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Merge tag 'range-macro' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...
[deliverable/linux.git] / arch / arm / include / asm / uaccess.h
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 #if __LINUX_ARM_ARCH__ < 6
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
111 #define __GUP_CLOBBER_1 "lr", "cc"
112 #ifdef CONFIG_CPU_USE_DOMAINS
113 #define __GUP_CLOBBER_2 "ip", "lr", "cc"
114 #else
115 #define __GUP_CLOBBER_2 "lr", "cc"
116 #endif
117 #define __GUP_CLOBBER_4 "lr", "cc"
118
119 #define __get_user_x(__r2,__p,__e,__l,__s) \
120 __asm__ __volatile__ ( \
121 __asmeq("%0", "r0") __asmeq("%1", "r2") \
122 __asmeq("%3", "r1") \
123 "bl __get_user_" #__s \
124 : "=&r" (__e), "=r" (__r2) \
125 : "0" (__p), "r" (__l) \
126 : __GUP_CLOBBER_##__s)
127
128 #define __get_user_check(x,p) \
129 ({ \
130 unsigned long __limit = current_thread_info()->addr_limit - 1; \
131 register const typeof(*(p)) __user *__p asm("r0") = (p);\
132 register unsigned long __r2 asm("r2"); \
133 register unsigned long __l asm("r1") = __limit; \
134 register int __e asm("r0"); \
135 switch (sizeof(*(__p))) { \
136 case 1: \
137 __get_user_x(__r2, __p, __e, __l, 1); \
138 break; \
139 case 2: \
140 __get_user_x(__r2, __p, __e, __l, 2); \
141 break; \
142 case 4: \
143 __get_user_x(__r2, __p, __e, __l, 4); \
144 break; \
145 default: __e = __get_user_bad(); break; \
146 } \
147 x = (typeof(*(p))) __r2; \
148 __e; \
149 })
150
151 #define get_user(x,p) \
152 ({ \
153 might_fault(); \
154 __get_user_check(x,p); \
155 })
156
157 extern int __put_user_1(void *, unsigned int);
158 extern int __put_user_2(void *, unsigned int);
159 extern int __put_user_4(void *, unsigned int);
160 extern int __put_user_8(void *, unsigned long long);
161
162 #define __put_user_x(__r2,__p,__e,__l,__s) \
163 __asm__ __volatile__ ( \
164 __asmeq("%0", "r0") __asmeq("%2", "r2") \
165 __asmeq("%3", "r1") \
166 "bl __put_user_" #__s \
167 : "=&r" (__e) \
168 : "0" (__p), "r" (__r2), "r" (__l) \
169 : "ip", "lr", "cc")
170
171 #define __put_user_check(x,p) \
172 ({ \
173 unsigned long __limit = current_thread_info()->addr_limit - 1; \
174 register const typeof(*(p)) __r2 asm("r2") = (x); \
175 register const typeof(*(p)) __user *__p asm("r0") = (p);\
176 register unsigned long __l asm("r1") = __limit; \
177 register int __e asm("r0"); \
178 switch (sizeof(*(__p))) { \
179 case 1: \
180 __put_user_x(__r2, __p, __e, __l, 1); \
181 break; \
182 case 2: \
183 __put_user_x(__r2, __p, __e, __l, 2); \
184 break; \
185 case 4: \
186 __put_user_x(__r2, __p, __e, __l, 4); \
187 break; \
188 case 8: \
189 __put_user_x(__r2, __p, __e, __l, 8); \
190 break; \
191 default: __e = __put_user_bad(); break; \
192 } \
193 __e; \
194 })
195
196 #define put_user(x,p) \
197 ({ \
198 might_fault(); \
199 __put_user_check(x,p); \
200 })
201
202 #else /* CONFIG_MMU */
203
204 /*
205 * uClinux has only one addr space, so has simplified address limits.
206 */
207 #define USER_DS KERNEL_DS
208
209 #define segment_eq(a,b) (1)
210 #define __addr_ok(addr) ((void)(addr),1)
211 #define __range_ok(addr,size) ((void)(addr),0)
212 #define get_fs() (KERNEL_DS)
213
214 static inline void set_fs(mm_segment_t fs)
215 {
216 }
217
218 #define get_user(x,p) __get_user(x,p)
219 #define put_user(x,p) __put_user(x,p)
220
221 #endif /* CONFIG_MMU */
222
223 #define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
224
225 #define user_addr_max() \
226 (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
227
228 /*
229 * The "__xxx" versions of the user access functions do not verify the
230 * address space - it must have been done previously with a separate
231 * "access_ok()" call.
232 *
233 * The "xxx_error" versions set the third argument to EFAULT if an
234 * error occurs, and leave it unchanged on success. Note that these
235 * versions are void (ie, don't return a value as such).
236 */
237 #define __get_user(x,ptr) \
238 ({ \
239 long __gu_err = 0; \
240 __get_user_err((x),(ptr),__gu_err); \
241 __gu_err; \
242 })
243
244 #define __get_user_error(x,ptr,err) \
245 ({ \
246 __get_user_err((x),(ptr),err); \
247 (void) 0; \
248 })
249
250 #define __get_user_err(x,ptr,err) \
251 do { \
252 unsigned long __gu_addr = (unsigned long)(ptr); \
253 unsigned long __gu_val; \
254 __chk_user_ptr(ptr); \
255 might_fault(); \
256 switch (sizeof(*(ptr))) { \
257 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
258 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
259 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
260 default: (__gu_val) = __get_user_bad(); \
261 } \
262 (x) = (__typeof__(*(ptr)))__gu_val; \
263 } while (0)
264
265 #define __get_user_asm_byte(x,addr,err) \
266 __asm__ __volatile__( \
267 "1: " TUSER(ldrb) " %1,[%2],#0\n" \
268 "2:\n" \
269 " .pushsection .fixup,\"ax\"\n" \
270 " .align 2\n" \
271 "3: mov %0, %3\n" \
272 " mov %1, #0\n" \
273 " b 2b\n" \
274 " .popsection\n" \
275 " .pushsection __ex_table,\"a\"\n" \
276 " .align 3\n" \
277 " .long 1b, 3b\n" \
278 " .popsection" \
279 : "+r" (err), "=&r" (x) \
280 : "r" (addr), "i" (-EFAULT) \
281 : "cc")
282
283 #ifndef __ARMEB__
284 #define __get_user_asm_half(x,__gu_addr,err) \
285 ({ \
286 unsigned long __b1, __b2; \
287 __get_user_asm_byte(__b1, __gu_addr, err); \
288 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
289 (x) = __b1 | (__b2 << 8); \
290 })
291 #else
292 #define __get_user_asm_half(x,__gu_addr,err) \
293 ({ \
294 unsigned long __b1, __b2; \
295 __get_user_asm_byte(__b1, __gu_addr, err); \
296 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
297 (x) = (__b1 << 8) | __b2; \
298 })
299 #endif
300
301 #define __get_user_asm_word(x,addr,err) \
302 __asm__ __volatile__( \
303 "1: " TUSER(ldr) " %1,[%2],#0\n" \
304 "2:\n" \
305 " .pushsection .fixup,\"ax\"\n" \
306 " .align 2\n" \
307 "3: mov %0, %3\n" \
308 " mov %1, #0\n" \
309 " b 2b\n" \
310 " .popsection\n" \
311 " .pushsection __ex_table,\"a\"\n" \
312 " .align 3\n" \
313 " .long 1b, 3b\n" \
314 " .popsection" \
315 : "+r" (err), "=&r" (x) \
316 : "r" (addr), "i" (-EFAULT) \
317 : "cc")
318
319 #define __put_user(x,ptr) \
320 ({ \
321 long __pu_err = 0; \
322 __put_user_err((x),(ptr),__pu_err); \
323 __pu_err; \
324 })
325
326 #define __put_user_error(x,ptr,err) \
327 ({ \
328 __put_user_err((x),(ptr),err); \
329 (void) 0; \
330 })
331
332 #define __put_user_err(x,ptr,err) \
333 do { \
334 unsigned long __pu_addr = (unsigned long)(ptr); \
335 __typeof__(*(ptr)) __pu_val = (x); \
336 __chk_user_ptr(ptr); \
337 might_fault(); \
338 switch (sizeof(*(ptr))) { \
339 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
340 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
341 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
342 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
343 default: __put_user_bad(); \
344 } \
345 } while (0)
346
347 #define __put_user_asm_byte(x,__pu_addr,err) \
348 __asm__ __volatile__( \
349 "1: " TUSER(strb) " %1,[%2],#0\n" \
350 "2:\n" \
351 " .pushsection .fixup,\"ax\"\n" \
352 " .align 2\n" \
353 "3: mov %0, %3\n" \
354 " b 2b\n" \
355 " .popsection\n" \
356 " .pushsection __ex_table,\"a\"\n" \
357 " .align 3\n" \
358 " .long 1b, 3b\n" \
359 " .popsection" \
360 : "+r" (err) \
361 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
362 : "cc")
363
364 #ifndef __ARMEB__
365 #define __put_user_asm_half(x,__pu_addr,err) \
366 ({ \
367 unsigned long __temp = (unsigned long)(x); \
368 __put_user_asm_byte(__temp, __pu_addr, err); \
369 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
370 })
371 #else
372 #define __put_user_asm_half(x,__pu_addr,err) \
373 ({ \
374 unsigned long __temp = (unsigned long)(x); \
375 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
376 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
377 })
378 #endif
379
380 #define __put_user_asm_word(x,__pu_addr,err) \
381 __asm__ __volatile__( \
382 "1: " TUSER(str) " %1,[%2],#0\n" \
383 "2:\n" \
384 " .pushsection .fixup,\"ax\"\n" \
385 " .align 2\n" \
386 "3: mov %0, %3\n" \
387 " b 2b\n" \
388 " .popsection\n" \
389 " .pushsection __ex_table,\"a\"\n" \
390 " .align 3\n" \
391 " .long 1b, 3b\n" \
392 " .popsection" \
393 : "+r" (err) \
394 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
395 : "cc")
396
397 #ifndef __ARMEB__
398 #define __reg_oper0 "%R2"
399 #define __reg_oper1 "%Q2"
400 #else
401 #define __reg_oper0 "%Q2"
402 #define __reg_oper1 "%R2"
403 #endif
404
405 #define __put_user_asm_dword(x,__pu_addr,err) \
406 __asm__ __volatile__( \
407 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
408 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
409 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
410 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
411 "3:\n" \
412 " .pushsection .fixup,\"ax\"\n" \
413 " .align 2\n" \
414 "4: mov %0, %3\n" \
415 " b 3b\n" \
416 " .popsection\n" \
417 " .pushsection __ex_table,\"a\"\n" \
418 " .align 3\n" \
419 " .long 1b, 4b\n" \
420 " .long 2b, 4b\n" \
421 " .popsection" \
422 : "+r" (err), "+r" (__pu_addr) \
423 : "r" (x), "i" (-EFAULT) \
424 : "cc")
425
426
427 #ifdef CONFIG_MMU
428 extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
429 extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
430 extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
431 extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
432 extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
433 #else
434 #define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
435 #define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
436 #define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
437 #endif
438
439 static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
440 {
441 if (access_ok(VERIFY_READ, from, n))
442 n = __copy_from_user(to, from, n);
443 else /* security hole - plug it */
444 memset(to, 0, n);
445 return n;
446 }
447
448 static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
449 {
450 if (access_ok(VERIFY_WRITE, to, n))
451 n = __copy_to_user(to, from, n);
452 return n;
453 }
454
455 #define __copy_to_user_inatomic __copy_to_user
456 #define __copy_from_user_inatomic __copy_from_user
457
458 static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
459 {
460 if (access_ok(VERIFY_WRITE, to, n))
461 n = __clear_user(to, n);
462 return n;
463 }
464
465 extern long strncpy_from_user(char *dest, const char __user *src, long count);
466
467 extern __must_check long strlen_user(const char __user *str);
468 extern __must_check long strnlen_user(const char __user *str, long n);
469
470 #endif /* _ASMARM_UACCESS_H */
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