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Commit | Line | Data |
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4f18cd31 AV |
1 | #include <linux/export.h> |
2 | #include <linux/uio.h> | |
3 | #include <linux/pagemap.h> | |
91f79c43 AV |
4 | #include <linux/slab.h> |
5 | #include <linux/vmalloc.h> | |
a604ec7e | 6 | #include <net/checksum.h> |
4f18cd31 | 7 | |
04a31165 AV |
8 | #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ |
9 | size_t left; \ | |
10 | size_t wanted = n; \ | |
11 | __p = i->iov; \ | |
12 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
13 | if (likely(__v.iov_len)) { \ | |
14 | __v.iov_base = __p->iov_base + skip; \ | |
15 | left = (STEP); \ | |
16 | __v.iov_len -= left; \ | |
17 | skip += __v.iov_len; \ | |
18 | n -= __v.iov_len; \ | |
19 | } else { \ | |
20 | left = 0; \ | |
21 | } \ | |
22 | while (unlikely(!left && n)) { \ | |
23 | __p++; \ | |
24 | __v.iov_len = min(n, __p->iov_len); \ | |
25 | if (unlikely(!__v.iov_len)) \ | |
26 | continue; \ | |
27 | __v.iov_base = __p->iov_base; \ | |
28 | left = (STEP); \ | |
29 | __v.iov_len -= left; \ | |
30 | skip = __v.iov_len; \ | |
31 | n -= __v.iov_len; \ | |
32 | } \ | |
33 | n = wanted - n; \ | |
34 | } | |
35 | ||
a280455f AV |
36 | #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ |
37 | size_t wanted = n; \ | |
38 | __p = i->kvec; \ | |
39 | __v.iov_len = min(n, __p->iov_len - skip); \ | |
40 | if (likely(__v.iov_len)) { \ | |
41 | __v.iov_base = __p->iov_base + skip; \ | |
42 | (void)(STEP); \ | |
43 | skip += __v.iov_len; \ | |
44 | n -= __v.iov_len; \ | |
45 | } \ | |
46 | while (unlikely(n)) { \ | |
47 | __p++; \ | |
48 | __v.iov_len = min(n, __p->iov_len); \ | |
49 | if (unlikely(!__v.iov_len)) \ | |
50 | continue; \ | |
51 | __v.iov_base = __p->iov_base; \ | |
52 | (void)(STEP); \ | |
53 | skip = __v.iov_len; \ | |
54 | n -= __v.iov_len; \ | |
55 | } \ | |
56 | n = wanted; \ | |
57 | } | |
58 | ||
04a31165 AV |
59 | #define iterate_bvec(i, n, __v, __p, skip, STEP) { \ |
60 | size_t wanted = n; \ | |
61 | __p = i->bvec; \ | |
62 | __v.bv_len = min_t(size_t, n, __p->bv_len - skip); \ | |
63 | if (likely(__v.bv_len)) { \ | |
64 | __v.bv_page = __p->bv_page; \ | |
65 | __v.bv_offset = __p->bv_offset + skip; \ | |
66 | (void)(STEP); \ | |
67 | skip += __v.bv_len; \ | |
68 | n -= __v.bv_len; \ | |
69 | } \ | |
70 | while (unlikely(n)) { \ | |
71 | __p++; \ | |
72 | __v.bv_len = min_t(size_t, n, __p->bv_len); \ | |
73 | if (unlikely(!__v.bv_len)) \ | |
74 | continue; \ | |
75 | __v.bv_page = __p->bv_page; \ | |
76 | __v.bv_offset = __p->bv_offset; \ | |
77 | (void)(STEP); \ | |
78 | skip = __v.bv_len; \ | |
79 | n -= __v.bv_len; \ | |
80 | } \ | |
81 | n = wanted; \ | |
82 | } | |
83 | ||
a280455f | 84 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
04a31165 AV |
85 | size_t skip = i->iov_offset; \ |
86 | if (unlikely(i->type & ITER_BVEC)) { \ | |
87 | const struct bio_vec *bvec; \ | |
88 | struct bio_vec v; \ | |
89 | iterate_bvec(i, n, v, bvec, skip, (B)) \ | |
a280455f AV |
90 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
91 | const struct kvec *kvec; \ | |
92 | struct kvec v; \ | |
93 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
04a31165 AV |
94 | } else { \ |
95 | const struct iovec *iov; \ | |
96 | struct iovec v; \ | |
97 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
98 | } \ | |
99 | } | |
100 | ||
a280455f | 101 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
7ce2a91e AV |
102 | size_t skip = i->iov_offset; \ |
103 | if (unlikely(i->type & ITER_BVEC)) { \ | |
104 | const struct bio_vec *bvec; \ | |
105 | struct bio_vec v; \ | |
106 | iterate_bvec(i, n, v, bvec, skip, (B)) \ | |
107 | if (skip == bvec->bv_len) { \ | |
108 | bvec++; \ | |
109 | skip = 0; \ | |
110 | } \ | |
111 | i->nr_segs -= bvec - i->bvec; \ | |
112 | i->bvec = bvec; \ | |
a280455f AV |
113 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
114 | const struct kvec *kvec; \ | |
115 | struct kvec v; \ | |
116 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
117 | if (skip == kvec->iov_len) { \ | |
118 | kvec++; \ | |
119 | skip = 0; \ | |
120 | } \ | |
121 | i->nr_segs -= kvec - i->kvec; \ | |
122 | i->kvec = kvec; \ | |
7ce2a91e AV |
123 | } else { \ |
124 | const struct iovec *iov; \ | |
125 | struct iovec v; \ | |
126 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
127 | if (skip == iov->iov_len) { \ | |
128 | iov++; \ | |
129 | skip = 0; \ | |
130 | } \ | |
131 | i->nr_segs -= iov - i->iov; \ | |
132 | i->iov = iov; \ | |
133 | } \ | |
134 | i->count -= n; \ | |
135 | i->iov_offset = skip; \ | |
136 | } | |
137 | ||
62a8067a | 138 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
139 | struct iov_iter *i) |
140 | { | |
141 | size_t skip, copy, left, wanted; | |
142 | const struct iovec *iov; | |
143 | char __user *buf; | |
144 | void *kaddr, *from; | |
145 | ||
146 | if (unlikely(bytes > i->count)) | |
147 | bytes = i->count; | |
148 | ||
149 | if (unlikely(!bytes)) | |
150 | return 0; | |
151 | ||
152 | wanted = bytes; | |
153 | iov = i->iov; | |
154 | skip = i->iov_offset; | |
155 | buf = iov->iov_base + skip; | |
156 | copy = min(bytes, iov->iov_len - skip); | |
157 | ||
158 | if (!fault_in_pages_writeable(buf, copy)) { | |
159 | kaddr = kmap_atomic(page); | |
160 | from = kaddr + offset; | |
161 | ||
162 | /* first chunk, usually the only one */ | |
163 | left = __copy_to_user_inatomic(buf, from, copy); | |
164 | copy -= left; | |
165 | skip += copy; | |
166 | from += copy; | |
167 | bytes -= copy; | |
168 | ||
169 | while (unlikely(!left && bytes)) { | |
170 | iov++; | |
171 | buf = iov->iov_base; | |
172 | copy = min(bytes, iov->iov_len); | |
173 | left = __copy_to_user_inatomic(buf, from, copy); | |
174 | copy -= left; | |
175 | skip = copy; | |
176 | from += copy; | |
177 | bytes -= copy; | |
178 | } | |
179 | if (likely(!bytes)) { | |
180 | kunmap_atomic(kaddr); | |
181 | goto done; | |
182 | } | |
183 | offset = from - kaddr; | |
184 | buf += copy; | |
185 | kunmap_atomic(kaddr); | |
186 | copy = min(bytes, iov->iov_len - skip); | |
187 | } | |
188 | /* Too bad - revert to non-atomic kmap */ | |
189 | kaddr = kmap(page); | |
190 | from = kaddr + offset; | |
191 | left = __copy_to_user(buf, from, copy); | |
192 | copy -= left; | |
193 | skip += copy; | |
194 | from += copy; | |
195 | bytes -= copy; | |
196 | while (unlikely(!left && bytes)) { | |
197 | iov++; | |
198 | buf = iov->iov_base; | |
199 | copy = min(bytes, iov->iov_len); | |
200 | left = __copy_to_user(buf, from, copy); | |
201 | copy -= left; | |
202 | skip = copy; | |
203 | from += copy; | |
204 | bytes -= copy; | |
205 | } | |
206 | kunmap(page); | |
207 | done: | |
81055e58 AV |
208 | if (skip == iov->iov_len) { |
209 | iov++; | |
210 | skip = 0; | |
211 | } | |
4f18cd31 AV |
212 | i->count -= wanted - bytes; |
213 | i->nr_segs -= iov - i->iov; | |
214 | i->iov = iov; | |
215 | i->iov_offset = skip; | |
216 | return wanted - bytes; | |
217 | } | |
4f18cd31 | 218 | |
62a8067a | 219 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
220 | struct iov_iter *i) |
221 | { | |
222 | size_t skip, copy, left, wanted; | |
223 | const struct iovec *iov; | |
224 | char __user *buf; | |
225 | void *kaddr, *to; | |
226 | ||
227 | if (unlikely(bytes > i->count)) | |
228 | bytes = i->count; | |
229 | ||
230 | if (unlikely(!bytes)) | |
231 | return 0; | |
232 | ||
233 | wanted = bytes; | |
234 | iov = i->iov; | |
235 | skip = i->iov_offset; | |
236 | buf = iov->iov_base + skip; | |
237 | copy = min(bytes, iov->iov_len - skip); | |
238 | ||
239 | if (!fault_in_pages_readable(buf, copy)) { | |
240 | kaddr = kmap_atomic(page); | |
241 | to = kaddr + offset; | |
242 | ||
243 | /* first chunk, usually the only one */ | |
244 | left = __copy_from_user_inatomic(to, buf, copy); | |
245 | copy -= left; | |
246 | skip += copy; | |
247 | to += copy; | |
248 | bytes -= copy; | |
249 | ||
250 | while (unlikely(!left && bytes)) { | |
251 | iov++; | |
252 | buf = iov->iov_base; | |
253 | copy = min(bytes, iov->iov_len); | |
254 | left = __copy_from_user_inatomic(to, buf, copy); | |
255 | copy -= left; | |
256 | skip = copy; | |
257 | to += copy; | |
258 | bytes -= copy; | |
259 | } | |
260 | if (likely(!bytes)) { | |
261 | kunmap_atomic(kaddr); | |
262 | goto done; | |
263 | } | |
264 | offset = to - kaddr; | |
265 | buf += copy; | |
266 | kunmap_atomic(kaddr); | |
267 | copy = min(bytes, iov->iov_len - skip); | |
268 | } | |
269 | /* Too bad - revert to non-atomic kmap */ | |
270 | kaddr = kmap(page); | |
271 | to = kaddr + offset; | |
272 | left = __copy_from_user(to, buf, copy); | |
273 | copy -= left; | |
274 | skip += copy; | |
275 | to += copy; | |
276 | bytes -= copy; | |
277 | while (unlikely(!left && bytes)) { | |
278 | iov++; | |
279 | buf = iov->iov_base; | |
280 | copy = min(bytes, iov->iov_len); | |
281 | left = __copy_from_user(to, buf, copy); | |
282 | copy -= left; | |
283 | skip = copy; | |
284 | to += copy; | |
285 | bytes -= copy; | |
286 | } | |
287 | kunmap(page); | |
288 | done: | |
81055e58 AV |
289 | if (skip == iov->iov_len) { |
290 | iov++; | |
291 | skip = 0; | |
292 | } | |
f0d1bec9 AV |
293 | i->count -= wanted - bytes; |
294 | i->nr_segs -= iov - i->iov; | |
295 | i->iov = iov; | |
296 | i->iov_offset = skip; | |
297 | return wanted - bytes; | |
298 | } | |
f0d1bec9 | 299 | |
171a0203 AA |
300 | /* |
301 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
302 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
303 | * | |
304 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
305 | * because it is an invalid address). | |
306 | */ | |
7876669d | 307 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
171a0203 AA |
308 | { |
309 | size_t skip = i->iov_offset; | |
310 | const struct iovec *iov; | |
311 | int err; | |
312 | struct iovec v; | |
313 | ||
314 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
315 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
316 | err = fault_in_multipages_readable(v.iov_base, | |
317 | v.iov_len); | |
318 | if (unlikely(err)) | |
319 | return err; | |
320 | 0;})) | |
321 | } | |
322 | return 0; | |
323 | } | |
7876669d | 324 | EXPORT_SYMBOL(iov_iter_fault_in_readable); |
171a0203 | 325 | |
71d8e532 AV |
326 | void iov_iter_init(struct iov_iter *i, int direction, |
327 | const struct iovec *iov, unsigned long nr_segs, | |
328 | size_t count) | |
329 | { | |
330 | /* It will get better. Eventually... */ | |
a280455f | 331 | if (segment_eq(get_fs(), KERNEL_DS)) { |
62a8067a | 332 | direction |= ITER_KVEC; |
a280455f AV |
333 | i->type = direction; |
334 | i->kvec = (struct kvec *)iov; | |
335 | } else { | |
336 | i->type = direction; | |
337 | i->iov = iov; | |
338 | } | |
71d8e532 AV |
339 | i->nr_segs = nr_segs; |
340 | i->iov_offset = 0; | |
341 | i->count = count; | |
342 | } | |
343 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 344 | |
62a8067a AV |
345 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
346 | { | |
347 | char *from = kmap_atomic(page); | |
348 | memcpy(to, from + offset, len); | |
349 | kunmap_atomic(from); | |
350 | } | |
351 | ||
352 | static void memcpy_to_page(struct page *page, size_t offset, char *from, size_t len) | |
353 | { | |
354 | char *to = kmap_atomic(page); | |
355 | memcpy(to + offset, from, len); | |
356 | kunmap_atomic(to); | |
357 | } | |
358 | ||
c35e0248 MW |
359 | static void memzero_page(struct page *page, size_t offset, size_t len) |
360 | { | |
361 | char *addr = kmap_atomic(page); | |
362 | memset(addr + offset, 0, len); | |
363 | kunmap_atomic(addr); | |
364 | } | |
365 | ||
3d4d3e48 | 366 | size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 367 | { |
3d4d3e48 | 368 | char *from = addr; |
62a8067a AV |
369 | if (unlikely(bytes > i->count)) |
370 | bytes = i->count; | |
371 | ||
372 | if (unlikely(!bytes)) | |
373 | return 0; | |
374 | ||
3d4d3e48 AV |
375 | iterate_and_advance(i, bytes, v, |
376 | __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, | |
377 | v.iov_len), | |
378 | memcpy_to_page(v.bv_page, v.bv_offset, | |
a280455f AV |
379 | (from += v.bv_len) - v.bv_len, v.bv_len), |
380 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 381 | ) |
62a8067a | 382 | |
3d4d3e48 | 383 | return bytes; |
c35e0248 | 384 | } |
d271524a | 385 | EXPORT_SYMBOL(copy_to_iter); |
c35e0248 | 386 | |
d271524a | 387 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 388 | { |
0dbca9a4 AV |
389 | char *to = addr; |
390 | if (unlikely(bytes > i->count)) | |
391 | bytes = i->count; | |
392 | ||
393 | if (unlikely(!bytes)) | |
394 | return 0; | |
395 | ||
396 | iterate_and_advance(i, bytes, v, | |
397 | __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, | |
398 | v.iov_len), | |
399 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
400 | v.bv_offset, v.bv_len), |
401 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
402 | ) |
403 | ||
404 | return bytes; | |
c35e0248 | 405 | } |
d271524a | 406 | EXPORT_SYMBOL(copy_from_iter); |
c35e0248 | 407 | |
aa583096 AV |
408 | size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
409 | { | |
410 | char *to = addr; | |
411 | if (unlikely(bytes > i->count)) | |
412 | bytes = i->count; | |
413 | ||
414 | if (unlikely(!bytes)) | |
415 | return 0; | |
416 | ||
417 | iterate_and_advance(i, bytes, v, | |
418 | __copy_from_user_nocache((to += v.iov_len) - v.iov_len, | |
419 | v.iov_base, v.iov_len), | |
420 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
421 | v.bv_offset, v.bv_len), | |
422 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
423 | ) | |
424 | ||
425 | return bytes; | |
426 | } | |
427 | EXPORT_SYMBOL(copy_from_iter_nocache); | |
428 | ||
62a8067a AV |
429 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
430 | struct iov_iter *i) | |
431 | { | |
d271524a AV |
432 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
433 | void *kaddr = kmap_atomic(page); | |
434 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
435 | kunmap_atomic(kaddr); | |
436 | return wanted; | |
437 | } else | |
62a8067a AV |
438 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
439 | } | |
440 | EXPORT_SYMBOL(copy_page_to_iter); | |
441 | ||
442 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
443 | struct iov_iter *i) | |
444 | { | |
a280455f | 445 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a AV |
446 | void *kaddr = kmap_atomic(page); |
447 | size_t wanted = copy_from_iter(kaddr + offset, bytes, i); | |
448 | kunmap_atomic(kaddr); | |
449 | return wanted; | |
450 | } else | |
62a8067a AV |
451 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
452 | } | |
453 | EXPORT_SYMBOL(copy_page_from_iter); | |
454 | ||
c35e0248 MW |
455 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
456 | { | |
8442fa46 AV |
457 | if (unlikely(bytes > i->count)) |
458 | bytes = i->count; | |
459 | ||
460 | if (unlikely(!bytes)) | |
461 | return 0; | |
462 | ||
463 | iterate_and_advance(i, bytes, v, | |
464 | __clear_user(v.iov_base, v.iov_len), | |
a280455f AV |
465 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
466 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
467 | ) |
468 | ||
469 | return bytes; | |
c35e0248 MW |
470 | } |
471 | EXPORT_SYMBOL(iov_iter_zero); | |
472 | ||
62a8067a AV |
473 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
474 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
475 | { | |
04a31165 AV |
476 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
477 | iterate_all_kinds(i, bytes, v, | |
478 | __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, | |
479 | v.iov_base, v.iov_len), | |
480 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
481 | v.bv_offset, v.bv_len), |
482 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
483 | ) |
484 | kunmap_atomic(kaddr); | |
485 | return bytes; | |
62a8067a AV |
486 | } |
487 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
488 | ||
489 | void iov_iter_advance(struct iov_iter *i, size_t size) | |
490 | { | |
a280455f | 491 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
492 | } |
493 | EXPORT_SYMBOL(iov_iter_advance); | |
494 | ||
495 | /* | |
496 | * Return the count of just the current iov_iter segment. | |
497 | */ | |
498 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
499 | { | |
500 | if (i->nr_segs == 1) | |
501 | return i->count; | |
502 | else if (i->type & ITER_BVEC) | |
62a8067a | 503 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
504 | else |
505 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
506 | } |
507 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
508 | ||
abb78f87 | 509 | void iov_iter_kvec(struct iov_iter *i, int direction, |
05afcb77 | 510 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
511 | size_t count) |
512 | { | |
513 | BUG_ON(!(direction & ITER_KVEC)); | |
514 | i->type = direction; | |
05afcb77 | 515 | i->kvec = kvec; |
abb78f87 AV |
516 | i->nr_segs = nr_segs; |
517 | i->iov_offset = 0; | |
518 | i->count = count; | |
519 | } | |
520 | EXPORT_SYMBOL(iov_iter_kvec); | |
521 | ||
05afcb77 AV |
522 | void iov_iter_bvec(struct iov_iter *i, int direction, |
523 | const struct bio_vec *bvec, unsigned long nr_segs, | |
524 | size_t count) | |
525 | { | |
526 | BUG_ON(!(direction & ITER_BVEC)); | |
527 | i->type = direction; | |
528 | i->bvec = bvec; | |
529 | i->nr_segs = nr_segs; | |
530 | i->iov_offset = 0; | |
531 | i->count = count; | |
532 | } | |
533 | EXPORT_SYMBOL(iov_iter_bvec); | |
534 | ||
62a8067a AV |
535 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
536 | { | |
04a31165 AV |
537 | unsigned long res = 0; |
538 | size_t size = i->count; | |
539 | ||
540 | if (!size) | |
541 | return 0; | |
542 | ||
543 | iterate_all_kinds(i, size, v, | |
544 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
545 | res |= v.bv_offset | v.bv_len, |
546 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
547 | ) |
548 | return res; | |
62a8067a AV |
549 | } |
550 | EXPORT_SYMBOL(iov_iter_alignment); | |
551 | ||
552 | ssize_t iov_iter_get_pages(struct iov_iter *i, | |
2c80929c | 553 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
554 | size_t *start) |
555 | { | |
e5393fae AV |
556 | if (maxsize > i->count) |
557 | maxsize = i->count; | |
558 | ||
559 | if (!maxsize) | |
560 | return 0; | |
561 | ||
562 | iterate_all_kinds(i, maxsize, v, ({ | |
563 | unsigned long addr = (unsigned long)v.iov_base; | |
564 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
565 | int n; | |
566 | int res; | |
567 | ||
568 | if (len > maxpages * PAGE_SIZE) | |
569 | len = maxpages * PAGE_SIZE; | |
570 | addr &= ~(PAGE_SIZE - 1); | |
571 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
572 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); | |
573 | if (unlikely(res < 0)) | |
574 | return res; | |
575 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
576 | 0;}),({ | |
577 | /* can't be more than PAGE_SIZE */ | |
578 | *start = v.bv_offset; | |
579 | get_page(*pages = v.bv_page); | |
580 | return v.bv_len; | |
a280455f AV |
581 | }),({ |
582 | return -EFAULT; | |
e5393fae AV |
583 | }) |
584 | ) | |
585 | return 0; | |
62a8067a AV |
586 | } |
587 | EXPORT_SYMBOL(iov_iter_get_pages); | |
588 | ||
1b17f1f2 AV |
589 | static struct page **get_pages_array(size_t n) |
590 | { | |
591 | struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); | |
592 | if (!p) | |
593 | p = vmalloc(n * sizeof(struct page *)); | |
594 | return p; | |
595 | } | |
596 | ||
62a8067a AV |
597 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
598 | struct page ***pages, size_t maxsize, | |
599 | size_t *start) | |
600 | { | |
1b17f1f2 AV |
601 | struct page **p; |
602 | ||
603 | if (maxsize > i->count) | |
604 | maxsize = i->count; | |
605 | ||
606 | if (!maxsize) | |
607 | return 0; | |
608 | ||
609 | iterate_all_kinds(i, maxsize, v, ({ | |
610 | unsigned long addr = (unsigned long)v.iov_base; | |
611 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
612 | int n; | |
613 | int res; | |
614 | ||
615 | addr &= ~(PAGE_SIZE - 1); | |
616 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
617 | p = get_pages_array(n); | |
618 | if (!p) | |
619 | return -ENOMEM; | |
620 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); | |
621 | if (unlikely(res < 0)) { | |
622 | kvfree(p); | |
623 | return res; | |
624 | } | |
625 | *pages = p; | |
626 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
627 | 0;}),({ | |
628 | /* can't be more than PAGE_SIZE */ | |
629 | *start = v.bv_offset; | |
630 | *pages = p = get_pages_array(1); | |
631 | if (!p) | |
632 | return -ENOMEM; | |
633 | get_page(*p = v.bv_page); | |
634 | return v.bv_len; | |
a280455f AV |
635 | }),({ |
636 | return -EFAULT; | |
1b17f1f2 AV |
637 | }) |
638 | ) | |
639 | return 0; | |
62a8067a AV |
640 | } |
641 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
642 | ||
a604ec7e AV |
643 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
644 | struct iov_iter *i) | |
645 | { | |
646 | char *to = addr; | |
647 | __wsum sum, next; | |
648 | size_t off = 0; | |
649 | if (unlikely(bytes > i->count)) | |
650 | bytes = i->count; | |
651 | ||
652 | if (unlikely(!bytes)) | |
653 | return 0; | |
654 | ||
655 | sum = *csum; | |
656 | iterate_and_advance(i, bytes, v, ({ | |
657 | int err = 0; | |
658 | next = csum_and_copy_from_user(v.iov_base, | |
659 | (to += v.iov_len) - v.iov_len, | |
660 | v.iov_len, 0, &err); | |
661 | if (!err) { | |
662 | sum = csum_block_add(sum, next, off); | |
663 | off += v.iov_len; | |
664 | } | |
665 | err ? v.iov_len : 0; | |
666 | }), ({ | |
667 | char *p = kmap_atomic(v.bv_page); | |
668 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
669 | (to += v.bv_len) - v.bv_len, | |
670 | v.bv_len, 0); | |
671 | kunmap_atomic(p); | |
672 | sum = csum_block_add(sum, next, off); | |
673 | off += v.bv_len; | |
674 | }),({ | |
675 | next = csum_partial_copy_nocheck(v.iov_base, | |
676 | (to += v.iov_len) - v.iov_len, | |
677 | v.iov_len, 0); | |
678 | sum = csum_block_add(sum, next, off); | |
679 | off += v.iov_len; | |
680 | }) | |
681 | ) | |
682 | *csum = sum; | |
683 | return bytes; | |
684 | } | |
685 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
686 | ||
687 | size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum, | |
688 | struct iov_iter *i) | |
689 | { | |
690 | char *from = addr; | |
691 | __wsum sum, next; | |
692 | size_t off = 0; | |
693 | if (unlikely(bytes > i->count)) | |
694 | bytes = i->count; | |
695 | ||
696 | if (unlikely(!bytes)) | |
697 | return 0; | |
698 | ||
699 | sum = *csum; | |
700 | iterate_and_advance(i, bytes, v, ({ | |
701 | int err = 0; | |
702 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
703 | v.iov_base, | |
704 | v.iov_len, 0, &err); | |
705 | if (!err) { | |
706 | sum = csum_block_add(sum, next, off); | |
707 | off += v.iov_len; | |
708 | } | |
709 | err ? v.iov_len : 0; | |
710 | }), ({ | |
711 | char *p = kmap_atomic(v.bv_page); | |
712 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
713 | p + v.bv_offset, | |
714 | v.bv_len, 0); | |
715 | kunmap_atomic(p); | |
716 | sum = csum_block_add(sum, next, off); | |
717 | off += v.bv_len; | |
718 | }),({ | |
719 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
720 | v.iov_base, | |
721 | v.iov_len, 0); | |
722 | sum = csum_block_add(sum, next, off); | |
723 | off += v.iov_len; | |
724 | }) | |
725 | ) | |
726 | *csum = sum; | |
727 | return bytes; | |
728 | } | |
729 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
730 | ||
62a8067a AV |
731 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
732 | { | |
e0f2dc40 AV |
733 | size_t size = i->count; |
734 | int npages = 0; | |
735 | ||
736 | if (!size) | |
737 | return 0; | |
738 | ||
739 | iterate_all_kinds(i, size, v, ({ | |
740 | unsigned long p = (unsigned long)v.iov_base; | |
741 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
742 | - p / PAGE_SIZE; | |
743 | if (npages >= maxpages) | |
744 | return maxpages; | |
745 | 0;}),({ | |
746 | npages++; | |
747 | if (npages >= maxpages) | |
748 | return maxpages; | |
a280455f AV |
749 | }),({ |
750 | unsigned long p = (unsigned long)v.iov_base; | |
751 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
752 | - p / PAGE_SIZE; | |
753 | if (npages >= maxpages) | |
754 | return maxpages; | |
e0f2dc40 AV |
755 | }) |
756 | ) | |
757 | return npages; | |
62a8067a | 758 | } |
f67da30c | 759 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
760 | |
761 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
762 | { | |
763 | *new = *old; | |
764 | if (new->type & ITER_BVEC) | |
765 | return new->bvec = kmemdup(new->bvec, | |
766 | new->nr_segs * sizeof(struct bio_vec), | |
767 | flags); | |
768 | else | |
769 | /* iovec and kvec have identical layout */ | |
770 | return new->iov = kmemdup(new->iov, | |
771 | new->nr_segs * sizeof(struct iovec), | |
772 | flags); | |
773 | } | |
774 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 AV |
775 | |
776 | int import_iovec(int type, const struct iovec __user * uvector, | |
777 | unsigned nr_segs, unsigned fast_segs, | |
778 | struct iovec **iov, struct iov_iter *i) | |
779 | { | |
780 | ssize_t n; | |
781 | struct iovec *p; | |
782 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
783 | *iov, &p); | |
784 | if (n < 0) { | |
785 | if (p != *iov) | |
786 | kfree(p); | |
787 | *iov = NULL; | |
788 | return n; | |
789 | } | |
790 | iov_iter_init(i, type, p, nr_segs, n); | |
791 | *iov = p == *iov ? NULL : p; | |
792 | return 0; | |
793 | } | |
794 | EXPORT_SYMBOL(import_iovec); | |
795 | ||
796 | #ifdef CONFIG_COMPAT | |
797 | #include <linux/compat.h> | |
798 | ||
799 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
800 | unsigned nr_segs, unsigned fast_segs, | |
801 | struct iovec **iov, struct iov_iter *i) | |
802 | { | |
803 | ssize_t n; | |
804 | struct iovec *p; | |
805 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
806 | *iov, &p); | |
807 | if (n < 0) { | |
808 | if (p != *iov) | |
809 | kfree(p); | |
810 | *iov = NULL; | |
811 | return n; | |
812 | } | |
813 | iov_iter_init(i, type, p, nr_segs, n); | |
814 | *iov = p == *iov ? NULL : p; | |
815 | return 0; | |
816 | } | |
817 | #endif | |
818 | ||
819 | int import_single_range(int rw, void __user *buf, size_t len, | |
820 | struct iovec *iov, struct iov_iter *i) | |
821 | { | |
822 | if (len > MAX_RW_COUNT) | |
823 | len = MAX_RW_COUNT; | |
824 | if (unlikely(!access_ok(!rw, buf, len))) | |
825 | return -EFAULT; | |
826 | ||
827 | iov->iov_base = buf; | |
828 | iov->iov_len = len; | |
829 | iov_iter_init(i, rw, iov, 1, len); | |
830 | return 0; | |
831 | } |