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Linux kernel mirror (for testing)
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linux
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
30typedef 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)
53static inline mm_segment_t get_fs(void)
54{
55 return USER_DS;
56}
57
58static 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 */
72static 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 */
79static inline mm_segment_t get_fs(void)
80{
81 return MAKE_MM_SEG(test_thread_flag(TIF_USERSPACE));
82}
83
84static 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 */
123static 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
143static 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/* this function will go away soon - use access_ok() instead */
150static inline int __deprecated verify_area(int type, const void __user * addr, unsigned long size)
151{
152 return access_ok(type,addr,size) ? 0 : -EFAULT;
153}
154
155/*
156 * Uh, these should become the main single-value transfer routines ...
157 * They automatically use the right size if we just have the right
158 * pointer type ...
159 *
160 * As SuperH uses the same address space for kernel and user data, we
161 * can just do these as direct assignments.
162 *
163 * Careful to not
164 * (a) re-use the arguments for side effects (sizeof is ok)
165 * (b) require any knowledge of processes at this stage
166 */
167#define put_user(x,ptr) __put_user_check((x),(ptr),sizeof(*(ptr)))
168#define get_user(x,ptr) __get_user_check((x),(ptr),sizeof(*(ptr)))
169
170/*
171 * The "__xxx" versions do not do address space checking, useful when
172 * doing multiple accesses to the same area (the user has to do the
173 * checks by hand with "access_ok()")
174 */
175#define __put_user(x,ptr) \
176 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
177#define __get_user(x,ptr) \
178 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
179
180struct __large_struct { unsigned long buf[100]; };
181#define __m(x) (*(struct __large_struct *)(x))
182
183#define __get_user_size(x,ptr,size,retval) \
184do { \
185 retval = 0; \
186 switch (size) { \
187 case 1: \
188 __get_user_asm(x, ptr, retval, "b"); \
189 break; \
190 case 2: \
191 __get_user_asm(x, ptr, retval, "w"); \
192 break; \
193 case 4: \
194 __get_user_asm(x, ptr, retval, "l"); \
195 break; \
196 default: \
197 __get_user_unknown(); \
198 break; \
199 } \
200} while (0)
201
202#define __get_user_nocheck(x,ptr,size) \
203({ \
204 long __gu_err, __gu_val; \
205 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
206 (x) = (__typeof__(*(ptr)))__gu_val; \
207 __gu_err; \
208})
209
210#define __get_user_check(x,ptr,size) \
211({ \
212 long __gu_err, __gu_val; \
213 switch (size) { \
214 case 1: \
215 __get_user_1(__gu_val, (ptr), __gu_err); \
216 break; \
217 case 2: \
218 __get_user_2(__gu_val, (ptr), __gu_err); \
219 break; \
220 case 4: \
221 __get_user_4(__gu_val, (ptr), __gu_err); \
222 break; \
223 default: \
224 __get_user_unknown(); \
225 break; \
226 } \
227 \
228 (x) = (__typeof__(*(ptr)))__gu_val; \
229 __gu_err; \
230})
231
232#define __get_user_1(x,addr,err) ({ \
233__asm__("stc r7_bank, %1\n\t" \
234 "mov.l @(8,%1), %1\n\t" \
235 "and %2, %1\n\t" \
236 "cmp/pz %1\n\t" \
237 "bt/s 1f\n\t" \
238 " mov #0, %0\n\t" \
239 "0:\n" \
240 "mov #-14, %0\n\t" \
241 "bra 2f\n\t" \
242 " mov #0, %1\n" \
243 "1:\n\t" \
244 "mov.b @%2, %1\n\t" \
245 "extu.b %1, %1\n" \
246 "2:\n" \
247 ".section __ex_table,\"a\"\n\t" \
248 ".long 1b, 0b\n\t" \
249 ".previous" \
250 : "=&r" (err), "=&r" (x) \
251 : "r" (addr) \
252 : "t"); \
253})
254
255#define __get_user_2(x,addr,err) ({ \
256__asm__("stc r7_bank, %1\n\t" \
257 "mov.l @(8,%1), %1\n\t" \
258 "and %2, %1\n\t" \
259 "cmp/pz %1\n\t" \
260 "bt/s 1f\n\t" \
261 " mov #0, %0\n\t" \
262 "0:\n" \
263 "mov #-14, %0\n\t" \
264 "bra 2f\n\t" \
265 " mov #0, %1\n" \
266 "1:\n\t" \
267 "mov.w @%2, %1\n\t" \
268 "extu.w %1, %1\n" \
269 "2:\n" \
270 ".section __ex_table,\"a\"\n\t" \
271 ".long 1b, 0b\n\t" \
272 ".previous" \
273 : "=&r" (err), "=&r" (x) \
274 : "r" (addr) \
275 : "t"); \
276})
277
278#define __get_user_4(x,addr,err) ({ \
279__asm__("stc r7_bank, %1\n\t" \
280 "mov.l @(8,%1), %1\n\t" \
281 "and %2, %1\n\t" \
282 "cmp/pz %1\n\t" \
283 "bt/s 1f\n\t" \
284 " mov #0, %0\n\t" \
285 "0:\n" \
286 "mov #-14, %0\n\t" \
287 "bra 2f\n\t" \
288 " mov #0, %1\n" \
289 "1:\n\t" \
290 "mov.l @%2, %1\n\t" \
291 "2:\n" \
292 ".section __ex_table,\"a\"\n\t" \
293 ".long 1b, 0b\n\t" \
294 ".previous" \
295 : "=&r" (err), "=&r" (x) \
296 : "r" (addr) \
297 : "t"); \
298})
299
300#define __get_user_asm(x, addr, err, insn) \
301({ \
302__asm__ __volatile__( \
303 "1:\n\t" \
304 "mov." insn " %2, %1\n\t" \
305 "mov #0, %0\n" \
306 "2:\n" \
307 ".section .fixup,\"ax\"\n" \
308 "3:\n\t" \
309 "mov #0, %1\n\t" \
310 "mov.l 4f, %0\n\t" \
311 "jmp @%0\n\t" \
312 " mov %3, %0\n" \
313 "4: .long 2b\n\t" \
314 ".previous\n" \
315 ".section __ex_table,\"a\"\n\t" \
316 ".long 1b, 3b\n\t" \
317 ".previous" \
318 :"=&r" (err), "=&r" (x) \
319 :"m" (__m(addr)), "i" (-EFAULT)); })
320
321extern void __get_user_unknown(void);
322
323#define __put_user_size(x,ptr,size,retval) \
324do { \
325 retval = 0; \
326 switch (size) { \
327 case 1: \
328 __put_user_asm(x, ptr, retval, "b"); \
329 break; \
330 case 2: \
331 __put_user_asm(x, ptr, retval, "w"); \
332 break; \
333 case 4: \
334 __put_user_asm(x, ptr, retval, "l"); \
335 break; \
336 case 8: \
337 __put_user_u64(x, ptr, retval); \
338 break; \
339 default: \
340 __put_user_unknown(); \
341 } \
342} while (0)
343
344#define __put_user_nocheck(x,ptr,size) \
345({ \
346 long __pu_err; \
347 __put_user_size((x),(ptr),(size),__pu_err); \
348 __pu_err; \
349})
350
351#define __put_user_check(x,ptr,size) \
352({ \
353 long __pu_err = -EFAULT; \
354 __typeof__(*(ptr)) *__pu_addr = (ptr); \
355 \
356 if (__access_ok((unsigned long)__pu_addr,size)) \
357 __put_user_size((x),__pu_addr,(size),__pu_err); \
358 __pu_err; \
359})
360
361#define __put_user_asm(x, addr, err, insn) \
362({ \
363__asm__ __volatile__( \
364 "1:\n\t" \
365 "mov." insn " %1, %2\n\t" \
366 "mov #0, %0\n" \
367 "2:\n" \
368 ".section .fixup,\"ax\"\n" \
369 "3:\n\t" \
370 "nop\n\t" \
371 "mov.l 4f, %0\n\t" \
372 "jmp @%0\n\t" \
373 "mov %3, %0\n" \
374 "4: .long 2b\n\t" \
375 ".previous\n" \
376 ".section __ex_table,\"a\"\n\t" \
377 ".long 1b, 3b\n\t" \
378 ".previous" \
379 :"=&r" (err) \
380 :"r" (x), "m" (__m(addr)), "i" (-EFAULT) \
381 :"memory"); })
382
383#if defined(__LITTLE_ENDIAN__)
384#define __put_user_u64(val,addr,retval) \
385({ \
386__asm__ __volatile__( \
387 "1:\n\t" \
388 "mov.l %R1,%2\n\t" \
389 "mov.l %S1,%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#else
407#define __put_user_u64(val,addr,retval) \
408({ \
409__asm__ __volatile__( \
410 "1:\n\t" \
411 "mov.l %S1,%2\n\t" \
412 "mov.l %R1,%T2\n\t" \
413 "mov #0,%0\n" \
414 "2:\n" \
415 ".section .fixup,\"ax\"\n" \
416 "3:\n\t" \
417 "nop\n\t" \
418 "mov.l 4f,%0\n\t" \
419 "jmp @%0\n\t" \
420 " mov %3,%0\n" \
421 "4: .long 2b\n\t" \
422 ".previous\n" \
423 ".section __ex_table,\"a\"\n\t" \
424 ".long 1b, 3b\n\t" \
425 ".previous" \
426 : "=r" (retval) \
427 : "r" (val), "m" (__m(addr)), "i" (-EFAULT) \
428 : "memory"); })
429#endif
430
431extern void __put_user_unknown(void);
432
433/* Generic arbitrary sized copy. */
434/* Return the number of bytes NOT copied */
435extern __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
436
437#define copy_to_user(to,from,n) ({ \
438void *__copy_to = (void *) (to); \
439__kernel_size_t __copy_size = (__kernel_size_t) (n); \
440__kernel_size_t __copy_res; \
441if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
442__copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
443} else __copy_res = __copy_size; \
444__copy_res; })
445
446#define __copy_to_user(to,from,n) \
447 __copy_user((void *)(to), \
448 (void *)(from), n)
449
450#define __copy_to_user_inatomic __copy_to_user
451#define __copy_from_user_inatomic __copy_from_user
452
453
454#define copy_from_user(to,from,n) ({ \
455void *__copy_to = (void *) (to); \
456void *__copy_from = (void *) (from); \
457__kernel_size_t __copy_size = (__kernel_size_t) (n); \
458__kernel_size_t __copy_res; \
459if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
460__copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
461} else __copy_res = __copy_size; \
462__copy_res; })
463
464#define __copy_from_user(to,from,n) \
465 __copy_user((void *)(to), \
466 (void *)(from), n)
467
468/*
469 * Clear the area and return remaining number of bytes
470 * (on failure. Usually it's 0.)
471 */
472extern __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
473
474#define clear_user(addr,n) ({ \
475void * __cl_addr = (addr); \
476unsigned long __cl_size = (n); \
477if (__cl_size && __access_ok(((unsigned long)(__cl_addr)), __cl_size)) \
478__cl_size = __clear_user(__cl_addr, __cl_size); \
479__cl_size; })
480
481static __inline__ int
482__strncpy_from_user(unsigned long __dest, unsigned long __user __src, int __count)
483{
484 __kernel_size_t res;
485 unsigned long __dummy, _d, _s;
486
487 __asm__ __volatile__(
488 "9:\n"
489 "mov.b @%2+, %1\n\t"
490 "cmp/eq #0, %1\n\t"
491 "bt/s 2f\n"
492 "1:\n"
493 "mov.b %1, @%3\n\t"
494 "dt %7\n\t"
495 "bf/s 9b\n\t"
496 " add #1, %3\n\t"
497 "2:\n\t"
498 "sub %7, %0\n"
499 "3:\n"
500 ".section .fixup,\"ax\"\n"
501 "4:\n\t"
502 "mov.l 5f, %1\n\t"
503 "jmp @%1\n\t"
504 " mov %8, %0\n\t"
505 ".balign 4\n"
506 "5: .long 3b\n"
507 ".previous\n"
508 ".section __ex_table,\"a\"\n"
509 " .balign 4\n"
510 " .long 9b,4b\n"
511 ".previous"
512 : "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d)
513 : "0" (__count), "2" (__src), "3" (__dest), "r" (__count),
514 "i" (-EFAULT)
515 : "memory", "t");
516
517 return res;
518}
519
520#define strncpy_from_user(dest,src,count) ({ \
521unsigned long __sfu_src = (unsigned long) (src); \
522int __sfu_count = (int) (count); \
523long __sfu_res = -EFAULT; \
524if(__access_ok(__sfu_src, __sfu_count)) { \
525__sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
526} __sfu_res; })
527
528/*
529 * Return the size of a string (including the ending 0!)
530 */
531static __inline__ long __strnlen_user(const char __user *__s, long __n)
532{
533 unsigned long res;
534 unsigned long __dummy;
535
536 __asm__ __volatile__(
537 "9:\n"
538 "cmp/eq %4, %0\n\t"
539 "bt 2f\n"
540 "1:\t"
541 "mov.b @(%0,%3), %1\n\t"
542 "tst %1, %1\n\t"
543 "bf/s 9b\n\t"
544 " add #1, %0\n"
545 "2:\n"
546 ".section .fixup,\"ax\"\n"
547 "3:\n\t"
548 "mov.l 4f, %1\n\t"
549 "jmp @%1\n\t"
550 " mov %5, %0\n"
551 ".balign 4\n"
552 "4: .long 2b\n"
553 ".previous\n"
554 ".section __ex_table,\"a\"\n"
555 " .balign 4\n"
556 " .long 1b,3b\n"
557 ".previous"
558 : "=z" (res), "=&r" (__dummy)
559 : "0" (0), "r" (__s), "r" (__n), "i" (-EFAULT)
560 : "t");
561 return res;
562}
563
564static __inline__ long strnlen_user(const char __user *s, long n)
565{
566 if (!access_ok(VERIFY_READ, s, n))
567 return 0;
568 else
569 return __strnlen_user(s, n);
570}
571
572static __inline__ long strlen_user(const char __user *s)
573{
574 if (!access_ok(VERIFY_READ, s, 0))
575 return 0;
576 else
577 return __strnlen_user(s, ~0UL >> 1);
578}
579
580/*
581 * The exception table consists of pairs of addresses: the first is the
582 * address of an instruction that is allowed to fault, and the second is
583 * the address at which the program should continue. No registers are
584 * modified, so it is entirely up to the continuation code to figure out
585 * what to do.
586 *
587 * All the routines below use bits of fixup code that are out of line
588 * with the main instruction path. This means when everything is well,
589 * we don't even have to jump over them. Further, they do not intrude
590 * on our cache or tlb entries.
591 */
592
593struct exception_table_entry
594{
595 unsigned long insn, fixup;
596};
597
598extern int fixup_exception(struct pt_regs *regs);
599
600#endif /* __ASM_SH_UACCESS_H */