1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * User address space access functions.
4 * The non inlined parts of asm-i386/uaccess.h are here.
5 *
6 * Copyright 1997 Andi Kleen <ak@muc.de>
7 * Copyright 1997 Linus Torvalds
8 */
9 #include <linux/export.h>
10 #include <linux/uaccess.h>
11 #include <asm/asm.h>
12
13 #ifdef CONFIG_X86_INTEL_USERCOPY
14 /*
15 * Alignment at which movsl is preferred for bulk memory copies.
16 */
17 struct movsl_mask movsl_mask __read_mostly;
18 #endif
19
20 static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n)
21 {
22 #ifdef CONFIG_X86_INTEL_USERCOPY
23 if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask))
24 return 0;
25 #endif
26 return 1;
27 }
28 #define movsl_is_ok(a1, a2, n) \
29 __movsl_is_ok((unsigned long)(a1), (unsigned long)(a2), (n))
30
31 /*
32 * Zero Userspace
33 */
34
35 #define __do_clear_user(addr,size) \
36 do { \
37 int __d0; \
38 might_fault(); \
39 __asm__ __volatile__( \
40 ASM_STAC "\n" \
41 "0: rep; stosl\n" \
42 " movl %2,%0\n" \
43 "1: rep; stosb\n" \
44 "2: " ASM_CLAC "\n" \
45 _ASM_EXTABLE_TYPE_REG(0b, 2b, EX_TYPE_UCOPY_LEN4, %2) \
46 _ASM_EXTABLE_UA(1b, 2b) \
47 : "=&c"(size), "=&D" (__d0) \
48 : "r"(size & 3), ""(size / 4), "1"(addr), "a"(0)); \
49 } while (0)
50
51 /**
52 * clear_user - Zero a block of memory in user space.
53 * @to: Destination address, in user space.
54 * @n: Number of bytes to zero.
55 *
56 * Zero a block of memory in user space.
57 *
58 * Return: number of bytes that could not be cleared.
59 * On success, this will be zero.
60 */
61 unsigned long
62 clear_user(void __user *to, unsigned long n)
63 {
64 might_fault();
65 if (access_ok(to, n))
66 __do_clear_user(to, n);
67 return n;
68 }
69 EXPORT_SYMBOL(clear_user);
70
71 /**
72 * __clear_user - Zero a block of memory in user space, with less checking.
73 * @to: Destination address, in user space.
74 * @n: Number of bytes to zero.
75 *
76 * Zero a block of memory in user space. Caller must check
77 * the specified block with access_ok() before calling this function.
78 *
79 * Return: number of bytes that could not be cleared.
80 * On success, this will be zero.
81 */
82 unsigned long
83 __clear_user(void __user *to, unsigned long n)
84 {
85 __do_clear_user(to, n);
86 return n;
87 }
88 EXPORT_SYMBOL(__clear_user);
89
90 #ifdef CONFIG_X86_INTEL_USERCOPY
91 static unsigned long
92 __copy_user_intel(void __user *to, const void *from, unsigned long size)
93 {
94 int d0, d1;
95 __asm__ __volatile__(
96 " .align 2,0x90\n"
97 "1: movl 32(%4), %%eax\n"
98 " cmpl $67, %0\n"
99 " jbe 3f\n"
100 "2: movl 64(%4), %%eax\n"
101 " .align 2,0x90\n"
102 "3: movl 0(%4), %%eax\n"
103 "4: movl 4(%4), %%edx\n"
104 "5: movl %%eax, 0(%3)\n"
105 "6: movl %%edx, 4(%3)\n"
106 "7: movl 8(%4), %%eax\n"
107 "8: movl 12(%4),%%edx\n"
108 "9: movl %%eax, 8(%3)\n"
109 "10: movl %%edx, 12(%3)\n"
110 "11: movl 16(%4), %%eax\n"
111 "12: movl 20(%4), %%edx\n"
112 "13: movl %%eax, 16(%3)\n"
113 "14: movl %%edx, 20(%3)\n"
114 "15: movl 24(%4), %%eax\n"
115 "16: movl 28(%4), %%edx\n"
116 "17: movl %%eax, 24(%3)\n"
117 "18: movl %%edx, 28(%3)\n"
118 "19: movl 32(%4), %%eax\n"
119 "20: movl 36(%4), %%edx\n"
120 "21: movl %%eax, 32(%3)\n"
121 "22: movl %%edx, 36(%3)\n"
122 "23: movl 40(%4), %%eax\n"
123 "24: movl 44(%4), %%edx\n"
124 "25: movl %%eax, 40(%3)\n"
125 "26: movl %%edx, 44(%3)\n"
126 "27: movl 48(%4), %%eax\n"
127 "28: movl 52(%4), %%edx\n"
128 "29: movl %%eax, 48(%3)\n"
129 "30: movl %%edx, 52(%3)\n"
130 "31: movl 56(%4), %%eax\n"
131 "32: movl 60(%4), %%edx\n"
132 "33: movl %%eax, 56(%3)\n"
133 "34: movl %%edx, 60(%3)\n"
134 " addl $-64, %0\n"
135 " addl $64, %4\n"
136 " addl $64, %3\n"
137 " cmpl $63, %0\n"
138 " ja 1b\n"
139 "35: movl %0, %%eax\n"
140 " shrl $2, %0\n"
141 " andl $3, %%eax\n"
142 " cld\n"
143 "99: rep; movsl\n"
144 "36: movl %%eax, %0\n"
145 "37: rep; movsb\n"
146 "100:\n"
147 _ASM_EXTABLE_UA(1b, 100b)
148 _ASM_EXTABLE_UA(2b, 100b)
149 _ASM_EXTABLE_UA(3b, 100b)
150 _ASM_EXTABLE_UA(4b, 100b)
151 _ASM_EXTABLE_UA(5b, 100b)
152 _ASM_EXTABLE_UA(6b, 100b)
153 _ASM_EXTABLE_UA(7b, 100b)
154 _ASM_EXTABLE_UA(8b, 100b)
155 _ASM_EXTABLE_UA(9b, 100b)
156 _ASM_EXTABLE_UA(10b, 100b)
157 _ASM_EXTABLE_UA(11b, 100b)
158 _ASM_EXTABLE_UA(12b, 100b)
159 _ASM_EXTABLE_UA(13b, 100b)
160 _ASM_EXTABLE_UA(14b, 100b)
161 _ASM_EXTABLE_UA(15b, 100b)
162 _ASM_EXTABLE_UA(16b, 100b)
163 _ASM_EXTABLE_UA(17b, 100b)
164 _ASM_EXTABLE_UA(18b, 100b)
165 _ASM_EXTABLE_UA(19b, 100b)
166 _ASM_EXTABLE_UA(20b, 100b)
167 _ASM_EXTABLE_UA(21b, 100b)
168 _ASM_EXTABLE_UA(22b, 100b)
169 _ASM_EXTABLE_UA(23b, 100b)
170 _ASM_EXTABLE_UA(24b, 100b)
171 _ASM_EXTABLE_UA(25b, 100b)
172 _ASM_EXTABLE_UA(26b, 100b)
173 _ASM_EXTABLE_UA(27b, 100b)
174 _ASM_EXTABLE_UA(28b, 100b)
175 _ASM_EXTABLE_UA(29b, 100b)
176 _ASM_EXTABLE_UA(30b, 100b)
177 _ASM_EXTABLE_UA(31b, 100b)
178 _ASM_EXTABLE_UA(32b, 100b)
179 _ASM_EXTABLE_UA(33b, 100b)
180 _ASM_EXTABLE_UA(34b, 100b)
181 _ASM_EXTABLE_UA(35b, 100b)
182 _ASM_EXTABLE_UA(36b, 100b)
183 _ASM_EXTABLE_UA(37b, 100b)
184 _ASM_EXTABLE_TYPE_REG(99b, 100b, EX_TYPE_UCOPY_LEN4, %%eax)
185 : "=&c"(size), "=&D" (d0), "=&S" (d1)
186 : "1"(to), "2"(from), ""(size)
187 : "eax", "edx", "memory");
188 return size;
189 }
190
191 static unsigned long __copy_user_intel_nocache(void *to,
192 const void __user *from, unsigned long size)
193 {
194 int d0, d1;
195
196 __asm__ __volatile__(
197 " .align 2,0x90\n"
198 "0: movl 32(%4), %%eax\n"
199 " cmpl $67, %0\n"
200 " jbe 2f\n"
201 "1: movl 64(%4), %%eax\n"
202 " .align 2,0x90\n"
203 "2: movl 0(%4), %%eax\n"
204 "21: movl 4(%4), %%edx\n"
205 " movnti %%eax, 0(%3)\n"
206 " movnti %%edx, 4(%3)\n"
207 "3: movl 8(%4), %%eax\n"
208 "31: movl 12(%4),%%edx\n"
209 " movnti %%eax, 8(%3)\n"
210 " movnti %%edx, 12(%3)\n"
211 "4: movl 16(%4), %%eax\n"
212 "41: movl 20(%4), %%edx\n"
213 " movnti %%eax, 16(%3)\n"
214 " movnti %%edx, 20(%3)\n"
215 "10: movl 24(%4), %%eax\n"
216 "51: movl 28(%4), %%edx\n"
217 " movnti %%eax, 24(%3)\n"
218 " movnti %%edx, 28(%3)\n"
219 "11: movl 32(%4), %%eax\n"
220 "61: movl 36(%4), %%edx\n"
221 " movnti %%eax, 32(%3)\n"
222 " movnti %%edx, 36(%3)\n"
223 "12: movl 40(%4), %%eax\n"
224 "71: movl 44(%4), %%edx\n"
225 " movnti %%eax, 40(%3)\n"
226 " movnti %%edx, 44(%3)\n"
227 "13: movl 48(%4), %%eax\n"
228 "81: movl 52(%4), %%edx\n"
229 " movnti %%eax, 48(%3)\n"
230 " movnti %%edx, 52(%3)\n"
231 "14: movl 56(%4), %%eax\n"
232 "91: movl 60(%4), %%edx\n"
233 " movnti %%eax, 56(%3)\n"
234 " movnti %%edx, 60(%3)\n"
235 " addl $-64, %0\n"
236 " addl $64, %4\n"
237 " addl $64, %3\n"
238 " cmpl $63, %0\n"
239 " ja 0b\n"
240 " sfence \n"
241 "5: movl %0, %%eax\n"
242 " shrl $2, %0\n"
243 " andl $3, %%eax\n"
244 " cld\n"
245 "6: rep; movsl\n"
246 " movl %%eax,%0\n"
247 "7: rep; movsb\n"
248 "8:\n"
249 _ASM_EXTABLE_UA(0b, 8b)
250 _ASM_EXTABLE_UA(1b, 8b)
251 _ASM_EXTABLE_UA(2b, 8b)
252 _ASM_EXTABLE_UA(21b, 8b)
253 _ASM_EXTABLE_UA(3b, 8b)
254 _ASM_EXTABLE_UA(31b, 8b)
255 _ASM_EXTABLE_UA(4b, 8b)
256 _ASM_EXTABLE_UA(41b, 8b)
257 _ASM_EXTABLE_UA(10b, 8b)
258 _ASM_EXTABLE_UA(51b, 8b)
259 _ASM_EXTABLE_UA(11b, 8b)
260 _ASM_EXTABLE_UA(61b, 8b)
261 _ASM_EXTABLE_UA(12b, 8b)
262 _ASM_EXTABLE_UA(71b, 8b)
263 _ASM_EXTABLE_UA(13b, 8b)
264 _ASM_EXTABLE_UA(81b, 8b)
265 _ASM_EXTABLE_UA(14b, 8b)
266 _ASM_EXTABLE_UA(91b, 8b)
267 _ASM_EXTABLE_TYPE_REG(6b, 8b, EX_TYPE_UCOPY_LEN4, %%eax)
268 _ASM_EXTABLE_UA(7b, 8b)
269 : "=&c"(size), "=&D" (d0), "=&S" (d1)
270 : "1"(to), "2"(from), ""(size)
271 : "eax", "edx", "memory");
272 return size;
273 }
274
275 #else
276
277 /*
278 * Leave these declared but undefined. They should not be any references to
279 * them
280 */
281 unsigned long __copy_user_intel(void __user *to, const void *from,
282 unsigned long size);
283 #endif /* CONFIG_X86_INTEL_USERCOPY */
284
285 /* Generic arbitrary sized copy. */
286 #define __copy_user(to, from, size) \
287 do { \
288 int __d0, __d1, __d2; \
289 __asm__ __volatile__( \
290 " cmp $7,%0\n" \
291 " jbe 1f\n" \
292 " movl %1,%0\n" \
293 " negl %0\n" \
294 " andl $7,%0\n" \
295 " subl %0,%3\n" \
296 "4: rep; movsb\n" \
297 " movl %3,%0\n" \
298 " shrl $2,%0\n" \
299 " andl $3,%3\n" \
300 " .align 2,0x90\n" \
301 "0: rep; movsl\n" \
302 " movl %3,%0\n" \
303 "1: rep; movsb\n" \
304 "2:\n" \
305 _ASM_EXTABLE_TYPE_REG(4b, 2b, EX_TYPE_UCOPY_LEN1, %3) \
306 _ASM_EXTABLE_TYPE_REG(0b, 2b, EX_TYPE_UCOPY_LEN4, %3) \
307 _ASM_EXTABLE_UA(1b, 2b) \
308 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
309 : "3"(size), ""(size), "1"(to), "2"(from) \
310 : "memory"); \
311 } while (0)
312
313 unsigned long __copy_user_ll(void *to, const void *from, unsigned long n)
314 {
315 __uaccess_begin_nospec();
316 if (movsl_is_ok(to, from, n))
317 __copy_user(to, from, n);
318 else
319 n = __copy_user_intel(to, from, n);
320 __uaccess_end();
321 return n;
322 }
323 EXPORT_SYMBOL(__copy_user_ll);
324
325 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
326 unsigned long n)
327 {
328 __uaccess_begin_nospec();
329 #ifdef CONFIG_X86_INTEL_USERCOPY
330 if (n > 64 && static_cpu_has(X86_FEATURE_XMM2))
331 n = __copy_user_intel_nocache(to, from, n);
332 else
333 __copy_user(to, from, n);
334 #else
335 __copy_user(to, from, n);
336 #endif
337 __uaccess_end();
338 return n;
339 }
340 EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);
341
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