1 /*
2 * User address space access functions.
3 * The non inlined parts of asm-i386/uaccess.h are here.
4 *
5 * Copyright 1997 Andi Kleen <ak@muc.de>
6 * Copyright 1997 Linus Torvalds
7 */
8 #include <linux/mm.h>
9 #include <linux/highmem.h>
10 #include <linux/blkdev.h>
11 #include <linux/module.h>
12 #include <linux/backing-dev.h>
13 #include <linux/interrupt.h>
14 #include <asm/uaccess.h>
15 #include <asm/mmx.h>
16
17 #ifdef CONFIG_X86_INTEL_USERCOPY
18 /*
19 * Alignment at which movsl is preferred for bulk memory copies.
20 */
21 struct movsl_mask movsl_mask __read_mostly;
22 #endif
23
__movsl_is_ok(unsigned long a1,unsigned long a2,unsigned long n)24 static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n)
25 {
26 #ifdef CONFIG_X86_INTEL_USERCOPY
27 if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask))
28 return 0;
29 #endif
30 return 1;
31 }
32 #define movsl_is_ok(a1, a2, n) \
33 __movsl_is_ok((unsigned long)(a1), (unsigned long)(a2), (n))
34
35 /*
36 * Zero Userspace
37 */
38
39 #define __do_clear_user(addr,size) \
40 do { \
41 int __d0; \
42 might_fault(); \
43 __asm__ __volatile__( \
44 "0: rep; stosl\n" \
45 " movl %2,%0\n" \
46 "1: rep; stosb\n" \
47 "2:\n" \
48 ".section .fixup,\"ax\"\n" \
49 "3: lea 0(%2,%0,4),%0\n" \
50 " jmp 2b\n" \
51 ".previous\n" \
52 _ASM_EXTABLE(0b,3b) \
53 _ASM_EXTABLE(1b,2b) \
54 : "=&c"(size), "=&D" (__d0) \
55 : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \
56 } while (0)
57
58 /**
59 * clear_user: - Zero a block of memory in user space.
60 * @to: Destination address, in user space.
61 * @n: Number of bytes to zero.
62 *
63 * Zero a block of memory in user space.
64 *
65 * Returns number of bytes that could not be cleared.
66 * On success, this will be zero.
67 */
68 unsigned long
clear_user(void __user * to,unsigned long n)69 clear_user(void __user *to, unsigned long n)
70 {
71 might_fault();
72 if (access_ok(VERIFY_WRITE, to, n))
73 __do_clear_user(to, n);
74 return n;
75 }
76 EXPORT_SYMBOL(clear_user);
77
78 /**
79 * __clear_user: - Zero a block of memory in user space, with less checking.
80 * @to: Destination address, in user space.
81 * @n: Number of bytes to zero.
82 *
83 * Zero a block of memory in user space. Caller must check
84 * the specified block with access_ok() before calling this function.
85 *
86 * Returns number of bytes that could not be cleared.
87 * On success, this will be zero.
88 */
89 unsigned long
__clear_user(void __user * to,unsigned long n)90 __clear_user(void __user *to, unsigned long n)
91 {
92 __do_clear_user(to, n);
93 return n;
94 }
95 EXPORT_SYMBOL(__clear_user);
96
97 /**
98 * strnlen_user: - Get the size of a string in user space.
99 * @s: The string to measure.
100 * @n: The maximum valid length
101 *
102 * Get the size of a NUL-terminated string in user space.
103 *
104 * Returns the size of the string INCLUDING the terminating NUL.
105 * On exception, returns 0.
106 * If the string is too long, returns a value greater than @n.
107 */
strnlen_user(const char __user * s,long n)108 long strnlen_user(const char __user *s, long n)
109 {
110 unsigned long mask = -__addr_ok(s);
111 unsigned long res, tmp;
112
113 might_fault();
114
115 __asm__ __volatile__(
116 " testl %0, %0\n"
117 " jz 3f\n"
118 " andl %0,%%ecx\n"
119 "0: repne; scasb\n"
120 " setne %%al\n"
121 " subl %%ecx,%0\n"
122 " addl %0,%%eax\n"
123 "1:\n"
124 ".section .fixup,\"ax\"\n"
125 "2: xorl %%eax,%%eax\n"
126 " jmp 1b\n"
127 "3: movb $1,%%al\n"
128 " jmp 1b\n"
129 ".previous\n"
130 ".section __ex_table,\"a\"\n"
131 " .align 4\n"
132 " .long 0b,2b\n"
133 ".previous"
134 :"=&r" (n), "=&D" (s), "=&a" (res), "=&c" (tmp)
135 :"0" (n), "1" (s), "2" (0), "3" (mask)
136 :"cc");
137 return res & mask;
138 }
139 EXPORT_SYMBOL(strnlen_user);
140
141 #ifdef CONFIG_X86_INTEL_USERCOPY
142 static unsigned long
__copy_user_intel(void __user * to,const void * from,unsigned long size)143 __copy_user_intel(void __user *to, const void *from, unsigned long size)
144 {
145 int d0, d1;
146 __asm__ __volatile__(
147 " .align 2,0x90\n"
148 "1: movl 32(%4), %%eax\n"
149 " cmpl $67, %0\n"
150 " jbe 3f\n"
151 "2: movl 64(%4), %%eax\n"
152 " .align 2,0x90\n"
153 "3: movl 0(%4), %%eax\n"
154 "4: movl 4(%4), %%edx\n"
155 "5: movl %%eax, 0(%3)\n"
156 "6: movl %%edx, 4(%3)\n"
157 "7: movl 8(%4), %%eax\n"
158 "8: movl 12(%4),%%edx\n"
159 "9: movl %%eax, 8(%3)\n"
160 "10: movl %%edx, 12(%3)\n"
161 "11: movl 16(%4), %%eax\n"
162 "12: movl 20(%4), %%edx\n"
163 "13: movl %%eax, 16(%3)\n"
164 "14: movl %%edx, 20(%3)\n"
165 "15: movl 24(%4), %%eax\n"
166 "16: movl 28(%4), %%edx\n"
167 "17: movl %%eax, 24(%3)\n"
168 "18: movl %%edx, 28(%3)\n"
169 "19: movl 32(%4), %%eax\n"
170 "20: movl 36(%4), %%edx\n"
171 "21: movl %%eax, 32(%3)\n"
172 "22: movl %%edx, 36(%3)\n"
173 "23: movl 40(%4), %%eax\n"
174 "24: movl 44(%4), %%edx\n"
175 "25: movl %%eax, 40(%3)\n"
176 "26: movl %%edx, 44(%3)\n"
177 "27: movl 48(%4), %%eax\n"
178 "28: movl 52(%4), %%edx\n"
179 "29: movl %%eax, 48(%3)\n"
180 "30: movl %%edx, 52(%3)\n"
181 "31: movl 56(%4), %%eax\n"
182 "32: movl 60(%4), %%edx\n"
183 "33: movl %%eax, 56(%3)\n"
184 "34: movl %%edx, 60(%3)\n"
185 " addl $-64, %0\n"
186 " addl $64, %4\n"
187 " addl $64, %3\n"
188 " cmpl $63, %0\n"
189 " ja 1b\n"
190 "35: movl %0, %%eax\n"
191 " shrl $2, %0\n"
192 " andl $3, %%eax\n"
193 " cld\n"
194 "99: rep; movsl\n"
195 "36: movl %%eax, %0\n"
196 "37: rep; movsb\n"
197 "100:\n"
198 ".section .fixup,\"ax\"\n"
199 "101: lea 0(%%eax,%0,4),%0\n"
200 " jmp 100b\n"
201 ".previous\n"
202 ".section __ex_table,\"a\"\n"
203 " .align 4\n"
204 " .long 1b,100b\n"
205 " .long 2b,100b\n"
206 " .long 3b,100b\n"
207 " .long 4b,100b\n"
208 " .long 5b,100b\n"
209 " .long 6b,100b\n"
210 " .long 7b,100b\n"
211 " .long 8b,100b\n"
212 " .long 9b,100b\n"
213 " .long 10b,100b\n"
214 " .long 11b,100b\n"
215 " .long 12b,100b\n"
216 " .long 13b,100b\n"
217 " .long 14b,100b\n"
218 " .long 15b,100b\n"
219 " .long 16b,100b\n"
220 " .long 17b,100b\n"
221 " .long 18b,100b\n"
222 " .long 19b,100b\n"
223 " .long 20b,100b\n"
224 " .long 21b,100b\n"
225 " .long 22b,100b\n"
226 " .long 23b,100b\n"
227 " .long 24b,100b\n"
228 " .long 25b,100b\n"
229 " .long 26b,100b\n"
230 " .long 27b,100b\n"
231 " .long 28b,100b\n"
232 " .long 29b,100b\n"
233 " .long 30b,100b\n"
234 " .long 31b,100b\n"
235 " .long 32b,100b\n"
236 " .long 33b,100b\n"
237 " .long 34b,100b\n"
238 " .long 35b,100b\n"
239 " .long 36b,100b\n"
240 " .long 37b,100b\n"
241 " .long 99b,101b\n"
242 ".previous"
243 : "=&c"(size), "=&D" (d0), "=&S" (d1)
244 : "1"(to), "2"(from), "0"(size)
245 : "eax", "edx", "memory");
246 return size;
247 }
248
249 static unsigned long
__copy_user_zeroing_intel(void * to,const void __user * from,unsigned long size)250 __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size)
251 {
252 int d0, d1;
253 __asm__ __volatile__(
254 " .align 2,0x90\n"
255 "0: movl 32(%4), %%eax\n"
256 " cmpl $67, %0\n"
257 " jbe 2f\n"
258 "1: movl 64(%4), %%eax\n"
259 " .align 2,0x90\n"
260 "2: movl 0(%4), %%eax\n"
261 "21: movl 4(%4), %%edx\n"
262 " movl %%eax, 0(%3)\n"
263 " movl %%edx, 4(%3)\n"
264 "3: movl 8(%4), %%eax\n"
265 "31: movl 12(%4),%%edx\n"
266 " movl %%eax, 8(%3)\n"
267 " movl %%edx, 12(%3)\n"
268 "4: movl 16(%4), %%eax\n"
269 "41: movl 20(%4), %%edx\n"
270 " movl %%eax, 16(%3)\n"
271 " movl %%edx, 20(%3)\n"
272 "10: movl 24(%4), %%eax\n"
273 "51: movl 28(%4), %%edx\n"
274 " movl %%eax, 24(%3)\n"
275 " movl %%edx, 28(%3)\n"
276 "11: movl 32(%4), %%eax\n"
277 "61: movl 36(%4), %%edx\n"
278 " movl %%eax, 32(%3)\n"
279 " movl %%edx, 36(%3)\n"
280 "12: movl 40(%4), %%eax\n"
281 "71: movl 44(%4), %%edx\n"
282 " movl %%eax, 40(%3)\n"
283 " movl %%edx, 44(%3)\n"
284 "13: movl 48(%4), %%eax\n"
285 "81: movl 52(%4), %%edx\n"
286 " movl %%eax, 48(%3)\n"
287 " movl %%edx, 52(%3)\n"
288 "14: movl 56(%4), %%eax\n"
289 "91: movl 60(%4), %%edx\n"
290 " movl %%eax, 56(%3)\n"
291 " movl %%edx, 60(%3)\n"
292 " addl $-64, %0\n"
293 " addl $64, %4\n"
294 " addl $64, %3\n"
295 " cmpl $63, %0\n"
296 " ja 0b\n"
297 "5: movl %0, %%eax\n"
298 " shrl $2, %0\n"
299 " andl $3, %%eax\n"
300 " cld\n"
301 "6: rep; movsl\n"
302 " movl %%eax,%0\n"
303 "7: rep; movsb\n"
304 "8:\n"
305 ".section .fixup,\"ax\"\n"
306 "9: lea 0(%%eax,%0,4),%0\n"
307 "16: pushl %0\n"
308 " pushl %%eax\n"
309 " xorl %%eax,%%eax\n"
310 " rep; stosb\n"
311 " popl %%eax\n"
312 " popl %0\n"
313 " jmp 8b\n"
314 ".previous\n"
315 ".section __ex_table,\"a\"\n"
316 " .align 4\n"
317 " .long 0b,16b\n"
318 " .long 1b,16b\n"
319 " .long 2b,16b\n"
320 " .long 21b,16b\n"
321 " .long 3b,16b\n"
322 " .long 31b,16b\n"
323 " .long 4b,16b\n"
324 " .long 41b,16b\n"
325 " .long 10b,16b\n"
326 " .long 51b,16b\n"
327 " .long 11b,16b\n"
328 " .long 61b,16b\n"
329 " .long 12b,16b\n"
330 " .long 71b,16b\n"
331 " .long 13b,16b\n"
332 " .long 81b,16b\n"
333 " .long 14b,16b\n"
334 " .long 91b,16b\n"
335 " .long 6b,9b\n"
336 " .long 7b,16b\n"
337 ".previous"
338 : "=&c"(size), "=&D" (d0), "=&S" (d1)
339 : "1"(to), "2"(from), "0"(size)
340 : "eax", "edx", "memory");
341 return size;
342 }
343
344 /*
345 * Non Temporal Hint version of __copy_user_zeroing_intel. It is cache aware.
346 * hyoshiok@miraclelinux.com
347 */
348
__copy_user_zeroing_intel_nocache(void * to,const void __user * from,unsigned long size)349 static unsigned long __copy_user_zeroing_intel_nocache(void *to,
350 const void __user *from, unsigned long size)
351 {
352 int d0, d1;
353
354 __asm__ __volatile__(
355 " .align 2,0x90\n"
356 "0: movl 32(%4), %%eax\n"
357 " cmpl $67, %0\n"
358 " jbe 2f\n"
359 "1: movl 64(%4), %%eax\n"
360 " .align 2,0x90\n"
361 "2: movl 0(%4), %%eax\n"
362 "21: movl 4(%4), %%edx\n"
363 " movnti %%eax, 0(%3)\n"
364 " movnti %%edx, 4(%3)\n"
365 "3: movl 8(%4), %%eax\n"
366 "31: movl 12(%4),%%edx\n"
367 " movnti %%eax, 8(%3)\n"
368 " movnti %%edx, 12(%3)\n"
369 "4: movl 16(%4), %%eax\n"
370 "41: movl 20(%4), %%edx\n"
371 " movnti %%eax, 16(%3)\n"
372 " movnti %%edx, 20(%3)\n"
373 "10: movl 24(%4), %%eax\n"
374 "51: movl 28(%4), %%edx\n"
375 " movnti %%eax, 24(%3)\n"
376 " movnti %%edx, 28(%3)\n"
377 "11: movl 32(%4), %%eax\n"
378 "61: movl 36(%4), %%edx\n"
379 " movnti %%eax, 32(%3)\n"
380 " movnti %%edx, 36(%3)\n"
381 "12: movl 40(%4), %%eax\n"
382 "71: movl 44(%4), %%edx\n"
383 " movnti %%eax, 40(%3)\n"
384 " movnti %%edx, 44(%3)\n"
385 "13: movl 48(%4), %%eax\n"
386 "81: movl 52(%4), %%edx\n"
387 " movnti %%eax, 48(%3)\n"
388 " movnti %%edx, 52(%3)\n"
389 "14: movl 56(%4), %%eax\n"
390 "91: movl 60(%4), %%edx\n"
391 " movnti %%eax, 56(%3)\n"
392 " movnti %%edx, 60(%3)\n"
393 " addl $-64, %0\n"
394 " addl $64, %4\n"
395 " addl $64, %3\n"
396 " cmpl $63, %0\n"
397 " ja 0b\n"
398 " sfence \n"
399 "5: movl %0, %%eax\n"
400 " shrl $2, %0\n"
401 " andl $3, %%eax\n"
402 " cld\n"
403 "6: rep; movsl\n"
404 " movl %%eax,%0\n"
405 "7: rep; movsb\n"
406 "8:\n"
407 ".section .fixup,\"ax\"\n"
408 "9: lea 0(%%eax,%0,4),%0\n"
409 "16: pushl %0\n"
410 " pushl %%eax\n"
411 " xorl %%eax,%%eax\n"
412 " rep; stosb\n"
413 " popl %%eax\n"
414 " popl %0\n"
415 " jmp 8b\n"
416 ".previous\n"
417 ".section __ex_table,\"a\"\n"
418 " .align 4\n"
419 " .long 0b,16b\n"
420 " .long 1b,16b\n"
421 " .long 2b,16b\n"
422 " .long 21b,16b\n"
423 " .long 3b,16b\n"
424 " .long 31b,16b\n"
425 " .long 4b,16b\n"
426 " .long 41b,16b\n"
427 " .long 10b,16b\n"
428 " .long 51b,16b\n"
429 " .long 11b,16b\n"
430 " .long 61b,16b\n"
431 " .long 12b,16b\n"
432 " .long 71b,16b\n"
433 " .long 13b,16b\n"
434 " .long 81b,16b\n"
435 " .long 14b,16b\n"
436 " .long 91b,16b\n"
437 " .long 6b,9b\n"
438 " .long 7b,16b\n"
439 ".previous"
440 : "=&c"(size), "=&D" (d0), "=&S" (d1)
441 : "1"(to), "2"(from), "0"(size)
442 : "eax", "edx", "memory");
443 return size;
444 }
445
__copy_user_intel_nocache(void * to,const void __user * from,unsigned long size)446 static unsigned long __copy_user_intel_nocache(void *to,
447 const void __user *from, unsigned long size)
448 {
449 int d0, d1;
450
451 __asm__ __volatile__(
452 " .align 2,0x90\n"
453 "0: movl 32(%4), %%eax\n"
454 " cmpl $67, %0\n"
455 " jbe 2f\n"
456 "1: movl 64(%4), %%eax\n"
457 " .align 2,0x90\n"
458 "2: movl 0(%4), %%eax\n"
459 "21: movl 4(%4), %%edx\n"
460 " movnti %%eax, 0(%3)\n"
461 " movnti %%edx, 4(%3)\n"
462 "3: movl 8(%4), %%eax\n"
463 "31: movl 12(%4),%%edx\n"
464 " movnti %%eax, 8(%3)\n"
465 " movnti %%edx, 12(%3)\n"
466 "4: movl 16(%4), %%eax\n"
467 "41: movl 20(%4), %%edx\n"
468 " movnti %%eax, 16(%3)\n"
469 " movnti %%edx, 20(%3)\n"
470 "10: movl 24(%4), %%eax\n"
471 "51: movl 28(%4), %%edx\n"
472 " movnti %%eax, 24(%3)\n"
473 " movnti %%edx, 28(%3)\n"
474 "11: movl 32(%4), %%eax\n"
475 "61: movl 36(%4), %%edx\n"
476 " movnti %%eax, 32(%3)\n"
477 " movnti %%edx, 36(%3)\n"
478 "12: movl 40(%4), %%eax\n"
479 "71: movl 44(%4), %%edx\n"
480 " movnti %%eax, 40(%3)\n"
481 " movnti %%edx, 44(%3)\n"
482 "13: movl 48(%4), %%eax\n"
483 "81: movl 52(%4), %%edx\n"
484 " movnti %%eax, 48(%3)\n"
485 " movnti %%edx, 52(%3)\n"
486 "14: movl 56(%4), %%eax\n"
487 "91: movl 60(%4), %%edx\n"
488 " movnti %%eax, 56(%3)\n"
489 " movnti %%edx, 60(%3)\n"
490 " addl $-64, %0\n"
491 " addl $64, %4\n"
492 " addl $64, %3\n"
493 " cmpl $63, %0\n"
494 " ja 0b\n"
495 " sfence \n"
496 "5: movl %0, %%eax\n"
497 " shrl $2, %0\n"
498 " andl $3, %%eax\n"
499 " cld\n"
500 "6: rep; movsl\n"
501 " movl %%eax,%0\n"
502 "7: rep; movsb\n"
503 "8:\n"
504 ".section .fixup,\"ax\"\n"
505 "9: lea 0(%%eax,%0,4),%0\n"
506 "16: jmp 8b\n"
507 ".previous\n"
508 ".section __ex_table,\"a\"\n"
509 " .align 4\n"
510 " .long 0b,16b\n"
511 " .long 1b,16b\n"
512 " .long 2b,16b\n"
513 " .long 21b,16b\n"
514 " .long 3b,16b\n"
515 " .long 31b,16b\n"
516 " .long 4b,16b\n"
517 " .long 41b,16b\n"
518 " .long 10b,16b\n"
519 " .long 51b,16b\n"
520 " .long 11b,16b\n"
521 " .long 61b,16b\n"
522 " .long 12b,16b\n"
523 " .long 71b,16b\n"
524 " .long 13b,16b\n"
525 " .long 81b,16b\n"
526 " .long 14b,16b\n"
527 " .long 91b,16b\n"
528 " .long 6b,9b\n"
529 " .long 7b,16b\n"
530 ".previous"
531 : "=&c"(size), "=&D" (d0), "=&S" (d1)
532 : "1"(to), "2"(from), "0"(size)
533 : "eax", "edx", "memory");
534 return size;
535 }
536
537 #else
538
539 /*
540 * Leave these declared but undefined. They should not be any references to
541 * them
542 */
543 unsigned long __copy_user_zeroing_intel(void *to, const void __user *from,
544 unsigned long size);
545 unsigned long __copy_user_intel(void __user *to, const void *from,
546 unsigned long size);
547 unsigned long __copy_user_zeroing_intel_nocache(void *to,
548 const void __user *from, unsigned long size);
549 #endif /* CONFIG_X86_INTEL_USERCOPY */
550
551 /* Generic arbitrary sized copy. */
552 #define __copy_user(to, from, size) \
553 do { \
554 int __d0, __d1, __d2; \
555 __asm__ __volatile__( \
556 " cmp $7,%0\n" \
557 " jbe 1f\n" \
558 " movl %1,%0\n" \
559 " negl %0\n" \
560 " andl $7,%0\n" \
561 " subl %0,%3\n" \
562 "4: rep; movsb\n" \
563 " movl %3,%0\n" \
564 " shrl $2,%0\n" \
565 " andl $3,%3\n" \
566 " .align 2,0x90\n" \
567 "0: rep; movsl\n" \
568 " movl %3,%0\n" \
569 "1: rep; movsb\n" \
570 "2:\n" \
571 ".section .fixup,\"ax\"\n" \
572 "5: addl %3,%0\n" \
573 " jmp 2b\n" \
574 "3: lea 0(%3,%0,4),%0\n" \
575 " jmp 2b\n" \
576 ".previous\n" \
577 ".section __ex_table,\"a\"\n" \
578 " .align 4\n" \
579 " .long 4b,5b\n" \
580 " .long 0b,3b\n" \
581 " .long 1b,2b\n" \
582 ".previous" \
583 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
584 : "3"(size), "0"(size), "1"(to), "2"(from) \
585 : "memory"); \
586 } while (0)
587
588 #define __copy_user_zeroing(to, from, size) \
589 do { \
590 int __d0, __d1, __d2; \
591 __asm__ __volatile__( \
592 " cmp $7,%0\n" \
593 " jbe 1f\n" \
594 " movl %1,%0\n" \
595 " negl %0\n" \
596 " andl $7,%0\n" \
597 " subl %0,%3\n" \
598 "4: rep; movsb\n" \
599 " movl %3,%0\n" \
600 " shrl $2,%0\n" \
601 " andl $3,%3\n" \
602 " .align 2,0x90\n" \
603 "0: rep; movsl\n" \
604 " movl %3,%0\n" \
605 "1: rep; movsb\n" \
606 "2:\n" \
607 ".section .fixup,\"ax\"\n" \
608 "5: addl %3,%0\n" \
609 " jmp 6f\n" \
610 "3: lea 0(%3,%0,4),%0\n" \
611 "6: pushl %0\n" \
612 " pushl %%eax\n" \
613 " xorl %%eax,%%eax\n" \
614 " rep; stosb\n" \
615 " popl %%eax\n" \
616 " popl %0\n" \
617 " jmp 2b\n" \
618 ".previous\n" \
619 ".section __ex_table,\"a\"\n" \
620 " .align 4\n" \
621 " .long 4b,5b\n" \
622 " .long 0b,3b\n" \
623 " .long 1b,6b\n" \
624 ".previous" \
625 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
626 : "3"(size), "0"(size), "1"(to), "2"(from) \
627 : "memory"); \
628 } while (0)
629
__copy_to_user_ll(void __user * to,const void * from,unsigned long n)630 unsigned long __copy_to_user_ll(void __user *to, const void *from,
631 unsigned long n)
632 {
633 #ifndef CONFIG_X86_WP_WORKS_OK
634 if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
635 ((unsigned long)to) < TASK_SIZE) {
636 /*
637 * When we are in an atomic section (see
638 * mm/filemap.c:file_read_actor), return the full
639 * length to take the slow path.
640 */
641 if (in_atomic())
642 return n;
643
644 /*
645 * CPU does not honor the WP bit when writing
646 * from supervisory mode, and due to preemption or SMP,
647 * the page tables can change at any time.
648 * Do it manually. Manfred <manfred@colorfullife.com>
649 */
650 while (n) {
651 unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
652 unsigned long len = PAGE_SIZE - offset;
653 int retval;
654 struct page *pg;
655 void *maddr;
656
657 if (len > n)
658 len = n;
659
660 survive:
661 down_read(¤t->mm->mmap_sem);
662 retval = get_user_pages(current, current->mm,
663 (unsigned long)to, 1, 1, 0, &pg, NULL);
664
665 if (retval == -ENOMEM && is_global_init(current)) {
666 up_read(¤t->mm->mmap_sem);
667 congestion_wait(BLK_RW_ASYNC, HZ/50);
668 goto survive;
669 }
670
671 if (retval != 1) {
672 up_read(¤t->mm->mmap_sem);
673 break;
674 }
675
676 maddr = kmap_atomic(pg);
677 memcpy(maddr + offset, from, len);
678 kunmap_atomic(maddr);
679 set_page_dirty_lock(pg);
680 put_page(pg);
681 up_read(¤t->mm->mmap_sem);
682
683 from += len;
684 to += len;
685 n -= len;
686 }
687 return n;
688 }
689 #endif
690 if (movsl_is_ok(to, from, n))
691 __copy_user(to, from, n);
692 else
693 n = __copy_user_intel(to, from, n);
694 return n;
695 }
696 EXPORT_SYMBOL(__copy_to_user_ll);
697
__copy_from_user_ll(void * to,const void __user * from,unsigned long n)698 unsigned long __copy_from_user_ll(void *to, const void __user *from,
699 unsigned long n)
700 {
701 if (movsl_is_ok(to, from, n))
702 __copy_user_zeroing(to, from, n);
703 else
704 n = __copy_user_zeroing_intel(to, from, n);
705 return n;
706 }
707 EXPORT_SYMBOL(__copy_from_user_ll);
708
__copy_from_user_ll_nozero(void * to,const void __user * from,unsigned long n)709 unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
710 unsigned long n)
711 {
712 if (movsl_is_ok(to, from, n))
713 __copy_user(to, from, n);
714 else
715 n = __copy_user_intel((void __user *)to,
716 (const void *)from, n);
717 return n;
718 }
719 EXPORT_SYMBOL(__copy_from_user_ll_nozero);
720
__copy_from_user_ll_nocache(void * to,const void __user * from,unsigned long n)721 unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from,
722 unsigned long n)
723 {
724 #ifdef CONFIG_X86_INTEL_USERCOPY
725 if (n > 64 && cpu_has_xmm2)
726 n = __copy_user_zeroing_intel_nocache(to, from, n);
727 else
728 __copy_user_zeroing(to, from, n);
729 #else
730 __copy_user_zeroing(to, from, n);
731 #endif
732 return n;
733 }
734 EXPORT_SYMBOL(__copy_from_user_ll_nocache);
735
__copy_from_user_ll_nocache_nozero(void * to,const void __user * from,unsigned long n)736 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
737 unsigned long n)
738 {
739 #ifdef CONFIG_X86_INTEL_USERCOPY
740 if (n > 64 && cpu_has_xmm2)
741 n = __copy_user_intel_nocache(to, from, n);
742 else
743 __copy_user(to, from, n);
744 #else
745 __copy_user(to, from, n);
746 #endif
747 return n;
748 }
749 EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);
750
751 /**
752 * copy_to_user: - Copy a block of data into user space.
753 * @to: Destination address, in user space.
754 * @from: Source address, in kernel space.
755 * @n: Number of bytes to copy.
756 *
757 * Context: User context only. This function may sleep.
758 *
759 * Copy data from kernel space to user space.
760 *
761 * Returns number of bytes that could not be copied.
762 * On success, this will be zero.
763 */
764 unsigned long
copy_to_user(void __user * to,const void * from,unsigned long n)765 copy_to_user(void __user *to, const void *from, unsigned long n)
766 {
767 if (access_ok(VERIFY_WRITE, to, n))
768 n = __copy_to_user(to, from, n);
769 return n;
770 }
771 EXPORT_SYMBOL(copy_to_user);
772
773 /**
774 * copy_from_user: - Copy a block of data from user space.
775 * @to: Destination address, in kernel space.
776 * @from: Source address, in user space.
777 * @n: Number of bytes to copy.
778 *
779 * Context: User context only. This function may sleep.
780 *
781 * Copy data from user space to kernel space.
782 *
783 * Returns number of bytes that could not be copied.
784 * On success, this will be zero.
785 *
786 * If some data could not be copied, this function will pad the copied
787 * data to the requested size using zero bytes.
788 */
789 unsigned long
_copy_from_user(void * to,const void __user * from,unsigned long n)790 _copy_from_user(void *to, const void __user *from, unsigned long n)
791 {
792 if (access_ok(VERIFY_READ, from, n))
793 n = __copy_from_user(to, from, n);
794 else
795 memset(to, 0, n);
796 return n;
797 }
798 EXPORT_SYMBOL(_copy_from_user);
799
copy_from_user_overflow(void)800 void copy_from_user_overflow(void)
801 {
802 WARN(1, "Buffer overflow detected!\n");
803 }
804 EXPORT_SYMBOL(copy_from_user_overflow);
805