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allow coexistance of N build and AC build.
[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / include / asm-mips / uaccess.h
blobb9f74f6bbcaabf49cf1e30600abc8d86cfd3e45e
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 */
9 #ifndef _ASM_UACCESS_H
10 #define _ASM_UACCESS_H
11
12 #include <linux/kernel.h>
13 #include <linux/errno.h>
14 #include <linux/thread_info.h>
15 #include <asm-generic/uaccess.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 * We're generating jump to subroutines which will be outside the range of
387 * jump instructions
388 */
389 #ifdef MODULE
390 #define __MODULE_JAL(destination) \
391 ".set\tnoat\n\t" \
392 __UA_LA "\t$1, " #destination "\n\t" \
393 "jalr\t$1\n\t" \
394 ".set\tat\n\t"
395 #else
396 #define __MODULE_JAL(destination) \
397 "jal\t" #destination "\n\t"
398 #endif
399
400 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
401
402 #define __invoke_copy_to_user(to,from,n) \
403 ({ \
404 register void __user *__cu_to_r __asm__ ("$4"); \
405 register const void *__cu_from_r __asm__ ("$5"); \
406 register long __cu_len_r __asm__ ("$6"); \
407 \
408 __cu_to_r = (to); \
409 __cu_from_r = (from); \
410 __cu_len_r = (n); \
411 __asm__ __volatile__( \
412 __MODULE_JAL(__copy_user) \
413 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
414 : \
415 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
416 "memory"); \
417 __cu_len_r; \
418 })
419
420 /*
421 * __copy_to_user: - Copy a block of data into user space, with less checking.
422 * @to: Destination address, in user space.
423 * @from: Source address, in kernel space.
424 * @n: Number of bytes to copy.
425 *
426 * Context: User context only. This function may sleep.
427 *
428 * Copy data from kernel space to user space. Caller must check
429 * the specified block with access_ok() before calling this function.
430 *
431 * Returns number of bytes that could not be copied.
432 * On success, this will be zero.
433 */
434 #define __copy_to_user(to,from,n) \
435 ({ \
436 void __user *__cu_to; \
437 const void *__cu_from; \
438 long __cu_len; \
439 \
440 might_sleep(); \
441 __cu_to = (to); \
442 __cu_from = (from); \
443 __cu_len = (n); \
444 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
445 __cu_len; \
446 })
447
448 extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
449
450 #define __copy_to_user_inatomic(to,from,n) \
451 ({ \
452 void __user *__cu_to; \
453 const void *__cu_from; \
454 long __cu_len; \
455 \
456 __cu_to = (to); \
457 __cu_from = (from); \
458 __cu_len = (n); \
459 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
460 __cu_len; \
461 })
462
463 #define __copy_from_user_inatomic(to,from,n) \
464 ({ \
465 void *__cu_to; \
466 const void __user *__cu_from; \
467 long __cu_len; \
468 \
469 __cu_to = (to); \
470 __cu_from = (from); \
471 __cu_len = (n); \
472 __cu_len = __invoke_copy_from_user_inatomic(__cu_to, __cu_from, \
473 __cu_len); \
474 __cu_len; \
475 })
476
477 /*
478 * copy_to_user: - Copy a block of data into user space.
479 * @to: Destination address, in user space.
480 * @from: Source address, in kernel space.
481 * @n: Number of bytes to copy.
482 *
483 * Context: User context only. This function may sleep.
484 *
485 * Copy data from kernel space to user space.
486 *
487 * Returns number of bytes that could not be copied.
488 * On success, this will be zero.
489 */
490 #define copy_to_user(to,from,n) \
491 ({ \
492 void __user *__cu_to; \
493 const void *__cu_from; \
494 long __cu_len; \
495 \
496 might_sleep(); \
497 __cu_to = (to); \
498 __cu_from = (from); \
499 __cu_len = (n); \
500 if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) \
501 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, \
502 __cu_len); \
503 __cu_len; \
504 })
505
506 #define __invoke_copy_from_user(to,from,n) \
507 ({ \
508 register void *__cu_to_r __asm__ ("$4"); \
509 register const void __user *__cu_from_r __asm__ ("$5"); \
510 register long __cu_len_r __asm__ ("$6"); \
511 \
512 __cu_to_r = (to); \
513 __cu_from_r = (from); \
514 __cu_len_r = (n); \
515 __asm__ __volatile__( \
516 ".set\tnoreorder\n\t" \
517 __MODULE_JAL(__copy_user) \
518 ".set\tnoat\n\t" \
519 __UA_ADDU "\t$1, %1, %2\n\t" \
520 ".set\tat\n\t" \
521 ".set\treorder" \
522 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
523 : \
524 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
525 "memory"); \
526 __cu_len_r; \
527 })
528
529 #define __invoke_copy_from_user_inatomic(to,from,n) \
530 ({ \
531 register void *__cu_to_r __asm__ ("$4"); \
532 register const void __user *__cu_from_r __asm__ ("$5"); \
533 register long __cu_len_r __asm__ ("$6"); \
534 \
535 __cu_to_r = (to); \
536 __cu_from_r = (from); \
537 __cu_len_r = (n); \
538 __asm__ __volatile__( \
539 ".set\tnoreorder\n\t" \
540 __MODULE_JAL(__copy_user_inatomic) \
541 ".set\tnoat\n\t" \
542 __UA_ADDU "\t$1, %1, %2\n\t" \
543 ".set\tat\n\t" \
544 ".set\treorder" \
545 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
546 : \
547 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
548 "memory"); \
549 __cu_len_r; \
550 })
551
552 /*
553 * __copy_from_user: - Copy a block of data from user space, with less checking.
554 * @to: Destination address, in kernel space.
555 * @from: Source address, in user space.
556 * @n: Number of bytes to copy.
557 *
558 * Context: User context only. This function may sleep.
559 *
560 * Copy data from user space to kernel space. Caller must check
561 * the specified block with access_ok() before calling this function.
562 *
563 * Returns number of bytes that could not be copied.
564 * On success, this will be zero.
565 *
566 * If some data could not be copied, this function will pad the copied
567 * data to the requested size using zero bytes.
568 */
569 #define __copy_from_user(to,from,n) \
570 ({ \
571 void *__cu_to; \
572 const void __user *__cu_from; \
573 long __cu_len; \
574 \
575 might_sleep(); \
576 __cu_to = (to); \
577 __cu_from = (from); \
578 __cu_len = (n); \
579 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
580 __cu_len); \
581 __cu_len; \
582 })
583
584 /*
585 * copy_from_user: - Copy a block of data from user space.
586 * @to: Destination address, in kernel space.
587 * @from: Source address, in user space.
588 * @n: Number of bytes to copy.
589 *
590 * Context: User context only. This function may sleep.
591 *
592 * Copy data from user space to kernel space.
593 *
594 * Returns number of bytes that could not be copied.
595 * On success, this will be zero.
596 *
597 * If some data could not be copied, this function will pad the copied
598 * data to the requested size using zero bytes.
599 */
600 #define copy_from_user(to,from,n) \
601 ({ \
602 void *__cu_to; \
603 const void __user *__cu_from; \
604 long __cu_len; \
605 \
606 might_sleep(); \
607 __cu_to = (to); \
608 __cu_from = (from); \
609 __cu_len = (n); \
610 if (access_ok(VERIFY_READ, __cu_from, __cu_len)) \
611 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
612 __cu_len); \
613 __cu_len; \
614 })
615
616 #define __copy_in_user(to, from, n) __copy_from_user(to, from, n)
617
618 #define copy_in_user(to,from,n) \
619 ({ \
620 void __user *__cu_to; \
621 const void __user *__cu_from; \
622 long __cu_len; \
623 \
624 might_sleep(); \
625 __cu_to = (to); \
626 __cu_from = (from); \
627 __cu_len = (n); \
628 if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) && \
629 access_ok(VERIFY_WRITE, __cu_to, __cu_len))) \
630 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
631 __cu_len); \
632 __cu_len; \
633 })
634
635 /*
636 * __clear_user: - Zero a block of memory in user space, with less checking.
637 * @to: Destination address, in user space.
638 * @n: Number of bytes to zero.
639 *
640 * Zero a block of memory in user space. Caller must check
641 * the specified block with access_ok() before calling this function.
642 *
643 * Returns number of bytes that could not be cleared.
644 * On success, this will be zero.
645 */
646 static inline __kernel_size_t
647 __clear_user(void __user *addr, __kernel_size_t size)
648 {
649 __kernel_size_t res;
650
651 might_sleep();
652 __asm__ __volatile__(
653 "move\t$4, %1\n\t"
654 "move\t$5, $0\n\t"
655 "move\t$6, %2\n\t"
656 __MODULE_JAL(__bzero)
657 "move\t%0, $6"
658 : "=r" (res)
659 : "r" (addr), "r" (size)
660 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
661
662 return res;
663 }
664
665 static inline unsigned long
666 clear_user(void __user *to, unsigned long n)
667 {
668 if (!access_ok(VERIFY_WRITE, to, n))
669 return n;
670
671 return __clear_user(to, n);
672 }
673
674 /*
675 * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
676 * @dst: Destination address, in kernel space. This buffer must be at
677 * least @count bytes long.
678 * @src: Source address, in user space.
679 * @count: Maximum number of bytes to copy, including the trailing NUL.
680 *
681 * Copies a NUL-terminated string from userspace to kernel space.
682 * Caller must check the specified block with access_ok() before calling
683 * this function.
684 *
685 * On success, returns the length of the string (not including the trailing
686 * NUL).
687 *
688 * If access to userspace fails, returns -EFAULT (some data may have been
689 * copied).
690 *
691 * If @count is smaller than the length of the string, copies @count bytes
692 * and returns @count.
693 */
694 static inline long
695 __strncpy_from_user(char *__to, const char __user *__from, long __len)
696 {
697 long res;
698
699 might_sleep();
700 __asm__ __volatile__(
701 "move\t$4, %1\n\t"
702 "move\t$5, %2\n\t"
703 "move\t$6, %3\n\t"
704 __MODULE_JAL(__strncpy_from_user_nocheck_asm)
705 "move\t%0, $2"
706 : "=r" (res)
707 : "r" (__to), "r" (__from), "r" (__len)
708 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
709
710 return res;
711 }
712
713 /*
714 * strncpy_from_user: - Copy a NUL terminated string from userspace.
715 * @dst: Destination address, in kernel space. This buffer must be at
716 * least @count bytes long.
717 * @src: Source address, in user space.
718 * @count: Maximum number of bytes to copy, including the trailing NUL.
719 *
720 * Copies a NUL-terminated string from userspace to kernel space.
721 *
722 * On success, returns the length of the string (not including the trailing
723 * NUL).
724 *
725 * If access to userspace fails, returns -EFAULT (some data may have been
726 * copied).
727 *
728 * If @count is smaller than the length of the string, copies @count bytes
729 * and returns @count.
730 */
731 static inline long
732 strncpy_from_user(char *__to, const char __user *__from, long __len)
733 {
734 long res;
735
736 might_sleep();
737 __asm__ __volatile__(
738 "move\t$4, %1\n\t"
739 "move\t$5, %2\n\t"
740 "move\t$6, %3\n\t"
741 __MODULE_JAL(__strncpy_from_user_asm)
742 "move\t%0, $2"
743 : "=r" (res)
744 : "r" (__to), "r" (__from), "r" (__len)
745 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
746
747 return res;
748 }
749
750 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
751 static inline long __strlen_user(const char __user *s)
752 {
753 long res;
754
755 might_sleep();
756 __asm__ __volatile__(
757 "move\t$4, %1\n\t"
758 __MODULE_JAL(__strlen_user_nocheck_asm)
759 "move\t%0, $2"
760 : "=r" (res)
761 : "r" (s)
762 : "$2", "$4", __UA_t0, "$31");
763
764 return res;
765 }
766
767 /*
768 * strlen_user: - Get the size of a string in user space.
769 * @str: The string to measure.
770 *
771 * Context: User context only. This function may sleep.
772 *
773 * Get the size of a NUL-terminated string in user space.
774 *
775 * Returns the size of the string INCLUDING the terminating NUL.
776 * On exception, returns 0.
777 *
778 * If there is a limit on the length of a valid string, you may wish to
779 * consider using strnlen_user() instead.
780 */
781 static inline long strlen_user(const char __user *s)
782 {
783 long res;
784
785 might_sleep();
786 __asm__ __volatile__(
787 "move\t$4, %1\n\t"
788 __MODULE_JAL(__strlen_user_asm)
789 "move\t%0, $2"
790 : "=r" (res)
791 : "r" (s)
792 : "$2", "$4", __UA_t0, "$31");
793
794 return res;
795 }
796
797 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
798 static inline long __strnlen_user(const char __user *s, long n)
799 {
800 long res;
801
802 might_sleep();
803 __asm__ __volatile__(
804 "move\t$4, %1\n\t"
805 "move\t$5, %2\n\t"
806 __MODULE_JAL(__strnlen_user_nocheck_asm)
807 "move\t%0, $2"
808 : "=r" (res)
809 : "r" (s), "r" (n)
810 : "$2", "$4", "$5", __UA_t0, "$31");
811
812 return res;
813 }
814
815 /*
816 * strlen_user: - Get the size of a string in user space.
817 * @str: The string to measure.
818 *
819 * Context: User context only. This function may sleep.
820 *
821 * Get the size of a NUL-terminated string in user space.
822 *
823 * Returns the size of the string INCLUDING the terminating NUL.
824 * On exception, returns 0.
825 *
826 * If there is a limit on the length of a valid string, you may wish to
827 * consider using strnlen_user() instead.
828 */
829 static inline long strnlen_user(const char __user *s, long n)
830 {
831 long res;
832
833 might_sleep();
834 __asm__ __volatile__(
835 "move\t$4, %1\n\t"
836 "move\t$5, %2\n\t"
837 __MODULE_JAL(__strnlen_user_asm)
838 "move\t%0, $2"
839 : "=r" (res)
840 : "r" (s), "r" (n)
841 : "$2", "$4", "$5", __UA_t0, "$31");
842
843 return res;
844 }
845
846 struct exception_table_entry
847 {
848 unsigned long insn;
849 unsigned long nextinsn;
850 };
851
852 extern int fixup_exception(struct pt_regs *regs);
853
854 #endif /* _ASM_UACCESS_H */
Tomato firmware and modifications.