Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
7999096f | 2 | #include <crypto/hash.h> |
4f18cd31 | 3 | #include <linux/export.h> |
2f8b5444 | 4 | #include <linux/bvec.h> |
4f18cd31 AV |
5 | #include <linux/uio.h> |
6 | #include <linux/pagemap.h> | |
91f79c43 AV |
7 | #include <linux/slab.h> |
8 | #include <linux/vmalloc.h> | |
241699cd | 9 | #include <linux/splice.h> |
a604ec7e | 10 | #include <net/checksum.h> |
d05f4435 | 11 | #include <linux/scatterlist.h> |
d0ef4c36 | 12 | #include <linux/instrumented.h> |
4f18cd31 | 13 | |
241699cd AV |
14 | #define PIPE_PARANOIA /* for now */ |
15 | ||
04a31165 AV |
16 | #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ |
17 | size_t left; \ | |
18 | size_t wanted = n; \ | |
19 | __p = i->iov; \ | |
20 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
21 | if (likely(__v.iov_len)) { \ | |
22 | __v.iov_base = __p->iov_base + skip; \ | |
23 | left = (STEP); \ | |
24 | __v.iov_len -= left; \ | |
25 | skip += __v.iov_len; \ | |
26 | n -= __v.iov_len; \ | |
27 | } else { \ | |
28 | left = 0; \ | |
29 | } \ | |
30 | while (unlikely(!left && n)) { \ | |
31 | __p++; \ | |
32 | __v.iov_len = min(n, __p->iov_len); \ | |
33 | if (unlikely(!__v.iov_len)) \ | |
34 | continue; \ | |
35 | __v.iov_base = __p->iov_base; \ | |
36 | left = (STEP); \ | |
37 | __v.iov_len -= left; \ | |
38 | skip = __v.iov_len; \ | |
39 | n -= __v.iov_len; \ | |
40 | } \ | |
41 | n = wanted - n; \ | |
42 | } | |
43 | ||
a280455f AV |
44 | #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ |
45 | size_t wanted = n; \ | |
46 | __p = i->kvec; \ | |
47 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
48 | if (likely(__v.iov_len)) { \ | |
49 | __v.iov_base = __p->iov_base + skip; \ | |
50 | (void)(STEP); \ | |
51 | skip += __v.iov_len; \ | |
52 | n -= __v.iov_len; \ | |
53 | } \ | |
54 | while (unlikely(n)) { \ | |
55 | __p++; \ | |
56 | __v.iov_len = min(n, __p->iov_len); \ | |
57 | if (unlikely(!__v.iov_len)) \ | |
58 | continue; \ | |
59 | __v.iov_base = __p->iov_base; \ | |
60 | (void)(STEP); \ | |
61 | skip = __v.iov_len; \ | |
62 | n -= __v.iov_len; \ | |
63 | } \ | |
64 | n = wanted; \ | |
65 | } | |
66 | ||
1bdc76ae ML |
67 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ |
68 | struct bvec_iter __start; \ | |
69 | __start.bi_size = n; \ | |
70 | __start.bi_bvec_done = skip; \ | |
71 | __start.bi_idx = 0; \ | |
72 | for_each_bvec(__v, i->bvec, __bi, __start) { \ | |
73 | if (!__v.bv_len) \ | |
04a31165 | 74 | continue; \ |
04a31165 | 75 | (void)(STEP); \ |
04a31165 | 76 | } \ |
04a31165 AV |
77 | } |
78 | ||
a280455f | 79 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
33844e66 AV |
80 | if (likely(n)) { \ |
81 | size_t skip = i->iov_offset; \ | |
82 | if (unlikely(i->type & ITER_BVEC)) { \ | |
83 | struct bio_vec v; \ | |
84 | struct bvec_iter __bi; \ | |
85 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
86 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
87 | const struct kvec *kvec; \ | |
88 | struct kvec v; \ | |
89 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
9ea9ce04 | 90 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
33844e66 AV |
91 | } else { \ |
92 | const struct iovec *iov; \ | |
93 | struct iovec v; \ | |
94 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
95 | } \ | |
04a31165 AV |
96 | } \ |
97 | } | |
98 | ||
a280455f | 99 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
100 | if (unlikely(i->count < n)) \ |
101 | n = i->count; \ | |
19f18459 | 102 | if (i->count) { \ |
dd254f5a AV |
103 | size_t skip = i->iov_offset; \ |
104 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 105 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 106 | struct bio_vec v; \ |
1bdc76ae ML |
107 | struct bvec_iter __bi; \ |
108 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
109 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
110 | i->nr_segs -= i->bvec - bvec; \ | |
111 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
112 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
113 | const struct kvec *kvec; \ | |
114 | struct kvec v; \ | |
115 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
116 | if (skip == kvec->iov_len) { \ | |
117 | kvec++; \ | |
118 | skip = 0; \ | |
119 | } \ | |
120 | i->nr_segs -= kvec - i->kvec; \ | |
121 | i->kvec = kvec; \ | |
9ea9ce04 DH |
122 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
123 | skip += n; \ | |
dd254f5a AV |
124 | } else { \ |
125 | const struct iovec *iov; \ | |
126 | struct iovec v; \ | |
127 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
128 | if (skip == iov->iov_len) { \ | |
129 | iov++; \ | |
130 | skip = 0; \ | |
131 | } \ | |
132 | i->nr_segs -= iov - i->iov; \ | |
133 | i->iov = iov; \ | |
7ce2a91e | 134 | } \ |
dd254f5a AV |
135 | i->count -= n; \ |
136 | i->iov_offset = skip; \ | |
7ce2a91e | 137 | } \ |
7ce2a91e AV |
138 | } |
139 | ||
09fc68dc AV |
140 | static int copyout(void __user *to, const void *from, size_t n) |
141 | { | |
96d4f267 | 142 | if (access_ok(to, n)) { |
d0ef4c36 | 143 | instrument_copy_to_user(to, from, n); |
09fc68dc AV |
144 | n = raw_copy_to_user(to, from, n); |
145 | } | |
146 | return n; | |
147 | } | |
148 | ||
149 | static int copyin(void *to, const void __user *from, size_t n) | |
150 | { | |
96d4f267 | 151 | if (access_ok(from, n)) { |
d0ef4c36 | 152 | instrument_copy_from_user(to, from, n); |
09fc68dc AV |
153 | n = raw_copy_from_user(to, from, n); |
154 | } | |
155 | return n; | |
156 | } | |
157 | ||
62a8067a | 158 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
159 | struct iov_iter *i) |
160 | { | |
161 | size_t skip, copy, left, wanted; | |
162 | const struct iovec *iov; | |
163 | char __user *buf; | |
164 | void *kaddr, *from; | |
165 | ||
166 | if (unlikely(bytes > i->count)) | |
167 | bytes = i->count; | |
168 | ||
169 | if (unlikely(!bytes)) | |
170 | return 0; | |
171 | ||
09fc68dc | 172 | might_fault(); |
4f18cd31 AV |
173 | wanted = bytes; |
174 | iov = i->iov; | |
175 | skip = i->iov_offset; | |
176 | buf = iov->iov_base + skip; | |
177 | copy = min(bytes, iov->iov_len - skip); | |
178 | ||
3fa6c507 | 179 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
180 | kaddr = kmap_atomic(page); |
181 | from = kaddr + offset; | |
182 | ||
183 | /* first chunk, usually the only one */ | |
09fc68dc | 184 | left = copyout(buf, from, copy); |
4f18cd31 AV |
185 | copy -= left; |
186 | skip += copy; | |
187 | from += copy; | |
188 | bytes -= copy; | |
189 | ||
190 | while (unlikely(!left && bytes)) { | |
191 | iov++; | |
192 | buf = iov->iov_base; | |
193 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 194 | left = copyout(buf, from, copy); |
4f18cd31 AV |
195 | copy -= left; |
196 | skip = copy; | |
197 | from += copy; | |
198 | bytes -= copy; | |
199 | } | |
200 | if (likely(!bytes)) { | |
201 | kunmap_atomic(kaddr); | |
202 | goto done; | |
203 | } | |
204 | offset = from - kaddr; | |
205 | buf += copy; | |
206 | kunmap_atomic(kaddr); | |
207 | copy = min(bytes, iov->iov_len - skip); | |
208 | } | |
209 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 210 | |
4f18cd31 AV |
211 | kaddr = kmap(page); |
212 | from = kaddr + offset; | |
09fc68dc | 213 | left = copyout(buf, from, copy); |
4f18cd31 AV |
214 | copy -= left; |
215 | skip += copy; | |
216 | from += copy; | |
217 | bytes -= copy; | |
218 | while (unlikely(!left && bytes)) { | |
219 | iov++; | |
220 | buf = iov->iov_base; | |
221 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 222 | left = copyout(buf, from, copy); |
4f18cd31 AV |
223 | copy -= left; |
224 | skip = copy; | |
225 | from += copy; | |
226 | bytes -= copy; | |
227 | } | |
228 | kunmap(page); | |
3fa6c507 | 229 | |
4f18cd31 | 230 | done: |
81055e58 AV |
231 | if (skip == iov->iov_len) { |
232 | iov++; | |
233 | skip = 0; | |
234 | } | |
4f18cd31 AV |
235 | i->count -= wanted - bytes; |
236 | i->nr_segs -= iov - i->iov; | |
237 | i->iov = iov; | |
238 | i->iov_offset = skip; | |
239 | return wanted - bytes; | |
240 | } | |
4f18cd31 | 241 | |
62a8067a | 242 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
243 | struct iov_iter *i) |
244 | { | |
245 | size_t skip, copy, left, wanted; | |
246 | const struct iovec *iov; | |
247 | char __user *buf; | |
248 | void *kaddr, *to; | |
249 | ||
250 | if (unlikely(bytes > i->count)) | |
251 | bytes = i->count; | |
252 | ||
253 | if (unlikely(!bytes)) | |
254 | return 0; | |
255 | ||
09fc68dc | 256 | might_fault(); |
f0d1bec9 AV |
257 | wanted = bytes; |
258 | iov = i->iov; | |
259 | skip = i->iov_offset; | |
260 | buf = iov->iov_base + skip; | |
261 | copy = min(bytes, iov->iov_len - skip); | |
262 | ||
3fa6c507 | 263 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
264 | kaddr = kmap_atomic(page); |
265 | to = kaddr + offset; | |
266 | ||
267 | /* first chunk, usually the only one */ | |
09fc68dc | 268 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
269 | copy -= left; |
270 | skip += copy; | |
271 | to += copy; | |
272 | bytes -= copy; | |
273 | ||
274 | while (unlikely(!left && bytes)) { | |
275 | iov++; | |
276 | buf = iov->iov_base; | |
277 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 278 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
279 | copy -= left; |
280 | skip = copy; | |
281 | to += copy; | |
282 | bytes -= copy; | |
283 | } | |
284 | if (likely(!bytes)) { | |
285 | kunmap_atomic(kaddr); | |
286 | goto done; | |
287 | } | |
288 | offset = to - kaddr; | |
289 | buf += copy; | |
290 | kunmap_atomic(kaddr); | |
291 | copy = min(bytes, iov->iov_len - skip); | |
292 | } | |
293 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 294 | |
f0d1bec9 AV |
295 | kaddr = kmap(page); |
296 | to = kaddr + offset; | |
09fc68dc | 297 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
298 | copy -= left; |
299 | skip += copy; | |
300 | to += copy; | |
301 | bytes -= copy; | |
302 | while (unlikely(!left && bytes)) { | |
303 | iov++; | |
304 | buf = iov->iov_base; | |
305 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 306 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
307 | copy -= left; |
308 | skip = copy; | |
309 | to += copy; | |
310 | bytes -= copy; | |
311 | } | |
312 | kunmap(page); | |
3fa6c507 | 313 | |
f0d1bec9 | 314 | done: |
81055e58 AV |
315 | if (skip == iov->iov_len) { |
316 | iov++; | |
317 | skip = 0; | |
318 | } | |
f0d1bec9 AV |
319 | i->count -= wanted - bytes; |
320 | i->nr_segs -= iov - i->iov; | |
321 | i->iov = iov; | |
322 | i->iov_offset = skip; | |
323 | return wanted - bytes; | |
324 | } | |
f0d1bec9 | 325 | |
241699cd AV |
326 | #ifdef PIPE_PARANOIA |
327 | static bool sanity(const struct iov_iter *i) | |
328 | { | |
329 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
330 | unsigned int p_head = pipe->head; |
331 | unsigned int p_tail = pipe->tail; | |
332 | unsigned int p_mask = pipe->ring_size - 1; | |
333 | unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); | |
334 | unsigned int i_head = i->head; | |
335 | unsigned int idx; | |
336 | ||
241699cd AV |
337 | if (i->iov_offset) { |
338 | struct pipe_buffer *p; | |
8cefc107 | 339 | if (unlikely(p_occupancy == 0)) |
241699cd | 340 | goto Bad; // pipe must be non-empty |
8cefc107 | 341 | if (unlikely(i_head != p_head - 1)) |
241699cd AV |
342 | goto Bad; // must be at the last buffer... |
343 | ||
8cefc107 | 344 | p = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
345 | if (unlikely(p->offset + p->len != i->iov_offset)) |
346 | goto Bad; // ... at the end of segment | |
347 | } else { | |
8cefc107 | 348 | if (i_head != p_head) |
241699cd AV |
349 | goto Bad; // must be right after the last buffer |
350 | } | |
351 | return true; | |
352 | Bad: | |
8cefc107 DH |
353 | printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); |
354 | printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", | |
355 | p_head, p_tail, pipe->ring_size); | |
356 | for (idx = 0; idx < pipe->ring_size; idx++) | |
241699cd AV |
357 | printk(KERN_ERR "[%p %p %d %d]\n", |
358 | pipe->bufs[idx].ops, | |
359 | pipe->bufs[idx].page, | |
360 | pipe->bufs[idx].offset, | |
361 | pipe->bufs[idx].len); | |
362 | WARN_ON(1); | |
363 | return false; | |
364 | } | |
365 | #else | |
366 | #define sanity(i) true | |
367 | #endif | |
368 | ||
241699cd AV |
369 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, |
370 | struct iov_iter *i) | |
371 | { | |
372 | struct pipe_inode_info *pipe = i->pipe; | |
373 | struct pipe_buffer *buf; | |
8cefc107 DH |
374 | unsigned int p_tail = pipe->tail; |
375 | unsigned int p_mask = pipe->ring_size - 1; | |
376 | unsigned int i_head = i->head; | |
241699cd | 377 | size_t off; |
241699cd AV |
378 | |
379 | if (unlikely(bytes > i->count)) | |
380 | bytes = i->count; | |
381 | ||
382 | if (unlikely(!bytes)) | |
383 | return 0; | |
384 | ||
385 | if (!sanity(i)) | |
386 | return 0; | |
387 | ||
388 | off = i->iov_offset; | |
8cefc107 | 389 | buf = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
390 | if (off) { |
391 | if (offset == off && buf->page == page) { | |
392 | /* merge with the last one */ | |
393 | buf->len += bytes; | |
394 | i->iov_offset += bytes; | |
395 | goto out; | |
396 | } | |
8cefc107 DH |
397 | i_head++; |
398 | buf = &pipe->bufs[i_head & p_mask]; | |
241699cd | 399 | } |
6718b6f8 | 400 | if (pipe_full(i_head, p_tail, pipe->max_usage)) |
241699cd | 401 | return 0; |
8cefc107 | 402 | |
241699cd | 403 | buf->ops = &page_cache_pipe_buf_ops; |
8cefc107 DH |
404 | get_page(page); |
405 | buf->page = page; | |
241699cd AV |
406 | buf->offset = offset; |
407 | buf->len = bytes; | |
8cefc107 DH |
408 | |
409 | pipe->head = i_head + 1; | |
241699cd | 410 | i->iov_offset = offset + bytes; |
8cefc107 | 411 | i->head = i_head; |
241699cd AV |
412 | out: |
413 | i->count -= bytes; | |
414 | return bytes; | |
415 | } | |
416 | ||
171a0203 AA |
417 | /* |
418 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
419 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
420 | * | |
421 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
422 | * because it is an invalid address). | |
423 | */ | |
d4690f1e | 424 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
425 | { |
426 | size_t skip = i->iov_offset; | |
427 | const struct iovec *iov; | |
428 | int err; | |
429 | struct iovec v; | |
430 | ||
431 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
432 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
4bce9f6e | 433 | err = fault_in_pages_readable(v.iov_base, v.iov_len); |
171a0203 AA |
434 | if (unlikely(err)) |
435 | return err; | |
436 | 0;})) | |
437 | } | |
438 | return 0; | |
439 | } | |
d4690f1e | 440 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 441 | |
aa563d7b | 442 | void iov_iter_init(struct iov_iter *i, unsigned int direction, |
71d8e532 AV |
443 | const struct iovec *iov, unsigned long nr_segs, |
444 | size_t count) | |
445 | { | |
aa563d7b DH |
446 | WARN_ON(direction & ~(READ | WRITE)); |
447 | direction &= READ | WRITE; | |
448 | ||
71d8e532 | 449 | /* It will get better. Eventually... */ |
db68ce10 | 450 | if (uaccess_kernel()) { |
aa563d7b | 451 | i->type = ITER_KVEC | direction; |
a280455f AV |
452 | i->kvec = (struct kvec *)iov; |
453 | } else { | |
aa563d7b | 454 | i->type = ITER_IOVEC | direction; |
a280455f AV |
455 | i->iov = iov; |
456 | } | |
71d8e532 AV |
457 | i->nr_segs = nr_segs; |
458 | i->iov_offset = 0; | |
459 | i->count = count; | |
460 | } | |
461 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 462 | |
62a8067a AV |
463 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
464 | { | |
465 | char *from = kmap_atomic(page); | |
466 | memcpy(to, from + offset, len); | |
467 | kunmap_atomic(from); | |
468 | } | |
469 | ||
36f7a8a4 | 470 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
471 | { |
472 | char *to = kmap_atomic(page); | |
473 | memcpy(to + offset, from, len); | |
474 | kunmap_atomic(to); | |
475 | } | |
476 | ||
c35e0248 MW |
477 | static void memzero_page(struct page *page, size_t offset, size_t len) |
478 | { | |
479 | char *addr = kmap_atomic(page); | |
480 | memset(addr + offset, 0, len); | |
481 | kunmap_atomic(addr); | |
482 | } | |
483 | ||
241699cd AV |
484 | static inline bool allocated(struct pipe_buffer *buf) |
485 | { | |
486 | return buf->ops == &default_pipe_buf_ops; | |
487 | } | |
488 | ||
8cefc107 DH |
489 | static inline void data_start(const struct iov_iter *i, |
490 | unsigned int *iter_headp, size_t *offp) | |
241699cd | 491 | { |
8cefc107 DH |
492 | unsigned int p_mask = i->pipe->ring_size - 1; |
493 | unsigned int iter_head = i->head; | |
241699cd | 494 | size_t off = i->iov_offset; |
8cefc107 DH |
495 | |
496 | if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || | |
497 | off == PAGE_SIZE)) { | |
498 | iter_head++; | |
241699cd AV |
499 | off = 0; |
500 | } | |
8cefc107 | 501 | *iter_headp = iter_head; |
241699cd AV |
502 | *offp = off; |
503 | } | |
504 | ||
505 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
8cefc107 | 506 | int *iter_headp, size_t *offp) |
241699cd AV |
507 | { |
508 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
509 | unsigned int p_tail = pipe->tail; |
510 | unsigned int p_mask = pipe->ring_size - 1; | |
511 | unsigned int iter_head; | |
241699cd | 512 | size_t off; |
241699cd AV |
513 | ssize_t left; |
514 | ||
515 | if (unlikely(size > i->count)) | |
516 | size = i->count; | |
517 | if (unlikely(!size)) | |
518 | return 0; | |
519 | ||
520 | left = size; | |
8cefc107 DH |
521 | data_start(i, &iter_head, &off); |
522 | *iter_headp = iter_head; | |
241699cd AV |
523 | *offp = off; |
524 | if (off) { | |
525 | left -= PAGE_SIZE - off; | |
526 | if (left <= 0) { | |
8cefc107 | 527 | pipe->bufs[iter_head & p_mask].len += size; |
241699cd AV |
528 | return size; |
529 | } | |
8cefc107 DH |
530 | pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; |
531 | iter_head++; | |
241699cd | 532 | } |
6718b6f8 | 533 | while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { |
8cefc107 | 534 | struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; |
241699cd AV |
535 | struct page *page = alloc_page(GFP_USER); |
536 | if (!page) | |
537 | break; | |
8cefc107 DH |
538 | |
539 | buf->ops = &default_pipe_buf_ops; | |
540 | buf->page = page; | |
541 | buf->offset = 0; | |
542 | buf->len = min_t(ssize_t, left, PAGE_SIZE); | |
543 | left -= buf->len; | |
544 | iter_head++; | |
545 | pipe->head = iter_head; | |
546 | ||
547 | if (left == 0) | |
241699cd | 548 | return size; |
241699cd AV |
549 | } |
550 | return size - left; | |
551 | } | |
552 | ||
553 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
554 | struct iov_iter *i) | |
555 | { | |
556 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
557 | unsigned int p_mask = pipe->ring_size - 1; |
558 | unsigned int i_head; | |
241699cd | 559 | size_t n, off; |
241699cd AV |
560 | |
561 | if (!sanity(i)) | |
562 | return 0; | |
563 | ||
8cefc107 | 564 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
565 | if (unlikely(!n)) |
566 | return 0; | |
8cefc107 | 567 | do { |
241699cd | 568 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
569 | memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); |
570 | i->head = i_head; | |
241699cd AV |
571 | i->iov_offset = off + chunk; |
572 | n -= chunk; | |
573 | addr += chunk; | |
8cefc107 DH |
574 | off = 0; |
575 | i_head++; | |
576 | } while (n); | |
241699cd AV |
577 | i->count -= bytes; |
578 | return bytes; | |
579 | } | |
580 | ||
f9152895 AV |
581 | static __wsum csum_and_memcpy(void *to, const void *from, size_t len, |
582 | __wsum sum, size_t off) | |
583 | { | |
584 | __wsum next = csum_partial_copy_nocheck(from, to, len, 0); | |
585 | return csum_block_add(sum, next, off); | |
586 | } | |
587 | ||
78e1f386 AV |
588 | static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, |
589 | __wsum *csum, struct iov_iter *i) | |
590 | { | |
591 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
592 | unsigned int p_mask = pipe->ring_size - 1; |
593 | unsigned int i_head; | |
78e1f386 AV |
594 | size_t n, r; |
595 | size_t off = 0; | |
f9152895 | 596 | __wsum sum = *csum; |
78e1f386 AV |
597 | |
598 | if (!sanity(i)) | |
599 | return 0; | |
600 | ||
8cefc107 | 601 | bytes = n = push_pipe(i, bytes, &i_head, &r); |
78e1f386 AV |
602 | if (unlikely(!n)) |
603 | return 0; | |
8cefc107 | 604 | do { |
78e1f386 | 605 | size_t chunk = min_t(size_t, n, PAGE_SIZE - r); |
8cefc107 | 606 | char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); |
f9152895 | 607 | sum = csum_and_memcpy(p + r, addr, chunk, sum, off); |
78e1f386 | 608 | kunmap_atomic(p); |
8cefc107 | 609 | i->head = i_head; |
78e1f386 AV |
610 | i->iov_offset = r + chunk; |
611 | n -= chunk; | |
612 | off += chunk; | |
613 | addr += chunk; | |
8cefc107 DH |
614 | r = 0; |
615 | i_head++; | |
616 | } while (n); | |
78e1f386 AV |
617 | i->count -= bytes; |
618 | *csum = sum; | |
619 | return bytes; | |
620 | } | |
621 | ||
aa28de27 | 622 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 623 | { |
36f7a8a4 | 624 | const char *from = addr; |
00e23707 | 625 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 626 | return copy_pipe_to_iter(addr, bytes, i); |
09fc68dc AV |
627 | if (iter_is_iovec(i)) |
628 | might_fault(); | |
3d4d3e48 | 629 | iterate_and_advance(i, bytes, v, |
09fc68dc | 630 | copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
3d4d3e48 | 631 | memcpy_to_page(v.bv_page, v.bv_offset, |
a280455f AV |
632 | (from += v.bv_len) - v.bv_len, v.bv_len), |
633 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 634 | ) |
62a8067a | 635 | |
3d4d3e48 | 636 | return bytes; |
c35e0248 | 637 | } |
aa28de27 | 638 | EXPORT_SYMBOL(_copy_to_iter); |
c35e0248 | 639 | |
8780356e DW |
640 | #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE |
641 | static int copyout_mcsafe(void __user *to, const void *from, size_t n) | |
642 | { | |
96d4f267 | 643 | if (access_ok(to, n)) { |
d0ef4c36 | 644 | instrument_copy_to_user(to, from, n); |
8780356e DW |
645 | n = copy_to_user_mcsafe((__force void *) to, from, n); |
646 | } | |
647 | return n; | |
648 | } | |
649 | ||
650 | static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, | |
651 | const char *from, size_t len) | |
652 | { | |
653 | unsigned long ret; | |
654 | char *to; | |
655 | ||
656 | to = kmap_atomic(page); | |
657 | ret = memcpy_mcsafe(to + offset, from, len); | |
658 | kunmap_atomic(to); | |
659 | ||
660 | return ret; | |
661 | } | |
662 | ||
ca146f6f DW |
663 | static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, |
664 | struct iov_iter *i) | |
665 | { | |
666 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
667 | unsigned int p_mask = pipe->ring_size - 1; |
668 | unsigned int i_head; | |
ca146f6f | 669 | size_t n, off, xfer = 0; |
ca146f6f DW |
670 | |
671 | if (!sanity(i)) | |
672 | return 0; | |
673 | ||
8cefc107 | 674 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
ca146f6f DW |
675 | if (unlikely(!n)) |
676 | return 0; | |
8cefc107 | 677 | do { |
ca146f6f DW |
678 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
679 | unsigned long rem; | |
680 | ||
8cefc107 DH |
681 | rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page, |
682 | off, addr, chunk); | |
683 | i->head = i_head; | |
ca146f6f DW |
684 | i->iov_offset = off + chunk - rem; |
685 | xfer += chunk - rem; | |
686 | if (rem) | |
687 | break; | |
688 | n -= chunk; | |
689 | addr += chunk; | |
8cefc107 DH |
690 | off = 0; |
691 | i_head++; | |
692 | } while (n); | |
ca146f6f DW |
693 | i->count -= xfer; |
694 | return xfer; | |
695 | } | |
696 | ||
bf3eeb9b DW |
697 | /** |
698 | * _copy_to_iter_mcsafe - copy to user with source-read error exception handling | |
699 | * @addr: source kernel address | |
700 | * @bytes: total transfer length | |
701 | * @iter: destination iterator | |
702 | * | |
703 | * The pmem driver arranges for filesystem-dax to use this facility via | |
704 | * dax_copy_to_iter() for protecting read/write to persistent memory. | |
705 | * Unless / until an architecture can guarantee identical performance | |
706 | * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a | |
707 | * performance regression to switch more users to the mcsafe version. | |
708 | * | |
709 | * Otherwise, the main differences between this and typical _copy_to_iter(). | |
710 | * | |
711 | * * Typical tail/residue handling after a fault retries the copy | |
712 | * byte-by-byte until the fault happens again. Re-triggering machine | |
713 | * checks is potentially fatal so the implementation uses source | |
714 | * alignment and poison alignment assumptions to avoid re-triggering | |
715 | * hardware exceptions. | |
716 | * | |
717 | * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. | |
718 | * Compare to copy_to_iter() where only ITER_IOVEC attempts might return | |
719 | * a short copy. | |
720 | * | |
721 | * See MCSAFE_TEST for self-test. | |
722 | */ | |
8780356e DW |
723 | size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) |
724 | { | |
725 | const char *from = addr; | |
726 | unsigned long rem, curr_addr, s_addr = (unsigned long) addr; | |
727 | ||
00e23707 | 728 | if (unlikely(iov_iter_is_pipe(i))) |
ca146f6f | 729 | return copy_pipe_to_iter_mcsafe(addr, bytes, i); |
8780356e DW |
730 | if (iter_is_iovec(i)) |
731 | might_fault(); | |
732 | iterate_and_advance(i, bytes, v, | |
733 | copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), | |
734 | ({ | |
735 | rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, | |
736 | (from += v.bv_len) - v.bv_len, v.bv_len); | |
737 | if (rem) { | |
738 | curr_addr = (unsigned long) from; | |
739 | bytes = curr_addr - s_addr - rem; | |
740 | return bytes; | |
741 | } | |
742 | }), | |
743 | ({ | |
744 | rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, | |
745 | v.iov_len); | |
746 | if (rem) { | |
747 | curr_addr = (unsigned long) from; | |
748 | bytes = curr_addr - s_addr - rem; | |
749 | return bytes; | |
750 | } | |
751 | }) | |
752 | ) | |
753 | ||
754 | return bytes; | |
755 | } | |
756 | EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); | |
757 | #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ | |
758 | ||
aa28de27 | 759 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 760 | { |
0dbca9a4 | 761 | char *to = addr; |
00e23707 | 762 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
763 | WARN_ON(1); |
764 | return 0; | |
765 | } | |
09fc68dc AV |
766 | if (iter_is_iovec(i)) |
767 | might_fault(); | |
0dbca9a4 | 768 | iterate_and_advance(i, bytes, v, |
09fc68dc | 769 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4 | 770 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
771 | v.bv_offset, v.bv_len), |
772 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
773 | ) |
774 | ||
775 | return bytes; | |
c35e0248 | 776 | } |
aa28de27 | 777 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 778 | |
aa28de27 | 779 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
780 | { |
781 | char *to = addr; | |
00e23707 | 782 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
783 | WARN_ON(1); |
784 | return false; | |
785 | } | |
33844e66 | 786 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
787 | return false; |
788 | ||
09fc68dc AV |
789 | if (iter_is_iovec(i)) |
790 | might_fault(); | |
cbbd26b8 | 791 | iterate_all_kinds(i, bytes, v, ({ |
09fc68dc | 792 | if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
793 | v.iov_base, v.iov_len)) |
794 | return false; | |
795 | 0;}), | |
796 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
797 | v.bv_offset, v.bv_len), | |
798 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
799 | ) | |
800 | ||
801 | iov_iter_advance(i, bytes); | |
802 | return true; | |
803 | } | |
aa28de27 | 804 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 805 | |
aa28de27 | 806 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
807 | { |
808 | char *to = addr; | |
00e23707 | 809 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
810 | WARN_ON(1); |
811 | return 0; | |
812 | } | |
aa583096 | 813 | iterate_and_advance(i, bytes, v, |
3f763453 | 814 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
815 | v.iov_base, v.iov_len), |
816 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
817 | v.bv_offset, v.bv_len), | |
818 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
819 | ) | |
820 | ||
821 | return bytes; | |
822 | } | |
aa28de27 | 823 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 824 | |
0aed55af | 825 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d DW |
826 | /** |
827 | * _copy_from_iter_flushcache - write destination through cpu cache | |
828 | * @addr: destination kernel address | |
829 | * @bytes: total transfer length | |
830 | * @iter: source iterator | |
831 | * | |
832 | * The pmem driver arranges for filesystem-dax to use this facility via | |
833 | * dax_copy_from_iter() for ensuring that writes to persistent memory | |
834 | * are flushed through the CPU cache. It is differentiated from | |
835 | * _copy_from_iter_nocache() in that guarantees all data is flushed for | |
836 | * all iterator types. The _copy_from_iter_nocache() only attempts to | |
837 | * bypass the cache for the ITER_IOVEC case, and on some archs may use | |
838 | * instructions that strand dirty-data in the cache. | |
839 | */ | |
6a37e940 | 840 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af DW |
841 | { |
842 | char *to = addr; | |
00e23707 | 843 | if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af DW |
844 | WARN_ON(1); |
845 | return 0; | |
846 | } | |
847 | iterate_and_advance(i, bytes, v, | |
848 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
849 | v.iov_base, v.iov_len), | |
850 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
851 | v.bv_offset, v.bv_len), | |
852 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
853 | v.iov_len) | |
854 | ) | |
855 | ||
856 | return bytes; | |
857 | } | |
6a37e940 | 858 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af DW |
859 | #endif |
860 | ||
aa28de27 | 861 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
862 | { |
863 | char *to = addr; | |
00e23707 | 864 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
865 | WARN_ON(1); |
866 | return false; | |
867 | } | |
33844e66 | 868 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
869 | return false; |
870 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 871 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
872 | v.iov_base, v.iov_len)) |
873 | return false; | |
874 | 0;}), | |
875 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
876 | v.bv_offset, v.bv_len), | |
877 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
878 | ) | |
879 | ||
880 | iov_iter_advance(i, bytes); | |
881 | return true; | |
882 | } | |
aa28de27 | 883 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 884 | |
72e809ed AV |
885 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
886 | { | |
6daef95b ED |
887 | struct page *head; |
888 | size_t v = n + offset; | |
889 | ||
890 | /* | |
891 | * The general case needs to access the page order in order | |
892 | * to compute the page size. | |
893 | * However, we mostly deal with order-0 pages and thus can | |
894 | * avoid a possible cache line miss for requests that fit all | |
895 | * page orders. | |
896 | */ | |
897 | if (n <= v && v <= PAGE_SIZE) | |
898 | return true; | |
899 | ||
900 | head = compound_head(page); | |
901 | v += (page - head) << PAGE_SHIFT; | |
a90bcb86 | 902 | |
a50b854e | 903 | if (likely(n <= v && v <= (page_size(head)))) |
72e809ed AV |
904 | return true; |
905 | WARN_ON(1); | |
906 | return false; | |
907 | } | |
cbbd26b8 | 908 | |
62a8067a AV |
909 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
910 | struct iov_iter *i) | |
911 | { | |
72e809ed AV |
912 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
913 | return 0; | |
d271524a AV |
914 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
915 | void *kaddr = kmap_atomic(page); | |
916 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
917 | kunmap_atomic(kaddr); | |
918 | return wanted; | |
9ea9ce04 DH |
919 | } else if (unlikely(iov_iter_is_discard(i))) |
920 | return bytes; | |
921 | else if (likely(!iov_iter_is_pipe(i))) | |
62a8067a | 922 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
923 | else |
924 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
925 | } |
926 | EXPORT_SYMBOL(copy_page_to_iter); | |
927 | ||
928 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
929 | struct iov_iter *i) | |
930 | { | |
72e809ed AV |
931 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
932 | return 0; | |
9ea9ce04 | 933 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
934 | WARN_ON(1); |
935 | return 0; | |
936 | } | |
a280455f | 937 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 938 | void *kaddr = kmap_atomic(page); |
aa28de27 | 939 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
940 | kunmap_atomic(kaddr); |
941 | return wanted; | |
942 | } else | |
62a8067a AV |
943 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
944 | } | |
945 | EXPORT_SYMBOL(copy_page_from_iter); | |
946 | ||
241699cd AV |
947 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
948 | { | |
949 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
950 | unsigned int p_mask = pipe->ring_size - 1; |
951 | unsigned int i_head; | |
241699cd | 952 | size_t n, off; |
241699cd AV |
953 | |
954 | if (!sanity(i)) | |
955 | return 0; | |
956 | ||
8cefc107 | 957 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
958 | if (unlikely(!n)) |
959 | return 0; | |
960 | ||
8cefc107 | 961 | do { |
241699cd | 962 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
963 | memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); |
964 | i->head = i_head; | |
241699cd AV |
965 | i->iov_offset = off + chunk; |
966 | n -= chunk; | |
8cefc107 DH |
967 | off = 0; |
968 | i_head++; | |
969 | } while (n); | |
241699cd AV |
970 | i->count -= bytes; |
971 | return bytes; | |
972 | } | |
973 | ||
c35e0248 MW |
974 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
975 | { | |
00e23707 | 976 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 977 | return pipe_zero(bytes, i); |
8442fa46 | 978 | iterate_and_advance(i, bytes, v, |
09fc68dc | 979 | clear_user(v.iov_base, v.iov_len), |
a280455f AV |
980 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
981 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
982 | ) |
983 | ||
984 | return bytes; | |
c35e0248 MW |
985 | } |
986 | EXPORT_SYMBOL(iov_iter_zero); | |
987 | ||
62a8067a AV |
988 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
989 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
990 | { | |
04a31165 | 991 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
992 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
993 | kunmap_atomic(kaddr); | |
994 | return 0; | |
995 | } | |
9ea9ce04 | 996 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
997 | kunmap_atomic(kaddr); |
998 | WARN_ON(1); | |
999 | return 0; | |
1000 | } | |
04a31165 | 1001 | iterate_all_kinds(i, bytes, v, |
09fc68dc | 1002 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a31165 | 1003 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
1004 | v.bv_offset, v.bv_len), |
1005 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
1006 | ) |
1007 | kunmap_atomic(kaddr); | |
1008 | return bytes; | |
62a8067a AV |
1009 | } |
1010 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
1011 | ||
b9dc6f65 AV |
1012 | static inline void pipe_truncate(struct iov_iter *i) |
1013 | { | |
1014 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1015 | unsigned int p_tail = pipe->tail; |
1016 | unsigned int p_head = pipe->head; | |
1017 | unsigned int p_mask = pipe->ring_size - 1; | |
1018 | ||
1019 | if (!pipe_empty(p_head, p_tail)) { | |
1020 | struct pipe_buffer *buf; | |
1021 | unsigned int i_head = i->head; | |
b9dc6f65 | 1022 | size_t off = i->iov_offset; |
8cefc107 | 1023 | |
b9dc6f65 | 1024 | if (off) { |
8cefc107 DH |
1025 | buf = &pipe->bufs[i_head & p_mask]; |
1026 | buf->len = off - buf->offset; | |
1027 | i_head++; | |
b9dc6f65 | 1028 | } |
8cefc107 DH |
1029 | while (p_head != i_head) { |
1030 | p_head--; | |
1031 | pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); | |
b9dc6f65 | 1032 | } |
8cefc107 DH |
1033 | |
1034 | pipe->head = p_head; | |
b9dc6f65 AV |
1035 | } |
1036 | } | |
1037 | ||
241699cd AV |
1038 | static void pipe_advance(struct iov_iter *i, size_t size) |
1039 | { | |
1040 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
1041 | if (unlikely(i->count < size)) |
1042 | size = i->count; | |
241699cd | 1043 | if (size) { |
b9dc6f65 | 1044 | struct pipe_buffer *buf; |
8cefc107 DH |
1045 | unsigned int p_mask = pipe->ring_size - 1; |
1046 | unsigned int i_head = i->head; | |
b9dc6f65 | 1047 | size_t off = i->iov_offset, left = size; |
8cefc107 | 1048 | |
241699cd | 1049 | if (off) /* make it relative to the beginning of buffer */ |
8cefc107 | 1050 | left += off - pipe->bufs[i_head & p_mask].offset; |
241699cd | 1051 | while (1) { |
8cefc107 | 1052 | buf = &pipe->bufs[i_head & p_mask]; |
b9dc6f65 | 1053 | if (left <= buf->len) |
241699cd | 1054 | break; |
b9dc6f65 | 1055 | left -= buf->len; |
8cefc107 | 1056 | i_head++; |
241699cd | 1057 | } |
8cefc107 | 1058 | i->head = i_head; |
b9dc6f65 | 1059 | i->iov_offset = buf->offset + left; |
241699cd | 1060 | } |
b9dc6f65 AV |
1061 | i->count -= size; |
1062 | /* ... and discard everything past that point */ | |
1063 | pipe_truncate(i); | |
241699cd AV |
1064 | } |
1065 | ||
62a8067a AV |
1066 | void iov_iter_advance(struct iov_iter *i, size_t size) |
1067 | { | |
00e23707 | 1068 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1069 | pipe_advance(i, size); |
1070 | return; | |
1071 | } | |
9ea9ce04 DH |
1072 | if (unlikely(iov_iter_is_discard(i))) { |
1073 | i->count -= size; | |
1074 | return; | |
1075 | } | |
a280455f | 1076 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
1077 | } |
1078 | EXPORT_SYMBOL(iov_iter_advance); | |
1079 | ||
27c0e374 AV |
1080 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
1081 | { | |
1082 | if (!unroll) | |
1083 | return; | |
5b47d59a AV |
1084 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
1085 | return; | |
27c0e374 | 1086 | i->count += unroll; |
00e23707 | 1087 | if (unlikely(iov_iter_is_pipe(i))) { |
27c0e374 | 1088 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 DH |
1089 | unsigned int p_mask = pipe->ring_size - 1; |
1090 | unsigned int i_head = i->head; | |
27c0e374 AV |
1091 | size_t off = i->iov_offset; |
1092 | while (1) { | |
8cefc107 DH |
1093 | struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; |
1094 | size_t n = off - b->offset; | |
27c0e374 | 1095 | if (unroll < n) { |
4fa55cef | 1096 | off -= unroll; |
27c0e374 AV |
1097 | break; |
1098 | } | |
1099 | unroll -= n; | |
8cefc107 | 1100 | if (!unroll && i_head == i->start_head) { |
27c0e374 AV |
1101 | off = 0; |
1102 | break; | |
1103 | } | |
8cefc107 DH |
1104 | i_head--; |
1105 | b = &pipe->bufs[i_head & p_mask]; | |
1106 | off = b->offset + b->len; | |
27c0e374 AV |
1107 | } |
1108 | i->iov_offset = off; | |
8cefc107 | 1109 | i->head = i_head; |
27c0e374 AV |
1110 | pipe_truncate(i); |
1111 | return; | |
1112 | } | |
9ea9ce04 DH |
1113 | if (unlikely(iov_iter_is_discard(i))) |
1114 | return; | |
27c0e374 AV |
1115 | if (unroll <= i->iov_offset) { |
1116 | i->iov_offset -= unroll; | |
1117 | return; | |
1118 | } | |
1119 | unroll -= i->iov_offset; | |
00e23707 | 1120 | if (iov_iter_is_bvec(i)) { |
27c0e374 AV |
1121 | const struct bio_vec *bvec = i->bvec; |
1122 | while (1) { | |
1123 | size_t n = (--bvec)->bv_len; | |
1124 | i->nr_segs++; | |
1125 | if (unroll <= n) { | |
1126 | i->bvec = bvec; | |
1127 | i->iov_offset = n - unroll; | |
1128 | return; | |
1129 | } | |
1130 | unroll -= n; | |
1131 | } | |
1132 | } else { /* same logics for iovec and kvec */ | |
1133 | const struct iovec *iov = i->iov; | |
1134 | while (1) { | |
1135 | size_t n = (--iov)->iov_len; | |
1136 | i->nr_segs++; | |
1137 | if (unroll <= n) { | |
1138 | i->iov = iov; | |
1139 | i->iov_offset = n - unroll; | |
1140 | return; | |
1141 | } | |
1142 | unroll -= n; | |
1143 | } | |
1144 | } | |
1145 | } | |
1146 | EXPORT_SYMBOL(iov_iter_revert); | |
1147 | ||
62a8067a AV |
1148 | /* |
1149 | * Return the count of just the current iov_iter segment. | |
1150 | */ | |
1151 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
1152 | { | |
00e23707 | 1153 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1154 | return i->count; // it is a silly place, anyway |
62a8067a AV |
1155 | if (i->nr_segs == 1) |
1156 | return i->count; | |
9ea9ce04 DH |
1157 | if (unlikely(iov_iter_is_discard(i))) |
1158 | return i->count; | |
00e23707 | 1159 | else if (iov_iter_is_bvec(i)) |
62a8067a | 1160 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
1161 | else |
1162 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
1163 | } |
1164 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
1165 | ||
aa563d7b | 1166 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77 | 1167 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
1168 | size_t count) |
1169 | { | |
aa563d7b DH |
1170 | WARN_ON(direction & ~(READ | WRITE)); |
1171 | i->type = ITER_KVEC | (direction & (READ | WRITE)); | |
05afcb77 | 1172 | i->kvec = kvec; |
abb78f87 AV |
1173 | i->nr_segs = nr_segs; |
1174 | i->iov_offset = 0; | |
1175 | i->count = count; | |
1176 | } | |
1177 | EXPORT_SYMBOL(iov_iter_kvec); | |
1178 | ||
aa563d7b | 1179 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77 AV |
1180 | const struct bio_vec *bvec, unsigned long nr_segs, |
1181 | size_t count) | |
1182 | { | |
aa563d7b DH |
1183 | WARN_ON(direction & ~(READ | WRITE)); |
1184 | i->type = ITER_BVEC | (direction & (READ | WRITE)); | |
05afcb77 AV |
1185 | i->bvec = bvec; |
1186 | i->nr_segs = nr_segs; | |
1187 | i->iov_offset = 0; | |
1188 | i->count = count; | |
1189 | } | |
1190 | EXPORT_SYMBOL(iov_iter_bvec); | |
1191 | ||
aa563d7b | 1192 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd AV |
1193 | struct pipe_inode_info *pipe, |
1194 | size_t count) | |
1195 | { | |
aa563d7b | 1196 | BUG_ON(direction != READ); |
8cefc107 | 1197 | WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); |
aa563d7b | 1198 | i->type = ITER_PIPE | READ; |
241699cd | 1199 | i->pipe = pipe; |
8cefc107 | 1200 | i->head = pipe->head; |
241699cd AV |
1201 | i->iov_offset = 0; |
1202 | i->count = count; | |
8cefc107 | 1203 | i->start_head = i->head; |
241699cd AV |
1204 | } |
1205 | EXPORT_SYMBOL(iov_iter_pipe); | |
1206 | ||
9ea9ce04 DH |
1207 | /** |
1208 | * iov_iter_discard - Initialise an I/O iterator that discards data | |
1209 | * @i: The iterator to initialise. | |
1210 | * @direction: The direction of the transfer. | |
1211 | * @count: The size of the I/O buffer in bytes. | |
1212 | * | |
1213 | * Set up an I/O iterator that just discards everything that's written to it. | |
1214 | * It's only available as a READ iterator. | |
1215 | */ | |
1216 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) | |
1217 | { | |
1218 | BUG_ON(direction != READ); | |
1219 | i->type = ITER_DISCARD | READ; | |
1220 | i->count = count; | |
1221 | i->iov_offset = 0; | |
1222 | } | |
1223 | EXPORT_SYMBOL(iov_iter_discard); | |
1224 | ||
62a8067a AV |
1225 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
1226 | { | |
04a31165 AV |
1227 | unsigned long res = 0; |
1228 | size_t size = i->count; | |
1229 | ||
00e23707 | 1230 | if (unlikely(iov_iter_is_pipe(i))) { |
e0ff126e JK |
1231 | unsigned int p_mask = i->pipe->ring_size - 1; |
1232 | ||
8cefc107 | 1233 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) |
241699cd AV |
1234 | return size | i->iov_offset; |
1235 | return size; | |
1236 | } | |
04a31165 AV |
1237 | iterate_all_kinds(i, size, v, |
1238 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
1239 | res |= v.bv_offset | v.bv_len, |
1240 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
1241 | ) |
1242 | return res; | |
62a8067a AV |
1243 | } |
1244 | EXPORT_SYMBOL(iov_iter_alignment); | |
1245 | ||
357f435d AV |
1246 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
1247 | { | |
33844e66 | 1248 | unsigned long res = 0; |
357f435d | 1249 | size_t size = i->count; |
357f435d | 1250 | |
9ea9ce04 | 1251 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1252 | WARN_ON(1); |
1253 | return ~0U; | |
1254 | } | |
1255 | ||
357f435d AV |
1256 | iterate_all_kinds(i, size, v, |
1257 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1258 | (size != v.iov_len ? size : 0), 0), | |
1259 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1260 | (size != v.bv_len ? size : 0)), | |
1261 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1262 | (size != v.iov_len ? size : 0)) | |
1263 | ); | |
33844e66 | 1264 | return res; |
357f435d AV |
1265 | } |
1266 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1267 | ||
e76b6312 | 1268 | static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd AV |
1269 | size_t maxsize, |
1270 | struct page **pages, | |
8cefc107 | 1271 | int iter_head, |
241699cd AV |
1272 | size_t *start) |
1273 | { | |
1274 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1275 | unsigned int p_mask = pipe->ring_size - 1; |
1276 | ssize_t n = push_pipe(i, maxsize, &iter_head, start); | |
241699cd AV |
1277 | if (!n) |
1278 | return -EFAULT; | |
1279 | ||
1280 | maxsize = n; | |
1281 | n += *start; | |
1689c73a | 1282 | while (n > 0) { |
8cefc107 DH |
1283 | get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); |
1284 | iter_head++; | |
241699cd AV |
1285 | n -= PAGE_SIZE; |
1286 | } | |
1287 | ||
1288 | return maxsize; | |
1289 | } | |
1290 | ||
1291 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1292 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1293 | size_t *start) | |
1294 | { | |
8cefc107 | 1295 | unsigned int iter_head, npages; |
241699cd | 1296 | size_t capacity; |
241699cd | 1297 | |
33844e66 AV |
1298 | if (!maxsize) |
1299 | return 0; | |
1300 | ||
241699cd AV |
1301 | if (!sanity(i)) |
1302 | return -EFAULT; | |
1303 | ||
8cefc107 DH |
1304 | data_start(i, &iter_head, start); |
1305 | /* Amount of free space: some of this one + all after this one */ | |
1306 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
1307 | capacity = min(npages, maxpages) * PAGE_SIZE - *start; | |
241699cd | 1308 | |
8cefc107 | 1309 | return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); |
241699cd AV |
1310 | } |
1311 | ||
62a8067a | 1312 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1313 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1314 | size_t *start) |
1315 | { | |
e5393fae AV |
1316 | if (maxsize > i->count) |
1317 | maxsize = i->count; | |
1318 | ||
00e23707 | 1319 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1320 | return pipe_get_pages(i, pages, maxsize, maxpages, start); |
9ea9ce04 DH |
1321 | if (unlikely(iov_iter_is_discard(i))) |
1322 | return -EFAULT; | |
1323 | ||
e5393fae AV |
1324 | iterate_all_kinds(i, maxsize, v, ({ |
1325 | unsigned long addr = (unsigned long)v.iov_base; | |
1326 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1327 | int n; | |
1328 | int res; | |
1329 | ||
1330 | if (len > maxpages * PAGE_SIZE) | |
1331 | len = maxpages * PAGE_SIZE; | |
1332 | addr &= ~(PAGE_SIZE - 1); | |
1333 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
73b0140b IW |
1334 | res = get_user_pages_fast(addr, n, |
1335 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, | |
1336 | pages); | |
e5393fae AV |
1337 | if (unlikely(res < 0)) |
1338 | return res; | |
1339 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1340 | 0;}),({ | |
1341 | /* can't be more than PAGE_SIZE */ | |
1342 | *start = v.bv_offset; | |
1343 | get_page(*pages = v.bv_page); | |
1344 | return v.bv_len; | |
a280455f AV |
1345 | }),({ |
1346 | return -EFAULT; | |
e5393fae AV |
1347 | }) |
1348 | ) | |
1349 | return 0; | |
62a8067a AV |
1350 | } |
1351 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1352 | ||
1b17f1f2 AV |
1353 | static struct page **get_pages_array(size_t n) |
1354 | { | |
752ade68 | 1355 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1356 | } |
1357 | ||
241699cd AV |
1358 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1359 | struct page ***pages, size_t maxsize, | |
1360 | size_t *start) | |
1361 | { | |
1362 | struct page **p; | |
8cefc107 | 1363 | unsigned int iter_head, npages; |
d7760d63 | 1364 | ssize_t n; |
241699cd | 1365 | |
33844e66 AV |
1366 | if (!maxsize) |
1367 | return 0; | |
1368 | ||
241699cd AV |
1369 | if (!sanity(i)) |
1370 | return -EFAULT; | |
1371 | ||
8cefc107 DH |
1372 | data_start(i, &iter_head, start); |
1373 | /* Amount of free space: some of this one + all after this one */ | |
1374 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
241699cd AV |
1375 | n = npages * PAGE_SIZE - *start; |
1376 | if (maxsize > n) | |
1377 | maxsize = n; | |
1378 | else | |
1379 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1380 | p = get_pages_array(npages); | |
1381 | if (!p) | |
1382 | return -ENOMEM; | |
8cefc107 | 1383 | n = __pipe_get_pages(i, maxsize, p, iter_head, start); |
241699cd AV |
1384 | if (n > 0) |
1385 | *pages = p; | |
1386 | else | |
1387 | kvfree(p); | |
1388 | return n; | |
1389 | } | |
1390 | ||
62a8067a AV |
1391 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1392 | struct page ***pages, size_t maxsize, | |
1393 | size_t *start) | |
1394 | { | |
1b17f1f2 AV |
1395 | struct page **p; |
1396 | ||
1397 | if (maxsize > i->count) | |
1398 | maxsize = i->count; | |
1399 | ||
00e23707 | 1400 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1401 | return pipe_get_pages_alloc(i, pages, maxsize, start); |
9ea9ce04 DH |
1402 | if (unlikely(iov_iter_is_discard(i))) |
1403 | return -EFAULT; | |
1404 | ||
1b17f1f2 AV |
1405 | iterate_all_kinds(i, maxsize, v, ({ |
1406 | unsigned long addr = (unsigned long)v.iov_base; | |
1407 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1408 | int n; | |
1409 | int res; | |
1410 | ||
1411 | addr &= ~(PAGE_SIZE - 1); | |
1412 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1413 | p = get_pages_array(n); | |
1414 | if (!p) | |
1415 | return -ENOMEM; | |
73b0140b IW |
1416 | res = get_user_pages_fast(addr, n, |
1417 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); | |
1b17f1f2 AV |
1418 | if (unlikely(res < 0)) { |
1419 | kvfree(p); | |
1420 | return res; | |
1421 | } | |
1422 | *pages = p; | |
1423 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1424 | 0;}),({ | |
1425 | /* can't be more than PAGE_SIZE */ | |
1426 | *start = v.bv_offset; | |
1427 | *pages = p = get_pages_array(1); | |
1428 | if (!p) | |
1429 | return -ENOMEM; | |
1430 | get_page(*p = v.bv_page); | |
1431 | return v.bv_len; | |
a280455f AV |
1432 | }),({ |
1433 | return -EFAULT; | |
1b17f1f2 AV |
1434 | }) |
1435 | ) | |
1436 | return 0; | |
62a8067a AV |
1437 | } |
1438 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1439 | ||
a604ec7e AV |
1440 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1441 | struct iov_iter *i) | |
1442 | { | |
1443 | char *to = addr; | |
1444 | __wsum sum, next; | |
1445 | size_t off = 0; | |
a604ec7e | 1446 | sum = *csum; |
9ea9ce04 | 1447 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1448 | WARN_ON(1); |
1449 | return 0; | |
1450 | } | |
a604ec7e AV |
1451 | iterate_and_advance(i, bytes, v, ({ |
1452 | int err = 0; | |
cbbd26b8 | 1453 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e AV |
1454 | (to += v.iov_len) - v.iov_len, |
1455 | v.iov_len, 0, &err); | |
1456 | if (!err) { | |
1457 | sum = csum_block_add(sum, next, off); | |
1458 | off += v.iov_len; | |
1459 | } | |
1460 | err ? v.iov_len : 0; | |
1461 | }), ({ | |
1462 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1463 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1464 | p + v.bv_offset, v.bv_len, | |
1465 | sum, off); | |
a604ec7e | 1466 | kunmap_atomic(p); |
a604ec7e AV |
1467 | off += v.bv_len; |
1468 | }),({ | |
f9152895 AV |
1469 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1470 | v.iov_base, v.iov_len, | |
1471 | sum, off); | |
a604ec7e AV |
1472 | off += v.iov_len; |
1473 | }) | |
1474 | ) | |
1475 | *csum = sum; | |
1476 | return bytes; | |
1477 | } | |
1478 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1479 | ||
cbbd26b8 AV |
1480 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
1481 | struct iov_iter *i) | |
1482 | { | |
1483 | char *to = addr; | |
1484 | __wsum sum, next; | |
1485 | size_t off = 0; | |
1486 | sum = *csum; | |
9ea9ce04 | 1487 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
cbbd26b8 AV |
1488 | WARN_ON(1); |
1489 | return false; | |
1490 | } | |
1491 | if (unlikely(i->count < bytes)) | |
1492 | return false; | |
1493 | iterate_all_kinds(i, bytes, v, ({ | |
1494 | int err = 0; | |
1495 | next = csum_and_copy_from_user(v.iov_base, | |
1496 | (to += v.iov_len) - v.iov_len, | |
1497 | v.iov_len, 0, &err); | |
1498 | if (err) | |
1499 | return false; | |
1500 | sum = csum_block_add(sum, next, off); | |
1501 | off += v.iov_len; | |
1502 | 0; | |
1503 | }), ({ | |
1504 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1505 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1506 | p + v.bv_offset, v.bv_len, | |
1507 | sum, off); | |
cbbd26b8 | 1508 | kunmap_atomic(p); |
cbbd26b8 AV |
1509 | off += v.bv_len; |
1510 | }),({ | |
f9152895 AV |
1511 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1512 | v.iov_base, v.iov_len, | |
1513 | sum, off); | |
cbbd26b8 AV |
1514 | off += v.iov_len; |
1515 | }) | |
1516 | ) | |
1517 | *csum = sum; | |
1518 | iov_iter_advance(i, bytes); | |
1519 | return true; | |
1520 | } | |
1521 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1522 | ||
cb002d07 | 1523 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, |
a604ec7e AV |
1524 | struct iov_iter *i) |
1525 | { | |
36f7a8a4 | 1526 | const char *from = addr; |
cb002d07 | 1527 | __wsum *csum = csump; |
a604ec7e AV |
1528 | __wsum sum, next; |
1529 | size_t off = 0; | |
78e1f386 AV |
1530 | |
1531 | if (unlikely(iov_iter_is_pipe(i))) | |
1532 | return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); | |
1533 | ||
a604ec7e | 1534 | sum = *csum; |
78e1f386 | 1535 | if (unlikely(iov_iter_is_discard(i))) { |
241699cd AV |
1536 | WARN_ON(1); /* for now */ |
1537 | return 0; | |
1538 | } | |
a604ec7e AV |
1539 | iterate_and_advance(i, bytes, v, ({ |
1540 | int err = 0; | |
1541 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
cbbd26b8 | 1542 | v.iov_base, |
a604ec7e AV |
1543 | v.iov_len, 0, &err); |
1544 | if (!err) { | |
1545 | sum = csum_block_add(sum, next, off); | |
1546 | off += v.iov_len; | |
1547 | } | |
1548 | err ? v.iov_len : 0; | |
1549 | }), ({ | |
1550 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1551 | sum = csum_and_memcpy(p + v.bv_offset, |
1552 | (from += v.bv_len) - v.bv_len, | |
1553 | v.bv_len, sum, off); | |
a604ec7e | 1554 | kunmap_atomic(p); |
a604ec7e AV |
1555 | off += v.bv_len; |
1556 | }),({ | |
f9152895 AV |
1557 | sum = csum_and_memcpy(v.iov_base, |
1558 | (from += v.iov_len) - v.iov_len, | |
1559 | v.iov_len, sum, off); | |
a604ec7e AV |
1560 | off += v.iov_len; |
1561 | }) | |
1562 | ) | |
1563 | *csum = sum; | |
1564 | return bytes; | |
1565 | } | |
1566 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1567 | ||
d05f4435 SG |
1568 | size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
1569 | struct iov_iter *i) | |
1570 | { | |
7999096f | 1571 | #ifdef CONFIG_CRYPTO_HASH |
d05f4435 SG |
1572 | struct ahash_request *hash = hashp; |
1573 | struct scatterlist sg; | |
1574 | size_t copied; | |
1575 | ||
1576 | copied = copy_to_iter(addr, bytes, i); | |
1577 | sg_init_one(&sg, addr, copied); | |
1578 | ahash_request_set_crypt(hash, &sg, NULL, copied); | |
1579 | crypto_ahash_update(hash); | |
1580 | return copied; | |
27fad74a Y |
1581 | #else |
1582 | return 0; | |
1583 | #endif | |
d05f4435 SG |
1584 | } |
1585 | EXPORT_SYMBOL(hash_and_copy_to_iter); | |
1586 | ||
62a8067a AV |
1587 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1588 | { | |
e0f2dc40 AV |
1589 | size_t size = i->count; |
1590 | int npages = 0; | |
1591 | ||
1592 | if (!size) | |
1593 | return 0; | |
9ea9ce04 DH |
1594 | if (unlikely(iov_iter_is_discard(i))) |
1595 | return 0; | |
e0f2dc40 | 1596 | |
00e23707 | 1597 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd | 1598 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 | 1599 | unsigned int iter_head; |
241699cd | 1600 | size_t off; |
241699cd AV |
1601 | |
1602 | if (!sanity(i)) | |
1603 | return 0; | |
1604 | ||
8cefc107 | 1605 | data_start(i, &iter_head, &off); |
241699cd | 1606 | /* some of this one + all after this one */ |
8cefc107 | 1607 | npages = pipe_space_for_user(iter_head, pipe->tail, pipe); |
241699cd AV |
1608 | if (npages >= maxpages) |
1609 | return maxpages; | |
1610 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1611 | unsigned long p = (unsigned long)v.iov_base; |
1612 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1613 | - p / PAGE_SIZE; | |
1614 | if (npages >= maxpages) | |
1615 | return maxpages; | |
1616 | 0;}),({ | |
1617 | npages++; | |
1618 | if (npages >= maxpages) | |
1619 | return maxpages; | |
a280455f AV |
1620 | }),({ |
1621 | unsigned long p = (unsigned long)v.iov_base; | |
1622 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1623 | - p / PAGE_SIZE; | |
1624 | if (npages >= maxpages) | |
1625 | return maxpages; | |
e0f2dc40 AV |
1626 | }) |
1627 | ) | |
1628 | return npages; | |
62a8067a | 1629 | } |
f67da30c | 1630 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1631 | |
1632 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1633 | { | |
1634 | *new = *old; | |
00e23707 | 1635 | if (unlikely(iov_iter_is_pipe(new))) { |
241699cd AV |
1636 | WARN_ON(1); |
1637 | return NULL; | |
1638 | } | |
9ea9ce04 DH |
1639 | if (unlikely(iov_iter_is_discard(new))) |
1640 | return NULL; | |
00e23707 | 1641 | if (iov_iter_is_bvec(new)) |
4b8164b9 AV |
1642 | return new->bvec = kmemdup(new->bvec, |
1643 | new->nr_segs * sizeof(struct bio_vec), | |
1644 | flags); | |
1645 | else | |
1646 | /* iovec and kvec have identical layout */ | |
1647 | return new->iov = kmemdup(new->iov, | |
1648 | new->nr_segs * sizeof(struct iovec), | |
1649 | flags); | |
1650 | } | |
1651 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1652 | |
ffecee4f VN |
1653 | /** |
1654 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1655 | * into the kernel, check that it is valid, and initialize a new | |
1656 | * &struct iov_iter iterator to access it. | |
1657 | * | |
1658 | * @type: One of %READ or %WRITE. | |
1659 | * @uvector: Pointer to the userspace array. | |
1660 | * @nr_segs: Number of elements in userspace array. | |
1661 | * @fast_segs: Number of elements in @iov. | |
1662 | * @iov: (input and output parameter) Pointer to pointer to (usually small | |
1663 | * on-stack) kernel array. | |
1664 | * @i: Pointer to iterator that will be initialized on success. | |
1665 | * | |
1666 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1667 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1668 | * array will be allocated and the result placed in *@iov. This means that | |
1669 | * the caller may call kfree() on *@iov regardless of whether the small | |
1670 | * on-stack array was used or not (and regardless of whether this function | |
1671 | * returns an error or not). | |
1672 | * | |
87e5e6da | 1673 | * Return: Negative error code on error, bytes imported on success |
ffecee4f | 1674 | */ |
87e5e6da | 1675 | ssize_t import_iovec(int type, const struct iovec __user * uvector, |
bc917be8 AV |
1676 | unsigned nr_segs, unsigned fast_segs, |
1677 | struct iovec **iov, struct iov_iter *i) | |
1678 | { | |
1679 | ssize_t n; | |
1680 | struct iovec *p; | |
1681 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1682 | *iov, &p); | |
1683 | if (n < 0) { | |
1684 | if (p != *iov) | |
1685 | kfree(p); | |
1686 | *iov = NULL; | |
1687 | return n; | |
1688 | } | |
1689 | iov_iter_init(i, type, p, nr_segs, n); | |
1690 | *iov = p == *iov ? NULL : p; | |
87e5e6da | 1691 | return n; |
bc917be8 AV |
1692 | } |
1693 | EXPORT_SYMBOL(import_iovec); | |
1694 | ||
1695 | #ifdef CONFIG_COMPAT | |
1696 | #include <linux/compat.h> | |
1697 | ||
87e5e6da JA |
1698 | ssize_t compat_import_iovec(int type, |
1699 | const struct compat_iovec __user * uvector, | |
1700 | unsigned nr_segs, unsigned fast_segs, | |
1701 | struct iovec **iov, struct iov_iter *i) | |
bc917be8 AV |
1702 | { |
1703 | ssize_t n; | |
1704 | struct iovec *p; | |
1705 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1706 | *iov, &p); | |
1707 | if (n < 0) { | |
1708 | if (p != *iov) | |
1709 | kfree(p); | |
1710 | *iov = NULL; | |
1711 | return n; | |
1712 | } | |
1713 | iov_iter_init(i, type, p, nr_segs, n); | |
1714 | *iov = p == *iov ? NULL : p; | |
87e5e6da | 1715 | return n; |
bc917be8 | 1716 | } |
98aaaec4 | 1717 | EXPORT_SYMBOL(compat_import_iovec); |
bc917be8 AV |
1718 | #endif |
1719 | ||
1720 | int import_single_range(int rw, void __user *buf, size_t len, | |
1721 | struct iovec *iov, struct iov_iter *i) | |
1722 | { | |
1723 | if (len > MAX_RW_COUNT) | |
1724 | len = MAX_RW_COUNT; | |
96d4f267 | 1725 | if (unlikely(!access_ok(buf, len))) |
bc917be8 AV |
1726 | return -EFAULT; |
1727 | ||
1728 | iov->iov_base = buf; | |
1729 | iov->iov_len = len; | |
1730 | iov_iter_init(i, rw, iov, 1, len); | |
1731 | return 0; | |
1732 | } | |
e1267585 | 1733 | EXPORT_SYMBOL(import_single_range); |
09cf698a AV |
1734 | |
1735 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1736 | int (*f)(struct kvec *vec, void *context), | |
1737 | void *context) | |
1738 | { | |
1739 | struct kvec w; | |
1740 | int err = -EINVAL; | |
1741 | if (!bytes) | |
1742 | return 0; | |
1743 | ||
1744 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1745 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1746 | w.iov_len = v.bv_len; | |
1747 | err = f(&w, context); | |
1748 | kunmap(v.bv_page); | |
1749 | err;}), ({ | |
1750 | w = v; | |
1751 | err = f(&w, context);}) | |
1752 | ) | |
1753 | return err; | |
1754 | } | |
1755 | EXPORT_SYMBOL(iov_iter_for_each_range); |