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[PATCH] network: axnet_cs: bug fix multicast code (support older ax88190 chipset)
[linux-2.6/x86.git] / arch / i386 / lib / usercopy.c
blob4cf981d70f45b621acbce1df4bf7097d27b6d85d
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/config.h>
9 #include <linux/mm.h>
10 #include <linux/highmem.h>
11 #include <linux/blkdev.h>
12 #include <linux/module.h>
13 #include <asm/uaccess.h>
14 #include <asm/mmx.h>
15
16 static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned long n)
17 {
18 #ifdef CONFIG_X86_INTEL_USERCOPY
19 if (n >= 64 && ((a1 ^ a2) & movsl_mask.mask))
20 return 0;
21 #endif
22 return 1;
23 }
24 #define movsl_is_ok(a1,a2,n) \
25 __movsl_is_ok((unsigned long)(a1),(unsigned long)(a2),(n))
26
27 /*
28 * Copy a null terminated string from userspace.
29 */
30
31 #define __do_strncpy_from_user(dst,src,count,res) \
32 do { \
33 int __d0, __d1, __d2; \
34 might_sleep(); \
35 __asm__ __volatile__( \
36 " testl %1,%1\n" \
37 " jz 2f\n" \
38 "0: lodsb\n" \
39 " stosb\n" \
40 " testb %%al,%%al\n" \
41 " jz 1f\n" \
42 " decl %1\n" \
43 " jnz 0b\n" \
44 "1: subl %1,%0\n" \
45 "2:\n" \
46 ".section .fixup,\"ax\"\n" \
47 "3: movl %5,%0\n" \
48 " jmp 2b\n" \
49 ".previous\n" \
50 ".section __ex_table,\"a\"\n" \
51 " .align 4\n" \
52 " .long 0b,3b\n" \
53 ".previous" \
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 __asm__ __volatile__( \
126 "0: rep; stosl\n" \
127 " movl %2,%0\n" \
128 "1: rep; stosb\n" \
129 "2:\n" \
130 ".section .fixup,\"ax\"\n" \
131 "3: lea 0(%2,%0,4),%0\n" \
132 " jmp 2b\n" \
133 ".previous\n" \
134 ".section __ex_table,\"a\"\n" \
135 " .align 4\n" \
136 " .long 0b,3b\n" \
137 " .long 1b,2b\n" \
138 ".previous" \
139 : "=&c"(size), "=&D" (__d0) \
140 : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \
141 } while (0)
142
143 /**
144 * clear_user: - Zero a block of memory in user space.
145 * @to: Destination address, in user space.
146 * @n: Number of bytes to zero.
147 *
148 * Zero a block of memory in user space.
149 *
150 * Returns number of bytes that could not be cleared.
151 * On success, this will be zero.
152 */
153 unsigned long
154 clear_user(void __user *to, unsigned long n)
155 {
156 might_sleep();
157 if (access_ok(VERIFY_WRITE, to, n))
158 __do_clear_user(to, n);
159 return n;
160 }
161 EXPORT_SYMBOL(clear_user);
162
163 /**
164 * __clear_user: - Zero a block of memory in user space, with less checking.
165 * @to: Destination address, in user space.
166 * @n: Number of bytes to zero.
167 *
168 * Zero a block of memory in user space. Caller must check
169 * the specified block with access_ok() before calling this function.
170 *
171 * Returns number of bytes that could not be cleared.
172 * On success, this will be zero.
173 */
174 unsigned long
175 __clear_user(void __user *to, unsigned long n)
176 {
177 __do_clear_user(to, n);
178 return n;
179 }
180 EXPORT_SYMBOL(__clear_user);
181
182 /**
183 * strlen_user: - Get the size of a string in user space.
184 * @s: The string to measure.
185 * @n: The maximum valid length
186 *
187 * Get the size of a NUL-terminated string in user space.
188 *
189 * Returns the size of the string INCLUDING the terminating NUL.
190 * On exception, returns 0.
191 * If the string is too long, returns a value greater than @n.
192 */
193 long strnlen_user(const char __user *s, long n)
194 {
195 unsigned long mask = -__addr_ok(s);
196 unsigned long res, tmp;
197
198 might_sleep();
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 #else
429 /*
430 * Leave these declared but undefined. They should not be any references to
431 * them
432 */
433 unsigned long
434 __copy_user_zeroing_intel(void *to, const void __user *from, unsigned long size);
435 unsigned long
436 __copy_user_intel(void __user *to, const void *from, unsigned long size);
437 #endif /* CONFIG_X86_INTEL_USERCOPY */
438
439 /* Generic arbitrary sized copy. */
440 #define __copy_user(to,from,size) \
441 do { \
442 int __d0, __d1, __d2; \
443 __asm__ __volatile__( \
444 " cmp $7,%0\n" \
445 " jbe 1f\n" \
446 " movl %1,%0\n" \
447 " negl %0\n" \
448 " andl $7,%0\n" \
449 " subl %0,%3\n" \
450 "4: rep; movsb\n" \
451 " movl %3,%0\n" \
452 " shrl $2,%0\n" \
453 " andl $3,%3\n" \
454 " .align 2,0x90\n" \
455 "0: rep; movsl\n" \
456 " movl %3,%0\n" \
457 "1: rep; movsb\n" \
458 "2:\n" \
459 ".section .fixup,\"ax\"\n" \
460 "5: addl %3,%0\n" \
461 " jmp 2b\n" \
462 "3: lea 0(%3,%0,4),%0\n" \
463 " jmp 2b\n" \
464 ".previous\n" \
465 ".section __ex_table,\"a\"\n" \
466 " .align 4\n" \
467 " .long 4b,5b\n" \
468 " .long 0b,3b\n" \
469 " .long 1b,2b\n" \
470 ".previous" \
471 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
472 : "3"(size), "0"(size), "1"(to), "2"(from) \
473 : "memory"); \
474 } while (0)
475
476 #define __copy_user_zeroing(to,from,size) \
477 do { \
478 int __d0, __d1, __d2; \
479 __asm__ __volatile__( \
480 " cmp $7,%0\n" \
481 " jbe 1f\n" \
482 " movl %1,%0\n" \
483 " negl %0\n" \
484 " andl $7,%0\n" \
485 " subl %0,%3\n" \
486 "4: rep; movsb\n" \
487 " movl %3,%0\n" \
488 " shrl $2,%0\n" \
489 " andl $3,%3\n" \
490 " .align 2,0x90\n" \
491 "0: rep; movsl\n" \
492 " movl %3,%0\n" \
493 "1: rep; movsb\n" \
494 "2:\n" \
495 ".section .fixup,\"ax\"\n" \
496 "5: addl %3,%0\n" \
497 " jmp 6f\n" \
498 "3: lea 0(%3,%0,4),%0\n" \
499 "6: pushl %0\n" \
500 " pushl %%eax\n" \
501 " xorl %%eax,%%eax\n" \
502 " rep; stosb\n" \
503 " popl %%eax\n" \
504 " popl %0\n" \
505 " jmp 2b\n" \
506 ".previous\n" \
507 ".section __ex_table,\"a\"\n" \
508 " .align 4\n" \
509 " .long 4b,5b\n" \
510 " .long 0b,3b\n" \
511 " .long 1b,6b\n" \
512 ".previous" \
513 : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
514 : "3"(size), "0"(size), "1"(to), "2"(from) \
515 : "memory"); \
516 } while (0)
517
518
519 unsigned long __copy_to_user_ll(void __user *to, const void *from, unsigned long n)
520 {
521 BUG_ON((long) n < 0);
522 #ifndef CONFIG_X86_WP_WORKS_OK
523 if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
524 ((unsigned long )to) < TASK_SIZE) {
525 /*
526 * CPU does not honor the WP bit when writing
527 * from supervisory mode, and due to preemption or SMP,
528 * the page tables can change at any time.
529 * Do it manually. Manfred <manfred@colorfullife.com>
530 */
531 while (n) {
532 unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
533 unsigned long len = PAGE_SIZE - offset;
534 int retval;
535 struct page *pg;
536 void *maddr;
537
538 if (len > n)
539 len = n;
540
541 survive:
542 down_read(&current->mm->mmap_sem);
543 retval = get_user_pages(current, current->mm,
544 (unsigned long )to, 1, 1, 0, &pg, NULL);
545
546 if (retval == -ENOMEM && current->pid == 1) {
547 up_read(&current->mm->mmap_sem);
548 blk_congestion_wait(WRITE, HZ/50);
549 goto survive;
550 }
551
552 if (retval != 1) {
553 up_read(&current->mm->mmap_sem);
554 break;
555 }
556
557 maddr = kmap_atomic(pg, KM_USER0);
558 memcpy(maddr + offset, from, len);
559 kunmap_atomic(maddr, KM_USER0);
560 set_page_dirty_lock(pg);
561 put_page(pg);
562 up_read(&current->mm->mmap_sem);
563
564 from += len;
565 to += len;
566 n -= len;
567 }
568 return n;
569 }
570 #endif
571 if (movsl_is_ok(to, from, n))
572 __copy_user(to, from, n);
573 else
574 n = __copy_user_intel(to, from, n);
575 return n;
576 }
577 EXPORT_SYMBOL(__copy_to_user_ll);
578
579 unsigned long
580 __copy_from_user_ll(void *to, const void __user *from, unsigned long n)
581 {
582 BUG_ON((long)n < 0);
583 if (movsl_is_ok(to, from, n))
584 __copy_user_zeroing(to, from, n);
585 else
586 n = __copy_user_zeroing_intel(to, from, n);
587 return n;
588 }
589 EXPORT_SYMBOL(__copy_from_user_ll);
590
591 /**
592 * copy_to_user: - Copy a block of data into user space.
593 * @to: Destination address, in user space.
594 * @from: Source address, in kernel space.
595 * @n: Number of bytes to copy.
596 *
597 * Context: User context only. This function may sleep.
598 *
599 * Copy data from kernel space to user space.
600 *
601 * Returns number of bytes that could not be copied.
602 * On success, this will be zero.
603 */
604 unsigned long
605 copy_to_user(void __user *to, const void *from, unsigned long n)
606 {
607 might_sleep();
608 BUG_ON((long) n < 0);
609 if (access_ok(VERIFY_WRITE, to, n))
610 n = __copy_to_user(to, from, n);
611 return n;
612 }
613 EXPORT_SYMBOL(copy_to_user);
614
615 /**
616 * copy_from_user: - Copy a block of data from user space.
617 * @to: Destination address, in kernel space.
618 * @from: Source address, in user space.
619 * @n: Number of bytes to copy.
620 *
621 * Context: User context only. This function may sleep.
622 *
623 * Copy data from user space to kernel space.
624 *
625 * Returns number of bytes that could not be copied.
626 * On success, this will be zero.
627 *
628 * If some data could not be copied, this function will pad the copied
629 * data to the requested size using zero bytes.
630 */
631 unsigned long
632 copy_from_user(void *to, const void __user *from, unsigned long n)
633 {
634 might_sleep();
635 BUG_ON((long) n < 0);
636 if (access_ok(VERIFY_READ, from, n))
637 n = __copy_from_user(to, from, n);
638 else
639 memset(to, 0, n);
640 return n;
641 }
642 EXPORT_SYMBOL(copy_from_user);
x86 "subsystem" repository