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x86: some lock annotations for user copy paths
[linux-2.6/mini2440.git] / arch / x86 / lib / usercopy_32.c
blob8eedde2a9cac614f97580d61e03b97662ad3e762
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 if (current->mm) \
37 might_lock_read(&current->mm->mmap_sem); \
38 __asm__ __volatile__( \
39 " testl %1,%1\n" \
40 " jz 2f\n" \
41 "0: lodsb\n" \
42 " stosb\n" \
43 " testb %%al,%%al\n" \
44 " jz 1f\n" \
45 " decl %1\n" \
46 " jnz 0b\n" \
47 "1: subl %1,%0\n" \
48 "2:\n" \
49 ".section .fixup,\"ax\"\n" \
50 "3: movl %5,%0\n" \
51 " jmp 2b\n" \
52 ".previous\n" \
53 _ASM_EXTABLE(0b,3b) \
54 : "=d"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1), \
55 "=&D" (__d2) \
56 : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \
57 : "memory"); \
58 } while (0)
59
60 /**
61 * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
62 * @dst: Destination address, in kernel space. This buffer must be at
63 * least @count bytes long.
64 * @src: Source address, in user space.
65 * @count: Maximum number of bytes to copy, including the trailing NUL.
66 *
67 * Copies a NUL-terminated string from userspace to kernel space.
68 * Caller must check the specified block with access_ok() before calling
69 * this function.
70 *
71 * On success, returns the length of the string (not including the trailing
72 * NUL).
73 *
74 * If access to userspace fails, returns -EFAULT (some data may have been
75 * copied).
76 *
77 * If @count is smaller than the length of the string, copies @count bytes
78 * and returns @count.
79 */
80 long
81 __strncpy_from_user(char *dst, const char __user *src, long count)
82 {
83 long res;
84 __do_strncpy_from_user(dst, src, count, res);
85 return res;
86 }
87 EXPORT_SYMBOL(__strncpy_from_user);
88
89 /**
90 * strncpy_from_user: - Copy a NUL terminated string from userspace.
91 * @dst: Destination address, in kernel space. This buffer must be at
92 * least @count bytes long.
93 * @src: Source address, in user space.
94 * @count: Maximum number of bytes to copy, including the trailing NUL.
95 *
96 * Copies a NUL-terminated string from userspace to kernel space.
97 *
98 * On success, returns the length of the string (not including the trailing
99 * NUL).
100 *
101 * If access to userspace fails, returns -EFAULT (some data may have been
102 * copied).
103 *
104 * If @count is smaller than the length of the string, copies @count bytes
105 * and returns @count.
106 */
107 long
108 strncpy_from_user(char *dst, const char __user *src, long count)
109 {
110 long res = -EFAULT;
111 if (access_ok(VERIFY_READ, src, 1))
112 __do_strncpy_from_user(dst, src, count, res);
113 return res;
114 }
115 EXPORT_SYMBOL(strncpy_from_user);
116
117 /*
118 * Zero Userspace
119 */
120
121 #define __do_clear_user(addr,size) \
122 do { \
123 int __d0; \
124 might_sleep(); \
125 if (current->mm) \
126 might_lock_read(&current->mm->mmap_sem); \
127 __asm__ __volatile__( \
128 "0: rep; stosl\n" \
129 " movl %2,%0\n" \
130 "1: rep; stosb\n" \
131 "2:\n" \
132 ".section .fixup,\"ax\"\n" \
133 "3: lea 0(%2,%0,4),%0\n" \
134 " jmp 2b\n" \
135 ".previous\n" \
136 _ASM_EXTABLE(0b,3b) \
137 _ASM_EXTABLE(1b,2b) \
138 : "=&c"(size), "=&D" (__d0) \
139 : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \
140 } while (0)
141
142 /**
143 * clear_user: - Zero a block of memory in user space.
144 * @to: Destination address, in user space.
145 * @n: Number of bytes to zero.
146 *
147 * Zero a block of memory in user space.
148 *
149 * Returns number of bytes that could not be cleared.
150 * On success, this will be zero.
151 */
152 unsigned long
153 clear_user(void __user *to, unsigned long n)
154 {
155 if (access_ok(VERIFY_WRITE, to, n))
156 __do_clear_user(to, n);
157 return n;
158 }
159 EXPORT_SYMBOL(clear_user);
160
161 /**
162 * __clear_user: - Zero a block of memory in user space, with less checking.
163 * @to: Destination address, in user space.
164 * @n: Number of bytes to zero.
165 *
166 * Zero a block of memory in user space. Caller must check
167 * the specified block with access_ok() before calling this function.
168 *
169 * Returns number of bytes that could not be cleared.
170 * On success, this will be zero.
171 */
172 unsigned long
173 __clear_user(void __user *to, unsigned long n)
174 {
175 __do_clear_user(to, n);
176 return n;
177 }
178 EXPORT_SYMBOL(__clear_user);
179
180 /**
181 * strnlen_user: - Get the size of a string in user space.
182 * @s: The string to measure.
183 * @n: The maximum valid length
184 *
185 * Get the size of a NUL-terminated string in user space.
186 *
187 * Returns the size of the string INCLUDING the terminating NUL.
188 * On exception, returns 0.
189 * If the string is too long, returns a value greater than @n.
190 */
191 long strnlen_user(const char __user *s, long n)
192 {
193 unsigned long mask = -__addr_ok(s);
194 unsigned long res, tmp;
195
196 might_sleep();
197 if (current->mm)
198 might_lock_read(&current->mm->mmap_sem);
199
200 __asm__ __volatile__(
201 " testl %0, %0\n"
202 " jz 3f\n"
203 " andl %0,%%ecx\n"
204 "0: repne; scasb\n"
205 " setne %%al\n"
206 " subl %%ecx,%0\n"
207 " addl %0,%%eax\n"
208 "1:\n"
209 ".section .fixup,\"ax\"\n"
210 "2: xorl %%eax,%%eax\n"
211 " jmp 1b\n"
212 "3: movb $1,%%al\n"
213 " jmp 1b\n"
214 ".previous\n"
215 ".section __ex_table,\"a\"\n"
216 " .align 4\n"
217 " .long 0b,2b\n"
218 ".previous"
219 :"=r" (n), "=D" (s), "=a" (res), "=c" (tmp)
220 :"0" (n), "1" (s), "2" (0), "3" (mask)
221 :"cc");
222 return res & mask;
223 }
224 EXPORT_SYMBOL(strnlen_user);
225
226 #ifdef CONFIG_X86_INTEL_USERCOPY
227 static unsigned long
228 __copy_user_intel(void __user *to, const void *from, unsigned long size)
229 {
230 int d0, d1;
231 __asm__ __volatile__(
232 " .align 2,0x90\n"
233 "1: movl 32(%4), %%eax\n"
234 " cmpl $67, %0\n"
235 " jbe 3f\n"
236 "2: movl 64(%4), %%eax\n"
237 " .align 2,0x90\n"
238 "3: movl 0(%4), %%eax\n"
239 "4: movl 4(%4), %%edx\n"
240 "5: movl %%eax, 0(%3)\n"
241 "6: movl %%edx, 4(%3)\n"
242 "7: movl 8(%4), %%eax\n"
243 "8: movl 12(%4),%%edx\n"
244 "9: movl %%eax, 8(%3)\n"
245 "10: movl %%edx, 12(%3)\n"
246 "11: movl 16(%4), %%eax\n"
247 "12: movl 20(%4), %%edx\n"
248 "13: movl %%eax, 16(%3)\n"
249 "14: movl %%edx, 20(%3)\n"
250 "15: movl 24(%4), %%eax\n"
251 "16: movl 28(%4), %%edx\n"
252 "17: movl %%eax, 24(%3)\n"
253 "18: movl %%edx, 28(%3)\n"
254 "19: movl 32(%4), %%eax\n"
255 "20: movl 36(%4), %%edx\n"
256 "21: movl %%eax, 32(%3)\n"
257 "22: movl %%edx, 36(%3)\n"
258 "23: movl 40(%4), %%eax\n"
259 "24: movl 44(%4), %%edx\n"
260 "25: movl %%eax, 40(%3)\n"
261 "26: movl %%edx, 44(%3)\n"
262 "27: movl 48(%4), %%eax\n"
263 "28: movl 52(%4), %%edx\n"
264 "29: movl %%eax, 48(%3)\n"
265 "30: movl %%edx, 52(%3)\n"
266 "31: movl 56(%4), %%eax\n"
267 "32: movl 60(%4), %%edx\n"
268 "33: movl %%eax, 56(%3)\n"
269 "34: movl %%edx, 60(%3)\n"
270 " addl $-64, %0\n"
271 " addl $64, %4\n"
272 " addl $64, %3\n"
273 " cmpl $63, %0\n"
274 " ja 1b\n"
275 "35: movl %0, %%eax\n"
276 " shrl $2, %0\n"
277 " andl $3, %%eax\n"
278 " cld\n"
279 "99: rep; movsl\n"
280 "36: movl %%eax, %0\n"
281 "37: rep; movsb\n"
282 "100:\n"
283 ".section .fixup,\"ax\"\n"
284 "101: lea 0(%%eax,%0,4),%0\n"
285 " jmp 100b\n"
286 ".previous\n"
287 ".section __ex_table,\"a\"\n"
288 " .align 4\n"
289 " .long 1b,100b\n"
290 " .long 2b,100b\n"
291 " .long 3b,100b\n"
292 " .long 4b,100b\n"
293 " .long 5b,100b\n"
294 " .long 6b,100b\n"
295 " .long 7b,100b\n"
296 " .long 8b,100b\n"
297 " .long 9b,100b\n"
298 " .long 10b,100b\n"
299 " .long 11b,100b\n"
300 " .long 12b,100b\n"
301 " .long 13b,100b\n"
302 " .long 14b,100b\n"
303 " .long 15b,100b\n"
304 " .long 16b,100b\n"
305 " .long 17b,100b\n"
306 " .long 18b,100b\n"
307 " .long 19b,100b\n"
308 " .long 20b,100b\n"
309 " .long 21b,100b\n"
310 " .long 22b,100b\n"
311 " .long 23b,100b\n"
312 " .long 24b,100b\n"
313 " .long 25b,100b\n"
314 " .long 26b,100b\n"
315 " .long 27b,100b\n"
316 " .long 28b,100b\n"
317 " .long 29b,100b\n"
318 " .long 30b,100b\n"
319 " .long 31b,100b\n"
320 " .long 32b,100b\n"
321 " .long 33b,100b\n"
322 " .long 34b,100b\n"
323 " .long 35b,100b\n"
324 " .long 36b,100b\n"
325 " .long 37b,100b\n"
326 " .long 99b,101b\n"
327 ".previous"
328 : "=&c"(size), "=&D" (d0), "=&S" (d1)
329 : "1"(to), "2"(from), "0"(size)
330 : "eax", "edx", "memory");
331 return size;
332 }
333
334 static unsigned long
335 __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size)
336 {
337 int d0, d1;
338 __asm__ __volatile__(
339 " .align 2,0x90\n"
340 "0: movl 32(%4), %%eax\n"
341 " cmpl $67, %0\n"
342 " jbe 2f\n"
343 "1: movl 64(%4), %%eax\n"
344 " .align 2,0x90\n"
345 "2: movl 0(%4), %%eax\n"
346 "21: movl 4(%4), %%edx\n"
347 " movl %%eax, 0(%3)\n"
348 " movl %%edx, 4(%3)\n"
349 "3: movl 8(%4), %%eax\n"
350 "31: movl 12(%4),%%edx\n"
351 " movl %%eax, 8(%3)\n"
352 " movl %%edx, 12(%3)\n"
353 "4: movl 16(%4), %%eax\n"
354 "41: movl 20(%4), %%edx\n"
355 " movl %%eax, 16(%3)\n"
356 " movl %%edx, 20(%3)\n"
357 "10: movl 24(%4), %%eax\n"
358 "51: movl 28(%4), %%edx\n"
359 " movl %%eax, 24(%3)\n"
360 " movl %%edx, 28(%3)\n"
361 "11: movl 32(%4), %%eax\n"
362 "61: movl 36(%4), %%edx\n"
363 " movl %%eax, 32(%3)\n"
364 " movl %%edx, 36(%3)\n"
365 "12: movl 40(%4), %%eax\n"
366 "71: movl 44(%4), %%edx\n"
367 " movl %%eax, 40(%3)\n"
368 " movl %%edx, 44(%3)\n"
369 "13: movl 48(%4), %%eax\n"
370 "81: movl 52(%4), %%edx\n"
371 " movl %%eax, 48(%3)\n"
372 " movl %%edx, 52(%3)\n"
373 "14: movl 56(%4), %%eax\n"
374 "91: movl 60(%4), %%edx\n"
375 " movl %%eax, 56(%3)\n"
376 " movl %%edx, 60(%3)\n"
377 " addl $-64, %0\n"
378 " addl $64, %4\n"
379 " addl $64, %3\n"
380 " cmpl $63, %0\n"
381 " ja 0b\n"
382 "5: movl %0, %%eax\n"
383 " shrl $2, %0\n"
384 " andl $3, %%eax\n"
385 " cld\n"
386 "6: rep; movsl\n"
387 " movl %%eax,%0\n"
388 "7: rep; movsb\n"
389 "8:\n"
390 ".section .fixup,\"ax\"\n"
391 "9: lea 0(%%eax,%0,4),%0\n"
392 "16: pushl %0\n"
393 " pushl %%eax\n"
394 " xorl %%eax,%%eax\n"
395 " rep; stosb\n"
396 " popl %%eax\n"
397 " popl %0\n"
398 " jmp 8b\n"
399 ".previous\n"
400 ".section __ex_table,\"a\"\n"
401 " .align 4\n"
402 " .long 0b,16b\n"
403 " .long 1b,16b\n"
404 " .long 2b,16b\n"
405 " .long 21b,16b\n"
406 " .long 3b,16b\n"
407 " .long 31b,16b\n"
408 " .long 4b,16b\n"
409 " .long 41b,16b\n"
410 " .long 10b,16b\n"
411 " .long 51b,16b\n"
412 " .long 11b,16b\n"
413 " .long 61b,16b\n"
414 " .long 12b,16b\n"
415 " .long 71b,16b\n"
416 " .long 13b,16b\n"
417 " .long 81b,16b\n"
418 " .long 14b,16b\n"
419 " .long 91b,16b\n"
420 " .long 6b,9b\n"
421 " .long 7b,16b\n"
422 ".previous"
423 : "=&c"(size), "=&D" (d0), "=&S" (d1)
424 : "1"(to), "2"(from), "0"(size)
425 : "eax", "edx", "memory");
426 return size;
427 }
428
429 /*
430 * Non Temporal Hint version of __copy_user_zeroing_intel. It is cache aware.
431 * hyoshiok@miraclelinux.com
432 */
433
434 static unsigned long __copy_user_zeroing_intel_nocache(void *to,
435 const void __user *from, unsigned long size)
436 {
437 int d0, d1;
438
439 __asm__ __volatile__(
440 " .align 2,0x90\n"
441 "0: movl 32(%4), %%eax\n"
442 " cmpl $67, %0\n"
443 " jbe 2f\n"
444 "1: movl 64(%4), %%eax\n"
445 " .align 2,0x90\n"
446 "2: movl 0(%4), %%eax\n"
447 "21: movl 4(%4), %%edx\n"
448 " movnti %%eax, 0(%3)\n"
449 " movnti %%edx, 4(%3)\n"
450 "3: movl 8(%4), %%eax\n"
451 "31: movl 12(%4),%%edx\n"
452 " movnti %%eax, 8(%3)\n"
453 " movnti %%edx, 12(%3)\n"
454 "4: movl 16(%4), %%eax\n"
455 "41: movl 20(%4), %%edx\n"
456 " movnti %%eax, 16(%3)\n"
457 " movnti %%edx, 20(%3)\n"
458 "10: movl 24(%4), %%eax\n"
459 "51: movl 28(%4), %%edx\n"
460 " movnti %%eax, 24(%3)\n"
461 " movnti %%edx, 28(%3)\n"
462 "11: movl 32(%4), %%eax\n"
463 "61: movl 36(%4), %%edx\n"
464 " movnti %%eax, 32(%3)\n"
465 " movnti %%edx, 36(%3)\n"
466 "12: movl 40(%4), %%eax\n"
467 "71: movl 44(%4), %%edx\n"
468 " movnti %%eax, 40(%3)\n"
469 " movnti %%edx, 44(%3)\n"
470 "13: movl 48(%4), %%eax\n"
471 "81: movl 52(%4), %%edx\n"
472 " movnti %%eax, 48(%3)\n"
473 " movnti %%edx, 52(%3)\n"
474 "14: movl 56(%4), %%eax\n"
475 "91: movl 60(%4), %%edx\n"
476 " movnti %%eax, 56(%3)\n"
477 " movnti %%edx, 60(%3)\n"
478 " addl $-64, %0\n"
479 " addl $64, %4\n"
480 " addl $64, %3\n"
481 " cmpl $63, %0\n"
482 " ja 0b\n"
483 " sfence \n"
484 "5: movl %0, %%eax\n"
485 " shrl $2, %0\n"
486 " andl $3, %%eax\n"
487 " cld\n"
488 "6: rep; movsl\n"
489 " movl %%eax,%0\n"
490 "7: rep; movsb\n"
491 "8:\n"
492 ".section .fixup,\"ax\"\n"
493 "9: lea 0(%%eax,%0,4),%0\n"
494 "16: pushl %0\n"
495 " pushl %%eax\n"
496 " xorl %%eax,%%eax\n"
497 " rep; stosb\n"
498 " popl %%eax\n"
499 " popl %0\n"
500 " jmp 8b\n"
501 ".previous\n"
502 ".section __ex_table,\"a\"\n"
503 " .align 4\n"
504 " .long 0b,16b\n"
505 " .long 1b,16b\n"
506 " .long 2b,16b\n"
507 " .long 21b,16b\n"
508 " .long 3b,16b\n"
509 " .long 31b,16b\n"
510 " .long 4b,16b\n"
511 " .long 41b,16b\n"
512 " .long 10b,16b\n"
513 " .long 51b,16b\n"
514 " .long 11b,16b\n"
515 " .long 61b,16b\n"
516 " .long 12b,16b\n"
517 " .long 71b,16b\n"
518 " .long 13b,16b\n"
519 " .long 81b,16b\n"
520 " .long 14b,16b\n"
521 " .long 91b,16b\n"
522 " .long 6b,9b\n"
523 " .long 7b,16b\n"
524 ".previous"
525 : "=&c"(size), "=&D" (d0), "=&S" (d1)
526 : "1"(to), "2"(from), "0"(size)
527 : "eax", "edx", "memory");
528 return size;
529 }
530
531 static unsigned long __copy_user_intel_nocache(void *to,
532 const void __user *from, unsigned long size)
533 {
534 int d0, d1;
535
536 __asm__ __volatile__(
537 " .align 2,0x90\n"
538 "0: movl 32(%4), %%eax\n"
539 " cmpl $67, %0\n"
540 " jbe 2f\n"
541 "1: movl 64(%4), %%eax\n"
542 " .align 2,0x90\n"
543 "2: movl 0(%4), %%eax\n"
544 "21: movl 4(%4), %%edx\n"
545 " movnti %%eax, 0(%3)\n"
546 " movnti %%edx, 4(%3)\n"
547 "3: movl 8(%4), %%eax\n"
548 "31: movl 12(%4),%%edx\n"
549 " movnti %%eax, 8(%3)\n"
550 " movnti %%edx, 12(%3)\n"
551 "4: movl 16(%4), %%eax\n"
552 "41: movl 20(%4), %%edx\n"
553 " movnti %%eax, 16(%3)\n"
554 " movnti %%edx, 20(%3)\n"
555 "10: movl 24(%4), %%eax\n"
556 "51: movl 28(%4), %%edx\n"
557 " movnti %%eax, 24(%3)\n"
558 " movnti %%edx, 28(%3)\n"
559 "11: movl 32(%4), %%eax\n"
560 "61: movl 36(%4), %%edx\n"
561 " movnti %%eax, 32(%3)\n"
562 " movnti %%edx, 36(%3)\n"
563 "12: movl 40(%4), %%eax\n"
564 "71: movl 44(%4), %%edx\n"
565 " movnti %%eax, 40(%3)\n"
566 " movnti %%edx, 44(%3)\n"
567 "13: movl 48(%4), %%eax\n"
568 "81: movl 52(%4), %%edx\n"
569 " movnti %%eax, 48(%3)\n"
570 " movnti %%edx, 52(%3)\n"
571 "14: movl 56(%4), %%eax\n"
572 "91: movl 60(%4), %%edx\n"
573 " movnti %%eax, 56(%3)\n"
574 " movnti %%edx, 60(%3)\n"
575 " addl $-64, %0\n"
576 " addl $64, %4\n"
577 " addl $64, %3\n"
578 " cmpl $63, %0\n"
579 " ja 0b\n"
580 " sfence \n"
581 "5: movl %0, %%eax\n"
582 " shrl $2, %0\n"
583 " andl $3, %%eax\n"
584 " cld\n"
585 "6: rep; movsl\n"
586 " movl %%eax,%0\n"
587 "7: rep; movsb\n"
588 "8:\n"
589 ".section .fixup,\"ax\"\n"
590 "9: lea 0(%%eax,%0,4),%0\n"
591 "16: jmp 8b\n"
592 ".previous\n"
593 ".section __ex_table,\"a\"\n"
594 " .align 4\n"
595 " .long 0b,16b\n"
596 " .long 1b,16b\n"
597 " .long 2b,16b\n"
598 " .long 21b,16b\n"
599 " .long 3b,16b\n"
600 " .long 31b,16b\n"
601 " .long 4b,16b\n"
602 " .long 41b,16b\n"
603 " .long 10b,16b\n"
604 " .long 51b,16b\n"
605 " .long 11b,16b\n"
606 " .long 61b,16b\n"
607 " .long 12b,16b\n"
608 " .long 71b,16b\n"
609 " .long 13b,16b\n"
610 " .long 81b,16b\n"
611 " .long 14b,16b\n"
612 " .long 91b,16b\n"
613 " .long 6b,9b\n"
614 " .long 7b,16b\n"
615 ".previous"
616 : "=&c"(size), "=&D" (d0), "=&S" (d1)
617 : "1"(to), "2"(from), "0"(size)
618 : "eax", "edx", "memory");
619 return size;
620 }
621
622 #else
623
624 /*
625 * Leave these declared but undefined. They should not be any references to
626 * them
627 */
628 unsigned long __copy_user_zeroing_intel(void *to, const void __user *from,
629 unsigned long size);
630 unsigned long __copy_user_intel(void __user *to, const void *from,
631 unsigned long size);
632 unsigned long __copy_user_zeroing_intel_nocache(void *to,
633 const void __user *from, unsigned long size);
634 #endif /* CONFIG_X86_INTEL_USERCOPY */
635
636 /* Generic arbitrary sized copy. */
637 #define __copy_user(to, from, size) \
638 do { \
639 int __d0, __d1, __d2; \
640 __asm__ __volatile__( \
641 " cmp $7,%0\n" \
642 " jbe 1f\n" \
643 " movl %1,%0\n" \
644 " negl %0\n" \
645 " andl $7,%0\n" \
646 " subl %0,%3\n" \
647 "4: rep; movsb\n" \
648 " movl %3,%0\n" \
649 " shrl $2,%0\n" \
650 " andl $3,%3\n" \
651 " .align 2,0x90\n" \
652 "0: rep; movsl\n" \
653 " movl %3,%0\n" \
654 "1: rep; movsb\n" \
655 "2:\n" \
656 ".section .fixup,\"ax\"\n" \
657 "5: addl %3,%0\n" \
658 " jmp 2b\n" \
659 "3: lea 0(%3,%0,4),%0\n" \
660 " jmp 2b\n" \
661 ".previous\n" \
662 ".section __ex_table,\"a\"\n" \
663 " .align 4\n" \
664 " .long 4b,5b\n" \
665 " .long 0b,3b\n" \
666 " .long 1b,2b\n" \
667 ".previous" \
668 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
669 : "3"(size), "0"(size), "1"(to), "2"(from) \
670 : "memory"); \
671 } while (0)
672
673 #define __copy_user_zeroing(to, from, size) \
674 do { \
675 int __d0, __d1, __d2; \
676 __asm__ __volatile__( \
677 " cmp $7,%0\n" \
678 " jbe 1f\n" \
679 " movl %1,%0\n" \
680 " negl %0\n" \
681 " andl $7,%0\n" \
682 " subl %0,%3\n" \
683 "4: rep; movsb\n" \
684 " movl %3,%0\n" \
685 " shrl $2,%0\n" \
686 " andl $3,%3\n" \
687 " .align 2,0x90\n" \
688 "0: rep; movsl\n" \
689 " movl %3,%0\n" \
690 "1: rep; movsb\n" \
691 "2:\n" \
692 ".section .fixup,\"ax\"\n" \
693 "5: addl %3,%0\n" \
694 " jmp 6f\n" \
695 "3: lea 0(%3,%0,4),%0\n" \
696 "6: pushl %0\n" \
697 " pushl %%eax\n" \
698 " xorl %%eax,%%eax\n" \
699 " rep; stosb\n" \
700 " popl %%eax\n" \
701 " popl %0\n" \
702 " jmp 2b\n" \
703 ".previous\n" \
704 ".section __ex_table,\"a\"\n" \
705 " .align 4\n" \
706 " .long 4b,5b\n" \
707 " .long 0b,3b\n" \
708 " .long 1b,6b\n" \
709 ".previous" \
710 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
711 : "3"(size), "0"(size), "1"(to), "2"(from) \
712 : "memory"); \
713 } while (0)
714
715 unsigned long __copy_to_user_ll(void __user *to, const void *from,
716 unsigned long n)
717 {
718 #ifndef CONFIG_X86_WP_WORKS_OK
719 if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
720 ((unsigned long)to) < TASK_SIZE) {
721 /*
722 * When we are in an atomic section (see
723 * mm/filemap.c:file_read_actor), return the full
724 * length to take the slow path.
725 */
726 if (in_atomic())
727 return n;
728
729 /*
730 * CPU does not honor the WP bit when writing
731 * from supervisory mode, and due to preemption or SMP,
732 * the page tables can change at any time.
733 * Do it manually. Manfred <manfred@colorfullife.com>
734 */
735 while (n) {
736 unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
737 unsigned long len = PAGE_SIZE - offset;
738 int retval;
739 struct page *pg;
740 void *maddr;
741
742 if (len > n)
743 len = n;
744
745 survive:
746 down_read(&current->mm->mmap_sem);
747 retval = get_user_pages(current, current->mm,
748 (unsigned long)to, 1, 1, 0, &pg, NULL);
749
750 if (retval == -ENOMEM && is_global_init(current)) {
751 up_read(&current->mm->mmap_sem);
752 congestion_wait(WRITE, HZ/50);
753 goto survive;
754 }
755
756 if (retval != 1) {
757 up_read(&current->mm->mmap_sem);
758 break;
759 }
760
761 maddr = kmap_atomic(pg, KM_USER0);
762 memcpy(maddr + offset, from, len);
763 kunmap_atomic(maddr, KM_USER0);
764 set_page_dirty_lock(pg);
765 put_page(pg);
766 up_read(&current->mm->mmap_sem);
767
768 from += len;
769 to += len;
770 n -= len;
771 }
772 return n;
773 }
774 #endif
775 if (movsl_is_ok(to, from, n))
776 __copy_user(to, from, n);
777 else
778 n = __copy_user_intel(to, from, n);
779 return n;
780 }
781 EXPORT_SYMBOL(__copy_to_user_ll);
782
783 unsigned long __copy_from_user_ll(void *to, const void __user *from,
784 unsigned long n)
785 {
786 if (movsl_is_ok(to, from, n))
787 __copy_user_zeroing(to, from, n);
788 else
789 n = __copy_user_zeroing_intel(to, from, n);
790 return n;
791 }
792 EXPORT_SYMBOL(__copy_from_user_ll);
793
794 unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
795 unsigned long n)
796 {
797 if (movsl_is_ok(to, from, n))
798 __copy_user(to, from, n);
799 else
800 n = __copy_user_intel((void __user *)to,
801 (const void *)from, n);
802 return n;
803 }
804 EXPORT_SYMBOL(__copy_from_user_ll_nozero);
805
806 unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from,
807 unsigned long n)
808 {
809 #ifdef CONFIG_X86_INTEL_USERCOPY
810 if (n > 64 && cpu_has_xmm2)
811 n = __copy_user_zeroing_intel_nocache(to, from, n);
812 else
813 __copy_user_zeroing(to, from, n);
814 #else
815 __copy_user_zeroing(to, from, n);
816 #endif
817 return n;
818 }
819 EXPORT_SYMBOL(__copy_from_user_ll_nocache);
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 EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);
835
836 /**
837 * copy_to_user: - Copy a block of data into user space.
838 * @to: Destination address, in user space.
839 * @from: Source address, in kernel space.
840 * @n: Number of bytes to copy.
841 *
842 * Context: User context only. This function may sleep.
843 *
844 * Copy data from kernel space to user space.
845 *
846 * Returns number of bytes that could not be copied.
847 * On success, this will be zero.
848 */
849 unsigned long
850 copy_to_user(void __user *to, const void *from, unsigned long n)
851 {
852 if (access_ok(VERIFY_WRITE, to, n))
853 n = __copy_to_user(to, from, n);
854 return n;
855 }
856 EXPORT_SYMBOL(copy_to_user);
857
858 /**
859 * copy_from_user: - Copy a block of data from user space.
860 * @to: Destination address, in kernel space.
861 * @from: Source address, in user space.
862 * @n: Number of bytes to copy.
863 *
864 * Context: User context only. This function may sleep.
865 *
866 * Copy data from user space to kernel space.
867 *
868 * Returns number of bytes that could not be copied.
869 * On success, this will be zero.
870 *
871 * If some data could not be copied, this function will pad the copied
872 * data to the requested size using zero bytes.
873 */
874 unsigned long
875 copy_from_user(void *to, const void __user *from, unsigned long n)
876 {
877 if (access_ok(VERIFY_READ, from, n))
878 n = __copy_from_user(to, from, n);
879 else
880 memset(to, 0, n);
881 return n;
882 }
883 EXPORT_SYMBOL(copy_from_user);
Support for the Chinese Samsung S3C2440 based development boards