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