xref: /openbmc/linux/arch/um/include/asm/uaccess.h (revision 75016ca3)
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 
25 extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n);
26 extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n);
27 extern unsigned long __clear_user(void __user *mem, unsigned long len);
28 static inline int __access_ok(unsigned long addr, 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 
39 static inline int __access_ok(unsigned long addr, unsigned long size)
40 {
41 	return __addr_range_nowrap(addr, size) &&
42 		(__under_task_size(addr, size) ||
43 		 __access_ok_vsyscall(addr, size));
44 }
45 
46 /* no pagefaults for kernel addresses in um */
47 #define HAVE_GET_KERNEL_NOFAULT 1
48 
49 #define __get_kernel_nofault(dst, src, type, err_label)			\
50 do {									\
51 	*((type *)dst) = get_unaligned((type *)(src));			\
52 	if (0) /* make sure the label looks used to the compiler */	\
53 		goto err_label;						\
54 } while (0)
55 
56 #define __put_kernel_nofault(dst, src, type, err_label)			\
57 do {									\
58 	put_unaligned(*((type *)src), (type *)(dst));			\
59 	if (0) /* make sure the label looks used to the compiler */	\
60 		goto err_label;						\
61 } while (0)
62 
63 #endif
64