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Automatic merge of rsync://rsync.kernel.org/pub/scm/linux/kernel/git/gregkh/driver...
[linux-2.6/verdex.git] / include / asm-m32r / uaccess.h
blobbbb8ac4018a070d615d9df5d6fa356da3ed91ded
1 #ifndef _ASM_M32R_UACCESS_H
2 #define _ASM_M32R_UACCESS_H
3
4 /*
5 * linux/include/asm-m32r/uaccess.h
6 *
7 * M32R version.
8 * Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
9 */
10
11 #undef UACCESS_DEBUG
12
13 #ifdef UACCESS_DEBUG
14 #define UAPRINTK(args...) printk(args)
15 #else
16 #define UAPRINTK(args...)
17 #endif /* UACCESS_DEBUG */
18
19 /*
20 * User space memory access functions
21 */
22 #include <linux/config.h>
23 #include <linux/errno.h>
24 #include <linux/thread_info.h>
25 #include <asm/page.h>
26
27 #define VERIFY_READ 0
28 #define VERIFY_WRITE 1
29
30 /*
31 * The fs value determines whether argument validity checking should be
32 * performed or not. If get_fs() == USER_DS, checking is performed, with
33 * get_fs() == KERNEL_DS, checking is bypassed.
34 *
35 * For historical reasons, these macros are grossly misnamed.
36 */
37
38 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
39
40 #ifdef CONFIG_MMU
41 #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
42 #define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
43 #else
44 #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
45 #define USER_DS MAKE_MM_SEG(0xFFFFFFFF)
46 #endif /* CONFIG_MMU */
47
48 #define get_ds() (KERNEL_DS)
49 #ifdef CONFIG_MMU
50 #define get_fs() (current_thread_info()->addr_limit)
51 #define set_fs(x) (current_thread_info()->addr_limit = (x))
52 #else
53 static inline mm_segment_t get_fs(void)
54 {
55 return USER_DS;
56 }
57
58 static inline void set_fs(mm_segment_t s)
59 {
60 }
61 #endif /* CONFIG_MMU */
62
63 #define segment_eq(a,b) ((a).seg == (b).seg)
64
65 #define __addr_ok(addr) \
66 ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
67
68 /*
69 * Test whether a block of memory is a valid user space address.
70 * Returns 0 if the range is valid, nonzero otherwise.
71 *
72 * This is equivalent to the following test:
73 * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
74 *
75 * This needs 33-bit arithmetic. We have a carry...
76 */
77 #define __range_ok(addr,size) ({ \
78 unsigned long flag, sum; \
79 __chk_user_ptr(addr); \
80 asm ( \
81 " cmpu %1, %1 ; clear cbit\n" \
82 " addx %1, %3 ; set cbit if overflow\n" \
83 " subx %0, %0\n" \
84 " cmpu %4, %1\n" \
85 " subx %0, %5\n" \
86 : "=&r"(flag), "=r"(sum) \
87 : "1"(addr), "r"((int)(size)), \
88 "r"(current_thread_info()->addr_limit.seg), "r"(0) \
89 : "cbit" ); \
90 flag; })
91
92 /**
93 * access_ok: - Checks if a user space pointer is valid
94 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
95 * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
96 * to write to a block, it is always safe to read from it.
97 * @addr: User space pointer to start of block to check
98 * @size: Size of block to check
99 *
100 * Context: User context only. This function may sleep.
101 *
102 * Checks if a pointer to a block of memory in user space is valid.
103 *
104 * Returns true (nonzero) if the memory block may be valid, false (zero)
105 * if it is definitely invalid.
106 *
107 * Note that, depending on architecture, this function probably just
108 * checks that the pointer is in the user space range - after calling
109 * this function, memory access functions may still return -EFAULT.
110 */
111 #ifdef CONFIG_MMU
112 #define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
113 #else
114 static inline int access_ok(int type, const void *addr, unsigned long size)
115 {
116 extern unsigned long memory_start, memory_end;
117 unsigned long val = (unsigned long)addr;
118
119 return ((val >= memory_start) && ((val + size) < memory_end));
120 }
121 #endif /* CONFIG_MMU */
122
123 /**
124 * verify_area: - Obsolete/deprecated and will go away soon,
125 * use access_ok() instead.
126 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE
127 * @addr: User space pointer to start of block to check
128 * @size: Size of block to check
129 *
130 * Context: User context only. This function may sleep.
131 *
132 * This function has been replaced by access_ok().
133 *
134 * Checks if a pointer to a block of memory in user space is valid.
135 *
136 * Returns zero if the memory block may be valid, -EFAULT
137 * if it is definitely invalid.
138 *
139 * See access_ok() for more details.
140 */
141 static inline int __deprecated verify_area(int type, const void __user *addr,
142 unsigned long size)
143 {
144 return access_ok(type, addr, size) ? 0 : -EFAULT;
145 }
146
147
148 /*
149 * The exception table consists of pairs of addresses: the first is the
150 * address of an instruction that is allowed to fault, and the second is
151 * the address at which the program should continue. No registers are
152 * modified, so it is entirely up to the continuation code to figure out
153 * what to do.
154 *
155 * All the routines below use bits of fixup code that are out of line
156 * with the main instruction path. This means when everything is well,
157 * we don't even have to jump over them. Further, they do not intrude
158 * on our cache or tlb entries.
159 */
160
161 struct exception_table_entry
162 {
163 unsigned long insn, fixup;
164 };
165
166 extern int fixup_exception(struct pt_regs *regs);
167
168 /*
169 * These are the main single-value transfer routines. They automatically
170 * use the right size if we just have the right pointer type.
171 *
172 * This gets kind of ugly. We want to return _two_ values in "get_user()"
173 * and yet we don't want to do any pointers, because that is too much
174 * of a performance impact. Thus we have a few rather ugly macros here,
175 * and hide all the uglyness from the user.
176 *
177 * The "__xxx" versions of the user access functions are versions that
178 * do not verify the address space, that must have been done previously
179 * with a separate "access_ok()" call (this is used when we do multiple
180 * accesses to the same area of user memory).
181 */
182
183 extern void __get_user_1(void);
184 extern void __get_user_2(void);
185 extern void __get_user_4(void);
186
187 #ifndef MODULE
188 #define __get_user_x(size,ret,x,ptr) \
189 __asm__ __volatile__( \
190 " mv r0, %0\n" \
191 " mv r1, %1\n" \
192 " bl __get_user_" #size "\n" \
193 " mv %0, r0\n" \
194 " mv %1, r1\n" \
195 : "=r"(ret), "=r"(x) \
196 : "0"(ptr) \
197 : "r0", "r1", "r14" )
198 #else /* MODULE */
199 /*
200 * Use "jl" instead of "bl" for MODULE
201 */
202 #define __get_user_x(size,ret,x,ptr) \
203 __asm__ __volatile__( \
204 " mv r0, %0\n" \
205 " mv r1, %1\n" \
206 " seth lr, #high(__get_user_" #size ")\n" \
207 " or3 lr, lr, #low(__get_user_" #size ")\n" \
208 " jl lr\n" \
209 " mv %0, r0\n" \
210 " mv %1, r1\n" \
211 : "=r"(ret), "=r"(x) \
212 : "0"(ptr) \
213 : "r0", "r1", "r14" )
214 #endif
215
216 /* Careful: we have to cast the result to the type of the pointer for sign
217 reasons */
218 /**
219 * get_user: - Get a simple variable from user space.
220 * @x: Variable to store result.
221 * @ptr: Source address, in user space.
222 *
223 * Context: User context only. This function may sleep.
224 *
225 * This macro copies a single simple variable from user space to kernel
226 * space. It supports simple types like char and int, but not larger
227 * data types like structures or arrays.
228 *
229 * @ptr must have pointer-to-simple-variable type, and the result of
230 * dereferencing @ptr must be assignable to @x without a cast.
231 *
232 * Returns zero on success, or -EFAULT on error.
233 * On error, the variable @x is set to zero.
234 */
235 #define get_user(x,ptr) \
236 ({ int __ret_gu,__val_gu; \
237 __chk_user_ptr(ptr); \
238 switch(sizeof (*(ptr))) { \
239 case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
240 case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
241 case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
242 default: __get_user_x(X,__ret_gu,__val_gu,ptr); break; \
243 } \
244 (x) = (__typeof__(*(ptr)))__val_gu; \
245 __ret_gu; \
246 })
247
248 extern void __put_user_bad(void);
249
250 /**
251 * put_user: - Write a simple value into user space.
252 * @x: Value to copy to user space.
253 * @ptr: Destination address, in user space.
254 *
255 * Context: User context only. This function may sleep.
256 *
257 * This macro copies a single simple value from kernel space to user
258 * space. It supports simple types like char and int, but not larger
259 * data types like structures or arrays.
260 *
261 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
262 * to the result of dereferencing @ptr.
263 *
264 * Returns zero on success, or -EFAULT on error.
265 */
266 #define put_user(x,ptr) \
267 __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
268
269
270 /**
271 * __get_user: - Get a simple variable from user space, with less checking.
272 * @x: Variable to store result.
273 * @ptr: Source address, in user space.
274 *
275 * Context: User context only. This function may sleep.
276 *
277 * This macro copies a single simple variable from user space to kernel
278 * space. It supports simple types like char and int, but not larger
279 * data types like structures or arrays.
280 *
281 * @ptr must have pointer-to-simple-variable type, and the result of
282 * dereferencing @ptr must be assignable to @x without a cast.
283 *
284 * Caller must check the pointer with access_ok() before calling this
285 * function.
286 *
287 * Returns zero on success, or -EFAULT on error.
288 * On error, the variable @x is set to zero.
289 */
290 #define __get_user(x,ptr) \
291 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
292
293
294 /**
295 * __put_user: - Write a simple value into user space, with less checking.
296 * @x: Value to copy to user space.
297 * @ptr: Destination address, in user space.
298 *
299 * Context: User context only. This function may sleep.
300 *
301 * This macro copies a single simple value from kernel space to user
302 * space. It supports simple types like char and int, but not larger
303 * data types like structures or arrays.
304 *
305 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
306 * to the result of dereferencing @ptr.
307 *
308 * Caller must check the pointer with access_ok() before calling this
309 * function.
310 *
311 * Returns zero on success, or -EFAULT on error.
312 */
313 #define __put_user(x,ptr) \
314 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
315
316 #define __put_user_nocheck(x,ptr,size) \
317 ({ \
318 long __pu_err; \
319 __put_user_size((x),(ptr),(size),__pu_err); \
320 __pu_err; \
321 })
322
323
324 #define __put_user_check(x,ptr,size) \
325 ({ \
326 long __pu_err = -EFAULT; \
327 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
328 might_sleep(); \
329 if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
330 __put_user_size((x),__pu_addr,(size),__pu_err); \
331 __pu_err; \
332 })
333
334 #if defined(__LITTLE_ENDIAN__)
335 #define __put_user_u64(x, addr, err) \
336 __asm__ __volatile__( \
337 " .fillinsn\n" \
338 "1: st %L1,@%2\n" \
339 " .fillinsn\n" \
340 "2: st %H1,@(4,%2)\n" \
341 " .fillinsn\n" \
342 "3:\n" \
343 ".section .fixup,\"ax\"\n" \
344 " .balign 4\n" \
345 "4: ldi %0,%3\n" \
346 " seth r14,#high(3b)\n" \
347 " or3 r14,r14,#low(3b)\n" \
348 " jmp r14\n" \
349 ".previous\n" \
350 ".section __ex_table,\"a\"\n" \
351 " .balign 4\n" \
352 " .long 1b,4b\n" \
353 " .long 2b,4b\n" \
354 ".previous" \
355 : "=r"(err) \
356 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
357 : "r14", "memory")
358
359 #elif defined(__BIG_ENDIAN__)
360 #define __put_user_u64(x, addr, err) \
361 __asm__ __volatile__( \
362 " .fillinsn\n" \
363 "1: st %H1,@%2\n" \
364 " .fillinsn\n" \
365 "2: st %L1,@(4,%2)\n" \
366 " .fillinsn\n" \
367 "3:\n" \
368 ".section .fixup,\"ax\"\n" \
369 " .balign 4\n" \
370 "4: ldi %0,%3\n" \
371 " seth r14,#high(3b)\n" \
372 " or3 r14,r14,#low(3b)\n" \
373 " jmp r14\n" \
374 ".previous\n" \
375 ".section __ex_table,\"a\"\n" \
376 " .balign 4\n" \
377 " .long 1b,4b\n" \
378 " .long 2b,4b\n" \
379 ".previous" \
380 : "=r"(err) \
381 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
382 : "r14", "memory")
383 #else
384 #error no endian defined
385 #endif
386
387 #define __put_user_size(x,ptr,size,retval) \
388 do { \
389 retval = 0; \
390 __chk_user_ptr(ptr); \
391 switch (size) { \
392 case 1: __put_user_asm(x,ptr,retval,"b"); break; \
393 case 2: __put_user_asm(x,ptr,retval,"h"); break; \
394 case 4: __put_user_asm(x,ptr,retval,""); break; \
395 case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
396 default: __put_user_bad(); \
397 } \
398 } while (0)
399
400 struct __large_struct { unsigned long buf[100]; };
401 #define __m(x) (*(struct __large_struct *)(x))
402
403 /*
404 * Tell gcc we read from memory instead of writing: this is because
405 * we do not write to any memory gcc knows about, so there are no
406 * aliasing issues.
407 */
408 #define __put_user_asm(x, addr, err, itype) \
409 __asm__ __volatile__( \
410 " .fillinsn\n" \
411 "1: st"itype" %1,@%2\n" \
412 " .fillinsn\n" \
413 "2:\n" \
414 ".section .fixup,\"ax\"\n" \
415 " .balign 4\n" \
416 "3: ldi %0,%3\n" \
417 " seth r14,#high(2b)\n" \
418 " or3 r14,r14,#low(2b)\n" \
419 " jmp r14\n" \
420 ".previous\n" \
421 ".section __ex_table,\"a\"\n" \
422 " .balign 4\n" \
423 " .long 1b,3b\n" \
424 ".previous" \
425 : "=r"(err) \
426 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err) \
427 : "r14", "memory")
428
429 #define __get_user_nocheck(x,ptr,size) \
430 ({ \
431 long __gu_err, __gu_val; \
432 __get_user_size(__gu_val,(ptr),(size),__gu_err); \
433 (x) = (__typeof__(*(ptr)))__gu_val; \
434 __gu_err; \
435 })
436
437 extern long __get_user_bad(void);
438
439 #define __get_user_size(x,ptr,size,retval) \
440 do { \
441 retval = 0; \
442 __chk_user_ptr(ptr); \
443 switch (size) { \
444 case 1: __get_user_asm(x,ptr,retval,"ub"); break; \
445 case 2: __get_user_asm(x,ptr,retval,"uh"); break; \
446 case 4: __get_user_asm(x,ptr,retval,""); break; \
447 default: (x) = __get_user_bad(); \
448 } \
449 } while (0)
450
451 #define __get_user_asm(x, addr, err, itype) \
452 __asm__ __volatile__( \
453 " .fillinsn\n" \
454 "1: ld"itype" %1,@%2\n" \
455 " .fillinsn\n" \
456 "2:\n" \
457 ".section .fixup,\"ax\"\n" \
458 " .balign 4\n" \
459 "3: ldi %0,%3\n" \
460 " seth r14,#high(2b)\n" \
461 " or3 r14,r14,#low(2b)\n" \
462 " jmp r14\n" \
463 ".previous\n" \
464 ".section __ex_table,\"a\"\n" \
465 " .balign 4\n" \
466 " .long 1b,3b\n" \
467 ".previous" \
468 : "=r"(err), "=&r"(x) \
469 : "r"(addr), "i"(-EFAULT), "0"(err) \
470 : "r14", "memory")
471
472 /*
473 * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault
474 * we return the initial request size (1, 2 or 4), as copy_*_user should do.
475 * If a store crosses a page boundary and gets a fault, the m32r will not write
476 * anything, so this is accurate.
477 */
478
479
480 /*
481 * Copy To/From Userspace
482 */
483
484 /* Generic arbitrary sized copy. */
485 /* Return the number of bytes NOT copied. */
486 #define __copy_user(to,from,size) \
487 do { \
488 unsigned long __dst, __src, __c; \
489 __asm__ __volatile__ ( \
490 " mv r14, %0\n" \
491 " or r14, %1\n" \
492 " beq %0, %1, 9f\n" \
493 " beqz %2, 9f\n" \
494 " and3 r14, r14, #3\n" \
495 " bnez r14, 2f\n" \
496 " and3 %2, %2, #3\n" \
497 " beqz %3, 2f\n" \
498 " addi %0, #-4 ; word_copy \n" \
499 " .fillinsn\n" \
500 "0: ld r14, @%1+\n" \
501 " addi %3, #-1\n" \
502 " .fillinsn\n" \
503 "1: st r14, @+%0\n" \
504 " bnez %3, 0b\n" \
505 " beqz %2, 9f\n" \
506 " addi %0, #4\n" \
507 " .fillinsn\n" \
508 "2: ldb r14, @%1 ; byte_copy \n" \
509 " .fillinsn\n" \
510 "3: stb r14, @%0\n" \
511 " addi %1, #1\n" \
512 " addi %2, #-1\n" \
513 " addi %0, #1\n" \
514 " bnez %2, 2b\n" \
515 " .fillinsn\n" \
516 "9:\n" \
517 ".section .fixup,\"ax\"\n" \
518 " .balign 4\n" \
519 "5: addi %3, #1\n" \
520 " addi %1, #-4\n" \
521 " .fillinsn\n" \
522 "6: slli %3, #2\n" \
523 " add %2, %3\n" \
524 " addi %0, #4\n" \
525 " .fillinsn\n" \
526 "7: seth r14, #high(9b)\n" \
527 " or3 r14, r14, #low(9b)\n" \
528 " jmp r14\n" \
529 ".previous\n" \
530 ".section __ex_table,\"a\"\n" \
531 " .balign 4\n" \
532 " .long 0b,6b\n" \
533 " .long 1b,5b\n" \
534 " .long 2b,9b\n" \
535 " .long 3b,9b\n" \
536 ".previous\n" \
537 : "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c) \
538 : "0"(to), "1"(from), "2"(size), "3"(size / 4) \
539 : "r14", "memory"); \
540 } while (0)
541
542 #define __copy_user_zeroing(to,from,size) \
543 do { \
544 unsigned long __dst, __src, __c; \
545 __asm__ __volatile__ ( \
546 " mv r14, %0\n" \
547 " or r14, %1\n" \
548 " beq %0, %1, 9f\n" \
549 " beqz %2, 9f\n" \
550 " and3 r14, r14, #3\n" \
551 " bnez r14, 2f\n" \
552 " and3 %2, %2, #3\n" \
553 " beqz %3, 2f\n" \
554 " addi %0, #-4 ; word_copy \n" \
555 " .fillinsn\n" \
556 "0: ld r14, @%1+\n" \
557 " addi %3, #-1\n" \
558 " .fillinsn\n" \
559 "1: st r14, @+%0\n" \
560 " bnez %3, 0b\n" \
561 " beqz %2, 9f\n" \
562 " addi %0, #4\n" \
563 " .fillinsn\n" \
564 "2: ldb r14, @%1 ; byte_copy \n" \
565 " .fillinsn\n" \
566 "3: stb r14, @%0\n" \
567 " addi %1, #1\n" \
568 " addi %2, #-1\n" \
569 " addi %0, #1\n" \
570 " bnez %2, 2b\n" \
571 " .fillinsn\n" \
572 "9:\n" \
573 ".section .fixup,\"ax\"\n" \
574 " .balign 4\n" \
575 "5: addi %3, #1\n" \
576 " addi %1, #-4\n" \
577 " .fillinsn\n" \
578 "6: slli %3, #2\n" \
579 " add %2, %3\n" \
580 " addi %0, #4\n" \
581 " .fillinsn\n" \
582 "7: ldi r14, #0 ; store zero \n" \
583 " .fillinsn\n" \
584 "8: addi %2, #-1\n" \
585 " stb r14, @%0 ; ACE? \n" \
586 " addi %0, #1\n" \
587 " bnez %2, 8b\n" \
588 " seth r14, #high(9b)\n" \
589 " or3 r14, r14, #low(9b)\n" \
590 " jmp r14\n" \
591 ".previous\n" \
592 ".section __ex_table,\"a\"\n" \
593 " .balign 4\n" \
594 " .long 0b,6b\n" \
595 " .long 1b,5b\n" \
596 " .long 2b,7b\n" \
597 " .long 3b,7b\n" \
598 ".previous\n" \
599 : "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c) \
600 : "0"(to), "1"(from), "2"(size), "3"(size / 4) \
601 : "r14", "memory"); \
602 } while (0)
603
604
605 /* We let the __ versions of copy_from/to_user inline, because they're often
606 * used in fast paths and have only a small space overhead.
607 */
608 static inline unsigned long __generic_copy_from_user_nocheck(void *to,
609 const void __user *from, unsigned long n)
610 {
611 __copy_user_zeroing(to,from,n);
612 return n;
613 }
614
615 static inline unsigned long __generic_copy_to_user_nocheck(void __user *to,
616 const void *from, unsigned long n)
617 {
618 __copy_user(to,from,n);
619 return n;
620 }
621
622 unsigned long __generic_copy_to_user(void *, const void *, unsigned long);
623 unsigned long __generic_copy_from_user(void *, const void *, unsigned long);
624
625 /**
626 * __copy_to_user: - Copy a block of data into user space, with less checking.
627 * @to: Destination address, in user space.
628 * @from: Source address, in kernel space.
629 * @n: Number of bytes to copy.
630 *
631 * Context: User context only. This function may sleep.
632 *
633 * Copy data from kernel space to user space. Caller must check
634 * the specified block with access_ok() before calling this function.
635 *
636 * Returns number of bytes that could not be copied.
637 * On success, this will be zero.
638 */
639 #define __copy_to_user(to,from,n) \
640 __generic_copy_to_user_nocheck((to),(from),(n))
641
642 #define __copy_to_user_inatomic __copy_to_user
643 #define __copy_from_user_inatomic __copy_from_user
644
645 /**
646 * copy_to_user: - Copy a block of data into user space.
647 * @to: Destination address, in user space.
648 * @from: Source address, in kernel space.
649 * @n: Number of bytes to copy.
650 *
651 * Context: User context only. This function may sleep.
652 *
653 * Copy data from kernel space to user space.
654 *
655 * Returns number of bytes that could not be copied.
656 * On success, this will be zero.
657 */
658 #define copy_to_user(to,from,n) \
659 ({ \
660 might_sleep(); \
661 __generic_copy_to_user((to),(from),(n)); \
662 })
663
664 /**
665 * __copy_from_user: - Copy a block of data from user space, with less checking. * @to: Destination address, in kernel space.
666 * @from: Source address, in user space.
667 * @n: Number of bytes to copy.
668 *
669 * Context: User context only. This function may sleep.
670 *
671 * Copy data from user space to kernel space. Caller must check
672 * the specified block with access_ok() before calling this function.
673 *
674 * Returns number of bytes that could not be copied.
675 * On success, this will be zero.
676 *
677 * If some data could not be copied, this function will pad the copied
678 * data to the requested size using zero bytes.
679 */
680 #define __copy_from_user(to,from,n) \
681 __generic_copy_from_user_nocheck((to),(from),(n))
682
683 /**
684 * copy_from_user: - Copy a block of data from user space.
685 * @to: Destination address, in kernel space.
686 * @from: Source address, in user space.
687 * @n: Number of bytes to copy.
688 *
689 * Context: User context only. This function may sleep.
690 *
691 * Copy data from user space to kernel space.
692 *
693 * Returns number of bytes that could not be copied.
694 * On success, this will be zero.
695 *
696 * If some data could not be copied, this function will pad the copied
697 * data to the requested size using zero bytes.
698 */
699 #define copy_from_user(to,from,n) \
700 ({ \
701 might_sleep(); \
702 __generic_copy_from_user((to),(from),(n)); \
703 })
704
705 long __must_check strncpy_from_user(char *dst, const char __user *src,
706 long count);
707 long __must_check __strncpy_from_user(char *dst,
708 const char __user *src, long count);
709
710 /**
711 * __clear_user: - Zero a block of memory in user space, with less checking.
712 * @to: Destination address, in user space.
713 * @n: Number of bytes to zero.
714 *
715 * Zero a block of memory in user space. Caller must check
716 * the specified block with access_ok() before calling this function.
717 *
718 * Returns number of bytes that could not be cleared.
719 * On success, this will be zero.
720 */
721 unsigned long __clear_user(void __user *mem, unsigned long len);
722
723 /**
724 * clear_user: - Zero a block of memory in user space.
725 * @to: Destination address, in user space.
726 * @n: Number of bytes to zero.
727 *
728 * Zero a block of memory in user space. Caller must check
729 * the specified block with access_ok() before calling this function.
730 *
731 * Returns number of bytes that could not be cleared.
732 * On success, this will be zero.
733 */
734 unsigned long clear_user(void __user *mem, unsigned long len);
735
736 /**
737 * strlen_user: - Get the size of a string in user space.
738 * @str: The string to measure.
739 *
740 * Context: User context only. This function may sleep.
741 *
742 * Get the size of a NUL-terminated string in user space.
743 *
744 * Returns the size of the string INCLUDING the terminating NUL.
745 * On exception, returns 0.
746 *
747 * If there is a limit on the length of a valid string, you may wish to
748 * consider using strnlen_user() instead.
749 */
750 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
751 long strnlen_user(const char __user *str, long n);
752
753 #endif /* _ASM_M32R_UACCESS_H */
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