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1da177e4 LT |
1 | /* uaccess.h: userspace accessor functions |
2 | * | |
3 | * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #ifndef _ASM_UACCESS_H | |
13 | #define _ASM_UACCESS_H | |
14 | ||
15 | /* | |
16 | * User space memory access functions | |
17 | */ | |
18 | #include <linux/sched.h> | |
19 | #include <linux/mm.h> | |
20 | #include <asm/segment.h> | |
21 | #include <asm/sections.h> | |
22 | ||
23 | #define HAVE_ARCH_UNMAPPED_AREA /* we decide where to put mmaps */ | |
24 | ||
a8a77573 | 25 | #define __ptr(x) ((unsigned long __force *)(x)) |
1da177e4 LT |
26 | |
27 | #define VERIFY_READ 0 | |
28 | #define VERIFY_WRITE 1 | |
29 | ||
1da177e4 LT |
30 | /* |
31 | * check that a range of addresses falls within the current address limit | |
32 | */ | |
33 | static inline int ___range_ok(unsigned long addr, unsigned long size) | |
34 | { | |
35 | #ifdef CONFIG_MMU | |
36 | int flag = -EFAULT, tmp; | |
37 | ||
38 | asm volatile ( | |
39 | " addcc %3,%2,%1,icc0 \n" /* set C-flag if addr+size>4GB */ | |
40 | " subcc.p %1,%4,gr0,icc1 \n" /* jump if addr+size>limit */ | |
41 | " bc icc0,#0,0f \n" | |
42 | " bhi icc1,#0,0f \n" | |
43 | " setlos #0,%0 \n" /* mark okay */ | |
44 | "0: \n" | |
45 | : "=r"(flag), "=&r"(tmp) | |
46 | : "r"(addr), "r"(size), "r"(get_addr_limit()), "0"(flag) | |
47 | ); | |
48 | ||
49 | return flag; | |
50 | ||
51 | #else | |
52 | ||
53 | if (addr < memory_start || | |
54 | addr > memory_end || | |
55 | size > memory_end - memory_start || | |
56 | addr + size > memory_end) | |
57 | return -EFAULT; | |
58 | ||
59 | return 0; | |
60 | #endif | |
61 | } | |
62 | ||
63 | #define __range_ok(addr,size) ___range_ok((unsigned long) (addr), (unsigned long) (size)) | |
64 | ||
a8a77573 | 65 | #define access_ok(type,addr,size) (__range_ok((void __user *)(addr), (size)) == 0) |
1da177e4 LT |
66 | #define __access_ok(addr,size) (__range_ok((addr), (size)) == 0) |
67 | ||
1da177e4 LT |
68 | /* |
69 | * The exception table consists of pairs of addresses: the first is the | |
70 | * address of an instruction that is allowed to fault, and the second is | |
71 | * the address at which the program should continue. No registers are | |
72 | * modified, so it is entirely up to the continuation code to figure out | |
73 | * what to do. | |
74 | * | |
75 | * All the routines below use bits of fixup code that are out of line | |
76 | * with the main instruction path. This means when everything is well, | |
77 | * we don't even have to jump over them. Further, they do not intrude | |
78 | * on our cache or tlb entries. | |
79 | */ | |
80 | struct exception_table_entry | |
81 | { | |
82 | unsigned long insn, fixup; | |
83 | }; | |
84 | ||
85 | /* Returns 0 if exception not found and fixup otherwise. */ | |
86 | extern unsigned long search_exception_table(unsigned long); | |
87 | ||
88 | ||
89 | /* | |
90 | * These are the main single-value transfer routines. They automatically | |
91 | * use the right size if we just have the right pointer type. | |
92 | */ | |
93 | #define __put_user(x, ptr) \ | |
94 | ({ \ | |
95 | int __pu_err = 0; \ | |
96 | \ | |
97 | typeof(*(ptr)) __pu_val = (x); \ | |
a8a77573 | 98 | __chk_user_ptr(ptr); \ |
1da177e4 LT |
99 | \ |
100 | switch (sizeof (*(ptr))) { \ | |
101 | case 1: \ | |
102 | __put_user_asm(__pu_err, __pu_val, ptr, "b", "r"); \ | |
103 | break; \ | |
104 | case 2: \ | |
105 | __put_user_asm(__pu_err, __pu_val, ptr, "h", "r"); \ | |
106 | break; \ | |
107 | case 4: \ | |
108 | __put_user_asm(__pu_err, __pu_val, ptr, "", "r"); \ | |
109 | break; \ | |
110 | case 8: \ | |
111 | __put_user_asm(__pu_err, __pu_val, ptr, "d", "e"); \ | |
112 | break; \ | |
113 | default: \ | |
114 | __pu_err = __put_user_bad(); \ | |
115 | break; \ | |
116 | } \ | |
117 | __pu_err; \ | |
118 | }) | |
119 | ||
120 | #define put_user(x, ptr) \ | |
121 | ({ \ | |
a8a77573 | 122 | typeof(*(ptr)) __user *_p = (ptr); \ |
1da177e4 LT |
123 | int _e; \ |
124 | \ | |
125 | _e = __range_ok(_p, sizeof(*_p)); \ | |
126 | if (_e == 0) \ | |
127 | _e = __put_user((x), _p); \ | |
128 | _e; \ | |
129 | }) | |
130 | ||
131 | extern int __put_user_bad(void); | |
132 | ||
133 | /* | |
134 | * Tell gcc we read from memory instead of writing: this is because | |
135 | * we do not write to any memory gcc knows about, so there are no | |
136 | * aliasing issues. | |
137 | */ | |
138 | ||
139 | #ifdef CONFIG_MMU | |
140 | ||
141 | #define __put_user_asm(err,x,ptr,dsize,constraint) \ | |
142 | do { \ | |
143 | asm volatile("1: st"dsize"%I1 %2,%M1 \n" \ | |
144 | "2: \n" \ | |
145 | ".subsection 2 \n" \ | |
146 | "3: setlos %3,%0 \n" \ | |
147 | " bra 2b \n" \ | |
148 | ".previous \n" \ | |
149 | ".section __ex_table,\"a\" \n" \ | |
150 | " .balign 8 \n" \ | |
151 | " .long 1b,3b \n" \ | |
152 | ".previous" \ | |
153 | : "=r" (err) \ | |
154 | : "m" (*__ptr(ptr)), constraint (x), "i"(-EFAULT), "0"(err) \ | |
155 | : "memory"); \ | |
156 | } while (0) | |
157 | ||
158 | #else | |
159 | ||
160 | #define __put_user_asm(err,x,ptr,bwl,con) \ | |
161 | do { \ | |
162 | asm(" st"bwl"%I0 %1,%M0 \n" \ | |
163 | " membar \n" \ | |
164 | : \ | |
165 | : "m" (*__ptr(ptr)), con (x) \ | |
166 | : "memory"); \ | |
167 | } while (0) | |
168 | ||
169 | #endif | |
170 | ||
171 | /*****************************************************************************/ | |
172 | /* | |
173 | * | |
174 | */ | |
175 | #define __get_user(x, ptr) \ | |
176 | ({ \ | |
1da177e4 | 177 | int __gu_err = 0; \ |
a8a77573 | 178 | __chk_user_ptr(ptr); \ |
1da177e4 LT |
179 | \ |
180 | switch (sizeof(*(ptr))) { \ | |
a8a77573 AV |
181 | case 1: { \ |
182 | unsigned char __gu_val; \ | |
183 | __get_user_asm(__gu_err, __gu_val, ptr, "ub", "=r"); \ | |
184 | (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \ | |
1da177e4 | 185 | break; \ |
a8a77573 AV |
186 | } \ |
187 | case 2: { \ | |
188 | unsigned short __gu_val; \ | |
189 | __get_user_asm(__gu_err, __gu_val, ptr, "uh", "=r"); \ | |
190 | (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \ | |
1da177e4 | 191 | break; \ |
a8a77573 AV |
192 | } \ |
193 | case 4: { \ | |
194 | unsigned int __gu_val; \ | |
195 | __get_user_asm(__gu_err, __gu_val, ptr, "", "=r"); \ | |
196 | (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \ | |
1da177e4 | 197 | break; \ |
a8a77573 AV |
198 | } \ |
199 | case 8: { \ | |
200 | unsigned long long __gu_val; \ | |
201 | __get_user_asm(__gu_err, __gu_val, ptr, "d", "=e"); \ | |
202 | (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \ | |
1da177e4 | 203 | break; \ |
a8a77573 | 204 | } \ |
1da177e4 LT |
205 | default: \ |
206 | __gu_err = __get_user_bad(); \ | |
207 | break; \ | |
208 | } \ | |
1da177e4 LT |
209 | __gu_err; \ |
210 | }) | |
211 | ||
212 | #define get_user(x, ptr) \ | |
213 | ({ \ | |
a8a77573 | 214 | const typeof(*(ptr)) __user *_p = (ptr);\ |
1da177e4 LT |
215 | int _e; \ |
216 | \ | |
217 | _e = __range_ok(_p, sizeof(*_p)); \ | |
218 | if (likely(_e == 0)) \ | |
219 | _e = __get_user((x), _p); \ | |
220 | else \ | |
221 | (x) = (typeof(x)) 0; \ | |
222 | _e; \ | |
223 | }) | |
224 | ||
225 | extern int __get_user_bad(void); | |
226 | ||
227 | #ifdef CONFIG_MMU | |
228 | ||
229 | #define __get_user_asm(err,x,ptr,dtype,constraint) \ | |
230 | do { \ | |
231 | asm("1: ld"dtype"%I2 %M2,%1 \n" \ | |
232 | "2: \n" \ | |
233 | ".subsection 2 \n" \ | |
234 | "3: setlos %3,%0 \n" \ | |
235 | " setlos #0,%1 \n" \ | |
236 | " bra 2b \n" \ | |
237 | ".previous \n" \ | |
238 | ".section __ex_table,\"a\" \n" \ | |
239 | " .balign 8 \n" \ | |
240 | " .long 1b,3b \n" \ | |
241 | ".previous" \ | |
242 | : "=r" (err), constraint (x) \ | |
243 | : "m" (*__ptr(ptr)), "i"(-EFAULT), "0"(err) \ | |
244 | ); \ | |
245 | } while(0) | |
246 | ||
247 | #else | |
248 | ||
249 | #define __get_user_asm(err,x,ptr,bwl,con) \ | |
250 | asm(" ld"bwl"%I1 %M1,%0 \n" \ | |
251 | " membar \n" \ | |
252 | : con(x) \ | |
253 | : "m" (*__ptr(ptr))) | |
254 | ||
255 | #endif | |
256 | ||
257 | /*****************************************************************************/ | |
258 | /* | |
259 | * | |
260 | */ | |
a8a77573 | 261 | #define ____force(x) (__force void *)(void __user *)(x) |
1da177e4 LT |
262 | #ifdef CONFIG_MMU |
263 | extern long __memset_user(void *dst, unsigned long count); | |
264 | extern long __memcpy_user(void *dst, const void *src, unsigned long count); | |
265 | ||
3b8767a8 | 266 | #define __clear_user(dst,count) __memset_user(____force(dst), (count)) |
a8a77573 AV |
267 | #define __copy_from_user_inatomic(to, from, n) __memcpy_user((to), ____force(from), (n)) |
268 | #define __copy_to_user_inatomic(to, from, n) __memcpy_user(____force(to), (from), (n)) | |
1da177e4 LT |
269 | |
270 | #else | |
271 | ||
3b8767a8 | 272 | #define __clear_user(dst,count) (memset(____force(dst), 0, (count)), 0) |
a8a77573 AV |
273 | #define __copy_from_user_inatomic(to, from, n) (memcpy((to), ____force(from), (n)), 0) |
274 | #define __copy_to_user_inatomic(to, from, n) (memcpy(____force(to), (from), (n)), 0) | |
1da177e4 LT |
275 | |
276 | #endif | |
277 | ||
3b8767a8 AV |
278 | static inline unsigned long __must_check |
279 | clear_user(void __user *to, unsigned long n) | |
280 | { | |
281 | if (likely(__access_ok(to, n))) | |
282 | n = __clear_user(to, n); | |
283 | return n; | |
284 | } | |
b4a06918 | 285 | |
1da177e4 LT |
286 | static inline unsigned long __must_check |
287 | __copy_to_user(void __user *to, const void *from, unsigned long n) | |
288 | { | |
b607ae78 | 289 | might_fault(); |
1da177e4 LT |
290 | return __copy_to_user_inatomic(to, from, n); |
291 | } | |
292 | ||
293 | static inline unsigned long | |
294 | __copy_from_user(void *to, const void __user *from, unsigned long n) | |
295 | { | |
b607ae78 | 296 | might_fault(); |
1da177e4 LT |
297 | return __copy_from_user_inatomic(to, from, n); |
298 | } | |
299 | ||
a8a77573 | 300 | static inline long copy_from_user(void *to, const void __user *from, unsigned long n) |
1da177e4 LT |
301 | { |
302 | unsigned long ret = n; | |
303 | ||
304 | if (likely(__access_ok(from, n))) | |
305 | ret = __copy_from_user(to, from, n); | |
306 | ||
307 | if (unlikely(ret != 0)) | |
308 | memset(to + (n - ret), 0, ret); | |
309 | ||
310 | return ret; | |
311 | } | |
312 | ||
a8a77573 | 313 | static inline long copy_to_user(void __user *to, const void *from, unsigned long n) |
1da177e4 LT |
314 | { |
315 | return likely(__access_ok(to, n)) ? __copy_to_user(to, from, n) : n; | |
316 | } | |
317 | ||
a8a77573 AV |
318 | extern long strncpy_from_user(char *dst, const char __user *src, long count); |
319 | extern long strnlen_user(const char __user *src, long count); | |
1da177e4 LT |
320 | |
321 | #define strlen_user(str) strnlen_user(str, 32767) | |
322 | ||
323 | extern unsigned long search_exception_table(unsigned long addr); | |
324 | ||
1da177e4 | 325 | #endif /* _ASM_UACCESS_H */ |