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) { \ | |
75 | if (!__v.bv_len) \ | |
04a31165 | 76 | continue; \ |
04a31165 | 77 | (void)(STEP); \ |
04a31165 | 78 | } \ |
04a31165 AV |
79 | } |
80 | ||
a280455f | 81 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
33844e66 AV |
82 | if (likely(n)) { \ |
83 | size_t skip = i->iov_offset; \ | |
84 | if (unlikely(i->type & ITER_BVEC)) { \ | |
85 | struct bio_vec v; \ | |
86 | struct bvec_iter __bi; \ | |
87 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
88 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
89 | const struct kvec *kvec; \ | |
90 | struct kvec v; \ | |
91 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
9ea9ce04 | 92 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
33844e66 AV |
93 | } else { \ |
94 | const struct iovec *iov; \ | |
95 | struct iovec v; \ | |
96 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
97 | } \ | |
04a31165 AV |
98 | } \ |
99 | } | |
100 | ||
a280455f | 101 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
102 | if (unlikely(i->count < n)) \ |
103 | n = i->count; \ | |
19f18459 | 104 | if (i->count) { \ |
dd254f5a AV |
105 | size_t skip = i->iov_offset; \ |
106 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 107 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 108 | struct bio_vec v; \ |
1bdc76ae ML |
109 | struct bvec_iter __bi; \ |
110 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
111 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
112 | i->nr_segs -= i->bvec - bvec; \ | |
113 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
114 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
115 | const struct kvec *kvec; \ | |
116 | struct kvec v; \ | |
117 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
118 | if (skip == kvec->iov_len) { \ | |
119 | kvec++; \ | |
120 | skip = 0; \ | |
121 | } \ | |
122 | i->nr_segs -= kvec - i->kvec; \ | |
123 | i->kvec = kvec; \ | |
9ea9ce04 DH |
124 | } else if (unlikely(i->type & ITER_DISCARD)) { \ |
125 | skip += n; \ | |
dd254f5a AV |
126 | } else { \ |
127 | const struct iovec *iov; \ | |
128 | struct iovec v; \ | |
129 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
130 | if (skip == iov->iov_len) { \ | |
131 | iov++; \ | |
132 | skip = 0; \ | |
133 | } \ | |
134 | i->nr_segs -= iov - i->iov; \ | |
135 | i->iov = iov; \ | |
7ce2a91e | 136 | } \ |
dd254f5a AV |
137 | i->count -= n; \ |
138 | i->iov_offset = skip; \ | |
7ce2a91e | 139 | } \ |
7ce2a91e AV |
140 | } |
141 | ||
09fc68dc AV |
142 | static int copyout(void __user *to, const void *from, size_t n) |
143 | { | |
4d0e9df5 AL |
144 | if (should_fail_usercopy()) |
145 | return n; | |
96d4f267 | 146 | if (access_ok(to, n)) { |
d0ef4c36 | 147 | instrument_copy_to_user(to, from, n); |
09fc68dc AV |
148 | n = raw_copy_to_user(to, from, n); |
149 | } | |
150 | return n; | |
151 | } | |
152 | ||
153 | static int copyin(void *to, const void __user *from, size_t n) | |
154 | { | |
4d0e9df5 AL |
155 | if (should_fail_usercopy()) |
156 | return n; | |
96d4f267 | 157 | if (access_ok(from, n)) { |
d0ef4c36 | 158 | instrument_copy_from_user(to, from, n); |
09fc68dc AV |
159 | n = raw_copy_from_user(to, from, n); |
160 | } | |
161 | return n; | |
162 | } | |
163 | ||
62a8067a | 164 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
165 | struct iov_iter *i) |
166 | { | |
167 | size_t skip, copy, left, wanted; | |
168 | const struct iovec *iov; | |
169 | char __user *buf; | |
170 | void *kaddr, *from; | |
171 | ||
172 | if (unlikely(bytes > i->count)) | |
173 | bytes = i->count; | |
174 | ||
175 | if (unlikely(!bytes)) | |
176 | return 0; | |
177 | ||
09fc68dc | 178 | might_fault(); |
4f18cd31 AV |
179 | wanted = bytes; |
180 | iov = i->iov; | |
181 | skip = i->iov_offset; | |
182 | buf = iov->iov_base + skip; | |
183 | copy = min(bytes, iov->iov_len - skip); | |
184 | ||
3fa6c507 | 185 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
186 | kaddr = kmap_atomic(page); |
187 | from = kaddr + offset; | |
188 | ||
189 | /* first chunk, usually the only one */ | |
09fc68dc | 190 | left = copyout(buf, from, copy); |
4f18cd31 AV |
191 | copy -= left; |
192 | skip += copy; | |
193 | from += copy; | |
194 | bytes -= copy; | |
195 | ||
196 | while (unlikely(!left && bytes)) { | |
197 | iov++; | |
198 | buf = iov->iov_base; | |
199 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 200 | left = copyout(buf, from, copy); |
4f18cd31 AV |
201 | copy -= left; |
202 | skip = copy; | |
203 | from += copy; | |
204 | bytes -= copy; | |
205 | } | |
206 | if (likely(!bytes)) { | |
207 | kunmap_atomic(kaddr); | |
208 | goto done; | |
209 | } | |
210 | offset = from - kaddr; | |
211 | buf += copy; | |
212 | kunmap_atomic(kaddr); | |
213 | copy = min(bytes, iov->iov_len - skip); | |
214 | } | |
215 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 216 | |
4f18cd31 AV |
217 | kaddr = kmap(page); |
218 | from = kaddr + offset; | |
09fc68dc | 219 | left = copyout(buf, from, copy); |
4f18cd31 AV |
220 | copy -= left; |
221 | skip += copy; | |
222 | from += copy; | |
223 | bytes -= copy; | |
224 | while (unlikely(!left && bytes)) { | |
225 | iov++; | |
226 | buf = iov->iov_base; | |
227 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 228 | left = copyout(buf, from, copy); |
4f18cd31 AV |
229 | copy -= left; |
230 | skip = copy; | |
231 | from += copy; | |
232 | bytes -= copy; | |
233 | } | |
234 | kunmap(page); | |
3fa6c507 | 235 | |
4f18cd31 | 236 | done: |
81055e58 AV |
237 | if (skip == iov->iov_len) { |
238 | iov++; | |
239 | skip = 0; | |
240 | } | |
4f18cd31 AV |
241 | i->count -= wanted - bytes; |
242 | i->nr_segs -= iov - i->iov; | |
243 | i->iov = iov; | |
244 | i->iov_offset = skip; | |
245 | return wanted - bytes; | |
246 | } | |
4f18cd31 | 247 | |
62a8067a | 248 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
249 | struct iov_iter *i) |
250 | { | |
251 | size_t skip, copy, left, wanted; | |
252 | const struct iovec *iov; | |
253 | char __user *buf; | |
254 | void *kaddr, *to; | |
255 | ||
256 | if (unlikely(bytes > i->count)) | |
257 | bytes = i->count; | |
258 | ||
259 | if (unlikely(!bytes)) | |
260 | return 0; | |
261 | ||
09fc68dc | 262 | might_fault(); |
f0d1bec9 AV |
263 | wanted = bytes; |
264 | iov = i->iov; | |
265 | skip = i->iov_offset; | |
266 | buf = iov->iov_base + skip; | |
267 | copy = min(bytes, iov->iov_len - skip); | |
268 | ||
3fa6c507 | 269 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
270 | kaddr = kmap_atomic(page); |
271 | to = kaddr + offset; | |
272 | ||
273 | /* first chunk, usually the only one */ | |
09fc68dc | 274 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
275 | copy -= left; |
276 | skip += copy; | |
277 | to += copy; | |
278 | bytes -= copy; | |
279 | ||
280 | while (unlikely(!left && bytes)) { | |
281 | iov++; | |
282 | buf = iov->iov_base; | |
283 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 284 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
285 | copy -= left; |
286 | skip = copy; | |
287 | to += copy; | |
288 | bytes -= copy; | |
289 | } | |
290 | if (likely(!bytes)) { | |
291 | kunmap_atomic(kaddr); | |
292 | goto done; | |
293 | } | |
294 | offset = to - kaddr; | |
295 | buf += copy; | |
296 | kunmap_atomic(kaddr); | |
297 | copy = min(bytes, iov->iov_len - skip); | |
298 | } | |
299 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 300 | |
f0d1bec9 AV |
301 | kaddr = kmap(page); |
302 | to = kaddr + offset; | |
09fc68dc | 303 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
304 | copy -= left; |
305 | skip += copy; | |
306 | to += copy; | |
307 | bytes -= copy; | |
308 | while (unlikely(!left && bytes)) { | |
309 | iov++; | |
310 | buf = iov->iov_base; | |
311 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 312 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
313 | copy -= left; |
314 | skip = copy; | |
315 | to += copy; | |
316 | bytes -= copy; | |
317 | } | |
318 | kunmap(page); | |
3fa6c507 | 319 | |
f0d1bec9 | 320 | done: |
81055e58 AV |
321 | if (skip == iov->iov_len) { |
322 | iov++; | |
323 | skip = 0; | |
324 | } | |
f0d1bec9 AV |
325 | i->count -= wanted - bytes; |
326 | i->nr_segs -= iov - i->iov; | |
327 | i->iov = iov; | |
328 | i->iov_offset = skip; | |
329 | return wanted - bytes; | |
330 | } | |
f0d1bec9 | 331 | |
241699cd AV |
332 | #ifdef PIPE_PARANOIA |
333 | static bool sanity(const struct iov_iter *i) | |
334 | { | |
335 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
336 | unsigned int p_head = pipe->head; |
337 | unsigned int p_tail = pipe->tail; | |
338 | unsigned int p_mask = pipe->ring_size - 1; | |
339 | unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); | |
340 | unsigned int i_head = i->head; | |
341 | unsigned int idx; | |
342 | ||
241699cd AV |
343 | if (i->iov_offset) { |
344 | struct pipe_buffer *p; | |
8cefc107 | 345 | if (unlikely(p_occupancy == 0)) |
241699cd | 346 | goto Bad; // pipe must be non-empty |
8cefc107 | 347 | if (unlikely(i_head != p_head - 1)) |
241699cd AV |
348 | goto Bad; // must be at the last buffer... |
349 | ||
8cefc107 | 350 | p = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
351 | if (unlikely(p->offset + p->len != i->iov_offset)) |
352 | goto Bad; // ... at the end of segment | |
353 | } else { | |
8cefc107 | 354 | if (i_head != p_head) |
241699cd AV |
355 | goto Bad; // must be right after the last buffer |
356 | } | |
357 | return true; | |
358 | Bad: | |
8cefc107 DH |
359 | printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); |
360 | printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", | |
361 | p_head, p_tail, pipe->ring_size); | |
362 | for (idx = 0; idx < pipe->ring_size; idx++) | |
241699cd AV |
363 | printk(KERN_ERR "[%p %p %d %d]\n", |
364 | pipe->bufs[idx].ops, | |
365 | pipe->bufs[idx].page, | |
366 | pipe->bufs[idx].offset, | |
367 | pipe->bufs[idx].len); | |
368 | WARN_ON(1); | |
369 | return false; | |
370 | } | |
371 | #else | |
372 | #define sanity(i) true | |
373 | #endif | |
374 | ||
241699cd AV |
375 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, |
376 | struct iov_iter *i) | |
377 | { | |
378 | struct pipe_inode_info *pipe = i->pipe; | |
379 | struct pipe_buffer *buf; | |
8cefc107 DH |
380 | unsigned int p_tail = pipe->tail; |
381 | unsigned int p_mask = pipe->ring_size - 1; | |
382 | unsigned int i_head = i->head; | |
241699cd | 383 | size_t off; |
241699cd AV |
384 | |
385 | if (unlikely(bytes > i->count)) | |
386 | bytes = i->count; | |
387 | ||
388 | if (unlikely(!bytes)) | |
389 | return 0; | |
390 | ||
391 | if (!sanity(i)) | |
392 | return 0; | |
393 | ||
394 | off = i->iov_offset; | |
8cefc107 | 395 | buf = &pipe->bufs[i_head & p_mask]; |
241699cd AV |
396 | if (off) { |
397 | if (offset == off && buf->page == page) { | |
398 | /* merge with the last one */ | |
399 | buf->len += bytes; | |
400 | i->iov_offset += bytes; | |
401 | goto out; | |
402 | } | |
8cefc107 DH |
403 | i_head++; |
404 | buf = &pipe->bufs[i_head & p_mask]; | |
241699cd | 405 | } |
6718b6f8 | 406 | if (pipe_full(i_head, p_tail, pipe->max_usage)) |
241699cd | 407 | return 0; |
8cefc107 | 408 | |
241699cd | 409 | buf->ops = &page_cache_pipe_buf_ops; |
8cefc107 DH |
410 | get_page(page); |
411 | buf->page = page; | |
241699cd AV |
412 | buf->offset = offset; |
413 | buf->len = bytes; | |
8cefc107 DH |
414 | |
415 | pipe->head = i_head + 1; | |
241699cd | 416 | i->iov_offset = offset + bytes; |
8cefc107 | 417 | i->head = i_head; |
241699cd AV |
418 | out: |
419 | i->count -= bytes; | |
420 | return bytes; | |
421 | } | |
422 | ||
171a0203 AA |
423 | /* |
424 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
425 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
426 | * | |
427 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
428 | * because it is an invalid address). | |
429 | */ | |
d4690f1e | 430 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
431 | { |
432 | size_t skip = i->iov_offset; | |
433 | const struct iovec *iov; | |
434 | int err; | |
435 | struct iovec v; | |
436 | ||
437 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
438 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
4bce9f6e | 439 | err = fault_in_pages_readable(v.iov_base, v.iov_len); |
171a0203 AA |
440 | if (unlikely(err)) |
441 | return err; | |
442 | 0;})) | |
443 | } | |
444 | return 0; | |
445 | } | |
d4690f1e | 446 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 447 | |
aa563d7b | 448 | void iov_iter_init(struct iov_iter *i, unsigned int direction, |
71d8e532 AV |
449 | const struct iovec *iov, unsigned long nr_segs, |
450 | size_t count) | |
451 | { | |
aa563d7b DH |
452 | WARN_ON(direction & ~(READ | WRITE)); |
453 | direction &= READ | WRITE; | |
454 | ||
71d8e532 | 455 | /* It will get better. Eventually... */ |
db68ce10 | 456 | if (uaccess_kernel()) { |
aa563d7b | 457 | i->type = ITER_KVEC | direction; |
a280455f AV |
458 | i->kvec = (struct kvec *)iov; |
459 | } else { | |
aa563d7b | 460 | i->type = ITER_IOVEC | direction; |
a280455f AV |
461 | i->iov = iov; |
462 | } | |
71d8e532 AV |
463 | i->nr_segs = nr_segs; |
464 | i->iov_offset = 0; | |
465 | i->count = count; | |
466 | } | |
467 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 468 | |
62a8067a AV |
469 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
470 | { | |
471 | char *from = kmap_atomic(page); | |
472 | memcpy(to, from + offset, len); | |
473 | kunmap_atomic(from); | |
474 | } | |
475 | ||
36f7a8a4 | 476 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
477 | { |
478 | char *to = kmap_atomic(page); | |
479 | memcpy(to + offset, from, len); | |
480 | kunmap_atomic(to); | |
481 | } | |
482 | ||
c35e0248 MW |
483 | static void memzero_page(struct page *page, size_t offset, size_t len) |
484 | { | |
485 | char *addr = kmap_atomic(page); | |
486 | memset(addr + offset, 0, len); | |
487 | kunmap_atomic(addr); | |
488 | } | |
489 | ||
241699cd AV |
490 | static inline bool allocated(struct pipe_buffer *buf) |
491 | { | |
492 | return buf->ops == &default_pipe_buf_ops; | |
493 | } | |
494 | ||
8cefc107 DH |
495 | static inline void data_start(const struct iov_iter *i, |
496 | unsigned int *iter_headp, size_t *offp) | |
241699cd | 497 | { |
8cefc107 DH |
498 | unsigned int p_mask = i->pipe->ring_size - 1; |
499 | unsigned int iter_head = i->head; | |
241699cd | 500 | size_t off = i->iov_offset; |
8cefc107 DH |
501 | |
502 | if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || | |
503 | off == PAGE_SIZE)) { | |
504 | iter_head++; | |
241699cd AV |
505 | off = 0; |
506 | } | |
8cefc107 | 507 | *iter_headp = iter_head; |
241699cd AV |
508 | *offp = off; |
509 | } | |
510 | ||
511 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
8cefc107 | 512 | int *iter_headp, size_t *offp) |
241699cd AV |
513 | { |
514 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
515 | unsigned int p_tail = pipe->tail; |
516 | unsigned int p_mask = pipe->ring_size - 1; | |
517 | unsigned int iter_head; | |
241699cd | 518 | size_t off; |
241699cd AV |
519 | ssize_t left; |
520 | ||
521 | if (unlikely(size > i->count)) | |
522 | size = i->count; | |
523 | if (unlikely(!size)) | |
524 | return 0; | |
525 | ||
526 | left = size; | |
8cefc107 DH |
527 | data_start(i, &iter_head, &off); |
528 | *iter_headp = iter_head; | |
241699cd AV |
529 | *offp = off; |
530 | if (off) { | |
531 | left -= PAGE_SIZE - off; | |
532 | if (left <= 0) { | |
8cefc107 | 533 | pipe->bufs[iter_head & p_mask].len += size; |
241699cd AV |
534 | return size; |
535 | } | |
8cefc107 DH |
536 | pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; |
537 | iter_head++; | |
241699cd | 538 | } |
6718b6f8 | 539 | while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { |
8cefc107 | 540 | struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; |
241699cd AV |
541 | struct page *page = alloc_page(GFP_USER); |
542 | if (!page) | |
543 | break; | |
8cefc107 DH |
544 | |
545 | buf->ops = &default_pipe_buf_ops; | |
546 | buf->page = page; | |
547 | buf->offset = 0; | |
548 | buf->len = min_t(ssize_t, left, PAGE_SIZE); | |
549 | left -= buf->len; | |
550 | iter_head++; | |
551 | pipe->head = iter_head; | |
552 | ||
553 | if (left == 0) | |
241699cd | 554 | return size; |
241699cd AV |
555 | } |
556 | return size - left; | |
557 | } | |
558 | ||
559 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
560 | struct iov_iter *i) | |
561 | { | |
562 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
563 | unsigned int p_mask = pipe->ring_size - 1; |
564 | unsigned int i_head; | |
241699cd | 565 | size_t n, off; |
241699cd AV |
566 | |
567 | if (!sanity(i)) | |
568 | return 0; | |
569 | ||
8cefc107 | 570 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
571 | if (unlikely(!n)) |
572 | return 0; | |
8cefc107 | 573 | do { |
241699cd | 574 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
575 | memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); |
576 | i->head = i_head; | |
241699cd AV |
577 | i->iov_offset = off + chunk; |
578 | n -= chunk; | |
579 | addr += chunk; | |
8cefc107 DH |
580 | off = 0; |
581 | i_head++; | |
582 | } while (n); | |
241699cd AV |
583 | i->count -= bytes; |
584 | return bytes; | |
585 | } | |
586 | ||
f9152895 AV |
587 | static __wsum csum_and_memcpy(void *to, const void *from, size_t len, |
588 | __wsum sum, size_t off) | |
589 | { | |
cc44c17b | 590 | __wsum next = csum_partial_copy_nocheck(from, to, len); |
f9152895 AV |
591 | return csum_block_add(sum, next, off); |
592 | } | |
593 | ||
78e1f386 AV |
594 | static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, |
595 | __wsum *csum, struct iov_iter *i) | |
596 | { | |
597 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
598 | unsigned int p_mask = pipe->ring_size - 1; |
599 | unsigned int i_head; | |
78e1f386 AV |
600 | size_t n, r; |
601 | size_t off = 0; | |
f9152895 | 602 | __wsum sum = *csum; |
78e1f386 AV |
603 | |
604 | if (!sanity(i)) | |
605 | return 0; | |
606 | ||
8cefc107 | 607 | bytes = n = push_pipe(i, bytes, &i_head, &r); |
78e1f386 AV |
608 | if (unlikely(!n)) |
609 | return 0; | |
8cefc107 | 610 | do { |
78e1f386 | 611 | size_t chunk = min_t(size_t, n, PAGE_SIZE - r); |
8cefc107 | 612 | char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); |
f9152895 | 613 | sum = csum_and_memcpy(p + r, addr, chunk, sum, off); |
78e1f386 | 614 | kunmap_atomic(p); |
8cefc107 | 615 | i->head = i_head; |
78e1f386 AV |
616 | i->iov_offset = r + chunk; |
617 | n -= chunk; | |
618 | off += chunk; | |
619 | addr += chunk; | |
8cefc107 DH |
620 | r = 0; |
621 | i_head++; | |
622 | } while (n); | |
78e1f386 AV |
623 | i->count -= bytes; |
624 | *csum = sum; | |
625 | return bytes; | |
626 | } | |
627 | ||
aa28de27 | 628 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 629 | { |
36f7a8a4 | 630 | const char *from = addr; |
00e23707 | 631 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 632 | return copy_pipe_to_iter(addr, bytes, i); |
09fc68dc AV |
633 | if (iter_is_iovec(i)) |
634 | might_fault(); | |
3d4d3e48 | 635 | iterate_and_advance(i, bytes, v, |
09fc68dc | 636 | copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
3d4d3e48 | 637 | memcpy_to_page(v.bv_page, v.bv_offset, |
a280455f AV |
638 | (from += v.bv_len) - v.bv_len, v.bv_len), |
639 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 640 | ) |
62a8067a | 641 | |
3d4d3e48 | 642 | return bytes; |
c35e0248 | 643 | } |
aa28de27 | 644 | EXPORT_SYMBOL(_copy_to_iter); |
c35e0248 | 645 | |
ec6347bb DW |
646 | #ifdef CONFIG_ARCH_HAS_COPY_MC |
647 | static int copyout_mc(void __user *to, const void *from, size_t n) | |
8780356e | 648 | { |
96d4f267 | 649 | if (access_ok(to, n)) { |
d0ef4c36 | 650 | instrument_copy_to_user(to, from, n); |
ec6347bb | 651 | n = copy_mc_to_user((__force void *) to, from, n); |
8780356e DW |
652 | } |
653 | return n; | |
654 | } | |
655 | ||
ec6347bb | 656 | static unsigned long copy_mc_to_page(struct page *page, size_t offset, |
8780356e DW |
657 | const char *from, size_t len) |
658 | { | |
659 | unsigned long ret; | |
660 | char *to; | |
661 | ||
662 | to = kmap_atomic(page); | |
ec6347bb | 663 | ret = copy_mc_to_kernel(to + offset, from, len); |
8780356e DW |
664 | kunmap_atomic(to); |
665 | ||
666 | return ret; | |
667 | } | |
668 | ||
ec6347bb | 669 | static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes, |
ca146f6f DW |
670 | struct iov_iter *i) |
671 | { | |
672 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
673 | unsigned int p_mask = pipe->ring_size - 1; |
674 | unsigned int i_head; | |
ca146f6f | 675 | size_t n, off, xfer = 0; |
ca146f6f DW |
676 | |
677 | if (!sanity(i)) | |
678 | return 0; | |
679 | ||
8cefc107 | 680 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
ca146f6f DW |
681 | if (unlikely(!n)) |
682 | return 0; | |
8cefc107 | 683 | do { |
ca146f6f DW |
684 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
685 | unsigned long rem; | |
686 | ||
ec6347bb | 687 | rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page, |
8cefc107 DH |
688 | off, addr, chunk); |
689 | i->head = i_head; | |
ca146f6f DW |
690 | i->iov_offset = off + chunk - rem; |
691 | xfer += chunk - rem; | |
692 | if (rem) | |
693 | break; | |
694 | n -= chunk; | |
695 | addr += chunk; | |
8cefc107 DH |
696 | off = 0; |
697 | i_head++; | |
698 | } while (n); | |
ca146f6f DW |
699 | i->count -= xfer; |
700 | return xfer; | |
701 | } | |
702 | ||
bf3eeb9b | 703 | /** |
ec6347bb | 704 | * _copy_mc_to_iter - copy to iter with source memory error exception handling |
bf3eeb9b DW |
705 | * @addr: source kernel address |
706 | * @bytes: total transfer length | |
707 | * @iter: destination iterator | |
708 | * | |
ec6347bb DW |
709 | * The pmem driver deploys this for the dax operation |
710 | * (dax_copy_to_iter()) for dax reads (bypass page-cache and the | |
711 | * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes | |
712 | * successfully copied. | |
bf3eeb9b | 713 | * |
ec6347bb | 714 | * The main differences between this and typical _copy_to_iter(). |
bf3eeb9b DW |
715 | * |
716 | * * Typical tail/residue handling after a fault retries the copy | |
717 | * byte-by-byte until the fault happens again. Re-triggering machine | |
718 | * checks is potentially fatal so the implementation uses source | |
719 | * alignment and poison alignment assumptions to avoid re-triggering | |
720 | * hardware exceptions. | |
721 | * | |
722 | * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. | |
723 | * Compare to copy_to_iter() where only ITER_IOVEC attempts might return | |
724 | * a short copy. | |
bf3eeb9b | 725 | */ |
ec6347bb | 726 | size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
8780356e DW |
727 | { |
728 | const char *from = addr; | |
729 | unsigned long rem, curr_addr, s_addr = (unsigned long) addr; | |
730 | ||
00e23707 | 731 | if (unlikely(iov_iter_is_pipe(i))) |
ec6347bb | 732 | return copy_mc_pipe_to_iter(addr, bytes, i); |
8780356e DW |
733 | if (iter_is_iovec(i)) |
734 | might_fault(); | |
735 | iterate_and_advance(i, bytes, v, | |
ec6347bb DW |
736 | copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len, |
737 | v.iov_len), | |
8780356e | 738 | ({ |
ec6347bb DW |
739 | rem = copy_mc_to_page(v.bv_page, v.bv_offset, |
740 | (from += v.bv_len) - v.bv_len, v.bv_len); | |
8780356e DW |
741 | if (rem) { |
742 | curr_addr = (unsigned long) from; | |
743 | bytes = curr_addr - s_addr - rem; | |
744 | return bytes; | |
745 | } | |
746 | }), | |
747 | ({ | |
ec6347bb DW |
748 | rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len) |
749 | - v.iov_len, v.iov_len); | |
8780356e DW |
750 | if (rem) { |
751 | curr_addr = (unsigned long) from; | |
752 | bytes = curr_addr - s_addr - rem; | |
753 | return bytes; | |
754 | } | |
755 | }) | |
756 | ) | |
757 | ||
758 | return bytes; | |
759 | } | |
ec6347bb DW |
760 | EXPORT_SYMBOL_GPL(_copy_mc_to_iter); |
761 | #endif /* CONFIG_ARCH_HAS_COPY_MC */ | |
8780356e | 762 | |
aa28de27 | 763 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 764 | { |
0dbca9a4 | 765 | char *to = addr; |
00e23707 | 766 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
767 | WARN_ON(1); |
768 | return 0; | |
769 | } | |
09fc68dc AV |
770 | if (iter_is_iovec(i)) |
771 | might_fault(); | |
0dbca9a4 | 772 | iterate_and_advance(i, bytes, v, |
09fc68dc | 773 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4 | 774 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
775 | v.bv_offset, v.bv_len), |
776 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
777 | ) |
778 | ||
779 | return bytes; | |
c35e0248 | 780 | } |
aa28de27 | 781 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 782 | |
aa28de27 | 783 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
784 | { |
785 | char *to = addr; | |
00e23707 | 786 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
787 | WARN_ON(1); |
788 | return false; | |
789 | } | |
33844e66 | 790 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
791 | return false; |
792 | ||
09fc68dc AV |
793 | if (iter_is_iovec(i)) |
794 | might_fault(); | |
cbbd26b8 | 795 | iterate_all_kinds(i, bytes, v, ({ |
09fc68dc | 796 | if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
797 | v.iov_base, v.iov_len)) |
798 | return false; | |
799 | 0;}), | |
800 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
801 | v.bv_offset, v.bv_len), | |
802 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
803 | ) | |
804 | ||
805 | iov_iter_advance(i, bytes); | |
806 | return true; | |
807 | } | |
aa28de27 | 808 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 809 | |
aa28de27 | 810 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
811 | { |
812 | char *to = addr; | |
00e23707 | 813 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
814 | WARN_ON(1); |
815 | return 0; | |
816 | } | |
aa583096 | 817 | iterate_and_advance(i, bytes, v, |
3f763453 | 818 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
819 | v.iov_base, v.iov_len), |
820 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
821 | v.bv_offset, v.bv_len), | |
822 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
823 | ) | |
824 | ||
825 | return bytes; | |
826 | } | |
aa28de27 | 827 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 828 | |
0aed55af | 829 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d DW |
830 | /** |
831 | * _copy_from_iter_flushcache - write destination through cpu cache | |
832 | * @addr: destination kernel address | |
833 | * @bytes: total transfer length | |
834 | * @iter: source iterator | |
835 | * | |
836 | * The pmem driver arranges for filesystem-dax to use this facility via | |
837 | * dax_copy_from_iter() for ensuring that writes to persistent memory | |
838 | * are flushed through the CPU cache. It is differentiated from | |
839 | * _copy_from_iter_nocache() in that guarantees all data is flushed for | |
840 | * all iterator types. The _copy_from_iter_nocache() only attempts to | |
841 | * bypass the cache for the ITER_IOVEC case, and on some archs may use | |
842 | * instructions that strand dirty-data in the cache. | |
843 | */ | |
6a37e940 | 844 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af DW |
845 | { |
846 | char *to = addr; | |
00e23707 | 847 | if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af DW |
848 | WARN_ON(1); |
849 | return 0; | |
850 | } | |
851 | iterate_and_advance(i, bytes, v, | |
852 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
853 | v.iov_base, v.iov_len), | |
854 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
855 | v.bv_offset, v.bv_len), | |
856 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
857 | v.iov_len) | |
858 | ) | |
859 | ||
860 | return bytes; | |
861 | } | |
6a37e940 | 862 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af DW |
863 | #endif |
864 | ||
aa28de27 | 865 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
866 | { |
867 | char *to = addr; | |
00e23707 | 868 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
869 | WARN_ON(1); |
870 | return false; | |
871 | } | |
33844e66 | 872 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
873 | return false; |
874 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 875 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
876 | v.iov_base, v.iov_len)) |
877 | return false; | |
878 | 0;}), | |
879 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
880 | v.bv_offset, v.bv_len), | |
881 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
882 | ) | |
883 | ||
884 | iov_iter_advance(i, bytes); | |
885 | return true; | |
886 | } | |
aa28de27 | 887 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 888 | |
72e809ed AV |
889 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
890 | { | |
6daef95b ED |
891 | struct page *head; |
892 | size_t v = n + offset; | |
893 | ||
894 | /* | |
895 | * The general case needs to access the page order in order | |
896 | * to compute the page size. | |
897 | * However, we mostly deal with order-0 pages and thus can | |
898 | * avoid a possible cache line miss for requests that fit all | |
899 | * page orders. | |
900 | */ | |
901 | if (n <= v && v <= PAGE_SIZE) | |
902 | return true; | |
903 | ||
904 | head = compound_head(page); | |
905 | v += (page - head) << PAGE_SHIFT; | |
a90bcb86 | 906 | |
a50b854e | 907 | if (likely(n <= v && v <= (page_size(head)))) |
72e809ed AV |
908 | return true; |
909 | WARN_ON(1); | |
910 | return false; | |
911 | } | |
cbbd26b8 | 912 | |
62a8067a AV |
913 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
914 | struct iov_iter *i) | |
915 | { | |
72e809ed AV |
916 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
917 | return 0; | |
d271524a AV |
918 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
919 | void *kaddr = kmap_atomic(page); | |
920 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
921 | kunmap_atomic(kaddr); | |
922 | return wanted; | |
9ea9ce04 DH |
923 | } else if (unlikely(iov_iter_is_discard(i))) |
924 | return bytes; | |
925 | else if (likely(!iov_iter_is_pipe(i))) | |
62a8067a | 926 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
927 | else |
928 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
929 | } |
930 | EXPORT_SYMBOL(copy_page_to_iter); | |
931 | ||
932 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
933 | struct iov_iter *i) | |
934 | { | |
72e809ed AV |
935 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
936 | return 0; | |
9ea9ce04 | 937 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
938 | WARN_ON(1); |
939 | return 0; | |
940 | } | |
a280455f | 941 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 942 | void *kaddr = kmap_atomic(page); |
aa28de27 | 943 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
944 | kunmap_atomic(kaddr); |
945 | return wanted; | |
946 | } else | |
62a8067a AV |
947 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
948 | } | |
949 | EXPORT_SYMBOL(copy_page_from_iter); | |
950 | ||
241699cd AV |
951 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
952 | { | |
953 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
954 | unsigned int p_mask = pipe->ring_size - 1; |
955 | unsigned int i_head; | |
241699cd | 956 | size_t n, off; |
241699cd AV |
957 | |
958 | if (!sanity(i)) | |
959 | return 0; | |
960 | ||
8cefc107 | 961 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
962 | if (unlikely(!n)) |
963 | return 0; | |
964 | ||
8cefc107 | 965 | do { |
241699cd | 966 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
967 | memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); |
968 | i->head = i_head; | |
241699cd AV |
969 | i->iov_offset = off + chunk; |
970 | n -= chunk; | |
8cefc107 DH |
971 | off = 0; |
972 | i_head++; | |
973 | } while (n); | |
241699cd AV |
974 | i->count -= bytes; |
975 | return bytes; | |
976 | } | |
977 | ||
c35e0248 MW |
978 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
979 | { | |
00e23707 | 980 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 981 | return pipe_zero(bytes, i); |
8442fa46 | 982 | iterate_and_advance(i, bytes, v, |
09fc68dc | 983 | clear_user(v.iov_base, v.iov_len), |
a280455f AV |
984 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
985 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
986 | ) |
987 | ||
988 | return bytes; | |
c35e0248 MW |
989 | } |
990 | EXPORT_SYMBOL(iov_iter_zero); | |
991 | ||
62a8067a AV |
992 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
993 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
994 | { | |
04a31165 | 995 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
996 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
997 | kunmap_atomic(kaddr); | |
998 | return 0; | |
999 | } | |
9ea9ce04 | 1000 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1001 | kunmap_atomic(kaddr); |
1002 | WARN_ON(1); | |
1003 | return 0; | |
1004 | } | |
04a31165 | 1005 | iterate_all_kinds(i, bytes, v, |
09fc68dc | 1006 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a31165 | 1007 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
1008 | v.bv_offset, v.bv_len), |
1009 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
1010 | ) |
1011 | kunmap_atomic(kaddr); | |
1012 | return bytes; | |
62a8067a AV |
1013 | } |
1014 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
1015 | ||
b9dc6f65 AV |
1016 | static inline void pipe_truncate(struct iov_iter *i) |
1017 | { | |
1018 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1019 | unsigned int p_tail = pipe->tail; |
1020 | unsigned int p_head = pipe->head; | |
1021 | unsigned int p_mask = pipe->ring_size - 1; | |
1022 | ||
1023 | if (!pipe_empty(p_head, p_tail)) { | |
1024 | struct pipe_buffer *buf; | |
1025 | unsigned int i_head = i->head; | |
b9dc6f65 | 1026 | size_t off = i->iov_offset; |
8cefc107 | 1027 | |
b9dc6f65 | 1028 | if (off) { |
8cefc107 DH |
1029 | buf = &pipe->bufs[i_head & p_mask]; |
1030 | buf->len = off - buf->offset; | |
1031 | i_head++; | |
b9dc6f65 | 1032 | } |
8cefc107 DH |
1033 | while (p_head != i_head) { |
1034 | p_head--; | |
1035 | pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); | |
b9dc6f65 | 1036 | } |
8cefc107 DH |
1037 | |
1038 | pipe->head = p_head; | |
b9dc6f65 AV |
1039 | } |
1040 | } | |
1041 | ||
241699cd AV |
1042 | static void pipe_advance(struct iov_iter *i, size_t size) |
1043 | { | |
1044 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
1045 | if (unlikely(i->count < size)) |
1046 | size = i->count; | |
241699cd | 1047 | if (size) { |
b9dc6f65 | 1048 | struct pipe_buffer *buf; |
8cefc107 DH |
1049 | unsigned int p_mask = pipe->ring_size - 1; |
1050 | unsigned int i_head = i->head; | |
b9dc6f65 | 1051 | size_t off = i->iov_offset, left = size; |
8cefc107 | 1052 | |
241699cd | 1053 | if (off) /* make it relative to the beginning of buffer */ |
8cefc107 | 1054 | left += off - pipe->bufs[i_head & p_mask].offset; |
241699cd | 1055 | while (1) { |
8cefc107 | 1056 | buf = &pipe->bufs[i_head & p_mask]; |
b9dc6f65 | 1057 | if (left <= buf->len) |
241699cd | 1058 | break; |
b9dc6f65 | 1059 | left -= buf->len; |
8cefc107 | 1060 | i_head++; |
241699cd | 1061 | } |
8cefc107 | 1062 | i->head = i_head; |
b9dc6f65 | 1063 | i->iov_offset = buf->offset + left; |
241699cd | 1064 | } |
b9dc6f65 AV |
1065 | i->count -= size; |
1066 | /* ... and discard everything past that point */ | |
1067 | pipe_truncate(i); | |
241699cd AV |
1068 | } |
1069 | ||
62a8067a AV |
1070 | void iov_iter_advance(struct iov_iter *i, size_t size) |
1071 | { | |
00e23707 | 1072 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1073 | pipe_advance(i, size); |
1074 | return; | |
1075 | } | |
9ea9ce04 DH |
1076 | if (unlikely(iov_iter_is_discard(i))) { |
1077 | i->count -= size; | |
1078 | return; | |
1079 | } | |
a280455f | 1080 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
1081 | } |
1082 | EXPORT_SYMBOL(iov_iter_advance); | |
1083 | ||
27c0e374 AV |
1084 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
1085 | { | |
1086 | if (!unroll) | |
1087 | return; | |
5b47d59a AV |
1088 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
1089 | return; | |
27c0e374 | 1090 | i->count += unroll; |
00e23707 | 1091 | if (unlikely(iov_iter_is_pipe(i))) { |
27c0e374 | 1092 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 DH |
1093 | unsigned int p_mask = pipe->ring_size - 1; |
1094 | unsigned int i_head = i->head; | |
27c0e374 AV |
1095 | size_t off = i->iov_offset; |
1096 | while (1) { | |
8cefc107 DH |
1097 | struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; |
1098 | size_t n = off - b->offset; | |
27c0e374 | 1099 | if (unroll < n) { |
4fa55cef | 1100 | off -= unroll; |
27c0e374 AV |
1101 | break; |
1102 | } | |
1103 | unroll -= n; | |
8cefc107 | 1104 | if (!unroll && i_head == i->start_head) { |
27c0e374 AV |
1105 | off = 0; |
1106 | break; | |
1107 | } | |
8cefc107 DH |
1108 | i_head--; |
1109 | b = &pipe->bufs[i_head & p_mask]; | |
1110 | off = b->offset + b->len; | |
27c0e374 AV |
1111 | } |
1112 | i->iov_offset = off; | |
8cefc107 | 1113 | i->head = i_head; |
27c0e374 AV |
1114 | pipe_truncate(i); |
1115 | return; | |
1116 | } | |
9ea9ce04 DH |
1117 | if (unlikely(iov_iter_is_discard(i))) |
1118 | return; | |
27c0e374 AV |
1119 | if (unroll <= i->iov_offset) { |
1120 | i->iov_offset -= unroll; | |
1121 | return; | |
1122 | } | |
1123 | unroll -= i->iov_offset; | |
00e23707 | 1124 | if (iov_iter_is_bvec(i)) { |
27c0e374 AV |
1125 | const struct bio_vec *bvec = i->bvec; |
1126 | while (1) { | |
1127 | size_t n = (--bvec)->bv_len; | |
1128 | i->nr_segs++; | |
1129 | if (unroll <= n) { | |
1130 | i->bvec = bvec; | |
1131 | i->iov_offset = n - unroll; | |
1132 | return; | |
1133 | } | |
1134 | unroll -= n; | |
1135 | } | |
1136 | } else { /* same logics for iovec and kvec */ | |
1137 | const struct iovec *iov = i->iov; | |
1138 | while (1) { | |
1139 | size_t n = (--iov)->iov_len; | |
1140 | i->nr_segs++; | |
1141 | if (unroll <= n) { | |
1142 | i->iov = iov; | |
1143 | i->iov_offset = n - unroll; | |
1144 | return; | |
1145 | } | |
1146 | unroll -= n; | |
1147 | } | |
1148 | } | |
1149 | } | |
1150 | EXPORT_SYMBOL(iov_iter_revert); | |
1151 | ||
62a8067a AV |
1152 | /* |
1153 | * Return the count of just the current iov_iter segment. | |
1154 | */ | |
1155 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
1156 | { | |
00e23707 | 1157 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1158 | return i->count; // it is a silly place, anyway |
62a8067a AV |
1159 | if (i->nr_segs == 1) |
1160 | return i->count; | |
9ea9ce04 DH |
1161 | if (unlikely(iov_iter_is_discard(i))) |
1162 | return i->count; | |
00e23707 | 1163 | else if (iov_iter_is_bvec(i)) |
62a8067a | 1164 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
1165 | else |
1166 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
1167 | } |
1168 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
1169 | ||
aa563d7b | 1170 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77 | 1171 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
1172 | size_t count) |
1173 | { | |
aa563d7b DH |
1174 | WARN_ON(direction & ~(READ | WRITE)); |
1175 | i->type = ITER_KVEC | (direction & (READ | WRITE)); | |
05afcb77 | 1176 | i->kvec = kvec; |
abb78f87 AV |
1177 | i->nr_segs = nr_segs; |
1178 | i->iov_offset = 0; | |
1179 | i->count = count; | |
1180 | } | |
1181 | EXPORT_SYMBOL(iov_iter_kvec); | |
1182 | ||
aa563d7b | 1183 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77 AV |
1184 | const struct bio_vec *bvec, unsigned long nr_segs, |
1185 | size_t count) | |
1186 | { | |
aa563d7b DH |
1187 | WARN_ON(direction & ~(READ | WRITE)); |
1188 | i->type = ITER_BVEC | (direction & (READ | WRITE)); | |
05afcb77 AV |
1189 | i->bvec = bvec; |
1190 | i->nr_segs = nr_segs; | |
1191 | i->iov_offset = 0; | |
1192 | i->count = count; | |
1193 | } | |
1194 | EXPORT_SYMBOL(iov_iter_bvec); | |
1195 | ||
aa563d7b | 1196 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd AV |
1197 | struct pipe_inode_info *pipe, |
1198 | size_t count) | |
1199 | { | |
aa563d7b | 1200 | BUG_ON(direction != READ); |
8cefc107 | 1201 | WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); |
aa563d7b | 1202 | i->type = ITER_PIPE | READ; |
241699cd | 1203 | i->pipe = pipe; |
8cefc107 | 1204 | i->head = pipe->head; |
241699cd AV |
1205 | i->iov_offset = 0; |
1206 | i->count = count; | |
8cefc107 | 1207 | i->start_head = i->head; |
241699cd AV |
1208 | } |
1209 | EXPORT_SYMBOL(iov_iter_pipe); | |
1210 | ||
9ea9ce04 DH |
1211 | /** |
1212 | * iov_iter_discard - Initialise an I/O iterator that discards data | |
1213 | * @i: The iterator to initialise. | |
1214 | * @direction: The direction of the transfer. | |
1215 | * @count: The size of the I/O buffer in bytes. | |
1216 | * | |
1217 | * Set up an I/O iterator that just discards everything that's written to it. | |
1218 | * It's only available as a READ iterator. | |
1219 | */ | |
1220 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) | |
1221 | { | |
1222 | BUG_ON(direction != READ); | |
1223 | i->type = ITER_DISCARD | READ; | |
1224 | i->count = count; | |
1225 | i->iov_offset = 0; | |
1226 | } | |
1227 | EXPORT_SYMBOL(iov_iter_discard); | |
1228 | ||
62a8067a AV |
1229 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
1230 | { | |
04a31165 AV |
1231 | unsigned long res = 0; |
1232 | size_t size = i->count; | |
1233 | ||
00e23707 | 1234 | if (unlikely(iov_iter_is_pipe(i))) { |
e0ff126e JK |
1235 | unsigned int p_mask = i->pipe->ring_size - 1; |
1236 | ||
8cefc107 | 1237 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) |
241699cd AV |
1238 | return size | i->iov_offset; |
1239 | return size; | |
1240 | } | |
04a31165 AV |
1241 | iterate_all_kinds(i, size, v, |
1242 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
1243 | res |= v.bv_offset | v.bv_len, |
1244 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
1245 | ) |
1246 | return res; | |
62a8067a AV |
1247 | } |
1248 | EXPORT_SYMBOL(iov_iter_alignment); | |
1249 | ||
357f435d AV |
1250 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
1251 | { | |
33844e66 | 1252 | unsigned long res = 0; |
357f435d | 1253 | size_t size = i->count; |
357f435d | 1254 | |
9ea9ce04 | 1255 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1256 | WARN_ON(1); |
1257 | return ~0U; | |
1258 | } | |
1259 | ||
357f435d AV |
1260 | iterate_all_kinds(i, size, v, |
1261 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1262 | (size != v.iov_len ? size : 0), 0), | |
1263 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1264 | (size != v.bv_len ? size : 0)), | |
1265 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1266 | (size != v.iov_len ? size : 0)) | |
1267 | ); | |
33844e66 | 1268 | return res; |
357f435d AV |
1269 | } |
1270 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1271 | ||
e76b6312 | 1272 | static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd AV |
1273 | size_t maxsize, |
1274 | struct page **pages, | |
8cefc107 | 1275 | int iter_head, |
241699cd AV |
1276 | size_t *start) |
1277 | { | |
1278 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1279 | unsigned int p_mask = pipe->ring_size - 1; |
1280 | ssize_t n = push_pipe(i, maxsize, &iter_head, start); | |
241699cd AV |
1281 | if (!n) |
1282 | return -EFAULT; | |
1283 | ||
1284 | maxsize = n; | |
1285 | n += *start; | |
1689c73a | 1286 | while (n > 0) { |
8cefc107 DH |
1287 | get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); |
1288 | iter_head++; | |
241699cd AV |
1289 | n -= PAGE_SIZE; |
1290 | } | |
1291 | ||
1292 | return maxsize; | |
1293 | } | |
1294 | ||
1295 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1296 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1297 | size_t *start) | |
1298 | { | |
8cefc107 | 1299 | unsigned int iter_head, npages; |
241699cd | 1300 | size_t capacity; |
241699cd | 1301 | |
33844e66 AV |
1302 | if (!maxsize) |
1303 | return 0; | |
1304 | ||
241699cd AV |
1305 | if (!sanity(i)) |
1306 | return -EFAULT; | |
1307 | ||
8cefc107 DH |
1308 | data_start(i, &iter_head, start); |
1309 | /* Amount of free space: some of this one + all after this one */ | |
1310 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
1311 | capacity = min(npages, maxpages) * PAGE_SIZE - *start; | |
241699cd | 1312 | |
8cefc107 | 1313 | return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); |
241699cd AV |
1314 | } |
1315 | ||
62a8067a | 1316 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1317 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1318 | size_t *start) |
1319 | { | |
e5393fae AV |
1320 | if (maxsize > i->count) |
1321 | maxsize = i->count; | |
1322 | ||
00e23707 | 1323 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1324 | return pipe_get_pages(i, pages, maxsize, maxpages, start); |
9ea9ce04 DH |
1325 | if (unlikely(iov_iter_is_discard(i))) |
1326 | return -EFAULT; | |
1327 | ||
e5393fae AV |
1328 | iterate_all_kinds(i, maxsize, v, ({ |
1329 | unsigned long addr = (unsigned long)v.iov_base; | |
1330 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1331 | int n; | |
1332 | int res; | |
1333 | ||
1334 | if (len > maxpages * PAGE_SIZE) | |
1335 | len = maxpages * PAGE_SIZE; | |
1336 | addr &= ~(PAGE_SIZE - 1); | |
1337 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
73b0140b IW |
1338 | res = get_user_pages_fast(addr, n, |
1339 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, | |
1340 | pages); | |
e5393fae AV |
1341 | if (unlikely(res < 0)) |
1342 | return res; | |
1343 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1344 | 0;}),({ | |
1345 | /* can't be more than PAGE_SIZE */ | |
1346 | *start = v.bv_offset; | |
1347 | get_page(*pages = v.bv_page); | |
1348 | return v.bv_len; | |
a280455f AV |
1349 | }),({ |
1350 | return -EFAULT; | |
e5393fae AV |
1351 | }) |
1352 | ) | |
1353 | return 0; | |
62a8067a AV |
1354 | } |
1355 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1356 | ||
1b17f1f2 AV |
1357 | static struct page **get_pages_array(size_t n) |
1358 | { | |
752ade68 | 1359 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1360 | } |
1361 | ||
241699cd AV |
1362 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1363 | struct page ***pages, size_t maxsize, | |
1364 | size_t *start) | |
1365 | { | |
1366 | struct page **p; | |
8cefc107 | 1367 | unsigned int iter_head, npages; |
d7760d63 | 1368 | ssize_t n; |
241699cd | 1369 | |
33844e66 AV |
1370 | if (!maxsize) |
1371 | return 0; | |
1372 | ||
241699cd AV |
1373 | if (!sanity(i)) |
1374 | return -EFAULT; | |
1375 | ||
8cefc107 DH |
1376 | data_start(i, &iter_head, start); |
1377 | /* Amount of free space: some of this one + all after this one */ | |
1378 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
241699cd AV |
1379 | n = npages * PAGE_SIZE - *start; |
1380 | if (maxsize > n) | |
1381 | maxsize = n; | |
1382 | else | |
1383 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1384 | p = get_pages_array(npages); | |
1385 | if (!p) | |
1386 | return -ENOMEM; | |
8cefc107 | 1387 | n = __pipe_get_pages(i, maxsize, p, iter_head, start); |
241699cd AV |
1388 | if (n > 0) |
1389 | *pages = p; | |
1390 | else | |
1391 | kvfree(p); | |
1392 | return n; | |
1393 | } | |
1394 | ||
62a8067a AV |
1395 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1396 | struct page ***pages, size_t maxsize, | |
1397 | size_t *start) | |
1398 | { | |
1b17f1f2 AV |
1399 | struct page **p; |
1400 | ||
1401 | if (maxsize > i->count) | |
1402 | maxsize = i->count; | |
1403 | ||
00e23707 | 1404 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1405 | return pipe_get_pages_alloc(i, pages, maxsize, start); |
9ea9ce04 DH |
1406 | if (unlikely(iov_iter_is_discard(i))) |
1407 | return -EFAULT; | |
1408 | ||
1b17f1f2 AV |
1409 | iterate_all_kinds(i, maxsize, v, ({ |
1410 | unsigned long addr = (unsigned long)v.iov_base; | |
1411 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1412 | int n; | |
1413 | int res; | |
1414 | ||
1415 | addr &= ~(PAGE_SIZE - 1); | |
1416 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1417 | p = get_pages_array(n); | |
1418 | if (!p) | |
1419 | return -ENOMEM; | |
73b0140b IW |
1420 | res = get_user_pages_fast(addr, n, |
1421 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); | |
1b17f1f2 AV |
1422 | if (unlikely(res < 0)) { |
1423 | kvfree(p); | |
1424 | return res; | |
1425 | } | |
1426 | *pages = p; | |
1427 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1428 | 0;}),({ | |
1429 | /* can't be more than PAGE_SIZE */ | |
1430 | *start = v.bv_offset; | |
1431 | *pages = p = get_pages_array(1); | |
1432 | if (!p) | |
1433 | return -ENOMEM; | |
1434 | get_page(*p = v.bv_page); | |
1435 | return v.bv_len; | |
a280455f AV |
1436 | }),({ |
1437 | return -EFAULT; | |
1b17f1f2 AV |
1438 | }) |
1439 | ) | |
1440 | return 0; | |
62a8067a AV |
1441 | } |
1442 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1443 | ||
a604ec7e AV |
1444 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1445 | struct iov_iter *i) | |
1446 | { | |
1447 | char *to = addr; | |
1448 | __wsum sum, next; | |
1449 | size_t off = 0; | |
a604ec7e | 1450 | sum = *csum; |
9ea9ce04 | 1451 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1452 | WARN_ON(1); |
1453 | return 0; | |
1454 | } | |
a604ec7e | 1455 | iterate_and_advance(i, bytes, v, ({ |
cbbd26b8 | 1456 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e | 1457 | (to += v.iov_len) - v.iov_len, |
c693cc46 AV |
1458 | v.iov_len); |
1459 | if (next) { | |
a604ec7e AV |
1460 | sum = csum_block_add(sum, next, off); |
1461 | off += v.iov_len; | |
1462 | } | |
c693cc46 | 1463 | next ? 0 : v.iov_len; |
a604ec7e AV |
1464 | }), ({ |
1465 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1466 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1467 | p + v.bv_offset, v.bv_len, | |
1468 | sum, off); | |
a604ec7e | 1469 | kunmap_atomic(p); |
a604ec7e AV |
1470 | off += v.bv_len; |
1471 | }),({ | |
f9152895 AV |
1472 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1473 | v.iov_base, v.iov_len, | |
1474 | sum, off); | |
a604ec7e AV |
1475 | off += v.iov_len; |
1476 | }) | |
1477 | ) | |
1478 | *csum = sum; | |
1479 | return bytes; | |
1480 | } | |
1481 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1482 | ||
cbbd26b8 AV |
1483 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
1484 | struct iov_iter *i) | |
1485 | { | |
1486 | char *to = addr; | |
1487 | __wsum sum, next; | |
1488 | size_t off = 0; | |
1489 | sum = *csum; | |
9ea9ce04 | 1490 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
cbbd26b8 AV |
1491 | WARN_ON(1); |
1492 | return false; | |
1493 | } | |
1494 | if (unlikely(i->count < bytes)) | |
1495 | return false; | |
1496 | iterate_all_kinds(i, bytes, v, ({ | |
cbbd26b8 AV |
1497 | next = csum_and_copy_from_user(v.iov_base, |
1498 | (to += v.iov_len) - v.iov_len, | |
c693cc46 AV |
1499 | v.iov_len); |
1500 | if (!next) | |
cbbd26b8 AV |
1501 | return false; |
1502 | sum = csum_block_add(sum, next, off); | |
1503 | off += v.iov_len; | |
1504 | 0; | |
1505 | }), ({ | |
1506 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1507 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1508 | p + v.bv_offset, v.bv_len, | |
1509 | sum, off); | |
cbbd26b8 | 1510 | kunmap_atomic(p); |
cbbd26b8 AV |
1511 | off += v.bv_len; |
1512 | }),({ | |
f9152895 AV |
1513 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1514 | v.iov_base, v.iov_len, | |
1515 | sum, off); | |
cbbd26b8 AV |
1516 | off += v.iov_len; |
1517 | }) | |
1518 | ) | |
1519 | *csum = sum; | |
1520 | iov_iter_advance(i, bytes); | |
1521 | return true; | |
1522 | } | |
1523 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1524 | ||
cb002d07 | 1525 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, |
a604ec7e AV |
1526 | struct iov_iter *i) |
1527 | { | |
36f7a8a4 | 1528 | const char *from = addr; |
cb002d07 | 1529 | __wsum *csum = csump; |
a604ec7e AV |
1530 | __wsum sum, next; |
1531 | size_t off = 0; | |
78e1f386 AV |
1532 | |
1533 | if (unlikely(iov_iter_is_pipe(i))) | |
1534 | return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); | |
1535 | ||
a604ec7e | 1536 | sum = *csum; |
78e1f386 | 1537 | if (unlikely(iov_iter_is_discard(i))) { |
241699cd AV |
1538 | WARN_ON(1); /* for now */ |
1539 | return 0; | |
1540 | } | |
a604ec7e | 1541 | iterate_and_advance(i, bytes, v, ({ |
a604ec7e | 1542 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, |
cbbd26b8 | 1543 | v.iov_base, |
c693cc46 AV |
1544 | v.iov_len); |
1545 | if (next) { | |
a604ec7e AV |
1546 | sum = csum_block_add(sum, next, off); |
1547 | off += v.iov_len; | |
1548 | } | |
c693cc46 | 1549 | next ? 0 : v.iov_len; |
a604ec7e AV |
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 | { |
89cd35c5 CH |
1809 | return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i, |
1810 | in_compat_syscall()); | |
bc917be8 AV |
1811 | } |
1812 | EXPORT_SYMBOL(import_iovec); | |
1813 | ||
bc917be8 AV |
1814 | int import_single_range(int rw, void __user *buf, size_t len, |
1815 | struct iovec *iov, struct iov_iter *i) | |
1816 | { | |
1817 | if (len > MAX_RW_COUNT) | |
1818 | len = MAX_RW_COUNT; | |
96d4f267 | 1819 | if (unlikely(!access_ok(buf, len))) |
bc917be8 AV |
1820 | return -EFAULT; |
1821 | ||
1822 | iov->iov_base = buf; | |
1823 | iov->iov_len = len; | |
1824 | iov_iter_init(i, rw, iov, 1, len); | |
1825 | return 0; | |
1826 | } | |
e1267585 | 1827 | EXPORT_SYMBOL(import_single_range); |
09cf698a AV |
1828 | |
1829 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1830 | int (*f)(struct kvec *vec, void *context), | |
1831 | void *context) | |
1832 | { | |
1833 | struct kvec w; | |
1834 | int err = -EINVAL; | |
1835 | if (!bytes) | |
1836 | return 0; | |
1837 | ||
1838 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1839 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1840 | w.iov_len = v.bv_len; | |
1841 | err = f(&w, context); | |
1842 | kunmap(v.bv_page); | |
1843 | err;}), ({ | |
1844 | w = v; | |
1845 | err = f(&w, context);}) | |
1846 | ) | |
1847 | return err; | |
1848 | } | |
1849 | EXPORT_SYMBOL(iov_iter_for_each_range); |