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1da177e4 LT |
1 | /* |
2 | * Authors: Bjorn Wesen (bjornw@axis.com) | |
3 | * Hans-Peter Nilsson (hp@axis.com) | |
4 | * | |
5 | * $Log: uaccess.h,v $ | |
6 | * Revision 1.8 2001/10/29 13:01:48 bjornw | |
7 | * Removed unused variable tmp2 in strnlen_user | |
8 | * | |
9 | * Revision 1.7 2001/10/02 12:44:52 hp | |
10 | * Add support for 64-bit put_user/get_user | |
11 | * | |
12 | * Revision 1.6 2001/10/01 14:51:17 bjornw | |
13 | * Added register prefixes and removed underscores | |
14 | * | |
15 | * Revision 1.5 2000/10/25 03:33:21 hp | |
16 | * - Provide implementation for everything else but get_user and put_user; | |
17 | * copying inline to/from user for constant length 0..16, 20, 24, and | |
18 | * clearing for 0..4, 8, 12, 16, 20, 24, strncpy_from_user and strnlen_user | |
19 | * always inline. | |
20 | * - Constraints for destination addr in get_user cannot be memory, only reg. | |
21 | * - Correct labels for PC at expected fault points. | |
22 | * - Nits with assembly code. | |
23 | * - Don't use statement expressions without value; use "do {} while (0)". | |
24 | * - Return correct values from __generic_... functions. | |
25 | * | |
26 | * Revision 1.4 2000/09/12 16:28:25 bjornw | |
27 | * * Removed comments from the get/put user asm code | |
28 | * * Constrains for destination addr in put_user cannot be memory, only reg | |
29 | * | |
30 | * Revision 1.3 2000/09/12 14:30:20 bjornw | |
31 | * MAX_ADDR_USER does not exist anymore | |
32 | * | |
33 | * Revision 1.2 2000/07/13 15:52:48 bjornw | |
34 | * New user-access functions | |
35 | * | |
36 | * Revision 1.1.1.1 2000/07/10 16:32:31 bjornw | |
37 | * CRIS architecture, working draft | |
38 | * | |
39 | * | |
40 | * | |
41 | */ | |
42 | ||
43 | /* Asm:s have been tweaked (within the domain of correctness) to give | |
44 | satisfactory results for "gcc version 2.96 20000427 (experimental)". | |
45 | ||
46 | Check regularly... | |
47 | ||
48 | Register $r9 is chosen for temporaries, being a call-clobbered register | |
49 | first in line to be used (notably for local blocks), not colliding with | |
50 | parameter registers. */ | |
51 | ||
52 | #ifndef _CRIS_UACCESS_H | |
53 | #define _CRIS_UACCESS_H | |
54 | ||
55 | #ifndef __ASSEMBLY__ | |
56 | #include <linux/sched.h> | |
57 | #include <linux/errno.h> | |
58 | #include <asm/processor.h> | |
59 | #include <asm/page.h> | |
60 | ||
61 | #define VERIFY_READ 0 | |
62 | #define VERIFY_WRITE 1 | |
63 | ||
64 | /* | |
65 | * The fs value determines whether argument validity checking should be | |
66 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
67 | * get_fs() == KERNEL_DS, checking is bypassed. | |
68 | * | |
69 | * For historical reasons, these macros are grossly misnamed. | |
70 | */ | |
71 | ||
72 | #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) | |
73 | ||
74 | /* addr_limit is the maximum accessible address for the task. we misuse | |
75 | * the KERNEL_DS and USER_DS values to both assign and compare the | |
76 | * addr_limit values through the equally misnamed get/set_fs macros. | |
77 | * (see above) | |
78 | */ | |
79 | ||
80 | #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) | |
81 | #define USER_DS MAKE_MM_SEG(TASK_SIZE) | |
82 | ||
83 | #define get_ds() (KERNEL_DS) | |
84 | #define get_fs() (current_thread_info()->addr_limit) | |
85 | #define set_fs(x) (current_thread_info()->addr_limit = (x)) | |
86 | ||
87 | #define segment_eq(a,b) ((a).seg == (b).seg) | |
88 | ||
89 | #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS)) | |
90 | #define __user_ok(addr,size) (((size) <= TASK_SIZE)&&((addr) <= TASK_SIZE-(size))) | |
91 | #define __access_ok(addr,size) (__kernel_ok || __user_ok((addr),(size))) | |
92 | #define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size)) | |
93 | ||
1da177e4 LT |
94 | #include <asm/arch/uaccess.h> |
95 | ||
96 | /* | |
97 | * The exception table consists of pairs of addresses: the first is the | |
98 | * address of an instruction that is allowed to fault, and the second is | |
99 | * the address at which the program should continue. No registers are | |
100 | * modified, so it is entirely up to the continuation code to figure out | |
101 | * what to do. | |
102 | * | |
103 | * All the routines below use bits of fixup code that are out of line | |
104 | * with the main instruction path. This means when everything is well, | |
105 | * we don't even have to jump over them. Further, they do not intrude | |
106 | * on our cache or tlb entries. | |
107 | */ | |
108 | ||
109 | struct exception_table_entry | |
110 | { | |
111 | unsigned long insn, fixup; | |
112 | }; | |
113 | ||
114 | /* | |
115 | * These are the main single-value transfer routines. They automatically | |
116 | * use the right size if we just have the right pointer type. | |
117 | * | |
118 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
119 | * and yet we don't want to do any pointers, because that is too much | |
120 | * of a performance impact. Thus we have a few rather ugly macros here, | |
121 | * and hide all the ugliness from the user. | |
122 | * | |
123 | * The "__xxx" versions of the user access functions are versions that | |
124 | * do not verify the address space, that must have been done previously | |
125 | * with a separate "access_ok()" call (this is used when we do multiple | |
126 | * accesses to the same area of user memory). | |
127 | * | |
128 | * As we use the same address space for kernel and user data on | |
129 | * CRIS, we can just do these as direct assignments. (Of course, the | |
130 | * exception handling means that it's no longer "just"...) | |
131 | */ | |
132 | #define get_user(x,ptr) \ | |
133 | __get_user_check((x),(ptr),sizeof(*(ptr))) | |
134 | #define put_user(x,ptr) \ | |
135 | __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) | |
136 | ||
137 | #define __get_user(x,ptr) \ | |
138 | __get_user_nocheck((x),(ptr),sizeof(*(ptr))) | |
139 | #define __put_user(x,ptr) \ | |
140 | __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) | |
141 | ||
142 | extern long __put_user_bad(void); | |
143 | ||
144 | #define __put_user_size(x,ptr,size,retval) \ | |
145 | do { \ | |
146 | retval = 0; \ | |
147 | switch (size) { \ | |
148 | case 1: __put_user_asm(x,ptr,retval,"move.b"); break; \ | |
149 | case 2: __put_user_asm(x,ptr,retval,"move.w"); break; \ | |
150 | case 4: __put_user_asm(x,ptr,retval,"move.d"); break; \ | |
151 | case 8: __put_user_asm_64(x,ptr,retval); break; \ | |
152 | default: __put_user_bad(); \ | |
153 | } \ | |
154 | } while (0) | |
155 | ||
156 | #define __get_user_size(x,ptr,size,retval) \ | |
157 | do { \ | |
158 | retval = 0; \ | |
159 | switch (size) { \ | |
160 | case 1: __get_user_asm(x,ptr,retval,"move.b"); break; \ | |
161 | case 2: __get_user_asm(x,ptr,retval,"move.w"); break; \ | |
162 | case 4: __get_user_asm(x,ptr,retval,"move.d"); break; \ | |
163 | case 8: __get_user_asm_64(x,ptr,retval); break; \ | |
164 | default: (x) = __get_user_bad(); \ | |
165 | } \ | |
166 | } while (0) | |
167 | ||
168 | #define __put_user_nocheck(x,ptr,size) \ | |
169 | ({ \ | |
170 | long __pu_err; \ | |
171 | __put_user_size((x),(ptr),(size),__pu_err); \ | |
172 | __pu_err; \ | |
173 | }) | |
174 | ||
175 | #define __put_user_check(x,ptr,size) \ | |
176 | ({ \ | |
177 | long __pu_err = -EFAULT; \ | |
178 | __typeof__(*(ptr)) *__pu_addr = (ptr); \ | |
179 | if (access_ok(VERIFY_WRITE,__pu_addr,size)) \ | |
180 | __put_user_size((x),__pu_addr,(size),__pu_err); \ | |
181 | __pu_err; \ | |
182 | }) | |
183 | ||
184 | struct __large_struct { unsigned long buf[100]; }; | |
185 | #define __m(x) (*(struct __large_struct *)(x)) | |
186 | ||
187 | ||
188 | ||
189 | #define __get_user_nocheck(x,ptr,size) \ | |
190 | ({ \ | |
191 | long __gu_err, __gu_val; \ | |
192 | __get_user_size(__gu_val,(ptr),(size),__gu_err); \ | |
193 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
194 | __gu_err; \ | |
195 | }) | |
196 | ||
197 | #define __get_user_check(x,ptr,size) \ | |
198 | ({ \ | |
199 | long __gu_err = -EFAULT, __gu_val = 0; \ | |
200 | const __typeof__(*(ptr)) *__gu_addr = (ptr); \ | |
201 | if (access_ok(VERIFY_READ,__gu_addr,size)) \ | |
202 | __get_user_size(__gu_val,__gu_addr,(size),__gu_err); \ | |
203 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
204 | __gu_err; \ | |
205 | }) | |
206 | ||
207 | extern long __get_user_bad(void); | |
208 | ||
209 | /* More complex functions. Most are inline, but some call functions that | |
210 | live in lib/usercopy.c */ | |
211 | ||
212 | extern unsigned long __copy_user(void *to, const void *from, unsigned long n); | |
213 | extern unsigned long __copy_user_zeroing(void *to, const void *from, unsigned long n); | |
214 | extern unsigned long __do_clear_user(void *to, unsigned long n); | |
215 | ||
d9b5444e | 216 | static inline unsigned long |
1da177e4 LT |
217 | __generic_copy_to_user(void __user *to, const void *from, unsigned long n) |
218 | { | |
219 | if (access_ok(VERIFY_WRITE, to, n)) | |
220 | return __copy_user(to,from,n); | |
221 | return n; | |
222 | } | |
223 | ||
d9b5444e | 224 | static inline unsigned long |
1da177e4 LT |
225 | __generic_copy_from_user(void *to, const void __user *from, unsigned long n) |
226 | { | |
227 | if (access_ok(VERIFY_READ, from, n)) | |
228 | return __copy_user_zeroing(to,from,n); | |
229 | return n; | |
230 | } | |
231 | ||
d9b5444e | 232 | static inline unsigned long |
1da177e4 LT |
233 | __generic_clear_user(void __user *to, unsigned long n) |
234 | { | |
235 | if (access_ok(VERIFY_WRITE, to, n)) | |
236 | return __do_clear_user(to,n); | |
237 | return n; | |
238 | } | |
239 | ||
d9b5444e | 240 | static inline long |
1da177e4 LT |
241 | __strncpy_from_user(char *dst, const char __user *src, long count) |
242 | { | |
243 | return __do_strncpy_from_user(dst, src, count); | |
244 | } | |
245 | ||
d9b5444e | 246 | static inline long |
1da177e4 LT |
247 | strncpy_from_user(char *dst, const char __user *src, long count) |
248 | { | |
249 | long res = -EFAULT; | |
250 | if (access_ok(VERIFY_READ, src, 1)) | |
251 | res = __do_strncpy_from_user(dst, src, count); | |
252 | return res; | |
253 | } | |
254 | ||
255 | ||
256 | /* Note that if these expand awfully if made into switch constructs, so | |
257 | don't do that. */ | |
258 | ||
d9b5444e | 259 | static inline unsigned long |
1da177e4 LT |
260 | __constant_copy_from_user(void *to, const void __user *from, unsigned long n) |
261 | { | |
262 | unsigned long ret = 0; | |
263 | if (n == 0) | |
264 | ; | |
265 | else if (n == 1) | |
266 | __asm_copy_from_user_1(to, from, ret); | |
267 | else if (n == 2) | |
268 | __asm_copy_from_user_2(to, from, ret); | |
269 | else if (n == 3) | |
270 | __asm_copy_from_user_3(to, from, ret); | |
271 | else if (n == 4) | |
272 | __asm_copy_from_user_4(to, from, ret); | |
273 | else if (n == 5) | |
274 | __asm_copy_from_user_5(to, from, ret); | |
275 | else if (n == 6) | |
276 | __asm_copy_from_user_6(to, from, ret); | |
277 | else if (n == 7) | |
278 | __asm_copy_from_user_7(to, from, ret); | |
279 | else if (n == 8) | |
280 | __asm_copy_from_user_8(to, from, ret); | |
281 | else if (n == 9) | |
282 | __asm_copy_from_user_9(to, from, ret); | |
283 | else if (n == 10) | |
284 | __asm_copy_from_user_10(to, from, ret); | |
285 | else if (n == 11) | |
286 | __asm_copy_from_user_11(to, from, ret); | |
287 | else if (n == 12) | |
288 | __asm_copy_from_user_12(to, from, ret); | |
289 | else if (n == 13) | |
290 | __asm_copy_from_user_13(to, from, ret); | |
291 | else if (n == 14) | |
292 | __asm_copy_from_user_14(to, from, ret); | |
293 | else if (n == 15) | |
294 | __asm_copy_from_user_15(to, from, ret); | |
295 | else if (n == 16) | |
296 | __asm_copy_from_user_16(to, from, ret); | |
297 | else if (n == 20) | |
298 | __asm_copy_from_user_20(to, from, ret); | |
299 | else if (n == 24) | |
300 | __asm_copy_from_user_24(to, from, ret); | |
301 | else | |
302 | ret = __generic_copy_from_user(to, from, n); | |
303 | ||
304 | return ret; | |
305 | } | |
306 | ||
307 | /* Ditto, don't make a switch out of this. */ | |
308 | ||
d9b5444e | 309 | static inline unsigned long |
1da177e4 LT |
310 | __constant_copy_to_user(void __user *to, const void *from, unsigned long n) |
311 | { | |
312 | unsigned long ret = 0; | |
313 | if (n == 0) | |
314 | ; | |
315 | else if (n == 1) | |
316 | __asm_copy_to_user_1(to, from, ret); | |
317 | else if (n == 2) | |
318 | __asm_copy_to_user_2(to, from, ret); | |
319 | else if (n == 3) | |
320 | __asm_copy_to_user_3(to, from, ret); | |
321 | else if (n == 4) | |
322 | __asm_copy_to_user_4(to, from, ret); | |
323 | else if (n == 5) | |
324 | __asm_copy_to_user_5(to, from, ret); | |
325 | else if (n == 6) | |
326 | __asm_copy_to_user_6(to, from, ret); | |
327 | else if (n == 7) | |
328 | __asm_copy_to_user_7(to, from, ret); | |
329 | else if (n == 8) | |
330 | __asm_copy_to_user_8(to, from, ret); | |
331 | else if (n == 9) | |
332 | __asm_copy_to_user_9(to, from, ret); | |
333 | else if (n == 10) | |
334 | __asm_copy_to_user_10(to, from, ret); | |
335 | else if (n == 11) | |
336 | __asm_copy_to_user_11(to, from, ret); | |
337 | else if (n == 12) | |
338 | __asm_copy_to_user_12(to, from, ret); | |
339 | else if (n == 13) | |
340 | __asm_copy_to_user_13(to, from, ret); | |
341 | else if (n == 14) | |
342 | __asm_copy_to_user_14(to, from, ret); | |
343 | else if (n == 15) | |
344 | __asm_copy_to_user_15(to, from, ret); | |
345 | else if (n == 16) | |
346 | __asm_copy_to_user_16(to, from, ret); | |
347 | else if (n == 20) | |
348 | __asm_copy_to_user_20(to, from, ret); | |
349 | else if (n == 24) | |
350 | __asm_copy_to_user_24(to, from, ret); | |
351 | else | |
352 | ret = __generic_copy_to_user(to, from, n); | |
353 | ||
354 | return ret; | |
355 | } | |
356 | ||
357 | /* No switch, please. */ | |
358 | ||
d9b5444e | 359 | static inline unsigned long |
1da177e4 LT |
360 | __constant_clear_user(void __user *to, unsigned long n) |
361 | { | |
362 | unsigned long ret = 0; | |
363 | if (n == 0) | |
364 | ; | |
365 | else if (n == 1) | |
366 | __asm_clear_1(to, ret); | |
367 | else if (n == 2) | |
368 | __asm_clear_2(to, ret); | |
369 | else if (n == 3) | |
370 | __asm_clear_3(to, ret); | |
371 | else if (n == 4) | |
372 | __asm_clear_4(to, ret); | |
373 | else if (n == 8) | |
374 | __asm_clear_8(to, ret); | |
375 | else if (n == 12) | |
376 | __asm_clear_12(to, ret); | |
377 | else if (n == 16) | |
378 | __asm_clear_16(to, ret); | |
379 | else if (n == 20) | |
380 | __asm_clear_20(to, ret); | |
381 | else if (n == 24) | |
382 | __asm_clear_24(to, ret); | |
383 | else | |
384 | ret = __generic_clear_user(to, n); | |
385 | ||
386 | return ret; | |
387 | } | |
388 | ||
389 | ||
390 | #define clear_user(to, n) \ | |
391 | (__builtin_constant_p(n) ? \ | |
392 | __constant_clear_user(to, n) : \ | |
393 | __generic_clear_user(to, n)) | |
394 | ||
395 | #define copy_from_user(to, from, n) \ | |
396 | (__builtin_constant_p(n) ? \ | |
397 | __constant_copy_from_user(to, from, n) : \ | |
398 | __generic_copy_from_user(to, from, n)) | |
399 | ||
400 | #define copy_to_user(to, from, n) \ | |
401 | (__builtin_constant_p(n) ? \ | |
402 | __constant_copy_to_user(to, from, n) : \ | |
403 | __generic_copy_to_user(to, from, n)) | |
404 | ||
405 | /* We let the __ versions of copy_from/to_user inline, because they're often | |
406 | * used in fast paths and have only a small space overhead. | |
407 | */ | |
408 | ||
d9b5444e | 409 | static inline unsigned long |
1da177e4 LT |
410 | __generic_copy_from_user_nocheck(void *to, const void *from, unsigned long n) |
411 | { | |
412 | return __copy_user_zeroing(to,from,n); | |
413 | } | |
414 | ||
d9b5444e | 415 | static inline unsigned long |
1da177e4 LT |
416 | __generic_copy_to_user_nocheck(void *to, const void *from, unsigned long n) |
417 | { | |
418 | return __copy_user(to,from,n); | |
419 | } | |
420 | ||
d9b5444e | 421 | static inline unsigned long |
1da177e4 LT |
422 | __generic_clear_user_nocheck(void *to, unsigned long n) |
423 | { | |
424 | return __do_clear_user(to,n); | |
425 | } | |
426 | ||
427 | /* without checking */ | |
428 | ||
429 | #define __copy_to_user(to,from,n) __generic_copy_to_user_nocheck((to),(from),(n)) | |
430 | #define __copy_from_user(to,from,n) __generic_copy_from_user_nocheck((to),(from),(n)) | |
431 | #define __copy_to_user_inatomic __copy_to_user | |
432 | #define __copy_from_user_inatomic __copy_from_user | |
433 | #define __clear_user(to,n) __generic_clear_user_nocheck((to),(n)) | |
434 | ||
435 | #define strlen_user(str) strnlen_user((str), 0x7ffffffe) | |
436 | ||
437 | #endif /* __ASSEMBLY__ */ | |
438 | ||
439 | #endif /* _CRIS_UACCESS_H */ |