Commit | Line | Data |
---|---|---|
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) { \ |
33844e66 AV |
76 | if (likely(n)) { \ |
77 | size_t skip = i->iov_offset; \ | |
78 | if (unlikely(i->type & ITER_BVEC)) { \ | |
79 | struct bio_vec v; \ | |
80 | struct bvec_iter __bi; \ | |
81 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
82 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
83 | const struct kvec *kvec; \ | |
84 | struct kvec v; \ | |
85 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
86 | } else { \ | |
87 | const struct iovec *iov; \ | |
88 | struct iovec v; \ | |
89 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
90 | } \ | |
04a31165 AV |
91 | } \ |
92 | } | |
93 | ||
a280455f | 94 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
95 | if (unlikely(i->count < n)) \ |
96 | n = i->count; \ | |
19f18459 | 97 | if (i->count) { \ |
dd254f5a AV |
98 | size_t skip = i->iov_offset; \ |
99 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 100 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 101 | struct bio_vec v; \ |
1bdc76ae ML |
102 | struct bvec_iter __bi; \ |
103 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
104 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
105 | i->nr_segs -= i->bvec - bvec; \ | |
106 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
107 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
108 | const struct kvec *kvec; \ | |
109 | struct kvec v; \ | |
110 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
111 | if (skip == kvec->iov_len) { \ | |
112 | kvec++; \ | |
113 | skip = 0; \ | |
114 | } \ | |
115 | i->nr_segs -= kvec - i->kvec; \ | |
116 | i->kvec = kvec; \ | |
117 | } else { \ | |
118 | const struct iovec *iov; \ | |
119 | struct iovec v; \ | |
120 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
121 | if (skip == iov->iov_len) { \ | |
122 | iov++; \ | |
123 | skip = 0; \ | |
124 | } \ | |
125 | i->nr_segs -= iov - i->iov; \ | |
126 | i->iov = iov; \ | |
7ce2a91e | 127 | } \ |
dd254f5a AV |
128 | i->count -= n; \ |
129 | i->iov_offset = skip; \ | |
7ce2a91e | 130 | } \ |
7ce2a91e AV |
131 | } |
132 | ||
62a8067a | 133 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
134 | struct iov_iter *i) |
135 | { | |
136 | size_t skip, copy, left, wanted; | |
137 | const struct iovec *iov; | |
138 | char __user *buf; | |
139 | void *kaddr, *from; | |
140 | ||
141 | if (unlikely(bytes > i->count)) | |
142 | bytes = i->count; | |
143 | ||
144 | if (unlikely(!bytes)) | |
145 | return 0; | |
146 | ||
147 | wanted = bytes; | |
148 | iov = i->iov; | |
149 | skip = i->iov_offset; | |
150 | buf = iov->iov_base + skip; | |
151 | copy = min(bytes, iov->iov_len - skip); | |
152 | ||
3fa6c507 | 153 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
154 | kaddr = kmap_atomic(page); |
155 | from = kaddr + offset; | |
156 | ||
157 | /* first chunk, usually the only one */ | |
158 | left = __copy_to_user_inatomic(buf, from, copy); | |
159 | copy -= left; | |
160 | skip += copy; | |
161 | from += copy; | |
162 | bytes -= copy; | |
163 | ||
164 | while (unlikely(!left && bytes)) { | |
165 | iov++; | |
166 | buf = iov->iov_base; | |
167 | copy = min(bytes, iov->iov_len); | |
168 | left = __copy_to_user_inatomic(buf, from, copy); | |
169 | copy -= left; | |
170 | skip = copy; | |
171 | from += copy; | |
172 | bytes -= copy; | |
173 | } | |
174 | if (likely(!bytes)) { | |
175 | kunmap_atomic(kaddr); | |
176 | goto done; | |
177 | } | |
178 | offset = from - kaddr; | |
179 | buf += copy; | |
180 | kunmap_atomic(kaddr); | |
181 | copy = min(bytes, iov->iov_len - skip); | |
182 | } | |
183 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 184 | |
4f18cd31 AV |
185 | kaddr = kmap(page); |
186 | from = kaddr + offset; | |
187 | left = __copy_to_user(buf, from, copy); | |
188 | copy -= left; | |
189 | skip += copy; | |
190 | from += copy; | |
191 | bytes -= copy; | |
192 | while (unlikely(!left && bytes)) { | |
193 | iov++; | |
194 | buf = iov->iov_base; | |
195 | copy = min(bytes, iov->iov_len); | |
196 | left = __copy_to_user(buf, from, copy); | |
197 | copy -= left; | |
198 | skip = copy; | |
199 | from += copy; | |
200 | bytes -= copy; | |
201 | } | |
202 | kunmap(page); | |
3fa6c507 | 203 | |
4f18cd31 | 204 | done: |
81055e58 AV |
205 | if (skip == iov->iov_len) { |
206 | iov++; | |
207 | skip = 0; | |
208 | } | |
4f18cd31 AV |
209 | i->count -= wanted - bytes; |
210 | i->nr_segs -= iov - i->iov; | |
211 | i->iov = iov; | |
212 | i->iov_offset = skip; | |
213 | return wanted - bytes; | |
214 | } | |
4f18cd31 | 215 | |
62a8067a | 216 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
217 | struct iov_iter *i) |
218 | { | |
219 | size_t skip, copy, left, wanted; | |
220 | const struct iovec *iov; | |
221 | char __user *buf; | |
222 | void *kaddr, *to; | |
223 | ||
224 | if (unlikely(bytes > i->count)) | |
225 | bytes = i->count; | |
226 | ||
227 | if (unlikely(!bytes)) | |
228 | return 0; | |
229 | ||
230 | wanted = bytes; | |
231 | iov = i->iov; | |
232 | skip = i->iov_offset; | |
233 | buf = iov->iov_base + skip; | |
234 | copy = min(bytes, iov->iov_len - skip); | |
235 | ||
3fa6c507 | 236 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
237 | kaddr = kmap_atomic(page); |
238 | to = kaddr + offset; | |
239 | ||
240 | /* first chunk, usually the only one */ | |
241 | left = __copy_from_user_inatomic(to, buf, copy); | |
242 | copy -= left; | |
243 | skip += copy; | |
244 | to += copy; | |
245 | bytes -= copy; | |
246 | ||
247 | while (unlikely(!left && bytes)) { | |
248 | iov++; | |
249 | buf = iov->iov_base; | |
250 | copy = min(bytes, iov->iov_len); | |
251 | left = __copy_from_user_inatomic(to, buf, copy); | |
252 | copy -= left; | |
253 | skip = copy; | |
254 | to += copy; | |
255 | bytes -= copy; | |
256 | } | |
257 | if (likely(!bytes)) { | |
258 | kunmap_atomic(kaddr); | |
259 | goto done; | |
260 | } | |
261 | offset = to - kaddr; | |
262 | buf += copy; | |
263 | kunmap_atomic(kaddr); | |
264 | copy = min(bytes, iov->iov_len - skip); | |
265 | } | |
266 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 267 | |
f0d1bec9 AV |
268 | kaddr = kmap(page); |
269 | to = kaddr + offset; | |
270 | left = __copy_from_user(to, buf, copy); | |
271 | copy -= left; | |
272 | skip += copy; | |
273 | to += copy; | |
274 | bytes -= copy; | |
275 | while (unlikely(!left && bytes)) { | |
276 | iov++; | |
277 | buf = iov->iov_base; | |
278 | copy = min(bytes, iov->iov_len); | |
279 | left = __copy_from_user(to, buf, copy); | |
280 | copy -= left; | |
281 | skip = copy; | |
282 | to += copy; | |
283 | bytes -= copy; | |
284 | } | |
285 | kunmap(page); | |
3fa6c507 | 286 | |
f0d1bec9 | 287 | done: |
81055e58 AV |
288 | if (skip == iov->iov_len) { |
289 | iov++; | |
290 | skip = 0; | |
291 | } | |
f0d1bec9 AV |
292 | i->count -= wanted - bytes; |
293 | i->nr_segs -= iov - i->iov; | |
294 | i->iov = iov; | |
295 | i->iov_offset = skip; | |
296 | return wanted - bytes; | |
297 | } | |
f0d1bec9 | 298 | |
241699cd AV |
299 | #ifdef PIPE_PARANOIA |
300 | static bool sanity(const struct iov_iter *i) | |
301 | { | |
302 | struct pipe_inode_info *pipe = i->pipe; | |
303 | int idx = i->idx; | |
304 | int next = pipe->curbuf + pipe->nrbufs; | |
305 | if (i->iov_offset) { | |
306 | struct pipe_buffer *p; | |
307 | if (unlikely(!pipe->nrbufs)) | |
308 | goto Bad; // pipe must be non-empty | |
309 | if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) | |
310 | goto Bad; // must be at the last buffer... | |
311 | ||
312 | p = &pipe->bufs[idx]; | |
313 | if (unlikely(p->offset + p->len != i->iov_offset)) | |
314 | goto Bad; // ... at the end of segment | |
315 | } else { | |
316 | if (idx != (next & (pipe->buffers - 1))) | |
317 | goto Bad; // must be right after the last buffer | |
318 | } | |
319 | return true; | |
320 | Bad: | |
321 | printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); | |
322 | printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", | |
323 | pipe->curbuf, pipe->nrbufs, pipe->buffers); | |
324 | for (idx = 0; idx < pipe->buffers; idx++) | |
325 | printk(KERN_ERR "[%p %p %d %d]\n", | |
326 | pipe->bufs[idx].ops, | |
327 | pipe->bufs[idx].page, | |
328 | pipe->bufs[idx].offset, | |
329 | pipe->bufs[idx].len); | |
330 | WARN_ON(1); | |
331 | return false; | |
332 | } | |
333 | #else | |
334 | #define sanity(i) true | |
335 | #endif | |
336 | ||
337 | static inline int next_idx(int idx, struct pipe_inode_info *pipe) | |
338 | { | |
339 | return (idx + 1) & (pipe->buffers - 1); | |
340 | } | |
341 | ||
342 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, | |
343 | struct iov_iter *i) | |
344 | { | |
345 | struct pipe_inode_info *pipe = i->pipe; | |
346 | struct pipe_buffer *buf; | |
347 | size_t off; | |
348 | int idx; | |
349 | ||
350 | if (unlikely(bytes > i->count)) | |
351 | bytes = i->count; | |
352 | ||
353 | if (unlikely(!bytes)) | |
354 | return 0; | |
355 | ||
356 | if (!sanity(i)) | |
357 | return 0; | |
358 | ||
359 | off = i->iov_offset; | |
360 | idx = i->idx; | |
361 | buf = &pipe->bufs[idx]; | |
362 | if (off) { | |
363 | if (offset == off && buf->page == page) { | |
364 | /* merge with the last one */ | |
365 | buf->len += bytes; | |
366 | i->iov_offset += bytes; | |
367 | goto out; | |
368 | } | |
369 | idx = next_idx(idx, pipe); | |
370 | buf = &pipe->bufs[idx]; | |
371 | } | |
372 | if (idx == pipe->curbuf && pipe->nrbufs) | |
373 | return 0; | |
374 | pipe->nrbufs++; | |
375 | buf->ops = &page_cache_pipe_buf_ops; | |
376 | get_page(buf->page = page); | |
377 | buf->offset = offset; | |
378 | buf->len = bytes; | |
379 | i->iov_offset = offset + bytes; | |
380 | i->idx = idx; | |
381 | out: | |
382 | i->count -= bytes; | |
383 | return bytes; | |
384 | } | |
385 | ||
171a0203 AA |
386 | /* |
387 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
388 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
389 | * | |
390 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
391 | * because it is an invalid address). | |
392 | */ | |
d4690f1e | 393 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
394 | { |
395 | size_t skip = i->iov_offset; | |
396 | const struct iovec *iov; | |
397 | int err; | |
398 | struct iovec v; | |
399 | ||
400 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
401 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
4bce9f6e | 402 | err = fault_in_pages_readable(v.iov_base, v.iov_len); |
171a0203 AA |
403 | if (unlikely(err)) |
404 | return err; | |
405 | 0;})) | |
406 | } | |
407 | return 0; | |
408 | } | |
d4690f1e | 409 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 410 | |
71d8e532 AV |
411 | void iov_iter_init(struct iov_iter *i, int direction, |
412 | const struct iovec *iov, unsigned long nr_segs, | |
413 | size_t count) | |
414 | { | |
415 | /* It will get better. Eventually... */ | |
db68ce10 | 416 | if (uaccess_kernel()) { |
62a8067a | 417 | direction |= ITER_KVEC; |
a280455f AV |
418 | i->type = direction; |
419 | i->kvec = (struct kvec *)iov; | |
420 | } else { | |
421 | i->type = direction; | |
422 | i->iov = iov; | |
423 | } | |
71d8e532 AV |
424 | i->nr_segs = nr_segs; |
425 | i->iov_offset = 0; | |
426 | i->count = count; | |
427 | } | |
428 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 429 | |
62a8067a AV |
430 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
431 | { | |
432 | char *from = kmap_atomic(page); | |
433 | memcpy(to, from + offset, len); | |
434 | kunmap_atomic(from); | |
435 | } | |
436 | ||
36f7a8a4 | 437 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
438 | { |
439 | char *to = kmap_atomic(page); | |
440 | memcpy(to + offset, from, len); | |
441 | kunmap_atomic(to); | |
442 | } | |
443 | ||
c35e0248 MW |
444 | static void memzero_page(struct page *page, size_t offset, size_t len) |
445 | { | |
446 | char *addr = kmap_atomic(page); | |
447 | memset(addr + offset, 0, len); | |
448 | kunmap_atomic(addr); | |
449 | } | |
450 | ||
241699cd AV |
451 | static inline bool allocated(struct pipe_buffer *buf) |
452 | { | |
453 | return buf->ops == &default_pipe_buf_ops; | |
454 | } | |
455 | ||
456 | static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) | |
457 | { | |
458 | size_t off = i->iov_offset; | |
459 | int idx = i->idx; | |
460 | if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { | |
461 | idx = next_idx(idx, i->pipe); | |
462 | off = 0; | |
463 | } | |
464 | *idxp = idx; | |
465 | *offp = off; | |
466 | } | |
467 | ||
468 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
469 | int *idxp, size_t *offp) | |
470 | { | |
471 | struct pipe_inode_info *pipe = i->pipe; | |
472 | size_t off; | |
473 | int idx; | |
474 | ssize_t left; | |
475 | ||
476 | if (unlikely(size > i->count)) | |
477 | size = i->count; | |
478 | if (unlikely(!size)) | |
479 | return 0; | |
480 | ||
481 | left = size; | |
482 | data_start(i, &idx, &off); | |
483 | *idxp = idx; | |
484 | *offp = off; | |
485 | if (off) { | |
486 | left -= PAGE_SIZE - off; | |
487 | if (left <= 0) { | |
488 | pipe->bufs[idx].len += size; | |
489 | return size; | |
490 | } | |
491 | pipe->bufs[idx].len = PAGE_SIZE; | |
492 | idx = next_idx(idx, pipe); | |
493 | } | |
494 | while (idx != pipe->curbuf || !pipe->nrbufs) { | |
495 | struct page *page = alloc_page(GFP_USER); | |
496 | if (!page) | |
497 | break; | |
498 | pipe->nrbufs++; | |
499 | pipe->bufs[idx].ops = &default_pipe_buf_ops; | |
500 | pipe->bufs[idx].page = page; | |
501 | pipe->bufs[idx].offset = 0; | |
502 | if (left <= PAGE_SIZE) { | |
503 | pipe->bufs[idx].len = left; | |
504 | return size; | |
505 | } | |
506 | pipe->bufs[idx].len = PAGE_SIZE; | |
507 | left -= PAGE_SIZE; | |
508 | idx = next_idx(idx, pipe); | |
509 | } | |
510 | return size - left; | |
511 | } | |
512 | ||
513 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
514 | struct iov_iter *i) | |
515 | { | |
516 | struct pipe_inode_info *pipe = i->pipe; | |
517 | size_t n, off; | |
518 | int idx; | |
519 | ||
520 | if (!sanity(i)) | |
521 | return 0; | |
522 | ||
523 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
524 | if (unlikely(!n)) | |
525 | return 0; | |
526 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
527 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
528 | memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); | |
529 | i->idx = idx; | |
530 | i->iov_offset = off + chunk; | |
531 | n -= chunk; | |
532 | addr += chunk; | |
533 | } | |
534 | i->count -= bytes; | |
535 | return bytes; | |
536 | } | |
537 | ||
aa28de27 | 538 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 539 | { |
36f7a8a4 | 540 | const char *from = addr; |
241699cd AV |
541 | if (unlikely(i->type & ITER_PIPE)) |
542 | return copy_pipe_to_iter(addr, bytes, i); | |
3d4d3e48 AV |
543 | iterate_and_advance(i, bytes, v, |
544 | __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, | |
545 | v.iov_len), | |
546 | memcpy_to_page(v.bv_page, v.bv_offset, | |
a280455f AV |
547 | (from += v.bv_len) - v.bv_len, v.bv_len), |
548 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 549 | ) |
62a8067a | 550 | |
3d4d3e48 | 551 | return bytes; |
c35e0248 | 552 | } |
aa28de27 | 553 | EXPORT_SYMBOL(_copy_to_iter); |
c35e0248 | 554 | |
aa28de27 | 555 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 556 | { |
0dbca9a4 | 557 | char *to = addr; |
241699cd AV |
558 | if (unlikely(i->type & ITER_PIPE)) { |
559 | WARN_ON(1); | |
560 | return 0; | |
561 | } | |
0dbca9a4 AV |
562 | iterate_and_advance(i, bytes, v, |
563 | __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, | |
564 | v.iov_len), | |
565 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
566 | v.bv_offset, v.bv_len), |
567 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
568 | ) |
569 | ||
570 | return bytes; | |
c35e0248 | 571 | } |
aa28de27 | 572 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 573 | |
aa28de27 | 574 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
575 | { |
576 | char *to = addr; | |
577 | if (unlikely(i->type & ITER_PIPE)) { | |
578 | WARN_ON(1); | |
579 | return false; | |
580 | } | |
33844e66 | 581 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
582 | return false; |
583 | ||
584 | iterate_all_kinds(i, bytes, v, ({ | |
585 | if (__copy_from_user((to += v.iov_len) - v.iov_len, | |
586 | v.iov_base, v.iov_len)) | |
587 | return false; | |
588 | 0;}), | |
589 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
590 | v.bv_offset, v.bv_len), | |
591 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
592 | ) | |
593 | ||
594 | iov_iter_advance(i, bytes); | |
595 | return true; | |
596 | } | |
aa28de27 | 597 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 598 | |
aa28de27 | 599 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
600 | { |
601 | char *to = addr; | |
241699cd AV |
602 | if (unlikely(i->type & ITER_PIPE)) { |
603 | WARN_ON(1); | |
604 | return 0; | |
605 | } | |
aa583096 | 606 | iterate_and_advance(i, bytes, v, |
3f763453 | 607 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
608 | v.iov_base, v.iov_len), |
609 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
610 | v.bv_offset, v.bv_len), | |
611 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
612 | ) | |
613 | ||
614 | return bytes; | |
615 | } | |
aa28de27 | 616 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 617 | |
aa28de27 | 618 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
619 | { |
620 | char *to = addr; | |
621 | if (unlikely(i->type & ITER_PIPE)) { | |
622 | WARN_ON(1); | |
623 | return false; | |
624 | } | |
33844e66 | 625 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
626 | return false; |
627 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 628 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
629 | v.iov_base, v.iov_len)) |
630 | return false; | |
631 | 0;}), | |
632 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
633 | v.bv_offset, v.bv_len), | |
634 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
635 | ) | |
636 | ||
637 | iov_iter_advance(i, bytes); | |
638 | return true; | |
639 | } | |
aa28de27 | 640 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 641 | |
72e809ed AV |
642 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
643 | { | |
644 | size_t v = n + offset; | |
645 | if (likely(n <= v && v <= (PAGE_SIZE << compound_order(page)))) | |
646 | return true; | |
647 | WARN_ON(1); | |
648 | return false; | |
649 | } | |
650 | ||
62a8067a AV |
651 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
652 | struct iov_iter *i) | |
653 | { | |
72e809ed AV |
654 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
655 | return 0; | |
d271524a AV |
656 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
657 | void *kaddr = kmap_atomic(page); | |
658 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
659 | kunmap_atomic(kaddr); | |
660 | return wanted; | |
241699cd | 661 | } else if (likely(!(i->type & ITER_PIPE))) |
62a8067a | 662 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
663 | else |
664 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
665 | } |
666 | EXPORT_SYMBOL(copy_page_to_iter); | |
667 | ||
668 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
669 | struct iov_iter *i) | |
670 | { | |
72e809ed AV |
671 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
672 | return 0; | |
241699cd AV |
673 | if (unlikely(i->type & ITER_PIPE)) { |
674 | WARN_ON(1); | |
675 | return 0; | |
676 | } | |
a280455f | 677 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 678 | void *kaddr = kmap_atomic(page); |
aa28de27 | 679 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
680 | kunmap_atomic(kaddr); |
681 | return wanted; | |
682 | } else | |
62a8067a AV |
683 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
684 | } | |
685 | EXPORT_SYMBOL(copy_page_from_iter); | |
686 | ||
241699cd AV |
687 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
688 | { | |
689 | struct pipe_inode_info *pipe = i->pipe; | |
690 | size_t n, off; | |
691 | int idx; | |
692 | ||
693 | if (!sanity(i)) | |
694 | return 0; | |
695 | ||
696 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
697 | if (unlikely(!n)) | |
698 | return 0; | |
699 | ||
700 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
701 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
702 | memzero_page(pipe->bufs[idx].page, off, chunk); | |
703 | i->idx = idx; | |
704 | i->iov_offset = off + chunk; | |
705 | n -= chunk; | |
706 | } | |
707 | i->count -= bytes; | |
708 | return bytes; | |
709 | } | |
710 | ||
c35e0248 MW |
711 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
712 | { | |
241699cd AV |
713 | if (unlikely(i->type & ITER_PIPE)) |
714 | return pipe_zero(bytes, i); | |
8442fa46 AV |
715 | iterate_and_advance(i, bytes, v, |
716 | __clear_user(v.iov_base, v.iov_len), | |
a280455f AV |
717 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
718 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
719 | ) |
720 | ||
721 | return bytes; | |
c35e0248 MW |
722 | } |
723 | EXPORT_SYMBOL(iov_iter_zero); | |
724 | ||
62a8067a AV |
725 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
726 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
727 | { | |
04a31165 | 728 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
729 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
730 | kunmap_atomic(kaddr); | |
731 | return 0; | |
732 | } | |
241699cd AV |
733 | if (unlikely(i->type & ITER_PIPE)) { |
734 | kunmap_atomic(kaddr); | |
735 | WARN_ON(1); | |
736 | return 0; | |
737 | } | |
04a31165 AV |
738 | iterate_all_kinds(i, bytes, v, |
739 | __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, | |
740 | v.iov_base, v.iov_len), | |
741 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
742 | v.bv_offset, v.bv_len), |
743 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
744 | ) |
745 | kunmap_atomic(kaddr); | |
746 | return bytes; | |
62a8067a AV |
747 | } |
748 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
749 | ||
b9dc6f65 AV |
750 | static inline void pipe_truncate(struct iov_iter *i) |
751 | { | |
752 | struct pipe_inode_info *pipe = i->pipe; | |
753 | if (pipe->nrbufs) { | |
754 | size_t off = i->iov_offset; | |
755 | int idx = i->idx; | |
756 | int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); | |
757 | if (off) { | |
758 | pipe->bufs[idx].len = off - pipe->bufs[idx].offset; | |
759 | idx = next_idx(idx, pipe); | |
760 | nrbufs++; | |
761 | } | |
762 | while (pipe->nrbufs > nrbufs) { | |
763 | pipe_buf_release(pipe, &pipe->bufs[idx]); | |
764 | idx = next_idx(idx, pipe); | |
765 | pipe->nrbufs--; | |
766 | } | |
767 | } | |
768 | } | |
769 | ||
241699cd AV |
770 | static void pipe_advance(struct iov_iter *i, size_t size) |
771 | { | |
772 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
773 | if (unlikely(i->count < size)) |
774 | size = i->count; | |
241699cd | 775 | if (size) { |
b9dc6f65 AV |
776 | struct pipe_buffer *buf; |
777 | size_t off = i->iov_offset, left = size; | |
778 | int idx = i->idx; | |
241699cd | 779 | if (off) /* make it relative to the beginning of buffer */ |
b9dc6f65 | 780 | left += off - pipe->bufs[idx].offset; |
241699cd AV |
781 | while (1) { |
782 | buf = &pipe->bufs[idx]; | |
b9dc6f65 | 783 | if (left <= buf->len) |
241699cd | 784 | break; |
b9dc6f65 | 785 | left -= buf->len; |
241699cd AV |
786 | idx = next_idx(idx, pipe); |
787 | } | |
241699cd | 788 | i->idx = idx; |
b9dc6f65 | 789 | i->iov_offset = buf->offset + left; |
241699cd | 790 | } |
b9dc6f65 AV |
791 | i->count -= size; |
792 | /* ... and discard everything past that point */ | |
793 | pipe_truncate(i); | |
241699cd AV |
794 | } |
795 | ||
62a8067a AV |
796 | void iov_iter_advance(struct iov_iter *i, size_t size) |
797 | { | |
241699cd AV |
798 | if (unlikely(i->type & ITER_PIPE)) { |
799 | pipe_advance(i, size); | |
800 | return; | |
801 | } | |
a280455f | 802 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
803 | } |
804 | EXPORT_SYMBOL(iov_iter_advance); | |
805 | ||
27c0e374 AV |
806 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
807 | { | |
808 | if (!unroll) | |
809 | return; | |
5b47d59a AV |
810 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
811 | return; | |
27c0e374 AV |
812 | i->count += unroll; |
813 | if (unlikely(i->type & ITER_PIPE)) { | |
814 | struct pipe_inode_info *pipe = i->pipe; | |
815 | int idx = i->idx; | |
816 | size_t off = i->iov_offset; | |
817 | while (1) { | |
818 | size_t n = off - pipe->bufs[idx].offset; | |
819 | if (unroll < n) { | |
4fa55cef | 820 | off -= unroll; |
27c0e374 AV |
821 | break; |
822 | } | |
823 | unroll -= n; | |
824 | if (!unroll && idx == i->start_idx) { | |
825 | off = 0; | |
826 | break; | |
827 | } | |
828 | if (!idx--) | |
829 | idx = pipe->buffers - 1; | |
830 | off = pipe->bufs[idx].offset + pipe->bufs[idx].len; | |
831 | } | |
832 | i->iov_offset = off; | |
833 | i->idx = idx; | |
834 | pipe_truncate(i); | |
835 | return; | |
836 | } | |
837 | if (unroll <= i->iov_offset) { | |
838 | i->iov_offset -= unroll; | |
839 | return; | |
840 | } | |
841 | unroll -= i->iov_offset; | |
842 | if (i->type & ITER_BVEC) { | |
843 | const struct bio_vec *bvec = i->bvec; | |
844 | while (1) { | |
845 | size_t n = (--bvec)->bv_len; | |
846 | i->nr_segs++; | |
847 | if (unroll <= n) { | |
848 | i->bvec = bvec; | |
849 | i->iov_offset = n - unroll; | |
850 | return; | |
851 | } | |
852 | unroll -= n; | |
853 | } | |
854 | } else { /* same logics for iovec and kvec */ | |
855 | const struct iovec *iov = i->iov; | |
856 | while (1) { | |
857 | size_t n = (--iov)->iov_len; | |
858 | i->nr_segs++; | |
859 | if (unroll <= n) { | |
860 | i->iov = iov; | |
861 | i->iov_offset = n - unroll; | |
862 | return; | |
863 | } | |
864 | unroll -= n; | |
865 | } | |
866 | } | |
867 | } | |
868 | EXPORT_SYMBOL(iov_iter_revert); | |
869 | ||
62a8067a AV |
870 | /* |
871 | * Return the count of just the current iov_iter segment. | |
872 | */ | |
873 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
874 | { | |
241699cd AV |
875 | if (unlikely(i->type & ITER_PIPE)) |
876 | return i->count; // it is a silly place, anyway | |
62a8067a AV |
877 | if (i->nr_segs == 1) |
878 | return i->count; | |
879 | else if (i->type & ITER_BVEC) | |
62a8067a | 880 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
881 | else |
882 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
883 | } |
884 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
885 | ||
abb78f87 | 886 | void iov_iter_kvec(struct iov_iter *i, int direction, |
05afcb77 | 887 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
888 | size_t count) |
889 | { | |
890 | BUG_ON(!(direction & ITER_KVEC)); | |
891 | i->type = direction; | |
05afcb77 | 892 | i->kvec = kvec; |
abb78f87 AV |
893 | i->nr_segs = nr_segs; |
894 | i->iov_offset = 0; | |
895 | i->count = count; | |
896 | } | |
897 | EXPORT_SYMBOL(iov_iter_kvec); | |
898 | ||
05afcb77 AV |
899 | void iov_iter_bvec(struct iov_iter *i, int direction, |
900 | const struct bio_vec *bvec, unsigned long nr_segs, | |
901 | size_t count) | |
902 | { | |
903 | BUG_ON(!(direction & ITER_BVEC)); | |
904 | i->type = direction; | |
905 | i->bvec = bvec; | |
906 | i->nr_segs = nr_segs; | |
907 | i->iov_offset = 0; | |
908 | i->count = count; | |
909 | } | |
910 | EXPORT_SYMBOL(iov_iter_bvec); | |
911 | ||
241699cd AV |
912 | void iov_iter_pipe(struct iov_iter *i, int direction, |
913 | struct pipe_inode_info *pipe, | |
914 | size_t count) | |
915 | { | |
916 | BUG_ON(direction != ITER_PIPE); | |
b9dc6f65 | 917 | WARN_ON(pipe->nrbufs == pipe->buffers); |
241699cd AV |
918 | i->type = direction; |
919 | i->pipe = pipe; | |
920 | i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); | |
921 | i->iov_offset = 0; | |
922 | i->count = count; | |
27c0e374 | 923 | i->start_idx = i->idx; |
241699cd AV |
924 | } |
925 | EXPORT_SYMBOL(iov_iter_pipe); | |
926 | ||
62a8067a AV |
927 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
928 | { | |
04a31165 AV |
929 | unsigned long res = 0; |
930 | size_t size = i->count; | |
931 | ||
241699cd | 932 | if (unlikely(i->type & ITER_PIPE)) { |
33844e66 | 933 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) |
241699cd AV |
934 | return size | i->iov_offset; |
935 | return size; | |
936 | } | |
04a31165 AV |
937 | iterate_all_kinds(i, size, v, |
938 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
939 | res |= v.bv_offset | v.bv_len, |
940 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
941 | ) |
942 | return res; | |
62a8067a AV |
943 | } |
944 | EXPORT_SYMBOL(iov_iter_alignment); | |
945 | ||
357f435d AV |
946 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
947 | { | |
33844e66 | 948 | unsigned long res = 0; |
357f435d | 949 | size_t size = i->count; |
357f435d | 950 | |
241699cd AV |
951 | if (unlikely(i->type & ITER_PIPE)) { |
952 | WARN_ON(1); | |
953 | return ~0U; | |
954 | } | |
955 | ||
357f435d AV |
956 | iterate_all_kinds(i, size, v, |
957 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
958 | (size != v.iov_len ? size : 0), 0), | |
959 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
960 | (size != v.bv_len ? size : 0)), | |
961 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
962 | (size != v.iov_len ? size : 0)) | |
963 | ); | |
33844e66 | 964 | return res; |
357f435d AV |
965 | } |
966 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
967 | ||
241699cd AV |
968 | static inline size_t __pipe_get_pages(struct iov_iter *i, |
969 | size_t maxsize, | |
970 | struct page **pages, | |
971 | int idx, | |
972 | size_t *start) | |
973 | { | |
974 | struct pipe_inode_info *pipe = i->pipe; | |
1689c73a | 975 | ssize_t n = push_pipe(i, maxsize, &idx, start); |
241699cd AV |
976 | if (!n) |
977 | return -EFAULT; | |
978 | ||
979 | maxsize = n; | |
980 | n += *start; | |
1689c73a | 981 | while (n > 0) { |
241699cd AV |
982 | get_page(*pages++ = pipe->bufs[idx].page); |
983 | idx = next_idx(idx, pipe); | |
984 | n -= PAGE_SIZE; | |
985 | } | |
986 | ||
987 | return maxsize; | |
988 | } | |
989 | ||
990 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
991 | struct page **pages, size_t maxsize, unsigned maxpages, | |
992 | size_t *start) | |
993 | { | |
994 | unsigned npages; | |
995 | size_t capacity; | |
996 | int idx; | |
997 | ||
33844e66 AV |
998 | if (!maxsize) |
999 | return 0; | |
1000 | ||
241699cd AV |
1001 | if (!sanity(i)) |
1002 | return -EFAULT; | |
1003 | ||
1004 | data_start(i, &idx, start); | |
1005 | /* some of this one + all after this one */ | |
1006 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
1007 | capacity = min(npages,maxpages) * PAGE_SIZE - *start; | |
1008 | ||
1009 | return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); | |
1010 | } | |
1011 | ||
62a8067a | 1012 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1013 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1014 | size_t *start) |
1015 | { | |
e5393fae AV |
1016 | if (maxsize > i->count) |
1017 | maxsize = i->count; | |
1018 | ||
241699cd AV |
1019 | if (unlikely(i->type & ITER_PIPE)) |
1020 | return pipe_get_pages(i, pages, maxsize, maxpages, start); | |
e5393fae AV |
1021 | iterate_all_kinds(i, maxsize, v, ({ |
1022 | unsigned long addr = (unsigned long)v.iov_base; | |
1023 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1024 | int n; | |
1025 | int res; | |
1026 | ||
1027 | if (len > maxpages * PAGE_SIZE) | |
1028 | len = maxpages * PAGE_SIZE; | |
1029 | addr &= ~(PAGE_SIZE - 1); | |
1030 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1031 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); | |
1032 | if (unlikely(res < 0)) | |
1033 | return res; | |
1034 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1035 | 0;}),({ | |
1036 | /* can't be more than PAGE_SIZE */ | |
1037 | *start = v.bv_offset; | |
1038 | get_page(*pages = v.bv_page); | |
1039 | return v.bv_len; | |
a280455f AV |
1040 | }),({ |
1041 | return -EFAULT; | |
e5393fae AV |
1042 | }) |
1043 | ) | |
1044 | return 0; | |
62a8067a AV |
1045 | } |
1046 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1047 | ||
1b17f1f2 AV |
1048 | static struct page **get_pages_array(size_t n) |
1049 | { | |
752ade68 | 1050 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1051 | } |
1052 | ||
241699cd AV |
1053 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1054 | struct page ***pages, size_t maxsize, | |
1055 | size_t *start) | |
1056 | { | |
1057 | struct page **p; | |
1058 | size_t n; | |
1059 | int idx; | |
1060 | int npages; | |
1061 | ||
33844e66 AV |
1062 | if (!maxsize) |
1063 | return 0; | |
1064 | ||
241699cd AV |
1065 | if (!sanity(i)) |
1066 | return -EFAULT; | |
1067 | ||
1068 | data_start(i, &idx, start); | |
1069 | /* some of this one + all after this one */ | |
1070 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
1071 | n = npages * PAGE_SIZE - *start; | |
1072 | if (maxsize > n) | |
1073 | maxsize = n; | |
1074 | else | |
1075 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1076 | p = get_pages_array(npages); | |
1077 | if (!p) | |
1078 | return -ENOMEM; | |
1079 | n = __pipe_get_pages(i, maxsize, p, idx, start); | |
1080 | if (n > 0) | |
1081 | *pages = p; | |
1082 | else | |
1083 | kvfree(p); | |
1084 | return n; | |
1085 | } | |
1086 | ||
62a8067a AV |
1087 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1088 | struct page ***pages, size_t maxsize, | |
1089 | size_t *start) | |
1090 | { | |
1b17f1f2 AV |
1091 | struct page **p; |
1092 | ||
1093 | if (maxsize > i->count) | |
1094 | maxsize = i->count; | |
1095 | ||
241699cd AV |
1096 | if (unlikely(i->type & ITER_PIPE)) |
1097 | return pipe_get_pages_alloc(i, pages, maxsize, start); | |
1b17f1f2 AV |
1098 | iterate_all_kinds(i, maxsize, v, ({ |
1099 | unsigned long addr = (unsigned long)v.iov_base; | |
1100 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1101 | int n; | |
1102 | int res; | |
1103 | ||
1104 | addr &= ~(PAGE_SIZE - 1); | |
1105 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1106 | p = get_pages_array(n); | |
1107 | if (!p) | |
1108 | return -ENOMEM; | |
1109 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); | |
1110 | if (unlikely(res < 0)) { | |
1111 | kvfree(p); | |
1112 | return res; | |
1113 | } | |
1114 | *pages = p; | |
1115 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1116 | 0;}),({ | |
1117 | /* can't be more than PAGE_SIZE */ | |
1118 | *start = v.bv_offset; | |
1119 | *pages = p = get_pages_array(1); | |
1120 | if (!p) | |
1121 | return -ENOMEM; | |
1122 | get_page(*p = v.bv_page); | |
1123 | return v.bv_len; | |
a280455f AV |
1124 | }),({ |
1125 | return -EFAULT; | |
1b17f1f2 AV |
1126 | }) |
1127 | ) | |
1128 | return 0; | |
62a8067a AV |
1129 | } |
1130 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1131 | ||
a604ec7e AV |
1132 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1133 | struct iov_iter *i) | |
1134 | { | |
1135 | char *to = addr; | |
1136 | __wsum sum, next; | |
1137 | size_t off = 0; | |
a604ec7e | 1138 | sum = *csum; |
241699cd AV |
1139 | if (unlikely(i->type & ITER_PIPE)) { |
1140 | WARN_ON(1); | |
1141 | return 0; | |
1142 | } | |
a604ec7e AV |
1143 | iterate_and_advance(i, bytes, v, ({ |
1144 | int err = 0; | |
cbbd26b8 | 1145 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e AV |
1146 | (to += v.iov_len) - v.iov_len, |
1147 | v.iov_len, 0, &err); | |
1148 | if (!err) { | |
1149 | sum = csum_block_add(sum, next, off); | |
1150 | off += v.iov_len; | |
1151 | } | |
1152 | err ? v.iov_len : 0; | |
1153 | }), ({ | |
1154 | char *p = kmap_atomic(v.bv_page); | |
1155 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
1156 | (to += v.bv_len) - v.bv_len, | |
1157 | v.bv_len, 0); | |
1158 | kunmap_atomic(p); | |
1159 | sum = csum_block_add(sum, next, off); | |
1160 | off += v.bv_len; | |
1161 | }),({ | |
1162 | next = csum_partial_copy_nocheck(v.iov_base, | |
1163 | (to += v.iov_len) - v.iov_len, | |
1164 | v.iov_len, 0); | |
1165 | sum = csum_block_add(sum, next, off); | |
1166 | off += v.iov_len; | |
1167 | }) | |
1168 | ) | |
1169 | *csum = sum; | |
1170 | return bytes; | |
1171 | } | |
1172 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1173 | ||
cbbd26b8 AV |
1174 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
1175 | struct iov_iter *i) | |
1176 | { | |
1177 | char *to = addr; | |
1178 | __wsum sum, next; | |
1179 | size_t off = 0; | |
1180 | sum = *csum; | |
1181 | if (unlikely(i->type & ITER_PIPE)) { | |
1182 | WARN_ON(1); | |
1183 | return false; | |
1184 | } | |
1185 | if (unlikely(i->count < bytes)) | |
1186 | return false; | |
1187 | iterate_all_kinds(i, bytes, v, ({ | |
1188 | int err = 0; | |
1189 | next = csum_and_copy_from_user(v.iov_base, | |
1190 | (to += v.iov_len) - v.iov_len, | |
1191 | v.iov_len, 0, &err); | |
1192 | if (err) | |
1193 | return false; | |
1194 | sum = csum_block_add(sum, next, off); | |
1195 | off += v.iov_len; | |
1196 | 0; | |
1197 | }), ({ | |
1198 | char *p = kmap_atomic(v.bv_page); | |
1199 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
1200 | (to += v.bv_len) - v.bv_len, | |
1201 | v.bv_len, 0); | |
1202 | kunmap_atomic(p); | |
1203 | sum = csum_block_add(sum, next, off); | |
1204 | off += v.bv_len; | |
1205 | }),({ | |
1206 | next = csum_partial_copy_nocheck(v.iov_base, | |
1207 | (to += v.iov_len) - v.iov_len, | |
1208 | v.iov_len, 0); | |
1209 | sum = csum_block_add(sum, next, off); | |
1210 | off += v.iov_len; | |
1211 | }) | |
1212 | ) | |
1213 | *csum = sum; | |
1214 | iov_iter_advance(i, bytes); | |
1215 | return true; | |
1216 | } | |
1217 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1218 | ||
36f7a8a4 | 1219 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, |
a604ec7e AV |
1220 | struct iov_iter *i) |
1221 | { | |
36f7a8a4 | 1222 | const char *from = addr; |
a604ec7e AV |
1223 | __wsum sum, next; |
1224 | size_t off = 0; | |
a604ec7e | 1225 | sum = *csum; |
241699cd AV |
1226 | if (unlikely(i->type & ITER_PIPE)) { |
1227 | WARN_ON(1); /* for now */ | |
1228 | return 0; | |
1229 | } | |
a604ec7e AV |
1230 | iterate_and_advance(i, bytes, v, ({ |
1231 | int err = 0; | |
1232 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
cbbd26b8 | 1233 | v.iov_base, |
a604ec7e AV |
1234 | v.iov_len, 0, &err); |
1235 | if (!err) { | |
1236 | sum = csum_block_add(sum, next, off); | |
1237 | off += v.iov_len; | |
1238 | } | |
1239 | err ? v.iov_len : 0; | |
1240 | }), ({ | |
1241 | char *p = kmap_atomic(v.bv_page); | |
1242 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
1243 | p + v.bv_offset, | |
1244 | v.bv_len, 0); | |
1245 | kunmap_atomic(p); | |
1246 | sum = csum_block_add(sum, next, off); | |
1247 | off += v.bv_len; | |
1248 | }),({ | |
1249 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
1250 | v.iov_base, | |
1251 | v.iov_len, 0); | |
1252 | sum = csum_block_add(sum, next, off); | |
1253 | off += v.iov_len; | |
1254 | }) | |
1255 | ) | |
1256 | *csum = sum; | |
1257 | return bytes; | |
1258 | } | |
1259 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1260 | ||
62a8067a AV |
1261 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1262 | { | |
e0f2dc40 AV |
1263 | size_t size = i->count; |
1264 | int npages = 0; | |
1265 | ||
1266 | if (!size) | |
1267 | return 0; | |
1268 | ||
241699cd AV |
1269 | if (unlikely(i->type & ITER_PIPE)) { |
1270 | struct pipe_inode_info *pipe = i->pipe; | |
1271 | size_t off; | |
1272 | int idx; | |
1273 | ||
1274 | if (!sanity(i)) | |
1275 | return 0; | |
1276 | ||
1277 | data_start(i, &idx, &off); | |
1278 | /* some of this one + all after this one */ | |
1279 | npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; | |
1280 | if (npages >= maxpages) | |
1281 | return maxpages; | |
1282 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1283 | unsigned long p = (unsigned long)v.iov_base; |
1284 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1285 | - p / PAGE_SIZE; | |
1286 | if (npages >= maxpages) | |
1287 | return maxpages; | |
1288 | 0;}),({ | |
1289 | npages++; | |
1290 | if (npages >= maxpages) | |
1291 | return maxpages; | |
a280455f AV |
1292 | }),({ |
1293 | unsigned long p = (unsigned long)v.iov_base; | |
1294 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1295 | - p / PAGE_SIZE; | |
1296 | if (npages >= maxpages) | |
1297 | return maxpages; | |
e0f2dc40 AV |
1298 | }) |
1299 | ) | |
1300 | return npages; | |
62a8067a | 1301 | } |
f67da30c | 1302 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1303 | |
1304 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1305 | { | |
1306 | *new = *old; | |
241699cd AV |
1307 | if (unlikely(new->type & ITER_PIPE)) { |
1308 | WARN_ON(1); | |
1309 | return NULL; | |
1310 | } | |
4b8164b9 AV |
1311 | if (new->type & ITER_BVEC) |
1312 | return new->bvec = kmemdup(new->bvec, | |
1313 | new->nr_segs * sizeof(struct bio_vec), | |
1314 | flags); | |
1315 | else | |
1316 | /* iovec and kvec have identical layout */ | |
1317 | return new->iov = kmemdup(new->iov, | |
1318 | new->nr_segs * sizeof(struct iovec), | |
1319 | flags); | |
1320 | } | |
1321 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1322 | |
ffecee4f VN |
1323 | /** |
1324 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1325 | * into the kernel, check that it is valid, and initialize a new | |
1326 | * &struct iov_iter iterator to access it. | |
1327 | * | |
1328 | * @type: One of %READ or %WRITE. | |
1329 | * @uvector: Pointer to the userspace array. | |
1330 | * @nr_segs: Number of elements in userspace array. | |
1331 | * @fast_segs: Number of elements in @iov. | |
1332 | * @iov: (input and output parameter) Pointer to pointer to (usually small | |
1333 | * on-stack) kernel array. | |
1334 | * @i: Pointer to iterator that will be initialized on success. | |
1335 | * | |
1336 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1337 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1338 | * array will be allocated and the result placed in *@iov. This means that | |
1339 | * the caller may call kfree() on *@iov regardless of whether the small | |
1340 | * on-stack array was used or not (and regardless of whether this function | |
1341 | * returns an error or not). | |
1342 | * | |
1343 | * Return: 0 on success or negative error code on error. | |
1344 | */ | |
bc917be8 AV |
1345 | int import_iovec(int type, const struct iovec __user * uvector, |
1346 | unsigned nr_segs, unsigned fast_segs, | |
1347 | struct iovec **iov, struct iov_iter *i) | |
1348 | { | |
1349 | ssize_t n; | |
1350 | struct iovec *p; | |
1351 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1352 | *iov, &p); | |
1353 | if (n < 0) { | |
1354 | if (p != *iov) | |
1355 | kfree(p); | |
1356 | *iov = NULL; | |
1357 | return n; | |
1358 | } | |
1359 | iov_iter_init(i, type, p, nr_segs, n); | |
1360 | *iov = p == *iov ? NULL : p; | |
1361 | return 0; | |
1362 | } | |
1363 | EXPORT_SYMBOL(import_iovec); | |
1364 | ||
1365 | #ifdef CONFIG_COMPAT | |
1366 | #include <linux/compat.h> | |
1367 | ||
1368 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
1369 | unsigned nr_segs, unsigned fast_segs, | |
1370 | struct iovec **iov, struct iov_iter *i) | |
1371 | { | |
1372 | ssize_t n; | |
1373 | struct iovec *p; | |
1374 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1375 | *iov, &p); | |
1376 | if (n < 0) { | |
1377 | if (p != *iov) | |
1378 | kfree(p); | |
1379 | *iov = NULL; | |
1380 | return n; | |
1381 | } | |
1382 | iov_iter_init(i, type, p, nr_segs, n); | |
1383 | *iov = p == *iov ? NULL : p; | |
1384 | return 0; | |
1385 | } | |
1386 | #endif | |
1387 | ||
1388 | int import_single_range(int rw, void __user *buf, size_t len, | |
1389 | struct iovec *iov, struct iov_iter *i) | |
1390 | { | |
1391 | if (len > MAX_RW_COUNT) | |
1392 | len = MAX_RW_COUNT; | |
1393 | if (unlikely(!access_ok(!rw, buf, len))) | |
1394 | return -EFAULT; | |
1395 | ||
1396 | iov->iov_base = buf; | |
1397 | iov->iov_len = len; | |
1398 | iov_iter_init(i, rw, iov, 1, len); | |
1399 | return 0; | |
1400 | } | |
e1267585 | 1401 | EXPORT_SYMBOL(import_single_range); |