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Diffstat (limited to 'arch/arm64/include/asm/uaccess.h')
-rw-r--r-- | arch/arm64/include/asm/uaccess.h | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h new file mode 100644 index 00000000000..008f8481da6 --- /dev/null +++ b/arch/arm64/include/asm/uaccess.h | |||
@@ -0,0 +1,297 @@ | |||
1 | /* | ||
2 | * Based on arch/arm/include/asm/uaccess.h | ||
3 | * | ||
4 | * Copyright (C) 2012 ARM Ltd. | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License version 2 as | ||
8 | * published by the Free Software Foundation. | ||
9 | * | ||
10 | * This program is distributed in the hope that it will be useful, | ||
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
13 | * GNU General Public License for more details. | ||
14 | * | ||
15 | * You should have received a copy of the GNU General Public License | ||
16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | ||
17 | */ | ||
18 | #ifndef __ASM_UACCESS_H | ||
19 | #define __ASM_UACCESS_H | ||
20 | |||
21 | /* | ||
22 | * User space memory access functions | ||
23 | */ | ||
24 | #include <linux/string.h> | ||
25 | #include <linux/thread_info.h> | ||
26 | |||
27 | #include <asm/ptrace.h> | ||
28 | #include <asm/errno.h> | ||
29 | #include <asm/memory.h> | ||
30 | #include <asm/compiler.h> | ||
31 | |||
32 | #define VERIFY_READ 0 | ||
33 | #define VERIFY_WRITE 1 | ||
34 | |||
35 | /* | ||
36 | * The exception table consists of pairs of addresses: the first is the | ||
37 | * address of an instruction that is allowed to fault, and the second is | ||
38 | * the address at which the program should continue. No registers are | ||
39 | * modified, so it is entirely up to the continuation code to figure out | ||
40 | * what to do. | ||
41 | * | ||
42 | * All the routines below use bits of fixup code that are out of line | ||
43 | * with the main instruction path. This means when everything is well, | ||
44 | * we don't even have to jump over them. Further, they do not intrude | ||
45 | * on our cache or tlb entries. | ||
46 | */ | ||
47 | |||
48 | struct exception_table_entry | ||
49 | { | ||
50 | unsigned long insn, fixup; | ||
51 | }; | ||
52 | |||
53 | extern int fixup_exception(struct pt_regs *regs); | ||
54 | |||
55 | #define KERNEL_DS (-1UL) | ||
56 | #define get_ds() (KERNEL_DS) | ||
57 | |||
58 | #define USER_DS TASK_SIZE_64 | ||
59 | #define get_fs() (current_thread_info()->addr_limit) | ||
60 | |||
61 | static inline void set_fs(mm_segment_t fs) | ||
62 | { | ||
63 | current_thread_info()->addr_limit = fs; | ||
64 | } | ||
65 | |||
66 | #define segment_eq(a,b) ((a) == (b)) | ||
67 | |||
68 | /* | ||
69 | * Return 1 if addr < current->addr_limit, 0 otherwise. | ||
70 | */ | ||
71 | #define __addr_ok(addr) \ | ||
72 | ({ \ | ||
73 | unsigned long flag; \ | ||
74 | asm("cmp %1, %0; cset %0, lo" \ | ||
75 | : "=&r" (flag) \ | ||
76 | : "r" (addr), "0" (current_thread_info()->addr_limit) \ | ||
77 | : "cc"); \ | ||
78 | flag; \ | ||
79 | }) | ||
80 | |||
81 | /* | ||
82 | * Test whether a block of memory is a valid user space address. | ||
83 | * Returns 1 if the range is valid, 0 otherwise. | ||
84 | * | ||
85 | * This is equivalent to the following test: | ||
86 | * (u65)addr + (u65)size < (u65)current->addr_limit | ||
87 | * | ||
88 | * This needs 65-bit arithmetic. | ||
89 | */ | ||
90 | #define __range_ok(addr, size) \ | ||
91 | ({ \ | ||
92 | unsigned long flag, roksum; \ | ||
93 | __chk_user_ptr(addr); \ | ||
94 | asm("adds %1, %1, %3; ccmp %1, %4, #2, cc; cset %0, cc" \ | ||
95 | : "=&r" (flag), "=&r" (roksum) \ | ||
96 | : "1" (addr), "Ir" (size), \ | ||
97 | "r" (current_thread_info()->addr_limit) \ | ||
98 | : "cc"); \ | ||
99 | flag; \ | ||
100 | }) | ||
101 | |||
102 | #define access_ok(type, addr, size) __range_ok(addr, size) | ||
103 | |||
104 | /* | ||
105 | * The "__xxx" versions of the user access functions do not verify the address | ||
106 | * space - it must have been done previously with a separate "access_ok()" | ||
107 | * call. | ||
108 | * | ||
109 | * The "__xxx_error" versions set the third argument to -EFAULT if an error | ||
110 | * occurs, and leave it unchanged on success. | ||
111 | */ | ||
112 | #define __get_user_asm(instr, reg, x, addr, err) \ | ||
113 | asm volatile( \ | ||
114 | "1: " instr " " reg "1, [%2]\n" \ | ||
115 | "2:\n" \ | ||
116 | " .section .fixup, \"ax\"\n" \ | ||
117 | " .align 2\n" \ | ||
118 | "3: mov %w0, %3\n" \ | ||
119 | " mov %1, #0\n" \ | ||
120 | " b 2b\n" \ | ||
121 | " .previous\n" \ | ||
122 | " .section __ex_table,\"a\"\n" \ | ||
123 | " .align 3\n" \ | ||
124 | " .quad 1b, 3b\n" \ | ||
125 | " .previous" \ | ||
126 | : "+r" (err), "=&r" (x) \ | ||
127 | : "r" (addr), "i" (-EFAULT)) | ||
128 | |||
129 | #define __get_user_err(x, ptr, err) \ | ||
130 | do { \ | ||
131 | unsigned long __gu_val; \ | ||
132 | __chk_user_ptr(ptr); \ | ||
133 | switch (sizeof(*(ptr))) { \ | ||
134 | case 1: \ | ||
135 | __get_user_asm("ldrb", "%w", __gu_val, (ptr), (err)); \ | ||
136 | break; \ | ||
137 | case 2: \ | ||
138 | __get_user_asm("ldrh", "%w", __gu_val, (ptr), (err)); \ | ||
139 | break; \ | ||
140 | case 4: \ | ||
141 | __get_user_asm("ldr", "%w", __gu_val, (ptr), (err)); \ | ||
142 | break; \ | ||
143 | case 8: \ | ||
144 | __get_user_asm("ldr", "%", __gu_val, (ptr), (err)); \ | ||
145 | break; \ | ||
146 | default: \ | ||
147 | BUILD_BUG(); \ | ||
148 | } \ | ||
149 | (x) = (__typeof__(*(ptr)))__gu_val; \ | ||
150 | } while (0) | ||
151 | |||
152 | #define __get_user(x, ptr) \ | ||
153 | ({ \ | ||
154 | int __gu_err = 0; \ | ||
155 | __get_user_err((x), (ptr), __gu_err); \ | ||
156 | __gu_err; \ | ||
157 | }) | ||
158 | |||
159 | #define __get_user_error(x, ptr, err) \ | ||
160 | ({ \ | ||
161 | __get_user_err((x), (ptr), (err)); \ | ||
162 | (void)0; \ | ||
163 | }) | ||
164 | |||
165 | #define __get_user_unaligned __get_user | ||
166 | |||
167 | #define get_user(x, ptr) \ | ||
168 | ({ \ | ||
169 | might_sleep(); \ | ||
170 | access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) ? \ | ||
171 | __get_user((x), (ptr)) : \ | ||
172 | ((x) = 0, -EFAULT); \ | ||
173 | }) | ||
174 | |||
175 | #define __put_user_asm(instr, reg, x, addr, err) \ | ||
176 | asm volatile( \ | ||
177 | "1: " instr " " reg "1, [%2]\n" \ | ||
178 | "2:\n" \ | ||
179 | " .section .fixup,\"ax\"\n" \ | ||
180 | " .align 2\n" \ | ||
181 | "3: mov %w0, %3\n" \ | ||
182 | " b 2b\n" \ | ||
183 | " .previous\n" \ | ||
184 | " .section __ex_table,\"a\"\n" \ | ||
185 | " .align 3\n" \ | ||
186 | " .quad 1b, 3b\n" \ | ||
187 | " .previous" \ | ||
188 | : "+r" (err) \ | ||
189 | : "r" (x), "r" (addr), "i" (-EFAULT)) | ||
190 | |||
191 | #define __put_user_err(x, ptr, err) \ | ||
192 | do { \ | ||
193 | __typeof__(*(ptr)) __pu_val = (x); \ | ||
194 | __chk_user_ptr(ptr); \ | ||
195 | switch (sizeof(*(ptr))) { \ | ||
196 | case 1: \ | ||
197 | __put_user_asm("strb", "%w", __pu_val, (ptr), (err)); \ | ||
198 | break; \ | ||
199 | case 2: \ | ||
200 | __put_user_asm("strh", "%w", __pu_val, (ptr), (err)); \ | ||
201 | break; \ | ||
202 | case 4: \ | ||
203 | __put_user_asm("str", "%w", __pu_val, (ptr), (err)); \ | ||
204 | break; \ | ||
205 | case 8: \ | ||
206 | __put_user_asm("str", "%", __pu_val, (ptr), (err)); \ | ||
207 | break; \ | ||
208 | default: \ | ||
209 | BUILD_BUG(); \ | ||
210 | } \ | ||
211 | } while (0) | ||
212 | |||
213 | #define __put_user(x, ptr) \ | ||
214 | ({ \ | ||
215 | int __pu_err = 0; \ | ||
216 | __put_user_err((x), (ptr), __pu_err); \ | ||
217 | __pu_err; \ | ||
218 | }) | ||
219 | |||
220 | #define __put_user_error(x, ptr, err) \ | ||
221 | ({ \ | ||
222 | __put_user_err((x), (ptr), (err)); \ | ||
223 | (void)0; \ | ||
224 | }) | ||
225 | |||
226 | #define __put_user_unaligned __put_user | ||
227 | |||
228 | #define put_user(x, ptr) \ | ||
229 | ({ \ | ||
230 | might_sleep(); \ | ||
231 | access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \ | ||
232 | __put_user((x), (ptr)) : \ | ||
233 | -EFAULT; \ | ||
234 | }) | ||
235 | |||
236 | extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n); | ||
237 | extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n); | ||
238 | extern unsigned long __must_check __copy_in_user(void __user *to, const void __user *from, unsigned long n); | ||
239 | extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n); | ||
240 | |||
241 | extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count); | ||
242 | extern unsigned long __must_check __strnlen_user(const char __user *s, long n); | ||
243 | |||
244 | static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) | ||
245 | { | ||
246 | if (access_ok(VERIFY_READ, from, n)) | ||
247 | n = __copy_from_user(to, from, n); | ||
248 | else /* security hole - plug it */ | ||
249 | memset(to, 0, n); | ||
250 | return n; | ||
251 | } | ||
252 | |||
253 | static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) | ||
254 | { | ||
255 | if (access_ok(VERIFY_WRITE, to, n)) | ||
256 | n = __copy_to_user(to, from, n); | ||
257 | return n; | ||
258 | } | ||
259 | |||
260 | static inline unsigned long __must_check copy_in_user(void __user *to, const void __user *from, unsigned long n) | ||
261 | { | ||
262 | if (access_ok(VERIFY_READ, from, n) && access_ok(VERIFY_WRITE, to, n)) | ||
263 | n = __copy_in_user(to, from, n); | ||
264 | return n; | ||
265 | } | ||
266 | |||
267 | #define __copy_to_user_inatomic __copy_to_user | ||
268 | #define __copy_from_user_inatomic __copy_from_user | ||
269 | |||
270 | static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) | ||
271 | { | ||
272 | if (access_ok(VERIFY_WRITE, to, n)) | ||
273 | n = __clear_user(to, n); | ||
274 | return n; | ||
275 | } | ||
276 | |||
277 | static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count) | ||
278 | { | ||
279 | long res = -EFAULT; | ||
280 | if (access_ok(VERIFY_READ, src, 1)) | ||
281 | res = __strncpy_from_user(dst, src, count); | ||
282 | return res; | ||
283 | } | ||
284 | |||
285 | #define strlen_user(s) strnlen_user(s, ~0UL >> 1) | ||
286 | |||
287 | static inline long __must_check strnlen_user(const char __user *s, long n) | ||
288 | { | ||
289 | unsigned long res = 0; | ||
290 | |||
291 | if (__addr_ok(s)) | ||
292 | res = __strnlen_user(s, n); | ||
293 | |||
294 | return res; | ||
295 | } | ||
296 | |||
297 | #endif /* __ASM_UACCESS_H */ | ||