Commit | Line | Data |
---|---|---|
4f18cd31 | 1 | #include <linux/export.h> |
2f8b5444 | 2 | #include <linux/bvec.h> |
4f18cd31 AV |
3 | #include <linux/uio.h> |
4 | #include <linux/pagemap.h> | |
91f79c43 AV |
5 | #include <linux/slab.h> |
6 | #include <linux/vmalloc.h> | |
241699cd | 7 | #include <linux/splice.h> |
a604ec7e | 8 | #include <net/checksum.h> |
4f18cd31 | 9 | |
241699cd AV |
10 | #define PIPE_PARANOIA /* for now */ |
11 | ||
04a31165 AV |
12 | #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ |
13 | size_t left; \ | |
14 | size_t wanted = n; \ | |
15 | __p = i->iov; \ | |
16 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
17 | if (likely(__v.iov_len)) { \ | |
18 | __v.iov_base = __p->iov_base + skip; \ | |
19 | left = (STEP); \ | |
20 | __v.iov_len -= left; \ | |
21 | skip += __v.iov_len; \ | |
22 | n -= __v.iov_len; \ | |
23 | } else { \ | |
24 | left = 0; \ | |
25 | } \ | |
26 | while (unlikely(!left && n)) { \ | |
27 | __p++; \ | |
28 | __v.iov_len = min(n, __p->iov_len); \ | |
29 | if (unlikely(!__v.iov_len)) \ | |
30 | continue; \ | |
31 | __v.iov_base = __p->iov_base; \ | |
32 | left = (STEP); \ | |
33 | __v.iov_len -= left; \ | |
34 | skip = __v.iov_len; \ | |
35 | n -= __v.iov_len; \ | |
36 | } \ | |
37 | n = wanted - n; \ | |
38 | } | |
39 | ||
a280455f AV |
40 | #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ |
41 | size_t wanted = n; \ | |
42 | __p = i->kvec; \ | |
43 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
44 | if (likely(__v.iov_len)) { \ | |
45 | __v.iov_base = __p->iov_base + skip; \ | |
46 | (void)(STEP); \ | |
47 | skip += __v.iov_len; \ | |
48 | n -= __v.iov_len; \ | |
49 | } \ | |
50 | while (unlikely(n)) { \ | |
51 | __p++; \ | |
52 | __v.iov_len = min(n, __p->iov_len); \ | |
53 | if (unlikely(!__v.iov_len)) \ | |
54 | continue; \ | |
55 | __v.iov_base = __p->iov_base; \ | |
56 | (void)(STEP); \ | |
57 | skip = __v.iov_len; \ | |
58 | n -= __v.iov_len; \ | |
59 | } \ | |
60 | n = wanted; \ | |
61 | } | |
62 | ||
1bdc76ae ML |
63 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ |
64 | struct bvec_iter __start; \ | |
65 | __start.bi_size = n; \ | |
66 | __start.bi_bvec_done = skip; \ | |
67 | __start.bi_idx = 0; \ | |
68 | for_each_bvec(__v, i->bvec, __bi, __start) { \ | |
69 | if (!__v.bv_len) \ | |
04a31165 | 70 | continue; \ |
04a31165 | 71 | (void)(STEP); \ |
04a31165 | 72 | } \ |
04a31165 AV |
73 | } |
74 | ||
a280455f | 75 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
33844e66 AV |
76 | if (likely(n)) { \ |
77 | size_t skip = i->iov_offset; \ | |
78 | if (unlikely(i->type & ITER_BVEC)) { \ | |
79 | struct bio_vec v; \ | |
80 | struct bvec_iter __bi; \ | |
81 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
82 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
83 | const struct kvec *kvec; \ | |
84 | struct kvec v; \ | |
85 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
86 | } else { \ | |
87 | const struct iovec *iov; \ | |
88 | struct iovec v; \ | |
89 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
90 | } \ | |
04a31165 AV |
91 | } \ |
92 | } | |
93 | ||
a280455f | 94 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
95 | if (unlikely(i->count < n)) \ |
96 | n = i->count; \ | |
19f18459 | 97 | if (i->count) { \ |
dd254f5a AV |
98 | size_t skip = i->iov_offset; \ |
99 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 100 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 101 | struct bio_vec v; \ |
1bdc76ae ML |
102 | struct bvec_iter __bi; \ |
103 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
104 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
105 | i->nr_segs -= i->bvec - bvec; \ | |
106 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
107 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
108 | const struct kvec *kvec; \ | |
109 | struct kvec v; \ | |
110 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
111 | if (skip == kvec->iov_len) { \ | |
112 | kvec++; \ | |
113 | skip = 0; \ | |
114 | } \ | |
115 | i->nr_segs -= kvec - i->kvec; \ | |
116 | i->kvec = kvec; \ | |
117 | } else { \ | |
118 | const struct iovec *iov; \ | |
119 | struct iovec v; \ | |
120 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
121 | if (skip == iov->iov_len) { \ | |
122 | iov++; \ | |
123 | skip = 0; \ | |
124 | } \ | |
125 | i->nr_segs -= iov - i->iov; \ | |
126 | i->iov = iov; \ | |
7ce2a91e | 127 | } \ |
dd254f5a AV |
128 | i->count -= n; \ |
129 | i->iov_offset = skip; \ | |
7ce2a91e | 130 | } \ |
7ce2a91e AV |
131 | } |
132 | ||
09fc68dc AV |
133 | static int copyout(void __user *to, const void *from, size_t n) |
134 | { | |
135 | if (access_ok(VERIFY_WRITE, to, n)) { | |
136 | kasan_check_read(from, n); | |
137 | n = raw_copy_to_user(to, from, n); | |
138 | } | |
139 | return n; | |
140 | } | |
141 | ||
142 | static int copyin(void *to, const void __user *from, size_t n) | |
143 | { | |
144 | if (access_ok(VERIFY_READ, from, n)) { | |
145 | kasan_check_write(to, n); | |
146 | n = raw_copy_from_user(to, from, n); | |
147 | } | |
148 | return n; | |
149 | } | |
150 | ||
62a8067a | 151 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
152 | struct iov_iter *i) |
153 | { | |
154 | size_t skip, copy, left, wanted; | |
155 | const struct iovec *iov; | |
156 | char __user *buf; | |
157 | void *kaddr, *from; | |
158 | ||
159 | if (unlikely(bytes > i->count)) | |
160 | bytes = i->count; | |
161 | ||
162 | if (unlikely(!bytes)) | |
163 | return 0; | |
164 | ||
09fc68dc | 165 | might_fault(); |
4f18cd31 AV |
166 | wanted = bytes; |
167 | iov = i->iov; | |
168 | skip = i->iov_offset; | |
169 | buf = iov->iov_base + skip; | |
170 | copy = min(bytes, iov->iov_len - skip); | |
171 | ||
3fa6c507 | 172 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
173 | kaddr = kmap_atomic(page); |
174 | from = kaddr + offset; | |
175 | ||
176 | /* first chunk, usually the only one */ | |
09fc68dc | 177 | left = copyout(buf, from, copy); |
4f18cd31 AV |
178 | copy -= left; |
179 | skip += copy; | |
180 | from += copy; | |
181 | bytes -= copy; | |
182 | ||
183 | while (unlikely(!left && bytes)) { | |
184 | iov++; | |
185 | buf = iov->iov_base; | |
186 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 187 | left = copyout(buf, from, copy); |
4f18cd31 AV |
188 | copy -= left; |
189 | skip = copy; | |
190 | from += copy; | |
191 | bytes -= copy; | |
192 | } | |
193 | if (likely(!bytes)) { | |
194 | kunmap_atomic(kaddr); | |
195 | goto done; | |
196 | } | |
197 | offset = from - kaddr; | |
198 | buf += copy; | |
199 | kunmap_atomic(kaddr); | |
200 | copy = min(bytes, iov->iov_len - skip); | |
201 | } | |
202 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 203 | |
4f18cd31 AV |
204 | kaddr = kmap(page); |
205 | from = kaddr + offset; | |
09fc68dc | 206 | left = copyout(buf, from, copy); |
4f18cd31 AV |
207 | copy -= left; |
208 | skip += copy; | |
209 | from += copy; | |
210 | bytes -= copy; | |
211 | while (unlikely(!left && bytes)) { | |
212 | iov++; | |
213 | buf = iov->iov_base; | |
214 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 215 | left = copyout(buf, from, copy); |
4f18cd31 AV |
216 | copy -= left; |
217 | skip = copy; | |
218 | from += copy; | |
219 | bytes -= copy; | |
220 | } | |
221 | kunmap(page); | |
3fa6c507 | 222 | |
4f18cd31 | 223 | done: |
81055e58 AV |
224 | if (skip == iov->iov_len) { |
225 | iov++; | |
226 | skip = 0; | |
227 | } | |
4f18cd31 AV |
228 | i->count -= wanted - bytes; |
229 | i->nr_segs -= iov - i->iov; | |
230 | i->iov = iov; | |
231 | i->iov_offset = skip; | |
232 | return wanted - bytes; | |
233 | } | |
4f18cd31 | 234 | |
62a8067a | 235 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
236 | struct iov_iter *i) |
237 | { | |
238 | size_t skip, copy, left, wanted; | |
239 | const struct iovec *iov; | |
240 | char __user *buf; | |
241 | void *kaddr, *to; | |
242 | ||
243 | if (unlikely(bytes > i->count)) | |
244 | bytes = i->count; | |
245 | ||
246 | if (unlikely(!bytes)) | |
247 | return 0; | |
248 | ||
09fc68dc | 249 | might_fault(); |
f0d1bec9 AV |
250 | wanted = bytes; |
251 | iov = i->iov; | |
252 | skip = i->iov_offset; | |
253 | buf = iov->iov_base + skip; | |
254 | copy = min(bytes, iov->iov_len - skip); | |
255 | ||
3fa6c507 | 256 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
257 | kaddr = kmap_atomic(page); |
258 | to = kaddr + offset; | |
259 | ||
260 | /* first chunk, usually the only one */ | |
09fc68dc | 261 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
262 | copy -= left; |
263 | skip += copy; | |
264 | to += copy; | |
265 | bytes -= copy; | |
266 | ||
267 | while (unlikely(!left && bytes)) { | |
268 | iov++; | |
269 | buf = iov->iov_base; | |
270 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 271 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
272 | copy -= left; |
273 | skip = copy; | |
274 | to += copy; | |
275 | bytes -= copy; | |
276 | } | |
277 | if (likely(!bytes)) { | |
278 | kunmap_atomic(kaddr); | |
279 | goto done; | |
280 | } | |
281 | offset = to - kaddr; | |
282 | buf += copy; | |
283 | kunmap_atomic(kaddr); | |
284 | copy = min(bytes, iov->iov_len - skip); | |
285 | } | |
286 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 287 | |
f0d1bec9 AV |
288 | kaddr = kmap(page); |
289 | to = kaddr + offset; | |
09fc68dc | 290 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
291 | copy -= left; |
292 | skip += copy; | |
293 | to += copy; | |
294 | bytes -= copy; | |
295 | while (unlikely(!left && bytes)) { | |
296 | iov++; | |
297 | buf = iov->iov_base; | |
298 | copy = min(bytes, iov->iov_len); | |
09fc68dc | 299 | left = copyin(to, buf, copy); |
f0d1bec9 AV |
300 | copy -= left; |
301 | skip = copy; | |
302 | to += copy; | |
303 | bytes -= copy; | |
304 | } | |
305 | kunmap(page); | |
3fa6c507 | 306 | |
f0d1bec9 | 307 | done: |
81055e58 AV |
308 | if (skip == iov->iov_len) { |
309 | iov++; | |
310 | skip = 0; | |
311 | } | |
f0d1bec9 AV |
312 | i->count -= wanted - bytes; |
313 | i->nr_segs -= iov - i->iov; | |
314 | i->iov = iov; | |
315 | i->iov_offset = skip; | |
316 | return wanted - bytes; | |
317 | } | |
f0d1bec9 | 318 | |
241699cd AV |
319 | #ifdef PIPE_PARANOIA |
320 | static bool sanity(const struct iov_iter *i) | |
321 | { | |
322 | struct pipe_inode_info *pipe = i->pipe; | |
323 | int idx = i->idx; | |
324 | int next = pipe->curbuf + pipe->nrbufs; | |
325 | if (i->iov_offset) { | |
326 | struct pipe_buffer *p; | |
327 | if (unlikely(!pipe->nrbufs)) | |
328 | goto Bad; // pipe must be non-empty | |
329 | if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) | |
330 | goto Bad; // must be at the last buffer... | |
331 | ||
332 | p = &pipe->bufs[idx]; | |
333 | if (unlikely(p->offset + p->len != i->iov_offset)) | |
334 | goto Bad; // ... at the end of segment | |
335 | } else { | |
336 | if (idx != (next & (pipe->buffers - 1))) | |
337 | goto Bad; // must be right after the last buffer | |
338 | } | |
339 | return true; | |
340 | Bad: | |
341 | printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); | |
342 | printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", | |
343 | pipe->curbuf, pipe->nrbufs, pipe->buffers); | |
344 | for (idx = 0; idx < pipe->buffers; idx++) | |
345 | printk(KERN_ERR "[%p %p %d %d]\n", | |
346 | pipe->bufs[idx].ops, | |
347 | pipe->bufs[idx].page, | |
348 | pipe->bufs[idx].offset, | |
349 | pipe->bufs[idx].len); | |
350 | WARN_ON(1); | |
351 | return false; | |
352 | } | |
353 | #else | |
354 | #define sanity(i) true | |
355 | #endif | |
356 | ||
357 | static inline int next_idx(int idx, struct pipe_inode_info *pipe) | |
358 | { | |
359 | return (idx + 1) & (pipe->buffers - 1); | |
360 | } | |
361 | ||
362 | static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, | |
363 | struct iov_iter *i) | |
364 | { | |
365 | struct pipe_inode_info *pipe = i->pipe; | |
366 | struct pipe_buffer *buf; | |
367 | size_t off; | |
368 | int idx; | |
369 | ||
370 | if (unlikely(bytes > i->count)) | |
371 | bytes = i->count; | |
372 | ||
373 | if (unlikely(!bytes)) | |
374 | return 0; | |
375 | ||
376 | if (!sanity(i)) | |
377 | return 0; | |
378 | ||
379 | off = i->iov_offset; | |
380 | idx = i->idx; | |
381 | buf = &pipe->bufs[idx]; | |
382 | if (off) { | |
383 | if (offset == off && buf->page == page) { | |
384 | /* merge with the last one */ | |
385 | buf->len += bytes; | |
386 | i->iov_offset += bytes; | |
387 | goto out; | |
388 | } | |
389 | idx = next_idx(idx, pipe); | |
390 | buf = &pipe->bufs[idx]; | |
391 | } | |
392 | if (idx == pipe->curbuf && pipe->nrbufs) | |
393 | return 0; | |
394 | pipe->nrbufs++; | |
395 | buf->ops = &page_cache_pipe_buf_ops; | |
396 | get_page(buf->page = page); | |
397 | buf->offset = offset; | |
398 | buf->len = bytes; | |
399 | i->iov_offset = offset + bytes; | |
400 | i->idx = idx; | |
401 | out: | |
402 | i->count -= bytes; | |
403 | return bytes; | |
404 | } | |
405 | ||
171a0203 AA |
406 | /* |
407 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
408 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
409 | * | |
410 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
411 | * because it is an invalid address). | |
412 | */ | |
d4690f1e | 413 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
414 | { |
415 | size_t skip = i->iov_offset; | |
416 | const struct iovec *iov; | |
417 | int err; | |
418 | struct iovec v; | |
419 | ||
420 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
421 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
4bce9f6e | 422 | err = fault_in_pages_readable(v.iov_base, v.iov_len); |
171a0203 AA |
423 | if (unlikely(err)) |
424 | return err; | |
425 | 0;})) | |
426 | } | |
427 | return 0; | |
428 | } | |
d4690f1e | 429 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 430 | |
aa563d7b | 431 | void iov_iter_init(struct iov_iter *i, unsigned int direction, |
71d8e532 AV |
432 | const struct iovec *iov, unsigned long nr_segs, |
433 | size_t count) | |
434 | { | |
aa563d7b DH |
435 | WARN_ON(direction & ~(READ | WRITE)); |
436 | direction &= READ | WRITE; | |
437 | ||
71d8e532 | 438 | /* It will get better. Eventually... */ |
db68ce10 | 439 | if (uaccess_kernel()) { |
aa563d7b | 440 | i->type = ITER_KVEC | direction; |
a280455f AV |
441 | i->kvec = (struct kvec *)iov; |
442 | } else { | |
aa563d7b | 443 | i->type = ITER_IOVEC | direction; |
a280455f AV |
444 | i->iov = iov; |
445 | } | |
71d8e532 AV |
446 | i->nr_segs = nr_segs; |
447 | i->iov_offset = 0; | |
448 | i->count = count; | |
449 | } | |
450 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 451 | |
62a8067a AV |
452 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
453 | { | |
454 | char *from = kmap_atomic(page); | |
455 | memcpy(to, from + offset, len); | |
456 | kunmap_atomic(from); | |
457 | } | |
458 | ||
36f7a8a4 | 459 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
460 | { |
461 | char *to = kmap_atomic(page); | |
462 | memcpy(to + offset, from, len); | |
463 | kunmap_atomic(to); | |
464 | } | |
465 | ||
c35e0248 MW |
466 | static void memzero_page(struct page *page, size_t offset, size_t len) |
467 | { | |
468 | char *addr = kmap_atomic(page); | |
469 | memset(addr + offset, 0, len); | |
470 | kunmap_atomic(addr); | |
471 | } | |
472 | ||
241699cd AV |
473 | static inline bool allocated(struct pipe_buffer *buf) |
474 | { | |
475 | return buf->ops == &default_pipe_buf_ops; | |
476 | } | |
477 | ||
478 | static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) | |
479 | { | |
480 | size_t off = i->iov_offset; | |
481 | int idx = i->idx; | |
482 | if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { | |
483 | idx = next_idx(idx, i->pipe); | |
484 | off = 0; | |
485 | } | |
486 | *idxp = idx; | |
487 | *offp = off; | |
488 | } | |
489 | ||
490 | static size_t push_pipe(struct iov_iter *i, size_t size, | |
491 | int *idxp, size_t *offp) | |
492 | { | |
493 | struct pipe_inode_info *pipe = i->pipe; | |
494 | size_t off; | |
495 | int idx; | |
496 | ssize_t left; | |
497 | ||
498 | if (unlikely(size > i->count)) | |
499 | size = i->count; | |
500 | if (unlikely(!size)) | |
501 | return 0; | |
502 | ||
503 | left = size; | |
504 | data_start(i, &idx, &off); | |
505 | *idxp = idx; | |
506 | *offp = off; | |
507 | if (off) { | |
508 | left -= PAGE_SIZE - off; | |
509 | if (left <= 0) { | |
510 | pipe->bufs[idx].len += size; | |
511 | return size; | |
512 | } | |
513 | pipe->bufs[idx].len = PAGE_SIZE; | |
514 | idx = next_idx(idx, pipe); | |
515 | } | |
516 | while (idx != pipe->curbuf || !pipe->nrbufs) { | |
517 | struct page *page = alloc_page(GFP_USER); | |
518 | if (!page) | |
519 | break; | |
520 | pipe->nrbufs++; | |
521 | pipe->bufs[idx].ops = &default_pipe_buf_ops; | |
522 | pipe->bufs[idx].page = page; | |
523 | pipe->bufs[idx].offset = 0; | |
524 | if (left <= PAGE_SIZE) { | |
525 | pipe->bufs[idx].len = left; | |
526 | return size; | |
527 | } | |
528 | pipe->bufs[idx].len = PAGE_SIZE; | |
529 | left -= PAGE_SIZE; | |
530 | idx = next_idx(idx, pipe); | |
531 | } | |
532 | return size - left; | |
533 | } | |
534 | ||
535 | static size_t copy_pipe_to_iter(const void *addr, size_t bytes, | |
536 | struct iov_iter *i) | |
537 | { | |
538 | struct pipe_inode_info *pipe = i->pipe; | |
539 | size_t n, off; | |
540 | int idx; | |
541 | ||
542 | if (!sanity(i)) | |
543 | return 0; | |
544 | ||
545 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
546 | if (unlikely(!n)) | |
547 | return 0; | |
548 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
549 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
550 | memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); | |
551 | i->idx = idx; | |
552 | i->iov_offset = off + chunk; | |
553 | n -= chunk; | |
554 | addr += chunk; | |
555 | } | |
556 | i->count -= bytes; | |
557 | return bytes; | |
558 | } | |
559 | ||
aa28de27 | 560 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 561 | { |
36f7a8a4 | 562 | const char *from = addr; |
00e23707 | 563 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 564 | return copy_pipe_to_iter(addr, bytes, i); |
09fc68dc AV |
565 | if (iter_is_iovec(i)) |
566 | might_fault(); | |
3d4d3e48 | 567 | iterate_and_advance(i, bytes, v, |
09fc68dc | 568 | copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), |
3d4d3e48 | 569 | memcpy_to_page(v.bv_page, v.bv_offset, |
a280455f AV |
570 | (from += v.bv_len) - v.bv_len, v.bv_len), |
571 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 572 | ) |
62a8067a | 573 | |
3d4d3e48 | 574 | return bytes; |
c35e0248 | 575 | } |
aa28de27 | 576 | EXPORT_SYMBOL(_copy_to_iter); |
c35e0248 | 577 | |
8780356e DW |
578 | #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE |
579 | static int copyout_mcsafe(void __user *to, const void *from, size_t n) | |
580 | { | |
581 | if (access_ok(VERIFY_WRITE, to, n)) { | |
582 | kasan_check_read(from, n); | |
583 | n = copy_to_user_mcsafe((__force void *) to, from, n); | |
584 | } | |
585 | return n; | |
586 | } | |
587 | ||
588 | static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, | |
589 | const char *from, size_t len) | |
590 | { | |
591 | unsigned long ret; | |
592 | char *to; | |
593 | ||
594 | to = kmap_atomic(page); | |
595 | ret = memcpy_mcsafe(to + offset, from, len); | |
596 | kunmap_atomic(to); | |
597 | ||
598 | return ret; | |
599 | } | |
600 | ||
ca146f6f DW |
601 | static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, |
602 | struct iov_iter *i) | |
603 | { | |
604 | struct pipe_inode_info *pipe = i->pipe; | |
605 | size_t n, off, xfer = 0; | |
606 | int idx; | |
607 | ||
608 | if (!sanity(i)) | |
609 | return 0; | |
610 | ||
611 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
612 | if (unlikely(!n)) | |
613 | return 0; | |
614 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
615 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
616 | unsigned long rem; | |
617 | ||
618 | rem = memcpy_mcsafe_to_page(pipe->bufs[idx].page, off, addr, | |
619 | chunk); | |
620 | i->idx = idx; | |
621 | i->iov_offset = off + chunk - rem; | |
622 | xfer += chunk - rem; | |
623 | if (rem) | |
624 | break; | |
625 | n -= chunk; | |
626 | addr += chunk; | |
627 | } | |
628 | i->count -= xfer; | |
629 | return xfer; | |
630 | } | |
631 | ||
bf3eeb9b DW |
632 | /** |
633 | * _copy_to_iter_mcsafe - copy to user with source-read error exception handling | |
634 | * @addr: source kernel address | |
635 | * @bytes: total transfer length | |
636 | * @iter: destination iterator | |
637 | * | |
638 | * The pmem driver arranges for filesystem-dax to use this facility via | |
639 | * dax_copy_to_iter() for protecting read/write to persistent memory. | |
640 | * Unless / until an architecture can guarantee identical performance | |
641 | * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a | |
642 | * performance regression to switch more users to the mcsafe version. | |
643 | * | |
644 | * Otherwise, the main differences between this and typical _copy_to_iter(). | |
645 | * | |
646 | * * Typical tail/residue handling after a fault retries the copy | |
647 | * byte-by-byte until the fault happens again. Re-triggering machine | |
648 | * checks is potentially fatal so the implementation uses source | |
649 | * alignment and poison alignment assumptions to avoid re-triggering | |
650 | * hardware exceptions. | |
651 | * | |
652 | * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. | |
653 | * Compare to copy_to_iter() where only ITER_IOVEC attempts might return | |
654 | * a short copy. | |
655 | * | |
656 | * See MCSAFE_TEST for self-test. | |
657 | */ | |
8780356e DW |
658 | size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) |
659 | { | |
660 | const char *from = addr; | |
661 | unsigned long rem, curr_addr, s_addr = (unsigned long) addr; | |
662 | ||
00e23707 | 663 | if (unlikely(iov_iter_is_pipe(i))) |
ca146f6f | 664 | return copy_pipe_to_iter_mcsafe(addr, bytes, i); |
8780356e DW |
665 | if (iter_is_iovec(i)) |
666 | might_fault(); | |
667 | iterate_and_advance(i, bytes, v, | |
668 | copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), | |
669 | ({ | |
670 | rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, | |
671 | (from += v.bv_len) - v.bv_len, v.bv_len); | |
672 | if (rem) { | |
673 | curr_addr = (unsigned long) from; | |
674 | bytes = curr_addr - s_addr - rem; | |
675 | return bytes; | |
676 | } | |
677 | }), | |
678 | ({ | |
679 | rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, | |
680 | v.iov_len); | |
681 | if (rem) { | |
682 | curr_addr = (unsigned long) from; | |
683 | bytes = curr_addr - s_addr - rem; | |
684 | return bytes; | |
685 | } | |
686 | }) | |
687 | ) | |
688 | ||
689 | return bytes; | |
690 | } | |
691 | EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); | |
692 | #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ | |
693 | ||
aa28de27 | 694 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 695 | { |
0dbca9a4 | 696 | char *to = addr; |
00e23707 | 697 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
698 | WARN_ON(1); |
699 | return 0; | |
700 | } | |
09fc68dc AV |
701 | if (iter_is_iovec(i)) |
702 | might_fault(); | |
0dbca9a4 | 703 | iterate_and_advance(i, bytes, v, |
09fc68dc | 704 | copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
0dbca9a4 | 705 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
706 | v.bv_offset, v.bv_len), |
707 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
708 | ) |
709 | ||
710 | return bytes; | |
c35e0248 | 711 | } |
aa28de27 | 712 | EXPORT_SYMBOL(_copy_from_iter); |
c35e0248 | 713 | |
aa28de27 | 714 | bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
715 | { |
716 | char *to = addr; | |
00e23707 | 717 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
718 | WARN_ON(1); |
719 | return false; | |
720 | } | |
33844e66 | 721 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
722 | return false; |
723 | ||
09fc68dc AV |
724 | if (iter_is_iovec(i)) |
725 | might_fault(); | |
cbbd26b8 | 726 | iterate_all_kinds(i, bytes, v, ({ |
09fc68dc | 727 | if (copyin((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
728 | v.iov_base, v.iov_len)) |
729 | return false; | |
730 | 0;}), | |
731 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
732 | v.bv_offset, v.bv_len), | |
733 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
734 | ) | |
735 | ||
736 | iov_iter_advance(i, bytes); | |
737 | return true; | |
738 | } | |
aa28de27 | 739 | EXPORT_SYMBOL(_copy_from_iter_full); |
cbbd26b8 | 740 | |
aa28de27 | 741 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
aa583096 AV |
742 | { |
743 | char *to = addr; | |
00e23707 | 744 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
745 | WARN_ON(1); |
746 | return 0; | |
747 | } | |
aa583096 | 748 | iterate_and_advance(i, bytes, v, |
3f763453 | 749 | __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
aa583096 AV |
750 | v.iov_base, v.iov_len), |
751 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
752 | v.bv_offset, v.bv_len), | |
753 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
754 | ) | |
755 | ||
756 | return bytes; | |
757 | } | |
aa28de27 | 758 | EXPORT_SYMBOL(_copy_from_iter_nocache); |
aa583096 | 759 | |
0aed55af | 760 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
abd08d7d DW |
761 | /** |
762 | * _copy_from_iter_flushcache - write destination through cpu cache | |
763 | * @addr: destination kernel address | |
764 | * @bytes: total transfer length | |
765 | * @iter: source iterator | |
766 | * | |
767 | * The pmem driver arranges for filesystem-dax to use this facility via | |
768 | * dax_copy_from_iter() for ensuring that writes to persistent memory | |
769 | * are flushed through the CPU cache. It is differentiated from | |
770 | * _copy_from_iter_nocache() in that guarantees all data is flushed for | |
771 | * all iterator types. The _copy_from_iter_nocache() only attempts to | |
772 | * bypass the cache for the ITER_IOVEC case, and on some archs may use | |
773 | * instructions that strand dirty-data in the cache. | |
774 | */ | |
6a37e940 | 775 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) |
0aed55af DW |
776 | { |
777 | char *to = addr; | |
00e23707 | 778 | if (unlikely(iov_iter_is_pipe(i))) { |
0aed55af DW |
779 | WARN_ON(1); |
780 | return 0; | |
781 | } | |
782 | iterate_and_advance(i, bytes, v, | |
783 | __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, | |
784 | v.iov_base, v.iov_len), | |
785 | memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, | |
786 | v.bv_offset, v.bv_len), | |
787 | memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, | |
788 | v.iov_len) | |
789 | ) | |
790 | ||
791 | return bytes; | |
792 | } | |
6a37e940 | 793 | EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); |
0aed55af DW |
794 | #endif |
795 | ||
aa28de27 | 796 | bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) |
cbbd26b8 AV |
797 | { |
798 | char *to = addr; | |
00e23707 | 799 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
800 | WARN_ON(1); |
801 | return false; | |
802 | } | |
33844e66 | 803 | if (unlikely(i->count < bytes)) |
cbbd26b8 AV |
804 | return false; |
805 | iterate_all_kinds(i, bytes, v, ({ | |
3f763453 | 806 | if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, |
cbbd26b8 AV |
807 | v.iov_base, v.iov_len)) |
808 | return false; | |
809 | 0;}), | |
810 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
811 | v.bv_offset, v.bv_len), | |
812 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
813 | ) | |
814 | ||
815 | iov_iter_advance(i, bytes); | |
816 | return true; | |
817 | } | |
aa28de27 | 818 | EXPORT_SYMBOL(_copy_from_iter_full_nocache); |
cbbd26b8 | 819 | |
72e809ed AV |
820 | static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) |
821 | { | |
a90bcb86 PP |
822 | struct page *head = compound_head(page); |
823 | size_t v = n + offset + page_address(page) - page_address(head); | |
824 | ||
825 | if (likely(n <= v && v <= (PAGE_SIZE << compound_order(head)))) | |
72e809ed AV |
826 | return true; |
827 | WARN_ON(1); | |
828 | return false; | |
829 | } | |
cbbd26b8 | 830 | |
62a8067a AV |
831 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
832 | struct iov_iter *i) | |
833 | { | |
72e809ed AV |
834 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
835 | return 0; | |
d271524a AV |
836 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
837 | void *kaddr = kmap_atomic(page); | |
838 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
839 | kunmap_atomic(kaddr); | |
840 | return wanted; | |
00e23707 | 841 | } else if (likely(!iov_iter_is_pipe(i))) |
62a8067a | 842 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
241699cd AV |
843 | else |
844 | return copy_page_to_iter_pipe(page, offset, bytes, i); | |
62a8067a AV |
845 | } |
846 | EXPORT_SYMBOL(copy_page_to_iter); | |
847 | ||
848 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
849 | struct iov_iter *i) | |
850 | { | |
72e809ed AV |
851 | if (unlikely(!page_copy_sane(page, offset, bytes))) |
852 | return 0; | |
00e23707 | 853 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
854 | WARN_ON(1); |
855 | return 0; | |
856 | } | |
a280455f | 857 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a | 858 | void *kaddr = kmap_atomic(page); |
aa28de27 | 859 | size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); |
d271524a AV |
860 | kunmap_atomic(kaddr); |
861 | return wanted; | |
862 | } else | |
62a8067a AV |
863 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
864 | } | |
865 | EXPORT_SYMBOL(copy_page_from_iter); | |
866 | ||
241699cd AV |
867 | static size_t pipe_zero(size_t bytes, struct iov_iter *i) |
868 | { | |
869 | struct pipe_inode_info *pipe = i->pipe; | |
870 | size_t n, off; | |
871 | int idx; | |
872 | ||
873 | if (!sanity(i)) | |
874 | return 0; | |
875 | ||
876 | bytes = n = push_pipe(i, bytes, &idx, &off); | |
877 | if (unlikely(!n)) | |
878 | return 0; | |
879 | ||
880 | for ( ; n; idx = next_idx(idx, pipe), off = 0) { | |
881 | size_t chunk = min_t(size_t, n, PAGE_SIZE - off); | |
882 | memzero_page(pipe->bufs[idx].page, off, chunk); | |
883 | i->idx = idx; | |
884 | i->iov_offset = off + chunk; | |
885 | n -= chunk; | |
886 | } | |
887 | i->count -= bytes; | |
888 | return bytes; | |
889 | } | |
890 | ||
c35e0248 MW |
891 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
892 | { | |
00e23707 | 893 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 894 | return pipe_zero(bytes, i); |
8442fa46 | 895 | iterate_and_advance(i, bytes, v, |
09fc68dc | 896 | clear_user(v.iov_base, v.iov_len), |
a280455f AV |
897 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
898 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
899 | ) |
900 | ||
901 | return bytes; | |
c35e0248 MW |
902 | } |
903 | EXPORT_SYMBOL(iov_iter_zero); | |
904 | ||
62a8067a AV |
905 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
906 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
907 | { | |
04a31165 | 908 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
72e809ed AV |
909 | if (unlikely(!page_copy_sane(page, offset, bytes))) { |
910 | kunmap_atomic(kaddr); | |
911 | return 0; | |
912 | } | |
00e23707 | 913 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
914 | kunmap_atomic(kaddr); |
915 | WARN_ON(1); | |
916 | return 0; | |
917 | } | |
04a31165 | 918 | iterate_all_kinds(i, bytes, v, |
09fc68dc | 919 | copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), |
04a31165 | 920 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, |
a280455f AV |
921 | v.bv_offset, v.bv_len), |
922 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
923 | ) |
924 | kunmap_atomic(kaddr); | |
925 | return bytes; | |
62a8067a AV |
926 | } |
927 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
928 | ||
b9dc6f65 AV |
929 | static inline void pipe_truncate(struct iov_iter *i) |
930 | { | |
931 | struct pipe_inode_info *pipe = i->pipe; | |
932 | if (pipe->nrbufs) { | |
933 | size_t off = i->iov_offset; | |
934 | int idx = i->idx; | |
935 | int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); | |
936 | if (off) { | |
937 | pipe->bufs[idx].len = off - pipe->bufs[idx].offset; | |
938 | idx = next_idx(idx, pipe); | |
939 | nrbufs++; | |
940 | } | |
941 | while (pipe->nrbufs > nrbufs) { | |
942 | pipe_buf_release(pipe, &pipe->bufs[idx]); | |
943 | idx = next_idx(idx, pipe); | |
944 | pipe->nrbufs--; | |
945 | } | |
946 | } | |
947 | } | |
948 | ||
241699cd AV |
949 | static void pipe_advance(struct iov_iter *i, size_t size) |
950 | { | |
951 | struct pipe_inode_info *pipe = i->pipe; | |
241699cd AV |
952 | if (unlikely(i->count < size)) |
953 | size = i->count; | |
241699cd | 954 | if (size) { |
b9dc6f65 AV |
955 | struct pipe_buffer *buf; |
956 | size_t off = i->iov_offset, left = size; | |
957 | int idx = i->idx; | |
241699cd | 958 | if (off) /* make it relative to the beginning of buffer */ |
b9dc6f65 | 959 | left += off - pipe->bufs[idx].offset; |
241699cd AV |
960 | while (1) { |
961 | buf = &pipe->bufs[idx]; | |
b9dc6f65 | 962 | if (left <= buf->len) |
241699cd | 963 | break; |
b9dc6f65 | 964 | left -= buf->len; |
241699cd AV |
965 | idx = next_idx(idx, pipe); |
966 | } | |
241699cd | 967 | i->idx = idx; |
b9dc6f65 | 968 | i->iov_offset = buf->offset + left; |
241699cd | 969 | } |
b9dc6f65 AV |
970 | i->count -= size; |
971 | /* ... and discard everything past that point */ | |
972 | pipe_truncate(i); | |
241699cd AV |
973 | } |
974 | ||
62a8067a AV |
975 | void iov_iter_advance(struct iov_iter *i, size_t size) |
976 | { | |
00e23707 | 977 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
978 | pipe_advance(i, size); |
979 | return; | |
980 | } | |
a280455f | 981 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
982 | } |
983 | EXPORT_SYMBOL(iov_iter_advance); | |
984 | ||
27c0e374 AV |
985 | void iov_iter_revert(struct iov_iter *i, size_t unroll) |
986 | { | |
987 | if (!unroll) | |
988 | return; | |
5b47d59a AV |
989 | if (WARN_ON(unroll > MAX_RW_COUNT)) |
990 | return; | |
27c0e374 | 991 | i->count += unroll; |
00e23707 | 992 | if (unlikely(iov_iter_is_pipe(i))) { |
27c0e374 AV |
993 | struct pipe_inode_info *pipe = i->pipe; |
994 | int idx = i->idx; | |
995 | size_t off = i->iov_offset; | |
996 | while (1) { | |
997 | size_t n = off - pipe->bufs[idx].offset; | |
998 | if (unroll < n) { | |
4fa55cef | 999 | off -= unroll; |
27c0e374 AV |
1000 | break; |
1001 | } | |
1002 | unroll -= n; | |
1003 | if (!unroll && idx == i->start_idx) { | |
1004 | off = 0; | |
1005 | break; | |
1006 | } | |
1007 | if (!idx--) | |
1008 | idx = pipe->buffers - 1; | |
1009 | off = pipe->bufs[idx].offset + pipe->bufs[idx].len; | |
1010 | } | |
1011 | i->iov_offset = off; | |
1012 | i->idx = idx; | |
1013 | pipe_truncate(i); | |
1014 | return; | |
1015 | } | |
1016 | if (unroll <= i->iov_offset) { | |
1017 | i->iov_offset -= unroll; | |
1018 | return; | |
1019 | } | |
1020 | unroll -= i->iov_offset; | |
00e23707 | 1021 | if (iov_iter_is_bvec(i)) { |
27c0e374 AV |
1022 | const struct bio_vec *bvec = i->bvec; |
1023 | while (1) { | |
1024 | size_t n = (--bvec)->bv_len; | |
1025 | i->nr_segs++; | |
1026 | if (unroll <= n) { | |
1027 | i->bvec = bvec; | |
1028 | i->iov_offset = n - unroll; | |
1029 | return; | |
1030 | } | |
1031 | unroll -= n; | |
1032 | } | |
1033 | } else { /* same logics for iovec and kvec */ | |
1034 | const struct iovec *iov = i->iov; | |
1035 | while (1) { | |
1036 | size_t n = (--iov)->iov_len; | |
1037 | i->nr_segs++; | |
1038 | if (unroll <= n) { | |
1039 | i->iov = iov; | |
1040 | i->iov_offset = n - unroll; | |
1041 | return; | |
1042 | } | |
1043 | unroll -= n; | |
1044 | } | |
1045 | } | |
1046 | } | |
1047 | EXPORT_SYMBOL(iov_iter_revert); | |
1048 | ||
62a8067a AV |
1049 | /* |
1050 | * Return the count of just the current iov_iter segment. | |
1051 | */ | |
1052 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
1053 | { | |
00e23707 | 1054 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1055 | return i->count; // it is a silly place, anyway |
62a8067a AV |
1056 | if (i->nr_segs == 1) |
1057 | return i->count; | |
00e23707 | 1058 | else if (iov_iter_is_bvec(i)) |
62a8067a | 1059 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
1060 | else |
1061 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
1062 | } |
1063 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
1064 | ||
aa563d7b | 1065 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, |
05afcb77 | 1066 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
1067 | size_t count) |
1068 | { | |
aa563d7b DH |
1069 | WARN_ON(direction & ~(READ | WRITE)); |
1070 | i->type = ITER_KVEC | (direction & (READ | WRITE)); | |
05afcb77 | 1071 | i->kvec = kvec; |
abb78f87 AV |
1072 | i->nr_segs = nr_segs; |
1073 | i->iov_offset = 0; | |
1074 | i->count = count; | |
1075 | } | |
1076 | EXPORT_SYMBOL(iov_iter_kvec); | |
1077 | ||
aa563d7b | 1078 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, |
05afcb77 AV |
1079 | const struct bio_vec *bvec, unsigned long nr_segs, |
1080 | size_t count) | |
1081 | { | |
aa563d7b DH |
1082 | WARN_ON(direction & ~(READ | WRITE)); |
1083 | i->type = ITER_BVEC | (direction & (READ | WRITE)); | |
05afcb77 AV |
1084 | i->bvec = bvec; |
1085 | i->nr_segs = nr_segs; | |
1086 | i->iov_offset = 0; | |
1087 | i->count = count; | |
1088 | } | |
1089 | EXPORT_SYMBOL(iov_iter_bvec); | |
1090 | ||
aa563d7b | 1091 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, |
241699cd AV |
1092 | struct pipe_inode_info *pipe, |
1093 | size_t count) | |
1094 | { | |
aa563d7b | 1095 | BUG_ON(direction != READ); |
b9dc6f65 | 1096 | WARN_ON(pipe->nrbufs == pipe->buffers); |
aa563d7b | 1097 | i->type = ITER_PIPE | READ; |
241699cd AV |
1098 | i->pipe = pipe; |
1099 | i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); | |
1100 | i->iov_offset = 0; | |
1101 | i->count = count; | |
27c0e374 | 1102 | i->start_idx = i->idx; |
241699cd AV |
1103 | } |
1104 | EXPORT_SYMBOL(iov_iter_pipe); | |
1105 | ||
62a8067a AV |
1106 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
1107 | { | |
04a31165 AV |
1108 | unsigned long res = 0; |
1109 | size_t size = i->count; | |
1110 | ||
00e23707 | 1111 | if (unlikely(iov_iter_is_pipe(i))) { |
33844e66 | 1112 | if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) |
241699cd AV |
1113 | return size | i->iov_offset; |
1114 | return size; | |
1115 | } | |
04a31165 AV |
1116 | iterate_all_kinds(i, size, v, |
1117 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
1118 | res |= v.bv_offset | v.bv_len, |
1119 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
1120 | ) |
1121 | return res; | |
62a8067a AV |
1122 | } |
1123 | EXPORT_SYMBOL(iov_iter_alignment); | |
1124 | ||
357f435d AV |
1125 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
1126 | { | |
33844e66 | 1127 | unsigned long res = 0; |
357f435d | 1128 | size_t size = i->count; |
357f435d | 1129 | |
00e23707 | 1130 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1131 | WARN_ON(1); |
1132 | return ~0U; | |
1133 | } | |
1134 | ||
357f435d AV |
1135 | iterate_all_kinds(i, size, v, |
1136 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1137 | (size != v.iov_len ? size : 0), 0), | |
1138 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
1139 | (size != v.bv_len ? size : 0)), | |
1140 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
1141 | (size != v.iov_len ? size : 0)) | |
1142 | ); | |
33844e66 | 1143 | return res; |
357f435d AV |
1144 | } |
1145 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
1146 | ||
e76b6312 | 1147 | static inline ssize_t __pipe_get_pages(struct iov_iter *i, |
241699cd AV |
1148 | size_t maxsize, |
1149 | struct page **pages, | |
1150 | int idx, | |
1151 | size_t *start) | |
1152 | { | |
1153 | struct pipe_inode_info *pipe = i->pipe; | |
1689c73a | 1154 | ssize_t n = push_pipe(i, maxsize, &idx, start); |
241699cd AV |
1155 | if (!n) |
1156 | return -EFAULT; | |
1157 | ||
1158 | maxsize = n; | |
1159 | n += *start; | |
1689c73a | 1160 | while (n > 0) { |
241699cd AV |
1161 | get_page(*pages++ = pipe->bufs[idx].page); |
1162 | idx = next_idx(idx, pipe); | |
1163 | n -= PAGE_SIZE; | |
1164 | } | |
1165 | ||
1166 | return maxsize; | |
1167 | } | |
1168 | ||
1169 | static ssize_t pipe_get_pages(struct iov_iter *i, | |
1170 | struct page **pages, size_t maxsize, unsigned maxpages, | |
1171 | size_t *start) | |
1172 | { | |
1173 | unsigned npages; | |
1174 | size_t capacity; | |
1175 | int idx; | |
1176 | ||
33844e66 AV |
1177 | if (!maxsize) |
1178 | return 0; | |
1179 | ||
241699cd AV |
1180 | if (!sanity(i)) |
1181 | return -EFAULT; | |
1182 | ||
1183 | data_start(i, &idx, start); | |
1184 | /* some of this one + all after this one */ | |
1185 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
1186 | capacity = min(npages,maxpages) * PAGE_SIZE - *start; | |
1187 | ||
1188 | return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); | |
1189 | } | |
1190 | ||
62a8067a | 1191 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 1192 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
1193 | size_t *start) |
1194 | { | |
e5393fae AV |
1195 | if (maxsize > i->count) |
1196 | maxsize = i->count; | |
1197 | ||
00e23707 | 1198 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1199 | return pipe_get_pages(i, pages, maxsize, maxpages, start); |
e5393fae AV |
1200 | iterate_all_kinds(i, maxsize, v, ({ |
1201 | unsigned long addr = (unsigned long)v.iov_base; | |
1202 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1203 | int n; | |
1204 | int res; | |
1205 | ||
1206 | if (len > maxpages * PAGE_SIZE) | |
1207 | len = maxpages * PAGE_SIZE; | |
1208 | addr &= ~(PAGE_SIZE - 1); | |
1209 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
00e23707 | 1210 | res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE, pages); |
e5393fae AV |
1211 | if (unlikely(res < 0)) |
1212 | return res; | |
1213 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1214 | 0;}),({ | |
1215 | /* can't be more than PAGE_SIZE */ | |
1216 | *start = v.bv_offset; | |
1217 | get_page(*pages = v.bv_page); | |
1218 | return v.bv_len; | |
a280455f AV |
1219 | }),({ |
1220 | return -EFAULT; | |
e5393fae AV |
1221 | }) |
1222 | ) | |
1223 | return 0; | |
62a8067a AV |
1224 | } |
1225 | EXPORT_SYMBOL(iov_iter_get_pages); | |
1226 | ||
1b17f1f2 AV |
1227 | static struct page **get_pages_array(size_t n) |
1228 | { | |
752ade68 | 1229 | return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); |
1b17f1f2 AV |
1230 | } |
1231 | ||
241699cd AV |
1232 | static ssize_t pipe_get_pages_alloc(struct iov_iter *i, |
1233 | struct page ***pages, size_t maxsize, | |
1234 | size_t *start) | |
1235 | { | |
1236 | struct page **p; | |
d7760d63 | 1237 | ssize_t n; |
241699cd AV |
1238 | int idx; |
1239 | int npages; | |
1240 | ||
33844e66 AV |
1241 | if (!maxsize) |
1242 | return 0; | |
1243 | ||
241699cd AV |
1244 | if (!sanity(i)) |
1245 | return -EFAULT; | |
1246 | ||
1247 | data_start(i, &idx, start); | |
1248 | /* some of this one + all after this one */ | |
1249 | npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; | |
1250 | n = npages * PAGE_SIZE - *start; | |
1251 | if (maxsize > n) | |
1252 | maxsize = n; | |
1253 | else | |
1254 | npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); | |
1255 | p = get_pages_array(npages); | |
1256 | if (!p) | |
1257 | return -ENOMEM; | |
1258 | n = __pipe_get_pages(i, maxsize, p, idx, start); | |
1259 | if (n > 0) | |
1260 | *pages = p; | |
1261 | else | |
1262 | kvfree(p); | |
1263 | return n; | |
1264 | } | |
1265 | ||
62a8067a AV |
1266 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
1267 | struct page ***pages, size_t maxsize, | |
1268 | size_t *start) | |
1269 | { | |
1b17f1f2 AV |
1270 | struct page **p; |
1271 | ||
1272 | if (maxsize > i->count) | |
1273 | maxsize = i->count; | |
1274 | ||
00e23707 | 1275 | if (unlikely(iov_iter_is_pipe(i))) |
241699cd | 1276 | return pipe_get_pages_alloc(i, pages, maxsize, start); |
1b17f1f2 AV |
1277 | iterate_all_kinds(i, maxsize, v, ({ |
1278 | unsigned long addr = (unsigned long)v.iov_base; | |
1279 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
1280 | int n; | |
1281 | int res; | |
1282 | ||
1283 | addr &= ~(PAGE_SIZE - 1); | |
1284 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
1285 | p = get_pages_array(n); | |
1286 | if (!p) | |
1287 | return -ENOMEM; | |
00e23707 | 1288 | res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE, p); |
1b17f1f2 AV |
1289 | if (unlikely(res < 0)) { |
1290 | kvfree(p); | |
1291 | return res; | |
1292 | } | |
1293 | *pages = p; | |
1294 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
1295 | 0;}),({ | |
1296 | /* can't be more than PAGE_SIZE */ | |
1297 | *start = v.bv_offset; | |
1298 | *pages = p = get_pages_array(1); | |
1299 | if (!p) | |
1300 | return -ENOMEM; | |
1301 | get_page(*p = v.bv_page); | |
1302 | return v.bv_len; | |
a280455f AV |
1303 | }),({ |
1304 | return -EFAULT; | |
1b17f1f2 AV |
1305 | }) |
1306 | ) | |
1307 | return 0; | |
62a8067a AV |
1308 | } |
1309 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
1310 | ||
a604ec7e AV |
1311 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
1312 | struct iov_iter *i) | |
1313 | { | |
1314 | char *to = addr; | |
1315 | __wsum sum, next; | |
1316 | size_t off = 0; | |
a604ec7e | 1317 | sum = *csum; |
00e23707 | 1318 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1319 | WARN_ON(1); |
1320 | return 0; | |
1321 | } | |
a604ec7e AV |
1322 | iterate_and_advance(i, bytes, v, ({ |
1323 | int err = 0; | |
cbbd26b8 | 1324 | next = csum_and_copy_from_user(v.iov_base, |
a604ec7e AV |
1325 | (to += v.iov_len) - v.iov_len, |
1326 | v.iov_len, 0, &err); | |
1327 | if (!err) { | |
1328 | sum = csum_block_add(sum, next, off); | |
1329 | off += v.iov_len; | |
1330 | } | |
1331 | err ? v.iov_len : 0; | |
1332 | }), ({ | |
1333 | char *p = kmap_atomic(v.bv_page); | |
1334 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
1335 | (to += v.bv_len) - v.bv_len, | |
1336 | v.bv_len, 0); | |
1337 | kunmap_atomic(p); | |
1338 | sum = csum_block_add(sum, next, off); | |
1339 | off += v.bv_len; | |
1340 | }),({ | |
1341 | next = csum_partial_copy_nocheck(v.iov_base, | |
1342 | (to += v.iov_len) - v.iov_len, | |
1343 | v.iov_len, 0); | |
1344 | sum = csum_block_add(sum, next, off); | |
1345 | off += v.iov_len; | |
1346 | }) | |
1347 | ) | |
1348 | *csum = sum; | |
1349 | return bytes; | |
1350 | } | |
1351 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
1352 | ||
cbbd26b8 AV |
1353 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, |
1354 | struct iov_iter *i) | |
1355 | { | |
1356 | char *to = addr; | |
1357 | __wsum sum, next; | |
1358 | size_t off = 0; | |
1359 | sum = *csum; | |
00e23707 | 1360 | if (unlikely(iov_iter_is_pipe(i))) { |
cbbd26b8 AV |
1361 | WARN_ON(1); |
1362 | return false; | |
1363 | } | |
1364 | if (unlikely(i->count < bytes)) | |
1365 | return false; | |
1366 | iterate_all_kinds(i, bytes, v, ({ | |
1367 | int err = 0; | |
1368 | next = csum_and_copy_from_user(v.iov_base, | |
1369 | (to += v.iov_len) - v.iov_len, | |
1370 | v.iov_len, 0, &err); | |
1371 | if (err) | |
1372 | return false; | |
1373 | sum = csum_block_add(sum, next, off); | |
1374 | off += v.iov_len; | |
1375 | 0; | |
1376 | }), ({ | |
1377 | char *p = kmap_atomic(v.bv_page); | |
1378 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
1379 | (to += v.bv_len) - v.bv_len, | |
1380 | v.bv_len, 0); | |
1381 | kunmap_atomic(p); | |
1382 | sum = csum_block_add(sum, next, off); | |
1383 | off += v.bv_len; | |
1384 | }),({ | |
1385 | next = csum_partial_copy_nocheck(v.iov_base, | |
1386 | (to += v.iov_len) - v.iov_len, | |
1387 | v.iov_len, 0); | |
1388 | sum = csum_block_add(sum, next, off); | |
1389 | off += v.iov_len; | |
1390 | }) | |
1391 | ) | |
1392 | *csum = sum; | |
1393 | iov_iter_advance(i, bytes); | |
1394 | return true; | |
1395 | } | |
1396 | EXPORT_SYMBOL(csum_and_copy_from_iter_full); | |
1397 | ||
36f7a8a4 | 1398 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, |
a604ec7e AV |
1399 | struct iov_iter *i) |
1400 | { | |
36f7a8a4 | 1401 | const char *from = addr; |
a604ec7e AV |
1402 | __wsum sum, next; |
1403 | size_t off = 0; | |
a604ec7e | 1404 | sum = *csum; |
00e23707 | 1405 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1406 | WARN_ON(1); /* for now */ |
1407 | return 0; | |
1408 | } | |
a604ec7e AV |
1409 | iterate_and_advance(i, bytes, v, ({ |
1410 | int err = 0; | |
1411 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
cbbd26b8 | 1412 | v.iov_base, |
a604ec7e AV |
1413 | v.iov_len, 0, &err); |
1414 | if (!err) { | |
1415 | sum = csum_block_add(sum, next, off); | |
1416 | off += v.iov_len; | |
1417 | } | |
1418 | err ? v.iov_len : 0; | |
1419 | }), ({ | |
1420 | char *p = kmap_atomic(v.bv_page); | |
1421 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
1422 | p + v.bv_offset, | |
1423 | v.bv_len, 0); | |
1424 | kunmap_atomic(p); | |
1425 | sum = csum_block_add(sum, next, off); | |
1426 | off += v.bv_len; | |
1427 | }),({ | |
1428 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
1429 | v.iov_base, | |
1430 | v.iov_len, 0); | |
1431 | sum = csum_block_add(sum, next, off); | |
1432 | off += v.iov_len; | |
1433 | }) | |
1434 | ) | |
1435 | *csum = sum; | |
1436 | return bytes; | |
1437 | } | |
1438 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
1439 | ||
62a8067a AV |
1440 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
1441 | { | |
e0f2dc40 AV |
1442 | size_t size = i->count; |
1443 | int npages = 0; | |
1444 | ||
1445 | if (!size) | |
1446 | return 0; | |
1447 | ||
00e23707 | 1448 | if (unlikely(iov_iter_is_pipe(i))) { |
241699cd AV |
1449 | struct pipe_inode_info *pipe = i->pipe; |
1450 | size_t off; | |
1451 | int idx; | |
1452 | ||
1453 | if (!sanity(i)) | |
1454 | return 0; | |
1455 | ||
1456 | data_start(i, &idx, &off); | |
1457 | /* some of this one + all after this one */ | |
1458 | npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; | |
1459 | if (npages >= maxpages) | |
1460 | return maxpages; | |
1461 | } else iterate_all_kinds(i, size, v, ({ | |
e0f2dc40 AV |
1462 | unsigned long p = (unsigned long)v.iov_base; |
1463 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1464 | - p / PAGE_SIZE; | |
1465 | if (npages >= maxpages) | |
1466 | return maxpages; | |
1467 | 0;}),({ | |
1468 | npages++; | |
1469 | if (npages >= maxpages) | |
1470 | return maxpages; | |
a280455f AV |
1471 | }),({ |
1472 | unsigned long p = (unsigned long)v.iov_base; | |
1473 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
1474 | - p / PAGE_SIZE; | |
1475 | if (npages >= maxpages) | |
1476 | return maxpages; | |
e0f2dc40 AV |
1477 | }) |
1478 | ) | |
1479 | return npages; | |
62a8067a | 1480 | } |
f67da30c | 1481 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
1482 | |
1483 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
1484 | { | |
1485 | *new = *old; | |
00e23707 | 1486 | if (unlikely(iov_iter_is_pipe(new))) { |
241699cd AV |
1487 | WARN_ON(1); |
1488 | return NULL; | |
1489 | } | |
00e23707 | 1490 | if (iov_iter_is_bvec(new)) |
4b8164b9 AV |
1491 | return new->bvec = kmemdup(new->bvec, |
1492 | new->nr_segs * sizeof(struct bio_vec), | |
1493 | flags); | |
1494 | else | |
1495 | /* iovec and kvec have identical layout */ | |
1496 | return new->iov = kmemdup(new->iov, | |
1497 | new->nr_segs * sizeof(struct iovec), | |
1498 | flags); | |
1499 | } | |
1500 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 | 1501 | |
ffecee4f VN |
1502 | /** |
1503 | * import_iovec() - Copy an array of &struct iovec from userspace | |
1504 | * into the kernel, check that it is valid, and initialize a new | |
1505 | * &struct iov_iter iterator to access it. | |
1506 | * | |
1507 | * @type: One of %READ or %WRITE. | |
1508 | * @uvector: Pointer to the userspace array. | |
1509 | * @nr_segs: Number of elements in userspace array. | |
1510 | * @fast_segs: Number of elements in @iov. | |
1511 | * @iov: (input and output parameter) Pointer to pointer to (usually small | |
1512 | * on-stack) kernel array. | |
1513 | * @i: Pointer to iterator that will be initialized on success. | |
1514 | * | |
1515 | * If the array pointed to by *@iov is large enough to hold all @nr_segs, | |
1516 | * then this function places %NULL in *@iov on return. Otherwise, a new | |
1517 | * array will be allocated and the result placed in *@iov. This means that | |
1518 | * the caller may call kfree() on *@iov regardless of whether the small | |
1519 | * on-stack array was used or not (and regardless of whether this function | |
1520 | * returns an error or not). | |
1521 | * | |
1522 | * Return: 0 on success or negative error code on error. | |
1523 | */ | |
bc917be8 AV |
1524 | int import_iovec(int type, const struct iovec __user * uvector, |
1525 | unsigned nr_segs, unsigned fast_segs, | |
1526 | struct iovec **iov, struct iov_iter *i) | |
1527 | { | |
1528 | ssize_t n; | |
1529 | struct iovec *p; | |
1530 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1531 | *iov, &p); | |
1532 | if (n < 0) { | |
1533 | if (p != *iov) | |
1534 | kfree(p); | |
1535 | *iov = NULL; | |
1536 | return n; | |
1537 | } | |
1538 | iov_iter_init(i, type, p, nr_segs, n); | |
1539 | *iov = p == *iov ? NULL : p; | |
1540 | return 0; | |
1541 | } | |
1542 | EXPORT_SYMBOL(import_iovec); | |
1543 | ||
1544 | #ifdef CONFIG_COMPAT | |
1545 | #include <linux/compat.h> | |
1546 | ||
1547 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
1548 | unsigned nr_segs, unsigned fast_segs, | |
1549 | struct iovec **iov, struct iov_iter *i) | |
1550 | { | |
1551 | ssize_t n; | |
1552 | struct iovec *p; | |
1553 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
1554 | *iov, &p); | |
1555 | if (n < 0) { | |
1556 | if (p != *iov) | |
1557 | kfree(p); | |
1558 | *iov = NULL; | |
1559 | return n; | |
1560 | } | |
1561 | iov_iter_init(i, type, p, nr_segs, n); | |
1562 | *iov = p == *iov ? NULL : p; | |
1563 | return 0; | |
1564 | } | |
1565 | #endif | |
1566 | ||
1567 | int import_single_range(int rw, void __user *buf, size_t len, | |
1568 | struct iovec *iov, struct iov_iter *i) | |
1569 | { | |
1570 | if (len > MAX_RW_COUNT) | |
1571 | len = MAX_RW_COUNT; | |
1572 | if (unlikely(!access_ok(!rw, buf, len))) | |
1573 | return -EFAULT; | |
1574 | ||
1575 | iov->iov_base = buf; | |
1576 | iov->iov_len = len; | |
1577 | iov_iter_init(i, rw, iov, 1, len); | |
1578 | return 0; | |
1579 | } | |
e1267585 | 1580 | EXPORT_SYMBOL(import_single_range); |
09cf698a AV |
1581 | |
1582 | int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, | |
1583 | int (*f)(struct kvec *vec, void *context), | |
1584 | void *context) | |
1585 | { | |
1586 | struct kvec w; | |
1587 | int err = -EINVAL; | |
1588 | if (!bytes) | |
1589 | return 0; | |
1590 | ||
1591 | iterate_all_kinds(i, bytes, v, -EINVAL, ({ | |
1592 | w.iov_base = kmap(v.bv_page) + v.bv_offset; | |
1593 | w.iov_len = v.bv_len; | |
1594 | err = f(&w, context); | |
1595 | kunmap(v.bv_page); | |
1596 | err;}), ({ | |
1597 | w = v; | |
1598 | err = f(&w, context);}) | |
1599 | ) | |
1600 | return err; | |
1601 | } | |
1602 | EXPORT_SYMBOL(iov_iter_for_each_range); |