]>
Commit | Line | Data |
---|---|---|
1 | #include <linux/export.h> | |
2 | #include <linux/uio.h> | |
3 | #include <linux/pagemap.h> | |
4 | #include <linux/slab.h> | |
5 | #include <linux/vmalloc.h> | |
6 | #include <linux/splice.h> | |
7 | #include <net/checksum.h> | |
8 | ||
9 | #define PIPE_PARANOIA /* for now */ | |
10 | ||
11 | #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ | |
12 | size_t left; \ | |
13 | size_t wanted = n; \ | |
14 | __p = i->iov; \ | |
15 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
16 | if (likely(__v.iov_len)) { \ | |
17 | __v.iov_base = __p->iov_base + skip; \ | |
18 | left = (STEP); \ | |
19 | __v.iov_len -= left; \ | |
20 | skip += __v.iov_len; \ | |
21 | n -= __v.iov_len; \ | |
22 | } else { \ | |
23 | left = 0; \ | |
24 | } \ | |
25 | while (unlikely(!left && n)) { \ | |
26 | __p++; \ | |
27 | __v.iov_len = min(n, __p->iov_len); \ | |
28 | if (unlikely(!__v.iov_len)) \ | |
29 | continue; \ | |
30 | __v.iov_base = __p->iov_base; \ | |
31 | left = (STEP); \ | |
32 | __v.iov_len -= left; \ | |
33 | skip = __v.iov_len; \ | |
34 | n -= __v.iov_len; \ | |
35 | } \ | |
36 | n = wanted - n; \ | |
37 | } | |
38 | ||
39 | #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ | |
40 | size_t wanted = n; \ | |
41 | __p = i->kvec; \ | |
42 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
43 | if (likely(__v.iov_len)) { \ | |
44 | __v.iov_base = __p->iov_base + skip; \ | |
45 | (void)(STEP); \ | |
46 | skip += __v.iov_len; \ | |
47 | n -= __v.iov_len; \ | |
48 | } \ | |
49 | while (unlikely(n)) { \ | |
50 | __p++; \ | |
51 | __v.iov_len = min(n, __p->iov_len); \ | |
52 | if (unlikely(!__v.iov_len)) \ | |
53 | continue; \ | |
54 | __v.iov_base = __p->iov_base; \ | |
55 | (void)(STEP); \ | |
56 | skip = __v.iov_len; \ | |
57 | n -= __v.iov_len; \ | |
58 | } \ | |
59 | n = wanted; \ | |
60 | } | |
61 | ||
62 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ | |
63 | struct bvec_iter __start; \ | |
64 | __start.bi_size = n; \ | |
65 | __start.bi_bvec_done = skip; \ | |
66 | __start.bi_idx = 0; \ | |
67 | for_each_bvec(__v, i->bvec, __bi, __start) { \ | |
68 | if (!__v.bv_len) \ | |
69 | continue; \ | |
70 | (void)(STEP); \ | |
71 | } \ | |
72 | } | |
73 | ||
74 | #define iterate_all_kinds(i, n, v, I, B, K) { \ | |
75 | size_t skip = i->iov_offset; \ | |
76 | if (unlikely(i->type & ITER_BVEC)) { \ | |
77 | struct bio_vec v; \ | |
78 | struct bvec_iter __bi; \ | |
79 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
80 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
81 | const struct kvec *kvec; \ | |
82 | struct kvec v; \ | |
83 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
84 | } else { \ | |
85 | const struct iovec *iov; \ | |
86 | struct iovec v; \ | |
87 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
88 | } \ | |
89 | } | |
90 | ||
91 | #define iterate_and_advance(i, n, v, I, B, K) { \ | |
92 | if (unlikely(i->count < n)) \ | |
93 | n = i->count; \ | |
94 | if (i->count) { \ | |
95 | size_t skip = i->iov_offset; \ | |
96 | if (unlikely(i->type & ITER_BVEC)) { \ | |
97 | const struct bio_vec *bvec = i->bvec; \ | |
98 | struct bio_vec v; \ | |
99 | struct bvec_iter __bi; \ | |
100 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
101 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
102 | i->nr_segs -= i->bvec - bvec; \ | |
103 | skip = __bi.bi_bvec_done; \ | |
104 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
105 | const struct kvec *kvec; \ | |
106 | struct kvec v; \ | |
107 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
108 | if (skip == kvec->iov_len) { \ | |
109 | kvec++; \ | |
110 | skip = 0; \ | |
111 | } \ | |
112 | i->nr_segs -= kvec - i->kvec; \ | |
113 | i->kvec = kvec; \ | |
114 | } else { \ | |
115 | const struct iovec *iov; \ | |
116 | struct iovec v; \ | |
117 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
118 | if (skip == iov->iov_len) { \ | |
119 | iov++; \ | |
120 | skip = 0; \ | |
121 | } \ | |
122 | i->nr_segs -= iov - i->iov; \ | |
123 | i->iov = iov; \ | |
124 | } \ | |
125 | i->count -= n; \ | |
126 | i->iov_offset = skip; \ | |
127 | } \ | |
128 | } | |
129 | ||
130 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, | |
131 | struct iov_iter *i) | |
132 | { | |
133 | size_t skip, copy, left, wanted; | |
134 | const struct iovec *iov; | |
135 | char __user *buf; | |
136 | void *kaddr, *from; | |
137 | ||
138 | if (unlikely(bytes > i->count)) | |
139 | bytes = i->count; | |
140 | ||
141 | if (unlikely(!bytes)) | |
142 | return 0; | |
143 | ||
144 | wanted = bytes; | |
145 | iov = i->iov; | |
146 | skip = i->iov_offset; | |
147 | buf = iov->iov_base + skip; | |
148 | copy = min(bytes, iov->iov_len - skip); | |
149 | ||
150 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { | |
151 | kaddr = kmap_atomic(page); | |
152 | from = kaddr + offset; | |
153 | ||
154 | /* first chunk, usually the only one */ | |
155 | left = __copy_to_user_inatomic(buf, from, copy); | |
156 | copy -= left; | |
157 | skip += copy; | |
158 | from += copy; | |
159 | bytes -= copy; | |
160 | ||
161 | while (unlikely(!left && bytes)) { | |
162 | iov++; | |
163 | buf = iov->iov_base; | |
164 | copy = min(bytes, iov->iov_len); | |
165 | left = __copy_to_user_inatomic(buf, from, copy); | |
166 | copy -= left; | |
167 | skip = copy; | |
168 | from += copy; | |
169 | bytes -= copy; | |
170 | } | |
171 | if (likely(!bytes)) { | |
172 | kunmap_atomic(kaddr); | |
173 | goto done; | |
174 | } | |
175 | offset = from - kaddr; | |
176 | buf += copy; | |
177 | kunmap_atomic(kaddr); | |
178 | copy = min(bytes, iov->iov_len - skip); | |
179 | } | |
180 | /* Too bad - revert to non-atomic kmap */ | |
181 | ||
182 | kaddr = kmap(page); | |
183 | from = kaddr + offset; | |
184 | left = __copy_to_user(buf, from, copy); | |
185 | copy -= left; | |
186 | skip += copy; | |
187 | from += copy; | |
188 | bytes -= copy; | |
189 | while (unlikely(!left && bytes)) { | |
190 | iov++; | |
191 | buf = iov->iov_base; | |
192 | copy = min(bytes, iov->iov_len); | |
193 | left = __copy_to_user(buf, from, copy); | |
194 | copy -= left; | |
195 | skip = copy; | |
196 | from += copy; | |
197 | bytes -= copy; | |
198 | } | |
199 | kunmap(page); | |
200 | ||
201 | done: | |
202 | if (skip == iov->iov_len) { | |
203 | iov++; | |
204 | skip = 0; | |
205 | } | |
206 | i->count -= wanted - bytes; | |
207 | i->nr_segs -= iov - i->iov; | |
208 | i->iov = iov; | |
209 | i->iov_offset = skip; | |
210 | return wanted - bytes; | |
211 | } | |
212 | ||
213 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, | |
214 | struct iov_iter *i) | |
215 | { | |
216 | size_t skip, copy, left, wanted; | |
217 | const struct iovec *iov; | |
218 | char __user *buf; | |
219 | void *kaddr, *to; | |
220 | ||
221 | if (unlikely(bytes > i->count)) | |
222 | bytes = i->count; | |
223 | ||
224 | if (unlikely(!bytes)) | |
225 | return 0; | |
226 | ||
227 | wanted = bytes; | |
228 | iov = i->iov; | |
229 | skip = i->iov_offset; | |
230 | buf = iov->iov_base + skip; | |
231 | copy = min(bytes, iov->iov_len - skip); | |
232 | ||
233 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { | |
234 | kaddr = kmap_atomic(page); | |
235 | to = kaddr + offset; | |
236 | ||
237 | /* first chunk, usually the only one */ | |
238 | left = __copy_from_user_inatomic(to, buf, copy); | |
239 | copy -= left; | |
240 | skip += copy; | |
241 | to += copy; | |
242 | bytes -= copy; | |
243 | ||
244 | while (unlikely(!left && bytes)) { | |
245 | iov++; | |
246 | buf = iov->iov_base; | |
247 | copy = min(bytes, iov->iov_len); | |
248 | left = __copy_from_user_inatomic(to, buf, copy); | |
249 | copy -= left; | |
250 | skip = copy; | |
251 | to += copy; | |
252 | bytes -= copy; | |
253 | } | |
254 | if (likely(!bytes)) { | |
255 | kunmap_atomic(kaddr); | |
256 | goto done; | |
257 | } | |
258 | offset = to - kaddr; | |
259 | buf += copy; | |
260 | kunmap_atomic(kaddr); | |
261 | copy = min(bytes, iov->iov_len - skip); | |
262 | } | |
263 | /* Too bad - revert to non-atomic kmap */ | |
264 | ||
265 | kaddr = kmap(page); | |
266 | to = kaddr + offset; | |
267 | left = __copy_from_user(to, buf, copy); | |
268 | copy -= left; | |
269 | skip += copy; | |
270 | to += copy; | |
271 | bytes -= copy; | |
272 | while (unlikely(!left && bytes)) { | |
273 | iov++; | |
274 | buf = iov->iov_base; | |
275 | copy = min(bytes, iov->iov_len); | |
276 | left = __copy_from_user(to, buf, copy); | |
277 | copy -= left; | |
278 | skip = copy; | |
279 | to += copy; | |
280 | bytes -= copy; | |
281 | } | |
282 | kunmap(page); | |
283 | ||
284 | done: | |
285 | if (skip == iov->iov_len) { | |
286 | iov++; | |
287 | skip = 0; | |
288 | } | |
289 | i->count -= wanted - bytes; | |
290 | i->nr_segs -= iov - i->iov; | |
291 | i->iov = iov; | |
292 | i->iov_offset = skip; | |
293 | return wanted - bytes; | |
294 | } | |
295 | ||
296 | #ifdef PIPE_PARANOIA | |
297 | static bool sanity(const struct iov_iter *i) | |
298 | { | |
299 | struct pipe_inode_info *pipe = i->pipe; | |
300 | int idx = i->idx; | |
301 | int next = pipe->curbuf + pipe->nrbufs; | |
302 | if (i->iov_offset) { | |
303 | struct pipe_buffer *p; | |
304 | if (unlikely(!pipe->nrbufs)) | |
305 | goto Bad; // pipe must be non-empty | |
306 | if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) | |
307 | goto Bad; // must be at the last buffer... | |
308 | ||
309 | p = &pipe->bufs[idx]; | |
310 | if (unlikely(p->offset + p->len != i->iov_offset)) | |
311 | goto Bad; // ... at the end of segment | |
312 | } else { | |
313 | if (idx != (next & (pipe->buffers - 1))) | |
314 | goto Bad; // must be right after the last buffer | |
315 | } | |
316 | return true; | |
317 | Bad: | |
318 | printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); | |
319 | printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", | |
320 | pipe->curbuf, pipe->nrbufs, pipe->buffers); | |
321 | for (idx = 0; idx < pipe->buffers; idx++) | |
322 | printk(KERN_ERR "[%p %p %d %d]\n", | |
323 | pipe->bufs[idx].ops, | |
324 | pipe->bufs[idx].page, | |
325 | pipe->bufs[idx].offset, | |
326 | pipe->bufs[idx].len); | |
327 | WARN_ON(1); | |
328 | return false; | |
329 | } | |
330 | #else | |
331 | #define sanity(i) true | |
332 | #endif | |
333 | ||
334 | static inline int next_idx(int idx, struct pipe_inode_info *pipe) | |
335 | { | |
336 | return (idx + 1) & (pipe->buffers - 1); | |
337 | } | |
338 | ||
339 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, | |
340 | struct iov_iter *i) | |
341 | { | |
342 | struct pipe_inode_info *pipe = i->pipe; | |
343 | struct pipe_buffer *buf; | |
344 | size_t off; | |
345 | int idx; | |
346 | ||
347 | if (unlikely(bytes > i->count)) | |
348 | bytes = i->count; | |
349 | ||
350 | if (unlikely(!bytes)) | |
351 | return 0; | |
352 | ||
353 | if (!sanity(i)) | |
354 | return 0; | |
355 | ||
356 | off = i->iov_offset; | |
357 | idx = i->idx; | |
358 | buf = &pipe->bufs[idx]; | |
359 | if (off) { | |
360 | if (offset == off && buf->page == page) { | |
361 | /* merge with the last one */ | |
362 | buf->len += bytes; | |
363 | i->iov_offset += bytes; | |
364 | goto out; | |
365 | } | |
366 | idx = next_idx(idx, pipe); | |
367 | buf = &pipe->bufs[idx]; | |
368 | } | |
369 | if (idx == pipe->curbuf && pipe->nrbufs) | |
370 | return 0; | |
371 | pipe->nrbufs++; | |
372 | buf->ops = &page_cache_pipe_buf_ops; | |
373 | get_page(buf->page = page); | |
374 | buf->offset = offset; | |
375 | buf->len = bytes; | |
376 | i->iov_offset = offset + bytes; | |
377 | i->idx = idx; | |
378 | out: | |
379 | i->count -= bytes; | |
380 | return bytes; | |
381 | } | |
382 | ||
383 | /* | |
384 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
385 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
386 | * | |
387 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
388 | * because it is an invalid address). | |
389 | */ | |
390 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) | |
391 | { | |
392 | size_t skip = i->iov_offset; | |
393 | const struct iovec *iov; | |
394 | int err; | |
395 | struct iovec v; | |
396 | ||
397 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
398 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
399 | err = fault_in_pages_readable(v.iov_base, v.iov_len); | |
400 | if (unlikely(err)) | |
401 | return err; | |
402 | 0;})) | |
403 | } | |
404 | return 0; | |
405 | } | |
406 | EXPORT_SYMBOL(iov_iter_fault_in_readable); | |
407 | ||
408 | void iov_iter_init(struct iov_iter *i, int direction, | |
409 | const struct iovec *iov, unsigned long nr_segs, | |
410 | size_t count) | |
411 | { | |
412 | /* It will get better. Eventually... */ | |
413 | if (segment_eq(get_fs(), KERNEL_DS)) { | |
414 | direction |= ITER_KVEC; | |
415 | i->type = direction; | |
416 | i->kvec = (struct kvec *)iov; | |
417 | } else { | |
418 | i->type = direction; | |
419 | i->iov = iov; | |
420 | } | |
421 | i->nr_segs = nr_segs; | |
422 | i->iov_offset = 0; | |
423 | i->count = count; | |
424 | } | |
425 | EXPORT_SYMBOL(iov_iter_init); | |
426 | ||
427 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) | |
428 | { | |
429 | char *from = kmap_atomic(page); | |
430 | memcpy(to, from + offset, len); | |
431 | kunmap_atomic(from); | |
432 | } | |
433 | ||
434 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) | |
435 | { | |
436 | char *to = kmap_atomic(page); | |
437 | memcpy(to + offset, from, len); | |
438 | kunmap_atomic(to); | |
439 | } | |
440 | ||
441 | static void memzero_page(struct page *page, size_t offset, size_t len) | |
442 | { | |
443 | char *addr = kmap_atomic(page); | |
444 | memset(addr + offset, 0, len); | |
445 | kunmap_atomic(addr); | |
446 | } | |
447 | ||
448 | static inline bool allocated(struct pipe_buffer *buf) | |
449 | { | |
450 | return buf->ops == &default_pipe_buf_ops; | |
451 | } | |
452 | ||
453 | static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) | |
454 | { | |
455 | size_t off = i->iov_offset; | |
456 | int idx = i->idx; | |
457 | if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { | |
458 | idx = next_idx(idx, i->pipe); | |
459 | off = 0; | |
460 | } | |
461 | *idxp = idx; | |
462 | *offp = off; | |
463 | } | |
464 | ||
465 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
466 | int *idxp, size_t *offp) | |
467 | { | |
468 | struct pipe_inode_info *pipe = i->pipe; | |
469 | size_t off; | |
470 | int idx; | |
471 | ssize_t left; | |
472 | ||
473 | if (unlikely(size > i->count)) | |
474 | size = i->count; | |
475 | if (unlikely(!size)) | |
476 | return 0; | |
477 | ||
478 | left = size; | |
479 | data_start(i, &idx, &off); | |
480 | *idxp = idx; | |
481 | *offp = off; | |
482 | if (off) { | |
483 | left -= PAGE_SIZE - off; | |
484 | if (left <= 0) { | |
485 | pipe->bufs[idx].len += size; | |
486 | return size; | |
487 | } | |
488 | pipe->bufs[idx].len = PAGE_SIZE; | |
489 | idx = next_idx(idx, pipe); | |
490 | } | |
491 | while (idx != pipe->curbuf || !pipe->nrbufs) { | |
492 | struct page *page = alloc_page(GFP_USER); | |
493 | if (!page) | |
494 | break; | |
495 | pipe->nrbufs++; | |
496 | pipe->bufs[idx].ops = &default_pipe_buf_ops; | |
497 | pipe->bufs[idx].page = page; | |
498 | pipe->bufs[idx].offset = 0; | |
499 | if (left <= PAGE_SIZE) { | |
500 | pipe->bufs[idx].len = left; | |
501 | return size; | |
502 | } | |
503 | pipe->bufs[idx].len = PAGE_SIZE; | |
504 | left -= PAGE_SIZE; | |
505 | idx = next_idx(idx, pipe); | |
506 | } | |
507 | return size - left; | |
508 | } | |
509 | ||
510 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
511 | struct iov_iter *i) | |
512 | { | |
513 | struct pipe_inode_info *pipe = i->pipe; | |
514 | size_t n, off; | |
515 | int idx; | |
516 | ||
517 | if (!sanity(i)) | |
518 | return 0; | |
519 | ||
520 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
521 | if (unlikely(!n)) | |
522 | return 0; | |
523 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
524 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
525 | memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); | |
526 | i->idx = idx; | |
527 | i->iov_offset = off + chunk; | |
528 | n -= chunk; | |
529 | addr += chunk; | |
530 | } | |
531 | i->count -= bytes; | |
532 | return bytes; | |
533 | } | |
534 | ||
535 | size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) | |
536 | { | |
537 | const char *from = addr; | |
538 | if (unlikely(i->type & ITER_PIPE)) | |
539 | return copy_pipe_to_iter(addr, bytes, i); | |
540 | iterate_and_advance(i, bytes, v, | |
541 | __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, | |
542 | v.iov_len), | |
543 | memcpy_to_page(v.bv_page, v.bv_offset, | |
544 | (from += v.bv_len) - v.bv_len, v.bv_len), | |
545 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
546 | ) | |
547 | ||
548 | return bytes; | |
549 | } | |
550 | EXPORT_SYMBOL(copy_to_iter); | |
551 | ||
552 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) | |
553 | { | |
554 | char *to = addr; | |
555 | if (unlikely(i->type & ITER_PIPE)) { | |
556 | WARN_ON(1); | |
557 | return 0; | |
558 | } | |
559 | iterate_and_advance(i, bytes, v, | |
560 | __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, | |
561 | v.iov_len), | |
562 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
563 | v.bv_offset, v.bv_len), | |
564 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
565 | ) | |
566 | ||
567 | return bytes; | |
568 | } | |
569 | EXPORT_SYMBOL(copy_from_iter); | |
570 | ||
571 | size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) | |
572 | { | |
573 | char *to = addr; | |
574 | if (unlikely(i->type & ITER_PIPE)) { | |
575 | WARN_ON(1); | |
576 | return 0; | |
577 | } | |
578 | iterate_and_advance(i, bytes, v, | |
579 | __copy_from_user_nocache((to += v.iov_len) - v.iov_len, | |
580 | v.iov_base, v.iov_len), | |
581 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
582 | v.bv_offset, v.bv_len), | |
583 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
584 | ) | |
585 | ||
586 | return bytes; | |
587 | } | |
588 | EXPORT_SYMBOL(copy_from_iter_nocache); | |
589 | ||
590 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, | |
591 | struct iov_iter *i) | |
592 | { | |
593 | if (i->type & (ITER_BVEC|ITER_KVEC)) { | |
594 | void *kaddr = kmap_atomic(page); | |
595 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
596 | kunmap_atomic(kaddr); | |
597 | return wanted; | |
598 | } else if (likely(!(i->type & ITER_PIPE))) | |
599 | return copy_page_to_iter_iovec(page, offset, bytes, i); | |
600 | else | |
601 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
602 | } | |
603 | EXPORT_SYMBOL(copy_page_to_iter); | |
604 | ||
605 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
606 | struct iov_iter *i) | |
607 | { | |
608 | if (unlikely(i->type & ITER_PIPE)) { | |
609 | WARN_ON(1); | |
610 | return 0; | |
611 | } | |
612 | if (i->type & (ITER_BVEC|ITER_KVEC)) { | |
613 | void *kaddr = kmap_atomic(page); | |
614 | size_t wanted = copy_from_iter(kaddr + offset, bytes, i); | |
615 | kunmap_atomic(kaddr); | |
616 | return wanted; | |
617 | } else | |
618 | return copy_page_from_iter_iovec(page, offset, bytes, i); | |
619 | } | |
620 | EXPORT_SYMBOL(copy_page_from_iter); | |
621 | ||
622 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) | |
623 | { | |
624 | struct pipe_inode_info *pipe = i->pipe; | |
625 | size_t n, off; | |
626 | int idx; | |
627 | ||
628 | if (!sanity(i)) | |
629 | return 0; | |
630 | ||
631 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
632 | if (unlikely(!n)) | |
633 | return 0; | |
634 | ||
635 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
636 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
637 | memzero_page(pipe->bufs[idx].page, off, chunk); | |
638 | i->idx = idx; | |
639 | i->iov_offset = off + chunk; | |
640 | n -= chunk; | |
641 | } | |
642 | i->count -= bytes; | |
643 | return bytes; | |
644 | } | |
645 | ||
646 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) | |
647 | { | |
648 | if (unlikely(i->type & ITER_PIPE)) | |
649 | return pipe_zero(bytes, i); | |
650 | iterate_and_advance(i, bytes, v, | |
651 | __clear_user(v.iov_base, v.iov_len), | |
652 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), | |
653 | memset(v.iov_base, 0, v.iov_len) | |
654 | ) | |
655 | ||
656 | return bytes; | |
657 | } | |
658 | EXPORT_SYMBOL(iov_iter_zero); | |
659 | ||
660 | size_t iov_iter_copy_from_user_atomic(struct page *page, | |
661 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
662 | { | |
663 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; | |
664 | if (unlikely(i->type & ITER_PIPE)) { | |
665 | kunmap_atomic(kaddr); | |
666 | WARN_ON(1); | |
667 | return 0; | |
668 | } | |
669 | iterate_all_kinds(i, bytes, v, | |
670 | __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, | |
671 | v.iov_base, v.iov_len), | |
672 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, | |
673 | v.bv_offset, v.bv_len), | |
674 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
675 | ) | |
676 | kunmap_atomic(kaddr); | |
677 | return bytes; | |
678 | } | |
679 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
680 | ||
681 | static void pipe_advance(struct iov_iter *i, size_t size) | |
682 | { | |
683 | struct pipe_inode_info *pipe = i->pipe; | |
684 | struct pipe_buffer *buf; | |
685 | int idx = i->idx; | |
686 | size_t off = i->iov_offset; | |
687 | ||
688 | if (unlikely(i->count < size)) | |
689 | size = i->count; | |
690 | ||
691 | if (size) { | |
692 | if (off) /* make it relative to the beginning of buffer */ | |
693 | size += off - pipe->bufs[idx].offset; | |
694 | while (1) { | |
695 | buf = &pipe->bufs[idx]; | |
696 | if (size <= buf->len) | |
697 | break; | |
698 | size -= buf->len; | |
699 | idx = next_idx(idx, pipe); | |
700 | } | |
701 | buf->len = size; | |
702 | i->idx = idx; | |
703 | off = i->iov_offset = buf->offset + size; | |
704 | } | |
705 | if (off) | |
706 | idx = next_idx(idx, pipe); | |
707 | if (pipe->nrbufs) { | |
708 | int unused = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); | |
709 | /* [curbuf,unused) is in use. Free [idx,unused) */ | |
710 | while (idx != unused) { | |
711 | pipe_buf_release(pipe, &pipe->bufs[idx]); | |
712 | idx = next_idx(idx, pipe); | |
713 | pipe->nrbufs--; | |
714 | } | |
715 | } | |
716 | } | |
717 | ||
718 | void iov_iter_advance(struct iov_iter *i, size_t size) | |
719 | { | |
720 | if (unlikely(i->type & ITER_PIPE)) { | |
721 | pipe_advance(i, size); | |
722 | return; | |
723 | } | |
724 | iterate_and_advance(i, size, v, 0, 0, 0) | |
725 | } | |
726 | EXPORT_SYMBOL(iov_iter_advance); | |
727 | ||
728 | /* | |
729 | * Return the count of just the current iov_iter segment. | |
730 | */ | |
731 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
732 | { | |
733 | if (unlikely(i->type & ITER_PIPE)) | |
734 | return i->count; // it is a silly place, anyway | |
735 | if (i->nr_segs == 1) | |
736 | return i->count; | |
737 | else if (i->type & ITER_BVEC) | |
738 | return min(i->count, i->bvec->bv_len - i->iov_offset); | |
739 | else | |
740 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
741 | } | |
742 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
743 | ||
744 | void iov_iter_kvec(struct iov_iter *i, int direction, | |
745 | const struct kvec *kvec, unsigned long nr_segs, | |
746 | size_t count) | |
747 | { | |
748 | BUG_ON(!(direction & ITER_KVEC)); | |
749 | i->type = direction; | |
750 | i->kvec = kvec; | |
751 | i->nr_segs = nr_segs; | |
752 | i->iov_offset = 0; | |
753 | i->count = count; | |
754 | } | |
755 | EXPORT_SYMBOL(iov_iter_kvec); | |
756 | ||
757 | void iov_iter_bvec(struct iov_iter *i, int direction, | |
758 | const struct bio_vec *bvec, unsigned long nr_segs, | |
759 | size_t count) | |
760 | { | |
761 | BUG_ON(!(direction & ITER_BVEC)); | |
762 | i->type = direction; | |
763 | i->bvec = bvec; | |
764 | i->nr_segs = nr_segs; | |
765 | i->iov_offset = 0; | |
766 | i->count = count; | |
767 | } | |
768 | EXPORT_SYMBOL(iov_iter_bvec); | |
769 | ||
770 | void iov_iter_pipe(struct iov_iter *i, int direction, | |
771 | struct pipe_inode_info *pipe, | |
772 | size_t count) | |
773 | { | |
774 | BUG_ON(direction != ITER_PIPE); | |
775 | i->type = direction; | |
776 | i->pipe = pipe; | |
777 | i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); | |
778 | i->iov_offset = 0; | |
779 | i->count = count; | |
780 | } | |
781 | EXPORT_SYMBOL(iov_iter_pipe); | |
782 | ||
783 | unsigned long iov_iter_alignment(const struct iov_iter *i) | |
784 | { | |
785 | unsigned long res = 0; | |
786 | size_t size = i->count; | |
787 | ||
788 | if (!size) | |
789 | return 0; | |
790 | ||
791 | if (unlikely(i->type & ITER_PIPE)) { | |
792 | if (i->iov_offset && allocated(&i->pipe->bufs[i->idx])) | |
793 | return size | i->iov_offset; | |
794 | return size; | |
795 | } | |
796 | iterate_all_kinds(i, size, v, | |
797 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
798 | res |= v.bv_offset | v.bv_len, | |
799 | res |= (unsigned long)v.iov_base | v.iov_len | |
800 | ) | |
801 | return res; | |
802 | } | |
803 | EXPORT_SYMBOL(iov_iter_alignment); | |
804 | ||
805 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) | |
806 | { | |
807 | unsigned long res = 0; | |
808 | size_t size = i->count; | |
809 | if (!size) | |
810 | return 0; | |
811 | ||
812 | if (unlikely(i->type & ITER_PIPE)) { | |
813 | WARN_ON(1); | |
814 | return ~0U; | |
815 | } | |
816 | ||
817 | iterate_all_kinds(i, size, v, | |
818 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
819 | (size != v.iov_len ? size : 0), 0), | |
820 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
821 | (size != v.bv_len ? size : 0)), | |
822 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
823 | (size != v.iov_len ? size : 0)) | |
824 | ); | |
825 | return res; | |
826 | } | |
827 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
828 | ||
829 | static inline size_t __pipe_get_pages(struct iov_iter *i, | |
830 | size_t maxsize, | |
831 | struct page **pages, | |
832 | int idx, | |
833 | size_t *start) | |
834 | { | |
835 | struct pipe_inode_info *pipe = i->pipe; | |
836 | ssize_t n = push_pipe(i, maxsize, &idx, start); | |
837 | if (!n) | |
838 | return -EFAULT; | |
839 | ||
840 | maxsize = n; | |
841 | n += *start; | |
842 | while (n > 0) { | |
843 | get_page(*pages++ = pipe->bufs[idx].page); | |
844 | idx = next_idx(idx, pipe); | |
845 | n -= PAGE_SIZE; | |
846 | } | |
847 | ||
848 | return maxsize; | |
849 | } | |
850 | ||
851 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
852 | struct page **pages, size_t maxsize, unsigned maxpages, | |
853 | size_t *start) | |
854 | { | |
855 | unsigned npages; | |
856 | size_t capacity; | |
857 | int idx; | |
858 | ||
859 | if (!sanity(i)) | |
860 | return -EFAULT; | |
861 | ||
862 | data_start(i, &idx, start); | |
863 | /* some of this one + all after this one */ | |
864 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
865 | capacity = min(npages,maxpages) * PAGE_SIZE - *start; | |
866 | ||
867 | return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); | |
868 | } | |
869 | ||
870 | ssize_t iov_iter_get_pages(struct iov_iter *i, | |
871 | struct page **pages, size_t maxsize, unsigned maxpages, | |
872 | size_t *start) | |
873 | { | |
874 | if (maxsize > i->count) | |
875 | maxsize = i->count; | |
876 | ||
877 | if (!maxsize) | |
878 | return 0; | |
879 | ||
880 | if (unlikely(i->type & ITER_PIPE)) | |
881 | return pipe_get_pages(i, pages, maxsize, maxpages, start); | |
882 | iterate_all_kinds(i, maxsize, v, ({ | |
883 | unsigned long addr = (unsigned long)v.iov_base; | |
884 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
885 | int n; | |
886 | int res; | |
887 | ||
888 | if (len > maxpages * PAGE_SIZE) | |
889 | len = maxpages * PAGE_SIZE; | |
890 | addr &= ~(PAGE_SIZE - 1); | |
891 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
892 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); | |
893 | if (unlikely(res < 0)) | |
894 | return res; | |
895 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
896 | 0;}),({ | |
897 | /* can't be more than PAGE_SIZE */ | |
898 | *start = v.bv_offset; | |
899 | get_page(*pages = v.bv_page); | |
900 | return v.bv_len; | |
901 | }),({ | |
902 | return -EFAULT; | |
903 | }) | |
904 | ) | |
905 | return 0; | |
906 | } | |
907 | EXPORT_SYMBOL(iov_iter_get_pages); | |
908 | ||
909 | static struct page **get_pages_array(size_t n) | |
910 | { | |
911 | struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); | |
912 | if (!p) | |
913 | p = vmalloc(n * sizeof(struct page *)); | |
914 | return p; | |
915 | } | |
916 | ||
917 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, | |
918 | struct page ***pages, size_t maxsize, | |
919 | size_t *start) | |
920 | { | |
921 | struct page **p; | |
922 | size_t n; | |
923 | int idx; | |
924 | int npages; | |
925 | ||
926 | if (!sanity(i)) | |
927 | return -EFAULT; | |
928 | ||
929 | data_start(i, &idx, start); | |
930 | /* some of this one + all after this one */ | |
931 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
932 | n = npages * PAGE_SIZE - *start; | |
933 | if (maxsize > n) | |
934 | maxsize = n; | |
935 | else | |
936 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
937 | p = get_pages_array(npages); | |
938 | if (!p) | |
939 | return -ENOMEM; | |
940 | n = __pipe_get_pages(i, maxsize, p, idx, start); | |
941 | if (n > 0) | |
942 | *pages = p; | |
943 | else | |
944 | kvfree(p); | |
945 | return n; | |
946 | } | |
947 | ||
948 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, | |
949 | struct page ***pages, size_t maxsize, | |
950 | size_t *start) | |
951 | { | |
952 | struct page **p; | |
953 | ||
954 | if (maxsize > i->count) | |
955 | maxsize = i->count; | |
956 | ||
957 | if (!maxsize) | |
958 | return 0; | |
959 | ||
960 | if (unlikely(i->type & ITER_PIPE)) | |
961 | return pipe_get_pages_alloc(i, pages, maxsize, start); | |
962 | iterate_all_kinds(i, maxsize, v, ({ | |
963 | unsigned long addr = (unsigned long)v.iov_base; | |
964 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
965 | int n; | |
966 | int res; | |
967 | ||
968 | addr &= ~(PAGE_SIZE - 1); | |
969 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
970 | p = get_pages_array(n); | |
971 | if (!p) | |
972 | return -ENOMEM; | |
973 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); | |
974 | if (unlikely(res < 0)) { | |
975 | kvfree(p); | |
976 | return res; | |
977 | } | |
978 | *pages = p; | |
979 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
980 | 0;}),({ | |
981 | /* can't be more than PAGE_SIZE */ | |
982 | *start = v.bv_offset; | |
983 | *pages = p = get_pages_array(1); | |
984 | if (!p) | |
985 | return -ENOMEM; | |
986 | get_page(*p = v.bv_page); | |
987 | return v.bv_len; | |
988 | }),({ | |
989 | return -EFAULT; | |
990 | }) | |
991 | ) | |
992 | return 0; | |
993 | } | |
994 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
995 | ||
996 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, | |
997 | struct iov_iter *i) | |
998 | { | |
999 | char *to = addr; | |
1000 | __wsum sum, next; | |
1001 | size_t off = 0; | |
1002 | sum = *csum; | |
1003 | if (unlikely(i->type & ITER_PIPE)) { | |
1004 | WARN_ON(1); | |
1005 | return 0; | |
1006 | } | |
1007 | iterate_and_advance(i, bytes, v, ({ | |
1008 | int err = 0; | |
1009 | next = csum_and_copy_from_user(v.iov_base, | |
1010 | (to += v.iov_len) - v.iov_len, | |
1011 | v.iov_len, 0, &err); | |
1012 | if (!err) { | |
1013 | sum = csum_block_add(sum, next, off); | |
1014 | off += v.iov_len; | |
1015 | } | |
1016 | err ? v.iov_len : 0; | |
1017 | }), ({ | |
1018 | char *p = kmap_atomic(v.bv_page); | |
1019 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
1020 | (to += v.bv_len) - v.bv_len, | |
1021 | v.bv_len, 0); | |
1022 | kunmap_atomic(p); | |
1023 | sum = csum_block_add(sum, next, off); | |
1024 | off += v.bv_len; | |
1025 | }),({ | |
1026 | next = csum_partial_copy_nocheck(v.iov_base, | |
1027 | (to += v.iov_len) - v.iov_len, | |
1028 | v.iov_len, 0); | |
1029 | sum = csum_block_add(sum, next, off); | |
1030 | off += v.iov_len; | |
1031 | }) | |
1032 | ) | |
1033 | *csum = sum; | |
1034 | return bytes; | |
1035 | } | |
1036 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1037 | ||
1038 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, | |
1039 | struct iov_iter *i) | |
1040 | { | |
1041 | const char *from = addr; | |
1042 | __wsum sum, next; | |
1043 | size_t off = 0; | |
1044 | sum = *csum; | |
1045 | if (unlikely(i->type & ITER_PIPE)) { | |
1046 | WARN_ON(1); /* for now */ | |
1047 | return 0; | |
1048 | } | |
1049 | iterate_and_advance(i, bytes, v, ({ | |
1050 | int err = 0; | |
1051 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
1052 | v.iov_base, | |
1053 | v.iov_len, 0, &err); | |
1054 | if (!err) { | |
1055 | sum = csum_block_add(sum, next, off); | |
1056 | off += v.iov_len; | |
1057 | } | |
1058 | err ? v.iov_len : 0; | |
1059 | }), ({ | |
1060 | char *p = kmap_atomic(v.bv_page); | |
1061 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
1062 | p + v.bv_offset, | |
1063 | v.bv_len, 0); | |
1064 | kunmap_atomic(p); | |
1065 | sum = csum_block_add(sum, next, off); | |
1066 | off += v.bv_len; | |
1067 | }),({ | |
1068 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
1069 | v.iov_base, | |
1070 | v.iov_len, 0); | |
1071 | sum = csum_block_add(sum, next, off); | |
1072 | off += v.iov_len; | |
1073 | }) | |
1074 | ) | |
1075 | *csum = sum; | |
1076 | return bytes; | |
1077 | } | |
1078 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1079 | ||
1080 | int iov_iter_npages(const struct iov_iter *i, int maxpages) | |
1081 | { | |
1082 | size_t size = i->count; | |
1083 | int npages = 0; | |
1084 | ||
1085 | if (!size) | |
1086 | return 0; | |
1087 | ||
1088 | if (unlikely(i->type & ITER_PIPE)) { | |
1089 | struct pipe_inode_info *pipe = i->pipe; | |
1090 | size_t off; | |
1091 | int idx; | |
1092 | ||
1093 | if (!sanity(i)) | |
1094 | return 0; | |
1095 | ||
1096 | data_start(i, &idx, &off); | |
1097 | /* some of this one + all after this one */ | |
1098 | npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; | |
1099 | if (npages >= maxpages) | |
1100 | return maxpages; | |
1101 | } else iterate_all_kinds(i, size, v, ({ | |
1102 | unsigned long p = (unsigned long)v.iov_base; | |
1103 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1104 | - p / PAGE_SIZE; | |
1105 | if (npages >= maxpages) | |
1106 | return maxpages; | |
1107 | 0;}),({ | |
1108 | npages++; | |
1109 | if (npages >= maxpages) | |
1110 | return maxpages; | |
1111 | }),({ | |
1112 | unsigned long p = (unsigned long)v.iov_base; | |
1113 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1114 | - p / PAGE_SIZE; | |
1115 | if (npages >= maxpages) | |
1116 | return maxpages; | |
1117 | }) | |
1118 | ) | |
1119 | return npages; | |
1120 | } | |
1121 | EXPORT_SYMBOL(iov_iter_npages); | |
1122 | ||
1123 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1124 | { | |
1125 | *new = *old; | |
1126 | if (unlikely(new->type & ITER_PIPE)) { | |
1127 | WARN_ON(1); | |
1128 | return NULL; | |
1129 | } | |
1130 | if (new->type & ITER_BVEC) | |
1131 | return new->bvec = kmemdup(new->bvec, | |
1132 | new->nr_segs * sizeof(struct bio_vec), | |
1133 | flags); | |
1134 | else | |
1135 | /* iovec and kvec have identical layout */ | |
1136 | return new->iov = kmemdup(new->iov, | |
1137 | new->nr_segs * sizeof(struct iovec), | |
1138 | flags); | |
1139 | } | |
1140 | EXPORT_SYMBOL(dup_iter); | |
1141 | ||
1142 | /** | |
1143 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1144 | * into the kernel, check that it is valid, and initialize a new | |
1145 | * &struct iov_iter iterator to access it. | |
1146 | * | |
1147 | * @type: One of %READ or %WRITE. | |
1148 | * @uvector: Pointer to the userspace array. | |
1149 | * @nr_segs: Number of elements in userspace array. | |
1150 | * @fast_segs: Number of elements in @iov. | |
1151 | * @iov: (input and output parameter) Pointer to pointer to (usually small | |
1152 | * on-stack) kernel array. | |
1153 | * @i: Pointer to iterator that will be initialized on success. | |
1154 | * | |
1155 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1156 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1157 | * array will be allocated and the result placed in *@iov. This means that | |
1158 | * the caller may call kfree() on *@iov regardless of whether the small | |
1159 | * on-stack array was used or not (and regardless of whether this function | |
1160 | * returns an error or not). | |
1161 | * | |
1162 | * Return: 0 on success or negative error code on error. | |
1163 | */ | |
1164 | int import_iovec(int type, const struct iovec __user * uvector, | |
1165 | unsigned nr_segs, unsigned fast_segs, | |
1166 | struct iovec **iov, struct iov_iter *i) | |
1167 | { | |
1168 | ssize_t n; | |
1169 | struct iovec *p; | |
1170 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1171 | *iov, &p); | |
1172 | if (n < 0) { | |
1173 | if (p != *iov) | |
1174 | kfree(p); | |
1175 | *iov = NULL; | |
1176 | return n; | |
1177 | } | |
1178 | iov_iter_init(i, type, p, nr_segs, n); | |
1179 | *iov = p == *iov ? NULL : p; | |
1180 | return 0; | |
1181 | } | |
1182 | EXPORT_SYMBOL(import_iovec); | |
1183 | ||
1184 | #ifdef CONFIG_COMPAT | |
1185 | #include <linux/compat.h> | |
1186 | ||
1187 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
1188 | unsigned nr_segs, unsigned fast_segs, | |
1189 | struct iovec **iov, struct iov_iter *i) | |
1190 | { | |
1191 | ssize_t n; | |
1192 | struct iovec *p; | |
1193 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1194 | *iov, &p); | |
1195 | if (n < 0) { | |
1196 | if (p != *iov) | |
1197 | kfree(p); | |
1198 | *iov = NULL; | |
1199 | return n; | |
1200 | } | |
1201 | iov_iter_init(i, type, p, nr_segs, n); | |
1202 | *iov = p == *iov ? NULL : p; | |
1203 | return 0; | |
1204 | } | |
1205 | #endif | |
1206 | ||
1207 | int import_single_range(int rw, void __user *buf, size_t len, | |
1208 | struct iovec *iov, struct iov_iter *i) | |
1209 | { | |
1210 | if (len > MAX_RW_COUNT) | |
1211 | len = MAX_RW_COUNT; | |
1212 | if (unlikely(!access_ok(!rw, buf, len))) | |
1213 | return -EFAULT; | |
1214 | ||
1215 | iov->iov_base = buf; | |
1216 | iov->iov_len = len; | |
1217 | iov_iter_init(i, rw, iov, 1, len); | |
1218 | return 0; | |
1219 | } | |
1220 | EXPORT_SYMBOL(import_single_range); |