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 | |
4f18cd31 AV |
300 | /* |
301 | * Fault in the first iovec of the given iov_iter, to a maximum length | |
302 | * of bytes. Returns 0 on success, or non-zero if the memory could not be | |
303 | * accessed (ie. because it is an invalid address). | |
304 | * | |
305 | * writev-intensive code may want this to prefault several iovecs -- that | |
306 | * would be possible (callers must not rely on the fact that _only_ the | |
307 | * first iovec will be faulted with the current implementation). | |
308 | */ | |
309 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) | |
310 | { | |
a280455f | 311 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { |
62a8067a AV |
312 | char __user *buf = i->iov->iov_base + i->iov_offset; |
313 | bytes = min(bytes, i->iov->iov_len - i->iov_offset); | |
314 | return fault_in_pages_readable(buf, bytes); | |
315 | } | |
316 | return 0; | |
4f18cd31 AV |
317 | } |
318 | EXPORT_SYMBOL(iov_iter_fault_in_readable); | |
319 | ||
71d8e532 AV |
320 | void iov_iter_init(struct iov_iter *i, int direction, |
321 | const struct iovec *iov, unsigned long nr_segs, | |
322 | size_t count) | |
323 | { | |
324 | /* It will get better. Eventually... */ | |
a280455f | 325 | if (segment_eq(get_fs(), KERNEL_DS)) { |
62a8067a | 326 | direction |= ITER_KVEC; |
a280455f AV |
327 | i->type = direction; |
328 | i->kvec = (struct kvec *)iov; | |
329 | } else { | |
330 | i->type = direction; | |
331 | i->iov = iov; | |
332 | } | |
71d8e532 AV |
333 | i->nr_segs = nr_segs; |
334 | i->iov_offset = 0; | |
335 | i->count = count; | |
336 | } | |
337 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 338 | |
62a8067a AV |
339 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
340 | { | |
341 | char *from = kmap_atomic(page); | |
342 | memcpy(to, from + offset, len); | |
343 | kunmap_atomic(from); | |
344 | } | |
345 | ||
346 | static void memcpy_to_page(struct page *page, size_t offset, char *from, size_t len) | |
347 | { | |
348 | char *to = kmap_atomic(page); | |
349 | memcpy(to + offset, from, len); | |
350 | kunmap_atomic(to); | |
351 | } | |
352 | ||
c35e0248 MW |
353 | static void memzero_page(struct page *page, size_t offset, size_t len) |
354 | { | |
355 | char *addr = kmap_atomic(page); | |
356 | memset(addr + offset, 0, len); | |
357 | kunmap_atomic(addr); | |
358 | } | |
359 | ||
3d4d3e48 | 360 | size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 361 | { |
3d4d3e48 | 362 | char *from = addr; |
62a8067a AV |
363 | if (unlikely(bytes > i->count)) |
364 | bytes = i->count; | |
365 | ||
366 | if (unlikely(!bytes)) | |
367 | return 0; | |
368 | ||
3d4d3e48 AV |
369 | iterate_and_advance(i, bytes, v, |
370 | __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, | |
371 | v.iov_len), | |
372 | memcpy_to_page(v.bv_page, v.bv_offset, | |
a280455f AV |
373 | (from += v.bv_len) - v.bv_len, v.bv_len), |
374 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 375 | ) |
62a8067a | 376 | |
3d4d3e48 | 377 | return bytes; |
c35e0248 | 378 | } |
d271524a | 379 | EXPORT_SYMBOL(copy_to_iter); |
c35e0248 | 380 | |
d271524a | 381 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 382 | { |
0dbca9a4 AV |
383 | char *to = addr; |
384 | if (unlikely(bytes > i->count)) | |
385 | bytes = i->count; | |
386 | ||
387 | if (unlikely(!bytes)) | |
388 | return 0; | |
389 | ||
390 | iterate_and_advance(i, bytes, v, | |
391 | __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, | |
392 | v.iov_len), | |
393 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
394 | v.bv_offset, v.bv_len), |
395 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
396 | ) |
397 | ||
398 | return bytes; | |
c35e0248 | 399 | } |
d271524a | 400 | EXPORT_SYMBOL(copy_from_iter); |
c35e0248 | 401 | |
62a8067a AV |
402 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
403 | struct iov_iter *i) | |
404 | { | |
d271524a AV |
405 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
406 | void *kaddr = kmap_atomic(page); | |
407 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
408 | kunmap_atomic(kaddr); | |
409 | return wanted; | |
410 | } else | |
62a8067a AV |
411 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
412 | } | |
413 | EXPORT_SYMBOL(copy_page_to_iter); | |
414 | ||
415 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
416 | struct iov_iter *i) | |
417 | { | |
a280455f | 418 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a AV |
419 | void *kaddr = kmap_atomic(page); |
420 | size_t wanted = copy_from_iter(kaddr + offset, bytes, i); | |
421 | kunmap_atomic(kaddr); | |
422 | return wanted; | |
423 | } else | |
62a8067a AV |
424 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
425 | } | |
426 | EXPORT_SYMBOL(copy_page_from_iter); | |
427 | ||
c35e0248 MW |
428 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
429 | { | |
8442fa46 AV |
430 | if (unlikely(bytes > i->count)) |
431 | bytes = i->count; | |
432 | ||
433 | if (unlikely(!bytes)) | |
434 | return 0; | |
435 | ||
436 | iterate_and_advance(i, bytes, v, | |
437 | __clear_user(v.iov_base, v.iov_len), | |
a280455f AV |
438 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
439 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
440 | ) |
441 | ||
442 | return bytes; | |
c35e0248 MW |
443 | } |
444 | EXPORT_SYMBOL(iov_iter_zero); | |
445 | ||
62a8067a AV |
446 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
447 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
448 | { | |
04a31165 AV |
449 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
450 | iterate_all_kinds(i, bytes, v, | |
451 | __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, | |
452 | v.iov_base, v.iov_len), | |
453 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
454 | v.bv_offset, v.bv_len), |
455 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
456 | ) |
457 | kunmap_atomic(kaddr); | |
458 | return bytes; | |
62a8067a AV |
459 | } |
460 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
461 | ||
462 | void iov_iter_advance(struct iov_iter *i, size_t size) | |
463 | { | |
a280455f | 464 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
465 | } |
466 | EXPORT_SYMBOL(iov_iter_advance); | |
467 | ||
468 | /* | |
469 | * Return the count of just the current iov_iter segment. | |
470 | */ | |
471 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
472 | { | |
473 | if (i->nr_segs == 1) | |
474 | return i->count; | |
475 | else if (i->type & ITER_BVEC) | |
62a8067a | 476 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
477 | else |
478 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
479 | } |
480 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
481 | ||
abb78f87 AV |
482 | void iov_iter_kvec(struct iov_iter *i, int direction, |
483 | const struct kvec *iov, unsigned long nr_segs, | |
484 | size_t count) | |
485 | { | |
486 | BUG_ON(!(direction & ITER_KVEC)); | |
487 | i->type = direction; | |
488 | i->kvec = (struct kvec *)iov; | |
489 | i->nr_segs = nr_segs; | |
490 | i->iov_offset = 0; | |
491 | i->count = count; | |
492 | } | |
493 | EXPORT_SYMBOL(iov_iter_kvec); | |
494 | ||
62a8067a AV |
495 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
496 | { | |
04a31165 AV |
497 | unsigned long res = 0; |
498 | size_t size = i->count; | |
499 | ||
500 | if (!size) | |
501 | return 0; | |
502 | ||
503 | iterate_all_kinds(i, size, v, | |
504 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
505 | res |= v.bv_offset | v.bv_len, |
506 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
507 | ) |
508 | return res; | |
62a8067a AV |
509 | } |
510 | EXPORT_SYMBOL(iov_iter_alignment); | |
511 | ||
512 | ssize_t iov_iter_get_pages(struct iov_iter *i, | |
2c80929c | 513 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
514 | size_t *start) |
515 | { | |
e5393fae AV |
516 | if (maxsize > i->count) |
517 | maxsize = i->count; | |
518 | ||
519 | if (!maxsize) | |
520 | return 0; | |
521 | ||
522 | iterate_all_kinds(i, maxsize, v, ({ | |
523 | unsigned long addr = (unsigned long)v.iov_base; | |
524 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
525 | int n; | |
526 | int res; | |
527 | ||
528 | if (len > maxpages * PAGE_SIZE) | |
529 | len = maxpages * PAGE_SIZE; | |
530 | addr &= ~(PAGE_SIZE - 1); | |
531 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
532 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); | |
533 | if (unlikely(res < 0)) | |
534 | return res; | |
535 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
536 | 0;}),({ | |
537 | /* can't be more than PAGE_SIZE */ | |
538 | *start = v.bv_offset; | |
539 | get_page(*pages = v.bv_page); | |
540 | return v.bv_len; | |
a280455f AV |
541 | }),({ |
542 | return -EFAULT; | |
e5393fae AV |
543 | }) |
544 | ) | |
545 | return 0; | |
62a8067a AV |
546 | } |
547 | EXPORT_SYMBOL(iov_iter_get_pages); | |
548 | ||
1b17f1f2 AV |
549 | static struct page **get_pages_array(size_t n) |
550 | { | |
551 | struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); | |
552 | if (!p) | |
553 | p = vmalloc(n * sizeof(struct page *)); | |
554 | return p; | |
555 | } | |
556 | ||
62a8067a AV |
557 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
558 | struct page ***pages, size_t maxsize, | |
559 | size_t *start) | |
560 | { | |
1b17f1f2 AV |
561 | struct page **p; |
562 | ||
563 | if (maxsize > i->count) | |
564 | maxsize = i->count; | |
565 | ||
566 | if (!maxsize) | |
567 | return 0; | |
568 | ||
569 | iterate_all_kinds(i, maxsize, v, ({ | |
570 | unsigned long addr = (unsigned long)v.iov_base; | |
571 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
572 | int n; | |
573 | int res; | |
574 | ||
575 | addr &= ~(PAGE_SIZE - 1); | |
576 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
577 | p = get_pages_array(n); | |
578 | if (!p) | |
579 | return -ENOMEM; | |
580 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); | |
581 | if (unlikely(res < 0)) { | |
582 | kvfree(p); | |
583 | return res; | |
584 | } | |
585 | *pages = p; | |
586 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
587 | 0;}),({ | |
588 | /* can't be more than PAGE_SIZE */ | |
589 | *start = v.bv_offset; | |
590 | *pages = p = get_pages_array(1); | |
591 | if (!p) | |
592 | return -ENOMEM; | |
593 | get_page(*p = v.bv_page); | |
594 | return v.bv_len; | |
a280455f AV |
595 | }),({ |
596 | return -EFAULT; | |
1b17f1f2 AV |
597 | }) |
598 | ) | |
599 | return 0; | |
62a8067a AV |
600 | } |
601 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
602 | ||
a604ec7e AV |
603 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
604 | struct iov_iter *i) | |
605 | { | |
606 | char *to = addr; | |
607 | __wsum sum, next; | |
608 | size_t off = 0; | |
609 | if (unlikely(bytes > i->count)) | |
610 | bytes = i->count; | |
611 | ||
612 | if (unlikely(!bytes)) | |
613 | return 0; | |
614 | ||
615 | sum = *csum; | |
616 | iterate_and_advance(i, bytes, v, ({ | |
617 | int err = 0; | |
618 | next = csum_and_copy_from_user(v.iov_base, | |
619 | (to += v.iov_len) - v.iov_len, | |
620 | v.iov_len, 0, &err); | |
621 | if (!err) { | |
622 | sum = csum_block_add(sum, next, off); | |
623 | off += v.iov_len; | |
624 | } | |
625 | err ? v.iov_len : 0; | |
626 | }), ({ | |
627 | char *p = kmap_atomic(v.bv_page); | |
628 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
629 | (to += v.bv_len) - v.bv_len, | |
630 | v.bv_len, 0); | |
631 | kunmap_atomic(p); | |
632 | sum = csum_block_add(sum, next, off); | |
633 | off += v.bv_len; | |
634 | }),({ | |
635 | next = csum_partial_copy_nocheck(v.iov_base, | |
636 | (to += v.iov_len) - v.iov_len, | |
637 | v.iov_len, 0); | |
638 | sum = csum_block_add(sum, next, off); | |
639 | off += v.iov_len; | |
640 | }) | |
641 | ) | |
642 | *csum = sum; | |
643 | return bytes; | |
644 | } | |
645 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
646 | ||
647 | size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum, | |
648 | struct iov_iter *i) | |
649 | { | |
650 | char *from = addr; | |
651 | __wsum sum, next; | |
652 | size_t off = 0; | |
653 | if (unlikely(bytes > i->count)) | |
654 | bytes = i->count; | |
655 | ||
656 | if (unlikely(!bytes)) | |
657 | return 0; | |
658 | ||
659 | sum = *csum; | |
660 | iterate_and_advance(i, bytes, v, ({ | |
661 | int err = 0; | |
662 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
663 | v.iov_base, | |
664 | v.iov_len, 0, &err); | |
665 | if (!err) { | |
666 | sum = csum_block_add(sum, next, off); | |
667 | off += v.iov_len; | |
668 | } | |
669 | err ? v.iov_len : 0; | |
670 | }), ({ | |
671 | char *p = kmap_atomic(v.bv_page); | |
672 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
673 | p + v.bv_offset, | |
674 | v.bv_len, 0); | |
675 | kunmap_atomic(p); | |
676 | sum = csum_block_add(sum, next, off); | |
677 | off += v.bv_len; | |
678 | }),({ | |
679 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
680 | v.iov_base, | |
681 | v.iov_len, 0); | |
682 | sum = csum_block_add(sum, next, off); | |
683 | off += v.iov_len; | |
684 | }) | |
685 | ) | |
686 | *csum = sum; | |
687 | return bytes; | |
688 | } | |
689 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
690 | ||
62a8067a AV |
691 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
692 | { | |
e0f2dc40 AV |
693 | size_t size = i->count; |
694 | int npages = 0; | |
695 | ||
696 | if (!size) | |
697 | return 0; | |
698 | ||
699 | iterate_all_kinds(i, size, v, ({ | |
700 | unsigned long p = (unsigned long)v.iov_base; | |
701 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
702 | - p / PAGE_SIZE; | |
703 | if (npages >= maxpages) | |
704 | return maxpages; | |
705 | 0;}),({ | |
706 | npages++; | |
707 | if (npages >= maxpages) | |
708 | return maxpages; | |
a280455f AV |
709 | }),({ |
710 | unsigned long p = (unsigned long)v.iov_base; | |
711 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
712 | - p / PAGE_SIZE; | |
713 | if (npages >= maxpages) | |
714 | return maxpages; | |
e0f2dc40 AV |
715 | }) |
716 | ) | |
717 | return npages; | |
62a8067a | 718 | } |
f67da30c | 719 | EXPORT_SYMBOL(iov_iter_npages); |