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> |
4d0e9df5 | 5 | #include <linux/fault-inject-usercopy.h> |
4f18cd31 AV |
6 | #include <linux/uio.h> |
7 | #include <linux/pagemap.h> | |
91f79c43 AV |
8 | #include <linux/slab.h> |
9 | #include <linux/vmalloc.h> | |
241699cd | 10 | #include <linux/splice.h> |
bfdc5970 | 11 | #include <linux/compat.h> |
a604ec7e | 12 | #include <net/checksum.h> |
d05f4435 | 13 | #include <linux/scatterlist.h> |
d0ef4c36 | 14 | #include <linux/instrumented.h> |
4f18cd31 | 15 | |
241699cd AV |
16 | #define PIPE_PARANOIA /* for now */ |
17 | ||
04a31165 AV |
18 | #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ |
19 | size_t left; \ | |
20 | size_t wanted = n; \ | |
21 | __p = i->iov; \ | |
22 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
23 | if (likely(__v.iov_len)) { \ | |
24 | __v.iov_base = __p->iov_base + skip; \ | |
25 | left = (STEP); \ | |
26 | __v.iov_len -= left; \ | |
27 | skip += __v.iov_len; \ | |
28 | n -= __v.iov_len; \ | |
29 | } else { \ | |
30 | left = 0; \ | |
31 | } \ | |
32 | while (unlikely(!left && n)) { \ | |
33 | __p++; \ | |
34 | __v.iov_len = min(n, __p->iov_len); \ | |
35 | if (unlikely(!__v.iov_len)) \ | |
36 | continue; \ | |
37 | __v.iov_base = __p->iov_base; \ | |
38 | left = (STEP); \ | |
39 | __v.iov_len -= left; \ | |
40 | skip = __v.iov_len; \ | |
41 | n -= __v.iov_len; \ | |
42 | } \ | |
43 | n = wanted - n; \ | |
44 | } | |
45 | ||
a280455f AV |
46 | #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ |
47 | size_t wanted = n; \ | |
48 | __p = i->kvec; \ | |
49 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
50 | if (likely(__v.iov_len)) { \ | |
51 | __v.iov_base = __p->iov_base + skip; \ | |
52 | (void)(STEP); \ | |
53 | skip += __v.iov_len; \ | |
54 | n -= __v.iov_len; \ | |
55 | } \ | |
56 | while (unlikely(n)) { \ | |
57 | __p++; \ | |
58 | __v.iov_len = min(n, __p->iov_len); \ | |
59 | if (unlikely(!__v.iov_len)) \ | |
60 | continue; \ | |
61 | __v.iov_base = __p->iov_base; \ | |
62 | (void)(STEP); \ | |
63 | skip = __v.iov_len; \ | |
64 | n -= __v.iov_len; \ | |
65 | } \ | |
66 | n = wanted; \ | |
67 | } | |
68 | ||
1bdc76ae ML |
69 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ |
70 | struct bvec_iter __start; \ | |
71 | __start.bi_size = n; \ | |
72 | __start.bi_bvec_done = skip; \ | |
73 | __start.bi_idx = 0; \ | |
74 | for_each_bvec(__v, i->bvec, __bi, __start) { \ | |
04a31165 | 75 | (void)(STEP); \ |
04a31165 | 76 | } \ |
04a31165 AV |
77 | } |
78 | ||
a280455f | 79 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
33844e66 AV |
80 | if (likely(n)) { \ |
81 | size_t skip = i->iov_offset; \ | |
82 | if (unlikely(i->type & ITER_BVEC)) { \ | |
83 | struct bio_vec v; \ | |
84 | struct bvec_iter __bi; \ | |
85 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
86 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
87 | const struct kvec *kvec; \ | |
88 | struct kvec v; \ | |
89 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
9ea9ce04 | 90 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
33844e66 AV |
91 | } else { \ |
92 | const struct iovec *iov; \ | |
93 | struct iovec v; \ | |
94 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
95 | } \ | |
04a31165 AV |
96 | } \ |
97 | } | |
98 | ||
a280455f | 99 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
100 | if (unlikely(i->count < n)) \ |
101 | n = i->count; \ | |
19f18459 | 102 | if (i->count) { \ |
dd254f5a AV |
103 | size_t skip = i->iov_offset; \ |
104 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 105 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 106 | struct bio_vec v; \ |
1bdc76ae ML |
107 | struct bvec_iter __bi; \ |
108 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
109 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
110 | i->nr_segs -= i->bvec - bvec; \ | |
111 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
112 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
113 | const struct kvec *kvec; \ | |
114 | struct kvec v; \ | |
115 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
116 | if (skip == kvec->iov_len) { \ | |
117 | kvec++; \ | |
118 | skip = 0; \ | |
119 | } \ | |
120 | i->nr_segs -= kvec - i->kvec; \ | |
121 | i->kvec = kvec; \ | |
9ea9ce04 DH |
122 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
123 | skip += n; \ | |
dd254f5a AV |
124 | } else { \ |
125 | const struct iovec *iov; \ | |
126 | struct iovec v; \ | |
127 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
128 | if (skip == iov->iov_len) { \ | |
129 | iov++; \ | |
130 | skip = 0; \ | |
131 | } \ | |
132 | i->nr_segs -= iov - i->iov; \ | |
133 | i->iov = iov; \ | |
7ce2a91e | 134 | } \ |
dd254f5a AV |
135 | i->count -= n; \ |
136 | i->iov_offset = skip; \ | |
7ce2a91e | 137 | } \ |
7ce2a91e AV |
138 | } |
139 | ||
09fc68dc AV |
140 | static int copyout(void __user *to, const void *from, size_t n) |
141 | { | |
4d0e9df5 AL |
142 | if (should_fail_usercopy()) |
143 | return n; | |
96d4f267 | 144 | if (access_ok(to, n)) { |
d0ef4c36 | 145 | instrument_copy_to_user(to, from, n); |
09fc68dc AV |
146 | n = raw_copy_to_user(to, from, n); |
147 | } | |
148 | return n; | |
149 | } | |
150 | ||
151 | static int copyin(void *to, const void __user *from, size_t n) | |
152 | { | |
4d0e9df5 AL |
153 | if (should_fail_usercopy()) |
154 | return n; | |
96d4f267 | 155 | if (access_ok(from, n)) { |
d0ef4c36 | 156 | instrument_copy_from_user(to, from, n); |
09fc68dc AV |
157 | n = raw_copy_from_user(to, from, n); |
158 | } | |
159 | return n; | |
160 | } | |
161 | ||
62a8067a | 162 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
163 | struct iov_iter *i) |
164 | { | |
165 | size_t skip, copy, left, wanted; | |
166 | const struct iovec *iov; | |
167 | char __user *buf; | |
168 | void *kaddr, *from; | |
169 | ||
170 | if (unlikely(bytes > i->count)) | |
171 | bytes = i->count; | |
172 | ||
173 | if (unlikely(!bytes)) | |
174 | return 0; | |
175 | ||
09fc68dc | 176 | might_fault(); |
4f18cd31 AV |
177 | wanted = bytes; |
178 | iov = i->iov; | |
179 | skip = i->iov_offset; | |
180 | buf = iov->iov_base + skip; | |
181 | copy = min(bytes, iov->iov_len - skip); | |
182 | ||
3fa6c507 | 183 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
184 | kaddr = kmap_atomic(page); |
185 | from = kaddr + offset; | |
186 | ||
187 | /* first chunk, usually the only one */ | |
09fc68dc | 188 | left = copyout(buf, from, copy); |
4f18cd31 AV |
189 | copy -= left; |
190 | skip += copy; | |
191 | from += copy; | |
192 | bytes -= copy; | |
193 | ||
194 | while (unlikely(!left && bytes)) { | |
195 | iov++; | |
196 | buf = iov->iov_base; | |
197 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 198 | left = copyout(buf, from, copy); |
4f18cd31 AV |
199 | copy -= left; |
200 | skip = copy; | |
201 | from += copy; | |
202 | bytes -= copy; | |
203 | } | |
204 | if (likely(!bytes)) { | |
205 | kunmap_atomic(kaddr); | |
206 | goto done; | |
207 | } | |
208 | offset = from - kaddr; | |
209 | buf += copy; | |
210 | kunmap_atomic(kaddr); | |
211 | copy = min(bytes, iov->iov_len - skip); | |
212 | } | |
213 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 214 | |
4f18cd31 AV |
215 | kaddr = kmap(page); |
216 | from = kaddr + offset; | |
09fc68dc | 217 | left = copyout(buf, from, copy); |
4f18cd31 AV |
218 | copy -= left; |
219 | skip += copy; | |
220 | from += copy; | |
221 | bytes -= copy; | |
222 | while (unlikely(!left && bytes)) { | |
223 | iov++; | |
224 | buf = iov->iov_base; | |
225 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 226 | left = copyout(buf, from, copy); |
4f18cd31 AV |
227 | copy -= left; |
228 | skip = copy; | |
229 | from += copy; | |
230 | bytes -= copy; | |
231 | } | |
232 | kunmap(page); | |
3fa6c507 | 233 | |
4f18cd31 | 234 | done: |
81055e58 AV |
235 | if (skip == iov->iov_len) { |
236 | iov++; | |
237 | skip = 0; | |
238 | } | |
4f18cd31 AV |
239 | i->count -= wanted - bytes; |
240 | i->nr_segs -= iov - i->iov; | |
241 | i->iov = iov; | |
242 | i->iov_offset = skip; | |
243 | return wanted - bytes; | |
244 | } | |
4f18cd31 | 245 | |
62a8067a | 246 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
247 | struct iov_iter *i) |
248 | { | |
249 | size_t skip, copy, left, wanted; | |
250 | const struct iovec *iov; | |
251 | char __user *buf; | |
252 | void *kaddr, *to; | |
253 | ||
254 | if (unlikely(bytes > i->count)) | |
255 | bytes = i->count; | |
256 | ||
257 | if (unlikely(!bytes)) | |
258 | return 0; | |
259 | ||
09fc68dc | 260 | might_fault(); |
f0d1bec9 AV |
261 | wanted = bytes; |
262 | iov = i->iov; | |
263 | skip = i->iov_offset; | |
264 | buf = iov->iov_base + skip; | |
265 | copy = min(bytes, iov->iov_len - skip); | |
266 | ||
3fa6c507 | 267 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
268 | kaddr = kmap_atomic(page); |
269 | to = kaddr + offset; | |
270 | ||
271 | /* first chunk, usually the only one */ | |
09fc68dc | 272 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
273 | copy -= left; |
274 | skip += copy; | |
275 | to += copy; | |
276 | bytes -= copy; | |
277 | ||
278 | while (unlikely(!left && bytes)) { | |
279 | iov++; | |
280 | buf = iov->iov_base; | |
281 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 282 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
283 | copy -= left; |
284 | skip = copy; | |
285 | to += copy; | |
286 | bytes -= copy; | |
287 | } | |
288 | if (likely(!bytes)) { | |
289 | kunmap_atomic(kaddr); | |
290 | goto done; | |
291 | } | |
292 | offset = to - kaddr; | |
293 | buf += copy; | |
294 | kunmap_atomic(kaddr); | |
295 | copy = min(bytes, iov->iov_len - skip); | |
296 | } | |
297 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 298 | |
f0d1bec9 AV |
299 | kaddr = kmap(page); |
300 | to = kaddr + offset; | |
09fc68dc | 301 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
302 | copy -= left; |
303 | skip += copy; | |
304 | to += copy; | |
305 | bytes -= copy; | |
306 | while (unlikely(!left && bytes)) { | |
307 | iov++; | |
308 | buf = iov->iov_base; | |
309 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 310 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
311 | copy -= left; |
312 | skip = copy; | |
313 | to += copy; | |
314 | bytes -= copy; | |
315 | } | |
316 | kunmap(page); | |
3fa6c507 | 317 | |
f0d1bec9 | 318 | done: |
81055e58 AV |
319 | if (skip == iov->iov_len) { |
320 | iov++; | |
321 | skip = 0; | |
322 | } | |
f0d1bec9 AV |
323 | i->count -= wanted - bytes; |
324 | i->nr_segs -= iov - i->iov; | |
325 | i->iov = iov; | |
326 | i->iov_offset = skip; | |
327 | return wanted - bytes; | |
328 | } | |
f0d1bec9 | 329 | |
241699cd AV |
330 | #ifdef PIPE_PARANOIA |
331 | static bool sanity(const struct iov_iter *i) | |
332 | { | |
333 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
334 | unsigned int p_head = pipe->head; |
335 | unsigned int p_tail = pipe->tail; | |
336 | unsigned int p_mask = pipe->ring_size - 1; | |
337 | unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); | |
338 | unsigned int i_head = i->head; | |
339 | unsigned int idx; | |
340 | ||
241699cd AV |
341 | if (i->iov_offset) { |
342 | struct pipe_buffer *p; | |
8cefc107 | 343 | if (unlikely(p_occupancy == 0)) |
241699cd | 344 | goto Bad; // pipe must be non-empty |
8cefc107 | 345 | if (unlikely(i_head != p_head - 1)) |
241699cd AV |
346 | goto Bad; // must be at the last buffer... |
347 | ||
8cefc107 | 348 | p = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
349 | if (unlikely(p->offset + p->len != i->iov_offset)) |
350 | goto Bad; // ... at the end of segment | |
351 | } else { | |
8cefc107 | 352 | if (i_head != p_head) |
241699cd AV |
353 | goto Bad; // must be right after the last buffer |
354 | } | |
355 | return true; | |
356 | Bad: | |
8cefc107 DH |
357 | printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); |
358 | printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", | |
359 | p_head, p_tail, pipe->ring_size); | |
360 | for (idx = 0; idx < pipe->ring_size; idx++) | |
241699cd AV |
361 | printk(KERN_ERR "[%p %p %d %d]\n", |
362 | pipe->bufs[idx].ops, | |
363 | pipe->bufs[idx].page, | |
364 | pipe->bufs[idx].offset, | |
365 | pipe->bufs[idx].len); | |
366 | WARN_ON(1); | |
367 | return false; | |
368 | } | |
369 | #else | |
370 | #define sanity(i) true | |
371 | #endif | |
372 | ||
241699cd AV |
373 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, |
374 | struct iov_iter *i) | |
375 | { | |
376 | struct pipe_inode_info *pipe = i->pipe; | |
377 | struct pipe_buffer *buf; | |
8cefc107 DH |
378 | unsigned int p_tail = pipe->tail; |
379 | unsigned int p_mask = pipe->ring_size - 1; | |
380 | unsigned int i_head = i->head; | |
241699cd | 381 | size_t off; |
241699cd AV |
382 | |
383 | if (unlikely(bytes > i->count)) | |
384 | bytes = i->count; | |
385 | ||
386 | if (unlikely(!bytes)) | |
387 | return 0; | |
388 | ||
389 | if (!sanity(i)) | |
390 | return 0; | |
391 | ||
392 | off = i->iov_offset; | |
8cefc107 | 393 | buf = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
394 | if (off) { |
395 | if (offset == off && buf->page == page) { | |
396 | /* merge with the last one */ | |
397 | buf->len += bytes; | |
398 | i->iov_offset += bytes; | |
399 | goto out; | |
400 | } | |
8cefc107 DH |
401 | i_head++; |
402 | buf = &pipe->bufs[i_head & p_mask]; | |
241699cd | 403 | } |
6718b6f8 | 404 | if (pipe_full(i_head, p_tail, pipe->max_usage)) |
241699cd | 405 | return 0; |
8cefc107 | 406 | |
241699cd | 407 | buf->ops = &page_cache_pipe_buf_ops; |
8cefc107 DH |
408 | get_page(page); |
409 | buf->page = page; | |
241699cd AV |
410 | buf->offset = offset; |
411 | buf->len = bytes; | |
8cefc107 DH |
412 | |
413 | pipe->head = i_head + 1; | |
241699cd | 414 | i->iov_offset = offset + bytes; |
8cefc107 | 415 | i->head = i_head; |
241699cd AV |
416 | out: |
417 | i->count -= bytes; | |
418 | return bytes; | |
419 | } | |
420 | ||
171a0203 AA |
421 | /* |
422 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
423 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
424 | * | |
425 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
426 | * because it is an invalid address). | |
427 | */ | |
d4690f1e | 428 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
429 | { |
430 | size_t skip = i->iov_offset; | |
431 | const struct iovec *iov; | |
432 | int err; | |
433 | struct iovec v; | |
434 | ||
435 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
436 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
4bce9f6e | 437 | err = fault_in_pages_readable(v.iov_base, v.iov_len); |
171a0203 AA |
438 | if (unlikely(err)) |
439 | return err; | |
440 | 0;})) | |
441 | } | |
442 | return 0; | |
443 | } | |
d4690f1e | 444 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 445 | |
aa563d7b | 446 | void iov_iter_init(struct iov_iter *i, unsigned int direction, |
71d8e532 AV |
447 | const struct iovec *iov, unsigned long nr_segs, |
448 | size_t count) | |
449 | { | |
aa563d7b DH |
450 | WARN_ON(direction & ~(READ | WRITE)); |
451 | direction &= READ | WRITE; | |
452 | ||
71d8e532 | 453 | /* It will get better. Eventually... */ |
db68ce10 | 454 | if (uaccess_kernel()) { |
aa563d7b | 455 | i->type = ITER_KVEC | direction; |
a280455f AV |
456 | i->kvec = (struct kvec *)iov; |
457 | } else { | |
aa563d7b | 458 | i->type = ITER_IOVEC | direction; |
a280455f AV |
459 | i->iov = iov; |
460 | } | |
71d8e532 AV |
461 | i->nr_segs = nr_segs; |
462 | i->iov_offset = 0; | |
463 | i->count = count; | |
464 | } | |
465 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 466 | |
c35e0248 MW |
467 | static void memzero_page(struct page *page, size_t offset, size_t len) |
468 | { | |
469 | char *addr = kmap_atomic(page); | |
470 | memset(addr + offset, 0, len); | |
471 | kunmap_atomic(addr); | |
472 | } | |
473 | ||
241699cd AV |
474 | static inline bool allocated(struct pipe_buffer *buf) |
475 | { | |
476 | return buf->ops == &default_pipe_buf_ops; | |
477 | } | |
478 | ||
8cefc107 DH |
479 | static inline void data_start(const struct iov_iter *i, |
480 | unsigned int *iter_headp, size_t *offp) | |
241699cd | 481 | { |
8cefc107 DH |
482 | unsigned int p_mask = i->pipe->ring_size - 1; |
483 | unsigned int iter_head = i->head; | |
241699cd | 484 | size_t off = i->iov_offset; |
8cefc107 DH |
485 | |
486 | if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || | |
487 | off == PAGE_SIZE)) { | |
488 | iter_head++; | |
241699cd AV |
489 | off = 0; |
490 | } | |
8cefc107 | 491 | *iter_headp = iter_head; |
241699cd AV |
492 | *offp = off; |
493 | } | |
494 | ||
495 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
8cefc107 | 496 | int *iter_headp, size_t *offp) |
241699cd AV |
497 | { |
498 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
499 | unsigned int p_tail = pipe->tail; |
500 | unsigned int p_mask = pipe->ring_size - 1; | |
501 | unsigned int iter_head; | |
241699cd | 502 | size_t off; |
241699cd AV |
503 | ssize_t left; |
504 | ||
505 | if (unlikely(size > i->count)) | |
506 | size = i->count; | |
507 | if (unlikely(!size)) | |
508 | return 0; | |
509 | ||
510 | left = size; | |
8cefc107 DH |
511 | data_start(i, &iter_head, &off); |
512 | *iter_headp = iter_head; | |
241699cd AV |
513 | *offp = off; |
514 | if (off) { | |
515 | left -= PAGE_SIZE - off; | |
516 | if (left <= 0) { | |
8cefc107 | 517 | pipe->bufs[iter_head & p_mask].len += size; |
241699cd AV |
518 | return size; |
519 | } | |
8cefc107 DH |
520 | pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; |
521 | iter_head++; | |
241699cd | 522 | } |
6718b6f8 | 523 | while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { |
8cefc107 | 524 | struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; |
241699cd AV |
525 | struct page *page = alloc_page(GFP_USER); |
526 | if (!page) | |
527 | break; | |
8cefc107 DH |
528 | |
529 | buf->ops = &default_pipe_buf_ops; | |
530 | buf->page = page; | |
531 | buf->offset = 0; | |
532 | buf->len = min_t(ssize_t, left, PAGE_SIZE); | |
533 | left -= buf->len; | |
534 | iter_head++; | |
535 | pipe->head = iter_head; | |
536 | ||
537 | if (left == 0) | |
241699cd | 538 | return size; |
241699cd AV |
539 | } |
540 | return size - left; | |
541 | } | |
542 | ||
543 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
544 | struct iov_iter *i) | |
545 | { | |
546 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
547 | unsigned int p_mask = pipe->ring_size - 1; |
548 | unsigned int i_head; | |
241699cd | 549 | size_t n, off; |
241699cd AV |
550 | |
551 | if (!sanity(i)) | |
552 | return 0; | |
553 | ||
8cefc107 | 554 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
555 | if (unlikely(!n)) |
556 | return 0; | |
8cefc107 | 557 | do { |
241699cd | 558 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
559 | memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); |
560 | i->head = i_head; | |
241699cd AV |
561 | i->iov_offset = off + chunk; |
562 | n -= chunk; | |
563 | addr += chunk; | |
8cefc107 DH |
564 | off = 0; |
565 | i_head++; | |
566 | } while (n); | |
241699cd AV |
567 | i->count -= bytes; |
568 | return bytes; | |
569 | } | |
570 | ||
f9152895 AV |
571 | static __wsum csum_and_memcpy(void *to, const void *from, size_t len, |
572 | __wsum sum, size_t off) | |
573 | { | |
cc44c17b | 574 | __wsum next = csum_partial_copy_nocheck(from, to, len); |
f9152895 AV |
575 | return csum_block_add(sum, next, off); |
576 | } | |
577 | ||
78e1f386 | 578 | static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, |
52cbd23a WB |
579 | struct csum_state *csstate, |
580 | struct iov_iter *i) | |
78e1f386 AV |
581 | { |
582 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 | 583 | unsigned int p_mask = pipe->ring_size - 1; |
52cbd23a WB |
584 | __wsum sum = csstate->csum; |
585 | size_t off = csstate->off; | |
8cefc107 | 586 | unsigned int i_head; |
78e1f386 | 587 | size_t n, r; |
78e1f386 AV |
588 | |
589 | if (!sanity(i)) | |
590 | return 0; | |
591 | ||
8cefc107 | 592 | bytes = n = push_pipe(i, bytes, &i_head, &r); |
78e1f386 AV |
593 | if (unlikely(!n)) |
594 | return 0; | |
8cefc107 | 595 | do { |
78e1f386 | 596 | size_t chunk = min_t(size_t, n, PAGE_SIZE - r); |
8cefc107 | 597 | char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); |
f9152895 | 598 | sum = csum_and_memcpy(p + r, addr, chunk, sum, off); |
78e1f386 | 599 | kunmap_atomic(p); |
8cefc107 | 600 | i->head = i_head; |
78e1f386 AV |
601 | i->iov_offset = r + chunk; |
602 | n -= chunk; | |
603 | off += chunk; | |
604 | addr += chunk; | |
8cefc107 DH |
605 | r = 0; |
606 | i_head++; | |
607 | } while (n); | |
78e1f386 | 608 | i->count -= bytes; |
52cbd23a WB |
609 | csstate->csum = sum; |
610 | csstate->off = off; | |
78e1f386 AV |
611 | return bytes; |
612 | } | |
613 | ||
aa28de27 | 614 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 615 | { |
36f7a8a4 | 616 | const char *from = addr; |
00e23707 | 617 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 618 | return copy_pipe_to_iter(addr, bytes, i); |
09fc68dc AV |
619 | if (iter_is_iovec(i)) |
620 | might_fault(); | |
3d4d3e48 | 621 | iterate_and_advance(i, bytes, v, |
09fc68dc | 622 | copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
3d4d3e48 | 623 | memcpy_to_page(v.bv_page, v.bv_offset, |
a280455f AV |
624 | (from += v.bv_len) - v.bv_len, v.bv_len), |
625 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 626 | ) |
62a8067a | 627 | |
3d4d3e48 | 628 | return bytes; |
c35e0248 | 629 | } |
aa28de27 | 630 | EXPORT_SYMBOL(_copy_to_iter); |
c35e0248 | 631 | |
ec6347bb DW |
632 | #ifdef CONFIG_ARCH_HAS_COPY_MC |
633 | static int copyout_mc(void __user *to, const void *from, size_t n) | |
8780356e | 634 | { |
96d4f267 | 635 | if (access_ok(to, n)) { |
d0ef4c36 | 636 | instrument_copy_to_user(to, from, n); |
ec6347bb | 637 | n = copy_mc_to_user((__force void *) to, from, n); |
8780356e DW |
638 | } |
639 | return n; | |
640 | } | |
641 | ||
ec6347bb | 642 | static unsigned long copy_mc_to_page(struct page *page, size_t offset, |
8780356e DW |
643 | const char *from, size_t len) |
644 | { | |
645 | unsigned long ret; | |
646 | char *to; | |
647 | ||
648 | to = kmap_atomic(page); | |
ec6347bb | 649 | ret = copy_mc_to_kernel(to + offset, from, len); |
8780356e DW |
650 | kunmap_atomic(to); |
651 | ||
652 | return ret; | |
653 | } | |
654 | ||
ec6347bb | 655 | static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes, |
ca146f6f DW |
656 | struct iov_iter *i) |
657 | { | |
658 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
659 | unsigned int p_mask = pipe->ring_size - 1; |
660 | unsigned int i_head; | |
ca146f6f | 661 | size_t n, off, xfer = 0; |
ca146f6f DW |
662 | |
663 | if (!sanity(i)) | |
664 | return 0; | |
665 | ||
8cefc107 | 666 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
ca146f6f DW |
667 | if (unlikely(!n)) |
668 | return 0; | |
8cefc107 | 669 | do { |
ca146f6f DW |
670 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
671 | unsigned long rem; | |
672 | ||
ec6347bb | 673 | rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page, |
8cefc107 DH |
674 | off, addr, chunk); |
675 | i->head = i_head; | |
ca146f6f DW |
676 | i->iov_offset = off + chunk - rem; |
677 | xfer += chunk - rem; | |
678 | if (rem) | |
679 | break; | |
680 | n -= chunk; | |
681 | addr += chunk; | |
8cefc107 DH |
682 | off = 0; |
683 | i_head++; | |
684 | } while (n); | |
ca146f6f DW |
685 | i->count -= xfer; |
686 | return xfer; | |
687 | } | |
688 | ||
bf3eeb9b | 689 | /** |
ec6347bb | 690 | * _copy_mc_to_iter - copy to iter with source memory error exception handling |
bf3eeb9b DW |
691 | * @addr: source kernel address |
692 | * @bytes: total transfer length | |
693 | * @iter: destination iterator | |
694 | * | |
ec6347bb DW |
695 | * The pmem driver deploys this for the dax operation |
696 | * (dax_copy_to_iter()) for dax reads (bypass page-cache and the | |
697 | * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes | |
698 | * successfully copied. | |
bf3eeb9b | 699 | * |
ec6347bb | 700 | * The main differences between this and typical _copy_to_iter(). |
bf3eeb9b DW |
701 | * |
702 | * * Typical tail/residue handling after a fault retries the copy | |
703 | * byte-by-byte until the fault happens again. Re-triggering machine | |
704 | * checks is potentially fatal so the implementation uses source | |
705 | * alignment and poison alignment assumptions to avoid re-triggering | |
706 | * hardware exceptions. | |
707 | * | |
708 | * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. | |
709 | * Compare to copy_to_iter() where only ITER_IOVEC attempts might return | |
710 | * a short copy. | |
bf3eeb9b | 711 | */ |
ec6347bb | 712 | size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
8780356e DW |
713 | { |
714 | const char *from = addr; | |
715 | unsigned long rem, curr_addr, s_addr = (unsigned long) addr; | |
716 | ||
00e23707 | 717 | if (unlikely(iov_iter_is_pipe(i))) |
ec6347bb | 718 | return copy_mc_pipe_to_iter(addr, bytes, i); |
8780356e DW |
719 | if (iter_is_iovec(i)) |
720 | might_fault(); | |
721 | iterate_and_advance(i, bytes, v, | |
ec6347bb DW |
722 | copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len, |
723 | v.iov_len), | |
8780356e | 724 | ({ |
ec6347bb DW |
725 | rem = copy_mc_to_page(v.bv_page, v.bv_offset, |
726 | (from += v.bv_len) - v.bv_len, v.bv_len); | |
8780356e DW |
727 | if (rem) { |
728 | curr_addr = (unsigned long) from; | |
729 | bytes = curr_addr - s_addr - rem; | |
730 | return bytes; | |
731 | } | |
732 | }), | |
733 | ({ | |
ec6347bb DW |
734 | rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len) |
735 | - v.iov_len, v.iov_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 | ) | |
743 | ||
744 | return bytes; | |
745 | } | |
ec6347bb DW |
746 | EXPORT_SYMBOL_GPL(_copy_mc_to_iter); |
747 | #endif /* CONFIG_ARCH_HAS_COPY_MC */ | |
8780356e | 748 | |
aa28de27 | 749 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 750 | { |
0dbca9a4 | 751 | char *to = addr; |
00e23707 | 752 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
753 | WARN_ON(1); |
754 | return 0; | |
755 | } | |
09fc68dc AV |
756 | if (iter_is_iovec(i)) |
757 | might_fault(); | |
0dbca9a4 | 758 | iterate_and_advance(i, bytes, v, |
09fc68dc | 759 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4 | 760 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
761 | v.bv_offset, v.bv_len), |
762 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
763 | ) |
764 | ||
765 | return bytes; | |
c35e0248 | 766 | } |
aa28de27 | 767 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 768 | |
aa28de27 | 769 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
770 | { |
771 | char *to = addr; | |
00e23707 | 772 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
773 | WARN_ON(1); |
774 | return false; | |
775 | } | |
33844e66 | 776 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
777 | return false; |
778 | ||
09fc68dc AV |
779 | if (iter_is_iovec(i)) |
780 | might_fault(); | |
cbbd26b8 | 781 | iterate_all_kinds(i, bytes, v, ({ |
09fc68dc | 782 | if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
783 | v.iov_base, v.iov_len)) |
784 | return false; | |
785 | 0;}), | |
786 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
787 | v.bv_offset, v.bv_len), | |
788 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
789 | ) | |
790 | ||
791 | iov_iter_advance(i, bytes); | |
792 | return true; | |
793 | } | |
aa28de27 | 794 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 795 | |
aa28de27 | 796 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
797 | { |
798 | char *to = addr; | |
00e23707 | 799 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
800 | WARN_ON(1); |
801 | return 0; | |
802 | } | |
aa583096 | 803 | iterate_and_advance(i, bytes, v, |
3f763453 | 804 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
805 | v.iov_base, v.iov_len), |
806 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
807 | v.bv_offset, v.bv_len), | |
808 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
809 | ) | |
810 | ||
811 | return bytes; | |
812 | } | |
aa28de27 | 813 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 814 | |
0aed55af | 815 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d DW |
816 | /** |
817 | * _copy_from_iter_flushcache - write destination through cpu cache | |
818 | * @addr: destination kernel address | |
819 | * @bytes: total transfer length | |
820 | * @iter: source iterator | |
821 | * | |
822 | * The pmem driver arranges for filesystem-dax to use this facility via | |
823 | * dax_copy_from_iter() for ensuring that writes to persistent memory | |
824 | * are flushed through the CPU cache. It is differentiated from | |
825 | * _copy_from_iter_nocache() in that guarantees all data is flushed for | |
826 | * all iterator types. The _copy_from_iter_nocache() only attempts to | |
827 | * bypass the cache for the ITER_IOVEC case, and on some archs may use | |
828 | * instructions that strand dirty-data in the cache. | |
829 | */ | |
6a37e940 | 830 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af DW |
831 | { |
832 | char *to = addr; | |
00e23707 | 833 | if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af DW |
834 | WARN_ON(1); |
835 | return 0; | |
836 | } | |
837 | iterate_and_advance(i, bytes, v, | |
838 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
839 | v.iov_base, v.iov_len), | |
840 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
841 | v.bv_offset, v.bv_len), | |
842 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
843 | v.iov_len) | |
844 | ) | |
845 | ||
846 | return bytes; | |
847 | } | |
6a37e940 | 848 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af DW |
849 | #endif |
850 | ||
aa28de27 | 851 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
852 | { |
853 | char *to = addr; | |
00e23707 | 854 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
855 | WARN_ON(1); |
856 | return false; | |
857 | } | |
33844e66 | 858 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
859 | return false; |
860 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 861 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
862 | v.iov_base, v.iov_len)) |
863 | return false; | |
864 | 0;}), | |
865 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
866 | v.bv_offset, v.bv_len), | |
867 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
868 | ) | |
869 | ||
870 | iov_iter_advance(i, bytes); | |
871 | return true; | |
872 | } | |
aa28de27 | 873 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 874 | |
72e809ed AV |
875 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
876 | { | |
6daef95b ED |
877 | struct page *head; |
878 | size_t v = n + offset; | |
879 | ||
880 | /* | |
881 | * The general case needs to access the page order in order | |
882 | * to compute the page size. | |
883 | * However, we mostly deal with order-0 pages and thus can | |
884 | * avoid a possible cache line miss for requests that fit all | |
885 | * page orders. | |
886 | */ | |
887 | if (n <= v && v <= PAGE_SIZE) | |
888 | return true; | |
889 | ||
890 | head = compound_head(page); | |
891 | v += (page - head) << PAGE_SHIFT; | |
a90bcb86 | 892 | |
a50b854e | 893 | if (likely(n <= v && v <= (page_size(head)))) |
72e809ed AV |
894 | return true; |
895 | WARN_ON(1); | |
896 | return false; | |
897 | } | |
cbbd26b8 | 898 | |
62a8067a AV |
899 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
900 | struct iov_iter *i) | |
901 | { | |
72e809ed AV |
902 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
903 | return 0; | |
d271524a AV |
904 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
905 | void *kaddr = kmap_atomic(page); | |
906 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
907 | kunmap_atomic(kaddr); | |
908 | return wanted; | |
9ea9ce04 DH |
909 | } else if (unlikely(iov_iter_is_discard(i))) |
910 | return bytes; | |
911 | else if (likely(!iov_iter_is_pipe(i))) | |
62a8067a | 912 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
913 | else |
914 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
915 | } |
916 | EXPORT_SYMBOL(copy_page_to_iter); | |
917 | ||
918 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
919 | struct iov_iter *i) | |
920 | { | |
72e809ed AV |
921 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
922 | return 0; | |
9ea9ce04 | 923 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
924 | WARN_ON(1); |
925 | return 0; | |
926 | } | |
a280455f | 927 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 928 | void *kaddr = kmap_atomic(page); |
aa28de27 | 929 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
930 | kunmap_atomic(kaddr); |
931 | return wanted; | |
932 | } else | |
62a8067a AV |
933 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
934 | } | |
935 | EXPORT_SYMBOL(copy_page_from_iter); | |
936 | ||
241699cd AV |
937 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
938 | { | |
939 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
940 | unsigned int p_mask = pipe->ring_size - 1; |
941 | unsigned int i_head; | |
241699cd | 942 | size_t n, off; |
241699cd AV |
943 | |
944 | if (!sanity(i)) | |
945 | return 0; | |
946 | ||
8cefc107 | 947 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
948 | if (unlikely(!n)) |
949 | return 0; | |
950 | ||
8cefc107 | 951 | do { |
241699cd | 952 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
953 | memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); |
954 | i->head = i_head; | |
241699cd AV |
955 | i->iov_offset = off + chunk; |
956 | n -= chunk; | |
8cefc107 DH |
957 | off = 0; |
958 | i_head++; | |
959 | } while (n); | |
241699cd AV |
960 | i->count -= bytes; |
961 | return bytes; | |
962 | } | |
963 | ||
c35e0248 MW |
964 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
965 | { | |
00e23707 | 966 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 967 | return pipe_zero(bytes, i); |
8442fa46 | 968 | iterate_and_advance(i, bytes, v, |
09fc68dc | 969 | clear_user(v.iov_base, v.iov_len), |
a280455f AV |
970 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
971 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
972 | ) |
973 | ||
974 | return bytes; | |
c35e0248 MW |
975 | } |
976 | EXPORT_SYMBOL(iov_iter_zero); | |
977 | ||
62a8067a AV |
978 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
979 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
980 | { | |
04a31165 | 981 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
982 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
983 | kunmap_atomic(kaddr); | |
984 | return 0; | |
985 | } | |
9ea9ce04 | 986 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
987 | kunmap_atomic(kaddr); |
988 | WARN_ON(1); | |
989 | return 0; | |
990 | } | |
04a31165 | 991 | iterate_all_kinds(i, bytes, v, |
09fc68dc | 992 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a31165 | 993 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
994 | v.bv_offset, v.bv_len), |
995 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
996 | ) |
997 | kunmap_atomic(kaddr); | |
998 | return bytes; | |
62a8067a AV |
999 | } |
1000 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
1001 | ||
b9dc6f65 AV |
1002 | static inline void pipe_truncate(struct iov_iter *i) |
1003 | { | |
1004 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1005 | unsigned int p_tail = pipe->tail; |
1006 | unsigned int p_head = pipe->head; | |
1007 | unsigned int p_mask = pipe->ring_size - 1; | |
1008 | ||
1009 | if (!pipe_empty(p_head, p_tail)) { | |
1010 | struct pipe_buffer *buf; | |
1011 | unsigned int i_head = i->head; | |
b9dc6f65 | 1012 | size_t off = i->iov_offset; |
8cefc107 | 1013 | |
b9dc6f65 | 1014 | if (off) { |
8cefc107 DH |
1015 | buf = &pipe->bufs[i_head & p_mask]; |
1016 | buf->len = off - buf->offset; | |
1017 | i_head++; | |
b9dc6f65 | 1018 | } |
8cefc107 DH |
1019 | while (p_head != i_head) { |
1020 | p_head--; | |
1021 | pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); | |
b9dc6f65 | 1022 | } |
8cefc107 DH |
1023 | |
1024 | pipe->head = p_head; | |
b9dc6f65 AV |
1025 | } |
1026 | } | |
1027 | ||
241699cd AV |
1028 | static void pipe_advance(struct iov_iter *i, size_t size) |
1029 | { | |
1030 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
1031 | if (unlikely(i->count < size)) |
1032 | size = i->count; | |
241699cd | 1033 | if (size) { |
b9dc6f65 | 1034 | struct pipe_buffer *buf; |
8cefc107 DH |
1035 | unsigned int p_mask = pipe->ring_size - 1; |
1036 | unsigned int i_head = i->head; | |
b9dc6f65 | 1037 | size_t off = i->iov_offset, left = size; |
8cefc107 | 1038 | |
241699cd | 1039 | if (off) /* make it relative to the beginning of buffer */ |
8cefc107 | 1040 | left += off - pipe->bufs[i_head & p_mask].offset; |
241699cd | 1041 | while (1) { |
8cefc107 | 1042 | buf = &pipe->bufs[i_head & p_mask]; |
b9dc6f65 | 1043 | if (left <= buf->len) |
241699cd | 1044 | break; |
b9dc6f65 | 1045 | left -= buf->len; |
8cefc107 | 1046 | i_head++; |
241699cd | 1047 | } |
8cefc107 | 1048 | i->head = i_head; |
b9dc6f65 | 1049 | i->iov_offset = buf->offset + left; |
241699cd | 1050 | } |
b9dc6f65 AV |
1051 | i->count -= size; |
1052 | /* ... and discard everything past that point */ | |
1053 | pipe_truncate(i); | |
241699cd AV |
1054 | } |
1055 | ||
54c8195b PB |
1056 | static void iov_iter_bvec_advance(struct iov_iter *i, size_t size) |
1057 | { | |
1058 | struct bvec_iter bi; | |
1059 | ||
1060 | bi.bi_size = i->count; | |
1061 | bi.bi_bvec_done = i->iov_offset; | |
1062 | bi.bi_idx = 0; | |
1063 | bvec_iter_advance(i->bvec, &bi, size); | |
1064 | ||
1065 | i->bvec += bi.bi_idx; | |
1066 | i->nr_segs -= bi.bi_idx; | |
1067 | i->count = bi.bi_size; | |
1068 | i->iov_offset = bi.bi_bvec_done; | |
1069 | } | |
1070 | ||
62a8067a AV |
1071 | void iov_iter_advance(struct iov_iter *i, size_t size) |
1072 | { | |
00e23707 | 1073 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1074 | pipe_advance(i, size); |
1075 | return; | |
1076 | } | |
9ea9ce04 DH |
1077 | if (unlikely(iov_iter_is_discard(i))) { |
1078 | i->count -= size; | |
1079 | return; | |
1080 | } | |
54c8195b PB |
1081 | if (iov_iter_is_bvec(i)) { |
1082 | iov_iter_bvec_advance(i, size); | |
1083 | return; | |
1084 | } | |
a280455f | 1085 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
1086 | } |
1087 | EXPORT_SYMBOL(iov_iter_advance); | |
1088 | ||
27c0e374 AV |
1089 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
1090 | { | |
1091 | if (!unroll) | |
1092 | return; | |
5b47d59a AV |
1093 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
1094 | return; | |
27c0e374 | 1095 | i->count += unroll; |
00e23707 | 1096 | if (unlikely(iov_iter_is_pipe(i))) { |
27c0e374 | 1097 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 DH |
1098 | unsigned int p_mask = pipe->ring_size - 1; |
1099 | unsigned int i_head = i->head; | |
27c0e374 AV |
1100 | size_t off = i->iov_offset; |
1101 | while (1) { | |
8cefc107 DH |
1102 | struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; |
1103 | size_t n = off - b->offset; | |
27c0e374 | 1104 | if (unroll < n) { |
4fa55cef | 1105 | off -= unroll; |
27c0e374 AV |
1106 | break; |
1107 | } | |
1108 | unroll -= n; | |
8cefc107 | 1109 | if (!unroll && i_head == i->start_head) { |
27c0e374 AV |
1110 | off = 0; |
1111 | break; | |
1112 | } | |
8cefc107 DH |
1113 | i_head--; |
1114 | b = &pipe->bufs[i_head & p_mask]; | |
1115 | off = b->offset + b->len; | |
27c0e374 AV |
1116 | } |
1117 | i->iov_offset = off; | |
8cefc107 | 1118 | i->head = i_head; |
27c0e374 AV |
1119 | pipe_truncate(i); |
1120 | return; | |
1121 | } | |
9ea9ce04 DH |
1122 | if (unlikely(iov_iter_is_discard(i))) |
1123 | return; | |
27c0e374 AV |
1124 | if (unroll <= i->iov_offset) { |
1125 | i->iov_offset -= unroll; | |
1126 | return; | |
1127 | } | |
1128 | unroll -= i->iov_offset; | |
00e23707 | 1129 | if (iov_iter_is_bvec(i)) { |
27c0e374 AV |
1130 | const struct bio_vec *bvec = i->bvec; |
1131 | while (1) { | |
1132 | size_t n = (--bvec)->bv_len; | |
1133 | i->nr_segs++; | |
1134 | if (unroll <= n) { | |
1135 | i->bvec = bvec; | |
1136 | i->iov_offset = n - unroll; | |
1137 | return; | |
1138 | } | |
1139 | unroll -= n; | |
1140 | } | |
1141 | } else { /* same logics for iovec and kvec */ | |
1142 | const struct iovec *iov = i->iov; | |
1143 | while (1) { | |
1144 | size_t n = (--iov)->iov_len; | |
1145 | i->nr_segs++; | |
1146 | if (unroll <= n) { | |
1147 | i->iov = iov; | |
1148 | i->iov_offset = n - unroll; | |
1149 | return; | |
1150 | } | |
1151 | unroll -= n; | |
1152 | } | |
1153 | } | |
1154 | } | |
1155 | EXPORT_SYMBOL(iov_iter_revert); | |
1156 | ||
62a8067a AV |
1157 | /* |
1158 | * Return the count of just the current iov_iter segment. | |
1159 | */ | |
1160 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
1161 | { | |
00e23707 | 1162 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1163 | return i->count; // it is a silly place, anyway |
62a8067a AV |
1164 | if (i->nr_segs == 1) |
1165 | return i->count; | |
9ea9ce04 DH |
1166 | if (unlikely(iov_iter_is_discard(i))) |
1167 | return i->count; | |
00e23707 | 1168 | else if (iov_iter_is_bvec(i)) |
62a8067a | 1169 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
1170 | else |
1171 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
1172 | } |
1173 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
1174 | ||
aa563d7b | 1175 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77 | 1176 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
1177 | size_t count) |
1178 | { | |
aa563d7b DH |
1179 | WARN_ON(direction & ~(READ | WRITE)); |
1180 | i->type = ITER_KVEC | (direction & (READ | WRITE)); | |
05afcb77 | 1181 | i->kvec = kvec; |
abb78f87 AV |
1182 | i->nr_segs = nr_segs; |
1183 | i->iov_offset = 0; | |
1184 | i->count = count; | |
1185 | } | |
1186 | EXPORT_SYMBOL(iov_iter_kvec); | |
1187 | ||
aa563d7b | 1188 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77 AV |
1189 | const struct bio_vec *bvec, unsigned long nr_segs, |
1190 | size_t count) | |
1191 | { | |
aa563d7b DH |
1192 | WARN_ON(direction & ~(READ | WRITE)); |
1193 | i->type = ITER_BVEC | (direction & (READ | WRITE)); | |
05afcb77 AV |
1194 | i->bvec = bvec; |
1195 | i->nr_segs = nr_segs; | |
1196 | i->iov_offset = 0; | |
1197 | i->count = count; | |
1198 | } | |
1199 | EXPORT_SYMBOL(iov_iter_bvec); | |
1200 | ||
aa563d7b | 1201 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd AV |
1202 | struct pipe_inode_info *pipe, |
1203 | size_t count) | |
1204 | { | |
aa563d7b | 1205 | BUG_ON(direction != READ); |
8cefc107 | 1206 | WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); |
aa563d7b | 1207 | i->type = ITER_PIPE | READ; |
241699cd | 1208 | i->pipe = pipe; |
8cefc107 | 1209 | i->head = pipe->head; |
241699cd AV |
1210 | i->iov_offset = 0; |
1211 | i->count = count; | |
8cefc107 | 1212 | i->start_head = i->head; |
241699cd AV |
1213 | } |
1214 | EXPORT_SYMBOL(iov_iter_pipe); | |
1215 | ||
9ea9ce04 DH |
1216 | /** |
1217 | * iov_iter_discard - Initialise an I/O iterator that discards data | |
1218 | * @i: The iterator to initialise. | |
1219 | * @direction: The direction of the transfer. | |
1220 | * @count: The size of the I/O buffer in bytes. | |
1221 | * | |
1222 | * Set up an I/O iterator that just discards everything that's written to it. | |
1223 | * It's only available as a READ iterator. | |
1224 | */ | |
1225 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) | |
1226 | { | |
1227 | BUG_ON(direction != READ); | |
1228 | i->type = ITER_DISCARD | READ; | |
1229 | i->count = count; | |
1230 | i->iov_offset = 0; | |
1231 | } | |
1232 | EXPORT_SYMBOL(iov_iter_discard); | |
1233 | ||
62a8067a AV |
1234 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
1235 | { | |
04a31165 AV |
1236 | unsigned long res = 0; |
1237 | size_t size = i->count; | |
1238 | ||
00e23707 | 1239 | if (unlikely(iov_iter_is_pipe(i))) { |
e0ff126e JK |
1240 | unsigned int p_mask = i->pipe->ring_size - 1; |
1241 | ||
8cefc107 | 1242 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) |
241699cd AV |
1243 | return size | i->iov_offset; |
1244 | return size; | |
1245 | } | |
04a31165 AV |
1246 | iterate_all_kinds(i, size, v, |
1247 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
1248 | res |= v.bv_offset | v.bv_len, |
1249 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
1250 | ) |
1251 | return res; | |
62a8067a AV |
1252 | } |
1253 | EXPORT_SYMBOL(iov_iter_alignment); | |
1254 | ||
357f435d AV |
1255 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
1256 | { | |
33844e66 | 1257 | unsigned long res = 0; |
357f435d | 1258 | size_t size = i->count; |
357f435d | 1259 | |
9ea9ce04 | 1260 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1261 | WARN_ON(1); |
1262 | return ~0U; | |
1263 | } | |
1264 | ||
357f435d AV |
1265 | iterate_all_kinds(i, size, v, |
1266 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1267 | (size != v.iov_len ? size : 0), 0), | |
1268 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1269 | (size != v.bv_len ? size : 0)), | |
1270 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1271 | (size != v.iov_len ? size : 0)) | |
1272 | ); | |
33844e66 | 1273 | return res; |
357f435d AV |
1274 | } |
1275 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1276 | ||
e76b6312 | 1277 | static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd AV |
1278 | size_t maxsize, |
1279 | struct page **pages, | |
8cefc107 | 1280 | int iter_head, |
241699cd AV |
1281 | size_t *start) |
1282 | { | |
1283 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1284 | unsigned int p_mask = pipe->ring_size - 1; |
1285 | ssize_t n = push_pipe(i, maxsize, &iter_head, start); | |
241699cd AV |
1286 | if (!n) |
1287 | return -EFAULT; | |
1288 | ||
1289 | maxsize = n; | |
1290 | n += *start; | |
1689c73a | 1291 | while (n > 0) { |
8cefc107 DH |
1292 | get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); |
1293 | iter_head++; | |
241699cd AV |
1294 | n -= PAGE_SIZE; |
1295 | } | |
1296 | ||
1297 | return maxsize; | |
1298 | } | |
1299 | ||
1300 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1301 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1302 | size_t *start) | |
1303 | { | |
8cefc107 | 1304 | unsigned int iter_head, npages; |
241699cd | 1305 | size_t capacity; |
241699cd | 1306 | |
33844e66 AV |
1307 | if (!maxsize) |
1308 | return 0; | |
1309 | ||
241699cd AV |
1310 | if (!sanity(i)) |
1311 | return -EFAULT; | |
1312 | ||
8cefc107 DH |
1313 | data_start(i, &iter_head, start); |
1314 | /* Amount of free space: some of this one + all after this one */ | |
1315 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
1316 | capacity = min(npages, maxpages) * PAGE_SIZE - *start; | |
241699cd | 1317 | |
8cefc107 | 1318 | return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); |
241699cd AV |
1319 | } |
1320 | ||
62a8067a | 1321 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1322 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1323 | size_t *start) |
1324 | { | |
e5393fae AV |
1325 | if (maxsize > i->count) |
1326 | maxsize = i->count; | |
1327 | ||
00e23707 | 1328 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1329 | return pipe_get_pages(i, pages, maxsize, maxpages, start); |
9ea9ce04 DH |
1330 | if (unlikely(iov_iter_is_discard(i))) |
1331 | return -EFAULT; | |
1332 | ||
e5393fae AV |
1333 | iterate_all_kinds(i, maxsize, v, ({ |
1334 | unsigned long addr = (unsigned long)v.iov_base; | |
1335 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1336 | int n; | |
1337 | int res; | |
1338 | ||
1339 | if (len > maxpages * PAGE_SIZE) | |
1340 | len = maxpages * PAGE_SIZE; | |
1341 | addr &= ~(PAGE_SIZE - 1); | |
1342 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
73b0140b IW |
1343 | res = get_user_pages_fast(addr, n, |
1344 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, | |
1345 | pages); | |
e5393fae AV |
1346 | if (unlikely(res < 0)) |
1347 | return res; | |
1348 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1349 | 0;}),({ | |
1350 | /* can't be more than PAGE_SIZE */ | |
1351 | *start = v.bv_offset; | |
1352 | get_page(*pages = v.bv_page); | |
1353 | return v.bv_len; | |
a280455f AV |
1354 | }),({ |
1355 | return -EFAULT; | |
e5393fae AV |
1356 | }) |
1357 | ) | |
1358 | return 0; | |
62a8067a AV |
1359 | } |
1360 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1361 | ||
1b17f1f2 AV |
1362 | static struct page **get_pages_array(size_t n) |
1363 | { | |
752ade68 | 1364 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1365 | } |
1366 | ||
241699cd AV |
1367 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1368 | struct page ***pages, size_t maxsize, | |
1369 | size_t *start) | |
1370 | { | |
1371 | struct page **p; | |
8cefc107 | 1372 | unsigned int iter_head, npages; |
d7760d63 | 1373 | ssize_t n; |
241699cd | 1374 | |
33844e66 AV |
1375 | if (!maxsize) |
1376 | return 0; | |
1377 | ||
241699cd AV |
1378 | if (!sanity(i)) |
1379 | return -EFAULT; | |
1380 | ||
8cefc107 DH |
1381 | data_start(i, &iter_head, start); |
1382 | /* Amount of free space: some of this one + all after this one */ | |
1383 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
241699cd AV |
1384 | n = npages * PAGE_SIZE - *start; |
1385 | if (maxsize > n) | |
1386 | maxsize = n; | |
1387 | else | |
1388 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1389 | p = get_pages_array(npages); | |
1390 | if (!p) | |
1391 | return -ENOMEM; | |
8cefc107 | 1392 | n = __pipe_get_pages(i, maxsize, p, iter_head, start); |
241699cd AV |
1393 | if (n > 0) |
1394 | *pages = p; | |
1395 | else | |
1396 | kvfree(p); | |
1397 | return n; | |
1398 | } | |
1399 | ||
62a8067a AV |
1400 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1401 | struct page ***pages, size_t maxsize, | |
1402 | size_t *start) | |
1403 | { | |
1b17f1f2 AV |
1404 | struct page **p; |
1405 | ||
1406 | if (maxsize > i->count) | |
1407 | maxsize = i->count; | |
1408 | ||
00e23707 | 1409 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1410 | return pipe_get_pages_alloc(i, pages, maxsize, start); |
9ea9ce04 DH |
1411 | if (unlikely(iov_iter_is_discard(i))) |
1412 | return -EFAULT; | |
1413 | ||
1b17f1f2 AV |
1414 | iterate_all_kinds(i, maxsize, v, ({ |
1415 | unsigned long addr = (unsigned long)v.iov_base; | |
1416 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1417 | int n; | |
1418 | int res; | |
1419 | ||
1420 | addr &= ~(PAGE_SIZE - 1); | |
1421 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1422 | p = get_pages_array(n); | |
1423 | if (!p) | |
1424 | return -ENOMEM; | |
73b0140b IW |
1425 | res = get_user_pages_fast(addr, n, |
1426 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); | |
1b17f1f2 AV |
1427 | if (unlikely(res < 0)) { |
1428 | kvfree(p); | |
1429 | return res; | |
1430 | } | |
1431 | *pages = p; | |
1432 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1433 | 0;}),({ | |
1434 | /* can't be more than PAGE_SIZE */ | |
1435 | *start = v.bv_offset; | |
1436 | *pages = p = get_pages_array(1); | |
1437 | if (!p) | |
1438 | return -ENOMEM; | |
1439 | get_page(*p = v.bv_page); | |
1440 | return v.bv_len; | |
a280455f AV |
1441 | }),({ |
1442 | return -EFAULT; | |
1b17f1f2 AV |
1443 | }) |
1444 | ) | |
1445 | return 0; | |
62a8067a AV |
1446 | } |
1447 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1448 | ||
a604ec7e AV |
1449 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1450 | struct iov_iter *i) | |
1451 | { | |
1452 | char *to = addr; | |
1453 | __wsum sum, next; | |
1454 | size_t off = 0; | |
a604ec7e | 1455 | sum = *csum; |
9ea9ce04 | 1456 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1457 | WARN_ON(1); |
1458 | return 0; | |
1459 | } | |
a604ec7e | 1460 | iterate_and_advance(i, bytes, v, ({ |
cbbd26b8 | 1461 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e | 1462 | (to += v.iov_len) - v.iov_len, |
c693cc46 AV |
1463 | v.iov_len); |
1464 | if (next) { | |
a604ec7e AV |
1465 | sum = csum_block_add(sum, next, off); |
1466 | off += v.iov_len; | |
1467 | } | |
c693cc46 | 1468 | next ? 0 : v.iov_len; |
a604ec7e AV |
1469 | }), ({ |
1470 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1471 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1472 | p + v.bv_offset, v.bv_len, | |
1473 | sum, off); | |
a604ec7e | 1474 | kunmap_atomic(p); |
a604ec7e AV |
1475 | off += v.bv_len; |
1476 | }),({ | |
f9152895 AV |
1477 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1478 | v.iov_base, v.iov_len, | |
1479 | sum, off); | |
a604ec7e AV |
1480 | off += v.iov_len; |
1481 | }) | |
1482 | ) | |
1483 | *csum = sum; | |
1484 | return bytes; | |
1485 | } | |
1486 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1487 | ||
cbbd26b8 AV |
1488 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
1489 | struct iov_iter *i) | |
1490 | { | |
1491 | char *to = addr; | |
1492 | __wsum sum, next; | |
1493 | size_t off = 0; | |
1494 | sum = *csum; | |
9ea9ce04 | 1495 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
cbbd26b8 AV |
1496 | WARN_ON(1); |
1497 | return false; | |
1498 | } | |
1499 | if (unlikely(i->count < bytes)) | |
1500 | return false; | |
1501 | iterate_all_kinds(i, bytes, v, ({ | |
cbbd26b8 AV |
1502 | next = csum_and_copy_from_user(v.iov_base, |
1503 | (to += v.iov_len) - v.iov_len, | |
c693cc46 AV |
1504 | v.iov_len); |
1505 | if (!next) | |
cbbd26b8 AV |
1506 | return false; |
1507 | sum = csum_block_add(sum, next, off); | |
1508 | off += v.iov_len; | |
1509 | 0; | |
1510 | }), ({ | |
1511 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1512 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1513 | p + v.bv_offset, v.bv_len, | |
1514 | sum, off); | |
cbbd26b8 | 1515 | kunmap_atomic(p); |
cbbd26b8 AV |
1516 | off += v.bv_len; |
1517 | }),({ | |
f9152895 AV |
1518 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1519 | v.iov_base, v.iov_len, | |
1520 | sum, off); | |
cbbd26b8 AV |
1521 | off += v.iov_len; |
1522 | }) | |
1523 | ) | |
1524 | *csum = sum; | |
1525 | iov_iter_advance(i, bytes); | |
1526 | return true; | |
1527 | } | |
1528 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1529 | ||
52cbd23a | 1530 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, |
a604ec7e AV |
1531 | struct iov_iter *i) |
1532 | { | |
52cbd23a | 1533 | struct csum_state *csstate = _csstate; |
36f7a8a4 | 1534 | const char *from = addr; |
a604ec7e | 1535 | __wsum sum, next; |
52cbd23a | 1536 | size_t off; |
78e1f386 AV |
1537 | |
1538 | if (unlikely(iov_iter_is_pipe(i))) | |
52cbd23a | 1539 | return csum_and_copy_to_pipe_iter(addr, bytes, _csstate, i); |
78e1f386 | 1540 | |
52cbd23a WB |
1541 | sum = csstate->csum; |
1542 | off = csstate->off; | |
78e1f386 | 1543 | if (unlikely(iov_iter_is_discard(i))) { |
241699cd AV |
1544 | WARN_ON(1); /* for now */ |
1545 | return 0; | |
1546 | } | |
a604ec7e | 1547 | iterate_and_advance(i, bytes, v, ({ |
a604ec7e | 1548 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, |
cbbd26b8 | 1549 | v.iov_base, |
c693cc46 AV |
1550 | v.iov_len); |
1551 | if (next) { | |
a604ec7e AV |
1552 | sum = csum_block_add(sum, next, off); |
1553 | off += v.iov_len; | |
1554 | } | |
c693cc46 | 1555 | next ? 0 : v.iov_len; |
a604ec7e AV |
1556 | }), ({ |
1557 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1558 | sum = csum_and_memcpy(p + v.bv_offset, |
1559 | (from += v.bv_len) - v.bv_len, | |
1560 | v.bv_len, sum, off); | |
a604ec7e | 1561 | kunmap_atomic(p); |
a604ec7e AV |
1562 | off += v.bv_len; |
1563 | }),({ | |
f9152895 AV |
1564 | sum = csum_and_memcpy(v.iov_base, |
1565 | (from += v.iov_len) - v.iov_len, | |
1566 | v.iov_len, sum, off); | |
a604ec7e AV |
1567 | off += v.iov_len; |
1568 | }) | |
1569 | ) | |
52cbd23a WB |
1570 | csstate->csum = sum; |
1571 | csstate->off = off; | |
a604ec7e AV |
1572 | return bytes; |
1573 | } | |
1574 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1575 | ||
d05f4435 SG |
1576 | size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
1577 | struct iov_iter *i) | |
1578 | { | |
7999096f | 1579 | #ifdef CONFIG_CRYPTO_HASH |
d05f4435 SG |
1580 | struct ahash_request *hash = hashp; |
1581 | struct scatterlist sg; | |
1582 | size_t copied; | |
1583 | ||
1584 | copied = copy_to_iter(addr, bytes, i); | |
1585 | sg_init_one(&sg, addr, copied); | |
1586 | ahash_request_set_crypt(hash, &sg, NULL, copied); | |
1587 | crypto_ahash_update(hash); | |
1588 | return copied; | |
27fad74a Y |
1589 | #else |
1590 | return 0; | |
1591 | #endif | |
d05f4435 SG |
1592 | } |
1593 | EXPORT_SYMBOL(hash_and_copy_to_iter); | |
1594 | ||
62a8067a AV |
1595 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1596 | { | |
e0f2dc40 AV |
1597 | size_t size = i->count; |
1598 | int npages = 0; | |
1599 | ||
1600 | if (!size) | |
1601 | return 0; | |
9ea9ce04 DH |
1602 | if (unlikely(iov_iter_is_discard(i))) |
1603 | return 0; | |
e0f2dc40 | 1604 | |
00e23707 | 1605 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd | 1606 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 | 1607 | unsigned int iter_head; |
241699cd | 1608 | size_t off; |
241699cd AV |
1609 | |
1610 | if (!sanity(i)) | |
1611 | return 0; | |
1612 | ||
8cefc107 | 1613 | data_start(i, &iter_head, &off); |
241699cd | 1614 | /* some of this one + all after this one */ |
8cefc107 | 1615 | npages = pipe_space_for_user(iter_head, pipe->tail, pipe); |
241699cd AV |
1616 | if (npages >= maxpages) |
1617 | return maxpages; | |
1618 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1619 | unsigned long p = (unsigned long)v.iov_base; |
1620 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1621 | - p / PAGE_SIZE; | |
1622 | if (npages >= maxpages) | |
1623 | return maxpages; | |
1624 | 0;}),({ | |
1625 | npages++; | |
1626 | if (npages >= maxpages) | |
1627 | return maxpages; | |
a280455f AV |
1628 | }),({ |
1629 | unsigned long p = (unsigned long)v.iov_base; | |
1630 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1631 | - p / PAGE_SIZE; | |
1632 | if (npages >= maxpages) | |
1633 | return maxpages; | |
e0f2dc40 AV |
1634 | }) |
1635 | ) | |
1636 | return npages; | |
62a8067a | 1637 | } |
f67da30c | 1638 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1639 | |
1640 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1641 | { | |
1642 | *new = *old; | |
00e23707 | 1643 | if (unlikely(iov_iter_is_pipe(new))) { |
241699cd AV |
1644 | WARN_ON(1); |
1645 | return NULL; | |
1646 | } | |
9ea9ce04 DH |
1647 | if (unlikely(iov_iter_is_discard(new))) |
1648 | return NULL; | |
00e23707 | 1649 | if (iov_iter_is_bvec(new)) |
4b8164b9 AV |
1650 | return new->bvec = kmemdup(new->bvec, |
1651 | new->nr_segs * sizeof(struct bio_vec), | |
1652 | flags); | |
1653 | else | |
1654 | /* iovec and kvec have identical layout */ | |
1655 | return new->iov = kmemdup(new->iov, | |
1656 | new->nr_segs * sizeof(struct iovec), | |
1657 | flags); | |
1658 | } | |
1659 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1660 | |
bfdc5970 CH |
1661 | static int copy_compat_iovec_from_user(struct iovec *iov, |
1662 | const struct iovec __user *uvec, unsigned long nr_segs) | |
1663 | { | |
1664 | const struct compat_iovec __user *uiov = | |
1665 | (const struct compat_iovec __user *)uvec; | |
1666 | int ret = -EFAULT, i; | |
1667 | ||
a959a978 | 1668 | if (!user_access_begin(uiov, nr_segs * sizeof(*uiov))) |
bfdc5970 CH |
1669 | return -EFAULT; |
1670 | ||
1671 | for (i = 0; i < nr_segs; i++) { | |
1672 | compat_uptr_t buf; | |
1673 | compat_ssize_t len; | |
1674 | ||
1675 | unsafe_get_user(len, &uiov[i].iov_len, uaccess_end); | |
1676 | unsafe_get_user(buf, &uiov[i].iov_base, uaccess_end); | |
1677 | ||
1678 | /* check for compat_size_t not fitting in compat_ssize_t .. */ | |
1679 | if (len < 0) { | |
1680 | ret = -EINVAL; | |
1681 | goto uaccess_end; | |
1682 | } | |
1683 | iov[i].iov_base = compat_ptr(buf); | |
1684 | iov[i].iov_len = len; | |
1685 | } | |
1686 | ||
1687 | ret = 0; | |
1688 | uaccess_end: | |
1689 | user_access_end(); | |
1690 | return ret; | |
1691 | } | |
1692 | ||
1693 | static int copy_iovec_from_user(struct iovec *iov, | |
1694 | const struct iovec __user *uvec, unsigned long nr_segs) | |
fb041b59 DL |
1695 | { |
1696 | unsigned long seg; | |
fb041b59 | 1697 | |
bfdc5970 CH |
1698 | if (copy_from_user(iov, uvec, nr_segs * sizeof(*uvec))) |
1699 | return -EFAULT; | |
1700 | for (seg = 0; seg < nr_segs; seg++) { | |
1701 | if ((ssize_t)iov[seg].iov_len < 0) | |
1702 | return -EINVAL; | |
fb041b59 DL |
1703 | } |
1704 | ||
bfdc5970 CH |
1705 | return 0; |
1706 | } | |
1707 | ||
1708 | struct iovec *iovec_from_user(const struct iovec __user *uvec, | |
1709 | unsigned long nr_segs, unsigned long fast_segs, | |
1710 | struct iovec *fast_iov, bool compat) | |
1711 | { | |
1712 | struct iovec *iov = fast_iov; | |
1713 | int ret; | |
1714 | ||
fb041b59 | 1715 | /* |
bfdc5970 CH |
1716 | * SuS says "The readv() function *may* fail if the iovcnt argument was |
1717 | * less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
1718 | * traditionally returned zero for zero segments, so... | |
fb041b59 | 1719 | */ |
bfdc5970 CH |
1720 | if (nr_segs == 0) |
1721 | return iov; | |
1722 | if (nr_segs > UIO_MAXIOV) | |
1723 | return ERR_PTR(-EINVAL); | |
fb041b59 DL |
1724 | if (nr_segs > fast_segs) { |
1725 | iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); | |
bfdc5970 CH |
1726 | if (!iov) |
1727 | return ERR_PTR(-ENOMEM); | |
fb041b59 | 1728 | } |
bfdc5970 CH |
1729 | |
1730 | if (compat) | |
1731 | ret = copy_compat_iovec_from_user(iov, uvec, nr_segs); | |
1732 | else | |
1733 | ret = copy_iovec_from_user(iov, uvec, nr_segs); | |
1734 | if (ret) { | |
1735 | if (iov != fast_iov) | |
1736 | kfree(iov); | |
1737 | return ERR_PTR(ret); | |
1738 | } | |
1739 | ||
1740 | return iov; | |
1741 | } | |
1742 | ||
1743 | ssize_t __import_iovec(int type, const struct iovec __user *uvec, | |
1744 | unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, | |
1745 | struct iov_iter *i, bool compat) | |
1746 | { | |
1747 | ssize_t total_len = 0; | |
1748 | unsigned long seg; | |
1749 | struct iovec *iov; | |
1750 | ||
1751 | iov = iovec_from_user(uvec, nr_segs, fast_segs, *iovp, compat); | |
1752 | if (IS_ERR(iov)) { | |
1753 | *iovp = NULL; | |
1754 | return PTR_ERR(iov); | |
fb041b59 DL |
1755 | } |
1756 | ||
1757 | /* | |
bfdc5970 CH |
1758 | * According to the Single Unix Specification we should return EINVAL if |
1759 | * an element length is < 0 when cast to ssize_t or if the total length | |
1760 | * would overflow the ssize_t return value of the system call. | |
fb041b59 DL |
1761 | * |
1762 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
1763 | * overflow case. | |
1764 | */ | |
fb041b59 | 1765 | for (seg = 0; seg < nr_segs; seg++) { |
fb041b59 DL |
1766 | ssize_t len = (ssize_t)iov[seg].iov_len; |
1767 | ||
bfdc5970 CH |
1768 | if (!access_ok(iov[seg].iov_base, len)) { |
1769 | if (iov != *iovp) | |
1770 | kfree(iov); | |
1771 | *iovp = NULL; | |
1772 | return -EFAULT; | |
fb041b59 | 1773 | } |
bfdc5970 CH |
1774 | |
1775 | if (len > MAX_RW_COUNT - total_len) { | |
1776 | len = MAX_RW_COUNT - total_len; | |
fb041b59 DL |
1777 | iov[seg].iov_len = len; |
1778 | } | |
bfdc5970 | 1779 | total_len += len; |
fb041b59 | 1780 | } |
bfdc5970 CH |
1781 | |
1782 | iov_iter_init(i, type, iov, nr_segs, total_len); | |
1783 | if (iov == *iovp) | |
1784 | *iovp = NULL; | |
1785 | else | |
1786 | *iovp = iov; | |
1787 | return total_len; | |
fb041b59 DL |
1788 | } |
1789 | ||
ffecee4f VN |
1790 | /** |
1791 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1792 | * into the kernel, check that it is valid, and initialize a new | |
1793 | * &struct iov_iter iterator to access it. | |
1794 | * | |
1795 | * @type: One of %READ or %WRITE. | |
bfdc5970 | 1796 | * @uvec: Pointer to the userspace array. |
ffecee4f VN |
1797 | * @nr_segs: Number of elements in userspace array. |
1798 | * @fast_segs: Number of elements in @iov. | |
bfdc5970 | 1799 | * @iovp: (input and output parameter) Pointer to pointer to (usually small |
ffecee4f VN |
1800 | * on-stack) kernel array. |
1801 | * @i: Pointer to iterator that will be initialized on success. | |
1802 | * | |
1803 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1804 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1805 | * array will be allocated and the result placed in *@iov. This means that | |
1806 | * the caller may call kfree() on *@iov regardless of whether the small | |
1807 | * on-stack array was used or not (and regardless of whether this function | |
1808 | * returns an error or not). | |
1809 | * | |
87e5e6da | 1810 | * Return: Negative error code on error, bytes imported on success |
ffecee4f | 1811 | */ |
bfdc5970 | 1812 | ssize_t import_iovec(int type, const struct iovec __user *uvec, |
bc917be8 | 1813 | unsigned nr_segs, unsigned fast_segs, |
bfdc5970 | 1814 | struct iovec **iovp, struct iov_iter *i) |
bc917be8 | 1815 | { |
89cd35c5 CH |
1816 | return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i, |
1817 | in_compat_syscall()); | |
bc917be8 AV |
1818 | } |
1819 | EXPORT_SYMBOL(import_iovec); | |
1820 | ||
bc917be8 AV |
1821 | int import_single_range(int rw, void __user *buf, size_t len, |
1822 | struct iovec *iov, struct iov_iter *i) | |
1823 | { | |
1824 | if (len > MAX_RW_COUNT) | |
1825 | len = MAX_RW_COUNT; | |
96d4f267 | 1826 | if (unlikely(!access_ok(buf, len))) |
bc917be8 AV |
1827 | return -EFAULT; |
1828 | ||
1829 | iov->iov_base = buf; | |
1830 | iov->iov_len = len; | |
1831 | iov_iter_init(i, rw, iov, 1, len); | |
1832 | return 0; | |
1833 | } | |
e1267585 | 1834 | EXPORT_SYMBOL(import_single_range); |
09cf698a AV |
1835 | |
1836 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1837 | int (*f)(struct kvec *vec, void *context), | |
1838 | void *context) | |
1839 | { | |
1840 | struct kvec w; | |
1841 | int err = -EINVAL; | |
1842 | if (!bytes) | |
1843 | return 0; | |
1844 | ||
1845 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1846 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1847 | w.iov_len = v.bv_len; | |
1848 | err = f(&w, context); | |
1849 | kunmap(v.bv_page); | |
1850 | err;}), ({ | |
1851 | w = v; | |
1852 | err = f(&w, context);}) | |
1853 | ) | |
1854 | return err; | |
1855 | } | |
1856 | EXPORT_SYMBOL(iov_iter_for_each_range); |