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Merge branch 'samsung/pinctrl' into next/drivers
[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 #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
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
52 /*
53 * Note that this is actually 0x1,0000,0000
54 */
55 #define KERNEL_DS 0x00000000
56 #define get_ds() (KERNEL_DS)
57
58 #ifdef CONFIG_MMU
59
60 #define USER_DS TASK_SIZE
61 #define get_fs() (current_thread_info()->addr_limit)
62
63 static inline void set_fs(mm_segment_t fs)
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) ({ \
81 unsigned long flag, roksum; \
82 __chk_user_ptr(addr); \
83 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
84 : "=&r" (flag), "=&r" (roksum) \
85 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
86 : "cc"); \
87 flag; })
88
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.
99 */
100 extern int __get_user_1(void *);
101 extern int __get_user_2(void *);
102 extern int __get_user_4(void *);
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 ({ \
114 register const typeof(*(p)) __user *__p asm("r0") = (p);\
115 register unsigned long __r2 asm("r2"); \
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; \
127 default: __e = __get_user_bad(); break; \
128 } \
129 x = (typeof(*(p))) __r2; \
130 __e; \
131 })
132
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 ({ \
148 register const typeof(*(p)) __r2 asm("r2") = (x); \
149 register const typeof(*(p)) __user *__p asm("r0") = (p);\
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 #define user_addr_max() \
193 (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
194
195 /*
196 * The "__xxx" versions of the user access functions do not verify the
197 * address space - it must have been done previously with a separate
198 * "access_ok()" call.
199 *
200 * The "xxx_error" versions set the third argument to EFAULT if an
201 * error occurs, and leave it unchanged on success. Note that these
202 * versions are void (ie, don't return a value as such).
203 */
204 #define __get_user(x,ptr) \
205 ({ \
206 long __gu_err = 0; \
207 __get_user_err((x),(ptr),__gu_err); \
208 __gu_err; \
209 })
210
211 #define __get_user_error(x,ptr,err) \
212 ({ \
213 __get_user_err((x),(ptr),err); \
214 (void) 0; \
215 })
216
217 #define __get_user_err(x,ptr,err) \
218 do { \
219 unsigned long __gu_addr = (unsigned long)(ptr); \
220 unsigned long __gu_val; \
221 __chk_user_ptr(ptr); \
222 switch (sizeof(*(ptr))) { \
223 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
224 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
225 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
226 default: (__gu_val) = __get_user_bad(); \
227 } \
228 (x) = (__typeof__(*(ptr)))__gu_val; \
229 } while (0)
230
231 #define __get_user_asm_byte(x,addr,err) \
232 __asm__ __volatile__( \
233 "1: " TUSER(ldrb) " %1,[%2],#0\n" \
234 "2:\n" \
235 " .pushsection .fixup,\"ax\"\n" \
236 " .align 2\n" \
237 "3: mov %0, %3\n" \
238 " mov %1, #0\n" \
239 " b 2b\n" \
240 " .popsection\n" \
241 " .pushsection __ex_table,\"a\"\n" \
242 " .align 3\n" \
243 " .long 1b, 3b\n" \
244 " .popsection" \
245 : "+r" (err), "=&r" (x) \
246 : "r" (addr), "i" (-EFAULT) \
247 : "cc")
248
249 #ifndef __ARMEB__
250 #define __get_user_asm_half(x,__gu_addr,err) \
251 ({ \
252 unsigned long __b1, __b2; \
253 __get_user_asm_byte(__b1, __gu_addr, err); \
254 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
255 (x) = __b1 | (__b2 << 8); \
256 })
257 #else
258 #define __get_user_asm_half(x,__gu_addr,err) \
259 ({ \
260 unsigned long __b1, __b2; \
261 __get_user_asm_byte(__b1, __gu_addr, err); \
262 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
263 (x) = (__b1 << 8) | __b2; \
264 })
265 #endif
266
267 #define __get_user_asm_word(x,addr,err) \
268 __asm__ __volatile__( \
269 "1: " TUSER(ldr) " %1,[%2],#0\n" \
270 "2:\n" \
271 " .pushsection .fixup,\"ax\"\n" \
272 " .align 2\n" \
273 "3: mov %0, %3\n" \
274 " mov %1, #0\n" \
275 " b 2b\n" \
276 " .popsection\n" \
277 " .pushsection __ex_table,\"a\"\n" \
278 " .align 3\n" \
279 " .long 1b, 3b\n" \
280 " .popsection" \
281 : "+r" (err), "=&r" (x) \
282 : "r" (addr), "i" (-EFAULT) \
283 : "cc")
284
285 #define __put_user(x,ptr) \
286 ({ \
287 long __pu_err = 0; \
288 __put_user_err((x),(ptr),__pu_err); \
289 __pu_err; \
290 })
291
292 #define __put_user_error(x,ptr,err) \
293 ({ \
294 __put_user_err((x),(ptr),err); \
295 (void) 0; \
296 })
297
298 #define __put_user_err(x,ptr,err) \
299 do { \
300 unsigned long __pu_addr = (unsigned long)(ptr); \
301 __typeof__(*(ptr)) __pu_val = (x); \
302 __chk_user_ptr(ptr); \
303 switch (sizeof(*(ptr))) { \
304 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
305 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
306 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
307 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
308 default: __put_user_bad(); \
309 } \
310 } while (0)
311
312 #define __put_user_asm_byte(x,__pu_addr,err) \
313 __asm__ __volatile__( \
314 "1: " TUSER(strb) " %1,[%2],#0\n" \
315 "2:\n" \
316 " .pushsection .fixup,\"ax\"\n" \
317 " .align 2\n" \
318 "3: mov %0, %3\n" \
319 " b 2b\n" \
320 " .popsection\n" \
321 " .pushsection __ex_table,\"a\"\n" \
322 " .align 3\n" \
323 " .long 1b, 3b\n" \
324 " .popsection" \
325 : "+r" (err) \
326 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
327 : "cc")
328
329 #ifndef __ARMEB__
330 #define __put_user_asm_half(x,__pu_addr,err) \
331 ({ \
332 unsigned long __temp = (unsigned long)(x); \
333 __put_user_asm_byte(__temp, __pu_addr, err); \
334 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
335 })
336 #else
337 #define __put_user_asm_half(x,__pu_addr,err) \
338 ({ \
339 unsigned long __temp = (unsigned long)(x); \
340 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
341 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
342 })
343 #endif
344
345 #define __put_user_asm_word(x,__pu_addr,err) \
346 __asm__ __volatile__( \
347 "1: " TUSER(str) " %1,[%2],#0\n" \
348 "2:\n" \
349 " .pushsection .fixup,\"ax\"\n" \
350 " .align 2\n" \
351 "3: mov %0, %3\n" \
352 " b 2b\n" \
353 " .popsection\n" \
354 " .pushsection __ex_table,\"a\"\n" \
355 " .align 3\n" \
356 " .long 1b, 3b\n" \
357 " .popsection" \
358 : "+r" (err) \
359 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
360 : "cc")
361
362 #ifndef __ARMEB__
363 #define __reg_oper0 "%R2"
364 #define __reg_oper1 "%Q2"
365 #else
366 #define __reg_oper0 "%Q2"
367 #define __reg_oper1 "%R2"
368 #endif
369
370 #define __put_user_asm_dword(x,__pu_addr,err) \
371 __asm__ __volatile__( \
372 ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
373 ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
374 THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
375 THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
376 "3:\n" \
377 " .pushsection .fixup,\"ax\"\n" \
378 " .align 2\n" \
379 "4: mov %0, %3\n" \
380 " b 3b\n" \
381 " .popsection\n" \
382 " .pushsection __ex_table,\"a\"\n" \
383 " .align 3\n" \
384 " .long 1b, 4b\n" \
385 " .long 2b, 4b\n" \
386 " .popsection" \
387 : "+r" (err), "+r" (__pu_addr) \
388 : "r" (x), "i" (-EFAULT) \
389 : "cc")
390
391
392 #ifdef CONFIG_MMU
393 extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
394 extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
395 extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
396 extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
397 extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
398 #else
399 #define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
400 #define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
401 #define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
402 #endif
403
404 static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
405 {
406 if (access_ok(VERIFY_READ, from, n))
407 n = __copy_from_user(to, from, n);
408 else /* security hole - plug it */
409 memset(to, 0, n);
410 return n;
411 }
412
413 static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
414 {
415 if (access_ok(VERIFY_WRITE, to, n))
416 n = __copy_to_user(to, from, n);
417 return n;
418 }
419
420 #define __copy_to_user_inatomic __copy_to_user
421 #define __copy_from_user_inatomic __copy_from_user
422
423 static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
424 {
425 if (access_ok(VERIFY_WRITE, to, n))
426 n = __clear_user(to, n);
427 return n;
428 }
429
430 extern long strncpy_from_user(char *dest, const char __user *src, long count);
431
432 extern __must_check long strlen_user(const char __user *str);
433 extern __must_check long strnlen_user(const char __user *str, long n);
434
435 #endif /* _ASMARM_UACCESS_H */
Linux kernel - Deliverables
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