[PATCH] fix sparse warnings from {asm,net}/checksum.h
[linux-3.10.git] / include / asm-arm / uaccess.h
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  * These two are intentionally not defined anywhere - if the kernel
45  * code generates any references to them, that's a bug.
46  */
47 extern int __get_user_bad(void);
48 extern int __put_user_bad(void);
49
50 /*
51  * Note that this is actually 0x1,0000,0000
52  */
53 #define KERNEL_DS       0x00000000
54 #define get_ds()        (KERNEL_DS)
55
56 #ifdef CONFIG_MMU
57
58 #define USER_DS         TASK_SIZE
59 #define get_fs()        (current_thread_info()->addr_limit)
60
61 static inline void set_fs(mm_segment_t fs)
62 {
63         current_thread_info()->addr_limit = fs;
64         modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
65 }
66
67 #define segment_eq(a,b) ((a) == (b))
68
69 #define __addr_ok(addr) ({ \
70         unsigned long flag; \
71         __asm__("cmp %2, %0; movlo %0, #0" \
72                 : "=&r" (flag) \
73                 : "0" (current_thread_info()->addr_limit), "r" (addr) \
74                 : "cc"); \
75         (flag == 0); })
76
77 /* We use 33-bit arithmetic here... */
78 #define __range_ok(addr,size) ({ \
79         unsigned long flag, roksum; \
80         __chk_user_ptr(addr);   \
81         __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
82                 : "=&r" (flag), "=&r" (roksum) \
83                 : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
84                 : "cc"); \
85         flag; })
86
87 /*
88  * Single-value transfer routines.  They automatically use the right
89  * size if we just have the right pointer type.  Note that the functions
90  * which read from user space (*get_*) need to take care not to leak
91  * kernel data even if the calling code is buggy and fails to check
92  * the return value.  This means zeroing out the destination variable
93  * or buffer on error.  Normally this is done out of line by the
94  * fixup code, but there are a few places where it intrudes on the
95  * main code path.  When we only write to user space, there is no
96  * problem.
97  */
98 extern int __get_user_1(void *);
99 extern int __get_user_2(void *);
100 extern int __get_user_4(void *);
101
102 #define __get_user_x(__r2,__p,__e,__s,__i...)                           \
103            __asm__ __volatile__ (                                       \
104                 __asmeq("%0", "r0") __asmeq("%1", "r2")                 \
105                 "bl     __get_user_" #__s                               \
106                 : "=&r" (__e), "=r" (__r2)                              \
107                 : "0" (__p)                                             \
108                 : __i, "cc")
109
110 #define get_user(x,p)                                                   \
111         ({                                                              \
112                 const register typeof(*(p)) __user *__p asm("r0") = (p);\
113                 register unsigned long __r2 asm("r2");                  \
114                 register int __e asm("r0");                             \
115                 switch (sizeof(*(__p))) {                               \
116                 case 1:                                                 \
117                         __get_user_x(__r2, __p, __e, 1, "lr");          \
118                         break;                                          \
119                 case 2:                                                 \
120                         __get_user_x(__r2, __p, __e, 2, "r3", "lr");    \
121                         break;                                          \
122                 case 4:                                                 \
123                         __get_user_x(__r2, __p, __e, 4, "lr");          \
124                         break;                                          \
125                 default: __e = __get_user_bad(); break;                 \
126                 }                                                       \
127                 x = (typeof(*(p))) __r2;                                \
128                 __e;                                                    \
129         })
130
131 extern int __put_user_1(void *, unsigned int);
132 extern int __put_user_2(void *, unsigned int);
133 extern int __put_user_4(void *, unsigned int);
134 extern int __put_user_8(void *, unsigned long long);
135
136 #define __put_user_x(__r2,__p,__e,__s)                                  \
137            __asm__ __volatile__ (                                       \
138                 __asmeq("%0", "r0") __asmeq("%2", "r2")                 \
139                 "bl     __put_user_" #__s                               \
140                 : "=&r" (__e)                                           \
141                 : "0" (__p), "r" (__r2)                                 \
142                 : "ip", "lr", "cc")
143
144 #define put_user(x,p)                                                   \
145         ({                                                              \
146                 const register typeof(*(p)) __r2 asm("r2") = (x);       \
147                 const register typeof(*(p)) __user *__p asm("r0") = (p);\
148                 register int __e asm("r0");                             \
149                 switch (sizeof(*(__p))) {                               \
150                 case 1:                                                 \
151                         __put_user_x(__r2, __p, __e, 1);                \
152                         break;                                          \
153                 case 2:                                                 \
154                         __put_user_x(__r2, __p, __e, 2);                \
155                         break;                                          \
156                 case 4:                                                 \
157                         __put_user_x(__r2, __p, __e, 4);                \
158                         break;                                          \
159                 case 8:                                                 \
160                         __put_user_x(__r2, __p, __e, 8);                \
161                         break;                                          \
162                 default: __e = __put_user_bad(); break;                 \
163                 }                                                       \
164                 __e;                                                    \
165         })
166
167 #else /* CONFIG_MMU */
168
169 /*
170  * uClinux has only one addr space, so has simplified address limits.
171  */
172 #define USER_DS                 KERNEL_DS
173
174 #define segment_eq(a,b)         (1)
175 #define __addr_ok(addr)         (1)
176 #define __range_ok(addr,size)   (0)
177 #define get_fs()                (KERNEL_DS)
178
179 static inline void set_fs(mm_segment_t fs)
180 {
181 }
182
183 #define get_user(x,p)   __get_user(x,p)
184 #define put_user(x,p)   __put_user(x,p)
185
186 #endif /* CONFIG_MMU */
187
188 #define access_ok(type,addr,size)       (__range_ok(addr,size) == 0)
189
190 /*
191  * The "__xxx" versions of the user access functions do not verify the
192  * address space - it must have been done previously with a separate
193  * "access_ok()" call.
194  *
195  * The "xxx_error" versions set the third argument to EFAULT if an
196  * error occurs, and leave it unchanged on success.  Note that these
197  * versions are void (ie, don't return a value as such).
198  */
199 #define __get_user(x,ptr)                                               \
200 ({                                                                      \
201         long __gu_err = 0;                                              \
202         __get_user_err((x),(ptr),__gu_err);                             \
203         __gu_err;                                                       \
204 })
205
206 #define __get_user_error(x,ptr,err)                                     \
207 ({                                                                      \
208         __get_user_err((x),(ptr),err);                                  \
209         (void) 0;                                                       \
210 })
211
212 #define __get_user_err(x,ptr,err)                                       \
213 do {                                                                    \
214         unsigned long __gu_addr = (unsigned long)(ptr);                 \
215         unsigned long __gu_val;                                         \
216         __chk_user_ptr(ptr);                                            \
217         switch (sizeof(*(ptr))) {                                       \
218         case 1: __get_user_asm_byte(__gu_val,__gu_addr,err);    break;  \
219         case 2: __get_user_asm_half(__gu_val,__gu_addr,err);    break;  \
220         case 4: __get_user_asm_word(__gu_val,__gu_addr,err);    break;  \
221         default: (__gu_val) = __get_user_bad();                         \
222         }                                                               \
223         (x) = (__typeof__(*(ptr)))__gu_val;                             \
224 } while (0)
225
226 #define __get_user_asm_byte(x,addr,err)                         \
227         __asm__ __volatile__(                                   \
228         "1:     ldrbt   %1,[%2],#0\n"                           \
229         "2:\n"                                                  \
230         "       .section .fixup,\"ax\"\n"                       \
231         "       .align  2\n"                                    \
232         "3:     mov     %0, %3\n"                               \
233         "       mov     %1, #0\n"                               \
234         "       b       2b\n"                                   \
235         "       .previous\n"                                    \
236         "       .section __ex_table,\"a\"\n"                    \
237         "       .align  3\n"                                    \
238         "       .long   1b, 3b\n"                               \
239         "       .previous"                                      \
240         : "+r" (err), "=&r" (x)                                 \
241         : "r" (addr), "i" (-EFAULT)                             \
242         : "cc")
243
244 #ifndef __ARMEB__
245 #define __get_user_asm_half(x,__gu_addr,err)                    \
246 ({                                                              \
247         unsigned long __b1, __b2;                               \
248         __get_user_asm_byte(__b1, __gu_addr, err);              \
249         __get_user_asm_byte(__b2, __gu_addr + 1, err);          \
250         (x) = __b1 | (__b2 << 8);                               \
251 })
252 #else
253 #define __get_user_asm_half(x,__gu_addr,err)                    \
254 ({                                                              \
255         unsigned long __b1, __b2;                               \
256         __get_user_asm_byte(__b1, __gu_addr, err);              \
257         __get_user_asm_byte(__b2, __gu_addr + 1, err);          \
258         (x) = (__b1 << 8) | __b2;                               \
259 })
260 #endif
261
262 #define __get_user_asm_word(x,addr,err)                         \
263         __asm__ __volatile__(                                   \
264         "1:     ldrt    %1,[%2],#0\n"                           \
265         "2:\n"                                                  \
266         "       .section .fixup,\"ax\"\n"                       \
267         "       .align  2\n"                                    \
268         "3:     mov     %0, %3\n"                               \
269         "       mov     %1, #0\n"                               \
270         "       b       2b\n"                                   \
271         "       .previous\n"                                    \
272         "       .section __ex_table,\"a\"\n"                    \
273         "       .align  3\n"                                    \
274         "       .long   1b, 3b\n"                               \
275         "       .previous"                                      \
276         : "+r" (err), "=&r" (x)                                 \
277         : "r" (addr), "i" (-EFAULT)                             \
278         : "cc")
279
280 #define __put_user(x,ptr)                                               \
281 ({                                                                      \
282         long __pu_err = 0;                                              \
283         __put_user_err((x),(ptr),__pu_err);                             \
284         __pu_err;                                                       \
285 })
286
287 #define __put_user_error(x,ptr,err)                                     \
288 ({                                                                      \
289         __put_user_err((x),(ptr),err);                                  \
290         (void) 0;                                                       \
291 })
292
293 #define __put_user_err(x,ptr,err)                                       \
294 do {                                                                    \
295         unsigned long __pu_addr = (unsigned long)(ptr);                 \
296         __typeof__(*(ptr)) __pu_val = (x);                              \
297         __chk_user_ptr(ptr);                                            \
298         switch (sizeof(*(ptr))) {                                       \
299         case 1: __put_user_asm_byte(__pu_val,__pu_addr,err);    break;  \
300         case 2: __put_user_asm_half(__pu_val,__pu_addr,err);    break;  \
301         case 4: __put_user_asm_word(__pu_val,__pu_addr,err);    break;  \
302         case 8: __put_user_asm_dword(__pu_val,__pu_addr,err);   break;  \
303         default: __put_user_bad();                                      \
304         }                                                               \
305 } while (0)
306
307 #define __put_user_asm_byte(x,__pu_addr,err)                    \
308         __asm__ __volatile__(                                   \
309         "1:     strbt   %1,[%2],#0\n"                           \
310         "2:\n"                                                  \
311         "       .section .fixup,\"ax\"\n"                       \
312         "       .align  2\n"                                    \
313         "3:     mov     %0, %3\n"                               \
314         "       b       2b\n"                                   \
315         "       .previous\n"                                    \
316         "       .section __ex_table,\"a\"\n"                    \
317         "       .align  3\n"                                    \
318         "       .long   1b, 3b\n"                               \
319         "       .previous"                                      \
320         : "+r" (err)                                            \
321         : "r" (x), "r" (__pu_addr), "i" (-EFAULT)               \
322         : "cc")
323
324 #ifndef __ARMEB__
325 #define __put_user_asm_half(x,__pu_addr,err)                    \
326 ({                                                              \
327         unsigned long __temp = (unsigned long)(x);              \
328         __put_user_asm_byte(__temp, __pu_addr, err);            \
329         __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err);   \
330 })
331 #else
332 #define __put_user_asm_half(x,__pu_addr,err)                    \
333 ({                                                              \
334         unsigned long __temp = (unsigned long)(x);              \
335         __put_user_asm_byte(__temp >> 8, __pu_addr, err);       \
336         __put_user_asm_byte(__temp, __pu_addr + 1, err);        \
337 })
338 #endif
339
340 #define __put_user_asm_word(x,__pu_addr,err)                    \
341         __asm__ __volatile__(                                   \
342         "1:     strt    %1,[%2],#0\n"                           \
343         "2:\n"                                                  \
344         "       .section .fixup,\"ax\"\n"                       \
345         "       .align  2\n"                                    \
346         "3:     mov     %0, %3\n"                               \
347         "       b       2b\n"                                   \
348         "       .previous\n"                                    \
349         "       .section __ex_table,\"a\"\n"                    \
350         "       .align  3\n"                                    \
351         "       .long   1b, 3b\n"                               \
352         "       .previous"                                      \
353         : "+r" (err)                                            \
354         : "r" (x), "r" (__pu_addr), "i" (-EFAULT)               \
355         : "cc")
356
357 #ifndef __ARMEB__
358 #define __reg_oper0     "%R2"
359 #define __reg_oper1     "%Q2"
360 #else
361 #define __reg_oper0     "%Q2"
362 #define __reg_oper1     "%R2"
363 #endif
364
365 #define __put_user_asm_dword(x,__pu_addr,err)                   \
366         __asm__ __volatile__(                                   \
367         "1:     strt    " __reg_oper1 ", [%1], #4\n"            \
368         "2:     strt    " __reg_oper0 ", [%1], #0\n"            \
369         "3:\n"                                                  \
370         "       .section .fixup,\"ax\"\n"                       \
371         "       .align  2\n"                                    \
372         "4:     mov     %0, %3\n"                               \
373         "       b       3b\n"                                   \
374         "       .previous\n"                                    \
375         "       .section __ex_table,\"a\"\n"                    \
376         "       .align  3\n"                                    \
377         "       .long   1b, 4b\n"                               \
378         "       .long   2b, 4b\n"                               \
379         "       .previous"                                      \
380         : "+r" (err), "+r" (__pu_addr)                          \
381         : "r" (x), "i" (-EFAULT)                                \
382         : "cc")
383
384
385 #ifdef CONFIG_MMU
386 extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
387 extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
388 extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
389 #else
390 #define __copy_from_user(to,from,n)     (memcpy(to, (void __force *)from, n), 0)
391 #define __copy_to_user(to,from,n)       (memcpy((void __force *)to, from, n), 0)
392 #define __clear_user(addr,n)            (memset((void __force *)addr, 0, n), 0)
393 #endif
394
395 extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count);
396 extern unsigned long __must_check __strnlen_user(const char __user *s, long n);
397
398 static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
399 {
400         if (access_ok(VERIFY_READ, from, n))
401                 n = __copy_from_user(to, from, n);
402         else /* security hole - plug it */
403                 memzero(to, n);
404         return n;
405 }
406
407 static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
408 {
409         if (access_ok(VERIFY_WRITE, to, n))
410                 n = __copy_to_user(to, from, n);
411         return n;
412 }
413
414 #define __copy_to_user_inatomic __copy_to_user
415 #define __copy_from_user_inatomic __copy_from_user
416
417 static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
418 {
419         if (access_ok(VERIFY_WRITE, to, n))
420                 n = __clear_user(to, n);
421         return n;
422 }
423
424 static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count)
425 {
426         long res = -EFAULT;
427         if (access_ok(VERIFY_READ, src, 1))
428                 res = __strncpy_from_user(dst, src, count);
429         return res;
430 }
431
432 #define strlen_user(s)  strnlen_user(s, ~0UL >> 1)
433
434 static inline long __must_check strnlen_user(const char __user *s, long n)
435 {
436         unsigned long res = 0;
437
438         if (__addr_ok(s))
439                 res = __strnlen_user(s, n);
440
441         return res;
442 }
443
444 #endif /* _ASMARM_UACCESS_H */