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powerpc: Make single-stepping emulation (mostly) usable on 32-bit
[linux-2.6/x86.git] / include / asm-arm / uaccess.h
bloba2fdad0138b3e5bf2e7e2500e97a8821fe7b036e
1 /*
2 * linux/include/asm-arm/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/sched.h>
15 #include <asm/errno.h>
16 #include <asm/memory.h>
17 #include <asm/domain.h>
18 #include <asm/system.h>
19
20 #define VERIFY_READ 0
21 #define VERIFY_WRITE 1
22
23 /*
24 * The exception table consists of pairs of addresses: the first is the
25 * address of an instruction that is allowed to fault, and the second is
26 * the address at which the program should continue. No registers are
27 * modified, so it is entirely up to the continuation code to figure out
28 * what to do.
29 *
30 * All the routines below use bits of fixup code that are out of line
31 * with the main instruction path. This means when everything is well,
32 * we don't even have to jump over them. Further, they do not intrude
33 * on our cache or tlb entries.
34 */
35
36 struct exception_table_entry
37 {
38 unsigned long insn, fixup;
39 };
40
41 extern int fixup_exception(struct pt_regs *regs);
42
43 /*
44 * Note that this is actually 0x1,0000,0000
45 */
46 #define KERNEL_DS 0x00000000
47 #define USER_DS TASK_SIZE
48
49 #define get_ds() (KERNEL_DS)
50 #define get_fs() (current_thread_info()->addr_limit)
51
52 static inline void set_fs (mm_segment_t fs)
53 {
54 current_thread_info()->addr_limit = fs;
55 modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
56 }
57
58 #define segment_eq(a,b) ((a) == (b))
59
60 #define __addr_ok(addr) ({ \
61 unsigned long flag; \
62 __asm__("cmp %2, %0; movlo %0, #0" \
63 : "=&r" (flag) \
64 : "0" (current_thread_info()->addr_limit), "r" (addr) \
65 : "cc"); \
66 (flag == 0); })
67
68 /* We use 33-bit arithmetic here... */
69 #define __range_ok(addr,size) ({ \
70 unsigned long flag, sum; \
71 __chk_user_ptr(addr); \
72 __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
73 : "=&r" (flag), "=&r" (sum) \
74 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
75 : "cc"); \
76 flag; })
77
78 #define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
79
80 /*
81 * Single-value transfer routines. They automatically use the right
82 * size if we just have the right pointer type. Note that the functions
83 * which read from user space (*get_*) need to take care not to leak
84 * kernel data even if the calling code is buggy and fails to check
85 * the return value. This means zeroing out the destination variable
86 * or buffer on error. Normally this is done out of line by the
87 * fixup code, but there are a few places where it intrudes on the
88 * main code path. When we only write to user space, there is no
89 * problem.
90 *
91 * The "__xxx" versions of the user access functions do not verify the
92 * address space - it must have been done previously with a separate
93 * "access_ok()" call.
94 *
95 * The "xxx_error" versions set the third argument to EFAULT if an
96 * error occurs, and leave it unchanged on success. Note that these
97 * versions are void (ie, don't return a value as such).
98 */
99
100 extern int __get_user_1(void *);
101 extern int __get_user_2(void *);
102 extern int __get_user_4(void *);
103 extern int __get_user_8(void *);
104 extern int __get_user_bad(void);
105
106 #define __get_user_x(__r2,__p,__e,__s,__i...) \
107 __asm__ __volatile__ ( \
108 __asmeq("%0", "r0") __asmeq("%1", "r2") \
109 "bl __get_user_" #__s \
110 : "=&r" (__e), "=r" (__r2) \
111 : "0" (__p) \
112 : __i, "cc")
113
114 #define get_user(x,p) \
115 ({ \
116 const register typeof(*(p)) __user *__p asm("r0") = (p);\
117 register typeof(*(p)) __r2 asm("r2"); \
118 register int __e asm("r0"); \
119 switch (sizeof(*(__p))) { \
120 case 1: \
121 __get_user_x(__r2, __p, __e, 1, "lr"); \
122 break; \
123 case 2: \
124 __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \
125 break; \
126 case 4: \
127 __get_user_x(__r2, __p, __e, 4, "lr"); \
128 break; \
129 case 8: \
130 __get_user_x(__r2, __p, __e, 8, "lr"); \
131 break; \
132 default: __e = __get_user_bad(); break; \
133 } \
134 x = __r2; \
135 __e; \
136 })
137
138 #define __get_user(x,ptr) \
139 ({ \
140 long __gu_err = 0; \
141 __get_user_err((x),(ptr),__gu_err); \
142 __gu_err; \
143 })
144
145 #define __get_user_error(x,ptr,err) \
146 ({ \
147 __get_user_err((x),(ptr),err); \
148 (void) 0; \
149 })
150
151 #define __get_user_err(x,ptr,err) \
152 do { \
153 unsigned long __gu_addr = (unsigned long)(ptr); \
154 unsigned long __gu_val; \
155 __chk_user_ptr(ptr); \
156 switch (sizeof(*(ptr))) { \
157 case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
158 case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
159 case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
160 default: (__gu_val) = __get_user_bad(); \
161 } \
162 (x) = (__typeof__(*(ptr)))__gu_val; \
163 } while (0)
164
165 #define __get_user_asm_byte(x,addr,err) \
166 __asm__ __volatile__( \
167 "1: ldrbt %1,[%2],#0\n" \
168 "2:\n" \
169 " .section .fixup,\"ax\"\n" \
170 " .align 2\n" \
171 "3: mov %0, %3\n" \
172 " mov %1, #0\n" \
173 " b 2b\n" \
174 " .previous\n" \
175 " .section __ex_table,\"a\"\n" \
176 " .align 3\n" \
177 " .long 1b, 3b\n" \
178 " .previous" \
179 : "+r" (err), "=&r" (x) \
180 : "r" (addr), "i" (-EFAULT) \
181 : "cc")
182
183 #ifndef __ARMEB__
184 #define __get_user_asm_half(x,__gu_addr,err) \
185 ({ \
186 unsigned long __b1, __b2; \
187 __get_user_asm_byte(__b1, __gu_addr, err); \
188 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
189 (x) = __b1 | (__b2 << 8); \
190 })
191 #else
192 #define __get_user_asm_half(x,__gu_addr,err) \
193 ({ \
194 unsigned long __b1, __b2; \
195 __get_user_asm_byte(__b1, __gu_addr, err); \
196 __get_user_asm_byte(__b2, __gu_addr + 1, err); \
197 (x) = (__b1 << 8) | __b2; \
198 })
199 #endif
200
201 #define __get_user_asm_word(x,addr,err) \
202 __asm__ __volatile__( \
203 "1: ldrt %1,[%2],#0\n" \
204 "2:\n" \
205 " .section .fixup,\"ax\"\n" \
206 " .align 2\n" \
207 "3: mov %0, %3\n" \
208 " mov %1, #0\n" \
209 " b 2b\n" \
210 " .previous\n" \
211 " .section __ex_table,\"a\"\n" \
212 " .align 3\n" \
213 " .long 1b, 3b\n" \
214 " .previous" \
215 : "+r" (err), "=&r" (x) \
216 : "r" (addr), "i" (-EFAULT) \
217 : "cc")
218
219 extern int __put_user_1(void *, unsigned int);
220 extern int __put_user_2(void *, unsigned int);
221 extern int __put_user_4(void *, unsigned int);
222 extern int __put_user_8(void *, unsigned long long);
223 extern int __put_user_bad(void);
224
225 #define __put_user_x(__r2,__p,__e,__s) \
226 __asm__ __volatile__ ( \
227 __asmeq("%0", "r0") __asmeq("%2", "r2") \
228 "bl __put_user_" #__s \
229 : "=&r" (__e) \
230 : "0" (__p), "r" (__r2) \
231 : "ip", "lr", "cc")
232
233 #define put_user(x,p) \
234 ({ \
235 const register typeof(*(p)) __r2 asm("r2") = (x); \
236 const register typeof(*(p)) __user *__p asm("r0") = (p);\
237 register int __e asm("r0"); \
238 switch (sizeof(*(__p))) { \
239 case 1: \
240 __put_user_x(__r2, __p, __e, 1); \
241 break; \
242 case 2: \
243 __put_user_x(__r2, __p, __e, 2); \
244 break; \
245 case 4: \
246 __put_user_x(__r2, __p, __e, 4); \
247 break; \
248 case 8: \
249 __put_user_x(__r2, __p, __e, 8); \
250 break; \
251 default: __e = __put_user_bad(); break; \
252 } \
253 __e; \
254 })
255
256 #define __put_user(x,ptr) \
257 ({ \
258 long __pu_err = 0; \
259 __put_user_err((x),(ptr),__pu_err); \
260 __pu_err; \
261 })
262
263 #define __put_user_error(x,ptr,err) \
264 ({ \
265 __put_user_err((x),(ptr),err); \
266 (void) 0; \
267 })
268
269 #define __put_user_err(x,ptr,err) \
270 do { \
271 unsigned long __pu_addr = (unsigned long)(ptr); \
272 __typeof__(*(ptr)) __pu_val = (x); \
273 __chk_user_ptr(ptr); \
274 switch (sizeof(*(ptr))) { \
275 case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
276 case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
277 case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
278 case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
279 default: __put_user_bad(); \
280 } \
281 } while (0)
282
283 #define __put_user_asm_byte(x,__pu_addr,err) \
284 __asm__ __volatile__( \
285 "1: strbt %1,[%2],#0\n" \
286 "2:\n" \
287 " .section .fixup,\"ax\"\n" \
288 " .align 2\n" \
289 "3: mov %0, %3\n" \
290 " b 2b\n" \
291 " .previous\n" \
292 " .section __ex_table,\"a\"\n" \
293 " .align 3\n" \
294 " .long 1b, 3b\n" \
295 " .previous" \
296 : "+r" (err) \
297 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
298 : "cc")
299
300 #ifndef __ARMEB__
301 #define __put_user_asm_half(x,__pu_addr,err) \
302 ({ \
303 unsigned long __temp = (unsigned long)(x); \
304 __put_user_asm_byte(__temp, __pu_addr, err); \
305 __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
306 })
307 #else
308 #define __put_user_asm_half(x,__pu_addr,err) \
309 ({ \
310 unsigned long __temp = (unsigned long)(x); \
311 __put_user_asm_byte(__temp >> 8, __pu_addr, err); \
312 __put_user_asm_byte(__temp, __pu_addr + 1, err); \
313 })
314 #endif
315
316 #define __put_user_asm_word(x,__pu_addr,err) \
317 __asm__ __volatile__( \
318 "1: strt %1,[%2],#0\n" \
319 "2:\n" \
320 " .section .fixup,\"ax\"\n" \
321 " .align 2\n" \
322 "3: mov %0, %3\n" \
323 " b 2b\n" \
324 " .previous\n" \
325 " .section __ex_table,\"a\"\n" \
326 " .align 3\n" \
327 " .long 1b, 3b\n" \
328 " .previous" \
329 : "+r" (err) \
330 : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
331 : "cc")
332
333 #ifndef __ARMEB__
334 #define __reg_oper0 "%R2"
335 #define __reg_oper1 "%Q2"
336 #else
337 #define __reg_oper0 "%Q2"
338 #define __reg_oper1 "%R2"
339 #endif
340
341 #define __put_user_asm_dword(x,__pu_addr,err) \
342 __asm__ __volatile__( \
343 "1: strt " __reg_oper1 ", [%1], #4\n" \
344 "2: strt " __reg_oper0 ", [%1], #0\n" \
345 "3:\n" \
346 " .section .fixup,\"ax\"\n" \
347 " .align 2\n" \
348 "4: mov %0, %3\n" \
349 " b 3b\n" \
350 " .previous\n" \
351 " .section __ex_table,\"a\"\n" \
352 " .align 3\n" \
353 " .long 1b, 4b\n" \
354 " .long 2b, 4b\n" \
355 " .previous" \
356 : "+r" (err), "+r" (__pu_addr) \
357 : "r" (x), "i" (-EFAULT) \
358 : "cc")
359
360 extern unsigned long __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
361 extern unsigned long __arch_copy_to_user(void __user *to, const void *from, unsigned long n);
362 extern unsigned long __arch_clear_user(void __user *addr, unsigned long n);
363 extern unsigned long __arch_strncpy_from_user(char *to, const char __user *from, unsigned long count);
364 extern unsigned long __arch_strnlen_user(const char __user *s, long n);
365
366 static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
367 {
368 if (access_ok(VERIFY_READ, from, n))
369 n = __arch_copy_from_user(to, from, n);
370 else /* security hole - plug it */
371 memzero(to, n);
372 return n;
373 }
374
375 static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
376 {
377 return __arch_copy_from_user(to, from, n);
378 }
379
380 static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
381 {
382 if (access_ok(VERIFY_WRITE, to, n))
383 n = __arch_copy_to_user(to, from, n);
384 return n;
385 }
386
387 static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
388 {
389 return __arch_copy_to_user(to, from, n);
390 }
391
392 #define __copy_to_user_inatomic __copy_to_user
393 #define __copy_from_user_inatomic __copy_from_user
394
395 static inline unsigned long clear_user (void __user *to, unsigned long n)
396 {
397 if (access_ok(VERIFY_WRITE, to, n))
398 n = __arch_clear_user(to, n);
399 return n;
400 }
401
402 static inline unsigned long __clear_user (void __user *to, unsigned long n)
403 {
404 return __arch_clear_user(to, n);
405 }
406
407 static inline long strncpy_from_user (char *dst, const char __user *src, long count)
408 {
409 long res = -EFAULT;
410 if (access_ok(VERIFY_READ, src, 1))
411 res = __arch_strncpy_from_user(dst, src, count);
412 return res;
413 }
414
415 static inline long __strncpy_from_user (char *dst, const char __user *src, long count)
416 {
417 return __arch_strncpy_from_user(dst, src, count);
418 }
419
420 #define strlen_user(s) strnlen_user(s, ~0UL >> 1)
421
422 static inline long strnlen_user(const char __user *s, long n)
423 {
424 unsigned long res = 0;
425
426 if (__addr_ok(s))
427 res = __arch_strnlen_user(s, n);
428
429 return res;
430 }
431
432 #endif /* _ASMARM_UACCESS_H */
x86 "subsystem" repository