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Linux 4.1.18
[linux/fpc-iii.git] / arch / arm / include / asm / uaccess.h
blob74b17d09ef7aa54cb98d22ccf5f068b4c39971be
1 /*
2 * arch/arm/include/asm/uaccess.h
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 */
14 #include <linux/string.h>
15 #include <linux/thread_info.h>
16 #include <asm/errno.h>
17 #include <asm/memory.h>
18 #include <asm/domain.h>
19 #include <asm/unified.h>
20 #include <asm/compiler.h>
21
22 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
23 #include <asm-generic/uaccess-unaligned.h>
24 #else
25 #define __get_user_unaligned __get_user
26 #define __put_user_unaligned __put_user
27 #endif
28
29 #define VERIFY_READ 0
30 #define VERIFY_WRITE 1
31
32 /*
33 * The exception table consists of pairs of addresses: the first is the
34 * address of an instruction that is allowed to fault, and the second is
35 * the address at which the program should continue. No registers are
36 * modified, so it is entirely up to the continuation code to figure out
37 * what to do.
38 *
39 * All the routines below use bits of fixup code that are out of line
40 * with the main instruction path. This means when everything is well,
41 * we don't even have to jump over them. Further, they do not intrude
42 * on our cache or tlb entries.
43 */
44
45 struct exception_table_entry
46 {
47 unsigned long insn, fixup;
48 };
49
50 extern int fixup_exception(struct pt_regs *regs);
51
52 /*
53 * These two are intentionally not defined anywhere - if the kernel
54 * code generates any references to them, that's a bug.
55 */
56 extern int __get_user_bad(void);
57 extern int __put_user_bad(void);
58
59 /*
60 * Note that this is actually 0x1,0000,0000
61 */
62 #define KERNEL_DS 0x00000000
63 #define get_ds() (KERNEL_DS)
64
65 #ifdef CONFIG_MMU
66
67 #define USER_DS TASK_SIZE
68 #define get_fs() (current_thread_info()->addr_limit)
69
70 static inline void set_fs(mm_segment_t fs)
71 {
72 current_thread_info()->addr_limit = fs;
73 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
74 }
75
76 #define segment_eq(a, b) ((a) == (b))
77
78 #define __addr_ok(addr) ({ \
79 unsigned long flag; \
80 __asm__("cmp %2, %0; movlo %0, #0" \
81 : "=&r" (flag) \
82 : "0" (current_thread_info()->addr_limit), "r" (addr) \
83 : "cc"); \
84 (flag == 0); })
85
86 /* We use 33-bit arithmetic here... */
87 #define __range_ok(addr, size) ({ \
88 unsigned long flag, roksum; \
89 __chk_user_ptr(addr); \
90 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
91 : "=&r" (flag), "=&r" (roksum) \
92 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
93 : "cc"); \
94 flag; })
95
96 /*
97 * Single-value transfer routines. They automatically use the right
98 * size if we just have the right pointer type. Note that the functions
99 * which read from user space (*get_*) need to take care not to leak
100 * kernel data even if the calling code is buggy and fails to check
101 * the return value. This means zeroing out the destination variable
102 * or buffer on error. Normally this is done out of line by the
103 * fixup code, but there are a few places where it intrudes on the
104 * main code path. When we only write to user space, there is no
105 * problem.
106 */
107 extern int __get_user_1(void *);
108 extern int __get_user_2(void *);
109 extern int __get_user_4(void *);
110 extern int __get_user_32t_8(void *);
111 extern int __get_user_8(void *);
112 extern int __get_user_64t_1(void *);
113 extern int __get_user_64t_2(void *);
114 extern int __get_user_64t_4(void *);
115
116 #define __GUP_CLOBBER_1 "lr", "cc"
117 #ifdef CONFIG_CPU_USE_DOMAINS
118 #define __GUP_CLOBBER_2 "ip", "lr", "cc"
119 #else
120 #define __GUP_CLOBBER_2 "lr", "cc"
121 #endif
122 #define __GUP_CLOBBER_4 "lr", "cc"
123 #define __GUP_CLOBBER_32t_8 "lr", "cc"
124 #define __GUP_CLOBBER_8 "lr", "cc"
125
126 #define __get_user_x(__r2, __p, __e, __l, __s) \
127 __asm__ __volatile__ ( \
128 __asmeq("%0", "r0") __asmeq("%1", "r2") \
129 __asmeq("%3", "r1") \
130 "bl __get_user_" #__s \
131 : "=&r" (__e), "=r" (__r2) \
132 : "0" (__p), "r" (__l) \
133 : __GUP_CLOBBER_##__s)
134
135 /* narrowing a double-word get into a single 32bit word register: */
136 #ifdef __ARMEB__
137 #define __get_user_x_32t(__r2, __p, __e, __l, __s) \
138 __get_user_x(__r2, __p, __e, __l, 32t_8)
139 #else
140 #define __get_user_x_32t __get_user_x
141 #endif
142
143 /*
144 * storing result into proper least significant word of 64bit target var,
145 * different only for big endian case where 64 bit __r2 lsw is r3:
146 */
147 #ifdef __ARMEB__
148 #define __get_user_x_64t(__r2, __p, __e, __l, __s) \
149 __asm__ __volatile__ ( \
150 __asmeq("%0", "r0") __asmeq("%1", "r2") \
151 __asmeq("%3", "r1") \
152 "bl __get_user_64t_" #__s \
153 : "=&r" (__e), "=r" (__r2) \
154 : "0" (__p), "r" (__l) \
155 : __GUP_CLOBBER_##__s)
156 #else
157 #define __get_user_x_64t __get_user_x
158 #endif
159
160
161 #define __get_user_check(x, p) \
162 ({ \
163 unsigned long __limit = current_thread_info()->addr_limit - 1; \
164 register const typeof(*(p)) __user *__p asm("r0") = (p);\
165 register typeof(x) __r2 asm("r2"); \
166 register unsigned long __l asm("r1") = __limit; \
167 register int __e asm("r0"); \
168 switch (sizeof(*(__p))) { \
169 case 1: \
170 if (sizeof((x)) >= 8) \
171 __get_user_x_64t(__r2, __p, __e, __l, 1); \
172 else \
173 __get_user_x(__r2, __p, __e, __l, 1); \
174 break; \
175 case 2: \
176 if (sizeof((x)) >= 8) \
177 __get_user_x_64t(__r2, __p, __e, __l, 2); \
178 else \
179 __get_user_x(__r2, __p, __e, __l, 2); \
180 break; \
181 case 4: \
182 if (sizeof((x)) >= 8) \
183 __get_user_x_64t(__r2, __p, __e, __l, 4); \
184 else \
185 __get_user_x(__r2, __p, __e, __l, 4); \
186 break; \
187 case 8: \
188 if (sizeof((x)) < 8) \
189 __get_user_x_32t(__r2, __p, __e, __l, 4); \
190 else \
191 __get_user_x(__r2, __p, __e, __l, 8); \
192 break; \
193 default: __e = __get_user_bad(); break; \
194 } \
195 x = (typeof(*(p))) __r2; \
196 __e; \
197 })
198
199 #define get_user(x, p) \
200 ({ \
201 might_fault(); \
202 __get_user_check(x, p); \
203 })
204
205 extern int __put_user_1(void *, unsigned int);
206 extern int __put_user_2(void *, unsigned int);
207 extern int __put_user_4(void *, unsigned int);
208 extern int __put_user_8(void *, unsigned long long);
209
210 #define __put_user_x(__r2, __p, __e, __l, __s) \
211 __asm__ __volatile__ ( \
212 __asmeq("%0", "r0") __asmeq("%2", "r2") \
213 __asmeq("%3", "r1") \
214 "bl __put_user_" #__s \
215 : "=&r" (__e) \
216 : "0" (__p), "r" (__r2), "r" (__l) \
217 : "ip", "lr", "cc")
218
219 #define __put_user_check(x, p) \
220 ({ \
221 unsigned long __limit = current_thread_info()->addr_limit - 1; \
222 const typeof(*(p)) __user *__tmp_p = (p); \
223 register const typeof(*(p)) __r2 asm("r2") = (x); \
224 register const typeof(*(p)) __user *__p asm("r0") = __tmp_p; \
225 register unsigned long __l asm("r1") = __limit; \
226 register int __e asm("r0"); \
227 switch (sizeof(*(__p))) { \
228 case 1: \
229 __put_user_x(__r2, __p, __e, __l, 1); \
230 break; \
231 case 2: \
232 __put_user_x(__r2, __p, __e, __l, 2); \
233 break; \
234 case 4: \
235 __put_user_x(__r2, __p, __e, __l, 4); \
236 break; \
237 case 8: \
238 __put_user_x(__r2, __p, __e, __l, 8); \
239 break; \
240 default: __e = __put_user_bad(); break; \
241 } \
242 __e; \
243 })
244
245 #define put_user(x, p) \
246 ({ \
247 might_fault(); \
248 __put_user_check(x, p); \
249 })
250
251 #else /* CONFIG_MMU */
252
253 /*
254 * uClinux has only one addr space, so has simplified address limits.
255 */
256 #define USER_DS KERNEL_DS
257
258 #define segment_eq(a, b) (1)
259 #define __addr_ok(addr) ((void)(addr), 1)
260 #define __range_ok(addr, size) ((void)(addr), 0)
261 #define get_fs() (KERNEL_DS)
262
263 static inline void set_fs(mm_segment_t fs)
264 {
265 }
266
267 #define get_user(x, p) __get_user(x, p)
268 #define put_user(x, p) __put_user(x, p)
269
270 #endif /* CONFIG_MMU */
271
272 #define access_ok(type, addr, size) (__range_ok(addr, size) == 0)
273
274 #define user_addr_max() \
275 (segment_eq(get_fs(), KERNEL_DS) ? ~0UL : get_fs())
276
277 /*
278 * The "__xxx" versions of the user access functions do not verify the
279 * address space - it must have been done previously with a separate
280 * "access_ok()" call.
281 *
282 * The "xxx_error" versions set the third argument to EFAULT if an
283 * error occurs, and leave it unchanged on success. Note that these
284 * versions are void (ie, don't return a value as such).
285 */
286 #define __get_user(x, ptr) \
287 ({ \
288 long __gu_err = 0; \
289 __get_user_err((x), (ptr), __gu_err); \
290 __gu_err; \
291 })
292
293 #define __get_user_error(x, ptr, err) \
294 ({ \
295 __get_user_err((x), (ptr), err); \
296 (void) 0; \
297 })
298
299 #define __get_user_err(x, ptr, err) \
300 do { \
301 unsigned long __gu_addr = (unsigned long)(ptr); \
302 unsigned long __gu_val; \
303 __chk_user_ptr(ptr); \
304 might_fault(); \
305 switch (sizeof(*(ptr))) { \
306 case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \
307 case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \
308 case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \
309 default: (__gu_val) = __get_user_bad(); \
310 } \
311 (x) = (__typeof__(*(ptr)))__gu_val; \
312 } while (0)
313
314 #define __get_user_asm_byte(x, addr, err) \
315 __asm__ __volatile__( \
316 "1: " TUSER(ldrb) " %1,[%2],#0\n" \
317 "2:\n" \
318 " .pushsection .text.fixup,\"ax\"\n" \
319 " .align 2\n" \
320 "3: mov %0, %3\n" \
321 " mov %1, #0\n" \
322 " b 2b\n" \
323 " .popsection\n" \
324 " .pushsection __ex_table,\"a\"\n" \
325 " .align 3\n" \
326 " .long 1b, 3b\n" \
327 " .popsection" \
328 : "+r" (err), "=&r" (x) \
329 : "r" (addr), "i" (-EFAULT) \
330 : "cc")
331
332 #ifndef __ARMEB__
333 #define __get_user_asm_half(x, __gu_addr, err) \
334 ({ \
335 unsigned long __b1, __b2; \
336 __get_user_asm_byte(__b1, __gu_addr, err); \
337 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
338 (x) = __b1 | (__b2 << 8); \
339 })
340 #else
341 #define __get_user_asm_half(x, __gu_addr, err) \
342 ({ \
343 unsigned long __b1, __b2; \
344 __get_user_asm_byte(__b1, __gu_addr, err); \
345 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
346 (x) = (__b1 << 8) | __b2; \
347 })
348 #endif
349
350 #define __get_user_asm_word(x, addr, err) \
351 __asm__ __volatile__( \
352 "1: " TUSER(ldr) " %1,[%2],#0\n" \
353 "2:\n" \
354 " .pushsection .text.fixup,\"ax\"\n" \
355 " .align 2\n" \
356 "3: mov %0, %3\n" \
357 " mov %1, #0\n" \
358 " b 2b\n" \
359 " .popsection\n" \
360 " .pushsection __ex_table,\"a\"\n" \
361 " .align 3\n" \
362 " .long 1b, 3b\n" \
363 " .popsection" \
364 : "+r" (err), "=&r" (x) \
365 : "r" (addr), "i" (-EFAULT) \
366 : "cc")
367
368 #define __put_user(x, ptr) \
369 ({ \
370 long __pu_err = 0; \
371 __put_user_err((x), (ptr), __pu_err); \
372 __pu_err; \
373 })
374
375 #define __put_user_error(x, ptr, err) \
376 ({ \
377 __put_user_err((x), (ptr), err); \
378 (void) 0; \
379 })
380
381 #define __put_user_err(x, ptr, err) \
382 do { \
383 unsigned long __pu_addr = (unsigned long)(ptr); \
384 __typeof__(*(ptr)) __pu_val = (x); \
385 __chk_user_ptr(ptr); \
386 might_fault(); \
387 switch (sizeof(*(ptr))) { \
388 case 1: __put_user_asm_byte(__pu_val, __pu_addr, err); break; \
389 case 2: __put_user_asm_half(__pu_val, __pu_addr, err); break; \
390 case 4: __put_user_asm_word(__pu_val, __pu_addr, err); break; \
391 case 8: __put_user_asm_dword(__pu_val, __pu_addr, err); break; \
392 default: __put_user_bad(); \
393 } \
394 } while (0)
395
396 #define __put_user_asm_byte(x, __pu_addr, err) \
397 __asm__ __volatile__( \
398 "1: " TUSER(strb) " %1,[%2],#0\n" \
399 "2:\n" \
400 " .pushsection .text.fixup,\"ax\"\n" \
401 " .align 2\n" \
402 "3: mov %0, %3\n" \
403 " b 2b\n" \
404 " .popsection\n" \
405 " .pushsection __ex_table,\"a\"\n" \
406 " .align 3\n" \
407 " .long 1b, 3b\n" \
408 " .popsection" \
409 : "+r" (err) \
410 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
411 : "cc")
412
413 #ifndef __ARMEB__
414 #define __put_user_asm_half(x, __pu_addr, err) \
415 ({ \
416 unsigned long __temp = (__force unsigned long)(x); \
417 __put_user_asm_byte(__temp, __pu_addr, err); \
418 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
419 })
420 #else
421 #define __put_user_asm_half(x, __pu_addr, err) \
422 ({ \
423 unsigned long __temp = (__force unsigned long)(x); \
424 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
425 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
426 })
427 #endif
428
429 #define __put_user_asm_word(x, __pu_addr, err) \
430 __asm__ __volatile__( \
431 "1: " TUSER(str) " %1,[%2],#0\n" \
432 "2:\n" \
433 " .pushsection .text.fixup,\"ax\"\n" \
434 " .align 2\n" \
435 "3: mov %0, %3\n" \
436 " b 2b\n" \
437 " .popsection\n" \
438 " .pushsection __ex_table,\"a\"\n" \
439 " .align 3\n" \
440 " .long 1b, 3b\n" \
441 " .popsection" \
442 : "+r" (err) \
443 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
444 : "cc")
445
446 #ifndef __ARMEB__
447 #define __reg_oper0 "%R2"
448 #define __reg_oper1 "%Q2"
449 #else
450 #define __reg_oper0 "%Q2"
451 #define __reg_oper1 "%R2"
452 #endif
453
454 #define __put_user_asm_dword(x, __pu_addr, err) \
455 __asm__ __volatile__( \
456 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
457 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
458 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
459 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
460 "3:\n" \
461 " .pushsection .text.fixup,\"ax\"\n" \
462 " .align 2\n" \
463 "4: mov %0, %3\n" \
464 " b 3b\n" \
465 " .popsection\n" \
466 " .pushsection __ex_table,\"a\"\n" \
467 " .align 3\n" \
468 " .long 1b, 4b\n" \
469 " .long 2b, 4b\n" \
470 " .popsection" \
471 : "+r" (err), "+r" (__pu_addr) \
472 : "r" (x), "i" (-EFAULT) \
473 : "cc")
474
475
476 #ifdef CONFIG_MMU
477 extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
478 extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
479 extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
480 extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
481 extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
482 #else
483 #define __copy_from_user(to, from, n) (memcpy(to, (void __force *)from, n), 0)
484 #define __copy_to_user(to, from, n) (memcpy((void __force *)to, from, n), 0)
485 #define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
486 #endif
487
488 static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
489 {
490 if (access_ok(VERIFY_READ, from, n))
491 n = __copy_from_user(to, from, n);
492 else /* security hole - plug it */
493 memset(to, 0, n);
494 return n;
495 }
496
497 static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
498 {
499 if (access_ok(VERIFY_WRITE, to, n))
500 n = __copy_to_user(to, from, n);
501 return n;
502 }
503
504 #define __copy_to_user_inatomic __copy_to_user
505 #define __copy_from_user_inatomic __copy_from_user
506
507 static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
508 {
509 if (access_ok(VERIFY_WRITE, to, n))
510 n = __clear_user(to, n);
511 return n;
512 }
513
514 extern long strncpy_from_user(char *dest, const char __user *src, long count);
515
516 extern __must_check long strlen_user(const char __user *str);
517 extern __must_check long strnlen_user(const char __user *str, long n);
518
519 #endif /* _ASMARM_UACCESS_H */
Linux with added FPC-III support