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Linux 4.18.10
[linux/fpc-iii.git] / arch / alpha / include / asm / uaccess.h
blob87d8c4f0307d11539c15df2aa8dace09656a6560
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ALPHA_UACCESS_H
3 #define __ALPHA_UACCESS_H
4
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
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
24 #define segment_eq(a, b) ((a).seg == (b).seg)
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 */
36 #define __access_ok(addr, size) \
37 ((get_fs().seg & (addr | size | (addr+size))) == 0)
38
39 #define access_ok(type, addr, size) \
40 ({ \
41 __chk_user_ptr(addr); \
42 __access_ok(((unsigned long)(addr)), (size)); \
43 })
44
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 */
57 #define put_user(x, ptr) \
58 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
59 #define get_user(x, ptr) \
60 __get_user_check((x), (ptr), sizeof(*(ptr)))
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 */
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)))
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 */
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"
83
84 extern void __get_user_unknown(void);
85
86 #define __get_user_nocheck(x, ptr, size) \
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 } \
98 (x) = (__force __typeof__(*(ptr))) __gu_val; \
99 __gu_err; \
100 })
101
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; \
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" \
127 EXC(1b,2b,%0,%1) \
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" \
134 EXC(1b,2b,%0,%1) \
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" \
144 EXC(1b,2b,%0,%1) \
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" \
151 EXC(1b,2b,%0,%1) \
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" \
167 EXC(1b,3b,%0,%2) \
168 EXC(2b,3b,%0,%2) \
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" \
177 EXC(1b,2b,%0,%1) \
178 : "=&r"(__gu_val), "=r"(__gu_err) \
179 : "r"(addr), "1"(__gu_err))
180 #endif
181
182 extern void __put_user_unknown(void);
183
184 #define __put_user_nocheck(x, ptr, size) \
185 ({ \
186 long __pu_err = 0; \
187 __chk_user_ptr(ptr); \
188 switch (size) { \
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; \
193 default: __put_user_unknown(); break; \
194 } \
195 __pu_err; \
196 })
197
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; \
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 */
220 #define __put_user_64(x, addr) \
221 __asm__ __volatile__("1: stq %r2,%1\n" \
222 "2:\n" \
223 EXC(1b,2b,$31,%0) \
224 : "=r"(__pu_err) \
225 : "m" (__m(addr)), "rJ" (x), "0"(__pu_err))
226
227 #define __put_user_32(x, addr) \
228 __asm__ __volatile__("1: stl %r2,%1\n" \
229 "2:\n" \
230 EXC(1b,2b,$31,%0) \
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
237 #define __put_user_16(x, addr) \
238 __asm__ __volatile__("1: stw %r2,%1\n" \
239 "2:\n" \
240 EXC(1b,2b,$31,%0) \
241 : "=r"(__pu_err) \
242 : "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
243
244 #define __put_user_8(x, addr) \
245 __asm__ __volatile__("1: stb %r2,%1\n" \
246 "2:\n" \
247 EXC(1b,2b,$31,%0) \
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
254 #define __put_user_16(x, addr) \
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" \
269 EXC(1b,5b,$31,%0) \
270 EXC(2b,5b,$31,%0) \
271 EXC(3b,5b,$31,%0) \
272 EXC(4b,5b,$31,%0) \
273 : "=r"(__pu_err), "=&r"(__pu_tmp1), \
274 "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \
275 "=&r"(__pu_tmp4) \
276 : "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \
277 }
278
279 #define __put_user_8(x, addr) \
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" \
289 EXC(1b,3b,$31,%0) \
290 EXC(2b,3b,$31,%0) \
291 : "=r"(__pu_err), \
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
302 extern long __copy_user(void *to, const void *from, long len);
303
304 static inline unsigned long
305 raw_copy_from_user(void *to, const void __user *from, unsigned long len)
306 {
307 return __copy_user(to, (__force const void *)from, len);
308 }
309
310 static inline unsigned long
311 raw_copy_to_user(void __user *to, const void *from, unsigned long len)
312 {
313 return __copy_user((__force void *)to, from, len);
314 }
315
316 extern long __clear_user(void __user *to, long len);
317
318 extern inline long
319 clear_user(void __user *to, long len)
320 {
321 if (__access_ok((unsigned long)to, len))
322 len = __clear_user(to, len);
323 return len;
324 }
325
326 #define user_addr_max() \
327 (uaccess_kernel() ? ~0UL : TASK_SIZE)
328
329 extern long strncpy_from_user(char *dest, const char __user *src, long count);
330 extern __must_check long strnlen_user(const char __user *str, long n);
331
332 #include <asm/extable.h>
333
334 #endif /* __ALPHA_UACCESS_H */
Linux with added FPC-III support