blob: 825fcbd9eabd30e0924002bc3a039ae2ace4d5ab [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#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 */
Ralf Baechle875d43e2005-09-03 15:56:16 -070024#ifdef CONFIG_32BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
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
Ralf Baechle875d43e2005-09-03 15:56:16 -070034#endif /* CONFIG_32BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
Ralf Baechle875d43e2005-09-03 15:56:16 -070036#ifdef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
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
Ralf Baechle875d43e2005-09-03 15:56:16 -070046#endif /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
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 (((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/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 * put_user: - Write a simple value into user space.
115 * @x: Value to copy to user space.
116 * @ptr: Destination address, in user space.
117 *
118 * Context: User context only. This function may sleep.
119 *
120 * This macro copies a single simple value from kernel space to user
121 * space. It supports simple types like char and int, but not larger
122 * data types like structures or arrays.
123 *
124 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
125 * to the result of dereferencing @ptr.
126 *
127 * Returns zero on success, or -EFAULT on error.
128 */
129#define put_user(x,ptr) \
130 __put_user_check((x),(ptr),sizeof(*(ptr)))
131
132/*
133 * get_user: - Get a simple variable from user space.
134 * @x: Variable to store result.
135 * @ptr: Source address, in user space.
136 *
137 * Context: User context only. This function may sleep.
138 *
139 * This macro copies a single simple variable from user space to kernel
140 * space. It supports simple types like char and int, but not larger
141 * data types like structures or arrays.
142 *
143 * @ptr must have pointer-to-simple-variable type, and the result of
144 * dereferencing @ptr must be assignable to @x without a cast.
145 *
146 * Returns zero on success, or -EFAULT on error.
147 * On error, the variable @x is set to zero.
148 */
149#define get_user(x,ptr) \
150 __get_user_check((x),(ptr),sizeof(*(ptr)))
151
152/*
153 * __put_user: - Write a simple value into user space, with less checking.
154 * @x: Value to copy to user space.
155 * @ptr: Destination address, in user space.
156 *
157 * Context: User context only. This function may sleep.
158 *
159 * This macro copies a single simple value from kernel space to user
160 * space. It supports simple types like char and int, but not larger
161 * data types like structures or arrays.
162 *
163 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
164 * to the result of dereferencing @ptr.
165 *
166 * Caller must check the pointer with access_ok() before calling this
167 * function.
168 *
169 * Returns zero on success, or -EFAULT on error.
170 */
171#define __put_user(x,ptr) \
172 __put_user_nocheck((x),(ptr),sizeof(*(ptr)))
173
174/*
175 * __get_user: - Get a simple variable from user space, with less checking.
176 * @x: Variable to store result.
177 * @ptr: Source address, in user space.
178 *
179 * Context: User context only. This function may sleep.
180 *
181 * This macro copies a single simple variable from user space to kernel
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 the result of
186 * dereferencing @ptr must be assignable to @x without a cast.
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 * On error, the variable @x is set to zero.
193 */
194#define __get_user(x,ptr) \
195 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
196
197struct __large_struct { unsigned long buf[100]; };
Ralf Baechlefe00f942005-03-01 19:22:29 +0000198#define __m(x) (*(struct __large_struct __user *)(x))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
200/*
201 * Yuck. We need two variants, one for 64bit operation and one
202 * for 32 bit mode and old iron.
203 */
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000204#ifdef CONFIG_32BIT
205#define __GET_USER_DW(val, ptr) __get_user_asm_ll32(val, ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206#endif
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000207#ifdef CONFIG_64BIT
208#define __GET_USER_DW(val, ptr) __get_user_asm(val, "ld", ptr)
209#endif
210
211extern void __get_user_unknown(void);
212
213#define __get_user_common(val, size, ptr) \
214do { \
215 switch (size) { \
216 case 1: __get_user_asm(val, "lb", ptr); break; \
217 case 2: __get_user_asm(val, "lh", ptr); break; \
218 case 4: __get_user_asm(val, "lw", ptr); break; \
219 case 8: __GET_USER_DW(val, ptr); break; \
220 default: __get_user_unknown(); break; \
221 } \
222} while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
224#define __get_user_nocheck(x,ptr,size) \
225({ \
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000226 long __gu_err; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 \
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000228 __get_user_common((x), size, ptr); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 __gu_err; \
230})
231
232#define __get_user_check(x,ptr,size) \
233({ \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000234 long __gu_err = -EFAULT; \
Atsushi Nemoto8ecbbca2006-02-14 15:57:50 +0900235 const __typeof__(*(ptr)) __user * __gu_ptr = (ptr); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 \
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000237 if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \
238 __get_user_common((x), size, __gu_ptr); \
239 \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 __gu_err; \
241})
242
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000243#define __get_user_asm(val, insn, addr) \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000244{ \
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000245 long __gu_tmp; \
246 \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 __asm__ __volatile__( \
248 "1: " insn " %1, %3 \n" \
249 "2: \n" \
250 " .section .fixup,\"ax\" \n" \
251 "3: li %0, %4 \n" \
252 " j 2b \n" \
253 " .previous \n" \
254 " .section __ex_table,\"a\" \n" \
255 " "__UA_ADDR "\t1b, 3b \n" \
256 " .previous \n" \
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000257 : "=r" (__gu_err), "=r" (__gu_tmp) \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000258 : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000259 \
Atsushi Nemoto8ecbbca2006-02-14 15:57:50 +0900260 (val) = (__typeof__(*(addr))) __gu_tmp; \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000261}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263/*
264 * Get a long long 64 using 32 bit registers.
265 */
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000266#define __get_user_asm_ll32(val, addr) \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000267{ \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 __asm__ __volatile__( \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000269 "1: lw %1, (%3) \n" \
270 "2: lw %D1, 4(%3) \n" \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 " move %0, $0 \n" \
272 "3: .section .fixup,\"ax\" \n" \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000273 "4: li %0, %4 \n" \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 " move %1, $0 \n" \
275 " move %D1, $0 \n" \
276 " j 3b \n" \
277 " .previous \n" \
278 " .section __ex_table,\"a\" \n" \
279 " " __UA_ADDR " 1b, 4b \n" \
280 " " __UA_ADDR " 2b, 4b \n" \
281 " .previous \n" \
Ralf Baechle4ed3a772007-02-10 21:43:54 +0000282 : "=r" (__gu_err), "=&r" (val) \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000283 : "0" (0), "r" (addr), "i" (-EFAULT)); \
284}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286/*
287 * Yuck. We need two variants, one for 64bit operation and one
288 * for 32 bit mode and old iron.
289 */
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000290#ifdef CONFIG_32BIT
Ralf Baechlefe00f942005-03-01 19:22:29 +0000291#define __PUT_USER_DW(ptr) __put_user_asm_ll32(ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292#endif
Ralf Baechle4feb8f82006-01-23 16:15:30 +0000293#ifdef CONFIG_64BIT
294#define __PUT_USER_DW(ptr) __put_user_asm("sd", ptr)
295#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
297#define __put_user_nocheck(x,ptr,size) \
298({ \
299 __typeof__(*(ptr)) __pu_val; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 long __pu_err = 0; \
301 \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 __pu_val = (x); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 switch (size) { \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000304 case 1: __put_user_asm("sb", ptr); break; \
305 case 2: __put_user_asm("sh", ptr); break; \
306 case 4: __put_user_asm("sw", ptr); break; \
307 case 8: __PUT_USER_DW(ptr); break; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 default: __put_user_unknown(); break; \
309 } \
310 __pu_err; \
311})
312
313#define __put_user_check(x,ptr,size) \
314({ \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000315 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
316 __typeof__(*(ptr)) __pu_val = (x); \
317 long __pu_err = -EFAULT; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000319 if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 switch (size) { \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000321 case 1: __put_user_asm("sb", __pu_addr); break; \
322 case 2: __put_user_asm("sh", __pu_addr); break; \
323 case 4: __put_user_asm("sw", __pu_addr); break; \
324 case 8: __PUT_USER_DW(__pu_addr); break; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 default: __put_user_unknown(); break; \
326 } \
327 } \
328 __pu_err; \
329})
330
Ralf Baechlefe00f942005-03-01 19:22:29 +0000331#define __put_user_asm(insn, ptr) \
332{ \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 __asm__ __volatile__( \
334 "1: " insn " %z2, %3 # __put_user_asm\n" \
335 "2: \n" \
336 " .section .fixup,\"ax\" \n" \
337 "3: li %0, %4 \n" \
338 " j 2b \n" \
339 " .previous \n" \
340 " .section __ex_table,\"a\" \n" \
341 " " __UA_ADDR " 1b, 3b \n" \
342 " .previous \n" \
343 : "=r" (__pu_err) \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000344 : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 "i" (-EFAULT)); \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000346}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
Ralf Baechlefe00f942005-03-01 19:22:29 +0000348#define __put_user_asm_ll32(ptr) \
349{ \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 __asm__ __volatile__( \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000351 "1: sw %2, (%3) # __put_user_asm_ll32 \n" \
352 "2: sw %D2, 4(%3) \n" \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 "3: \n" \
354 " .section .fixup,\"ax\" \n" \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000355 "4: li %0, %4 \n" \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 " j 3b \n" \
357 " .previous \n" \
358 " .section __ex_table,\"a\" \n" \
359 " " __UA_ADDR " 1b, 4b \n" \
360 " " __UA_ADDR " 2b, 4b \n" \
361 " .previous" \
362 : "=r" (__pu_err) \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000363 : "0" (0), "r" (__pu_val), "r" (ptr), \
364 "i" (-EFAULT)); \
365}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
367extern void __put_user_unknown(void);
368
369/*
370 * We're generating jump to subroutines which will be outside the range of
371 * jump instructions
372 */
373#ifdef MODULE
374#define __MODULE_JAL(destination) \
375 ".set\tnoat\n\t" \
376 __UA_LA "\t$1, " #destination "\n\t" \
377 "jalr\t$1\n\t" \
378 ".set\tat\n\t"
379#else
380#define __MODULE_JAL(destination) \
381 "jal\t" #destination "\n\t"
382#endif
383
384extern size_t __copy_user(void *__to, const void *__from, size_t __n);
385
386#define __invoke_copy_to_user(to,from,n) \
387({ \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000388 register void __user *__cu_to_r __asm__ ("$4"); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 register const void *__cu_from_r __asm__ ("$5"); \
390 register long __cu_len_r __asm__ ("$6"); \
391 \
392 __cu_to_r = (to); \
393 __cu_from_r = (from); \
394 __cu_len_r = (n); \
395 __asm__ __volatile__( \
396 __MODULE_JAL(__copy_user) \
397 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
398 : \
399 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
400 "memory"); \
401 __cu_len_r; \
402})
403
404/*
405 * __copy_to_user: - Copy a block of data into user space, with less checking.
406 * @to: Destination address, in user space.
407 * @from: Source address, in kernel space.
408 * @n: Number of bytes to copy.
409 *
410 * Context: User context only. This function may sleep.
411 *
412 * Copy data from kernel space to user space. Caller must check
413 * the specified block with access_ok() before calling this function.
414 *
415 * Returns number of bytes that could not be copied.
416 * On success, this will be zero.
417 */
418#define __copy_to_user(to,from,n) \
419({ \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000420 void __user *__cu_to; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 const void *__cu_from; \
422 long __cu_len; \
423 \
424 might_sleep(); \
425 __cu_to = (to); \
426 __cu_from = (from); \
427 __cu_len = (n); \
428 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
429 __cu_len; \
430})
431
432#define __copy_to_user_inatomic __copy_to_user
433#define __copy_from_user_inatomic __copy_from_user
434
435/*
436 * copy_to_user: - Copy a block of data into user space.
437 * @to: Destination address, in user space.
438 * @from: Source address, in kernel space.
439 * @n: Number of bytes to copy.
440 *
441 * Context: User context only. This function may sleep.
442 *
443 * Copy data from kernel space to user space.
444 *
445 * Returns number of bytes that could not be copied.
446 * On success, this will be zero.
447 */
448#define copy_to_user(to,from,n) \
449({ \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000450 void __user *__cu_to; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 const void *__cu_from; \
452 long __cu_len; \
453 \
454 might_sleep(); \
455 __cu_to = (to); \
456 __cu_from = (from); \
457 __cu_len = (n); \
458 if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) \
459 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, \
460 __cu_len); \
461 __cu_len; \
462})
463
464#define __invoke_copy_from_user(to,from,n) \
465({ \
466 register void *__cu_to_r __asm__ ("$4"); \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000467 register const void __user *__cu_from_r __asm__ ("$5"); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 register long __cu_len_r __asm__ ("$6"); \
469 \
470 __cu_to_r = (to); \
471 __cu_from_r = (from); \
472 __cu_len_r = (n); \
473 __asm__ __volatile__( \
474 ".set\tnoreorder\n\t" \
475 __MODULE_JAL(__copy_user) \
476 ".set\tnoat\n\t" \
477 __UA_ADDU "\t$1, %1, %2\n\t" \
478 ".set\tat\n\t" \
479 ".set\treorder" \
480 : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \
481 : \
482 : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
483 "memory"); \
484 __cu_len_r; \
485})
486
487/*
Chris Dearman131c1a22007-02-01 19:54:13 +0000488 * __copy_from_user: - Copy a block of data from user space, with less checking.
489 * @to: Destination address, in kernel space.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 * @from: Source address, in user space.
491 * @n: Number of bytes to copy.
492 *
493 * Context: User context only. This function may sleep.
494 *
495 * Copy data from user space to kernel space. Caller must check
496 * the specified block with access_ok() before calling this function.
497 *
498 * Returns number of bytes that could not be copied.
499 * On success, this will be zero.
500 *
501 * If some data could not be copied, this function will pad the copied
502 * data to the requested size using zero bytes.
503 */
504#define __copy_from_user(to,from,n) \
505({ \
506 void *__cu_to; \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000507 const void __user *__cu_from; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 long __cu_len; \
509 \
510 might_sleep(); \
511 __cu_to = (to); \
512 __cu_from = (from); \
513 __cu_len = (n); \
514 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
515 __cu_len); \
516 __cu_len; \
517})
518
519/*
520 * copy_from_user: - Copy a block of data from user space.
521 * @to: Destination address, in kernel space.
522 * @from: Source address, in user space.
523 * @n: Number of bytes to copy.
524 *
525 * Context: User context only. This function may sleep.
526 *
527 * Copy data from user space to kernel space.
528 *
529 * Returns number of bytes that could not be copied.
530 * On success, this will be zero.
531 *
532 * If some data could not be copied, this function will pad the copied
533 * data to the requested size using zero bytes.
534 */
535#define copy_from_user(to,from,n) \
536({ \
537 void *__cu_to; \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000538 const void __user *__cu_from; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 long __cu_len; \
540 \
541 might_sleep(); \
542 __cu_to = (to); \
543 __cu_from = (from); \
544 __cu_len = (n); \
545 if (access_ok(VERIFY_READ, __cu_from, __cu_len)) \
546 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
547 __cu_len); \
548 __cu_len; \
549})
550
551#define __copy_in_user(to, from, n) __copy_from_user(to, from, n)
552
553#define copy_in_user(to,from,n) \
554({ \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000555 void __user *__cu_to; \
556 const void __user *__cu_from; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 long __cu_len; \
558 \
559 might_sleep(); \
560 __cu_to = (to); \
561 __cu_from = (from); \
562 __cu_len = (n); \
563 if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) && \
564 access_ok(VERIFY_WRITE, __cu_to, __cu_len))) \
565 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \
566 __cu_len); \
567 __cu_len; \
568})
569
570/*
571 * __clear_user: - Zero a block of memory in user space, with less checking.
572 * @to: Destination address, in user space.
573 * @n: Number of bytes to zero.
574 *
575 * Zero a block of memory in user space. Caller must check
576 * the specified block with access_ok() before calling this function.
577 *
578 * Returns number of bytes that could not be cleared.
579 * On success, this will be zero.
580 */
581static inline __kernel_size_t
Ralf Baechlefe00f942005-03-01 19:22:29 +0000582__clear_user(void __user *addr, __kernel_size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583{
584 __kernel_size_t res;
585
586 might_sleep();
587 __asm__ __volatile__(
588 "move\t$4, %1\n\t"
589 "move\t$5, $0\n\t"
590 "move\t$6, %2\n\t"
591 __MODULE_JAL(__bzero)
592 "move\t%0, $6"
593 : "=r" (res)
594 : "r" (addr), "r" (size)
595 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
596
597 return res;
598}
599
600#define clear_user(addr,n) \
601({ \
Ralf Baechlefe00f942005-03-01 19:22:29 +0000602 void __user * __cl_addr = (addr); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 unsigned long __cl_size = (n); \
604 if (__cl_size && access_ok(VERIFY_WRITE, \
605 ((unsigned long)(__cl_addr)), __cl_size)) \
606 __cl_size = __clear_user(__cl_addr, __cl_size); \
607 __cl_size; \
608})
609
610/*
611 * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
612 * @dst: Destination address, in kernel space. This buffer must be at
613 * least @count bytes long.
614 * @src: Source address, in user space.
615 * @count: Maximum number of bytes to copy, including the trailing NUL.
616 *
617 * Copies a NUL-terminated string from userspace to kernel space.
618 * Caller must check the specified block with access_ok() before calling
619 * this function.
620 *
621 * On success, returns the length of the string (not including the trailing
622 * NUL).
623 *
624 * If access to userspace fails, returns -EFAULT (some data may have been
625 * copied).
626 *
627 * If @count is smaller than the length of the string, copies @count bytes
628 * and returns @count.
629 */
630static inline long
Ralf Baechlefe00f942005-03-01 19:22:29 +0000631__strncpy_from_user(char *__to, const char __user *__from, long __len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632{
633 long res;
634
635 might_sleep();
636 __asm__ __volatile__(
637 "move\t$4, %1\n\t"
638 "move\t$5, %2\n\t"
639 "move\t$6, %3\n\t"
640 __MODULE_JAL(__strncpy_from_user_nocheck_asm)
641 "move\t%0, $2"
642 : "=r" (res)
643 : "r" (__to), "r" (__from), "r" (__len)
644 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
645
646 return res;
647}
648
649/*
650 * strncpy_from_user: - Copy a NUL terminated string from userspace.
651 * @dst: Destination address, in kernel space. This buffer must be at
652 * least @count bytes long.
653 * @src: Source address, in user space.
654 * @count: Maximum number of bytes to copy, including the trailing NUL.
655 *
656 * Copies a NUL-terminated string from userspace to kernel space.
657 *
658 * On success, returns the length of the string (not including the trailing
659 * NUL).
660 *
661 * If access to userspace fails, returns -EFAULT (some data may have been
662 * copied).
663 *
664 * If @count is smaller than the length of the string, copies @count bytes
665 * and returns @count.
666 */
667static inline long
Ralf Baechlefe00f942005-03-01 19:22:29 +0000668strncpy_from_user(char *__to, const char __user *__from, long __len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669{
670 long res;
671
672 might_sleep();
673 __asm__ __volatile__(
674 "move\t$4, %1\n\t"
675 "move\t$5, %2\n\t"
676 "move\t$6, %3\n\t"
677 __MODULE_JAL(__strncpy_from_user_asm)
678 "move\t%0, $2"
679 : "=r" (res)
680 : "r" (__to), "r" (__from), "r" (__len)
681 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
682
683 return res;
684}
685
686/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
Ralf Baechlefe00f942005-03-01 19:22:29 +0000687static inline long __strlen_user(const char __user *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688{
689 long res;
690
691 might_sleep();
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 */
Ralf Baechlefe00f942005-03-01 19:22:29 +0000717static inline long strlen_user(const char __user *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718{
719 long res;
720
721 might_sleep();
722 __asm__ __volatile__(
723 "move\t$4, %1\n\t"
724 __MODULE_JAL(__strlen_user_asm)
725 "move\t%0, $2"
726 : "=r" (res)
727 : "r" (s)
728 : "$2", "$4", __UA_t0, "$31");
729
730 return res;
731}
732
733/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
Ralf Baechlefe00f942005-03-01 19:22:29 +0000734static inline long __strnlen_user(const char __user *s, long n)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735{
736 long res;
737
738 might_sleep();
739 __asm__ __volatile__(
740 "move\t$4, %1\n\t"
741 "move\t$5, %2\n\t"
742 __MODULE_JAL(__strnlen_user_nocheck_asm)
743 "move\t%0, $2"
744 : "=r" (res)
745 : "r" (s), "r" (n)
746 : "$2", "$4", "$5", __UA_t0, "$31");
747
748 return res;
749}
750
751/*
752 * strlen_user: - Get the size of a string in user space.
753 * @str: The string to measure.
754 *
755 * Context: User context only. This function may sleep.
756 *
757 * Get the size of a NUL-terminated string in user space.
758 *
759 * Returns the size of the string INCLUDING the terminating NUL.
760 * On exception, returns 0.
761 *
762 * If there is a limit on the length of a valid string, you may wish to
763 * consider using strnlen_user() instead.
764 */
Ralf Baechlefe00f942005-03-01 19:22:29 +0000765static inline long strnlen_user(const char __user *s, long n)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766{
767 long res;
768
769 might_sleep();
770 __asm__ __volatile__(
771 "move\t$4, %1\n\t"
772 "move\t$5, %2\n\t"
773 __MODULE_JAL(__strnlen_user_asm)
774 "move\t%0, $2"
775 : "=r" (res)
776 : "r" (s), "r" (n)
777 : "$2", "$4", "$5", __UA_t0, "$31");
778
779 return res;
780}
781
782struct exception_table_entry
783{
784 unsigned long insn;
785 unsigned long nextinsn;
786};
787
788extern int fixup_exception(struct pt_regs *regs);
789
790#endif /* _ASM_UACCESS_H */