xref: /openbmc/linux/arch/um/include/asm/uaccess.h (revision 887069f4)
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 
12 #define __under_task_size(addr, size) \
13 	(((unsigned long) (addr) < TASK_SIZE) && \
14 	 (((unsigned long) (addr) + (size)) < TASK_SIZE))
15 
16 #define __access_ok_vsyscall(addr, size) \
17 	  (((unsigned long) (addr) >= FIXADDR_USER_START) && \
18 	  ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
19 	  ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
20 
21 #define __addr_range_nowrap(addr, size) \
22 	((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
23 
24 extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n);
25 extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n);
26 extern unsigned long __clear_user(void __user *mem, unsigned long len);
27 static inline int __access_ok(unsigned long addr, unsigned long size);
28 
29 /* Teach asm-generic/uaccess.h that we have C functions for these. */
30 #define __access_ok __access_ok
31 #define __clear_user __clear_user
32 
33 #define INLINE_COPY_FROM_USER
34 #define INLINE_COPY_TO_USER
35 
36 #include <asm-generic/uaccess.h>
37 
38 static inline int __access_ok(unsigned long addr, unsigned long size)
39 {
40 	return __addr_range_nowrap(addr, size) &&
41 		(__under_task_size(addr, size) ||
42 		__access_ok_vsyscall(addr, size) ||
43 		uaccess_kernel());
44 }
45 
46 #endif
47