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9b01bd9e PM |
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 | #define VERIFY_READ 0 | |
20 | #define VERIFY_WRITE 1 | |
21 | ||
22 | /* | |
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) }) | |
31 | ||
32 | #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFUL) | |
33 | #define USER_DS MAKE_MM_SEG(PAGE_OFFSET) | |
34 | ||
35 | #define segment_eq(a,b) ((a).seg == (b).seg) | |
36 | ||
37 | #define get_ds() (KERNEL_DS) | |
38 | ||
39 | #if !defined(CONFIG_MMU) | |
40 | /* NOMMU is always true */ | |
41 | #define __addr_ok(addr) (1) | |
42 | ||
43 | static inline mm_segment_t get_fs(void) | |
44 | { | |
45 | return USER_DS; | |
46 | } | |
47 | ||
48 | static 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 | */ | |
62 | static inline int __access_ok(unsigned long addr, unsigned long size) | |
63 | { | |
64 | return ((addr >= memory_start) && ((addr + size) < memory_end)); | |
65 | } | |
66 | #else /* CONFIG_MMU */ | |
67 | #define __addr_ok(addr) \ | |
68 | ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg)) | |
69 | ||
70 | #define get_fs() (current_thread_info()->addr_limit) | |
71 | #define set_fs(x) (current_thread_info()->addr_limit = (x)) | |
72 | ||
73 | /* | |
74 | * __access_ok: Check if address with size is OK or not. | |
75 | * | |
0fb19dcb | 76 | * Uhhuh, this needs 33-bit arithmetic. We have a carry.. |
9b01bd9e | 77 | * |
0fb19dcb SM |
78 | * sum := addr + size; carry? --> flag = true; |
79 | * if (sum >= addr_limit) flag = true; | |
9b01bd9e PM |
80 | */ |
81 | static inline int __access_ok(unsigned long addr, unsigned long size) | |
82 | { | |
0fb19dcb SM |
83 | unsigned long flag, sum; |
84 | ||
85 | __asm__("clrt\n\t" | |
86 | "addc %3, %1\n\t" | |
87 | "movt %0\n\t" | |
88 | "cmp/hi %4, %1\n\t" | |
89 | "rotcl %0" | |
90 | :"=&r" (flag), "=r" (sum) | |
91 | :"1" (addr), "r" (size), | |
92 | "r" (current_thread_info()->addr_limit.seg) | |
93 | :"t"); | |
9b01bd9e PM |
94 | return flag == 0; |
95 | } | |
96 | #endif /* CONFIG_MMU */ | |
97 | ||
0465b9fb PM |
98 | #define access_ok(type, addr, size) \ |
99 | (__chk_user_ptr(addr), \ | |
100 | __access_ok((unsigned long __force)(addr), (size))) | |
9b01bd9e PM |
101 | |
102 | /* | |
103 | * Uh, these should become the main single-value transfer routines ... | |
104 | * They automatically use the right size if we just have the right | |
105 | * pointer type ... | |
106 | * | |
107 | * As SuperH uses the same address space for kernel and user data, we | |
108 | * can just do these as direct assignments. | |
109 | * | |
110 | * Careful to not | |
111 | * (a) re-use the arguments for side effects (sizeof is ok) | |
112 | * (b) require any knowledge of processes at this stage | |
113 | */ | |
0465b9fb PM |
114 | #define put_user(x,ptr) __put_user_check((x), (ptr), sizeof(*(ptr))) |
115 | #define get_user(x,ptr) __get_user_check((x), (ptr), sizeof(*(ptr))) | |
9b01bd9e PM |
116 | |
117 | /* | |
118 | * The "__xxx" versions do not do address space checking, useful when | |
119 | * doing multiple accesses to the same area (the user has to do the | |
120 | * checks by hand with "access_ok()") | |
121 | */ | |
0465b9fb PM |
122 | #define __put_user(x,ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr))) |
123 | #define __get_user(x,ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
9b01bd9e PM |
124 | |
125 | struct __large_struct { unsigned long buf[100]; }; | |
126 | #define __m(x) (*(struct __large_struct __user *)(x)) | |
127 | ||
128 | #define __get_user_size(x,ptr,size,retval) \ | |
129 | do { \ | |
130 | retval = 0; \ | |
9b01bd9e PM |
131 | switch (size) { \ |
132 | case 1: \ | |
133 | __get_user_asm(x, ptr, retval, "b"); \ | |
134 | break; \ | |
135 | case 2: \ | |
136 | __get_user_asm(x, ptr, retval, "w"); \ | |
137 | break; \ | |
138 | case 4: \ | |
139 | __get_user_asm(x, ptr, retval, "l"); \ | |
140 | break; \ | |
141 | default: \ | |
142 | __get_user_unknown(); \ | |
143 | break; \ | |
144 | } \ | |
145 | } while (0) | |
146 | ||
147 | #define __get_user_nocheck(x,ptr,size) \ | |
148 | ({ \ | |
0465b9fb PM |
149 | long __gu_err; \ |
150 | unsigned long __gu_val; \ | |
151 | const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ | |
152 | __chk_user_ptr(ptr); \ | |
153 | __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ | |
9b01bd9e PM |
154 | (x) = (__typeof__(*(ptr)))__gu_val; \ |
155 | __gu_err; \ | |
156 | }) | |
157 | ||
9b01bd9e PM |
158 | #define __get_user_check(x,ptr,size) \ |
159 | ({ \ | |
0465b9fb PM |
160 | long __gu_err = -EFAULT; \ |
161 | unsigned long __gu_val = 0; \ | |
162 | const __typeof__(*(ptr)) *__gu_addr = (ptr); \ | |
163 | if (likely(access_ok(VERIFY_READ, __gu_addr, (size)))) \ | |
164 | __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ | |
0fb19dcb | 165 | (x) = (__typeof__(*(ptr)))__gu_val; \ |
9b01bd9e PM |
166 | __gu_err; \ |
167 | }) | |
9b01bd9e PM |
168 | |
169 | #define __get_user_asm(x, addr, err, insn) \ | |
170 | ({ \ | |
171 | __asm__ __volatile__( \ | |
172 | "1:\n\t" \ | |
173 | "mov." insn " %2, %1\n\t" \ | |
9b01bd9e PM |
174 | "2:\n" \ |
175 | ".section .fixup,\"ax\"\n" \ | |
176 | "3:\n\t" \ | |
177 | "mov #0, %1\n\t" \ | |
178 | "mov.l 4f, %0\n\t" \ | |
179 | "jmp @%0\n\t" \ | |
0fb19dcb SM |
180 | " mov %3, %0\n\t" \ |
181 | ".balign 4\n" \ | |
9b01bd9e PM |
182 | "4: .long 2b\n\t" \ |
183 | ".previous\n" \ | |
184 | ".section __ex_table,\"a\"\n\t" \ | |
185 | ".long 1b, 3b\n\t" \ | |
186 | ".previous" \ | |
187 | :"=&r" (err), "=&r" (x) \ | |
0fb19dcb | 188 | :"m" (__m(addr)), "i" (-EFAULT), "0" (err)); }) |
9b01bd9e PM |
189 | |
190 | extern void __get_user_unknown(void); | |
191 | ||
192 | #define __put_user_size(x,ptr,size,retval) \ | |
193 | do { \ | |
194 | retval = 0; \ | |
9b01bd9e PM |
195 | switch (size) { \ |
196 | case 1: \ | |
197 | __put_user_asm(x, ptr, retval, "b"); \ | |
198 | break; \ | |
199 | case 2: \ | |
200 | __put_user_asm(x, ptr, retval, "w"); \ | |
201 | break; \ | |
202 | case 4: \ | |
203 | __put_user_asm(x, ptr, retval, "l"); \ | |
204 | break; \ | |
205 | case 8: \ | |
206 | __put_user_u64(x, ptr, retval); \ | |
207 | break; \ | |
208 | default: \ | |
209 | __put_user_unknown(); \ | |
210 | } \ | |
211 | } while (0) | |
212 | ||
0465b9fb PM |
213 | #define __put_user_nocheck(x,ptr,size) \ |
214 | ({ \ | |
215 | long __pu_err; \ | |
216 | __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ | |
217 | __chk_user_ptr(ptr); \ | |
218 | __put_user_size((x), __pu_addr, (size), __pu_err); \ | |
219 | __pu_err; \ | |
9b01bd9e PM |
220 | }) |
221 | ||
222 | #define __put_user_check(x,ptr,size) \ | |
223 | ({ \ | |
0465b9fb | 224 | long __pu_err = -EFAULT; \ |
9b01bd9e | 225 | __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ |
0465b9fb PM |
226 | if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) \ |
227 | __put_user_size((x), __pu_addr, (size), \ | |
228 | __pu_err); \ | |
9b01bd9e PM |
229 | __pu_err; \ |
230 | }) | |
231 | ||
232 | #define __put_user_asm(x, addr, err, insn) \ | |
233 | ({ \ | |
234 | __asm__ __volatile__( \ | |
235 | "1:\n\t" \ | |
236 | "mov." insn " %1, %2\n\t" \ | |
9b01bd9e PM |
237 | "2:\n" \ |
238 | ".section .fixup,\"ax\"\n" \ | |
239 | "3:\n\t" \ | |
9b01bd9e PM |
240 | "mov.l 4f, %0\n\t" \ |
241 | "jmp @%0\n\t" \ | |
0fb19dcb SM |
242 | " mov %3, %0\n\t" \ |
243 | ".balign 4\n" \ | |
9b01bd9e PM |
244 | "4: .long 2b\n\t" \ |
245 | ".previous\n" \ | |
246 | ".section __ex_table,\"a\"\n\t" \ | |
247 | ".long 1b, 3b\n\t" \ | |
248 | ".previous" \ | |
249 | :"=&r" (err) \ | |
0fb19dcb | 250 | :"r" (x), "m" (__m(addr)), "i" (-EFAULT), "0" (err) \ |
9b01bd9e PM |
251 | :"memory"); }) |
252 | ||
0fb19dcb | 253 | #if defined(CONFIG_CPU_LITTLE_ENDIAN) |
9b01bd9e PM |
254 | #define __put_user_u64(val,addr,retval) \ |
255 | ({ \ | |
256 | __asm__ __volatile__( \ | |
257 | "1:\n\t" \ | |
258 | "mov.l %R1,%2\n\t" \ | |
259 | "mov.l %S1,%T2\n\t" \ | |
9b01bd9e PM |
260 | "2:\n" \ |
261 | ".section .fixup,\"ax\"\n" \ | |
262 | "3:\n\t" \ | |
9b01bd9e PM |
263 | "mov.l 4f,%0\n\t" \ |
264 | "jmp @%0\n\t" \ | |
0fb19dcb SM |
265 | " mov %3,%0\n\t" \ |
266 | ".balign 4\n" \ | |
9b01bd9e PM |
267 | "4: .long 2b\n\t" \ |
268 | ".previous\n" \ | |
269 | ".section __ex_table,\"a\"\n\t" \ | |
270 | ".long 1b, 3b\n\t" \ | |
271 | ".previous" \ | |
272 | : "=r" (retval) \ | |
0fb19dcb | 273 | : "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \ |
9b01bd9e PM |
274 | : "memory"); }) |
275 | #else | |
276 | #define __put_user_u64(val,addr,retval) \ | |
277 | ({ \ | |
278 | __asm__ __volatile__( \ | |
279 | "1:\n\t" \ | |
280 | "mov.l %S1,%2\n\t" \ | |
281 | "mov.l %R1,%T2\n\t" \ | |
9b01bd9e PM |
282 | "2:\n" \ |
283 | ".section .fixup,\"ax\"\n" \ | |
284 | "3:\n\t" \ | |
9b01bd9e PM |
285 | "mov.l 4f,%0\n\t" \ |
286 | "jmp @%0\n\t" \ | |
0fb19dcb SM |
287 | " mov %3,%0\n\t" \ |
288 | ".balign 4\n" \ | |
9b01bd9e PM |
289 | "4: .long 2b\n\t" \ |
290 | ".previous\n" \ | |
291 | ".section __ex_table,\"a\"\n\t" \ | |
292 | ".long 1b, 3b\n\t" \ | |
293 | ".previous" \ | |
294 | : "=r" (retval) \ | |
0fb19dcb | 295 | : "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \ |
9b01bd9e PM |
296 | : "memory"); }) |
297 | #endif | |
298 | ||
299 | extern void __put_user_unknown(void); | |
300 | ||
301 | /* Generic arbitrary sized copy. */ | |
302 | /* Return the number of bytes NOT copied */ | |
303 | __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n); | |
304 | ||
305 | #define copy_to_user(to,from,n) ({ \ | |
306 | void *__copy_to = (void *) (to); \ | |
307 | __kernel_size_t __copy_size = (__kernel_size_t) (n); \ | |
308 | __kernel_size_t __copy_res; \ | |
309 | if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \ | |
310 | __copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \ | |
311 | } else __copy_res = __copy_size; \ | |
312 | __copy_res; }) | |
313 | ||
314 | #define copy_from_user(to,from,n) ({ \ | |
315 | void *__copy_to = (void *) (to); \ | |
316 | void *__copy_from = (void *) (from); \ | |
317 | __kernel_size_t __copy_size = (__kernel_size_t) (n); \ | |
318 | __kernel_size_t __copy_res; \ | |
319 | if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \ | |
320 | __copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \ | |
321 | } else __copy_res = __copy_size; \ | |
322 | __copy_res; }) | |
323 | ||
324 | static __always_inline unsigned long | |
325 | __copy_from_user(void *to, const void __user *from, unsigned long n) | |
326 | { | |
327 | return __copy_user(to, (__force void *)from, n); | |
328 | } | |
329 | ||
330 | static __always_inline unsigned long __must_check | |
331 | __copy_to_user(void __user *to, const void *from, unsigned long n) | |
332 | { | |
333 | return __copy_user((__force void *)to, from, n); | |
334 | } | |
335 | ||
336 | #define __copy_to_user_inatomic __copy_to_user | |
337 | #define __copy_from_user_inatomic __copy_from_user | |
338 | ||
339 | /* | |
340 | * Clear the area and return remaining number of bytes | |
341 | * (on failure. Usually it's 0.) | |
342 | */ | |
343 | extern __kernel_size_t __clear_user(void *addr, __kernel_size_t size); | |
344 | ||
345 | #define clear_user(addr,n) ({ \ | |
346 | void * __cl_addr = (addr); \ | |
347 | unsigned long __cl_size = (n); \ | |
348 | if (__cl_size && __access_ok(((unsigned long)(__cl_addr)), __cl_size)) \ | |
349 | __cl_size = __clear_user(__cl_addr, __cl_size); \ | |
350 | __cl_size; }) | |
351 | ||
352 | static __inline__ int | |
353 | __strncpy_from_user(unsigned long __dest, unsigned long __user __src, int __count) | |
354 | { | |
355 | __kernel_size_t res; | |
0fb19dcb | 356 | unsigned long __dummy, _d, _s, _c; |
9b01bd9e PM |
357 | |
358 | __asm__ __volatile__( | |
359 | "9:\n" | |
360 | "mov.b @%2+, %1\n\t" | |
361 | "cmp/eq #0, %1\n\t" | |
362 | "bt/s 2f\n" | |
363 | "1:\n" | |
364 | "mov.b %1, @%3\n\t" | |
0fb19dcb | 365 | "dt %4\n\t" |
9b01bd9e PM |
366 | "bf/s 9b\n\t" |
367 | " add #1, %3\n\t" | |
368 | "2:\n\t" | |
0fb19dcb | 369 | "sub %4, %0\n" |
9b01bd9e PM |
370 | "3:\n" |
371 | ".section .fixup,\"ax\"\n" | |
372 | "4:\n\t" | |
373 | "mov.l 5f, %1\n\t" | |
374 | "jmp @%1\n\t" | |
0fb19dcb | 375 | " mov %9, %0\n\t" |
9b01bd9e PM |
376 | ".balign 4\n" |
377 | "5: .long 3b\n" | |
378 | ".previous\n" | |
379 | ".section __ex_table,\"a\"\n" | |
380 | " .balign 4\n" | |
381 | " .long 9b,4b\n" | |
382 | ".previous" | |
0fb19dcb SM |
383 | : "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d), "=r"(_c) |
384 | : "0" (__count), "2" (__src), "3" (__dest), "4" (__count), | |
9b01bd9e PM |
385 | "i" (-EFAULT) |
386 | : "memory", "t"); | |
387 | ||
388 | return res; | |
389 | } | |
390 | ||
0fb19dcb SM |
391 | /** |
392 | * strncpy_from_user: - Copy a NUL terminated string from userspace. | |
393 | * @dst: Destination address, in kernel space. This buffer must be at | |
394 | * least @count bytes long. | |
395 | * @src: Source address, in user space. | |
396 | * @count: Maximum number of bytes to copy, including the trailing NUL. | |
397 | * | |
398 | * Copies a NUL-terminated string from userspace to kernel space. | |
399 | * | |
400 | * On success, returns the length of the string (not including the trailing | |
401 | * NUL). | |
402 | * | |
403 | * If access to userspace fails, returns -EFAULT (some data may have been | |
404 | * copied). | |
405 | * | |
406 | * If @count is smaller than the length of the string, copies @count bytes | |
407 | * and returns @count. | |
408 | */ | |
9b01bd9e PM |
409 | #define strncpy_from_user(dest,src,count) ({ \ |
410 | unsigned long __sfu_src = (unsigned long) (src); \ | |
411 | int __sfu_count = (int) (count); \ | |
412 | long __sfu_res = -EFAULT; \ | |
413 | if(__access_ok(__sfu_src, __sfu_count)) { \ | |
414 | __sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \ | |
415 | } __sfu_res; }) | |
416 | ||
417 | /* | |
0fb19dcb SM |
418 | * Return the size of a string (including the ending 0 even when we have |
419 | * exceeded the maximum string length). | |
9b01bd9e PM |
420 | */ |
421 | static __inline__ long __strnlen_user(const char __user *__s, long __n) | |
422 | { | |
423 | unsigned long res; | |
424 | unsigned long __dummy; | |
425 | ||
426 | __asm__ __volatile__( | |
9b01bd9e PM |
427 | "1:\t" |
428 | "mov.b @(%0,%3), %1\n\t" | |
0fb19dcb SM |
429 | "cmp/eq %4, %0\n\t" |
430 | "bt/s 2f\n\t" | |
431 | " add #1, %0\n\t" | |
9b01bd9e | 432 | "tst %1, %1\n\t" |
0fb19dcb | 433 | "bf 1b\n\t" |
9b01bd9e PM |
434 | "2:\n" |
435 | ".section .fixup,\"ax\"\n" | |
436 | "3:\n\t" | |
437 | "mov.l 4f, %1\n\t" | |
438 | "jmp @%1\n\t" | |
439 | " mov #0, %0\n" | |
440 | ".balign 4\n" | |
441 | "4: .long 2b\n" | |
442 | ".previous\n" | |
443 | ".section __ex_table,\"a\"\n" | |
444 | " .balign 4\n" | |
445 | " .long 1b,3b\n" | |
446 | ".previous" | |
447 | : "=z" (res), "=&r" (__dummy) | |
448 | : "0" (0), "r" (__s), "r" (__n) | |
449 | : "t"); | |
450 | return res; | |
451 | } | |
452 | ||
0fb19dcb SM |
453 | /** |
454 | * strnlen_user: - Get the size of a string in user space. | |
455 | * @s: The string to measure. | |
456 | * @n: The maximum valid length | |
457 | * | |
458 | * Context: User context only. This function may sleep. | |
459 | * | |
460 | * Get the size of a NUL-terminated string in user space. | |
461 | * | |
462 | * Returns the size of the string INCLUDING the terminating NUL. | |
463 | * On exception, returns 0. | |
464 | * If the string is too long, returns a value greater than @n. | |
465 | */ | |
9b01bd9e PM |
466 | static __inline__ long strnlen_user(const char __user *s, long n) |
467 | { | |
468 | if (!__addr_ok(s)) | |
469 | return 0; | |
470 | else | |
471 | return __strnlen_user(s, n); | |
472 | } | |
473 | ||
0fb19dcb SM |
474 | /** |
475 | * strlen_user: - Get the size of a string in user space. | |
476 | * @str: The string to measure. | |
477 | * | |
478 | * Context: User context only. This function may sleep. | |
479 | * | |
480 | * Get the size of a NUL-terminated string in user space. | |
481 | * | |
482 | * Returns the size of the string INCLUDING the terminating NUL. | |
483 | * On exception, returns 0. | |
484 | * | |
485 | * If there is a limit on the length of a valid string, you may wish to | |
486 | * consider using strnlen_user() instead. | |
487 | */ | |
9b01bd9e PM |
488 | #define strlen_user(str) strnlen_user(str, ~0UL >> 1) |
489 | ||
490 | /* | |
491 | * The exception table consists of pairs of addresses: the first is the | |
492 | * address of an instruction that is allowed to fault, and the second is | |
493 | * the address at which the program should continue. No registers are | |
494 | * modified, so it is entirely up to the continuation code to figure out | |
495 | * what to do. | |
496 | * | |
497 | * All the routines below use bits of fixup code that are out of line | |
498 | * with the main instruction path. This means when everything is well, | |
499 | * we don't even have to jump over them. Further, they do not intrude | |
500 | * on our cache or tlb entries. | |
501 | */ | |
502 | ||
503 | struct exception_table_entry | |
504 | { | |
505 | unsigned long insn, fixup; | |
506 | }; | |
507 | ||
508 | extern int fixup_exception(struct pt_regs *regs); | |
509 | ||
510 | #endif /* __ASM_SH_UACCESS_H */ |