xref: /linux/arch/sh/include/asm/uaccess.h (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 #ifndef __ASM_SH_UACCESS_H
2 #define __ASM_SH_UACCESS_H
3 
4 #include <linux/errno.h>
5 #include <linux/sched.h>
6 #include <asm/segment.h>
7 
8 #define VERIFY_READ    0
9 #define VERIFY_WRITE   1
10 
11 #define __addr_ok(addr) \
12 	((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)
13 
14 /*
15  * __access_ok: Check if address with size is OK or not.
16  *
17  * Uhhuh, this needs 33-bit arithmetic. We have a carry..
18  *
19  * sum := addr + size;  carry? --> flag = true;
20  * if (sum >= addr_limit) flag = true;
21  */
22 #define __access_ok(addr, size)		\
23 	(__addr_ok((addr) + (size)))
24 #define access_ok(type, 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) = (__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(VERIFY_READ, __gu_addr, (size))))		\
73 		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
74 	(x) = (__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(VERIFY_WRITE, __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 strlen_user(const char __user *str);
108 extern __must_check long strnlen_user(const char __user *str, long n);
109 
110 /* Generic arbitrary sized copy.  */
111 /* Return the number of bytes NOT copied */
112 __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
113 
114 static __always_inline unsigned long
115 __copy_from_user(void *to, const void __user *from, unsigned long n)
116 {
117 	return __copy_user(to, (__force void *)from, n);
118 }
119 
120 static __always_inline unsigned long __must_check
121 __copy_to_user(void __user *to, const void *from, unsigned long n)
122 {
123 	return __copy_user((__force void *)to, from, n);
124 }
125 
126 #define __copy_to_user_inatomic __copy_to_user
127 #define __copy_from_user_inatomic __copy_from_user
128 
129 /*
130  * Clear the area and return remaining number of bytes
131  * (on failure.  Usually it's 0.)
132  */
133 __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
134 
135 #define clear_user(addr,n)						\
136 ({									\
137 	void __user * __cl_addr = (addr);				\
138 	unsigned long __cl_size = (n);					\
139 									\
140 	if (__cl_size && access_ok(VERIFY_WRITE,			\
141 		((unsigned long)(__cl_addr)), __cl_size))		\
142 		__cl_size = __clear_user(__cl_addr, __cl_size);		\
143 									\
144 	__cl_size;							\
145 })
146 
147 static inline unsigned long
148 copy_from_user(void *to, const void __user *from, unsigned long n)
149 {
150 	unsigned long __copy_from = (unsigned long) from;
151 	__kernel_size_t __copy_size = (__kernel_size_t) n;
152 
153 	if (__copy_size && __access_ok(__copy_from, __copy_size))
154 		return __copy_user(to, from, __copy_size);
155 
156 	return __copy_size;
157 }
158 
159 static inline unsigned long
160 copy_to_user(void __user *to, const void *from, unsigned long n)
161 {
162 	unsigned long __copy_to = (unsigned long) to;
163 	__kernel_size_t __copy_size = (__kernel_size_t) n;
164 
165 	if (__copy_size && __access_ok(__copy_to, __copy_size))
166 		return __copy_user(to, from, __copy_size);
167 
168 	return __copy_size;
169 }
170 
171 /*
172  * The exception table consists of pairs of addresses: the first is the
173  * address of an instruction that is allowed to fault, and the second is
174  * the address at which the program should continue.  No registers are
175  * modified, so it is entirely up to the continuation code to figure out
176  * what to do.
177  *
178  * All the routines below use bits of fixup code that are out of line
179  * with the main instruction path.  This means when everything is well,
180  * we don't even have to jump over them.  Further, they do not intrude
181  * on our cache or tlb entries.
182  */
183 struct exception_table_entry {
184 	unsigned long insn, fixup;
185 };
186 
187 #if defined(CONFIG_SUPERH64) && defined(CONFIG_MMU)
188 #define ARCH_HAS_SEARCH_EXTABLE
189 #endif
190 
191 int fixup_exception(struct pt_regs *regs);
192 /* Returns 0 if exception not found and fixup.unit otherwise.  */
193 unsigned long search_exception_table(unsigned long addr);
194 const struct exception_table_entry *search_exception_tables(unsigned long addr);
195 
196 extern void *set_exception_table_vec(unsigned int vec, void *handler);
197 
198 static inline void *set_exception_table_evt(unsigned int evt, void *handler)
199 {
200 	return set_exception_table_vec(evt >> 5, handler);
201 }
202 
203 struct mem_access {
204 	unsigned long (*from)(void *dst, const void __user *src, unsigned long cnt);
205 	unsigned long (*to)(void __user *dst, const void *src, unsigned long cnt);
206 };
207 
208 int handle_unaligned_access(insn_size_t instruction, struct pt_regs *regs,
209 			    struct mem_access *ma, int, unsigned long address);
210 
211 #endif /* __ASM_SH_UACCESS_H */
212