Commit | Line | Data |
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1da177e4 | 1 | /* |
4baa9922 | 2 | * arch/arm/include/asm/uaccess.h |
1da177e4 LT |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | #ifndef _ASMARM_UACCESS_H | |
9 | #define _ASMARM_UACCESS_H | |
10 | ||
11 | /* | |
12 | * User space memory access functions | |
13 | */ | |
87c52578 RK |
14 | #include <linux/string.h> |
15 | #include <linux/thread_info.h> | |
1da177e4 LT |
16 | #include <asm/errno.h> |
17 | #include <asm/memory.h> | |
18 | #include <asm/domain.h> | |
19 | #include <asm/system.h> | |
20 | ||
21 | #define VERIFY_READ 0 | |
22 | #define VERIFY_WRITE 1 | |
23 | ||
24 | /* | |
25 | * The exception table consists of pairs of addresses: the first is the | |
26 | * address of an instruction that is allowed to fault, and the second is | |
27 | * the address at which the program should continue. No registers are | |
28 | * modified, so it is entirely up to the continuation code to figure out | |
29 | * what to do. | |
30 | * | |
31 | * All the routines below use bits of fixup code that are out of line | |
32 | * with the main instruction path. This means when everything is well, | |
33 | * we don't even have to jump over them. Further, they do not intrude | |
34 | * on our cache or tlb entries. | |
35 | */ | |
36 | ||
37 | struct exception_table_entry | |
38 | { | |
39 | unsigned long insn, fixup; | |
40 | }; | |
41 | ||
42 | extern int fixup_exception(struct pt_regs *regs); | |
43 | ||
9641c7cc RK |
44 | /* |
45 | * These two are intentionally not defined anywhere - if the kernel | |
46 | * code generates any references to them, that's a bug. | |
47 | */ | |
48 | extern int __get_user_bad(void); | |
49 | extern int __put_user_bad(void); | |
50 | ||
1da177e4 LT |
51 | /* |
52 | * Note that this is actually 0x1,0000,0000 | |
53 | */ | |
54 | #define KERNEL_DS 0x00000000 | |
1da177e4 | 55 | #define get_ds() (KERNEL_DS) |
9641c7cc RK |
56 | |
57 | #ifdef CONFIG_MMU | |
58 | ||
59 | #define USER_DS TASK_SIZE | |
1da177e4 LT |
60 | #define get_fs() (current_thread_info()->addr_limit) |
61 | ||
9641c7cc | 62 | static inline void set_fs(mm_segment_t fs) |
1da177e4 LT |
63 | { |
64 | current_thread_info()->addr_limit = fs; | |
65 | modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER); | |
66 | } | |
67 | ||
68 | #define segment_eq(a,b) ((a) == (b)) | |
69 | ||
70 | #define __addr_ok(addr) ({ \ | |
71 | unsigned long flag; \ | |
72 | __asm__("cmp %2, %0; movlo %0, #0" \ | |
73 | : "=&r" (flag) \ | |
74 | : "0" (current_thread_info()->addr_limit), "r" (addr) \ | |
75 | : "cc"); \ | |
76 | (flag == 0); }) | |
77 | ||
78 | /* We use 33-bit arithmetic here... */ | |
79 | #define __range_ok(addr,size) ({ \ | |
16cf5b39 | 80 | unsigned long flag, roksum; \ |
1da177e4 LT |
81 | __chk_user_ptr(addr); \ |
82 | __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \ | |
16cf5b39 | 83 | : "=&r" (flag), "=&r" (roksum) \ |
1da177e4 LT |
84 | : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \ |
85 | : "cc"); \ | |
86 | flag; }) | |
87 | ||
1da177e4 LT |
88 | /* |
89 | * Single-value transfer routines. They automatically use the right | |
90 | * size if we just have the right pointer type. Note that the functions | |
91 | * which read from user space (*get_*) need to take care not to leak | |
92 | * kernel data even if the calling code is buggy and fails to check | |
93 | * the return value. This means zeroing out the destination variable | |
94 | * or buffer on error. Normally this is done out of line by the | |
95 | * fixup code, but there are a few places where it intrudes on the | |
96 | * main code path. When we only write to user space, there is no | |
97 | * problem. | |
1da177e4 | 98 | */ |
1da177e4 LT |
99 | extern int __get_user_1(void *); |
100 | extern int __get_user_2(void *); | |
101 | extern int __get_user_4(void *); | |
1da177e4 LT |
102 | |
103 | #define __get_user_x(__r2,__p,__e,__s,__i...) \ | |
104 | __asm__ __volatile__ ( \ | |
105 | __asmeq("%0", "r0") __asmeq("%1", "r2") \ | |
106 | "bl __get_user_" #__s \ | |
107 | : "=&r" (__e), "=r" (__r2) \ | |
108 | : "0" (__p) \ | |
109 | : __i, "cc") | |
110 | ||
111 | #define get_user(x,p) \ | |
112 | ({ \ | |
c5a69d57 | 113 | register const typeof(*(p)) __user *__p asm("r0") = (p);\ |
fc048b5b | 114 | register unsigned long __r2 asm("r2"); \ |
1da177e4 LT |
115 | register int __e asm("r0"); \ |
116 | switch (sizeof(*(__p))) { \ | |
117 | case 1: \ | |
118 | __get_user_x(__r2, __p, __e, 1, "lr"); \ | |
119 | break; \ | |
120 | case 2: \ | |
121 | __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \ | |
122 | break; \ | |
123 | case 4: \ | |
124 | __get_user_x(__r2, __p, __e, 4, "lr"); \ | |
125 | break; \ | |
1da177e4 LT |
126 | default: __e = __get_user_bad(); break; \ |
127 | } \ | |
d2c5b690 | 128 | x = (typeof(*(p))) __r2; \ |
1da177e4 LT |
129 | __e; \ |
130 | }) | |
131 | ||
9641c7cc RK |
132 | extern int __put_user_1(void *, unsigned int); |
133 | extern int __put_user_2(void *, unsigned int); | |
134 | extern int __put_user_4(void *, unsigned int); | |
135 | extern int __put_user_8(void *, unsigned long long); | |
136 | ||
137 | #define __put_user_x(__r2,__p,__e,__s) \ | |
138 | __asm__ __volatile__ ( \ | |
139 | __asmeq("%0", "r0") __asmeq("%2", "r2") \ | |
140 | "bl __put_user_" #__s \ | |
141 | : "=&r" (__e) \ | |
142 | : "0" (__p), "r" (__r2) \ | |
143 | : "ip", "lr", "cc") | |
144 | ||
145 | #define put_user(x,p) \ | |
146 | ({ \ | |
c5a69d57 TK |
147 | register const typeof(*(p)) __r2 asm("r2") = (x); \ |
148 | register const typeof(*(p)) __user *__p asm("r0") = (p);\ | |
9641c7cc RK |
149 | register int __e asm("r0"); \ |
150 | switch (sizeof(*(__p))) { \ | |
151 | case 1: \ | |
152 | __put_user_x(__r2, __p, __e, 1); \ | |
153 | break; \ | |
154 | case 2: \ | |
155 | __put_user_x(__r2, __p, __e, 2); \ | |
156 | break; \ | |
157 | case 4: \ | |
158 | __put_user_x(__r2, __p, __e, 4); \ | |
159 | break; \ | |
160 | case 8: \ | |
161 | __put_user_x(__r2, __p, __e, 8); \ | |
162 | break; \ | |
163 | default: __e = __put_user_bad(); break; \ | |
164 | } \ | |
165 | __e; \ | |
166 | }) | |
167 | ||
168 | #else /* CONFIG_MMU */ | |
169 | ||
170 | /* | |
171 | * uClinux has only one addr space, so has simplified address limits. | |
172 | */ | |
173 | #define USER_DS KERNEL_DS | |
174 | ||
175 | #define segment_eq(a,b) (1) | |
176 | #define __addr_ok(addr) (1) | |
177 | #define __range_ok(addr,size) (0) | |
178 | #define get_fs() (KERNEL_DS) | |
179 | ||
180 | static inline void set_fs(mm_segment_t fs) | |
181 | { | |
182 | } | |
183 | ||
184 | #define get_user(x,p) __get_user(x,p) | |
185 | #define put_user(x,p) __put_user(x,p) | |
186 | ||
187 | #endif /* CONFIG_MMU */ | |
188 | ||
189 | #define access_ok(type,addr,size) (__range_ok(addr,size) == 0) | |
190 | ||
191 | /* | |
192 | * The "__xxx" versions of the user access functions do not verify the | |
193 | * address space - it must have been done previously with a separate | |
194 | * "access_ok()" call. | |
195 | * | |
196 | * The "xxx_error" versions set the third argument to EFAULT if an | |
197 | * error occurs, and leave it unchanged on success. Note that these | |
198 | * versions are void (ie, don't return a value as such). | |
199 | */ | |
1da177e4 LT |
200 | #define __get_user(x,ptr) \ |
201 | ({ \ | |
202 | long __gu_err = 0; \ | |
203 | __get_user_err((x),(ptr),__gu_err); \ | |
204 | __gu_err; \ | |
205 | }) | |
206 | ||
207 | #define __get_user_error(x,ptr,err) \ | |
208 | ({ \ | |
209 | __get_user_err((x),(ptr),err); \ | |
210 | (void) 0; \ | |
211 | }) | |
212 | ||
213 | #define __get_user_err(x,ptr,err) \ | |
214 | do { \ | |
215 | unsigned long __gu_addr = (unsigned long)(ptr); \ | |
216 | unsigned long __gu_val; \ | |
217 | __chk_user_ptr(ptr); \ | |
218 | switch (sizeof(*(ptr))) { \ | |
219 | case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \ | |
220 | case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \ | |
221 | case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \ | |
222 | default: (__gu_val) = __get_user_bad(); \ | |
223 | } \ | |
224 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
225 | } while (0) | |
226 | ||
227 | #define __get_user_asm_byte(x,addr,err) \ | |
228 | __asm__ __volatile__( \ | |
4e6a0c39 | 229 | "1: ldrbt %1,[%2]\n" \ |
1da177e4 LT |
230 | "2:\n" \ |
231 | " .section .fixup,\"ax\"\n" \ | |
232 | " .align 2\n" \ | |
233 | "3: mov %0, %3\n" \ | |
234 | " mov %1, #0\n" \ | |
235 | " b 2b\n" \ | |
236 | " .previous\n" \ | |
237 | " .section __ex_table,\"a\"\n" \ | |
238 | " .align 3\n" \ | |
239 | " .long 1b, 3b\n" \ | |
240 | " .previous" \ | |
241 | : "+r" (err), "=&r" (x) \ | |
242 | : "r" (addr), "i" (-EFAULT) \ | |
243 | : "cc") | |
244 | ||
245 | #ifndef __ARMEB__ | |
246 | #define __get_user_asm_half(x,__gu_addr,err) \ | |
247 | ({ \ | |
248 | unsigned long __b1, __b2; \ | |
249 | __get_user_asm_byte(__b1, __gu_addr, err); \ | |
250 | __get_user_asm_byte(__b2, __gu_addr + 1, err); \ | |
251 | (x) = __b1 | (__b2 << 8); \ | |
252 | }) | |
253 | #else | |
254 | #define __get_user_asm_half(x,__gu_addr,err) \ | |
255 | ({ \ | |
256 | unsigned long __b1, __b2; \ | |
257 | __get_user_asm_byte(__b1, __gu_addr, err); \ | |
258 | __get_user_asm_byte(__b2, __gu_addr + 1, err); \ | |
259 | (x) = (__b1 << 8) | __b2; \ | |
260 | }) | |
261 | #endif | |
262 | ||
263 | #define __get_user_asm_word(x,addr,err) \ | |
264 | __asm__ __volatile__( \ | |
4e6a0c39 | 265 | "1: ldrt %1,[%2]\n" \ |
1da177e4 LT |
266 | "2:\n" \ |
267 | " .section .fixup,\"ax\"\n" \ | |
268 | " .align 2\n" \ | |
269 | "3: mov %0, %3\n" \ | |
270 | " mov %1, #0\n" \ | |
271 | " b 2b\n" \ | |
272 | " .previous\n" \ | |
273 | " .section __ex_table,\"a\"\n" \ | |
274 | " .align 3\n" \ | |
275 | " .long 1b, 3b\n" \ | |
276 | " .previous" \ | |
277 | : "+r" (err), "=&r" (x) \ | |
278 | : "r" (addr), "i" (-EFAULT) \ | |
279 | : "cc") | |
280 | ||
1da177e4 LT |
281 | #define __put_user(x,ptr) \ |
282 | ({ \ | |
283 | long __pu_err = 0; \ | |
284 | __put_user_err((x),(ptr),__pu_err); \ | |
285 | __pu_err; \ | |
286 | }) | |
287 | ||
288 | #define __put_user_error(x,ptr,err) \ | |
289 | ({ \ | |
290 | __put_user_err((x),(ptr),err); \ | |
291 | (void) 0; \ | |
292 | }) | |
293 | ||
294 | #define __put_user_err(x,ptr,err) \ | |
295 | do { \ | |
296 | unsigned long __pu_addr = (unsigned long)(ptr); \ | |
297 | __typeof__(*(ptr)) __pu_val = (x); \ | |
298 | __chk_user_ptr(ptr); \ | |
299 | switch (sizeof(*(ptr))) { \ | |
300 | case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \ | |
301 | case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \ | |
302 | case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \ | |
303 | case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \ | |
304 | default: __put_user_bad(); \ | |
305 | } \ | |
306 | } while (0) | |
307 | ||
308 | #define __put_user_asm_byte(x,__pu_addr,err) \ | |
309 | __asm__ __volatile__( \ | |
4e6a0c39 | 310 | "1: strbt %1,[%2]\n" \ |
1da177e4 LT |
311 | "2:\n" \ |
312 | " .section .fixup,\"ax\"\n" \ | |
313 | " .align 2\n" \ | |
314 | "3: mov %0, %3\n" \ | |
315 | " b 2b\n" \ | |
316 | " .previous\n" \ | |
317 | " .section __ex_table,\"a\"\n" \ | |
318 | " .align 3\n" \ | |
319 | " .long 1b, 3b\n" \ | |
320 | " .previous" \ | |
321 | : "+r" (err) \ | |
322 | : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ | |
323 | : "cc") | |
324 | ||
325 | #ifndef __ARMEB__ | |
326 | #define __put_user_asm_half(x,__pu_addr,err) \ | |
327 | ({ \ | |
328 | unsigned long __temp = (unsigned long)(x); \ | |
329 | __put_user_asm_byte(__temp, __pu_addr, err); \ | |
330 | __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \ | |
331 | }) | |
332 | #else | |
333 | #define __put_user_asm_half(x,__pu_addr,err) \ | |
334 | ({ \ | |
335 | unsigned long __temp = (unsigned long)(x); \ | |
336 | __put_user_asm_byte(__temp >> 8, __pu_addr, err); \ | |
337 | __put_user_asm_byte(__temp, __pu_addr + 1, err); \ | |
338 | }) | |
339 | #endif | |
340 | ||
341 | #define __put_user_asm_word(x,__pu_addr,err) \ | |
342 | __asm__ __volatile__( \ | |
4e6a0c39 | 343 | "1: strt %1,[%2]\n" \ |
1da177e4 LT |
344 | "2:\n" \ |
345 | " .section .fixup,\"ax\"\n" \ | |
346 | " .align 2\n" \ | |
347 | "3: mov %0, %3\n" \ | |
348 | " b 2b\n" \ | |
349 | " .previous\n" \ | |
350 | " .section __ex_table,\"a\"\n" \ | |
351 | " .align 3\n" \ | |
352 | " .long 1b, 3b\n" \ | |
353 | " .previous" \ | |
354 | : "+r" (err) \ | |
355 | : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ | |
356 | : "cc") | |
357 | ||
358 | #ifndef __ARMEB__ | |
359 | #define __reg_oper0 "%R2" | |
360 | #define __reg_oper1 "%Q2" | |
361 | #else | |
362 | #define __reg_oper0 "%Q2" | |
363 | #define __reg_oper1 "%R2" | |
364 | #endif | |
365 | ||
366 | #define __put_user_asm_dword(x,__pu_addr,err) \ | |
367 | __asm__ __volatile__( \ | |
368 | "1: strt " __reg_oper1 ", [%1], #4\n" \ | |
4e6a0c39 | 369 | "2: strt " __reg_oper0 ", [%1]\n" \ |
1da177e4 LT |
370 | "3:\n" \ |
371 | " .section .fixup,\"ax\"\n" \ | |
372 | " .align 2\n" \ | |
373 | "4: mov %0, %3\n" \ | |
374 | " b 3b\n" \ | |
375 | " .previous\n" \ | |
376 | " .section __ex_table,\"a\"\n" \ | |
377 | " .align 3\n" \ | |
378 | " .long 1b, 4b\n" \ | |
379 | " .long 2b, 4b\n" \ | |
380 | " .previous" \ | |
381 | : "+r" (err), "+r" (__pu_addr) \ | |
382 | : "r" (x), "i" (-EFAULT) \ | |
383 | : "cc") | |
384 | ||
02fcb974 | 385 | |
9641c7cc | 386 | #ifdef CONFIG_MMU |
99573298 RK |
387 | extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n); |
388 | extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n); | |
a1f98849 | 389 | extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n); |
99573298 | 390 | extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n); |
a1f98849 | 391 | extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n); |
9641c7cc RK |
392 | #else |
393 | #define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0) | |
394 | #define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0) | |
395 | #define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0) | |
396 | #endif | |
397 | ||
99573298 RK |
398 | extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count); |
399 | extern unsigned long __must_check __strnlen_user(const char __user *s, long n); | |
1da177e4 | 400 | |
99573298 | 401 | static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) |
1da177e4 LT |
402 | { |
403 | if (access_ok(VERIFY_READ, from, n)) | |
02fcb974 | 404 | n = __copy_from_user(to, from, n); |
1da177e4 | 405 | else /* security hole - plug it */ |
59f0cb0f | 406 | memset(to, 0, n); |
1da177e4 LT |
407 | return n; |
408 | } | |
409 | ||
99573298 | 410 | static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) |
1da177e4 LT |
411 | { |
412 | if (access_ok(VERIFY_WRITE, to, n)) | |
02fcb974 | 413 | n = __copy_to_user(to, from, n); |
1da177e4 LT |
414 | return n; |
415 | } | |
416 | ||
1da177e4 LT |
417 | #define __copy_to_user_inatomic __copy_to_user |
418 | #define __copy_from_user_inatomic __copy_from_user | |
419 | ||
99573298 | 420 | static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) |
1da177e4 LT |
421 | { |
422 | if (access_ok(VERIFY_WRITE, to, n)) | |
02fcb974 | 423 | n = __clear_user(to, n); |
1da177e4 LT |
424 | return n; |
425 | } | |
426 | ||
99573298 | 427 | static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count) |
1da177e4 LT |
428 | { |
429 | long res = -EFAULT; | |
430 | if (access_ok(VERIFY_READ, src, 1)) | |
02fcb974 | 431 | res = __strncpy_from_user(dst, src, count); |
1da177e4 LT |
432 | return res; |
433 | } | |
434 | ||
1da177e4 LT |
435 | #define strlen_user(s) strnlen_user(s, ~0UL >> 1) |
436 | ||
99573298 | 437 | static inline long __must_check strnlen_user(const char __user *s, long n) |
1da177e4 LT |
438 | { |
439 | unsigned long res = 0; | |
440 | ||
441 | if (__addr_ok(s)) | |
02fcb974 | 442 | res = __strnlen_user(s, n); |
1da177e4 LT |
443 | |
444 | return res; | |
445 | } | |
446 | ||
447 | #endif /* _ASMARM_UACCESS_H */ |