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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 | 594 | static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, |
52cbd23a WB |
595 | struct csum_state *csstate, |
596 | struct iov_iter *i) | |
78e1f386 AV |
597 | { |
598 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 | 599 | unsigned int p_mask = pipe->ring_size - 1; |
52cbd23a WB |
600 | __wsum sum = csstate->csum; |
601 | size_t off = csstate->off; | |
8cefc107 | 602 | unsigned int i_head; |
78e1f386 | 603 | size_t n, r; |
78e1f386 AV |
604 | |
605 | if (!sanity(i)) | |
606 | return 0; | |
607 | ||
8cefc107 | 608 | bytes = n = push_pipe(i, bytes, &i_head, &r); |
78e1f386 AV |
609 | if (unlikely(!n)) |
610 | return 0; | |
8cefc107 | 611 | do { |
78e1f386 | 612 | size_t chunk = min_t(size_t, n, PAGE_SIZE - r); |
8cefc107 | 613 | char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); |
f9152895 | 614 | sum = csum_and_memcpy(p + r, addr, chunk, sum, off); |
78e1f386 | 615 | kunmap_atomic(p); |
8cefc107 | 616 | i->head = i_head; |
78e1f386 AV |
617 | i->iov_offset = r + chunk; |
618 | n -= chunk; | |
619 | off += chunk; | |
620 | addr += chunk; | |
8cefc107 DH |
621 | r = 0; |
622 | i_head++; | |
623 | } while (n); | |
78e1f386 | 624 | i->count -= bytes; |
52cbd23a WB |
625 | csstate->csum = sum; |
626 | csstate->off = off; | |
78e1f386 AV |
627 | return bytes; |
628 | } | |
629 | ||
aa28de27 | 630 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 631 | { |
36f7a8a4 | 632 | const char *from = addr; |
00e23707 | 633 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 634 | return copy_pipe_to_iter(addr, bytes, i); |
09fc68dc AV |
635 | if (iter_is_iovec(i)) |
636 | might_fault(); | |
3d4d3e48 | 637 | iterate_and_advance(i, bytes, v, |
09fc68dc | 638 | copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
3d4d3e48 | 639 | memcpy_to_page(v.bv_page, v.bv_offset, |
a280455f AV |
640 | (from += v.bv_len) - v.bv_len, v.bv_len), |
641 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 642 | ) |
62a8067a | 643 | |
3d4d3e48 | 644 | return bytes; |
c35e0248 | 645 | } |
aa28de27 | 646 | EXPORT_SYMBOL(_copy_to_iter); |
c35e0248 | 647 | |
ec6347bb DW |
648 | #ifdef CONFIG_ARCH_HAS_COPY_MC |
649 | static int copyout_mc(void __user *to, const void *from, size_t n) | |
8780356e | 650 | { |
96d4f267 | 651 | if (access_ok(to, n)) { |
d0ef4c36 | 652 | instrument_copy_to_user(to, from, n); |
ec6347bb | 653 | n = copy_mc_to_user((__force void *) to, from, n); |
8780356e DW |
654 | } |
655 | return n; | |
656 | } | |
657 | ||
ec6347bb | 658 | static unsigned long copy_mc_to_page(struct page *page, size_t offset, |
8780356e DW |
659 | const char *from, size_t len) |
660 | { | |
661 | unsigned long ret; | |
662 | char *to; | |
663 | ||
664 | to = kmap_atomic(page); | |
ec6347bb | 665 | ret = copy_mc_to_kernel(to + offset, from, len); |
8780356e DW |
666 | kunmap_atomic(to); |
667 | ||
668 | return ret; | |
669 | } | |
670 | ||
ec6347bb | 671 | static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes, |
ca146f6f DW |
672 | struct iov_iter *i) |
673 | { | |
674 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
675 | unsigned int p_mask = pipe->ring_size - 1; |
676 | unsigned int i_head; | |
ca146f6f | 677 | size_t n, off, xfer = 0; |
ca146f6f DW |
678 | |
679 | if (!sanity(i)) | |
680 | return 0; | |
681 | ||
8cefc107 | 682 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
ca146f6f DW |
683 | if (unlikely(!n)) |
684 | return 0; | |
8cefc107 | 685 | do { |
ca146f6f DW |
686 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
687 | unsigned long rem; | |
688 | ||
ec6347bb | 689 | rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page, |
8cefc107 DH |
690 | off, addr, chunk); |
691 | i->head = i_head; | |
ca146f6f DW |
692 | i->iov_offset = off + chunk - rem; |
693 | xfer += chunk - rem; | |
694 | if (rem) | |
695 | break; | |
696 | n -= chunk; | |
697 | addr += chunk; | |
8cefc107 DH |
698 | off = 0; |
699 | i_head++; | |
700 | } while (n); | |
ca146f6f DW |
701 | i->count -= xfer; |
702 | return xfer; | |
703 | } | |
704 | ||
bf3eeb9b | 705 | /** |
ec6347bb | 706 | * _copy_mc_to_iter - copy to iter with source memory error exception handling |
bf3eeb9b DW |
707 | * @addr: source kernel address |
708 | * @bytes: total transfer length | |
709 | * @iter: destination iterator | |
710 | * | |
ec6347bb DW |
711 | * The pmem driver deploys this for the dax operation |
712 | * (dax_copy_to_iter()) for dax reads (bypass page-cache and the | |
713 | * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes | |
714 | * successfully copied. | |
bf3eeb9b | 715 | * |
ec6347bb | 716 | * The main differences between this and typical _copy_to_iter(). |
bf3eeb9b DW |
717 | * |
718 | * * Typical tail/residue handling after a fault retries the copy | |
719 | * byte-by-byte until the fault happens again. Re-triggering machine | |
720 | * checks is potentially fatal so the implementation uses source | |
721 | * alignment and poison alignment assumptions to avoid re-triggering | |
722 | * hardware exceptions. | |
723 | * | |
724 | * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. | |
725 | * Compare to copy_to_iter() where only ITER_IOVEC attempts might return | |
726 | * a short copy. | |
bf3eeb9b | 727 | */ |
ec6347bb | 728 | size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
8780356e DW |
729 | { |
730 | const char *from = addr; | |
731 | unsigned long rem, curr_addr, s_addr = (unsigned long) addr; | |
732 | ||
00e23707 | 733 | if (unlikely(iov_iter_is_pipe(i))) |
ec6347bb | 734 | return copy_mc_pipe_to_iter(addr, bytes, i); |
8780356e DW |
735 | if (iter_is_iovec(i)) |
736 | might_fault(); | |
737 | iterate_and_advance(i, bytes, v, | |
ec6347bb DW |
738 | copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len, |
739 | v.iov_len), | |
8780356e | 740 | ({ |
ec6347bb DW |
741 | rem = copy_mc_to_page(v.bv_page, v.bv_offset, |
742 | (from += v.bv_len) - v.bv_len, v.bv_len); | |
8780356e DW |
743 | if (rem) { |
744 | curr_addr = (unsigned long) from; | |
745 | bytes = curr_addr - s_addr - rem; | |
746 | return bytes; | |
747 | } | |
748 | }), | |
749 | ({ | |
ec6347bb DW |
750 | rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len) |
751 | - v.iov_len, v.iov_len); | |
8780356e DW |
752 | if (rem) { |
753 | curr_addr = (unsigned long) from; | |
754 | bytes = curr_addr - s_addr - rem; | |
755 | return bytes; | |
756 | } | |
757 | }) | |
758 | ) | |
759 | ||
760 | return bytes; | |
761 | } | |
ec6347bb DW |
762 | EXPORT_SYMBOL_GPL(_copy_mc_to_iter); |
763 | #endif /* CONFIG_ARCH_HAS_COPY_MC */ | |
8780356e | 764 | |
aa28de27 | 765 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 766 | { |
0dbca9a4 | 767 | char *to = addr; |
00e23707 | 768 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
769 | WARN_ON(1); |
770 | return 0; | |
771 | } | |
09fc68dc AV |
772 | if (iter_is_iovec(i)) |
773 | might_fault(); | |
0dbca9a4 | 774 | iterate_and_advance(i, bytes, v, |
09fc68dc | 775 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4 | 776 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
777 | v.bv_offset, v.bv_len), |
778 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
779 | ) |
780 | ||
781 | return bytes; | |
c35e0248 | 782 | } |
aa28de27 | 783 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 784 | |
aa28de27 | 785 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
786 | { |
787 | char *to = addr; | |
00e23707 | 788 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
789 | WARN_ON(1); |
790 | return false; | |
791 | } | |
33844e66 | 792 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
793 | return false; |
794 | ||
09fc68dc AV |
795 | if (iter_is_iovec(i)) |
796 | might_fault(); | |
cbbd26b8 | 797 | iterate_all_kinds(i, bytes, v, ({ |
09fc68dc | 798 | if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
799 | v.iov_base, v.iov_len)) |
800 | return false; | |
801 | 0;}), | |
802 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
803 | v.bv_offset, v.bv_len), | |
804 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
805 | ) | |
806 | ||
807 | iov_iter_advance(i, bytes); | |
808 | return true; | |
809 | } | |
aa28de27 | 810 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 811 | |
aa28de27 | 812 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
813 | { |
814 | char *to = addr; | |
00e23707 | 815 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
816 | WARN_ON(1); |
817 | return 0; | |
818 | } | |
aa583096 | 819 | iterate_and_advance(i, bytes, v, |
3f763453 | 820 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
821 | v.iov_base, v.iov_len), |
822 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
823 | v.bv_offset, v.bv_len), | |
824 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
825 | ) | |
826 | ||
827 | return bytes; | |
828 | } | |
aa28de27 | 829 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 830 | |
0aed55af | 831 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d DW |
832 | /** |
833 | * _copy_from_iter_flushcache - write destination through cpu cache | |
834 | * @addr: destination kernel address | |
835 | * @bytes: total transfer length | |
836 | * @iter: source iterator | |
837 | * | |
838 | * The pmem driver arranges for filesystem-dax to use this facility via | |
839 | * dax_copy_from_iter() for ensuring that writes to persistent memory | |
840 | * are flushed through the CPU cache. It is differentiated from | |
841 | * _copy_from_iter_nocache() in that guarantees all data is flushed for | |
842 | * all iterator types. The _copy_from_iter_nocache() only attempts to | |
843 | * bypass the cache for the ITER_IOVEC case, and on some archs may use | |
844 | * instructions that strand dirty-data in the cache. | |
845 | */ | |
6a37e940 | 846 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af DW |
847 | { |
848 | char *to = addr; | |
00e23707 | 849 | if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af DW |
850 | WARN_ON(1); |
851 | return 0; | |
852 | } | |
853 | iterate_and_advance(i, bytes, v, | |
854 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
855 | v.iov_base, v.iov_len), | |
856 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
857 | v.bv_offset, v.bv_len), | |
858 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
859 | v.iov_len) | |
860 | ) | |
861 | ||
862 | return bytes; | |
863 | } | |
6a37e940 | 864 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af DW |
865 | #endif |
866 | ||
aa28de27 | 867 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
868 | { |
869 | char *to = addr; | |
00e23707 | 870 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
871 | WARN_ON(1); |
872 | return false; | |
873 | } | |
33844e66 | 874 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
875 | return false; |
876 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 877 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
878 | v.iov_base, v.iov_len)) |
879 | return false; | |
880 | 0;}), | |
881 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
882 | v.bv_offset, v.bv_len), | |
883 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
884 | ) | |
885 | ||
886 | iov_iter_advance(i, bytes); | |
887 | return true; | |
888 | } | |
aa28de27 | 889 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 890 | |
72e809ed AV |
891 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
892 | { | |
6daef95b ED |
893 | struct page *head; |
894 | size_t v = n + offset; | |
895 | ||
896 | /* | |
897 | * The general case needs to access the page order in order | |
898 | * to compute the page size. | |
899 | * However, we mostly deal with order-0 pages and thus can | |
900 | * avoid a possible cache line miss for requests that fit all | |
901 | * page orders. | |
902 | */ | |
903 | if (n <= v && v <= PAGE_SIZE) | |
904 | return true; | |
905 | ||
906 | head = compound_head(page); | |
907 | v += (page - head) << PAGE_SHIFT; | |
a90bcb86 | 908 | |
a50b854e | 909 | if (likely(n <= v && v <= (page_size(head)))) |
72e809ed AV |
910 | return true; |
911 | WARN_ON(1); | |
912 | return false; | |
913 | } | |
cbbd26b8 | 914 | |
62a8067a AV |
915 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
916 | struct iov_iter *i) | |
917 | { | |
72e809ed AV |
918 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
919 | return 0; | |
d271524a AV |
920 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
921 | void *kaddr = kmap_atomic(page); | |
922 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
923 | kunmap_atomic(kaddr); | |
924 | return wanted; | |
9ea9ce04 DH |
925 | } else if (unlikely(iov_iter_is_discard(i))) |
926 | return bytes; | |
927 | else if (likely(!iov_iter_is_pipe(i))) | |
62a8067a | 928 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
929 | else |
930 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
931 | } |
932 | EXPORT_SYMBOL(copy_page_to_iter); | |
933 | ||
934 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
935 | struct iov_iter *i) | |
936 | { | |
72e809ed AV |
937 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
938 | return 0; | |
9ea9ce04 | 939 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
940 | WARN_ON(1); |
941 | return 0; | |
942 | } | |
a280455f | 943 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 944 | void *kaddr = kmap_atomic(page); |
aa28de27 | 945 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
946 | kunmap_atomic(kaddr); |
947 | return wanted; | |
948 | } else | |
62a8067a AV |
949 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
950 | } | |
951 | EXPORT_SYMBOL(copy_page_from_iter); | |
952 | ||
241699cd AV |
953 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
954 | { | |
955 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
956 | unsigned int p_mask = pipe->ring_size - 1; |
957 | unsigned int i_head; | |
241699cd | 958 | size_t n, off; |
241699cd AV |
959 | |
960 | if (!sanity(i)) | |
961 | return 0; | |
962 | ||
8cefc107 | 963 | bytes = n = push_pipe(i, bytes, &i_head, &off); |
241699cd AV |
964 | if (unlikely(!n)) |
965 | return 0; | |
966 | ||
8cefc107 | 967 | do { |
241699cd | 968 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); |
8cefc107 DH |
969 | memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); |
970 | i->head = i_head; | |
241699cd AV |
971 | i->iov_offset = off + chunk; |
972 | n -= chunk; | |
8cefc107 DH |
973 | off = 0; |
974 | i_head++; | |
975 | } while (n); | |
241699cd AV |
976 | i->count -= bytes; |
977 | return bytes; | |
978 | } | |
979 | ||
c35e0248 MW |
980 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
981 | { | |
00e23707 | 982 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 983 | return pipe_zero(bytes, i); |
8442fa46 | 984 | iterate_and_advance(i, bytes, v, |
09fc68dc | 985 | clear_user(v.iov_base, v.iov_len), |
a280455f AV |
986 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
987 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
988 | ) |
989 | ||
990 | return bytes; | |
c35e0248 MW |
991 | } |
992 | EXPORT_SYMBOL(iov_iter_zero); | |
993 | ||
62a8067a AV |
994 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
995 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
996 | { | |
04a31165 | 997 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
998 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
999 | kunmap_atomic(kaddr); | |
1000 | return 0; | |
1001 | } | |
9ea9ce04 | 1002 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1003 | kunmap_atomic(kaddr); |
1004 | WARN_ON(1); | |
1005 | return 0; | |
1006 | } | |
04a31165 | 1007 | iterate_all_kinds(i, bytes, v, |
09fc68dc | 1008 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a31165 | 1009 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
1010 | v.bv_offset, v.bv_len), |
1011 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
1012 | ) |
1013 | kunmap_atomic(kaddr); | |
1014 | return bytes; | |
62a8067a AV |
1015 | } |
1016 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
1017 | ||
b9dc6f65 AV |
1018 | static inline void pipe_truncate(struct iov_iter *i) |
1019 | { | |
1020 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1021 | unsigned int p_tail = pipe->tail; |
1022 | unsigned int p_head = pipe->head; | |
1023 | unsigned int p_mask = pipe->ring_size - 1; | |
1024 | ||
1025 | if (!pipe_empty(p_head, p_tail)) { | |
1026 | struct pipe_buffer *buf; | |
1027 | unsigned int i_head = i->head; | |
b9dc6f65 | 1028 | size_t off = i->iov_offset; |
8cefc107 | 1029 | |
b9dc6f65 | 1030 | if (off) { |
8cefc107 DH |
1031 | buf = &pipe->bufs[i_head & p_mask]; |
1032 | buf->len = off - buf->offset; | |
1033 | i_head++; | |
b9dc6f65 | 1034 | } |
8cefc107 DH |
1035 | while (p_head != i_head) { |
1036 | p_head--; | |
1037 | pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); | |
b9dc6f65 | 1038 | } |
8cefc107 DH |
1039 | |
1040 | pipe->head = p_head; | |
b9dc6f65 AV |
1041 | } |
1042 | } | |
1043 | ||
241699cd AV |
1044 | static void pipe_advance(struct iov_iter *i, size_t size) |
1045 | { | |
1046 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
1047 | if (unlikely(i->count < size)) |
1048 | size = i->count; | |
241699cd | 1049 | if (size) { |
b9dc6f65 | 1050 | struct pipe_buffer *buf; |
8cefc107 DH |
1051 | unsigned int p_mask = pipe->ring_size - 1; |
1052 | unsigned int i_head = i->head; | |
b9dc6f65 | 1053 | size_t off = i->iov_offset, left = size; |
8cefc107 | 1054 | |
241699cd | 1055 | if (off) /* make it relative to the beginning of buffer */ |
8cefc107 | 1056 | left += off - pipe->bufs[i_head & p_mask].offset; |
241699cd | 1057 | while (1) { |
8cefc107 | 1058 | buf = &pipe->bufs[i_head & p_mask]; |
b9dc6f65 | 1059 | if (left <= buf->len) |
241699cd | 1060 | break; |
b9dc6f65 | 1061 | left -= buf->len; |
8cefc107 | 1062 | i_head++; |
241699cd | 1063 | } |
8cefc107 | 1064 | i->head = i_head; |
b9dc6f65 | 1065 | i->iov_offset = buf->offset + left; |
241699cd | 1066 | } |
b9dc6f65 AV |
1067 | i->count -= size; |
1068 | /* ... and discard everything past that point */ | |
1069 | pipe_truncate(i); | |
241699cd AV |
1070 | } |
1071 | ||
62a8067a AV |
1072 | void iov_iter_advance(struct iov_iter *i, size_t size) |
1073 | { | |
00e23707 | 1074 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1075 | pipe_advance(i, size); |
1076 | return; | |
1077 | } | |
9ea9ce04 DH |
1078 | if (unlikely(iov_iter_is_discard(i))) { |
1079 | i->count -= size; | |
1080 | return; | |
1081 | } | |
a280455f | 1082 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
1083 | } |
1084 | EXPORT_SYMBOL(iov_iter_advance); | |
1085 | ||
27c0e374 AV |
1086 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
1087 | { | |
1088 | if (!unroll) | |
1089 | return; | |
5b47d59a AV |
1090 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
1091 | return; | |
27c0e374 | 1092 | i->count += unroll; |
00e23707 | 1093 | if (unlikely(iov_iter_is_pipe(i))) { |
27c0e374 | 1094 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 DH |
1095 | unsigned int p_mask = pipe->ring_size - 1; |
1096 | unsigned int i_head = i->head; | |
27c0e374 AV |
1097 | size_t off = i->iov_offset; |
1098 | while (1) { | |
8cefc107 DH |
1099 | struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; |
1100 | size_t n = off - b->offset; | |
27c0e374 | 1101 | if (unroll < n) { |
4fa55cef | 1102 | off -= unroll; |
27c0e374 AV |
1103 | break; |
1104 | } | |
1105 | unroll -= n; | |
8cefc107 | 1106 | if (!unroll && i_head == i->start_head) { |
27c0e374 AV |
1107 | off = 0; |
1108 | break; | |
1109 | } | |
8cefc107 DH |
1110 | i_head--; |
1111 | b = &pipe->bufs[i_head & p_mask]; | |
1112 | off = b->offset + b->len; | |
27c0e374 AV |
1113 | } |
1114 | i->iov_offset = off; | |
8cefc107 | 1115 | i->head = i_head; |
27c0e374 AV |
1116 | pipe_truncate(i); |
1117 | return; | |
1118 | } | |
9ea9ce04 DH |
1119 | if (unlikely(iov_iter_is_discard(i))) |
1120 | return; | |
27c0e374 AV |
1121 | if (unroll <= i->iov_offset) { |
1122 | i->iov_offset -= unroll; | |
1123 | return; | |
1124 | } | |
1125 | unroll -= i->iov_offset; | |
00e23707 | 1126 | if (iov_iter_is_bvec(i)) { |
27c0e374 AV |
1127 | const struct bio_vec *bvec = i->bvec; |
1128 | while (1) { | |
1129 | size_t n = (--bvec)->bv_len; | |
1130 | i->nr_segs++; | |
1131 | if (unroll <= n) { | |
1132 | i->bvec = bvec; | |
1133 | i->iov_offset = n - unroll; | |
1134 | return; | |
1135 | } | |
1136 | unroll -= n; | |
1137 | } | |
1138 | } else { /* same logics for iovec and kvec */ | |
1139 | const struct iovec *iov = i->iov; | |
1140 | while (1) { | |
1141 | size_t n = (--iov)->iov_len; | |
1142 | i->nr_segs++; | |
1143 | if (unroll <= n) { | |
1144 | i->iov = iov; | |
1145 | i->iov_offset = n - unroll; | |
1146 | return; | |
1147 | } | |
1148 | unroll -= n; | |
1149 | } | |
1150 | } | |
1151 | } | |
1152 | EXPORT_SYMBOL(iov_iter_revert); | |
1153 | ||
62a8067a AV |
1154 | /* |
1155 | * Return the count of just the current iov_iter segment. | |
1156 | */ | |
1157 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
1158 | { | |
00e23707 | 1159 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1160 | return i->count; // it is a silly place, anyway |
62a8067a AV |
1161 | if (i->nr_segs == 1) |
1162 | return i->count; | |
9ea9ce04 DH |
1163 | if (unlikely(iov_iter_is_discard(i))) |
1164 | return i->count; | |
00e23707 | 1165 | else if (iov_iter_is_bvec(i)) |
62a8067a | 1166 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
1167 | else |
1168 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
1169 | } |
1170 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
1171 | ||
aa563d7b | 1172 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77 | 1173 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
1174 | size_t count) |
1175 | { | |
aa563d7b DH |
1176 | WARN_ON(direction & ~(READ | WRITE)); |
1177 | i->type = ITER_KVEC | (direction & (READ | WRITE)); | |
05afcb77 | 1178 | i->kvec = kvec; |
abb78f87 AV |
1179 | i->nr_segs = nr_segs; |
1180 | i->iov_offset = 0; | |
1181 | i->count = count; | |
1182 | } | |
1183 | EXPORT_SYMBOL(iov_iter_kvec); | |
1184 | ||
aa563d7b | 1185 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77 AV |
1186 | const struct bio_vec *bvec, unsigned long nr_segs, |
1187 | size_t count) | |
1188 | { | |
aa563d7b DH |
1189 | WARN_ON(direction & ~(READ | WRITE)); |
1190 | i->type = ITER_BVEC | (direction & (READ | WRITE)); | |
05afcb77 AV |
1191 | i->bvec = bvec; |
1192 | i->nr_segs = nr_segs; | |
1193 | i->iov_offset = 0; | |
1194 | i->count = count; | |
1195 | } | |
1196 | EXPORT_SYMBOL(iov_iter_bvec); | |
1197 | ||
aa563d7b | 1198 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd AV |
1199 | struct pipe_inode_info *pipe, |
1200 | size_t count) | |
1201 | { | |
aa563d7b | 1202 | BUG_ON(direction != READ); |
8cefc107 | 1203 | WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); |
aa563d7b | 1204 | i->type = ITER_PIPE | READ; |
241699cd | 1205 | i->pipe = pipe; |
8cefc107 | 1206 | i->head = pipe->head; |
241699cd AV |
1207 | i->iov_offset = 0; |
1208 | i->count = count; | |
8cefc107 | 1209 | i->start_head = i->head; |
241699cd AV |
1210 | } |
1211 | EXPORT_SYMBOL(iov_iter_pipe); | |
1212 | ||
9ea9ce04 DH |
1213 | /** |
1214 | * iov_iter_discard - Initialise an I/O iterator that discards data | |
1215 | * @i: The iterator to initialise. | |
1216 | * @direction: The direction of the transfer. | |
1217 | * @count: The size of the I/O buffer in bytes. | |
1218 | * | |
1219 | * Set up an I/O iterator that just discards everything that's written to it. | |
1220 | * It's only available as a READ iterator. | |
1221 | */ | |
1222 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) | |
1223 | { | |
1224 | BUG_ON(direction != READ); | |
1225 | i->type = ITER_DISCARD | READ; | |
1226 | i->count = count; | |
1227 | i->iov_offset = 0; | |
1228 | } | |
1229 | EXPORT_SYMBOL(iov_iter_discard); | |
1230 | ||
62a8067a AV |
1231 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
1232 | { | |
04a31165 AV |
1233 | unsigned long res = 0; |
1234 | size_t size = i->count; | |
1235 | ||
00e23707 | 1236 | if (unlikely(iov_iter_is_pipe(i))) { |
e0ff126e JK |
1237 | unsigned int p_mask = i->pipe->ring_size - 1; |
1238 | ||
8cefc107 | 1239 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) |
241699cd AV |
1240 | return size | i->iov_offset; |
1241 | return size; | |
1242 | } | |
04a31165 AV |
1243 | iterate_all_kinds(i, size, v, |
1244 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
1245 | res |= v.bv_offset | v.bv_len, |
1246 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
1247 | ) |
1248 | return res; | |
62a8067a AV |
1249 | } |
1250 | EXPORT_SYMBOL(iov_iter_alignment); | |
1251 | ||
357f435d AV |
1252 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
1253 | { | |
33844e66 | 1254 | unsigned long res = 0; |
357f435d | 1255 | size_t size = i->count; |
357f435d | 1256 | |
9ea9ce04 | 1257 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1258 | WARN_ON(1); |
1259 | return ~0U; | |
1260 | } | |
1261 | ||
357f435d AV |
1262 | iterate_all_kinds(i, size, v, |
1263 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1264 | (size != v.iov_len ? size : 0), 0), | |
1265 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1266 | (size != v.bv_len ? size : 0)), | |
1267 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1268 | (size != v.iov_len ? size : 0)) | |
1269 | ); | |
33844e66 | 1270 | return res; |
357f435d AV |
1271 | } |
1272 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1273 | ||
e76b6312 | 1274 | static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd AV |
1275 | size_t maxsize, |
1276 | struct page **pages, | |
8cefc107 | 1277 | int iter_head, |
241699cd AV |
1278 | size_t *start) |
1279 | { | |
1280 | struct pipe_inode_info *pipe = i->pipe; | |
8cefc107 DH |
1281 | unsigned int p_mask = pipe->ring_size - 1; |
1282 | ssize_t n = push_pipe(i, maxsize, &iter_head, start); | |
241699cd AV |
1283 | if (!n) |
1284 | return -EFAULT; | |
1285 | ||
1286 | maxsize = n; | |
1287 | n += *start; | |
1689c73a | 1288 | while (n > 0) { |
8cefc107 DH |
1289 | get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); |
1290 | iter_head++; | |
241699cd AV |
1291 | n -= PAGE_SIZE; |
1292 | } | |
1293 | ||
1294 | return maxsize; | |
1295 | } | |
1296 | ||
1297 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1298 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1299 | size_t *start) | |
1300 | { | |
8cefc107 | 1301 | unsigned int iter_head, npages; |
241699cd | 1302 | size_t capacity; |
241699cd | 1303 | |
33844e66 AV |
1304 | if (!maxsize) |
1305 | return 0; | |
1306 | ||
241699cd AV |
1307 | if (!sanity(i)) |
1308 | return -EFAULT; | |
1309 | ||
8cefc107 DH |
1310 | data_start(i, &iter_head, start); |
1311 | /* Amount of free space: some of this one + all after this one */ | |
1312 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
1313 | capacity = min(npages, maxpages) * PAGE_SIZE - *start; | |
241699cd | 1314 | |
8cefc107 | 1315 | return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); |
241699cd AV |
1316 | } |
1317 | ||
62a8067a | 1318 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1319 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1320 | size_t *start) |
1321 | { | |
e5393fae AV |
1322 | if (maxsize > i->count) |
1323 | maxsize = i->count; | |
1324 | ||
00e23707 | 1325 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1326 | return pipe_get_pages(i, pages, maxsize, maxpages, start); |
9ea9ce04 DH |
1327 | if (unlikely(iov_iter_is_discard(i))) |
1328 | return -EFAULT; | |
1329 | ||
e5393fae AV |
1330 | iterate_all_kinds(i, maxsize, v, ({ |
1331 | unsigned long addr = (unsigned long)v.iov_base; | |
1332 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1333 | int n; | |
1334 | int res; | |
1335 | ||
1336 | if (len > maxpages * PAGE_SIZE) | |
1337 | len = maxpages * PAGE_SIZE; | |
1338 | addr &= ~(PAGE_SIZE - 1); | |
1339 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
73b0140b IW |
1340 | res = get_user_pages_fast(addr, n, |
1341 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, | |
1342 | pages); | |
e5393fae AV |
1343 | if (unlikely(res < 0)) |
1344 | return res; | |
1345 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1346 | 0;}),({ | |
1347 | /* can't be more than PAGE_SIZE */ | |
1348 | *start = v.bv_offset; | |
1349 | get_page(*pages = v.bv_page); | |
1350 | return v.bv_len; | |
a280455f AV |
1351 | }),({ |
1352 | return -EFAULT; | |
e5393fae AV |
1353 | }) |
1354 | ) | |
1355 | return 0; | |
62a8067a AV |
1356 | } |
1357 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1358 | ||
1b17f1f2 AV |
1359 | static struct page **get_pages_array(size_t n) |
1360 | { | |
752ade68 | 1361 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1362 | } |
1363 | ||
241699cd AV |
1364 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1365 | struct page ***pages, size_t maxsize, | |
1366 | size_t *start) | |
1367 | { | |
1368 | struct page **p; | |
8cefc107 | 1369 | unsigned int iter_head, npages; |
d7760d63 | 1370 | ssize_t n; |
241699cd | 1371 | |
33844e66 AV |
1372 | if (!maxsize) |
1373 | return 0; | |
1374 | ||
241699cd AV |
1375 | if (!sanity(i)) |
1376 | return -EFAULT; | |
1377 | ||
8cefc107 DH |
1378 | data_start(i, &iter_head, start); |
1379 | /* Amount of free space: some of this one + all after this one */ | |
1380 | npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); | |
241699cd AV |
1381 | n = npages * PAGE_SIZE - *start; |
1382 | if (maxsize > n) | |
1383 | maxsize = n; | |
1384 | else | |
1385 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1386 | p = get_pages_array(npages); | |
1387 | if (!p) | |
1388 | return -ENOMEM; | |
8cefc107 | 1389 | n = __pipe_get_pages(i, maxsize, p, iter_head, start); |
241699cd AV |
1390 | if (n > 0) |
1391 | *pages = p; | |
1392 | else | |
1393 | kvfree(p); | |
1394 | return n; | |
1395 | } | |
1396 | ||
62a8067a AV |
1397 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1398 | struct page ***pages, size_t maxsize, | |
1399 | size_t *start) | |
1400 | { | |
1b17f1f2 AV |
1401 | struct page **p; |
1402 | ||
1403 | if (maxsize > i->count) | |
1404 | maxsize = i->count; | |
1405 | ||
00e23707 | 1406 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1407 | return pipe_get_pages_alloc(i, pages, maxsize, start); |
9ea9ce04 DH |
1408 | if (unlikely(iov_iter_is_discard(i))) |
1409 | return -EFAULT; | |
1410 | ||
1b17f1f2 AV |
1411 | iterate_all_kinds(i, maxsize, v, ({ |
1412 | unsigned long addr = (unsigned long)v.iov_base; | |
1413 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1414 | int n; | |
1415 | int res; | |
1416 | ||
1417 | addr &= ~(PAGE_SIZE - 1); | |
1418 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1419 | p = get_pages_array(n); | |
1420 | if (!p) | |
1421 | return -ENOMEM; | |
73b0140b IW |
1422 | res = get_user_pages_fast(addr, n, |
1423 | iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); | |
1b17f1f2 AV |
1424 | if (unlikely(res < 0)) { |
1425 | kvfree(p); | |
1426 | return res; | |
1427 | } | |
1428 | *pages = p; | |
1429 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1430 | 0;}),({ | |
1431 | /* can't be more than PAGE_SIZE */ | |
1432 | *start = v.bv_offset; | |
1433 | *pages = p = get_pages_array(1); | |
1434 | if (!p) | |
1435 | return -ENOMEM; | |
1436 | get_page(*p = v.bv_page); | |
1437 | return v.bv_len; | |
a280455f AV |
1438 | }),({ |
1439 | return -EFAULT; | |
1b17f1f2 AV |
1440 | }) |
1441 | ) | |
1442 | return 0; | |
62a8067a AV |
1443 | } |
1444 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1445 | ||
a604ec7e AV |
1446 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1447 | struct iov_iter *i) | |
1448 | { | |
1449 | char *to = addr; | |
1450 | __wsum sum, next; | |
1451 | size_t off = 0; | |
a604ec7e | 1452 | sum = *csum; |
9ea9ce04 | 1453 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
241699cd AV |
1454 | WARN_ON(1); |
1455 | return 0; | |
1456 | } | |
a604ec7e | 1457 | iterate_and_advance(i, bytes, v, ({ |
cbbd26b8 | 1458 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e | 1459 | (to += v.iov_len) - v.iov_len, |
c693cc46 AV |
1460 | v.iov_len); |
1461 | if (next) { | |
a604ec7e AV |
1462 | sum = csum_block_add(sum, next, off); |
1463 | off += v.iov_len; | |
1464 | } | |
c693cc46 | 1465 | next ? 0 : v.iov_len; |
a604ec7e AV |
1466 | }), ({ |
1467 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1468 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1469 | p + v.bv_offset, v.bv_len, | |
1470 | sum, off); | |
a604ec7e | 1471 | kunmap_atomic(p); |
a604ec7e AV |
1472 | off += v.bv_len; |
1473 | }),({ | |
f9152895 AV |
1474 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1475 | v.iov_base, v.iov_len, | |
1476 | sum, off); | |
a604ec7e AV |
1477 | off += v.iov_len; |
1478 | }) | |
1479 | ) | |
1480 | *csum = sum; | |
1481 | return bytes; | |
1482 | } | |
1483 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1484 | ||
cbbd26b8 AV |
1485 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
1486 | struct iov_iter *i) | |
1487 | { | |
1488 | char *to = addr; | |
1489 | __wsum sum, next; | |
1490 | size_t off = 0; | |
1491 | sum = *csum; | |
9ea9ce04 | 1492 | if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { |
cbbd26b8 AV |
1493 | WARN_ON(1); |
1494 | return false; | |
1495 | } | |
1496 | if (unlikely(i->count < bytes)) | |
1497 | return false; | |
1498 | iterate_all_kinds(i, bytes, v, ({ | |
cbbd26b8 AV |
1499 | next = csum_and_copy_from_user(v.iov_base, |
1500 | (to += v.iov_len) - v.iov_len, | |
c693cc46 AV |
1501 | v.iov_len); |
1502 | if (!next) | |
cbbd26b8 AV |
1503 | return false; |
1504 | sum = csum_block_add(sum, next, off); | |
1505 | off += v.iov_len; | |
1506 | 0; | |
1507 | }), ({ | |
1508 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1509 | sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, |
1510 | p + v.bv_offset, v.bv_len, | |
1511 | sum, off); | |
cbbd26b8 | 1512 | kunmap_atomic(p); |
cbbd26b8 AV |
1513 | off += v.bv_len; |
1514 | }),({ | |
f9152895 AV |
1515 | sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, |
1516 | v.iov_base, v.iov_len, | |
1517 | sum, off); | |
cbbd26b8 AV |
1518 | off += v.iov_len; |
1519 | }) | |
1520 | ) | |
1521 | *csum = sum; | |
1522 | iov_iter_advance(i, bytes); | |
1523 | return true; | |
1524 | } | |
1525 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1526 | ||
52cbd23a | 1527 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, |
a604ec7e AV |
1528 | struct iov_iter *i) |
1529 | { | |
52cbd23a | 1530 | struct csum_state *csstate = _csstate; |
36f7a8a4 | 1531 | const char *from = addr; |
a604ec7e | 1532 | __wsum sum, next; |
52cbd23a | 1533 | size_t off; |
78e1f386 AV |
1534 | |
1535 | if (unlikely(iov_iter_is_pipe(i))) | |
52cbd23a | 1536 | return csum_and_copy_to_pipe_iter(addr, bytes, _csstate, i); |
78e1f386 | 1537 | |
52cbd23a WB |
1538 | sum = csstate->csum; |
1539 | off = csstate->off; | |
78e1f386 | 1540 | if (unlikely(iov_iter_is_discard(i))) { |
241699cd AV |
1541 | WARN_ON(1); /* for now */ |
1542 | return 0; | |
1543 | } | |
a604ec7e | 1544 | iterate_and_advance(i, bytes, v, ({ |
a604ec7e | 1545 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, |
cbbd26b8 | 1546 | v.iov_base, |
c693cc46 AV |
1547 | v.iov_len); |
1548 | if (next) { | |
a604ec7e AV |
1549 | sum = csum_block_add(sum, next, off); |
1550 | off += v.iov_len; | |
1551 | } | |
c693cc46 | 1552 | next ? 0 : v.iov_len; |
a604ec7e AV |
1553 | }), ({ |
1554 | char *p = kmap_atomic(v.bv_page); | |
f9152895 AV |
1555 | sum = csum_and_memcpy(p + v.bv_offset, |
1556 | (from += v.bv_len) - v.bv_len, | |
1557 | v.bv_len, sum, off); | |
a604ec7e | 1558 | kunmap_atomic(p); |
a604ec7e AV |
1559 | off += v.bv_len; |
1560 | }),({ | |
f9152895 AV |
1561 | sum = csum_and_memcpy(v.iov_base, |
1562 | (from += v.iov_len) - v.iov_len, | |
1563 | v.iov_len, sum, off); | |
a604ec7e AV |
1564 | off += v.iov_len; |
1565 | }) | |
1566 | ) | |
52cbd23a WB |
1567 | csstate->csum = sum; |
1568 | csstate->off = off; | |
a604ec7e AV |
1569 | return bytes; |
1570 | } | |
1571 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1572 | ||
d05f4435 SG |
1573 | size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
1574 | struct iov_iter *i) | |
1575 | { | |
7999096f | 1576 | #ifdef CONFIG_CRYPTO_HASH |
d05f4435 SG |
1577 | struct ahash_request *hash = hashp; |
1578 | struct scatterlist sg; | |
1579 | size_t copied; | |
1580 | ||
1581 | copied = copy_to_iter(addr, bytes, i); | |
1582 | sg_init_one(&sg, addr, copied); | |
1583 | ahash_request_set_crypt(hash, &sg, NULL, copied); | |
1584 | crypto_ahash_update(hash); | |
1585 | return copied; | |
27fad74a Y |
1586 | #else |
1587 | return 0; | |
1588 | #endif | |
d05f4435 SG |
1589 | } |
1590 | EXPORT_SYMBOL(hash_and_copy_to_iter); | |
1591 | ||
62a8067a AV |
1592 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1593 | { | |
e0f2dc40 AV |
1594 | size_t size = i->count; |
1595 | int npages = 0; | |
1596 | ||
1597 | if (!size) | |
1598 | return 0; | |
9ea9ce04 DH |
1599 | if (unlikely(iov_iter_is_discard(i))) |
1600 | return 0; | |
e0f2dc40 | 1601 | |
00e23707 | 1602 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd | 1603 | struct pipe_inode_info *pipe = i->pipe; |
8cefc107 | 1604 | unsigned int iter_head; |
241699cd | 1605 | size_t off; |
241699cd AV |
1606 | |
1607 | if (!sanity(i)) | |
1608 | return 0; | |
1609 | ||
8cefc107 | 1610 | data_start(i, &iter_head, &off); |
241699cd | 1611 | /* some of this one + all after this one */ |
8cefc107 | 1612 | npages = pipe_space_for_user(iter_head, pipe->tail, pipe); |
241699cd AV |
1613 | if (npages >= maxpages) |
1614 | return maxpages; | |
1615 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1616 | unsigned long p = (unsigned long)v.iov_base; |
1617 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1618 | - p / PAGE_SIZE; | |
1619 | if (npages >= maxpages) | |
1620 | return maxpages; | |
1621 | 0;}),({ | |
1622 | npages++; | |
1623 | if (npages >= maxpages) | |
1624 | return maxpages; | |
a280455f AV |
1625 | }),({ |
1626 | unsigned long p = (unsigned long)v.iov_base; | |
1627 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1628 | - p / PAGE_SIZE; | |
1629 | if (npages >= maxpages) | |
1630 | return maxpages; | |
e0f2dc40 AV |
1631 | }) |
1632 | ) | |
1633 | return npages; | |
62a8067a | 1634 | } |
f67da30c | 1635 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1636 | |
1637 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1638 | { | |
1639 | *new = *old; | |
00e23707 | 1640 | if (unlikely(iov_iter_is_pipe(new))) { |
241699cd AV |
1641 | WARN_ON(1); |
1642 | return NULL; | |
1643 | } | |
9ea9ce04 DH |
1644 | if (unlikely(iov_iter_is_discard(new))) |
1645 | return NULL; | |
00e23707 | 1646 | if (iov_iter_is_bvec(new)) |
4b8164b9 AV |
1647 | return new->bvec = kmemdup(new->bvec, |
1648 | new->nr_segs * sizeof(struct bio_vec), | |
1649 | flags); | |
1650 | else | |
1651 | /* iovec and kvec have identical layout */ | |
1652 | return new->iov = kmemdup(new->iov, | |
1653 | new->nr_segs * sizeof(struct iovec), | |
1654 | flags); | |
1655 | } | |
1656 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1657 | |
bfdc5970 CH |
1658 | static int copy_compat_iovec_from_user(struct iovec *iov, |
1659 | const struct iovec __user *uvec, unsigned long nr_segs) | |
1660 | { | |
1661 | const struct compat_iovec __user *uiov = | |
1662 | (const struct compat_iovec __user *)uvec; | |
1663 | int ret = -EFAULT, i; | |
1664 | ||
a959a978 | 1665 | if (!user_access_begin(uiov, nr_segs * sizeof(*uiov))) |
bfdc5970 CH |
1666 | return -EFAULT; |
1667 | ||
1668 | for (i = 0; i < nr_segs; i++) { | |
1669 | compat_uptr_t buf; | |
1670 | compat_ssize_t len; | |
1671 | ||
1672 | unsafe_get_user(len, &uiov[i].iov_len, uaccess_end); | |
1673 | unsafe_get_user(buf, &uiov[i].iov_base, uaccess_end); | |
1674 | ||
1675 | /* check for compat_size_t not fitting in compat_ssize_t .. */ | |
1676 | if (len < 0) { | |
1677 | ret = -EINVAL; | |
1678 | goto uaccess_end; | |
1679 | } | |
1680 | iov[i].iov_base = compat_ptr(buf); | |
1681 | iov[i].iov_len = len; | |
1682 | } | |
1683 | ||
1684 | ret = 0; | |
1685 | uaccess_end: | |
1686 | user_access_end(); | |
1687 | return ret; | |
1688 | } | |
1689 | ||
1690 | static int copy_iovec_from_user(struct iovec *iov, | |
1691 | const struct iovec __user *uvec, unsigned long nr_segs) | |
fb041b59 DL |
1692 | { |
1693 | unsigned long seg; | |
fb041b59 | 1694 | |
bfdc5970 CH |
1695 | if (copy_from_user(iov, uvec, nr_segs * sizeof(*uvec))) |
1696 | return -EFAULT; | |
1697 | for (seg = 0; seg < nr_segs; seg++) { | |
1698 | if ((ssize_t)iov[seg].iov_len < 0) | |
1699 | return -EINVAL; | |
fb041b59 DL |
1700 | } |
1701 | ||
bfdc5970 CH |
1702 | return 0; |
1703 | } | |
1704 | ||
1705 | struct iovec *iovec_from_user(const struct iovec __user *uvec, | |
1706 | unsigned long nr_segs, unsigned long fast_segs, | |
1707 | struct iovec *fast_iov, bool compat) | |
1708 | { | |
1709 | struct iovec *iov = fast_iov; | |
1710 | int ret; | |
1711 | ||
fb041b59 | 1712 | /* |
bfdc5970 CH |
1713 | * SuS says "The readv() function *may* fail if the iovcnt argument was |
1714 | * less than or equal to 0, or greater than {IOV_MAX}. Linux has | |
1715 | * traditionally returned zero for zero segments, so... | |
fb041b59 | 1716 | */ |
bfdc5970 CH |
1717 | if (nr_segs == 0) |
1718 | return iov; | |
1719 | if (nr_segs > UIO_MAXIOV) | |
1720 | return ERR_PTR(-EINVAL); | |
fb041b59 DL |
1721 | if (nr_segs > fast_segs) { |
1722 | iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); | |
bfdc5970 CH |
1723 | if (!iov) |
1724 | return ERR_PTR(-ENOMEM); | |
fb041b59 | 1725 | } |
bfdc5970 CH |
1726 | |
1727 | if (compat) | |
1728 | ret = copy_compat_iovec_from_user(iov, uvec, nr_segs); | |
1729 | else | |
1730 | ret = copy_iovec_from_user(iov, uvec, nr_segs); | |
1731 | if (ret) { | |
1732 | if (iov != fast_iov) | |
1733 | kfree(iov); | |
1734 | return ERR_PTR(ret); | |
1735 | } | |
1736 | ||
1737 | return iov; | |
1738 | } | |
1739 | ||
1740 | ssize_t __import_iovec(int type, const struct iovec __user *uvec, | |
1741 | unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, | |
1742 | struct iov_iter *i, bool compat) | |
1743 | { | |
1744 | ssize_t total_len = 0; | |
1745 | unsigned long seg; | |
1746 | struct iovec *iov; | |
1747 | ||
1748 | iov = iovec_from_user(uvec, nr_segs, fast_segs, *iovp, compat); | |
1749 | if (IS_ERR(iov)) { | |
1750 | *iovp = NULL; | |
1751 | return PTR_ERR(iov); | |
fb041b59 DL |
1752 | } |
1753 | ||
1754 | /* | |
bfdc5970 CH |
1755 | * According to the Single Unix Specification we should return EINVAL if |
1756 | * an element length is < 0 when cast to ssize_t or if the total length | |
1757 | * would overflow the ssize_t return value of the system call. | |
fb041b59 DL |
1758 | * |
1759 | * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the | |
1760 | * overflow case. | |
1761 | */ | |
fb041b59 | 1762 | for (seg = 0; seg < nr_segs; seg++) { |
fb041b59 DL |
1763 | ssize_t len = (ssize_t)iov[seg].iov_len; |
1764 | ||
bfdc5970 CH |
1765 | if (!access_ok(iov[seg].iov_base, len)) { |
1766 | if (iov != *iovp) | |
1767 | kfree(iov); | |
1768 | *iovp = NULL; | |
1769 | return -EFAULT; | |
fb041b59 | 1770 | } |
bfdc5970 CH |
1771 | |
1772 | if (len > MAX_RW_COUNT - total_len) { | |
1773 | len = MAX_RW_COUNT - total_len; | |
fb041b59 DL |
1774 | iov[seg].iov_len = len; |
1775 | } | |
bfdc5970 | 1776 | total_len += len; |
fb041b59 | 1777 | } |
bfdc5970 CH |
1778 | |
1779 | iov_iter_init(i, type, iov, nr_segs, total_len); | |
1780 | if (iov == *iovp) | |
1781 | *iovp = NULL; | |
1782 | else | |
1783 | *iovp = iov; | |
1784 | return total_len; | |
fb041b59 DL |
1785 | } |
1786 | ||
ffecee4f VN |
1787 | /** |
1788 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1789 | * into the kernel, check that it is valid, and initialize a new | |
1790 | * &struct iov_iter iterator to access it. | |
1791 | * | |
1792 | * @type: One of %READ or %WRITE. | |
bfdc5970 | 1793 | * @uvec: Pointer to the userspace array. |
ffecee4f VN |
1794 | * @nr_segs: Number of elements in userspace array. |
1795 | * @fast_segs: Number of elements in @iov. | |
bfdc5970 | 1796 | * @iovp: (input and output parameter) Pointer to pointer to (usually small |
ffecee4f VN |
1797 | * on-stack) kernel array. |
1798 | * @i: Pointer to iterator that will be initialized on success. | |
1799 | * | |
1800 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1801 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1802 | * array will be allocated and the result placed in *@iov. This means that | |
1803 | * the caller may call kfree() on *@iov regardless of whether the small | |
1804 | * on-stack array was used or not (and regardless of whether this function | |
1805 | * returns an error or not). | |
1806 | * | |
87e5e6da | 1807 | * Return: Negative error code on error, bytes imported on success |
ffecee4f | 1808 | */ |
bfdc5970 | 1809 | ssize_t import_iovec(int type, const struct iovec __user *uvec, |
bc917be8 | 1810 | unsigned nr_segs, unsigned fast_segs, |
bfdc5970 | 1811 | struct iovec **iovp, struct iov_iter *i) |
bc917be8 | 1812 | { |
89cd35c5 CH |
1813 | return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i, |
1814 | in_compat_syscall()); | |
bc917be8 AV |
1815 | } |
1816 | EXPORT_SYMBOL(import_iovec); | |
1817 | ||
bc917be8 AV |
1818 | int import_single_range(int rw, void __user *buf, size_t len, |
1819 | struct iovec *iov, struct iov_iter *i) | |
1820 | { | |
1821 | if (len > MAX_RW_COUNT) | |
1822 | len = MAX_RW_COUNT; | |
96d4f267 | 1823 | if (unlikely(!access_ok(buf, len))) |
bc917be8 AV |
1824 | return -EFAULT; |
1825 | ||
1826 | iov->iov_base = buf; | |
1827 | iov->iov_len = len; | |
1828 | iov_iter_init(i, rw, iov, 1, len); | |
1829 | return 0; | |
1830 | } | |
e1267585 | 1831 | EXPORT_SYMBOL(import_single_range); |
09cf698a AV |
1832 | |
1833 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1834 | int (*f)(struct kvec *vec, void *context), | |
1835 | void *context) | |
1836 | { | |
1837 | struct kvec w; | |
1838 | int err = -EINVAL; | |
1839 | if (!bytes) | |
1840 | return 0; | |
1841 | ||
1842 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1843 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1844 | w.iov_len = v.bv_len; | |
1845 | err = f(&w, context); | |
1846 | kunmap(v.bv_page); | |
1847 | err;}), ({ | |
1848 | w = v; | |
1849 | err = f(&w, context);}) | |
1850 | ) | |
1851 | return err; | |
1852 | } | |
1853 | EXPORT_SYMBOL(iov_iter_for_each_range); |