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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* $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
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#define VERIFY_READ 0
20#define VERIFY_WRITE 1
21
Linus Torvalds1da177e2005-04-16 15:20:36 -070022/*
23 * The fs value determines whether argument validity checking should be
24 * performed or not. If get_fs() == USER_DS, checking is performed, with
25 * get_fs() == KERNEL_DS, checking is bypassed.
26 *
27 * For historical reasons (Data Segment Register?), these macros are misnamed.
28 */
29
30#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
Paul Mundt2991be72006-09-27 17:07:07 +090032#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFUL)
33#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Paul Mundt2991be72006-09-27 17:07:07 +090035#define segment_eq(a,b) ((a).seg == (b).seg)
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#define get_ds() (KERNEL_DS)
38
39#if !defined(CONFIG_MMU)
Yoshinori Satoa2d1a5f2006-09-27 17:25:07 +090040/* NOMMU is always true */
41#define __addr_ok(addr) (1)
42
Linus Torvalds1da177e2005-04-16 15:20:36 -070043static inline mm_segment_t get_fs(void)
44{
45 return USER_DS;
46}
47
48static inline void set_fs(mm_segment_t s)
49{
50}
51
52/*
53 * __access_ok: Check if address with size is OK or not.
54 *
55 * If we don't have an MMU (or if its disabled) the only thing we really have
56 * to look out for is if the address resides somewhere outside of what
57 * available RAM we have.
58 *
59 * TODO: This check could probably also stand to be restricted somewhat more..
60 * though it still does the Right Thing(tm) for the time being.
61 */
62static inline int __access_ok(unsigned long addr, unsigned long size)
63{
64 extern unsigned long memory_start, memory_end;
65
66 return ((addr >= memory_start) && ((addr + size) < memory_end));
67}
68#else /* CONFIG_MMU */
Yoshinori Satoa2d1a5f2006-09-27 17:25:07 +090069#define __addr_ok(addr) \
70 ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
71
Paul Mundt2991be72006-09-27 17:07:07 +090072#define get_fs() (current_thread_info()->addr_limit)
73#define set_fs(x) (current_thread_info()->addr_limit = (x))
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75/*
76 * __access_ok: Check if address with size is OK or not.
77 *
78 * We do three checks:
79 * (1) is it user space?
80 * (2) addr + size --> carry?
Paul Mundt2991be72006-09-27 17:07:07 +090081 * (3) addr + size >= 0x80000000 (PAGE_OFFSET)
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 *
83 * (1) (2) (3) | RESULT
84 * 0 0 0 | ok
85 * 0 0 1 | ok
86 * 0 1 0 | bad
87 * 0 1 1 | bad
88 * 1 0 0 | ok
89 * 1 0 1 | bad
90 * 1 1 0 | bad
91 * 1 1 1 | bad
92 */
93static inline int __access_ok(unsigned long addr, unsigned long size)
94{
95 unsigned long flag, tmp;
96
97 __asm__("stc r7_bank, %0\n\t"
98 "mov.l @(8,%0), %0\n\t"
99 "clrt\n\t"
100 "addc %2, %1\n\t"
101 "and %1, %0\n\t"
102 "rotcl %0\n\t"
103 "rotcl %0\n\t"
104 "and #3, %0"
105 : "=&z" (flag), "=r" (tmp)
106 : "r" (addr), "1" (size)
107 : "t");
108
109 return flag == 0;
110}
111#endif /* CONFIG_MMU */
112
113static inline int access_ok(int type, const void __user *p, unsigned long size)
114{
115 unsigned long addr = (unsigned long)p;
116 return __access_ok(addr, size);
117}
118
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119/*
120 * Uh, these should become the main single-value transfer routines ...
121 * They automatically use the right size if we just have the right
122 * pointer type ...
123 *
124 * As SuperH uses the same address space for kernel and user data, we
125 * can just do these as direct assignments.
126 *
127 * Careful to not
128 * (a) re-use the arguments for side effects (sizeof is ok)
129 * (b) require any knowledge of processes at this stage
130 */
131#define put_user(x,ptr) __put_user_check((x),(ptr),sizeof(*(ptr)))
132#define get_user(x,ptr) __get_user_check((x),(ptr),sizeof(*(ptr)))
133
134/*
135 * The "__xxx" versions do not do address space checking, useful when
136 * doing multiple accesses to the same area (the user has to do the
137 * checks by hand with "access_ok()")
138 */
139#define __put_user(x,ptr) \
140 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
141#define __get_user(x,ptr) \
142 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
143
144struct __large_struct { unsigned long buf[100]; };
145#define __m(x) (*(struct __large_struct *)(x))
146
147#define __get_user_size(x,ptr,size,retval) \
148do { \
149 retval = 0; \
150 switch (size) { \
151 case 1: \
152 __get_user_asm(x, ptr, retval, "b"); \
153 break; \
154 case 2: \
155 __get_user_asm(x, ptr, retval, "w"); \
156 break; \
157 case 4: \
158 __get_user_asm(x, ptr, retval, "l"); \
159 break; \
160 default: \
161 __get_user_unknown(); \
162 break; \
163 } \
164} while (0)
165
166#define __get_user_nocheck(x,ptr,size) \
167({ \
168 long __gu_err, __gu_val; \
169 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
170 (x) = (__typeof__(*(ptr)))__gu_val; \
171 __gu_err; \
172})
173
Yoshinori Satoe96636c2006-09-27 17:21:02 +0900174#ifdef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175#define __get_user_check(x,ptr,size) \
176({ \
177 long __gu_err, __gu_val; \
178 switch (size) { \
179 case 1: \
180 __get_user_1(__gu_val, (ptr), __gu_err); \
181 break; \
182 case 2: \
183 __get_user_2(__gu_val, (ptr), __gu_err); \
184 break; \
185 case 4: \
186 __get_user_4(__gu_val, (ptr), __gu_err); \
187 break; \
188 default: \
189 __get_user_unknown(); \
190 break; \
191 } \
192 \
193 (x) = (__typeof__(*(ptr)))__gu_val; \
194 __gu_err; \
195})
196
197#define __get_user_1(x,addr,err) ({ \
198__asm__("stc r7_bank, %1\n\t" \
199 "mov.l @(8,%1), %1\n\t" \
200 "and %2, %1\n\t" \
201 "cmp/pz %1\n\t" \
202 "bt/s 1f\n\t" \
203 " mov #0, %0\n\t" \
204 "0:\n" \
205 "mov #-14, %0\n\t" \
206 "bra 2f\n\t" \
207 " mov #0, %1\n" \
208 "1:\n\t" \
209 "mov.b @%2, %1\n\t" \
210 "extu.b %1, %1\n" \
211 "2:\n" \
212 ".section __ex_table,\"a\"\n\t" \
213 ".long 1b, 0b\n\t" \
214 ".previous" \
215 : "=&r" (err), "=&r" (x) \
216 : "r" (addr) \
217 : "t"); \
218})
219
220#define __get_user_2(x,addr,err) ({ \
221__asm__("stc r7_bank, %1\n\t" \
222 "mov.l @(8,%1), %1\n\t" \
223 "and %2, %1\n\t" \
224 "cmp/pz %1\n\t" \
225 "bt/s 1f\n\t" \
226 " mov #0, %0\n\t" \
227 "0:\n" \
228 "mov #-14, %0\n\t" \
229 "bra 2f\n\t" \
230 " mov #0, %1\n" \
231 "1:\n\t" \
232 "mov.w @%2, %1\n\t" \
233 "extu.w %1, %1\n" \
234 "2:\n" \
235 ".section __ex_table,\"a\"\n\t" \
236 ".long 1b, 0b\n\t" \
237 ".previous" \
238 : "=&r" (err), "=&r" (x) \
239 : "r" (addr) \
240 : "t"); \
241})
242
243#define __get_user_4(x,addr,err) ({ \
244__asm__("stc r7_bank, %1\n\t" \
245 "mov.l @(8,%1), %1\n\t" \
246 "and %2, %1\n\t" \
247 "cmp/pz %1\n\t" \
248 "bt/s 1f\n\t" \
249 " mov #0, %0\n\t" \
250 "0:\n" \
251 "mov #-14, %0\n\t" \
252 "bra 2f\n\t" \
253 " mov #0, %1\n" \
254 "1:\n\t" \
255 "mov.l @%2, %1\n\t" \
256 "2:\n" \
257 ".section __ex_table,\"a\"\n\t" \
258 ".long 1b, 0b\n\t" \
259 ".previous" \
260 : "=&r" (err), "=&r" (x) \
261 : "r" (addr) \
262 : "t"); \
263})
Yoshinori Satoe96636c2006-09-27 17:21:02 +0900264#else /* CONFIG_MMU */
265#define __get_user_check(x,ptr,size) \
266({ \
267 long __gu_err, __gu_val; \
268 if (__access_ok((unsigned long)(ptr), (size))) { \
269 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
270 (x) = (__typeof__(*(ptr)))__gu_val; \
271 } else \
272 __gu_err = -EFAULT; \
273 __gu_err; \
274})
275#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276
277#define __get_user_asm(x, addr, err, insn) \
278({ \
279__asm__ __volatile__( \
280 "1:\n\t" \
281 "mov." insn " %2, %1\n\t" \
282 "mov #0, %0\n" \
283 "2:\n" \
284 ".section .fixup,\"ax\"\n" \
285 "3:\n\t" \
286 "mov #0, %1\n\t" \
287 "mov.l 4f, %0\n\t" \
288 "jmp @%0\n\t" \
289 " mov %3, %0\n" \
290 "4: .long 2b\n\t" \
291 ".previous\n" \
292 ".section __ex_table,\"a\"\n\t" \
293 ".long 1b, 3b\n\t" \
294 ".previous" \
295 :"=&r" (err), "=&r" (x) \
296 :"m" (__m(addr)), "i" (-EFAULT)); })
297
298extern void __get_user_unknown(void);
299
300#define __put_user_size(x,ptr,size,retval) \
301do { \
302 retval = 0; \
303 switch (size) { \
304 case 1: \
305 __put_user_asm(x, ptr, retval, "b"); \
306 break; \
307 case 2: \
308 __put_user_asm(x, ptr, retval, "w"); \
309 break; \
310 case 4: \
311 __put_user_asm(x, ptr, retval, "l"); \
312 break; \
313 case 8: \
314 __put_user_u64(x, ptr, retval); \
315 break; \
316 default: \
317 __put_user_unknown(); \
318 } \
319} while (0)
320
321#define __put_user_nocheck(x,ptr,size) \
322({ \
323 long __pu_err; \
324 __put_user_size((x),(ptr),(size),__pu_err); \
325 __pu_err; \
326})
327
328#define __put_user_check(x,ptr,size) \
329({ \
330 long __pu_err = -EFAULT; \
331 __typeof__(*(ptr)) *__pu_addr = (ptr); \
332 \
333 if (__access_ok((unsigned long)__pu_addr,size)) \
334 __put_user_size((x),__pu_addr,(size),__pu_err); \
335 __pu_err; \
336})
337
338#define __put_user_asm(x, addr, err, insn) \
339({ \
340__asm__ __volatile__( \
341 "1:\n\t" \
342 "mov." insn " %1, %2\n\t" \
343 "mov #0, %0\n" \
344 "2:\n" \
345 ".section .fixup,\"ax\"\n" \
346 "3:\n\t" \
347 "nop\n\t" \
348 "mov.l 4f, %0\n\t" \
349 "jmp @%0\n\t" \
350 "mov %3, %0\n" \
351 "4: .long 2b\n\t" \
352 ".previous\n" \
353 ".section __ex_table,\"a\"\n\t" \
354 ".long 1b, 3b\n\t" \
355 ".previous" \
356 :"=&r" (err) \
357 :"r" (x), "m" (__m(addr)), "i" (-EFAULT) \
358 :"memory"); })
359
360#if defined(__LITTLE_ENDIAN__)
361#define __put_user_u64(val,addr,retval) \
362({ \
363__asm__ __volatile__( \
364 "1:\n\t" \
365 "mov.l %R1,%2\n\t" \
366 "mov.l %S1,%T2\n\t" \
367 "mov #0,%0\n" \
368 "2:\n" \
369 ".section .fixup,\"ax\"\n" \
370 "3:\n\t" \
371 "nop\n\t" \
372 "mov.l 4f,%0\n\t" \
373 "jmp @%0\n\t" \
374 " mov %3,%0\n" \
375 "4: .long 2b\n\t" \
376 ".previous\n" \
377 ".section __ex_table,\"a\"\n\t" \
378 ".long 1b, 3b\n\t" \
379 ".previous" \
380 : "=r" (retval) \
381 : "r" (val), "m" (__m(addr)), "i" (-EFAULT) \
382 : "memory"); })
383#else
384#define __put_user_u64(val,addr,retval) \
385({ \
386__asm__ __volatile__( \
387 "1:\n\t" \
388 "mov.l %S1,%2\n\t" \
389 "mov.l %R1,%T2\n\t" \
390 "mov #0,%0\n" \
391 "2:\n" \
392 ".section .fixup,\"ax\"\n" \
393 "3:\n\t" \
394 "nop\n\t" \
395 "mov.l 4f,%0\n\t" \
396 "jmp @%0\n\t" \
397 " mov %3,%0\n" \
398 "4: .long 2b\n\t" \
399 ".previous\n" \
400 ".section __ex_table,\"a\"\n\t" \
401 ".long 1b, 3b\n\t" \
402 ".previous" \
403 : "=r" (retval) \
404 : "r" (val), "m" (__m(addr)), "i" (-EFAULT) \
405 : "memory"); })
406#endif
407
408extern void __put_user_unknown(void);
409
410/* Generic arbitrary sized copy. */
411/* Return the number of bytes NOT copied */
412extern __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
413
414#define copy_to_user(to,from,n) ({ \
415void *__copy_to = (void *) (to); \
416__kernel_size_t __copy_size = (__kernel_size_t) (n); \
417__kernel_size_t __copy_res; \
418if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
419__copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
420} else __copy_res = __copy_size; \
421__copy_res; })
422
423#define __copy_to_user(to,from,n) \
424 __copy_user((void *)(to), \
425 (void *)(from), n)
426
427#define __copy_to_user_inatomic __copy_to_user
428#define __copy_from_user_inatomic __copy_from_user
429
430
431#define copy_from_user(to,from,n) ({ \
432void *__copy_to = (void *) (to); \
433void *__copy_from = (void *) (from); \
434__kernel_size_t __copy_size = (__kernel_size_t) (n); \
435__kernel_size_t __copy_res; \
436if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
437__copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
438} else __copy_res = __copy_size; \
439__copy_res; })
440
441#define __copy_from_user(to,from,n) \
442 __copy_user((void *)(to), \
443 (void *)(from), n)
444
445/*
446 * Clear the area and return remaining number of bytes
447 * (on failure. Usually it's 0.)
448 */
449extern __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
450
451#define clear_user(addr,n) ({ \
452void * __cl_addr = (addr); \
453unsigned long __cl_size = (n); \
454if (__cl_size && __access_ok(((unsigned long)(__cl_addr)), __cl_size)) \
455__cl_size = __clear_user(__cl_addr, __cl_size); \
456__cl_size; })
457
458static __inline__ int
459__strncpy_from_user(unsigned long __dest, unsigned long __user __src, int __count)
460{
461 __kernel_size_t res;
462 unsigned long __dummy, _d, _s;
463
464 __asm__ __volatile__(
465 "9:\n"
466 "mov.b @%2+, %1\n\t"
467 "cmp/eq #0, %1\n\t"
468 "bt/s 2f\n"
469 "1:\n"
470 "mov.b %1, @%3\n\t"
471 "dt %7\n\t"
472 "bf/s 9b\n\t"
473 " add #1, %3\n\t"
474 "2:\n\t"
475 "sub %7, %0\n"
476 "3:\n"
477 ".section .fixup,\"ax\"\n"
478 "4:\n\t"
479 "mov.l 5f, %1\n\t"
480 "jmp @%1\n\t"
481 " mov %8, %0\n\t"
482 ".balign 4\n"
483 "5: .long 3b\n"
484 ".previous\n"
485 ".section __ex_table,\"a\"\n"
486 " .balign 4\n"
487 " .long 9b,4b\n"
488 ".previous"
489 : "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d)
490 : "0" (__count), "2" (__src), "3" (__dest), "r" (__count),
491 "i" (-EFAULT)
492 : "memory", "t");
493
494 return res;
495}
496
497#define strncpy_from_user(dest,src,count) ({ \
498unsigned long __sfu_src = (unsigned long) (src); \
499int __sfu_count = (int) (count); \
500long __sfu_res = -EFAULT; \
501if(__access_ok(__sfu_src, __sfu_count)) { \
502__sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
503} __sfu_res; })
504
505/*
506 * Return the size of a string (including the ending 0!)
507 */
508static __inline__ long __strnlen_user(const char __user *__s, long __n)
509{
510 unsigned long res;
511 unsigned long __dummy;
512
513 __asm__ __volatile__(
514 "9:\n"
515 "cmp/eq %4, %0\n\t"
516 "bt 2f\n"
517 "1:\t"
518 "mov.b @(%0,%3), %1\n\t"
519 "tst %1, %1\n\t"
520 "bf/s 9b\n\t"
521 " add #1, %0\n"
522 "2:\n"
523 ".section .fixup,\"ax\"\n"
524 "3:\n\t"
525 "mov.l 4f, %1\n\t"
526 "jmp @%1\n\t"
Paul Mundt2991be72006-09-27 17:07:07 +0900527 " mov #0, %0\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 ".balign 4\n"
529 "4: .long 2b\n"
530 ".previous\n"
531 ".section __ex_table,\"a\"\n"
532 " .balign 4\n"
533 " .long 1b,3b\n"
534 ".previous"
535 : "=z" (res), "=&r" (__dummy)
Paul Mundt2991be72006-09-27 17:07:07 +0900536 : "0" (0), "r" (__s), "r" (__n)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 : "t");
538 return res;
539}
540
541static __inline__ long strnlen_user(const char __user *s, long n)
542{
Paul Mundt2991be72006-09-27 17:07:07 +0900543 if (!__addr_ok(s))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 return 0;
545 else
546 return __strnlen_user(s, n);
547}
548
Paul Mundt2991be72006-09-27 17:07:07 +0900549#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
551/*
552 * The exception table consists of pairs of addresses: the first is the
553 * address of an instruction that is allowed to fault, and the second is
554 * the address at which the program should continue. No registers are
555 * modified, so it is entirely up to the continuation code to figure out
556 * what to do.
557 *
558 * All the routines below use bits of fixup code that are out of line
559 * with the main instruction path. This means when everything is well,
560 * we don't even have to jump over them. Further, they do not intrude
561 * on our cache or tlb entries.
562 */
563
564struct exception_table_entry
565{
566 unsigned long insn, fixup;
567};
568
569extern int fixup_exception(struct pt_regs *regs);
570
571#endif /* __ASM_SH_UACCESS_H */