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