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 | { | |
585 | __wsum next = csum_partial_copy_nocheck(from, to, len, 0); | |
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 | |
8780356e DW |
641 | #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE |
642 | static int copyout_mcsafe(void __user *to, const void *from, size_t n) | |
643 | { | |
96d4f267 | 644 | if (access_ok(to, n)) { |
d0ef4c36 | 645 | instrument_copy_to_user(to, from, n); |
8780356e DW |
646 | n = copy_to_user_mcsafe((__force void *) to, from, n); |
647 | } | |
648 | return n; | |
649 | } | |
650 | ||
651 | static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, | |
652 | const char *from, size_t len) | |
653 | { | |
654 | unsigned long ret; | |
655 | char *to; | |
656 | ||
657 | to = kmap_atomic(page); | |
658 | ret = memcpy_mcsafe(to + offset, from, len); | |
659 | kunmap_atomic(to); | |
660 | ||
661 | return ret; | |
662 | } | |
663 | ||
ca146f6f DW |
664 | static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, |
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 | ||
8cefc107 DH |
682 | rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page, |
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 DW |
698 | /** |
699 | * _copy_to_iter_mcsafe - copy to user with source-read error exception handling | |
700 | * @addr: source kernel address | |
701 | * @bytes: total transfer length | |
702 | * @iter: destination iterator | |
703 | * | |
704 | * The pmem driver arranges for filesystem-dax to use this facility via | |
705 | * dax_copy_to_iter() for protecting read/write to persistent memory. | |
706 | * Unless / until an architecture can guarantee identical performance | |
707 | * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a | |
708 | * performance regression to switch more users to the mcsafe version. | |
709 | * | |
710 | * Otherwise, the main differences between this and typical _copy_to_iter(). | |
711 | * | |
712 | * * Typical tail/residue handling after a fault retries the copy | |
713 | * byte-by-byte until the fault happens again. Re-triggering machine | |
714 | * checks is potentially fatal so the implementation uses source | |
715 | * alignment and poison alignment assumptions to avoid re-triggering | |
716 | * hardware exceptions. | |
717 | * | |
718 | * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. | |
719 | * Compare to copy_to_iter() where only ITER_IOVEC attempts might return | |
720 | * a short copy. | |
721 | * | |
722 | * See MCSAFE_TEST for self-test. | |
723 | */ | |
8780356e DW |
724 | size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) |
725 | { | |
726 | const char *from = addr; | |
727 | unsigned long rem, curr_addr, s_addr = (unsigned long) addr; | |
728 | ||
00e23707 | 729 | if (unlikely(iov_iter_is_pipe(i))) |
ca146f6f | 730 | return copy_pipe_to_iter_mcsafe(addr, bytes, i); |
8780356e DW |
731 | if (iter_is_iovec(i)) |
732 | might_fault(); | |
733 | iterate_and_advance(i, bytes, v, | |
734 | copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), | |
735 | ({ | |
736 | rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, | |
737 | (from += v.bv_len) - v.bv_len, v.bv_len); | |
738 | if (rem) { | |
739 | curr_addr = (unsigned long) from; | |
740 | bytes = curr_addr - s_addr - rem; | |
741 | return bytes; | |
742 | } | |
743 | }), | |
744 | ({ | |
745 | rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, | |
746 | v.iov_len); | |
747 | if (rem) { | |
748 | curr_addr = (unsigned long) from; | |
749 | bytes = curr_addr - s_addr - rem; | |
750 | return bytes; | |
751 | } | |
752 | }) | |
753 | ) | |
754 | ||
755 | return bytes; | |
756 | } | |
757 | EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); | |
758 | #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ | |
759 | ||
aa28de27 | 760 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 761 | { |
0dbca9a4 | 762 | char *to = addr; |
00e23707 | 763 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
764 | WARN_ON(1); |
765 | return 0; | |
766 | } | |
09fc68dc AV |
767 | if (iter_is_iovec(i)) |
768 | might_fault(); | |
0dbca9a4 | 769 | iterate_and_advance(i, bytes, v, |
09fc68dc | 770 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4 | 771 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
772 | v.bv_offset, v.bv_len), |
773 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
774 | ) |
775 | ||
776 | return bytes; | |
c35e0248 | 777 | } |
aa28de27 | 778 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 779 | |
aa28de27 | 780 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
781 | { |
782 | char *to = addr; | |
00e23707 | 783 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
784 | WARN_ON(1); |
785 | return false; | |
786 | } | |
33844e66 | 787 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
788 | return false; |
789 | ||
09fc68dc AV |
790 | if (iter_is_iovec(i)) |
791 | might_fault(); | |
cbbd26b8 | 792 | iterate_all_kinds(i, bytes, v, ({ |
09fc68dc | 793 | if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
794 | v.iov_base, v.iov_len)) |
795 | return false; | |
796 | 0;}), | |
797 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
798 | v.bv_offset, v.bv_len), | |
799 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
800 | ) | |
801 | ||
802 | iov_iter_advance(i, bytes); | |
803 | return true; | |
804 | } | |
aa28de27 | 805 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 806 | |
aa28de27 | 807 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
808 | { |
809 | char *to = addr; | |
00e23707 | 810 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
811 | WARN_ON(1); |
812 | return 0; | |
813 | } | |
aa583096 | 814 | iterate_and_advance(i, bytes, v, |
3f763453 | 815 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
816 | v.iov_base, v.iov_len), |
817 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
818 | v.bv_offset, v.bv_len), | |
819 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
820 | ) | |
821 | ||
822 | return bytes; | |
823 | } | |
aa28de27 | 824 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 825 | |
0aed55af | 826 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d DW |
827 | /** |
828 | * _copy_from_iter_flushcache - write destination through cpu cache | |
829 | * @addr: destination kernel address | |
830 | * @bytes: total transfer length | |
831 | * @iter: source iterator | |
832 | * | |
833 | * The pmem driver arranges for filesystem-dax to use this facility via | |
834 | * dax_copy_from_iter() for ensuring that writes to persistent memory | |
835 | * are flushed through the CPU cache. It is differentiated from | |
836 | * _copy_from_iter_nocache() in that guarantees all data is flushed for | |
837 | * all iterator types. The _copy_from_iter_nocache() only attempts to | |
838 | * bypass the cache for the ITER_IOVEC case, and on some archs may use | |
839 | * instructions that strand dirty-data in the cache. | |
840 | */ | |
6a37e940 | 841 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af DW |
842 | { |
843 | char *to = addr; | |
00e23707 | 844 | if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af DW |
845 | WARN_ON(1); |
846 | return 0; | |
847 | } | |
848 | iterate_and_advance(i, bytes, v, | |
849 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
850 | v.iov_base, v.iov_len), | |
851 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
852 | v.bv_offset, v.bv_len), | |
853 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
854 | v.iov_len) | |
855 | ) | |
856 | ||
857 | return bytes; | |
858 | } | |
6a37e940 | 859 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af DW |
860 | #endif |
861 | ||
aa28de27 | 862 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
863 | { |
864 | char *to = addr; | |
00e23707 | 865 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
866 | WARN_ON(1); |
867 | return false; | |
868 | } | |
33844e66 | 869 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
870 | return false; |
871 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 872 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
873 | v.iov_base, v.iov_len)) |
874 | return false; | |
875 | 0;}), | |
876 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
877 | v.bv_offset, v.bv_len), | |
878 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
879 | ) | |
880 | ||
881 | iov_iter_advance(i, bytes); | |
882 | return true; | |
883 | } | |
aa28de27 | 884 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 885 | |
72e809ed AV |
886 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
887 | { | |
6daef95b ED |
888 | struct page *head; |
889 | size_t v = n + offset; | |
890 | ||
891 | /* | |
892 | * The general case needs to access the page order in order | |
893 | * to compute the page size. | |
894 | * However, we mostly deal with order-0 pages and thus can | |
895 | * avoid a possible cache line miss for requests that fit all | |
896 | * page orders. | |
897 | */ | |
898 | if (n <= v && v <= PAGE_SIZE) | |
899 | return true; | |
900 | ||
901 | head = compound_head(page); | |
902 | v += (page - head) << PAGE_SHIFT; | |
a90bcb86 | 903 | |
a50b854e | 904 | if (likely(n <= v && v <= (page_size(head)))) |
72e809ed AV |
905 | return true; |
906 | WARN_ON(1); | |
907 | return false; | |
908 | } | |
cbbd26b8 | 909 | |
62a8067a AV |
910 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
911 | struct iov_iter *i) | |
912 | { | |
72e809ed AV |
913 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
914 | return 0; | |
d271524a AV |
915 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
916 | void *kaddr = kmap_atomic(page); | |
917 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
918 | kunmap_atomic(kaddr); | |
919 | return wanted; | |
9ea9ce04 DH |
920 | } else if (unlikely(iov_iter_is_discard(i))) |
921 | return bytes; | |
922 | else if (likely(!iov_iter_is_pipe(i))) | |
62a8067a | 923 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
924 | else |
925 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
926 | } |
927 | EXPORT_SYMBOL(copy_page_to_iter); | |
928 | ||
929 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
930 | struct iov_iter *i) | |
931 | { | |
72e809ed AV |
932 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
933 | return 0; | |
9ea9ce04 | 934 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
935 | WARN_ON(1); |
936 | return 0; | |
937 | } | |
a280455f | 938 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 939 | void *kaddr = kmap_atomic(page); |
aa28de27 | 940 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
941 | kunmap_atomic(kaddr); |
942 | return wanted; | |
943 | } else | |
62a8067a AV |
944 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
945 | } | |
946 | EXPORT_SYMBOL(copy_page_from_iter); | |
947 | ||
241699cd AV |
948 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
949 | { | |
950 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
951 | unsigned int p_mask = pipe->ring_size - 1; |
952 | unsigned int i_head; | |
241699cd | 953 | size_t n, off; |
241699cd AV |
954 | |
955 | if (!sanity(i)) | |
956 | return 0; | |
957 | ||
8cefc107 | 958 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
959 | if (unlikely(!n)) |
960 | return 0; | |
961 | ||
8cefc107 | 962 | do { |
241699cd | 963 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
964 | memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); |
965 | i->head = i_head; | |
241699cd AV |
966 | i->iov_offset = off + chunk; |
967 | n -= chunk; | |
8cefc107 DH |
968 | off = 0; |
969 | i_head++; | |
970 | } while (n); | |
241699cd AV |
971 | i->count -= bytes; |
972 | return bytes; | |
973 | } | |
974 | ||
c35e0248 MW |
975 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
976 | { | |
00e23707 | 977 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 978 | return pipe_zero(bytes, i); |
8442fa46 | 979 | iterate_and_advance(i, bytes, v, |
09fc68dc | 980 | clear_user(v.iov_base, v.iov_len), |
a280455f AV |
981 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
982 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
983 | ) |
984 | ||
985 | return bytes; | |
c35e0248 MW |
986 | } |
987 | EXPORT_SYMBOL(iov_iter_zero); | |
988 | ||
62a8067a AV |
989 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
990 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
991 | { | |
04a31165 | 992 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
993 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
994 | kunmap_atomic(kaddr); | |
995 | return 0; | |
996 | } | |
9ea9ce04 | 997 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
998 | kunmap_atomic(kaddr); |
999 | WARN_ON(1); | |
1000 | return 0; | |
1001 | } | |
04a31165 | 1002 | iterate_all_kinds(i, bytes, v, |
09fc68dc | 1003 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a31165 | 1004 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
1005 | v.bv_offset, v.bv_len), |
1006 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
1007 | ) |
1008 | kunmap_atomic(kaddr); | |
1009 | return bytes; | |
62a8067a AV |
1010 | } |
1011 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
1012 | ||
b9dc6f65 AV |
1013 | static inline void pipe_truncate(struct iov_iter *i) |
1014 | { | |
1015 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1016 | unsigned int p_tail = pipe->tail; |
1017 | unsigned int p_head = pipe->head; | |
1018 | unsigned int p_mask = pipe->ring_size - 1; | |
1019 | ||
1020 | if (!pipe_empty(p_head, p_tail)) { | |
1021 | struct pipe_buffer *buf; | |
1022 | unsigned int i_head = i->head; | |
b9dc6f65 | 1023 | size_t off = i->iov_offset; |
8cefc107 | 1024 | |
b9dc6f65 | 1025 | if (off) { |
8cefc107 DH |
1026 | buf = &pipe->bufs[i_head & p_mask]; |
1027 | buf->len = off - buf->offset; | |
1028 | i_head++; | |
b9dc6f65 | 1029 | } |
8cefc107 DH |
1030 | while (p_head != i_head) { |
1031 | p_head--; | |
1032 | pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); | |
b9dc6f65 | 1033 | } |
8cefc107 DH |
1034 | |
1035 | pipe->head = p_head; | |
b9dc6f65 AV |
1036 | } |
1037 | } | |
1038 | ||
241699cd AV |
1039 | static void pipe_advance(struct iov_iter *i, size_t size) |
1040 | { | |
1041 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
1042 | if (unlikely(i->count < size)) |
1043 | size = i->count; | |
241699cd | 1044 | if (size) { |
b9dc6f65 | 1045 | struct pipe_buffer *buf; |
8cefc107 DH |
1046 | unsigned int p_mask = pipe->ring_size - 1; |
1047 | unsigned int i_head = i->head; | |
b9dc6f65 | 1048 | size_t off = i->iov_offset, left = size; |
8cefc107 | 1049 | |
241699cd | 1050 | if (off) /* make it relative to the beginning of buffer */ |
8cefc107 | 1051 | left += off - pipe->bufs[i_head & p_mask].offset; |
241699cd | 1052 | while (1) { |
8cefc107 | 1053 | buf = &pipe->bufs[i_head & p_mask]; |
b9dc6f65 | 1054 | if (left <= buf->len) |
241699cd | 1055 | break; |
b9dc6f65 | 1056 | left -= buf->len; |
8cefc107 | 1057 | i_head++; |
241699cd | 1058 | } |
8cefc107 | 1059 | i->head = i_head; |
b9dc6f65 | 1060 | i->iov_offset = buf->offset + left; |
241699cd | 1061 | } |
b9dc6f65 AV |
1062 | i->count -= size; |
1063 | /* ... and discard everything past that point */ | |
1064 | pipe_truncate(i); | |
241699cd AV |
1065 | } |
1066 | ||
62a8067a AV |
1067 | void iov_iter_advance(struct iov_iter *i, size_t size) |
1068 | { | |
00e23707 | 1069 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1070 | pipe_advance(i, size); |
1071 | return; | |
1072 | } | |
9ea9ce04 DH |
1073 | if (unlikely(iov_iter_is_discard(i))) { |
1074 | i->count -= size; | |
1075 | return; | |
1076 | } | |
a280455f | 1077 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
1078 | } |
1079 | EXPORT_SYMBOL(iov_iter_advance); | |
1080 | ||
27c0e374 AV |
1081 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
1082 | { | |
1083 | if (!unroll) | |
1084 | return; | |
5b47d59a AV |
1085 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
1086 | return; | |
27c0e374 | 1087 | i->count += unroll; |
00e23707 | 1088 | if (unlikely(iov_iter_is_pipe(i))) { |
27c0e374 | 1089 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 DH |
1090 | unsigned int p_mask = pipe->ring_size - 1; |
1091 | unsigned int i_head = i->head; | |
27c0e374 AV |
1092 | size_t off = i->iov_offset; |
1093 | while (1) { | |
8cefc107 DH |
1094 | struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; |
1095 | size_t n = off - b->offset; | |
27c0e374 | 1096 | if (unroll < n) { |
4fa55cef | 1097 | off -= unroll; |
27c0e374 AV |
1098 | break; |
1099 | } | |
1100 | unroll -= n; | |
8cefc107 | 1101 | if (!unroll && i_head == i->start_head) { |
27c0e374 AV |
1102 | off = 0; |
1103 | break; | |
1104 | } | |
8cefc107 DH |
1105 | i_head--; |
1106 | b = &pipe->bufs[i_head & p_mask]; | |
1107 | off = b->offset + b->len; | |
27c0e374 AV |
1108 | } |
1109 | i->iov_offset = off; | |
8cefc107 | 1110 | i->head = i_head; |
27c0e374 AV |
1111 | pipe_truncate(i); |
1112 | return; | |
1113 | } | |
9ea9ce04 DH |
1114 | if (unlikely(iov_iter_is_discard(i))) |
1115 | return; | |
27c0e374 AV |
1116 | if (unroll <= i->iov_offset) { |
1117 | i->iov_offset -= unroll; | |
1118 | return; | |
1119 | } | |
1120 | unroll -= i->iov_offset; | |
00e23707 | 1121 | if (iov_iter_is_bvec(i)) { |
27c0e374 AV |
1122 | const struct bio_vec *bvec = i->bvec; |
1123 | while (1) { | |
1124 | size_t n = (--bvec)->bv_len; | |
1125 | i->nr_segs++; | |
1126 | if (unroll <= n) { | |
1127 | i->bvec = bvec; | |
1128 | i->iov_offset = n - unroll; | |
1129 | return; | |
1130 | } | |
1131 | unroll -= n; | |
1132 | } | |
1133 | } else { /* same logics for iovec and kvec */ | |
1134 | const struct iovec *iov = i->iov; | |
1135 | while (1) { | |
1136 | size_t n = (--iov)->iov_len; | |
1137 | i->nr_segs++; | |
1138 | if (unroll <= n) { | |
1139 | i->iov = iov; | |
1140 | i->iov_offset = n - unroll; | |
1141 | return; | |
1142 | } | |
1143 | unroll -= n; | |
1144 | } | |
1145 | } | |
1146 | } | |
1147 | EXPORT_SYMBOL(iov_iter_revert); | |
1148 | ||
62a8067a AV |
1149 | /* |
1150 | * Return the count of just the current iov_iter segment. | |
1151 | */ | |
1152 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
1153 | { | |
00e23707 | 1154 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1155 | return i->count; // it is a silly place, anyway |
62a8067a AV |
1156 | if (i->nr_segs == 1) |
1157 | return i->count; | |
9ea9ce04 DH |
1158 | if (unlikely(iov_iter_is_discard(i))) |
1159 | return i->count; | |
00e23707 | 1160 | else if (iov_iter_is_bvec(i)) |
62a8067a | 1161 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
1162 | else |
1163 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
1164 | } |
1165 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
1166 | ||
aa563d7b | 1167 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77 | 1168 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
1169 | size_t count) |
1170 | { | |
aa563d7b DH |
1171 | WARN_ON(direction & ~(READ | WRITE)); |
1172 | i->type = ITER_KVEC | (direction & (READ | WRITE)); | |
05afcb77 | 1173 | i->kvec = kvec; |
abb78f87 AV |
1174 | i->nr_segs = nr_segs; |
1175 | i->iov_offset = 0; | |
1176 | i->count = count; | |
1177 | } | |
1178 | EXPORT_SYMBOL(iov_iter_kvec); | |
1179 | ||
aa563d7b | 1180 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77 AV |
1181 | const struct bio_vec *bvec, unsigned long nr_segs, |
1182 | size_t count) | |
1183 | { | |
aa563d7b DH |
1184 | WARN_ON(direction & ~(READ | WRITE)); |
1185 | i->type = ITER_BVEC | (direction & (READ | WRITE)); | |
05afcb77 AV |
1186 | i->bvec = bvec; |
1187 | i->nr_segs = nr_segs; | |
1188 | i->iov_offset = 0; | |
1189 | i->count = count; | |
1190 | } | |
1191 | EXPORT_SYMBOL(iov_iter_bvec); | |
1192 | ||
aa563d7b | 1193 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd AV |
1194 | struct pipe_inode_info *pipe, |
1195 | size_t count) | |
1196 | { | |
aa563d7b | 1197 | BUG_ON(direction != READ); |
8cefc107 | 1198 | WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); |
aa563d7b | 1199 | i->type = ITER_PIPE | READ; |
241699cd | 1200 | i->pipe = pipe; |
8cefc107 | 1201 | i->head = pipe->head; |
241699cd AV |
1202 | i->iov_offset = 0; |
1203 | i->count = count; | |
8cefc107 | 1204 | i->start_head = i->head; |
241699cd AV |
1205 | } |
1206 | EXPORT_SYMBOL(iov_iter_pipe); | |
1207 | ||
9ea9ce04 DH |
1208 | /** |
1209 | * iov_iter_discard - Initialise an I/O iterator that discards data | |
1210 | * @i: The iterator to initialise. | |
1211 | * @direction: The direction of the transfer. | |
1212 | * @count: The size of the I/O buffer in bytes. | |
1213 | * | |
1214 | * Set up an I/O iterator that just discards everything that's written to it. | |
1215 | * It's only available as a READ iterator. | |
1216 | */ | |
1217 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) | |
1218 | { | |
1219 | BUG_ON(direction != READ); | |
1220 | i->type = ITER_DISCARD | READ; | |
1221 | i->count = count; | |
1222 | i->iov_offset = 0; | |
1223 | } | |
1224 | EXPORT_SYMBOL(iov_iter_discard); | |
1225 | ||
62a8067a AV |
1226 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
1227 | { | |
04a31165 AV |
1228 | unsigned long res = 0; |
1229 | size_t size = i->count; | |
1230 | ||
00e23707 | 1231 | if (unlikely(iov_iter_is_pipe(i))) { |
e0ff126e JK |
1232 | unsigned int p_mask = i->pipe->ring_size - 1; |
1233 | ||
8cefc107 | 1234 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) |
241699cd AV |
1235 | return size | i->iov_offset; |
1236 | return size; | |
1237 | } | |
04a31165 AV |
1238 | iterate_all_kinds(i, size, v, |
1239 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
1240 | res |= v.bv_offset | v.bv_len, |
1241 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
1242 | ) |
1243 | return res; | |
62a8067a AV |
1244 | } |
1245 | EXPORT_SYMBOL(iov_iter_alignment); | |
1246 | ||
357f435d AV |
1247 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
1248 | { | |
33844e66 | 1249 | unsigned long res = 0; |
357f435d | 1250 | size_t size = i->count; |
357f435d | 1251 | |
9ea9ce04 | 1252 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1253 | WARN_ON(1); |
1254 | return ~0U; | |
1255 | } | |
1256 | ||
357f435d AV |
1257 | iterate_all_kinds(i, size, v, |
1258 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1259 | (size != v.iov_len ? size : 0), 0), | |
1260 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1261 | (size != v.bv_len ? size : 0)), | |
1262 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1263 | (size != v.iov_len ? size : 0)) | |
1264 | ); | |
33844e66 | 1265 | return res; |
357f435d AV |
1266 | } |
1267 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1268 | ||
e76b6312 | 1269 | static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd AV |
1270 | size_t maxsize, |
1271 | struct page **pages, | |
8cefc107 | 1272 | int iter_head, |
241699cd AV |
1273 | size_t *start) |
1274 | { | |
1275 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1276 | unsigned int p_mask = pipe->ring_size - 1; |
1277 | ssize_t n = push_pipe(i, maxsize, &iter_head, start); | |
241699cd AV |
1278 | if (!n) |
1279 | return -EFAULT; | |
1280 | ||
1281 | maxsize = n; | |
1282 | n += *start; | |
1689c73a | 1283 | while (n > 0) { |
8cefc107 DH |
1284 | get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); |
1285 | iter_head++; | |
241699cd AV |
1286 | n -= PAGE_SIZE; |
1287 | } | |
1288 | ||
1289 | return maxsize; | |
1290 | } | |
1291 | ||
1292 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1293 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1294 | size_t *start) | |
1295 | { | |
8cefc107 | 1296 | unsigned int iter_head, npages; |
241699cd | 1297 | size_t capacity; |
241699cd | 1298 | |
33844e66 AV |
1299 | if (!maxsize) |
1300 | return 0; | |
1301 | ||
241699cd AV |
1302 | if (!sanity(i)) |
1303 | return -EFAULT; | |
1304 | ||
8cefc107 DH |
1305 | data_start(i, &iter_head, start); |
1306 | /* Amount of free space: some of this one + all after this one */ | |
1307 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
1308 | capacity = min(npages, maxpages) * PAGE_SIZE - *start; | |
241699cd | 1309 | |
8cefc107 | 1310 | return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); |
241699cd AV |
1311 | } |
1312 | ||
62a8067a | 1313 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1314 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1315 | size_t *start) |
1316 | { | |
e5393fae AV |
1317 | if (maxsize > i->count) |
1318 | maxsize = i->count; | |
1319 | ||
00e23707 | 1320 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1321 | return pipe_get_pages(i, pages, maxsize, maxpages, start); |
9ea9ce04 DH |
1322 | if (unlikely(iov_iter_is_discard(i))) |
1323 | return -EFAULT; | |
1324 | ||
e5393fae AV |
1325 | iterate_all_kinds(i, maxsize, v, ({ |
1326 | unsigned long addr = (unsigned long)v.iov_base; | |
1327 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1328 | int n; | |
1329 | int res; | |
1330 | ||
1331 | if (len > maxpages * PAGE_SIZE) | |
1332 | len = maxpages * PAGE_SIZE; | |
1333 | addr &= ~(PAGE_SIZE - 1); | |
1334 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
73b0140b IW |
1335 | res = get_user_pages_fast(addr, n, |
1336 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, | |
1337 | pages); | |
e5393fae AV |
1338 | if (unlikely(res < 0)) |
1339 | return res; | |
1340 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1341 | 0;}),({ | |
1342 | /* can't be more than PAGE_SIZE */ | |
1343 | *start = v.bv_offset; | |
1344 | get_page(*pages = v.bv_page); | |
1345 | return v.bv_len; | |
a280455f AV |
1346 | }),({ |
1347 | return -EFAULT; | |
e5393fae AV |
1348 | }) |
1349 | ) | |
1350 | return 0; | |
62a8067a AV |
1351 | } |
1352 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1353 | ||
1b17f1f2 AV |
1354 | static struct page **get_pages_array(size_t n) |
1355 | { | |
752ade68 | 1356 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1357 | } |
1358 | ||
241699cd AV |
1359 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1360 | struct page ***pages, size_t maxsize, | |
1361 | size_t *start) | |
1362 | { | |
1363 | struct page **p; | |
8cefc107 | 1364 | unsigned int iter_head, npages; |
d7760d63 | 1365 | ssize_t n; |
241699cd | 1366 | |
33844e66 AV |
1367 | if (!maxsize) |
1368 | return 0; | |
1369 | ||
241699cd AV |
1370 | if (!sanity(i)) |
1371 | return -EFAULT; | |
1372 | ||
8cefc107 DH |
1373 | data_start(i, &iter_head, start); |
1374 | /* Amount of free space: some of this one + all after this one */ | |
1375 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
241699cd AV |
1376 | n = npages * PAGE_SIZE - *start; |
1377 | if (maxsize > n) | |
1378 | maxsize = n; | |
1379 | else | |
1380 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1381 | p = get_pages_array(npages); | |
1382 | if (!p) | |
1383 | return -ENOMEM; | |
8cefc107 | 1384 | n = __pipe_get_pages(i, maxsize, p, iter_head, start); |
241699cd AV |
1385 | if (n > 0) |
1386 | *pages = p; | |
1387 | else | |
1388 | kvfree(p); | |
1389 | return n; | |
1390 | } | |
1391 | ||
62a8067a AV |
1392 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1393 | struct page ***pages, size_t maxsize, | |
1394 | size_t *start) | |
1395 | { | |
1b17f1f2 AV |
1396 | struct page **p; |
1397 | ||
1398 | if (maxsize > i->count) | |
1399 | maxsize = i->count; | |
1400 | ||
00e23707 | 1401 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1402 | return pipe_get_pages_alloc(i, pages, maxsize, start); |
9ea9ce04 DH |
1403 | if (unlikely(iov_iter_is_discard(i))) |
1404 | return -EFAULT; | |
1405 | ||
1b17f1f2 AV |
1406 | iterate_all_kinds(i, maxsize, v, ({ |
1407 | unsigned long addr = (unsigned long)v.iov_base; | |
1408 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1409 | int n; | |
1410 | int res; | |
1411 | ||
1412 | addr &= ~(PAGE_SIZE - 1); | |
1413 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1414 | p = get_pages_array(n); | |
1415 | if (!p) | |
1416 | return -ENOMEM; | |
73b0140b IW |
1417 | res = get_user_pages_fast(addr, n, |
1418 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); | |
1b17f1f2 AV |
1419 | if (unlikely(res < 0)) { |
1420 | kvfree(p); | |
1421 | return res; | |
1422 | } | |
1423 | *pages = p; | |
1424 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1425 | 0;}),({ | |
1426 | /* can't be more than PAGE_SIZE */ | |
1427 | *start = v.bv_offset; | |
1428 | *pages = p = get_pages_array(1); | |
1429 | if (!p) | |
1430 | return -ENOMEM; | |
1431 | get_page(*p = v.bv_page); | |
1432 | return v.bv_len; | |
a280455f AV |
1433 | }),({ |
1434 | return -EFAULT; | |
1b17f1f2 AV |
1435 | }) |
1436 | ) | |
1437 | return 0; | |
62a8067a AV |
1438 | } |
1439 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1440 | ||
a604ec7e AV |
1441 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1442 | struct iov_iter *i) | |
1443 | { | |
1444 | char *to = addr; | |
1445 | __wsum sum, next; | |
1446 | size_t off = 0; | |
a604ec7e | 1447 | sum = *csum; |
9ea9ce04 | 1448 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1449 | WARN_ON(1); |
1450 | return 0; | |
1451 | } | |
a604ec7e AV |
1452 | iterate_and_advance(i, bytes, v, ({ |
1453 | int err = 0; | |
cbbd26b8 | 1454 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e AV |
1455 | (to += v.iov_len) - v.iov_len, |
1456 | v.iov_len, 0, &err); | |
1457 | if (!err) { | |
1458 | sum = csum_block_add(sum, next, off); | |
1459 | off += v.iov_len; | |
1460 | } | |
1461 | err ? v.iov_len : 0; | |
1462 | }), ({ | |
1463 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1464 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1465 | p + v.bv_offset, v.bv_len, | |
1466 | sum, off); | |
a604ec7e | 1467 | kunmap_atomic(p); |
a604ec7e AV |
1468 | off += v.bv_len; |
1469 | }),({ | |
f9152895 AV |
1470 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1471 | v.iov_base, v.iov_len, | |
1472 | sum, off); | |
a604ec7e AV |
1473 | off += v.iov_len; |
1474 | }) | |
1475 | ) | |
1476 | *csum = sum; | |
1477 | return bytes; | |
1478 | } | |
1479 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1480 | ||
cbbd26b8 AV |
1481 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
1482 | struct iov_iter *i) | |
1483 | { | |
1484 | char *to = addr; | |
1485 | __wsum sum, next; | |
1486 | size_t off = 0; | |
1487 | sum = *csum; | |
9ea9ce04 | 1488 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
cbbd26b8 AV |
1489 | WARN_ON(1); |
1490 | return false; | |
1491 | } | |
1492 | if (unlikely(i->count < bytes)) | |
1493 | return false; | |
1494 | iterate_all_kinds(i, bytes, v, ({ | |
1495 | int err = 0; | |
1496 | next = csum_and_copy_from_user(v.iov_base, | |
1497 | (to += v.iov_len) - v.iov_len, | |
1498 | v.iov_len, 0, &err); | |
1499 | if (err) | |
1500 | return false; | |
1501 | sum = csum_block_add(sum, next, off); | |
1502 | off += v.iov_len; | |
1503 | 0; | |
1504 | }), ({ | |
1505 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1506 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1507 | p + v.bv_offset, v.bv_len, | |
1508 | sum, off); | |
cbbd26b8 | 1509 | kunmap_atomic(p); |
cbbd26b8 AV |
1510 | off += v.bv_len; |
1511 | }),({ | |
f9152895 AV |
1512 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1513 | v.iov_base, v.iov_len, | |
1514 | sum, off); | |
cbbd26b8 AV |
1515 | off += v.iov_len; |
1516 | }) | |
1517 | ) | |
1518 | *csum = sum; | |
1519 | iov_iter_advance(i, bytes); | |
1520 | return true; | |
1521 | } | |
1522 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1523 | ||
cb002d07 | 1524 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, |
a604ec7e AV |
1525 | struct iov_iter *i) |
1526 | { | |
36f7a8a4 | 1527 | const char *from = addr; |
cb002d07 | 1528 | __wsum *csum = csump; |
a604ec7e AV |
1529 | __wsum sum, next; |
1530 | size_t off = 0; | |
78e1f386 AV |
1531 | |
1532 | if (unlikely(iov_iter_is_pipe(i))) | |
1533 | return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); | |
1534 | ||
a604ec7e | 1535 | sum = *csum; |
78e1f386 | 1536 | if (unlikely(iov_iter_is_discard(i))) { |
241699cd AV |
1537 | WARN_ON(1); /* for now */ |
1538 | return 0; | |
1539 | } | |
a604ec7e AV |
1540 | iterate_and_advance(i, bytes, v, ({ |
1541 | int err = 0; | |
1542 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
cbbd26b8 | 1543 | v.iov_base, |
a604ec7e AV |
1544 | v.iov_len, 0, &err); |
1545 | if (!err) { | |
1546 | sum = csum_block_add(sum, next, off); | |
1547 | off += v.iov_len; | |
1548 | } | |
1549 | err ? v.iov_len : 0; | |
1550 | }), ({ | |
1551 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1552 | sum = csum_and_memcpy(p + v.bv_offset, |
1553 | (from += v.bv_len) - v.bv_len, | |
1554 | v.bv_len, sum, off); | |
a604ec7e | 1555 | kunmap_atomic(p); |
a604ec7e AV |
1556 | off += v.bv_len; |
1557 | }),({ | |
f9152895 AV |
1558 | sum = csum_and_memcpy(v.iov_base, |
1559 | (from += v.iov_len) - v.iov_len, | |
1560 | v.iov_len, sum, off); | |
a604ec7e AV |
1561 | off += v.iov_len; |
1562 | }) | |
1563 | ) | |
1564 | *csum = sum; | |
1565 | return bytes; | |
1566 | } | |
1567 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1568 | ||
d05f4435 SG |
1569 | size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
1570 | struct iov_iter *i) | |
1571 | { | |
7999096f | 1572 | #ifdef CONFIG_CRYPTO_HASH |
d05f4435 SG |
1573 | struct ahash_request *hash = hashp; |
1574 | struct scatterlist sg; | |
1575 | size_t copied; | |
1576 | ||
1577 | copied = copy_to_iter(addr, bytes, i); | |
1578 | sg_init_one(&sg, addr, copied); | |
1579 | ahash_request_set_crypt(hash, &sg, NULL, copied); | |
1580 | crypto_ahash_update(hash); | |
1581 | return copied; | |
27fad74a Y |
1582 | #else |
1583 | return 0; | |
1584 | #endif | |
d05f4435 SG |
1585 | } |
1586 | EXPORT_SYMBOL(hash_and_copy_to_iter); | |
1587 | ||
62a8067a AV |
1588 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1589 | { | |
e0f2dc40 AV |
1590 | size_t size = i->count; |
1591 | int npages = 0; | |
1592 | ||
1593 | if (!size) | |
1594 | return 0; | |
9ea9ce04 DH |
1595 | if (unlikely(iov_iter_is_discard(i))) |
1596 | return 0; | |
e0f2dc40 | 1597 | |
00e23707 | 1598 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd | 1599 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 | 1600 | unsigned int iter_head; |
241699cd | 1601 | size_t off; |
241699cd AV |
1602 | |
1603 | if (!sanity(i)) | |
1604 | return 0; | |
1605 | ||
8cefc107 | 1606 | data_start(i, &iter_head, &off); |
241699cd | 1607 | /* some of this one + all after this one */ |
8cefc107 | 1608 | npages = pipe_space_for_user(iter_head, pipe->tail, pipe); |
241699cd AV |
1609 | if (npages >= maxpages) |
1610 | return maxpages; | |
1611 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1612 | unsigned long p = (unsigned long)v.iov_base; |
1613 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1614 | - p / PAGE_SIZE; | |
1615 | if (npages >= maxpages) | |
1616 | return maxpages; | |
1617 | 0;}),({ | |
1618 | npages++; | |
1619 | if (npages >= maxpages) | |
1620 | return maxpages; | |
a280455f AV |
1621 | }),({ |
1622 | unsigned long p = (unsigned long)v.iov_base; | |
1623 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1624 | - p / PAGE_SIZE; | |
1625 | if (npages >= maxpages) | |
1626 | return maxpages; | |
e0f2dc40 AV |
1627 | }) |
1628 | ) | |
1629 | return npages; | |
62a8067a | 1630 | } |
f67da30c | 1631 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1632 | |
1633 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1634 | { | |
1635 | *new = *old; | |
00e23707 | 1636 | if (unlikely(iov_iter_is_pipe(new))) { |
241699cd AV |
1637 | WARN_ON(1); |
1638 | return NULL; | |
1639 | } | |
9ea9ce04 DH |
1640 | if (unlikely(iov_iter_is_discard(new))) |
1641 | return NULL; | |
00e23707 | 1642 | if (iov_iter_is_bvec(new)) |
4b8164b9 AV |
1643 | return new->bvec = kmemdup(new->bvec, |
1644 | new->nr_segs * sizeof(struct bio_vec), | |
1645 | flags); | |
1646 | else | |
1647 | /* iovec and kvec have identical layout */ | |
1648 | return new->iov = kmemdup(new->iov, | |
1649 | new->nr_segs * sizeof(struct iovec), | |
1650 | flags); | |
1651 | } | |
1652 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1653 | |
bfdc5970 CH |
1654 | static int copy_compat_iovec_from_user(struct iovec *iov, |
1655 | const struct iovec __user *uvec, unsigned long nr_segs) | |
1656 | { | |
1657 | const struct compat_iovec __user *uiov = | |
1658 | (const struct compat_iovec __user *)uvec; | |
1659 | int ret = -EFAULT, i; | |
1660 | ||
1661 | if (!user_access_begin(uvec, nr_segs * sizeof(*uvec))) | |
1662 | return -EFAULT; | |
1663 | ||
1664 | for (i = 0; i < nr_segs; i++) { | |
1665 | compat_uptr_t buf; | |
1666 | compat_ssize_t len; | |
1667 | ||
1668 | unsafe_get_user(len, &uiov[i].iov_len, uaccess_end); | |
1669 | unsafe_get_user(buf, &uiov[i].iov_base, uaccess_end); | |
1670 | ||
1671 | /* check for compat_size_t not fitting in compat_ssize_t .. */ | |
1672 | if (len < 0) { | |
1673 | ret = -EINVAL; | |
1674 | goto uaccess_end; | |
1675 | } | |
1676 | iov[i].iov_base = compat_ptr(buf); | |
1677 | iov[i].iov_len = len; | |
1678 | } | |
1679 | ||
1680 | ret = 0; | |
1681 | uaccess_end: | |
1682 | user_access_end(); | |
1683 | return ret; | |
1684 | } | |
1685 | ||
1686 | static int copy_iovec_from_user(struct iovec *iov, | |
1687 | const struct iovec __user *uvec, unsigned long nr_segs) | |
fb041b59 DL |
1688 | { |
1689 | unsigned long seg; | |
fb041b59 | 1690 | |
bfdc5970 CH |
1691 | if (copy_from_user(iov, uvec, nr_segs * sizeof(*uvec))) |
1692 | return -EFAULT; | |
1693 | for (seg = 0; seg < nr_segs; seg++) { | |
1694 | if ((ssize_t)iov[seg].iov_len < 0) | |
1695 | return -EINVAL; | |
fb041b59 DL |
1696 | } |
1697 | ||
bfdc5970 CH |
1698 | return 0; |
1699 | } | |
1700 | ||
1701 | struct iovec *iovec_from_user(const struct iovec __user *uvec, | |
1702 | unsigned long nr_segs, unsigned long fast_segs, | |
1703 | struct iovec *fast_iov, bool compat) | |
1704 | { | |
1705 | struct iovec *iov = fast_iov; | |
1706 | int ret; | |
1707 | ||
fb041b59 | 1708 | /* |
bfdc5970 CH |
1709 | * SuS says "The readv() function *may* fail if the iovcnt argument was |
1710 | * less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
1711 | * traditionally returned zero for zero segments, so... | |
fb041b59 | 1712 | */ |
bfdc5970 CH |
1713 | if (nr_segs == 0) |
1714 | return iov; | |
1715 | if (nr_segs > UIO_MAXIOV) | |
1716 | return ERR_PTR(-EINVAL); | |
fb041b59 DL |
1717 | if (nr_segs > fast_segs) { |
1718 | iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); | |
bfdc5970 CH |
1719 | if (!iov) |
1720 | return ERR_PTR(-ENOMEM); | |
fb041b59 | 1721 | } |
bfdc5970 CH |
1722 | |
1723 | if (compat) | |
1724 | ret = copy_compat_iovec_from_user(iov, uvec, nr_segs); | |
1725 | else | |
1726 | ret = copy_iovec_from_user(iov, uvec, nr_segs); | |
1727 | if (ret) { | |
1728 | if (iov != fast_iov) | |
1729 | kfree(iov); | |
1730 | return ERR_PTR(ret); | |
1731 | } | |
1732 | ||
1733 | return iov; | |
1734 | } | |
1735 | ||
1736 | ssize_t __import_iovec(int type, const struct iovec __user *uvec, | |
1737 | unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, | |
1738 | struct iov_iter *i, bool compat) | |
1739 | { | |
1740 | ssize_t total_len = 0; | |
1741 | unsigned long seg; | |
1742 | struct iovec *iov; | |
1743 | ||
1744 | iov = iovec_from_user(uvec, nr_segs, fast_segs, *iovp, compat); | |
1745 | if (IS_ERR(iov)) { | |
1746 | *iovp = NULL; | |
1747 | return PTR_ERR(iov); | |
fb041b59 DL |
1748 | } |
1749 | ||
1750 | /* | |
bfdc5970 CH |
1751 | * According to the Single Unix Specification we should return EINVAL if |
1752 | * an element length is < 0 when cast to ssize_t or if the total length | |
1753 | * would overflow the ssize_t return value of the system call. | |
fb041b59 DL |
1754 | * |
1755 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
1756 | * overflow case. | |
1757 | */ | |
fb041b59 | 1758 | for (seg = 0; seg < nr_segs; seg++) { |
fb041b59 DL |
1759 | ssize_t len = (ssize_t)iov[seg].iov_len; |
1760 | ||
bfdc5970 CH |
1761 | if (!access_ok(iov[seg].iov_base, len)) { |
1762 | if (iov != *iovp) | |
1763 | kfree(iov); | |
1764 | *iovp = NULL; | |
1765 | return -EFAULT; | |
fb041b59 | 1766 | } |
bfdc5970 CH |
1767 | |
1768 | if (len > MAX_RW_COUNT - total_len) { | |
1769 | len = MAX_RW_COUNT - total_len; | |
fb041b59 DL |
1770 | iov[seg].iov_len = len; |
1771 | } | |
bfdc5970 | 1772 | total_len += len; |
fb041b59 | 1773 | } |
bfdc5970 CH |
1774 | |
1775 | iov_iter_init(i, type, iov, nr_segs, total_len); | |
1776 | if (iov == *iovp) | |
1777 | *iovp = NULL; | |
1778 | else | |
1779 | *iovp = iov; | |
1780 | return total_len; | |
fb041b59 DL |
1781 | } |
1782 | ||
ffecee4f VN |
1783 | /** |
1784 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1785 | * into the kernel, check that it is valid, and initialize a new | |
1786 | * &struct iov_iter iterator to access it. | |
1787 | * | |
1788 | * @type: One of %READ or %WRITE. | |
bfdc5970 | 1789 | * @uvec: Pointer to the userspace array. |
ffecee4f VN |
1790 | * @nr_segs: Number of elements in userspace array. |
1791 | * @fast_segs: Number of elements in @iov. | |
bfdc5970 | 1792 | * @iovp: (input and output parameter) Pointer to pointer to (usually small |
ffecee4f VN |
1793 | * on-stack) kernel array. |
1794 | * @i: Pointer to iterator that will be initialized on success. | |
1795 | * | |
1796 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1797 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1798 | * array will be allocated and the result placed in *@iov. This means that | |
1799 | * the caller may call kfree() on *@iov regardless of whether the small | |
1800 | * on-stack array was used or not (and regardless of whether this function | |
1801 | * returns an error or not). | |
1802 | * | |
87e5e6da | 1803 | * Return: Negative error code on error, bytes imported on success |
ffecee4f | 1804 | */ |
bfdc5970 | 1805 | ssize_t import_iovec(int type, const struct iovec __user *uvec, |
bc917be8 | 1806 | unsigned nr_segs, unsigned fast_segs, |
bfdc5970 | 1807 | struct iovec **iovp, struct iov_iter *i) |
bc917be8 | 1808 | { |
bfdc5970 | 1809 | return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i, false); |
bc917be8 AV |
1810 | } |
1811 | EXPORT_SYMBOL(import_iovec); | |
1812 | ||
1813 | #ifdef CONFIG_COMPAT | |
bfdc5970 CH |
1814 | ssize_t compat_import_iovec(int type, const struct compat_iovec __user *uvec, |
1815 | unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, | |
1816 | struct iov_iter *i) | |
bc917be8 | 1817 | { |
bfdc5970 CH |
1818 | return __import_iovec(type, (const struct iovec __user *)uvec, nr_segs, |
1819 | fast_segs, iovp, i, true); | |
bc917be8 | 1820 | } |
98aaaec4 | 1821 | EXPORT_SYMBOL(compat_import_iovec); |
bc917be8 AV |
1822 | #endif |
1823 | ||
1824 | int import_single_range(int rw, void __user *buf, size_t len, | |
1825 | struct iovec *iov, struct iov_iter *i) | |
1826 | { | |
1827 | if (len > MAX_RW_COUNT) | |
1828 | len = MAX_RW_COUNT; | |
96d4f267 | 1829 | if (unlikely(!access_ok(buf, len))) |
bc917be8 AV |
1830 | return -EFAULT; |
1831 | ||
1832 | iov->iov_base = buf; | |
1833 | iov->iov_len = len; | |
1834 | iov_iter_init(i, rw, iov, 1, len); | |
1835 | return 0; | |
1836 | } | |
e1267585 | 1837 | EXPORT_SYMBOL(import_single_range); |
09cf698a AV |
1838 | |
1839 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1840 | int (*f)(struct kvec *vec, void *context), | |
1841 | void *context) | |
1842 | { | |
1843 | struct kvec w; | |
1844 | int err = -EINVAL; | |
1845 | if (!bytes) | |
1846 | return 0; | |
1847 | ||
1848 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1849 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1850 | w.iov_len = v.bv_len; | |
1851 | err = f(&w, context); | |
1852 | kunmap(v.bv_page); | |
1853 | err;}), ({ | |
1854 | w = v; | |
1855 | err = f(&w, context);}) | |
1856 | ) | |
1857 | return err; | |
1858 | } | |
1859 | EXPORT_SYMBOL(iov_iter_for_each_range); |