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Commit | Line | Data |
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4f18cd31 | 1 | #include <linux/export.h> |
2f8b5444 | 2 | #include <linux/bvec.h> |
4f18cd31 AV |
3 | #include <linux/uio.h> |
4 | #include <linux/pagemap.h> | |
91f79c43 AV |
5 | #include <linux/slab.h> |
6 | #include <linux/vmalloc.h> | |
241699cd | 7 | #include <linux/splice.h> |
a604ec7e | 8 | #include <net/checksum.h> |
4f18cd31 | 9 | |
241699cd AV |
10 | #define PIPE_PARANOIA /* for now */ |
11 | ||
04a31165 AV |
12 | #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ |
13 | size_t left; \ | |
14 | size_t wanted = n; \ | |
15 | __p = i->iov; \ | |
16 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
17 | if (likely(__v.iov_len)) { \ | |
18 | __v.iov_base = __p->iov_base + skip; \ | |
19 | left = (STEP); \ | |
20 | __v.iov_len -= left; \ | |
21 | skip += __v.iov_len; \ | |
22 | n -= __v.iov_len; \ | |
23 | } else { \ | |
24 | left = 0; \ | |
25 | } \ | |
26 | while (unlikely(!left && n)) { \ | |
27 | __p++; \ | |
28 | __v.iov_len = min(n, __p->iov_len); \ | |
29 | if (unlikely(!__v.iov_len)) \ | |
30 | continue; \ | |
31 | __v.iov_base = __p->iov_base; \ | |
32 | left = (STEP); \ | |
33 | __v.iov_len -= left; \ | |
34 | skip = __v.iov_len; \ | |
35 | n -= __v.iov_len; \ | |
36 | } \ | |
37 | n = wanted - n; \ | |
38 | } | |
39 | ||
a280455f AV |
40 | #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ |
41 | size_t wanted = n; \ | |
42 | __p = i->kvec; \ | |
43 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
44 | if (likely(__v.iov_len)) { \ | |
45 | __v.iov_base = __p->iov_base + skip; \ | |
46 | (void)(STEP); \ | |
47 | skip += __v.iov_len; \ | |
48 | n -= __v.iov_len; \ | |
49 | } \ | |
50 | while (unlikely(n)) { \ | |
51 | __p++; \ | |
52 | __v.iov_len = min(n, __p->iov_len); \ | |
53 | if (unlikely(!__v.iov_len)) \ | |
54 | continue; \ | |
55 | __v.iov_base = __p->iov_base; \ | |
56 | (void)(STEP); \ | |
57 | skip = __v.iov_len; \ | |
58 | n -= __v.iov_len; \ | |
59 | } \ | |
60 | n = wanted; \ | |
61 | } | |
62 | ||
1bdc76ae ML |
63 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ |
64 | struct bvec_iter __start; \ | |
65 | __start.bi_size = n; \ | |
66 | __start.bi_bvec_done = skip; \ | |
67 | __start.bi_idx = 0; \ | |
68 | for_each_bvec(__v, i->bvec, __bi, __start) { \ | |
69 | if (!__v.bv_len) \ | |
04a31165 | 70 | continue; \ |
04a31165 | 71 | (void)(STEP); \ |
04a31165 | 72 | } \ |
04a31165 AV |
73 | } |
74 | ||
a280455f | 75 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
04a31165 AV |
76 | size_t skip = i->iov_offset; \ |
77 | if (unlikely(i->type & ITER_BVEC)) { \ | |
04a31165 | 78 | struct bio_vec v; \ |
1bdc76ae ML |
79 | struct bvec_iter __bi; \ |
80 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
a280455f AV |
81 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
82 | const struct kvec *kvec; \ | |
83 | struct kvec v; \ | |
84 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
04a31165 AV |
85 | } else { \ |
86 | const struct iovec *iov; \ | |
87 | struct iovec v; \ | |
88 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
89 | } \ | |
90 | } | |
91 | ||
a280455f | 92 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
93 | if (unlikely(i->count < n)) \ |
94 | n = i->count; \ | |
19f18459 | 95 | if (i->count) { \ |
dd254f5a AV |
96 | size_t skip = i->iov_offset; \ |
97 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 98 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 99 | struct bio_vec v; \ |
1bdc76ae ML |
100 | struct bvec_iter __bi; \ |
101 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
102 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
103 | i->nr_segs -= i->bvec - bvec; \ | |
104 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
105 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
106 | const struct kvec *kvec; \ | |
107 | struct kvec v; \ | |
108 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
109 | if (skip == kvec->iov_len) { \ | |
110 | kvec++; \ | |
111 | skip = 0; \ | |
112 | } \ | |
113 | i->nr_segs -= kvec - i->kvec; \ | |
114 | i->kvec = kvec; \ | |
115 | } else { \ | |
116 | const struct iovec *iov; \ | |
117 | struct iovec v; \ | |
118 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
119 | if (skip == iov->iov_len) { \ | |
120 | iov++; \ | |
121 | skip = 0; \ | |
122 | } \ | |
123 | i->nr_segs -= iov - i->iov; \ | |
124 | i->iov = iov; \ | |
7ce2a91e | 125 | } \ |
dd254f5a AV |
126 | i->count -= n; \ |
127 | i->iov_offset = skip; \ | |
7ce2a91e | 128 | } \ |
7ce2a91e AV |
129 | } |
130 | ||
62a8067a | 131 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
132 | struct iov_iter *i) |
133 | { | |
134 | size_t skip, copy, left, wanted; | |
135 | const struct iovec *iov; | |
136 | char __user *buf; | |
137 | void *kaddr, *from; | |
138 | ||
139 | if (unlikely(bytes > i->count)) | |
140 | bytes = i->count; | |
141 | ||
142 | if (unlikely(!bytes)) | |
143 | return 0; | |
144 | ||
145 | wanted = bytes; | |
146 | iov = i->iov; | |
147 | skip = i->iov_offset; | |
148 | buf = iov->iov_base + skip; | |
149 | copy = min(bytes, iov->iov_len - skip); | |
150 | ||
3fa6c507 | 151 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
152 | kaddr = kmap_atomic(page); |
153 | from = kaddr + offset; | |
154 | ||
155 | /* first chunk, usually the only one */ | |
156 | left = __copy_to_user_inatomic(buf, from, copy); | |
157 | copy -= left; | |
158 | skip += copy; | |
159 | from += copy; | |
160 | bytes -= copy; | |
161 | ||
162 | while (unlikely(!left && bytes)) { | |
163 | iov++; | |
164 | buf = iov->iov_base; | |
165 | copy = min(bytes, iov->iov_len); | |
166 | left = __copy_to_user_inatomic(buf, from, copy); | |
167 | copy -= left; | |
168 | skip = copy; | |
169 | from += copy; | |
170 | bytes -= copy; | |
171 | } | |
172 | if (likely(!bytes)) { | |
173 | kunmap_atomic(kaddr); | |
174 | goto done; | |
175 | } | |
176 | offset = from - kaddr; | |
177 | buf += copy; | |
178 | kunmap_atomic(kaddr); | |
179 | copy = min(bytes, iov->iov_len - skip); | |
180 | } | |
181 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 182 | |
4f18cd31 AV |
183 | kaddr = kmap(page); |
184 | from = kaddr + offset; | |
185 | left = __copy_to_user(buf, from, copy); | |
186 | copy -= left; | |
187 | skip += copy; | |
188 | from += copy; | |
189 | bytes -= copy; | |
190 | while (unlikely(!left && bytes)) { | |
191 | iov++; | |
192 | buf = iov->iov_base; | |
193 | copy = min(bytes, iov->iov_len); | |
194 | left = __copy_to_user(buf, from, copy); | |
195 | copy -= left; | |
196 | skip = copy; | |
197 | from += copy; | |
198 | bytes -= copy; | |
199 | } | |
200 | kunmap(page); | |
3fa6c507 | 201 | |
4f18cd31 | 202 | done: |
81055e58 AV |
203 | if (skip == iov->iov_len) { |
204 | iov++; | |
205 | skip = 0; | |
206 | } | |
4f18cd31 AV |
207 | i->count -= wanted - bytes; |
208 | i->nr_segs -= iov - i->iov; | |
209 | i->iov = iov; | |
210 | i->iov_offset = skip; | |
211 | return wanted - bytes; | |
212 | } | |
4f18cd31 | 213 | |
62a8067a | 214 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
215 | struct iov_iter *i) |
216 | { | |
217 | size_t skip, copy, left, wanted; | |
218 | const struct iovec *iov; | |
219 | char __user *buf; | |
220 | void *kaddr, *to; | |
221 | ||
222 | if (unlikely(bytes > i->count)) | |
223 | bytes = i->count; | |
224 | ||
225 | if (unlikely(!bytes)) | |
226 | return 0; | |
227 | ||
228 | wanted = bytes; | |
229 | iov = i->iov; | |
230 | skip = i->iov_offset; | |
231 | buf = iov->iov_base + skip; | |
232 | copy = min(bytes, iov->iov_len - skip); | |
233 | ||
3fa6c507 | 234 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
235 | kaddr = kmap_atomic(page); |
236 | to = kaddr + offset; | |
237 | ||
238 | /* first chunk, usually the only one */ | |
239 | left = __copy_from_user_inatomic(to, buf, copy); | |
240 | copy -= left; | |
241 | skip += copy; | |
242 | to += copy; | |
243 | bytes -= copy; | |
244 | ||
245 | while (unlikely(!left && bytes)) { | |
246 | iov++; | |
247 | buf = iov->iov_base; | |
248 | copy = min(bytes, iov->iov_len); | |
249 | left = __copy_from_user_inatomic(to, buf, copy); | |
250 | copy -= left; | |
251 | skip = copy; | |
252 | to += copy; | |
253 | bytes -= copy; | |
254 | } | |
255 | if (likely(!bytes)) { | |
256 | kunmap_atomic(kaddr); | |
257 | goto done; | |
258 | } | |
259 | offset = to - kaddr; | |
260 | buf += copy; | |
261 | kunmap_atomic(kaddr); | |
262 | copy = min(bytes, iov->iov_len - skip); | |
263 | } | |
264 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 265 | |
f0d1bec9 AV |
266 | kaddr = kmap(page); |
267 | to = kaddr + offset; | |
268 | left = __copy_from_user(to, buf, copy); | |
269 | copy -= left; | |
270 | skip += copy; | |
271 | to += copy; | |
272 | bytes -= copy; | |
273 | while (unlikely(!left && bytes)) { | |
274 | iov++; | |
275 | buf = iov->iov_base; | |
276 | copy = min(bytes, iov->iov_len); | |
277 | left = __copy_from_user(to, buf, copy); | |
278 | copy -= left; | |
279 | skip = copy; | |
280 | to += copy; | |
281 | bytes -= copy; | |
282 | } | |
283 | kunmap(page); | |
3fa6c507 | 284 | |
f0d1bec9 | 285 | done: |
81055e58 AV |
286 | if (skip == iov->iov_len) { |
287 | iov++; | |
288 | skip = 0; | |
289 | } | |
f0d1bec9 AV |
290 | i->count -= wanted - bytes; |
291 | i->nr_segs -= iov - i->iov; | |
292 | i->iov = iov; | |
293 | i->iov_offset = skip; | |
294 | return wanted - bytes; | |
295 | } | |
f0d1bec9 | 296 | |
241699cd AV |
297 | #ifdef PIPE_PARANOIA |
298 | static bool sanity(const struct iov_iter *i) | |
299 | { | |
300 | struct pipe_inode_info *pipe = i->pipe; | |
301 | int idx = i->idx; | |
302 | int next = pipe->curbuf + pipe->nrbufs; | |
303 | if (i->iov_offset) { | |
304 | struct pipe_buffer *p; | |
305 | if (unlikely(!pipe->nrbufs)) | |
306 | goto Bad; // pipe must be non-empty | |
307 | if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) | |
308 | goto Bad; // must be at the last buffer... | |
309 | ||
310 | p = &pipe->bufs[idx]; | |
311 | if (unlikely(p->offset + p->len != i->iov_offset)) | |
312 | goto Bad; // ... at the end of segment | |
313 | } else { | |
314 | if (idx != (next & (pipe->buffers - 1))) | |
315 | goto Bad; // must be right after the last buffer | |
316 | } | |
317 | return true; | |
318 | Bad: | |
319 | printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); | |
320 | printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", | |
321 | pipe->curbuf, pipe->nrbufs, pipe->buffers); | |
322 | for (idx = 0; idx < pipe->buffers; idx++) | |
323 | printk(KERN_ERR "[%p %p %d %d]\n", | |
324 | pipe->bufs[idx].ops, | |
325 | pipe->bufs[idx].page, | |
326 | pipe->bufs[idx].offset, | |
327 | pipe->bufs[idx].len); | |
328 | WARN_ON(1); | |
329 | return false; | |
330 | } | |
331 | #else | |
332 | #define sanity(i) true | |
333 | #endif | |
334 | ||
335 | static inline int next_idx(int idx, struct pipe_inode_info *pipe) | |
336 | { | |
337 | return (idx + 1) & (pipe->buffers - 1); | |
338 | } | |
339 | ||
340 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, | |
341 | struct iov_iter *i) | |
342 | { | |
343 | struct pipe_inode_info *pipe = i->pipe; | |
344 | struct pipe_buffer *buf; | |
345 | size_t off; | |
346 | int idx; | |
347 | ||
348 | if (unlikely(bytes > i->count)) | |
349 | bytes = i->count; | |
350 | ||
351 | if (unlikely(!bytes)) | |
352 | return 0; | |
353 | ||
354 | if (!sanity(i)) | |
355 | return 0; | |
356 | ||
357 | off = i->iov_offset; | |
358 | idx = i->idx; | |
359 | buf = &pipe->bufs[idx]; | |
360 | if (off) { | |
361 | if (offset == off && buf->page == page) { | |
362 | /* merge with the last one */ | |
363 | buf->len += bytes; | |
364 | i->iov_offset += bytes; | |
365 | goto out; | |
366 | } | |
367 | idx = next_idx(idx, pipe); | |
368 | buf = &pipe->bufs[idx]; | |
369 | } | |
370 | if (idx == pipe->curbuf && pipe->nrbufs) | |
371 | return 0; | |
372 | pipe->nrbufs++; | |
373 | buf->ops = &page_cache_pipe_buf_ops; | |
374 | get_page(buf->page = page); | |
375 | buf->offset = offset; | |
376 | buf->len = bytes; | |
377 | i->iov_offset = offset + bytes; | |
378 | i->idx = idx; | |
379 | out: | |
380 | i->count -= bytes; | |
381 | return bytes; | |
382 | } | |
383 | ||
171a0203 AA |
384 | /* |
385 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
386 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
387 | * | |
388 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
389 | * because it is an invalid address). | |
390 | */ | |
d4690f1e | 391 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
392 | { |
393 | size_t skip = i->iov_offset; | |
394 | const struct iovec *iov; | |
395 | int err; | |
396 | struct iovec v; | |
397 | ||
398 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
399 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
4bce9f6e | 400 | err = fault_in_pages_readable(v.iov_base, v.iov_len); |
171a0203 AA |
401 | if (unlikely(err)) |
402 | return err; | |
403 | 0;})) | |
404 | } | |
405 | return 0; | |
406 | } | |
d4690f1e | 407 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 408 | |
71d8e532 AV |
409 | void iov_iter_init(struct iov_iter *i, int direction, |
410 | const struct iovec *iov, unsigned long nr_segs, | |
411 | size_t count) | |
412 | { | |
413 | /* It will get better. Eventually... */ | |
a280455f | 414 | if (segment_eq(get_fs(), KERNEL_DS)) { |
62a8067a | 415 | direction |= ITER_KVEC; |
a280455f AV |
416 | i->type = direction; |
417 | i->kvec = (struct kvec *)iov; | |
418 | } else { | |
419 | i->type = direction; | |
420 | i->iov = iov; | |
421 | } | |
71d8e532 AV |
422 | i->nr_segs = nr_segs; |
423 | i->iov_offset = 0; | |
424 | i->count = count; | |
425 | } | |
426 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 427 | |
62a8067a AV |
428 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
429 | { | |
430 | char *from = kmap_atomic(page); | |
431 | memcpy(to, from + offset, len); | |
432 | kunmap_atomic(from); | |
433 | } | |
434 | ||
36f7a8a4 | 435 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
436 | { |
437 | char *to = kmap_atomic(page); | |
438 | memcpy(to + offset, from, len); | |
439 | kunmap_atomic(to); | |
440 | } | |
441 | ||
c35e0248 MW |
442 | static void memzero_page(struct page *page, size_t offset, size_t len) |
443 | { | |
444 | char *addr = kmap_atomic(page); | |
445 | memset(addr + offset, 0, len); | |
446 | kunmap_atomic(addr); | |
447 | } | |
448 | ||
241699cd AV |
449 | static inline bool allocated(struct pipe_buffer *buf) |
450 | { | |
451 | return buf->ops == &default_pipe_buf_ops; | |
452 | } | |
453 | ||
454 | static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) | |
455 | { | |
456 | size_t off = i->iov_offset; | |
457 | int idx = i->idx; | |
458 | if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { | |
459 | idx = next_idx(idx, i->pipe); | |
460 | off = 0; | |
461 | } | |
462 | *idxp = idx; | |
463 | *offp = off; | |
464 | } | |
465 | ||
466 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
467 | int *idxp, size_t *offp) | |
468 | { | |
469 | struct pipe_inode_info *pipe = i->pipe; | |
470 | size_t off; | |
471 | int idx; | |
472 | ssize_t left; | |
473 | ||
474 | if (unlikely(size > i->count)) | |
475 | size = i->count; | |
476 | if (unlikely(!size)) | |
477 | return 0; | |
478 | ||
479 | left = size; | |
480 | data_start(i, &idx, &off); | |
481 | *idxp = idx; | |
482 | *offp = off; | |
483 | if (off) { | |
484 | left -= PAGE_SIZE - off; | |
485 | if (left <= 0) { | |
486 | pipe->bufs[idx].len += size; | |
487 | return size; | |
488 | } | |
489 | pipe->bufs[idx].len = PAGE_SIZE; | |
490 | idx = next_idx(idx, pipe); | |
491 | } | |
492 | while (idx != pipe->curbuf || !pipe->nrbufs) { | |
493 | struct page *page = alloc_page(GFP_USER); | |
494 | if (!page) | |
495 | break; | |
496 | pipe->nrbufs++; | |
497 | pipe->bufs[idx].ops = &default_pipe_buf_ops; | |
498 | pipe->bufs[idx].page = page; | |
499 | pipe->bufs[idx].offset = 0; | |
500 | if (left <= PAGE_SIZE) { | |
501 | pipe->bufs[idx].len = left; | |
502 | return size; | |
503 | } | |
504 | pipe->bufs[idx].len = PAGE_SIZE; | |
505 | left -= PAGE_SIZE; | |
506 | idx = next_idx(idx, pipe); | |
507 | } | |
508 | return size - left; | |
509 | } | |
510 | ||
511 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
512 | struct iov_iter *i) | |
513 | { | |
514 | struct pipe_inode_info *pipe = i->pipe; | |
515 | size_t n, off; | |
516 | int idx; | |
517 | ||
518 | if (!sanity(i)) | |
519 | return 0; | |
520 | ||
521 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
522 | if (unlikely(!n)) | |
523 | return 0; | |
524 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
525 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
526 | memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); | |
527 | i->idx = idx; | |
528 | i->iov_offset = off + chunk; | |
529 | n -= chunk; | |
530 | addr += chunk; | |
531 | } | |
532 | i->count -= bytes; | |
533 | return bytes; | |
534 | } | |
535 | ||
36f7a8a4 | 536 | size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 537 | { |
36f7a8a4 | 538 | const char *from = addr; |
241699cd AV |
539 | if (unlikely(i->type & ITER_PIPE)) |
540 | return copy_pipe_to_iter(addr, bytes, i); | |
3d4d3e48 AV |
541 | iterate_and_advance(i, bytes, v, |
542 | __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, | |
543 | v.iov_len), | |
544 | memcpy_to_page(v.bv_page, v.bv_offset, | |
a280455f AV |
545 | (from += v.bv_len) - v.bv_len, v.bv_len), |
546 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 547 | ) |
62a8067a | 548 | |
3d4d3e48 | 549 | return bytes; |
c35e0248 | 550 | } |
d271524a | 551 | EXPORT_SYMBOL(copy_to_iter); |
c35e0248 | 552 | |
d271524a | 553 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 554 | { |
0dbca9a4 | 555 | char *to = addr; |
241699cd AV |
556 | if (unlikely(i->type & ITER_PIPE)) { |
557 | WARN_ON(1); | |
558 | return 0; | |
559 | } | |
0dbca9a4 AV |
560 | iterate_and_advance(i, bytes, v, |
561 | __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, | |
562 | v.iov_len), | |
563 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
564 | v.bv_offset, v.bv_len), |
565 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
566 | ) |
567 | ||
568 | return bytes; | |
c35e0248 | 569 | } |
d271524a | 570 | EXPORT_SYMBOL(copy_from_iter); |
c35e0248 | 571 | |
aa583096 AV |
572 | size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
573 | { | |
574 | char *to = addr; | |
241699cd AV |
575 | if (unlikely(i->type & ITER_PIPE)) { |
576 | WARN_ON(1); | |
577 | return 0; | |
578 | } | |
aa583096 AV |
579 | iterate_and_advance(i, bytes, v, |
580 | __copy_from_user_nocache((to += v.iov_len) - v.iov_len, | |
581 | v.iov_base, v.iov_len), | |
582 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
583 | v.bv_offset, v.bv_len), | |
584 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
585 | ) | |
586 | ||
587 | return bytes; | |
588 | } | |
589 | EXPORT_SYMBOL(copy_from_iter_nocache); | |
590 | ||
62a8067a AV |
591 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
592 | struct iov_iter *i) | |
593 | { | |
d271524a AV |
594 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
595 | void *kaddr = kmap_atomic(page); | |
596 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
597 | kunmap_atomic(kaddr); | |
598 | return wanted; | |
241699cd | 599 | } else if (likely(!(i->type & ITER_PIPE))) |
62a8067a | 600 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
601 | else |
602 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
603 | } |
604 | EXPORT_SYMBOL(copy_page_to_iter); | |
605 | ||
606 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
607 | struct iov_iter *i) | |
608 | { | |
241699cd AV |
609 | if (unlikely(i->type & ITER_PIPE)) { |
610 | WARN_ON(1); | |
611 | return 0; | |
612 | } | |
a280455f | 613 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a AV |
614 | void *kaddr = kmap_atomic(page); |
615 | size_t wanted = copy_from_iter(kaddr + offset, bytes, i); | |
616 | kunmap_atomic(kaddr); | |
617 | return wanted; | |
618 | } else | |
62a8067a AV |
619 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
620 | } | |
621 | EXPORT_SYMBOL(copy_page_from_iter); | |
622 | ||
241699cd AV |
623 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
624 | { | |
625 | struct pipe_inode_info *pipe = i->pipe; | |
626 | size_t n, off; | |
627 | int idx; | |
628 | ||
629 | if (!sanity(i)) | |
630 | return 0; | |
631 | ||
632 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
633 | if (unlikely(!n)) | |
634 | return 0; | |
635 | ||
636 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
637 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
638 | memzero_page(pipe->bufs[idx].page, off, chunk); | |
639 | i->idx = idx; | |
640 | i->iov_offset = off + chunk; | |
641 | n -= chunk; | |
642 | } | |
643 | i->count -= bytes; | |
644 | return bytes; | |
645 | } | |
646 | ||
c35e0248 MW |
647 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
648 | { | |
241699cd AV |
649 | if (unlikely(i->type & ITER_PIPE)) |
650 | return pipe_zero(bytes, i); | |
8442fa46 AV |
651 | iterate_and_advance(i, bytes, v, |
652 | __clear_user(v.iov_base, v.iov_len), | |
a280455f AV |
653 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
654 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
655 | ) |
656 | ||
657 | return bytes; | |
c35e0248 MW |
658 | } |
659 | EXPORT_SYMBOL(iov_iter_zero); | |
660 | ||
62a8067a AV |
661 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
662 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
663 | { | |
04a31165 | 664 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
241699cd AV |
665 | if (unlikely(i->type & ITER_PIPE)) { |
666 | kunmap_atomic(kaddr); | |
667 | WARN_ON(1); | |
668 | return 0; | |
669 | } | |
04a31165 AV |
670 | iterate_all_kinds(i, bytes, v, |
671 | __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, | |
672 | v.iov_base, v.iov_len), | |
673 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
674 | v.bv_offset, v.bv_len), |
675 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
676 | ) |
677 | kunmap_atomic(kaddr); | |
678 | return bytes; | |
62a8067a AV |
679 | } |
680 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
681 | ||
241699cd AV |
682 | static void pipe_advance(struct iov_iter *i, size_t size) |
683 | { | |
684 | struct pipe_inode_info *pipe = i->pipe; | |
685 | struct pipe_buffer *buf; | |
686 | int idx = i->idx; | |
687 | size_t off = i->iov_offset; | |
688 | ||
689 | if (unlikely(i->count < size)) | |
690 | size = i->count; | |
691 | ||
692 | if (size) { | |
693 | if (off) /* make it relative to the beginning of buffer */ | |
694 | size += off - pipe->bufs[idx].offset; | |
695 | while (1) { | |
696 | buf = &pipe->bufs[idx]; | |
697 | if (size <= buf->len) | |
698 | break; | |
699 | size -= buf->len; | |
700 | idx = next_idx(idx, pipe); | |
701 | } | |
702 | buf->len = size; | |
703 | i->idx = idx; | |
704 | off = i->iov_offset = buf->offset + size; | |
705 | } | |
706 | if (off) | |
707 | idx = next_idx(idx, pipe); | |
708 | if (pipe->nrbufs) { | |
709 | int unused = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); | |
710 | /* [curbuf,unused) is in use. Free [idx,unused) */ | |
711 | while (idx != unused) { | |
a779638c | 712 | pipe_buf_release(pipe, &pipe->bufs[idx]); |
241699cd AV |
713 | idx = next_idx(idx, pipe); |
714 | pipe->nrbufs--; | |
715 | } | |
716 | } | |
717 | } | |
718 | ||
62a8067a AV |
719 | void iov_iter_advance(struct iov_iter *i, size_t size) |
720 | { | |
241699cd AV |
721 | if (unlikely(i->type & ITER_PIPE)) { |
722 | pipe_advance(i, size); | |
723 | return; | |
724 | } | |
a280455f | 725 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
726 | } |
727 | EXPORT_SYMBOL(iov_iter_advance); | |
728 | ||
729 | /* | |
730 | * Return the count of just the current iov_iter segment. | |
731 | */ | |
732 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
733 | { | |
241699cd AV |
734 | if (unlikely(i->type & ITER_PIPE)) |
735 | return i->count; // it is a silly place, anyway | |
62a8067a AV |
736 | if (i->nr_segs == 1) |
737 | return i->count; | |
738 | else if (i->type & ITER_BVEC) | |
62a8067a | 739 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
740 | else |
741 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
742 | } |
743 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
744 | ||
abb78f87 | 745 | void iov_iter_kvec(struct iov_iter *i, int direction, |
05afcb77 | 746 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
747 | size_t count) |
748 | { | |
749 | BUG_ON(!(direction & ITER_KVEC)); | |
750 | i->type = direction; | |
05afcb77 | 751 | i->kvec = kvec; |
abb78f87 AV |
752 | i->nr_segs = nr_segs; |
753 | i->iov_offset = 0; | |
754 | i->count = count; | |
755 | } | |
756 | EXPORT_SYMBOL(iov_iter_kvec); | |
757 | ||
05afcb77 AV |
758 | void iov_iter_bvec(struct iov_iter *i, int direction, |
759 | const struct bio_vec *bvec, unsigned long nr_segs, | |
760 | size_t count) | |
761 | { | |
762 | BUG_ON(!(direction & ITER_BVEC)); | |
763 | i->type = direction; | |
764 | i->bvec = bvec; | |
765 | i->nr_segs = nr_segs; | |
766 | i->iov_offset = 0; | |
767 | i->count = count; | |
768 | } | |
769 | EXPORT_SYMBOL(iov_iter_bvec); | |
770 | ||
241699cd AV |
771 | void iov_iter_pipe(struct iov_iter *i, int direction, |
772 | struct pipe_inode_info *pipe, | |
773 | size_t count) | |
774 | { | |
775 | BUG_ON(direction != ITER_PIPE); | |
776 | i->type = direction; | |
777 | i->pipe = pipe; | |
778 | i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); | |
779 | i->iov_offset = 0; | |
780 | i->count = count; | |
781 | } | |
782 | EXPORT_SYMBOL(iov_iter_pipe); | |
783 | ||
62a8067a AV |
784 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
785 | { | |
04a31165 AV |
786 | unsigned long res = 0; |
787 | size_t size = i->count; | |
788 | ||
789 | if (!size) | |
790 | return 0; | |
791 | ||
241699cd AV |
792 | if (unlikely(i->type & ITER_PIPE)) { |
793 | if (i->iov_offset && allocated(&i->pipe->bufs[i->idx])) | |
794 | return size | i->iov_offset; | |
795 | return size; | |
796 | } | |
04a31165 AV |
797 | iterate_all_kinds(i, size, v, |
798 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
799 | res |= v.bv_offset | v.bv_len, |
800 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
801 | ) |
802 | return res; | |
62a8067a AV |
803 | } |
804 | EXPORT_SYMBOL(iov_iter_alignment); | |
805 | ||
357f435d AV |
806 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
807 | { | |
808 | unsigned long res = 0; | |
809 | size_t size = i->count; | |
810 | if (!size) | |
811 | return 0; | |
812 | ||
241699cd AV |
813 | if (unlikely(i->type & ITER_PIPE)) { |
814 | WARN_ON(1); | |
815 | return ~0U; | |
816 | } | |
817 | ||
357f435d AV |
818 | iterate_all_kinds(i, size, v, |
819 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
820 | (size != v.iov_len ? size : 0), 0), | |
821 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
822 | (size != v.bv_len ? size : 0)), | |
823 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
824 | (size != v.iov_len ? size : 0)) | |
825 | ); | |
826 | return res; | |
827 | } | |
828 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
829 | ||
241699cd AV |
830 | static inline size_t __pipe_get_pages(struct iov_iter *i, |
831 | size_t maxsize, | |
832 | struct page **pages, | |
833 | int idx, | |
834 | size_t *start) | |
835 | { | |
836 | struct pipe_inode_info *pipe = i->pipe; | |
1689c73a | 837 | ssize_t n = push_pipe(i, maxsize, &idx, start); |
241699cd AV |
838 | if (!n) |
839 | return -EFAULT; | |
840 | ||
841 | maxsize = n; | |
842 | n += *start; | |
1689c73a | 843 | while (n > 0) { |
241699cd AV |
844 | get_page(*pages++ = pipe->bufs[idx].page); |
845 | idx = next_idx(idx, pipe); | |
846 | n -= PAGE_SIZE; | |
847 | } | |
848 | ||
849 | return maxsize; | |
850 | } | |
851 | ||
852 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
853 | struct page **pages, size_t maxsize, unsigned maxpages, | |
854 | size_t *start) | |
855 | { | |
856 | unsigned npages; | |
857 | size_t capacity; | |
858 | int idx; | |
859 | ||
860 | if (!sanity(i)) | |
861 | return -EFAULT; | |
862 | ||
863 | data_start(i, &idx, start); | |
864 | /* some of this one + all after this one */ | |
865 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
866 | capacity = min(npages,maxpages) * PAGE_SIZE - *start; | |
867 | ||
868 | return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); | |
869 | } | |
870 | ||
62a8067a | 871 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 872 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
873 | size_t *start) |
874 | { | |
e5393fae AV |
875 | if (maxsize > i->count) |
876 | maxsize = i->count; | |
877 | ||
878 | if (!maxsize) | |
879 | return 0; | |
880 | ||
241699cd AV |
881 | if (unlikely(i->type & ITER_PIPE)) |
882 | return pipe_get_pages(i, pages, maxsize, maxpages, start); | |
e5393fae AV |
883 | iterate_all_kinds(i, maxsize, v, ({ |
884 | unsigned long addr = (unsigned long)v.iov_base; | |
885 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
886 | int n; | |
887 | int res; | |
888 | ||
889 | if (len > maxpages * PAGE_SIZE) | |
890 | len = maxpages * PAGE_SIZE; | |
891 | addr &= ~(PAGE_SIZE - 1); | |
892 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
893 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); | |
894 | if (unlikely(res < 0)) | |
895 | return res; | |
896 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
897 | 0;}),({ | |
898 | /* can't be more than PAGE_SIZE */ | |
899 | *start = v.bv_offset; | |
900 | get_page(*pages = v.bv_page); | |
901 | return v.bv_len; | |
a280455f AV |
902 | }),({ |
903 | return -EFAULT; | |
e5393fae AV |
904 | }) |
905 | ) | |
906 | return 0; | |
62a8067a AV |
907 | } |
908 | EXPORT_SYMBOL(iov_iter_get_pages); | |
909 | ||
1b17f1f2 AV |
910 | static struct page **get_pages_array(size_t n) |
911 | { | |
912 | struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); | |
913 | if (!p) | |
914 | p = vmalloc(n * sizeof(struct page *)); | |
915 | return p; | |
916 | } | |
917 | ||
241699cd AV |
918 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
919 | struct page ***pages, size_t maxsize, | |
920 | size_t *start) | |
921 | { | |
922 | struct page **p; | |
923 | size_t n; | |
924 | int idx; | |
925 | int npages; | |
926 | ||
927 | if (!sanity(i)) | |
928 | return -EFAULT; | |
929 | ||
930 | data_start(i, &idx, start); | |
931 | /* some of this one + all after this one */ | |
932 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
933 | n = npages * PAGE_SIZE - *start; | |
934 | if (maxsize > n) | |
935 | maxsize = n; | |
936 | else | |
937 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
938 | p = get_pages_array(npages); | |
939 | if (!p) | |
940 | return -ENOMEM; | |
941 | n = __pipe_get_pages(i, maxsize, p, idx, start); | |
942 | if (n > 0) | |
943 | *pages = p; | |
944 | else | |
945 | kvfree(p); | |
946 | return n; | |
947 | } | |
948 | ||
62a8067a AV |
949 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
950 | struct page ***pages, size_t maxsize, | |
951 | size_t *start) | |
952 | { | |
1b17f1f2 AV |
953 | struct page **p; |
954 | ||
955 | if (maxsize > i->count) | |
956 | maxsize = i->count; | |
957 | ||
958 | if (!maxsize) | |
959 | return 0; | |
960 | ||
241699cd AV |
961 | if (unlikely(i->type & ITER_PIPE)) |
962 | return pipe_get_pages_alloc(i, pages, maxsize, start); | |
1b17f1f2 AV |
963 | iterate_all_kinds(i, maxsize, v, ({ |
964 | unsigned long addr = (unsigned long)v.iov_base; | |
965 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
966 | int n; | |
967 | int res; | |
968 | ||
969 | addr &= ~(PAGE_SIZE - 1); | |
970 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
971 | p = get_pages_array(n); | |
972 | if (!p) | |
973 | return -ENOMEM; | |
974 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); | |
975 | if (unlikely(res < 0)) { | |
976 | kvfree(p); | |
977 | return res; | |
978 | } | |
979 | *pages = p; | |
980 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
981 | 0;}),({ | |
982 | /* can't be more than PAGE_SIZE */ | |
983 | *start = v.bv_offset; | |
984 | *pages = p = get_pages_array(1); | |
985 | if (!p) | |
986 | return -ENOMEM; | |
987 | get_page(*p = v.bv_page); | |
988 | return v.bv_len; | |
a280455f AV |
989 | }),({ |
990 | return -EFAULT; | |
1b17f1f2 AV |
991 | }) |
992 | ) | |
993 | return 0; | |
62a8067a AV |
994 | } |
995 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
996 | ||
a604ec7e AV |
997 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
998 | struct iov_iter *i) | |
999 | { | |
1000 | char *to = addr; | |
1001 | __wsum sum, next; | |
1002 | size_t off = 0; | |
a604ec7e | 1003 | sum = *csum; |
241699cd AV |
1004 | if (unlikely(i->type & ITER_PIPE)) { |
1005 | WARN_ON(1); | |
1006 | return 0; | |
1007 | } | |
a604ec7e AV |
1008 | iterate_and_advance(i, bytes, v, ({ |
1009 | int err = 0; | |
1010 | next = csum_and_copy_from_user(v.iov_base, | |
1011 | (to += v.iov_len) - v.iov_len, | |
1012 | v.iov_len, 0, &err); | |
1013 | if (!err) { | |
1014 | sum = csum_block_add(sum, next, off); | |
1015 | off += v.iov_len; | |
1016 | } | |
1017 | err ? v.iov_len : 0; | |
1018 | }), ({ | |
1019 | char *p = kmap_atomic(v.bv_page); | |
1020 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
1021 | (to += v.bv_len) - v.bv_len, | |
1022 | v.bv_len, 0); | |
1023 | kunmap_atomic(p); | |
1024 | sum = csum_block_add(sum, next, off); | |
1025 | off += v.bv_len; | |
1026 | }),({ | |
1027 | next = csum_partial_copy_nocheck(v.iov_base, | |
1028 | (to += v.iov_len) - v.iov_len, | |
1029 | v.iov_len, 0); | |
1030 | sum = csum_block_add(sum, next, off); | |
1031 | off += v.iov_len; | |
1032 | }) | |
1033 | ) | |
1034 | *csum = sum; | |
1035 | return bytes; | |
1036 | } | |
1037 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1038 | ||
36f7a8a4 | 1039 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, |
a604ec7e AV |
1040 | struct iov_iter *i) |
1041 | { | |
36f7a8a4 | 1042 | const char *from = addr; |
a604ec7e AV |
1043 | __wsum sum, next; |
1044 | size_t off = 0; | |
a604ec7e | 1045 | sum = *csum; |
241699cd AV |
1046 | if (unlikely(i->type & ITER_PIPE)) { |
1047 | WARN_ON(1); /* for now */ | |
1048 | return 0; | |
1049 | } | |
a604ec7e AV |
1050 | iterate_and_advance(i, bytes, v, ({ |
1051 | int err = 0; | |
1052 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
1053 | v.iov_base, | |
1054 | v.iov_len, 0, &err); | |
1055 | if (!err) { | |
1056 | sum = csum_block_add(sum, next, off); | |
1057 | off += v.iov_len; | |
1058 | } | |
1059 | err ? v.iov_len : 0; | |
1060 | }), ({ | |
1061 | char *p = kmap_atomic(v.bv_page); | |
1062 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
1063 | p + v.bv_offset, | |
1064 | v.bv_len, 0); | |
1065 | kunmap_atomic(p); | |
1066 | sum = csum_block_add(sum, next, off); | |
1067 | off += v.bv_len; | |
1068 | }),({ | |
1069 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
1070 | v.iov_base, | |
1071 | v.iov_len, 0); | |
1072 | sum = csum_block_add(sum, next, off); | |
1073 | off += v.iov_len; | |
1074 | }) | |
1075 | ) | |
1076 | *csum = sum; | |
1077 | return bytes; | |
1078 | } | |
1079 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1080 | ||
62a8067a AV |
1081 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1082 | { | |
e0f2dc40 AV |
1083 | size_t size = i->count; |
1084 | int npages = 0; | |
1085 | ||
1086 | if (!size) | |
1087 | return 0; | |
1088 | ||
241699cd AV |
1089 | if (unlikely(i->type & ITER_PIPE)) { |
1090 | struct pipe_inode_info *pipe = i->pipe; | |
1091 | size_t off; | |
1092 | int idx; | |
1093 | ||
1094 | if (!sanity(i)) | |
1095 | return 0; | |
1096 | ||
1097 | data_start(i, &idx, &off); | |
1098 | /* some of this one + all after this one */ | |
1099 | npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; | |
1100 | if (npages >= maxpages) | |
1101 | return maxpages; | |
1102 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1103 | unsigned long p = (unsigned long)v.iov_base; |
1104 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1105 | - p / PAGE_SIZE; | |
1106 | if (npages >= maxpages) | |
1107 | return maxpages; | |
1108 | 0;}),({ | |
1109 | npages++; | |
1110 | if (npages >= maxpages) | |
1111 | return maxpages; | |
a280455f AV |
1112 | }),({ |
1113 | unsigned long p = (unsigned long)v.iov_base; | |
1114 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1115 | - p / PAGE_SIZE; | |
1116 | if (npages >= maxpages) | |
1117 | return maxpages; | |
e0f2dc40 AV |
1118 | }) |
1119 | ) | |
1120 | return npages; | |
62a8067a | 1121 | } |
f67da30c | 1122 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1123 | |
1124 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1125 | { | |
1126 | *new = *old; | |
241699cd AV |
1127 | if (unlikely(new->type & ITER_PIPE)) { |
1128 | WARN_ON(1); | |
1129 | return NULL; | |
1130 | } | |
4b8164b9 AV |
1131 | if (new->type & ITER_BVEC) |
1132 | return new->bvec = kmemdup(new->bvec, | |
1133 | new->nr_segs * sizeof(struct bio_vec), | |
1134 | flags); | |
1135 | else | |
1136 | /* iovec and kvec have identical layout */ | |
1137 | return new->iov = kmemdup(new->iov, | |
1138 | new->nr_segs * sizeof(struct iovec), | |
1139 | flags); | |
1140 | } | |
1141 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1142 | |
ffecee4f VN |
1143 | /** |
1144 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1145 | * into the kernel, check that it is valid, and initialize a new | |
1146 | * &struct iov_iter iterator to access it. | |
1147 | * | |
1148 | * @type: One of %READ or %WRITE. | |
1149 | * @uvector: Pointer to the userspace array. | |
1150 | * @nr_segs: Number of elements in userspace array. | |
1151 | * @fast_segs: Number of elements in @iov. | |
1152 | * @iov: (input and output parameter) Pointer to pointer to (usually small | |
1153 | * on-stack) kernel array. | |
1154 | * @i: Pointer to iterator that will be initialized on success. | |
1155 | * | |
1156 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1157 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1158 | * array will be allocated and the result placed in *@iov. This means that | |
1159 | * the caller may call kfree() on *@iov regardless of whether the small | |
1160 | * on-stack array was used or not (and regardless of whether this function | |
1161 | * returns an error or not). | |
1162 | * | |
1163 | * Return: 0 on success or negative error code on error. | |
1164 | */ | |
bc917be8 AV |
1165 | int import_iovec(int type, const struct iovec __user * uvector, |
1166 | unsigned nr_segs, unsigned fast_segs, | |
1167 | struct iovec **iov, struct iov_iter *i) | |
1168 | { | |
1169 | ssize_t n; | |
1170 | struct iovec *p; | |
1171 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1172 | *iov, &p); | |
1173 | if (n < 0) { | |
1174 | if (p != *iov) | |
1175 | kfree(p); | |
1176 | *iov = NULL; | |
1177 | return n; | |
1178 | } | |
1179 | iov_iter_init(i, type, p, nr_segs, n); | |
1180 | *iov = p == *iov ? NULL : p; | |
1181 | return 0; | |
1182 | } | |
1183 | EXPORT_SYMBOL(import_iovec); | |
1184 | ||
1185 | #ifdef CONFIG_COMPAT | |
1186 | #include <linux/compat.h> | |
1187 | ||
1188 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
1189 | unsigned nr_segs, unsigned fast_segs, | |
1190 | struct iovec **iov, struct iov_iter *i) | |
1191 | { | |
1192 | ssize_t n; | |
1193 | struct iovec *p; | |
1194 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1195 | *iov, &p); | |
1196 | if (n < 0) { | |
1197 | if (p != *iov) | |
1198 | kfree(p); | |
1199 | *iov = NULL; | |
1200 | return n; | |
1201 | } | |
1202 | iov_iter_init(i, type, p, nr_segs, n); | |
1203 | *iov = p == *iov ? NULL : p; | |
1204 | return 0; | |
1205 | } | |
1206 | #endif | |
1207 | ||
1208 | int import_single_range(int rw, void __user *buf, size_t len, | |
1209 | struct iovec *iov, struct iov_iter *i) | |
1210 | { | |
1211 | if (len > MAX_RW_COUNT) | |
1212 | len = MAX_RW_COUNT; | |
1213 | if (unlikely(!access_ok(!rw, buf, len))) | |
1214 | return -EFAULT; | |
1215 | ||
1216 | iov->iov_base = buf; | |
1217 | iov->iov_len = len; | |
1218 | iov_iter_init(i, rw, iov, 1, len); | |
1219 | return 0; | |
1220 | } | |
e1267585 | 1221 | EXPORT_SYMBOL(import_single_range); |