultinfo.h>
13
14#define __under_task_size(addr, size) \
15	(((unsigned long) (addr) < TASK_SIZE) && \
16	 (((unsigned long) (addr) + (size)) < TASK_SIZE))
17
18#define __addr_range_nowrap(addr, size) \
19	((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
20
21extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n);
22extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n);
23extern unsigned long __clear_user(void __user *mem, unsigned long len);
24static inline int __access_ok(const void __user *ptr, unsigned long size);
25
26/* Teach asm-generic/uaccess.h that we have C functions for these. */
27#define __access_ok __access_ok
28#define __clear_user __clear_user
29
30#define INLINE_COPY_FROM_USER
31#define INLINE_COPY_TO_USER
32
33#include <asm-generic/uaccess.h>
34
35static inline int __access_ok(const void __user *ptr, unsigned long size)
36{
37	unsigned long addr = (unsigned long)ptr;
38	return __addr_range_nowrap(addr, size) && __under_task_size(addr, size);
39}
40
41#define __get_kernel_nofault(dst, src, type, err_label)			\
42do {									\
43	int __faulted;							\
44									\
45	___backtrack_faulted(__faulted);				\
46	if (__faulted) {						\
47		*((type *)dst) = (type) 0;				\
48		goto err_label;						\
49	}								\
50	*((type *)dst) = get_unaligned((type *)(src));			\
51	barrier();							\
52	current->thread.segv_continue = NULL;				\
53} while (0)
54
55#define __put_kernel_nofault(dst, src, type, err_label)			\
56do {									\
57	int __faulted;							\
58									\
59	___backtrack_faulted(__faulted);				\
60	if (__faulted)							\
61		goto err_label;						\
62	put_unaligned(*((type *)src), (type *)(dst));			\
63	barrier();							\
64	current->thread.segv_continue = NULL;				\
65} while (0)
66
67#endif