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1 | /* |
2 | * OpenRISC Linux | |
3 | * | |
4 | * Linux architectural port borrowing liberally from similar works of | |
5 | * others. All original copyrights apply as per the original source | |
6 | * declaration. | |
7 | * | |
8 | * OpenRISC implementation: | |
9 | * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> | |
10 | * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> | |
11 | * et al. | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or | |
16 | * (at your option) any later version. | |
17 | */ | |
18 | ||
19 | #ifndef __ASM_OPENRISC_UACCESS_H | |
20 | #define __ASM_OPENRISC_UACCESS_H | |
21 | ||
22 | /* | |
23 | * User space memory access functions | |
24 | */ | |
25 | #include <linux/errno.h> | |
26 | #include <linux/thread_info.h> | |
27 | #include <linux/prefetch.h> | |
28 | #include <linux/string.h> | |
61e85e36 JB |
29 | #include <asm/page.h> |
30 | ||
31 | #define VERIFY_READ 0 | |
32 | #define VERIFY_WRITE 1 | |
33 | ||
34 | /* | |
35 | * The fs value determines whether argument validity checking should be | |
36 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
37 | * get_fs() == KERNEL_DS, checking is bypassed. | |
38 | * | |
39 | * For historical reasons, these macros are grossly misnamed. | |
40 | */ | |
41 | ||
42 | /* addr_limit is the maximum accessible address for the task. we misuse | |
43 | * the KERNEL_DS and USER_DS values to both assign and compare the | |
44 | * addr_limit values through the equally misnamed get/set_fs macros. | |
45 | * (see above) | |
46 | */ | |
47 | ||
48 | #define KERNEL_DS (~0UL) | |
49 | #define get_ds() (KERNEL_DS) | |
50 | ||
51 | #define USER_DS (TASK_SIZE) | |
52 | #define get_fs() (current_thread_info()->addr_limit) | |
53 | #define set_fs(x) (current_thread_info()->addr_limit = (x)) | |
54 | ||
55 | #define segment_eq(a, b) ((a) == (b)) | |
56 | ||
57 | /* Ensure that the range from addr to addr+size is all within the process' | |
58 | * address space | |
59 | */ | |
60 | #define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size)) | |
61 | ||
62 | /* Ensure that addr is below task's addr_limit */ | |
63 | #define __addr_ok(addr) ((unsigned long) addr < get_fs()) | |
64 | ||
65 | #define access_ok(type, addr, size) \ | |
66 | __range_ok((unsigned long)addr, (unsigned long)size) | |
67 | ||
68 | /* | |
69 | * The exception table consists of pairs of addresses: the first is the | |
70 | * address of an instruction that is allowed to fault, and the second is | |
71 | * the address at which the program should continue. No registers are | |
72 | * modified, so it is entirely up to the continuation code to figure out | |
73 | * what to do. | |
74 | * | |
75 | * All the routines below use bits of fixup code that are out of line | |
76 | * with the main instruction path. This means when everything is well, | |
77 | * we don't even have to jump over them. Further, they do not intrude | |
78 | * on our cache or tlb entries. | |
79 | */ | |
80 | ||
81 | struct exception_table_entry { | |
82 | unsigned long insn, fixup; | |
83 | }; | |
84 | ||
61e85e36 JB |
85 | /* |
86 | * These are the main single-value transfer routines. They automatically | |
87 | * use the right size if we just have the right pointer type. | |
88 | * | |
89 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
90 | * and yet we don't want to do any pointers, because that is too much | |
91 | * of a performance impact. Thus we have a few rather ugly macros here, | |
92 | * and hide all the uglyness from the user. | |
93 | * | |
94 | * The "__xxx" versions of the user access functions are versions that | |
95 | * do not verify the address space, that must have been done previously | |
96 | * with a separate "access_ok()" call (this is used when we do multiple | |
97 | * accesses to the same area of user memory). | |
98 | * | |
99 | * As we use the same address space for kernel and user data on the | |
100 | * PowerPC, we can just do these as direct assignments. (Of course, the | |
101 | * exception handling means that it's no longer "just"...) | |
102 | */ | |
103 | #define get_user(x, ptr) \ | |
104 | __get_user_check((x), (ptr), sizeof(*(ptr))) | |
105 | #define put_user(x, ptr) \ | |
106 | __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
107 | ||
108 | #define __get_user(x, ptr) \ | |
109 | __get_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
110 | #define __put_user(x, ptr) \ | |
111 | __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
112 | ||
113 | extern long __put_user_bad(void); | |
114 | ||
115 | #define __put_user_nocheck(x, ptr, size) \ | |
116 | ({ \ | |
117 | long __pu_err; \ | |
118 | __put_user_size((x), (ptr), (size), __pu_err); \ | |
119 | __pu_err; \ | |
120 | }) | |
121 | ||
122 | #define __put_user_check(x, ptr, size) \ | |
123 | ({ \ | |
124 | long __pu_err = -EFAULT; \ | |
125 | __typeof__(*(ptr)) *__pu_addr = (ptr); \ | |
126 | if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ | |
127 | __put_user_size((x), __pu_addr, (size), __pu_err); \ | |
128 | __pu_err; \ | |
129 | }) | |
130 | ||
131 | #define __put_user_size(x, ptr, size, retval) \ | |
132 | do { \ | |
133 | retval = 0; \ | |
134 | switch (size) { \ | |
135 | case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \ | |
136 | case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \ | |
137 | case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \ | |
138 | case 8: __put_user_asm2(x, ptr, retval); break; \ | |
139 | default: __put_user_bad(); \ | |
140 | } \ | |
141 | } while (0) | |
142 | ||
143 | struct __large_struct { | |
144 | unsigned long buf[100]; | |
145 | }; | |
146 | #define __m(x) (*(struct __large_struct *)(x)) | |
147 | ||
148 | /* | |
149 | * We don't tell gcc that we are accessing memory, but this is OK | |
150 | * because we do not write to any memory gcc knows about, so there | |
151 | * are no aliasing issues. | |
152 | */ | |
153 | #define __put_user_asm(x, addr, err, op) \ | |
154 | __asm__ __volatile__( \ | |
155 | "1: "op" 0(%2),%1\n" \ | |
156 | "2:\n" \ | |
157 | ".section .fixup,\"ax\"\n" \ | |
158 | "3: l.addi %0,r0,%3\n" \ | |
159 | " l.j 2b\n" \ | |
160 | " l.nop\n" \ | |
161 | ".previous\n" \ | |
162 | ".section __ex_table,\"a\"\n" \ | |
163 | " .align 2\n" \ | |
164 | " .long 1b,3b\n" \ | |
165 | ".previous" \ | |
166 | : "=r"(err) \ | |
167 | : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) | |
168 | ||
169 | #define __put_user_asm2(x, addr, err) \ | |
170 | __asm__ __volatile__( \ | |
171 | "1: l.sw 0(%2),%1\n" \ | |
172 | "2: l.sw 4(%2),%H1\n" \ | |
173 | "3:\n" \ | |
174 | ".section .fixup,\"ax\"\n" \ | |
175 | "4: l.addi %0,r0,%3\n" \ | |
176 | " l.j 3b\n" \ | |
177 | " l.nop\n" \ | |
178 | ".previous\n" \ | |
179 | ".section __ex_table,\"a\"\n" \ | |
180 | " .align 2\n" \ | |
181 | " .long 1b,4b\n" \ | |
182 | " .long 2b,4b\n" \ | |
183 | ".previous" \ | |
184 | : "=r"(err) \ | |
185 | : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) | |
186 | ||
187 | #define __get_user_nocheck(x, ptr, size) \ | |
188 | ({ \ | |
189 | long __gu_err, __gu_val; \ | |
190 | __get_user_size(__gu_val, (ptr), (size), __gu_err); \ | |
582a6783 | 191 | (x) = (__force __typeof__(*(ptr)))__gu_val; \ |
61e85e36 JB |
192 | __gu_err; \ |
193 | }) | |
194 | ||
195 | #define __get_user_check(x, ptr, size) \ | |
196 | ({ \ | |
197 | long __gu_err = -EFAULT, __gu_val = 0; \ | |
198 | const __typeof__(*(ptr)) * __gu_addr = (ptr); \ | |
199 | if (access_ok(VERIFY_READ, __gu_addr, size)) \ | |
200 | __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ | |
582a6783 | 201 | (x) = (__force __typeof__(*(ptr)))__gu_val; \ |
61e85e36 JB |
202 | __gu_err; \ |
203 | }) | |
204 | ||
205 | extern long __get_user_bad(void); | |
206 | ||
207 | #define __get_user_size(x, ptr, size, retval) \ | |
208 | do { \ | |
209 | retval = 0; \ | |
210 | switch (size) { \ | |
211 | case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \ | |
212 | case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \ | |
213 | case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \ | |
154e67cd | 214 | case 8: __get_user_asm2(x, ptr, retval); break; \ |
61e85e36 JB |
215 | default: (x) = __get_user_bad(); \ |
216 | } \ | |
217 | } while (0) | |
218 | ||
219 | #define __get_user_asm(x, addr, err, op) \ | |
220 | __asm__ __volatile__( \ | |
221 | "1: "op" %1,0(%2)\n" \ | |
222 | "2:\n" \ | |
223 | ".section .fixup,\"ax\"\n" \ | |
224 | "3: l.addi %0,r0,%3\n" \ | |
225 | " l.addi %1,r0,0\n" \ | |
226 | " l.j 2b\n" \ | |
227 | " l.nop\n" \ | |
228 | ".previous\n" \ | |
229 | ".section __ex_table,\"a\"\n" \ | |
230 | " .align 2\n" \ | |
231 | " .long 1b,3b\n" \ | |
232 | ".previous" \ | |
233 | : "=r"(err), "=r"(x) \ | |
234 | : "r"(addr), "i"(-EFAULT), "0"(err)) | |
235 | ||
236 | #define __get_user_asm2(x, addr, err) \ | |
237 | __asm__ __volatile__( \ | |
238 | "1: l.lwz %1,0(%2)\n" \ | |
239 | "2: l.lwz %H1,4(%2)\n" \ | |
240 | "3:\n" \ | |
241 | ".section .fixup,\"ax\"\n" \ | |
242 | "4: l.addi %0,r0,%3\n" \ | |
243 | " l.addi %1,r0,0\n" \ | |
244 | " l.addi %H1,r0,0\n" \ | |
245 | " l.j 3b\n" \ | |
246 | " l.nop\n" \ | |
247 | ".previous\n" \ | |
248 | ".section __ex_table,\"a\"\n" \ | |
249 | " .align 2\n" \ | |
250 | " .long 1b,4b\n" \ | |
251 | " .long 2b,4b\n" \ | |
252 | ".previous" \ | |
253 | : "=r"(err), "=&r"(x) \ | |
254 | : "r"(addr), "i"(-EFAULT), "0"(err)) | |
255 | ||
256 | /* more complex routines */ | |
257 | ||
258 | extern unsigned long __must_check | |
259 | __copy_tofrom_user(void *to, const void *from, unsigned long size); | |
260 | ||
261 | #define __copy_from_user(to, from, size) \ | |
262 | __copy_tofrom_user(to, from, size) | |
263 | #define __copy_to_user(to, from, size) \ | |
264 | __copy_tofrom_user(to, from, size) | |
265 | ||
266 | #define __copy_to_user_inatomic __copy_to_user | |
267 | #define __copy_from_user_inatomic __copy_from_user | |
268 | ||
269 | static inline unsigned long | |
270 | copy_from_user(void *to, const void *from, unsigned long n) | |
271 | { | |
acb2505d AV |
272 | unsigned long res = n; |
273 | ||
274 | if (likely(access_ok(VERIFY_READ, from, n))) | |
8e4b7205 | 275 | res = __copy_tofrom_user(to, from, n); |
acb2505d AV |
276 | if (unlikely(res)) |
277 | memset(to + (n - res), 0, res); | |
278 | return res; | |
61e85e36 JB |
279 | } |
280 | ||
281 | static inline unsigned long | |
282 | copy_to_user(void *to, const void *from, unsigned long n) | |
283 | { | |
acb2505d AV |
284 | if (likely(access_ok(VERIFY_WRITE, to, n))) |
285 | n = __copy_tofrom_user(to, from, n); | |
61e85e36 JB |
286 | return n; |
287 | } | |
288 | ||
289 | extern unsigned long __clear_user(void *addr, unsigned long size); | |
290 | ||
291 | static inline __must_check unsigned long | |
292 | clear_user(void *addr, unsigned long size) | |
293 | { | |
acb2505d AV |
294 | if (likely(access_ok(VERIFY_WRITE, addr, size))) |
295 | size = __clear_user(addr, size); | |
61e85e36 JB |
296 | return size; |
297 | } | |
298 | ||
603d6637 JB |
299 | #define user_addr_max() \ |
300 | (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL) | |
61e85e36 | 301 | |
603d6637 | 302 | extern long strncpy_from_user(char *dest, const char __user *src, long count); |
61e85e36 | 303 | |
b48b2c3e JB |
304 | extern __must_check long strlen_user(const char __user *str); |
305 | extern __must_check long strnlen_user(const char __user *str, long n); | |
61e85e36 JB |
306 | |
307 | #endif /* __ASM_OPENRISC_UACCESS_H */ |