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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[deliverable/linux.git] / arch / mips / include / asm / uaccess.h
1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2007 Maciej W. Rozycki
9 */
10 #ifndef _ASM_UACCESS_H
11 #define _ASM_UACCESS_H
12
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/thread_info.h>
16
17 /*
18 * The fs value determines whether argument validity checking should be
19 * performed or not. If get_fs() == USER_DS, checking is performed, with
20 * get_fs() == KERNEL_DS, checking is bypassed.
21 *
22 * For historical reasons, these macros are grossly misnamed.
23 */
24 #ifdef CONFIG_32BIT
25
26 #define __UA_LIMIT 0x80000000UL
27
28 #define __UA_ADDR ".word"
29 #define __UA_LA "la"
30 #define __UA_ADDU "addu"
31 #define __UA_t0 "$8"
32 #define __UA_t1 "$9"
33
34 #endif /* CONFIG_32BIT */
35
36 #ifdef CONFIG_64BIT
37
38 extern u64 __ua_limit;
39
40 #define __UA_LIMIT __ua_limit
41
42 #define __UA_ADDR ".dword"
43 #define __UA_LA "dla"
44 #define __UA_ADDU "daddu"
45 #define __UA_t0 "$12"
46 #define __UA_t1 "$13"
47
48 #endif /* CONFIG_64BIT */
49
50 /*
51 * USER_DS is a bitmask that has the bits set that may not be set in a valid
52 * userspace address. Note that we limit 32-bit userspace to 0x7fff8000 but
53 * the arithmetic we're doing only works if the limit is a power of two, so
54 * we use 0x80000000 here on 32-bit kernels. If a process passes an invalid
55 * address in this range it's the process's problem, not ours :-)
56 */
57
58 #define KERNEL_DS ((mm_segment_t) { 0UL })
59 #define USER_DS ((mm_segment_t) { __UA_LIMIT })
60
61 #define VERIFY_READ 0
62 #define VERIFY_WRITE 1
63
64 #define get_ds() (KERNEL_DS)
65 #define get_fs() (current_thread_info()->addr_limit)
66 #define set_fs(x) (current_thread_info()->addr_limit = (x))
67
68 #define segment_eq(a, b) ((a).seg == (b).seg)
69
70
71 /*
72 * Is a address valid? This does a straighforward calculation rather
73 * than tests.
74 *
75 * Address valid if:
76 * - "addr" doesn't have any high-bits set
77 * - AND "size" doesn't have any high-bits set
78 * - AND "addr+size" doesn't have any high-bits set
79 * - OR we are in kernel mode.
80 *
81 * __ua_size() is a trick to avoid runtime checking of positive constant
82 * sizes; for those we already know at compile time that the size is ok.
83 */
84 #define __ua_size(size) \
85 ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
86
87 /*
88 * access_ok: - Checks if a user space pointer is valid
89 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
90 * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
91 * to write to a block, it is always safe to read from it.
92 * @addr: User space pointer to start of block to check
93 * @size: Size of block to check
94 *
95 * Context: User context only. This function may sleep.
96 *
97 * Checks if a pointer to a block of memory in user space is valid.
98 *
99 * Returns true (nonzero) if the memory block may be valid, false (zero)
100 * if it is definitely invalid.
101 *
102 * Note that, depending on architecture, this function probably just
103 * checks that the pointer is in the user space range - after calling
104 * this function, memory access functions may still return -EFAULT.
105 */
106
107 #define __access_mask get_fs().seg
108
109 #define __access_ok(addr, size, mask) \
110 ({ \
111 unsigned long __addr = (unsigned long) (addr); \
112 unsigned long __size = size; \
113 unsigned long __mask = mask; \
114 unsigned long __ok; \
115 \
116 __chk_user_ptr(addr); \
117 __ok = (signed long)(__mask & (__addr | (__addr + __size) | \
118 __ua_size(__size))); \
119 __ok == 0; \
120 })
121
122 #define access_ok(type, addr, size) \
123 likely(__access_ok((addr), (size), __access_mask))
124
125 /*
126 * put_user: - Write a simple value into user space.
127 * @x: Value to copy to user space.
128 * @ptr: Destination address, in user space.
129 *
130 * Context: User context only. This function may sleep.
131 *
132 * This macro copies a single simple value from kernel space to user
133 * space. It supports simple types like char and int, but not larger
134 * data types like structures or arrays.
135 *
136 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
137 * to the result of dereferencing @ptr.
138 *
139 * Returns zero on success, or -EFAULT on error.
140 */
141 #define put_user(x,ptr) \
142 __put_user_check((x), (ptr), sizeof(*(ptr)))
143
144 /*
145 * get_user: - Get a simple variable from user space.
146 * @x: Variable to store result.
147 * @ptr: Source address, in user space.
148 *
149 * Context: User context only. This function may sleep.
150 *
151 * This macro copies a single simple variable from user space to kernel
152 * space. It supports simple types like char and int, but not larger
153 * data types like structures or arrays.
154 *
155 * @ptr must have pointer-to-simple-variable type, and the result of
156 * dereferencing @ptr must be assignable to @x without a cast.
157 *
158 * Returns zero on success, or -EFAULT on error.
159 * On error, the variable @x is set to zero.
160 */
161 #define get_user(x,ptr) \
162 __get_user_check((x), (ptr), sizeof(*(ptr)))
163
164 /*
165 * __put_user: - Write a simple value into user space, with less checking.
166 * @x: Value to copy to user space.
167 * @ptr: Destination address, in user space.
168 *
169 * Context: User context only. This function may sleep.
170 *
171 * This macro copies a single simple value from kernel space to user
172 * space. It supports simple types like char and int, but not larger
173 * data types like structures or arrays.
174 *
175 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
176 * to the result of dereferencing @ptr.
177 *
178 * Caller must check the pointer with access_ok() before calling this
179 * function.
180 *
181 * Returns zero on success, or -EFAULT on error.
182 */
183 #define __put_user(x,ptr) \
184 __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
185
186 /*
187 * __get_user: - Get a simple variable from user space, with less checking.
188 * @x: Variable to store result.
189 * @ptr: Source address, in user space.
190 *
191 * Context: User context only. This function may sleep.
192 *
193 * This macro copies a single simple variable from user space to kernel
194 * space. It supports simple types like char and int, but not larger
195 * data types like structures or arrays.
196 *
197 * @ptr must have pointer-to-simple-variable type, and the result of
198 * dereferencing @ptr must be assignable to @x without a cast.
199 *
200 * Caller must check the pointer with access_ok() before calling this
201 * function.
202 *
203 * Returns zero on success, or -EFAULT on error.
204 * On error, the variable @x is set to zero.
205 */
206 #define __get_user(x,ptr) \
207 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
208
209 struct __large_struct { unsigned long buf[100]; };
210 #define __m(x) (*(struct __large_struct __user *)(x))
211
212 /*
213 * Yuck. We need two variants, one for 64bit operation and one
214 * for 32 bit mode and old iron.
215 */
216 #ifdef CONFIG_32BIT
217 #define __GET_USER_DW(val, ptr) __get_user_asm_ll32(val, ptr)
218 #endif
219 #ifdef CONFIG_64BIT
220 #define __GET_USER_DW(val, ptr) __get_user_asm(val, "ld", ptr)
221 #endif
222
223 extern void __get_user_unknown(void);
224
225 #define __get_user_common(val, size, ptr) \
226 do { \
227 switch (size) { \
228 case 1: __get_user_asm(val, "lb", ptr); break; \
229 case 2: __get_user_asm(val, "lh", ptr); break; \
230 case 4: __get_user_asm(val, "lw", ptr); break; \
231 case 8: __GET_USER_DW(val, ptr); break; \
232 default: __get_user_unknown(); break; \
233 } \
234 } while (0)
235
236 #define __get_user_nocheck(x, ptr, size) \
237 ({ \
238 int __gu_err; \
239 \
240 __chk_user_ptr(ptr); \
241 __get_user_common((x), size, ptr); \
242 __gu_err; \
243 })
244
245 #define __get_user_check(x, ptr, size) \
246 ({ \
247 int __gu_err = -EFAULT; \
248 const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
249 \
250 might_fault(); \
251 if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \
252 __get_user_common((x), size, __gu_ptr); \
253 \
254 __gu_err; \
255 })
256
257 #define __get_user_asm(val, insn, addr) \
258 { \
259 long __gu_tmp; \
260 \
261 __asm__ __volatile__( \
262 "1: " insn " %1, %3 \n" \
263 "2: \n" \
264 " .section .fixup,\"ax\" \n" \
265 "3: li %0, %4 \n" \
266 " j 2b \n" \
267 " .previous \n" \
268 " .section __ex_table,\"a\" \n" \
269 " "__UA_ADDR "\t1b, 3b \n" \
270 " .previous \n" \
271 : "=r" (__gu_err), "=r" (__gu_tmp) \
272 : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
273 \
274 (val) = (__typeof__(*(addr))) __gu_tmp; \
275 }
276
277 /*
278 * Get a long long 64 using 32 bit registers.
279 */
280 #define __get_user_asm_ll32(val, addr) \
281 { \
282 union { \
283 unsigned long long l; \
284 __typeof__(*(addr)) t; \
285 } __gu_tmp; \
286 \
287 __asm__ __volatile__( \
288 "1: lw %1, (%3) \n" \
289 "2: lw %D1, 4(%3) \n" \
290 "3: .section .fixup,\"ax\" \n" \
291 "4: li %0, %4 \n" \
292 " move %1, $0 \n" \
293 " move %D1, $0 \n" \
294 " j 3b \n" \
295 " .previous \n" \
296 " .section __ex_table,\"a\" \n" \
297 " " __UA_ADDR " 1b, 4b \n" \
298 " " __UA_ADDR " 2b, 4b \n" \
299 " .previous \n" \
300 : "=r" (__gu_err), "=&r" (__gu_tmp.l) \
301 : "0" (0), "r" (addr), "i" (-EFAULT)); \
302 \
303 (val) = __gu_tmp.t; \
304 }
305
306 /*
307 * Yuck. We need two variants, one for 64bit operation and one
308 * for 32 bit mode and old iron.
309 */
310 #ifdef CONFIG_32BIT
311 #define __PUT_USER_DW(ptr) __put_user_asm_ll32(ptr)
312 #endif
313 #ifdef CONFIG_64BIT
314 #define __PUT_USER_DW(ptr) __put_user_asm("sd", ptr)
315 #endif
316
317 #define __put_user_nocheck(x, ptr, size) \
318 ({ \
319 __typeof__(*(ptr)) __pu_val; \
320 int __pu_err = 0; \
321 \
322 __chk_user_ptr(ptr); \
323 __pu_val = (x); \
324 switch (size) { \
325 case 1: __put_user_asm("sb", ptr); break; \
326 case 2: __put_user_asm("sh", ptr); break; \
327 case 4: __put_user_asm("sw", ptr); break; \
328 case 8: __PUT_USER_DW(ptr); break; \
329 default: __put_user_unknown(); break; \
330 } \
331 __pu_err; \
332 })
333
334 #define __put_user_check(x, ptr, size) \
335 ({ \
336 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
337 __typeof__(*(ptr)) __pu_val = (x); \
338 int __pu_err = -EFAULT; \
339 \
340 might_fault(); \
341 if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
342 switch (size) { \
343 case 1: __put_user_asm("sb", __pu_addr); break; \
344 case 2: __put_user_asm("sh", __pu_addr); break; \
345 case 4: __put_user_asm("sw", __pu_addr); break; \
346 case 8: __PUT_USER_DW(__pu_addr); break; \
347 default: __put_user_unknown(); break; \
348 } \
349 } \
350 __pu_err; \
351 })
352
353 #define __put_user_asm(insn, ptr) \
354 { \
355 __asm__ __volatile__( \
356 "1: " insn " %z2, %3 # __put_user_asm\n" \
357 "2: \n" \
358 " .section .fixup,\"ax\" \n" \
359 "3: li %0, %4 \n" \
360 " j 2b \n" \
361 " .previous \n" \
362 " .section __ex_table,\"a\" \n" \
363 " " __UA_ADDR " 1b, 3b \n" \
364 " .previous \n" \
365 : "=r" (__pu_err) \
366 : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
367 "i" (-EFAULT)); \
368 }
369
370 #define __put_user_asm_ll32(ptr) \
371 { \
372 __asm__ __volatile__( \
373 "1: sw %2, (%3) # __put_user_asm_ll32 \n" \
374 "2: sw %D2, 4(%3) \n" \
375 "3: \n" \
376 " .section .fixup,\"ax\" \n" \
377 "4: li %0, %4 \n" \
378 " j 3b \n" \
379 " .previous \n" \
380 " .section __ex_table,\"a\" \n" \
381 " " __UA_ADDR " 1b, 4b \n" \
382 " " __UA_ADDR " 2b, 4b \n" \
383 " .previous" \
384 : "=r" (__pu_err) \
385 : "0" (0), "r" (__pu_val), "r" (ptr), \
386 "i" (-EFAULT)); \
387 }
388
389 extern void __put_user_unknown(void);
390
391 /*
392 * put_user_unaligned: - Write a simple value into user space.
393 * @x: Value to copy to user space.
394 * @ptr: Destination address, in user space.
395 *
396 * Context: User context only. This function may sleep.
397 *
398 * This macro copies a single simple value from kernel space to user
399 * space. It supports simple types like char and int, but not larger
400 * data types like structures or arrays.
401 *
402 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
403 * to the result of dereferencing @ptr.
404 *
405 * Returns zero on success, or -EFAULT on error.
406 */
407 #define put_user_unaligned(x,ptr) \
408 __put_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
409
410 /*
411 * get_user_unaligned: - Get a simple variable from user space.
412 * @x: Variable to store result.
413 * @ptr: Source address, in user space.
414 *
415 * Context: User context only. This function may sleep.
416 *
417 * This macro copies a single simple variable from user space to kernel
418 * space. It supports simple types like char and int, but not larger
419 * data types like structures or arrays.
420 *
421 * @ptr must have pointer-to-simple-variable type, and the result of
422 * dereferencing @ptr must be assignable to @x without a cast.
423 *
424 * Returns zero on success, or -EFAULT on error.
425 * On error, the variable @x is set to zero.
426 */
427 #define get_user_unaligned(x,ptr) \
428 __get_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
429
430 /*
431 * __put_user_unaligned: - Write a simple value into user space, with less checking.
432 * @x: Value to copy to user space.
433 * @ptr: Destination address, in user space.
434 *
435 * Context: User context only. This function may sleep.
436 *
437 * This macro copies a single simple value from kernel space to user
438 * space. It supports simple types like char and int, but not larger
439 * data types like structures or arrays.
440 *
441 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
442 * to the result of dereferencing @ptr.
443 *
444 * Caller must check the pointer with access_ok() before calling this
445 * function.
446 *
447 * Returns zero on success, or -EFAULT on error.
448 */
449 #define __put_user_unaligned(x,ptr) \
450 __put_user_unaligned_nocheck((x),(ptr),sizeof(*(ptr)))
451
452 /*
453 * __get_user_unaligned: - Get a simple variable from user space, with less checking.
454 * @x: Variable to store result.
455 * @ptr: Source address, in user space.
456 *
457 * Context: User context only. This function may sleep.
458 *
459 * This macro copies a single simple variable from user space to kernel
460 * space. It supports simple types like char and int, but not larger
461 * data types like structures or arrays.
462 *
463 * @ptr must have pointer-to-simple-variable type, and the result of
464 * dereferencing @ptr must be assignable to @x without a cast.
465 *
466 * Caller must check the pointer with access_ok() before calling this
467 * function.
468 *
469 * Returns zero on success, or -EFAULT on error.
470 * On error, the variable @x is set to zero.
471 */
472 #define __get_user_unaligned(x,ptr) \
473 __get_user__unalignednocheck((x),(ptr),sizeof(*(ptr)))
474
475 /*
476 * Yuck. We need two variants, one for 64bit operation and one
477 * for 32 bit mode and old iron.
478 */
479 #ifdef CONFIG_32BIT
480 #define __GET_USER_UNALIGNED_DW(val, ptr) \
481 __get_user_unaligned_asm_ll32(val, ptr)
482 #endif
483 #ifdef CONFIG_64BIT
484 #define __GET_USER_UNALIGNED_DW(val, ptr) \
485 __get_user_unaligned_asm(val, "uld", ptr)
486 #endif
487
488 extern void __get_user_unaligned_unknown(void);
489
490 #define __get_user_unaligned_common(val, size, ptr) \
491 do { \
492 switch (size) { \
493 case 1: __get_user_asm(val, "lb", ptr); break; \
494 case 2: __get_user_unaligned_asm(val, "ulh", ptr); break; \
495 case 4: __get_user_unaligned_asm(val, "ulw", ptr); break; \
496 case 8: __GET_USER_UNALIGNED_DW(val, ptr); break; \
497 default: __get_user_unaligned_unknown(); break; \
498 } \
499 } while (0)
500
501 #define __get_user_unaligned_nocheck(x,ptr,size) \
502 ({ \
503 int __gu_err; \
504 \
505 __get_user_unaligned_common((x), size, ptr); \
506 __gu_err; \
507 })
508
509 #define __get_user_unaligned_check(x,ptr,size) \
510 ({ \
511 int __gu_err = -EFAULT; \
512 const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
513 \
514 if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \
515 __get_user_unaligned_common((x), size, __gu_ptr); \
516 \
517 __gu_err; \
518 })
519
520 #define __get_user_unaligned_asm(val, insn, addr) \
521 { \
522 long __gu_tmp; \
523 \
524 __asm__ __volatile__( \
525 "1: " insn " %1, %3 \n" \
526 "2: \n" \
527 " .section .fixup,\"ax\" \n" \
528 "3: li %0, %4 \n" \
529 " j 2b \n" \
530 " .previous \n" \
531 " .section __ex_table,\"a\" \n" \
532 " "__UA_ADDR "\t1b, 3b \n" \
533 " "__UA_ADDR "\t1b + 4, 3b \n" \
534 " .previous \n" \
535 : "=r" (__gu_err), "=r" (__gu_tmp) \
536 : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
537 \
538 (val) = (__typeof__(*(addr))) __gu_tmp; \
539 }
540
541 /*
542 * Get a long long 64 using 32 bit registers.
543 */
544 #define __get_user_unaligned_asm_ll32(val, addr) \
545 { \
546 unsigned long long __gu_tmp; \
547 \
548 __asm__ __volatile__( \
549 "1: ulw %1, (%3) \n" \
550 "2: ulw %D1, 4(%3) \n" \
551 " move %0, $0 \n" \
552 "3: .section .fixup,\"ax\" \n" \
553 "4: li %0, %4 \n" \
554 " move %1, $0 \n" \
555 " move %D1, $0 \n" \
556 " j 3b \n" \
557 " .previous \n" \
558 " .section __ex_table,\"a\" \n" \
559 " " __UA_ADDR " 1b, 4b \n" \
560 " " __UA_ADDR " 1b + 4, 4b \n" \
561 " " __UA_ADDR " 2b, 4b \n" \
562 " " __UA_ADDR " 2b + 4, 4b \n" \
563 " .previous \n" \
564 : "=r" (__gu_err), "=&r" (__gu_tmp) \
565 : "0" (0), "r" (addr), "i" (-EFAULT)); \
566 (val) = (__typeof__(*(addr))) __gu_tmp; \
567 }
568
569 /*
570 * Yuck. We need two variants, one for 64bit operation and one
571 * for 32 bit mode and old iron.
572 */
573 #ifdef CONFIG_32BIT
574 #define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm_ll32(ptr)
575 #endif
576 #ifdef CONFIG_64BIT
577 #define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm("usd", ptr)
578 #endif
579
580 #define __put_user_unaligned_nocheck(x,ptr,size) \
581 ({ \
582 __typeof__(*(ptr)) __pu_val; \
583 int __pu_err = 0; \
584 \
585 __pu_val = (x); \
586 switch (size) { \
587 case 1: __put_user_asm("sb", ptr); break; \
588 case 2: __put_user_unaligned_asm("ush", ptr); break; \
589 case 4: __put_user_unaligned_asm("usw", ptr); break; \
590 case 8: __PUT_USER_UNALIGNED_DW(ptr); break; \
591 default: __put_user_unaligned_unknown(); break; \
592 } \
593 __pu_err; \
594 })
595
596 #define __put_user_unaligned_check(x,ptr,size) \
597 ({ \
598 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
599 __typeof__(*(ptr)) __pu_val = (x); \
600 int __pu_err = -EFAULT; \
601 \
602 if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
603 switch (size) { \
604 case 1: __put_user_asm("sb", __pu_addr); break; \
605 case 2: __put_user_unaligned_asm("ush", __pu_addr); break; \
606 case 4: __put_user_unaligned_asm("usw", __pu_addr); break; \
607 case 8: __PUT_USER_UNALGINED_DW(__pu_addr); break; \
608 default: __put_user_unaligned_unknown(); break; \
609 } \
610 } \
611 __pu_err; \
612 })
613
614 #define __put_user_unaligned_asm(insn, ptr) \
615 { \
616 __asm__ __volatile__( \
617 "1: " insn " %z2, %3 # __put_user_unaligned_asm\n" \
618 "2: \n" \
619 " .section .fixup,\"ax\" \n" \
620 "3: li %0, %4 \n" \
621 " j 2b \n" \
622 " .previous \n" \
623 " .section __ex_table,\"a\" \n" \
624 " " __UA_ADDR " 1b, 3b \n" \
625 " .previous \n" \
626 : "=r" (__pu_err) \
627 : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
628 "i" (-EFAULT)); \
629 }
630
631 #define __put_user_unaligned_asm_ll32(ptr) \
632 { \
633 __asm__ __volatile__( \
634 "1: sw %2, (%3) # __put_user_unaligned_asm_ll32 \n" \
635 "2: sw %D2, 4(%3) \n" \
636 "3: \n" \
637 " .section .fixup,\"ax\" \n" \
638 "4: li %0, %4 \n" \
639 " j 3b \n" \
640 " .previous \n" \
641 " .section __ex_table,\"a\" \n" \
642 " " __UA_ADDR " 1b, 4b \n" \
643 " " __UA_ADDR " 1b + 4, 4b \n" \
644 " " __UA_ADDR " 2b, 4b \n" \
645 " " __UA_ADDR " 2b + 4, 4b \n" \
646 " .previous" \
647 : "=r" (__pu_err) \
648 : "0" (0), "r" (__pu_val), "r" (ptr), \
649 "i" (-EFAULT)); \
650 }
651
652 extern void __put_user_unaligned_unknown(void);
653
654 /*
655 * We're generating jump to subroutines which will be outside the range of
656 * jump instructions
657 */
658 #ifdef MODULE
659 #define __MODULE_JAL(destination) \
660 ".set\tnoat\n\t" \
661 __UA_LA "\t$1, " #destination "\n\t" \
662 "jalr\t$1\n\t" \
663 ".set\tat\n\t"
664 #else
665 #define __MODULE_JAL(destination) \
666 "jal\t" #destination "\n\t"
667 #endif
668
669 #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
670 #define DADDI_SCRATCH "$0"
671 #else
672 #define DADDI_SCRATCH "$3"
673 #endif
674
675 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
676
677 #define __invoke_copy_to_user(to, from, n) \
678 ({ \
679 register void __user *__cu_to_r __asm__("$4"); \
680 register const void *__cu_from_r __asm__("$5"); \
681 register long __cu_len_r __asm__("$6"); \
682 \
683 __cu_to_r = (to); \
684 __cu_from_r = (from); \
685 __cu_len_r = (n); \
686 __asm__ __volatile__( \
687 __MODULE_JAL(__copy_user) \
688 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
689 : \
690 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
691 DADDI_SCRATCH, "memory"); \
692 __cu_len_r; \
693 })
694
695 /*
696 * __copy_to_user: - Copy a block of data into user space, with less checking.
697 * @to: Destination address, in user space.
698 * @from: Source address, in kernel space.
699 * @n: Number of bytes to copy.
700 *
701 * Context: User context only. This function may sleep.
702 *
703 * Copy data from kernel space to user space. Caller must check
704 * the specified block with access_ok() before calling this function.
705 *
706 * Returns number of bytes that could not be copied.
707 * On success, this will be zero.
708 */
709 #define __copy_to_user(to, from, n) \
710 ({ \
711 void __user *__cu_to; \
712 const void *__cu_from; \
713 long __cu_len; \
714 \
715 __cu_to = (to); \
716 __cu_from = (from); \
717 __cu_len = (n); \
718 might_fault(); \
719 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
720 __cu_len; \
721 })
722
723 extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
724
725 #define __copy_to_user_inatomic(to, from, n) \
726 ({ \
727 void __user *__cu_to; \
728 const void *__cu_from; \
729 long __cu_len; \
730 \
731 __cu_to = (to); \
732 __cu_from = (from); \
733 __cu_len = (n); \
734 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
735 __cu_len; \
736 })
737
738 #define __copy_from_user_inatomic(to, from, n) \
739 ({ \
740 void *__cu_to; \
741 const void __user *__cu_from; \
742 long __cu_len; \
743 \
744 __cu_to = (to); \
745 __cu_from = (from); \
746 __cu_len = (n); \
747 __cu_len = __invoke_copy_from_user_inatomic(__cu_to, __cu_from, \
748 __cu_len); \
749 __cu_len; \
750 })
751
752 /*
753 * copy_to_user: - Copy a block of data into user space.
754 * @to: Destination address, in user space.
755 * @from: Source address, in kernel space.
756 * @n: Number of bytes to copy.
757 *
758 * Context: User context only. This function may sleep.
759 *
760 * Copy data from kernel space to user space.
761 *
762 * Returns number of bytes that could not be copied.
763 * On success, this will be zero.
764 */
765 #define copy_to_user(to, from, n) \
766 ({ \
767 void __user *__cu_to; \
768 const void *__cu_from; \
769 long __cu_len; \
770 \
771 __cu_to = (to); \
772 __cu_from = (from); \
773 __cu_len = (n); \
774 if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) { \
775 might_fault(); \
776 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, \
777 __cu_len); \
778 } \
779 __cu_len; \
780 })
781
782 #define __invoke_copy_from_user(to, from, n) \
783 ({ \
784 register void *__cu_to_r __asm__("$4"); \
785 register const void __user *__cu_from_r __asm__("$5"); \
786 register long __cu_len_r __asm__("$6"); \
787 \
788 __cu_to_r = (to); \
789 __cu_from_r = (from); \
790 __cu_len_r = (n); \
791 __asm__ __volatile__( \
792 ".set\tnoreorder\n\t" \
793 __MODULE_JAL(__copy_user) \
794 ".set\tnoat\n\t" \
795 __UA_ADDU "\t$1, %1, %2\n\t" \
796 ".set\tat\n\t" \
797 ".set\treorder" \
798 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
799 : \
800 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
801 DADDI_SCRATCH, "memory"); \
802 __cu_len_r; \
803 })
804
805 #define __invoke_copy_from_user_inatomic(to, from, n) \
806 ({ \
807 register void *__cu_to_r __asm__("$4"); \
808 register const void __user *__cu_from_r __asm__("$5"); \
809 register long __cu_len_r __asm__("$6"); \
810 \
811 __cu_to_r = (to); \
812 __cu_from_r = (from); \
813 __cu_len_r = (n); \
814 __asm__ __volatile__( \
815 ".set\tnoreorder\n\t" \
816 __MODULE_JAL(__copy_user_inatomic) \
817 ".set\tnoat\n\t" \
818 __UA_ADDU "\t$1, %1, %2\n\t" \
819 ".set\tat\n\t" \
820 ".set\treorder" \
821 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
822 : \
823 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
824 DADDI_SCRATCH, "memory"); \
825 __cu_len_r; \
826 })
827
828 /*
829 * __copy_from_user: - Copy a block of data from user space, with less checking.
830 * @to: Destination address, in kernel space.
831 * @from: Source address, in user space.
832 * @n: Number of bytes to copy.
833 *
834 * Context: User context only. This function may sleep.
835 *
836 * Copy data from user space to kernel space. Caller must check
837 * the specified block with access_ok() before calling this function.
838 *
839 * Returns number of bytes that could not be copied.
840 * On success, this will be zero.
841 *
842 * If some data could not be copied, this function will pad the copied
843 * data to the requested size using zero bytes.
844 */
845 #define __copy_from_user(to, from, n) \
846 ({ \
847 void *__cu_to; \
848 const void __user *__cu_from; \
849 long __cu_len; \
850 \
851 __cu_to = (to); \
852 __cu_from = (from); \
853 __cu_len = (n); \
854 might_fault(); \
855 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
856 __cu_len); \
857 __cu_len; \
858 })
859
860 /*
861 * copy_from_user: - Copy a block of data from user space.
862 * @to: Destination address, in kernel space.
863 * @from: Source address, in user space.
864 * @n: Number of bytes to copy.
865 *
866 * Context: User context only. This function may sleep.
867 *
868 * Copy data from user space to kernel space.
869 *
870 * Returns number of bytes that could not be copied.
871 * On success, this will be zero.
872 *
873 * If some data could not be copied, this function will pad the copied
874 * data to the requested size using zero bytes.
875 */
876 #define copy_from_user(to, from, n) \
877 ({ \
878 void *__cu_to; \
879 const void __user *__cu_from; \
880 long __cu_len; \
881 \
882 __cu_to = (to); \
883 __cu_from = (from); \
884 __cu_len = (n); \
885 if (access_ok(VERIFY_READ, __cu_from, __cu_len)) { \
886 might_fault(); \
887 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
888 __cu_len); \
889 } \
890 __cu_len; \
891 })
892
893 #define __copy_in_user(to, from, n) \
894 ({ \
895 void __user *__cu_to; \
896 const void __user *__cu_from; \
897 long __cu_len; \
898 \
899 __cu_to = (to); \
900 __cu_from = (from); \
901 __cu_len = (n); \
902 might_fault(); \
903 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
904 __cu_len); \
905 __cu_len; \
906 })
907
908 #define copy_in_user(to, from, n) \
909 ({ \
910 void __user *__cu_to; \
911 const void __user *__cu_from; \
912 long __cu_len; \
913 \
914 __cu_to = (to); \
915 __cu_from = (from); \
916 __cu_len = (n); \
917 if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) && \
918 access_ok(VERIFY_WRITE, __cu_to, __cu_len))) { \
919 might_fault(); \
920 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
921 __cu_len); \
922 } \
923 __cu_len; \
924 })
925
926 /*
927 * __clear_user: - Zero a block of memory in user space, with less checking.
928 * @to: Destination address, in user space.
929 * @n: Number of bytes to zero.
930 *
931 * Zero a block of memory in user space. Caller must check
932 * the specified block with access_ok() before calling this function.
933 *
934 * Returns number of bytes that could not be cleared.
935 * On success, this will be zero.
936 */
937 static inline __kernel_size_t
938 __clear_user(void __user *addr, __kernel_size_t size)
939 {
940 __kernel_size_t res;
941
942 might_fault();
943 __asm__ __volatile__(
944 "move\t$4, %1\n\t"
945 "move\t$5, $0\n\t"
946 "move\t$6, %2\n\t"
947 __MODULE_JAL(__bzero)
948 "move\t%0, $6"
949 : "=r" (res)
950 : "r" (addr), "r" (size)
951 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
952
953 return res;
954 }
955
956 #define clear_user(addr,n) \
957 ({ \
958 void __user * __cl_addr = (addr); \
959 unsigned long __cl_size = (n); \
960 if (__cl_size && access_ok(VERIFY_WRITE, \
961 __cl_addr, __cl_size)) \
962 __cl_size = __clear_user(__cl_addr, __cl_size); \
963 __cl_size; \
964 })
965
966 /*
967 * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
968 * @dst: Destination address, in kernel space. This buffer must be at
969 * least @count bytes long.
970 * @src: Source address, in user space.
971 * @count: Maximum number of bytes to copy, including the trailing NUL.
972 *
973 * Copies a NUL-terminated string from userspace to kernel space.
974 * Caller must check the specified block with access_ok() before calling
975 * this function.
976 *
977 * On success, returns the length of the string (not including the trailing
978 * NUL).
979 *
980 * If access to userspace fails, returns -EFAULT (some data may have been
981 * copied).
982 *
983 * If @count is smaller than the length of the string, copies @count bytes
984 * and returns @count.
985 */
986 static inline long
987 __strncpy_from_user(char *__to, const char __user *__from, long __len)
988 {
989 long res;
990
991 might_fault();
992 __asm__ __volatile__(
993 "move\t$4, %1\n\t"
994 "move\t$5, %2\n\t"
995 "move\t$6, %3\n\t"
996 __MODULE_JAL(__strncpy_from_user_nocheck_asm)
997 "move\t%0, $2"
998 : "=r" (res)
999 : "r" (__to), "r" (__from), "r" (__len)
1000 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1001
1002 return res;
1003 }
1004
1005 /*
1006 * strncpy_from_user: - Copy a NUL terminated string from userspace.
1007 * @dst: Destination address, in kernel space. This buffer must be at
1008 * least @count bytes long.
1009 * @src: Source address, in user space.
1010 * @count: Maximum number of bytes to copy, including the trailing NUL.
1011 *
1012 * Copies a NUL-terminated string from userspace to kernel space.
1013 *
1014 * On success, returns the length of the string (not including the trailing
1015 * NUL).
1016 *
1017 * If access to userspace fails, returns -EFAULT (some data may have been
1018 * copied).
1019 *
1020 * If @count is smaller than the length of the string, copies @count bytes
1021 * and returns @count.
1022 */
1023 static inline long
1024 strncpy_from_user(char *__to, const char __user *__from, long __len)
1025 {
1026 long res;
1027
1028 might_fault();
1029 __asm__ __volatile__(
1030 "move\t$4, %1\n\t"
1031 "move\t$5, %2\n\t"
1032 "move\t$6, %3\n\t"
1033 __MODULE_JAL(__strncpy_from_user_asm)
1034 "move\t%0, $2"
1035 : "=r" (res)
1036 : "r" (__to), "r" (__from), "r" (__len)
1037 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1038
1039 return res;
1040 }
1041
1042 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
1043 static inline long __strlen_user(const char __user *s)
1044 {
1045 long res;
1046
1047 might_fault();
1048 __asm__ __volatile__(
1049 "move\t$4, %1\n\t"
1050 __MODULE_JAL(__strlen_user_nocheck_asm)
1051 "move\t%0, $2"
1052 : "=r" (res)
1053 : "r" (s)
1054 : "$2", "$4", __UA_t0, "$31");
1055
1056 return res;
1057 }
1058
1059 /*
1060 * strlen_user: - Get the size of a string in user space.
1061 * @str: The string to measure.
1062 *
1063 * Context: User context only. This function may sleep.
1064 *
1065 * Get the size of a NUL-terminated string in user space.
1066 *
1067 * Returns the size of the string INCLUDING the terminating NUL.
1068 * On exception, returns 0.
1069 *
1070 * If there is a limit on the length of a valid string, you may wish to
1071 * consider using strnlen_user() instead.
1072 */
1073 static inline long strlen_user(const char __user *s)
1074 {
1075 long res;
1076
1077 might_fault();
1078 __asm__ __volatile__(
1079 "move\t$4, %1\n\t"
1080 __MODULE_JAL(__strlen_user_asm)
1081 "move\t%0, $2"
1082 : "=r" (res)
1083 : "r" (s)
1084 : "$2", "$4", __UA_t0, "$31");
1085
1086 return res;
1087 }
1088
1089 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
1090 static inline long __strnlen_user(const char __user *s, long n)
1091 {
1092 long res;
1093
1094 might_fault();
1095 __asm__ __volatile__(
1096 "move\t$4, %1\n\t"
1097 "move\t$5, %2\n\t"
1098 __MODULE_JAL(__strnlen_user_nocheck_asm)
1099 "move\t%0, $2"
1100 : "=r" (res)
1101 : "r" (s), "r" (n)
1102 : "$2", "$4", "$5", __UA_t0, "$31");
1103
1104 return res;
1105 }
1106
1107 /*
1108 * strlen_user: - Get the size of a string in user space.
1109 * @str: The string to measure.
1110 *
1111 * Context: User context only. This function may sleep.
1112 *
1113 * Get the size of a NUL-terminated string in user space.
1114 *
1115 * Returns the size of the string INCLUDING the terminating NUL.
1116 * On exception, returns 0.
1117 *
1118 * If there is a limit on the length of a valid string, you may wish to
1119 * consider using strnlen_user() instead.
1120 */
1121 static inline long strnlen_user(const char __user *s, long n)
1122 {
1123 long res;
1124
1125 might_fault();
1126 __asm__ __volatile__(
1127 "move\t$4, %1\n\t"
1128 "move\t$5, %2\n\t"
1129 __MODULE_JAL(__strnlen_user_asm)
1130 "move\t%0, $2"
1131 : "=r" (res)
1132 : "r" (s), "r" (n)
1133 : "$2", "$4", "$5", __UA_t0, "$31");
1134
1135 return res;
1136 }
1137
1138 struct exception_table_entry
1139 {
1140 unsigned long insn;
1141 unsigned long nextinsn;
1142 };
1143
1144 extern int fixup_exception(struct pt_regs *regs);
1145
1146 #endif /* _ASM_UACCESS_H */
Linux kernel - Deliverables
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