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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 | ||
1bdc76ae ML |
59 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ |
60 | struct bvec_iter __start; \ | |
61 | __start.bi_size = n; \ | |
62 | __start.bi_bvec_done = skip; \ | |
63 | __start.bi_idx = 0; \ | |
64 | for_each_bvec(__v, i->bvec, __bi, __start) { \ | |
65 | if (!__v.bv_len) \ | |
04a31165 | 66 | continue; \ |
04a31165 | 67 | (void)(STEP); \ |
04a31165 | 68 | } \ |
04a31165 AV |
69 | } |
70 | ||
a280455f | 71 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
04a31165 AV |
72 | size_t skip = i->iov_offset; \ |
73 | if (unlikely(i->type & ITER_BVEC)) { \ | |
04a31165 | 74 | struct bio_vec v; \ |
1bdc76ae ML |
75 | struct bvec_iter __bi; \ |
76 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
a280455f AV |
77 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
78 | const struct kvec *kvec; \ | |
79 | struct kvec v; \ | |
80 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
04a31165 AV |
81 | } else { \ |
82 | const struct iovec *iov; \ | |
83 | struct iovec v; \ | |
84 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
85 | } \ | |
86 | } | |
87 | ||
a280455f | 88 | #define iterate_and_advance(i, n, v, I, B, K) { \ |
dd254f5a AV |
89 | if (unlikely(i->count < n)) \ |
90 | n = i->count; \ | |
19f18459 | 91 | if (i->count) { \ |
dd254f5a AV |
92 | size_t skip = i->iov_offset; \ |
93 | if (unlikely(i->type & ITER_BVEC)) { \ | |
1bdc76ae | 94 | const struct bio_vec *bvec = i->bvec; \ |
dd254f5a | 95 | struct bio_vec v; \ |
1bdc76ae ML |
96 | struct bvec_iter __bi; \ |
97 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | |
98 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ | |
99 | i->nr_segs -= i->bvec - bvec; \ | |
100 | skip = __bi.bi_bvec_done; \ | |
dd254f5a AV |
101 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
102 | const struct kvec *kvec; \ | |
103 | struct kvec v; \ | |
104 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
105 | if (skip == kvec->iov_len) { \ | |
106 | kvec++; \ | |
107 | skip = 0; \ | |
108 | } \ | |
109 | i->nr_segs -= kvec - i->kvec; \ | |
110 | i->kvec = kvec; \ | |
111 | } else { \ | |
112 | const struct iovec *iov; \ | |
113 | struct iovec v; \ | |
114 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
115 | if (skip == iov->iov_len) { \ | |
116 | iov++; \ | |
117 | skip = 0; \ | |
118 | } \ | |
119 | i->nr_segs -= iov - i->iov; \ | |
120 | i->iov = iov; \ | |
7ce2a91e | 121 | } \ |
dd254f5a AV |
122 | i->count -= n; \ |
123 | i->iov_offset = skip; \ | |
7ce2a91e | 124 | } \ |
7ce2a91e AV |
125 | } |
126 | ||
62a8067a | 127 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
128 | struct iov_iter *i) |
129 | { | |
130 | size_t skip, copy, left, wanted; | |
131 | const struct iovec *iov; | |
132 | char __user *buf; | |
133 | void *kaddr, *from; | |
134 | ||
135 | if (unlikely(bytes > i->count)) | |
136 | bytes = i->count; | |
137 | ||
138 | if (unlikely(!bytes)) | |
139 | return 0; | |
140 | ||
141 | wanted = bytes; | |
142 | iov = i->iov; | |
143 | skip = i->iov_offset; | |
144 | buf = iov->iov_base + skip; | |
145 | copy = min(bytes, iov->iov_len - skip); | |
146 | ||
147 | if (!fault_in_pages_writeable(buf, copy)) { | |
148 | kaddr = kmap_atomic(page); | |
149 | from = kaddr + offset; | |
150 | ||
151 | /* first chunk, usually the only one */ | |
152 | left = __copy_to_user_inatomic(buf, from, copy); | |
153 | copy -= left; | |
154 | skip += copy; | |
155 | from += copy; | |
156 | bytes -= copy; | |
157 | ||
158 | while (unlikely(!left && bytes)) { | |
159 | iov++; | |
160 | buf = iov->iov_base; | |
161 | copy = min(bytes, iov->iov_len); | |
162 | left = __copy_to_user_inatomic(buf, from, copy); | |
163 | copy -= left; | |
164 | skip = copy; | |
165 | from += copy; | |
166 | bytes -= copy; | |
167 | } | |
168 | if (likely(!bytes)) { | |
169 | kunmap_atomic(kaddr); | |
170 | goto done; | |
171 | } | |
172 | offset = from - kaddr; | |
173 | buf += copy; | |
174 | kunmap_atomic(kaddr); | |
175 | copy = min(bytes, iov->iov_len - skip); | |
176 | } | |
177 | /* Too bad - revert to non-atomic kmap */ | |
178 | kaddr = kmap(page); | |
179 | from = kaddr + offset; | |
180 | left = __copy_to_user(buf, from, copy); | |
181 | copy -= left; | |
182 | skip += copy; | |
183 | from += copy; | |
184 | bytes -= copy; | |
185 | while (unlikely(!left && bytes)) { | |
186 | iov++; | |
187 | buf = iov->iov_base; | |
188 | copy = min(bytes, iov->iov_len); | |
189 | left = __copy_to_user(buf, from, copy); | |
190 | copy -= left; | |
191 | skip = copy; | |
192 | from += copy; | |
193 | bytes -= copy; | |
194 | } | |
195 | kunmap(page); | |
196 | done: | |
81055e58 AV |
197 | if (skip == iov->iov_len) { |
198 | iov++; | |
199 | skip = 0; | |
200 | } | |
4f18cd31 AV |
201 | i->count -= wanted - bytes; |
202 | i->nr_segs -= iov - i->iov; | |
203 | i->iov = iov; | |
204 | i->iov_offset = skip; | |
205 | return wanted - bytes; | |
206 | } | |
4f18cd31 | 207 | |
62a8067a | 208 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
209 | struct iov_iter *i) |
210 | { | |
211 | size_t skip, copy, left, wanted; | |
212 | const struct iovec *iov; | |
213 | char __user *buf; | |
214 | void *kaddr, *to; | |
215 | ||
216 | if (unlikely(bytes > i->count)) | |
217 | bytes = i->count; | |
218 | ||
219 | if (unlikely(!bytes)) | |
220 | return 0; | |
221 | ||
222 | wanted = bytes; | |
223 | iov = i->iov; | |
224 | skip = i->iov_offset; | |
225 | buf = iov->iov_base + skip; | |
226 | copy = min(bytes, iov->iov_len - skip); | |
227 | ||
228 | if (!fault_in_pages_readable(buf, copy)) { | |
229 | kaddr = kmap_atomic(page); | |
230 | to = kaddr + offset; | |
231 | ||
232 | /* first chunk, usually the only one */ | |
233 | left = __copy_from_user_inatomic(to, buf, copy); | |
234 | copy -= left; | |
235 | skip += copy; | |
236 | to += copy; | |
237 | bytes -= copy; | |
238 | ||
239 | while (unlikely(!left && bytes)) { | |
240 | iov++; | |
241 | buf = iov->iov_base; | |
242 | copy = min(bytes, iov->iov_len); | |
243 | left = __copy_from_user_inatomic(to, buf, copy); | |
244 | copy -= left; | |
245 | skip = copy; | |
246 | to += copy; | |
247 | bytes -= copy; | |
248 | } | |
249 | if (likely(!bytes)) { | |
250 | kunmap_atomic(kaddr); | |
251 | goto done; | |
252 | } | |
253 | offset = to - kaddr; | |
254 | buf += copy; | |
255 | kunmap_atomic(kaddr); | |
256 | copy = min(bytes, iov->iov_len - skip); | |
257 | } | |
258 | /* Too bad - revert to non-atomic kmap */ | |
259 | kaddr = kmap(page); | |
260 | to = kaddr + offset; | |
261 | left = __copy_from_user(to, buf, copy); | |
262 | copy -= left; | |
263 | skip += copy; | |
264 | to += copy; | |
265 | bytes -= copy; | |
266 | while (unlikely(!left && bytes)) { | |
267 | iov++; | |
268 | buf = iov->iov_base; | |
269 | copy = min(bytes, iov->iov_len); | |
270 | left = __copy_from_user(to, buf, copy); | |
271 | copy -= left; | |
272 | skip = copy; | |
273 | to += copy; | |
274 | bytes -= copy; | |
275 | } | |
276 | kunmap(page); | |
277 | done: | |
81055e58 AV |
278 | if (skip == iov->iov_len) { |
279 | iov++; | |
280 | skip = 0; | |
281 | } | |
f0d1bec9 AV |
282 | i->count -= wanted - bytes; |
283 | i->nr_segs -= iov - i->iov; | |
284 | i->iov = iov; | |
285 | i->iov_offset = skip; | |
286 | return wanted - bytes; | |
287 | } | |
f0d1bec9 | 288 | |
4f18cd31 AV |
289 | /* |
290 | * Fault in the first iovec of the given iov_iter, to a maximum length | |
291 | * of bytes. Returns 0 on success, or non-zero if the memory could not be | |
292 | * accessed (ie. because it is an invalid address). | |
293 | * | |
294 | * writev-intensive code may want this to prefault several iovecs -- that | |
295 | * would be possible (callers must not rely on the fact that _only_ the | |
296 | * first iovec will be faulted with the current implementation). | |
297 | */ | |
298 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) | |
299 | { | |
a280455f | 300 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { |
62a8067a AV |
301 | char __user *buf = i->iov->iov_base + i->iov_offset; |
302 | bytes = min(bytes, i->iov->iov_len - i->iov_offset); | |
303 | return fault_in_pages_readable(buf, bytes); | |
304 | } | |
305 | return 0; | |
4f18cd31 AV |
306 | } |
307 | EXPORT_SYMBOL(iov_iter_fault_in_readable); | |
308 | ||
171a0203 AA |
309 | /* |
310 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
311 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
312 | * | |
313 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
314 | * because it is an invalid address). | |
315 | */ | |
316 | int iov_iter_fault_in_multipages_readable(struct iov_iter *i, size_t bytes) | |
317 | { | |
318 | size_t skip = i->iov_offset; | |
319 | const struct iovec *iov; | |
320 | int err; | |
321 | struct iovec v; | |
322 | ||
323 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
324 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
325 | err = fault_in_multipages_readable(v.iov_base, | |
326 | v.iov_len); | |
327 | if (unlikely(err)) | |
328 | return err; | |
329 | 0;})) | |
330 | } | |
331 | return 0; | |
332 | } | |
333 | EXPORT_SYMBOL(iov_iter_fault_in_multipages_readable); | |
334 | ||
71d8e532 AV |
335 | void iov_iter_init(struct iov_iter *i, int direction, |
336 | const struct iovec *iov, unsigned long nr_segs, | |
337 | size_t count) | |
338 | { | |
339 | /* It will get better. Eventually... */ | |
a280455f | 340 | if (segment_eq(get_fs(), KERNEL_DS)) { |
62a8067a | 341 | direction |= ITER_KVEC; |
a280455f AV |
342 | i->type = direction; |
343 | i->kvec = (struct kvec *)iov; | |
344 | } else { | |
345 | i->type = direction; | |
346 | i->iov = iov; | |
347 | } | |
71d8e532 AV |
348 | i->nr_segs = nr_segs; |
349 | i->iov_offset = 0; | |
350 | i->count = count; | |
351 | } | |
352 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 353 | |
62a8067a AV |
354 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
355 | { | |
356 | char *from = kmap_atomic(page); | |
357 | memcpy(to, from + offset, len); | |
358 | kunmap_atomic(from); | |
359 | } | |
360 | ||
36f7a8a4 | 361 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
362 | { |
363 | char *to = kmap_atomic(page); | |
364 | memcpy(to + offset, from, len); | |
365 | kunmap_atomic(to); | |
366 | } | |
367 | ||
c35e0248 MW |
368 | static void memzero_page(struct page *page, size_t offset, size_t len) |
369 | { | |
370 | char *addr = kmap_atomic(page); | |
371 | memset(addr + offset, 0, len); | |
372 | kunmap_atomic(addr); | |
373 | } | |
374 | ||
36f7a8a4 | 375 | size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 376 | { |
36f7a8a4 | 377 | const char *from = addr; |
3d4d3e48 AV |
378 | iterate_and_advance(i, bytes, v, |
379 | __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, | |
380 | v.iov_len), | |
381 | memcpy_to_page(v.bv_page, v.bv_offset, | |
a280455f AV |
382 | (from += v.bv_len) - v.bv_len, v.bv_len), |
383 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 384 | ) |
62a8067a | 385 | |
3d4d3e48 | 386 | return bytes; |
c35e0248 | 387 | } |
d271524a | 388 | EXPORT_SYMBOL(copy_to_iter); |
c35e0248 | 389 | |
d271524a | 390 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 391 | { |
0dbca9a4 | 392 | char *to = addr; |
0dbca9a4 AV |
393 | iterate_and_advance(i, bytes, v, |
394 | __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, | |
395 | v.iov_len), | |
396 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
397 | v.bv_offset, v.bv_len), |
398 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
399 | ) |
400 | ||
401 | return bytes; | |
c35e0248 | 402 | } |
d271524a | 403 | EXPORT_SYMBOL(copy_from_iter); |
c35e0248 | 404 | |
aa583096 AV |
405 | size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
406 | { | |
407 | char *to = addr; | |
aa583096 AV |
408 | iterate_and_advance(i, bytes, v, |
409 | __copy_from_user_nocache((to += v.iov_len) - v.iov_len, | |
410 | v.iov_base, v.iov_len), | |
411 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
412 | v.bv_offset, v.bv_len), | |
413 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
414 | ) | |
415 | ||
416 | return bytes; | |
417 | } | |
418 | EXPORT_SYMBOL(copy_from_iter_nocache); | |
419 | ||
62a8067a AV |
420 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
421 | struct iov_iter *i) | |
422 | { | |
d271524a AV |
423 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
424 | void *kaddr = kmap_atomic(page); | |
425 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
426 | kunmap_atomic(kaddr); | |
427 | return wanted; | |
428 | } else | |
62a8067a AV |
429 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
430 | } | |
431 | EXPORT_SYMBOL(copy_page_to_iter); | |
432 | ||
433 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
434 | struct iov_iter *i) | |
435 | { | |
a280455f | 436 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a AV |
437 | void *kaddr = kmap_atomic(page); |
438 | size_t wanted = copy_from_iter(kaddr + offset, bytes, i); | |
439 | kunmap_atomic(kaddr); | |
440 | return wanted; | |
441 | } else | |
62a8067a AV |
442 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
443 | } | |
444 | EXPORT_SYMBOL(copy_page_from_iter); | |
445 | ||
c35e0248 MW |
446 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
447 | { | |
8442fa46 AV |
448 | iterate_and_advance(i, bytes, v, |
449 | __clear_user(v.iov_base, v.iov_len), | |
a280455f AV |
450 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
451 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
452 | ) |
453 | ||
454 | return bytes; | |
c35e0248 MW |
455 | } |
456 | EXPORT_SYMBOL(iov_iter_zero); | |
457 | ||
62a8067a AV |
458 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
459 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
460 | { | |
04a31165 AV |
461 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
462 | iterate_all_kinds(i, bytes, v, | |
463 | __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, | |
464 | v.iov_base, v.iov_len), | |
465 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
466 | v.bv_offset, v.bv_len), |
467 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
468 | ) |
469 | kunmap_atomic(kaddr); | |
470 | return bytes; | |
62a8067a AV |
471 | } |
472 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
473 | ||
474 | void iov_iter_advance(struct iov_iter *i, size_t size) | |
475 | { | |
a280455f | 476 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
477 | } |
478 | EXPORT_SYMBOL(iov_iter_advance); | |
479 | ||
480 | /* | |
481 | * Return the count of just the current iov_iter segment. | |
482 | */ | |
483 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
484 | { | |
485 | if (i->nr_segs == 1) | |
486 | return i->count; | |
487 | else if (i->type & ITER_BVEC) | |
62a8067a | 488 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
489 | else |
490 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
491 | } |
492 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
493 | ||
abb78f87 | 494 | void iov_iter_kvec(struct iov_iter *i, int direction, |
05afcb77 | 495 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
496 | size_t count) |
497 | { | |
498 | BUG_ON(!(direction & ITER_KVEC)); | |
499 | i->type = direction; | |
05afcb77 | 500 | i->kvec = kvec; |
abb78f87 AV |
501 | i->nr_segs = nr_segs; |
502 | i->iov_offset = 0; | |
503 | i->count = count; | |
504 | } | |
505 | EXPORT_SYMBOL(iov_iter_kvec); | |
506 | ||
05afcb77 AV |
507 | void iov_iter_bvec(struct iov_iter *i, int direction, |
508 | const struct bio_vec *bvec, unsigned long nr_segs, | |
509 | size_t count) | |
510 | { | |
511 | BUG_ON(!(direction & ITER_BVEC)); | |
512 | i->type = direction; | |
513 | i->bvec = bvec; | |
514 | i->nr_segs = nr_segs; | |
515 | i->iov_offset = 0; | |
516 | i->count = count; | |
517 | } | |
518 | EXPORT_SYMBOL(iov_iter_bvec); | |
519 | ||
62a8067a AV |
520 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
521 | { | |
04a31165 AV |
522 | unsigned long res = 0; |
523 | size_t size = i->count; | |
524 | ||
525 | if (!size) | |
526 | return 0; | |
527 | ||
528 | iterate_all_kinds(i, size, v, | |
529 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
530 | res |= v.bv_offset | v.bv_len, |
531 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
532 | ) |
533 | return res; | |
62a8067a AV |
534 | } |
535 | EXPORT_SYMBOL(iov_iter_alignment); | |
536 | ||
357f435d AV |
537 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
538 | { | |
539 | unsigned long res = 0; | |
540 | size_t size = i->count; | |
541 | if (!size) | |
542 | return 0; | |
543 | ||
544 | iterate_all_kinds(i, size, v, | |
545 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
546 | (size != v.iov_len ? size : 0), 0), | |
547 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
548 | (size != v.bv_len ? size : 0)), | |
549 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
550 | (size != v.iov_len ? size : 0)) | |
551 | ); | |
552 | return res; | |
553 | } | |
554 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
555 | ||
62a8067a | 556 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 557 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
558 | size_t *start) |
559 | { | |
e5393fae AV |
560 | if (maxsize > i->count) |
561 | maxsize = i->count; | |
562 | ||
563 | if (!maxsize) | |
564 | return 0; | |
565 | ||
566 | iterate_all_kinds(i, maxsize, v, ({ | |
567 | unsigned long addr = (unsigned long)v.iov_base; | |
568 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
569 | int n; | |
570 | int res; | |
571 | ||
572 | if (len > maxpages * PAGE_SIZE) | |
573 | len = maxpages * PAGE_SIZE; | |
574 | addr &= ~(PAGE_SIZE - 1); | |
575 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
576 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); | |
577 | if (unlikely(res < 0)) | |
578 | return res; | |
579 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
580 | 0;}),({ | |
581 | /* can't be more than PAGE_SIZE */ | |
582 | *start = v.bv_offset; | |
583 | get_page(*pages = v.bv_page); | |
584 | return v.bv_len; | |
a280455f AV |
585 | }),({ |
586 | return -EFAULT; | |
e5393fae AV |
587 | }) |
588 | ) | |
589 | return 0; | |
62a8067a AV |
590 | } |
591 | EXPORT_SYMBOL(iov_iter_get_pages); | |
592 | ||
1b17f1f2 AV |
593 | static struct page **get_pages_array(size_t n) |
594 | { | |
595 | struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); | |
596 | if (!p) | |
597 | p = vmalloc(n * sizeof(struct page *)); | |
598 | return p; | |
599 | } | |
600 | ||
62a8067a AV |
601 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
602 | struct page ***pages, size_t maxsize, | |
603 | size_t *start) | |
604 | { | |
1b17f1f2 AV |
605 | struct page **p; |
606 | ||
607 | if (maxsize > i->count) | |
608 | maxsize = i->count; | |
609 | ||
610 | if (!maxsize) | |
611 | return 0; | |
612 | ||
613 | iterate_all_kinds(i, maxsize, v, ({ | |
614 | unsigned long addr = (unsigned long)v.iov_base; | |
615 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
616 | int n; | |
617 | int res; | |
618 | ||
619 | addr &= ~(PAGE_SIZE - 1); | |
620 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
621 | p = get_pages_array(n); | |
622 | if (!p) | |
623 | return -ENOMEM; | |
624 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); | |
625 | if (unlikely(res < 0)) { | |
626 | kvfree(p); | |
627 | return res; | |
628 | } | |
629 | *pages = p; | |
630 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
631 | 0;}),({ | |
632 | /* can't be more than PAGE_SIZE */ | |
633 | *start = v.bv_offset; | |
634 | *pages = p = get_pages_array(1); | |
635 | if (!p) | |
636 | return -ENOMEM; | |
637 | get_page(*p = v.bv_page); | |
638 | return v.bv_len; | |
a280455f AV |
639 | }),({ |
640 | return -EFAULT; | |
1b17f1f2 AV |
641 | }) |
642 | ) | |
643 | return 0; | |
62a8067a AV |
644 | } |
645 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
646 | ||
a604ec7e AV |
647 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
648 | struct iov_iter *i) | |
649 | { | |
650 | char *to = addr; | |
651 | __wsum sum, next; | |
652 | size_t off = 0; | |
a604ec7e AV |
653 | sum = *csum; |
654 | iterate_and_advance(i, bytes, v, ({ | |
655 | int err = 0; | |
656 | next = csum_and_copy_from_user(v.iov_base, | |
657 | (to += v.iov_len) - v.iov_len, | |
658 | v.iov_len, 0, &err); | |
659 | if (!err) { | |
660 | sum = csum_block_add(sum, next, off); | |
661 | off += v.iov_len; | |
662 | } | |
663 | err ? v.iov_len : 0; | |
664 | }), ({ | |
665 | char *p = kmap_atomic(v.bv_page); | |
666 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
667 | (to += v.bv_len) - v.bv_len, | |
668 | v.bv_len, 0); | |
669 | kunmap_atomic(p); | |
670 | sum = csum_block_add(sum, next, off); | |
671 | off += v.bv_len; | |
672 | }),({ | |
673 | next = csum_partial_copy_nocheck(v.iov_base, | |
674 | (to += v.iov_len) - v.iov_len, | |
675 | v.iov_len, 0); | |
676 | sum = csum_block_add(sum, next, off); | |
677 | off += v.iov_len; | |
678 | }) | |
679 | ) | |
680 | *csum = sum; | |
681 | return bytes; | |
682 | } | |
683 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
684 | ||
36f7a8a4 | 685 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, |
a604ec7e AV |
686 | struct iov_iter *i) |
687 | { | |
36f7a8a4 | 688 | const char *from = addr; |
a604ec7e AV |
689 | __wsum sum, next; |
690 | size_t off = 0; | |
a604ec7e AV |
691 | sum = *csum; |
692 | iterate_and_advance(i, bytes, v, ({ | |
693 | int err = 0; | |
694 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
695 | v.iov_base, | |
696 | v.iov_len, 0, &err); | |
697 | if (!err) { | |
698 | sum = csum_block_add(sum, next, off); | |
699 | off += v.iov_len; | |
700 | } | |
701 | err ? v.iov_len : 0; | |
702 | }), ({ | |
703 | char *p = kmap_atomic(v.bv_page); | |
704 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
705 | p + v.bv_offset, | |
706 | v.bv_len, 0); | |
707 | kunmap_atomic(p); | |
708 | sum = csum_block_add(sum, next, off); | |
709 | off += v.bv_len; | |
710 | }),({ | |
711 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
712 | v.iov_base, | |
713 | v.iov_len, 0); | |
714 | sum = csum_block_add(sum, next, off); | |
715 | off += v.iov_len; | |
716 | }) | |
717 | ) | |
718 | *csum = sum; | |
719 | return bytes; | |
720 | } | |
721 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
722 | ||
62a8067a AV |
723 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
724 | { | |
e0f2dc40 AV |
725 | size_t size = i->count; |
726 | int npages = 0; | |
727 | ||
728 | if (!size) | |
729 | return 0; | |
730 | ||
731 | iterate_all_kinds(i, size, v, ({ | |
732 | unsigned long p = (unsigned long)v.iov_base; | |
733 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
734 | - p / PAGE_SIZE; | |
735 | if (npages >= maxpages) | |
736 | return maxpages; | |
737 | 0;}),({ | |
738 | npages++; | |
739 | if (npages >= maxpages) | |
740 | return maxpages; | |
a280455f AV |
741 | }),({ |
742 | unsigned long p = (unsigned long)v.iov_base; | |
743 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
744 | - p / PAGE_SIZE; | |
745 | if (npages >= maxpages) | |
746 | return maxpages; | |
e0f2dc40 AV |
747 | }) |
748 | ) | |
749 | return npages; | |
62a8067a | 750 | } |
f67da30c | 751 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
752 | |
753 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
754 | { | |
755 | *new = *old; | |
756 | if (new->type & ITER_BVEC) | |
757 | return new->bvec = kmemdup(new->bvec, | |
758 | new->nr_segs * sizeof(struct bio_vec), | |
759 | flags); | |
760 | else | |
761 | /* iovec and kvec have identical layout */ | |
762 | return new->iov = kmemdup(new->iov, | |
763 | new->nr_segs * sizeof(struct iovec), | |
764 | flags); | |
765 | } | |
766 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 AV |
767 | |
768 | int import_iovec(int type, const struct iovec __user * uvector, | |
769 | unsigned nr_segs, unsigned fast_segs, | |
770 | struct iovec **iov, struct iov_iter *i) | |
771 | { | |
772 | ssize_t n; | |
773 | struct iovec *p; | |
774 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
775 | *iov, &p); | |
776 | if (n < 0) { | |
777 | if (p != *iov) | |
778 | kfree(p); | |
779 | *iov = NULL; | |
780 | return n; | |
781 | } | |
782 | iov_iter_init(i, type, p, nr_segs, n); | |
783 | *iov = p == *iov ? NULL : p; | |
784 | return 0; | |
785 | } | |
786 | EXPORT_SYMBOL(import_iovec); | |
787 | ||
788 | #ifdef CONFIG_COMPAT | |
789 | #include <linux/compat.h> | |
790 | ||
791 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
792 | unsigned nr_segs, unsigned fast_segs, | |
793 | struct iovec **iov, struct iov_iter *i) | |
794 | { | |
795 | ssize_t n; | |
796 | struct iovec *p; | |
797 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
798 | *iov, &p); | |
799 | if (n < 0) { | |
800 | if (p != *iov) | |
801 | kfree(p); | |
802 | *iov = NULL; | |
803 | return n; | |
804 | } | |
805 | iov_iter_init(i, type, p, nr_segs, n); | |
806 | *iov = p == *iov ? NULL : p; | |
807 | return 0; | |
808 | } | |
809 | #endif | |
810 | ||
811 | int import_single_range(int rw, void __user *buf, size_t len, | |
812 | struct iovec *iov, struct iov_iter *i) | |
813 | { | |
814 | if (len > MAX_RW_COUNT) | |
815 | len = MAX_RW_COUNT; | |
816 | if (unlikely(!access_ok(!rw, buf, len))) | |
817 | return -EFAULT; | |
818 | ||
819 | iov->iov_base = buf; | |
820 | iov->iov_len = len; | |
821 | iov_iter_init(i, rw, iov, 1, len); | |
822 | return 0; | |
823 | } | |
e1267585 | 824 | EXPORT_SYMBOL(import_single_range); |