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RT-AC66 3.0.0.4.374.130 core
[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / arch / i386 / lib / usercopy.c
blob9f38b12b4af1bf103b1261b1ceee185c541a28cd
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 static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n)
18 {
19 #ifdef CONFIG_X86_INTEL_USERCOPY
20 if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask))
21 return 0;
22 #endif
23 return 1;
24 }
25 #define movsl_is_ok(a1,a2,n) \
26 __movsl_is_ok((unsigned long)(a1),(unsigned long)(a2),(n))
27
28 /*
29 * Copy a null terminated string from userspace.
30 */
31
32 #define __do_strncpy_from_user(dst,src,count,res) \
33 do { \
34 int __d0, __d1, __d2; \
35 might_sleep(); \
36 __asm__ __volatile__( \
37 " testl %1,%1\n" \
38 " jz 2f\n" \
39 "0: lodsb\n" \
40 " stosb\n" \
41 " testb %%al,%%al\n" \
42 " jz 1f\n" \
43 " decl %1\n" \
44 " jnz 0b\n" \
45 "1: subl %1,%0\n" \
46 "2:\n" \
47 ".section .fixup,\"ax\"\n" \
48 "3: movl %5,%0\n" \
49 " jmp 2b\n" \
50 ".previous\n" \
51 ".section __ex_table,\"a\"\n" \
52 " .align 4\n" \
53 " .long 0b,3b\n" \
54 ".previous" \
55 : "=d"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1), \
56 "=&D" (__d2) \
57 : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
58 : "memory"); \
59 } while (0)
60
61 /**
62 * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
63 * @dst: Destination address, in kernel space. This buffer must be at
64 * least @count bytes long.
65 * @src: Source address, in user space.
66 * @count: Maximum number of bytes to copy, including the trailing NUL.
67 *
68 * Copies a NUL-terminated string from userspace to kernel space.
69 * Caller must check the specified block with access_ok() before calling
70 * this function.
71 *
72 * On success, returns the length of the string (not including the trailing
73 * NUL).
74 *
75 * If access to userspace fails, returns -EFAULT (some data may have been
76 * copied).
77 *
78 * If @count is smaller than the length of the string, copies @count bytes
79 * and returns @count.
80 */
81 long
82 __strncpy_from_user(char *dst, const char __user *src, long count)
83 {
84 long res;
85 __do_strncpy_from_user(dst, src, count, res);
86 return res;
87 }
88 EXPORT_SYMBOL(__strncpy_from_user);
89
90 /**
91 * strncpy_from_user: - Copy a NUL terminated string from userspace.
92 * @dst: Destination address, in kernel space. This buffer must be at
93 * least @count bytes long.
94 * @src: Source address, in user space.
95 * @count: Maximum number of bytes to copy, including the trailing NUL.
96 *
97 * Copies a NUL-terminated string from userspace to kernel space.
98 *
99 * On success, returns the length of the string (not including the trailing
100 * NUL).
101 *
102 * If access to userspace fails, returns -EFAULT (some data may have been
103 * copied).
104 *
105 * If @count is smaller than the length of the string, copies @count bytes
106 * and returns @count.
107 */
108 long
109 strncpy_from_user(char *dst, const char __user *src, long count)
110 {
111 long res = -EFAULT;
112 if (access_ok(VERIFY_READ, src, 1))
113 __do_strncpy_from_user(dst, src, count, res);
114 return res;
115 }
116 EXPORT_SYMBOL(strncpy_from_user);
117
118 /*
119 * Zero Userspace
120 */
121
122 #define __do_clear_user(addr,size) \
123 do { \
124 int __d0; \
125 might_sleep(); \
126 __asm__ __volatile__( \
127 "0: rep; stosl\n" \
128 " movl %2,%0\n" \
129 "1: rep; stosb\n" \
130 "2:\n" \
131 ".section .fixup,\"ax\"\n" \
132 "3: lea 0(%2,%0,4),%0\n" \
133 " jmp 2b\n" \
134 ".previous\n" \
135 ".section __ex_table,\"a\"\n" \
136 " .align 4\n" \
137 " .long 0b,3b\n" \
138 " .long 1b,2b\n" \
139 ".previous" \
140 : "=&c"(size), "=&D" (__d0) \
141 : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \
142 } while (0)
143
144 /**
145 * clear_user: - Zero a block of memory in user space.
146 * @to: Destination address, in user space.
147 * @n: Number of bytes to zero.
148 *
149 * Zero a block of memory in user space.
150 *
151 * Returns number of bytes that could not be cleared.
152 * On success, this will be zero.
153 */
154 unsigned long
155 clear_user(void __user *to, unsigned long n)
156 {
157 might_sleep();
158 if (access_ok(VERIFY_WRITE, to, n))
159 __do_clear_user(to, n);
160 return n;
161 }
162 EXPORT_SYMBOL(clear_user);
163
164 /**
165 * __clear_user: - Zero a block of memory in user space, with less checking.
166 * @to: Destination address, in user space.
167 * @n: Number of bytes to zero.
168 *
169 * Zero a block of memory in user space. Caller must check
170 * the specified block with access_ok() before calling this function.
171 *
172 * Returns number of bytes that could not be cleared.
173 * On success, this will be zero.
174 */
175 unsigned long
176 __clear_user(void __user *to, unsigned long n)
177 {
178 __do_clear_user(to, n);
179 return n;
180 }
181 EXPORT_SYMBOL(__clear_user);
182
183 /**
184 * strnlen_user: - Get the size of a string in user space.
185 * @s: The string to measure.
186 * @n: The maximum valid length
187 *
188 * Get the size of a NUL-terminated string in user space.
189 *
190 * Returns the size of the string INCLUDING the terminating NUL.
191 * On exception, returns 0.
192 * If the string is too long, returns a value greater than @n.
193 */
194 long strnlen_user(const char __user *s, long n)
195 {
196 unsigned long mask = -__addr_ok(s);
197 unsigned long res, tmp;
198
199 might_sleep();
200
201 __asm__ __volatile__(
202 " testl %0, %0\n"
203 " jz 3f\n"
204 " andl %0,%%ecx\n"
205 "0: repne; scasb\n"
206 " setne %%al\n"
207 " subl %%ecx,%0\n"
208 " addl %0,%%eax\n"
209 "1:\n"
210 ".section .fixup,\"ax\"\n"
211 "2: xorl %%eax,%%eax\n"
212 " jmp 1b\n"
213 "3: movb $1,%%al\n"
214 " jmp 1b\n"
215 ".previous\n"
216 ".section __ex_table,\"a\"\n"
217 " .align 4\n"
218 " .long 0b,2b\n"
219 ".previous"
220 :"=r" (n), "=D" (s), "=a" (res), "=c" (tmp)
221 :"0" (n), "1" (s), "2" (0), "3" (mask)
222 :"cc");
223 return res & mask;
224 }
225 EXPORT_SYMBOL(strnlen_user);
226
227 #ifdef CONFIG_X86_INTEL_USERCOPY
228 static unsigned long
229 __copy_user_intel(void __user *to, const void *from, unsigned long size)
230 {
231 int d0, d1;
232 __asm__ __volatile__(
233 " .align 2,0x90\n"
234 "1: movl 32(%4), %%eax\n"
235 " cmpl $67, %0\n"
236 " jbe 3f\n"
237 "2: movl 64(%4), %%eax\n"
238 " .align 2,0x90\n"
239 "3: movl 0(%4), %%eax\n"
240 "4: movl 4(%4), %%edx\n"
241 "5: movl %%eax, 0(%3)\n"
242 "6: movl %%edx, 4(%3)\n"
243 "7: movl 8(%4), %%eax\n"
244 "8: movl 12(%4),%%edx\n"
245 "9: movl %%eax, 8(%3)\n"
246 "10: movl %%edx, 12(%3)\n"
247 "11: movl 16(%4), %%eax\n"
248 "12: movl 20(%4), %%edx\n"
249 "13: movl %%eax, 16(%3)\n"
250 "14: movl %%edx, 20(%3)\n"
251 "15: movl 24(%4), %%eax\n"
252 "16: movl 28(%4), %%edx\n"
253 "17: movl %%eax, 24(%3)\n"
254 "18: movl %%edx, 28(%3)\n"
255 "19: movl 32(%4), %%eax\n"
256 "20: movl 36(%4), %%edx\n"
257 "21: movl %%eax, 32(%3)\n"
258 "22: movl %%edx, 36(%3)\n"
259 "23: movl 40(%4), %%eax\n"
260 "24: movl 44(%4), %%edx\n"
261 "25: movl %%eax, 40(%3)\n"
262 "26: movl %%edx, 44(%3)\n"
263 "27: movl 48(%4), %%eax\n"
264 "28: movl 52(%4), %%edx\n"
265 "29: movl %%eax, 48(%3)\n"
266 "30: movl %%edx, 52(%3)\n"
267 "31: movl 56(%4), %%eax\n"
268 "32: movl 60(%4), %%edx\n"
269 "33: movl %%eax, 56(%3)\n"
270 "34: movl %%edx, 60(%3)\n"
271 " addl $-64, %0\n"
272 " addl $64, %4\n"
273 " addl $64, %3\n"
274 " cmpl $63, %0\n"
275 " ja 1b\n"
276 "35: movl %0, %%eax\n"
277 " shrl $2, %0\n"
278 " andl $3, %%eax\n"
279 " cld\n"
280 "99: rep; movsl\n"
281 "36: movl %%eax, %0\n"
282 "37: rep; movsb\n"
283 "100:\n"
284 ".section .fixup,\"ax\"\n"
285 "101: lea 0(%%eax,%0,4),%0\n"
286 " jmp 100b\n"
287 ".previous\n"
288 ".section __ex_table,\"a\"\n"
289 " .align 4\n"
290 " .long 1b,100b\n"
291 " .long 2b,100b\n"
292 " .long 3b,100b\n"
293 " .long 4b,100b\n"
294 " .long 5b,100b\n"
295 " .long 6b,100b\n"
296 " .long 7b,100b\n"
297 " .long 8b,100b\n"
298 " .long 9b,100b\n"
299 " .long 10b,100b\n"
300 " .long 11b,100b\n"
301 " .long 12b,100b\n"
302 " .long 13b,100b\n"
303 " .long 14b,100b\n"
304 " .long 15b,100b\n"
305 " .long 16b,100b\n"
306 " .long 17b,100b\n"
307 " .long 18b,100b\n"
308 " .long 19b,100b\n"
309 " .long 20b,100b\n"
310 " .long 21b,100b\n"
311 " .long 22b,100b\n"
312 " .long 23b,100b\n"
313 " .long 24b,100b\n"
314 " .long 25b,100b\n"
315 " .long 26b,100b\n"
316 " .long 27b,100b\n"
317 " .long 28b,100b\n"
318 " .long 29b,100b\n"
319 " .long 30b,100b\n"
320 " .long 31b,100b\n"
321 " .long 32b,100b\n"
322 " .long 33b,100b\n"
323 " .long 34b,100b\n"
324 " .long 35b,100b\n"
325 " .long 36b,100b\n"
326 " .long 37b,100b\n"
327 " .long 99b,101b\n"
328 ".previous"
329 : "=&c"(size), "=&D" (d0), "=&S" (d1)
330 : "1"(to), "2"(from), "0"(size)
331 : "eax", "edx", "memory");
332 return size;
333 }
334
335 static unsigned long
336 __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size)
337 {
338 int d0, d1;
339 __asm__ __volatile__(
340 " .align 2,0x90\n"
341 "0: movl 32(%4), %%eax\n"
342 " cmpl $67, %0\n"
343 " jbe 2f\n"
344 "1: movl 64(%4), %%eax\n"
345 " .align 2,0x90\n"
346 "2: movl 0(%4), %%eax\n"
347 "21: movl 4(%4), %%edx\n"
348 " movl %%eax, 0(%3)\n"
349 " movl %%edx, 4(%3)\n"
350 "3: movl 8(%4), %%eax\n"
351 "31: movl 12(%4),%%edx\n"
352 " movl %%eax, 8(%3)\n"
353 " movl %%edx, 12(%3)\n"
354 "4: movl 16(%4), %%eax\n"
355 "41: movl 20(%4), %%edx\n"
356 " movl %%eax, 16(%3)\n"
357 " movl %%edx, 20(%3)\n"
358 "10: movl 24(%4), %%eax\n"
359 "51: movl 28(%4), %%edx\n"
360 " movl %%eax, 24(%3)\n"
361 " movl %%edx, 28(%3)\n"
362 "11: movl 32(%4), %%eax\n"
363 "61: movl 36(%4), %%edx\n"
364 " movl %%eax, 32(%3)\n"
365 " movl %%edx, 36(%3)\n"
366 "12: movl 40(%4), %%eax\n"
367 "71: movl 44(%4), %%edx\n"
368 " movl %%eax, 40(%3)\n"
369 " movl %%edx, 44(%3)\n"
370 "13: movl 48(%4), %%eax\n"
371 "81: movl 52(%4), %%edx\n"
372 " movl %%eax, 48(%3)\n"
373 " movl %%edx, 52(%3)\n"
374 "14: movl 56(%4), %%eax\n"
375 "91: movl 60(%4), %%edx\n"
376 " movl %%eax, 56(%3)\n"
377 " movl %%edx, 60(%3)\n"
378 " addl $-64, %0\n"
379 " addl $64, %4\n"
380 " addl $64, %3\n"
381 " cmpl $63, %0\n"
382 " ja 0b\n"
383 "5: movl %0, %%eax\n"
384 " shrl $2, %0\n"
385 " andl $3, %%eax\n"
386 " cld\n"
387 "6: rep; movsl\n"
388 " movl %%eax,%0\n"
389 "7: rep; movsb\n"
390 "8:\n"
391 ".section .fixup,\"ax\"\n"
392 "9: lea 0(%%eax,%0,4),%0\n"
393 "16: pushl %0\n"
394 " pushl %%eax\n"
395 " xorl %%eax,%%eax\n"
396 " rep; stosb\n"
397 " popl %%eax\n"
398 " popl %0\n"
399 " jmp 8b\n"
400 ".previous\n"
401 ".section __ex_table,\"a\"\n"
402 " .align 4\n"
403 " .long 0b,16b\n"
404 " .long 1b,16b\n"
405 " .long 2b,16b\n"
406 " .long 21b,16b\n"
407 " .long 3b,16b\n"
408 " .long 31b,16b\n"
409 " .long 4b,16b\n"
410 " .long 41b,16b\n"
411 " .long 10b,16b\n"
412 " .long 51b,16b\n"
413 " .long 11b,16b\n"
414 " .long 61b,16b\n"
415 " .long 12b,16b\n"
416 " .long 71b,16b\n"
417 " .long 13b,16b\n"
418 " .long 81b,16b\n"
419 " .long 14b,16b\n"
420 " .long 91b,16b\n"
421 " .long 6b,9b\n"
422 " .long 7b,16b\n"
423 ".previous"
424 : "=&c"(size), "=&D" (d0), "=&S" (d1)
425 : "1"(to), "2"(from), "0"(size)
426 : "eax", "edx", "memory");
427 return size;
428 }
429
430 /*
431 * Non Temporal Hint version of __copy_user_zeroing_intel. It is cache aware.
432 * hyoshiok@miraclelinux.com
433 */
434
435 static unsigned long __copy_user_zeroing_intel_nocache(void *to,
436 const void __user *from, unsigned long size)
437 {
438 int d0, d1;
439
440 __asm__ __volatile__(
441 " .align 2,0x90\n"
442 "0: movl 32(%4), %%eax\n"
443 " cmpl $67, %0\n"
444 " jbe 2f\n"
445 "1: movl 64(%4), %%eax\n"
446 " .align 2,0x90\n"
447 "2: movl 0(%4), %%eax\n"
448 "21: movl 4(%4), %%edx\n"
449 " movnti %%eax, 0(%3)\n"
450 " movnti %%edx, 4(%3)\n"
451 "3: movl 8(%4), %%eax\n"
452 "31: movl 12(%4),%%edx\n"
453 " movnti %%eax, 8(%3)\n"
454 " movnti %%edx, 12(%3)\n"
455 "4: movl 16(%4), %%eax\n"
456 "41: movl 20(%4), %%edx\n"
457 " movnti %%eax, 16(%3)\n"
458 " movnti %%edx, 20(%3)\n"
459 "10: movl 24(%4), %%eax\n"
460 "51: movl 28(%4), %%edx\n"
461 " movnti %%eax, 24(%3)\n"
462 " movnti %%edx, 28(%3)\n"
463 "11: movl 32(%4), %%eax\n"
464 "61: movl 36(%4), %%edx\n"
465 " movnti %%eax, 32(%3)\n"
466 " movnti %%edx, 36(%3)\n"
467 "12: movl 40(%4), %%eax\n"
468 "71: movl 44(%4), %%edx\n"
469 " movnti %%eax, 40(%3)\n"
470 " movnti %%edx, 44(%3)\n"
471 "13: movl 48(%4), %%eax\n"
472 "81: movl 52(%4), %%edx\n"
473 " movnti %%eax, 48(%3)\n"
474 " movnti %%edx, 52(%3)\n"
475 "14: movl 56(%4), %%eax\n"
476 "91: movl 60(%4), %%edx\n"
477 " movnti %%eax, 56(%3)\n"
478 " movnti %%edx, 60(%3)\n"
479 " addl $-64, %0\n"
480 " addl $64, %4\n"
481 " addl $64, %3\n"
482 " cmpl $63, %0\n"
483 " ja 0b\n"
484 " sfence \n"
485 "5: movl %0, %%eax\n"
486 " shrl $2, %0\n"
487 " andl $3, %%eax\n"
488 " cld\n"
489 "6: rep; movsl\n"
490 " movl %%eax,%0\n"
491 "7: rep; movsb\n"
492 "8:\n"
493 ".section .fixup,\"ax\"\n"
494 "9: lea 0(%%eax,%0,4),%0\n"
495 "16: pushl %0\n"
496 " pushl %%eax\n"
497 " xorl %%eax,%%eax\n"
498 " rep; stosb\n"
499 " popl %%eax\n"
500 " popl %0\n"
501 " jmp 8b\n"
502 ".previous\n"
503 ".section __ex_table,\"a\"\n"
504 " .align 4\n"
505 " .long 0b,16b\n"
506 " .long 1b,16b\n"
507 " .long 2b,16b\n"
508 " .long 21b,16b\n"
509 " .long 3b,16b\n"
510 " .long 31b,16b\n"
511 " .long 4b,16b\n"
512 " .long 41b,16b\n"
513 " .long 10b,16b\n"
514 " .long 51b,16b\n"
515 " .long 11b,16b\n"
516 " .long 61b,16b\n"
517 " .long 12b,16b\n"
518 " .long 71b,16b\n"
519 " .long 13b,16b\n"
520 " .long 81b,16b\n"
521 " .long 14b,16b\n"
522 " .long 91b,16b\n"
523 " .long 6b,9b\n"
524 " .long 7b,16b\n"
525 ".previous"
526 : "=&c"(size), "=&D" (d0), "=&S" (d1)
527 : "1"(to), "2"(from), "0"(size)
528 : "eax", "edx", "memory");
529 return size;
530 }
531
532 static unsigned long __copy_user_intel_nocache(void *to,
533 const void __user *from, unsigned long size)
534 {
535 int d0, d1;
536
537 __asm__ __volatile__(
538 " .align 2,0x90\n"
539 "0: movl 32(%4), %%eax\n"
540 " cmpl $67, %0\n"
541 " jbe 2f\n"
542 "1: movl 64(%4), %%eax\n"
543 " .align 2,0x90\n"
544 "2: movl 0(%4), %%eax\n"
545 "21: movl 4(%4), %%edx\n"
546 " movnti %%eax, 0(%3)\n"
547 " movnti %%edx, 4(%3)\n"
548 "3: movl 8(%4), %%eax\n"
549 "31: movl 12(%4),%%edx\n"
550 " movnti %%eax, 8(%3)\n"
551 " movnti %%edx, 12(%3)\n"
552 "4: movl 16(%4), %%eax\n"
553 "41: movl 20(%4), %%edx\n"
554 " movnti %%eax, 16(%3)\n"
555 " movnti %%edx, 20(%3)\n"
556 "10: movl 24(%4), %%eax\n"
557 "51: movl 28(%4), %%edx\n"
558 " movnti %%eax, 24(%3)\n"
559 " movnti %%edx, 28(%3)\n"
560 "11: movl 32(%4), %%eax\n"
561 "61: movl 36(%4), %%edx\n"
562 " movnti %%eax, 32(%3)\n"
563 " movnti %%edx, 36(%3)\n"
564 "12: movl 40(%4), %%eax\n"
565 "71: movl 44(%4), %%edx\n"
566 " movnti %%eax, 40(%3)\n"
567 " movnti %%edx, 44(%3)\n"
568 "13: movl 48(%4), %%eax\n"
569 "81: movl 52(%4), %%edx\n"
570 " movnti %%eax, 48(%3)\n"
571 " movnti %%edx, 52(%3)\n"
572 "14: movl 56(%4), %%eax\n"
573 "91: movl 60(%4), %%edx\n"
574 " movnti %%eax, 56(%3)\n"
575 " movnti %%edx, 60(%3)\n"
576 " addl $-64, %0\n"
577 " addl $64, %4\n"
578 " addl $64, %3\n"
579 " cmpl $63, %0\n"
580 " ja 0b\n"
581 " sfence \n"
582 "5: movl %0, %%eax\n"
583 " shrl $2, %0\n"
584 " andl $3, %%eax\n"
585 " cld\n"
586 "6: rep; movsl\n"
587 " movl %%eax,%0\n"
588 "7: rep; movsb\n"
589 "8:\n"
590 ".section .fixup,\"ax\"\n"
591 "9: lea 0(%%eax,%0,4),%0\n"
592 "16: jmp 8b\n"
593 ".previous\n"
594 ".section __ex_table,\"a\"\n"
595 " .align 4\n"
596 " .long 0b,16b\n"
597 " .long 1b,16b\n"
598 " .long 2b,16b\n"
599 " .long 21b,16b\n"
600 " .long 3b,16b\n"
601 " .long 31b,16b\n"
602 " .long 4b,16b\n"
603 " .long 41b,16b\n"
604 " .long 10b,16b\n"
605 " .long 51b,16b\n"
606 " .long 11b,16b\n"
607 " .long 61b,16b\n"
608 " .long 12b,16b\n"
609 " .long 71b,16b\n"
610 " .long 13b,16b\n"
611 " .long 81b,16b\n"
612 " .long 14b,16b\n"
613 " .long 91b,16b\n"
614 " .long 6b,9b\n"
615 " .long 7b,16b\n"
616 ".previous"
617 : "=&c"(size), "=&D" (d0), "=&S" (d1)
618 : "1"(to), "2"(from), "0"(size)
619 : "eax", "edx", "memory");
620 return size;
621 }
622
623 #else
624
625 /*
626 * Leave these declared but undefined. They should not be any references to
627 * them
628 */
629 unsigned long __copy_user_zeroing_intel(void *to, const void __user *from,
630 unsigned long size);
631 unsigned long __copy_user_intel(void __user *to, const void *from,
632 unsigned long size);
633 unsigned long __copy_user_zeroing_intel_nocache(void *to,
634 const void __user *from, unsigned long size);
635 #endif /* CONFIG_X86_INTEL_USERCOPY */
636
637 /* Generic arbitrary sized copy. */
638 #define __copy_user(to,from,size) \
639 do { \
640 int __d0, __d1, __d2; \
641 __asm__ __volatile__( \
642 " cmp $7,%0\n" \
643 " jbe 1f\n" \
644 " movl %1,%0\n" \
645 " negl %0\n" \
646 " andl $7,%0\n" \
647 " subl %0,%3\n" \
648 "4: rep; movsb\n" \
649 " movl %3,%0\n" \
650 " shrl $2,%0\n" \
651 " andl $3,%3\n" \
652 " .align 2,0x90\n" \
653 "0: rep; movsl\n" \
654 " movl %3,%0\n" \
655 "1: rep; movsb\n" \
656 "2:\n" \
657 ".section .fixup,\"ax\"\n" \
658 "5: addl %3,%0\n" \
659 " jmp 2b\n" \
660 "3: lea 0(%3,%0,4),%0\n" \
661 " jmp 2b\n" \
662 ".previous\n" \
663 ".section __ex_table,\"a\"\n" \
664 " .align 4\n" \
665 " .long 4b,5b\n" \
666 " .long 0b,3b\n" \
667 " .long 1b,2b\n" \
668 ".previous" \
669 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
670 : "3"(size), "0"(size), "1"(to), "2"(from) \
671 : "memory"); \
672 } while (0)
673
674 #define __copy_user_zeroing(to,from,size) \
675 do { \
676 int __d0, __d1, __d2; \
677 __asm__ __volatile__( \
678 " cmp $7,%0\n" \
679 " jbe 1f\n" \
680 " movl %1,%0\n" \
681 " negl %0\n" \
682 " andl $7,%0\n" \
683 " subl %0,%3\n" \
684 "4: rep; movsb\n" \
685 " movl %3,%0\n" \
686 " shrl $2,%0\n" \
687 " andl $3,%3\n" \
688 " .align 2,0x90\n" \
689 "0: rep; movsl\n" \
690 " movl %3,%0\n" \
691 "1: rep; movsb\n" \
692 "2:\n" \
693 ".section .fixup,\"ax\"\n" \
694 "5: addl %3,%0\n" \
695 " jmp 6f\n" \
696 "3: lea 0(%3,%0,4),%0\n" \
697 "6: pushl %0\n" \
698 " pushl %%eax\n" \
699 " xorl %%eax,%%eax\n" \
700 " rep; stosb\n" \
701 " popl %%eax\n" \
702 " popl %0\n" \
703 " jmp 2b\n" \
704 ".previous\n" \
705 ".section __ex_table,\"a\"\n" \
706 " .align 4\n" \
707 " .long 4b,5b\n" \
708 " .long 0b,3b\n" \
709 " .long 1b,6b\n" \
710 ".previous" \
711 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
712 : "3"(size), "0"(size), "1"(to), "2"(from) \
713 : "memory"); \
714 } while (0)
715
716 unsigned long __copy_to_user_ll(void __user *to, const void *from,
717 unsigned long n)
718 {
719 #ifndef CONFIG_X86_WP_WORKS_OK
720 if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
721 ((unsigned long )to) < TASK_SIZE) {
722 /*
723 * When we are in an atomic section (see
724 * mm/filemap.c:file_read_actor), return the full
725 * length to take the slow path.
726 */
727 if (in_atomic())
728 return n;
729
730 /*
731 * CPU does not honor the WP bit when writing
732 * from supervisory mode, and due to preemption or SMP,
733 * the page tables can change at any time.
734 * Do it manually. Manfred <manfred@colorfullife.com>
735 */
736 while (n) {
737 unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
738 unsigned long len = PAGE_SIZE - offset;
739 int retval;
740 struct page *pg;
741 void *maddr;
742
743 if (len > n)
744 len = n;
745
746 survive:
747 down_read(&current->mm->mmap_sem);
748 retval = get_user_pages(current, current->mm,
749 (unsigned long )to, 1, 1, 0, &pg, NULL);
750
751 if (retval == -ENOMEM && is_init(current)) {
752 up_read(&current->mm->mmap_sem);
753 congestion_wait(WRITE, HZ/50);
754 goto survive;
755 }
756
757 if (retval != 1) {
758 up_read(&current->mm->mmap_sem);
759 break;
760 }
761
762 maddr = kmap_atomic(pg, KM_USER0);
763 memcpy(maddr + offset, from, len);
764 kunmap_atomic(maddr, KM_USER0);
765 set_page_dirty_lock(pg);
766 put_page(pg);
767 up_read(&current->mm->mmap_sem);
768
769 from += len;
770 to += len;
771 n -= len;
772 }
773 return n;
774 }
775 #endif
776 if (movsl_is_ok(to, from, n))
777 __copy_user(to, from, n);
778 else
779 n = __copy_user_intel(to, from, n);
780 return n;
781 }
782 EXPORT_SYMBOL(__copy_to_user_ll);
783
784 unsigned long __copy_from_user_ll(void *to, const void __user *from,
785 unsigned long n)
786 {
787 if (movsl_is_ok(to, from, n))
788 __copy_user_zeroing(to, from, n);
789 else
790 n = __copy_user_zeroing_intel(to, from, n);
791 return n;
792 }
793 EXPORT_SYMBOL(__copy_from_user_ll);
794
795 unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
796 unsigned long n)
797 {
798 if (movsl_is_ok(to, from, n))
799 __copy_user(to, from, n);
800 else
801 n = __copy_user_intel((void __user *)to,
802 (const void *)from, n);
803 return n;
804 }
805 EXPORT_SYMBOL(__copy_from_user_ll_nozero);
806
807 unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from,
808 unsigned long n)
809 {
810 #ifdef CONFIG_X86_INTEL_USERCOPY
811 if ( n > 64 && cpu_has_xmm2)
812 n = __copy_user_zeroing_intel_nocache(to, from, n);
813 else
814 __copy_user_zeroing(to, from, n);
815 #else
816 __copy_user_zeroing(to, from, n);
817 #endif
818 return n;
819 }
820
821 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
822 unsigned long n)
823 {
824 #ifdef CONFIG_X86_INTEL_USERCOPY
825 if ( n > 64 && cpu_has_xmm2)
826 n = __copy_user_intel_nocache(to, from, n);
827 else
828 __copy_user(to, from, n);
829 #else
830 __copy_user(to, from, n);
831 #endif
832 return n;
833 }
834
835 /**
836 * copy_to_user: - Copy a block of data into user space.
837 * @to: Destination address, in user space.
838 * @from: Source address, in kernel space.
839 * @n: Number of bytes to copy.
840 *
841 * Context: User context only. This function may sleep.
842 *
843 * Copy data from kernel space to user space.
844 *
845 * Returns number of bytes that could not be copied.
846 * On success, this will be zero.
847 */
848 unsigned long
849 copy_to_user(void __user *to, const void *from, unsigned long n)
850 {
851 if (access_ok(VERIFY_WRITE, to, n))
852 n = __copy_to_user(to, from, n);
853 return n;
854 }
855 EXPORT_SYMBOL(copy_to_user);
856
857 /**
858 * copy_from_user: - Copy a block of data from user space.
859 * @to: Destination address, in kernel space.
860 * @from: Source address, in user space.
861 * @n: Number of bytes to copy.
862 *
863 * Context: User context only. This function may sleep.
864 *
865 * Copy data from user space to kernel space.
866 *
867 * Returns number of bytes that could not be copied.
868 * On success, this will be zero.
869 *
870 * If some data could not be copied, this function will pad the copied
871 * data to the requested size using zero bytes.
872 */
873 unsigned long
874 copy_from_user(void *to, const void __user *from, unsigned long n)
875 {
876 if (access_ok(VERIFY_READ, from, n))
877 n = __copy_from_user(to, from, n);
878 else
879 memset(to, 0, n);
880 return n;
881 }
882 EXPORT_SYMBOL(copy_from_user);
Tomato firmware and modifications.