projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
x86: use the new generic strnlen_user() function
[deliverable/linux.git] / arch / x86 / lib / usercopy_32.c
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 #include <asm/asm.h>
17
18 #ifdef CONFIG_X86_INTEL_USERCOPY
19 /*
20 * Alignment at which movsl is preferred for bulk memory copies.
21 */
22 struct movsl_mask movsl_mask __read_mostly;
23 #endif
24
25 static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n)
26 {
27 #ifdef CONFIG_X86_INTEL_USERCOPY
28 if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask))
29 return 0;
30 #endif
31 return 1;
32 }
33 #define movsl_is_ok(a1, a2, n) \
34 __movsl_is_ok((unsigned long)(a1), (unsigned long)(a2), (n))
35
36 /*
37 * Zero Userspace
38 */
39
40 #define __do_clear_user(addr,size) \
41 do { \
42 int __d0; \
43 might_fault(); \
44 __asm__ __volatile__( \
45 "0: rep; stosl\n" \
46 " movl %2,%0\n" \
47 "1: rep; stosb\n" \
48 "2:\n" \
49 ".section .fixup,\"ax\"\n" \
50 "3: lea 0(%2,%0,4),%0\n" \
51 " jmp 2b\n" \
52 ".previous\n" \
53 _ASM_EXTABLE(0b,3b) \
54 _ASM_EXTABLE(1b,2b) \
55 : "=&c"(size), "=&D" (__d0) \
56 : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \
57 } while (0)
58
59 /**
60 * clear_user: - Zero a block of memory in user space.
61 * @to: Destination address, in user space.
62 * @n: Number of bytes to zero.
63 *
64 * Zero a block of memory in user space.
65 *
66 * Returns number of bytes that could not be cleared.
67 * On success, this will be zero.
68 */
69 unsigned long
70 clear_user(void __user *to, unsigned long n)
71 {
72 might_fault();
73 if (access_ok(VERIFY_WRITE, to, n))
74 __do_clear_user(to, n);
75 return n;
76 }
77 EXPORT_SYMBOL(clear_user);
78
79 /**
80 * __clear_user: - Zero a block of memory in user space, with less checking.
81 * @to: Destination address, in user space.
82 * @n: Number of bytes to zero.
83 *
84 * Zero a block of memory in user space. Caller must check
85 * the specified block with access_ok() before calling this function.
86 *
87 * Returns number of bytes that could not be cleared.
88 * On success, this will be zero.
89 */
90 unsigned long
91 __clear_user(void __user *to, unsigned long n)
92 {
93 __do_clear_user(to, n);
94 return n;
95 }
96 EXPORT_SYMBOL(__clear_user);
97
98 #ifdef CONFIG_X86_INTEL_USERCOPY
99 static unsigned long
100 __copy_user_intel(void __user *to, const void *from, unsigned long size)
101 {
102 int d0, d1;
103 __asm__ __volatile__(
104 " .align 2,0x90\n"
105 "1: movl 32(%4), %%eax\n"
106 " cmpl $67, %0\n"
107 " jbe 3f\n"
108 "2: movl 64(%4), %%eax\n"
109 " .align 2,0x90\n"
110 "3: movl 0(%4), %%eax\n"
111 "4: movl 4(%4), %%edx\n"
112 "5: movl %%eax, 0(%3)\n"
113 "6: movl %%edx, 4(%3)\n"
114 "7: movl 8(%4), %%eax\n"
115 "8: movl 12(%4),%%edx\n"
116 "9: movl %%eax, 8(%3)\n"
117 "10: movl %%edx, 12(%3)\n"
118 "11: movl 16(%4), %%eax\n"
119 "12: movl 20(%4), %%edx\n"
120 "13: movl %%eax, 16(%3)\n"
121 "14: movl %%edx, 20(%3)\n"
122 "15: movl 24(%4), %%eax\n"
123 "16: movl 28(%4), %%edx\n"
124 "17: movl %%eax, 24(%3)\n"
125 "18: movl %%edx, 28(%3)\n"
126 "19: movl 32(%4), %%eax\n"
127 "20: movl 36(%4), %%edx\n"
128 "21: movl %%eax, 32(%3)\n"
129 "22: movl %%edx, 36(%3)\n"
130 "23: movl 40(%4), %%eax\n"
131 "24: movl 44(%4), %%edx\n"
132 "25: movl %%eax, 40(%3)\n"
133 "26: movl %%edx, 44(%3)\n"
134 "27: movl 48(%4), %%eax\n"
135 "28: movl 52(%4), %%edx\n"
136 "29: movl %%eax, 48(%3)\n"
137 "30: movl %%edx, 52(%3)\n"
138 "31: movl 56(%4), %%eax\n"
139 "32: movl 60(%4), %%edx\n"
140 "33: movl %%eax, 56(%3)\n"
141 "34: movl %%edx, 60(%3)\n"
142 " addl $-64, %0\n"
143 " addl $64, %4\n"
144 " addl $64, %3\n"
145 " cmpl $63, %0\n"
146 " ja 1b\n"
147 "35: movl %0, %%eax\n"
148 " shrl $2, %0\n"
149 " andl $3, %%eax\n"
150 " cld\n"
151 "99: rep; movsl\n"
152 "36: movl %%eax, %0\n"
153 "37: rep; movsb\n"
154 "100:\n"
155 ".section .fixup,\"ax\"\n"
156 "101: lea 0(%%eax,%0,4),%0\n"
157 " jmp 100b\n"
158 ".previous\n"
159 _ASM_EXTABLE(1b,100b)
160 _ASM_EXTABLE(2b,100b)
161 _ASM_EXTABLE(3b,100b)
162 _ASM_EXTABLE(4b,100b)
163 _ASM_EXTABLE(5b,100b)
164 _ASM_EXTABLE(6b,100b)
165 _ASM_EXTABLE(7b,100b)
166 _ASM_EXTABLE(8b,100b)
167 _ASM_EXTABLE(9b,100b)
168 _ASM_EXTABLE(10b,100b)
169 _ASM_EXTABLE(11b,100b)
170 _ASM_EXTABLE(12b,100b)
171 _ASM_EXTABLE(13b,100b)
172 _ASM_EXTABLE(14b,100b)
173 _ASM_EXTABLE(15b,100b)
174 _ASM_EXTABLE(16b,100b)
175 _ASM_EXTABLE(17b,100b)
176 _ASM_EXTABLE(18b,100b)
177 _ASM_EXTABLE(19b,100b)
178 _ASM_EXTABLE(20b,100b)
179 _ASM_EXTABLE(21b,100b)
180 _ASM_EXTABLE(22b,100b)
181 _ASM_EXTABLE(23b,100b)
182 _ASM_EXTABLE(24b,100b)
183 _ASM_EXTABLE(25b,100b)
184 _ASM_EXTABLE(26b,100b)
185 _ASM_EXTABLE(27b,100b)
186 _ASM_EXTABLE(28b,100b)
187 _ASM_EXTABLE(29b,100b)
188 _ASM_EXTABLE(30b,100b)
189 _ASM_EXTABLE(31b,100b)
190 _ASM_EXTABLE(32b,100b)
191 _ASM_EXTABLE(33b,100b)
192 _ASM_EXTABLE(34b,100b)
193 _ASM_EXTABLE(35b,100b)
194 _ASM_EXTABLE(36b,100b)
195 _ASM_EXTABLE(37b,100b)
196 _ASM_EXTABLE(99b,101b)
197 : "=&c"(size), "=&D" (d0), "=&S" (d1)
198 : "1"(to), "2"(from), "0"(size)
199 : "eax", "edx", "memory");
200 return size;
201 }
202
203 static unsigned long
204 __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size)
205 {
206 int d0, d1;
207 __asm__ __volatile__(
208 " .align 2,0x90\n"
209 "0: movl 32(%4), %%eax\n"
210 " cmpl $67, %0\n"
211 " jbe 2f\n"
212 "1: movl 64(%4), %%eax\n"
213 " .align 2,0x90\n"
214 "2: movl 0(%4), %%eax\n"
215 "21: movl 4(%4), %%edx\n"
216 " movl %%eax, 0(%3)\n"
217 " movl %%edx, 4(%3)\n"
218 "3: movl 8(%4), %%eax\n"
219 "31: movl 12(%4),%%edx\n"
220 " movl %%eax, 8(%3)\n"
221 " movl %%edx, 12(%3)\n"
222 "4: movl 16(%4), %%eax\n"
223 "41: movl 20(%4), %%edx\n"
224 " movl %%eax, 16(%3)\n"
225 " movl %%edx, 20(%3)\n"
226 "10: movl 24(%4), %%eax\n"
227 "51: movl 28(%4), %%edx\n"
228 " movl %%eax, 24(%3)\n"
229 " movl %%edx, 28(%3)\n"
230 "11: movl 32(%4), %%eax\n"
231 "61: movl 36(%4), %%edx\n"
232 " movl %%eax, 32(%3)\n"
233 " movl %%edx, 36(%3)\n"
234 "12: movl 40(%4), %%eax\n"
235 "71: movl 44(%4), %%edx\n"
236 " movl %%eax, 40(%3)\n"
237 " movl %%edx, 44(%3)\n"
238 "13: movl 48(%4), %%eax\n"
239 "81: movl 52(%4), %%edx\n"
240 " movl %%eax, 48(%3)\n"
241 " movl %%edx, 52(%3)\n"
242 "14: movl 56(%4), %%eax\n"
243 "91: movl 60(%4), %%edx\n"
244 " movl %%eax, 56(%3)\n"
245 " movl %%edx, 60(%3)\n"
246 " addl $-64, %0\n"
247 " addl $64, %4\n"
248 " addl $64, %3\n"
249 " cmpl $63, %0\n"
250 " ja 0b\n"
251 "5: movl %0, %%eax\n"
252 " shrl $2, %0\n"
253 " andl $3, %%eax\n"
254 " cld\n"
255 "6: rep; movsl\n"
256 " movl %%eax,%0\n"
257 "7: rep; movsb\n"
258 "8:\n"
259 ".section .fixup,\"ax\"\n"
260 "9: lea 0(%%eax,%0,4),%0\n"
261 "16: pushl %0\n"
262 " pushl %%eax\n"
263 " xorl %%eax,%%eax\n"
264 " rep; stosb\n"
265 " popl %%eax\n"
266 " popl %0\n"
267 " jmp 8b\n"
268 ".previous\n"
269 _ASM_EXTABLE(0b,16b)
270 _ASM_EXTABLE(1b,16b)
271 _ASM_EXTABLE(2b,16b)
272 _ASM_EXTABLE(21b,16b)
273 _ASM_EXTABLE(3b,16b)
274 _ASM_EXTABLE(31b,16b)
275 _ASM_EXTABLE(4b,16b)
276 _ASM_EXTABLE(41b,16b)
277 _ASM_EXTABLE(10b,16b)
278 _ASM_EXTABLE(51b,16b)
279 _ASM_EXTABLE(11b,16b)
280 _ASM_EXTABLE(61b,16b)
281 _ASM_EXTABLE(12b,16b)
282 _ASM_EXTABLE(71b,16b)
283 _ASM_EXTABLE(13b,16b)
284 _ASM_EXTABLE(81b,16b)
285 _ASM_EXTABLE(14b,16b)
286 _ASM_EXTABLE(91b,16b)
287 _ASM_EXTABLE(6b,9b)
288 _ASM_EXTABLE(7b,16b)
289 : "=&c"(size), "=&D" (d0), "=&S" (d1)
290 : "1"(to), "2"(from), "0"(size)
291 : "eax", "edx", "memory");
292 return size;
293 }
294
295 /*
296 * Non Temporal Hint version of __copy_user_zeroing_intel. It is cache aware.
297 * hyoshiok@miraclelinux.com
298 */
299
300 static unsigned long __copy_user_zeroing_intel_nocache(void *to,
301 const void __user *from, unsigned long size)
302 {
303 int d0, d1;
304
305 __asm__ __volatile__(
306 " .align 2,0x90\n"
307 "0: movl 32(%4), %%eax\n"
308 " cmpl $67, %0\n"
309 " jbe 2f\n"
310 "1: movl 64(%4), %%eax\n"
311 " .align 2,0x90\n"
312 "2: movl 0(%4), %%eax\n"
313 "21: movl 4(%4), %%edx\n"
314 " movnti %%eax, 0(%3)\n"
315 " movnti %%edx, 4(%3)\n"
316 "3: movl 8(%4), %%eax\n"
317 "31: movl 12(%4),%%edx\n"
318 " movnti %%eax, 8(%3)\n"
319 " movnti %%edx, 12(%3)\n"
320 "4: movl 16(%4), %%eax\n"
321 "41: movl 20(%4), %%edx\n"
322 " movnti %%eax, 16(%3)\n"
323 " movnti %%edx, 20(%3)\n"
324 "10: movl 24(%4), %%eax\n"
325 "51: movl 28(%4), %%edx\n"
326 " movnti %%eax, 24(%3)\n"
327 " movnti %%edx, 28(%3)\n"
328 "11: movl 32(%4), %%eax\n"
329 "61: movl 36(%4), %%edx\n"
330 " movnti %%eax, 32(%3)\n"
331 " movnti %%edx, 36(%3)\n"
332 "12: movl 40(%4), %%eax\n"
333 "71: movl 44(%4), %%edx\n"
334 " movnti %%eax, 40(%3)\n"
335 " movnti %%edx, 44(%3)\n"
336 "13: movl 48(%4), %%eax\n"
337 "81: movl 52(%4), %%edx\n"
338 " movnti %%eax, 48(%3)\n"
339 " movnti %%edx, 52(%3)\n"
340 "14: movl 56(%4), %%eax\n"
341 "91: movl 60(%4), %%edx\n"
342 " movnti %%eax, 56(%3)\n"
343 " movnti %%edx, 60(%3)\n"
344 " addl $-64, %0\n"
345 " addl $64, %4\n"
346 " addl $64, %3\n"
347 " cmpl $63, %0\n"
348 " ja 0b\n"
349 " sfence \n"
350 "5: movl %0, %%eax\n"
351 " shrl $2, %0\n"
352 " andl $3, %%eax\n"
353 " cld\n"
354 "6: rep; movsl\n"
355 " movl %%eax,%0\n"
356 "7: rep; movsb\n"
357 "8:\n"
358 ".section .fixup,\"ax\"\n"
359 "9: lea 0(%%eax,%0,4),%0\n"
360 "16: pushl %0\n"
361 " pushl %%eax\n"
362 " xorl %%eax,%%eax\n"
363 " rep; stosb\n"
364 " popl %%eax\n"
365 " popl %0\n"
366 " jmp 8b\n"
367 ".previous\n"
368 _ASM_EXTABLE(0b,16b)
369 _ASM_EXTABLE(1b,16b)
370 _ASM_EXTABLE(2b,16b)
371 _ASM_EXTABLE(21b,16b)
372 _ASM_EXTABLE(3b,16b)
373 _ASM_EXTABLE(31b,16b)
374 _ASM_EXTABLE(4b,16b)
375 _ASM_EXTABLE(41b,16b)
376 _ASM_EXTABLE(10b,16b)
377 _ASM_EXTABLE(51b,16b)
378 _ASM_EXTABLE(11b,16b)
379 _ASM_EXTABLE(61b,16b)
380 _ASM_EXTABLE(12b,16b)
381 _ASM_EXTABLE(71b,16b)
382 _ASM_EXTABLE(13b,16b)
383 _ASM_EXTABLE(81b,16b)
384 _ASM_EXTABLE(14b,16b)
385 _ASM_EXTABLE(91b,16b)
386 _ASM_EXTABLE(6b,9b)
387 _ASM_EXTABLE(7b,16b)
388 : "=&c"(size), "=&D" (d0), "=&S" (d1)
389 : "1"(to), "2"(from), "0"(size)
390 : "eax", "edx", "memory");
391 return size;
392 }
393
394 static unsigned long __copy_user_intel_nocache(void *to,
395 const void __user *from, unsigned long size)
396 {
397 int d0, d1;
398
399 __asm__ __volatile__(
400 " .align 2,0x90\n"
401 "0: movl 32(%4), %%eax\n"
402 " cmpl $67, %0\n"
403 " jbe 2f\n"
404 "1: movl 64(%4), %%eax\n"
405 " .align 2,0x90\n"
406 "2: movl 0(%4), %%eax\n"
407 "21: movl 4(%4), %%edx\n"
408 " movnti %%eax, 0(%3)\n"
409 " movnti %%edx, 4(%3)\n"
410 "3: movl 8(%4), %%eax\n"
411 "31: movl 12(%4),%%edx\n"
412 " movnti %%eax, 8(%3)\n"
413 " movnti %%edx, 12(%3)\n"
414 "4: movl 16(%4), %%eax\n"
415 "41: movl 20(%4), %%edx\n"
416 " movnti %%eax, 16(%3)\n"
417 " movnti %%edx, 20(%3)\n"
418 "10: movl 24(%4), %%eax\n"
419 "51: movl 28(%4), %%edx\n"
420 " movnti %%eax, 24(%3)\n"
421 " movnti %%edx, 28(%3)\n"
422 "11: movl 32(%4), %%eax\n"
423 "61: movl 36(%4), %%edx\n"
424 " movnti %%eax, 32(%3)\n"
425 " movnti %%edx, 36(%3)\n"
426 "12: movl 40(%4), %%eax\n"
427 "71: movl 44(%4), %%edx\n"
428 " movnti %%eax, 40(%3)\n"
429 " movnti %%edx, 44(%3)\n"
430 "13: movl 48(%4), %%eax\n"
431 "81: movl 52(%4), %%edx\n"
432 " movnti %%eax, 48(%3)\n"
433 " movnti %%edx, 52(%3)\n"
434 "14: movl 56(%4), %%eax\n"
435 "91: movl 60(%4), %%edx\n"
436 " movnti %%eax, 56(%3)\n"
437 " movnti %%edx, 60(%3)\n"
438 " addl $-64, %0\n"
439 " addl $64, %4\n"
440 " addl $64, %3\n"
441 " cmpl $63, %0\n"
442 " ja 0b\n"
443 " sfence \n"
444 "5: movl %0, %%eax\n"
445 " shrl $2, %0\n"
446 " andl $3, %%eax\n"
447 " cld\n"
448 "6: rep; movsl\n"
449 " movl %%eax,%0\n"
450 "7: rep; movsb\n"
451 "8:\n"
452 ".section .fixup,\"ax\"\n"
453 "9: lea 0(%%eax,%0,4),%0\n"
454 "16: jmp 8b\n"
455 ".previous\n"
456 _ASM_EXTABLE(0b,16b)
457 _ASM_EXTABLE(1b,16b)
458 _ASM_EXTABLE(2b,16b)
459 _ASM_EXTABLE(21b,16b)
460 _ASM_EXTABLE(3b,16b)
461 _ASM_EXTABLE(31b,16b)
462 _ASM_EXTABLE(4b,16b)
463 _ASM_EXTABLE(41b,16b)
464 _ASM_EXTABLE(10b,16b)
465 _ASM_EXTABLE(51b,16b)
466 _ASM_EXTABLE(11b,16b)
467 _ASM_EXTABLE(61b,16b)
468 _ASM_EXTABLE(12b,16b)
469 _ASM_EXTABLE(71b,16b)
470 _ASM_EXTABLE(13b,16b)
471 _ASM_EXTABLE(81b,16b)
472 _ASM_EXTABLE(14b,16b)
473 _ASM_EXTABLE(91b,16b)
474 _ASM_EXTABLE(6b,9b)
475 _ASM_EXTABLE(7b,16b)
476 : "=&c"(size), "=&D" (d0), "=&S" (d1)
477 : "1"(to), "2"(from), "0"(size)
478 : "eax", "edx", "memory");
479 return size;
480 }
481
482 #else
483
484 /*
485 * Leave these declared but undefined. They should not be any references to
486 * them
487 */
488 unsigned long __copy_user_zeroing_intel(void *to, const void __user *from,
489 unsigned long size);
490 unsigned long __copy_user_intel(void __user *to, const void *from,
491 unsigned long size);
492 unsigned long __copy_user_zeroing_intel_nocache(void *to,
493 const void __user *from, unsigned long size);
494 #endif /* CONFIG_X86_INTEL_USERCOPY */
495
496 /* Generic arbitrary sized copy. */
497 #define __copy_user(to, from, size) \
498 do { \
499 int __d0, __d1, __d2; \
500 __asm__ __volatile__( \
501 " cmp $7,%0\n" \
502 " jbe 1f\n" \
503 " movl %1,%0\n" \
504 " negl %0\n" \
505 " andl $7,%0\n" \
506 " subl %0,%3\n" \
507 "4: rep; movsb\n" \
508 " movl %3,%0\n" \
509 " shrl $2,%0\n" \
510 " andl $3,%3\n" \
511 " .align 2,0x90\n" \
512 "0: rep; movsl\n" \
513 " movl %3,%0\n" \
514 "1: rep; movsb\n" \
515 "2:\n" \
516 ".section .fixup,\"ax\"\n" \
517 "5: addl %3,%0\n" \
518 " jmp 2b\n" \
519 "3: lea 0(%3,%0,4),%0\n" \
520 " jmp 2b\n" \
521 ".previous\n" \
522 _ASM_EXTABLE(4b,5b) \
523 _ASM_EXTABLE(0b,3b) \
524 _ASM_EXTABLE(1b,2b) \
525 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
526 : "3"(size), "0"(size), "1"(to), "2"(from) \
527 : "memory"); \
528 } while (0)
529
530 #define __copy_user_zeroing(to, from, size) \
531 do { \
532 int __d0, __d1, __d2; \
533 __asm__ __volatile__( \
534 " cmp $7,%0\n" \
535 " jbe 1f\n" \
536 " movl %1,%0\n" \
537 " negl %0\n" \
538 " andl $7,%0\n" \
539 " subl %0,%3\n" \
540 "4: rep; movsb\n" \
541 " movl %3,%0\n" \
542 " shrl $2,%0\n" \
543 " andl $3,%3\n" \
544 " .align 2,0x90\n" \
545 "0: rep; movsl\n" \
546 " movl %3,%0\n" \
547 "1: rep; movsb\n" \
548 "2:\n" \
549 ".section .fixup,\"ax\"\n" \
550 "5: addl %3,%0\n" \
551 " jmp 6f\n" \
552 "3: lea 0(%3,%0,4),%0\n" \
553 "6: pushl %0\n" \
554 " pushl %%eax\n" \
555 " xorl %%eax,%%eax\n" \
556 " rep; stosb\n" \
557 " popl %%eax\n" \
558 " popl %0\n" \
559 " jmp 2b\n" \
560 ".previous\n" \
561 _ASM_EXTABLE(4b,5b) \
562 _ASM_EXTABLE(0b,3b) \
563 _ASM_EXTABLE(1b,6b) \
564 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
565 : "3"(size), "0"(size), "1"(to), "2"(from) \
566 : "memory"); \
567 } while (0)
568
569 unsigned long __copy_to_user_ll(void __user *to, const void *from,
570 unsigned long n)
571 {
572 #ifndef CONFIG_X86_WP_WORKS_OK
573 if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
574 ((unsigned long)to) < TASK_SIZE) {
575 /*
576 * When we are in an atomic section (see
577 * mm/filemap.c:file_read_actor), return the full
578 * length to take the slow path.
579 */
580 if (in_atomic())
581 return n;
582
583 /*
584 * CPU does not honor the WP bit when writing
585 * from supervisory mode, and due to preemption or SMP,
586 * the page tables can change at any time.
587 * Do it manually. Manfred <manfred@colorfullife.com>
588 */
589 while (n) {
590 unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
591 unsigned long len = PAGE_SIZE - offset;
592 int retval;
593 struct page *pg;
594 void *maddr;
595
596 if (len > n)
597 len = n;
598
599 survive:
600 down_read(&current->mm->mmap_sem);
601 retval = get_user_pages(current, current->mm,
602 (unsigned long)to, 1, 1, 0, &pg, NULL);
603
604 if (retval == -ENOMEM && is_global_init(current)) {
605 up_read(&current->mm->mmap_sem);
606 congestion_wait(BLK_RW_ASYNC, HZ/50);
607 goto survive;
608 }
609
610 if (retval != 1) {
611 up_read(&current->mm->mmap_sem);
612 break;
613 }
614
615 maddr = kmap_atomic(pg);
616 memcpy(maddr + offset, from, len);
617 kunmap_atomic(maddr);
618 set_page_dirty_lock(pg);
619 put_page(pg);
620 up_read(&current->mm->mmap_sem);
621
622 from += len;
623 to += len;
624 n -= len;
625 }
626 return n;
627 }
628 #endif
629 if (movsl_is_ok(to, from, n))
630 __copy_user(to, from, n);
631 else
632 n = __copy_user_intel(to, from, n);
633 return n;
634 }
635 EXPORT_SYMBOL(__copy_to_user_ll);
636
637 unsigned long __copy_from_user_ll(void *to, const void __user *from,
638 unsigned long n)
639 {
640 if (movsl_is_ok(to, from, n))
641 __copy_user_zeroing(to, from, n);
642 else
643 n = __copy_user_zeroing_intel(to, from, n);
644 return n;
645 }
646 EXPORT_SYMBOL(__copy_from_user_ll);
647
648 unsigned long __copy_from_user_ll_nozero(void *to, const void __user *from,
649 unsigned long n)
650 {
651 if (movsl_is_ok(to, from, n))
652 __copy_user(to, from, n);
653 else
654 n = __copy_user_intel((void __user *)to,
655 (const void *)from, n);
656 return n;
657 }
658 EXPORT_SYMBOL(__copy_from_user_ll_nozero);
659
660 unsigned long __copy_from_user_ll_nocache(void *to, const void __user *from,
661 unsigned long n)
662 {
663 #ifdef CONFIG_X86_INTEL_USERCOPY
664 if (n > 64 && cpu_has_xmm2)
665 n = __copy_user_zeroing_intel_nocache(to, from, n);
666 else
667 __copy_user_zeroing(to, from, n);
668 #else
669 __copy_user_zeroing(to, from, n);
670 #endif
671 return n;
672 }
673 EXPORT_SYMBOL(__copy_from_user_ll_nocache);
674
675 unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *from,
676 unsigned long n)
677 {
678 #ifdef CONFIG_X86_INTEL_USERCOPY
679 if (n > 64 && cpu_has_xmm2)
680 n = __copy_user_intel_nocache(to, from, n);
681 else
682 __copy_user(to, from, n);
683 #else
684 __copy_user(to, from, n);
685 #endif
686 return n;
687 }
688 EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);
689
690 /**
691 * copy_to_user: - Copy a block of data into user space.
692 * @to: Destination address, in user space.
693 * @from: Source address, in kernel space.
694 * @n: Number of bytes to copy.
695 *
696 * Context: User context only. This function may sleep.
697 *
698 * Copy data from kernel space to user space.
699 *
700 * Returns number of bytes that could not be copied.
701 * On success, this will be zero.
702 */
703 unsigned long
704 copy_to_user(void __user *to, const void *from, unsigned long n)
705 {
706 if (access_ok(VERIFY_WRITE, to, n))
707 n = __copy_to_user(to, from, n);
708 return n;
709 }
710 EXPORT_SYMBOL(copy_to_user);
711
712 /**
713 * copy_from_user: - Copy a block of data from user space.
714 * @to: Destination address, in kernel space.
715 * @from: Source address, in user space.
716 * @n: Number of bytes to copy.
717 *
718 * Context: User context only. This function may sleep.
719 *
720 * Copy data from user space to kernel space.
721 *
722 * Returns number of bytes that could not be copied.
723 * On success, this will be zero.
724 *
725 * If some data could not be copied, this function will pad the copied
726 * data to the requested size using zero bytes.
727 */
728 unsigned long
729 _copy_from_user(void *to, const void __user *from, unsigned long n)
730 {
731 if (access_ok(VERIFY_READ, from, n))
732 n = __copy_from_user(to, from, n);
733 else
734 memset(to, 0, n);
735 return n;
736 }
737 EXPORT_SYMBOL(_copy_from_user);
738
739 void copy_from_user_overflow(void)
740 {
741 WARN(1, "Buffer overflow detected!\n");
742 }
743 EXPORT_SYMBOL(copy_from_user_overflow);
Linux kernel - Deliverables
This page took 0.064991 seconds and 5 git commands to generate.