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> |
bfdc5970 | 10 | #include <linux/compat.h> |
a604ec7e | 11 | #include <net/checksum.h> |
d05f4435 | 12 | #include <linux/scatterlist.h> |
d0ef4c36 | 13 | #include <linux/instrumented.h> |
4f18cd31 | 14 | |
241699cd AV |
15 | #define PIPE_PARANOIA /* for now */ |
16 | ||
04a31165 AV |
17 | #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ |
18 | size_t left; \ | |
19 | size_t wanted = n; \ | |
20 | __p = i->iov; \ | |
21 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
22 | if (likely(__v.iov_len)) { \ | |
23 | __v.iov_base = __p->iov_base + skip; \ | |
24 | left = (STEP); \ | |
25 | __v.iov_len -= left; \ | |
26 | skip += __v.iov_len; \ | |
27 | n -= __v.iov_len; \ | |
28 | } else { \ | |
29 | left = 0; \ | |
30 | } \ | |
31 | while (unlikely(!left && n)) { \ | |
32 | __p++; \ | |
33 | __v.iov_len = min(n, __p->iov_len); \ | |
34 | if (unlikely(!__v.iov_len)) \ | |
35 | continue; \ | |
36 | __v.iov_base = __p->iov_base; \ | |
37 | left = (STEP); \ | |
38 | __v.iov_len -= left; \ | |
39 | skip = __v.iov_len; \ | |
40 | n -= __v.iov_len; \ | |
41 | } \ | |
42 | n = wanted - n; \ | |
43 | } | |
44 | ||
a280455f AV |
45 | #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ |
46 | size_t wanted = n; \ | |
47 | __p = i->kvec; \ | |
48 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
49 | if (likely(__v.iov_len)) { \ | |
50 | __v.iov_base = __p->iov_base + skip; \ | |
51 | (void)(STEP); \ | |
52 | skip += __v.iov_len; \ | |
53 | n -= __v.iov_len; \ | |
54 | } \ | |
55 | while (unlikely(n)) { \ | |
56 | __p++; \ | |
57 | __v.iov_len = min(n, __p->iov_len); \ | |
58 | if (unlikely(!__v.iov_len)) \ | |
59 | continue; \ | |
60 | __v.iov_base = __p->iov_base; \ | |
61 | (void)(STEP); \ | |
62 | skip = __v.iov_len; \ | |
63 | n -= __v.iov_len; \ | |
64 | } \ | |
65 | n = wanted; \ | |
66 | } | |
67 | ||
1bdc76ae ML |
68 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ |
69 | struct bvec_iter __start; \ | |
70 | __start.bi_size = n; \ | |
71 | __start.bi_bvec_done = skip; \ | |
72 | __start.bi_idx = 0; \ | |
73 | for_each_bvec(__v, i->bvec, __bi, __start) { \ | |
74 | if (!__v.bv_len) \ | |
04a31165 | 75 | continue; \ |
04a31165 | 76 | (void)(STEP); \ |
04a31165 | 77 | } \ |
04a31165 AV |
78 | } |
79 | ||
a280455f | 80 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
33844e66 AV |
81 | if (likely(n)) { \ |
82 | size_t skip = i->iov_offset; \ | |
83 | if (unlikely(i->type & ITER_BVEC)) { \ | |
84 | struct bio_vec v; \ | |
85 | struct bvec_iter __bi; \ | |
86 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
87 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
88 | const struct kvec *kvec; \ | |
89 | struct kvec v; \ | |
90 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
9ea9ce04 | 91 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
33844e66 AV |
92 | } else { \ |
93 | const struct iovec *iov; \ | |
94 | struct iovec v; \ | |
95 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
96 | } \ | |
04a31165 AV |
97 | } \ |
98 | } | |
99 | ||
a280455f | 100 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
101 | if (unlikely(i->count < n)) \ |
102 | n = i->count; \ | |
19f18459 | 103 | if (i->count) { \ |
dd254f5a AV |
104 | size_t skip = i->iov_offset; \ |
105 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 106 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 107 | struct bio_vec v; \ |
1bdc76ae ML |
108 | struct bvec_iter __bi; \ |
109 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
110 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
111 | i->nr_segs -= i->bvec - bvec; \ | |
112 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
113 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
114 | const struct kvec *kvec; \ | |
115 | struct kvec v; \ | |
116 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
117 | if (skip == kvec->iov_len) { \ | |
118 | kvec++; \ | |
119 | skip = 0; \ | |
120 | } \ | |
121 | i->nr_segs -= kvec - i->kvec; \ | |
122 | i->kvec = kvec; \ | |
9ea9ce04 DH |
123 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
124 | skip += n; \ | |
dd254f5a AV |
125 | } else { \ |
126 | const struct iovec *iov; \ | |
127 | struct iovec v; \ | |
128 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
129 | if (skip == iov->iov_len) { \ | |
130 | iov++; \ | |
131 | skip = 0; \ | |
132 | } \ | |
133 | i->nr_segs -= iov - i->iov; \ | |
134 | i->iov = iov; \ | |
7ce2a91e | 135 | } \ |
dd254f5a AV |
136 | i->count -= n; \ |
137 | i->iov_offset = skip; \ | |
7ce2a91e | 138 | } \ |
7ce2a91e AV |
139 | } |
140 | ||
09fc68dc AV |
141 | static int copyout(void __user *to, const void *from, size_t n) |
142 | { | |
96d4f267 | 143 | if (access_ok(to, n)) { |
d0ef4c36 | 144 | instrument_copy_to_user(to, from, n); |
09fc68dc AV |
145 | n = raw_copy_to_user(to, from, n); |
146 | } | |
147 | return n; | |
148 | } | |
149 | ||
150 | static int copyin(void *to, const void __user *from, size_t n) | |
151 | { | |
96d4f267 | 152 | if (access_ok(from, n)) { |
d0ef4c36 | 153 | instrument_copy_from_user(to, from, n); |
09fc68dc AV |
154 | n = raw_copy_from_user(to, from, n); |
155 | } | |
156 | return n; | |
157 | } | |
158 | ||
62a8067a | 159 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
160 | struct iov_iter *i) |
161 | { | |
162 | size_t skip, copy, left, wanted; | |
163 | const struct iovec *iov; | |
164 | char __user *buf; | |
165 | void *kaddr, *from; | |
166 | ||
167 | if (unlikely(bytes > i->count)) | |
168 | bytes = i->count; | |
169 | ||
170 | if (unlikely(!bytes)) | |
171 | return 0; | |
172 | ||
09fc68dc | 173 | might_fault(); |
4f18cd31 AV |
174 | wanted = bytes; |
175 | iov = i->iov; | |
176 | skip = i->iov_offset; | |
177 | buf = iov->iov_base + skip; | |
178 | copy = min(bytes, iov->iov_len - skip); | |
179 | ||
3fa6c507 | 180 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
181 | kaddr = kmap_atomic(page); |
182 | from = kaddr + offset; | |
183 | ||
184 | /* first chunk, usually the only one */ | |
09fc68dc | 185 | left = copyout(buf, from, copy); |
4f18cd31 AV |
186 | copy -= left; |
187 | skip += copy; | |
188 | from += copy; | |
189 | bytes -= copy; | |
190 | ||
191 | while (unlikely(!left && bytes)) { | |
192 | iov++; | |
193 | buf = iov->iov_base; | |
194 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 195 | left = copyout(buf, from, copy); |
4f18cd31 AV |
196 | copy -= left; |
197 | skip = copy; | |
198 | from += copy; | |
199 | bytes -= copy; | |
200 | } | |
201 | if (likely(!bytes)) { | |
202 | kunmap_atomic(kaddr); | |
203 | goto done; | |
204 | } | |
205 | offset = from - kaddr; | |
206 | buf += copy; | |
207 | kunmap_atomic(kaddr); | |
208 | copy = min(bytes, iov->iov_len - skip); | |
209 | } | |
210 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 211 | |
4f18cd31 AV |
212 | kaddr = kmap(page); |
213 | from = kaddr + offset; | |
09fc68dc | 214 | left = copyout(buf, from, copy); |
4f18cd31 AV |
215 | copy -= left; |
216 | skip += copy; | |
217 | from += copy; | |
218 | bytes -= copy; | |
219 | while (unlikely(!left && bytes)) { | |
220 | iov++; | |
221 | buf = iov->iov_base; | |
222 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 223 | left = copyout(buf, from, copy); |
4f18cd31 AV |
224 | copy -= left; |
225 | skip = copy; | |
226 | from += copy; | |
227 | bytes -= copy; | |
228 | } | |
229 | kunmap(page); | |
3fa6c507 | 230 | |
4f18cd31 | 231 | done: |
81055e58 AV |
232 | if (skip == iov->iov_len) { |
233 | iov++; | |
234 | skip = 0; | |
235 | } | |
4f18cd31 AV |
236 | i->count -= wanted - bytes; |
237 | i->nr_segs -= iov - i->iov; | |
238 | i->iov = iov; | |
239 | i->iov_offset = skip; | |
240 | return wanted - bytes; | |
241 | } | |
4f18cd31 | 242 | |
62a8067a | 243 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
244 | struct iov_iter *i) |
245 | { | |
246 | size_t skip, copy, left, wanted; | |
247 | const struct iovec *iov; | |
248 | char __user *buf; | |
249 | void *kaddr, *to; | |
250 | ||
251 | if (unlikely(bytes > i->count)) | |
252 | bytes = i->count; | |
253 | ||
254 | if (unlikely(!bytes)) | |
255 | return 0; | |
256 | ||
09fc68dc | 257 | might_fault(); |
f0d1bec9 AV |
258 | wanted = bytes; |
259 | iov = i->iov; | |
260 | skip = i->iov_offset; | |
261 | buf = iov->iov_base + skip; | |
262 | copy = min(bytes, iov->iov_len - skip); | |
263 | ||
3fa6c507 | 264 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
265 | kaddr = kmap_atomic(page); |
266 | to = kaddr + offset; | |
267 | ||
268 | /* first chunk, usually the only one */ | |
09fc68dc | 269 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
270 | copy -= left; |
271 | skip += copy; | |
272 | to += copy; | |
273 | bytes -= copy; | |
274 | ||
275 | while (unlikely(!left && bytes)) { | |
276 | iov++; | |
277 | buf = iov->iov_base; | |
278 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 279 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
280 | copy -= left; |
281 | skip = copy; | |
282 | to += copy; | |
283 | bytes -= copy; | |
284 | } | |
285 | if (likely(!bytes)) { | |
286 | kunmap_atomic(kaddr); | |
287 | goto done; | |
288 | } | |
289 | offset = to - kaddr; | |
290 | buf += copy; | |
291 | kunmap_atomic(kaddr); | |
292 | copy = min(bytes, iov->iov_len - skip); | |
293 | } | |
294 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 295 | |
f0d1bec9 AV |
296 | kaddr = kmap(page); |
297 | to = kaddr + offset; | |
09fc68dc | 298 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
299 | copy -= left; |
300 | skip += copy; | |
301 | to += copy; | |
302 | bytes -= copy; | |
303 | while (unlikely(!left && bytes)) { | |
304 | iov++; | |
305 | buf = iov->iov_base; | |
306 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 307 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
308 | copy -= left; |
309 | skip = copy; | |
310 | to += copy; | |
311 | bytes -= copy; | |
312 | } | |
313 | kunmap(page); | |
3fa6c507 | 314 | |
f0d1bec9 | 315 | done: |
81055e58 AV |
316 | if (skip == iov->iov_len) { |
317 | iov++; | |
318 | skip = 0; | |
319 | } | |
f0d1bec9 AV |
320 | i->count -= wanted - bytes; |
321 | i->nr_segs -= iov - i->iov; | |
322 | i->iov = iov; | |
323 | i->iov_offset = skip; | |
324 | return wanted - bytes; | |
325 | } | |
f0d1bec9 | 326 | |
241699cd AV |
327 | #ifdef PIPE_PARANOIA |
328 | static bool sanity(const struct iov_iter *i) | |
329 | { | |
330 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
331 | unsigned int p_head = pipe->head; |
332 | unsigned int p_tail = pipe->tail; | |
333 | unsigned int p_mask = pipe->ring_size - 1; | |
334 | unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); | |
335 | unsigned int i_head = i->head; | |
336 | unsigned int idx; | |
337 | ||
241699cd AV |
338 | if (i->iov_offset) { |
339 | struct pipe_buffer *p; | |
8cefc107 | 340 | if (unlikely(p_occupancy == 0)) |
241699cd | 341 | goto Bad; // pipe must be non-empty |
8cefc107 | 342 | if (unlikely(i_head != p_head - 1)) |
241699cd AV |
343 | goto Bad; // must be at the last buffer... |
344 | ||
8cefc107 | 345 | p = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
346 | if (unlikely(p->offset + p->len != i->iov_offset)) |
347 | goto Bad; // ... at the end of segment | |
348 | } else { | |
8cefc107 | 349 | if (i_head != p_head) |
241699cd AV |
350 | goto Bad; // must be right after the last buffer |
351 | } | |
352 | return true; | |
353 | Bad: | |
8cefc107 DH |
354 | printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); |
355 | printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", | |
356 | p_head, p_tail, pipe->ring_size); | |
357 | for (idx = 0; idx < pipe->ring_size; idx++) | |
241699cd AV |
358 | printk(KERN_ERR "[%p %p %d %d]\n", |
359 | pipe->bufs[idx].ops, | |
360 | pipe->bufs[idx].page, | |
361 | pipe->bufs[idx].offset, | |
362 | pipe->bufs[idx].len); | |
363 | WARN_ON(1); | |
364 | return false; | |
365 | } | |
366 | #else | |
367 | #define sanity(i) true | |
368 | #endif | |
369 | ||
241699cd AV |
370 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, |
371 | struct iov_iter *i) | |
372 | { | |
373 | struct pipe_inode_info *pipe = i->pipe; | |
374 | struct pipe_buffer *buf; | |
8cefc107 DH |
375 | unsigned int p_tail = pipe->tail; |
376 | unsigned int p_mask = pipe->ring_size - 1; | |
377 | unsigned int i_head = i->head; | |
241699cd | 378 | size_t off; |
241699cd AV |
379 | |
380 | if (unlikely(bytes > i->count)) | |
381 | bytes = i->count; | |
382 | ||
383 | if (unlikely(!bytes)) | |
384 | return 0; | |
385 | ||
386 | if (!sanity(i)) | |
387 | return 0; | |
388 | ||
389 | off = i->iov_offset; | |
8cefc107 | 390 | buf = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
391 | if (off) { |
392 | if (offset == off && buf->page == page) { | |
393 | /* merge with the last one */ | |
394 | buf->len += bytes; | |
395 | i->iov_offset += bytes; | |
396 | goto out; | |
397 | } | |
8cefc107 DH |
398 | i_head++; |
399 | buf = &pipe->bufs[i_head & p_mask]; | |
241699cd | 400 | } |
6718b6f8 | 401 | if (pipe_full(i_head, p_tail, pipe->max_usage)) |
241699cd | 402 | return 0; |
8cefc107 | 403 | |
241699cd | 404 | buf->ops = &page_cache_pipe_buf_ops; |
8cefc107 DH |
405 | get_page(page); |
406 | buf->page = page; | |
241699cd AV |
407 | buf->offset = offset; |
408 | buf->len = bytes; | |
8cefc107 DH |
409 | |
410 | pipe->head = i_head + 1; | |
241699cd | 411 | i->iov_offset = offset + bytes; |
8cefc107 | 412 | i->head = i_head; |
241699cd AV |
413 | out: |
414 | i->count -= bytes; | |
415 | return bytes; | |
416 | } | |
417 | ||
171a0203 AA |
418 | /* |
419 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
420 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
421 | * | |
422 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
423 | * because it is an invalid address). | |
424 | */ | |
d4690f1e | 425 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
426 | { |
427 | size_t skip = i->iov_offset; | |
428 | const struct iovec *iov; | |
429 | int err; | |
430 | struct iovec v; | |
431 | ||
432 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
433 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
4bce9f6e | 434 | err = fault_in_pages_readable(v.iov_base, v.iov_len); |
171a0203 AA |
435 | if (unlikely(err)) |
436 | return err; | |
437 | 0;})) | |
438 | } | |
439 | return 0; | |
440 | } | |
d4690f1e | 441 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 442 | |
aa563d7b | 443 | void iov_iter_init(struct iov_iter *i, unsigned int direction, |
71d8e532 AV |
444 | const struct iovec *iov, unsigned long nr_segs, |
445 | size_t count) | |
446 | { | |
aa563d7b DH |
447 | WARN_ON(direction & ~(READ | WRITE)); |
448 | direction &= READ | WRITE; | |
449 | ||
71d8e532 | 450 | /* It will get better. Eventually... */ |
db68ce10 | 451 | if (uaccess_kernel()) { |
aa563d7b | 452 | i->type = ITER_KVEC | direction; |
a280455f AV |
453 | i->kvec = (struct kvec *)iov; |
454 | } else { | |
aa563d7b | 455 | i->type = ITER_IOVEC | direction; |
a280455f AV |
456 | i->iov = iov; |
457 | } | |
71d8e532 AV |
458 | i->nr_segs = nr_segs; |
459 | i->iov_offset = 0; | |
460 | i->count = count; | |
461 | } | |
462 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 463 | |
62a8067a AV |
464 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
465 | { | |
466 | char *from = kmap_atomic(page); | |
467 | memcpy(to, from + offset, len); | |
468 | kunmap_atomic(from); | |
469 | } | |
470 | ||
36f7a8a4 | 471 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
472 | { |
473 | char *to = kmap_atomic(page); | |
474 | memcpy(to + offset, from, len); | |
475 | kunmap_atomic(to); | |
476 | } | |
477 | ||
c35e0248 MW |
478 | static void memzero_page(struct page *page, size_t offset, size_t len) |
479 | { | |
480 | char *addr = kmap_atomic(page); | |
481 | memset(addr + offset, 0, len); | |
482 | kunmap_atomic(addr); | |
483 | } | |
484 | ||
241699cd AV |
485 | static inline bool allocated(struct pipe_buffer *buf) |
486 | { | |
487 | return buf->ops == &default_pipe_buf_ops; | |
488 | } | |
489 | ||
8cefc107 DH |
490 | static inline void data_start(const struct iov_iter *i, |
491 | unsigned int *iter_headp, size_t *offp) | |
241699cd | 492 | { |
8cefc107 DH |
493 | unsigned int p_mask = i->pipe->ring_size - 1; |
494 | unsigned int iter_head = i->head; | |
241699cd | 495 | size_t off = i->iov_offset; |
8cefc107 DH |
496 | |
497 | if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || | |
498 | off == PAGE_SIZE)) { | |
499 | iter_head++; | |
241699cd AV |
500 | off = 0; |
501 | } | |
8cefc107 | 502 | *iter_headp = iter_head; |
241699cd AV |
503 | *offp = off; |
504 | } | |
505 | ||
506 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
8cefc107 | 507 | int *iter_headp, size_t *offp) |
241699cd AV |
508 | { |
509 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
510 | unsigned int p_tail = pipe->tail; |
511 | unsigned int p_mask = pipe->ring_size - 1; | |
512 | unsigned int iter_head; | |
241699cd | 513 | size_t off; |
241699cd AV |
514 | ssize_t left; |
515 | ||
516 | if (unlikely(size > i->count)) | |
517 | size = i->count; | |
518 | if (unlikely(!size)) | |
519 | return 0; | |
520 | ||
521 | left = size; | |
8cefc107 DH |
522 | data_start(i, &iter_head, &off); |
523 | *iter_headp = iter_head; | |
241699cd AV |
524 | *offp = off; |
525 | if (off) { | |
526 | left -= PAGE_SIZE - off; | |
527 | if (left <= 0) { | |
8cefc107 | 528 | pipe->bufs[iter_head & p_mask].len += size; |
241699cd AV |
529 | return size; |
530 | } | |
8cefc107 DH |
531 | pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; |
532 | iter_head++; | |
241699cd | 533 | } |
6718b6f8 | 534 | while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { |
8cefc107 | 535 | struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; |
241699cd AV |
536 | struct page *page = alloc_page(GFP_USER); |
537 | if (!page) | |
538 | break; | |
8cefc107 DH |
539 | |
540 | buf->ops = &default_pipe_buf_ops; | |
541 | buf->page = page; | |
542 | buf->offset = 0; | |
543 | buf->len = min_t(ssize_t, left, PAGE_SIZE); | |
544 | left -= buf->len; | |
545 | iter_head++; | |
546 | pipe->head = iter_head; | |
547 | ||
548 | if (left == 0) | |
241699cd | 549 | return size; |
241699cd AV |
550 | } |
551 | return size - left; | |
552 | } | |
553 | ||
554 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
555 | struct iov_iter *i) | |
556 | { | |
557 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
558 | unsigned int p_mask = pipe->ring_size - 1; |
559 | unsigned int i_head; | |
241699cd | 560 | size_t n, off; |
241699cd AV |
561 | |
562 | if (!sanity(i)) | |
563 | return 0; | |
564 | ||
8cefc107 | 565 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
566 | if (unlikely(!n)) |
567 | return 0; | |
8cefc107 | 568 | do { |
241699cd | 569 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
570 | memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); |
571 | i->head = i_head; | |
241699cd AV |
572 | i->iov_offset = off + chunk; |
573 | n -= chunk; | |
574 | addr += chunk; | |
8cefc107 DH |
575 | off = 0; |
576 | i_head++; | |
577 | } while (n); | |
241699cd AV |
578 | i->count -= bytes; |
579 | return bytes; | |
580 | } | |
581 | ||
f9152895 AV |
582 | static __wsum csum_and_memcpy(void *to, const void *from, size_t len, |
583 | __wsum sum, size_t off) | |
584 | { | |
cc44c17b | 585 | __wsum next = csum_partial_copy_nocheck(from, to, len); |
f9152895 AV |
586 | return csum_block_add(sum, next, off); |
587 | } | |
588 | ||
78e1f386 AV |
589 | static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, |
590 | __wsum *csum, struct iov_iter *i) | |
591 | { | |
592 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
593 | unsigned int p_mask = pipe->ring_size - 1; |
594 | unsigned int i_head; | |
78e1f386 AV |
595 | size_t n, r; |
596 | size_t off = 0; | |
f9152895 | 597 | __wsum sum = *csum; |
78e1f386 AV |
598 | |
599 | if (!sanity(i)) | |
600 | return 0; | |
601 | ||
8cefc107 | 602 | bytes = n = push_pipe(i, bytes, &i_head, &r); |
78e1f386 AV |
603 | if (unlikely(!n)) |
604 | return 0; | |
8cefc107 | 605 | do { |
78e1f386 | 606 | size_t chunk = min_t(size_t, n, PAGE_SIZE - r); |
8cefc107 | 607 | char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); |
f9152895 | 608 | sum = csum_and_memcpy(p + r, addr, chunk, sum, off); |
78e1f386 | 609 | kunmap_atomic(p); |
8cefc107 | 610 | i->head = i_head; |
78e1f386 AV |
611 | i->iov_offset = r + chunk; |
612 | n -= chunk; | |
613 | off += chunk; | |
614 | addr += chunk; | |
8cefc107 DH |
615 | r = 0; |
616 | i_head++; | |
617 | } while (n); | |
78e1f386 AV |
618 | i->count -= bytes; |
619 | *csum = sum; | |
620 | return bytes; | |
621 | } | |
622 | ||
aa28de27 | 623 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 624 | { |
36f7a8a4 | 625 | const char *from = addr; |
00e23707 | 626 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 627 | return copy_pipe_to_iter(addr, bytes, i); |
09fc68dc AV |
628 | if (iter_is_iovec(i)) |
629 | might_fault(); | |
3d4d3e48 | 630 | iterate_and_advance(i, bytes, v, |
09fc68dc | 631 | copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
3d4d3e48 | 632 | memcpy_to_page(v.bv_page, v.bv_offset, |
a280455f AV |
633 | (from += v.bv_len) - v.bv_len, v.bv_len), |
634 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 635 | ) |
62a8067a | 636 | |
3d4d3e48 | 637 | return bytes; |
c35e0248 | 638 | } |
aa28de27 | 639 | EXPORT_SYMBOL(_copy_to_iter); |
c35e0248 | 640 | |
ec6347bb DW |
641 | #ifdef CONFIG_ARCH_HAS_COPY_MC |
642 | static int copyout_mc(void __user *to, const void *from, size_t n) | |
8780356e | 643 | { |
96d4f267 | 644 | if (access_ok(to, n)) { |
d0ef4c36 | 645 | instrument_copy_to_user(to, from, n); |
ec6347bb | 646 | n = copy_mc_to_user((__force void *) to, from, n); |
8780356e DW |
647 | } |
648 | return n; | |
649 | } | |
650 | ||
ec6347bb | 651 | static unsigned long copy_mc_to_page(struct page *page, size_t offset, |
8780356e DW |
652 | const char *from, size_t len) |
653 | { | |
654 | unsigned long ret; | |
655 | char *to; | |
656 | ||
657 | to = kmap_atomic(page); | |
ec6347bb | 658 | ret = copy_mc_to_kernel(to + offset, from, len); |
8780356e DW |
659 | kunmap_atomic(to); |
660 | ||
661 | return ret; | |
662 | } | |
663 | ||
ec6347bb | 664 | static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes, |
ca146f6f DW |
665 | struct iov_iter *i) |
666 | { | |
667 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
668 | unsigned int p_mask = pipe->ring_size - 1; |
669 | unsigned int i_head; | |
ca146f6f | 670 | size_t n, off, xfer = 0; |
ca146f6f DW |
671 | |
672 | if (!sanity(i)) | |
673 | return 0; | |
674 | ||
8cefc107 | 675 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
ca146f6f DW |
676 | if (unlikely(!n)) |
677 | return 0; | |
8cefc107 | 678 | do { |
ca146f6f DW |
679 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
680 | unsigned long rem; | |
681 | ||
ec6347bb | 682 | rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page, |
8cefc107 DH |
683 | off, addr, chunk); |
684 | i->head = i_head; | |
ca146f6f DW |
685 | i->iov_offset = off + chunk - rem; |
686 | xfer += chunk - rem; | |
687 | if (rem) | |
688 | break; | |
689 | n -= chunk; | |
690 | addr += chunk; | |
8cefc107 DH |
691 | off = 0; |
692 | i_head++; | |
693 | } while (n); | |
ca146f6f DW |
694 | i->count -= xfer; |
695 | return xfer; | |
696 | } | |
697 | ||
bf3eeb9b | 698 | /** |
ec6347bb | 699 | * _copy_mc_to_iter - copy to iter with source memory error exception handling |
bf3eeb9b DW |
700 | * @addr: source kernel address |
701 | * @bytes: total transfer length | |
702 | * @iter: destination iterator | |
703 | * | |
ec6347bb DW |
704 | * The pmem driver deploys this for the dax operation |
705 | * (dax_copy_to_iter()) for dax reads (bypass page-cache and the | |
706 | * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes | |
707 | * successfully copied. | |
bf3eeb9b | 708 | * |
ec6347bb | 709 | * The main differences between this and typical _copy_to_iter(). |
bf3eeb9b DW |
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. | |
bf3eeb9b | 720 | */ |
ec6347bb | 721 | size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
8780356e DW |
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))) |
ec6347bb | 727 | return copy_mc_pipe_to_iter(addr, bytes, i); |
8780356e DW |
728 | if (iter_is_iovec(i)) |
729 | might_fault(); | |
730 | iterate_and_advance(i, bytes, v, | |
ec6347bb DW |
731 | copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len, |
732 | v.iov_len), | |
8780356e | 733 | ({ |
ec6347bb DW |
734 | rem = copy_mc_to_page(v.bv_page, v.bv_offset, |
735 | (from += v.bv_len) - v.bv_len, v.bv_len); | |
8780356e DW |
736 | if (rem) { |
737 | curr_addr = (unsigned long) from; | |
738 | bytes = curr_addr - s_addr - rem; | |
739 | return bytes; | |
740 | } | |
741 | }), | |
742 | ({ | |
ec6347bb DW |
743 | rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len) |
744 | - v.iov_len, v.iov_len); | |
8780356e DW |
745 | if (rem) { |
746 | curr_addr = (unsigned long) from; | |
747 | bytes = curr_addr - s_addr - rem; | |
748 | return bytes; | |
749 | } | |
750 | }) | |
751 | ) | |
752 | ||
753 | return bytes; | |
754 | } | |
ec6347bb DW |
755 | EXPORT_SYMBOL_GPL(_copy_mc_to_iter); |
756 | #endif /* CONFIG_ARCH_HAS_COPY_MC */ | |
8780356e | 757 | |
aa28de27 | 758 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 759 | { |
0dbca9a4 | 760 | char *to = addr; |
00e23707 | 761 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
762 | WARN_ON(1); |
763 | return 0; | |
764 | } | |
09fc68dc AV |
765 | if (iter_is_iovec(i)) |
766 | might_fault(); | |
0dbca9a4 | 767 | iterate_and_advance(i, bytes, v, |
09fc68dc | 768 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4 | 769 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
770 | v.bv_offset, v.bv_len), |
771 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
772 | ) |
773 | ||
774 | return bytes; | |
c35e0248 | 775 | } |
aa28de27 | 776 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 777 | |
aa28de27 | 778 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
779 | { |
780 | char *to = addr; | |
00e23707 | 781 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
782 | WARN_ON(1); |
783 | return false; | |
784 | } | |
33844e66 | 785 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
786 | return false; |
787 | ||
09fc68dc AV |
788 | if (iter_is_iovec(i)) |
789 | might_fault(); | |
cbbd26b8 | 790 | iterate_all_kinds(i, bytes, v, ({ |
09fc68dc | 791 | if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
792 | v.iov_base, v.iov_len)) |
793 | return false; | |
794 | 0;}), | |
795 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
796 | v.bv_offset, v.bv_len), | |
797 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
798 | ) | |
799 | ||
800 | iov_iter_advance(i, bytes); | |
801 | return true; | |
802 | } | |
aa28de27 | 803 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 804 | |
aa28de27 | 805 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
806 | { |
807 | char *to = addr; | |
00e23707 | 808 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
809 | WARN_ON(1); |
810 | return 0; | |
811 | } | |
aa583096 | 812 | iterate_and_advance(i, bytes, v, |
3f763453 | 813 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
814 | v.iov_base, v.iov_len), |
815 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
816 | v.bv_offset, v.bv_len), | |
817 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
818 | ) | |
819 | ||
820 | return bytes; | |
821 | } | |
aa28de27 | 822 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 823 | |
0aed55af | 824 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d DW |
825 | /** |
826 | * _copy_from_iter_flushcache - write destination through cpu cache | |
827 | * @addr: destination kernel address | |
828 | * @bytes: total transfer length | |
829 | * @iter: source iterator | |
830 | * | |
831 | * The pmem driver arranges for filesystem-dax to use this facility via | |
832 | * dax_copy_from_iter() for ensuring that writes to persistent memory | |
833 | * are flushed through the CPU cache. It is differentiated from | |
834 | * _copy_from_iter_nocache() in that guarantees all data is flushed for | |
835 | * all iterator types. The _copy_from_iter_nocache() only attempts to | |
836 | * bypass the cache for the ITER_IOVEC case, and on some archs may use | |
837 | * instructions that strand dirty-data in the cache. | |
838 | */ | |
6a37e940 | 839 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af DW |
840 | { |
841 | char *to = addr; | |
00e23707 | 842 | if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af DW |
843 | WARN_ON(1); |
844 | return 0; | |
845 | } | |
846 | iterate_and_advance(i, bytes, v, | |
847 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
848 | v.iov_base, v.iov_len), | |
849 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
850 | v.bv_offset, v.bv_len), | |
851 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
852 | v.iov_len) | |
853 | ) | |
854 | ||
855 | return bytes; | |
856 | } | |
6a37e940 | 857 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af DW |
858 | #endif |
859 | ||
aa28de27 | 860 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
861 | { |
862 | char *to = addr; | |
00e23707 | 863 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
864 | WARN_ON(1); |
865 | return false; | |
866 | } | |
33844e66 | 867 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
868 | return false; |
869 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 870 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
871 | v.iov_base, v.iov_len)) |
872 | return false; | |
873 | 0;}), | |
874 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
875 | v.bv_offset, v.bv_len), | |
876 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
877 | ) | |
878 | ||
879 | iov_iter_advance(i, bytes); | |
880 | return true; | |
881 | } | |
aa28de27 | 882 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 883 | |
72e809ed AV |
884 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
885 | { | |
6daef95b ED |
886 | struct page *head; |
887 | size_t v = n + offset; | |
888 | ||
889 | /* | |
890 | * The general case needs to access the page order in order | |
891 | * to compute the page size. | |
892 | * However, we mostly deal with order-0 pages and thus can | |
893 | * avoid a possible cache line miss for requests that fit all | |
894 | * page orders. | |
895 | */ | |
896 | if (n <= v && v <= PAGE_SIZE) | |
897 | return true; | |
898 | ||
899 | head = compound_head(page); | |
900 | v += (page - head) << PAGE_SHIFT; | |
a90bcb86 | 901 | |
a50b854e | 902 | if (likely(n <= v && v <= (page_size(head)))) |
72e809ed AV |
903 | return true; |
904 | WARN_ON(1); | |
905 | return false; | |
906 | } | |
cbbd26b8 | 907 | |
62a8067a AV |
908 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
909 | struct iov_iter *i) | |
910 | { | |
72e809ed AV |
911 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
912 | return 0; | |
d271524a AV |
913 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
914 | void *kaddr = kmap_atomic(page); | |
915 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
916 | kunmap_atomic(kaddr); | |
917 | return wanted; | |
9ea9ce04 DH |
918 | } else if (unlikely(iov_iter_is_discard(i))) |
919 | return bytes; | |
920 | else if (likely(!iov_iter_is_pipe(i))) | |
62a8067a | 921 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
922 | else |
923 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
924 | } |
925 | EXPORT_SYMBOL(copy_page_to_iter); | |
926 | ||
927 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
928 | struct iov_iter *i) | |
929 | { | |
72e809ed AV |
930 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
931 | return 0; | |
9ea9ce04 | 932 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
933 | WARN_ON(1); |
934 | return 0; | |
935 | } | |
a280455f | 936 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 937 | void *kaddr = kmap_atomic(page); |
aa28de27 | 938 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
939 | kunmap_atomic(kaddr); |
940 | return wanted; | |
941 | } else | |
62a8067a AV |
942 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
943 | } | |
944 | EXPORT_SYMBOL(copy_page_from_iter); | |
945 | ||
241699cd AV |
946 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
947 | { | |
948 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
949 | unsigned int p_mask = pipe->ring_size - 1; |
950 | unsigned int i_head; | |
241699cd | 951 | size_t n, off; |
241699cd AV |
952 | |
953 | if (!sanity(i)) | |
954 | return 0; | |
955 | ||
8cefc107 | 956 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
957 | if (unlikely(!n)) |
958 | return 0; | |
959 | ||
8cefc107 | 960 | do { |
241699cd | 961 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
962 | memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); |
963 | i->head = i_head; | |
241699cd AV |
964 | i->iov_offset = off + chunk; |
965 | n -= chunk; | |
8cefc107 DH |
966 | off = 0; |
967 | i_head++; | |
968 | } while (n); | |
241699cd AV |
969 | i->count -= bytes; |
970 | return bytes; | |
971 | } | |
972 | ||
c35e0248 MW |
973 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
974 | { | |
00e23707 | 975 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 976 | return pipe_zero(bytes, i); |
8442fa46 | 977 | iterate_and_advance(i, bytes, v, |
09fc68dc | 978 | clear_user(v.iov_base, v.iov_len), |
a280455f AV |
979 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
980 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
981 | ) |
982 | ||
983 | return bytes; | |
c35e0248 MW |
984 | } |
985 | EXPORT_SYMBOL(iov_iter_zero); | |
986 | ||
62a8067a AV |
987 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
988 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
989 | { | |
04a31165 | 990 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
991 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
992 | kunmap_atomic(kaddr); | |
993 | return 0; | |
994 | } | |
9ea9ce04 | 995 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
996 | kunmap_atomic(kaddr); |
997 | WARN_ON(1); | |
998 | return 0; | |
999 | } | |
04a31165 | 1000 | iterate_all_kinds(i, bytes, v, |
09fc68dc | 1001 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a31165 | 1002 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
1003 | v.bv_offset, v.bv_len), |
1004 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
1005 | ) |
1006 | kunmap_atomic(kaddr); | |
1007 | return bytes; | |
62a8067a AV |
1008 | } |
1009 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
1010 | ||
b9dc6f65 AV |
1011 | static inline void pipe_truncate(struct iov_iter *i) |
1012 | { | |
1013 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1014 | unsigned int p_tail = pipe->tail; |
1015 | unsigned int p_head = pipe->head; | |
1016 | unsigned int p_mask = pipe->ring_size - 1; | |
1017 | ||
1018 | if (!pipe_empty(p_head, p_tail)) { | |
1019 | struct pipe_buffer *buf; | |
1020 | unsigned int i_head = i->head; | |
b9dc6f65 | 1021 | size_t off = i->iov_offset; |
8cefc107 | 1022 | |
b9dc6f65 | 1023 | if (off) { |
8cefc107 DH |
1024 | buf = &pipe->bufs[i_head & p_mask]; |
1025 | buf->len = off - buf->offset; | |
1026 | i_head++; | |
b9dc6f65 | 1027 | } |
8cefc107 DH |
1028 | while (p_head != i_head) { |
1029 | p_head--; | |
1030 | pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); | |
b9dc6f65 | 1031 | } |
8cefc107 DH |
1032 | |
1033 | pipe->head = p_head; | |
b9dc6f65 AV |
1034 | } |
1035 | } | |
1036 | ||
241699cd AV |
1037 | static void pipe_advance(struct iov_iter *i, size_t size) |
1038 | { | |
1039 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
1040 | if (unlikely(i->count < size)) |
1041 | size = i->count; | |
241699cd | 1042 | if (size) { |
b9dc6f65 | 1043 | struct pipe_buffer *buf; |
8cefc107 DH |
1044 | unsigned int p_mask = pipe->ring_size - 1; |
1045 | unsigned int i_head = i->head; | |
b9dc6f65 | 1046 | size_t off = i->iov_offset, left = size; |
8cefc107 | 1047 | |
241699cd | 1048 | if (off) /* make it relative to the beginning of buffer */ |
8cefc107 | 1049 | left += off - pipe->bufs[i_head & p_mask].offset; |
241699cd | 1050 | while (1) { |
8cefc107 | 1051 | buf = &pipe->bufs[i_head & p_mask]; |
b9dc6f65 | 1052 | if (left <= buf->len) |
241699cd | 1053 | break; |
b9dc6f65 | 1054 | left -= buf->len; |
8cefc107 | 1055 | i_head++; |
241699cd | 1056 | } |
8cefc107 | 1057 | i->head = i_head; |
b9dc6f65 | 1058 | i->iov_offset = buf->offset + left; |
241699cd | 1059 | } |
b9dc6f65 AV |
1060 | i->count -= size; |
1061 | /* ... and discard everything past that point */ | |
1062 | pipe_truncate(i); | |
241699cd AV |
1063 | } |
1064 | ||
62a8067a AV |
1065 | void iov_iter_advance(struct iov_iter *i, size_t size) |
1066 | { | |
00e23707 | 1067 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1068 | pipe_advance(i, size); |
1069 | return; | |
1070 | } | |
9ea9ce04 DH |
1071 | if (unlikely(iov_iter_is_discard(i))) { |
1072 | i->count -= size; | |
1073 | return; | |
1074 | } | |
a280455f | 1075 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
1076 | } |
1077 | EXPORT_SYMBOL(iov_iter_advance); | |
1078 | ||
27c0e374 AV |
1079 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
1080 | { | |
1081 | if (!unroll) | |
1082 | return; | |
5b47d59a AV |
1083 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
1084 | return; | |
27c0e374 | 1085 | i->count += unroll; |
00e23707 | 1086 | if (unlikely(iov_iter_is_pipe(i))) { |
27c0e374 | 1087 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 DH |
1088 | unsigned int p_mask = pipe->ring_size - 1; |
1089 | unsigned int i_head = i->head; | |
27c0e374 AV |
1090 | size_t off = i->iov_offset; |
1091 | while (1) { | |
8cefc107 DH |
1092 | struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; |
1093 | size_t n = off - b->offset; | |
27c0e374 | 1094 | if (unroll < n) { |
4fa55cef | 1095 | off -= unroll; |
27c0e374 AV |
1096 | break; |
1097 | } | |
1098 | unroll -= n; | |
8cefc107 | 1099 | if (!unroll && i_head == i->start_head) { |
27c0e374 AV |
1100 | off = 0; |
1101 | break; | |
1102 | } | |
8cefc107 DH |
1103 | i_head--; |
1104 | b = &pipe->bufs[i_head & p_mask]; | |
1105 | off = b->offset + b->len; | |
27c0e374 AV |
1106 | } |
1107 | i->iov_offset = off; | |
8cefc107 | 1108 | i->head = i_head; |
27c0e374 AV |
1109 | pipe_truncate(i); |
1110 | return; | |
1111 | } | |
9ea9ce04 DH |
1112 | if (unlikely(iov_iter_is_discard(i))) |
1113 | return; | |
27c0e374 AV |
1114 | if (unroll <= i->iov_offset) { |
1115 | i->iov_offset -= unroll; | |
1116 | return; | |
1117 | } | |
1118 | unroll -= i->iov_offset; | |
00e23707 | 1119 | if (iov_iter_is_bvec(i)) { |
27c0e374 AV |
1120 | const struct bio_vec *bvec = i->bvec; |
1121 | while (1) { | |
1122 | size_t n = (--bvec)->bv_len; | |
1123 | i->nr_segs++; | |
1124 | if (unroll <= n) { | |
1125 | i->bvec = bvec; | |
1126 | i->iov_offset = n - unroll; | |
1127 | return; | |
1128 | } | |
1129 | unroll -= n; | |
1130 | } | |
1131 | } else { /* same logics for iovec and kvec */ | |
1132 | const struct iovec *iov = i->iov; | |
1133 | while (1) { | |
1134 | size_t n = (--iov)->iov_len; | |
1135 | i->nr_segs++; | |
1136 | if (unroll <= n) { | |
1137 | i->iov = iov; | |
1138 | i->iov_offset = n - unroll; | |
1139 | return; | |
1140 | } | |
1141 | unroll -= n; | |
1142 | } | |
1143 | } | |
1144 | } | |
1145 | EXPORT_SYMBOL(iov_iter_revert); | |
1146 | ||
62a8067a AV |
1147 | /* |
1148 | * Return the count of just the current iov_iter segment. | |
1149 | */ | |
1150 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
1151 | { | |
00e23707 | 1152 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1153 | return i->count; // it is a silly place, anyway |
62a8067a AV |
1154 | if (i->nr_segs == 1) |
1155 | return i->count; | |
9ea9ce04 DH |
1156 | if (unlikely(iov_iter_is_discard(i))) |
1157 | return i->count; | |
00e23707 | 1158 | else if (iov_iter_is_bvec(i)) |
62a8067a | 1159 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
1160 | else |
1161 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
1162 | } |
1163 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
1164 | ||
aa563d7b | 1165 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77 | 1166 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
1167 | size_t count) |
1168 | { | |
aa563d7b DH |
1169 | WARN_ON(direction & ~(READ | WRITE)); |
1170 | i->type = ITER_KVEC | (direction & (READ | WRITE)); | |
05afcb77 | 1171 | i->kvec = kvec; |
abb78f87 AV |
1172 | i->nr_segs = nr_segs; |
1173 | i->iov_offset = 0; | |
1174 | i->count = count; | |
1175 | } | |
1176 | EXPORT_SYMBOL(iov_iter_kvec); | |
1177 | ||
aa563d7b | 1178 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77 AV |
1179 | const struct bio_vec *bvec, unsigned long nr_segs, |
1180 | size_t count) | |
1181 | { | |
aa563d7b DH |
1182 | WARN_ON(direction & ~(READ | WRITE)); |
1183 | i->type = ITER_BVEC | (direction & (READ | WRITE)); | |
05afcb77 AV |
1184 | i->bvec = bvec; |
1185 | i->nr_segs = nr_segs; | |
1186 | i->iov_offset = 0; | |
1187 | i->count = count; | |
1188 | } | |
1189 | EXPORT_SYMBOL(iov_iter_bvec); | |
1190 | ||
aa563d7b | 1191 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd AV |
1192 | struct pipe_inode_info *pipe, |
1193 | size_t count) | |
1194 | { | |
aa563d7b | 1195 | BUG_ON(direction != READ); |
8cefc107 | 1196 | WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); |
aa563d7b | 1197 | i->type = ITER_PIPE | READ; |
241699cd | 1198 | i->pipe = pipe; |
8cefc107 | 1199 | i->head = pipe->head; |
241699cd AV |
1200 | i->iov_offset = 0; |
1201 | i->count = count; | |
8cefc107 | 1202 | i->start_head = i->head; |
241699cd AV |
1203 | } |
1204 | EXPORT_SYMBOL(iov_iter_pipe); | |
1205 | ||
9ea9ce04 DH |
1206 | /** |
1207 | * iov_iter_discard - Initialise an I/O iterator that discards data | |
1208 | * @i: The iterator to initialise. | |
1209 | * @direction: The direction of the transfer. | |
1210 | * @count: The size of the I/O buffer in bytes. | |
1211 | * | |
1212 | * Set up an I/O iterator that just discards everything that's written to it. | |
1213 | * It's only available as a READ iterator. | |
1214 | */ | |
1215 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) | |
1216 | { | |
1217 | BUG_ON(direction != READ); | |
1218 | i->type = ITER_DISCARD | READ; | |
1219 | i->count = count; | |
1220 | i->iov_offset = 0; | |
1221 | } | |
1222 | EXPORT_SYMBOL(iov_iter_discard); | |
1223 | ||
62a8067a AV |
1224 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
1225 | { | |
04a31165 AV |
1226 | unsigned long res = 0; |
1227 | size_t size = i->count; | |
1228 | ||
00e23707 | 1229 | if (unlikely(iov_iter_is_pipe(i))) { |
e0ff126e JK |
1230 | unsigned int p_mask = i->pipe->ring_size - 1; |
1231 | ||
8cefc107 | 1232 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) |
241699cd AV |
1233 | return size | i->iov_offset; |
1234 | return size; | |
1235 | } | |
04a31165 AV |
1236 | iterate_all_kinds(i, size, v, |
1237 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
1238 | res |= v.bv_offset | v.bv_len, |
1239 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
1240 | ) |
1241 | return res; | |
62a8067a AV |
1242 | } |
1243 | EXPORT_SYMBOL(iov_iter_alignment); | |
1244 | ||
357f435d AV |
1245 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
1246 | { | |
33844e66 | 1247 | unsigned long res = 0; |
357f435d | 1248 | size_t size = i->count; |
357f435d | 1249 | |
9ea9ce04 | 1250 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1251 | WARN_ON(1); |
1252 | return ~0U; | |
1253 | } | |
1254 | ||
357f435d AV |
1255 | iterate_all_kinds(i, size, v, |
1256 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1257 | (size != v.iov_len ? size : 0), 0), | |
1258 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1259 | (size != v.bv_len ? size : 0)), | |
1260 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1261 | (size != v.iov_len ? size : 0)) | |
1262 | ); | |
33844e66 | 1263 | return res; |
357f435d AV |
1264 | } |
1265 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1266 | ||
e76b6312 | 1267 | static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd AV |
1268 | size_t maxsize, |
1269 | struct page **pages, | |
8cefc107 | 1270 | int iter_head, |
241699cd AV |
1271 | size_t *start) |
1272 | { | |
1273 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1274 | unsigned int p_mask = pipe->ring_size - 1; |
1275 | ssize_t n = push_pipe(i, maxsize, &iter_head, start); | |
241699cd AV |
1276 | if (!n) |
1277 | return -EFAULT; | |
1278 | ||
1279 | maxsize = n; | |
1280 | n += *start; | |
1689c73a | 1281 | while (n > 0) { |
8cefc107 DH |
1282 | get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); |
1283 | iter_head++; | |
241699cd AV |
1284 | n -= PAGE_SIZE; |
1285 | } | |
1286 | ||
1287 | return maxsize; | |
1288 | } | |
1289 | ||
1290 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1291 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1292 | size_t *start) | |
1293 | { | |
8cefc107 | 1294 | unsigned int iter_head, npages; |
241699cd | 1295 | size_t capacity; |
241699cd | 1296 | |
33844e66 AV |
1297 | if (!maxsize) |
1298 | return 0; | |
1299 | ||
241699cd AV |
1300 | if (!sanity(i)) |
1301 | return -EFAULT; | |
1302 | ||
8cefc107 DH |
1303 | data_start(i, &iter_head, start); |
1304 | /* Amount of free space: some of this one + all after this one */ | |
1305 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
1306 | capacity = min(npages, maxpages) * PAGE_SIZE - *start; | |
241699cd | 1307 | |
8cefc107 | 1308 | return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); |
241699cd AV |
1309 | } |
1310 | ||
62a8067a | 1311 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1312 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1313 | size_t *start) |
1314 | { | |
e5393fae AV |
1315 | if (maxsize > i->count) |
1316 | maxsize = i->count; | |
1317 | ||
00e23707 | 1318 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1319 | return pipe_get_pages(i, pages, maxsize, maxpages, start); |
9ea9ce04 DH |
1320 | if (unlikely(iov_iter_is_discard(i))) |
1321 | return -EFAULT; | |
1322 | ||
e5393fae AV |
1323 | iterate_all_kinds(i, maxsize, v, ({ |
1324 | unsigned long addr = (unsigned long)v.iov_base; | |
1325 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1326 | int n; | |
1327 | int res; | |
1328 | ||
1329 | if (len > maxpages * PAGE_SIZE) | |
1330 | len = maxpages * PAGE_SIZE; | |
1331 | addr &= ~(PAGE_SIZE - 1); | |
1332 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
73b0140b IW |
1333 | res = get_user_pages_fast(addr, n, |
1334 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, | |
1335 | pages); | |
e5393fae AV |
1336 | if (unlikely(res < 0)) |
1337 | return res; | |
1338 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1339 | 0;}),({ | |
1340 | /* can't be more than PAGE_SIZE */ | |
1341 | *start = v.bv_offset; | |
1342 | get_page(*pages = v.bv_page); | |
1343 | return v.bv_len; | |
a280455f AV |
1344 | }),({ |
1345 | return -EFAULT; | |
e5393fae AV |
1346 | }) |
1347 | ) | |
1348 | return 0; | |
62a8067a AV |
1349 | } |
1350 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1351 | ||
1b17f1f2 AV |
1352 | static struct page **get_pages_array(size_t n) |
1353 | { | |
752ade68 | 1354 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1355 | } |
1356 | ||
241699cd AV |
1357 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1358 | struct page ***pages, size_t maxsize, | |
1359 | size_t *start) | |
1360 | { | |
1361 | struct page **p; | |
8cefc107 | 1362 | unsigned int iter_head, npages; |
d7760d63 | 1363 | ssize_t n; |
241699cd | 1364 | |
33844e66 AV |
1365 | if (!maxsize) |
1366 | return 0; | |
1367 | ||
241699cd AV |
1368 | if (!sanity(i)) |
1369 | return -EFAULT; | |
1370 | ||
8cefc107 DH |
1371 | data_start(i, &iter_head, start); |
1372 | /* Amount of free space: some of this one + all after this one */ | |
1373 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
241699cd AV |
1374 | n = npages * PAGE_SIZE - *start; |
1375 | if (maxsize > n) | |
1376 | maxsize = n; | |
1377 | else | |
1378 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1379 | p = get_pages_array(npages); | |
1380 | if (!p) | |
1381 | return -ENOMEM; | |
8cefc107 | 1382 | n = __pipe_get_pages(i, maxsize, p, iter_head, start); |
241699cd AV |
1383 | if (n > 0) |
1384 | *pages = p; | |
1385 | else | |
1386 | kvfree(p); | |
1387 | return n; | |
1388 | } | |
1389 | ||
62a8067a AV |
1390 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1391 | struct page ***pages, size_t maxsize, | |
1392 | size_t *start) | |
1393 | { | |
1b17f1f2 AV |
1394 | struct page **p; |
1395 | ||
1396 | if (maxsize > i->count) | |
1397 | maxsize = i->count; | |
1398 | ||
00e23707 | 1399 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1400 | return pipe_get_pages_alloc(i, pages, maxsize, start); |
9ea9ce04 DH |
1401 | if (unlikely(iov_iter_is_discard(i))) |
1402 | return -EFAULT; | |
1403 | ||
1b17f1f2 AV |
1404 | iterate_all_kinds(i, maxsize, v, ({ |
1405 | unsigned long addr = (unsigned long)v.iov_base; | |
1406 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1407 | int n; | |
1408 | int res; | |
1409 | ||
1410 | addr &= ~(PAGE_SIZE - 1); | |
1411 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1412 | p = get_pages_array(n); | |
1413 | if (!p) | |
1414 | return -ENOMEM; | |
73b0140b IW |
1415 | res = get_user_pages_fast(addr, n, |
1416 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); | |
1b17f1f2 AV |
1417 | if (unlikely(res < 0)) { |
1418 | kvfree(p); | |
1419 | return res; | |
1420 | } | |
1421 | *pages = p; | |
1422 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1423 | 0;}),({ | |
1424 | /* can't be more than PAGE_SIZE */ | |
1425 | *start = v.bv_offset; | |
1426 | *pages = p = get_pages_array(1); | |
1427 | if (!p) | |
1428 | return -ENOMEM; | |
1429 | get_page(*p = v.bv_page); | |
1430 | return v.bv_len; | |
a280455f AV |
1431 | }),({ |
1432 | return -EFAULT; | |
1b17f1f2 AV |
1433 | }) |
1434 | ) | |
1435 | return 0; | |
62a8067a AV |
1436 | } |
1437 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1438 | ||
a604ec7e AV |
1439 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1440 | struct iov_iter *i) | |
1441 | { | |
1442 | char *to = addr; | |
1443 | __wsum sum, next; | |
1444 | size_t off = 0; | |
a604ec7e | 1445 | sum = *csum; |
9ea9ce04 | 1446 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1447 | WARN_ON(1); |
1448 | return 0; | |
1449 | } | |
a604ec7e | 1450 | iterate_and_advance(i, bytes, v, ({ |
cbbd26b8 | 1451 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e | 1452 | (to += v.iov_len) - v.iov_len, |
c693cc46 AV |
1453 | v.iov_len); |
1454 | if (next) { | |
a604ec7e AV |
1455 | sum = csum_block_add(sum, next, off); |
1456 | off += v.iov_len; | |
1457 | } | |
c693cc46 | 1458 | next ? 0 : v.iov_len; |
a604ec7e AV |
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, ({ | |
cbbd26b8 AV |
1492 | next = csum_and_copy_from_user(v.iov_base, |
1493 | (to += v.iov_len) - v.iov_len, | |
c693cc46 AV |
1494 | v.iov_len); |
1495 | if (!next) | |
cbbd26b8 AV |
1496 | return false; |
1497 | sum = csum_block_add(sum, next, off); | |
1498 | off += v.iov_len; | |
1499 | 0; | |
1500 | }), ({ | |
1501 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1502 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1503 | p + v.bv_offset, v.bv_len, | |
1504 | sum, off); | |
cbbd26b8 | 1505 | kunmap_atomic(p); |
cbbd26b8 AV |
1506 | off += v.bv_len; |
1507 | }),({ | |
f9152895 AV |
1508 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1509 | v.iov_base, v.iov_len, | |
1510 | sum, off); | |
cbbd26b8 AV |
1511 | off += v.iov_len; |
1512 | }) | |
1513 | ) | |
1514 | *csum = sum; | |
1515 | iov_iter_advance(i, bytes); | |
1516 | return true; | |
1517 | } | |
1518 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1519 | ||
cb002d07 | 1520 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, |
a604ec7e AV |
1521 | struct iov_iter *i) |
1522 | { | |
36f7a8a4 | 1523 | const char *from = addr; |
cb002d07 | 1524 | __wsum *csum = csump; |
a604ec7e AV |
1525 | __wsum sum, next; |
1526 | size_t off = 0; | |
78e1f386 AV |
1527 | |
1528 | if (unlikely(iov_iter_is_pipe(i))) | |
1529 | return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); | |
1530 | ||
a604ec7e | 1531 | sum = *csum; |
78e1f386 | 1532 | if (unlikely(iov_iter_is_discard(i))) { |
241699cd AV |
1533 | WARN_ON(1); /* for now */ |
1534 | return 0; | |
1535 | } | |
a604ec7e | 1536 | iterate_and_advance(i, bytes, v, ({ |
a604ec7e | 1537 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, |
cbbd26b8 | 1538 | v.iov_base, |
c693cc46 AV |
1539 | v.iov_len); |
1540 | if (next) { | |
a604ec7e AV |
1541 | sum = csum_block_add(sum, next, off); |
1542 | off += v.iov_len; | |
1543 | } | |
c693cc46 | 1544 | next ? 0 : v.iov_len; |
a604ec7e AV |
1545 | }), ({ |
1546 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1547 | sum = csum_and_memcpy(p + v.bv_offset, |
1548 | (from += v.bv_len) - v.bv_len, | |
1549 | v.bv_len, sum, off); | |
a604ec7e | 1550 | kunmap_atomic(p); |
a604ec7e AV |
1551 | off += v.bv_len; |
1552 | }),({ | |
f9152895 AV |
1553 | sum = csum_and_memcpy(v.iov_base, |
1554 | (from += v.iov_len) - v.iov_len, | |
1555 | v.iov_len, sum, off); | |
a604ec7e AV |
1556 | off += v.iov_len; |
1557 | }) | |
1558 | ) | |
1559 | *csum = sum; | |
1560 | return bytes; | |
1561 | } | |
1562 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1563 | ||
d05f4435 SG |
1564 | size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
1565 | struct iov_iter *i) | |
1566 | { | |
7999096f | 1567 | #ifdef CONFIG_CRYPTO_HASH |
d05f4435 SG |
1568 | struct ahash_request *hash = hashp; |
1569 | struct scatterlist sg; | |
1570 | size_t copied; | |
1571 | ||
1572 | copied = copy_to_iter(addr, bytes, i); | |
1573 | sg_init_one(&sg, addr, copied); | |
1574 | ahash_request_set_crypt(hash, &sg, NULL, copied); | |
1575 | crypto_ahash_update(hash); | |
1576 | return copied; | |
27fad74a Y |
1577 | #else |
1578 | return 0; | |
1579 | #endif | |
d05f4435 SG |
1580 | } |
1581 | EXPORT_SYMBOL(hash_and_copy_to_iter); | |
1582 | ||
62a8067a AV |
1583 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1584 | { | |
e0f2dc40 AV |
1585 | size_t size = i->count; |
1586 | int npages = 0; | |
1587 | ||
1588 | if (!size) | |
1589 | return 0; | |
9ea9ce04 DH |
1590 | if (unlikely(iov_iter_is_discard(i))) |
1591 | return 0; | |
e0f2dc40 | 1592 | |
00e23707 | 1593 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd | 1594 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 | 1595 | unsigned int iter_head; |
241699cd | 1596 | size_t off; |
241699cd AV |
1597 | |
1598 | if (!sanity(i)) | |
1599 | return 0; | |
1600 | ||
8cefc107 | 1601 | data_start(i, &iter_head, &off); |
241699cd | 1602 | /* some of this one + all after this one */ |
8cefc107 | 1603 | npages = pipe_space_for_user(iter_head, pipe->tail, pipe); |
241699cd AV |
1604 | if (npages >= maxpages) |
1605 | return maxpages; | |
1606 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1607 | unsigned long p = (unsigned long)v.iov_base; |
1608 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1609 | - p / PAGE_SIZE; | |
1610 | if (npages >= maxpages) | |
1611 | return maxpages; | |
1612 | 0;}),({ | |
1613 | npages++; | |
1614 | if (npages >= maxpages) | |
1615 | return maxpages; | |
a280455f AV |
1616 | }),({ |
1617 | unsigned long p = (unsigned long)v.iov_base; | |
1618 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1619 | - p / PAGE_SIZE; | |
1620 | if (npages >= maxpages) | |
1621 | return maxpages; | |
e0f2dc40 AV |
1622 | }) |
1623 | ) | |
1624 | return npages; | |
62a8067a | 1625 | } |
f67da30c | 1626 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1627 | |
1628 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1629 | { | |
1630 | *new = *old; | |
00e23707 | 1631 | if (unlikely(iov_iter_is_pipe(new))) { |
241699cd AV |
1632 | WARN_ON(1); |
1633 | return NULL; | |
1634 | } | |
9ea9ce04 DH |
1635 | if (unlikely(iov_iter_is_discard(new))) |
1636 | return NULL; | |
00e23707 | 1637 | if (iov_iter_is_bvec(new)) |
4b8164b9 AV |
1638 | return new->bvec = kmemdup(new->bvec, |
1639 | new->nr_segs * sizeof(struct bio_vec), | |
1640 | flags); | |
1641 | else | |
1642 | /* iovec and kvec have identical layout */ | |
1643 | return new->iov = kmemdup(new->iov, | |
1644 | new->nr_segs * sizeof(struct iovec), | |
1645 | flags); | |
1646 | } | |
1647 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1648 | |
bfdc5970 CH |
1649 | static int copy_compat_iovec_from_user(struct iovec *iov, |
1650 | const struct iovec __user *uvec, unsigned long nr_segs) | |
1651 | { | |
1652 | const struct compat_iovec __user *uiov = | |
1653 | (const struct compat_iovec __user *)uvec; | |
1654 | int ret = -EFAULT, i; | |
1655 | ||
1656 | if (!user_access_begin(uvec, nr_segs * sizeof(*uvec))) | |
1657 | return -EFAULT; | |
1658 | ||
1659 | for (i = 0; i < nr_segs; i++) { | |
1660 | compat_uptr_t buf; | |
1661 | compat_ssize_t len; | |
1662 | ||
1663 | unsafe_get_user(len, &uiov[i].iov_len, uaccess_end); | |
1664 | unsafe_get_user(buf, &uiov[i].iov_base, uaccess_end); | |
1665 | ||
1666 | /* check for compat_size_t not fitting in compat_ssize_t .. */ | |
1667 | if (len < 0) { | |
1668 | ret = -EINVAL; | |
1669 | goto uaccess_end; | |
1670 | } | |
1671 | iov[i].iov_base = compat_ptr(buf); | |
1672 | iov[i].iov_len = len; | |
1673 | } | |
1674 | ||
1675 | ret = 0; | |
1676 | uaccess_end: | |
1677 | user_access_end(); | |
1678 | return ret; | |
1679 | } | |
1680 | ||
1681 | static int copy_iovec_from_user(struct iovec *iov, | |
1682 | const struct iovec __user *uvec, unsigned long nr_segs) | |
fb041b59 DL |
1683 | { |
1684 | unsigned long seg; | |
fb041b59 | 1685 | |
bfdc5970 CH |
1686 | if (copy_from_user(iov, uvec, nr_segs * sizeof(*uvec))) |
1687 | return -EFAULT; | |
1688 | for (seg = 0; seg < nr_segs; seg++) { | |
1689 | if ((ssize_t)iov[seg].iov_len < 0) | |
1690 | return -EINVAL; | |
fb041b59 DL |
1691 | } |
1692 | ||
bfdc5970 CH |
1693 | return 0; |
1694 | } | |
1695 | ||
1696 | struct iovec *iovec_from_user(const struct iovec __user *uvec, | |
1697 | unsigned long nr_segs, unsigned long fast_segs, | |
1698 | struct iovec *fast_iov, bool compat) | |
1699 | { | |
1700 | struct iovec *iov = fast_iov; | |
1701 | int ret; | |
1702 | ||
fb041b59 | 1703 | /* |
bfdc5970 CH |
1704 | * SuS says "The readv() function *may* fail if the iovcnt argument was |
1705 | * less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
1706 | * traditionally returned zero for zero segments, so... | |
fb041b59 | 1707 | */ |
bfdc5970 CH |
1708 | if (nr_segs == 0) |
1709 | return iov; | |
1710 | if (nr_segs > UIO_MAXIOV) | |
1711 | return ERR_PTR(-EINVAL); | |
fb041b59 DL |
1712 | if (nr_segs > fast_segs) { |
1713 | iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); | |
bfdc5970 CH |
1714 | if (!iov) |
1715 | return ERR_PTR(-ENOMEM); | |
fb041b59 | 1716 | } |
bfdc5970 CH |
1717 | |
1718 | if (compat) | |
1719 | ret = copy_compat_iovec_from_user(iov, uvec, nr_segs); | |
1720 | else | |
1721 | ret = copy_iovec_from_user(iov, uvec, nr_segs); | |
1722 | if (ret) { | |
1723 | if (iov != fast_iov) | |
1724 | kfree(iov); | |
1725 | return ERR_PTR(ret); | |
1726 | } | |
1727 | ||
1728 | return iov; | |
1729 | } | |
1730 | ||
1731 | ssize_t __import_iovec(int type, const struct iovec __user *uvec, | |
1732 | unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, | |
1733 | struct iov_iter *i, bool compat) | |
1734 | { | |
1735 | ssize_t total_len = 0; | |
1736 | unsigned long seg; | |
1737 | struct iovec *iov; | |
1738 | ||
1739 | iov = iovec_from_user(uvec, nr_segs, fast_segs, *iovp, compat); | |
1740 | if (IS_ERR(iov)) { | |
1741 | *iovp = NULL; | |
1742 | return PTR_ERR(iov); | |
fb041b59 DL |
1743 | } |
1744 | ||
1745 | /* | |
bfdc5970 CH |
1746 | * According to the Single Unix Specification we should return EINVAL if |
1747 | * an element length is < 0 when cast to ssize_t or if the total length | |
1748 | * would overflow the ssize_t return value of the system call. | |
fb041b59 DL |
1749 | * |
1750 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
1751 | * overflow case. | |
1752 | */ | |
fb041b59 | 1753 | for (seg = 0; seg < nr_segs; seg++) { |
fb041b59 DL |
1754 | ssize_t len = (ssize_t)iov[seg].iov_len; |
1755 | ||
bfdc5970 CH |
1756 | if (!access_ok(iov[seg].iov_base, len)) { |
1757 | if (iov != *iovp) | |
1758 | kfree(iov); | |
1759 | *iovp = NULL; | |
1760 | return -EFAULT; | |
fb041b59 | 1761 | } |
bfdc5970 CH |
1762 | |
1763 | if (len > MAX_RW_COUNT - total_len) { | |
1764 | len = MAX_RW_COUNT - total_len; | |
fb041b59 DL |
1765 | iov[seg].iov_len = len; |
1766 | } | |
bfdc5970 | 1767 | total_len += len; |
fb041b59 | 1768 | } |
bfdc5970 CH |
1769 | |
1770 | iov_iter_init(i, type, iov, nr_segs, total_len); | |
1771 | if (iov == *iovp) | |
1772 | *iovp = NULL; | |
1773 | else | |
1774 | *iovp = iov; | |
1775 | return total_len; | |
fb041b59 DL |
1776 | } |
1777 | ||
ffecee4f VN |
1778 | /** |
1779 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1780 | * into the kernel, check that it is valid, and initialize a new | |
1781 | * &struct iov_iter iterator to access it. | |
1782 | * | |
1783 | * @type: One of %READ or %WRITE. | |
bfdc5970 | 1784 | * @uvec: Pointer to the userspace array. |
ffecee4f VN |
1785 | * @nr_segs: Number of elements in userspace array. |
1786 | * @fast_segs: Number of elements in @iov. | |
bfdc5970 | 1787 | * @iovp: (input and output parameter) Pointer to pointer to (usually small |
ffecee4f VN |
1788 | * on-stack) kernel array. |
1789 | * @i: Pointer to iterator that will be initialized on success. | |
1790 | * | |
1791 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1792 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1793 | * array will be allocated and the result placed in *@iov. This means that | |
1794 | * the caller may call kfree() on *@iov regardless of whether the small | |
1795 | * on-stack array was used or not (and regardless of whether this function | |
1796 | * returns an error or not). | |
1797 | * | |
87e5e6da | 1798 | * Return: Negative error code on error, bytes imported on success |
ffecee4f | 1799 | */ |
bfdc5970 | 1800 | ssize_t import_iovec(int type, const struct iovec __user *uvec, |
bc917be8 | 1801 | unsigned nr_segs, unsigned fast_segs, |
bfdc5970 | 1802 | struct iovec **iovp, struct iov_iter *i) |
bc917be8 | 1803 | { |
89cd35c5 CH |
1804 | return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i, |
1805 | in_compat_syscall()); | |
bc917be8 AV |
1806 | } |
1807 | EXPORT_SYMBOL(import_iovec); | |
1808 | ||
bc917be8 AV |
1809 | int import_single_range(int rw, void __user *buf, size_t len, |
1810 | struct iovec *iov, struct iov_iter *i) | |
1811 | { | |
1812 | if (len > MAX_RW_COUNT) | |
1813 | len = MAX_RW_COUNT; | |
96d4f267 | 1814 | if (unlikely(!access_ok(buf, len))) |
bc917be8 AV |
1815 | return -EFAULT; |
1816 | ||
1817 | iov->iov_base = buf; | |
1818 | iov->iov_len = len; | |
1819 | iov_iter_init(i, rw, iov, 1, len); | |
1820 | return 0; | |
1821 | } | |
e1267585 | 1822 | EXPORT_SYMBOL(import_single_range); |
09cf698a AV |
1823 | |
1824 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1825 | int (*f)(struct kvec *vec, void *context), | |
1826 | void *context) | |
1827 | { | |
1828 | struct kvec w; | |
1829 | int err = -EINVAL; | |
1830 | if (!bytes) | |
1831 | return 0; | |
1832 | ||
1833 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1834 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1835 | w.iov_len = v.bv_len; | |
1836 | err = f(&w, context); | |
1837 | kunmap(v.bv_page); | |
1838 | err;}), ({ | |
1839 | w = v; | |
1840 | err = f(&w, context);}) | |
1841 | ) | |
1842 | return err; | |
1843 | } | |
1844 | EXPORT_SYMBOL(iov_iter_for_each_range); |