Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
4f18cd31 | 2 | #include <linux/export.h> |
2f8b5444 | 3 | #include <linux/bvec.h> |
4f18cd31 AV |
4 | #include <linux/uio.h> |
5 | #include <linux/pagemap.h> | |
91f79c43 AV |
6 | #include <linux/slab.h> |
7 | #include <linux/vmalloc.h> | |
241699cd | 8 | #include <linux/splice.h> |
a604ec7e | 9 | #include <net/checksum.h> |
d05f4435 | 10 | #include <linux/scatterlist.h> |
4f18cd31 | 11 | |
241699cd AV |
12 | #define PIPE_PARANOIA /* for now */ |
13 | ||
04a31165 AV |
14 | #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ |
15 | size_t left; \ | |
16 | size_t wanted = n; \ | |
17 | __p = i->iov; \ | |
18 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
19 | if (likely(__v.iov_len)) { \ | |
20 | __v.iov_base = __p->iov_base + skip; \ | |
21 | left = (STEP); \ | |
22 | __v.iov_len -= left; \ | |
23 | skip += __v.iov_len; \ | |
24 | n -= __v.iov_len; \ | |
25 | } else { \ | |
26 | left = 0; \ | |
27 | } \ | |
28 | while (unlikely(!left && n)) { \ | |
29 | __p++; \ | |
30 | __v.iov_len = min(n, __p->iov_len); \ | |
31 | if (unlikely(!__v.iov_len)) \ | |
32 | continue; \ | |
33 | __v.iov_base = __p->iov_base; \ | |
34 | left = (STEP); \ | |
35 | __v.iov_len -= left; \ | |
36 | skip = __v.iov_len; \ | |
37 | n -= __v.iov_len; \ | |
38 | } \ | |
39 | n = wanted - n; \ | |
40 | } | |
41 | ||
a280455f AV |
42 | #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ |
43 | size_t wanted = n; \ | |
44 | __p = i->kvec; \ | |
45 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
46 | if (likely(__v.iov_len)) { \ | |
47 | __v.iov_base = __p->iov_base + skip; \ | |
48 | (void)(STEP); \ | |
49 | skip += __v.iov_len; \ | |
50 | n -= __v.iov_len; \ | |
51 | } \ | |
52 | while (unlikely(n)) { \ | |
53 | __p++; \ | |
54 | __v.iov_len = min(n, __p->iov_len); \ | |
55 | if (unlikely(!__v.iov_len)) \ | |
56 | continue; \ | |
57 | __v.iov_base = __p->iov_base; \ | |
58 | (void)(STEP); \ | |
59 | skip = __v.iov_len; \ | |
60 | n -= __v.iov_len; \ | |
61 | } \ | |
62 | n = wanted; \ | |
63 | } | |
64 | ||
1bdc76ae ML |
65 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ |
66 | struct bvec_iter __start; \ | |
67 | __start.bi_size = n; \ | |
68 | __start.bi_bvec_done = skip; \ | |
69 | __start.bi_idx = 0; \ | |
70 | for_each_bvec(__v, i->bvec, __bi, __start) { \ | |
71 | if (!__v.bv_len) \ | |
04a31165 | 72 | continue; \ |
04a31165 | 73 | (void)(STEP); \ |
04a31165 | 74 | } \ |
04a31165 AV |
75 | } |
76 | ||
a280455f | 77 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
33844e66 AV |
78 | if (likely(n)) { \ |
79 | size_t skip = i->iov_offset; \ | |
80 | if (unlikely(i->type & ITER_BVEC)) { \ | |
81 | struct bio_vec v; \ | |
82 | struct bvec_iter __bi; \ | |
83 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
84 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
85 | const struct kvec *kvec; \ | |
86 | struct kvec v; \ | |
87 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
9ea9ce04 | 88 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
33844e66 AV |
89 | } else { \ |
90 | const struct iovec *iov; \ | |
91 | struct iovec v; \ | |
92 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
93 | } \ | |
04a31165 AV |
94 | } \ |
95 | } | |
96 | ||
a280455f | 97 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
98 | if (unlikely(i->count < n)) \ |
99 | n = i->count; \ | |
19f18459 | 100 | if (i->count) { \ |
dd254f5a AV |
101 | size_t skip = i->iov_offset; \ |
102 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 103 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 104 | struct bio_vec v; \ |
1bdc76ae ML |
105 | struct bvec_iter __bi; \ |
106 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
107 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
108 | i->nr_segs -= i->bvec - bvec; \ | |
109 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
110 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
111 | const struct kvec *kvec; \ | |
112 | struct kvec v; \ | |
113 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
114 | if (skip == kvec->iov_len) { \ | |
115 | kvec++; \ | |
116 | skip = 0; \ | |
117 | } \ | |
118 | i->nr_segs -= kvec - i->kvec; \ | |
119 | i->kvec = kvec; \ | |
9ea9ce04 DH |
120 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
121 | skip += n; \ | |
dd254f5a AV |
122 | } else { \ |
123 | const struct iovec *iov; \ | |
124 | struct iovec v; \ | |
125 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
126 | if (skip == iov->iov_len) { \ | |
127 | iov++; \ | |
128 | skip = 0; \ | |
129 | } \ | |
130 | i->nr_segs -= iov - i->iov; \ | |
131 | i->iov = iov; \ | |
7ce2a91e | 132 | } \ |
dd254f5a AV |
133 | i->count -= n; \ |
134 | i->iov_offset = skip; \ | |
7ce2a91e | 135 | } \ |
7ce2a91e AV |
136 | } |
137 | ||
09fc68dc AV |
138 | static int copyout(void __user *to, const void *from, size_t n) |
139 | { | |
96d4f267 | 140 | if (access_ok(to, n)) { |
09fc68dc AV |
141 | kasan_check_read(from, n); |
142 | n = raw_copy_to_user(to, from, n); | |
143 | } | |
144 | return n; | |
145 | } | |
146 | ||
147 | static int copyin(void *to, const void __user *from, size_t n) | |
148 | { | |
96d4f267 | 149 | if (access_ok(from, n)) { |
09fc68dc AV |
150 | kasan_check_write(to, n); |
151 | n = raw_copy_from_user(to, from, n); | |
152 | } | |
153 | return n; | |
154 | } | |
155 | ||
62a8067a | 156 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
157 | struct iov_iter *i) |
158 | { | |
159 | size_t skip, copy, left, wanted; | |
160 | const struct iovec *iov; | |
161 | char __user *buf; | |
162 | void *kaddr, *from; | |
163 | ||
164 | if (unlikely(bytes > i->count)) | |
165 | bytes = i->count; | |
166 | ||
167 | if (unlikely(!bytes)) | |
168 | return 0; | |
169 | ||
09fc68dc | 170 | might_fault(); |
4f18cd31 AV |
171 | wanted = bytes; |
172 | iov = i->iov; | |
173 | skip = i->iov_offset; | |
174 | buf = iov->iov_base + skip; | |
175 | copy = min(bytes, iov->iov_len - skip); | |
176 | ||
3fa6c507 | 177 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
178 | kaddr = kmap_atomic(page); |
179 | from = kaddr + offset; | |
180 | ||
181 | /* first chunk, usually the only one */ | |
09fc68dc | 182 | left = copyout(buf, from, copy); |
4f18cd31 AV |
183 | copy -= left; |
184 | skip += copy; | |
185 | from += copy; | |
186 | bytes -= copy; | |
187 | ||
188 | while (unlikely(!left && bytes)) { | |
189 | iov++; | |
190 | buf = iov->iov_base; | |
191 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 192 | left = copyout(buf, from, copy); |
4f18cd31 AV |
193 | copy -= left; |
194 | skip = copy; | |
195 | from += copy; | |
196 | bytes -= copy; | |
197 | } | |
198 | if (likely(!bytes)) { | |
199 | kunmap_atomic(kaddr); | |
200 | goto done; | |
201 | } | |
202 | offset = from - kaddr; | |
203 | buf += copy; | |
204 | kunmap_atomic(kaddr); | |
205 | copy = min(bytes, iov->iov_len - skip); | |
206 | } | |
207 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 208 | |
4f18cd31 AV |
209 | kaddr = kmap(page); |
210 | from = kaddr + offset; | |
09fc68dc | 211 | left = copyout(buf, from, copy); |
4f18cd31 AV |
212 | copy -= left; |
213 | skip += copy; | |
214 | from += copy; | |
215 | bytes -= copy; | |
216 | while (unlikely(!left && bytes)) { | |
217 | iov++; | |
218 | buf = iov->iov_base; | |
219 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 220 | left = copyout(buf, from, copy); |
4f18cd31 AV |
221 | copy -= left; |
222 | skip = copy; | |
223 | from += copy; | |
224 | bytes -= copy; | |
225 | } | |
226 | kunmap(page); | |
3fa6c507 | 227 | |
4f18cd31 | 228 | done: |
81055e58 AV |
229 | if (skip == iov->iov_len) { |
230 | iov++; | |
231 | skip = 0; | |
232 | } | |
4f18cd31 AV |
233 | i->count -= wanted - bytes; |
234 | i->nr_segs -= iov - i->iov; | |
235 | i->iov = iov; | |
236 | i->iov_offset = skip; | |
237 | return wanted - bytes; | |
238 | } | |
4f18cd31 | 239 | |
62a8067a | 240 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
241 | struct iov_iter *i) |
242 | { | |
243 | size_t skip, copy, left, wanted; | |
244 | const struct iovec *iov; | |
245 | char __user *buf; | |
246 | void *kaddr, *to; | |
247 | ||
248 | if (unlikely(bytes > i->count)) | |
249 | bytes = i->count; | |
250 | ||
251 | if (unlikely(!bytes)) | |
252 | return 0; | |
253 | ||
09fc68dc | 254 | might_fault(); |
f0d1bec9 AV |
255 | wanted = bytes; |
256 | iov = i->iov; | |
257 | skip = i->iov_offset; | |
258 | buf = iov->iov_base + skip; | |
259 | copy = min(bytes, iov->iov_len - skip); | |
260 | ||
3fa6c507 | 261 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
262 | kaddr = kmap_atomic(page); |
263 | to = kaddr + offset; | |
264 | ||
265 | /* first chunk, usually the only one */ | |
09fc68dc | 266 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
267 | copy -= left; |
268 | skip += copy; | |
269 | to += copy; | |
270 | bytes -= copy; | |
271 | ||
272 | while (unlikely(!left && bytes)) { | |
273 | iov++; | |
274 | buf = iov->iov_base; | |
275 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 276 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
277 | copy -= left; |
278 | skip = copy; | |
279 | to += copy; | |
280 | bytes -= copy; | |
281 | } | |
282 | if (likely(!bytes)) { | |
283 | kunmap_atomic(kaddr); | |
284 | goto done; | |
285 | } | |
286 | offset = to - kaddr; | |
287 | buf += copy; | |
288 | kunmap_atomic(kaddr); | |
289 | copy = min(bytes, iov->iov_len - skip); | |
290 | } | |
291 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 292 | |
f0d1bec9 AV |
293 | kaddr = kmap(page); |
294 | to = kaddr + offset; | |
09fc68dc | 295 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
296 | copy -= left; |
297 | skip += copy; | |
298 | to += copy; | |
299 | bytes -= copy; | |
300 | while (unlikely(!left && bytes)) { | |
301 | iov++; | |
302 | buf = iov->iov_base; | |
303 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 304 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
305 | copy -= left; |
306 | skip = copy; | |
307 | to += copy; | |
308 | bytes -= copy; | |
309 | } | |
310 | kunmap(page); | |
3fa6c507 | 311 | |
f0d1bec9 | 312 | done: |
81055e58 AV |
313 | if (skip == iov->iov_len) { |
314 | iov++; | |
315 | skip = 0; | |
316 | } | |
f0d1bec9 AV |
317 | i->count -= wanted - bytes; |
318 | i->nr_segs -= iov - i->iov; | |
319 | i->iov = iov; | |
320 | i->iov_offset = skip; | |
321 | return wanted - bytes; | |
322 | } | |
f0d1bec9 | 323 | |
241699cd AV |
324 | #ifdef PIPE_PARANOIA |
325 | static bool sanity(const struct iov_iter *i) | |
326 | { | |
327 | struct pipe_inode_info *pipe = i->pipe; | |
328 | int idx = i->idx; | |
329 | int next = pipe->curbuf + pipe->nrbufs; | |
330 | if (i->iov_offset) { | |
331 | struct pipe_buffer *p; | |
332 | if (unlikely(!pipe->nrbufs)) | |
333 | goto Bad; // pipe must be non-empty | |
334 | if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) | |
335 | goto Bad; // must be at the last buffer... | |
336 | ||
337 | p = &pipe->bufs[idx]; | |
338 | if (unlikely(p->offset + p->len != i->iov_offset)) | |
339 | goto Bad; // ... at the end of segment | |
340 | } else { | |
341 | if (idx != (next & (pipe->buffers - 1))) | |
342 | goto Bad; // must be right after the last buffer | |
343 | } | |
344 | return true; | |
345 | Bad: | |
346 | printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); | |
347 | printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", | |
348 | pipe->curbuf, pipe->nrbufs, pipe->buffers); | |
349 | for (idx = 0; idx < pipe->buffers; idx++) | |
350 | printk(KERN_ERR "[%p %p %d %d]\n", | |
351 | pipe->bufs[idx].ops, | |
352 | pipe->bufs[idx].page, | |
353 | pipe->bufs[idx].offset, | |
354 | pipe->bufs[idx].len); | |
355 | WARN_ON(1); | |
356 | return false; | |
357 | } | |
358 | #else | |
359 | #define sanity(i) true | |
360 | #endif | |
361 | ||
362 | static inline int next_idx(int idx, struct pipe_inode_info *pipe) | |
363 | { | |
364 | return (idx + 1) & (pipe->buffers - 1); | |
365 | } | |
366 | ||
367 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, | |
368 | struct iov_iter *i) | |
369 | { | |
370 | struct pipe_inode_info *pipe = i->pipe; | |
371 | struct pipe_buffer *buf; | |
372 | size_t off; | |
373 | int idx; | |
374 | ||
375 | if (unlikely(bytes > i->count)) | |
376 | bytes = i->count; | |
377 | ||
378 | if (unlikely(!bytes)) | |
379 | return 0; | |
380 | ||
381 | if (!sanity(i)) | |
382 | return 0; | |
383 | ||
384 | off = i->iov_offset; | |
385 | idx = i->idx; | |
386 | buf = &pipe->bufs[idx]; | |
387 | if (off) { | |
388 | if (offset == off && buf->page == page) { | |
389 | /* merge with the last one */ | |
390 | buf->len += bytes; | |
391 | i->iov_offset += bytes; | |
392 | goto out; | |
393 | } | |
394 | idx = next_idx(idx, pipe); | |
395 | buf = &pipe->bufs[idx]; | |
396 | } | |
397 | if (idx == pipe->curbuf && pipe->nrbufs) | |
398 | return 0; | |
399 | pipe->nrbufs++; | |
400 | buf->ops = &page_cache_pipe_buf_ops; | |
401 | get_page(buf->page = page); | |
402 | buf->offset = offset; | |
403 | buf->len = bytes; | |
404 | i->iov_offset = offset + bytes; | |
405 | i->idx = idx; | |
406 | out: | |
407 | i->count -= bytes; | |
408 | return bytes; | |
409 | } | |
410 | ||
171a0203 AA |
411 | /* |
412 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
413 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
414 | * | |
415 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
416 | * because it is an invalid address). | |
417 | */ | |
d4690f1e | 418 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
419 | { |
420 | size_t skip = i->iov_offset; | |
421 | const struct iovec *iov; | |
422 | int err; | |
423 | struct iovec v; | |
424 | ||
425 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
426 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
4bce9f6e | 427 | err = fault_in_pages_readable(v.iov_base, v.iov_len); |
171a0203 AA |
428 | if (unlikely(err)) |
429 | return err; | |
430 | 0;})) | |
431 | } | |
432 | return 0; | |
433 | } | |
d4690f1e | 434 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 435 | |
aa563d7b | 436 | void iov_iter_init(struct iov_iter *i, unsigned int direction, |
71d8e532 AV |
437 | const struct iovec *iov, unsigned long nr_segs, |
438 | size_t count) | |
439 | { | |
aa563d7b DH |
440 | WARN_ON(direction & ~(READ | WRITE)); |
441 | direction &= READ | WRITE; | |
442 | ||
71d8e532 | 443 | /* It will get better. Eventually... */ |
db68ce10 | 444 | if (uaccess_kernel()) { |
aa563d7b | 445 | i->type = ITER_KVEC | direction; |
a280455f AV |
446 | i->kvec = (struct kvec *)iov; |
447 | } else { | |
aa563d7b | 448 | i->type = ITER_IOVEC | direction; |
a280455f AV |
449 | i->iov = iov; |
450 | } | |
71d8e532 AV |
451 | i->nr_segs = nr_segs; |
452 | i->iov_offset = 0; | |
453 | i->count = count; | |
454 | } | |
455 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 456 | |
62a8067a AV |
457 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
458 | { | |
459 | char *from = kmap_atomic(page); | |
460 | memcpy(to, from + offset, len); | |
461 | kunmap_atomic(from); | |
462 | } | |
463 | ||
36f7a8a4 | 464 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
465 | { |
466 | char *to = kmap_atomic(page); | |
467 | memcpy(to + offset, from, len); | |
468 | kunmap_atomic(to); | |
469 | } | |
470 | ||
c35e0248 MW |
471 | static void memzero_page(struct page *page, size_t offset, size_t len) |
472 | { | |
473 | char *addr = kmap_atomic(page); | |
474 | memset(addr + offset, 0, len); | |
475 | kunmap_atomic(addr); | |
476 | } | |
477 | ||
241699cd AV |
478 | static inline bool allocated(struct pipe_buffer *buf) |
479 | { | |
480 | return buf->ops == &default_pipe_buf_ops; | |
481 | } | |
482 | ||
483 | static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) | |
484 | { | |
485 | size_t off = i->iov_offset; | |
486 | int idx = i->idx; | |
487 | if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { | |
488 | idx = next_idx(idx, i->pipe); | |
489 | off = 0; | |
490 | } | |
491 | *idxp = idx; | |
492 | *offp = off; | |
493 | } | |
494 | ||
495 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
496 | int *idxp, size_t *offp) | |
497 | { | |
498 | struct pipe_inode_info *pipe = i->pipe; | |
499 | size_t off; | |
500 | int idx; | |
501 | ssize_t left; | |
502 | ||
503 | if (unlikely(size > i->count)) | |
504 | size = i->count; | |
505 | if (unlikely(!size)) | |
506 | return 0; | |
507 | ||
508 | left = size; | |
509 | data_start(i, &idx, &off); | |
510 | *idxp = idx; | |
511 | *offp = off; | |
512 | if (off) { | |
513 | left -= PAGE_SIZE - off; | |
514 | if (left <= 0) { | |
515 | pipe->bufs[idx].len += size; | |
516 | return size; | |
517 | } | |
518 | pipe->bufs[idx].len = PAGE_SIZE; | |
519 | idx = next_idx(idx, pipe); | |
520 | } | |
521 | while (idx != pipe->curbuf || !pipe->nrbufs) { | |
522 | struct page *page = alloc_page(GFP_USER); | |
523 | if (!page) | |
524 | break; | |
525 | pipe->nrbufs++; | |
526 | pipe->bufs[idx].ops = &default_pipe_buf_ops; | |
527 | pipe->bufs[idx].page = page; | |
528 | pipe->bufs[idx].offset = 0; | |
529 | if (left <= PAGE_SIZE) { | |
530 | pipe->bufs[idx].len = left; | |
531 | return size; | |
532 | } | |
533 | pipe->bufs[idx].len = PAGE_SIZE; | |
534 | left -= PAGE_SIZE; | |
535 | idx = next_idx(idx, pipe); | |
536 | } | |
537 | return size - left; | |
538 | } | |
539 | ||
540 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
541 | struct iov_iter *i) | |
542 | { | |
543 | struct pipe_inode_info *pipe = i->pipe; | |
544 | size_t n, off; | |
545 | int idx; | |
546 | ||
547 | if (!sanity(i)) | |
548 | return 0; | |
549 | ||
550 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
551 | if (unlikely(!n)) | |
552 | return 0; | |
553 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
554 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
555 | memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); | |
556 | i->idx = idx; | |
557 | i->iov_offset = off + chunk; | |
558 | n -= chunk; | |
559 | addr += chunk; | |
560 | } | |
561 | i->count -= bytes; | |
562 | return bytes; | |
563 | } | |
564 | ||
f9152895 AV |
565 | static __wsum csum_and_memcpy(void *to, const void *from, size_t len, |
566 | __wsum sum, size_t off) | |
567 | { | |
568 | __wsum next = csum_partial_copy_nocheck(from, to, len, 0); | |
569 | return csum_block_add(sum, next, off); | |
570 | } | |
571 | ||
78e1f386 AV |
572 | static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, |
573 | __wsum *csum, struct iov_iter *i) | |
574 | { | |
575 | struct pipe_inode_info *pipe = i->pipe; | |
576 | size_t n, r; | |
577 | size_t off = 0; | |
f9152895 | 578 | __wsum sum = *csum; |
78e1f386 AV |
579 | int idx; |
580 | ||
581 | if (!sanity(i)) | |
582 | return 0; | |
583 | ||
584 | bytes = n = push_pipe(i, bytes, &idx, &r); | |
585 | if (unlikely(!n)) | |
586 | return 0; | |
587 | for ( ; n; idx = next_idx(idx, pipe), r = 0) { | |
588 | size_t chunk = min_t(size_t, n, PAGE_SIZE - r); | |
589 | char *p = kmap_atomic(pipe->bufs[idx].page); | |
f9152895 | 590 | sum = csum_and_memcpy(p + r, addr, chunk, sum, off); |
78e1f386 AV |
591 | kunmap_atomic(p); |
592 | i->idx = idx; | |
593 | i->iov_offset = r + chunk; | |
594 | n -= chunk; | |
595 | off += chunk; | |
596 | addr += chunk; | |
597 | } | |
598 | i->count -= bytes; | |
599 | *csum = sum; | |
600 | return bytes; | |
601 | } | |
602 | ||
aa28de27 | 603 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 604 | { |
36f7a8a4 | 605 | const char *from = addr; |
00e23707 | 606 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 607 | return copy_pipe_to_iter(addr, bytes, i); |
09fc68dc AV |
608 | if (iter_is_iovec(i)) |
609 | might_fault(); | |
3d4d3e48 | 610 | iterate_and_advance(i, bytes, v, |
09fc68dc | 611 | copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
3d4d3e48 | 612 | memcpy_to_page(v.bv_page, v.bv_offset, |
a280455f AV |
613 | (from += v.bv_len) - v.bv_len, v.bv_len), |
614 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 615 | ) |
62a8067a | 616 | |
3d4d3e48 | 617 | return bytes; |
c35e0248 | 618 | } |
aa28de27 | 619 | EXPORT_SYMBOL(_copy_to_iter); |
c35e0248 | 620 | |
8780356e DW |
621 | #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE |
622 | static int copyout_mcsafe(void __user *to, const void *from, size_t n) | |
623 | { | |
96d4f267 | 624 | if (access_ok(to, n)) { |
8780356e DW |
625 | kasan_check_read(from, n); |
626 | n = copy_to_user_mcsafe((__force void *) to, from, n); | |
627 | } | |
628 | return n; | |
629 | } | |
630 | ||
631 | static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, | |
632 | const char *from, size_t len) | |
633 | { | |
634 | unsigned long ret; | |
635 | char *to; | |
636 | ||
637 | to = kmap_atomic(page); | |
638 | ret = memcpy_mcsafe(to + offset, from, len); | |
639 | kunmap_atomic(to); | |
640 | ||
641 | return ret; | |
642 | } | |
643 | ||
ca146f6f DW |
644 | static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, |
645 | struct iov_iter *i) | |
646 | { | |
647 | struct pipe_inode_info *pipe = i->pipe; | |
648 | size_t n, off, xfer = 0; | |
649 | int idx; | |
650 | ||
651 | if (!sanity(i)) | |
652 | return 0; | |
653 | ||
654 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
655 | if (unlikely(!n)) | |
656 | return 0; | |
657 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
658 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
659 | unsigned long rem; | |
660 | ||
661 | rem = memcpy_mcsafe_to_page(pipe->bufs[idx].page, off, addr, | |
662 | chunk); | |
663 | i->idx = idx; | |
664 | i->iov_offset = off + chunk - rem; | |
665 | xfer += chunk - rem; | |
666 | if (rem) | |
667 | break; | |
668 | n -= chunk; | |
669 | addr += chunk; | |
670 | } | |
671 | i->count -= xfer; | |
672 | return xfer; | |
673 | } | |
674 | ||
bf3eeb9b DW |
675 | /** |
676 | * _copy_to_iter_mcsafe - copy to user with source-read error exception handling | |
677 | * @addr: source kernel address | |
678 | * @bytes: total transfer length | |
679 | * @iter: destination iterator | |
680 | * | |
681 | * The pmem driver arranges for filesystem-dax to use this facility via | |
682 | * dax_copy_to_iter() for protecting read/write to persistent memory. | |
683 | * Unless / until an architecture can guarantee identical performance | |
684 | * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a | |
685 | * performance regression to switch more users to the mcsafe version. | |
686 | * | |
687 | * Otherwise, the main differences between this and typical _copy_to_iter(). | |
688 | * | |
689 | * * Typical tail/residue handling after a fault retries the copy | |
690 | * byte-by-byte until the fault happens again. Re-triggering machine | |
691 | * checks is potentially fatal so the implementation uses source | |
692 | * alignment and poison alignment assumptions to avoid re-triggering | |
693 | * hardware exceptions. | |
694 | * | |
695 | * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. | |
696 | * Compare to copy_to_iter() where only ITER_IOVEC attempts might return | |
697 | * a short copy. | |
698 | * | |
699 | * See MCSAFE_TEST for self-test. | |
700 | */ | |
8780356e DW |
701 | size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) |
702 | { | |
703 | const char *from = addr; | |
704 | unsigned long rem, curr_addr, s_addr = (unsigned long) addr; | |
705 | ||
00e23707 | 706 | if (unlikely(iov_iter_is_pipe(i))) |
ca146f6f | 707 | return copy_pipe_to_iter_mcsafe(addr, bytes, i); |
8780356e DW |
708 | if (iter_is_iovec(i)) |
709 | might_fault(); | |
710 | iterate_and_advance(i, bytes, v, | |
711 | copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), | |
712 | ({ | |
713 | rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, | |
714 | (from += v.bv_len) - v.bv_len, v.bv_len); | |
715 | if (rem) { | |
716 | curr_addr = (unsigned long) from; | |
717 | bytes = curr_addr - s_addr - rem; | |
718 | return bytes; | |
719 | } | |
720 | }), | |
721 | ({ | |
722 | rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, | |
723 | v.iov_len); | |
724 | if (rem) { | |
725 | curr_addr = (unsigned long) from; | |
726 | bytes = curr_addr - s_addr - rem; | |
727 | return bytes; | |
728 | } | |
729 | }) | |
730 | ) | |
731 | ||
732 | return bytes; | |
733 | } | |
734 | EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); | |
735 | #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ | |
736 | ||
aa28de27 | 737 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 738 | { |
0dbca9a4 | 739 | char *to = addr; |
00e23707 | 740 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
741 | WARN_ON(1); |
742 | return 0; | |
743 | } | |
09fc68dc AV |
744 | if (iter_is_iovec(i)) |
745 | might_fault(); | |
0dbca9a4 | 746 | iterate_and_advance(i, bytes, v, |
09fc68dc | 747 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4 | 748 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
749 | v.bv_offset, v.bv_len), |
750 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
751 | ) |
752 | ||
753 | return bytes; | |
c35e0248 | 754 | } |
aa28de27 | 755 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 756 | |
aa28de27 | 757 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
758 | { |
759 | char *to = addr; | |
00e23707 | 760 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
761 | WARN_ON(1); |
762 | return false; | |
763 | } | |
33844e66 | 764 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
765 | return false; |
766 | ||
09fc68dc AV |
767 | if (iter_is_iovec(i)) |
768 | might_fault(); | |
cbbd26b8 | 769 | iterate_all_kinds(i, bytes, v, ({ |
09fc68dc | 770 | if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
771 | v.iov_base, v.iov_len)) |
772 | return false; | |
773 | 0;}), | |
774 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
775 | v.bv_offset, v.bv_len), | |
776 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
777 | ) | |
778 | ||
779 | iov_iter_advance(i, bytes); | |
780 | return true; | |
781 | } | |
aa28de27 | 782 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 783 | |
aa28de27 | 784 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
785 | { |
786 | char *to = addr; | |
00e23707 | 787 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
788 | WARN_ON(1); |
789 | return 0; | |
790 | } | |
aa583096 | 791 | iterate_and_advance(i, bytes, v, |
3f763453 | 792 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
793 | v.iov_base, v.iov_len), |
794 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
795 | v.bv_offset, v.bv_len), | |
796 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
797 | ) | |
798 | ||
799 | return bytes; | |
800 | } | |
aa28de27 | 801 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 802 | |
0aed55af | 803 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d DW |
804 | /** |
805 | * _copy_from_iter_flushcache - write destination through cpu cache | |
806 | * @addr: destination kernel address | |
807 | * @bytes: total transfer length | |
808 | * @iter: source iterator | |
809 | * | |
810 | * The pmem driver arranges for filesystem-dax to use this facility via | |
811 | * dax_copy_from_iter() for ensuring that writes to persistent memory | |
812 | * are flushed through the CPU cache. It is differentiated from | |
813 | * _copy_from_iter_nocache() in that guarantees all data is flushed for | |
814 | * all iterator types. The _copy_from_iter_nocache() only attempts to | |
815 | * bypass the cache for the ITER_IOVEC case, and on some archs may use | |
816 | * instructions that strand dirty-data in the cache. | |
817 | */ | |
6a37e940 | 818 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af DW |
819 | { |
820 | char *to = addr; | |
00e23707 | 821 | if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af DW |
822 | WARN_ON(1); |
823 | return 0; | |
824 | } | |
825 | iterate_and_advance(i, bytes, v, | |
826 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
827 | v.iov_base, v.iov_len), | |
828 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
829 | v.bv_offset, v.bv_len), | |
830 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
831 | v.iov_len) | |
832 | ) | |
833 | ||
834 | return bytes; | |
835 | } | |
6a37e940 | 836 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af DW |
837 | #endif |
838 | ||
aa28de27 | 839 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
840 | { |
841 | char *to = addr; | |
00e23707 | 842 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
843 | WARN_ON(1); |
844 | return false; | |
845 | } | |
33844e66 | 846 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
847 | return false; |
848 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 849 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
850 | v.iov_base, v.iov_len)) |
851 | return false; | |
852 | 0;}), | |
853 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
854 | v.bv_offset, v.bv_len), | |
855 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
856 | ) | |
857 | ||
858 | iov_iter_advance(i, bytes); | |
859 | return true; | |
860 | } | |
aa28de27 | 861 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 862 | |
72e809ed AV |
863 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
864 | { | |
6daef95b ED |
865 | struct page *head; |
866 | size_t v = n + offset; | |
867 | ||
868 | /* | |
869 | * The general case needs to access the page order in order | |
870 | * to compute the page size. | |
871 | * However, we mostly deal with order-0 pages and thus can | |
872 | * avoid a possible cache line miss for requests that fit all | |
873 | * page orders. | |
874 | */ | |
875 | if (n <= v && v <= PAGE_SIZE) | |
876 | return true; | |
877 | ||
878 | head = compound_head(page); | |
879 | v += (page - head) << PAGE_SHIFT; | |
a90bcb86 PP |
880 | |
881 | if (likely(n <= v && v <= (PAGE_SIZE << compound_order(head)))) | |
72e809ed AV |
882 | return true; |
883 | WARN_ON(1); | |
884 | return false; | |
885 | } | |
cbbd26b8 | 886 | |
62a8067a AV |
887 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
888 | struct iov_iter *i) | |
889 | { | |
72e809ed AV |
890 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
891 | return 0; | |
d271524a AV |
892 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
893 | void *kaddr = kmap_atomic(page); | |
894 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
895 | kunmap_atomic(kaddr); | |
896 | return wanted; | |
9ea9ce04 DH |
897 | } else if (unlikely(iov_iter_is_discard(i))) |
898 | return bytes; | |
899 | else if (likely(!iov_iter_is_pipe(i))) | |
62a8067a | 900 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
901 | else |
902 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
903 | } |
904 | EXPORT_SYMBOL(copy_page_to_iter); | |
905 | ||
906 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
907 | struct iov_iter *i) | |
908 | { | |
72e809ed AV |
909 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
910 | return 0; | |
9ea9ce04 | 911 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
912 | WARN_ON(1); |
913 | return 0; | |
914 | } | |
a280455f | 915 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 916 | void *kaddr = kmap_atomic(page); |
aa28de27 | 917 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
918 | kunmap_atomic(kaddr); |
919 | return wanted; | |
920 | } else | |
62a8067a AV |
921 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
922 | } | |
923 | EXPORT_SYMBOL(copy_page_from_iter); | |
924 | ||
241699cd AV |
925 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
926 | { | |
927 | struct pipe_inode_info *pipe = i->pipe; | |
928 | size_t n, off; | |
929 | int idx; | |
930 | ||
931 | if (!sanity(i)) | |
932 | return 0; | |
933 | ||
934 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
935 | if (unlikely(!n)) | |
936 | return 0; | |
937 | ||
938 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
939 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
940 | memzero_page(pipe->bufs[idx].page, off, chunk); | |
941 | i->idx = idx; | |
942 | i->iov_offset = off + chunk; | |
943 | n -= chunk; | |
944 | } | |
945 | i->count -= bytes; | |
946 | return bytes; | |
947 | } | |
948 | ||
c35e0248 MW |
949 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
950 | { | |
00e23707 | 951 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 952 | return pipe_zero(bytes, i); |
8442fa46 | 953 | iterate_and_advance(i, bytes, v, |
09fc68dc | 954 | clear_user(v.iov_base, v.iov_len), |
a280455f AV |
955 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
956 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
957 | ) |
958 | ||
959 | return bytes; | |
c35e0248 MW |
960 | } |
961 | EXPORT_SYMBOL(iov_iter_zero); | |
962 | ||
62a8067a AV |
963 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
964 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
965 | { | |
04a31165 | 966 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
967 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
968 | kunmap_atomic(kaddr); | |
969 | return 0; | |
970 | } | |
9ea9ce04 | 971 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
972 | kunmap_atomic(kaddr); |
973 | WARN_ON(1); | |
974 | return 0; | |
975 | } | |
04a31165 | 976 | iterate_all_kinds(i, bytes, v, |
09fc68dc | 977 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a31165 | 978 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
979 | v.bv_offset, v.bv_len), |
980 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
981 | ) |
982 | kunmap_atomic(kaddr); | |
983 | return bytes; | |
62a8067a AV |
984 | } |
985 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
986 | ||
b9dc6f65 AV |
987 | static inline void pipe_truncate(struct iov_iter *i) |
988 | { | |
989 | struct pipe_inode_info *pipe = i->pipe; | |
990 | if (pipe->nrbufs) { | |
991 | size_t off = i->iov_offset; | |
992 | int idx = i->idx; | |
993 | int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); | |
994 | if (off) { | |
995 | pipe->bufs[idx].len = off - pipe->bufs[idx].offset; | |
996 | idx = next_idx(idx, pipe); | |
997 | nrbufs++; | |
998 | } | |
999 | while (pipe->nrbufs > nrbufs) { | |
1000 | pipe_buf_release(pipe, &pipe->bufs[idx]); | |
1001 | idx = next_idx(idx, pipe); | |
1002 | pipe->nrbufs--; | |
1003 | } | |
1004 | } | |
1005 | } | |
1006 | ||
241699cd AV |
1007 | static void pipe_advance(struct iov_iter *i, size_t size) |
1008 | { | |
1009 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
1010 | if (unlikely(i->count < size)) |
1011 | size = i->count; | |
241699cd | 1012 | if (size) { |
b9dc6f65 AV |
1013 | struct pipe_buffer *buf; |
1014 | size_t off = i->iov_offset, left = size; | |
1015 | int idx = i->idx; | |
241699cd | 1016 | if (off) /* make it relative to the beginning of buffer */ |
b9dc6f65 | 1017 | left += off - pipe->bufs[idx].offset; |
241699cd AV |
1018 | while (1) { |
1019 | buf = &pipe->bufs[idx]; | |
b9dc6f65 | 1020 | if (left <= buf->len) |
241699cd | 1021 | break; |
b9dc6f65 | 1022 | left -= buf->len; |
241699cd AV |
1023 | idx = next_idx(idx, pipe); |
1024 | } | |
241699cd | 1025 | i->idx = idx; |
b9dc6f65 | 1026 | i->iov_offset = buf->offset + left; |
241699cd | 1027 | } |
b9dc6f65 AV |
1028 | i->count -= size; |
1029 | /* ... and discard everything past that point */ | |
1030 | pipe_truncate(i); | |
241699cd AV |
1031 | } |
1032 | ||
62a8067a AV |
1033 | void iov_iter_advance(struct iov_iter *i, size_t size) |
1034 | { | |
00e23707 | 1035 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1036 | pipe_advance(i, size); |
1037 | return; | |
1038 | } | |
9ea9ce04 DH |
1039 | if (unlikely(iov_iter_is_discard(i))) { |
1040 | i->count -= size; | |
1041 | return; | |
1042 | } | |
a280455f | 1043 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
1044 | } |
1045 | EXPORT_SYMBOL(iov_iter_advance); | |
1046 | ||
27c0e374 AV |
1047 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
1048 | { | |
1049 | if (!unroll) | |
1050 | return; | |
5b47d59a AV |
1051 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
1052 | return; | |
27c0e374 | 1053 | i->count += unroll; |
00e23707 | 1054 | if (unlikely(iov_iter_is_pipe(i))) { |
27c0e374 AV |
1055 | struct pipe_inode_info *pipe = i->pipe; |
1056 | int idx = i->idx; | |
1057 | size_t off = i->iov_offset; | |
1058 | while (1) { | |
1059 | size_t n = off - pipe->bufs[idx].offset; | |
1060 | if (unroll < n) { | |
4fa55cef | 1061 | off -= unroll; |
27c0e374 AV |
1062 | break; |
1063 | } | |
1064 | unroll -= n; | |
1065 | if (!unroll && idx == i->start_idx) { | |
1066 | off = 0; | |
1067 | break; | |
1068 | } | |
1069 | if (!idx--) | |
1070 | idx = pipe->buffers - 1; | |
1071 | off = pipe->bufs[idx].offset + pipe->bufs[idx].len; | |
1072 | } | |
1073 | i->iov_offset = off; | |
1074 | i->idx = idx; | |
1075 | pipe_truncate(i); | |
1076 | return; | |
1077 | } | |
9ea9ce04 DH |
1078 | if (unlikely(iov_iter_is_discard(i))) |
1079 | return; | |
27c0e374 AV |
1080 | if (unroll <= i->iov_offset) { |
1081 | i->iov_offset -= unroll; | |
1082 | return; | |
1083 | } | |
1084 | unroll -= i->iov_offset; | |
00e23707 | 1085 | if (iov_iter_is_bvec(i)) { |
27c0e374 AV |
1086 | const struct bio_vec *bvec = i->bvec; |
1087 | while (1) { | |
1088 | size_t n = (--bvec)->bv_len; | |
1089 | i->nr_segs++; | |
1090 | if (unroll <= n) { | |
1091 | i->bvec = bvec; | |
1092 | i->iov_offset = n - unroll; | |
1093 | return; | |
1094 | } | |
1095 | unroll -= n; | |
1096 | } | |
1097 | } else { /* same logics for iovec and kvec */ | |
1098 | const struct iovec *iov = i->iov; | |
1099 | while (1) { | |
1100 | size_t n = (--iov)->iov_len; | |
1101 | i->nr_segs++; | |
1102 | if (unroll <= n) { | |
1103 | i->iov = iov; | |
1104 | i->iov_offset = n - unroll; | |
1105 | return; | |
1106 | } | |
1107 | unroll -= n; | |
1108 | } | |
1109 | } | |
1110 | } | |
1111 | EXPORT_SYMBOL(iov_iter_revert); | |
1112 | ||
62a8067a AV |
1113 | /* |
1114 | * Return the count of just the current iov_iter segment. | |
1115 | */ | |
1116 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
1117 | { | |
00e23707 | 1118 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1119 | return i->count; // it is a silly place, anyway |
62a8067a AV |
1120 | if (i->nr_segs == 1) |
1121 | return i->count; | |
9ea9ce04 DH |
1122 | if (unlikely(iov_iter_is_discard(i))) |
1123 | return i->count; | |
00e23707 | 1124 | else if (iov_iter_is_bvec(i)) |
62a8067a | 1125 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
1126 | else |
1127 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
1128 | } |
1129 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
1130 | ||
aa563d7b | 1131 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77 | 1132 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
1133 | size_t count) |
1134 | { | |
aa563d7b DH |
1135 | WARN_ON(direction & ~(READ | WRITE)); |
1136 | i->type = ITER_KVEC | (direction & (READ | WRITE)); | |
05afcb77 | 1137 | i->kvec = kvec; |
abb78f87 AV |
1138 | i->nr_segs = nr_segs; |
1139 | i->iov_offset = 0; | |
1140 | i->count = count; | |
1141 | } | |
1142 | EXPORT_SYMBOL(iov_iter_kvec); | |
1143 | ||
aa563d7b | 1144 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77 AV |
1145 | const struct bio_vec *bvec, unsigned long nr_segs, |
1146 | size_t count) | |
1147 | { | |
aa563d7b DH |
1148 | WARN_ON(direction & ~(READ | WRITE)); |
1149 | i->type = ITER_BVEC | (direction & (READ | WRITE)); | |
05afcb77 AV |
1150 | i->bvec = bvec; |
1151 | i->nr_segs = nr_segs; | |
1152 | i->iov_offset = 0; | |
1153 | i->count = count; | |
1154 | } | |
1155 | EXPORT_SYMBOL(iov_iter_bvec); | |
1156 | ||
aa563d7b | 1157 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd AV |
1158 | struct pipe_inode_info *pipe, |
1159 | size_t count) | |
1160 | { | |
aa563d7b | 1161 | BUG_ON(direction != READ); |
b9dc6f65 | 1162 | WARN_ON(pipe->nrbufs == pipe->buffers); |
aa563d7b | 1163 | i->type = ITER_PIPE | READ; |
241699cd AV |
1164 | i->pipe = pipe; |
1165 | i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); | |
1166 | i->iov_offset = 0; | |
1167 | i->count = count; | |
27c0e374 | 1168 | i->start_idx = i->idx; |
241699cd AV |
1169 | } |
1170 | EXPORT_SYMBOL(iov_iter_pipe); | |
1171 | ||
9ea9ce04 DH |
1172 | /** |
1173 | * iov_iter_discard - Initialise an I/O iterator that discards data | |
1174 | * @i: The iterator to initialise. | |
1175 | * @direction: The direction of the transfer. | |
1176 | * @count: The size of the I/O buffer in bytes. | |
1177 | * | |
1178 | * Set up an I/O iterator that just discards everything that's written to it. | |
1179 | * It's only available as a READ iterator. | |
1180 | */ | |
1181 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) | |
1182 | { | |
1183 | BUG_ON(direction != READ); | |
1184 | i->type = ITER_DISCARD | READ; | |
1185 | i->count = count; | |
1186 | i->iov_offset = 0; | |
1187 | } | |
1188 | EXPORT_SYMBOL(iov_iter_discard); | |
1189 | ||
62a8067a AV |
1190 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
1191 | { | |
04a31165 AV |
1192 | unsigned long res = 0; |
1193 | size_t size = i->count; | |
1194 | ||
00e23707 | 1195 | if (unlikely(iov_iter_is_pipe(i))) { |
33844e66 | 1196 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) |
241699cd AV |
1197 | return size | i->iov_offset; |
1198 | return size; | |
1199 | } | |
04a31165 AV |
1200 | iterate_all_kinds(i, size, v, |
1201 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
1202 | res |= v.bv_offset | v.bv_len, |
1203 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
1204 | ) |
1205 | return res; | |
62a8067a AV |
1206 | } |
1207 | EXPORT_SYMBOL(iov_iter_alignment); | |
1208 | ||
357f435d AV |
1209 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
1210 | { | |
33844e66 | 1211 | unsigned long res = 0; |
357f435d | 1212 | size_t size = i->count; |
357f435d | 1213 | |
9ea9ce04 | 1214 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1215 | WARN_ON(1); |
1216 | return ~0U; | |
1217 | } | |
1218 | ||
357f435d AV |
1219 | iterate_all_kinds(i, size, v, |
1220 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1221 | (size != v.iov_len ? size : 0), 0), | |
1222 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1223 | (size != v.bv_len ? size : 0)), | |
1224 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1225 | (size != v.iov_len ? size : 0)) | |
1226 | ); | |
33844e66 | 1227 | return res; |
357f435d AV |
1228 | } |
1229 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1230 | ||
e76b6312 | 1231 | static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd AV |
1232 | size_t maxsize, |
1233 | struct page **pages, | |
1234 | int idx, | |
1235 | size_t *start) | |
1236 | { | |
1237 | struct pipe_inode_info *pipe = i->pipe; | |
1689c73a | 1238 | ssize_t n = push_pipe(i, maxsize, &idx, start); |
241699cd AV |
1239 | if (!n) |
1240 | return -EFAULT; | |
1241 | ||
1242 | maxsize = n; | |
1243 | n += *start; | |
1689c73a | 1244 | while (n > 0) { |
241699cd AV |
1245 | get_page(*pages++ = pipe->bufs[idx].page); |
1246 | idx = next_idx(idx, pipe); | |
1247 | n -= PAGE_SIZE; | |
1248 | } | |
1249 | ||
1250 | return maxsize; | |
1251 | } | |
1252 | ||
1253 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1254 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1255 | size_t *start) | |
1256 | { | |
1257 | unsigned npages; | |
1258 | size_t capacity; | |
1259 | int idx; | |
1260 | ||
33844e66 AV |
1261 | if (!maxsize) |
1262 | return 0; | |
1263 | ||
241699cd AV |
1264 | if (!sanity(i)) |
1265 | return -EFAULT; | |
1266 | ||
1267 | data_start(i, &idx, start); | |
1268 | /* some of this one + all after this one */ | |
1269 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
1270 | capacity = min(npages,maxpages) * PAGE_SIZE - *start; | |
1271 | ||
1272 | return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); | |
1273 | } | |
1274 | ||
62a8067a | 1275 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1276 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1277 | size_t *start) |
1278 | { | |
e5393fae AV |
1279 | if (maxsize > i->count) |
1280 | maxsize = i->count; | |
1281 | ||
00e23707 | 1282 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1283 | return pipe_get_pages(i, pages, maxsize, maxpages, start); |
9ea9ce04 DH |
1284 | if (unlikely(iov_iter_is_discard(i))) |
1285 | return -EFAULT; | |
1286 | ||
e5393fae AV |
1287 | iterate_all_kinds(i, maxsize, v, ({ |
1288 | unsigned long addr = (unsigned long)v.iov_base; | |
1289 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1290 | int n; | |
1291 | int res; | |
1292 | ||
1293 | if (len > maxpages * PAGE_SIZE) | |
1294 | len = maxpages * PAGE_SIZE; | |
1295 | addr &= ~(PAGE_SIZE - 1); | |
1296 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
73b0140b IW |
1297 | res = get_user_pages_fast(addr, n, |
1298 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, | |
1299 | pages); | |
e5393fae AV |
1300 | if (unlikely(res < 0)) |
1301 | return res; | |
1302 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1303 | 0;}),({ | |
1304 | /* can't be more than PAGE_SIZE */ | |
1305 | *start = v.bv_offset; | |
1306 | get_page(*pages = v.bv_page); | |
1307 | return v.bv_len; | |
a280455f AV |
1308 | }),({ |
1309 | return -EFAULT; | |
e5393fae AV |
1310 | }) |
1311 | ) | |
1312 | return 0; | |
62a8067a AV |
1313 | } |
1314 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1315 | ||
1b17f1f2 AV |
1316 | static struct page **get_pages_array(size_t n) |
1317 | { | |
752ade68 | 1318 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1319 | } |
1320 | ||
241699cd AV |
1321 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1322 | struct page ***pages, size_t maxsize, | |
1323 | size_t *start) | |
1324 | { | |
1325 | struct page **p; | |
d7760d63 | 1326 | ssize_t n; |
241699cd AV |
1327 | int idx; |
1328 | int npages; | |
1329 | ||
33844e66 AV |
1330 | if (!maxsize) |
1331 | return 0; | |
1332 | ||
241699cd AV |
1333 | if (!sanity(i)) |
1334 | return -EFAULT; | |
1335 | ||
1336 | data_start(i, &idx, start); | |
1337 | /* some of this one + all after this one */ | |
1338 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
1339 | n = npages * PAGE_SIZE - *start; | |
1340 | if (maxsize > n) | |
1341 | maxsize = n; | |
1342 | else | |
1343 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1344 | p = get_pages_array(npages); | |
1345 | if (!p) | |
1346 | return -ENOMEM; | |
1347 | n = __pipe_get_pages(i, maxsize, p, idx, start); | |
1348 | if (n > 0) | |
1349 | *pages = p; | |
1350 | else | |
1351 | kvfree(p); | |
1352 | return n; | |
1353 | } | |
1354 | ||
62a8067a AV |
1355 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1356 | struct page ***pages, size_t maxsize, | |
1357 | size_t *start) | |
1358 | { | |
1b17f1f2 AV |
1359 | struct page **p; |
1360 | ||
1361 | if (maxsize > i->count) | |
1362 | maxsize = i->count; | |
1363 | ||
00e23707 | 1364 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1365 | return pipe_get_pages_alloc(i, pages, maxsize, start); |
9ea9ce04 DH |
1366 | if (unlikely(iov_iter_is_discard(i))) |
1367 | return -EFAULT; | |
1368 | ||
1b17f1f2 AV |
1369 | iterate_all_kinds(i, maxsize, v, ({ |
1370 | unsigned long addr = (unsigned long)v.iov_base; | |
1371 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1372 | int n; | |
1373 | int res; | |
1374 | ||
1375 | addr &= ~(PAGE_SIZE - 1); | |
1376 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1377 | p = get_pages_array(n); | |
1378 | if (!p) | |
1379 | return -ENOMEM; | |
73b0140b IW |
1380 | res = get_user_pages_fast(addr, n, |
1381 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); | |
1b17f1f2 AV |
1382 | if (unlikely(res < 0)) { |
1383 | kvfree(p); | |
1384 | return res; | |
1385 | } | |
1386 | *pages = p; | |
1387 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1388 | 0;}),({ | |
1389 | /* can't be more than PAGE_SIZE */ | |
1390 | *start = v.bv_offset; | |
1391 | *pages = p = get_pages_array(1); | |
1392 | if (!p) | |
1393 | return -ENOMEM; | |
1394 | get_page(*p = v.bv_page); | |
1395 | return v.bv_len; | |
a280455f AV |
1396 | }),({ |
1397 | return -EFAULT; | |
1b17f1f2 AV |
1398 | }) |
1399 | ) | |
1400 | return 0; | |
62a8067a AV |
1401 | } |
1402 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1403 | ||
a604ec7e AV |
1404 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1405 | struct iov_iter *i) | |
1406 | { | |
1407 | char *to = addr; | |
1408 | __wsum sum, next; | |
1409 | size_t off = 0; | |
a604ec7e | 1410 | sum = *csum; |
9ea9ce04 | 1411 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1412 | WARN_ON(1); |
1413 | return 0; | |
1414 | } | |
a604ec7e AV |
1415 | iterate_and_advance(i, bytes, v, ({ |
1416 | int err = 0; | |
cbbd26b8 | 1417 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e AV |
1418 | (to += v.iov_len) - v.iov_len, |
1419 | v.iov_len, 0, &err); | |
1420 | if (!err) { | |
1421 | sum = csum_block_add(sum, next, off); | |
1422 | off += v.iov_len; | |
1423 | } | |
1424 | err ? v.iov_len : 0; | |
1425 | }), ({ | |
1426 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1427 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1428 | p + v.bv_offset, v.bv_len, | |
1429 | sum, off); | |
a604ec7e | 1430 | kunmap_atomic(p); |
a604ec7e AV |
1431 | off += v.bv_len; |
1432 | }),({ | |
f9152895 AV |
1433 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1434 | v.iov_base, v.iov_len, | |
1435 | sum, off); | |
a604ec7e AV |
1436 | off += v.iov_len; |
1437 | }) | |
1438 | ) | |
1439 | *csum = sum; | |
1440 | return bytes; | |
1441 | } | |
1442 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1443 | ||
cbbd26b8 AV |
1444 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
1445 | struct iov_iter *i) | |
1446 | { | |
1447 | char *to = addr; | |
1448 | __wsum sum, next; | |
1449 | size_t off = 0; | |
1450 | sum = *csum; | |
9ea9ce04 | 1451 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
cbbd26b8 AV |
1452 | WARN_ON(1); |
1453 | return false; | |
1454 | } | |
1455 | if (unlikely(i->count < bytes)) | |
1456 | return false; | |
1457 | iterate_all_kinds(i, bytes, v, ({ | |
1458 | int err = 0; | |
1459 | next = csum_and_copy_from_user(v.iov_base, | |
1460 | (to += v.iov_len) - v.iov_len, | |
1461 | v.iov_len, 0, &err); | |
1462 | if (err) | |
1463 | return false; | |
1464 | sum = csum_block_add(sum, next, off); | |
1465 | off += v.iov_len; | |
1466 | 0; | |
1467 | }), ({ | |
1468 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1469 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1470 | p + v.bv_offset, v.bv_len, | |
1471 | sum, off); | |
cbbd26b8 | 1472 | kunmap_atomic(p); |
cbbd26b8 AV |
1473 | off += v.bv_len; |
1474 | }),({ | |
f9152895 AV |
1475 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1476 | v.iov_base, v.iov_len, | |
1477 | sum, off); | |
cbbd26b8 AV |
1478 | off += v.iov_len; |
1479 | }) | |
1480 | ) | |
1481 | *csum = sum; | |
1482 | iov_iter_advance(i, bytes); | |
1483 | return true; | |
1484 | } | |
1485 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1486 | ||
cb002d07 | 1487 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, |
a604ec7e AV |
1488 | struct iov_iter *i) |
1489 | { | |
36f7a8a4 | 1490 | const char *from = addr; |
cb002d07 | 1491 | __wsum *csum = csump; |
a604ec7e AV |
1492 | __wsum sum, next; |
1493 | size_t off = 0; | |
78e1f386 AV |
1494 | |
1495 | if (unlikely(iov_iter_is_pipe(i))) | |
1496 | return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); | |
1497 | ||
a604ec7e | 1498 | sum = *csum; |
78e1f386 | 1499 | if (unlikely(iov_iter_is_discard(i))) { |
241699cd AV |
1500 | WARN_ON(1); /* for now */ |
1501 | return 0; | |
1502 | } | |
a604ec7e AV |
1503 | iterate_and_advance(i, bytes, v, ({ |
1504 | int err = 0; | |
1505 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
cbbd26b8 | 1506 | v.iov_base, |
a604ec7e AV |
1507 | v.iov_len, 0, &err); |
1508 | if (!err) { | |
1509 | sum = csum_block_add(sum, next, off); | |
1510 | off += v.iov_len; | |
1511 | } | |
1512 | err ? v.iov_len : 0; | |
1513 | }), ({ | |
1514 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1515 | sum = csum_and_memcpy(p + v.bv_offset, |
1516 | (from += v.bv_len) - v.bv_len, | |
1517 | v.bv_len, sum, off); | |
a604ec7e | 1518 | kunmap_atomic(p); |
a604ec7e AV |
1519 | off += v.bv_len; |
1520 | }),({ | |
f9152895 AV |
1521 | sum = csum_and_memcpy(v.iov_base, |
1522 | (from += v.iov_len) - v.iov_len, | |
1523 | v.iov_len, sum, off); | |
a604ec7e AV |
1524 | off += v.iov_len; |
1525 | }) | |
1526 | ) | |
1527 | *csum = sum; | |
1528 | return bytes; | |
1529 | } | |
1530 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1531 | ||
d05f4435 SG |
1532 | size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
1533 | struct iov_iter *i) | |
1534 | { | |
27fad74a | 1535 | #ifdef CONFIG_CRYPTO |
d05f4435 SG |
1536 | struct ahash_request *hash = hashp; |
1537 | struct scatterlist sg; | |
1538 | size_t copied; | |
1539 | ||
1540 | copied = copy_to_iter(addr, bytes, i); | |
1541 | sg_init_one(&sg, addr, copied); | |
1542 | ahash_request_set_crypt(hash, &sg, NULL, copied); | |
1543 | crypto_ahash_update(hash); | |
1544 | return copied; | |
27fad74a Y |
1545 | #else |
1546 | return 0; | |
1547 | #endif | |
d05f4435 SG |
1548 | } |
1549 | EXPORT_SYMBOL(hash_and_copy_to_iter); | |
1550 | ||
62a8067a AV |
1551 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1552 | { | |
e0f2dc40 AV |
1553 | size_t size = i->count; |
1554 | int npages = 0; | |
1555 | ||
1556 | if (!size) | |
1557 | return 0; | |
9ea9ce04 DH |
1558 | if (unlikely(iov_iter_is_discard(i))) |
1559 | return 0; | |
e0f2dc40 | 1560 | |
00e23707 | 1561 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1562 | struct pipe_inode_info *pipe = i->pipe; |
1563 | size_t off; | |
1564 | int idx; | |
1565 | ||
1566 | if (!sanity(i)) | |
1567 | return 0; | |
1568 | ||
1569 | data_start(i, &idx, &off); | |
1570 | /* some of this one + all after this one */ | |
1571 | npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; | |
1572 | if (npages >= maxpages) | |
1573 | return maxpages; | |
1574 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1575 | unsigned long p = (unsigned long)v.iov_base; |
1576 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1577 | - p / PAGE_SIZE; | |
1578 | if (npages >= maxpages) | |
1579 | return maxpages; | |
1580 | 0;}),({ | |
1581 | npages++; | |
1582 | if (npages >= maxpages) | |
1583 | return maxpages; | |
a280455f AV |
1584 | }),({ |
1585 | unsigned long p = (unsigned long)v.iov_base; | |
1586 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1587 | - p / PAGE_SIZE; | |
1588 | if (npages >= maxpages) | |
1589 | return maxpages; | |
e0f2dc40 AV |
1590 | }) |
1591 | ) | |
1592 | return npages; | |
62a8067a | 1593 | } |
f67da30c | 1594 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1595 | |
1596 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1597 | { | |
1598 | *new = *old; | |
00e23707 | 1599 | if (unlikely(iov_iter_is_pipe(new))) { |
241699cd AV |
1600 | WARN_ON(1); |
1601 | return NULL; | |
1602 | } | |
9ea9ce04 DH |
1603 | if (unlikely(iov_iter_is_discard(new))) |
1604 | return NULL; | |
00e23707 | 1605 | if (iov_iter_is_bvec(new)) |
4b8164b9 AV |
1606 | return new->bvec = kmemdup(new->bvec, |
1607 | new->nr_segs * sizeof(struct bio_vec), | |
1608 | flags); | |
1609 | else | |
1610 | /* iovec and kvec have identical layout */ | |
1611 | return new->iov = kmemdup(new->iov, | |
1612 | new->nr_segs * sizeof(struct iovec), | |
1613 | flags); | |
1614 | } | |
1615 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1616 | |
ffecee4f VN |
1617 | /** |
1618 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1619 | * into the kernel, check that it is valid, and initialize a new | |
1620 | * &struct iov_iter iterator to access it. | |
1621 | * | |
1622 | * @type: One of %READ or %WRITE. | |
1623 | * @uvector: Pointer to the userspace array. | |
1624 | * @nr_segs: Number of elements in userspace array. | |
1625 | * @fast_segs: Number of elements in @iov. | |
1626 | * @iov: (input and output parameter) Pointer to pointer to (usually small | |
1627 | * on-stack) kernel array. | |
1628 | * @i: Pointer to iterator that will be initialized on success. | |
1629 | * | |
1630 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1631 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1632 | * array will be allocated and the result placed in *@iov. This means that | |
1633 | * the caller may call kfree() on *@iov regardless of whether the small | |
1634 | * on-stack array was used or not (and regardless of whether this function | |
1635 | * returns an error or not). | |
1636 | * | |
1637 | * Return: 0 on success or negative error code on error. | |
1638 | */ | |
bc917be8 AV |
1639 | int import_iovec(int type, const struct iovec __user * uvector, |
1640 | unsigned nr_segs, unsigned fast_segs, | |
1641 | struct iovec **iov, struct iov_iter *i) | |
1642 | { | |
1643 | ssize_t n; | |
1644 | struct iovec *p; | |
1645 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1646 | *iov, &p); | |
1647 | if (n < 0) { | |
1648 | if (p != *iov) | |
1649 | kfree(p); | |
1650 | *iov = NULL; | |
1651 | return n; | |
1652 | } | |
1653 | iov_iter_init(i, type, p, nr_segs, n); | |
1654 | *iov = p == *iov ? NULL : p; | |
1655 | return 0; | |
1656 | } | |
1657 | EXPORT_SYMBOL(import_iovec); | |
1658 | ||
1659 | #ifdef CONFIG_COMPAT | |
1660 | #include <linux/compat.h> | |
1661 | ||
1662 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
1663 | unsigned nr_segs, unsigned fast_segs, | |
1664 | struct iovec **iov, struct iov_iter *i) | |
1665 | { | |
1666 | ssize_t n; | |
1667 | struct iovec *p; | |
1668 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1669 | *iov, &p); | |
1670 | if (n < 0) { | |
1671 | if (p != *iov) | |
1672 | kfree(p); | |
1673 | *iov = NULL; | |
1674 | return n; | |
1675 | } | |
1676 | iov_iter_init(i, type, p, nr_segs, n); | |
1677 | *iov = p == *iov ? NULL : p; | |
1678 | return 0; | |
1679 | } | |
1680 | #endif | |
1681 | ||
1682 | int import_single_range(int rw, void __user *buf, size_t len, | |
1683 | struct iovec *iov, struct iov_iter *i) | |
1684 | { | |
1685 | if (len > MAX_RW_COUNT) | |
1686 | len = MAX_RW_COUNT; | |
96d4f267 | 1687 | if (unlikely(!access_ok(buf, len))) |
bc917be8 AV |
1688 | return -EFAULT; |
1689 | ||
1690 | iov->iov_base = buf; | |
1691 | iov->iov_len = len; | |
1692 | iov_iter_init(i, rw, iov, 1, len); | |
1693 | return 0; | |
1694 | } | |
e1267585 | 1695 | EXPORT_SYMBOL(import_single_range); |
09cf698a AV |
1696 | |
1697 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1698 | int (*f)(struct kvec *vec, void *context), | |
1699 | void *context) | |
1700 | { | |
1701 | struct kvec w; | |
1702 | int err = -EINVAL; | |
1703 | if (!bytes) | |
1704 | return 0; | |
1705 | ||
1706 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1707 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1708 | w.iov_len = v.bv_len; | |
1709 | err = f(&w, context); | |
1710 | kunmap(v.bv_page); | |
1711 | err;}), ({ | |
1712 | w = v; | |
1713 | err = f(&w, context);}) | |
1714 | ) | |
1715 | return err; | |
1716 | } | |
1717 | EXPORT_SYMBOL(iov_iter_for_each_range); |