xref: /linux/arch/um/include/asm/uaccess.h (revision bba2c3615bd6cfee7456d1130f2e6b01b3f4e9ba)
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 
21 extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n);
22 extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n);
23 extern unsigned long __clear_user(void __user *mem, unsigned long len);
24 static 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_USER
31 
32 #include <asm-generic/uaccess.h>
33 
34 static inline int __access_ok(const void __user *ptr, unsigned long size)
35 {
36 	unsigned long addr = (unsigned long)ptr;
37 	return __addr_range_nowrap(addr, size) && __under_task_size(addr, size);
38 }
39 
40 #define __get_kernel_nofault(dst, src, type, err_label)			\
41 do {									\
42 	int __faulted;							\
43 									\
44 	___backtrack_faulted(__faulted);				\
45 	if (__faulted) {						\
46 		*((type *)dst) = (type) 0;				\
47 		goto err_label;						\
48 	}								\
49 	*((type *)dst) = get_unaligned((type *)(src));			\
50 	barrier();							\
51 	current->thread.segv_continue = NULL;				\
52 } while (0)
53 
54 #define __put_kernel_nofault(dst, src, type, err_label)			\
55 do {									\
56 	int __faulted;							\
57 									\
58 	___backtrack_faulted(__faulted);				\
59 	if (__faulted)							\
60 		goto err_label;						\
61 	put_unaligned(*((type *)src), (type *)(dst));			\
62 	barrier();							\
63 	current->thread.segv_continue = NULL;				\
64 } while (0)
65 
66 #endif
67