1 /* $Id: uaccess.h,v 1.34 2001/09/27 04:36:24 kanoj Exp $ */
2 #ifndef _ASM_UACCESS_H
3 #define _ASM_UACCESS_H
4
5 /*
6 * User space memory access functions
7 */
8
9 #ifdef __KERNEL__
10 #include <linux/sched.h>
11 #include <linux/string.h>
12 #include <asm/a.out.h>
13 #include <asm/asi.h>
14 #include <asm/system.h>
15 #include <asm/spitfire.h>
16 #endif
17
18 #ifndef __ASSEMBLY__
19
20 /*
21 * Sparc64 is segmented, though more like the M68K than the I386.
22 * We use the secondary ASI to address user memory, which references a
23 * completely different VM map, thus there is zero chance of the user
24 * doing something queer and tricking us into poking kernel memory.
25 *
26 * What is left here is basically what is needed for the other parts of
27 * the kernel that expect to be able to manipulate, erum, "segments".
28 * Or perhaps more properly, permissions.
29 *
30 * "For historical reasons, these macros are grossly misnamed." -Linus
31 */
32
33 #define KERNEL_DS ((mm_segment_t) { ASI_P })
34 #define USER_DS ((mm_segment_t) { ASI_AIUS }) /* har har har */
35
36 #define VERIFY_READ 0
37 #define VERIFY_WRITE 1
38
39 #define get_fs() (current->thread.current_ds)
40 #define get_ds() (KERNEL_DS)
41
42 #define segment_eq(a,b) ((a).seg == (b).seg)
43
44 #define set_fs(val) \
45 do { \
46 current->thread.current_ds = (val); \
47 __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg)); \
48 } while(0)
49
50 #define __user_ok(addr,size) 1
51 #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
52 #define __access_ok(addr,size) 1
53 #define access_ok(type,addr,size) 1
54
verify_area(int type,const void * addr,unsigned long size)55 extern inline int verify_area(int type, const void * addr, unsigned long size)
56 {
57 return 0;
58 }
59
60 /*
61 * The exception table consists of pairs of addresses: the first is the
62 * address of an instruction that is allowed to fault, and the second is
63 * the address at which the program should continue. No registers are
64 * modified, so it is entirely up to the continuation code to figure out
65 * what to do.
66 *
67 * All the routines below use bits of fixup code that are out of line
68 * with the main instruction path. This means when everything is well,
69 * we don't even have to jump over them. Further, they do not intrude
70 * on our cache or tlb entries.
71 *
72 * There is a special way how to put a range of potentially faulting
73 * insns (like twenty ldd/std's with now intervening other instructions)
74 * You specify address of first in insn and 0 in fixup and in the next
75 * exception_table_entry you specify last potentially faulting insn + 1
76 * and in fixup the routine which should handle the fault.
77 * That fixup code will get
78 * (faulting_insn_address - first_insn_in_the_range_address)/4
79 * in %g2 (ie. index of the faulting instruction in the range).
80 */
81
82 struct exception_table_entry
83 {
84 unsigned insn, fixup;
85 };
86
87 /* Returns 0 if exception not found and fixup otherwise. */
88 extern unsigned long search_exception_table(unsigned long, unsigned long *);
89
90 extern void __ret_efault(void);
91
92 /* Uh, these should become the main single-value transfer routines..
93 * They automatically use the right size if we just have the right
94 * pointer type..
95 *
96 * This gets kind of ugly. We want to return _two_ values in "get_user()"
97 * and yet we don't want to do any pointers, because that is too much
98 * of a performance impact. Thus we have a few rather ugly macros here,
99 * and hide all the uglyness from the user.
100 */
101 #define put_user(x,ptr) ({ \
102 unsigned long __pu_addr = (unsigned long)(ptr); \
103 __put_user_nocheck((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
104
105 #define get_user(x,ptr) ({ \
106 unsigned long __gu_addr = (unsigned long)(ptr); \
107 __get_user_nocheck((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
108
109 #define __put_user(x,ptr) put_user(x,ptr)
110 #define __get_user(x,ptr) get_user(x,ptr)
111
112 struct __large_struct { unsigned long buf[100]; };
113 #define __m(x) ((struct __large_struct *)(x))
114
115 #define __put_user_nocheck(data,addr,size) ({ \
116 register int __pu_ret; \
117 switch (size) { \
118 case 1: __put_user_asm(data,b,addr,__pu_ret); break; \
119 case 2: __put_user_asm(data,h,addr,__pu_ret); break; \
120 case 4: __put_user_asm(data,w,addr,__pu_ret); break; \
121 case 8: __put_user_asm(data,x,addr,__pu_ret); break; \
122 default: __pu_ret = __put_user_bad(); break; \
123 } __pu_ret; })
124
125 #define __put_user_nocheck_ret(data,addr,size,retval) ({ \
126 register int __foo __asm__ ("l1"); \
127 switch (size) { \
128 case 1: __put_user_asm_ret(data,b,addr,retval,__foo); break; \
129 case 2: __put_user_asm_ret(data,h,addr,retval,__foo); break; \
130 case 4: __put_user_asm_ret(data,w,addr,retval,__foo); break; \
131 case 8: __put_user_asm_ret(data,x,addr,retval,__foo); break; \
132 default: if (__put_user_bad()) return retval; break; \
133 } })
134
135 #define __put_user_asm(x,size,addr,ret) \
136 __asm__ __volatile__( \
137 "/* Put user asm, inline. */\n" \
138 "1:\t" "st"#size "a %1, [%2] %%asi\n\t" \
139 "clr %0\n" \
140 "2:\n\n\t" \
141 ".section .fixup,#alloc,#execinstr\n\t" \
142 ".align 4\n" \
143 "3:\n\t" \
144 "b 2b\n\t" \
145 " mov %3, %0\n\n\t" \
146 ".previous\n\t" \
147 ".section __ex_table,#alloc\n\t" \
148 ".align 4\n\t" \
149 ".word 1b, 3b\n\t" \
150 ".previous\n\n\t" \
151 : "=r" (ret) : "r" (x), "r" (__m(addr)), \
152 "i" (-EFAULT))
153
154 #define __put_user_asm_ret(x,size,addr,ret,foo) \
155 if (__builtin_constant_p(ret) && ret == -EFAULT) \
156 __asm__ __volatile__( \
157 "/* Put user asm ret, inline. */\n" \
158 "1:\t" "st"#size "a %1, [%2] %%asi\n\n\t" \
159 ".section __ex_table,#alloc\n\t" \
160 ".align 4\n\t" \
161 ".word 1b, __ret_efault\n\n\t" \
162 ".previous\n\n\t" \
163 : "=r" (foo) : "r" (x), "r" (__m(addr))); \
164 else \
165 __asm__ __volatile( \
166 "/* Put user asm ret, inline. */\n" \
167 "1:\t" "st"#size "a %1, [%2] %%asi\n\n\t" \
168 ".section .fixup,#alloc,#execinstr\n\t" \
169 ".align 4\n" \
170 "3:\n\t" \
171 "ret\n\t" \
172 " restore %%g0, %3, %%o0\n\n\t" \
173 ".previous\n\t" \
174 ".section __ex_table,#alloc\n\t" \
175 ".align 4\n\t" \
176 ".word 1b, 3b\n\n\t" \
177 ".previous\n\n\t" \
178 : "=r" (foo) : "r" (x), "r" (__m(addr)), \
179 "i" (ret))
180
181 extern int __put_user_bad(void);
182
183 #define __get_user_nocheck(data,addr,size,type) ({ \
184 register int __gu_ret; \
185 register unsigned long __gu_val; \
186 switch (size) { \
187 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
188 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
189 case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
190 case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
191 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
192 } data = (type) __gu_val; __gu_ret; })
193
194 #define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
195 register unsigned long __gu_val __asm__ ("l1"); \
196 switch (size) { \
197 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
198 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
199 case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
200 case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
201 default: if (__get_user_bad()) return retval; \
202 } data = (type) __gu_val; })
203
204 #define __get_user_asm(x,size,addr,ret) \
205 __asm__ __volatile__( \
206 "/* Get user asm, inline. */\n" \
207 "1:\t" "ld"#size "a [%2] %%asi, %1\n\t" \
208 "clr %0\n" \
209 "2:\n\n\t" \
210 ".section .fixup,#alloc,#execinstr\n\t" \
211 ".align 4\n" \
212 "3:\n\t" \
213 "clr %1\n\t" \
214 "b 2b\n\t" \
215 " mov %3, %0\n\n\t" \
216 ".previous\n\t" \
217 ".section __ex_table,#alloc\n\t" \
218 ".align 4\n\t" \
219 ".word 1b, 3b\n\n\t" \
220 ".previous\n\t" \
221 : "=r" (ret), "=r" (x) : "r" (__m(addr)), \
222 "i" (-EFAULT))
223
224 #define __get_user_asm_ret(x,size,addr,retval) \
225 if (__builtin_constant_p(retval) && retval == -EFAULT) \
226 __asm__ __volatile__( \
227 "/* Get user asm ret, inline. */\n" \
228 "1:\t" "ld"#size "a [%1] %%asi, %0\n\n\t" \
229 ".section __ex_table,#alloc\n\t" \
230 ".align 4\n\t" \
231 ".word 1b,__ret_efault\n\n\t" \
232 ".previous\n\t" \
233 : "=r" (x) : "r" (__m(addr))); \
234 else \
235 __asm__ __volatile__( \
236 "/* Get user asm ret, inline. */\n" \
237 "1:\t" "ld"#size "a [%1] %%asi, %0\n\n\t" \
238 ".section .fixup,#alloc,#execinstr\n\t" \
239 ".align 4\n" \
240 "3:\n\t" \
241 "ret\n\t" \
242 " restore %%g0, %2, %%o0\n\n\t" \
243 ".previous\n\t" \
244 ".section __ex_table,#alloc\n\t" \
245 ".align 4\n\t" \
246 ".word 1b, 3b\n\n\t" \
247 ".previous\n\t" \
248 : "=r" (x) : "r" (__m(addr)), "i" (retval))
249
250 extern int __get_user_bad(void);
251
252 extern unsigned long ___copy_from_user(void *to, const void *from,
253 unsigned long size);
254 extern unsigned long copy_from_user_fixup(void *to, const void *from,
255 unsigned long size);
copy_from_user(void * to,const void * from,unsigned long size)256 static inline unsigned long copy_from_user(void *to, const void *from,
257 unsigned long size)
258 {
259 unsigned long ret = ___copy_from_user(to, from, size);
260
261 if (ret)
262 ret = copy_from_user_fixup(to, from, size);
263 return ret;
264 }
265 #define __copy_from_user copy_from_user
266
267 extern unsigned long ___copy_to_user(void *to, const void *from,
268 unsigned long size);
269 extern unsigned long copy_to_user_fixup(void *to, const void *from,
270 unsigned long size);
copy_to_user(void * to,const void * from,unsigned long size)271 static inline unsigned long copy_to_user(void *to, const void *from,
272 unsigned long size)
273 {
274 unsigned long ret = ___copy_to_user(to, from, size);
275
276 if (ret)
277 ret = copy_to_user_fixup(to, from, size);
278 return ret;
279 }
280 #define __copy_to_user copy_to_user
281
282 extern unsigned long ___copy_in_user(void *to, const void *from,
283 unsigned long size);
284 extern unsigned long copy_in_user_fixup(void *to, void *from,
285 unsigned long size);
copy_in_user(void * to,void * from,unsigned long size)286 static inline unsigned long copy_in_user(void *to, void *from,
287 unsigned long size)
288 {
289 unsigned long ret = ___copy_in_user(to, from, size);
290
291 if (ret)
292 ret = copy_in_user_fixup(to, from, size);
293 return ret;
294 }
295 #define __copy_in_user copy_in_user
296
297 extern __kernel_size_t __bzero_noasi(void *addr, __kernel_size_t size);
298
__clear_user(void * addr,__kernel_size_t size)299 extern __inline__ __kernel_size_t __clear_user(void *addr, __kernel_size_t size)
300 {
301 return __bzero_noasi(addr, size);
302 }
303
304 #define clear_user(addr,n) \
305 __clear_user((void *)(addr), (__kernel_size_t)(n))
306
307 extern int __strncpy_from_user(unsigned long dest, unsigned long src, int count);
308
309 #define strncpy_from_user(dest,src,count) \
310 __strncpy_from_user((unsigned long)(dest), (unsigned long)(src), (int)(count))
311
312 extern int __strlen_user(const char *);
313 extern int __strnlen_user(const char *, long len);
314
315 #define strlen_user __strlen_user
316 #define strnlen_user __strnlen_user
317
318 #endif /* __ASSEMBLY__ */
319
320 #endif /* _ASM_UACCESS_H */
321