SLUB: return ZERO_SIZE_PTR for kmalloc(0)
[linux-2.6] / include / asm-m68k / uaccess.h
1 #ifndef __M68K_UACCESS_H
2 #define __M68K_UACCESS_H
3
4 /*
5  * User space memory access functions
6  */
7 #include <linux/compiler.h>
8 #include <linux/errno.h>
9 #include <linux/types.h>
10 #include <linux/sched.h>
11 #include <asm/segment.h>
12
13 #define VERIFY_READ     0
14 #define VERIFY_WRITE    1
15
16 /* We let the MMU do all checking */
17 #define access_ok(type,addr,size) 1
18
19 /*
20  * The exception table consists of pairs of addresses: the first is the
21  * address of an instruction that is allowed to fault, and the second is
22  * the address at which the program should continue.  No registers are
23  * modified, so it is entirely up to the continuation code to figure out
24  * what to do.
25  *
26  * All the routines below use bits of fixup code that are out of line
27  * with the main instruction path.  This means when everything is well,
28  * we don't even have to jump over them.  Further, they do not intrude
29  * on our cache or tlb entries.
30  */
31
32 struct exception_table_entry
33 {
34         unsigned long insn, fixup;
35 };
36
37 extern int __put_user_bad(void);
38 extern int __get_user_bad(void);
39
40 #define __put_user_asm(res, x, ptr, bwl, reg, err)      \
41 asm volatile ("\n"                                      \
42         "1:     moves."#bwl"    %2,%1\n"                \
43         "2:\n"                                          \
44         "       .section .fixup,\"ax\"\n"               \
45         "       .even\n"                                \
46         "10:    moveq.l %3,%0\n"                        \
47         "       jra 2b\n"                               \
48         "       .previous\n"                            \
49         "\n"                                            \
50         "       .section __ex_table,\"a\"\n"            \
51         "       .align  4\n"                            \
52         "       .long   1b,10b\n"                       \
53         "       .long   2b,10b\n"                       \
54         "       .previous"                              \
55         : "+d" (res), "=m" (*(ptr))                     \
56         : #reg (x), "i" (err))
57
58 /*
59  * These are the main single-value transfer routines.  They automatically
60  * use the right size if we just have the right pointer type.
61  */
62
63 #define __put_user(x, ptr)                                              \
64 ({                                                                      \
65         typeof(*(ptr)) __pu_val = (x);                                  \
66         int __pu_err = 0;                                               \
67         __chk_user_ptr(ptr);                                            \
68         switch (sizeof (*(ptr))) {                                      \
69         case 1:                                                         \
70                 __put_user_asm(__pu_err, __pu_val, ptr, b, d, -EFAULT); \
71                 break;                                                  \
72         case 2:                                                         \
73                 __put_user_asm(__pu_err, __pu_val, ptr, w, d, -EFAULT); \
74                 break;                                                  \
75         case 4:                                                         \
76                 __put_user_asm(__pu_err, __pu_val, ptr, l, r, -EFAULT); \
77                 break;                                                  \
78         case 8:                                                         \
79             {                                                           \
80                 const void __user *__pu_ptr = (ptr);                    \
81                 asm volatile ("\n"                                      \
82                         "1:     moves.l %2,(%1)+\n"                     \
83                         "2:     moves.l %R2,(%1)\n"                     \
84                         "3:\n"                                          \
85                         "       .section .fixup,\"ax\"\n"               \
86                         "       .even\n"                                \
87                         "10:    movel %3,%0\n"                          \
88                         "       jra 3b\n"                               \
89                         "       .previous\n"                            \
90                         "\n"                                            \
91                         "       .section __ex_table,\"a\"\n"            \
92                         "       .align 4\n"                             \
93                         "       .long 1b,10b\n"                         \
94                         "       .long 2b,10b\n"                         \
95                         "       .long 3b,10b\n"                         \
96                         "       .previous"                              \
97                         : "+d" (__pu_err), "+a" (__pu_ptr)              \
98                         : "r" (__pu_val), "i" (-EFAULT)                 \
99                         : "memory");                                    \
100                 break;                                                  \
101             }                                                           \
102         default:                                                        \
103                 __pu_err = __put_user_bad();                            \
104                 break;                                                  \
105         }                                                               \
106         __pu_err;                                                       \
107 })
108 #define put_user(x, ptr)        __put_user(x, ptr)
109
110
111 #define __get_user_asm(res, x, ptr, type, bwl, reg, err) ({     \
112         type __gu_val;                                          \
113         asm volatile ("\n"                                      \
114                 "1:     moves."#bwl"    %2,%1\n"                \
115                 "2:\n"                                          \
116                 "       .section .fixup,\"ax\"\n"               \
117                 "       .even\n"                                \
118                 "10:    move.l  %3,%0\n"                        \
119                 "       sub."#bwl"      %1,%1\n"                \
120                 "       jra     2b\n"                           \
121                 "       .previous\n"                            \
122                 "\n"                                            \
123                 "       .section __ex_table,\"a\"\n"            \
124                 "       .align  4\n"                            \
125                 "       .long   1b,10b\n"                       \
126                 "       .previous"                              \
127                 : "+d" (res), "=&" #reg (__gu_val)              \
128                 : "m" (*(ptr)), "i" (err));                     \
129         (x) = (typeof(*(ptr)))(unsigned long)__gu_val;          \
130 })
131
132 #define __get_user(x, ptr)                                              \
133 ({                                                                      \
134         int __gu_err = 0;                                               \
135         __chk_user_ptr(ptr);                                            \
136         switch (sizeof(*(ptr))) {                                       \
137         case 1:                                                         \
138                 __get_user_asm(__gu_err, x, ptr, u8, b, d, -EFAULT);    \
139                 break;                                                  \
140         case 2:                                                         \
141                 __get_user_asm(__gu_err, x, ptr, u16, w, d, -EFAULT);   \
142                 break;                                                  \
143         case 4:                                                         \
144                 __get_user_asm(__gu_err, x, ptr, u32, l, r, -EFAULT);   \
145                 break;                                                  \
146 /*      case 8: disabled because gcc-4.1 has a broken typeof            \
147             {                                                           \
148                 const void *__gu_ptr = (ptr);                           \
149                 u64 __gu_val;                                           \
150                 asm volatile ("\n"                                      \
151                         "1:     moves.l (%2)+,%1\n"                     \
152                         "2:     moves.l (%2),%R1\n"                     \
153                         "3:\n"                                          \
154                         "       .section .fixup,\"ax\"\n"               \
155                         "       .even\n"                                \
156                         "10:    move.l  %3,%0\n"                        \
157                         "       sub.l   %1,%1\n"                        \
158                         "       sub.l   %R1,%R1\n"                      \
159                         "       jra     3b\n"                           \
160                         "       .previous\n"                            \
161                         "\n"                                            \
162                         "       .section __ex_table,\"a\"\n"            \
163                         "       .align  4\n"                            \
164                         "       .long   1b,10b\n"                       \
165                         "       .long   2b,10b\n"                       \
166                         "       .previous"                              \
167                         : "+d" (__gu_err), "=&r" (__gu_val),            \
168                           "+a" (__gu_ptr)                               \
169                         : "i" (-EFAULT)                                 \
170                         : "memory");                                    \
171                 (x) = (typeof(*(ptr)))__gu_val;                         \
172                 break;                                                  \
173             }   */                                                      \
174         default:                                                        \
175                 __gu_err = __get_user_bad();                            \
176                 break;                                                  \
177         }                                                               \
178         __gu_err;                                                       \
179 })
180 #define get_user(x, ptr) __get_user(x, ptr)
181
182 unsigned long __generic_copy_from_user(void *to, const void __user *from, unsigned long n);
183 unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned long n);
184
185 #define __constant_copy_from_user_asm(res, to, from, tmp, n, s1, s2, s3)\
186         asm volatile ("\n"                                              \
187                 "1:     moves."#s1"     (%2)+,%3\n"                     \
188                 "       move."#s1"      %3,(%1)+\n"                     \
189                 "2:     moves."#s2"     (%2)+,%3\n"                     \
190                 "       move."#s2"      %3,(%1)+\n"                     \
191                 "       .ifnc   \""#s3"\",\"\"\n"                       \
192                 "3:     moves."#s3"     (%2)+,%3\n"                     \
193                 "       move."#s3"      %3,(%1)+\n"                     \
194                 "       .endif\n"                                       \
195                 "4:\n"                                                  \
196                 "       .section __ex_table,\"a\"\n"                    \
197                 "       .align  4\n"                                    \
198                 "       .long   1b,10f\n"                               \
199                 "       .long   2b,20f\n"                               \
200                 "       .ifnc   \""#s3"\",\"\"\n"                       \
201                 "       .long   3b,30f\n"                               \
202                 "       .endif\n"                                       \
203                 "       .previous\n"                                    \
204                 "\n"                                                    \
205                 "       .section .fixup,\"ax\"\n"                       \
206                 "       .even\n"                                        \
207                 "10:    clr."#s1"       (%1)+\n"                        \
208                 "20:    clr."#s2"       (%1)+\n"                        \
209                 "       .ifnc   \""#s3"\",\"\"\n"                       \
210                 "30:    clr."#s3"       (%1)+\n"                        \
211                 "       .endif\n"                                       \
212                 "       moveq.l #"#n",%0\n"                             \
213                 "       jra     4b\n"                                   \
214                 "       .previous\n"                                    \
215                 : "+d" (res), "+&a" (to), "+a" (from), "=&d" (tmp)      \
216                 : : "memory")
217
218 static __always_inline unsigned long
219 __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
220 {
221         unsigned long res = 0, tmp;
222
223         switch (n) {
224         case 1:
225                 __get_user_asm(res, *(u8 *)to, (u8 __user *)from, u8, b, d, 1);
226                 break;
227         case 2:
228                 __get_user_asm(res, *(u16 *)to, (u16 __user *)from, u16, w, d, 2);
229                 break;
230         case 3:
231                 __constant_copy_from_user_asm(res, to, from, tmp, 3, w, b,);
232                 break;
233         case 4:
234                 __get_user_asm(res, *(u32 *)to, (u32 __user *)from, u32, l, r, 4);
235                 break;
236         case 5:
237                 __constant_copy_from_user_asm(res, to, from, tmp, 5, l, b,);
238                 break;
239         case 6:
240                 __constant_copy_from_user_asm(res, to, from, tmp, 6, l, w,);
241                 break;
242         case 7:
243                 __constant_copy_from_user_asm(res, to, from, tmp, 7, l, w, b);
244                 break;
245         case 8:
246                 __constant_copy_from_user_asm(res, to, from, tmp, 8, l, l,);
247                 break;
248         case 9:
249                 __constant_copy_from_user_asm(res, to, from, tmp, 9, l, l, b);
250                 break;
251         case 10:
252                 __constant_copy_from_user_asm(res, to, from, tmp, 10, l, l, w);
253                 break;
254         case 12:
255                 __constant_copy_from_user_asm(res, to, from, tmp, 12, l, l, l);
256                 break;
257         default:
258                 /* we limit the inlined version to 3 moves */
259                 return __generic_copy_from_user(to, from, n);
260         }
261
262         return res;
263 }
264
265 #define __constant_copy_to_user_asm(res, to, from, tmp, n, s1, s2, s3)  \
266         asm volatile ("\n"                                              \
267                 "       move."#s1"      (%2)+,%3\n"                     \
268                 "11:    moves."#s1"     %3,(%1)+\n"                     \
269                 "12:    move."#s2"      (%2)+,%3\n"                     \
270                 "21:    moves."#s2"     %3,(%1)+\n"                     \
271                 "22:\n"                                                 \
272                 "       .ifnc   \""#s3"\",\"\"\n"                       \
273                 "       move."#s3"      (%2)+,%3\n"                     \
274                 "31:    moves."#s3"     %3,(%1)+\n"                     \
275                 "32:\n"                                                 \
276                 "       .endif\n"                                       \
277                 "4:\n"                                                  \
278                 "\n"                                                    \
279                 "       .section __ex_table,\"a\"\n"                    \
280                 "       .align  4\n"                                    \
281                 "       .long   11b,5f\n"                               \
282                 "       .long   12b,5f\n"                               \
283                 "       .long   21b,5f\n"                               \
284                 "       .long   22b,5f\n"                               \
285                 "       .ifnc   \""#s3"\",\"\"\n"                       \
286                 "       .long   31b,5f\n"                               \
287                 "       .long   32b,5f\n"                               \
288                 "       .endif\n"                                       \
289                 "       .previous\n"                                    \
290                 "\n"                                                    \
291                 "       .section .fixup,\"ax\"\n"                       \
292                 "       .even\n"                                        \
293                 "5:     moveq.l #"#n",%0\n"                             \
294                 "       jra     4b\n"                                   \
295                 "       .previous\n"                                    \
296                 : "+d" (res), "+a" (to), "+a" (from), "=&d" (tmp)       \
297                 : : "memory")
298
299 static __always_inline unsigned long
300 __constant_copy_to_user(void __user *to, const void *from, unsigned long n)
301 {
302         unsigned long res = 0, tmp;
303
304         switch (n) {
305         case 1:
306                 __put_user_asm(res, *(u8 *)from, (u8 __user *)to, b, d, 1);
307                 break;
308         case 2:
309                 __put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, d, 2);
310                 break;
311         case 3:
312                 __constant_copy_to_user_asm(res, to, from, tmp, 3, w, b,);
313                 break;
314         case 4:
315                 __put_user_asm(res, *(u32 *)from, (u32 __user *)to, l, r, 4);
316                 break;
317         case 5:
318                 __constant_copy_to_user_asm(res, to, from, tmp, 5, l, b,);
319                 break;
320         case 6:
321                 __constant_copy_to_user_asm(res, to, from, tmp, 6, l, w,);
322                 break;
323         case 7:
324                 __constant_copy_to_user_asm(res, to, from, tmp, 7, l, w, b);
325                 break;
326         case 8:
327                 __constant_copy_to_user_asm(res, to, from, tmp, 8, l, l,);
328                 break;
329         case 9:
330                 __constant_copy_to_user_asm(res, to, from, tmp, 9, l, l, b);
331                 break;
332         case 10:
333                 __constant_copy_to_user_asm(res, to, from, tmp, 10, l, l, w);
334                 break;
335         case 12:
336                 __constant_copy_to_user_asm(res, to, from, tmp, 12, l, l, l);
337                 break;
338         default:
339                 /* limit the inlined version to 3 moves */
340                 return __generic_copy_to_user(to, from, n);
341         }
342
343         return res;
344 }
345
346 #define __copy_from_user(to, from, n)           \
347 (__builtin_constant_p(n) ?                      \
348  __constant_copy_from_user(to, from, n) :       \
349  __generic_copy_from_user(to, from, n))
350
351 #define __copy_to_user(to, from, n)             \
352 (__builtin_constant_p(n) ?                      \
353  __constant_copy_to_user(to, from, n) :         \
354  __generic_copy_to_user(to, from, n))
355
356 #define __copy_to_user_inatomic         __copy_to_user
357 #define __copy_from_user_inatomic       __copy_from_user
358
359 #define copy_from_user(to, from, n)     __copy_from_user(to, from, n)
360 #define copy_to_user(to, from, n)       __copy_to_user(to, from, n)
361
362 long strncpy_from_user(char *dst, const char __user *src, long count);
363 long strnlen_user(const char __user *src, long n);
364 unsigned long __clear_user(void __user *to, unsigned long n);
365
366 #define clear_user      __clear_user
367
368 #define strlen_user(str) strnlen_user(str, 32767)
369
370 #endif /* _M68K_UACCESS_H */