xref: /linux/arch/sh/include/asm/uaccess.h (revision b8d312aa075f33282565467662c4628dae0a2aff)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_SH_UACCESS_H
3 #define __ASM_SH_UACCESS_H
4 
5 #include <asm/segment.h>
6 #include <asm/extable.h>
7 
8 #define __addr_ok(addr) \
9 	((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)
10 
11 /*
12  * __access_ok: Check if address with size is OK or not.
13  *
14  * Uhhuh, this needs 33-bit arithmetic. We have a carry..
15  *
16  * sum := addr + size;  carry? --> flag = true;
17  * if (sum >= addr_limit) flag = true;
18  */
19 #define __access_ok(addr, size)	({				\
20 	unsigned long __ao_a = (addr), __ao_b = (size);		\
21 	unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b;	\
22 	__ao_end >= __ao_a && __addr_ok(__ao_end); })
23 
24 #define access_ok(addr, size)	\
25 	(__chk_user_ptr(addr),		\
26 	 __access_ok((unsigned long __force)(addr), (size)))
27 
28 #define user_addr_max()	(current_thread_info()->addr_limit.seg)
29 
30 /*
31  * Uh, these should become the main single-value transfer routines ...
32  * They automatically use the right size if we just have the right
33  * pointer type ...
34  *
35  * As SuperH uses the same address space for kernel and user data, we
36  * can just do these as direct assignments.
37  *
38  * Careful to not
39  * (a) re-use the arguments for side effects (sizeof is ok)
40  * (b) require any knowledge of processes at this stage
41  */
42 #define put_user(x,ptr)		__put_user_check((x), (ptr), sizeof(*(ptr)))
43 #define get_user(x,ptr)		__get_user_check((x), (ptr), sizeof(*(ptr)))
44 
45 /*
46  * The "__xxx" versions do not do address space checking, useful when
47  * doing multiple accesses to the same area (the user has to do the
48  * checks by hand with "access_ok()")
49  */
50 #define __put_user(x,ptr)	__put_user_nocheck((x), (ptr), sizeof(*(ptr)))
51 #define __get_user(x,ptr)	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
52 
53 struct __large_struct { unsigned long buf[100]; };
54 #define __m(x) (*(struct __large_struct __user *)(x))
55 
56 #define __get_user_nocheck(x,ptr,size)				\
57 ({								\
58 	long __gu_err;						\
59 	unsigned long __gu_val;					\
60 	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
61 	__chk_user_ptr(ptr);					\
62 	__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
63 	(x) = (__force __typeof__(*(ptr)))__gu_val;		\
64 	__gu_err;						\
65 })
66 
67 #define __get_user_check(x,ptr,size)					\
68 ({									\
69 	long __gu_err = -EFAULT;					\
70 	unsigned long __gu_val = 0;					\
71 	const __typeof__(*(ptr)) *__gu_addr = (ptr);			\
72 	if (likely(access_ok(__gu_addr, (size))))		\
73 		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
74 	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
75 	__gu_err;							\
76 })
77 
78 #define __put_user_nocheck(x,ptr,size)				\
79 ({								\
80 	long __pu_err;						\
81 	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
82 	__typeof__(*(ptr)) __pu_val = x;			\
83 	__chk_user_ptr(ptr);					\
84 	__put_user_size(__pu_val, __pu_addr, (size), __pu_err);	\
85 	__pu_err;						\
86 })
87 
88 #define __put_user_check(x,ptr,size)				\
89 ({								\
90 	long __pu_err = -EFAULT;				\
91 	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
92 	__typeof__(*(ptr)) __pu_val = x;			\
93 	if (likely(access_ok(__pu_addr, size)))	\
94 		__put_user_size(__pu_val, __pu_addr, (size),	\
95 				__pu_err);			\
96 	__pu_err;						\
97 })
98 
99 #ifdef CONFIG_SUPERH32
100 # include <asm/uaccess_32.h>
101 #else
102 # include <asm/uaccess_64.h>
103 #endif
104 
105 extern long strncpy_from_user(char *dest, const char __user *src, long count);
106 
107 extern __must_check long strnlen_user(const char __user *str, long n);
108 
109 /* Generic arbitrary sized copy.  */
110 /* Return the number of bytes NOT copied */
111 __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
112 
113 static __always_inline unsigned long
114 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
115 {
116 	return __copy_user(to, (__force void *)from, n);
117 }
118 
119 static __always_inline unsigned long __must_check
120 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
121 {
122 	return __copy_user((__force void *)to, from, n);
123 }
124 #define INLINE_COPY_FROM_USER
125 #define INLINE_COPY_TO_USER
126 
127 /*
128  * Clear the area and return remaining number of bytes
129  * (on failure.  Usually it's 0.)
130  */
131 __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
132 
133 #define clear_user(addr,n)						\
134 ({									\
135 	void __user * __cl_addr = (addr);				\
136 	unsigned long __cl_size = (n);					\
137 									\
138 	if (__cl_size && access_ok(__cl_addr, __cl_size))		\
139 		__cl_size = __clear_user(__cl_addr, __cl_size);		\
140 									\
141 	__cl_size;							\
142 })
143 
144 extern void *set_exception_table_vec(unsigned int vec, void *handler);
145 
146 static inline void *set_exception_table_evt(unsigned int evt, void *handler)
147 {
148 	return set_exception_table_vec(evt >> 5, handler);
149 }
150 
151 struct mem_access {
152 	unsigned long (*from)(void *dst, const void __user *src, unsigned long cnt);
153 	unsigned long (*to)(void __user *dst, const void *src, unsigned long cnt);
154 };
155 
156 int handle_unaligned_access(insn_size_t instruction, struct pt_regs *regs,
157 			    struct mem_access *ma, int, unsigned long address);
158 
159 #endif /* __ASM_SH_UACCESS_H */
160