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> | |
8b592783 | 19 | #include <asm/unified.h> |
9f97da78 | 20 | #include <asm/compiler.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 | 103 | |
8404663f RK |
104 | #define __GUP_CLOBBER_1 "lr", "cc" |
105 | #ifdef CONFIG_CPU_USE_DOMAINS | |
106 | #define __GUP_CLOBBER_2 "ip", "lr", "cc" | |
107 | #else | |
108 | #define __GUP_CLOBBER_2 "lr", "cc" | |
109 | #endif | |
110 | #define __GUP_CLOBBER_4 "lr", "cc" | |
111 | ||
112 | #define __get_user_x(__r2,__p,__e,__l,__s) \ | |
1da177e4 LT |
113 | __asm__ __volatile__ ( \ |
114 | __asmeq("%0", "r0") __asmeq("%1", "r2") \ | |
8404663f | 115 | __asmeq("%3", "r1") \ |
1da177e4 LT |
116 | "bl __get_user_" #__s \ |
117 | : "=&r" (__e), "=r" (__r2) \ | |
8404663f RK |
118 | : "0" (__p), "r" (__l) \ |
119 | : __GUP_CLOBBER_##__s) | |
1da177e4 LT |
120 | |
121 | #define get_user(x,p) \ | |
122 | ({ \ | |
8404663f | 123 | unsigned long __limit = current_thread_info()->addr_limit - 1; \ |
c5a69d57 | 124 | register const typeof(*(p)) __user *__p asm("r0") = (p);\ |
fc048b5b | 125 | register unsigned long __r2 asm("r2"); \ |
8404663f | 126 | register unsigned long __l asm("r1") = __limit; \ |
1da177e4 LT |
127 | register int __e asm("r0"); \ |
128 | switch (sizeof(*(__p))) { \ | |
129 | case 1: \ | |
8404663f RK |
130 | __get_user_x(__r2, __p, __e, __l, 1); \ |
131 | break; \ | |
1da177e4 | 132 | case 2: \ |
8404663f | 133 | __get_user_x(__r2, __p, __e, __l, 2); \ |
1da177e4 LT |
134 | break; \ |
135 | case 4: \ | |
8404663f | 136 | __get_user_x(__r2, __p, __e, __l, 4); \ |
1da177e4 | 137 | break; \ |
1da177e4 LT |
138 | default: __e = __get_user_bad(); break; \ |
139 | } \ | |
d2c5b690 | 140 | x = (typeof(*(p))) __r2; \ |
1da177e4 LT |
141 | __e; \ |
142 | }) | |
143 | ||
9641c7cc RK |
144 | extern int __put_user_1(void *, unsigned int); |
145 | extern int __put_user_2(void *, unsigned int); | |
146 | extern int __put_user_4(void *, unsigned int); | |
147 | extern int __put_user_8(void *, unsigned long long); | |
148 | ||
8404663f | 149 | #define __put_user_x(__r2,__p,__e,__l,__s) \ |
9641c7cc RK |
150 | __asm__ __volatile__ ( \ |
151 | __asmeq("%0", "r0") __asmeq("%2", "r2") \ | |
8404663f | 152 | __asmeq("%3", "r1") \ |
9641c7cc RK |
153 | "bl __put_user_" #__s \ |
154 | : "=&r" (__e) \ | |
8404663f | 155 | : "0" (__p), "r" (__r2), "r" (__l) \ |
9641c7cc RK |
156 | : "ip", "lr", "cc") |
157 | ||
158 | #define put_user(x,p) \ | |
159 | ({ \ | |
8404663f | 160 | unsigned long __limit = current_thread_info()->addr_limit - 1; \ |
c5a69d57 TK |
161 | register const typeof(*(p)) __r2 asm("r2") = (x); \ |
162 | register const typeof(*(p)) __user *__p asm("r0") = (p);\ | |
8404663f | 163 | register unsigned long __l asm("r1") = __limit; \ |
9641c7cc RK |
164 | register int __e asm("r0"); \ |
165 | switch (sizeof(*(__p))) { \ | |
166 | case 1: \ | |
8404663f | 167 | __put_user_x(__r2, __p, __e, __l, 1); \ |
9641c7cc RK |
168 | break; \ |
169 | case 2: \ | |
8404663f | 170 | __put_user_x(__r2, __p, __e, __l, 2); \ |
9641c7cc RK |
171 | break; \ |
172 | case 4: \ | |
8404663f | 173 | __put_user_x(__r2, __p, __e, __l, 4); \ |
9641c7cc RK |
174 | break; \ |
175 | case 8: \ | |
8404663f | 176 | __put_user_x(__r2, __p, __e, __l, 8); \ |
9641c7cc RK |
177 | break; \ |
178 | default: __e = __put_user_bad(); break; \ | |
179 | } \ | |
180 | __e; \ | |
181 | }) | |
182 | ||
183 | #else /* CONFIG_MMU */ | |
184 | ||
185 | /* | |
186 | * uClinux has only one addr space, so has simplified address limits. | |
187 | */ | |
188 | #define USER_DS KERNEL_DS | |
189 | ||
190 | #define segment_eq(a,b) (1) | |
191 | #define __addr_ok(addr) (1) | |
192 | #define __range_ok(addr,size) (0) | |
193 | #define get_fs() (KERNEL_DS) | |
194 | ||
195 | static inline void set_fs(mm_segment_t fs) | |
196 | { | |
197 | } | |
198 | ||
199 | #define get_user(x,p) __get_user(x,p) | |
200 | #define put_user(x,p) __put_user(x,p) | |
201 | ||
202 | #endif /* CONFIG_MMU */ | |
203 | ||
204 | #define access_ok(type,addr,size) (__range_ok(addr,size) == 0) | |
205 | ||
8c56cc8b WD |
206 | #define user_addr_max() \ |
207 | (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL) | |
208 | ||
9641c7cc RK |
209 | /* |
210 | * The "__xxx" versions of the user access functions do not verify the | |
211 | * address space - it must have been done previously with a separate | |
212 | * "access_ok()" call. | |
213 | * | |
214 | * The "xxx_error" versions set the third argument to EFAULT if an | |
215 | * error occurs, and leave it unchanged on success. Note that these | |
216 | * versions are void (ie, don't return a value as such). | |
217 | */ | |
1da177e4 LT |
218 | #define __get_user(x,ptr) \ |
219 | ({ \ | |
220 | long __gu_err = 0; \ | |
221 | __get_user_err((x),(ptr),__gu_err); \ | |
222 | __gu_err; \ | |
223 | }) | |
224 | ||
225 | #define __get_user_error(x,ptr,err) \ | |
226 | ({ \ | |
227 | __get_user_err((x),(ptr),err); \ | |
228 | (void) 0; \ | |
229 | }) | |
230 | ||
231 | #define __get_user_err(x,ptr,err) \ | |
232 | do { \ | |
233 | unsigned long __gu_addr = (unsigned long)(ptr); \ | |
234 | unsigned long __gu_val; \ | |
235 | __chk_user_ptr(ptr); \ | |
236 | switch (sizeof(*(ptr))) { \ | |
237 | case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \ | |
238 | case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \ | |
239 | case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \ | |
240 | default: (__gu_val) = __get_user_bad(); \ | |
241 | } \ | |
242 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
243 | } while (0) | |
244 | ||
245 | #define __get_user_asm_byte(x,addr,err) \ | |
246 | __asm__ __volatile__( \ | |
4e7682d0 | 247 | "1: " TUSER(ldrb) " %1,[%2],#0\n" \ |
1da177e4 | 248 | "2:\n" \ |
4260415f | 249 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
250 | " .align 2\n" \ |
251 | "3: mov %0, %3\n" \ | |
252 | " mov %1, #0\n" \ | |
253 | " b 2b\n" \ | |
4260415f RK |
254 | " .popsection\n" \ |
255 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
256 | " .align 3\n" \ |
257 | " .long 1b, 3b\n" \ | |
4260415f | 258 | " .popsection" \ |
1da177e4 LT |
259 | : "+r" (err), "=&r" (x) \ |
260 | : "r" (addr), "i" (-EFAULT) \ | |
261 | : "cc") | |
262 | ||
263 | #ifndef __ARMEB__ | |
264 | #define __get_user_asm_half(x,__gu_addr,err) \ | |
265 | ({ \ | |
266 | unsigned long __b1, __b2; \ | |
267 | __get_user_asm_byte(__b1, __gu_addr, err); \ | |
268 | __get_user_asm_byte(__b2, __gu_addr + 1, err); \ | |
269 | (x) = __b1 | (__b2 << 8); \ | |
270 | }) | |
271 | #else | |
272 | #define __get_user_asm_half(x,__gu_addr,err) \ | |
273 | ({ \ | |
274 | unsigned long __b1, __b2; \ | |
275 | __get_user_asm_byte(__b1, __gu_addr, err); \ | |
276 | __get_user_asm_byte(__b2, __gu_addr + 1, err); \ | |
277 | (x) = (__b1 << 8) | __b2; \ | |
278 | }) | |
279 | #endif | |
280 | ||
281 | #define __get_user_asm_word(x,addr,err) \ | |
282 | __asm__ __volatile__( \ | |
4e7682d0 | 283 | "1: " TUSER(ldr) " %1,[%2],#0\n" \ |
1da177e4 | 284 | "2:\n" \ |
4260415f | 285 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
286 | " .align 2\n" \ |
287 | "3: mov %0, %3\n" \ | |
288 | " mov %1, #0\n" \ | |
289 | " b 2b\n" \ | |
4260415f RK |
290 | " .popsection\n" \ |
291 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
292 | " .align 3\n" \ |
293 | " .long 1b, 3b\n" \ | |
4260415f | 294 | " .popsection" \ |
1da177e4 LT |
295 | : "+r" (err), "=&r" (x) \ |
296 | : "r" (addr), "i" (-EFAULT) \ | |
297 | : "cc") | |
298 | ||
1da177e4 LT |
299 | #define __put_user(x,ptr) \ |
300 | ({ \ | |
301 | long __pu_err = 0; \ | |
302 | __put_user_err((x),(ptr),__pu_err); \ | |
303 | __pu_err; \ | |
304 | }) | |
305 | ||
306 | #define __put_user_error(x,ptr,err) \ | |
307 | ({ \ | |
308 | __put_user_err((x),(ptr),err); \ | |
309 | (void) 0; \ | |
310 | }) | |
311 | ||
312 | #define __put_user_err(x,ptr,err) \ | |
313 | do { \ | |
314 | unsigned long __pu_addr = (unsigned long)(ptr); \ | |
315 | __typeof__(*(ptr)) __pu_val = (x); \ | |
316 | __chk_user_ptr(ptr); \ | |
317 | switch (sizeof(*(ptr))) { \ | |
318 | case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \ | |
319 | case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \ | |
320 | case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \ | |
321 | case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \ | |
322 | default: __put_user_bad(); \ | |
323 | } \ | |
324 | } while (0) | |
325 | ||
326 | #define __put_user_asm_byte(x,__pu_addr,err) \ | |
327 | __asm__ __volatile__( \ | |
4e7682d0 | 328 | "1: " TUSER(strb) " %1,[%2],#0\n" \ |
1da177e4 | 329 | "2:\n" \ |
4260415f | 330 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
331 | " .align 2\n" \ |
332 | "3: mov %0, %3\n" \ | |
333 | " b 2b\n" \ | |
4260415f RK |
334 | " .popsection\n" \ |
335 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
336 | " .align 3\n" \ |
337 | " .long 1b, 3b\n" \ | |
4260415f | 338 | " .popsection" \ |
1da177e4 LT |
339 | : "+r" (err) \ |
340 | : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ | |
341 | : "cc") | |
342 | ||
343 | #ifndef __ARMEB__ | |
344 | #define __put_user_asm_half(x,__pu_addr,err) \ | |
345 | ({ \ | |
346 | unsigned long __temp = (unsigned long)(x); \ | |
347 | __put_user_asm_byte(__temp, __pu_addr, err); \ | |
348 | __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \ | |
349 | }) | |
350 | #else | |
351 | #define __put_user_asm_half(x,__pu_addr,err) \ | |
352 | ({ \ | |
353 | unsigned long __temp = (unsigned long)(x); \ | |
354 | __put_user_asm_byte(__temp >> 8, __pu_addr, err); \ | |
355 | __put_user_asm_byte(__temp, __pu_addr + 1, err); \ | |
356 | }) | |
357 | #endif | |
358 | ||
359 | #define __put_user_asm_word(x,__pu_addr,err) \ | |
360 | __asm__ __volatile__( \ | |
4e7682d0 | 361 | "1: " TUSER(str) " %1,[%2],#0\n" \ |
1da177e4 | 362 | "2:\n" \ |
4260415f | 363 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
364 | " .align 2\n" \ |
365 | "3: mov %0, %3\n" \ | |
366 | " b 2b\n" \ | |
4260415f RK |
367 | " .popsection\n" \ |
368 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
369 | " .align 3\n" \ |
370 | " .long 1b, 3b\n" \ | |
4260415f | 371 | " .popsection" \ |
1da177e4 LT |
372 | : "+r" (err) \ |
373 | : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ | |
374 | : "cc") | |
375 | ||
376 | #ifndef __ARMEB__ | |
377 | #define __reg_oper0 "%R2" | |
378 | #define __reg_oper1 "%Q2" | |
379 | #else | |
380 | #define __reg_oper0 "%Q2" | |
381 | #define __reg_oper1 "%R2" | |
382 | #endif | |
383 | ||
384 | #define __put_user_asm_dword(x,__pu_addr,err) \ | |
385 | __asm__ __volatile__( \ | |
4e7682d0 CM |
386 | ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \ |
387 | ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \ | |
388 | THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \ | |
389 | THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \ | |
1da177e4 | 390 | "3:\n" \ |
4260415f | 391 | " .pushsection .fixup,\"ax\"\n" \ |
1da177e4 LT |
392 | " .align 2\n" \ |
393 | "4: mov %0, %3\n" \ | |
394 | " b 3b\n" \ | |
4260415f RK |
395 | " .popsection\n" \ |
396 | " .pushsection __ex_table,\"a\"\n" \ | |
1da177e4 LT |
397 | " .align 3\n" \ |
398 | " .long 1b, 4b\n" \ | |
399 | " .long 2b, 4b\n" \ | |
4260415f | 400 | " .popsection" \ |
1da177e4 LT |
401 | : "+r" (err), "+r" (__pu_addr) \ |
402 | : "r" (x), "i" (-EFAULT) \ | |
403 | : "cc") | |
404 | ||
02fcb974 | 405 | |
9641c7cc | 406 | #ifdef CONFIG_MMU |
99573298 RK |
407 | extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n); |
408 | extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n); | |
a1f98849 | 409 | extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n); |
99573298 | 410 | extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n); |
a1f98849 | 411 | extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n); |
9641c7cc RK |
412 | #else |
413 | #define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0) | |
414 | #define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0) | |
415 | #define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0) | |
416 | #endif | |
417 | ||
99573298 | 418 | static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) |
1da177e4 LT |
419 | { |
420 | if (access_ok(VERIFY_READ, from, n)) | |
02fcb974 | 421 | n = __copy_from_user(to, from, n); |
1da177e4 | 422 | else /* security hole - plug it */ |
59f0cb0f | 423 | memset(to, 0, n); |
1da177e4 LT |
424 | return n; |
425 | } | |
426 | ||
99573298 | 427 | static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) |
1da177e4 LT |
428 | { |
429 | if (access_ok(VERIFY_WRITE, to, n)) | |
02fcb974 | 430 | n = __copy_to_user(to, from, n); |
1da177e4 LT |
431 | return n; |
432 | } | |
433 | ||
1da177e4 LT |
434 | #define __copy_to_user_inatomic __copy_to_user |
435 | #define __copy_from_user_inatomic __copy_from_user | |
436 | ||
99573298 | 437 | static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) |
1da177e4 LT |
438 | { |
439 | if (access_ok(VERIFY_WRITE, to, n)) | |
02fcb974 | 440 | n = __clear_user(to, n); |
1da177e4 LT |
441 | return n; |
442 | } | |
443 | ||
8c56cc8b | 444 | extern long strncpy_from_user(char *dest, const char __user *src, long count); |
1da177e4 | 445 | |
8c56cc8b WD |
446 | extern __must_check long strlen_user(const char __user *str); |
447 | extern __must_check long strnlen_user(const char __user *str, long n); | |
1da177e4 LT |
448 | |
449 | #endif /* _ASMARM_UACCESS_H */ |