ARM: 6384/1: Remove the domain switching on ARMv6k/v7 CPUs
[linux-3.10.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/system.h>
20 #include <asm/unified.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 /*
193  * The "__xxx" versions of the user access functions do not verify the
194  * address space - it must have been done previously with a separate
195  * "access_ok()" call.
196  *
197  * The "xxx_error" versions set the third argument to EFAULT if an
198  * error occurs, and leave it unchanged on success.  Note that these
199  * versions are void (ie, don't return a value as such).
200  */
201 #define __get_user(x,ptr)                                               \
202 ({                                                                      \
203         long __gu_err = 0;                                              \
204         __get_user_err((x),(ptr),__gu_err);                             \
205         __gu_err;                                                       \
206 })
207
208 #define __get_user_error(x,ptr,err)                                     \
209 ({                                                                      \
210         __get_user_err((x),(ptr),err);                                  \
211         (void) 0;                                                       \
212 })
213
214 #define __get_user_err(x,ptr,err)                                       \
215 do {                                                                    \
216         unsigned long __gu_addr = (unsigned long)(ptr);                 \
217         unsigned long __gu_val;                                         \
218         __chk_user_ptr(ptr);                                            \
219         switch (sizeof(*(ptr))) {                                       \
220         case 1: __get_user_asm_byte(__gu_val,__gu_addr,err);    break;  \
221         case 2: __get_user_asm_half(__gu_val,__gu_addr,err);    break;  \
222         case 4: __get_user_asm_word(__gu_val,__gu_addr,err);    break;  \
223         default: (__gu_val) = __get_user_bad();                         \
224         }                                                               \
225         (x) = (__typeof__(*(ptr)))__gu_val;                             \
226 } while (0)
227
228 #define __get_user_asm_byte(x,addr,err)                         \
229         __asm__ __volatile__(                                   \
230         "1:     " T(ldrb) "     %1,[%2],#0\n"                   \
231         "2:\n"                                                  \
232         "       .pushsection .fixup,\"ax\"\n"                   \
233         "       .align  2\n"                                    \
234         "3:     mov     %0, %3\n"                               \
235         "       mov     %1, #0\n"                               \
236         "       b       2b\n"                                   \
237         "       .popsection\n"                                  \
238         "       .pushsection __ex_table,\"a\"\n"                \
239         "       .align  3\n"                                    \
240         "       .long   1b, 3b\n"                               \
241         "       .popsection"                                    \
242         : "+r" (err), "=&r" (x)                                 \
243         : "r" (addr), "i" (-EFAULT)                             \
244         : "cc")
245
246 #ifndef __ARMEB__
247 #define __get_user_asm_half(x,__gu_addr,err)                    \
248 ({                                                              \
249         unsigned long __b1, __b2;                               \
250         __get_user_asm_byte(__b1, __gu_addr, err);              \
251         __get_user_asm_byte(__b2, __gu_addr + 1, err);          \
252         (x) = __b1 | (__b2 << 8);                               \
253 })
254 #else
255 #define __get_user_asm_half(x,__gu_addr,err)                    \
256 ({                                                              \
257         unsigned long __b1, __b2;                               \
258         __get_user_asm_byte(__b1, __gu_addr, err);              \
259         __get_user_asm_byte(__b2, __gu_addr + 1, err);          \
260         (x) = (__b1 << 8) | __b2;                               \
261 })
262 #endif
263
264 #define __get_user_asm_word(x,addr,err)                         \
265         __asm__ __volatile__(                                   \
266         "1:     " T(ldr) "      %1,[%2],#0\n"                   \
267         "2:\n"                                                  \
268         "       .pushsection .fixup,\"ax\"\n"                   \
269         "       .align  2\n"                                    \
270         "3:     mov     %0, %3\n"                               \
271         "       mov     %1, #0\n"                               \
272         "       b       2b\n"                                   \
273         "       .popsection\n"                                  \
274         "       .pushsection __ex_table,\"a\"\n"                \
275         "       .align  3\n"                                    \
276         "       .long   1b, 3b\n"                               \
277         "       .popsection"                                    \
278         : "+r" (err), "=&r" (x)                                 \
279         : "r" (addr), "i" (-EFAULT)                             \
280         : "cc")
281
282 #define __put_user(x,ptr)                                               \
283 ({                                                                      \
284         long __pu_err = 0;                                              \
285         __put_user_err((x),(ptr),__pu_err);                             \
286         __pu_err;                                                       \
287 })
288
289 #define __put_user_error(x,ptr,err)                                     \
290 ({                                                                      \
291         __put_user_err((x),(ptr),err);                                  \
292         (void) 0;                                                       \
293 })
294
295 #define __put_user_err(x,ptr,err)                                       \
296 do {                                                                    \
297         unsigned long __pu_addr = (unsigned long)(ptr);                 \
298         __typeof__(*(ptr)) __pu_val = (x);                              \
299         __chk_user_ptr(ptr);                                            \
300         switch (sizeof(*(ptr))) {                                       \
301         case 1: __put_user_asm_byte(__pu_val,__pu_addr,err);    break;  \
302         case 2: __put_user_asm_half(__pu_val,__pu_addr,err);    break;  \
303         case 4: __put_user_asm_word(__pu_val,__pu_addr,err);    break;  \
304         case 8: __put_user_asm_dword(__pu_val,__pu_addr,err);   break;  \
305         default: __put_user_bad();                                      \
306         }                                                               \
307 } while (0)
308
309 #define __put_user_asm_byte(x,__pu_addr,err)                    \
310         __asm__ __volatile__(                                   \
311         "1:     " T(strb) "     %1,[%2],#0\n"                   \
312         "2:\n"                                                  \
313         "       .pushsection .fixup,\"ax\"\n"                   \
314         "       .align  2\n"                                    \
315         "3:     mov     %0, %3\n"                               \
316         "       b       2b\n"                                   \
317         "       .popsection\n"                                  \
318         "       .pushsection __ex_table,\"a\"\n"                \
319         "       .align  3\n"                                    \
320         "       .long   1b, 3b\n"                               \
321         "       .popsection"                                    \
322         : "+r" (err)                                            \
323         : "r" (x), "r" (__pu_addr), "i" (-EFAULT)               \
324         : "cc")
325
326 #ifndef __ARMEB__
327 #define __put_user_asm_half(x,__pu_addr,err)                    \
328 ({                                                              \
329         unsigned long __temp = (unsigned long)(x);              \
330         __put_user_asm_byte(__temp, __pu_addr, err);            \
331         __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err);   \
332 })
333 #else
334 #define __put_user_asm_half(x,__pu_addr,err)                    \
335 ({                                                              \
336         unsigned long __temp = (unsigned long)(x);              \
337         __put_user_asm_byte(__temp >> 8, __pu_addr, err);       \
338         __put_user_asm_byte(__temp, __pu_addr + 1, err);        \
339 })
340 #endif
341
342 #define __put_user_asm_word(x,__pu_addr,err)                    \
343         __asm__ __volatile__(                                   \
344         "1:     " T(str) "      %1,[%2],#0\n"                   \
345         "2:\n"                                                  \
346         "       .pushsection .fixup,\"ax\"\n"                   \
347         "       .align  2\n"                                    \
348         "3:     mov     %0, %3\n"                               \
349         "       b       2b\n"                                   \
350         "       .popsection\n"                                  \
351         "       .pushsection __ex_table,\"a\"\n"                \
352         "       .align  3\n"                                    \
353         "       .long   1b, 3b\n"                               \
354         "       .popsection"                                    \
355         : "+r" (err)                                            \
356         : "r" (x), "r" (__pu_addr), "i" (-EFAULT)               \
357         : "cc")
358
359 #ifndef __ARMEB__
360 #define __reg_oper0     "%R2"
361 #define __reg_oper1     "%Q2"
362 #else
363 #define __reg_oper0     "%Q2"
364 #define __reg_oper1     "%R2"
365 #endif
366
367 #define __put_user_asm_dword(x,__pu_addr,err)                   \
368         __asm__ __volatile__(                                   \
369  ARM(   "1:     " T(str) "      " __reg_oper1 ", [%1], #4\n"    )       \
370  ARM(   "2:     " T(str) "      " __reg_oper0 ", [%1]\n"        )       \
371  THUMB( "1:     " T(str) "      " __reg_oper1 ", [%1]\n"        )       \
372  THUMB( "2:     " T(str) "      " __reg_oper0 ", [%1, #4]\n"    )       \
373         "3:\n"                                                  \
374         "       .pushsection .fixup,\"ax\"\n"                   \
375         "       .align  2\n"                                    \
376         "4:     mov     %0, %3\n"                               \
377         "       b       3b\n"                                   \
378         "       .popsection\n"                                  \
379         "       .pushsection __ex_table,\"a\"\n"                \
380         "       .align  3\n"                                    \
381         "       .long   1b, 4b\n"                               \
382         "       .long   2b, 4b\n"                               \
383         "       .popsection"                                    \
384         : "+r" (err), "+r" (__pu_addr)                          \
385         : "r" (x), "i" (-EFAULT)                                \
386         : "cc")
387
388
389 #ifdef CONFIG_MMU
390 extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
391 extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
392 extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
393 extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
394 extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
395 #else
396 #define __copy_from_user(to,from,n)     (memcpy(to, (void __force *)from, n), 0)
397 #define __copy_to_user(to,from,n)       (memcpy((void __force *)to, from, n), 0)
398 #define __clear_user(addr,n)            (memset((void __force *)addr, 0, n), 0)
399 #endif
400
401 extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count);
402 extern unsigned long __must_check __strnlen_user(const char __user *s, long n);
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 static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count)
431 {
432         long res = -EFAULT;
433         if (access_ok(VERIFY_READ, src, 1))
434                 res = __strncpy_from_user(dst, src, count);
435         return res;
436 }
437
438 #define strlen_user(s)  strnlen_user(s, ~0UL >> 1)
439
440 static inline long __must_check strnlen_user(const char __user *s, long n)
441 {
442         unsigned long res = 0;
443
444         if (__addr_ok(s))
445                 res = __strnlen_user(s, n);
446
447         return res;
448 }
449
450 #endif /* _ASMARM_UACCESS_H */