xref: /linux/arch/um/include/asm/uaccess.h (revision 399ead3a6d76cbdd29a716660db5c84a314dab70)
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_FROM_USER
31 #define INLINE_COPY_TO_USER
32 
33 #include <asm-generic/uaccess.h>
34 
__access_ok(const void __user * ptr,unsigned long size)35 static 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)			\
42 do {									\
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)			\
56 do {									\
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
68