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> | |
8b592783 | 20 | #include <asm/unified.h> |
1da177e4 LT |
21 | |
22 | #define VERIFY_READ 0 | |
23 | #define VERIFY_WRITE 1 | |
24 | ||
25 | /* | |
26 | * The exception table consists of pairs of addresses: the first is the | |
27 | * address of an instruction that is allowed to fault, and the second is | |
28 | * the address at which the program should continue. No registers are | |
29 | * modified, so it is entirely up to the continuation code to figure out | |
30 | * what to do. | |
31 | * | |
32 | * All the routines below use bits of fixup code that are out of line | |
33 | * with the main instruction path. This means when everything is well, | |
34 | * we don't even have to jump over them. Further, they do not intrude | |
35 | * on our cache or tlb entries. | |
36 | */ | |
37 | ||
38 | struct exception_table_entry | |
39 | { | |
40 | unsigned long insn, fixup; | |
41 | }; | |
42 | ||
43 | extern int fixup_exception(struct pt_regs *regs); | |
44 | ||
9641c7cc RK |
45 | /* |
46 | * These two are intentionally not defined anywhere - if the kernel | |
47 | * code generates any references to them, that's a bug. | |
48 | */ | |
49 | extern int __get_user_bad(void); | |
50 | extern int __put_user_bad(void); | |
51 | ||
1da177e4 LT |
52 | /* |
53 | * Note that this is actually 0x1,0000,0000 | |
54 | */ | |
55 | #define KERNEL_DS 0x00000000 | |
1da177e4 | 56 | #define get_ds() (KERNEL_DS) |
9641c7cc RK |
57 | |
58 | #ifdef CONFIG_MMU | |
59 | ||
60 | #define USER_DS TASK_SIZE | |
1da177e4 LT |
61 | #define get_fs() (current_thread_info()->addr_limit) |
62 | ||
9641c7cc | 63 | static inline void set_fs(mm_segment_t fs) |
1da177e4 LT |
64 | { |
65 | current_thread_info()->addr_limit = fs; | |
66 | modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER); | |
67 | } | |
68 | ||
69 | #define segment_eq(a,b) ((a) == (b)) | |
70 | ||
71 | #define __addr_ok(addr) ({ \ | |
72 | unsigned long flag; \ | |
73 | __asm__("cmp %2, %0; movlo %0, #0" \ | |
74 | : "=&r" (flag) \ | |
75 | : "0" (current_thread_info()->addr_limit), "r" (addr) \ | |
76 | : "cc"); \ | |
77 | (flag == 0); }) | |
78 | ||
79 | /* We use 33-bit arithmetic here... */ | |
80 | #define __range_ok(addr,size) ({ \ | |
16cf5b39 | 81 | unsigned long flag, roksum; \ |
1da177e4 LT |
82 | __chk_user_ptr(addr); \ |
83 | __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \ | |
16cf5b39 | 84 | : "=&r" (flag), "=&r" (roksum) \ |
1da177e4 LT |
85 | : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \ |
86 | : "cc"); \ | |
87 | flag; }) | |
88 | ||
1da177e4 LT |
89 | /* |
90 | * Single-value transfer routines. They automatically use the right | |
91 | * size if we just have the right pointer type. Note that the functions | |
92 | * which read from user space (*get_*) need to take care not to leak | |
93 | * kernel data even if the calling code is buggy and fails to check | |
94 | * the return value. This means zeroing out the destination variable | |
95 | * or buffer on error. Normally this is done out of line by the | |
96 | * fixup code, but there are a few places where it intrudes on the | |
97 | * main code path. When we only write to user space, there is no | |
98 | * problem. | |
1da177e4 | 99 | */ |
1da177e4 LT |
100 | extern int __get_user_1(void *); |
101 | extern int __get_user_2(void *); | |
102 | extern int __get_user_4(void *); | |
1da177e4 LT |
103 | |
104 | #define __get_user_x(__r2,__p,__e,__s,__i...) \ | |
105 | __asm__ __volatile__ ( \ | |
106 | __asmeq("%0", "r0") __asmeq("%1", "r2") \ | |
107 | "bl __get_user_" #__s \ | |
108 | : "=&r" (__e), "=r" (__r2) \ | |
109 | : "0" (__p) \ | |
110 | : __i, "cc") | |
111 | ||
112 | #define get_user(x,p) \ | |
113 | ({ \ | |
c5a69d57 | 114 | register const typeof(*(p)) __user *__p asm("r0") = (p);\ |
fc048b5b | 115 | register unsigned long __r2 asm("r2"); \ |
1da177e4 LT |
116 | register int __e asm("r0"); \ |
117 | switch (sizeof(*(__p))) { \ | |
118 | case 1: \ | |
119 | __get_user_x(__r2, __p, __e, 1, "lr"); \ | |
120 | break; \ | |
121 | case 2: \ | |
122 | __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \ | |
123 | break; \ | |
124 | case 4: \ | |
125 | __get_user_x(__r2, __p, __e, 4, "lr"); \ | |
126 | break; \ | |
1da177e4 LT |
127 | default: __e = __get_user_bad(); break; \ |
128 | } \ | |
d2c5b690 | 129 | x = (typeof(*(p))) __r2; \ |
1da177e4 LT |
130 | __e; \ |
131 | }) | |
132 | ||
9641c7cc RK |
133 | extern int __put_user_1(void *, unsigned int); |
134 | extern int __put_user_2(void *, unsigned int); | |
135 | extern int __put_user_4(void *, unsigned int); | |
136 | extern int __put_user_8(void *, unsigned long long); | |
137 | ||
138 | #define __put_user_x(__r2,__p,__e,__s) \ | |
139 | __asm__ __volatile__ ( \ | |
140 | __asmeq("%0", "r0") __asmeq("%2", "r2") \ | |
141 | "bl __put_user_" #__s \ | |
142 | : "=&r" (__e) \ | |
143 | : "0" (__p), "r" (__r2) \ | |
144 | : "ip", "lr", "cc") | |
145 | ||
146 | #define put_user(x,p) \ | |
147 | ({ \ | |
c5a69d57 TK |
148 | register const typeof(*(p)) __r2 asm("r2") = (x); \ |
149 | register const typeof(*(p)) __user *__p asm("r0") = (p);\ | |
9641c7cc RK |
150 | register int __e asm("r0"); \ |
151 | switch (sizeof(*(__p))) { \ | |
152 | case 1: \ | |
153 | __put_user_x(__r2, __p, __e, 1); \ | |
154 | break; \ | |
155 | case 2: \ | |
156 | __put_user_x(__r2, __p, __e, 2); \ | |
157 | break; \ | |
158 | case 4: \ | |
159 | __put_user_x(__r2, __p, __e, 4); \ | |
160 | break; \ | |
161 | case 8: \ | |
162 | __put_user_x(__r2, __p, __e, 8); \ | |
163 | break; \ | |
164 | default: __e = __put_user_bad(); break; \ | |
165 | } \ | |
166 | __e; \ | |
167 | }) | |
168 | ||
169 | #else /* CONFIG_MMU */ | |
170 | ||
171 | /* | |
172 | * uClinux has only one addr space, so has simplified address limits. | |
173 | */ | |
174 | #define USER_DS KERNEL_DS | |
175 | ||
176 | #define segment_eq(a,b) (1) | |
177 | #define __addr_ok(addr) (1) | |
178 | #define __range_ok(addr,size) (0) | |
179 | #define get_fs() (KERNEL_DS) | |
180 | ||
181 | static inline void set_fs(mm_segment_t fs) | |
182 | { | |
183 | } | |
184 | ||
185 | #define get_user(x,p) __get_user(x,p) | |
186 | #define put_user(x,p) __put_user(x,p) | |
187 | ||
188 | #endif /* CONFIG_MMU */ | |
189 | ||
190 | #define access_ok(type,addr,size) (__range_ok(addr,size) == 0) | |
191 | ||
192 | /* | |
193 | * The "__xxx" versions of the user access functions do not verify the | |
194 | * address space - it must have been done previously with a separate | |
195 | * "access_ok()" call. | |
196 | * | |
197 | * The "xxx_error" versions set the third argument to EFAULT if an | |
198 | * error occurs, and leave it unchanged on success. Note that these | |
199 | * versions are void (ie, don't return a value as such). | |
200 | */ | |
1da177e4 LT |
201 | #define __get_user(x,ptr) \ |
202 | ({ \ | |
203 | long __gu_err = 0; \ | |
204 | __get_user_err((x),(ptr),__gu_err); \ | |
205 | __gu_err; \ | |
206 | }) | |
207 | ||
208 | #define __get_user_error(x,ptr,err) \ | |
209 | ({ \ | |
210 | __get_user_err((x),(ptr),err); \ | |
211 | (void) 0; \ | |
212 | }) | |
213 | ||
214 | #define __get_user_err(x,ptr,err) \ | |
215 | do { \ | |
216 | unsigned long __gu_addr = (unsigned long)(ptr); \ | |
217 | unsigned long __gu_val; \ | |
218 | __chk_user_ptr(ptr); \ | |
219 | switch (sizeof(*(ptr))) { \ | |
220 | case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \ | |
221 | case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \ | |
222 | case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \ | |
223 | default: (__gu_val) = __get_user_bad(); \ | |
224 | } \ | |
225 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
226 | } while (0) | |
227 | ||
228 | #define __get_user_asm_byte(x,addr,err) \ | |
229 | __asm__ __volatile__( \ | |
247055aa | 230 | "1: " T(ldrb) " %1,[%2],#0\n" \ |
1da177e4 | 231 | "2:\n" \ |
4260415f | 232 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
233 | " .align 2\n" \ |
234 | "3: mov %0, %3\n" \ | |
235 | " mov %1, #0\n" \ | |
236 | " b 2b\n" \ | |
4260415f RK |
237 | " .popsection\n" \ |
238 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
239 | " .align 3\n" \ |
240 | " .long 1b, 3b\n" \ | |
4260415f | 241 | " .popsection" \ |
1da177e4 LT |
242 | : "+r" (err), "=&r" (x) \ |
243 | : "r" (addr), "i" (-EFAULT) \ | |
244 | : "cc") | |
245 | ||
246 | #ifndef __ARMEB__ | |
247 | #define __get_user_asm_half(x,__gu_addr,err) \ | |
248 | ({ \ | |
249 | unsigned long __b1, __b2; \ | |
250 | __get_user_asm_byte(__b1, __gu_addr, err); \ | |
251 | __get_user_asm_byte(__b2, __gu_addr + 1, err); \ | |
252 | (x) = __b1 | (__b2 << 8); \ | |
253 | }) | |
254 | #else | |
255 | #define __get_user_asm_half(x,__gu_addr,err) \ | |
256 | ({ \ | |
257 | unsigned long __b1, __b2; \ | |
258 | __get_user_asm_byte(__b1, __gu_addr, err); \ | |
259 | __get_user_asm_byte(__b2, __gu_addr + 1, err); \ | |
260 | (x) = (__b1 << 8) | __b2; \ | |
261 | }) | |
262 | #endif | |
263 | ||
264 | #define __get_user_asm_word(x,addr,err) \ | |
265 | __asm__ __volatile__( \ | |
247055aa | 266 | "1: " T(ldr) " %1,[%2],#0\n" \ |
1da177e4 | 267 | "2:\n" \ |
4260415f | 268 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
269 | " .align 2\n" \ |
270 | "3: mov %0, %3\n" \ | |
271 | " mov %1, #0\n" \ | |
272 | " b 2b\n" \ | |
4260415f RK |
273 | " .popsection\n" \ |
274 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
275 | " .align 3\n" \ |
276 | " .long 1b, 3b\n" \ | |
4260415f | 277 | " .popsection" \ |
1da177e4 LT |
278 | : "+r" (err), "=&r" (x) \ |
279 | : "r" (addr), "i" (-EFAULT) \ | |
280 | : "cc") | |
281 | ||
1da177e4 LT |
282 | #define __put_user(x,ptr) \ |
283 | ({ \ | |
284 | long __pu_err = 0; \ | |
285 | __put_user_err((x),(ptr),__pu_err); \ | |
286 | __pu_err; \ | |
287 | }) | |
288 | ||
289 | #define __put_user_error(x,ptr,err) \ | |
290 | ({ \ | |
291 | __put_user_err((x),(ptr),err); \ | |
292 | (void) 0; \ | |
293 | }) | |
294 | ||
295 | #define __put_user_err(x,ptr,err) \ | |
296 | do { \ | |
297 | unsigned long __pu_addr = (unsigned long)(ptr); \ | |
298 | __typeof__(*(ptr)) __pu_val = (x); \ | |
299 | __chk_user_ptr(ptr); \ | |
300 | switch (sizeof(*(ptr))) { \ | |
301 | case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \ | |
302 | case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \ | |
303 | case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \ | |
304 | case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \ | |
305 | default: __put_user_bad(); \ | |
306 | } \ | |
307 | } while (0) | |
308 | ||
309 | #define __put_user_asm_byte(x,__pu_addr,err) \ | |
310 | __asm__ __volatile__( \ | |
247055aa | 311 | "1: " T(strb) " %1,[%2],#0\n" \ |
1da177e4 | 312 | "2:\n" \ |
4260415f | 313 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
314 | " .align 2\n" \ |
315 | "3: mov %0, %3\n" \ | |
316 | " b 2b\n" \ | |
4260415f RK |
317 | " .popsection\n" \ |
318 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
319 | " .align 3\n" \ |
320 | " .long 1b, 3b\n" \ | |
4260415f | 321 | " .popsection" \ |
1da177e4 LT |
322 | : "+r" (err) \ |
323 | : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ | |
324 | : "cc") | |
325 | ||
326 | #ifndef __ARMEB__ | |
327 | #define __put_user_asm_half(x,__pu_addr,err) \ | |
328 | ({ \ | |
329 | unsigned long __temp = (unsigned long)(x); \ | |
330 | __put_user_asm_byte(__temp, __pu_addr, err); \ | |
331 | __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \ | |
332 | }) | |
333 | #else | |
334 | #define __put_user_asm_half(x,__pu_addr,err) \ | |
335 | ({ \ | |
336 | unsigned long __temp = (unsigned long)(x); \ | |
337 | __put_user_asm_byte(__temp >> 8, __pu_addr, err); \ | |
338 | __put_user_asm_byte(__temp, __pu_addr + 1, err); \ | |
339 | }) | |
340 | #endif | |
341 | ||
342 | #define __put_user_asm_word(x,__pu_addr,err) \ | |
343 | __asm__ __volatile__( \ | |
247055aa | 344 | "1: " T(str) " %1,[%2],#0\n" \ |
1da177e4 | 345 | "2:\n" \ |
4260415f | 346 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
347 | " .align 2\n" \ |
348 | "3: mov %0, %3\n" \ | |
349 | " b 2b\n" \ | |
4260415f RK |
350 | " .popsection\n" \ |
351 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
352 | " .align 3\n" \ |
353 | " .long 1b, 3b\n" \ | |
4260415f | 354 | " .popsection" \ |
1da177e4 LT |
355 | : "+r" (err) \ |
356 | : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ | |
357 | : "cc") | |
358 | ||
359 | #ifndef __ARMEB__ | |
360 | #define __reg_oper0 "%R2" | |
361 | #define __reg_oper1 "%Q2" | |
362 | #else | |
363 | #define __reg_oper0 "%Q2" | |
364 | #define __reg_oper1 "%R2" | |
365 | #endif | |
366 | ||
367 | #define __put_user_asm_dword(x,__pu_addr,err) \ | |
368 | __asm__ __volatile__( \ | |
247055aa CM |
369 | ARM( "1: " T(str) " " __reg_oper1 ", [%1], #4\n" ) \ |
370 | ARM( "2: " T(str) " " __reg_oper0 ", [%1]\n" ) \ | |
371 | THUMB( "1: " T(str) " " __reg_oper1 ", [%1]\n" ) \ | |
372 | THUMB( "2: " T(str) " " __reg_oper0 ", [%1, #4]\n" ) \ | |
1da177e4 | 373 | "3:\n" \ |
4260415f | 374 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
375 | " .align 2\n" \ |
376 | "4: mov %0, %3\n" \ | |
377 | " b 3b\n" \ | |
4260415f RK |
378 | " .popsection\n" \ |
379 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
380 | " .align 3\n" \ |
381 | " .long 1b, 4b\n" \ | |
382 | " .long 2b, 4b\n" \ | |
4260415f | 383 | " .popsection" \ |
1da177e4 LT |
384 | : "+r" (err), "+r" (__pu_addr) \ |
385 | : "r" (x), "i" (-EFAULT) \ | |
386 | : "cc") | |
387 | ||
02fcb974 | 388 | |
9641c7cc | 389 | #ifdef CONFIG_MMU |
99573298 RK |
390 | extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n); |
391 | extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n); | |
a1f98849 | 392 | extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n); |
99573298 | 393 | extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n); |
a1f98849 | 394 | extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n); |
9641c7cc RK |
395 | #else |
396 | #define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0) | |
397 | #define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0) | |
398 | #define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0) | |
399 | #endif | |
400 | ||
99573298 RK |
401 | extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count); |
402 | extern unsigned long __must_check __strnlen_user(const char __user *s, long n); | |
1da177e4 | 403 | |
99573298 | 404 | static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) |
1da177e4 LT |
405 | { |
406 | if (access_ok(VERIFY_READ, from, n)) | |
02fcb974 | 407 | n = __copy_from_user(to, from, n); |
1da177e4 | 408 | else /* security hole - plug it */ |
59f0cb0f | 409 | memset(to, 0, n); |
1da177e4 LT |
410 | return n; |
411 | } | |
412 | ||
99573298 | 413 | static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) |
1da177e4 LT |
414 | { |
415 | if (access_ok(VERIFY_WRITE, to, n)) | |
02fcb974 | 416 | n = __copy_to_user(to, from, n); |
1da177e4 LT |
417 | return n; |
418 | } | |
419 | ||
1da177e4 LT |
420 | #define __copy_to_user_inatomic __copy_to_user |
421 | #define __copy_from_user_inatomic __copy_from_user | |
422 | ||
99573298 | 423 | static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) |
1da177e4 LT |
424 | { |
425 | if (access_ok(VERIFY_WRITE, to, n)) | |
02fcb974 | 426 | n = __clear_user(to, n); |
1da177e4 LT |
427 | return n; |
428 | } | |
429 | ||
99573298 | 430 | static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count) |
1da177e4 LT |
431 | { |
432 | long res = -EFAULT; | |
433 | if (access_ok(VERIFY_READ, src, 1)) | |
02fcb974 | 434 | res = __strncpy_from_user(dst, src, count); |
1da177e4 LT |
435 | return res; |
436 | } | |
437 | ||
1da177e4 LT |
438 | #define strlen_user(s) strnlen_user(s, ~0UL >> 1) |
439 | ||
99573298 | 440 | static inline long __must_check strnlen_user(const char __user *s, long n) |
1da177e4 LT |
441 | { |
442 | unsigned long res = 0; | |
443 | ||
444 | if (__addr_ok(s)) | |
02fcb974 | 445 | res = __strnlen_user(s, n); |
1da177e4 LT |
446 | |
447 | return res; | |
448 | } | |
449 | ||
450 | #endif /* _ASMARM_UACCESS_H */ |