summaryrefslogtreecommitdiff
path: root/arch/sh/include/asm/uaccess.h
blob: 050f221fa898219b40e2faca0bbb9cebae93dd7e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
#ifndef __ASM_SH_UACCESS_H
#define __ASM_SH_UACCESS_H

#include <linux/errno.h>
#include <linux/sched.h>
#include <asm/segment.h>

#define VERIFY_READ    0
#define VERIFY_WRITE   1

#define __addr_ok(addr) \
	((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)

/*
 * __access_ok: Check if address with size is OK or not.
 *
 * Uhhuh, this needs 33-bit arithmetic. We have a carry..
 *
 * sum := addr + size;  carry? --> flag = true;
 * if (sum >= addr_limit) flag = true;
 */
#define __access_ok(addr, size)		\
	(__addr_ok((addr) + (size)))
#define access_ok(type, addr, size)	\
	(__chk_user_ptr(addr),		\
	 __access_ok((unsigned long __force)(addr), (size)))

/*
 * Uh, these should become the main single-value transfer routines ...
 * They automatically use the right size if we just have the right
 * pointer type ...
 *
 * As SuperH uses the same address space for kernel and user data, we
 * can just do these as direct assignments.
 *
 * Careful to not
 * (a) re-use the arguments for side effects (sizeof is ok)
 * (b) require any knowledge of processes at this stage
 */
#define put_user(x,ptr)		__put_user_check((x), (ptr), sizeof(*(ptr)))
#define get_user(x,ptr)		__get_user_check((x), (ptr), sizeof(*(ptr)))

/*
 * The "__xxx" versions do not do address space checking, useful when
 * doing multiple accesses to the same area (the user has to do the
 * checks by hand with "access_ok()")
 */
#define __put_user(x,ptr)	__put_user_nocheck((x), (ptr), sizeof(*(ptr)))
#define __get_user(x,ptr)	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))

struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct __user *)(x))

#define __get_user_nocheck(x,ptr,size)				\
({								\
	long __gu_err;						\
	unsigned long __gu_val;					\
	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
	__chk_user_ptr(ptr);					\
	__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
	(x) = (__typeof__(*(ptr)))__gu_val;			\
	__gu_err;						\
})

#define __get_user_check(x,ptr,size)					\
({									\
	long __gu_err = -EFAULT;					\
	unsigned long __gu_val = 0;					\
	const __typeof__(*(ptr)) *__gu_addr = (ptr);			\
	if (likely(access_ok(VERIFY_READ, __gu_addr, (size))))		\
		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
	(x) = (__typeof__(*(ptr)))__gu_val;				\
	__gu_err;							\
})

#define __put_user_nocheck(x,ptr,size)				\
({								\
	long __pu_err;						\
	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
	__typeof__(*(ptr)) __pu_val = x;			\
	__chk_user_ptr(ptr);					\
	__put_user_size(__pu_val, __pu_addr, (size), __pu_err);	\
	__pu_err;						\
})

#define __put_user_check(x,ptr,size)				\
({								\
	long __pu_err = -EFAULT;				\
	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
	__typeof__(*(ptr)) __pu_val = x;			\
	if (likely(access_ok(VERIFY_WRITE, __pu_addr, size)))	\
		__put_user_size(__pu_val, __pu_addr, (size),	\
				__pu_err);			\
	__pu_err;						\
})

#ifdef CONFIG_SUPERH32
# include "uaccess_32.h"
#else
# include "uaccess_64.h"
#endif

/* Generic arbitrary sized copy.  */
/* Return the number of bytes NOT copied */
__kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);

static __always_inline unsigned long
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
	return __copy_user(to, (__force void *)from, n);
}

static __always_inline unsigned long __must_check
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
	return __copy_user((__force void *)to, from, n);
}

#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user

/*
 * Clear the area and return remaining number of bytes
 * (on failure.  Usually it's 0.)
 */
__kernel_size_t __clear_user(void *addr, __kernel_size_t size);

#define clear_user(addr,n)						\
({									\
	void __user * __cl_addr = (addr);				\
	unsigned long __cl_size = (n);					\
									\
	if (__cl_size && access_ok(VERIFY_WRITE,			\
		((unsigned long)(__cl_addr)), __cl_size))		\
		__cl_size = __clear_user(__cl_addr, __cl_size);		\
									\
	__cl_size;							\
})

/**
 * strncpy_from_user: - Copy a NUL terminated string from userspace.
 * @dst:   Destination address, in kernel space.  This buffer must be at
 *         least @count bytes long.
 * @src:   Source address, in user space.
 * @count: Maximum number of bytes to copy, including the trailing NUL.
 *
 * Copies a NUL-terminated string from userspace to kernel space.
 *
 * On success, returns the length of the string (not including the trailing
 * NUL).
 *
 * If access to userspace fails, returns -EFAULT (some data may have been
 * copied).
 *
 * If @count is smaller than the length of the string, copies @count bytes
 * and returns @count.
 */
#define strncpy_from_user(dest,src,count)				\
({									\
	unsigned long __sfu_src = (unsigned long)(src);			\
	int __sfu_count = (int)(count);					\
	long __sfu_res = -EFAULT;					\
									\
	if (__access_ok(__sfu_src, __sfu_count))			\
		__sfu_res = __strncpy_from_user((unsigned long)(dest),	\
				__sfu_src, __sfu_count);		\
									\
	__sfu_res;							\
})

static inline unsigned long
copy_from_user(void *to, const void __user *from, unsigned long n)
{
	unsigned long __copy_from = (unsigned long) from;
	__kernel_size_t __copy_size = (__kernel_size_t) n;

	if (__copy_size && __access_ok(__copy_from, __copy_size))
		return __copy_user(to, from, __copy_size);

	return __copy_size;
}

static inline unsigned long
copy_to_user(void __user *to, const void *from, unsigned long n)
{
	unsigned long __copy_to = (unsigned long) to;
	__kernel_size_t __copy_size = (__kernel_size_t) n;

	if (__copy_size && __access_ok(__copy_to, __copy_size))
		return __copy_user(to, from, __copy_size);

	return __copy_size;
}

/**
 * strnlen_user: - Get the size of a string in user space.
 * @s: The string to measure.
 * @n: The maximum valid length
 *
 * Context: User context only.  This function may sleep.
 *
 * Get the size of a NUL-terminated string in user space.
 *
 * Returns the size of the string INCLUDING the terminating NUL.
 * On exception, returns 0.
 * If the string is too long, returns a value greater than @n.
 */
static inline long strnlen_user(const char __user *s, long n)
{
	if (!__addr_ok(s))
		return 0;
	else
		return __strnlen_user(s, n);
}

/**
 * strlen_user: - Get the size of a string in user space.
 * @str: The string to measure.
 *
 * Context: User context only.  This function may sleep.
 *
 * Get the size of a NUL-terminated string in user space.
 *
 * Returns the size of the string INCLUDING the terminating NUL.
 * On exception, returns 0.
 *
 * If there is a limit on the length of a valid string, you may wish to
 * consider using strnlen_user() instead.
 */
#define strlen_user(str)	strnlen_user(str, ~0UL >> 1)

/*
 * The exception table consists of pairs of addresses: the first is the
 * address of an instruction that is allowed to fault, and the second is
 * the address at which the program should continue.  No registers are
 * modified, so it is entirely up to the continuation code to figure out
 * what to do.
 *
 * All the routines below use bits of fixup code that are out of line
 * with the main instruction path.  This means when everything is well,
 * we don't even have to jump over them.  Further, they do not intrude
 * on our cache or tlb entries.
 */
struct exception_table_entry {
	unsigned long insn, fixup;
};

#if defined(CONFIG_SUPERH64) && defined(CONFIG_MMU)
#define ARCH_HAS_SEARCH_EXTABLE
#endif

int fixup_exception(struct pt_regs *regs);
/* Returns 0 if exception not found and fixup.unit otherwise.  */
unsigned long search_exception_table(unsigned long addr);
const struct exception_table_entry *search_exception_tables(unsigned long addr);

extern void *set_exception_table_vec(unsigned int vec, void *handler);

static inline void *set_exception_table_evt(unsigned int evt, void *handler)
{
	return set_exception_table_vec(evt >> 5, handler);
}

struct mem_access {
	unsigned long (*from)(void *dst, const void __user *src, unsigned long cnt);
	unsigned long (*to)(void __user *dst, const void *src, unsigned long cnt);
};

int handle_unaligned_access(insn_size_t instruction, struct pt_regs *regs,
			    struct mem_access *ma, int, unsigned long address);

#endif /* __ASM_SH_UACCESS_H */