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