x86: be careful about tailcall breakage for sys_open[at] too
[pandora-kernel.git] / include / asm-sparc64 / uaccess.h
1 /* $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)                                                             \
47 do {                                                                            \
48         set_thread_current_ds((val).seg);                                       \
49         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
50 } while(0)
51
52 static inline int __access_ok(const void __user * addr, unsigned long size)
53 {
54         return 1;
55 }
56
57 static inline int access_ok(int type, const void __user * addr, unsigned long size)
58 {
59         return 1;
60 }
61
62 /*
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.
73  */
74
75 struct exception_table_entry {
76         unsigned int insn, fixup;
77 };
78
79 extern void __ret_efault(void);
80 extern void __retl_efault(void);
81
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) ({ \
92 unsigned 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) ({ \
97 unsigned 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
104 struct __large_struct { unsigned long buf[100]; };
105 #define __m(x) ((struct __large_struct *)(x))
106
107 #define __put_user_nocheck(data,addr,size) ({ \
108 register int __pu_ret; \
109 switch (size) { \
110 case 1: __put_user_asm(data,b,addr,__pu_ret); break; \
111 case 2: __put_user_asm(data,h,addr,__pu_ret); break; \
112 case 4: __put_user_asm(data,w,addr,__pu_ret); break; \
113 case 8: __put_user_asm(data,x,addr,__pu_ret); break; \
114 default: __pu_ret = __put_user_bad(); break; \
115 } __pu_ret; })
116
117 #define __put_user_asm(x,size,addr,ret)                                 \
118 __asm__ __volatile__(                                                   \
119         "/* Put user asm, inline. */\n"                                 \
120 "1:\t"  "st"#size "a %1, [%2] %%asi\n\t"                                \
121         "clr    %0\n"                                                   \
122 "2:\n\n\t"                                                              \
123         ".section .fixup,#alloc,#execinstr\n\t"                         \
124         ".align 4\n"                                                    \
125 "3:\n\t"                                                                \
126         "b      2b\n\t"                                                 \
127         " mov   %3, %0\n\n\t"                                           \
128         ".previous\n\t"                                                 \
129         ".section __ex_table,\"a\"\n\t"                                 \
130         ".align 4\n\t"                                                  \
131         ".word  1b, 3b\n\t"                                             \
132         ".previous\n\n\t"                                               \
133        : "=r" (ret) : "r" (x), "r" (__m(addr)),                         \
134          "i" (-EFAULT))
135
136 extern int __put_user_bad(void);
137
138 #define __get_user_nocheck(data,addr,size,type) ({ \
139 register int __gu_ret; \
140 register unsigned long __gu_val; \
141 switch (size) { \
142 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
143 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
144 case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
145 case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
146 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
147 } data = (type) __gu_val; __gu_ret; })
148
149 #define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
150 register unsigned long __gu_val __asm__ ("l1"); \
151 switch (size) { \
152 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
153 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
154 case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
155 case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
156 default: if (__get_user_bad()) return retval; \
157 } data = (type) __gu_val; })
158
159 #define __get_user_asm(x,size,addr,ret)                                 \
160 __asm__ __volatile__(                                                   \
161         "/* Get user asm, inline. */\n"                                 \
162 "1:\t"  "ld"#size "a [%2] %%asi, %1\n\t"                                \
163         "clr    %0\n"                                                   \
164 "2:\n\n\t"                                                              \
165         ".section .fixup,#alloc,#execinstr\n\t"                         \
166         ".align 4\n"                                                    \
167 "3:\n\t"                                                                \
168         "clr    %1\n\t"                                                 \
169         "b      2b\n\t"                                                 \
170         " mov   %3, %0\n\n\t"                                           \
171         ".previous\n\t"                                                 \
172         ".section __ex_table,\"a\"\n\t"                                 \
173         ".align 4\n\t"                                                  \
174         ".word  1b, 3b\n\n\t"                                           \
175         ".previous\n\t"                                                 \
176        : "=r" (ret), "=r" (x) : "r" (__m(addr)),                        \
177          "i" (-EFAULT))
178
179 #define __get_user_asm_ret(x,size,addr,retval)                          \
180 if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
181 __asm__ __volatile__(                                                   \
182         "/* Get user asm ret, inline. */\n"                             \
183 "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
184         ".section __ex_table,\"a\"\n\t"                                 \
185         ".align 4\n\t"                                                  \
186         ".word  1b,__ret_efault\n\n\t"                                  \
187         ".previous\n\t"                                                 \
188        : "=r" (x) : "r" (__m(addr)));                                   \
189 else                                                                    \
190 __asm__ __volatile__(                                                   \
191         "/* Get user asm ret, inline. */\n"                             \
192 "1:\t"  "ld"#size "a [%1] %%asi, %0\n\n\t"                              \
193         ".section .fixup,#alloc,#execinstr\n\t"                         \
194         ".align 4\n"                                                    \
195 "3:\n\t"                                                                \
196         "ret\n\t"                                                       \
197         " restore %%g0, %2, %%o0\n\n\t"                                 \
198         ".previous\n\t"                                                 \
199         ".section __ex_table,\"a\"\n\t"                                 \
200         ".align 4\n\t"                                                  \
201         ".word  1b, 3b\n\n\t"                                           \
202         ".previous\n\t"                                                 \
203        : "=r" (x) : "r" (__m(addr)), "i" (retval))
204
205 extern int __get_user_bad(void);
206
207 extern unsigned long __must_check ___copy_from_user(void *to,
208                                                     const void __user *from,
209                                                     unsigned long size);
210 extern unsigned long copy_from_user_fixup(void *to, const void __user *from,
211                                           unsigned long size);
212 static inline unsigned long __must_check
213 copy_from_user(void *to, const void __user *from, unsigned long size)
214 {
215         unsigned long ret = ___copy_from_user(to, from, size);
216
217         if (unlikely(ret))
218                 ret = copy_from_user_fixup(to, from, size);
219         return ret;
220 }
221 #define __copy_from_user copy_from_user
222
223 extern unsigned long __must_check ___copy_to_user(void __user *to,
224                                                   const void *from,
225                                                   unsigned long size);
226 extern unsigned long copy_to_user_fixup(void __user *to, const void *from,
227                                         unsigned long size);
228 static inline unsigned long __must_check
229 copy_to_user(void __user *to, const void *from, unsigned long size)
230 {
231         unsigned long ret = ___copy_to_user(to, from, size);
232
233         if (unlikely(ret))
234                 ret = copy_to_user_fixup(to, from, size);
235         return ret;
236 }
237 #define __copy_to_user copy_to_user
238
239 extern unsigned long __must_check ___copy_in_user(void __user *to,
240                                                   const void __user *from,
241                                                   unsigned long size);
242 extern unsigned long copy_in_user_fixup(void __user *to, void __user *from,
243                                         unsigned long size);
244 static inline unsigned long __must_check
245 copy_in_user(void __user *to, void __user *from, unsigned long size)
246 {
247         unsigned long ret = ___copy_in_user(to, from, size);
248
249         if (unlikely(ret))
250                 ret = copy_in_user_fixup(to, from, size);
251         return ret;
252 }
253 #define __copy_in_user copy_in_user
254
255 extern unsigned long __must_check __clear_user(void __user *, unsigned long);
256
257 #define clear_user __clear_user
258
259 extern long __must_check __strncpy_from_user(char *dest, const char __user *src, long count);
260
261 #define strncpy_from_user __strncpy_from_user
262
263 extern long __strlen_user(const char __user *);
264 extern long __strnlen_user(const char __user *, long len);
265
266 #define strlen_user __strlen_user
267 #define strnlen_user __strnlen_user
268 #define __copy_to_user_inatomic __copy_to_user
269 #define __copy_from_user_inatomic __copy_from_user
270
271 #endif  /* __ASSEMBLY__ */
272
273 #endif /* _ASM_UACCESS_H */