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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef __ALPHA_UACCESS_H |
3 | #define __ALPHA_UACCESS_H | |
4 | ||
1da177e4 LT |
5 | /* |
6 | * The fs value determines whether argument validity checking should be | |
7 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
8 | * get_fs() == KERNEL_DS, checking is bypassed. | |
9 | * | |
10 | * Or at least it did once upon a time. Nowadays it is a mask that | |
11 | * defines which bits of the address space are off limits. This is a | |
12 | * wee bit faster than the above. | |
13 | * | |
14 | * For historical reasons, these macros are grossly misnamed. | |
15 | */ | |
16 | ||
17 | #define KERNEL_DS ((mm_segment_t) { 0UL }) | |
18 | #define USER_DS ((mm_segment_t) { -0x40000000000UL }) | |
19 | ||
1da177e4 LT |
20 | #define get_fs() (current_thread_info()->addr_limit) |
21 | #define get_ds() (KERNEL_DS) | |
22 | #define set_fs(x) (current_thread_info()->addr_limit = (x)) | |
23 | ||
4fb9bccb | 24 | #define segment_eq(a, b) ((a).seg == (b).seg) |
1da177e4 LT |
25 | |
26 | /* | |
27 | * Is a address valid? This does a straightforward calculation rather | |
28 | * than tests. | |
29 | * | |
30 | * Address valid if: | |
31 | * - "addr" doesn't have any high-bits set | |
32 | * - AND "size" doesn't have any high-bits set | |
33 | * - AND "addr+size" doesn't have any high-bits set | |
34 | * - OR we are in kernel mode. | |
35 | */ | |
c9df6025 AV |
36 | #define __access_ok(addr, size) \ |
37 | ((get_fs().seg & (addr | size | (addr+size))) == 0) | |
1da177e4 | 38 | |
c9df6025 AV |
39 | #define access_ok(type, addr, size) \ |
40 | ({ \ | |
41 | __chk_user_ptr(addr); \ | |
42 | __access_ok(((unsigned long)(addr)), (size)); \ | |
1da177e4 LT |
43 | }) |
44 | ||
1da177e4 LT |
45 | /* |
46 | * These are the main single-value transfer routines. They automatically | |
47 | * use the right size if we just have the right pointer type. | |
48 | * | |
49 | * As the alpha uses the same address space for kernel and user | |
50 | * data, we can just do these as direct assignments. (Of course, the | |
51 | * exception handling means that it's no longer "just"...) | |
52 | * | |
53 | * Careful to not | |
54 | * (a) re-use the arguments for side effects (sizeof/typeof is ok) | |
55 | * (b) require any knowledge of processes at this stage | |
56 | */ | |
4fb9bccb | 57 | #define put_user(x, ptr) \ |
d78d834b | 58 | __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) |
4fb9bccb | 59 | #define get_user(x, ptr) \ |
d78d834b | 60 | __get_user_check((x), (ptr), sizeof(*(ptr))) |
1da177e4 LT |
61 | |
62 | /* | |
63 | * The "__xxx" versions do not do address space checking, useful when | |
64 | * doing multiple accesses to the same area (the programmer has to do the | |
65 | * checks by hand with "access_ok()") | |
66 | */ | |
4fb9bccb MT |
67 | #define __put_user(x, ptr) \ |
68 | __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
69 | #define __get_user(x, ptr) \ | |
70 | __get_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
1da177e4 LT |
71 | |
72 | /* | |
73 | * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to | |
74 | * encode the bits we need for resolving the exception. See the | |
75 | * more extensive comments with fixup_inline_exception below for | |
76 | * more information. | |
77 | */ | |
ca282f69 AV |
78 | #define EXC(label,cont,res,err) \ |
79 | ".section __ex_table,\"a\"\n" \ | |
80 | " .long "#label"-.\n" \ | |
81 | " lda "#res","#cont"-"#label"("#err")\n" \ | |
82 | ".previous\n" | |
1da177e4 LT |
83 | |
84 | extern void __get_user_unknown(void); | |
85 | ||
4fb9bccb | 86 | #define __get_user_nocheck(x, ptr, size) \ |
1da177e4 LT |
87 | ({ \ |
88 | long __gu_err = 0; \ | |
89 | unsigned long __gu_val; \ | |
90 | __chk_user_ptr(ptr); \ | |
91 | switch (size) { \ | |
92 | case 1: __get_user_8(ptr); break; \ | |
93 | case 2: __get_user_16(ptr); break; \ | |
94 | case 4: __get_user_32(ptr); break; \ | |
95 | case 8: __get_user_64(ptr); break; \ | |
96 | default: __get_user_unknown(); break; \ | |
97 | } \ | |
1ab5786a | 98 | (x) = (__force __typeof__(*(ptr))) __gu_val; \ |
1da177e4 LT |
99 | __gu_err; \ |
100 | }) | |
101 | ||
c9df6025 AV |
102 | #define __get_user_check(x, ptr, size) \ |
103 | ({ \ | |
104 | long __gu_err = -EFAULT; \ | |
105 | unsigned long __gu_val = 0; \ | |
106 | const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ | |
107 | if (__access_ok((unsigned long)__gu_addr, size)) { \ | |
108 | __gu_err = 0; \ | |
109 | switch (size) { \ | |
110 | case 1: __get_user_8(__gu_addr); break; \ | |
111 | case 2: __get_user_16(__gu_addr); break; \ | |
112 | case 4: __get_user_32(__gu_addr); break; \ | |
113 | case 8: __get_user_64(__gu_addr); break; \ | |
114 | default: __get_user_unknown(); break; \ | |
115 | } \ | |
116 | } \ | |
117 | (x) = (__force __typeof__(*(ptr))) __gu_val; \ | |
118 | __gu_err; \ | |
1da177e4 LT |
119 | }) |
120 | ||
121 | struct __large_struct { unsigned long buf[100]; }; | |
122 | #define __m(x) (*(struct __large_struct __user *)(x)) | |
123 | ||
124 | #define __get_user_64(addr) \ | |
125 | __asm__("1: ldq %0,%2\n" \ | |
126 | "2:\n" \ | |
ca282f69 | 127 | EXC(1b,2b,%0,%1) \ |
1da177e4 LT |
128 | : "=r"(__gu_val), "=r"(__gu_err) \ |
129 | : "m"(__m(addr)), "1"(__gu_err)) | |
130 | ||
131 | #define __get_user_32(addr) \ | |
132 | __asm__("1: ldl %0,%2\n" \ | |
133 | "2:\n" \ | |
ca282f69 | 134 | EXC(1b,2b,%0,%1) \ |
1da177e4 LT |
135 | : "=r"(__gu_val), "=r"(__gu_err) \ |
136 | : "m"(__m(addr)), "1"(__gu_err)) | |
137 | ||
138 | #ifdef __alpha_bwx__ | |
139 | /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ | |
140 | ||
141 | #define __get_user_16(addr) \ | |
142 | __asm__("1: ldwu %0,%2\n" \ | |
143 | "2:\n" \ | |
ca282f69 | 144 | EXC(1b,2b,%0,%1) \ |
1da177e4 LT |
145 | : "=r"(__gu_val), "=r"(__gu_err) \ |
146 | : "m"(__m(addr)), "1"(__gu_err)) | |
147 | ||
148 | #define __get_user_8(addr) \ | |
149 | __asm__("1: ldbu %0,%2\n" \ | |
150 | "2:\n" \ | |
ca282f69 | 151 | EXC(1b,2b,%0,%1) \ |
1da177e4 LT |
152 | : "=r"(__gu_val), "=r"(__gu_err) \ |
153 | : "m"(__m(addr)), "1"(__gu_err)) | |
154 | #else | |
155 | /* Unfortunately, we can't get an unaligned access trap for the sub-word | |
156 | load, so we have to do a general unaligned operation. */ | |
157 | ||
158 | #define __get_user_16(addr) \ | |
159 | { \ | |
160 | long __gu_tmp; \ | |
161 | __asm__("1: ldq_u %0,0(%3)\n" \ | |
162 | "2: ldq_u %1,1(%3)\n" \ | |
163 | " extwl %0,%3,%0\n" \ | |
164 | " extwh %1,%3,%1\n" \ | |
165 | " or %0,%1,%0\n" \ | |
166 | "3:\n" \ | |
ca282f69 AV |
167 | EXC(1b,3b,%0,%2) \ |
168 | EXC(2b,3b,%0,%2) \ | |
1da177e4 LT |
169 | : "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \ |
170 | : "r"(addr), "2"(__gu_err)); \ | |
171 | } | |
172 | ||
173 | #define __get_user_8(addr) \ | |
174 | __asm__("1: ldq_u %0,0(%2)\n" \ | |
175 | " extbl %0,%2,%0\n" \ | |
176 | "2:\n" \ | |
ca282f69 | 177 | EXC(1b,2b,%0,%1) \ |
1da177e4 LT |
178 | : "=&r"(__gu_val), "=r"(__gu_err) \ |
179 | : "r"(addr), "1"(__gu_err)) | |
180 | #endif | |
181 | ||
182 | extern void __put_user_unknown(void); | |
183 | ||
4fb9bccb | 184 | #define __put_user_nocheck(x, ptr, size) \ |
1da177e4 LT |
185 | ({ \ |
186 | long __pu_err = 0; \ | |
187 | __chk_user_ptr(ptr); \ | |
188 | switch (size) { \ | |
4fb9bccb MT |
189 | case 1: __put_user_8(x, ptr); break; \ |
190 | case 2: __put_user_16(x, ptr); break; \ | |
191 | case 4: __put_user_32(x, ptr); break; \ | |
192 | case 8: __put_user_64(x, ptr); break; \ | |
1da177e4 LT |
193 | default: __put_user_unknown(); break; \ |
194 | } \ | |
195 | __pu_err; \ | |
196 | }) | |
197 | ||
c9df6025 AV |
198 | #define __put_user_check(x, ptr, size) \ |
199 | ({ \ | |
200 | long __pu_err = -EFAULT; \ | |
201 | __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ | |
202 | if (__access_ok((unsigned long)__pu_addr, size)) { \ | |
203 | __pu_err = 0; \ | |
204 | switch (size) { \ | |
205 | case 1: __put_user_8(x, __pu_addr); break; \ | |
206 | case 2: __put_user_16(x, __pu_addr); break; \ | |
207 | case 4: __put_user_32(x, __pu_addr); break; \ | |
208 | case 8: __put_user_64(x, __pu_addr); break; \ | |
209 | default: __put_user_unknown(); break; \ | |
210 | } \ | |
211 | } \ | |
212 | __pu_err; \ | |
1da177e4 LT |
213 | }) |
214 | ||
215 | /* | |
216 | * The "__put_user_xx()" macros tell gcc they read from memory | |
217 | * instead of writing: this is because they do not write to | |
218 | * any memory gcc knows about, so there are no aliasing issues | |
219 | */ | |
4fb9bccb | 220 | #define __put_user_64(x, addr) \ |
1da177e4 LT |
221 | __asm__ __volatile__("1: stq %r2,%1\n" \ |
222 | "2:\n" \ | |
ca282f69 | 223 | EXC(1b,2b,$31,%0) \ |
1da177e4 LT |
224 | : "=r"(__pu_err) \ |
225 | : "m" (__m(addr)), "rJ" (x), "0"(__pu_err)) | |
226 | ||
4fb9bccb | 227 | #define __put_user_32(x, addr) \ |
1da177e4 LT |
228 | __asm__ __volatile__("1: stl %r2,%1\n" \ |
229 | "2:\n" \ | |
ca282f69 | 230 | EXC(1b,2b,$31,%0) \ |
1da177e4 LT |
231 | : "=r"(__pu_err) \ |
232 | : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) | |
233 | ||
234 | #ifdef __alpha_bwx__ | |
235 | /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */ | |
236 | ||
4fb9bccb | 237 | #define __put_user_16(x, addr) \ |
1da177e4 LT |
238 | __asm__ __volatile__("1: stw %r2,%1\n" \ |
239 | "2:\n" \ | |
ca282f69 | 240 | EXC(1b,2b,$31,%0) \ |
1da177e4 LT |
241 | : "=r"(__pu_err) \ |
242 | : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) | |
243 | ||
4fb9bccb | 244 | #define __put_user_8(x, addr) \ |
1da177e4 LT |
245 | __asm__ __volatile__("1: stb %r2,%1\n" \ |
246 | "2:\n" \ | |
ca282f69 | 247 | EXC(1b,2b,$31,%0) \ |
1da177e4 LT |
248 | : "=r"(__pu_err) \ |
249 | : "m"(__m(addr)), "rJ"(x), "0"(__pu_err)) | |
250 | #else | |
251 | /* Unfortunately, we can't get an unaligned access trap for the sub-word | |
252 | write, so we have to do a general unaligned operation. */ | |
253 | ||
4fb9bccb | 254 | #define __put_user_16(x, addr) \ |
1da177e4 LT |
255 | { \ |
256 | long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4; \ | |
257 | __asm__ __volatile__( \ | |
258 | "1: ldq_u %2,1(%5)\n" \ | |
259 | "2: ldq_u %1,0(%5)\n" \ | |
260 | " inswh %6,%5,%4\n" \ | |
261 | " inswl %6,%5,%3\n" \ | |
262 | " mskwh %2,%5,%2\n" \ | |
263 | " mskwl %1,%5,%1\n" \ | |
264 | " or %2,%4,%2\n" \ | |
265 | " or %1,%3,%1\n" \ | |
266 | "3: stq_u %2,1(%5)\n" \ | |
267 | "4: stq_u %1,0(%5)\n" \ | |
268 | "5:\n" \ | |
ca282f69 AV |
269 | EXC(1b,5b,$31,%0) \ |
270 | EXC(2b,5b,$31,%0) \ | |
271 | EXC(3b,5b,$31,%0) \ | |
272 | EXC(4b,5b,$31,%0) \ | |
4fb9bccb MT |
273 | : "=r"(__pu_err), "=&r"(__pu_tmp1), \ |
274 | "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \ | |
1da177e4 LT |
275 | "=&r"(__pu_tmp4) \ |
276 | : "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \ | |
277 | } | |
278 | ||
4fb9bccb | 279 | #define __put_user_8(x, addr) \ |
1da177e4 LT |
280 | { \ |
281 | long __pu_tmp1, __pu_tmp2; \ | |
282 | __asm__ __volatile__( \ | |
283 | "1: ldq_u %1,0(%4)\n" \ | |
284 | " insbl %3,%4,%2\n" \ | |
285 | " mskbl %1,%4,%1\n" \ | |
286 | " or %1,%2,%1\n" \ | |
287 | "2: stq_u %1,0(%4)\n" \ | |
288 | "3:\n" \ | |
ca282f69 AV |
289 | EXC(1b,3b,$31,%0) \ |
290 | EXC(2b,3b,$31,%0) \ | |
4fb9bccb | 291 | : "=r"(__pu_err), \ |
1da177e4 LT |
292 | "=&r"(__pu_tmp1), "=&r"(__pu_tmp2) \ |
293 | : "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \ | |
294 | } | |
295 | #endif | |
296 | ||
297 | ||
298 | /* | |
299 | * Complex access routines | |
300 | */ | |
301 | ||
85250231 | 302 | extern long __copy_user(void *to, const void *from, long len); |
1da177e4 | 303 | |
ec022681 AV |
304 | static inline unsigned long |
305 | raw_copy_from_user(void *to, const void __user *from, unsigned long len) | |
1da177e4 | 306 | { |
ec022681 | 307 | return __copy_user(to, (__force const void *)from, len); |
1da177e4 LT |
308 | } |
309 | ||
ec022681 AV |
310 | static inline unsigned long |
311 | raw_copy_to_user(void __user *to, const void *from, unsigned long len) | |
1da177e4 | 312 | { |
ec022681 | 313 | return __copy_user((__force void *)to, from, len); |
1da177e4 LT |
314 | } |
315 | ||
85250231 | 316 | extern long __clear_user(void __user *to, long len); |
1da177e4 LT |
317 | |
318 | extern inline long | |
319 | clear_user(void __user *to, long len) | |
320 | { | |
c9df6025 | 321 | if (__access_ok((unsigned long)to, len)) |
1da177e4 LT |
322 | len = __clear_user(to, len); |
323 | return len; | |
324 | } | |
325 | ||
f2db633d | 326 | #define user_addr_max() \ |
db68ce10 | 327 | (uaccess_kernel() ? ~0UL : TASK_SIZE) |
1da177e4 | 328 | |
f2db633d | 329 | extern long strncpy_from_user(char *dest, const char __user *src, long count); |
f2db633d | 330 | extern __must_check long strnlen_user(const char __user *str, long n); |
1da177e4 | 331 | |
b5478c1b | 332 | #include <asm/extable.h> |
1da177e4 LT |
333 | |
334 | #endif /* __ALPHA_UACCESS_H */ |