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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / arch / mips / include / asm / uaccess.h
blobb713069472903c26f21c11424113765a5156d955
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 * Copyright (C) 2014, Imagination Technologies Ltd.
10 */
11 #ifndef _ASM_UACCESS_H
12 #define _ASM_UACCESS_H
13
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <asm/asm-eva.h>
17 #include <asm/extable.h>
18
19 /*
20 * The fs value determines whether argument validity checking should be
21 * performed or not. If get_fs() == USER_DS, checking is performed, with
22 * get_fs() == KERNEL_DS, checking is bypassed.
23 *
24 * For historical reasons, these macros are grossly misnamed.
25 */
26 #ifdef CONFIG_32BIT
27
28 #ifdef CONFIG_KVM_GUEST
29 #define __UA_LIMIT 0x40000000UL
30 #else
31 #define __UA_LIMIT 0x80000000UL
32 #endif
33
34 #define __UA_ADDR ".word"
35 #define __UA_LA "la"
36 #define __UA_ADDU "addu"
37 #define __UA_t0 "$8"
38 #define __UA_t1 "$9"
39
40 #endif /* CONFIG_32BIT */
41
42 #ifdef CONFIG_64BIT
43
44 extern u64 __ua_limit;
45
46 #define __UA_LIMIT __ua_limit
47
48 #define __UA_ADDR ".dword"
49 #define __UA_LA "dla"
50 #define __UA_ADDU "daddu"
51 #define __UA_t0 "$12"
52 #define __UA_t1 "$13"
53
54 #endif /* CONFIG_64BIT */
55
56 /*
57 * USER_DS is a bitmask that has the bits set that may not be set in a valid
58 * userspace address. Note that we limit 32-bit userspace to 0x7fff8000 but
59 * the arithmetic we're doing only works if the limit is a power of two, so
60 * we use 0x80000000 here on 32-bit kernels. If a process passes an invalid
61 * address in this range it's the process's problem, not ours :-)
62 */
63
64 #ifdef CONFIG_KVM_GUEST
65 #define KERNEL_DS ((mm_segment_t) { 0x80000000UL })
66 #define USER_DS ((mm_segment_t) { 0xC0000000UL })
67 #else
68 #define KERNEL_DS ((mm_segment_t) { 0UL })
69 #define USER_DS ((mm_segment_t) { __UA_LIMIT })
70 #endif
71
72 #define get_ds() (KERNEL_DS)
73 #define get_fs() (current_thread_info()->addr_limit)
74 #define set_fs(x) (current_thread_info()->addr_limit = (x))
75
76 #define segment_eq(a, b) ((a).seg == (b).seg)
77
78 /*
79 * eva_kernel_access() - determine whether kernel memory access on an EVA system
80 *
81 * Determines whether memory accesses should be performed to kernel memory
82 * on a system using Extended Virtual Addressing (EVA).
83 *
84 * Return: true if a kernel memory access on an EVA system, else false.
85 */
86 static inline bool eva_kernel_access(void)
87 {
88 if (!IS_ENABLED(CONFIG_EVA))
89 return false;
90
91 return uaccess_kernel();
92 }
93
94 /*
95 * Is a address valid? This does a straightforward calculation rather
96 * than tests.
97 *
98 * Address valid if:
99 * - "addr" doesn't have any high-bits set
100 * - AND "size" doesn't have any high-bits set
101 * - AND "addr+size" doesn't have any high-bits set
102 * - OR we are in kernel mode.
103 *
104 * __ua_size() is a trick to avoid runtime checking of positive constant
105 * sizes; for those we already know at compile time that the size is ok.
106 */
107 #define __ua_size(size) \
108 ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
109
110 /*
111 * access_ok: - Checks if a user space pointer is valid
112 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
113 * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
114 * to write to a block, it is always safe to read from it.
115 * @addr: User space pointer to start of block to check
116 * @size: Size of block to check
117 *
118 * Context: User context only. This function may sleep if pagefaults are
119 * enabled.
120 *
121 * Checks if a pointer to a block of memory in user space is valid.
122 *
123 * Returns true (nonzero) if the memory block may be valid, false (zero)
124 * if it is definitely invalid.
125 *
126 * Note that, depending on architecture, this function probably just
127 * checks that the pointer is in the user space range - after calling
128 * this function, memory access functions may still return -EFAULT.
129 */
130
131 static inline int __access_ok(const void __user *p, unsigned long size)
132 {
133 unsigned long addr = (unsigned long)p;
134 return (get_fs().seg & (addr | (addr + size) | __ua_size(size))) == 0;
135 }
136
137 #define access_ok(type, addr, size) \
138 likely(__access_ok((addr), (size)))
139
140 /*
141 * put_user: - Write a simple value into user space.
142 * @x: Value to copy to user space.
143 * @ptr: Destination address, in user space.
144 *
145 * Context: User context only. This function may sleep if pagefaults are
146 * enabled.
147 *
148 * This macro copies a single simple value from kernel space to user
149 * space. It supports simple types like char and int, but not larger
150 * data types like structures or arrays.
151 *
152 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
153 * to the result of dereferencing @ptr.
154 *
155 * Returns zero on success, or -EFAULT on error.
156 */
157 #define put_user(x,ptr) \
158 __put_user_check((x), (ptr), sizeof(*(ptr)))
159
160 /*
161 * get_user: - Get a simple variable from user space.
162 * @x: Variable to store result.
163 * @ptr: Source address, in user space.
164 *
165 * Context: User context only. This function may sleep if pagefaults are
166 * enabled.
167 *
168 * This macro copies a single simple variable from user space to kernel
169 * space. It supports simple types like char and int, but not larger
170 * data types like structures or arrays.
171 *
172 * @ptr must have pointer-to-simple-variable type, and the result of
173 * dereferencing @ptr must be assignable to @x without a cast.
174 *
175 * Returns zero on success, or -EFAULT on error.
176 * On error, the variable @x is set to zero.
177 */
178 #define get_user(x,ptr) \
179 __get_user_check((x), (ptr), sizeof(*(ptr)))
180
181 /*
182 * __put_user: - Write a simple value into user space, with less checking.
183 * @x: Value to copy to user space.
184 * @ptr: Destination address, in user space.
185 *
186 * Context: User context only. This function may sleep if pagefaults are
187 * enabled.
188 *
189 * This macro copies a single simple value from kernel space to user
190 * space. It supports simple types like char and int, but not larger
191 * data types like structures or arrays.
192 *
193 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
194 * to the result of dereferencing @ptr.
195 *
196 * Caller must check the pointer with access_ok() before calling this
197 * function.
198 *
199 * Returns zero on success, or -EFAULT on error.
200 */
201 #define __put_user(x,ptr) \
202 __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
203
204 /*
205 * __get_user: - Get a simple variable from user space, with less checking.
206 * @x: Variable to store result.
207 * @ptr: Source address, in user space.
208 *
209 * Context: User context only. This function may sleep if pagefaults are
210 * enabled.
211 *
212 * This macro copies a single simple variable from user space to kernel
213 * space. It supports simple types like char and int, but not larger
214 * data types like structures or arrays.
215 *
216 * @ptr must have pointer-to-simple-variable type, and the result of
217 * dereferencing @ptr must be assignable to @x without a cast.
218 *
219 * Caller must check the pointer with access_ok() before calling this
220 * function.
221 *
222 * Returns zero on success, or -EFAULT on error.
223 * On error, the variable @x is set to zero.
224 */
225 #define __get_user(x,ptr) \
226 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
227
228 struct __large_struct { unsigned long buf[100]; };
229 #define __m(x) (*(struct __large_struct __user *)(x))
230
231 /*
232 * Yuck. We need two variants, one for 64bit operation and one
233 * for 32 bit mode and old iron.
234 */
235 #ifndef CONFIG_EVA
236 #define __get_kernel_common(val, size, ptr) __get_user_common(val, size, ptr)
237 #else
238 /*
239 * Kernel specific functions for EVA. We need to use normal load instructions
240 * to read data from kernel when operating in EVA mode. We use these macros to
241 * avoid redefining __get_user_asm for EVA.
242 */
243 #undef _loadd
244 #undef _loadw
245 #undef _loadh
246 #undef _loadb
247 #ifdef CONFIG_32BIT
248 #define _loadd _loadw
249 #else
250 #define _loadd(reg, addr) "ld " reg ", " addr
251 #endif
252 #define _loadw(reg, addr) "lw " reg ", " addr
253 #define _loadh(reg, addr) "lh " reg ", " addr
254 #define _loadb(reg, addr) "lb " reg ", " addr
255
256 #define __get_kernel_common(val, size, ptr) \
257 do { \
258 switch (size) { \
259 case 1: __get_data_asm(val, _loadb, ptr); break; \
260 case 2: __get_data_asm(val, _loadh, ptr); break; \
261 case 4: __get_data_asm(val, _loadw, ptr); break; \
262 case 8: __GET_DW(val, _loadd, ptr); break; \
263 default: __get_user_unknown(); break; \
264 } \
265 } while (0)
266 #endif
267
268 #ifdef CONFIG_32BIT
269 #define __GET_DW(val, insn, ptr) __get_data_asm_ll32(val, insn, ptr)
270 #endif
271 #ifdef CONFIG_64BIT
272 #define __GET_DW(val, insn, ptr) __get_data_asm(val, insn, ptr)
273 #endif
274
275 extern void __get_user_unknown(void);
276
277 #define __get_user_common(val, size, ptr) \
278 do { \
279 switch (size) { \
280 case 1: __get_data_asm(val, user_lb, ptr); break; \
281 case 2: __get_data_asm(val, user_lh, ptr); break; \
282 case 4: __get_data_asm(val, user_lw, ptr); break; \
283 case 8: __GET_DW(val, user_ld, ptr); break; \
284 default: __get_user_unknown(); break; \
285 } \
286 } while (0)
287
288 #define __get_user_nocheck(x, ptr, size) \
289 ({ \
290 int __gu_err; \
291 \
292 if (eva_kernel_access()) { \
293 __get_kernel_common((x), size, ptr); \
294 } else { \
295 __chk_user_ptr(ptr); \
296 __get_user_common((x), size, ptr); \
297 } \
298 __gu_err; \
299 })
300
301 #define __get_user_check(x, ptr, size) \
302 ({ \
303 int __gu_err = -EFAULT; \
304 const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
305 \
306 might_fault(); \
307 if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) { \
308 if (eva_kernel_access()) \
309 __get_kernel_common((x), size, __gu_ptr); \
310 else \
311 __get_user_common((x), size, __gu_ptr); \
312 } else \
313 (x) = 0; \
314 \
315 __gu_err; \
316 })
317
318 #define __get_data_asm(val, insn, addr) \
319 { \
320 long __gu_tmp; \
321 \
322 __asm__ __volatile__( \
323 "1: "insn("%1", "%3")" \n" \
324 "2: \n" \
325 " .insn \n" \
326 " .section .fixup,\"ax\" \n" \
327 "3: li %0, %4 \n" \
328 " move %1, $0 \n" \
329 " j 2b \n" \
330 " .previous \n" \
331 " .section __ex_table,\"a\" \n" \
332 " "__UA_ADDR "\t1b, 3b \n" \
333 " .previous \n" \
334 : "=r" (__gu_err), "=r" (__gu_tmp) \
335 : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
336 \
337 (val) = (__typeof__(*(addr))) __gu_tmp; \
338 }
339
340 /*
341 * Get a long long 64 using 32 bit registers.
342 */
343 #define __get_data_asm_ll32(val, insn, addr) \
344 { \
345 union { \
346 unsigned long long l; \
347 __typeof__(*(addr)) t; \
348 } __gu_tmp; \
349 \
350 __asm__ __volatile__( \
351 "1: " insn("%1", "(%3)")" \n" \
352 "2: " insn("%D1", "4(%3)")" \n" \
353 "3: \n" \
354 " .insn \n" \
355 " .section .fixup,\"ax\" \n" \
356 "4: li %0, %4 \n" \
357 " move %1, $0 \n" \
358 " move %D1, $0 \n" \
359 " j 3b \n" \
360 " .previous \n" \
361 " .section __ex_table,\"a\" \n" \
362 " " __UA_ADDR " 1b, 4b \n" \
363 " " __UA_ADDR " 2b, 4b \n" \
364 " .previous \n" \
365 : "=r" (__gu_err), "=&r" (__gu_tmp.l) \
366 : "0" (0), "r" (addr), "i" (-EFAULT)); \
367 \
368 (val) = __gu_tmp.t; \
369 }
370
371 #ifndef CONFIG_EVA
372 #define __put_kernel_common(ptr, size) __put_user_common(ptr, size)
373 #else
374 /*
375 * Kernel specific functions for EVA. We need to use normal load instructions
376 * to read data from kernel when operating in EVA mode. We use these macros to
377 * avoid redefining __get_data_asm for EVA.
378 */
379 #undef _stored
380 #undef _storew
381 #undef _storeh
382 #undef _storeb
383 #ifdef CONFIG_32BIT
384 #define _stored _storew
385 #else
386 #define _stored(reg, addr) "ld " reg ", " addr
387 #endif
388
389 #define _storew(reg, addr) "sw " reg ", " addr
390 #define _storeh(reg, addr) "sh " reg ", " addr
391 #define _storeb(reg, addr) "sb " reg ", " addr
392
393 #define __put_kernel_common(ptr, size) \
394 do { \
395 switch (size) { \
396 case 1: __put_data_asm(_storeb, ptr); break; \
397 case 2: __put_data_asm(_storeh, ptr); break; \
398 case 4: __put_data_asm(_storew, ptr); break; \
399 case 8: __PUT_DW(_stored, ptr); break; \
400 default: __put_user_unknown(); break; \
401 } \
402 } while(0)
403 #endif
404
405 /*
406 * Yuck. We need two variants, one for 64bit operation and one
407 * for 32 bit mode and old iron.
408 */
409 #ifdef CONFIG_32BIT
410 #define __PUT_DW(insn, ptr) __put_data_asm_ll32(insn, ptr)
411 #endif
412 #ifdef CONFIG_64BIT
413 #define __PUT_DW(insn, ptr) __put_data_asm(insn, ptr)
414 #endif
415
416 #define __put_user_common(ptr, size) \
417 do { \
418 switch (size) { \
419 case 1: __put_data_asm(user_sb, ptr); break; \
420 case 2: __put_data_asm(user_sh, ptr); break; \
421 case 4: __put_data_asm(user_sw, ptr); break; \
422 case 8: __PUT_DW(user_sd, ptr); break; \
423 default: __put_user_unknown(); break; \
424 } \
425 } while (0)
426
427 #define __put_user_nocheck(x, ptr, size) \
428 ({ \
429 __typeof__(*(ptr)) __pu_val; \
430 int __pu_err = 0; \
431 \
432 __pu_val = (x); \
433 if (eva_kernel_access()) { \
434 __put_kernel_common(ptr, size); \
435 } else { \
436 __chk_user_ptr(ptr); \
437 __put_user_common(ptr, size); \
438 } \
439 __pu_err; \
440 })
441
442 #define __put_user_check(x, ptr, size) \
443 ({ \
444 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
445 __typeof__(*(ptr)) __pu_val = (x); \
446 int __pu_err = -EFAULT; \
447 \
448 might_fault(); \
449 if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
450 if (eva_kernel_access()) \
451 __put_kernel_common(__pu_addr, size); \
452 else \
453 __put_user_common(__pu_addr, size); \
454 } \
455 \
456 __pu_err; \
457 })
458
459 #define __put_data_asm(insn, ptr) \
460 { \
461 __asm__ __volatile__( \
462 "1: "insn("%z2", "%3")" # __put_data_asm \n" \
463 "2: \n" \
464 " .insn \n" \
465 " .section .fixup,\"ax\" \n" \
466 "3: li %0, %4 \n" \
467 " j 2b \n" \
468 " .previous \n" \
469 " .section __ex_table,\"a\" \n" \
470 " " __UA_ADDR " 1b, 3b \n" \
471 " .previous \n" \
472 : "=r" (__pu_err) \
473 : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
474 "i" (-EFAULT)); \
475 }
476
477 #define __put_data_asm_ll32(insn, ptr) \
478 { \
479 __asm__ __volatile__( \
480 "1: "insn("%2", "(%3)")" # __put_data_asm_ll32 \n" \
481 "2: "insn("%D2", "4(%3)")" \n" \
482 "3: \n" \
483 " .insn \n" \
484 " .section .fixup,\"ax\" \n" \
485 "4: li %0, %4 \n" \
486 " j 3b \n" \
487 " .previous \n" \
488 " .section __ex_table,\"a\" \n" \
489 " " __UA_ADDR " 1b, 4b \n" \
490 " " __UA_ADDR " 2b, 4b \n" \
491 " .previous" \
492 : "=r" (__pu_err) \
493 : "0" (0), "r" (__pu_val), "r" (ptr), \
494 "i" (-EFAULT)); \
495 }
496
497 extern void __put_user_unknown(void);
498
499 /*
500 * We're generating jump to subroutines which will be outside the range of
501 * jump instructions
502 */
503 #ifdef MODULE
504 #define __MODULE_JAL(destination) \
505 ".set\tnoat\n\t" \
506 __UA_LA "\t$1, " #destination "\n\t" \
507 "jalr\t$1\n\t" \
508 ".set\tat\n\t"
509 #else
510 #define __MODULE_JAL(destination) \
511 "jal\t" #destination "\n\t"
512 #endif
513
514 #if defined(CONFIG_CPU_DADDI_WORKAROUNDS) || (defined(CONFIG_EVA) && \
515 defined(CONFIG_CPU_HAS_PREFETCH))
516 #define DADDI_SCRATCH "$3"
517 #else
518 #define DADDI_SCRATCH "$0"
519 #endif
520
521 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
522
523 #define __invoke_copy_from(func, to, from, n) \
524 ({ \
525 register void *__cu_to_r __asm__("$4"); \
526 register const void __user *__cu_from_r __asm__("$5"); \
527 register long __cu_len_r __asm__("$6"); \
528 \
529 __cu_to_r = (to); \
530 __cu_from_r = (from); \
531 __cu_len_r = (n); \
532 __asm__ __volatile__( \
533 ".set\tnoreorder\n\t" \
534 __MODULE_JAL(func) \
535 ".set\tnoat\n\t" \
536 __UA_ADDU "\t$1, %1, %2\n\t" \
537 ".set\tat\n\t" \
538 ".set\treorder" \
539 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
540 : \
541 : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31", \
542 DADDI_SCRATCH, "memory"); \
543 __cu_len_r; \
544 })
545
546 #define __invoke_copy_to(func, to, from, n) \
547 ({ \
548 register void __user *__cu_to_r __asm__("$4"); \
549 register const void *__cu_from_r __asm__("$5"); \
550 register long __cu_len_r __asm__("$6"); \
551 \
552 __cu_to_r = (to); \
553 __cu_from_r = (from); \
554 __cu_len_r = (n); \
555 __asm__ __volatile__( \
556 __MODULE_JAL(func) \
557 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
558 : \
559 : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31", \
560 DADDI_SCRATCH, "memory"); \
561 __cu_len_r; \
562 })
563
564 #define __invoke_copy_from_kernel(to, from, n) \
565 __invoke_copy_from(__copy_user, to, from, n)
566
567 #define __invoke_copy_to_kernel(to, from, n) \
568 __invoke_copy_to(__copy_user, to, from, n)
569
570 #define ___invoke_copy_in_kernel(to, from, n) \
571 __invoke_copy_from(__copy_user, to, from, n)
572
573 #ifndef CONFIG_EVA
574 #define __invoke_copy_from_user(to, from, n) \
575 __invoke_copy_from(__copy_user, to, from, n)
576
577 #define __invoke_copy_to_user(to, from, n) \
578 __invoke_copy_to(__copy_user, to, from, n)
579
580 #define ___invoke_copy_in_user(to, from, n) \
581 __invoke_copy_from(__copy_user, to, from, n)
582
583 #else
584
585 /* EVA specific functions */
586
587 extern size_t __copy_from_user_eva(void *__to, const void *__from,
588 size_t __n);
589 extern size_t __copy_to_user_eva(void *__to, const void *__from,
590 size_t __n);
591 extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
592
593 /*
594 * Source or destination address is in userland. We need to go through
595 * the TLB
596 */
597 #define __invoke_copy_from_user(to, from, n) \
598 __invoke_copy_from(__copy_from_user_eva, to, from, n)
599
600 #define __invoke_copy_to_user(to, from, n) \
601 __invoke_copy_to(__copy_to_user_eva, to, from, n)
602
603 #define ___invoke_copy_in_user(to, from, n) \
604 __invoke_copy_from(__copy_in_user_eva, to, from, n)
605
606 #endif /* CONFIG_EVA */
607
608 static inline unsigned long
609 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
610 {
611 if (eva_kernel_access())
612 return __invoke_copy_to_kernel(to, from, n);
613 else
614 return __invoke_copy_to_user(to, from, n);
615 }
616
617 static inline unsigned long
618 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
619 {
620 if (eva_kernel_access())
621 return __invoke_copy_from_kernel(to, from, n);
622 else
623 return __invoke_copy_from_user(to, from, n);
624 }
625
626 #define INLINE_COPY_FROM_USER
627 #define INLINE_COPY_TO_USER
628
629 static inline unsigned long
630 raw_copy_in_user(void __user*to, const void __user *from, unsigned long n)
631 {
632 if (eva_kernel_access())
633 return ___invoke_copy_in_kernel(to, from, n);
634 else
635 return ___invoke_copy_in_user(to, from, n);
636 }
637
638 extern __kernel_size_t __bzero_kernel(void __user *addr, __kernel_size_t size);
639 extern __kernel_size_t __bzero(void __user *addr, __kernel_size_t size);
640
641 /*
642 * __clear_user: - Zero a block of memory in user space, with less checking.
643 * @to: Destination address, in user space.
644 * @n: Number of bytes to zero.
645 *
646 * Zero a block of memory in user space. Caller must check
647 * the specified block with access_ok() before calling this function.
648 *
649 * Returns number of bytes that could not be cleared.
650 * On success, this will be zero.
651 */
652 static inline __kernel_size_t
653 __clear_user(void __user *addr, __kernel_size_t size)
654 {
655 __kernel_size_t res;
656
657 if (eva_kernel_access()) {
658 __asm__ __volatile__(
659 "move\t$4, %1\n\t"
660 "move\t$5, $0\n\t"
661 "move\t$6, %2\n\t"
662 __MODULE_JAL(__bzero_kernel)
663 "move\t%0, $6"
664 : "=r" (res)
665 : "r" (addr), "r" (size)
666 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
667 } else {
668 might_fault();
669 __asm__ __volatile__(
670 "move\t$4, %1\n\t"
671 "move\t$5, $0\n\t"
672 "move\t$6, %2\n\t"
673 __MODULE_JAL(__bzero)
674 "move\t%0, $6"
675 : "=r" (res)
676 : "r" (addr), "r" (size)
677 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
678 }
679
680 return res;
681 }
682
683 #define clear_user(addr,n) \
684 ({ \
685 void __user * __cl_addr = (addr); \
686 unsigned long __cl_size = (n); \
687 if (__cl_size && access_ok(VERIFY_WRITE, \
688 __cl_addr, __cl_size)) \
689 __cl_size = __clear_user(__cl_addr, __cl_size); \
690 __cl_size; \
691 })
692
693 extern long __strncpy_from_kernel_asm(char *__to, const char __user *__from, long __len);
694 extern long __strncpy_from_user_asm(char *__to, const char __user *__from, long __len);
695
696 /*
697 * strncpy_from_user: - Copy a NUL terminated string from userspace.
698 * @dst: Destination address, in kernel space. This buffer must be at
699 * least @count bytes long.
700 * @src: Source address, in user space.
701 * @count: Maximum number of bytes to copy, including the trailing NUL.
702 *
703 * Copies a NUL-terminated string from userspace to kernel space.
704 *
705 * On success, returns the length of the string (not including the trailing
706 * NUL).
707 *
708 * If access to userspace fails, returns -EFAULT (some data may have been
709 * copied).
710 *
711 * If @count is smaller than the length of the string, copies @count bytes
712 * and returns @count.
713 */
714 static inline long
715 strncpy_from_user(char *__to, const char __user *__from, long __len)
716 {
717 long res;
718
719 if (eva_kernel_access()) {
720 __asm__ __volatile__(
721 "move\t$4, %1\n\t"
722 "move\t$5, %2\n\t"
723 "move\t$6, %3\n\t"
724 __MODULE_JAL(__strncpy_from_kernel_asm)
725 "move\t%0, $2"
726 : "=r" (res)
727 : "r" (__to), "r" (__from), "r" (__len)
728 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
729 } else {
730 might_fault();
731 __asm__ __volatile__(
732 "move\t$4, %1\n\t"
733 "move\t$5, %2\n\t"
734 "move\t$6, %3\n\t"
735 __MODULE_JAL(__strncpy_from_user_asm)
736 "move\t%0, $2"
737 : "=r" (res)
738 : "r" (__to), "r" (__from), "r" (__len)
739 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
740 }
741
742 return res;
743 }
744
745 extern long __strnlen_kernel_asm(const char __user *s, long n);
746 extern long __strnlen_user_asm(const char __user *s, long n);
747
748 /*
749 * strnlen_user: - Get the size of a string in user space.
750 * @str: The string to measure.
751 *
752 * Context: User context only. This function may sleep if pagefaults are
753 * enabled.
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 * If the string is too long, returns a value greater than @n.
760 */
761 static inline long strnlen_user(const char __user *s, long n)
762 {
763 long res;
764
765 might_fault();
766 if (eva_kernel_access()) {
767 __asm__ __volatile__(
768 "move\t$4, %1\n\t"
769 "move\t$5, %2\n\t"
770 __MODULE_JAL(__strnlen_kernel_asm)
771 "move\t%0, $2"
772 : "=r" (res)
773 : "r" (s), "r" (n)
774 : "$2", "$4", "$5", __UA_t0, "$31");
775 } else {
776 __asm__ __volatile__(
777 "move\t$4, %1\n\t"
778 "move\t$5, %2\n\t"
779 __MODULE_JAL(__strnlen_user_asm)
780 "move\t%0, $2"
781 : "=r" (res)
782 : "r" (s), "r" (n)
783 : "$2", "$4", "$5", __UA_t0, "$31");
784 }
785
786 return res;
787 }
788
789 #endif /* _ASM_UACCESS_H */
CRIS linux kernel tree