summaryrefslogtreecommitdiff
path: root/arch/sparc/include/asm/uaccess_32.h
blob: 12ebee2d97c7bc1b61c9afe65e996ca039aafc7e (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
273
274
275
276
277
278
279
280
281
282
283
/*
 * uaccess.h: User space memore access functions.
 *
 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 */
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H

#include <linux/compiler.h>
#include <linux/string.h>

#include <asm/processor.h>

#define ARCH_HAS_SORT_EXTABLE
#define ARCH_HAS_SEARCH_EXTABLE

/* Sparc is not segmented, however we need to be able to fool access_ok()
 * when doing system calls from kernel mode legitimately.
 *
 * "For historical reasons, these macros are grossly misnamed." -Linus
 */

#define KERNEL_DS   ((mm_segment_t) { 0 })
#define USER_DS     ((mm_segment_t) { -1 })

#define get_ds()	(KERNEL_DS)
#define get_fs()	(current->thread.current_ds)
#define set_fs(val)	((current->thread.current_ds) = (val))

#define segment_eq(a, b) ((a).seg == (b).seg)

/* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
 * can be fairly lightweight.
 * No one can read/write anything from userland in the kernel space by setting
 * large size and address near to PAGE_OFFSET - a fault will break his intentions.
 */
#define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; })
#define __kernel_ok (uaccess_kernel())
#define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size)))
#define access_ok(type, addr, size) \
	({ (void)(type); __access_ok((unsigned long)(addr), size); })

/*
 * 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.
 *
 * There is a special way how to put a range of potentially faulting
 * insns (like twenty ldd/std's with now intervening other instructions)
 * You specify address of first in insn and 0 in fixup and in the next
 * exception_table_entry you specify last potentially faulting insn + 1
 * and in fixup the routine which should handle the fault.
 * That fixup code will get
 * (faulting_insn_address - first_insn_in_the_range_address)/4
 * in %g2 (ie. index of the faulting instruction in the range).
 */

struct exception_table_entry
{
        unsigned long insn, fixup;
};

/* Returns 0 if exception not found and fixup otherwise.  */
unsigned long search_extables_range(unsigned long addr, unsigned long *g2);

/* Uh, these should become the main single-value transfer routines..
 * They automatically use the right size if we just have the right
 * pointer type..
 *
 * This gets kind of ugly. We want to return _two_ values in "get_user()"
 * and yet we don't want to do any pointers, because that is too much
 * of a performance impact. Thus we have a few rather ugly macros here,
 * and hide all the ugliness from the user.
 */
#define put_user(x, ptr) ({ \
	unsigned long __pu_addr = (unsigned long)(ptr); \
	__chk_user_ptr(ptr); \
	__put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \
})

#define get_user(x, ptr) ({ \
	unsigned long __gu_addr = (unsigned long)(ptr); \
	__chk_user_ptr(ptr); \
	__get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(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((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#define __get_user(x, ptr) \
    __get_user_nocheck((x), (ptr), sizeof(*(ptr)), __typeof__(*(ptr)))

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

#define __put_user_check(x, addr, size) ({ \
	register int __pu_ret; \
	if (__access_ok(addr, size)) { \
		switch (size) { \
		case 1: \
			__put_user_asm(x, b, addr, __pu_ret); \
			break; \
		case 2: \
			__put_user_asm(x, h, addr, __pu_ret); \
			break; \
		case 4: \
			__put_user_asm(x, , addr, __pu_ret); \
			break; \
		case 8: \
			__put_user_asm(x, d, addr, __pu_ret); \
			break; \
		default: \
			__pu_ret = __put_user_bad(); \
			break; \
		} \
	} else { \
		__pu_ret = -EFAULT; \
	} \
	__pu_ret; \
})

#define __put_user_nocheck(x, addr, size) ({			\
	register int __pu_ret;					\
	switch (size) {						\
	case 1: __put_user_asm(x, b, addr, __pu_ret); break;	\
	case 2: __put_user_asm(x, h, addr, __pu_ret); break;	\
	case 4: __put_user_asm(x, , addr, __pu_ret); break;	\
	case 8: __put_user_asm(x, d, addr, __pu_ret); break;	\
	default: __pu_ret = __put_user_bad(); break;		\
	} \
	__pu_ret; \
})

#define __put_user_asm(x, size, addr, ret)				\
__asm__ __volatile__(							\
		"/* Put user asm, inline. */\n"				\
	"1:\t"	"st"#size " %1, %2\n\t"					\
		"clr	%0\n"						\
	"2:\n\n\t"							\
		".section .fixup,#alloc,#execinstr\n\t"			\
		".align	4\n"						\
	"3:\n\t"							\
		"b	2b\n\t"						\
		" mov	%3, %0\n\t"					\
		".previous\n\n\t"					\
		".section __ex_table,#alloc\n\t"			\
		".align	4\n\t"						\
		".word	1b, 3b\n\t"					\
		".previous\n\n\t"					\
	       : "=&r" (ret) : "r" (x), "m" (*__m(addr)),		\
		 "i" (-EFAULT))

int __put_user_bad(void);

#define __get_user_check(x, addr, size, type) ({ \
	register int __gu_ret; \
	register unsigned long __gu_val; \
	if (__access_ok(addr, size)) { \
		switch (size) { \
		case 1: \
			 __get_user_asm(__gu_val, ub, addr, __gu_ret); \
			break; \
		case 2: \
			__get_user_asm(__gu_val, uh, addr, __gu_ret); \
			break; \
		case 4: \
			__get_user_asm(__gu_val, , addr, __gu_ret); \
			break; \
		case 8: \
			__get_user_asm(__gu_val, d, addr, __gu_ret); \
			break; \
		default: \
			__gu_val = 0; \
			__gu_ret = __get_user_bad(); \
			break; \
		} \
	 } else { \
		 __gu_val = 0; \
		 __gu_ret = -EFAULT; \
	} \
	x = (__force type) __gu_val; \
	__gu_ret; \
})

#define __get_user_nocheck(x, addr, size, type) ({			\
	register int __gu_ret;						\
	register unsigned long __gu_val;				\
	switch (size) {							\
	case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break;	\
	case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break;	\
	case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break;	\
	case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break;	\
	default:							\
		__gu_val = 0;						\
		__gu_ret = __get_user_bad();				\
		break;							\
	}								\
	x = (__force type) __gu_val;					\
	__gu_ret;							\
})

#define __get_user_asm(x, size, addr, ret)				\
__asm__ __volatile__(							\
		"/* Get user asm, inline. */\n"				\
	"1:\t"	"ld"#size " %2, %1\n\t"					\
		"clr	%0\n"						\
	"2:\n\n\t"							\
		".section .fixup,#alloc,#execinstr\n\t"			\
		".align	4\n"						\
	"3:\n\t"							\
		"clr	%1\n\t"						\
		"b	2b\n\t"						\
		" mov	%3, %0\n\n\t"					\
		".previous\n\t"						\
		".section __ex_table,#alloc\n\t"			\
		".align	4\n\t"						\
		".word	1b, 3b\n\n\t"					\
		".previous\n\t"						\
	       : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)),		\
		 "i" (-EFAULT))

int __get_user_bad(void);

unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);

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

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

#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER

static inline unsigned long __clear_user(void __user *addr, unsigned long size)
{
	unsigned long ret;

	__asm__ __volatile__ (
		".section __ex_table,#alloc\n\t"
		".align 4\n\t"
		".word 1f,3\n\t"
		".previous\n\t"
		"mov %2, %%o1\n"
		"1:\n\t"
		"call __bzero\n\t"
		" mov %1, %%o0\n\t"
		"mov %%o0, %0\n"
		: "=r" (ret) : "r" (addr), "r" (size) :
		"o0", "o1", "o2", "o3", "o4", "o5", "o7",
		"g1", "g2", "g3", "g4", "g5", "g7", "cc");

	return ret;
}

static inline unsigned long clear_user(void __user *addr, unsigned long n)
{
	if (n && __access_ok((unsigned long) addr, n))
		return __clear_user(addr, n);
	else
		return n;
}

__must_check long strlen_user(const char __user *str);
__must_check long strnlen_user(const char __user *str, long n);

#endif /* _ASM_UACCESS_H */