tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4#include <linux/uaccess.h>
5#include <linux/types.h>
6
7unsigned long raw_copy_from_user(void *to, const void *from,
8 unsigned long n)
9{
10 int tmp, nsave;
11
12 __asm__ __volatile__(
13 "0: cmpnei %1, 0 \n"
14 " bf 7f \n"
15 " mov %3, %1 \n"
16 " or %3, %2 \n"
17 " andi %3, 3 \n"
18 " cmpnei %3, 0 \n"
19 " bf 1f \n"
20 " br 5f \n"
21 "1: cmplti %0, 16 \n"
22 " bt 3f \n"
23 "2: ldw %3, (%2, 0) \n"
24 "10: ldw %4, (%2, 4) \n"
25 " stw %3, (%1, 0) \n"
26 " stw %4, (%1, 4) \n"
27 "11: ldw %3, (%2, 8) \n"
28 "12: ldw %4, (%2, 12) \n"
29 " stw %3, (%1, 8) \n"
30 " stw %4, (%1, 12) \n"
31 " addi %2, 16 \n"
32 " addi %1, 16 \n"
33 " subi %0, 16 \n"
34 " br 1b \n"
35 "3: cmplti %0, 4 \n"
36 " bt 5f \n"
37 "4: ldw %3, (%2, 0) \n"
38 " stw %3, (%1, 0) \n"
39 " addi %2, 4 \n"
40 " addi %1, 4 \n"
41 " subi %0, 4 \n"
42 " br 3b \n"
43 "5: cmpnei %0, 0 \n"
44 " bf 7f \n"
45 "6: ldb %3, (%2, 0) \n"
46 " stb %3, (%1, 0) \n"
47 " addi %2, 1 \n"
48 " addi %1, 1 \n"
49 " subi %0, 1 \n"
50 " br 5b \n"
51 "8: stw %3, (%1, 0) \n"
52 " subi %0, 4 \n"
53 " bf 7f \n"
54 "9: subi %0, 8 \n"
55 " bf 7f \n"
56 "13: stw %3, (%1, 8) \n"
57 " subi %0, 12 \n"
58 " bf 7f \n"
59 ".section __ex_table, \"a\" \n"
60 ".align 2 \n"
61 ".long 2b, 7f \n"
62 ".long 4b, 7f \n"
63 ".long 6b, 7f \n"
64 ".long 10b, 8b \n"
65 ".long 11b, 9b \n"
66 ".long 12b,13b \n"
67 ".previous \n"
68 "7: \n"
69 : "=r"(n), "=r"(to), "=r"(from), "=r"(nsave),
70 "=r"(tmp)
71 : "0"(n), "1"(to), "2"(from)
72 : "memory");
73
74 return n;
75}
76EXPORT_SYMBOL(raw_copy_from_user);
77
78unsigned long raw_copy_to_user(void *to, const void *from,
79 unsigned long n)
80{
81 int w0, w1, w2, w3;
82
83 __asm__ __volatile__(
84 "0: cmpnei %1, 0 \n"
85 " bf 8f \n"
86 " mov %3, %1 \n"
87 " or %3, %2 \n"
88 " andi %3, 3 \n"
89 " cmpnei %3, 0 \n"
90 " bf 1f \n"
91 " br 5f \n"
92 "1: cmplti %0, 16 \n" /* 4W */
93 " bt 3f \n"
94 " ldw %3, (%2, 0) \n"
95 " ldw %4, (%2, 4) \n"
96 " ldw %5, (%2, 8) \n"
97 " ldw %6, (%2, 12) \n"
98 "2: stw %3, (%1, 0) \n"
99 "9: stw %4, (%1, 4) \n"
100 "10: stw %5, (%1, 8) \n"
101 "11: stw %6, (%1, 12) \n"
102 " addi %2, 16 \n"
103 " addi %1, 16 \n"
104 " subi %0, 16 \n"
105 " br 1b \n"
106 "3: cmplti %0, 4 \n" /* 1W */
107 " bt 5f \n"
108 " ldw %3, (%2, 0) \n"
109 "4: stw %3, (%1, 0) \n"
110 " addi %2, 4 \n"
111 " addi %1, 4 \n"
112 " subi %0, 4 \n"
113 " br 3b \n"
114 "5: cmpnei %0, 0 \n" /* 1B */
115 " bf 13f \n"
116 " ldb %3, (%2, 0) \n"
117 "6: stb %3, (%1, 0) \n"
118 " addi %2, 1 \n"
119 " addi %1, 1 \n"
120 " subi %0, 1 \n"
121 " br 5b \n"
122 "7: subi %0, 4 \n"
123 "8: subi %0, 4 \n"
124 "12: subi %0, 4 \n"
125 " br 13f \n"
126 ".section __ex_table, \"a\" \n"
127 ".align 2 \n"
128 ".long 2b, 13f \n"
129 ".long 4b, 13f \n"
130 ".long 6b, 13f \n"
131 ".long 9b, 12b \n"
132 ".long 10b, 8b \n"
133 ".long 11b, 7b \n"
134 ".previous \n"
135 "13: \n"
136 : "=r"(n), "=r"(to), "=r"(from), "=r"(w0),
137 "=r"(w1), "=r"(w2), "=r"(w3)
138 : "0"(n), "1"(to), "2"(from)
139 : "memory");
140
141 return n;
142}
143EXPORT_SYMBOL(raw_copy_to_user);
144
145/*
146 * __strncpy_from_user: - Copy a NUL terminated string from userspace,
147 * with less checking.
148 * @dst: Destination address, in kernel space. This buffer must be at
149 * least @count bytes long.
150 * @src: Source address, in user space.
151 * @count: Maximum number of bytes to copy, including the trailing NUL.
152 *
153 * Copies a NUL-terminated string from userspace to kernel space.
154 * Caller must check the specified block with access_ok() before calling
155 * this function.
156 *
157 * On success, returns the length of the string (not including the trailing
158 * NUL).
159 *
160 * If access to userspace fails, returns -EFAULT (some data may have been
161 * copied).
162 *
163 * If @count is smaller than the length of the string, copies @count bytes
164 * and returns @count.
165 */
166long __strncpy_from_user(char *dst, const char *src, long count)
167{
168 long res, faultres;
169 int tmp;
170
171 __asm__ __volatile__(
172 " cmpnei %3, 0 \n"
173 " bf 4f \n"
174 "1: cmpnei %1, 0 \n"
175 " bf 5f \n"
176 "2: ldb %4, (%3, 0) \n"
177 " stb %4, (%2, 0) \n"
178 " cmpnei %4, 0 \n"
179 " bf 3f \n"
180 " addi %3, 1 \n"
181 " addi %2, 1 \n"
182 " subi %1, 1 \n"
183 " br 1b \n"
184 "3: subu %0, %1 \n"
185 " br 5f \n"
186 "4: mov %0, %5 \n"
187 " br 5f \n"
188 ".section __ex_table, \"a\" \n"
189 ".align 2 \n"
190 ".long 2b, 4b \n"
191 ".previous \n"
192 "5: \n"
193 : "=r"(res), "=r"(count), "=r"(dst),
194 "=r"(src), "=r"(tmp), "=r"(faultres)
195 : "5"(-EFAULT), "0"(count), "1"(count),
196 "2"(dst), "3"(src)
197 : "memory");
198
199 return res;
200}
201EXPORT_SYMBOL(__strncpy_from_user);
202
203/*
204 * strnlen_user: - Get the size of a string in user space.
205 * @str: The string to measure.
206 * @n: The maximum valid length
207 *
208 * Get the size of a NUL-terminated string in user space.
209 *
210 * Returns the size of the string INCLUDING the terminating NUL.
211 * On exception, returns 0.
212 * If the string is too long, returns a value greater than @n.
213 */
214long __strnlen_user(const char *s, long n)
215{
216 unsigned long res, tmp;
217
218 __asm__ __volatile__(
219 " cmpnei %1, 0 \n"
220 " bf 3f \n"
221 "1: cmpnei %0, 0 \n"
222 " bf 3f \n"
223 "2: ldb %3, (%1, 0) \n"
224 " cmpnei %3, 0 \n"
225 " bf 3f \n"
226 " subi %0, 1 \n"
227 " addi %1, 1 \n"
228 " br 1b \n"
229 "3: subu %2, %0 \n"
230 " addi %2, 1 \n"
231 " br 5f \n"
232 "4: movi %0, 0 \n"
233 " br 5f \n"
234 ".section __ex_table, \"a\" \n"
235 ".align 2 \n"
236 ".long 2b, 4b \n"
237 ".previous \n"
238 "5: \n"
239 : "=r"(n), "=r"(s), "=r"(res), "=r"(tmp)
240 : "0"(n), "1"(s), "2"(n)
241 : "memory");
242
243 return res;
244}
245EXPORT_SYMBOL(__strnlen_user);
246
247/*
248 * __clear_user: - Zero a block of memory in user space, with less checking.
249 * @to: Destination address, in user space.
250 * @n: Number of bytes to zero.
251 *
252 * Zero a block of memory in user space. Caller must check
253 * the specified block with access_ok() before calling this function.
254 *
255 * Returns number of bytes that could not be cleared.
256 * On success, this will be zero.
257 */
258unsigned long
259__clear_user(void __user *to, unsigned long n)
260{
261 int data, value, tmp;
262
263 __asm__ __volatile__(
264 "0: cmpnei %1, 0 \n"
265 " bf 7f \n"
266 " mov %3, %1 \n"
267 " andi %3, 3 \n"
268 " cmpnei %3, 0 \n"
269 " bf 1f \n"
270 " br 5f \n"
271 "1: cmplti %0, 32 \n" /* 4W */
272 " bt 3f \n"
273 "8: stw %2, (%1, 0) \n"
274 "10: stw %2, (%1, 4) \n"
275 "11: stw %2, (%1, 8) \n"
276 "12: stw %2, (%1, 12) \n"
277 "13: stw %2, (%1, 16) \n"
278 "14: stw %2, (%1, 20) \n"
279 "15: stw %2, (%1, 24) \n"
280 "16: stw %2, (%1, 28) \n"
281 " addi %1, 32 \n"
282 " subi %0, 32 \n"
283 " br 1b \n"
284 "3: cmplti %0, 4 \n" /* 1W */
285 " bt 5f \n"
286 "4: stw %2, (%1, 0) \n"
287 " addi %1, 4 \n"
288 " subi %0, 4 \n"
289 " br 3b \n"
290 "5: cmpnei %0, 0 \n" /* 1B */
291 "9: bf 7f \n"
292 "6: stb %2, (%1, 0) \n"
293 " addi %1, 1 \n"
294 " subi %0, 1 \n"
295 " br 5b \n"
296 ".section __ex_table,\"a\" \n"
297 ".align 2 \n"
298 ".long 8b, 9b \n"
299 ".long 10b, 9b \n"
300 ".long 11b, 9b \n"
301 ".long 12b, 9b \n"
302 ".long 13b, 9b \n"
303 ".long 14b, 9b \n"
304 ".long 15b, 9b \n"
305 ".long 16b, 9b \n"
306 ".long 4b, 9b \n"
307 ".long 6b, 9b \n"
308 ".previous \n"
309 "7: \n"
310 : "=r"(n), "=r" (data), "=r"(value), "=r"(tmp)
311 : "0"(n), "1"(to), "2"(0)
312 : "memory");
313
314 return n;
315}
316EXPORT_SYMBOL(__clear_user);