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MIPS: Make uaccess.h slightly more sparse friendly.
[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 unsigned long __addr = (unsigned long) (addr); \
110 unsigned long __size = size; \
111 unsigned long __mask = mask; \
112 unsigned long __ok; \
113 \
114 __chk_user_ptr(addr); \
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 __chk_user_ptr(ptr); \
239 __get_user_common((x), size, ptr); \
240 __gu_err; \
241 })
242
243 #define __get_user_check(x, ptr, size) \
244 ({ \
245 int __gu_err = -EFAULT; \
246 const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
247 \
248 if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \
249 __get_user_common((x), size, __gu_ptr); \
250 \
251 __gu_err; \
252 })
253
254 #define __get_user_asm(val, insn, addr) \
255 { \
256 long __gu_tmp; \
257 \
258 __asm__ __volatile__( \
259 "1: " insn " %1, %3 \n" \
260 "2: \n" \
261 " .section .fixup,\"ax\" \n" \
262 "3: li %0, %4 \n" \
263 " j 2b \n" \
264 " .previous \n" \
265 " .section __ex_table,\"a\" \n" \
266 " "__UA_ADDR "\t1b, 3b \n" \
267 " .previous \n" \
268 : "=r" (__gu_err), "=r" (__gu_tmp) \
269 : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
270 \
271 (val) = (__typeof__(*(addr))) __gu_tmp; \
272 }
273
274 /*
275 * Get a long long 64 using 32 bit registers.
276 */
277 #define __get_user_asm_ll32(val, addr) \
278 { \
279 union { \
280 unsigned long long l; \
281 __typeof__(*(addr)) t; \
282 } __gu_tmp; \
283 \
284 __asm__ __volatile__( \
285 "1: lw %1, (%3) \n" \
286 "2: lw %D1, 4(%3) \n" \
287 "3: .section .fixup,\"ax\" \n" \
288 "4: li %0, %4 \n" \
289 " move %1, $0 \n" \
290 " move %D1, $0 \n" \
291 " j 3b \n" \
292 " .previous \n" \
293 " .section __ex_table,\"a\" \n" \
294 " " __UA_ADDR " 1b, 4b \n" \
295 " " __UA_ADDR " 2b, 4b \n" \
296 " .previous \n" \
297 : "=r" (__gu_err), "=&r" (__gu_tmp.l) \
298 : "0" (0), "r" (addr), "i" (-EFAULT)); \
299 \
300 (val) = __gu_tmp.t; \
301 }
302
303 /*
304 * Yuck. We need two variants, one for 64bit operation and one
305 * for 32 bit mode and old iron.
306 */
307 #ifdef CONFIG_32BIT
308 #define __PUT_USER_DW(ptr) __put_user_asm_ll32(ptr)
309 #endif
310 #ifdef CONFIG_64BIT
311 #define __PUT_USER_DW(ptr) __put_user_asm("sd", ptr)
312 #endif
313
314 #define __put_user_nocheck(x, ptr, size) \
315 ({ \
316 __typeof__(*(ptr)) __pu_val; \
317 int __pu_err = 0; \
318 \
319 __chk_user_ptr(ptr); \
320 __pu_val = (x); \
321 switch (size) { \
322 case 1: __put_user_asm("sb", ptr); break; \
323 case 2: __put_user_asm("sh", ptr); break; \
324 case 4: __put_user_asm("sw", ptr); break; \
325 case 8: __PUT_USER_DW(ptr); break; \
326 default: __put_user_unknown(); break; \
327 } \
328 __pu_err; \
329 })
330
331 #define __put_user_check(x, ptr, size) \
332 ({ \
333 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
334 __typeof__(*(ptr)) __pu_val = (x); \
335 int __pu_err = -EFAULT; \
336 \
337 if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
338 switch (size) { \
339 case 1: __put_user_asm("sb", __pu_addr); break; \
340 case 2: __put_user_asm("sh", __pu_addr); break; \
341 case 4: __put_user_asm("sw", __pu_addr); break; \
342 case 8: __PUT_USER_DW(__pu_addr); break; \
343 default: __put_user_unknown(); break; \
344 } \
345 } \
346 __pu_err; \
347 })
348
349 #define __put_user_asm(insn, ptr) \
350 { \
351 __asm__ __volatile__( \
352 "1: " insn " %z2, %3 # __put_user_asm\n" \
353 "2: \n" \
354 " .section .fixup,\"ax\" \n" \
355 "3: li %0, %4 \n" \
356 " j 2b \n" \
357 " .previous \n" \
358 " .section __ex_table,\"a\" \n" \
359 " " __UA_ADDR " 1b, 3b \n" \
360 " .previous \n" \
361 : "=r" (__pu_err) \
362 : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
363 "i" (-EFAULT)); \
364 }
365
366 #define __put_user_asm_ll32(ptr) \
367 { \
368 __asm__ __volatile__( \
369 "1: sw %2, (%3) # __put_user_asm_ll32 \n" \
370 "2: sw %D2, 4(%3) \n" \
371 "3: \n" \
372 " .section .fixup,\"ax\" \n" \
373 "4: li %0, %4 \n" \
374 " j 3b \n" \
375 " .previous \n" \
376 " .section __ex_table,\"a\" \n" \
377 " " __UA_ADDR " 1b, 4b \n" \
378 " " __UA_ADDR " 2b, 4b \n" \
379 " .previous" \
380 : "=r" (__pu_err) \
381 : "0" (0), "r" (__pu_val), "r" (ptr), \
382 "i" (-EFAULT)); \
383 }
384
385 extern void __put_user_unknown(void);
386
387 /*
388 * put_user_unaligned: - Write a simple value into user space.
389 * @x: Value to copy to user space.
390 * @ptr: Destination address, in user space.
391 *
392 * Context: User context only. This function may sleep.
393 *
394 * This macro copies a single simple value from kernel space to user
395 * space. It supports simple types like char and int, but not larger
396 * data types like structures or arrays.
397 *
398 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
399 * to the result of dereferencing @ptr.
400 *
401 * Returns zero on success, or -EFAULT on error.
402 */
403 #define put_user_unaligned(x,ptr) \
404 __put_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
405
406 /*
407 * get_user_unaligned: - Get a simple variable from user space.
408 * @x: Variable to store result.
409 * @ptr: Source address, in user space.
410 *
411 * Context: User context only. This function may sleep.
412 *
413 * This macro copies a single simple variable from user space to kernel
414 * space. It supports simple types like char and int, but not larger
415 * data types like structures or arrays.
416 *
417 * @ptr must have pointer-to-simple-variable type, and the result of
418 * dereferencing @ptr must be assignable to @x without a cast.
419 *
420 * Returns zero on success, or -EFAULT on error.
421 * On error, the variable @x is set to zero.
422 */
423 #define get_user_unaligned(x,ptr) \
424 __get_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
425
426 /*
427 * __put_user_unaligned: - Write a simple value into user space, with less checking.
428 * @x: Value to copy to user space.
429 * @ptr: Destination address, in user space.
430 *
431 * Context: User context only. This function may sleep.
432 *
433 * This macro copies a single simple value from kernel space to user
434 * space. It supports simple types like char and int, but not larger
435 * data types like structures or arrays.
436 *
437 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
438 * to the result of dereferencing @ptr.
439 *
440 * Caller must check the pointer with access_ok() before calling this
441 * function.
442 *
443 * Returns zero on success, or -EFAULT on error.
444 */
445 #define __put_user_unaligned(x,ptr) \
446 __put_user_unaligned_nocheck((x),(ptr),sizeof(*(ptr)))
447
448 /*
449 * __get_user_unaligned: - Get a simple variable from user space, with less checking.
450 * @x: Variable to store result.
451 * @ptr: Source address, in user space.
452 *
453 * Context: User context only. This function may sleep.
454 *
455 * This macro copies a single simple variable from user space to kernel
456 * space. It supports simple types like char and int, but not larger
457 * data types like structures or arrays.
458 *
459 * @ptr must have pointer-to-simple-variable type, and the result of
460 * dereferencing @ptr must be assignable to @x without a cast.
461 *
462 * Caller must check the pointer with access_ok() before calling this
463 * function.
464 *
465 * Returns zero on success, or -EFAULT on error.
466 * On error, the variable @x is set to zero.
467 */
468 #define __get_user_unaligned(x,ptr) \
469 __get_user__unalignednocheck((x),(ptr),sizeof(*(ptr)))
470
471 /*
472 * Yuck. We need two variants, one for 64bit operation and one
473 * for 32 bit mode and old iron.
474 */
475 #ifdef CONFIG_32BIT
476 #define __GET_USER_UNALIGNED_DW(val, ptr) \
477 __get_user_unaligned_asm_ll32(val, ptr)
478 #endif
479 #ifdef CONFIG_64BIT
480 #define __GET_USER_UNALIGNED_DW(val, ptr) \
481 __get_user_unaligned_asm(val, "uld", ptr)
482 #endif
483
484 extern void __get_user_unaligned_unknown(void);
485
486 #define __get_user_unaligned_common(val, size, ptr) \
487 do { \
488 switch (size) { \
489 case 1: __get_user_asm(val, "lb", ptr); break; \
490 case 2: __get_user_unaligned_asm(val, "ulh", ptr); break; \
491 case 4: __get_user_unaligned_asm(val, "ulw", ptr); break; \
492 case 8: __GET_USER_UNALIGNED_DW(val, ptr); break; \
493 default: __get_user_unaligned_unknown(); break; \
494 } \
495 } while (0)
496
497 #define __get_user_unaligned_nocheck(x,ptr,size) \
498 ({ \
499 int __gu_err; \
500 \
501 __get_user_unaligned_common((x), size, ptr); \
502 __gu_err; \
503 })
504
505 #define __get_user_unaligned_check(x,ptr,size) \
506 ({ \
507 int __gu_err = -EFAULT; \
508 const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
509 \
510 if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \
511 __get_user_unaligned_common((x), size, __gu_ptr); \
512 \
513 __gu_err; \
514 })
515
516 #define __get_user_unaligned_asm(val, insn, addr) \
517 { \
518 long __gu_tmp; \
519 \
520 __asm__ __volatile__( \
521 "1: " insn " %1, %3 \n" \
522 "2: \n" \
523 " .section .fixup,\"ax\" \n" \
524 "3: li %0, %4 \n" \
525 " j 2b \n" \
526 " .previous \n" \
527 " .section __ex_table,\"a\" \n" \
528 " "__UA_ADDR "\t1b, 3b \n" \
529 " "__UA_ADDR "\t1b + 4, 3b \n" \
530 " .previous \n" \
531 : "=r" (__gu_err), "=r" (__gu_tmp) \
532 : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
533 \
534 (val) = (__typeof__(*(addr))) __gu_tmp; \
535 }
536
537 /*
538 * Get a long long 64 using 32 bit registers.
539 */
540 #define __get_user_unaligned_asm_ll32(val, addr) \
541 { \
542 unsigned long long __gu_tmp; \
543 \
544 __asm__ __volatile__( \
545 "1: ulw %1, (%3) \n" \
546 "2: ulw %D1, 4(%3) \n" \
547 " move %0, $0 \n" \
548 "3: .section .fixup,\"ax\" \n" \
549 "4: li %0, %4 \n" \
550 " move %1, $0 \n" \
551 " move %D1, $0 \n" \
552 " j 3b \n" \
553 " .previous \n" \
554 " .section __ex_table,\"a\" \n" \
555 " " __UA_ADDR " 1b, 4b \n" \
556 " " __UA_ADDR " 1b + 4, 4b \n" \
557 " " __UA_ADDR " 2b, 4b \n" \
558 " " __UA_ADDR " 2b + 4, 4b \n" \
559 " .previous \n" \
560 : "=r" (__gu_err), "=&r" (__gu_tmp) \
561 : "0" (0), "r" (addr), "i" (-EFAULT)); \
562 (val) = (__typeof__(*(addr))) __gu_tmp; \
563 }
564
565 /*
566 * Yuck. We need two variants, one for 64bit operation and one
567 * for 32 bit mode and old iron.
568 */
569 #ifdef CONFIG_32BIT
570 #define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm_ll32(ptr)
571 #endif
572 #ifdef CONFIG_64BIT
573 #define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm("usd", ptr)
574 #endif
575
576 #define __put_user_unaligned_nocheck(x,ptr,size) \
577 ({ \
578 __typeof__(*(ptr)) __pu_val; \
579 int __pu_err = 0; \
580 \
581 __pu_val = (x); \
582 switch (size) { \
583 case 1: __put_user_asm("sb", ptr); break; \
584 case 2: __put_user_unaligned_asm("ush", ptr); break; \
585 case 4: __put_user_unaligned_asm("usw", ptr); break; \
586 case 8: __PUT_USER_UNALIGNED_DW(ptr); break; \
587 default: __put_user_unaligned_unknown(); break; \
588 } \
589 __pu_err; \
590 })
591
592 #define __put_user_unaligned_check(x,ptr,size) \
593 ({ \
594 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
595 __typeof__(*(ptr)) __pu_val = (x); \
596 int __pu_err = -EFAULT; \
597 \
598 if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
599 switch (size) { \
600 case 1: __put_user_asm("sb", __pu_addr); break; \
601 case 2: __put_user_unaligned_asm("ush", __pu_addr); break; \
602 case 4: __put_user_unaligned_asm("usw", __pu_addr); break; \
603 case 8: __PUT_USER_UNALGINED_DW(__pu_addr); break; \
604 default: __put_user_unaligned_unknown(); break; \
605 } \
606 } \
607 __pu_err; \
608 })
609
610 #define __put_user_unaligned_asm(insn, ptr) \
611 { \
612 __asm__ __volatile__( \
613 "1: " insn " %z2, %3 # __put_user_unaligned_asm\n" \
614 "2: \n" \
615 " .section .fixup,\"ax\" \n" \
616 "3: li %0, %4 \n" \
617 " j 2b \n" \
618 " .previous \n" \
619 " .section __ex_table,\"a\" \n" \
620 " " __UA_ADDR " 1b, 3b \n" \
621 " .previous \n" \
622 : "=r" (__pu_err) \
623 : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
624 "i" (-EFAULT)); \
625 }
626
627 #define __put_user_unaligned_asm_ll32(ptr) \
628 { \
629 __asm__ __volatile__( \
630 "1: sw %2, (%3) # __put_user_unaligned_asm_ll32 \n" \
631 "2: sw %D2, 4(%3) \n" \
632 "3: \n" \
633 " .section .fixup,\"ax\" \n" \
634 "4: li %0, %4 \n" \
635 " j 3b \n" \
636 " .previous \n" \
637 " .section __ex_table,\"a\" \n" \
638 " " __UA_ADDR " 1b, 4b \n" \
639 " " __UA_ADDR " 1b + 4, 4b \n" \
640 " " __UA_ADDR " 2b, 4b \n" \
641 " " __UA_ADDR " 2b + 4, 4b \n" \
642 " .previous" \
643 : "=r" (__pu_err) \
644 : "0" (0), "r" (__pu_val), "r" (ptr), \
645 "i" (-EFAULT)); \
646 }
647
648 extern void __put_user_unaligned_unknown(void);
649
650 /*
651 * We're generating jump to subroutines which will be outside the range of
652 * jump instructions
653 */
654 #ifdef MODULE
655 #define __MODULE_JAL(destination) \
656 ".set\tnoat\n\t" \
657 __UA_LA "\t$1, " #destination "\n\t" \
658 "jalr\t$1\n\t" \
659 ".set\tat\n\t"
660 #else
661 #define __MODULE_JAL(destination) \
662 "jal\t" #destination "\n\t"
663 #endif
664
665 #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
666 #define DADDI_SCRATCH "$0"
667 #else
668 #define DADDI_SCRATCH "$3"
669 #endif
670
671 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
672
673 #define __invoke_copy_to_user(to, from, n) \
674 ({ \
675 register void __user *__cu_to_r __asm__("$4"); \
676 register const void *__cu_from_r __asm__("$5"); \
677 register long __cu_len_r __asm__("$6"); \
678 \
679 __cu_to_r = (to); \
680 __cu_from_r = (from); \
681 __cu_len_r = (n); \
682 __asm__ __volatile__( \
683 __MODULE_JAL(__copy_user) \
684 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
685 : \
686 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
687 DADDI_SCRATCH, "memory"); \
688 __cu_len_r; \
689 })
690
691 /*
692 * __copy_to_user: - Copy a block of data into user space, with less checking.
693 * @to: Destination address, in user space.
694 * @from: Source address, in kernel space.
695 * @n: Number of bytes to copy.
696 *
697 * Context: User context only. This function may sleep.
698 *
699 * Copy data from kernel space to user space. Caller must check
700 * the specified block with access_ok() before calling this function.
701 *
702 * Returns number of bytes that could not be copied.
703 * On success, this will be zero.
704 */
705 #define __copy_to_user(to, from, n) \
706 ({ \
707 void __user *__cu_to; \
708 const void *__cu_from; \
709 long __cu_len; \
710 \
711 might_sleep(); \
712 __cu_to = (to); \
713 __cu_from = (from); \
714 __cu_len = (n); \
715 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
716 __cu_len; \
717 })
718
719 extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
720
721 #define __copy_to_user_inatomic(to, from, n) \
722 ({ \
723 void __user *__cu_to; \
724 const void *__cu_from; \
725 long __cu_len; \
726 \
727 __cu_to = (to); \
728 __cu_from = (from); \
729 __cu_len = (n); \
730 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
731 __cu_len; \
732 })
733
734 #define __copy_from_user_inatomic(to, from, n) \
735 ({ \
736 void *__cu_to; \
737 const void __user *__cu_from; \
738 long __cu_len; \
739 \
740 __cu_to = (to); \
741 __cu_from = (from); \
742 __cu_len = (n); \
743 __cu_len = __invoke_copy_from_user_inatomic(__cu_to, __cu_from, \
744 __cu_len); \
745 __cu_len; \
746 })
747
748 /*
749 * copy_to_user: - Copy a block of data into user space.
750 * @to: Destination address, in user space.
751 * @from: Source address, in kernel space.
752 * @n: Number of bytes to copy.
753 *
754 * Context: User context only. This function may sleep.
755 *
756 * Copy data from kernel space to user space.
757 *
758 * Returns number of bytes that could not be copied.
759 * On success, this will be zero.
760 */
761 #define copy_to_user(to, from, n) \
762 ({ \
763 void __user *__cu_to; \
764 const void *__cu_from; \
765 long __cu_len; \
766 \
767 might_sleep(); \
768 __cu_to = (to); \
769 __cu_from = (from); \
770 __cu_len = (n); \
771 if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) \
772 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, \
773 __cu_len); \
774 __cu_len; \
775 })
776
777 #define __invoke_copy_from_user(to, from, n) \
778 ({ \
779 register void *__cu_to_r __asm__("$4"); \
780 register const void __user *__cu_from_r __asm__("$5"); \
781 register long __cu_len_r __asm__("$6"); \
782 \
783 __cu_to_r = (to); \
784 __cu_from_r = (from); \
785 __cu_len_r = (n); \
786 __asm__ __volatile__( \
787 ".set\tnoreorder\n\t" \
788 __MODULE_JAL(__copy_user) \
789 ".set\tnoat\n\t" \
790 __UA_ADDU "\t$1, %1, %2\n\t" \
791 ".set\tat\n\t" \
792 ".set\treorder" \
793 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
794 : \
795 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
796 DADDI_SCRATCH, "memory"); \
797 __cu_len_r; \
798 })
799
800 #define __invoke_copy_from_user_inatomic(to, from, n) \
801 ({ \
802 register void *__cu_to_r __asm__("$4"); \
803 register const void __user *__cu_from_r __asm__("$5"); \
804 register long __cu_len_r __asm__("$6"); \
805 \
806 __cu_to_r = (to); \
807 __cu_from_r = (from); \
808 __cu_len_r = (n); \
809 __asm__ __volatile__( \
810 ".set\tnoreorder\n\t" \
811 __MODULE_JAL(__copy_user_inatomic) \
812 ".set\tnoat\n\t" \
813 __UA_ADDU "\t$1, %1, %2\n\t" \
814 ".set\tat\n\t" \
815 ".set\treorder" \
816 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
817 : \
818 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
819 DADDI_SCRATCH, "memory"); \
820 __cu_len_r; \
821 })
822
823 /*
824 * __copy_from_user: - Copy a block of data from user space, with less checking.
825 * @to: Destination address, in kernel space.
826 * @from: Source address, in user space.
827 * @n: Number of bytes to copy.
828 *
829 * Context: User context only. This function may sleep.
830 *
831 * Copy data from user space to kernel space. Caller must check
832 * the specified block with access_ok() before calling this function.
833 *
834 * Returns number of bytes that could not be copied.
835 * On success, this will be zero.
836 *
837 * If some data could not be copied, this function will pad the copied
838 * data to the requested size using zero bytes.
839 */
840 #define __copy_from_user(to, from, n) \
841 ({ \
842 void *__cu_to; \
843 const void __user *__cu_from; \
844 long __cu_len; \
845 \
846 might_sleep(); \
847 __cu_to = (to); \
848 __cu_from = (from); \
849 __cu_len = (n); \
850 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
851 __cu_len); \
852 __cu_len; \
853 })
854
855 /*
856 * copy_from_user: - Copy a block of data from user space.
857 * @to: Destination address, in kernel space.
858 * @from: Source address, in user space.
859 * @n: Number of bytes to copy.
860 *
861 * Context: User context only. This function may sleep.
862 *
863 * Copy data from user space to kernel space.
864 *
865 * Returns number of bytes that could not be copied.
866 * On success, this will be zero.
867 *
868 * If some data could not be copied, this function will pad the copied
869 * data to the requested size using zero bytes.
870 */
871 #define copy_from_user(to, from, n) \
872 ({ \
873 void *__cu_to; \
874 const void __user *__cu_from; \
875 long __cu_len; \
876 \
877 might_sleep(); \
878 __cu_to = (to); \
879 __cu_from = (from); \
880 __cu_len = (n); \
881 if (access_ok(VERIFY_READ, __cu_from, __cu_len)) \
882 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
883 __cu_len); \
884 __cu_len; \
885 })
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 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
898 __cu_len); \
899 __cu_len; \
900 })
901
902 #define copy_in_user(to, from, n) \
903 ({ \
904 void __user *__cu_to; \
905 const void __user *__cu_from; \
906 long __cu_len; \
907 \
908 might_sleep(); \
909 __cu_to = (to); \
910 __cu_from = (from); \
911 __cu_len = (n); \
912 if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) && \
913 access_ok(VERIFY_WRITE, __cu_to, __cu_len))) \
914 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
915 __cu_len); \
916 __cu_len; \
917 })
918
919 /*
920 * __clear_user: - Zero a block of memory in user space, with less checking.
921 * @to: Destination address, in user space.
922 * @n: Number of bytes to zero.
923 *
924 * Zero a block of memory in user space. Caller must check
925 * the specified block with access_ok() before calling this function.
926 *
927 * Returns number of bytes that could not be cleared.
928 * On success, this will be zero.
929 */
930 static inline __kernel_size_t
931 __clear_user(void __user *addr, __kernel_size_t size)
932 {
933 __kernel_size_t res;
934
935 might_sleep();
936 __asm__ __volatile__(
937 "move\t$4, %1\n\t"
938 "move\t$5, $0\n\t"
939 "move\t$6, %2\n\t"
940 __MODULE_JAL(__bzero)
941 "move\t%0, $6"
942 : "=r" (res)
943 : "r" (addr), "r" (size)
944 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
945
946 return res;
947 }
948
949 #define clear_user(addr,n) \
950 ({ \
951 void __user * __cl_addr = (addr); \
952 unsigned long __cl_size = (n); \
953 if (__cl_size && access_ok(VERIFY_WRITE, \
954 ((unsigned long)(__cl_addr)), __cl_size)) \
955 __cl_size = __clear_user(__cl_addr, __cl_size); \
956 __cl_size; \
957 })
958
959 /*
960 * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
961 * @dst: Destination address, in kernel space. This buffer must be at
962 * least @count bytes long.
963 * @src: Source address, in user space.
964 * @count: Maximum number of bytes to copy, including the trailing NUL.
965 *
966 * Copies a NUL-terminated string from userspace to kernel space.
967 * Caller must check the specified block with access_ok() before calling
968 * this function.
969 *
970 * On success, returns the length of the string (not including the trailing
971 * NUL).
972 *
973 * If access to userspace fails, returns -EFAULT (some data may have been
974 * copied).
975 *
976 * If @count is smaller than the length of the string, copies @count bytes
977 * and returns @count.
978 */
979 static inline long
980 __strncpy_from_user(char *__to, const char __user *__from, long __len)
981 {
982 long res;
983
984 might_sleep();
985 __asm__ __volatile__(
986 "move\t$4, %1\n\t"
987 "move\t$5, %2\n\t"
988 "move\t$6, %3\n\t"
989 __MODULE_JAL(__strncpy_from_user_nocheck_asm)
990 "move\t%0, $2"
991 : "=r" (res)
992 : "r" (__to), "r" (__from), "r" (__len)
993 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
994
995 return res;
996 }
997
998 /*
999 * strncpy_from_user: - Copy a NUL terminated string from userspace.
1000 * @dst: Destination address, in kernel space. This buffer must be at
1001 * least @count bytes long.
1002 * @src: Source address, in user space.
1003 * @count: Maximum number of bytes to copy, including the trailing NUL.
1004 *
1005 * Copies a NUL-terminated string from userspace to kernel space.
1006 *
1007 * On success, returns the length of the string (not including the trailing
1008 * NUL).
1009 *
1010 * If access to userspace fails, returns -EFAULT (some data may have been
1011 * copied).
1012 *
1013 * If @count is smaller than the length of the string, copies @count bytes
1014 * and returns @count.
1015 */
1016 static inline long
1017 strncpy_from_user(char *__to, const char __user *__from, long __len)
1018 {
1019 long res;
1020
1021 might_sleep();
1022 __asm__ __volatile__(
1023 "move\t$4, %1\n\t"
1024 "move\t$5, %2\n\t"
1025 "move\t$6, %3\n\t"
1026 __MODULE_JAL(__strncpy_from_user_asm)
1027 "move\t%0, $2"
1028 : "=r" (res)
1029 : "r" (__to), "r" (__from), "r" (__len)
1030 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1031
1032 return res;
1033 }
1034
1035 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
1036 static inline long __strlen_user(const char __user *s)
1037 {
1038 long res;
1039
1040 might_sleep();
1041 __asm__ __volatile__(
1042 "move\t$4, %1\n\t"
1043 __MODULE_JAL(__strlen_user_nocheck_asm)
1044 "move\t%0, $2"
1045 : "=r" (res)
1046 : "r" (s)
1047 : "$2", "$4", __UA_t0, "$31");
1048
1049 return res;
1050 }
1051
1052 /*
1053 * strlen_user: - Get the size of a string in user space.
1054 * @str: The string to measure.
1055 *
1056 * Context: User context only. This function may sleep.
1057 *
1058 * Get the size of a NUL-terminated string in user space.
1059 *
1060 * Returns the size of the string INCLUDING the terminating NUL.
1061 * On exception, returns 0.
1062 *
1063 * If there is a limit on the length of a valid string, you may wish to
1064 * consider using strnlen_user() instead.
1065 */
1066 static inline long strlen_user(const char __user *s)
1067 {
1068 long res;
1069
1070 might_sleep();
1071 __asm__ __volatile__(
1072 "move\t$4, %1\n\t"
1073 __MODULE_JAL(__strlen_user_asm)
1074 "move\t%0, $2"
1075 : "=r" (res)
1076 : "r" (s)
1077 : "$2", "$4", __UA_t0, "$31");
1078
1079 return res;
1080 }
1081
1082 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
1083 static inline long __strnlen_user(const char __user *s, long n)
1084 {
1085 long res;
1086
1087 might_sleep();
1088 __asm__ __volatile__(
1089 "move\t$4, %1\n\t"
1090 "move\t$5, %2\n\t"
1091 __MODULE_JAL(__strnlen_user_nocheck_asm)
1092 "move\t%0, $2"
1093 : "=r" (res)
1094 : "r" (s), "r" (n)
1095 : "$2", "$4", "$5", __UA_t0, "$31");
1096
1097 return res;
1098 }
1099
1100 /*
1101 * strlen_user: - Get the size of a string in user space.
1102 * @str: The string to measure.
1103 *
1104 * Context: User context only. This function may sleep.
1105 *
1106 * Get the size of a NUL-terminated string in user space.
1107 *
1108 * Returns the size of the string INCLUDING the terminating NUL.
1109 * On exception, returns 0.
1110 *
1111 * If there is a limit on the length of a valid string, you may wish to
1112 * consider using strnlen_user() instead.
1113 */
1114 static inline long strnlen_user(const char __user *s, long n)
1115 {
1116 long res;
1117
1118 might_sleep();
1119 __asm__ __volatile__(
1120 "move\t$4, %1\n\t"
1121 "move\t$5, %2\n\t"
1122 __MODULE_JAL(__strnlen_user_asm)
1123 "move\t%0, $2"
1124 : "=r" (res)
1125 : "r" (s), "r" (n)
1126 : "$2", "$4", "$5", __UA_t0, "$31");
1127
1128 return res;
1129 }
1130
1131 struct exception_table_entry
1132 {
1133 unsigned long insn;
1134 unsigned long nextinsn;
1135 };
1136
1137 extern int fixup_exception(struct pt_regs *regs);
1138
1139 #endif /* _ASM_UACCESS_H */
Linux kernel - Deliverables
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