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1 | #include <linux/export.h> | |
2 | #include <linux/bvec.h> | |
3 | #include <linux/uio.h> | |
4 | #include <linux/pagemap.h> | |
5 | #include <linux/slab.h> | |
6 | #include <linux/vmalloc.h> | |
7 | #include <linux/splice.h> | |
8 | #include <net/checksum.h> | |
9 | ||
10 | #define PIPE_PARANOIA /* for now */ | |
11 | ||
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 | ||
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 | ||
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) \ | |
70 | continue; \ | |
71 | (void)(STEP); \ | |
72 | } \ | |
73 | } | |
74 | ||
75 | #define iterate_all_kinds(i, n, v, I, B, K) { \ | |
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 | } \ | |
91 | } \ | |
92 | } | |
93 | ||
94 | #define iterate_and_advance(i, n, v, I, B, K) { \ | |
95 | if (unlikely(i->count < n)) \ | |
96 | n = i->count; \ | |
97 | if (i->count) { \ | |
98 | size_t skip = i->iov_offset; \ | |
99 | if (unlikely(i->type & ITER_BVEC)) { \ | |
100 | const struct bio_vec *bvec = i->bvec; \ | |
101 | struct bio_vec v; \ | |
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; \ | |
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; \ | |
127 | } \ | |
128 | i->count -= n; \ | |
129 | i->iov_offset = skip; \ | |
130 | } \ | |
131 | } | |
132 | ||
133 | static int copyout(void __user *to, const void *from, size_t n) | |
134 | { | |
135 | if (access_ok(VERIFY_WRITE, to, n)) { | |
136 | kasan_check_read(from, n); | |
137 | n = raw_copy_to_user(to, from, n); | |
138 | } | |
139 | return n; | |
140 | } | |
141 | ||
142 | static int copyin(void *to, const void __user *from, size_t n) | |
143 | { | |
144 | if (access_ok(VERIFY_READ, from, n)) { | |
145 | kasan_check_write(to, n); | |
146 | n = raw_copy_from_user(to, from, n); | |
147 | } | |
148 | return n; | |
149 | } | |
150 | ||
151 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, | |
152 | struct iov_iter *i) | |
153 | { | |
154 | size_t skip, copy, left, wanted; | |
155 | const struct iovec *iov; | |
156 | char __user *buf; | |
157 | void *kaddr, *from; | |
158 | ||
159 | if (unlikely(bytes > i->count)) | |
160 | bytes = i->count; | |
161 | ||
162 | if (unlikely(!bytes)) | |
163 | return 0; | |
164 | ||
165 | might_fault(); | |
166 | wanted = bytes; | |
167 | iov = i->iov; | |
168 | skip = i->iov_offset; | |
169 | buf = iov->iov_base + skip; | |
170 | copy = min(bytes, iov->iov_len - skip); | |
171 | ||
172 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { | |
173 | kaddr = kmap_atomic(page); | |
174 | from = kaddr + offset; | |
175 | ||
176 | /* first chunk, usually the only one */ | |
177 | left = copyout(buf, from, copy); | |
178 | copy -= left; | |
179 | skip += copy; | |
180 | from += copy; | |
181 | bytes -= copy; | |
182 | ||
183 | while (unlikely(!left && bytes)) { | |
184 | iov++; | |
185 | buf = iov->iov_base; | |
186 | copy = min(bytes, iov->iov_len); | |
187 | left = copyout(buf, from, copy); | |
188 | copy -= left; | |
189 | skip = copy; | |
190 | from += copy; | |
191 | bytes -= copy; | |
192 | } | |
193 | if (likely(!bytes)) { | |
194 | kunmap_atomic(kaddr); | |
195 | goto done; | |
196 | } | |
197 | offset = from - kaddr; | |
198 | buf += copy; | |
199 | kunmap_atomic(kaddr); | |
200 | copy = min(bytes, iov->iov_len - skip); | |
201 | } | |
202 | /* Too bad - revert to non-atomic kmap */ | |
203 | ||
204 | kaddr = kmap(page); | |
205 | from = kaddr + offset; | |
206 | left = copyout(buf, from, copy); | |
207 | copy -= left; | |
208 | skip += copy; | |
209 | from += copy; | |
210 | bytes -= copy; | |
211 | while (unlikely(!left && bytes)) { | |
212 | iov++; | |
213 | buf = iov->iov_base; | |
214 | copy = min(bytes, iov->iov_len); | |
215 | left = copyout(buf, from, copy); | |
216 | copy -= left; | |
217 | skip = copy; | |
218 | from += copy; | |
219 | bytes -= copy; | |
220 | } | |
221 | kunmap(page); | |
222 | ||
223 | done: | |
224 | if (skip == iov->iov_len) { | |
225 | iov++; | |
226 | skip = 0; | |
227 | } | |
228 | i->count -= wanted - bytes; | |
229 | i->nr_segs -= iov - i->iov; | |
230 | i->iov = iov; | |
231 | i->iov_offset = skip; | |
232 | return wanted - bytes; | |
233 | } | |
234 | ||
235 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, | |
236 | struct iov_iter *i) | |
237 | { | |
238 | size_t skip, copy, left, wanted; | |
239 | const struct iovec *iov; | |
240 | char __user *buf; | |
241 | void *kaddr, *to; | |
242 | ||
243 | if (unlikely(bytes > i->count)) | |
244 | bytes = i->count; | |
245 | ||
246 | if (unlikely(!bytes)) | |
247 | return 0; | |
248 | ||
249 | might_fault(); | |
250 | wanted = bytes; | |
251 | iov = i->iov; | |
252 | skip = i->iov_offset; | |
253 | buf = iov->iov_base + skip; | |
254 | copy = min(bytes, iov->iov_len - skip); | |
255 | ||
256 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { | |
257 | kaddr = kmap_atomic(page); | |
258 | to = kaddr + offset; | |
259 | ||
260 | /* first chunk, usually the only one */ | |
261 | left = copyin(to, buf, copy); | |
262 | copy -= left; | |
263 | skip += copy; | |
264 | to += copy; | |
265 | bytes -= copy; | |
266 | ||
267 | while (unlikely(!left && bytes)) { | |
268 | iov++; | |
269 | buf = iov->iov_base; | |
270 | copy = min(bytes, iov->iov_len); | |
271 | left = copyin(to, buf, copy); | |
272 | copy -= left; | |
273 | skip = copy; | |
274 | to += copy; | |
275 | bytes -= copy; | |
276 | } | |
277 | if (likely(!bytes)) { | |
278 | kunmap_atomic(kaddr); | |
279 | goto done; | |
280 | } | |
281 | offset = to - kaddr; | |
282 | buf += copy; | |
283 | kunmap_atomic(kaddr); | |
284 | copy = min(bytes, iov->iov_len - skip); | |
285 | } | |
286 | /* Too bad - revert to non-atomic kmap */ | |
287 | ||
288 | kaddr = kmap(page); | |
289 | to = kaddr + offset; | |
290 | left = copyin(to, buf, copy); | |
291 | copy -= left; | |
292 | skip += copy; | |
293 | to += copy; | |
294 | bytes -= copy; | |
295 | while (unlikely(!left && bytes)) { | |
296 | iov++; | |
297 | buf = iov->iov_base; | |
298 | copy = min(bytes, iov->iov_len); | |
299 | left = copyin(to, buf, copy); | |
300 | copy -= left; | |
301 | skip = copy; | |
302 | to += copy; | |
303 | bytes -= copy; | |
304 | } | |
305 | kunmap(page); | |
306 | ||
307 | done: | |
308 | if (skip == iov->iov_len) { | |
309 | iov++; | |
310 | skip = 0; | |
311 | } | |
312 | i->count -= wanted - bytes; | |
313 | i->nr_segs -= iov - i->iov; | |
314 | i->iov = iov; | |
315 | i->iov_offset = skip; | |
316 | return wanted - bytes; | |
317 | } | |
318 | ||
319 | #ifdef PIPE_PARANOIA | |
320 | static bool sanity(const struct iov_iter *i) | |
321 | { | |
322 | struct pipe_inode_info *pipe = i->pipe; | |
323 | int idx = i->idx; | |
324 | int next = pipe->curbuf + pipe->nrbufs; | |
325 | if (i->iov_offset) { | |
326 | struct pipe_buffer *p; | |
327 | if (unlikely(!pipe->nrbufs)) | |
328 | goto Bad; // pipe must be non-empty | |
329 | if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) | |
330 | goto Bad; // must be at the last buffer... | |
331 | ||
332 | p = &pipe->bufs[idx]; | |
333 | if (unlikely(p->offset + p->len != i->iov_offset)) | |
334 | goto Bad; // ... at the end of segment | |
335 | } else { | |
336 | if (idx != (next & (pipe->buffers - 1))) | |
337 | goto Bad; // must be right after the last buffer | |
338 | } | |
339 | return true; | |
340 | Bad: | |
341 | printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); | |
342 | printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", | |
343 | pipe->curbuf, pipe->nrbufs, pipe->buffers); | |
344 | for (idx = 0; idx < pipe->buffers; idx++) | |
345 | printk(KERN_ERR "[%p %p %d %d]\n", | |
346 | pipe->bufs[idx].ops, | |
347 | pipe->bufs[idx].page, | |
348 | pipe->bufs[idx].offset, | |
349 | pipe->bufs[idx].len); | |
350 | WARN_ON(1); | |
351 | return false; | |
352 | } | |
353 | #else | |
354 | #define sanity(i) true | |
355 | #endif | |
356 | ||
357 | static inline int next_idx(int idx, struct pipe_inode_info *pipe) | |
358 | { | |
359 | return (idx + 1) & (pipe->buffers - 1); | |
360 | } | |
361 | ||
362 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, | |
363 | struct iov_iter *i) | |
364 | { | |
365 | struct pipe_inode_info *pipe = i->pipe; | |
366 | struct pipe_buffer *buf; | |
367 | size_t off; | |
368 | int idx; | |
369 | ||
370 | if (unlikely(bytes > i->count)) | |
371 | bytes = i->count; | |
372 | ||
373 | if (unlikely(!bytes)) | |
374 | return 0; | |
375 | ||
376 | if (!sanity(i)) | |
377 | return 0; | |
378 | ||
379 | off = i->iov_offset; | |
380 | idx = i->idx; | |
381 | buf = &pipe->bufs[idx]; | |
382 | if (off) { | |
383 | if (offset == off && buf->page == page) { | |
384 | /* merge with the last one */ | |
385 | buf->len += bytes; | |
386 | i->iov_offset += bytes; | |
387 | goto out; | |
388 | } | |
389 | idx = next_idx(idx, pipe); | |
390 | buf = &pipe->bufs[idx]; | |
391 | } | |
392 | if (idx == pipe->curbuf && pipe->nrbufs) | |
393 | return 0; | |
394 | pipe->nrbufs++; | |
395 | buf->ops = &page_cache_pipe_buf_ops; | |
396 | get_page(buf->page = page); | |
397 | buf->offset = offset; | |
398 | buf->len = bytes; | |
399 | i->iov_offset = offset + bytes; | |
400 | i->idx = idx; | |
401 | out: | |
402 | i->count -= bytes; | |
403 | return bytes; | |
404 | } | |
405 | ||
406 | /* | |
407 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
408 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
409 | * | |
410 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
411 | * because it is an invalid address). | |
412 | */ | |
413 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) | |
414 | { | |
415 | size_t skip = i->iov_offset; | |
416 | const struct iovec *iov; | |
417 | int err; | |
418 | struct iovec v; | |
419 | ||
420 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
421 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
422 | err = fault_in_pages_readable(v.iov_base, v.iov_len); | |
423 | if (unlikely(err)) | |
424 | return err; | |
425 | 0;})) | |
426 | } | |
427 | return 0; | |
428 | } | |
429 | EXPORT_SYMBOL(iov_iter_fault_in_readable); | |
430 | ||
431 | void iov_iter_init(struct iov_iter *i, int direction, | |
432 | const struct iovec *iov, unsigned long nr_segs, | |
433 | size_t count) | |
434 | { | |
435 | /* It will get better. Eventually... */ | |
436 | if (uaccess_kernel()) { | |
437 | direction |= ITER_KVEC; | |
438 | i->type = direction; | |
439 | i->kvec = (struct kvec *)iov; | |
440 | } else { | |
441 | i->type = direction; | |
442 | i->iov = iov; | |
443 | } | |
444 | i->nr_segs = nr_segs; | |
445 | i->iov_offset = 0; | |
446 | i->count = count; | |
447 | } | |
448 | EXPORT_SYMBOL(iov_iter_init); | |
449 | ||
450 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) | |
451 | { | |
452 | char *from = kmap_atomic(page); | |
453 | memcpy(to, from + offset, len); | |
454 | kunmap_atomic(from); | |
455 | } | |
456 | ||
457 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) | |
458 | { | |
459 | char *to = kmap_atomic(page); | |
460 | memcpy(to + offset, from, len); | |
461 | kunmap_atomic(to); | |
462 | } | |
463 | ||
464 | static void memzero_page(struct page *page, size_t offset, size_t len) | |
465 | { | |
466 | char *addr = kmap_atomic(page); | |
467 | memset(addr + offset, 0, len); | |
468 | kunmap_atomic(addr); | |
469 | } | |
470 | ||
471 | static inline bool allocated(struct pipe_buffer *buf) | |
472 | { | |
473 | return buf->ops == &default_pipe_buf_ops; | |
474 | } | |
475 | ||
476 | static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) | |
477 | { | |
478 | size_t off = i->iov_offset; | |
479 | int idx = i->idx; | |
480 | if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { | |
481 | idx = next_idx(idx, i->pipe); | |
482 | off = 0; | |
483 | } | |
484 | *idxp = idx; | |
485 | *offp = off; | |
486 | } | |
487 | ||
488 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
489 | int *idxp, size_t *offp) | |
490 | { | |
491 | struct pipe_inode_info *pipe = i->pipe; | |
492 | size_t off; | |
493 | int idx; | |
494 | ssize_t left; | |
495 | ||
496 | if (unlikely(size > i->count)) | |
497 | size = i->count; | |
498 | if (unlikely(!size)) | |
499 | return 0; | |
500 | ||
501 | left = size; | |
502 | data_start(i, &idx, &off); | |
503 | *idxp = idx; | |
504 | *offp = off; | |
505 | if (off) { | |
506 | left -= PAGE_SIZE - off; | |
507 | if (left <= 0) { | |
508 | pipe->bufs[idx].len += size; | |
509 | return size; | |
510 | } | |
511 | pipe->bufs[idx].len = PAGE_SIZE; | |
512 | idx = next_idx(idx, pipe); | |
513 | } | |
514 | while (idx != pipe->curbuf || !pipe->nrbufs) { | |
515 | struct page *page = alloc_page(GFP_USER); | |
516 | if (!page) | |
517 | break; | |
518 | pipe->nrbufs++; | |
519 | pipe->bufs[idx].ops = &default_pipe_buf_ops; | |
520 | pipe->bufs[idx].page = page; | |
521 | pipe->bufs[idx].offset = 0; | |
522 | if (left <= PAGE_SIZE) { | |
523 | pipe->bufs[idx].len = left; | |
524 | return size; | |
525 | } | |
526 | pipe->bufs[idx].len = PAGE_SIZE; | |
527 | left -= PAGE_SIZE; | |
528 | idx = next_idx(idx, pipe); | |
529 | } | |
530 | return size - left; | |
531 | } | |
532 | ||
533 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
534 | struct iov_iter *i) | |
535 | { | |
536 | struct pipe_inode_info *pipe = i->pipe; | |
537 | size_t n, off; | |
538 | int idx; | |
539 | ||
540 | if (!sanity(i)) | |
541 | return 0; | |
542 | ||
543 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
544 | if (unlikely(!n)) | |
545 | return 0; | |
546 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
547 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
548 | memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); | |
549 | i->idx = idx; | |
550 | i->iov_offset = off + chunk; | |
551 | n -= chunk; | |
552 | addr += chunk; | |
553 | } | |
554 | i->count -= bytes; | |
555 | return bytes; | |
556 | } | |
557 | ||
558 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) | |
559 | { | |
560 | const char *from = addr; | |
561 | if (unlikely(i->type & ITER_PIPE)) | |
562 | return copy_pipe_to_iter(addr, bytes, i); | |
563 | if (iter_is_iovec(i)) | |
564 | might_fault(); | |
565 | iterate_and_advance(i, bytes, v, | |
566 | copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), | |
567 | memcpy_to_page(v.bv_page, v.bv_offset, | |
568 | (from += v.bv_len) - v.bv_len, v.bv_len), | |
569 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
570 | ) | |
571 | ||
572 | return bytes; | |
573 | } | |
574 | EXPORT_SYMBOL(_copy_to_iter); | |
575 | ||
576 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) | |
577 | { | |
578 | char *to = addr; | |
579 | if (unlikely(i->type & ITER_PIPE)) { | |
580 | WARN_ON(1); | |
581 | return 0; | |
582 | } | |
583 | if (iter_is_iovec(i)) | |
584 | might_fault(); | |
585 | iterate_and_advance(i, bytes, v, | |
586 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), | |
587 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
588 | v.bv_offset, v.bv_len), | |
589 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
590 | ) | |
591 | ||
592 | return bytes; | |
593 | } | |
594 | EXPORT_SYMBOL(_copy_from_iter); | |
595 | ||
596 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) | |
597 | { | |
598 | char *to = addr; | |
599 | if (unlikely(i->type & ITER_PIPE)) { | |
600 | WARN_ON(1); | |
601 | return false; | |
602 | } | |
603 | if (unlikely(i->count < bytes)) | |
604 | return false; | |
605 | ||
606 | if (iter_is_iovec(i)) | |
607 | might_fault(); | |
608 | iterate_all_kinds(i, bytes, v, ({ | |
609 | if (copyin((to += v.iov_len) - v.iov_len, | |
610 | v.iov_base, v.iov_len)) | |
611 | return false; | |
612 | 0;}), | |
613 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
614 | v.bv_offset, v.bv_len), | |
615 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
616 | ) | |
617 | ||
618 | iov_iter_advance(i, bytes); | |
619 | return true; | |
620 | } | |
621 | EXPORT_SYMBOL(_copy_from_iter_full); | |
622 | ||
623 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) | |
624 | { | |
625 | char *to = addr; | |
626 | if (unlikely(i->type & ITER_PIPE)) { | |
627 | WARN_ON(1); | |
628 | return 0; | |
629 | } | |
630 | iterate_and_advance(i, bytes, v, | |
631 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, | |
632 | v.iov_base, v.iov_len), | |
633 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
634 | v.bv_offset, v.bv_len), | |
635 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
636 | ) | |
637 | ||
638 | return bytes; | |
639 | } | |
640 | EXPORT_SYMBOL(_copy_from_iter_nocache); | |
641 | ||
642 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE | |
643 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) | |
644 | { | |
645 | char *to = addr; | |
646 | if (unlikely(i->type & ITER_PIPE)) { | |
647 | WARN_ON(1); | |
648 | return 0; | |
649 | } | |
650 | iterate_and_advance(i, bytes, v, | |
651 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
652 | v.iov_base, v.iov_len), | |
653 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
654 | v.bv_offset, v.bv_len), | |
655 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
656 | v.iov_len) | |
657 | ) | |
658 | ||
659 | return bytes; | |
660 | } | |
661 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); | |
662 | #endif | |
663 | ||
664 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) | |
665 | { | |
666 | char *to = addr; | |
667 | if (unlikely(i->type & ITER_PIPE)) { | |
668 | WARN_ON(1); | |
669 | return false; | |
670 | } | |
671 | if (unlikely(i->count < bytes)) | |
672 | return false; | |
673 | iterate_all_kinds(i, bytes, v, ({ | |
674 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, | |
675 | v.iov_base, v.iov_len)) | |
676 | return false; | |
677 | 0;}), | |
678 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
679 | v.bv_offset, v.bv_len), | |
680 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
681 | ) | |
682 | ||
683 | iov_iter_advance(i, bytes); | |
684 | return true; | |
685 | } | |
686 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); | |
687 | ||
688 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) | |
689 | { | |
690 | struct page *head = compound_head(page); | |
691 | size_t v = n + offset + page_address(page) - page_address(head); | |
692 | ||
693 | if (likely(n <= v && v <= (PAGE_SIZE << compound_order(head)))) | |
694 | return true; | |
695 | WARN_ON(1); | |
696 | return false; | |
697 | } | |
698 | ||
699 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, | |
700 | struct iov_iter *i) | |
701 | { | |
702 | if (unlikely(!page_copy_sane(page, offset, bytes))) | |
703 | return 0; | |
704 | if (i->type & (ITER_BVEC|ITER_KVEC)) { | |
705 | void *kaddr = kmap_atomic(page); | |
706 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
707 | kunmap_atomic(kaddr); | |
708 | return wanted; | |
709 | } else if (likely(!(i->type & ITER_PIPE))) | |
710 | return copy_page_to_iter_iovec(page, offset, bytes, i); | |
711 | else | |
712 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
713 | } | |
714 | EXPORT_SYMBOL(copy_page_to_iter); | |
715 | ||
716 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
717 | struct iov_iter *i) | |
718 | { | |
719 | if (unlikely(!page_copy_sane(page, offset, bytes))) | |
720 | return 0; | |
721 | if (unlikely(i->type & ITER_PIPE)) { | |
722 | WARN_ON(1); | |
723 | return 0; | |
724 | } | |
725 | if (i->type & (ITER_BVEC|ITER_KVEC)) { | |
726 | void *kaddr = kmap_atomic(page); | |
727 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); | |
728 | kunmap_atomic(kaddr); | |
729 | return wanted; | |
730 | } else | |
731 | return copy_page_from_iter_iovec(page, offset, bytes, i); | |
732 | } | |
733 | EXPORT_SYMBOL(copy_page_from_iter); | |
734 | ||
735 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) | |
736 | { | |
737 | struct pipe_inode_info *pipe = i->pipe; | |
738 | size_t n, off; | |
739 | int idx; | |
740 | ||
741 | if (!sanity(i)) | |
742 | return 0; | |
743 | ||
744 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
745 | if (unlikely(!n)) | |
746 | return 0; | |
747 | ||
748 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
749 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
750 | memzero_page(pipe->bufs[idx].page, off, chunk); | |
751 | i->idx = idx; | |
752 | i->iov_offset = off + chunk; | |
753 | n -= chunk; | |
754 | } | |
755 | i->count -= bytes; | |
756 | return bytes; | |
757 | } | |
758 | ||
759 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) | |
760 | { | |
761 | if (unlikely(i->type & ITER_PIPE)) | |
762 | return pipe_zero(bytes, i); | |
763 | iterate_and_advance(i, bytes, v, | |
764 | clear_user(v.iov_base, v.iov_len), | |
765 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), | |
766 | memset(v.iov_base, 0, v.iov_len) | |
767 | ) | |
768 | ||
769 | return bytes; | |
770 | } | |
771 | EXPORT_SYMBOL(iov_iter_zero); | |
772 | ||
773 | size_t iov_iter_copy_from_user_atomic(struct page *page, | |
774 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
775 | { | |
776 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; | |
777 | if (unlikely(!page_copy_sane(page, offset, bytes))) { | |
778 | kunmap_atomic(kaddr); | |
779 | return 0; | |
780 | } | |
781 | if (unlikely(i->type & ITER_PIPE)) { | |
782 | kunmap_atomic(kaddr); | |
783 | WARN_ON(1); | |
784 | return 0; | |
785 | } | |
786 | iterate_all_kinds(i, bytes, v, | |
787 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), | |
788 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, | |
789 | v.bv_offset, v.bv_len), | |
790 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
791 | ) | |
792 | kunmap_atomic(kaddr); | |
793 | return bytes; | |
794 | } | |
795 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
796 | ||
797 | static inline void pipe_truncate(struct iov_iter *i) | |
798 | { | |
799 | struct pipe_inode_info *pipe = i->pipe; | |
800 | if (pipe->nrbufs) { | |
801 | size_t off = i->iov_offset; | |
802 | int idx = i->idx; | |
803 | int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); | |
804 | if (off) { | |
805 | pipe->bufs[idx].len = off - pipe->bufs[idx].offset; | |
806 | idx = next_idx(idx, pipe); | |
807 | nrbufs++; | |
808 | } | |
809 | while (pipe->nrbufs > nrbufs) { | |
810 | pipe_buf_release(pipe, &pipe->bufs[idx]); | |
811 | idx = next_idx(idx, pipe); | |
812 | pipe->nrbufs--; | |
813 | } | |
814 | } | |
815 | } | |
816 | ||
817 | static void pipe_advance(struct iov_iter *i, size_t size) | |
818 | { | |
819 | struct pipe_inode_info *pipe = i->pipe; | |
820 | if (unlikely(i->count < size)) | |
821 | size = i->count; | |
822 | if (size) { | |
823 | struct pipe_buffer *buf; | |
824 | size_t off = i->iov_offset, left = size; | |
825 | int idx = i->idx; | |
826 | if (off) /* make it relative to the beginning of buffer */ | |
827 | left += off - pipe->bufs[idx].offset; | |
828 | while (1) { | |
829 | buf = &pipe->bufs[idx]; | |
830 | if (left <= buf->len) | |
831 | break; | |
832 | left -= buf->len; | |
833 | idx = next_idx(idx, pipe); | |
834 | } | |
835 | i->idx = idx; | |
836 | i->iov_offset = buf->offset + left; | |
837 | } | |
838 | i->count -= size; | |
839 | /* ... and discard everything past that point */ | |
840 | pipe_truncate(i); | |
841 | } | |
842 | ||
843 | void iov_iter_advance(struct iov_iter *i, size_t size) | |
844 | { | |
845 | if (unlikely(i->type & ITER_PIPE)) { | |
846 | pipe_advance(i, size); | |
847 | return; | |
848 | } | |
849 | iterate_and_advance(i, size, v, 0, 0, 0) | |
850 | } | |
851 | EXPORT_SYMBOL(iov_iter_advance); | |
852 | ||
853 | void iov_iter_revert(struct iov_iter *i, size_t unroll) | |
854 | { | |
855 | if (!unroll) | |
856 | return; | |
857 | if (WARN_ON(unroll > MAX_RW_COUNT)) | |
858 | return; | |
859 | i->count += unroll; | |
860 | if (unlikely(i->type & ITER_PIPE)) { | |
861 | struct pipe_inode_info *pipe = i->pipe; | |
862 | int idx = i->idx; | |
863 | size_t off = i->iov_offset; | |
864 | while (1) { | |
865 | size_t n = off - pipe->bufs[idx].offset; | |
866 | if (unroll < n) { | |
867 | off -= unroll; | |
868 | break; | |
869 | } | |
870 | unroll -= n; | |
871 | if (!unroll && idx == i->start_idx) { | |
872 | off = 0; | |
873 | break; | |
874 | } | |
875 | if (!idx--) | |
876 | idx = pipe->buffers - 1; | |
877 | off = pipe->bufs[idx].offset + pipe->bufs[idx].len; | |
878 | } | |
879 | i->iov_offset = off; | |
880 | i->idx = idx; | |
881 | pipe_truncate(i); | |
882 | return; | |
883 | } | |
884 | if (unroll <= i->iov_offset) { | |
885 | i->iov_offset -= unroll; | |
886 | return; | |
887 | } | |
888 | unroll -= i->iov_offset; | |
889 | if (i->type & ITER_BVEC) { | |
890 | const struct bio_vec *bvec = i->bvec; | |
891 | while (1) { | |
892 | size_t n = (--bvec)->bv_len; | |
893 | i->nr_segs++; | |
894 | if (unroll <= n) { | |
895 | i->bvec = bvec; | |
896 | i->iov_offset = n - unroll; | |
897 | return; | |
898 | } | |
899 | unroll -= n; | |
900 | } | |
901 | } else { /* same logics for iovec and kvec */ | |
902 | const struct iovec *iov = i->iov; | |
903 | while (1) { | |
904 | size_t n = (--iov)->iov_len; | |
905 | i->nr_segs++; | |
906 | if (unroll <= n) { | |
907 | i->iov = iov; | |
908 | i->iov_offset = n - unroll; | |
909 | return; | |
910 | } | |
911 | unroll -= n; | |
912 | } | |
913 | } | |
914 | } | |
915 | EXPORT_SYMBOL(iov_iter_revert); | |
916 | ||
917 | /* | |
918 | * Return the count of just the current iov_iter segment. | |
919 | */ | |
920 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
921 | { | |
922 | if (unlikely(i->type & ITER_PIPE)) | |
923 | return i->count; // it is a silly place, anyway | |
924 | if (i->nr_segs == 1) | |
925 | return i->count; | |
926 | else if (i->type & ITER_BVEC) | |
927 | return min(i->count, i->bvec->bv_len - i->iov_offset); | |
928 | else | |
929 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
930 | } | |
931 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
932 | ||
933 | void iov_iter_kvec(struct iov_iter *i, int direction, | |
934 | const struct kvec *kvec, unsigned long nr_segs, | |
935 | size_t count) | |
936 | { | |
937 | BUG_ON(!(direction & ITER_KVEC)); | |
938 | i->type = direction; | |
939 | i->kvec = kvec; | |
940 | i->nr_segs = nr_segs; | |
941 | i->iov_offset = 0; | |
942 | i->count = count; | |
943 | } | |
944 | EXPORT_SYMBOL(iov_iter_kvec); | |
945 | ||
946 | void iov_iter_bvec(struct iov_iter *i, int direction, | |
947 | const struct bio_vec *bvec, unsigned long nr_segs, | |
948 | size_t count) | |
949 | { | |
950 | BUG_ON(!(direction & ITER_BVEC)); | |
951 | i->type = direction; | |
952 | i->bvec = bvec; | |
953 | i->nr_segs = nr_segs; | |
954 | i->iov_offset = 0; | |
955 | i->count = count; | |
956 | } | |
957 | EXPORT_SYMBOL(iov_iter_bvec); | |
958 | ||
959 | void iov_iter_pipe(struct iov_iter *i, int direction, | |
960 | struct pipe_inode_info *pipe, | |
961 | size_t count) | |
962 | { | |
963 | BUG_ON(direction != ITER_PIPE); | |
964 | WARN_ON(pipe->nrbufs == pipe->buffers); | |
965 | i->type = direction; | |
966 | i->pipe = pipe; | |
967 | i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); | |
968 | i->iov_offset = 0; | |
969 | i->count = count; | |
970 | i->start_idx = i->idx; | |
971 | } | |
972 | EXPORT_SYMBOL(iov_iter_pipe); | |
973 | ||
974 | unsigned long iov_iter_alignment(const struct iov_iter *i) | |
975 | { | |
976 | unsigned long res = 0; | |
977 | size_t size = i->count; | |
978 | ||
979 | if (unlikely(i->type & ITER_PIPE)) { | |
980 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) | |
981 | return size | i->iov_offset; | |
982 | return size; | |
983 | } | |
984 | iterate_all_kinds(i, size, v, | |
985 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
986 | res |= v.bv_offset | v.bv_len, | |
987 | res |= (unsigned long)v.iov_base | v.iov_len | |
988 | ) | |
989 | return res; | |
990 | } | |
991 | EXPORT_SYMBOL(iov_iter_alignment); | |
992 | ||
993 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) | |
994 | { | |
995 | unsigned long res = 0; | |
996 | size_t size = i->count; | |
997 | ||
998 | if (unlikely(i->type & ITER_PIPE)) { | |
999 | WARN_ON(1); | |
1000 | return ~0U; | |
1001 | } | |
1002 | ||
1003 | iterate_all_kinds(i, size, v, | |
1004 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1005 | (size != v.iov_len ? size : 0), 0), | |
1006 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1007 | (size != v.bv_len ? size : 0)), | |
1008 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1009 | (size != v.iov_len ? size : 0)) | |
1010 | ); | |
1011 | return res; | |
1012 | } | |
1013 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1014 | ||
1015 | static inline size_t __pipe_get_pages(struct iov_iter *i, | |
1016 | size_t maxsize, | |
1017 | struct page **pages, | |
1018 | int idx, | |
1019 | size_t *start) | |
1020 | { | |
1021 | struct pipe_inode_info *pipe = i->pipe; | |
1022 | ssize_t n = push_pipe(i, maxsize, &idx, start); | |
1023 | if (!n) | |
1024 | return -EFAULT; | |
1025 | ||
1026 | maxsize = n; | |
1027 | n += *start; | |
1028 | while (n > 0) { | |
1029 | get_page(*pages++ = pipe->bufs[idx].page); | |
1030 | idx = next_idx(idx, pipe); | |
1031 | n -= PAGE_SIZE; | |
1032 | } | |
1033 | ||
1034 | return maxsize; | |
1035 | } | |
1036 | ||
1037 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1038 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1039 | size_t *start) | |
1040 | { | |
1041 | unsigned npages; | |
1042 | size_t capacity; | |
1043 | int idx; | |
1044 | ||
1045 | if (!maxsize) | |
1046 | return 0; | |
1047 | ||
1048 | if (!sanity(i)) | |
1049 | return -EFAULT; | |
1050 | ||
1051 | data_start(i, &idx, start); | |
1052 | /* some of this one + all after this one */ | |
1053 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
1054 | capacity = min(npages,maxpages) * PAGE_SIZE - *start; | |
1055 | ||
1056 | return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); | |
1057 | } | |
1058 | ||
1059 | ssize_t iov_iter_get_pages(struct iov_iter *i, | |
1060 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1061 | size_t *start) | |
1062 | { | |
1063 | if (maxsize > i->count) | |
1064 | maxsize = i->count; | |
1065 | ||
1066 | if (unlikely(i->type & ITER_PIPE)) | |
1067 | return pipe_get_pages(i, pages, maxsize, maxpages, start); | |
1068 | iterate_all_kinds(i, maxsize, v, ({ | |
1069 | unsigned long addr = (unsigned long)v.iov_base; | |
1070 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1071 | int n; | |
1072 | int res; | |
1073 | ||
1074 | if (len > maxpages * PAGE_SIZE) | |
1075 | len = maxpages * PAGE_SIZE; | |
1076 | addr &= ~(PAGE_SIZE - 1); | |
1077 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1078 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); | |
1079 | if (unlikely(res < 0)) | |
1080 | return res; | |
1081 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1082 | 0;}),({ | |
1083 | /* can't be more than PAGE_SIZE */ | |
1084 | *start = v.bv_offset; | |
1085 | get_page(*pages = v.bv_page); | |
1086 | return v.bv_len; | |
1087 | }),({ | |
1088 | return -EFAULT; | |
1089 | }) | |
1090 | ) | |
1091 | return 0; | |
1092 | } | |
1093 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1094 | ||
1095 | static struct page **get_pages_array(size_t n) | |
1096 | { | |
1097 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); | |
1098 | } | |
1099 | ||
1100 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, | |
1101 | struct page ***pages, size_t maxsize, | |
1102 | size_t *start) | |
1103 | { | |
1104 | struct page **p; | |
1105 | size_t n; | |
1106 | int idx; | |
1107 | int npages; | |
1108 | ||
1109 | if (!maxsize) | |
1110 | return 0; | |
1111 | ||
1112 | if (!sanity(i)) | |
1113 | return -EFAULT; | |
1114 | ||
1115 | data_start(i, &idx, start); | |
1116 | /* some of this one + all after this one */ | |
1117 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
1118 | n = npages * PAGE_SIZE - *start; | |
1119 | if (maxsize > n) | |
1120 | maxsize = n; | |
1121 | else | |
1122 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1123 | p = get_pages_array(npages); | |
1124 | if (!p) | |
1125 | return -ENOMEM; | |
1126 | n = __pipe_get_pages(i, maxsize, p, idx, start); | |
1127 | if (n > 0) | |
1128 | *pages = p; | |
1129 | else | |
1130 | kvfree(p); | |
1131 | return n; | |
1132 | } | |
1133 | ||
1134 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, | |
1135 | struct page ***pages, size_t maxsize, | |
1136 | size_t *start) | |
1137 | { | |
1138 | struct page **p; | |
1139 | ||
1140 | if (maxsize > i->count) | |
1141 | maxsize = i->count; | |
1142 | ||
1143 | if (unlikely(i->type & ITER_PIPE)) | |
1144 | return pipe_get_pages_alloc(i, pages, maxsize, start); | |
1145 | iterate_all_kinds(i, maxsize, v, ({ | |
1146 | unsigned long addr = (unsigned long)v.iov_base; | |
1147 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1148 | int n; | |
1149 | int res; | |
1150 | ||
1151 | addr &= ~(PAGE_SIZE - 1); | |
1152 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1153 | p = get_pages_array(n); | |
1154 | if (!p) | |
1155 | return -ENOMEM; | |
1156 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); | |
1157 | if (unlikely(res < 0)) { | |
1158 | kvfree(p); | |
1159 | return res; | |
1160 | } | |
1161 | *pages = p; | |
1162 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1163 | 0;}),({ | |
1164 | /* can't be more than PAGE_SIZE */ | |
1165 | *start = v.bv_offset; | |
1166 | *pages = p = get_pages_array(1); | |
1167 | if (!p) | |
1168 | return -ENOMEM; | |
1169 | get_page(*p = v.bv_page); | |
1170 | return v.bv_len; | |
1171 | }),({ | |
1172 | return -EFAULT; | |
1173 | }) | |
1174 | ) | |
1175 | return 0; | |
1176 | } | |
1177 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1178 | ||
1179 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, | |
1180 | struct iov_iter *i) | |
1181 | { | |
1182 | char *to = addr; | |
1183 | __wsum sum, next; | |
1184 | size_t off = 0; | |
1185 | sum = *csum; | |
1186 | if (unlikely(i->type & ITER_PIPE)) { | |
1187 | WARN_ON(1); | |
1188 | return 0; | |
1189 | } | |
1190 | iterate_and_advance(i, bytes, v, ({ | |
1191 | int err = 0; | |
1192 | next = csum_and_copy_from_user(v.iov_base, | |
1193 | (to += v.iov_len) - v.iov_len, | |
1194 | v.iov_len, 0, &err); | |
1195 | if (!err) { | |
1196 | sum = csum_block_add(sum, next, off); | |
1197 | off += v.iov_len; | |
1198 | } | |
1199 | err ? v.iov_len : 0; | |
1200 | }), ({ | |
1201 | char *p = kmap_atomic(v.bv_page); | |
1202 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
1203 | (to += v.bv_len) - v.bv_len, | |
1204 | v.bv_len, 0); | |
1205 | kunmap_atomic(p); | |
1206 | sum = csum_block_add(sum, next, off); | |
1207 | off += v.bv_len; | |
1208 | }),({ | |
1209 | next = csum_partial_copy_nocheck(v.iov_base, | |
1210 | (to += v.iov_len) - v.iov_len, | |
1211 | v.iov_len, 0); | |
1212 | sum = csum_block_add(sum, next, off); | |
1213 | off += v.iov_len; | |
1214 | }) | |
1215 | ) | |
1216 | *csum = sum; | |
1217 | return bytes; | |
1218 | } | |
1219 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1220 | ||
1221 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, | |
1222 | struct iov_iter *i) | |
1223 | { | |
1224 | char *to = addr; | |
1225 | __wsum sum, next; | |
1226 | size_t off = 0; | |
1227 | sum = *csum; | |
1228 | if (unlikely(i->type & ITER_PIPE)) { | |
1229 | WARN_ON(1); | |
1230 | return false; | |
1231 | } | |
1232 | if (unlikely(i->count < bytes)) | |
1233 | return false; | |
1234 | iterate_all_kinds(i, bytes, v, ({ | |
1235 | int err = 0; | |
1236 | next = csum_and_copy_from_user(v.iov_base, | |
1237 | (to += v.iov_len) - v.iov_len, | |
1238 | v.iov_len, 0, &err); | |
1239 | if (err) | |
1240 | return false; | |
1241 | sum = csum_block_add(sum, next, off); | |
1242 | off += v.iov_len; | |
1243 | 0; | |
1244 | }), ({ | |
1245 | char *p = kmap_atomic(v.bv_page); | |
1246 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
1247 | (to += v.bv_len) - v.bv_len, | |
1248 | v.bv_len, 0); | |
1249 | kunmap_atomic(p); | |
1250 | sum = csum_block_add(sum, next, off); | |
1251 | off += v.bv_len; | |
1252 | }),({ | |
1253 | next = csum_partial_copy_nocheck(v.iov_base, | |
1254 | (to += v.iov_len) - v.iov_len, | |
1255 | v.iov_len, 0); | |
1256 | sum = csum_block_add(sum, next, off); | |
1257 | off += v.iov_len; | |
1258 | }) | |
1259 | ) | |
1260 | *csum = sum; | |
1261 | iov_iter_advance(i, bytes); | |
1262 | return true; | |
1263 | } | |
1264 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1265 | ||
1266 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, | |
1267 | struct iov_iter *i) | |
1268 | { | |
1269 | const char *from = addr; | |
1270 | __wsum sum, next; | |
1271 | size_t off = 0; | |
1272 | sum = *csum; | |
1273 | if (unlikely(i->type & ITER_PIPE)) { | |
1274 | WARN_ON(1); /* for now */ | |
1275 | return 0; | |
1276 | } | |
1277 | iterate_and_advance(i, bytes, v, ({ | |
1278 | int err = 0; | |
1279 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
1280 | v.iov_base, | |
1281 | v.iov_len, 0, &err); | |
1282 | if (!err) { | |
1283 | sum = csum_block_add(sum, next, off); | |
1284 | off += v.iov_len; | |
1285 | } | |
1286 | err ? v.iov_len : 0; | |
1287 | }), ({ | |
1288 | char *p = kmap_atomic(v.bv_page); | |
1289 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
1290 | p + v.bv_offset, | |
1291 | v.bv_len, 0); | |
1292 | kunmap_atomic(p); | |
1293 | sum = csum_block_add(sum, next, off); | |
1294 | off += v.bv_len; | |
1295 | }),({ | |
1296 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
1297 | v.iov_base, | |
1298 | v.iov_len, 0); | |
1299 | sum = csum_block_add(sum, next, off); | |
1300 | off += v.iov_len; | |
1301 | }) | |
1302 | ) | |
1303 | *csum = sum; | |
1304 | return bytes; | |
1305 | } | |
1306 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1307 | ||
1308 | int iov_iter_npages(const struct iov_iter *i, int maxpages) | |
1309 | { | |
1310 | size_t size = i->count; | |
1311 | int npages = 0; | |
1312 | ||
1313 | if (!size) | |
1314 | return 0; | |
1315 | ||
1316 | if (unlikely(i->type & ITER_PIPE)) { | |
1317 | struct pipe_inode_info *pipe = i->pipe; | |
1318 | size_t off; | |
1319 | int idx; | |
1320 | ||
1321 | if (!sanity(i)) | |
1322 | return 0; | |
1323 | ||
1324 | data_start(i, &idx, &off); | |
1325 | /* some of this one + all after this one */ | |
1326 | npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; | |
1327 | if (npages >= maxpages) | |
1328 | return maxpages; | |
1329 | } else iterate_all_kinds(i, size, v, ({ | |
1330 | unsigned long p = (unsigned long)v.iov_base; | |
1331 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1332 | - p / PAGE_SIZE; | |
1333 | if (npages >= maxpages) | |
1334 | return maxpages; | |
1335 | 0;}),({ | |
1336 | npages++; | |
1337 | if (npages >= maxpages) | |
1338 | return maxpages; | |
1339 | }),({ | |
1340 | unsigned long p = (unsigned long)v.iov_base; | |
1341 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1342 | - p / PAGE_SIZE; | |
1343 | if (npages >= maxpages) | |
1344 | return maxpages; | |
1345 | }) | |
1346 | ) | |
1347 | return npages; | |
1348 | } | |
1349 | EXPORT_SYMBOL(iov_iter_npages); | |
1350 | ||
1351 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1352 | { | |
1353 | *new = *old; | |
1354 | if (unlikely(new->type & ITER_PIPE)) { | |
1355 | WARN_ON(1); | |
1356 | return NULL; | |
1357 | } | |
1358 | if (new->type & ITER_BVEC) | |
1359 | return new->bvec = kmemdup(new->bvec, | |
1360 | new->nr_segs * sizeof(struct bio_vec), | |
1361 | flags); | |
1362 | else | |
1363 | /* iovec and kvec have identical layout */ | |
1364 | return new->iov = kmemdup(new->iov, | |
1365 | new->nr_segs * sizeof(struct iovec), | |
1366 | flags); | |
1367 | } | |
1368 | EXPORT_SYMBOL(dup_iter); | |
1369 | ||
1370 | /** | |
1371 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1372 | * into the kernel, check that it is valid, and initialize a new | |
1373 | * &struct iov_iter iterator to access it. | |
1374 | * | |
1375 | * @type: One of %READ or %WRITE. | |
1376 | * @uvector: Pointer to the userspace array. | |
1377 | * @nr_segs: Number of elements in userspace array. | |
1378 | * @fast_segs: Number of elements in @iov. | |
1379 | * @iov: (input and output parameter) Pointer to pointer to (usually small | |
1380 | * on-stack) kernel array. | |
1381 | * @i: Pointer to iterator that will be initialized on success. | |
1382 | * | |
1383 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1384 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1385 | * array will be allocated and the result placed in *@iov. This means that | |
1386 | * the caller may call kfree() on *@iov regardless of whether the small | |
1387 | * on-stack array was used or not (and regardless of whether this function | |
1388 | * returns an error or not). | |
1389 | * | |
1390 | * Return: 0 on success or negative error code on error. | |
1391 | */ | |
1392 | int import_iovec(int type, const struct iovec __user * uvector, | |
1393 | unsigned nr_segs, unsigned fast_segs, | |
1394 | struct iovec **iov, struct iov_iter *i) | |
1395 | { | |
1396 | ssize_t n; | |
1397 | struct iovec *p; | |
1398 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1399 | *iov, &p); | |
1400 | if (n < 0) { | |
1401 | if (p != *iov) | |
1402 | kfree(p); | |
1403 | *iov = NULL; | |
1404 | return n; | |
1405 | } | |
1406 | iov_iter_init(i, type, p, nr_segs, n); | |
1407 | *iov = p == *iov ? NULL : p; | |
1408 | return 0; | |
1409 | } | |
1410 | EXPORT_SYMBOL(import_iovec); | |
1411 | ||
1412 | #ifdef CONFIG_COMPAT | |
1413 | #include <linux/compat.h> | |
1414 | ||
1415 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
1416 | unsigned nr_segs, unsigned fast_segs, | |
1417 | struct iovec **iov, struct iov_iter *i) | |
1418 | { | |
1419 | ssize_t n; | |
1420 | struct iovec *p; | |
1421 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1422 | *iov, &p); | |
1423 | if (n < 0) { | |
1424 | if (p != *iov) | |
1425 | kfree(p); | |
1426 | *iov = NULL; | |
1427 | return n; | |
1428 | } | |
1429 | iov_iter_init(i, type, p, nr_segs, n); | |
1430 | *iov = p == *iov ? NULL : p; | |
1431 | return 0; | |
1432 | } | |
1433 | #endif | |
1434 | ||
1435 | int import_single_range(int rw, void __user *buf, size_t len, | |
1436 | struct iovec *iov, struct iov_iter *i) | |
1437 | { | |
1438 | if (len > MAX_RW_COUNT) | |
1439 | len = MAX_RW_COUNT; | |
1440 | if (unlikely(!access_ok(!rw, buf, len))) | |
1441 | return -EFAULT; | |
1442 | ||
1443 | iov->iov_base = buf; | |
1444 | iov->iov_len = len; | |
1445 | iov_iter_init(i, rw, iov, 1, len); | |
1446 | return 0; | |
1447 | } | |
1448 | EXPORT_SYMBOL(import_single_range); | |
1449 | ||
1450 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1451 | int (*f)(struct kvec *vec, void *context), | |
1452 | void *context) | |
1453 | { | |
1454 | struct kvec w; | |
1455 | int err = -EINVAL; | |
1456 | if (!bytes) | |
1457 | return 0; | |
1458 | ||
1459 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1460 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1461 | w.iov_len = v.bv_len; | |
1462 | err = f(&w, context); | |
1463 | kunmap(v.bv_page); | |
1464 | err;}), ({ | |
1465 | w = v; | |
1466 | err = f(&w, context);}) | |
1467 | ) | |
1468 | return err; | |
1469 | } | |
1470 | EXPORT_SYMBOL(iov_iter_for_each_range); |