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/config.h>
13 #include <linux/compiler.h>
14 #include <linux/errno.h>
15 #include <linux/sched.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_MIPS32
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_MIPS32 */
35
36 #ifdef CONFIG_MIPS64
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_MIPS64 */
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.current_ds)
64 #define set_fs(x) (current->thread.current_ds = (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 (((signed long)((mask) & ((addr) | ((addr) + (size)) | __ua_size(size)))) == 0)
109
110 #define access_ok(type, addr, size) \
111 likely(__access_ok((unsigned long)(addr), (size),__access_mask))
112
113 /*
114 * verify_area: - Obsolete, use access_ok()
115 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE
116 * @addr: User space pointer to start of block to check
117 * @size: Size of block to check
118 *
119 * Context: User context only. This function may sleep.
120 *
121 * This function has been replaced by access_ok().
122 *
123 * Checks if a pointer to a block of memory in user space is valid.
124 *
125 * Returns zero if the memory block may be valid, -EFAULT
126 * if it is definitely invalid.
127 *
128 * See access_ok() for more details.
129 */
verify_area(int type,const void * addr,unsigned long size)130 static inline int verify_area(int type, const void * addr, unsigned long size)
131 {
132 return access_ok(type, addr, size) ? 0 : -EFAULT;
133 }
134
135 /*
136 * put_user: - Write a simple value into user space.
137 * @x: Value to copy to user space.
138 * @ptr: Destination address, in user space.
139 *
140 * Context: User context only. This function may sleep.
141 *
142 * This macro copies a single simple value from kernel space to user
143 * space. It supports simple types like char and int, but not larger
144 * data types like structures or arrays.
145 *
146 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
147 * to the result of dereferencing @ptr.
148 *
149 * Returns zero on success, or -EFAULT on error.
150 */
151 #define put_user(x,ptr) \
152 __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
153
154 /*
155 * get_user: - Get a simple variable from user space.
156 * @x: Variable to store result.
157 * @ptr: Source address, in user space.
158 *
159 * Context: User context only. This function may sleep.
160 *
161 * This macro copies a single simple variable from user space to kernel
162 * space. It supports simple types like char and int, but not larger
163 * data types like structures or arrays.
164 *
165 * @ptr must have pointer-to-simple-variable type, and the result of
166 * dereferencing @ptr must be assignable to @x without a cast.
167 *
168 * Returns zero on success, or -EFAULT on error.
169 * On error, the variable @x is set to zero.
170 */
171 #define get_user(x,ptr) \
172 __get_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
173
174 /*
175 * __put_user: - Write a simple value into user space, with less checking.
176 * @x: Value to copy to user space.
177 * @ptr: Destination address, in user space.
178 *
179 * Context: User context only. This function may sleep.
180 *
181 * This macro copies a single simple value from kernel space to user
182 * space. It supports simple types like char and int, but not larger
183 * data types like structures or arrays.
184 *
185 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
186 * to the result of dereferencing @ptr.
187 *
188 * Caller must check the pointer with access_ok() before calling this
189 * function.
190 *
191 * Returns zero on success, or -EFAULT on error.
192 */
193 #define __put_user(x,ptr) \
194 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
195
196 /*
197 * __get_user: - Get a simple variable from user space, with less checking.
198 * @x: Variable to store result.
199 * @ptr: Source address, in user space.
200 *
201 * Context: User context only. This function may sleep.
202 *
203 * This macro copies a single simple variable from user space to kernel
204 * space. It supports simple types like char and int, but not larger
205 * data types like structures or arrays.
206 *
207 * @ptr must have pointer-to-simple-variable type, and the result of
208 * dereferencing @ptr must be assignable to @x without a cast.
209 *
210 * Caller must check the pointer with access_ok() before calling this
211 * function.
212 *
213 * Returns zero on success, or -EFAULT on error.
214 * On error, the variable @x is set to zero.
215 */
216 #define __get_user(x,ptr) \
217 __get_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
218
219 struct __large_struct { unsigned long buf[100]; };
220 #define __m(x) (*(struct __large_struct *)(x))
221
222 /*
223 * Yuck. We need two variants, one for 64bit operation and one
224 * for 32 bit mode and old iron.
225 */
226 #ifdef __mips64
227 #define __GET_USER_DW(__gu_err) __get_user_asm("ld", __gu_err)
228 #else
229 #define __GET_USER_DW(__gu_err) __get_user_asm_ll32(__gu_err)
230 #endif
231
232 #define __get_user_nocheck(x,ptr,size) \
233 ({ \
234 long __gu_err = 0; \
235 __typeof(*(ptr)) __gu_val = 0; \
236 long __gu_addr; \
237 __gu_addr = (long) (ptr); \
238 switch (size) { \
239 case 1: __get_user_asm("lb", __gu_err); break; \
240 case 2: __get_user_asm("lh", __gu_err); break; \
241 case 4: __get_user_asm("lw", __gu_err); break; \
242 case 8: __GET_USER_DW(__gu_err); break; \
243 default: __get_user_unknown(); break; \
244 } \
245 x = (__typeof__(*(ptr))) __gu_val; \
246 __gu_err; \
247 })
248
249 #define __get_user_check(x,ptr,size) \
250 ({ \
251 __typeof__(*(ptr)) __gu_val = 0; \
252 long __gu_addr = (long) (ptr); \
253 long __gu_err; \
254 \
255 __gu_err = verify_area(VERIFY_READ, (void *) __gu_addr, size); \
256 \
257 if (likely(!__gu_err)) { \
258 switch (size) { \
259 case 1: __get_user_asm("lb", __gu_err); break; \
260 case 2: __get_user_asm("lh", __gu_err); break; \
261 case 4: __get_user_asm("lw", __gu_err); break; \
262 case 8: __GET_USER_DW(__gu_err); break; \
263 default: __get_user_unknown(); break; \
264 } \
265 } \
266 x = (__typeof__(*(ptr))) __gu_val; \
267 __gu_err; \
268 })
269
270 #define __get_user_asm(insn,__gu_err) \
271 ({ \
272 __asm__ __volatile__( \
273 "1: " insn " %1, %3 \n" \
274 "2: \n" \
275 " .section .fixup,\"ax\" \n" \
276 "3: li %0, %4 \n" \
277 " j 2b \n" \
278 " .previous \n" \
279 " .section __ex_table,\"a\" \n" \
280 " "__UA_ADDR "\t1b, 3b \n" \
281 " .previous \n" \
282 : "=r" (__gu_err), "=r" (__gu_val) \
283 : "0" (__gu_err), "o" (__m(__gu_addr)), "i" (-EFAULT)); \
284 })
285
286 /*
287 * Get a long long 64 using 32 bit registers.
288 */
289 #define __get_user_asm_ll32(__gu_err) \
290 ({ \
291 __asm__ __volatile__( \
292 "1: lw %1, %3 \n" \
293 "2: lw %D1, %4 \n" \
294 " move %0, $0 \n" \
295 "3: .section .fixup,\"ax\" \n" \
296 "4: li %0, %5 \n" \
297 " move %1, $0 \n" \
298 " move %D1, $0 \n" \
299 " j 3b \n" \
300 " .previous \n" \
301 " .section __ex_table,\"a\" \n" \
302 " " __UA_ADDR " 1b, 4b \n" \
303 " " __UA_ADDR " 2b, 4b \n" \
304 " .previous \n" \
305 : "=r" (__gu_err), "=&r" (__gu_val) \
306 : "0" (__gu_err), "o" (__m(__gu_addr)), \
307 "o" (__m(__gu_addr + 4)), "i" (-EFAULT)); \
308 })
309
310 extern void __get_user_unknown(void);
311
312 /*
313 * Yuck. We need two variants, one for 64bit operation and one
314 * for 32 bit mode and old iron.
315 */
316 #ifdef __mips64
317 #define __PUT_USER_DW(__pu_val) __put_user_asm("sd", __pu_val)
318 #else
319 #define __PUT_USER_DW(__pu_val) __put_user_asm_ll32(__pu_val)
320 #endif
321
322 #define __put_user_nocheck(x,ptr,size) \
323 ({ \
324 long __pu_err = 0; \
325 __typeof__(*(ptr)) __pu_val; \
326 long __pu_addr; \
327 __pu_val = (x); \
328 __pu_addr = (long) (ptr); \
329 switch (size) { \
330 case 1: __put_user_asm("sb", __pu_val); break; \
331 case 2: __put_user_asm("sh", __pu_val); break; \
332 case 4: __put_user_asm("sw", __pu_val); break; \
333 case 8: __PUT_USER_DW(__pu_val); break; \
334 default: __put_user_unknown(); break; \
335 } \
336 __pu_err; \
337 })
338
339 #define __put_user_check(x,ptr,size) \
340 ({ \
341 __typeof__(*(ptr)) __pu_val = (x); \
342 long __pu_addr = (long) (ptr); \
343 long __pu_err; \
344 \
345 __pu_err = verify_area(VERIFY_WRITE, (void *) __pu_addr, size); \
346 \
347 if (likely(!__pu_err)) { \
348 switch (size) { \
349 case 1: __put_user_asm("sb", __pu_val); break; \
350 case 2: __put_user_asm("sh", __pu_val); break; \
351 case 4: __put_user_asm("sw", __pu_val); break; \
352 case 8: __PUT_USER_DW(__pu_val); break; \
353 default: __put_user_unknown(); break; \
354 } \
355 } \
356 __pu_err; \
357 })
358
359 #define __put_user_asm(insn, __pu_val) \
360 ({ \
361 __asm__ __volatile__( \
362 "1: " insn " %z2, %3 # __put_user_asm\n" \
363 "2: \n" \
364 " .section .fixup,\"ax\" \n" \
365 "3: li %0, %4 \n" \
366 " j 2b \n" \
367 " .previous \n" \
368 " .section __ex_table,\"a\" \n" \
369 " " __UA_ADDR " 1b, 3b \n" \
370 " .previous \n" \
371 : "=r" (__pu_err) \
372 : "0" (__pu_err), "Jr" (__pu_val), "o" (__m(__pu_addr)), \
373 "i" (-EFAULT)); \
374 })
375
376 #define __put_user_asm_ll32(__pu_val) \
377 ({ \
378 __asm__ __volatile__( \
379 "1: sw %2, %3 # __put_user_asm_ll32 \n" \
380 "2: sw %D2, %4 \n" \
381 "3: \n" \
382 " .section .fixup,\"ax\" \n" \
383 "4: li %0, %5 \n" \
384 " j 3b \n" \
385 " .previous \n" \
386 " .section __ex_table,\"a\" \n" \
387 " " __UA_ADDR " 1b, 4b \n" \
388 " " __UA_ADDR " 2b, 4b \n" \
389 " .previous" \
390 : "=r" (__pu_err) \
391 : "0" (__pu_err), "r" (__pu_val), "o" (__m(__pu_addr)), \
392 "o" (__m(__pu_addr + 4)), "i" (-EFAULT)); \
393 })
394
395 extern void __put_user_unknown(void);
396
397 /*
398 * We're generating jump to subroutines which will be outside the range of
399 * jump instructions
400 */
401 #ifdef MODULE
402 #define __MODULE_JAL(destination) \
403 ".set\tnoat\n\t" \
404 __UA_LA "\t$1, " #destination "\n\t" \
405 "jalr\t$1\n\t" \
406 ".set\tat\n\t"
407 #else
408 #define __MODULE_JAL(destination) \
409 "jal\t" #destination "\n\t"
410 #endif
411
412 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
413
414 #define __invoke_copy_to_user(to,from,n) \
415 ({ \
416 register void *__cu_to_r __asm__ ("$4"); \
417 register const void *__cu_from_r __asm__ ("$5"); \
418 register long __cu_len_r __asm__ ("$6"); \
419 \
420 __cu_to_r = (to); \
421 __cu_from_r = (from); \
422 __cu_len_r = (n); \
423 __asm__ __volatile__( \
424 __MODULE_JAL(__copy_user) \
425 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
426 : \
427 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
428 "memory"); \
429 __cu_len_r; \
430 })
431
432 /*
433 * __copy_to_user: - Copy a block of data into user space, with less checking.
434 * @to: Destination address, in user space.
435 * @from: Source address, in kernel space.
436 * @n: Number of bytes to copy.
437 *
438 * Context: User context only. This function may sleep.
439 *
440 * Copy data from kernel space to user space. Caller must check
441 * the specified block with access_ok() before calling this function.
442 *
443 * Returns number of bytes that could not be copied.
444 * On success, this will be zero.
445 */
446 #define __copy_to_user(to,from,n) \
447 ({ \
448 void *__cu_to; \
449 const void *__cu_from; \
450 long __cu_len; \
451 \
452 __cu_to = (to); \
453 __cu_from = (from); \
454 __cu_len = (n); \
455 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
456 __cu_len; \
457 })
458
459 #define __copy_to_user_inatomic __copy_to_user
460 #define __copy_from_user_inatomic __copy_from_user
461
462 /*
463 * copy_to_user: - Copy a block of data into user space.
464 * @to: Destination address, in user space.
465 * @from: Source address, in kernel space.
466 * @n: Number of bytes to copy.
467 *
468 * Context: User context only. This function may sleep.
469 *
470 * Copy data from kernel space to user space.
471 *
472 * Returns number of bytes that could not be copied.
473 * On success, this will be zero.
474 */
475 #define copy_to_user(to,from,n) \
476 ({ \
477 void *__cu_to; \
478 const void *__cu_from; \
479 long __cu_len; \
480 \
481 __cu_to = (to); \
482 __cu_from = (from); \
483 __cu_len = (n); \
484 if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) \
485 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, \
486 __cu_len); \
487 __cu_len; \
488 })
489
490 #define __invoke_copy_from_user(to,from,n) \
491 ({ \
492 register void *__cu_to_r __asm__ ("$4"); \
493 register const void *__cu_from_r __asm__ ("$5"); \
494 register long __cu_len_r __asm__ ("$6"); \
495 \
496 __cu_to_r = (to); \
497 __cu_from_r = (from); \
498 __cu_len_r = (n); \
499 __asm__ __volatile__( \
500 ".set\tnoreorder\n\t" \
501 __MODULE_JAL(__copy_user) \
502 ".set\tnoat\n\t" \
503 __UA_ADDU "\t$1, %1, %2\n\t" \
504 ".set\tat\n\t" \
505 ".set\treorder" \
506 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
507 : \
508 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
509 "memory"); \
510 __cu_len_r; \
511 })
512
513 /*
514 * __copy_from_user: - Copy a block of data from user space, with less checking. * @to: Destination address, in kernel space.
515 * @from: Source address, in user space.
516 * @n: Number of bytes to copy.
517 *
518 * Context: User context only. This function may sleep.
519 *
520 * Copy data from user space to kernel space. Caller must check
521 * the specified block with access_ok() before calling this function.
522 *
523 * Returns number of bytes that could not be copied.
524 * On success, this will be zero.
525 *
526 * If some data could not be copied, this function will pad the copied
527 * data to the requested size using zero bytes.
528 */
529 #define __copy_from_user(to,from,n) \
530 ({ \
531 void *__cu_to; \
532 const void *__cu_from; \
533 long __cu_len; \
534 \
535 __cu_to = (to); \
536 __cu_from = (from); \
537 __cu_len = (n); \
538 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
539 __cu_len); \
540 __cu_len; \
541 })
542
543 /*
544 * copy_from_user: - Copy a block of data from user space.
545 * @to: Destination address, in kernel space.
546 * @from: Source address, in user space.
547 * @n: Number of bytes to copy.
548 *
549 * Context: User context only. This function may sleep.
550 *
551 * Copy data from user space to kernel space.
552 *
553 * Returns number of bytes that could not be copied.
554 * On success, this will be zero.
555 *
556 * If some data could not be copied, this function will pad the copied
557 * data to the requested size using zero bytes.
558 */
559 #define copy_from_user(to,from,n) \
560 ({ \
561 void *__cu_to; \
562 const void *__cu_from; \
563 long __cu_len; \
564 \
565 __cu_to = (to); \
566 __cu_from = (from); \
567 __cu_len = (n); \
568 if (access_ok(VERIFY_READ, __cu_from, __cu_len)) \
569 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
570 __cu_len); \
571 __cu_len; \
572 })
573
574 /*
575 * __clear_user: - Zero a block of memory in user space, with less checking.
576 * @to: Destination address, in user space.
577 * @n: Number of bytes to zero.
578 *
579 * Zero a block of memory in user space. Caller must check
580 * the specified block with access_ok() before calling this function.
581 *
582 * Returns number of bytes that could not be cleared.
583 * On success, this will be zero.
584 */
585 static inline __kernel_size_t
__clear_user(void * addr,__kernel_size_t size)586 __clear_user(void *addr, __kernel_size_t size)
587 {
588 __kernel_size_t res;
589
590 __asm__ __volatile__(
591 "move\t$4, %1\n\t"
592 "move\t$5, $0\n\t"
593 "move\t$6, %2\n\t"
594 __MODULE_JAL(__bzero)
595 "move\t%0, $6"
596 : "=r" (res)
597 : "r" (addr), "r" (size)
598 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
599
600 return res;
601 }
602
603 #define clear_user(addr,n) \
604 ({ \
605 void * __cl_addr = (addr); \
606 unsigned long __cl_size = (n); \
607 if (__cl_size && access_ok(VERIFY_WRITE, \
608 ((unsigned long)(__cl_addr)), __cl_size)) \
609 __cl_size = __clear_user(__cl_addr, __cl_size); \
610 __cl_size; \
611 })
612
613 /*
614 * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
615 * @dst: Destination address, in kernel space. This buffer must be at
616 * least @count bytes long.
617 * @src: Source address, in user space.
618 * @count: Maximum number of bytes to copy, including the trailing NUL.
619 *
620 * Copies a NUL-terminated string from userspace to kernel space.
621 * Caller must check the specified block with access_ok() before calling
622 * this function.
623 *
624 * On success, returns the length of the string (not including the trailing
625 * NUL).
626 *
627 * If access to userspace fails, returns -EFAULT (some data may have been
628 * copied).
629 *
630 * If @count is smaller than the length of the string, copies @count bytes
631 * and returns @count.
632 */
633 static inline long
__strncpy_from_user(char * __to,const char * __from,long __len)634 __strncpy_from_user(char *__to, const char *__from, long __len)
635 {
636 long res;
637
638 __asm__ __volatile__(
639 "move\t$4, %1\n\t"
640 "move\t$5, %2\n\t"
641 "move\t$6, %3\n\t"
642 __MODULE_JAL(__strncpy_from_user_nocheck_asm)
643 "move\t%0, $2"
644 : "=r" (res)
645 : "r" (__to), "r" (__from), "r" (__len)
646 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
647
648 return res;
649 }
650
651 /*
652 * strncpy_from_user: - Copy a NUL terminated string from userspace.
653 * @dst: Destination address, in kernel space. This buffer must be at
654 * least @count bytes long.
655 * @src: Source address, in user space.
656 * @count: Maximum number of bytes to copy, including the trailing NUL.
657 *
658 * Copies a NUL-terminated string from userspace to kernel space.
659 *
660 * On success, returns the length of the string (not including the trailing
661 * NUL).
662 *
663 * If access to userspace fails, returns -EFAULT (some data may have been
664 * copied).
665 *
666 * If @count is smaller than the length of the string, copies @count bytes
667 * and returns @count.
668 */
669 static inline long
strncpy_from_user(char * __to,const char * __from,long __len)670 strncpy_from_user(char *__to, const char *__from, long __len)
671 {
672 long res;
673
674 __asm__ __volatile__(
675 "move\t$4, %1\n\t"
676 "move\t$5, %2\n\t"
677 "move\t$6, %3\n\t"
678 __MODULE_JAL(__strncpy_from_user_asm)
679 "move\t%0, $2"
680 : "=r" (res)
681 : "r" (__to), "r" (__from), "r" (__len)
682 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
683
684 return res;
685 }
686
687 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
__strlen_user(const char * s)688 static inline long __strlen_user(const char *s)
689 {
690 long res;
691
692 __asm__ __volatile__(
693 "move\t$4, %1\n\t"
694 __MODULE_JAL(__strlen_user_nocheck_asm)
695 "move\t%0, $2"
696 : "=r" (res)
697 : "r" (s)
698 : "$2", "$4", __UA_t0, "$31");
699
700 return res;
701 }
702
703 /*
704 * strlen_user: - Get the size of a string in user space.
705 * @str: The string to measure.
706 *
707 * Context: User context only. This function may sleep.
708 *
709 * Get the size of a NUL-terminated string in user space.
710 *
711 * Returns the size of the string INCLUDING the terminating NUL.
712 * On exception, returns 0.
713 *
714 * If there is a limit on the length of a valid string, you may wish to
715 * consider using strnlen_user() instead.
716 */
strlen_user(const char * s)717 static inline long strlen_user(const char *s)
718 {
719 long res;
720
721 __asm__ __volatile__(
722 "move\t$4, %1\n\t"
723 __MODULE_JAL(__strlen_user_asm)
724 "move\t%0, $2"
725 : "=r" (res)
726 : "r" (s)
727 : "$2", "$4", __UA_t0, "$31");
728
729 return res;
730 }
731
732 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
__strnlen_user(const char * s,long n)733 static inline long __strnlen_user(const char *s, long n)
734 {
735 long res;
736
737 __asm__ __volatile__(
738 "move\t$4, %1\n\t"
739 "move\t$5, %2\n\t"
740 __MODULE_JAL(__strnlen_user_nocheck_asm)
741 "move\t%0, $2"
742 : "=r" (res)
743 : "r" (s), "r" (n)
744 : "$2", "$4", "$5", __UA_t0, "$31");
745
746 return res;
747 }
748
749 /*
750 * strlen_user: - Get the size of a string in user space.
751 * @str: The string to measure.
752 *
753 * Context: User context only. This function may sleep.
754 *
755 * Get the size of a NUL-terminated string in user space.
756 *
757 * Returns the size of the string INCLUDING the terminating NUL.
758 * On exception, returns 0.
759 *
760 * If there is a limit on the length of a valid string, you may wish to
761 * consider using strnlen_user() instead.
762 */
strnlen_user(const char * s,long n)763 static inline long strnlen_user(const char *s, long n)
764 {
765 long res;
766
767 __asm__ __volatile__(
768 "move\t$4, %1\n\t"
769 "move\t$5, %2\n\t"
770 __MODULE_JAL(__strnlen_user_asm)
771 "move\t%0, $2"
772 : "=r" (res)
773 : "r" (s), "r" (n)
774 : "$2", "$4", "$5", __UA_t0, "$31");
775
776 return res;
777 }
778
779 struct exception_table_entry
780 {
781 unsigned long insn;
782 unsigned long nextinsn;
783 };
784
785 /* Returns 0 if exception not found and fixup.unit otherwise. */
786 extern unsigned long search_exception_table(unsigned long addr);
787
788 /* Returns the new pc */
789 #define fixup_exception(map_reg, fixup_unit, pc) \
790 ({ \
791 fixup_unit; \
792 })
793
794 #endif /* _ASM_UACCESS_H */
795