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1 | #ifndef _PPC64_UACCESS_H |
2 | #define _PPC64_UACCESS_H | |
3 | ||
4 | /* | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License | |
7 | * as published by the Free Software Foundation; either version | |
8 | * 2 of the License, or (at your option) any later version. | |
9 | */ | |
10 | ||
11 | #ifndef __ASSEMBLY__ | |
12 | #include <linux/sched.h> | |
13 | #include <linux/errno.h> | |
14 | #include <asm/processor.h> | |
15 | ||
16 | #define VERIFY_READ 0 | |
17 | #define VERIFY_WRITE 1 | |
18 | ||
19 | /* | |
20 | * The fs value determines whether argument validity checking should be | |
21 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
22 | * get_fs() == KERNEL_DS, checking is bypassed. | |
23 | * | |
24 | * For historical reasons, these macros are grossly misnamed. | |
25 | */ | |
26 | ||
27 | #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) | |
28 | ||
29 | #define KERNEL_DS MAKE_MM_SEG(0UL) | |
30 | #define USER_DS MAKE_MM_SEG(0xf000000000000000UL) | |
31 | ||
32 | #define get_ds() (KERNEL_DS) | |
33 | #define get_fs() (current->thread.fs) | |
34 | #define set_fs(val) (current->thread.fs = (val)) | |
35 | ||
36 | #define segment_eq(a,b) ((a).seg == (b).seg) | |
37 | ||
38 | /* | |
39 | * Use the alpha trick for checking ranges: | |
40 | * | |
41 | * Is a address valid? This does a straightforward calculation rather | |
42 | * than tests. | |
43 | * | |
44 | * Address valid if: | |
45 | * - "addr" doesn't have any high-bits set | |
46 | * - AND "size" doesn't have any high-bits set | |
47 | * - OR we are in kernel mode. | |
48 | * | |
49 | * We dont have to check for high bits in (addr+size) because the first | |
50 | * two checks force the maximum result to be below the start of the | |
51 | * kernel region. | |
52 | */ | |
53 | #define __access_ok(addr,size,segment) \ | |
54 | (((segment).seg & (addr | size )) == 0) | |
55 | ||
56 | #define access_ok(type,addr,size) \ | |
57 | __access_ok(((__force unsigned long)(addr)),(size),get_fs()) | |
58 | ||
59 | /* this function will go away soon - use access_ok() instead */ | |
60 | static inline int __deprecated verify_area(int type, const void __user *addr, unsigned long size) | |
61 | { | |
62 | return access_ok(type,addr,size) ? 0 : -EFAULT; | |
63 | } | |
64 | ||
65 | ||
66 | /* | |
67 | * The exception table consists of pairs of addresses: the first is the | |
68 | * address of an instruction that is allowed to fault, and the second is | |
69 | * the address at which the program should continue. No registers are | |
70 | * modified, so it is entirely up to the continuation code to figure out | |
71 | * what to do. | |
72 | * | |
73 | * All the routines below use bits of fixup code that are out of line | |
74 | * with the main instruction path. This means when everything is well, | |
75 | * we don't even have to jump over them. Further, they do not intrude | |
76 | * on our cache or tlb entries. | |
77 | */ | |
78 | ||
79 | struct exception_table_entry | |
80 | { | |
81 | unsigned long insn, fixup; | |
82 | }; | |
83 | ||
84 | /* Returns 0 if exception not found and fixup otherwise. */ | |
85 | extern unsigned long search_exception_table(unsigned long); | |
86 | ||
87 | /* | |
88 | * These are the main single-value transfer routines. They automatically | |
89 | * use the right size if we just have the right pointer type. | |
90 | * | |
91 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
92 | * and yet we don't want to do any pointers, because that is too much | |
93 | * of a performance impact. Thus we have a few rather ugly macros here, | |
94 | * and hide all the ugliness from the user. | |
95 | * | |
96 | * The "__xxx" versions of the user access functions are versions that | |
97 | * do not verify the address space, that must have been done previously | |
98 | * with a separate "access_ok()" call (this is used when we do multiple | |
99 | * accesses to the same area of user memory). | |
100 | * | |
101 | * As we use the same address space for kernel and user data on the | |
102 | * PowerPC, we can just do these as direct assignments. (Of course, the | |
103 | * exception handling means that it's no longer "just"...) | |
104 | */ | |
105 | #define get_user(x,ptr) \ | |
106 | __get_user_check((x),(ptr),sizeof(*(ptr))) | |
107 | #define put_user(x,ptr) \ | |
108 | __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) | |
109 | ||
110 | #define __get_user(x,ptr) \ | |
111 | __get_user_nocheck((x),(ptr),sizeof(*(ptr))) | |
112 | #define __put_user(x,ptr) \ | |
113 | __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) | |
114 | ||
115 | #define __get_user_unaligned __get_user | |
116 | #define __put_user_unaligned __put_user | |
117 | ||
118 | extern long __put_user_bad(void); | |
119 | ||
120 | #define __put_user_nocheck(x,ptr,size) \ | |
121 | ({ \ | |
122 | long __pu_err; \ | |
123 | might_sleep(); \ | |
124 | __chk_user_ptr(ptr); \ | |
125 | __put_user_size((x),(ptr),(size),__pu_err,-EFAULT); \ | |
126 | __pu_err; \ | |
127 | }) | |
128 | ||
129 | #define __put_user_check(x,ptr,size) \ | |
130 | ({ \ | |
131 | long __pu_err = -EFAULT; \ | |
132 | void __user *__pu_addr = (ptr); \ | |
133 | might_sleep(); \ | |
134 | if (access_ok(VERIFY_WRITE,__pu_addr,size)) \ | |
135 | __put_user_size((x),__pu_addr,(size),__pu_err,-EFAULT); \ | |
136 | __pu_err; \ | |
137 | }) | |
138 | ||
139 | #define __put_user_size(x,ptr,size,retval,errret) \ | |
140 | do { \ | |
141 | retval = 0; \ | |
142 | switch (size) { \ | |
143 | case 1: __put_user_asm(x,ptr,retval,"stb",errret); break; \ | |
144 | case 2: __put_user_asm(x,ptr,retval,"sth",errret); break; \ | |
145 | case 4: __put_user_asm(x,ptr,retval,"stw",errret); break; \ | |
146 | case 8: __put_user_asm(x,ptr,retval,"std",errret); break; \ | |
147 | default: __put_user_bad(); \ | |
148 | } \ | |
149 | } while (0) | |
150 | ||
151 | /* | |
152 | * We don't tell gcc that we are accessing memory, but this is OK | |
153 | * because we do not write to any memory gcc knows about, so there | |
154 | * are no aliasing issues. | |
155 | */ | |
156 | #define __put_user_asm(x, addr, err, op, errret) \ | |
157 | __asm__ __volatile__( \ | |
158 | "1: "op" %1,0(%2) # put_user\n" \ | |
159 | "2:\n" \ | |
160 | ".section .fixup,\"ax\"\n" \ | |
161 | "3: li %0,%3\n" \ | |
162 | " b 2b\n" \ | |
163 | ".previous\n" \ | |
164 | ".section __ex_table,\"a\"\n" \ | |
165 | " .align 3\n" \ | |
166 | " .llong 1b,3b\n" \ | |
167 | ".previous" \ | |
168 | : "=r"(err) \ | |
169 | : "r"(x), "b"(addr), "i"(errret), "0"(err)) | |
170 | ||
171 | ||
172 | #define __get_user_nocheck(x,ptr,size) \ | |
173 | ({ \ | |
174 | long __gu_err, __gu_val; \ | |
175 | might_sleep(); \ | |
176 | __get_user_size(__gu_val,(ptr),(size),__gu_err,-EFAULT);\ | |
177 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
178 | __gu_err; \ | |
179 | }) | |
180 | ||
181 | #define __get_user_check(x,ptr,size) \ | |
182 | ({ \ | |
183 | long __gu_err = -EFAULT, __gu_val = 0; \ | |
184 | const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ | |
185 | might_sleep(); \ | |
186 | if (access_ok(VERIFY_READ,__gu_addr,size)) \ | |
187 | __get_user_size(__gu_val,__gu_addr,(size),__gu_err,-EFAULT);\ | |
188 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
189 | __gu_err; \ | |
190 | }) | |
191 | ||
192 | extern long __get_user_bad(void); | |
193 | ||
194 | #define __get_user_size(x,ptr,size,retval,errret) \ | |
195 | do { \ | |
196 | retval = 0; \ | |
197 | __chk_user_ptr(ptr); \ | |
198 | switch (size) { \ | |
199 | case 1: __get_user_asm(x,ptr,retval,"lbz",errret); break; \ | |
200 | case 2: __get_user_asm(x,ptr,retval,"lhz",errret); break; \ | |
201 | case 4: __get_user_asm(x,ptr,retval,"lwz",errret); break; \ | |
202 | case 8: __get_user_asm(x,ptr,retval,"ld",errret); break; \ | |
203 | default: (x) = __get_user_bad(); \ | |
204 | } \ | |
205 | } while (0) | |
206 | ||
207 | #define __get_user_asm(x, addr, err, op, errret) \ | |
208 | __asm__ __volatile__( \ | |
209 | "1: "op" %1,0(%2) # get_user\n" \ | |
210 | "2:\n" \ | |
211 | ".section .fixup,\"ax\"\n" \ | |
212 | "3: li %0,%3\n" \ | |
213 | " li %1,0\n" \ | |
214 | " b 2b\n" \ | |
215 | ".previous\n" \ | |
216 | ".section __ex_table,\"a\"\n" \ | |
217 | " .align 3\n" \ | |
218 | " .llong 1b,3b\n" \ | |
219 | ".previous" \ | |
220 | : "=r"(err), "=r"(x) \ | |
221 | : "b"(addr), "i"(errret), "0"(err)) | |
222 | ||
223 | /* more complex routines */ | |
224 | ||
225 | extern unsigned long __copy_tofrom_user(void __user *to, const void __user *from, | |
226 | unsigned long size); | |
227 | ||
228 | static inline unsigned long | |
229 | __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) | |
230 | { | |
231 | if (__builtin_constant_p(n)) { | |
232 | unsigned long ret; | |
233 | ||
234 | switch (n) { | |
235 | case 1: | |
236 | __get_user_size(*(u8 *)to, from, 1, ret, 1); | |
237 | return ret; | |
238 | case 2: | |
239 | __get_user_size(*(u16 *)to, from, 2, ret, 2); | |
240 | return ret; | |
241 | case 4: | |
242 | __get_user_size(*(u32 *)to, from, 4, ret, 4); | |
243 | return ret; | |
244 | case 8: | |
245 | __get_user_size(*(u64 *)to, from, 8, ret, 8); | |
246 | return ret; | |
247 | } | |
248 | } | |
249 | return __copy_tofrom_user((__force void __user *) to, from, n); | |
250 | } | |
251 | ||
252 | static inline unsigned long | |
253 | __copy_from_user(void *to, const void __user *from, unsigned long n) | |
254 | { | |
255 | might_sleep(); | |
256 | return __copy_from_user_inatomic(to, from, n); | |
257 | } | |
258 | ||
259 | static inline unsigned long | |
260 | __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) | |
261 | { | |
262 | if (__builtin_constant_p(n)) { | |
263 | unsigned long ret; | |
264 | ||
265 | switch (n) { | |
266 | case 1: | |
267 | __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1); | |
268 | return ret; | |
269 | case 2: | |
270 | __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2); | |
271 | return ret; | |
272 | case 4: | |
273 | __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4); | |
274 | return ret; | |
275 | case 8: | |
276 | __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret, 8); | |
277 | return ret; | |
278 | } | |
279 | } | |
280 | return __copy_tofrom_user(to, (__force const void __user *) from, n); | |
281 | } | |
282 | ||
283 | static inline unsigned long | |
284 | __copy_to_user(void __user *to, const void *from, unsigned long n) | |
285 | { | |
286 | might_sleep(); | |
287 | return __copy_to_user_inatomic(to, from, n); | |
288 | } | |
289 | ||
290 | #define __copy_in_user(to, from, size) \ | |
291 | __copy_tofrom_user((to), (from), (size)) | |
292 | ||
293 | extern unsigned long copy_from_user(void *to, const void __user *from, | |
294 | unsigned long n); | |
295 | extern unsigned long copy_to_user(void __user *to, const void *from, | |
296 | unsigned long n); | |
297 | extern unsigned long copy_in_user(void __user *to, const void __user *from, | |
298 | unsigned long n); | |
299 | ||
300 | extern unsigned long __clear_user(void __user *addr, unsigned long size); | |
301 | ||
302 | static inline unsigned long | |
303 | clear_user(void __user *addr, unsigned long size) | |
304 | { | |
305 | might_sleep(); | |
306 | if (likely(access_ok(VERIFY_WRITE, addr, size))) | |
307 | size = __clear_user(addr, size); | |
308 | return size; | |
309 | } | |
310 | ||
311 | extern int __strncpy_from_user(char *dst, const char __user *src, long count); | |
312 | ||
313 | static inline long | |
314 | strncpy_from_user(char *dst, const char __user *src, long count) | |
315 | { | |
316 | might_sleep(); | |
317 | if (likely(access_ok(VERIFY_READ, src, 1))) | |
318 | return __strncpy_from_user(dst, src, count); | |
319 | return -EFAULT; | |
320 | } | |
321 | ||
322 | /* | |
323 | * Return the size of a string (including the ending 0) | |
324 | * | |
325 | * Return 0 for error | |
326 | */ | |
327 | extern int __strnlen_user(const char __user *str, long len); | |
328 | ||
329 | /* | |
330 | * Returns the length of the string at str (including the null byte), | |
331 | * or 0 if we hit a page we can't access, | |
332 | * or something > len if we didn't find a null byte. | |
333 | */ | |
334 | static inline int strnlen_user(const char __user *str, long len) | |
335 | { | |
336 | might_sleep(); | |
337 | if (likely(access_ok(VERIFY_READ, str, 1))) | |
338 | return __strnlen_user(str, len); | |
339 | return 0; | |
340 | } | |
341 | ||
342 | #define strlen_user(str) strnlen_user((str), 0x7ffffffe) | |
343 | ||
344 | #endif /* __ASSEMBLY__ */ | |
345 | ||
346 | #endif /* _PPC64_UACCESS_H */ |