]>
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> |
d0ef4c36 | 11 | #include <linux/instrumented.h> |
4f18cd31 | 12 | |
241699cd AV |
13 | #define PIPE_PARANOIA /* for now */ |
14 | ||
04a31165 AV |
15 | #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ |
16 | size_t left; \ | |
17 | size_t wanted = n; \ | |
18 | __p = i->iov; \ | |
19 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
20 | if (likely(__v.iov_len)) { \ | |
21 | __v.iov_base = __p->iov_base + skip; \ | |
22 | left = (STEP); \ | |
23 | __v.iov_len -= left; \ | |
24 | skip += __v.iov_len; \ | |
25 | n -= __v.iov_len; \ | |
26 | } else { \ | |
27 | left = 0; \ | |
28 | } \ | |
29 | while (unlikely(!left && n)) { \ | |
30 | __p++; \ | |
31 | __v.iov_len = min(n, __p->iov_len); \ | |
32 | if (unlikely(!__v.iov_len)) \ | |
33 | continue; \ | |
34 | __v.iov_base = __p->iov_base; \ | |
35 | left = (STEP); \ | |
36 | __v.iov_len -= left; \ | |
37 | skip = __v.iov_len; \ | |
38 | n -= __v.iov_len; \ | |
39 | } \ | |
40 | n = wanted - n; \ | |
41 | } | |
42 | ||
a280455f AV |
43 | #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ |
44 | size_t wanted = n; \ | |
45 | __p = i->kvec; \ | |
46 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
47 | if (likely(__v.iov_len)) { \ | |
48 | __v.iov_base = __p->iov_base + skip; \ | |
49 | (void)(STEP); \ | |
50 | skip += __v.iov_len; \ | |
51 | n -= __v.iov_len; \ | |
52 | } \ | |
53 | while (unlikely(n)) { \ | |
54 | __p++; \ | |
55 | __v.iov_len = min(n, __p->iov_len); \ | |
56 | if (unlikely(!__v.iov_len)) \ | |
57 | continue; \ | |
58 | __v.iov_base = __p->iov_base; \ | |
59 | (void)(STEP); \ | |
60 | skip = __v.iov_len; \ | |
61 | n -= __v.iov_len; \ | |
62 | } \ | |
63 | n = wanted; \ | |
64 | } | |
65 | ||
1bdc76ae ML |
66 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ |
67 | struct bvec_iter __start; \ | |
68 | __start.bi_size = n; \ | |
69 | __start.bi_bvec_done = skip; \ | |
70 | __start.bi_idx = 0; \ | |
71 | for_each_bvec(__v, i->bvec, __bi, __start) { \ | |
72 | if (!__v.bv_len) \ | |
04a31165 | 73 | continue; \ |
04a31165 | 74 | (void)(STEP); \ |
04a31165 | 75 | } \ |
04a31165 AV |
76 | } |
77 | ||
a280455f | 78 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
33844e66 AV |
79 | if (likely(n)) { \ |
80 | size_t skip = i->iov_offset; \ | |
81 | if (unlikely(i->type & ITER_BVEC)) { \ | |
82 | struct bio_vec v; \ | |
83 | struct bvec_iter __bi; \ | |
84 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
85 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
86 | const struct kvec *kvec; \ | |
87 | struct kvec v; \ | |
88 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
9ea9ce04 | 89 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
33844e66 AV |
90 | } else { \ |
91 | const struct iovec *iov; \ | |
92 | struct iovec v; \ | |
93 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
94 | } \ | |
04a31165 AV |
95 | } \ |
96 | } | |
97 | ||
a280455f | 98 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
99 | if (unlikely(i->count < n)) \ |
100 | n = i->count; \ | |
19f18459 | 101 | if (i->count) { \ |
dd254f5a AV |
102 | size_t skip = i->iov_offset; \ |
103 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 104 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 105 | struct bio_vec v; \ |
1bdc76ae ML |
106 | struct bvec_iter __bi; \ |
107 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
108 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
109 | i->nr_segs -= i->bvec - bvec; \ | |
110 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
111 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
112 | const struct kvec *kvec; \ | |
113 | struct kvec v; \ | |
114 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
115 | if (skip == kvec->iov_len) { \ | |
116 | kvec++; \ | |
117 | skip = 0; \ | |
118 | } \ | |
119 | i->nr_segs -= kvec - i->kvec; \ | |
120 | i->kvec = kvec; \ | |
9ea9ce04 DH |
121 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
122 | skip += n; \ | |
dd254f5a AV |
123 | } else { \ |
124 | const struct iovec *iov; \ | |
125 | struct iovec v; \ | |
126 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
127 | if (skip == iov->iov_len) { \ | |
128 | iov++; \ | |
129 | skip = 0; \ | |
130 | } \ | |
131 | i->nr_segs -= iov - i->iov; \ | |
132 | i->iov = iov; \ | |
7ce2a91e | 133 | } \ |
dd254f5a AV |
134 | i->count -= n; \ |
135 | i->iov_offset = skip; \ | |
7ce2a91e | 136 | } \ |
7ce2a91e AV |
137 | } |
138 | ||
09fc68dc AV |
139 | static int copyout(void __user *to, const void *from, size_t n) |
140 | { | |
96d4f267 | 141 | if (access_ok(to, n)) { |
d0ef4c36 | 142 | instrument_copy_to_user(to, from, n); |
09fc68dc AV |
143 | n = raw_copy_to_user(to, from, n); |
144 | } | |
145 | return n; | |
146 | } | |
147 | ||
148 | static int copyin(void *to, const void __user *from, size_t n) | |
149 | { | |
96d4f267 | 150 | if (access_ok(from, n)) { |
d0ef4c36 | 151 | instrument_copy_from_user(to, from, n); |
09fc68dc AV |
152 | n = raw_copy_from_user(to, from, n); |
153 | } | |
154 | return n; | |
155 | } | |
156 | ||
62a8067a | 157 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
158 | struct iov_iter *i) |
159 | { | |
160 | size_t skip, copy, left, wanted; | |
161 | const struct iovec *iov; | |
162 | char __user *buf; | |
163 | void *kaddr, *from; | |
164 | ||
165 | if (unlikely(bytes > i->count)) | |
166 | bytes = i->count; | |
167 | ||
168 | if (unlikely(!bytes)) | |
169 | return 0; | |
170 | ||
09fc68dc | 171 | might_fault(); |
4f18cd31 AV |
172 | wanted = bytes; |
173 | iov = i->iov; | |
174 | skip = i->iov_offset; | |
175 | buf = iov->iov_base + skip; | |
176 | copy = min(bytes, iov->iov_len - skip); | |
177 | ||
3fa6c507 | 178 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
179 | kaddr = kmap_atomic(page); |
180 | from = kaddr + offset; | |
181 | ||
182 | /* first chunk, usually the only one */ | |
09fc68dc | 183 | left = copyout(buf, from, copy); |
4f18cd31 AV |
184 | copy -= left; |
185 | skip += copy; | |
186 | from += copy; | |
187 | bytes -= copy; | |
188 | ||
189 | while (unlikely(!left && bytes)) { | |
190 | iov++; | |
191 | buf = iov->iov_base; | |
192 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 193 | left = copyout(buf, from, copy); |
4f18cd31 AV |
194 | copy -= left; |
195 | skip = copy; | |
196 | from += copy; | |
197 | bytes -= copy; | |
198 | } | |
199 | if (likely(!bytes)) { | |
200 | kunmap_atomic(kaddr); | |
201 | goto done; | |
202 | } | |
203 | offset = from - kaddr; | |
204 | buf += copy; | |
205 | kunmap_atomic(kaddr); | |
206 | copy = min(bytes, iov->iov_len - skip); | |
207 | } | |
208 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 209 | |
4f18cd31 AV |
210 | kaddr = kmap(page); |
211 | from = kaddr + offset; | |
09fc68dc | 212 | left = copyout(buf, from, copy); |
4f18cd31 AV |
213 | copy -= left; |
214 | skip += copy; | |
215 | from += copy; | |
216 | bytes -= copy; | |
217 | while (unlikely(!left && bytes)) { | |
218 | iov++; | |
219 | buf = iov->iov_base; | |
220 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 221 | left = copyout(buf, from, copy); |
4f18cd31 AV |
222 | copy -= left; |
223 | skip = copy; | |
224 | from += copy; | |
225 | bytes -= copy; | |
226 | } | |
227 | kunmap(page); | |
3fa6c507 | 228 | |
4f18cd31 | 229 | done: |
81055e58 AV |
230 | if (skip == iov->iov_len) { |
231 | iov++; | |
232 | skip = 0; | |
233 | } | |
4f18cd31 AV |
234 | i->count -= wanted - bytes; |
235 | i->nr_segs -= iov - i->iov; | |
236 | i->iov = iov; | |
237 | i->iov_offset = skip; | |
238 | return wanted - bytes; | |
239 | } | |
4f18cd31 | 240 | |
62a8067a | 241 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
242 | struct iov_iter *i) |
243 | { | |
244 | size_t skip, copy, left, wanted; | |
245 | const struct iovec *iov; | |
246 | char __user *buf; | |
247 | void *kaddr, *to; | |
248 | ||
249 | if (unlikely(bytes > i->count)) | |
250 | bytes = i->count; | |
251 | ||
252 | if (unlikely(!bytes)) | |
253 | return 0; | |
254 | ||
09fc68dc | 255 | might_fault(); |
f0d1bec9 AV |
256 | wanted = bytes; |
257 | iov = i->iov; | |
258 | skip = i->iov_offset; | |
259 | buf = iov->iov_base + skip; | |
260 | copy = min(bytes, iov->iov_len - skip); | |
261 | ||
3fa6c507 | 262 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
263 | kaddr = kmap_atomic(page); |
264 | to = kaddr + offset; | |
265 | ||
266 | /* first chunk, usually the only one */ | |
09fc68dc | 267 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
268 | copy -= left; |
269 | skip += copy; | |
270 | to += copy; | |
271 | bytes -= copy; | |
272 | ||
273 | while (unlikely(!left && bytes)) { | |
274 | iov++; | |
275 | buf = iov->iov_base; | |
276 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 277 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
278 | copy -= left; |
279 | skip = copy; | |
280 | to += copy; | |
281 | bytes -= copy; | |
282 | } | |
283 | if (likely(!bytes)) { | |
284 | kunmap_atomic(kaddr); | |
285 | goto done; | |
286 | } | |
287 | offset = to - kaddr; | |
288 | buf += copy; | |
289 | kunmap_atomic(kaddr); | |
290 | copy = min(bytes, iov->iov_len - skip); | |
291 | } | |
292 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 293 | |
f0d1bec9 AV |
294 | kaddr = kmap(page); |
295 | to = kaddr + offset; | |
09fc68dc | 296 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
297 | copy -= left; |
298 | skip += copy; | |
299 | to += copy; | |
300 | bytes -= copy; | |
301 | while (unlikely(!left && bytes)) { | |
302 | iov++; | |
303 | buf = iov->iov_base; | |
304 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 305 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
306 | copy -= left; |
307 | skip = copy; | |
308 | to += copy; | |
309 | bytes -= copy; | |
310 | } | |
311 | kunmap(page); | |
3fa6c507 | 312 | |
f0d1bec9 | 313 | done: |
81055e58 AV |
314 | if (skip == iov->iov_len) { |
315 | iov++; | |
316 | skip = 0; | |
317 | } | |
f0d1bec9 AV |
318 | i->count -= wanted - bytes; |
319 | i->nr_segs -= iov - i->iov; | |
320 | i->iov = iov; | |
321 | i->iov_offset = skip; | |
322 | return wanted - bytes; | |
323 | } | |
f0d1bec9 | 324 | |
241699cd AV |
325 | #ifdef PIPE_PARANOIA |
326 | static bool sanity(const struct iov_iter *i) | |
327 | { | |
328 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
329 | unsigned int p_head = pipe->head; |
330 | unsigned int p_tail = pipe->tail; | |
331 | unsigned int p_mask = pipe->ring_size - 1; | |
332 | unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); | |
333 | unsigned int i_head = i->head; | |
334 | unsigned int idx; | |
335 | ||
241699cd AV |
336 | if (i->iov_offset) { |
337 | struct pipe_buffer *p; | |
8cefc107 | 338 | if (unlikely(p_occupancy == 0)) |
241699cd | 339 | goto Bad; // pipe must be non-empty |
8cefc107 | 340 | if (unlikely(i_head != p_head - 1)) |
241699cd AV |
341 | goto Bad; // must be at the last buffer... |
342 | ||
8cefc107 | 343 | p = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
344 | if (unlikely(p->offset + p->len != i->iov_offset)) |
345 | goto Bad; // ... at the end of segment | |
346 | } else { | |
8cefc107 | 347 | if (i_head != p_head) |
241699cd AV |
348 | goto Bad; // must be right after the last buffer |
349 | } | |
350 | return true; | |
351 | Bad: | |
8cefc107 DH |
352 | printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); |
353 | printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", | |
354 | p_head, p_tail, pipe->ring_size); | |
355 | for (idx = 0; idx < pipe->ring_size; idx++) | |
241699cd AV |
356 | printk(KERN_ERR "[%p %p %d %d]\n", |
357 | pipe->bufs[idx].ops, | |
358 | pipe->bufs[idx].page, | |
359 | pipe->bufs[idx].offset, | |
360 | pipe->bufs[idx].len); | |
361 | WARN_ON(1); | |
362 | return false; | |
363 | } | |
364 | #else | |
365 | #define sanity(i) true | |
366 | #endif | |
367 | ||
241699cd AV |
368 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, |
369 | struct iov_iter *i) | |
370 | { | |
371 | struct pipe_inode_info *pipe = i->pipe; | |
372 | struct pipe_buffer *buf; | |
8cefc107 DH |
373 | unsigned int p_tail = pipe->tail; |
374 | unsigned int p_mask = pipe->ring_size - 1; | |
375 | unsigned int i_head = i->head; | |
241699cd | 376 | size_t off; |
241699cd AV |
377 | |
378 | if (unlikely(bytes > i->count)) | |
379 | bytes = i->count; | |
380 | ||
381 | if (unlikely(!bytes)) | |
382 | return 0; | |
383 | ||
384 | if (!sanity(i)) | |
385 | return 0; | |
386 | ||
387 | off = i->iov_offset; | |
8cefc107 | 388 | buf = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
389 | if (off) { |
390 | if (offset == off && buf->page == page) { | |
391 | /* merge with the last one */ | |
392 | buf->len += bytes; | |
393 | i->iov_offset += bytes; | |
394 | goto out; | |
395 | } | |
8cefc107 DH |
396 | i_head++; |
397 | buf = &pipe->bufs[i_head & p_mask]; | |
241699cd | 398 | } |
6718b6f8 | 399 | if (pipe_full(i_head, p_tail, pipe->max_usage)) |
241699cd | 400 | return 0; |
8cefc107 | 401 | |
241699cd | 402 | buf->ops = &page_cache_pipe_buf_ops; |
8cefc107 DH |
403 | get_page(page); |
404 | buf->page = page; | |
241699cd AV |
405 | buf->offset = offset; |
406 | buf->len = bytes; | |
8cefc107 DH |
407 | |
408 | pipe->head = i_head + 1; | |
241699cd | 409 | i->iov_offset = offset + bytes; |
8cefc107 | 410 | i->head = i_head; |
241699cd AV |
411 | out: |
412 | i->count -= bytes; | |
413 | return bytes; | |
414 | } | |
415 | ||
171a0203 AA |
416 | /* |
417 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
418 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
419 | * | |
420 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
421 | * because it is an invalid address). | |
422 | */ | |
d4690f1e | 423 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
424 | { |
425 | size_t skip = i->iov_offset; | |
426 | const struct iovec *iov; | |
427 | int err; | |
428 | struct iovec v; | |
429 | ||
430 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
431 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
4bce9f6e | 432 | err = fault_in_pages_readable(v.iov_base, v.iov_len); |
171a0203 AA |
433 | if (unlikely(err)) |
434 | return err; | |
435 | 0;})) | |
436 | } | |
437 | return 0; | |
438 | } | |
d4690f1e | 439 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 440 | |
aa563d7b | 441 | void iov_iter_init(struct iov_iter *i, unsigned int direction, |
71d8e532 AV |
442 | const struct iovec *iov, unsigned long nr_segs, |
443 | size_t count) | |
444 | { | |
aa563d7b DH |
445 | WARN_ON(direction & ~(READ | WRITE)); |
446 | direction &= READ | WRITE; | |
447 | ||
71d8e532 | 448 | /* It will get better. Eventually... */ |
db68ce10 | 449 | if (uaccess_kernel()) { |
aa563d7b | 450 | i->type = ITER_KVEC | direction; |
a280455f AV |
451 | i->kvec = (struct kvec *)iov; |
452 | } else { | |
aa563d7b | 453 | i->type = ITER_IOVEC | direction; |
a280455f AV |
454 | i->iov = iov; |
455 | } | |
71d8e532 AV |
456 | i->nr_segs = nr_segs; |
457 | i->iov_offset = 0; | |
458 | i->count = count; | |
459 | } | |
460 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 461 | |
62a8067a AV |
462 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
463 | { | |
464 | char *from = kmap_atomic(page); | |
465 | memcpy(to, from + offset, len); | |
466 | kunmap_atomic(from); | |
467 | } | |
468 | ||
36f7a8a4 | 469 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
470 | { |
471 | char *to = kmap_atomic(page); | |
472 | memcpy(to + offset, from, len); | |
473 | kunmap_atomic(to); | |
474 | } | |
475 | ||
c35e0248 MW |
476 | static void memzero_page(struct page *page, size_t offset, size_t len) |
477 | { | |
478 | char *addr = kmap_atomic(page); | |
479 | memset(addr + offset, 0, len); | |
480 | kunmap_atomic(addr); | |
481 | } | |
482 | ||
241699cd AV |
483 | static inline bool allocated(struct pipe_buffer *buf) |
484 | { | |
485 | return buf->ops == &default_pipe_buf_ops; | |
486 | } | |
487 | ||
8cefc107 DH |
488 | static inline void data_start(const struct iov_iter *i, |
489 | unsigned int *iter_headp, size_t *offp) | |
241699cd | 490 | { |
8cefc107 DH |
491 | unsigned int p_mask = i->pipe->ring_size - 1; |
492 | unsigned int iter_head = i->head; | |
241699cd | 493 | size_t off = i->iov_offset; |
8cefc107 DH |
494 | |
495 | if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || | |
496 | off == PAGE_SIZE)) { | |
497 | iter_head++; | |
241699cd AV |
498 | off = 0; |
499 | } | |
8cefc107 | 500 | *iter_headp = iter_head; |
241699cd AV |
501 | *offp = off; |
502 | } | |
503 | ||
504 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
8cefc107 | 505 | int *iter_headp, size_t *offp) |
241699cd AV |
506 | { |
507 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
508 | unsigned int p_tail = pipe->tail; |
509 | unsigned int p_mask = pipe->ring_size - 1; | |
510 | unsigned int iter_head; | |
241699cd | 511 | size_t off; |
241699cd AV |
512 | ssize_t left; |
513 | ||
514 | if (unlikely(size > i->count)) | |
515 | size = i->count; | |
516 | if (unlikely(!size)) | |
517 | return 0; | |
518 | ||
519 | left = size; | |
8cefc107 DH |
520 | data_start(i, &iter_head, &off); |
521 | *iter_headp = iter_head; | |
241699cd AV |
522 | *offp = off; |
523 | if (off) { | |
524 | left -= PAGE_SIZE - off; | |
525 | if (left <= 0) { | |
8cefc107 | 526 | pipe->bufs[iter_head & p_mask].len += size; |
241699cd AV |
527 | return size; |
528 | } | |
8cefc107 DH |
529 | pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; |
530 | iter_head++; | |
241699cd | 531 | } |
6718b6f8 | 532 | while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { |
8cefc107 | 533 | struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; |
241699cd AV |
534 | struct page *page = alloc_page(GFP_USER); |
535 | if (!page) | |
536 | break; | |
8cefc107 DH |
537 | |
538 | buf->ops = &default_pipe_buf_ops; | |
539 | buf->page = page; | |
540 | buf->offset = 0; | |
541 | buf->len = min_t(ssize_t, left, PAGE_SIZE); | |
542 | left -= buf->len; | |
543 | iter_head++; | |
544 | pipe->head = iter_head; | |
545 | ||
546 | if (left == 0) | |
241699cd | 547 | return size; |
241699cd AV |
548 | } |
549 | return size - left; | |
550 | } | |
551 | ||
552 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
553 | struct iov_iter *i) | |
554 | { | |
555 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
556 | unsigned int p_mask = pipe->ring_size - 1; |
557 | unsigned int i_head; | |
241699cd | 558 | size_t n, off; |
241699cd AV |
559 | |
560 | if (!sanity(i)) | |
561 | return 0; | |
562 | ||
8cefc107 | 563 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
564 | if (unlikely(!n)) |
565 | return 0; | |
8cefc107 | 566 | do { |
241699cd | 567 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
568 | memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); |
569 | i->head = i_head; | |
241699cd AV |
570 | i->iov_offset = off + chunk; |
571 | n -= chunk; | |
572 | addr += chunk; | |
8cefc107 DH |
573 | off = 0; |
574 | i_head++; | |
575 | } while (n); | |
241699cd AV |
576 | i->count -= bytes; |
577 | return bytes; | |
578 | } | |
579 | ||
f9152895 AV |
580 | static __wsum csum_and_memcpy(void *to, const void *from, size_t len, |
581 | __wsum sum, size_t off) | |
582 | { | |
583 | __wsum next = csum_partial_copy_nocheck(from, to, len, 0); | |
584 | return csum_block_add(sum, next, off); | |
585 | } | |
586 | ||
78e1f386 AV |
587 | static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, |
588 | __wsum *csum, struct iov_iter *i) | |
589 | { | |
590 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
591 | unsigned int p_mask = pipe->ring_size - 1; |
592 | unsigned int i_head; | |
78e1f386 AV |
593 | size_t n, r; |
594 | size_t off = 0; | |
f9152895 | 595 | __wsum sum = *csum; |
78e1f386 AV |
596 | |
597 | if (!sanity(i)) | |
598 | return 0; | |
599 | ||
8cefc107 | 600 | bytes = n = push_pipe(i, bytes, &i_head, &r); |
78e1f386 AV |
601 | if (unlikely(!n)) |
602 | return 0; | |
8cefc107 | 603 | do { |
78e1f386 | 604 | size_t chunk = min_t(size_t, n, PAGE_SIZE - r); |
8cefc107 | 605 | char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); |
f9152895 | 606 | sum = csum_and_memcpy(p + r, addr, chunk, sum, off); |
78e1f386 | 607 | kunmap_atomic(p); |
8cefc107 | 608 | i->head = i_head; |
78e1f386 AV |
609 | i->iov_offset = r + chunk; |
610 | n -= chunk; | |
611 | off += chunk; | |
612 | addr += chunk; | |
8cefc107 DH |
613 | r = 0; |
614 | i_head++; | |
615 | } while (n); | |
78e1f386 AV |
616 | i->count -= bytes; |
617 | *csum = sum; | |
618 | return bytes; | |
619 | } | |
620 | ||
aa28de27 | 621 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 622 | { |
36f7a8a4 | 623 | const char *from = addr; |
00e23707 | 624 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 625 | return copy_pipe_to_iter(addr, bytes, i); |
09fc68dc AV |
626 | if (iter_is_iovec(i)) |
627 | might_fault(); | |
3d4d3e48 | 628 | iterate_and_advance(i, bytes, v, |
09fc68dc | 629 | copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
3d4d3e48 | 630 | memcpy_to_page(v.bv_page, v.bv_offset, |
a280455f AV |
631 | (from += v.bv_len) - v.bv_len, v.bv_len), |
632 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 633 | ) |
62a8067a | 634 | |
3d4d3e48 | 635 | return bytes; |
c35e0248 | 636 | } |
aa28de27 | 637 | EXPORT_SYMBOL(_copy_to_iter); |
c35e0248 | 638 | |
8780356e DW |
639 | #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE |
640 | static int copyout_mcsafe(void __user *to, const void *from, size_t n) | |
641 | { | |
96d4f267 | 642 | if (access_ok(to, n)) { |
d0ef4c36 | 643 | instrument_copy_to_user(to, from, n); |
8780356e DW |
644 | n = copy_to_user_mcsafe((__force void *) to, from, n); |
645 | } | |
646 | return n; | |
647 | } | |
648 | ||
649 | static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, | |
650 | const char *from, size_t len) | |
651 | { | |
652 | unsigned long ret; | |
653 | char *to; | |
654 | ||
655 | to = kmap_atomic(page); | |
656 | ret = memcpy_mcsafe(to + offset, from, len); | |
657 | kunmap_atomic(to); | |
658 | ||
659 | return ret; | |
660 | } | |
661 | ||
ca146f6f DW |
662 | static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, |
663 | struct iov_iter *i) | |
664 | { | |
665 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
666 | unsigned int p_mask = pipe->ring_size - 1; |
667 | unsigned int i_head; | |
ca146f6f | 668 | size_t n, off, xfer = 0; |
ca146f6f DW |
669 | |
670 | if (!sanity(i)) | |
671 | return 0; | |
672 | ||
8cefc107 | 673 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
ca146f6f DW |
674 | if (unlikely(!n)) |
675 | return 0; | |
8cefc107 | 676 | do { |
ca146f6f DW |
677 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
678 | unsigned long rem; | |
679 | ||
8cefc107 DH |
680 | rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page, |
681 | off, addr, chunk); | |
682 | i->head = i_head; | |
ca146f6f DW |
683 | i->iov_offset = off + chunk - rem; |
684 | xfer += chunk - rem; | |
685 | if (rem) | |
686 | break; | |
687 | n -= chunk; | |
688 | addr += chunk; | |
8cefc107 DH |
689 | off = 0; |
690 | i_head++; | |
691 | } while (n); | |
ca146f6f DW |
692 | i->count -= xfer; |
693 | return xfer; | |
694 | } | |
695 | ||
bf3eeb9b DW |
696 | /** |
697 | * _copy_to_iter_mcsafe - copy to user with source-read error exception handling | |
698 | * @addr: source kernel address | |
699 | * @bytes: total transfer length | |
700 | * @iter: destination iterator | |
701 | * | |
702 | * The pmem driver arranges for filesystem-dax to use this facility via | |
703 | * dax_copy_to_iter() for protecting read/write to persistent memory. | |
704 | * Unless / until an architecture can guarantee identical performance | |
705 | * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a | |
706 | * performance regression to switch more users to the mcsafe version. | |
707 | * | |
708 | * Otherwise, the main differences between this and typical _copy_to_iter(). | |
709 | * | |
710 | * * Typical tail/residue handling after a fault retries the copy | |
711 | * byte-by-byte until the fault happens again. Re-triggering machine | |
712 | * checks is potentially fatal so the implementation uses source | |
713 | * alignment and poison alignment assumptions to avoid re-triggering | |
714 | * hardware exceptions. | |
715 | * | |
716 | * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. | |
717 | * Compare to copy_to_iter() where only ITER_IOVEC attempts might return | |
718 | * a short copy. | |
719 | * | |
720 | * See MCSAFE_TEST for self-test. | |
721 | */ | |
8780356e DW |
722 | size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) |
723 | { | |
724 | const char *from = addr; | |
725 | unsigned long rem, curr_addr, s_addr = (unsigned long) addr; | |
726 | ||
00e23707 | 727 | if (unlikely(iov_iter_is_pipe(i))) |
ca146f6f | 728 | return copy_pipe_to_iter_mcsafe(addr, bytes, i); |
8780356e DW |
729 | if (iter_is_iovec(i)) |
730 | might_fault(); | |
731 | iterate_and_advance(i, bytes, v, | |
732 | copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), | |
733 | ({ | |
734 | rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, | |
735 | (from += v.bv_len) - v.bv_len, v.bv_len); | |
736 | if (rem) { | |
737 | curr_addr = (unsigned long) from; | |
738 | bytes = curr_addr - s_addr - rem; | |
739 | return bytes; | |
740 | } | |
741 | }), | |
742 | ({ | |
743 | rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, | |
744 | v.iov_len); | |
745 | if (rem) { | |
746 | curr_addr = (unsigned long) from; | |
747 | bytes = curr_addr - s_addr - rem; | |
748 | return bytes; | |
749 | } | |
750 | }) | |
751 | ) | |
752 | ||
753 | return bytes; | |
754 | } | |
755 | EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); | |
756 | #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ | |
757 | ||
aa28de27 | 758 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 759 | { |
0dbca9a4 | 760 | char *to = addr; |
00e23707 | 761 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
762 | WARN_ON(1); |
763 | return 0; | |
764 | } | |
09fc68dc AV |
765 | if (iter_is_iovec(i)) |
766 | might_fault(); | |
0dbca9a4 | 767 | iterate_and_advance(i, bytes, v, |
09fc68dc | 768 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4 | 769 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
770 | v.bv_offset, v.bv_len), |
771 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
772 | ) |
773 | ||
774 | return bytes; | |
c35e0248 | 775 | } |
aa28de27 | 776 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 777 | |
aa28de27 | 778 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
779 | { |
780 | char *to = addr; | |
00e23707 | 781 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
782 | WARN_ON(1); |
783 | return false; | |
784 | } | |
33844e66 | 785 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
786 | return false; |
787 | ||
09fc68dc AV |
788 | if (iter_is_iovec(i)) |
789 | might_fault(); | |
cbbd26b8 | 790 | iterate_all_kinds(i, bytes, v, ({ |
09fc68dc | 791 | if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
792 | v.iov_base, v.iov_len)) |
793 | return false; | |
794 | 0;}), | |
795 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
796 | v.bv_offset, v.bv_len), | |
797 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
798 | ) | |
799 | ||
800 | iov_iter_advance(i, bytes); | |
801 | return true; | |
802 | } | |
aa28de27 | 803 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 804 | |
aa28de27 | 805 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
806 | { |
807 | char *to = addr; | |
00e23707 | 808 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
809 | WARN_ON(1); |
810 | return 0; | |
811 | } | |
aa583096 | 812 | iterate_and_advance(i, bytes, v, |
3f763453 | 813 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
814 | v.iov_base, v.iov_len), |
815 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
816 | v.bv_offset, v.bv_len), | |
817 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
818 | ) | |
819 | ||
820 | return bytes; | |
821 | } | |
aa28de27 | 822 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 823 | |
0aed55af | 824 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d DW |
825 | /** |
826 | * _copy_from_iter_flushcache - write destination through cpu cache | |
827 | * @addr: destination kernel address | |
828 | * @bytes: total transfer length | |
829 | * @iter: source iterator | |
830 | * | |
831 | * The pmem driver arranges for filesystem-dax to use this facility via | |
832 | * dax_copy_from_iter() for ensuring that writes to persistent memory | |
833 | * are flushed through the CPU cache. It is differentiated from | |
834 | * _copy_from_iter_nocache() in that guarantees all data is flushed for | |
835 | * all iterator types. The _copy_from_iter_nocache() only attempts to | |
836 | * bypass the cache for the ITER_IOVEC case, and on some archs may use | |
837 | * instructions that strand dirty-data in the cache. | |
838 | */ | |
6a37e940 | 839 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af DW |
840 | { |
841 | char *to = addr; | |
00e23707 | 842 | if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af DW |
843 | WARN_ON(1); |
844 | return 0; | |
845 | } | |
846 | iterate_and_advance(i, bytes, v, | |
847 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
848 | v.iov_base, v.iov_len), | |
849 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
850 | v.bv_offset, v.bv_len), | |
851 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
852 | v.iov_len) | |
853 | ) | |
854 | ||
855 | return bytes; | |
856 | } | |
6a37e940 | 857 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af DW |
858 | #endif |
859 | ||
aa28de27 | 860 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
861 | { |
862 | char *to = addr; | |
00e23707 | 863 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
864 | WARN_ON(1); |
865 | return false; | |
866 | } | |
33844e66 | 867 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
868 | return false; |
869 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 870 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
871 | v.iov_base, v.iov_len)) |
872 | return false; | |
873 | 0;}), | |
874 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
875 | v.bv_offset, v.bv_len), | |
876 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
877 | ) | |
878 | ||
879 | iov_iter_advance(i, bytes); | |
880 | return true; | |
881 | } | |
aa28de27 | 882 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 883 | |
72e809ed AV |
884 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
885 | { | |
6daef95b ED |
886 | struct page *head; |
887 | size_t v = n + offset; | |
888 | ||
889 | /* | |
890 | * The general case needs to access the page order in order | |
891 | * to compute the page size. | |
892 | * However, we mostly deal with order-0 pages and thus can | |
893 | * avoid a possible cache line miss for requests that fit all | |
894 | * page orders. | |
895 | */ | |
896 | if (n <= v && v <= PAGE_SIZE) | |
897 | return true; | |
898 | ||
899 | head = compound_head(page); | |
900 | v += (page - head) << PAGE_SHIFT; | |
a90bcb86 | 901 | |
a50b854e | 902 | if (likely(n <= v && v <= (page_size(head)))) |
72e809ed AV |
903 | return true; |
904 | WARN_ON(1); | |
905 | return false; | |
906 | } | |
cbbd26b8 | 907 | |
62a8067a AV |
908 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
909 | struct iov_iter *i) | |
910 | { | |
72e809ed AV |
911 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
912 | return 0; | |
d271524a AV |
913 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
914 | void *kaddr = kmap_atomic(page); | |
915 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
916 | kunmap_atomic(kaddr); | |
917 | return wanted; | |
9ea9ce04 DH |
918 | } else if (unlikely(iov_iter_is_discard(i))) |
919 | return bytes; | |
920 | else if (likely(!iov_iter_is_pipe(i))) | |
62a8067a | 921 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
922 | else |
923 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
924 | } |
925 | EXPORT_SYMBOL(copy_page_to_iter); | |
926 | ||
927 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
928 | struct iov_iter *i) | |
929 | { | |
72e809ed AV |
930 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
931 | return 0; | |
9ea9ce04 | 932 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
933 | WARN_ON(1); |
934 | return 0; | |
935 | } | |
a280455f | 936 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 937 | void *kaddr = kmap_atomic(page); |
aa28de27 | 938 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
939 | kunmap_atomic(kaddr); |
940 | return wanted; | |
941 | } else | |
62a8067a AV |
942 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
943 | } | |
944 | EXPORT_SYMBOL(copy_page_from_iter); | |
945 | ||
241699cd AV |
946 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
947 | { | |
948 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
949 | unsigned int p_mask = pipe->ring_size - 1; |
950 | unsigned int i_head; | |
241699cd | 951 | size_t n, off; |
241699cd AV |
952 | |
953 | if (!sanity(i)) | |
954 | return 0; | |
955 | ||
8cefc107 | 956 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
957 | if (unlikely(!n)) |
958 | return 0; | |
959 | ||
8cefc107 | 960 | do { |
241699cd | 961 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
962 | memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); |
963 | i->head = i_head; | |
241699cd AV |
964 | i->iov_offset = off + chunk; |
965 | n -= chunk; | |
8cefc107 DH |
966 | off = 0; |
967 | i_head++; | |
968 | } while (n); | |
241699cd AV |
969 | i->count -= bytes; |
970 | return bytes; | |
971 | } | |
972 | ||
c35e0248 MW |
973 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
974 | { | |
00e23707 | 975 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 976 | return pipe_zero(bytes, i); |
8442fa46 | 977 | iterate_and_advance(i, bytes, v, |
09fc68dc | 978 | clear_user(v.iov_base, v.iov_len), |
a280455f AV |
979 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
980 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
981 | ) |
982 | ||
983 | return bytes; | |
c35e0248 MW |
984 | } |
985 | EXPORT_SYMBOL(iov_iter_zero); | |
986 | ||
62a8067a AV |
987 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
988 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
989 | { | |
04a31165 | 990 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
991 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
992 | kunmap_atomic(kaddr); | |
993 | return 0; | |
994 | } | |
9ea9ce04 | 995 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
996 | kunmap_atomic(kaddr); |
997 | WARN_ON(1); | |
998 | return 0; | |
999 | } | |
04a31165 | 1000 | iterate_all_kinds(i, bytes, v, |
09fc68dc | 1001 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a31165 | 1002 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
1003 | v.bv_offset, v.bv_len), |
1004 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
1005 | ) |
1006 | kunmap_atomic(kaddr); | |
1007 | return bytes; | |
62a8067a AV |
1008 | } |
1009 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
1010 | ||
b9dc6f65 AV |
1011 | static inline void pipe_truncate(struct iov_iter *i) |
1012 | { | |
1013 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1014 | unsigned int p_tail = pipe->tail; |
1015 | unsigned int p_head = pipe->head; | |
1016 | unsigned int p_mask = pipe->ring_size - 1; | |
1017 | ||
1018 | if (!pipe_empty(p_head, p_tail)) { | |
1019 | struct pipe_buffer *buf; | |
1020 | unsigned int i_head = i->head; | |
b9dc6f65 | 1021 | size_t off = i->iov_offset; |
8cefc107 | 1022 | |
b9dc6f65 | 1023 | if (off) { |
8cefc107 DH |
1024 | buf = &pipe->bufs[i_head & p_mask]; |
1025 | buf->len = off - buf->offset; | |
1026 | i_head++; | |
b9dc6f65 | 1027 | } |
8cefc107 DH |
1028 | while (p_head != i_head) { |
1029 | p_head--; | |
1030 | pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); | |
b9dc6f65 | 1031 | } |
8cefc107 DH |
1032 | |
1033 | pipe->head = p_head; | |
b9dc6f65 AV |
1034 | } |
1035 | } | |
1036 | ||
241699cd AV |
1037 | static void pipe_advance(struct iov_iter *i, size_t size) |
1038 | { | |
1039 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
1040 | if (unlikely(i->count < size)) |
1041 | size = i->count; | |
241699cd | 1042 | if (size) { |
b9dc6f65 | 1043 | struct pipe_buffer *buf; |
8cefc107 DH |
1044 | unsigned int p_mask = pipe->ring_size - 1; |
1045 | unsigned int i_head = i->head; | |
b9dc6f65 | 1046 | size_t off = i->iov_offset, left = size; |
8cefc107 | 1047 | |
241699cd | 1048 | if (off) /* make it relative to the beginning of buffer */ |
8cefc107 | 1049 | left += off - pipe->bufs[i_head & p_mask].offset; |
241699cd | 1050 | while (1) { |
8cefc107 | 1051 | buf = &pipe->bufs[i_head & p_mask]; |
b9dc6f65 | 1052 | if (left <= buf->len) |
241699cd | 1053 | break; |
b9dc6f65 | 1054 | left -= buf->len; |
8cefc107 | 1055 | i_head++; |
241699cd | 1056 | } |
8cefc107 | 1057 | i->head = i_head; |
b9dc6f65 | 1058 | i->iov_offset = buf->offset + left; |
241699cd | 1059 | } |
b9dc6f65 AV |
1060 | i->count -= size; |
1061 | /* ... and discard everything past that point */ | |
1062 | pipe_truncate(i); | |
241699cd AV |
1063 | } |
1064 | ||
62a8067a AV |
1065 | void iov_iter_advance(struct iov_iter *i, size_t size) |
1066 | { | |
00e23707 | 1067 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1068 | pipe_advance(i, size); |
1069 | return; | |
1070 | } | |
9ea9ce04 DH |
1071 | if (unlikely(iov_iter_is_discard(i))) { |
1072 | i->count -= size; | |
1073 | return; | |
1074 | } | |
a280455f | 1075 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
1076 | } |
1077 | EXPORT_SYMBOL(iov_iter_advance); | |
1078 | ||
27c0e374 AV |
1079 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
1080 | { | |
1081 | if (!unroll) | |
1082 | return; | |
5b47d59a AV |
1083 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
1084 | return; | |
27c0e374 | 1085 | i->count += unroll; |
00e23707 | 1086 | if (unlikely(iov_iter_is_pipe(i))) { |
27c0e374 | 1087 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 DH |
1088 | unsigned int p_mask = pipe->ring_size - 1; |
1089 | unsigned int i_head = i->head; | |
27c0e374 AV |
1090 | size_t off = i->iov_offset; |
1091 | while (1) { | |
8cefc107 DH |
1092 | struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; |
1093 | size_t n = off - b->offset; | |
27c0e374 | 1094 | if (unroll < n) { |
4fa55cef | 1095 | off -= unroll; |
27c0e374 AV |
1096 | break; |
1097 | } | |
1098 | unroll -= n; | |
8cefc107 | 1099 | if (!unroll && i_head == i->start_head) { |
27c0e374 AV |
1100 | off = 0; |
1101 | break; | |
1102 | } | |
8cefc107 DH |
1103 | i_head--; |
1104 | b = &pipe->bufs[i_head & p_mask]; | |
1105 | off = b->offset + b->len; | |
27c0e374 AV |
1106 | } |
1107 | i->iov_offset = off; | |
8cefc107 | 1108 | i->head = i_head; |
27c0e374 AV |
1109 | pipe_truncate(i); |
1110 | return; | |
1111 | } | |
9ea9ce04 DH |
1112 | if (unlikely(iov_iter_is_discard(i))) |
1113 | return; | |
27c0e374 AV |
1114 | if (unroll <= i->iov_offset) { |
1115 | i->iov_offset -= unroll; | |
1116 | return; | |
1117 | } | |
1118 | unroll -= i->iov_offset; | |
00e23707 | 1119 | if (iov_iter_is_bvec(i)) { |
27c0e374 AV |
1120 | const struct bio_vec *bvec = i->bvec; |
1121 | while (1) { | |
1122 | size_t n = (--bvec)->bv_len; | |
1123 | i->nr_segs++; | |
1124 | if (unroll <= n) { | |
1125 | i->bvec = bvec; | |
1126 | i->iov_offset = n - unroll; | |
1127 | return; | |
1128 | } | |
1129 | unroll -= n; | |
1130 | } | |
1131 | } else { /* same logics for iovec and kvec */ | |
1132 | const struct iovec *iov = i->iov; | |
1133 | while (1) { | |
1134 | size_t n = (--iov)->iov_len; | |
1135 | i->nr_segs++; | |
1136 | if (unroll <= n) { | |
1137 | i->iov = iov; | |
1138 | i->iov_offset = n - unroll; | |
1139 | return; | |
1140 | } | |
1141 | unroll -= n; | |
1142 | } | |
1143 | } | |
1144 | } | |
1145 | EXPORT_SYMBOL(iov_iter_revert); | |
1146 | ||
62a8067a AV |
1147 | /* |
1148 | * Return the count of just the current iov_iter segment. | |
1149 | */ | |
1150 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
1151 | { | |
00e23707 | 1152 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1153 | return i->count; // it is a silly place, anyway |
62a8067a AV |
1154 | if (i->nr_segs == 1) |
1155 | return i->count; | |
9ea9ce04 DH |
1156 | if (unlikely(iov_iter_is_discard(i))) |
1157 | return i->count; | |
00e23707 | 1158 | else if (iov_iter_is_bvec(i)) |
62a8067a | 1159 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
1160 | else |
1161 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
1162 | } |
1163 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
1164 | ||
aa563d7b | 1165 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77 | 1166 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
1167 | size_t count) |
1168 | { | |
aa563d7b DH |
1169 | WARN_ON(direction & ~(READ | WRITE)); |
1170 | i->type = ITER_KVEC | (direction & (READ | WRITE)); | |
05afcb77 | 1171 | i->kvec = kvec; |
abb78f87 AV |
1172 | i->nr_segs = nr_segs; |
1173 | i->iov_offset = 0; | |
1174 | i->count = count; | |
1175 | } | |
1176 | EXPORT_SYMBOL(iov_iter_kvec); | |
1177 | ||
aa563d7b | 1178 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77 AV |
1179 | const struct bio_vec *bvec, unsigned long nr_segs, |
1180 | size_t count) | |
1181 | { | |
aa563d7b DH |
1182 | WARN_ON(direction & ~(READ | WRITE)); |
1183 | i->type = ITER_BVEC | (direction & (READ | WRITE)); | |
05afcb77 AV |
1184 | i->bvec = bvec; |
1185 | i->nr_segs = nr_segs; | |
1186 | i->iov_offset = 0; | |
1187 | i->count = count; | |
1188 | } | |
1189 | EXPORT_SYMBOL(iov_iter_bvec); | |
1190 | ||
aa563d7b | 1191 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd AV |
1192 | struct pipe_inode_info *pipe, |
1193 | size_t count) | |
1194 | { | |
aa563d7b | 1195 | BUG_ON(direction != READ); |
8cefc107 | 1196 | WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); |
aa563d7b | 1197 | i->type = ITER_PIPE | READ; |
241699cd | 1198 | i->pipe = pipe; |
8cefc107 | 1199 | i->head = pipe->head; |
241699cd AV |
1200 | i->iov_offset = 0; |
1201 | i->count = count; | |
8cefc107 | 1202 | i->start_head = i->head; |
241699cd AV |
1203 | } |
1204 | EXPORT_SYMBOL(iov_iter_pipe); | |
1205 | ||
9ea9ce04 DH |
1206 | /** |
1207 | * iov_iter_discard - Initialise an I/O iterator that discards data | |
1208 | * @i: The iterator to initialise. | |
1209 | * @direction: The direction of the transfer. | |
1210 | * @count: The size of the I/O buffer in bytes. | |
1211 | * | |
1212 | * Set up an I/O iterator that just discards everything that's written to it. | |
1213 | * It's only available as a READ iterator. | |
1214 | */ | |
1215 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) | |
1216 | { | |
1217 | BUG_ON(direction != READ); | |
1218 | i->type = ITER_DISCARD | READ; | |
1219 | i->count = count; | |
1220 | i->iov_offset = 0; | |
1221 | } | |
1222 | EXPORT_SYMBOL(iov_iter_discard); | |
1223 | ||
62a8067a AV |
1224 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
1225 | { | |
04a31165 AV |
1226 | unsigned long res = 0; |
1227 | size_t size = i->count; | |
1228 | ||
00e23707 | 1229 | if (unlikely(iov_iter_is_pipe(i))) { |
e0ff126e JK |
1230 | unsigned int p_mask = i->pipe->ring_size - 1; |
1231 | ||
8cefc107 | 1232 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) |
241699cd AV |
1233 | return size | i->iov_offset; |
1234 | return size; | |
1235 | } | |
04a31165 AV |
1236 | iterate_all_kinds(i, size, v, |
1237 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
1238 | res |= v.bv_offset | v.bv_len, |
1239 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
1240 | ) |
1241 | return res; | |
62a8067a AV |
1242 | } |
1243 | EXPORT_SYMBOL(iov_iter_alignment); | |
1244 | ||
357f435d AV |
1245 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
1246 | { | |
33844e66 | 1247 | unsigned long res = 0; |
357f435d | 1248 | size_t size = i->count; |
357f435d | 1249 | |
9ea9ce04 | 1250 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1251 | WARN_ON(1); |
1252 | return ~0U; | |
1253 | } | |
1254 | ||
357f435d AV |
1255 | iterate_all_kinds(i, size, v, |
1256 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1257 | (size != v.iov_len ? size : 0), 0), | |
1258 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1259 | (size != v.bv_len ? size : 0)), | |
1260 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1261 | (size != v.iov_len ? size : 0)) | |
1262 | ); | |
33844e66 | 1263 | return res; |
357f435d AV |
1264 | } |
1265 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1266 | ||
e76b6312 | 1267 | static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd AV |
1268 | size_t maxsize, |
1269 | struct page **pages, | |
8cefc107 | 1270 | int iter_head, |
241699cd AV |
1271 | size_t *start) |
1272 | { | |
1273 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1274 | unsigned int p_mask = pipe->ring_size - 1; |
1275 | ssize_t n = push_pipe(i, maxsize, &iter_head, start); | |
241699cd AV |
1276 | if (!n) |
1277 | return -EFAULT; | |
1278 | ||
1279 | maxsize = n; | |
1280 | n += *start; | |
1689c73a | 1281 | while (n > 0) { |
8cefc107 DH |
1282 | get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); |
1283 | iter_head++; | |
241699cd AV |
1284 | n -= PAGE_SIZE; |
1285 | } | |
1286 | ||
1287 | return maxsize; | |
1288 | } | |
1289 | ||
1290 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1291 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1292 | size_t *start) | |
1293 | { | |
8cefc107 | 1294 | unsigned int iter_head, npages; |
241699cd | 1295 | size_t capacity; |
241699cd | 1296 | |
33844e66 AV |
1297 | if (!maxsize) |
1298 | return 0; | |
1299 | ||
241699cd AV |
1300 | if (!sanity(i)) |
1301 | return -EFAULT; | |
1302 | ||
8cefc107 DH |
1303 | data_start(i, &iter_head, start); |
1304 | /* Amount of free space: some of this one + all after this one */ | |
1305 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
1306 | capacity = min(npages, maxpages) * PAGE_SIZE - *start; | |
241699cd | 1307 | |
8cefc107 | 1308 | return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); |
241699cd AV |
1309 | } |
1310 | ||
62a8067a | 1311 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1312 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1313 | size_t *start) |
1314 | { | |
e5393fae AV |
1315 | if (maxsize > i->count) |
1316 | maxsize = i->count; | |
1317 | ||
00e23707 | 1318 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1319 | return pipe_get_pages(i, pages, maxsize, maxpages, start); |
9ea9ce04 DH |
1320 | if (unlikely(iov_iter_is_discard(i))) |
1321 | return -EFAULT; | |
1322 | ||
e5393fae AV |
1323 | iterate_all_kinds(i, maxsize, v, ({ |
1324 | unsigned long addr = (unsigned long)v.iov_base; | |
1325 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1326 | int n; | |
1327 | int res; | |
1328 | ||
1329 | if (len > maxpages * PAGE_SIZE) | |
1330 | len = maxpages * PAGE_SIZE; | |
1331 | addr &= ~(PAGE_SIZE - 1); | |
1332 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
73b0140b IW |
1333 | res = get_user_pages_fast(addr, n, |
1334 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, | |
1335 | pages); | |
e5393fae AV |
1336 | if (unlikely(res < 0)) |
1337 | return res; | |
1338 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1339 | 0;}),({ | |
1340 | /* can't be more than PAGE_SIZE */ | |
1341 | *start = v.bv_offset; | |
1342 | get_page(*pages = v.bv_page); | |
1343 | return v.bv_len; | |
a280455f AV |
1344 | }),({ |
1345 | return -EFAULT; | |
e5393fae AV |
1346 | }) |
1347 | ) | |
1348 | return 0; | |
62a8067a AV |
1349 | } |
1350 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1351 | ||
1b17f1f2 AV |
1352 | static struct page **get_pages_array(size_t n) |
1353 | { | |
752ade68 | 1354 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1355 | } |
1356 | ||
241699cd AV |
1357 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1358 | struct page ***pages, size_t maxsize, | |
1359 | size_t *start) | |
1360 | { | |
1361 | struct page **p; | |
8cefc107 | 1362 | unsigned int iter_head, npages; |
d7760d63 | 1363 | ssize_t n; |
241699cd | 1364 | |
33844e66 AV |
1365 | if (!maxsize) |
1366 | return 0; | |
1367 | ||
241699cd AV |
1368 | if (!sanity(i)) |
1369 | return -EFAULT; | |
1370 | ||
8cefc107 DH |
1371 | data_start(i, &iter_head, start); |
1372 | /* Amount of free space: some of this one + all after this one */ | |
1373 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
241699cd AV |
1374 | n = npages * PAGE_SIZE - *start; |
1375 | if (maxsize > n) | |
1376 | maxsize = n; | |
1377 | else | |
1378 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1379 | p = get_pages_array(npages); | |
1380 | if (!p) | |
1381 | return -ENOMEM; | |
8cefc107 | 1382 | n = __pipe_get_pages(i, maxsize, p, iter_head, start); |
241699cd AV |
1383 | if (n > 0) |
1384 | *pages = p; | |
1385 | else | |
1386 | kvfree(p); | |
1387 | return n; | |
1388 | } | |
1389 | ||
62a8067a AV |
1390 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1391 | struct page ***pages, size_t maxsize, | |
1392 | size_t *start) | |
1393 | { | |
1b17f1f2 AV |
1394 | struct page **p; |
1395 | ||
1396 | if (maxsize > i->count) | |
1397 | maxsize = i->count; | |
1398 | ||
00e23707 | 1399 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1400 | return pipe_get_pages_alloc(i, pages, maxsize, start); |
9ea9ce04 DH |
1401 | if (unlikely(iov_iter_is_discard(i))) |
1402 | return -EFAULT; | |
1403 | ||
1b17f1f2 AV |
1404 | iterate_all_kinds(i, maxsize, v, ({ |
1405 | unsigned long addr = (unsigned long)v.iov_base; | |
1406 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1407 | int n; | |
1408 | int res; | |
1409 | ||
1410 | addr &= ~(PAGE_SIZE - 1); | |
1411 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1412 | p = get_pages_array(n); | |
1413 | if (!p) | |
1414 | return -ENOMEM; | |
73b0140b IW |
1415 | res = get_user_pages_fast(addr, n, |
1416 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); | |
1b17f1f2 AV |
1417 | if (unlikely(res < 0)) { |
1418 | kvfree(p); | |
1419 | return res; | |
1420 | } | |
1421 | *pages = p; | |
1422 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1423 | 0;}),({ | |
1424 | /* can't be more than PAGE_SIZE */ | |
1425 | *start = v.bv_offset; | |
1426 | *pages = p = get_pages_array(1); | |
1427 | if (!p) | |
1428 | return -ENOMEM; | |
1429 | get_page(*p = v.bv_page); | |
1430 | return v.bv_len; | |
a280455f AV |
1431 | }),({ |
1432 | return -EFAULT; | |
1b17f1f2 AV |
1433 | }) |
1434 | ) | |
1435 | return 0; | |
62a8067a AV |
1436 | } |
1437 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1438 | ||
a604ec7e AV |
1439 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1440 | struct iov_iter *i) | |
1441 | { | |
1442 | char *to = addr; | |
1443 | __wsum sum, next; | |
1444 | size_t off = 0; | |
a604ec7e | 1445 | sum = *csum; |
9ea9ce04 | 1446 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1447 | WARN_ON(1); |
1448 | return 0; | |
1449 | } | |
a604ec7e AV |
1450 | iterate_and_advance(i, bytes, v, ({ |
1451 | int err = 0; | |
cbbd26b8 | 1452 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e AV |
1453 | (to += v.iov_len) - v.iov_len, |
1454 | v.iov_len, 0, &err); | |
1455 | if (!err) { | |
1456 | sum = csum_block_add(sum, next, off); | |
1457 | off += v.iov_len; | |
1458 | } | |
1459 | err ? v.iov_len : 0; | |
1460 | }), ({ | |
1461 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1462 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1463 | p + v.bv_offset, v.bv_len, | |
1464 | sum, off); | |
a604ec7e | 1465 | kunmap_atomic(p); |
a604ec7e AV |
1466 | off += v.bv_len; |
1467 | }),({ | |
f9152895 AV |
1468 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1469 | v.iov_base, v.iov_len, | |
1470 | sum, off); | |
a604ec7e AV |
1471 | off += v.iov_len; |
1472 | }) | |
1473 | ) | |
1474 | *csum = sum; | |
1475 | return bytes; | |
1476 | } | |
1477 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1478 | ||
cbbd26b8 AV |
1479 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
1480 | struct iov_iter *i) | |
1481 | { | |
1482 | char *to = addr; | |
1483 | __wsum sum, next; | |
1484 | size_t off = 0; | |
1485 | sum = *csum; | |
9ea9ce04 | 1486 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
cbbd26b8 AV |
1487 | WARN_ON(1); |
1488 | return false; | |
1489 | } | |
1490 | if (unlikely(i->count < bytes)) | |
1491 | return false; | |
1492 | iterate_all_kinds(i, bytes, v, ({ | |
1493 | int err = 0; | |
1494 | next = csum_and_copy_from_user(v.iov_base, | |
1495 | (to += v.iov_len) - v.iov_len, | |
1496 | v.iov_len, 0, &err); | |
1497 | if (err) | |
1498 | return false; | |
1499 | sum = csum_block_add(sum, next, off); | |
1500 | off += v.iov_len; | |
1501 | 0; | |
1502 | }), ({ | |
1503 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1504 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1505 | p + v.bv_offset, v.bv_len, | |
1506 | sum, off); | |
cbbd26b8 | 1507 | kunmap_atomic(p); |
cbbd26b8 AV |
1508 | off += v.bv_len; |
1509 | }),({ | |
f9152895 AV |
1510 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1511 | v.iov_base, v.iov_len, | |
1512 | sum, off); | |
cbbd26b8 AV |
1513 | off += v.iov_len; |
1514 | }) | |
1515 | ) | |
1516 | *csum = sum; | |
1517 | iov_iter_advance(i, bytes); | |
1518 | return true; | |
1519 | } | |
1520 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1521 | ||
cb002d07 | 1522 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, |
a604ec7e AV |
1523 | struct iov_iter *i) |
1524 | { | |
36f7a8a4 | 1525 | const char *from = addr; |
cb002d07 | 1526 | __wsum *csum = csump; |
a604ec7e AV |
1527 | __wsum sum, next; |
1528 | size_t off = 0; | |
78e1f386 AV |
1529 | |
1530 | if (unlikely(iov_iter_is_pipe(i))) | |
1531 | return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); | |
1532 | ||
a604ec7e | 1533 | sum = *csum; |
78e1f386 | 1534 | if (unlikely(iov_iter_is_discard(i))) { |
241699cd AV |
1535 | WARN_ON(1); /* for now */ |
1536 | return 0; | |
1537 | } | |
a604ec7e AV |
1538 | iterate_and_advance(i, bytes, v, ({ |
1539 | int err = 0; | |
1540 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
cbbd26b8 | 1541 | v.iov_base, |
a604ec7e AV |
1542 | v.iov_len, 0, &err); |
1543 | if (!err) { | |
1544 | sum = csum_block_add(sum, next, off); | |
1545 | off += v.iov_len; | |
1546 | } | |
1547 | err ? v.iov_len : 0; | |
1548 | }), ({ | |
1549 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1550 | sum = csum_and_memcpy(p + v.bv_offset, |
1551 | (from += v.bv_len) - v.bv_len, | |
1552 | v.bv_len, sum, off); | |
a604ec7e | 1553 | kunmap_atomic(p); |
a604ec7e AV |
1554 | off += v.bv_len; |
1555 | }),({ | |
f9152895 AV |
1556 | sum = csum_and_memcpy(v.iov_base, |
1557 | (from += v.iov_len) - v.iov_len, | |
1558 | v.iov_len, sum, off); | |
a604ec7e AV |
1559 | off += v.iov_len; |
1560 | }) | |
1561 | ) | |
1562 | *csum = sum; | |
1563 | return bytes; | |
1564 | } | |
1565 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1566 | ||
d05f4435 SG |
1567 | size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
1568 | struct iov_iter *i) | |
1569 | { | |
27fad74a | 1570 | #ifdef CONFIG_CRYPTO |
d05f4435 SG |
1571 | struct ahash_request *hash = hashp; |
1572 | struct scatterlist sg; | |
1573 | size_t copied; | |
1574 | ||
1575 | copied = copy_to_iter(addr, bytes, i); | |
1576 | sg_init_one(&sg, addr, copied); | |
1577 | ahash_request_set_crypt(hash, &sg, NULL, copied); | |
1578 | crypto_ahash_update(hash); | |
1579 | return copied; | |
27fad74a Y |
1580 | #else |
1581 | return 0; | |
1582 | #endif | |
d05f4435 SG |
1583 | } |
1584 | EXPORT_SYMBOL(hash_and_copy_to_iter); | |
1585 | ||
62a8067a AV |
1586 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1587 | { | |
e0f2dc40 AV |
1588 | size_t size = i->count; |
1589 | int npages = 0; | |
1590 | ||
1591 | if (!size) | |
1592 | return 0; | |
9ea9ce04 DH |
1593 | if (unlikely(iov_iter_is_discard(i))) |
1594 | return 0; | |
e0f2dc40 | 1595 | |
00e23707 | 1596 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd | 1597 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 | 1598 | unsigned int iter_head; |
241699cd | 1599 | size_t off; |
241699cd AV |
1600 | |
1601 | if (!sanity(i)) | |
1602 | return 0; | |
1603 | ||
8cefc107 | 1604 | data_start(i, &iter_head, &off); |
241699cd | 1605 | /* some of this one + all after this one */ |
8cefc107 | 1606 | npages = pipe_space_for_user(iter_head, pipe->tail, pipe); |
241699cd AV |
1607 | if (npages >= maxpages) |
1608 | return maxpages; | |
1609 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1610 | unsigned long p = (unsigned long)v.iov_base; |
1611 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1612 | - p / PAGE_SIZE; | |
1613 | if (npages >= maxpages) | |
1614 | return maxpages; | |
1615 | 0;}),({ | |
1616 | npages++; | |
1617 | if (npages >= maxpages) | |
1618 | return maxpages; | |
a280455f AV |
1619 | }),({ |
1620 | unsigned long p = (unsigned long)v.iov_base; | |
1621 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1622 | - p / PAGE_SIZE; | |
1623 | if (npages >= maxpages) | |
1624 | return maxpages; | |
e0f2dc40 AV |
1625 | }) |
1626 | ) | |
1627 | return npages; | |
62a8067a | 1628 | } |
f67da30c | 1629 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1630 | |
1631 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1632 | { | |
1633 | *new = *old; | |
00e23707 | 1634 | if (unlikely(iov_iter_is_pipe(new))) { |
241699cd AV |
1635 | WARN_ON(1); |
1636 | return NULL; | |
1637 | } | |
9ea9ce04 DH |
1638 | if (unlikely(iov_iter_is_discard(new))) |
1639 | return NULL; | |
00e23707 | 1640 | if (iov_iter_is_bvec(new)) |
4b8164b9 AV |
1641 | return new->bvec = kmemdup(new->bvec, |
1642 | new->nr_segs * sizeof(struct bio_vec), | |
1643 | flags); | |
1644 | else | |
1645 | /* iovec and kvec have identical layout */ | |
1646 | return new->iov = kmemdup(new->iov, | |
1647 | new->nr_segs * sizeof(struct iovec), | |
1648 | flags); | |
1649 | } | |
1650 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1651 | |
ffecee4f VN |
1652 | /** |
1653 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1654 | * into the kernel, check that it is valid, and initialize a new | |
1655 | * &struct iov_iter iterator to access it. | |
1656 | * | |
1657 | * @type: One of %READ or %WRITE. | |
1658 | * @uvector: Pointer to the userspace array. | |
1659 | * @nr_segs: Number of elements in userspace array. | |
1660 | * @fast_segs: Number of elements in @iov. | |
1661 | * @iov: (input and output parameter) Pointer to pointer to (usually small | |
1662 | * on-stack) kernel array. | |
1663 | * @i: Pointer to iterator that will be initialized on success. | |
1664 | * | |
1665 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1666 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1667 | * array will be allocated and the result placed in *@iov. This means that | |
1668 | * the caller may call kfree() on *@iov regardless of whether the small | |
1669 | * on-stack array was used or not (and regardless of whether this function | |
1670 | * returns an error or not). | |
1671 | * | |
87e5e6da | 1672 | * Return: Negative error code on error, bytes imported on success |
ffecee4f | 1673 | */ |
87e5e6da | 1674 | ssize_t import_iovec(int type, const struct iovec __user * uvector, |
bc917be8 AV |
1675 | unsigned nr_segs, unsigned fast_segs, |
1676 | struct iovec **iov, struct iov_iter *i) | |
1677 | { | |
1678 | ssize_t n; | |
1679 | struct iovec *p; | |
1680 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1681 | *iov, &p); | |
1682 | if (n < 0) { | |
1683 | if (p != *iov) | |
1684 | kfree(p); | |
1685 | *iov = NULL; | |
1686 | return n; | |
1687 | } | |
1688 | iov_iter_init(i, type, p, nr_segs, n); | |
1689 | *iov = p == *iov ? NULL : p; | |
87e5e6da | 1690 | return n; |
bc917be8 AV |
1691 | } |
1692 | EXPORT_SYMBOL(import_iovec); | |
1693 | ||
1694 | #ifdef CONFIG_COMPAT | |
1695 | #include <linux/compat.h> | |
1696 | ||
87e5e6da JA |
1697 | ssize_t compat_import_iovec(int type, |
1698 | const struct compat_iovec __user * uvector, | |
1699 | unsigned nr_segs, unsigned fast_segs, | |
1700 | struct iovec **iov, struct iov_iter *i) | |
bc917be8 AV |
1701 | { |
1702 | ssize_t n; | |
1703 | struct iovec *p; | |
1704 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1705 | *iov, &p); | |
1706 | if (n < 0) { | |
1707 | if (p != *iov) | |
1708 | kfree(p); | |
1709 | *iov = NULL; | |
1710 | return n; | |
1711 | } | |
1712 | iov_iter_init(i, type, p, nr_segs, n); | |
1713 | *iov = p == *iov ? NULL : p; | |
87e5e6da | 1714 | return n; |
bc917be8 | 1715 | } |
98aaaec4 | 1716 | EXPORT_SYMBOL(compat_import_iovec); |
bc917be8 AV |
1717 | #endif |
1718 | ||
1719 | int import_single_range(int rw, void __user *buf, size_t len, | |
1720 | struct iovec *iov, struct iov_iter *i) | |
1721 | { | |
1722 | if (len > MAX_RW_COUNT) | |
1723 | len = MAX_RW_COUNT; | |
96d4f267 | 1724 | if (unlikely(!access_ok(buf, len))) |
bc917be8 AV |
1725 | return -EFAULT; |
1726 | ||
1727 | iov->iov_base = buf; | |
1728 | iov->iov_len = len; | |
1729 | iov_iter_init(i, rw, iov, 1, len); | |
1730 | return 0; | |
1731 | } | |
e1267585 | 1732 | EXPORT_SYMBOL(import_single_range); |
09cf698a AV |
1733 | |
1734 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1735 | int (*f)(struct kvec *vec, void *context), | |
1736 | void *context) | |
1737 | { | |
1738 | struct kvec w; | |
1739 | int err = -EINVAL; | |
1740 | if (!bytes) | |
1741 | return 0; | |
1742 | ||
1743 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1744 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1745 | w.iov_len = v.bv_len; | |
1746 | err = f(&w, context); | |
1747 | kunmap(v.bv_page); | |
1748 | err;}), ({ | |
1749 | w = v; | |
1750 | err = f(&w, context);}) | |
1751 | ) | |
1752 | return err; | |
1753 | } | |
1754 | EXPORT_SYMBOL(iov_iter_for_each_range); |