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) { \ |
dd254f5a AV |
102 | if (unlikely(i->count < n)) \ |
103 | n = i->count; \ | |
19f18459 | 104 | if (i->count) { \ |
dd254f5a AV |
105 | size_t skip = i->iov_offset; \ |
106 | if (unlikely(i->type & ITER_BVEC)) { \ | |
107 | const struct bio_vec *bvec; \ | |
108 | struct bio_vec v; \ | |
109 | iterate_bvec(i, n, v, bvec, skip, (B)) \ | |
110 | if (skip == bvec->bv_len) { \ | |
111 | bvec++; \ | |
112 | skip = 0; \ | |
113 | } \ | |
114 | i->nr_segs -= bvec - i->bvec; \ | |
115 | i->bvec = bvec; \ | |
116 | } else if (unlikely(i->type & ITER_KVEC)) { \ | |
117 | const struct kvec *kvec; \ | |
118 | struct kvec v; \ | |
119 | iterate_kvec(i, n, v, kvec, skip, (K)) \ | |
120 | if (skip == kvec->iov_len) { \ | |
121 | kvec++; \ | |
122 | skip = 0; \ | |
123 | } \ | |
124 | i->nr_segs -= kvec - i->kvec; \ | |
125 | i->kvec = kvec; \ | |
126 | } else { \ | |
127 | const struct iovec *iov; \ | |
128 | struct iovec v; \ | |
129 | iterate_iovec(i, n, v, iov, skip, (I)) \ | |
130 | if (skip == iov->iov_len) { \ | |
131 | iov++; \ | |
132 | skip = 0; \ | |
133 | } \ | |
134 | i->nr_segs -= iov - i->iov; \ | |
135 | i->iov = iov; \ | |
7ce2a91e | 136 | } \ |
dd254f5a AV |
137 | i->count -= n; \ |
138 | i->iov_offset = skip; \ | |
7ce2a91e | 139 | } \ |
7ce2a91e AV |
140 | } |
141 | ||
62a8067a | 142 | static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, |
4f18cd31 AV |
143 | struct iov_iter *i) |
144 | { | |
145 | size_t skip, copy, left, wanted; | |
146 | const struct iovec *iov; | |
147 | char __user *buf; | |
148 | void *kaddr, *from; | |
149 | ||
150 | if (unlikely(bytes > i->count)) | |
151 | bytes = i->count; | |
152 | ||
153 | if (unlikely(!bytes)) | |
154 | return 0; | |
155 | ||
156 | wanted = bytes; | |
157 | iov = i->iov; | |
158 | skip = i->iov_offset; | |
159 | buf = iov->iov_base + skip; | |
160 | copy = min(bytes, iov->iov_len - skip); | |
161 | ||
162 | if (!fault_in_pages_writeable(buf, copy)) { | |
163 | kaddr = kmap_atomic(page); | |
164 | from = kaddr + offset; | |
165 | ||
166 | /* first chunk, usually the only one */ | |
167 | left = __copy_to_user_inatomic(buf, from, copy); | |
168 | copy -= left; | |
169 | skip += copy; | |
170 | from += copy; | |
171 | bytes -= copy; | |
172 | ||
173 | while (unlikely(!left && bytes)) { | |
174 | iov++; | |
175 | buf = iov->iov_base; | |
176 | copy = min(bytes, iov->iov_len); | |
177 | left = __copy_to_user_inatomic(buf, from, copy); | |
178 | copy -= left; | |
179 | skip = copy; | |
180 | from += copy; | |
181 | bytes -= copy; | |
182 | } | |
183 | if (likely(!bytes)) { | |
184 | kunmap_atomic(kaddr); | |
185 | goto done; | |
186 | } | |
187 | offset = from - kaddr; | |
188 | buf += copy; | |
189 | kunmap_atomic(kaddr); | |
190 | copy = min(bytes, iov->iov_len - skip); | |
191 | } | |
192 | /* Too bad - revert to non-atomic kmap */ | |
193 | kaddr = kmap(page); | |
194 | from = kaddr + offset; | |
195 | left = __copy_to_user(buf, from, copy); | |
196 | copy -= left; | |
197 | skip += copy; | |
198 | from += copy; | |
199 | bytes -= copy; | |
200 | while (unlikely(!left && bytes)) { | |
201 | iov++; | |
202 | buf = iov->iov_base; | |
203 | copy = min(bytes, iov->iov_len); | |
204 | left = __copy_to_user(buf, from, copy); | |
205 | copy -= left; | |
206 | skip = copy; | |
207 | from += copy; | |
208 | bytes -= copy; | |
209 | } | |
210 | kunmap(page); | |
211 | done: | |
81055e58 AV |
212 | if (skip == iov->iov_len) { |
213 | iov++; | |
214 | skip = 0; | |
215 | } | |
4f18cd31 AV |
216 | i->count -= wanted - bytes; |
217 | i->nr_segs -= iov - i->iov; | |
218 | i->iov = iov; | |
219 | i->iov_offset = skip; | |
220 | return wanted - bytes; | |
221 | } | |
4f18cd31 | 222 | |
62a8067a | 223 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
224 | struct iov_iter *i) |
225 | { | |
226 | size_t skip, copy, left, wanted; | |
227 | const struct iovec *iov; | |
228 | char __user *buf; | |
229 | void *kaddr, *to; | |
230 | ||
231 | if (unlikely(bytes > i->count)) | |
232 | bytes = i->count; | |
233 | ||
234 | if (unlikely(!bytes)) | |
235 | return 0; | |
236 | ||
237 | wanted = bytes; | |
238 | iov = i->iov; | |
239 | skip = i->iov_offset; | |
240 | buf = iov->iov_base + skip; | |
241 | copy = min(bytes, iov->iov_len - skip); | |
242 | ||
243 | if (!fault_in_pages_readable(buf, copy)) { | |
244 | kaddr = kmap_atomic(page); | |
245 | to = kaddr + offset; | |
246 | ||
247 | /* first chunk, usually the only one */ | |
248 | left = __copy_from_user_inatomic(to, buf, copy); | |
249 | copy -= left; | |
250 | skip += copy; | |
251 | to += copy; | |
252 | bytes -= copy; | |
253 | ||
254 | while (unlikely(!left && bytes)) { | |
255 | iov++; | |
256 | buf = iov->iov_base; | |
257 | copy = min(bytes, iov->iov_len); | |
258 | left = __copy_from_user_inatomic(to, buf, copy); | |
259 | copy -= left; | |
260 | skip = copy; | |
261 | to += copy; | |
262 | bytes -= copy; | |
263 | } | |
264 | if (likely(!bytes)) { | |
265 | kunmap_atomic(kaddr); | |
266 | goto done; | |
267 | } | |
268 | offset = to - kaddr; | |
269 | buf += copy; | |
270 | kunmap_atomic(kaddr); | |
271 | copy = min(bytes, iov->iov_len - skip); | |
272 | } | |
273 | /* Too bad - revert to non-atomic kmap */ | |
274 | kaddr = kmap(page); | |
275 | to = kaddr + offset; | |
276 | left = __copy_from_user(to, buf, copy); | |
277 | copy -= left; | |
278 | skip += copy; | |
279 | to += copy; | |
280 | bytes -= copy; | |
281 | while (unlikely(!left && bytes)) { | |
282 | iov++; | |
283 | buf = iov->iov_base; | |
284 | copy = min(bytes, iov->iov_len); | |
285 | left = __copy_from_user(to, buf, copy); | |
286 | copy -= left; | |
287 | skip = copy; | |
288 | to += copy; | |
289 | bytes -= copy; | |
290 | } | |
291 | kunmap(page); | |
292 | done: | |
81055e58 AV |
293 | if (skip == iov->iov_len) { |
294 | iov++; | |
295 | skip = 0; | |
296 | } | |
f0d1bec9 AV |
297 | i->count -= wanted - bytes; |
298 | i->nr_segs -= iov - i->iov; | |
299 | i->iov = iov; | |
300 | i->iov_offset = skip; | |
301 | return wanted - bytes; | |
302 | } | |
f0d1bec9 | 303 | |
4f18cd31 AV |
304 | /* |
305 | * Fault in the first iovec of the given iov_iter, to a maximum length | |
306 | * of bytes. Returns 0 on success, or non-zero if the memory could not be | |
307 | * accessed (ie. because it is an invalid address). | |
308 | * | |
309 | * writev-intensive code may want this to prefault several iovecs -- that | |
310 | * would be possible (callers must not rely on the fact that _only_ the | |
311 | * first iovec will be faulted with the current implementation). | |
312 | */ | |
313 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) | |
314 | { | |
a280455f | 315 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { |
62a8067a AV |
316 | char __user *buf = i->iov->iov_base + i->iov_offset; |
317 | bytes = min(bytes, i->iov->iov_len - i->iov_offset); | |
318 | return fault_in_pages_readable(buf, bytes); | |
319 | } | |
320 | return 0; | |
4f18cd31 AV |
321 | } |
322 | EXPORT_SYMBOL(iov_iter_fault_in_readable); | |
323 | ||
171a0203 AA |
324 | /* |
325 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
326 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
327 | * | |
328 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
329 | * because it is an invalid address). | |
330 | */ | |
331 | int iov_iter_fault_in_multipages_readable(struct iov_iter *i, size_t bytes) | |
332 | { | |
333 | size_t skip = i->iov_offset; | |
334 | const struct iovec *iov; | |
335 | int err; | |
336 | struct iovec v; | |
337 | ||
338 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
339 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
340 | err = fault_in_multipages_readable(v.iov_base, | |
341 | v.iov_len); | |
342 | if (unlikely(err)) | |
343 | return err; | |
344 | 0;})) | |
345 | } | |
346 | return 0; | |
347 | } | |
348 | EXPORT_SYMBOL(iov_iter_fault_in_multipages_readable); | |
349 | ||
71d8e532 AV |
350 | void iov_iter_init(struct iov_iter *i, int direction, |
351 | const struct iovec *iov, unsigned long nr_segs, | |
352 | size_t count) | |
353 | { | |
354 | /* It will get better. Eventually... */ | |
a280455f | 355 | if (segment_eq(get_fs(), KERNEL_DS)) { |
62a8067a | 356 | direction |= ITER_KVEC; |
a280455f AV |
357 | i->type = direction; |
358 | i->kvec = (struct kvec *)iov; | |
359 | } else { | |
360 | i->type = direction; | |
361 | i->iov = iov; | |
362 | } | |
71d8e532 AV |
363 | i->nr_segs = nr_segs; |
364 | i->iov_offset = 0; | |
365 | i->count = count; | |
366 | } | |
367 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 368 | |
62a8067a AV |
369 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
370 | { | |
371 | char *from = kmap_atomic(page); | |
372 | memcpy(to, from + offset, len); | |
373 | kunmap_atomic(from); | |
374 | } | |
375 | ||
36f7a8a4 | 376 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
377 | { |
378 | char *to = kmap_atomic(page); | |
379 | memcpy(to + offset, from, len); | |
380 | kunmap_atomic(to); | |
381 | } | |
382 | ||
c35e0248 MW |
383 | static void memzero_page(struct page *page, size_t offset, size_t len) |
384 | { | |
385 | char *addr = kmap_atomic(page); | |
386 | memset(addr + offset, 0, len); | |
387 | kunmap_atomic(addr); | |
388 | } | |
389 | ||
36f7a8a4 | 390 | size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 391 | { |
36f7a8a4 | 392 | const char *from = addr; |
3d4d3e48 AV |
393 | iterate_and_advance(i, bytes, v, |
394 | __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, | |
395 | v.iov_len), | |
396 | memcpy_to_page(v.bv_page, v.bv_offset, | |
a280455f AV |
397 | (from += v.bv_len) - v.bv_len, v.bv_len), |
398 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 399 | ) |
62a8067a | 400 | |
3d4d3e48 | 401 | return bytes; |
c35e0248 | 402 | } |
d271524a | 403 | EXPORT_SYMBOL(copy_to_iter); |
c35e0248 | 404 | |
d271524a | 405 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 406 | { |
0dbca9a4 | 407 | char *to = addr; |
0dbca9a4 AV |
408 | iterate_and_advance(i, bytes, v, |
409 | __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, | |
410 | v.iov_len), | |
411 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
412 | v.bv_offset, v.bv_len), |
413 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
414 | ) |
415 | ||
416 | return bytes; | |
c35e0248 | 417 | } |
d271524a | 418 | EXPORT_SYMBOL(copy_from_iter); |
c35e0248 | 419 | |
aa583096 AV |
420 | size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
421 | { | |
422 | char *to = addr; | |
aa583096 AV |
423 | iterate_and_advance(i, bytes, v, |
424 | __copy_from_user_nocache((to += v.iov_len) - v.iov_len, | |
425 | v.iov_base, v.iov_len), | |
426 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
427 | v.bv_offset, v.bv_len), | |
428 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
429 | ) | |
430 | ||
431 | return bytes; | |
432 | } | |
433 | EXPORT_SYMBOL(copy_from_iter_nocache); | |
434 | ||
62a8067a AV |
435 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
436 | struct iov_iter *i) | |
437 | { | |
d271524a AV |
438 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
439 | void *kaddr = kmap_atomic(page); | |
440 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
441 | kunmap_atomic(kaddr); | |
442 | return wanted; | |
443 | } else | |
62a8067a AV |
444 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
445 | } | |
446 | EXPORT_SYMBOL(copy_page_to_iter); | |
447 | ||
448 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
449 | struct iov_iter *i) | |
450 | { | |
a280455f | 451 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a AV |
452 | void *kaddr = kmap_atomic(page); |
453 | size_t wanted = copy_from_iter(kaddr + offset, bytes, i); | |
454 | kunmap_atomic(kaddr); | |
455 | return wanted; | |
456 | } else | |
62a8067a AV |
457 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
458 | } | |
459 | EXPORT_SYMBOL(copy_page_from_iter); | |
460 | ||
c35e0248 MW |
461 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
462 | { | |
8442fa46 AV |
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 | ||
357f435d AV |
552 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
553 | { | |
554 | unsigned long res = 0; | |
555 | size_t size = i->count; | |
556 | if (!size) | |
557 | return 0; | |
558 | ||
559 | iterate_all_kinds(i, size, v, | |
560 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
561 | (size != v.iov_len ? size : 0), 0), | |
562 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
563 | (size != v.bv_len ? size : 0)), | |
564 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
565 | (size != v.iov_len ? size : 0)) | |
566 | ); | |
567 | return res; | |
568 | } | |
569 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
570 | ||
62a8067a | 571 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 572 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
573 | size_t *start) |
574 | { | |
e5393fae AV |
575 | if (maxsize > i->count) |
576 | maxsize = i->count; | |
577 | ||
578 | if (!maxsize) | |
579 | return 0; | |
580 | ||
581 | iterate_all_kinds(i, maxsize, v, ({ | |
582 | unsigned long addr = (unsigned long)v.iov_base; | |
583 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
584 | int n; | |
585 | int res; | |
586 | ||
587 | if (len > maxpages * PAGE_SIZE) | |
588 | len = maxpages * PAGE_SIZE; | |
589 | addr &= ~(PAGE_SIZE - 1); | |
590 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
591 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); | |
592 | if (unlikely(res < 0)) | |
593 | return res; | |
594 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
595 | 0;}),({ | |
596 | /* can't be more than PAGE_SIZE */ | |
597 | *start = v.bv_offset; | |
598 | get_page(*pages = v.bv_page); | |
599 | return v.bv_len; | |
a280455f AV |
600 | }),({ |
601 | return -EFAULT; | |
e5393fae AV |
602 | }) |
603 | ) | |
604 | return 0; | |
62a8067a AV |
605 | } |
606 | EXPORT_SYMBOL(iov_iter_get_pages); | |
607 | ||
1b17f1f2 AV |
608 | static struct page **get_pages_array(size_t n) |
609 | { | |
610 | struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); | |
611 | if (!p) | |
612 | p = vmalloc(n * sizeof(struct page *)); | |
613 | return p; | |
614 | } | |
615 | ||
62a8067a AV |
616 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
617 | struct page ***pages, size_t maxsize, | |
618 | size_t *start) | |
619 | { | |
1b17f1f2 AV |
620 | struct page **p; |
621 | ||
622 | if (maxsize > i->count) | |
623 | maxsize = i->count; | |
624 | ||
625 | if (!maxsize) | |
626 | return 0; | |
627 | ||
628 | iterate_all_kinds(i, maxsize, v, ({ | |
629 | unsigned long addr = (unsigned long)v.iov_base; | |
630 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
631 | int n; | |
632 | int res; | |
633 | ||
634 | addr &= ~(PAGE_SIZE - 1); | |
635 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
636 | p = get_pages_array(n); | |
637 | if (!p) | |
638 | return -ENOMEM; | |
639 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); | |
640 | if (unlikely(res < 0)) { | |
641 | kvfree(p); | |
642 | return res; | |
643 | } | |
644 | *pages = p; | |
645 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
646 | 0;}),({ | |
647 | /* can't be more than PAGE_SIZE */ | |
648 | *start = v.bv_offset; | |
649 | *pages = p = get_pages_array(1); | |
650 | if (!p) | |
651 | return -ENOMEM; | |
652 | get_page(*p = v.bv_page); | |
653 | return v.bv_len; | |
a280455f AV |
654 | }),({ |
655 | return -EFAULT; | |
1b17f1f2 AV |
656 | }) |
657 | ) | |
658 | return 0; | |
62a8067a AV |
659 | } |
660 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
661 | ||
a604ec7e AV |
662 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
663 | struct iov_iter *i) | |
664 | { | |
665 | char *to = addr; | |
666 | __wsum sum, next; | |
667 | size_t off = 0; | |
a604ec7e AV |
668 | sum = *csum; |
669 | iterate_and_advance(i, bytes, v, ({ | |
670 | int err = 0; | |
671 | next = csum_and_copy_from_user(v.iov_base, | |
672 | (to += v.iov_len) - v.iov_len, | |
673 | v.iov_len, 0, &err); | |
674 | if (!err) { | |
675 | sum = csum_block_add(sum, next, off); | |
676 | off += v.iov_len; | |
677 | } | |
678 | err ? v.iov_len : 0; | |
679 | }), ({ | |
680 | char *p = kmap_atomic(v.bv_page); | |
681 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
682 | (to += v.bv_len) - v.bv_len, | |
683 | v.bv_len, 0); | |
684 | kunmap_atomic(p); | |
685 | sum = csum_block_add(sum, next, off); | |
686 | off += v.bv_len; | |
687 | }),({ | |
688 | next = csum_partial_copy_nocheck(v.iov_base, | |
689 | (to += v.iov_len) - v.iov_len, | |
690 | v.iov_len, 0); | |
691 | sum = csum_block_add(sum, next, off); | |
692 | off += v.iov_len; | |
693 | }) | |
694 | ) | |
695 | *csum = sum; | |
696 | return bytes; | |
697 | } | |
698 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
699 | ||
36f7a8a4 | 700 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, |
a604ec7e AV |
701 | struct iov_iter *i) |
702 | { | |
36f7a8a4 | 703 | const char *from = addr; |
a604ec7e AV |
704 | __wsum sum, next; |
705 | size_t off = 0; | |
a604ec7e AV |
706 | sum = *csum; |
707 | iterate_and_advance(i, bytes, v, ({ | |
708 | int err = 0; | |
709 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
710 | v.iov_base, | |
711 | v.iov_len, 0, &err); | |
712 | if (!err) { | |
713 | sum = csum_block_add(sum, next, off); | |
714 | off += v.iov_len; | |
715 | } | |
716 | err ? v.iov_len : 0; | |
717 | }), ({ | |
718 | char *p = kmap_atomic(v.bv_page); | |
719 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
720 | p + v.bv_offset, | |
721 | v.bv_len, 0); | |
722 | kunmap_atomic(p); | |
723 | sum = csum_block_add(sum, next, off); | |
724 | off += v.bv_len; | |
725 | }),({ | |
726 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
727 | v.iov_base, | |
728 | v.iov_len, 0); | |
729 | sum = csum_block_add(sum, next, off); | |
730 | off += v.iov_len; | |
731 | }) | |
732 | ) | |
733 | *csum = sum; | |
734 | return bytes; | |
735 | } | |
736 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
737 | ||
62a8067a AV |
738 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
739 | { | |
e0f2dc40 AV |
740 | size_t size = i->count; |
741 | int npages = 0; | |
742 | ||
743 | if (!size) | |
744 | return 0; | |
745 | ||
746 | iterate_all_kinds(i, size, v, ({ | |
747 | unsigned long p = (unsigned long)v.iov_base; | |
748 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
749 | - p / PAGE_SIZE; | |
750 | if (npages >= maxpages) | |
751 | return maxpages; | |
752 | 0;}),({ | |
753 | npages++; | |
754 | if (npages >= maxpages) | |
755 | return maxpages; | |
a280455f AV |
756 | }),({ |
757 | unsigned long p = (unsigned long)v.iov_base; | |
758 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
759 | - p / PAGE_SIZE; | |
760 | if (npages >= maxpages) | |
761 | return maxpages; | |
e0f2dc40 AV |
762 | }) |
763 | ) | |
764 | return npages; | |
62a8067a | 765 | } |
f67da30c | 766 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
767 | |
768 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
769 | { | |
770 | *new = *old; | |
771 | if (new->type & ITER_BVEC) | |
772 | return new->bvec = kmemdup(new->bvec, | |
773 | new->nr_segs * sizeof(struct bio_vec), | |
774 | flags); | |
775 | else | |
776 | /* iovec and kvec have identical layout */ | |
777 | return new->iov = kmemdup(new->iov, | |
778 | new->nr_segs * sizeof(struct iovec), | |
779 | flags); | |
780 | } | |
781 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 AV |
782 | |
783 | int import_iovec(int type, const struct iovec __user * uvector, | |
784 | unsigned nr_segs, unsigned fast_segs, | |
785 | struct iovec **iov, struct iov_iter *i) | |
786 | { | |
787 | ssize_t n; | |
788 | struct iovec *p; | |
789 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
790 | *iov, &p); | |
791 | if (n < 0) { | |
792 | if (p != *iov) | |
793 | kfree(p); | |
794 | *iov = NULL; | |
795 | return n; | |
796 | } | |
797 | iov_iter_init(i, type, p, nr_segs, n); | |
798 | *iov = p == *iov ? NULL : p; | |
799 | return 0; | |
800 | } | |
801 | EXPORT_SYMBOL(import_iovec); | |
802 | ||
803 | #ifdef CONFIG_COMPAT | |
804 | #include <linux/compat.h> | |
805 | ||
806 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
807 | unsigned nr_segs, unsigned fast_segs, | |
808 | struct iovec **iov, struct iov_iter *i) | |
809 | { | |
810 | ssize_t n; | |
811 | struct iovec *p; | |
812 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
813 | *iov, &p); | |
814 | if (n < 0) { | |
815 | if (p != *iov) | |
816 | kfree(p); | |
817 | *iov = NULL; | |
818 | return n; | |
819 | } | |
820 | iov_iter_init(i, type, p, nr_segs, n); | |
821 | *iov = p == *iov ? NULL : p; | |
822 | return 0; | |
823 | } | |
824 | #endif | |
825 | ||
826 | int import_single_range(int rw, void __user *buf, size_t len, | |
827 | struct iovec *iov, struct iov_iter *i) | |
828 | { | |
829 | if (len > MAX_RW_COUNT) | |
830 | len = MAX_RW_COUNT; | |
831 | if (unlikely(!access_ok(!rw, buf, len))) | |
832 | return -EFAULT; | |
833 | ||
834 | iov->iov_base = buf; | |
835 | iov->iov_len = len; | |
836 | iov_iter_init(i, rw, iov, 1, len); | |
837 | return 0; | |
838 | } | |
e1267585 | 839 | EXPORT_SYMBOL(import_single_range); |