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nfsd4: typo logical vs bitwise negate for want_mask
[linux-btrfs-devel.git] / arch / x86 / lib / usercopy_32.c
blobe218d5df85ff23445c277c2fe89d611dcab433ae
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
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 * Copy a null terminated string from userspace.
37 */
38
39 #define __do_strncpy_from_user(dst, src, count, res) \
40 do { \
41 int __d0, __d1, __d2; \
42 might_fault(); \
43 __asm__ __volatile__( \
44 " testl %1,%1\n" \
45 " jz 2f\n" \
46 "0: lodsb\n" \
47 " stosb\n" \
48 " testb %%al,%%al\n" \
49 " jz 1f\n" \
50 " decl %1\n" \
51 " jnz 0b\n" \
52 "1: subl %1,%0\n" \
53 "2:\n" \
54 ".section .fixup,\"ax\"\n" \
55 "3: movl %5,%0\n" \
56 " jmp 2b\n" \
57 ".previous\n" \
58 _ASM_EXTABLE(0b,3b) \
59 : "=&d"(res), "=&c"(count), "=&a" (__d0), "=&S" (__d1), \
60 "=&D" (__d2) \
61 : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
62 : "memory"); \
63 } while (0)
64
65 /**
66 * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
67 * @dst: Destination address, in kernel space. This buffer must be at
68 * least @count bytes long.
69 * @src: Source address, in user space.
70 * @count: Maximum number of bytes to copy, including the trailing NUL.
71 *
72 * Copies a NUL-terminated string from userspace to kernel space.
73 * Caller must check the specified block with access_ok() before calling
74 * this function.
75 *
76 * On success, returns the length of the string (not including the trailing
77 * NUL).
78 *
79 * If access to userspace fails, returns -EFAULT (some data may have been
80 * copied).
81 *
82 * If @count is smaller than the length of the string, copies @count bytes
83 * and returns @count.
84 */
85 long
86 __strncpy_from_user(char *dst, const char __user *src, long count)
87 {
88 long res;
89 __do_strncpy_from_user(dst, src, count, res);
90 return res;
91 }
92 EXPORT_SYMBOL(__strncpy_from_user);
93
94 /**
95 * strncpy_from_user: - Copy a NUL terminated string from userspace.
96 * @dst: Destination address, in kernel space. This buffer must be at
97 * least @count bytes long.
98 * @src: Source address, in user space.
99 * @count: Maximum number of bytes to copy, including the trailing NUL.
100 *
101 * Copies a NUL-terminated string from userspace to kernel space.
102 *
103 * On success, returns the length of the string (not including the trailing
104 * NUL).
105 *
106 * If access to userspace fails, returns -EFAULT (some data may have been
107 * copied).
108 *
109 * If @count is smaller than the length of the string, copies @count bytes
110 * and returns @count.
111 */
112 long
113 strncpy_from_user(char *dst, const char __user *src, long count)
114 {
115 long res = -EFAULT;
116 if (access_ok(VERIFY_READ, src, 1))
117 __do_strncpy_from_user(dst, src, count, res);
118 return res;
119 }
120 EXPORT_SYMBOL(strncpy_from_user);
121
122 /*
123 * Zero Userspace
124 */
125
126 #define __do_clear_user(addr,size) \
127 do { \
128 int __d0; \
129 might_fault(); \
130 __asm__ __volatile__( \
131 "0: rep; stosl\n" \
132 " movl %2,%0\n" \
133 "1: rep; stosb\n" \
134 "2:\n" \
135 ".section .fixup,\"ax\"\n" \
136 "3: lea 0(%2,%0,4),%0\n" \
137 " jmp 2b\n" \
138 ".previous\n" \
139 _ASM_EXTABLE(0b,3b) \
140 _ASM_EXTABLE(1b,2b) \
141 : "=&c"(size), "=&D" (__d0) \
142 : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \
143 } while (0)
144
145 /**
146 * clear_user: - Zero a block of memory in user space.
147 * @to: Destination address, in user space.
148 * @n: Number of bytes to zero.
149 *
150 * Zero a block of memory in user space.
151 *
152 * Returns number of bytes that could not be cleared.
153 * On success, this will be zero.
154 */
155 unsigned long
156 clear_user(void __user *to, unsigned long n)
157 {
158 might_fault();
159 if (access_ok(VERIFY_WRITE, to, n))
160 __do_clear_user(to, n);
161 return n;
162 }
163 EXPORT_SYMBOL(clear_user);
164
165 /**
166 * __clear_user: - Zero a block of memory in user space, with less checking.
167 * @to: Destination address, in user space.
168 * @n: Number of bytes to zero.
169 *
170 * Zero a block of memory in user space. Caller must check
171 * the specified block with access_ok() before calling this function.
172 *
173 * Returns number of bytes that could not be cleared.
174 * On success, this will be zero.
175 */
176 unsigned long
177 __clear_user(void __user *to, unsigned long n)
178 {
179 __do_clear_user(to, n);
180 return n;
181 }
182 EXPORT_SYMBOL(__clear_user);
183
184 /**
185 * strnlen_user: - Get the size of a string in user space.
186 * @s: The string to measure.
187 * @n: The maximum valid length
188 *
189 * Get the size of a NUL-terminated string in user space.
190 *
191 * Returns the size of the string INCLUDING the terminating NUL.
192 * On exception, returns 0.
193 * If the string is too long, returns a value greater than @n.
194 */
195 long strnlen_user(const char __user *s, long n)
196 {
197 unsigned long mask = -__addr_ok(s);
198 unsigned long res, tmp;
199
200 might_fault();
201
202 __asm__ __volatile__(
203 " testl %0, %0\n"
204 " jz 3f\n"
205 " andl %0,%%ecx\n"
206 "0: repne; scasb\n"
207 " setne %%al\n"
208 " subl %%ecx,%0\n"
209 " addl %0,%%eax\n"
210 "1:\n"
211 ".section .fixup,\"ax\"\n"
212 "2: xorl %%eax,%%eax\n"
213 " jmp 1b\n"
214 "3: movb $1,%%al\n"
215 " jmp 1b\n"
216 ".previous\n"
217 ".section __ex_table,\"a\"\n"
218 " .align 4\n"
219 " .long 0b,2b\n"
220 ".previous"
221 :"=&r" (n), "=&D" (s), "=&a" (res), "=&c" (tmp)
222 :"0" (n), "1" (s), "2" (0), "3" (mask)
223 :"cc");
224 return res & mask;
225 }
226 EXPORT_SYMBOL(strnlen_user);
227
228 #ifdef CONFIG_X86_INTEL_USERCOPY
229 static unsigned long
230 __copy_user_intel(void __user *to, const void *from, unsigned long size)
231 {
232 int d0, d1;
233 __asm__ __volatile__(
234 " .align 2,0x90\n"
235 "1: movl 32(%4), %%eax\n"
236 " cmpl $67, %0\n"
237 " jbe 3f\n"
238 "2: movl 64(%4), %%eax\n"
239 " .align 2,0x90\n"
240 "3: movl 0(%4), %%eax\n"
241 "4: movl 4(%4), %%edx\n"
242 "5: movl %%eax, 0(%3)\n"
243 "6: movl %%edx, 4(%3)\n"
244 "7: movl 8(%4), %%eax\n"
245 "8: movl 12(%4),%%edx\n"
246 "9: movl %%eax, 8(%3)\n"
247 "10: movl %%edx, 12(%3)\n"
248 "11: movl 16(%4), %%eax\n"
249 "12: movl 20(%4), %%edx\n"
250 "13: movl %%eax, 16(%3)\n"
251 "14: movl %%edx, 20(%3)\n"
252 "15: movl 24(%4), %%eax\n"
253 "16: movl 28(%4), %%edx\n"
254 "17: movl %%eax, 24(%3)\n"
255 "18: movl %%edx, 28(%3)\n"
256 "19: movl 32(%4), %%eax\n"
257 "20: movl 36(%4), %%edx\n"
258 "21: movl %%eax, 32(%3)\n"
259 "22: movl %%edx, 36(%3)\n"
260 "23: movl 40(%4), %%eax\n"
261 "24: movl 44(%4), %%edx\n"
262 "25: movl %%eax, 40(%3)\n"
263 "26: movl %%edx, 44(%3)\n"
264 "27: movl 48(%4), %%eax\n"
265 "28: movl 52(%4), %%edx\n"
266 "29: movl %%eax, 48(%3)\n"
267 "30: movl %%edx, 52(%3)\n"
268 "31: movl 56(%4), %%eax\n"
269 "32: movl 60(%4), %%edx\n"
270 "33: movl %%eax, 56(%3)\n"
271 "34: movl %%edx, 60(%3)\n"
272 " addl $-64, %0\n"
273 " addl $64, %4\n"
274 " addl $64, %3\n"
275 " cmpl $63, %0\n"
276 " ja 1b\n"
277 "35: movl %0, %%eax\n"
278 " shrl $2, %0\n"
279 " andl $3, %%eax\n"
280 " cld\n"
281 "99: rep; movsl\n"
282 "36: movl %%eax, %0\n"
283 "37: rep; movsb\n"
284 "100:\n"
285 ".section .fixup,\"ax\"\n"
286 "101: lea 0(%%eax,%0,4),%0\n"
287 " jmp 100b\n"
288 ".previous\n"
289 ".section __ex_table,\"a\"\n"
290 " .align 4\n"
291 " .long 1b,100b\n"
292 " .long 2b,100b\n"
293 " .long 3b,100b\n"
294 " .long 4b,100b\n"
295 " .long 5b,100b\n"
296 " .long 6b,100b\n"
297 " .long 7b,100b\n"
298 " .long 8b,100b\n"
299 " .long 9b,100b\n"
300 " .long 10b,100b\n"
301 " .long 11b,100b\n"
302 " .long 12b,100b\n"
303 " .long 13b,100b\n"
304 " .long 14b,100b\n"
305 " .long 15b,100b\n"
306 " .long 16b,100b\n"
307 " .long 17b,100b\n"
308 " .long 18b,100b\n"
309 " .long 19b,100b\n"
310 " .long 20b,100b\n"
311 " .long 21b,100b\n"
312 " .long 22b,100b\n"
313 " .long 23b,100b\n"
314 " .long 24b,100b\n"
315 " .long 25b,100b\n"
316 " .long 26b,100b\n"
317 " .long 27b,100b\n"
318 " .long 28b,100b\n"
319 " .long 29b,100b\n"
320 " .long 30b,100b\n"
321 " .long 31b,100b\n"
322 " .long 32b,100b\n"
323 " .long 33b,100b\n"
324 " .long 34b,100b\n"
325 " .long 35b,100b\n"
326 " .long 36b,100b\n"
327 " .long 37b,100b\n"
328 " .long 99b,101b\n"
329 ".previous"
330 : "=&c"(size), "=&D" (d0), "=&S" (d1)
331 : "1"(to), "2"(from), "0"(size)
332 : "eax", "edx", "memory");
333 return size;
334 }
335
336 static unsigned long
337 __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size)
338 {
339 int d0, d1;
340 __asm__ __volatile__(
341 " .align 2,0x90\n"
342 "0: movl 32(%4), %%eax\n"
343 " cmpl $67, %0\n"
344 " jbe 2f\n"
345 "1: movl 64(%4), %%eax\n"
346 " .align 2,0x90\n"
347 "2: movl 0(%4), %%eax\n"
348 "21: movl 4(%4), %%edx\n"
349 " movl %%eax, 0(%3)\n"
350 " movl %%edx, 4(%3)\n"
351 "3: movl 8(%4), %%eax\n"
352 "31: movl 12(%4),%%edx\n"
353 " movl %%eax, 8(%3)\n"
354 " movl %%edx, 12(%3)\n"
355 "4: movl 16(%4), %%eax\n"
356 "41: movl 20(%4), %%edx\n"
357 " movl %%eax, 16(%3)\n"
358 " movl %%edx, 20(%3)\n"
359 "10: movl 24(%4), %%eax\n"
360 "51: movl 28(%4), %%edx\n"
361 " movl %%eax, 24(%3)\n"
362 " movl %%edx, 28(%3)\n"
363 "11: movl 32(%4), %%eax\n"
364 "61: movl 36(%4), %%edx\n"
365 " movl %%eax, 32(%3)\n"
366 " movl %%edx, 36(%3)\n"
367 "12: movl 40(%4), %%eax\n"
368 "71: movl 44(%4), %%edx\n"
369 " movl %%eax, 40(%3)\n"
370 " movl %%edx, 44(%3)\n"
371 "13: movl 48(%4), %%eax\n"
372 "81: movl 52(%4), %%edx\n"
373 " movl %%eax, 48(%3)\n"
374 " movl %%edx, 52(%3)\n"
375 "14: movl 56(%4), %%eax\n"
376 "91: movl 60(%4), %%edx\n"
377 " movl %%eax, 56(%3)\n"
378 " movl %%edx, 60(%3)\n"
379 " addl $-64, %0\n"
380 " addl $64, %4\n"
381 " addl $64, %3\n"
382 " cmpl $63, %0\n"
383 " ja 0b\n"
384 "5: movl %0, %%eax\n"
385 " shrl $2, %0\n"
386 " andl $3, %%eax\n"
387 " cld\n"
388 "6: rep; movsl\n"
389 " movl %%eax,%0\n"
390 "7: rep; movsb\n"
391 "8:\n"
392 ".section .fixup,\"ax\"\n"
393 "9: lea 0(%%eax,%0,4),%0\n"
394 "16: pushl %0\n"
395 " pushl %%eax\n"
396 " xorl %%eax,%%eax\n"
397 " rep; stosb\n"
398 " popl %%eax\n"
399 " popl %0\n"
400 " jmp 8b\n"
401 ".previous\n"
402 ".section __ex_table,\"a\"\n"
403 " .align 4\n"
404 " .long 0b,16b\n"
405 " .long 1b,16b\n"
406 " .long 2b,16b\n"
407 " .long 21b,16b\n"
408 " .long 3b,16b\n"
409 " .long 31b,16b\n"
410 " .long 4b,16b\n"
411 " .long 41b,16b\n"
412 " .long 10b,16b\n"
413 " .long 51b,16b\n"
414 " .long 11b,16b\n"
415 " .long 61b,16b\n"
416 " .long 12b,16b\n"
417 " .long 71b,16b\n"
418 " .long 13b,16b\n"
419 " .long 81b,16b\n"
420 " .long 14b,16b\n"
421 " .long 91b,16b\n"
422 " .long 6b,9b\n"
423 " .long 7b,16b\n"
424 ".previous"
425 : "=&c"(size), "=&D" (d0), "=&S" (d1)
426 : "1"(to), "2"(from), "0"(size)
427 : "eax", "edx", "memory");
428 return size;
429 }
430
431 /*
432 * Non Temporal Hint version of __copy_user_zeroing_intel. It is cache aware.
433 * hyoshiok@miraclelinux.com
434 */
435
436 static unsigned long __copy_user_zeroing_intel_nocache(void *to,
437 const void __user *from, unsigned long size)
438 {
439 int d0, d1;
440
441 __asm__ __volatile__(
442 " .align 2,0x90\n"
443 "0: movl 32(%4), %%eax\n"
444 " cmpl $67, %0\n"
445 " jbe 2f\n"
446 "1: movl 64(%4), %%eax\n"
447 " .align 2,0x90\n"
448 "2: movl 0(%4), %%eax\n"
449 "21: movl 4(%4), %%edx\n"
450 " movnti %%eax, 0(%3)\n"
451 " movnti %%edx, 4(%3)\n"
452 "3: movl 8(%4), %%eax\n"
453 "31: movl 12(%4),%%edx\n"
454 " movnti %%eax, 8(%3)\n"
455 " movnti %%edx, 12(%3)\n"
456 "4: movl 16(%4), %%eax\n"
457 "41: movl 20(%4), %%edx\n"
458 " movnti %%eax, 16(%3)\n"
459 " movnti %%edx, 20(%3)\n"
460 "10: movl 24(%4), %%eax\n"
461 "51: movl 28(%4), %%edx\n"
462 " movnti %%eax, 24(%3)\n"
463 " movnti %%edx, 28(%3)\n"
464 "11: movl 32(%4), %%eax\n"
465 "61: movl 36(%4), %%edx\n"
466 " movnti %%eax, 32(%3)\n"
467 " movnti %%edx, 36(%3)\n"
468 "12: movl 40(%4), %%eax\n"
469 "71: movl 44(%4), %%edx\n"
470 " movnti %%eax, 40(%3)\n"
471 " movnti %%edx, 44(%3)\n"
472 "13: movl 48(%4), %%eax\n"
473 "81: movl 52(%4), %%edx\n"
474 " movnti %%eax, 48(%3)\n"
475 " movnti %%edx, 52(%3)\n"
476 "14: movl 56(%4), %%eax\n"
477 "91: movl 60(%4), %%edx\n"
478 " movnti %%eax, 56(%3)\n"
479 " movnti %%edx, 60(%3)\n"
480 " addl $-64, %0\n"
481 " addl $64, %4\n"
482 " addl $64, %3\n"
483 " cmpl $63, %0\n"
484 " ja 0b\n"
485 " sfence \n"
486 "5: movl %0, %%eax\n"
487 " shrl $2, %0\n"
488 " andl $3, %%eax\n"
489 " cld\n"
490 "6: rep; movsl\n"
491 " movl %%eax,%0\n"
492 "7: rep; movsb\n"
493 "8:\n"
494 ".section .fixup,\"ax\"\n"
495 "9: lea 0(%%eax,%0,4),%0\n"
496 "16: pushl %0\n"
497 " pushl %%eax\n"
498 " xorl %%eax,%%eax\n"
499 " rep; stosb\n"
500 " popl %%eax\n"
501 " popl %0\n"
502 " jmp 8b\n"
503 ".previous\n"
504 ".section __ex_table,\"a\"\n"
505 " .align 4\n"
506 " .long 0b,16b\n"
507 " .long 1b,16b\n"
508 " .long 2b,16b\n"
509 " .long 21b,16b\n"
510 " .long 3b,16b\n"
511 " .long 31b,16b\n"
512 " .long 4b,16b\n"
513 " .long 41b,16b\n"
514 " .long 10b,16b\n"
515 " .long 51b,16b\n"
516 " .long 11b,16b\n"
517 " .long 61b,16b\n"
518 " .long 12b,16b\n"
519 " .long 71b,16b\n"
520 " .long 13b,16b\n"
521 " .long 81b,16b\n"
522 " .long 14b,16b\n"
523 " .long 91b,16b\n"
524 " .long 6b,9b\n"
525 " .long 7b,16b\n"
526 ".previous"
527 : "=&c"(size), "=&D" (d0), "=&S" (d1)
528 : "1"(to), "2"(from), "0"(size)
529 : "eax", "edx", "memory");
530 return size;
531 }
532
533 static unsigned long __copy_user_intel_nocache(void *to,
534 const void __user *from, unsigned long size)
535 {
536 int d0, d1;
537
538 __asm__ __volatile__(
539 " .align 2,0x90\n"
540 "0: movl 32(%4), %%eax\n"
541 " cmpl $67, %0\n"
542 " jbe 2f\n"
543 "1: movl 64(%4), %%eax\n"
544 " .align 2,0x90\n"
545 "2: movl 0(%4), %%eax\n"
546 "21: movl 4(%4), %%edx\n"
547 " movnti %%eax, 0(%3)\n"
548 " movnti %%edx, 4(%3)\n"
549 "3: movl 8(%4), %%eax\n"
550 "31: movl 12(%4),%%edx\n"
551 " movnti %%eax, 8(%3)\n"
552 " movnti %%edx, 12(%3)\n"
553 "4: movl 16(%4), %%eax\n"
554 "41: movl 20(%4), %%edx\n"
555 " movnti %%eax, 16(%3)\n"
556 " movnti %%edx, 20(%3)\n"
557 "10: movl 24(%4), %%eax\n"
558 "51: movl 28(%4), %%edx\n"
559 " movnti %%eax, 24(%3)\n"
560 " movnti %%edx, 28(%3)\n"
561 "11: movl 32(%4), %%eax\n"
562 "61: movl 36(%4), %%edx\n"
563 " movnti %%eax, 32(%3)\n"
564 " movnti %%edx, 36(%3)\n"
565 "12: movl 40(%4), %%eax\n"
566 "71: movl 44(%4), %%edx\n"
567 " movnti %%eax, 40(%3)\n"
568 " movnti %%edx, 44(%3)\n"
569 "13: movl 48(%4), %%eax\n"
570 "81: movl 52(%4), %%edx\n"
571 " movnti %%eax, 48(%3)\n"
572 " movnti %%edx, 52(%3)\n"
573 "14: movl 56(%4), %%eax\n"
574 "91: movl 60(%4), %%edx\n"
575 " movnti %%eax, 56(%3)\n"
576 " movnti %%edx, 60(%3)\n"
577 " addl $-64, %0\n"
578 " addl $64, %4\n"
579 " addl $64, %3\n"
580 " cmpl $63, %0\n"
581 " ja 0b\n"
582 " sfence \n"
583 "5: movl %0, %%eax\n"
584 " shrl $2, %0\n"
585 " andl $3, %%eax\n"
586 " cld\n"
587 "6: rep; movsl\n"
588 " movl %%eax,%0\n"
589 "7: rep; movsb\n"
590 "8:\n"
591 ".section .fixup,\"ax\"\n"
592 "9: lea 0(%%eax,%0,4),%0\n"
593 "16: jmp 8b\n"
594 ".previous\n"
595 ".section __ex_table,\"a\"\n"
596 " .align 4\n"
597 " .long 0b,16b\n"
598 " .long 1b,16b\n"
599 " .long 2b,16b\n"
600 " .long 21b,16b\n"
601 " .long 3b,16b\n"
602 " .long 31b,16b\n"
603 " .long 4b,16b\n"
604 " .long 41b,16b\n"
605 " .long 10b,16b\n"
606 " .long 51b,16b\n"
607 " .long 11b,16b\n"
608 " .long 61b,16b\n"
609 " .long 12b,16b\n"
610 " .long 71b,16b\n"
611 " .long 13b,16b\n"
612 " .long 81b,16b\n"
613 " .long 14b,16b\n"
614 " .long 91b,16b\n"
615 " .long 6b,9b\n"
616 " .long 7b,16b\n"
617 ".previous"
618 : "=&c"(size), "=&D" (d0), "=&S" (d1)
619 : "1"(to), "2"(from), "0"(size)
620 : "eax", "edx", "memory");
621 return size;
622 }
623
624 #else
625
626 /*
627 * Leave these declared but undefined. They should not be any references to
628 * them
629 */
630 unsigned long __copy_user_zeroing_intel(void *to, const void __user *from,
631 unsigned long size);
632 unsigned long __copy_user_intel(void __user *to, const void *from,
633 unsigned long size);
634 unsigned long __copy_user_zeroing_intel_nocache(void *to,
635 const void __user *from, unsigned long size);
636 #endif /* CONFIG_X86_INTEL_USERCOPY */
637
638 /* Generic arbitrary sized copy. */
639 #define __copy_user(to, from, size) \
640 do { \
641 int __d0, __d1, __d2; \
642 __asm__ __volatile__( \
643 " cmp $7,%0\n" \
644 " jbe 1f\n" \
645 " movl %1,%0\n" \
646 " negl %0\n" \
647 " andl $7,%0\n" \
648 " subl %0,%3\n" \
649 "4: rep; movsb\n" \
650 " movl %3,%0\n" \
651 " shrl $2,%0\n" \
652 " andl $3,%3\n" \
653 " .align 2,0x90\n" \
654 "0: rep; movsl\n" \
655 " movl %3,%0\n" \
656 "1: rep; movsb\n" \
657 "2:\n" \
658 ".section .fixup,\"ax\"\n" \
659 "5: addl %3,%0\n" \
660 " jmp 2b\n" \
661 "3: lea 0(%3,%0,4),%0\n" \
662 " jmp 2b\n" \
663 ".previous\n" \
664 ".section __ex_table,\"a\"\n" \
665 " .align 4\n" \
666 " .long 4b,5b\n" \
667 " .long 0b,3b\n" \
668 " .long 1b,2b\n" \
669 ".previous" \
670 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
671 : "3"(size), "0"(size), "1"(to), "2"(from) \
672 : "memory"); \
673 } while (0)
674
675 #define __copy_user_zeroing(to, from, size) \
676 do { \
677 int __d0, __d1, __d2; \
678 __asm__ __volatile__( \
679 " cmp $7,%0\n" \
680 " jbe 1f\n" \
681 " movl %1,%0\n" \
682 " negl %0\n" \
683 " andl $7,%0\n" \
684 " subl %0,%3\n" \
685 "4: rep; movsb\n" \
686 " movl %3,%0\n" \
687 " shrl $2,%0\n" \
688 " andl $3,%3\n" \
689 " .align 2,0x90\n" \
690 "0: rep; movsl\n" \
691 " movl %3,%0\n" \
692 "1: rep; movsb\n" \
693 "2:\n" \
694 ".section .fixup,\"ax\"\n" \
695 "5: addl %3,%0\n" \
696 " jmp 6f\n" \
697 "3: lea 0(%3,%0,4),%0\n" \
698 "6: pushl %0\n" \
699 " pushl %%eax\n" \
700 " xorl %%eax,%%eax\n" \
701 " rep; stosb\n" \
702 " popl %%eax\n" \
703 " popl %0\n" \
704 " jmp 2b\n" \
705 ".previous\n" \
706 ".section __ex_table,\"a\"\n" \
707 " .align 4\n" \
708 " .long 4b,5b\n" \
709 " .long 0b,3b\n" \
710 " .long 1b,6b\n" \
711 ".previous" \
712 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
713 : "3"(size), "0"(size), "1"(to), "2"(from) \
714 : "memory"); \
715 } while (0)
716
717 unsigned long __copy_to_user_ll(void __user *to, const void *from,
718 unsigned long n)
719 {
720 #ifndef CONFIG_X86_WP_WORKS_OK
721 if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
722 ((unsigned long)to) < TASK_SIZE) {
723 /*
724 * When we are in an atomic section (see
725 * mm/filemap.c:file_read_actor), return the full
726 * length to take the slow path.
727 */
728 if (in_atomic())
729 return n;
730
731 /*
732 * CPU does not honor the WP bit when writing
733 * from supervisory mode, and due to preemption or SMP,
734 * the page tables can change at any time.
735 * Do it manually. Manfred <manfred@colorfullife.com>
736 */
737 while (n) {
738 unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
739 unsigned long len = PAGE_SIZE - offset;
740 int retval;
741 struct page *pg;
742 void *maddr;
743
744 if (len > n)
745 len = n;
746
747 survive:
748 down_read(&current->mm->mmap_sem);
749 retval = get_user_pages(current, current->mm,
750 (unsigned long)to, 1, 1, 0, &pg, NULL);
751
752 if (retval == -ENOMEM && is_global_init(current)) {
753 up_read(&current->mm->mmap_sem);
754 congestion_wait(BLK_RW_ASYNC, HZ/50);
755 goto survive;
756 }
757
758 if (retval != 1) {
759 up_read(&current->mm->mmap_sem);
760 break;
761 }
762
763 maddr = kmap_atomic(pg, KM_USER0);
764 memcpy(maddr + offset, from, len);
765 kunmap_atomic(maddr, KM_USER0);
766 set_page_dirty_lock(pg);
767 put_page(pg);
768 up_read(&current->mm->mmap_sem);
769
770 from += len;
771 to += len;
772 n -= len;
773 }
774 return n;
775 }
776 #endif
777 if (movsl_is_ok(to, from, n))
778 __copy_user(to, from, n);
779 else
780 n = __copy_user_intel(to, from, n);
781 return n;
782 }
783 EXPORT_SYMBOL(__copy_to_user_ll);
784
785 unsigned long __copy_from_user_ll(void *to, const void __user *from,
786 unsigned long n)
787 {
788 if (movsl_is_ok(to, from, n))
789 __copy_user_zeroing(to, from, n);
790 else
791 n = __copy_user_zeroing_intel(to, from, n);
792 return n;
793 }
794 EXPORT_SYMBOL(__copy_from_user_ll);
795
796 unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
797 unsigned long n)
798 {
799 if (movsl_is_ok(to, from, n))
800 __copy_user(to, from, n);
801 else
802 n = __copy_user_intel((void __user *)to,
803 (const void *)from, n);
804 return n;
805 }
806 EXPORT_SYMBOL(__copy_from_user_ll_nozero);
807
808 unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from,
809 unsigned long n)
810 {
811 #ifdef CONFIG_X86_INTEL_USERCOPY
812 if (n > 64 && cpu_has_xmm2)
813 n = __copy_user_zeroing_intel_nocache(to, from, n);
814 else
815 __copy_user_zeroing(to, from, n);
816 #else
817 __copy_user_zeroing(to, from, n);
818 #endif
819 return n;
820 }
821 EXPORT_SYMBOL(__copy_from_user_ll_nocache);
822
823 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
824 unsigned long n)
825 {
826 #ifdef CONFIG_X86_INTEL_USERCOPY
827 if (n > 64 && cpu_has_xmm2)
828 n = __copy_user_intel_nocache(to, from, n);
829 else
830 __copy_user(to, from, n);
831 #else
832 __copy_user(to, from, n);
833 #endif
834 return n;
835 }
836 EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);
837
838 /**
839 * copy_to_user: - Copy a block of data into user space.
840 * @to: Destination address, in user space.
841 * @from: Source address, in kernel space.
842 * @n: Number of bytes to copy.
843 *
844 * Context: User context only. This function may sleep.
845 *
846 * Copy data from kernel space to user space.
847 *
848 * Returns number of bytes that could not be copied.
849 * On success, this will be zero.
850 */
851 unsigned long
852 copy_to_user(void __user *to, const void *from, unsigned long n)
853 {
854 if (access_ok(VERIFY_WRITE, to, n))
855 n = __copy_to_user(to, from, n);
856 return n;
857 }
858 EXPORT_SYMBOL(copy_to_user);
859
860 /**
861 * copy_from_user: - Copy a block of data from user space.
862 * @to: Destination address, in kernel space.
863 * @from: Source address, in user space.
864 * @n: Number of bytes to copy.
865 *
866 * Context: User context only. This function may sleep.
867 *
868 * Copy data from user space to kernel space.
869 *
870 * Returns number of bytes that could not be copied.
871 * On success, this will be zero.
872 *
873 * If some data could not be copied, this function will pad the copied
874 * data to the requested size using zero bytes.
875 */
876 unsigned long
877 _copy_from_user(void *to, const void __user *from, unsigned long n)
878 {
879 if (access_ok(VERIFY_READ, from, n))
880 n = __copy_from_user(to, from, n);
881 else
882 memset(to, 0, n);
883 return n;
884 }
885 EXPORT_SYMBOL(_copy_from_user);
886
887 void copy_from_user_overflow(void)
888 {
889 WARN(1, "Buffer overflow detected!\n");
890 }
891 EXPORT_SYMBOL(copy_from_user_overflow);
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