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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* $Id: uaccess.h,v 1.35 2002/02/09 19:49:31 davem 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/compiler.h>
11#include <linux/sched.h>
12#include <linux/string.h>
13#include <asm/a.out.h>
14#include <asm/asi.h>
15#include <asm/system.h>
16#include <asm/spitfire.h>
17#include <asm-generic/uaccess.h>
18#endif
19
20#ifndef __ASSEMBLY__
21
22/*
23 * Sparc64 is segmented, though more like the M68K than the I386.
24 * We use the secondary ASI to address user memory, which references a
25 * completely different VM map, thus there is zero chance of the user
26 * doing something queer and tricking us into poking kernel memory.
27 *
28 * What is left here is basically what is needed for the other parts of
29 * the kernel that expect to be able to manipulate, erum, "segments".
30 * Or perhaps more properly, permissions.
31 *
32 * "For historical reasons, these macros are grossly misnamed." -Linus
33 */
34
35#define KERNEL_DS ((mm_segment_t) { ASI_P })
36#define USER_DS ((mm_segment_t) { ASI_AIUS }) /* har har har */
37
38#define VERIFY_READ 0
39#define VERIFY_WRITE 1
40
41#define get_fs() ((mm_segment_t) { get_thread_current_ds() })
42#define get_ds() (KERNEL_DS)
43
44#define segment_eq(a,b) ((a).seg == (b).seg)
45
46#define set_fs(val) \
47do { \
48 set_thread_current_ds((val).seg); \
49 __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg)); \
50} while(0)
51
52static inline int __access_ok(const void __user * addr, unsigned long size)
53{
54 return 1;
55}
56
57static inline int access_ok(int type, const void __user * addr, unsigned long size)
58{
59 return 1;
60}
61
Linus Torvalds1da177e2005-04-16 15:20:36 -070062/*
63 * The exception table consists of pairs of addresses: the first is the
64 * address of an instruction that is allowed to fault, and the second is
65 * the address at which the program should continue. No registers are
66 * modified, so it is entirely up to the continuation code to figure out
67 * what to do.
68 *
69 * All the routines below use bits of fixup code that are out of line
70 * with the main instruction path. This means when everything is well,
71 * we don't even have to jump over them. Further, they do not intrude
72 * on our cache or tlb entries.
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 */
74
David S. Miller8cf14af2005-09-28 20:21:11 -070075struct exception_table_entry {
76 unsigned int insn, fixup;
Linus Torvalds1da177e2005-04-16 15:20:36 -070077};
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079extern void __ret_efault(void);
David S. Miller5fd29752005-09-28 20:41:45 -070080extern void __retl_efault(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82/* Uh, these should become the main single-value transfer routines..
83 * They automatically use the right size if we just have the right
84 * pointer type..
85 *
86 * This gets kind of ugly. We want to return _two_ values in "get_user()"
87 * and yet we don't want to do any pointers, because that is too much
88 * of a performance impact. Thus we have a few rather ugly macros here,
89 * and hide all the ugliness from the user.
90 */
91#define put_user(x,ptr) ({ \
92unsigned long __pu_addr = (unsigned long)(ptr); \
93__chk_user_ptr(ptr); \
94__put_user_nocheck((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
95
96#define get_user(x,ptr) ({ \
97unsigned long __gu_addr = (unsigned long)(ptr); \
98__chk_user_ptr(ptr); \
99__get_user_nocheck((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
100
101#define __put_user(x,ptr) put_user(x,ptr)
102#define __get_user(x,ptr) get_user(x,ptr)
103
104struct __large_struct { unsigned long buf[100]; };
105#define __m(x) ((struct __large_struct *)(x))
106
107#define __put_user_nocheck(data,addr,size) ({ \
108register int __pu_ret; \
109switch (size) { \
110case 1: __put_user_asm(data,b,addr,__pu_ret); break; \
111case 2: __put_user_asm(data,h,addr,__pu_ret); break; \
112case 4: __put_user_asm(data,w,addr,__pu_ret); break; \
113case 8: __put_user_asm(data,x,addr,__pu_ret); break; \
114default: __pu_ret = __put_user_bad(); break; \
115} __pu_ret; })
116
117#define __put_user_nocheck_ret(data,addr,size,retval) ({ \
118register int __foo __asm__ ("l1"); \
119switch (size) { \
120case 1: __put_user_asm_ret(data,b,addr,retval,__foo); break; \
121case 2: __put_user_asm_ret(data,h,addr,retval,__foo); break; \
122case 4: __put_user_asm_ret(data,w,addr,retval,__foo); break; \
123case 8: __put_user_asm_ret(data,x,addr,retval,__foo); break; \
124default: if (__put_user_bad()) return retval; break; \
125} })
126
127#define __put_user_asm(x,size,addr,ret) \
128__asm__ __volatile__( \
129 "/* Put user asm, inline. */\n" \
130"1:\t" "st"#size "a %1, [%2] %%asi\n\t" \
131 "clr %0\n" \
132"2:\n\n\t" \
133 ".section .fixup,#alloc,#execinstr\n\t" \
134 ".align 4\n" \
135"3:\n\t" \
136 "b 2b\n\t" \
137 " mov %3, %0\n\n\t" \
138 ".previous\n\t" \
139 ".section __ex_table,#alloc\n\t" \
140 ".align 4\n\t" \
141 ".word 1b, 3b\n\t" \
142 ".previous\n\n\t" \
143 : "=r" (ret) : "r" (x), "r" (__m(addr)), \
144 "i" (-EFAULT))
145
146#define __put_user_asm_ret(x,size,addr,ret,foo) \
147if (__builtin_constant_p(ret) && ret == -EFAULT) \
148__asm__ __volatile__( \
149 "/* Put user asm ret, inline. */\n" \
150"1:\t" "st"#size "a %1, [%2] %%asi\n\n\t" \
151 ".section __ex_table,#alloc\n\t" \
152 ".align 4\n\t" \
153 ".word 1b, __ret_efault\n\n\t" \
154 ".previous\n\n\t" \
155 : "=r" (foo) : "r" (x), "r" (__m(addr))); \
156else \
157__asm__ __volatile__( \
158 "/* Put user asm ret, inline. */\n" \
159"1:\t" "st"#size "a %1, [%2] %%asi\n\n\t" \
160 ".section .fixup,#alloc,#execinstr\n\t" \
161 ".align 4\n" \
162"3:\n\t" \
163 "ret\n\t" \
164 " restore %%g0, %3, %%o0\n\n\t" \
165 ".previous\n\t" \
166 ".section __ex_table,#alloc\n\t" \
167 ".align 4\n\t" \
168 ".word 1b, 3b\n\n\t" \
169 ".previous\n\n\t" \
170 : "=r" (foo) : "r" (x), "r" (__m(addr)), \
171 "i" (ret))
172
173extern int __put_user_bad(void);
174
175#define __get_user_nocheck(data,addr,size,type) ({ \
176register int __gu_ret; \
177register unsigned long __gu_val; \
178switch (size) { \
179case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
180case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
181case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
182case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
183default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
184} data = (type) __gu_val; __gu_ret; })
185
186#define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
187register unsigned long __gu_val __asm__ ("l1"); \
188switch (size) { \
189case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
190case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
191case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
192case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
193default: if (__get_user_bad()) return retval; \
194} data = (type) __gu_val; })
195
196#define __get_user_asm(x,size,addr,ret) \
197__asm__ __volatile__( \
198 "/* Get user asm, inline. */\n" \
199"1:\t" "ld"#size "a [%2] %%asi, %1\n\t" \
200 "clr %0\n" \
201"2:\n\n\t" \
202 ".section .fixup,#alloc,#execinstr\n\t" \
203 ".align 4\n" \
204"3:\n\t" \
205 "clr %1\n\t" \
206 "b 2b\n\t" \
207 " mov %3, %0\n\n\t" \
208 ".previous\n\t" \
209 ".section __ex_table,#alloc\n\t" \
210 ".align 4\n\t" \
211 ".word 1b, 3b\n\n\t" \
212 ".previous\n\t" \
213 : "=r" (ret), "=r" (x) : "r" (__m(addr)), \
214 "i" (-EFAULT))
215
216#define __get_user_asm_ret(x,size,addr,retval) \
217if (__builtin_constant_p(retval) && retval == -EFAULT) \
218__asm__ __volatile__( \
219 "/* Get user asm ret, inline. */\n" \
220"1:\t" "ld"#size "a [%1] %%asi, %0\n\n\t" \
221 ".section __ex_table,#alloc\n\t" \
222 ".align 4\n\t" \
223 ".word 1b,__ret_efault\n\n\t" \
224 ".previous\n\t" \
225 : "=r" (x) : "r" (__m(addr))); \
226else \
227__asm__ __volatile__( \
228 "/* Get user asm ret, inline. */\n" \
229"1:\t" "ld"#size "a [%1] %%asi, %0\n\n\t" \
230 ".section .fixup,#alloc,#execinstr\n\t" \
231 ".align 4\n" \
232"3:\n\t" \
233 "ret\n\t" \
234 " restore %%g0, %2, %%o0\n\n\t" \
235 ".previous\n\t" \
236 ".section __ex_table,#alloc\n\t" \
237 ".align 4\n\t" \
238 ".word 1b, 3b\n\n\t" \
239 ".previous\n\t" \
240 : "=r" (x) : "r" (__m(addr)), "i" (retval))
241
242extern int __get_user_bad(void);
243
244extern unsigned long __must_check ___copy_from_user(void *to,
245 const void __user *from,
246 unsigned long size);
247extern unsigned long copy_from_user_fixup(void *to, const void __user *from,
248 unsigned long size);
249static inline unsigned long __must_check
250copy_from_user(void *to, const void __user *from, unsigned long size)
251{
252 unsigned long ret = ___copy_from_user(to, from, size);
253
David S. Millerefdc1e22005-09-28 21:06:47 -0700254 if (unlikely(ret))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 ret = copy_from_user_fixup(to, from, size);
256 return ret;
257}
258#define __copy_from_user copy_from_user
259
260extern unsigned long __must_check ___copy_to_user(void __user *to,
261 const void *from,
262 unsigned long size);
263extern unsigned long copy_to_user_fixup(void __user *to, const void *from,
264 unsigned long size);
265static inline unsigned long __must_check
266copy_to_user(void __user *to, const void *from, unsigned long size)
267{
268 unsigned long ret = ___copy_to_user(to, from, size);
269
David S. Millerefdc1e22005-09-28 21:06:47 -0700270 if (unlikely(ret))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 ret = copy_to_user_fixup(to, from, size);
272 return ret;
273}
274#define __copy_to_user copy_to_user
275
276extern unsigned long __must_check ___copy_in_user(void __user *to,
277 const void __user *from,
278 unsigned long size);
279extern unsigned long copy_in_user_fixup(void __user *to, void __user *from,
280 unsigned long size);
281static inline unsigned long __must_check
282copy_in_user(void __user *to, void __user *from, unsigned long size)
283{
284 unsigned long ret = ___copy_in_user(to, from, size);
285
David S. Millerefdc1e22005-09-28 21:06:47 -0700286 if (unlikely(ret))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 ret = copy_in_user_fixup(to, from, size);
288 return ret;
289}
290#define __copy_in_user copy_in_user
291
292extern unsigned long __must_check __bzero_noasi(void __user *, unsigned long);
293
294static inline unsigned long __must_check
295__clear_user(void __user *addr, unsigned long size)
296{
297
298 return __bzero_noasi(addr, size);
299}
300
301#define clear_user __clear_user
302
303extern long __must_check __strncpy_from_user(char *dest, const char __user *src, long count);
304
305#define strncpy_from_user __strncpy_from_user
306
307extern long __strlen_user(const char __user *);
308extern long __strnlen_user(const char __user *, long len);
309
310#define strlen_user __strlen_user
311#define strnlen_user __strnlen_user
312#define __copy_to_user_inatomic __copy_to_user
313#define __copy_from_user_inatomic __copy_from_user
314
315#endif /* __ASSEMBLY__ */
316
317#endif /* _ASM_UACCESS_H */