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initial commit with v2.6.9
[linux-2.6.9-moxart.git] / include / asm-sh / uaccess.h
blobdf9a9b28eff9aef5237dc790e19b7ba74b1aab2f
1 /* $Id: uaccess.h,v 1.11 2003/10/13 07:21:20 lethal Exp $
2 *
3 * User space memory access functions
4 *
5 * Copyright (C) 1999, 2002 Niibe Yutaka
6 * Copyright (C) 2003 Paul Mundt
7 *
8 * Based on:
9 * MIPS implementation version 1.15 by
10 * Copyright (C) 1996, 1997, 1998 by Ralf Baechle
11 * and i386 version.
12 */
13 #ifndef __ASM_SH_UACCESS_H
14 #define __ASM_SH_UACCESS_H
15
16 #include <linux/errno.h>
17 #include <linux/sched.h>
18
19 /*
20 * NOTE: Macro/functions in this file depends on threads_info.h implementation.
21 * Assumes:
22 * TI_FLAGS == 8
23 * TIF_USERSPACE == 31
24 * USER_ADDR_LIMIT == 0x80000000
25 */
26
27 #define VERIFY_READ 0
28 #define VERIFY_WRITE 1
29
30 typedef struct {
31 unsigned int is_user_space;
32 } mm_segment_t;
33
34 /*
35 * The fs value determines whether argument validity checking should be
36 * performed or not. If get_fs() == USER_DS, checking is performed, with
37 * get_fs() == KERNEL_DS, checking is bypassed.
38 *
39 * For historical reasons (Data Segment Register?), these macros are misnamed.
40 */
41
42 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
43 #define segment_eq(a,b) ((a).is_user_space == (b).is_user_space)
44
45 #define USER_ADDR_LIMIT 0x80000000
46
47 #define KERNEL_DS MAKE_MM_SEG(0)
48 #define USER_DS MAKE_MM_SEG(1)
49
50 #define get_ds() (KERNEL_DS)
51
52 #if !defined(CONFIG_MMU)
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
62 /*
63 * __access_ok: Check if address with size is OK or not.
64 *
65 * If we don't have an MMU (or if its disabled) the only thing we really have
66 * to look out for is if the address resides somewhere outside of what
67 * available RAM we have.
68 *
69 * TODO: This check could probably also stand to be restricted somewhat more..
70 * though it still does the Right Thing(tm) for the time being.
71 */
72 static inline int __access_ok(unsigned long addr, unsigned long size)
73 {
74 extern unsigned long memory_start, memory_end;
75
76 return ((addr >= memory_start) && ((addr + size) < memory_end));
77 }
78 #else /* CONFIG_MMU */
79 static inline mm_segment_t get_fs(void)
80 {
81 return MAKE_MM_SEG(test_thread_flag(TIF_USERSPACE));
82 }
83
84 static inline void set_fs(mm_segment_t s)
85 {
86 unsigned long ti, flag;
87 __asm__ __volatile__(
88 "stc r7_bank, %0\n\t"
89 "mov.l @(8,%0), %1\n\t"
90 "shal %1\n\t"
91 "cmp/pl %2\n\t"
92 "rotcr %1\n\t"
93 "mov.l %1, @(8,%0)"
94 : "=&r" (ti), "=&r" (flag)
95 : "r" (s.is_user_space)
96 : "t");
97 /****
98 if (s.is_user_space)
99 set_thread_flag(TIF_USERSPACE);
100 else
101 clear_thread_flag(TIF_USERSPACE);
102 ****/
103 }
104
105 /*
106 * __access_ok: Check if address with size is OK or not.
107 *
108 * We do three checks:
109 * (1) is it user space?
110 * (2) addr + size --> carry?
111 * (3) addr + size >= 0x80000000 (USER_ADDR_LIMIT)
112 *
113 * (1) (2) (3) | RESULT
114 * 0 0 0 | ok
115 * 0 0 1 | ok
116 * 0 1 0 | bad
117 * 0 1 1 | bad
118 * 1 0 0 | ok
119 * 1 0 1 | bad
120 * 1 1 0 | bad
121 * 1 1 1 | bad
122 */
123 static inline int __access_ok(unsigned long addr, unsigned long size)
124 {
125 unsigned long flag, tmp;
126
127 __asm__("stc r7_bank, %0\n\t"
128 "mov.l @(8,%0), %0\n\t"
129 "clrt\n\t"
130 "addc %2, %1\n\t"
131 "and %1, %0\n\t"
132 "rotcl %0\n\t"
133 "rotcl %0\n\t"
134 "and #3, %0"
135 : "=&z" (flag), "=r" (tmp)
136 : "r" (addr), "1" (size)
137 : "t");
138
139 return flag == 0;
140 }
141 #endif /* CONFIG_MMU */
142
143 static inline int access_ok(int type, const void __user *p, unsigned long size)
144 {
145 unsigned long addr = (unsigned long)p;
146 return __access_ok(addr, size);
147 }
148
149 static inline int verify_area(int type, const void __user * addr, unsigned long size)
150 {
151 return access_ok(type,addr,size) ? 0 : -EFAULT;
152 }
153
154 /*
155 * Uh, these should become the main single-value transfer routines ...
156 * They automatically use the right size if we just have the right
157 * pointer type ...
158 *
159 * As SuperH uses the same address space for kernel and user data, we
160 * can just do these as direct assignments.
161 *
162 * Careful to not
163 * (a) re-use the arguments for side effects (sizeof is ok)
164 * (b) require any knowledge of processes at this stage
165 */
166 #define put_user(x,ptr) __put_user_check((x),(ptr),sizeof(*(ptr)))
167 #define get_user(x,ptr) __get_user_check((x),(ptr),sizeof(*(ptr)))
168
169 /*
170 * The "__xxx" versions do not do address space checking, useful when
171 * doing multiple accesses to the same area (the user has to do the
172 * checks by hand with "access_ok()")
173 */
174 #define __put_user(x,ptr) \
175 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
176 #define __get_user(x,ptr) \
177 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
178
179 struct __large_struct { unsigned long buf[100]; };
180 #define __m(x) (*(struct __large_struct *)(x))
181
182 #define __get_user_size(x,ptr,size,retval) \
183 do { \
184 retval = 0; \
185 switch (size) { \
186 case 1: \
187 __get_user_asm(x, ptr, retval, "b"); \
188 break; \
189 case 2: \
190 __get_user_asm(x, ptr, retval, "w"); \
191 break; \
192 case 4: \
193 __get_user_asm(x, ptr, retval, "l"); \
194 break; \
195 default: \
196 __get_user_unknown(); \
197 break; \
198 } \
199 } while (0)
200
201 #define __get_user_nocheck(x,ptr,size) \
202 ({ \
203 long __gu_err, __gu_val; \
204 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
205 (x) = (__typeof__(*(ptr)))__gu_val; \
206 __gu_err; \
207 })
208
209 #define __get_user_check(x,ptr,size) \
210 ({ \
211 long __gu_err, __gu_val; \
212 switch (size) { \
213 case 1: \
214 __get_user_1(__gu_val, (ptr), __gu_err); \
215 break; \
216 case 2: \
217 __get_user_2(__gu_val, (ptr), __gu_err); \
218 break; \
219 case 4: \
220 __get_user_4(__gu_val, (ptr), __gu_err); \
221 break; \
222 default: \
223 __get_user_unknown(); \
224 break; \
225 } \
226 \
227 (x) = (__typeof__(*(ptr)))__gu_val; \
228 __gu_err; \
229 })
230
231 #define __get_user_1(x,addr,err) ({ \
232 __asm__("stc r7_bank, %1\n\t" \
233 "mov.l @(8,%1), %1\n\t" \
234 "and %2, %1\n\t" \
235 "cmp/pz %1\n\t" \
236 "bt/s 1f\n\t" \
237 " mov #0, %0\n\t" \
238 "0:\n" \
239 "mov #-14, %0\n\t" \
240 "bra 2f\n\t" \
241 " mov #0, %1\n" \
242 "1:\n\t" \
243 "mov.b @%2, %1\n\t" \
244 "extu.b %1, %1\n" \
245 "2:\n" \
246 ".section __ex_table,\"a\"\n\t" \
247 ".long 1b, 0b\n\t" \
248 ".previous" \
249 : "=&r" (err), "=&r" (x) \
250 : "r" (addr) \
251 : "t"); \
252 })
253
254 #define __get_user_2(x,addr,err) ({ \
255 __asm__("stc r7_bank, %1\n\t" \
256 "mov.l @(8,%1), %1\n\t" \
257 "and %2, %1\n\t" \
258 "cmp/pz %1\n\t" \
259 "bt/s 1f\n\t" \
260 " mov #0, %0\n\t" \
261 "0:\n" \
262 "mov #-14, %0\n\t" \
263 "bra 2f\n\t" \
264 " mov #0, %1\n" \
265 "1:\n\t" \
266 "mov.w @%2, %1\n\t" \
267 "extu.w %1, %1\n" \
268 "2:\n" \
269 ".section __ex_table,\"a\"\n\t" \
270 ".long 1b, 0b\n\t" \
271 ".previous" \
272 : "=&r" (err), "=&r" (x) \
273 : "r" (addr) \
274 : "t"); \
275 })
276
277 #define __get_user_4(x,addr,err) ({ \
278 __asm__("stc r7_bank, %1\n\t" \
279 "mov.l @(8,%1), %1\n\t" \
280 "and %2, %1\n\t" \
281 "cmp/pz %1\n\t" \
282 "bt/s 1f\n\t" \
283 " mov #0, %0\n\t" \
284 "0:\n" \
285 "mov #-14, %0\n\t" \
286 "bra 2f\n\t" \
287 " mov #0, %1\n" \
288 "1:\n\t" \
289 "mov.l @%2, %1\n\t" \
290 "2:\n" \
291 ".section __ex_table,\"a\"\n\t" \
292 ".long 1b, 0b\n\t" \
293 ".previous" \
294 : "=&r" (err), "=&r" (x) \
295 : "r" (addr) \
296 : "t"); \
297 })
298
299 #define __get_user_asm(x, addr, err, insn) \
300 ({ \
301 __asm__ __volatile__( \
302 "1:\n\t" \
303 "mov." insn " %2, %1\n\t" \
304 "mov #0, %0\n" \
305 "2:\n" \
306 ".section .fixup,\"ax\"\n" \
307 "3:\n\t" \
308 "mov #0, %1\n\t" \
309 "mov.l 4f, %0\n\t" \
310 "jmp @%0\n\t" \
311 " mov %3, %0\n" \
312 "4: .long 2b\n\t" \
313 ".previous\n" \
314 ".section __ex_table,\"a\"\n\t" \
315 ".long 1b, 3b\n\t" \
316 ".previous" \
317 :"=&r" (err), "=&r" (x) \
318 :"m" (__m(addr)), "i" (-EFAULT)); })
319
320 extern void __get_user_unknown(void);
321
322 #define __put_user_size(x,ptr,size,retval) \
323 do { \
324 retval = 0; \
325 switch (size) { \
326 case 1: \
327 __put_user_asm(x, ptr, retval, "b"); \
328 break; \
329 case 2: \
330 __put_user_asm(x, ptr, retval, "w"); \
331 break; \
332 case 4: \
333 __put_user_asm(x, ptr, retval, "l"); \
334 break; \
335 case 8: \
336 __put_user_u64(x, ptr, retval); \
337 break; \
338 default: \
339 __put_user_unknown(); \
340 } \
341 } while (0)
342
343 #define __put_user_nocheck(x,ptr,size) \
344 ({ \
345 long __pu_err; \
346 __put_user_size((x),(ptr),(size),__pu_err); \
347 __pu_err; \
348 })
349
350 #define __put_user_check(x,ptr,size) \
351 ({ \
352 long __pu_err = -EFAULT; \
353 __typeof__(*(ptr)) *__pu_addr = (ptr); \
354 \
355 if (__access_ok((unsigned long)__pu_addr,size)) \
356 __put_user_size((x),__pu_addr,(size),__pu_err); \
357 __pu_err; \
358 })
359
360 #define __put_user_asm(x, addr, err, insn) \
361 ({ \
362 __asm__ __volatile__( \
363 "1:\n\t" \
364 "mov." insn " %1, %2\n\t" \
365 "mov #0, %0\n" \
366 "2:\n" \
367 ".section .fixup,\"ax\"\n" \
368 "3:\n\t" \
369 "nop\n\t" \
370 "mov.l 4f, %0\n\t" \
371 "jmp @%0\n\t" \
372 "mov %3, %0\n" \
373 "4: .long 2b\n\t" \
374 ".previous\n" \
375 ".section __ex_table,\"a\"\n\t" \
376 ".long 1b, 3b\n\t" \
377 ".previous" \
378 :"=&r" (err) \
379 :"r" (x), "m" (__m(addr)), "i" (-EFAULT) \
380 :"memory"); })
381
382 #if defined(__LITTLE_ENDIAN__)
383 #define __put_user_u64(val,addr,retval) \
384 ({ \
385 __asm__ __volatile__( \
386 "1:\n\t" \
387 "mov.l %R1,%2\n\t" \
388 "mov.l %S1,%T2\n\t" \
389 "mov #0,%0\n" \
390 "2:\n" \
391 ".section .fixup,\"ax\"\n" \
392 "3:\n\t" \
393 "nop\n\t" \
394 "mov.l 4f,%0\n\t" \
395 "jmp @%0\n\t" \
396 " mov %3,%0\n" \
397 "4: .long 2b\n\t" \
398 ".previous\n" \
399 ".section __ex_table,\"a\"\n\t" \
400 ".long 1b, 3b\n\t" \
401 ".previous" \
402 : "=r" (retval) \
403 : "r" (val), "m" (__m(addr)), "i" (-EFAULT) \
404 : "memory"); })
405 #else
406 #define __put_user_u64(val,addr,retval) \
407 ({ \
408 __asm__ __volatile__( \
409 "1:\n\t" \
410 "mov.l %S1,%2\n\t" \
411 "mov.l %R1,%T2\n\t" \
412 "mov #0,%0\n" \
413 "2:\n" \
414 ".section .fixup,\"ax\"\n" \
415 "3:\n\t" \
416 "nop\n\t" \
417 "mov.l 4f,%0\n\t" \
418 "jmp @%0\n\t" \
419 " mov %3,%0\n" \
420 "4: .long 2b\n\t" \
421 ".previous\n" \
422 ".section __ex_table,\"a\"\n\t" \
423 ".long 1b, 3b\n\t" \
424 ".previous" \
425 : "=r" (retval) \
426 : "r" (val), "m" (__m(addr)), "i" (-EFAULT) \
427 : "memory"); })
428 #endif
429
430 extern void __put_user_unknown(void);
431 \f
432 /* Generic arbitrary sized copy. */
433 /* Return the number of bytes NOT copied */
434 extern __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
435
436 #define copy_to_user(to,from,n) ({ \
437 void *__copy_to = (void *) (to); \
438 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
439 __kernel_size_t __copy_res; \
440 if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
441 __copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
442 } else __copy_res = __copy_size; \
443 __copy_res; })
444
445 #define __copy_to_user(to,from,n) \
446 __copy_user((void *)(to), \
447 (void *)(from), n)
448
449 #define __copy_to_user_inatomic __copy_to_user
450 #define __copy_from_user_inatomic __copy_from_user
451
452
453 #define copy_from_user(to,from,n) ({ \
454 void *__copy_to = (void *) (to); \
455 void *__copy_from = (void *) (from); \
456 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
457 __kernel_size_t __copy_res; \
458 if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
459 __copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
460 } else __copy_res = __copy_size; \
461 __copy_res; })
462
463 #define __copy_from_user(to,from,n) \
464 __copy_user((void *)(to), \
465 (void *)(from), n)
466
467 /*
468 * Clear the area and return remaining number of bytes
469 * (on failure. Usually it's 0.)
470 */
471 extern __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
472
473 #define clear_user(addr,n) ({ \
474 void * __cl_addr = (addr); \
475 unsigned long __cl_size = (n); \
476 if (__cl_size && __access_ok(((unsigned long)(__cl_addr)), __cl_size)) \
477 __cl_size = __clear_user(__cl_addr, __cl_size); \
478 __cl_size; })
479
480 static __inline__ int
481 __strncpy_from_user(unsigned long __dest, unsigned long __user __src, int __count)
482 {
483 __kernel_size_t res;
484 unsigned long __dummy, _d, _s;
485
486 __asm__ __volatile__(
487 "9:\n"
488 "mov.b @%2+, %1\n\t"
489 "cmp/eq #0, %1\n\t"
490 "bt/s 2f\n"
491 "1:\n"
492 "mov.b %1, @%3\n\t"
493 "dt %7\n\t"
494 "bf/s 9b\n\t"
495 " add #1, %3\n\t"
496 "2:\n\t"
497 "sub %7, %0\n"
498 "3:\n"
499 ".section .fixup,\"ax\"\n"
500 "4:\n\t"
501 "mov.l 5f, %1\n\t"
502 "jmp @%1\n\t"
503 " mov %8, %0\n\t"
504 ".balign 4\n"
505 "5: .long 3b\n"
506 ".previous\n"
507 ".section __ex_table,\"a\"\n"
508 " .balign 4\n"
509 " .long 9b,4b\n"
510 ".previous"
511 : "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d)
512 : "0" (__count), "2" (__src), "3" (__dest), "r" (__count),
513 "i" (-EFAULT)
514 : "memory", "t");
515
516 return res;
517 }
518
519 #define strncpy_from_user(dest,src,count) ({ \
520 unsigned long __sfu_src = (unsigned long) (src); \
521 int __sfu_count = (int) (count); \
522 long __sfu_res = -EFAULT; \
523 if(__access_ok(__sfu_src, __sfu_count)) { \
524 __sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
525 } __sfu_res; })
526
527 /*
528 * Return the size of a string (including the ending 0!)
529 */
530 static __inline__ long __strnlen_user(const char __user *__s, long __n)
531 {
532 unsigned long res;
533 unsigned long __dummy;
534
535 __asm__ __volatile__(
536 "9:\n"
537 "cmp/eq %4, %0\n\t"
538 "bt 2f\n"
539 "1:\t"
540 "mov.b @(%0,%3), %1\n\t"
541 "tst %1, %1\n\t"
542 "bf/s 9b\n\t"
543 " add #1, %0\n"
544 "2:\n"
545 ".section .fixup,\"ax\"\n"
546 "3:\n\t"
547 "mov.l 4f, %1\n\t"
548 "jmp @%1\n\t"
549 " mov %5, %0\n"
550 ".balign 4\n"
551 "4: .long 2b\n"
552 ".previous\n"
553 ".section __ex_table,\"a\"\n"
554 " .balign 4\n"
555 " .long 1b,3b\n"
556 ".previous"
557 : "=z" (res), "=&r" (__dummy)
558 : "0" (0), "r" (__s), "r" (__n), "i" (-EFAULT)
559 : "t");
560 return res;
561 }
562
563 static __inline__ long strnlen_user(const char __user *s, long n)
564 {
565 if (!access_ok(VERIFY_READ, s, n))
566 return 0;
567 else
568 return __strnlen_user(s, n);
569 }
570
571 static __inline__ long strlen_user(const char __user *s)
572 {
573 if (!access_ok(VERIFY_READ, s, 0))
574 return 0;
575 else
576 return __strnlen_user(s, ~0UL >> 1);
577 }
578
579 /*
580 * The exception table consists of pairs of addresses: the first is the
581 * address of an instruction that is allowed to fault, and the second is
582 * the address at which the program should continue. No registers are
583 * modified, so it is entirely up to the continuation code to figure out
584 * what to do.
585 *
586 * All the routines below use bits of fixup code that are out of line
587 * with the main instruction path. This means when everything is well,
588 * we don't even have to jump over them. Further, they do not intrude
589 * on our cache or tlb entries.
590 */
591
592 struct exception_table_entry
593 {
594 unsigned long insn, fixup;
595 };
596
597 extern int fixup_exception(struct pt_regs *regs);
598
599 #endif /* __ASM_SH_UACCESS_H */
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