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 | ||
3fa6c507 | 147 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { |
4f18cd31 AV |
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 */ | |
3fa6c507 | 178 | |
4f18cd31 AV |
179 | kaddr = kmap(page); |
180 | from = kaddr + offset; | |
181 | left = __copy_to_user(buf, from, copy); | |
182 | copy -= left; | |
183 | skip += copy; | |
184 | from += copy; | |
185 | bytes -= copy; | |
186 | while (unlikely(!left && bytes)) { | |
187 | iov++; | |
188 | buf = iov->iov_base; | |
189 | copy = min(bytes, iov->iov_len); | |
190 | left = __copy_to_user(buf, from, copy); | |
191 | copy -= left; | |
192 | skip = copy; | |
193 | from += copy; | |
194 | bytes -= copy; | |
195 | } | |
196 | kunmap(page); | |
3fa6c507 | 197 | |
4f18cd31 | 198 | done: |
81055e58 AV |
199 | if (skip == iov->iov_len) { |
200 | iov++; | |
201 | skip = 0; | |
202 | } | |
4f18cd31 AV |
203 | i->count -= wanted - bytes; |
204 | i->nr_segs -= iov - i->iov; | |
205 | i->iov = iov; | |
206 | i->iov_offset = skip; | |
207 | return wanted - bytes; | |
208 | } | |
4f18cd31 | 209 | |
62a8067a | 210 | static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, |
f0d1bec9 AV |
211 | struct iov_iter *i) |
212 | { | |
213 | size_t skip, copy, left, wanted; | |
214 | const struct iovec *iov; | |
215 | char __user *buf; | |
216 | void *kaddr, *to; | |
217 | ||
218 | if (unlikely(bytes > i->count)) | |
219 | bytes = i->count; | |
220 | ||
221 | if (unlikely(!bytes)) | |
222 | return 0; | |
223 | ||
224 | wanted = bytes; | |
225 | iov = i->iov; | |
226 | skip = i->iov_offset; | |
227 | buf = iov->iov_base + skip; | |
228 | copy = min(bytes, iov->iov_len - skip); | |
229 | ||
3fa6c507 | 230 | if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { |
f0d1bec9 AV |
231 | kaddr = kmap_atomic(page); |
232 | to = kaddr + offset; | |
233 | ||
234 | /* first chunk, usually the only one */ | |
235 | left = __copy_from_user_inatomic(to, buf, copy); | |
236 | copy -= left; | |
237 | skip += copy; | |
238 | to += copy; | |
239 | bytes -= copy; | |
240 | ||
241 | while (unlikely(!left && bytes)) { | |
242 | iov++; | |
243 | buf = iov->iov_base; | |
244 | copy = min(bytes, iov->iov_len); | |
245 | left = __copy_from_user_inatomic(to, buf, copy); | |
246 | copy -= left; | |
247 | skip = copy; | |
248 | to += copy; | |
249 | bytes -= copy; | |
250 | } | |
251 | if (likely(!bytes)) { | |
252 | kunmap_atomic(kaddr); | |
253 | goto done; | |
254 | } | |
255 | offset = to - kaddr; | |
256 | buf += copy; | |
257 | kunmap_atomic(kaddr); | |
258 | copy = min(bytes, iov->iov_len - skip); | |
259 | } | |
260 | /* Too bad - revert to non-atomic kmap */ | |
3fa6c507 | 261 | |
f0d1bec9 AV |
262 | kaddr = kmap(page); |
263 | to = kaddr + offset; | |
264 | left = __copy_from_user(to, buf, copy); | |
265 | copy -= left; | |
266 | skip += copy; | |
267 | to += copy; | |
268 | bytes -= copy; | |
269 | while (unlikely(!left && bytes)) { | |
270 | iov++; | |
271 | buf = iov->iov_base; | |
272 | copy = min(bytes, iov->iov_len); | |
273 | left = __copy_from_user(to, buf, copy); | |
274 | copy -= left; | |
275 | skip = copy; | |
276 | to += copy; | |
277 | bytes -= copy; | |
278 | } | |
279 | kunmap(page); | |
3fa6c507 | 280 | |
f0d1bec9 | 281 | done: |
81055e58 AV |
282 | if (skip == iov->iov_len) { |
283 | iov++; | |
284 | skip = 0; | |
285 | } | |
f0d1bec9 AV |
286 | i->count -= wanted - bytes; |
287 | i->nr_segs -= iov - i->iov; | |
288 | i->iov = iov; | |
289 | i->iov_offset = skip; | |
290 | return wanted - bytes; | |
291 | } | |
f0d1bec9 | 292 | |
4f18cd31 AV |
293 | /* |
294 | * Fault in the first iovec of the given iov_iter, to a maximum length | |
295 | * of bytes. Returns 0 on success, or non-zero if the memory could not be | |
296 | * accessed (ie. because it is an invalid address). | |
297 | * | |
298 | * writev-intensive code may want this to prefault several iovecs -- that | |
299 | * would be possible (callers must not rely on the fact that _only_ the | |
300 | * first iovec will be faulted with the current implementation). | |
301 | */ | |
302 | int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) | |
303 | { | |
a280455f | 304 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { |
62a8067a AV |
305 | char __user *buf = i->iov->iov_base + i->iov_offset; |
306 | bytes = min(bytes, i->iov->iov_len - i->iov_offset); | |
307 | return fault_in_pages_readable(buf, bytes); | |
308 | } | |
309 | return 0; | |
4f18cd31 AV |
310 | } |
311 | EXPORT_SYMBOL(iov_iter_fault_in_readable); | |
312 | ||
171a0203 AA |
313 | /* |
314 | * Fault in one or more iovecs of the given iov_iter, to a maximum length of | |
315 | * bytes. For each iovec, fault in each page that constitutes the iovec. | |
316 | * | |
317 | * Return 0 on success, or non-zero if the memory could not be accessed (i.e. | |
318 | * because it is an invalid address). | |
319 | */ | |
320 | int iov_iter_fault_in_multipages_readable(struct iov_iter *i, size_t bytes) | |
321 | { | |
322 | size_t skip = i->iov_offset; | |
323 | const struct iovec *iov; | |
324 | int err; | |
325 | struct iovec v; | |
326 | ||
327 | if (!(i->type & (ITER_BVEC|ITER_KVEC))) { | |
328 | iterate_iovec(i, bytes, v, iov, skip, ({ | |
329 | err = fault_in_multipages_readable(v.iov_base, | |
330 | v.iov_len); | |
331 | if (unlikely(err)) | |
332 | return err; | |
333 | 0;})) | |
334 | } | |
335 | return 0; | |
336 | } | |
337 | EXPORT_SYMBOL(iov_iter_fault_in_multipages_readable); | |
338 | ||
71d8e532 AV |
339 | void iov_iter_init(struct iov_iter *i, int direction, |
340 | const struct iovec *iov, unsigned long nr_segs, | |
341 | size_t count) | |
342 | { | |
343 | /* It will get better. Eventually... */ | |
a280455f | 344 | if (segment_eq(get_fs(), KERNEL_DS)) { |
62a8067a | 345 | direction |= ITER_KVEC; |
a280455f AV |
346 | i->type = direction; |
347 | i->kvec = (struct kvec *)iov; | |
348 | } else { | |
349 | i->type = direction; | |
350 | i->iov = iov; | |
351 | } | |
71d8e532 AV |
352 | i->nr_segs = nr_segs; |
353 | i->iov_offset = 0; | |
354 | i->count = count; | |
355 | } | |
356 | EXPORT_SYMBOL(iov_iter_init); | |
7b2c99d1 | 357 | |
62a8067a AV |
358 | static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) |
359 | { | |
360 | char *from = kmap_atomic(page); | |
361 | memcpy(to, from + offset, len); | |
362 | kunmap_atomic(from); | |
363 | } | |
364 | ||
36f7a8a4 | 365 | static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) |
62a8067a AV |
366 | { |
367 | char *to = kmap_atomic(page); | |
368 | memcpy(to + offset, from, len); | |
369 | kunmap_atomic(to); | |
370 | } | |
371 | ||
c35e0248 MW |
372 | static void memzero_page(struct page *page, size_t offset, size_t len) |
373 | { | |
374 | char *addr = kmap_atomic(page); | |
375 | memset(addr + offset, 0, len); | |
376 | kunmap_atomic(addr); | |
377 | } | |
378 | ||
36f7a8a4 | 379 | size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) |
62a8067a | 380 | { |
36f7a8a4 | 381 | const char *from = addr; |
3d4d3e48 AV |
382 | iterate_and_advance(i, bytes, v, |
383 | __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, | |
384 | v.iov_len), | |
385 | memcpy_to_page(v.bv_page, v.bv_offset, | |
a280455f AV |
386 | (from += v.bv_len) - v.bv_len, v.bv_len), |
387 | memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) | |
3d4d3e48 | 388 | ) |
62a8067a | 389 | |
3d4d3e48 | 390 | return bytes; |
c35e0248 | 391 | } |
d271524a | 392 | EXPORT_SYMBOL(copy_to_iter); |
c35e0248 | 393 | |
d271524a | 394 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) |
c35e0248 | 395 | { |
0dbca9a4 | 396 | char *to = addr; |
0dbca9a4 AV |
397 | iterate_and_advance(i, bytes, v, |
398 | __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, | |
399 | v.iov_len), | |
400 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
401 | v.bv_offset, v.bv_len), |
402 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
0dbca9a4 AV |
403 | ) |
404 | ||
405 | return bytes; | |
c35e0248 | 406 | } |
d271524a | 407 | EXPORT_SYMBOL(copy_from_iter); |
c35e0248 | 408 | |
aa583096 AV |
409 | size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) |
410 | { | |
411 | char *to = addr; | |
aa583096 AV |
412 | iterate_and_advance(i, bytes, v, |
413 | __copy_from_user_nocache((to += v.iov_len) - v.iov_len, | |
414 | v.iov_base, v.iov_len), | |
415 | memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, | |
416 | v.bv_offset, v.bv_len), | |
417 | memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
418 | ) | |
419 | ||
420 | return bytes; | |
421 | } | |
422 | EXPORT_SYMBOL(copy_from_iter_nocache); | |
423 | ||
62a8067a AV |
424 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
425 | struct iov_iter *i) | |
426 | { | |
d271524a AV |
427 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
428 | void *kaddr = kmap_atomic(page); | |
429 | size_t wanted = copy_to_iter(kaddr + offset, bytes, i); | |
430 | kunmap_atomic(kaddr); | |
431 | return wanted; | |
432 | } else | |
62a8067a AV |
433 | return copy_page_to_iter_iovec(page, offset, bytes, i); |
434 | } | |
435 | EXPORT_SYMBOL(copy_page_to_iter); | |
436 | ||
437 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, | |
438 | struct iov_iter *i) | |
439 | { | |
a280455f | 440 | if (i->type & (ITER_BVEC|ITER_KVEC)) { |
d271524a AV |
441 | void *kaddr = kmap_atomic(page); |
442 | size_t wanted = copy_from_iter(kaddr + offset, bytes, i); | |
443 | kunmap_atomic(kaddr); | |
444 | return wanted; | |
445 | } else | |
62a8067a AV |
446 | return copy_page_from_iter_iovec(page, offset, bytes, i); |
447 | } | |
448 | EXPORT_SYMBOL(copy_page_from_iter); | |
449 | ||
c35e0248 MW |
450 | size_t iov_iter_zero(size_t bytes, struct iov_iter *i) |
451 | { | |
8442fa46 AV |
452 | iterate_and_advance(i, bytes, v, |
453 | __clear_user(v.iov_base, v.iov_len), | |
a280455f AV |
454 | memzero_page(v.bv_page, v.bv_offset, v.bv_len), |
455 | memset(v.iov_base, 0, v.iov_len) | |
8442fa46 AV |
456 | ) |
457 | ||
458 | return bytes; | |
c35e0248 MW |
459 | } |
460 | EXPORT_SYMBOL(iov_iter_zero); | |
461 | ||
62a8067a AV |
462 | size_t iov_iter_copy_from_user_atomic(struct page *page, |
463 | struct iov_iter *i, unsigned long offset, size_t bytes) | |
464 | { | |
04a31165 AV |
465 | char *kaddr = kmap_atomic(page), *p = kaddr + offset; |
466 | iterate_all_kinds(i, bytes, v, | |
467 | __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, | |
468 | v.iov_base, v.iov_len), | |
469 | memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, | |
a280455f AV |
470 | v.bv_offset, v.bv_len), |
471 | memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) | |
04a31165 AV |
472 | ) |
473 | kunmap_atomic(kaddr); | |
474 | return bytes; | |
62a8067a AV |
475 | } |
476 | EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); | |
477 | ||
478 | void iov_iter_advance(struct iov_iter *i, size_t size) | |
479 | { | |
a280455f | 480 | iterate_and_advance(i, size, v, 0, 0, 0) |
62a8067a AV |
481 | } |
482 | EXPORT_SYMBOL(iov_iter_advance); | |
483 | ||
484 | /* | |
485 | * Return the count of just the current iov_iter segment. | |
486 | */ | |
487 | size_t iov_iter_single_seg_count(const struct iov_iter *i) | |
488 | { | |
489 | if (i->nr_segs == 1) | |
490 | return i->count; | |
491 | else if (i->type & ITER_BVEC) | |
62a8067a | 492 | return min(i->count, i->bvec->bv_len - i->iov_offset); |
ad0eab92 PM |
493 | else |
494 | return min(i->count, i->iov->iov_len - i->iov_offset); | |
62a8067a AV |
495 | } |
496 | EXPORT_SYMBOL(iov_iter_single_seg_count); | |
497 | ||
abb78f87 | 498 | void iov_iter_kvec(struct iov_iter *i, int direction, |
05afcb77 | 499 | const struct kvec *kvec, unsigned long nr_segs, |
abb78f87 AV |
500 | size_t count) |
501 | { | |
502 | BUG_ON(!(direction & ITER_KVEC)); | |
503 | i->type = direction; | |
05afcb77 | 504 | i->kvec = kvec; |
abb78f87 AV |
505 | i->nr_segs = nr_segs; |
506 | i->iov_offset = 0; | |
507 | i->count = count; | |
508 | } | |
509 | EXPORT_SYMBOL(iov_iter_kvec); | |
510 | ||
05afcb77 AV |
511 | void iov_iter_bvec(struct iov_iter *i, int direction, |
512 | const struct bio_vec *bvec, unsigned long nr_segs, | |
513 | size_t count) | |
514 | { | |
515 | BUG_ON(!(direction & ITER_BVEC)); | |
516 | i->type = direction; | |
517 | i->bvec = bvec; | |
518 | i->nr_segs = nr_segs; | |
519 | i->iov_offset = 0; | |
520 | i->count = count; | |
521 | } | |
522 | EXPORT_SYMBOL(iov_iter_bvec); | |
523 | ||
62a8067a AV |
524 | unsigned long iov_iter_alignment(const struct iov_iter *i) |
525 | { | |
04a31165 AV |
526 | unsigned long res = 0; |
527 | size_t size = i->count; | |
528 | ||
529 | if (!size) | |
530 | return 0; | |
531 | ||
532 | iterate_all_kinds(i, size, v, | |
533 | (res |= (unsigned long)v.iov_base | v.iov_len, 0), | |
a280455f AV |
534 | res |= v.bv_offset | v.bv_len, |
535 | res |= (unsigned long)v.iov_base | v.iov_len | |
04a31165 AV |
536 | ) |
537 | return res; | |
62a8067a AV |
538 | } |
539 | EXPORT_SYMBOL(iov_iter_alignment); | |
540 | ||
357f435d AV |
541 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i) |
542 | { | |
543 | unsigned long res = 0; | |
544 | size_t size = i->count; | |
545 | if (!size) | |
546 | return 0; | |
547 | ||
548 | iterate_all_kinds(i, size, v, | |
549 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
550 | (size != v.iov_len ? size : 0), 0), | |
551 | (res |= (!res ? 0 : (unsigned long)v.bv_offset) | | |
552 | (size != v.bv_len ? size : 0)), | |
553 | (res |= (!res ? 0 : (unsigned long)v.iov_base) | | |
554 | (size != v.iov_len ? size : 0)) | |
555 | ); | |
556 | return res; | |
557 | } | |
558 | EXPORT_SYMBOL(iov_iter_gap_alignment); | |
559 | ||
62a8067a | 560 | ssize_t iov_iter_get_pages(struct iov_iter *i, |
2c80929c | 561 | struct page **pages, size_t maxsize, unsigned maxpages, |
62a8067a AV |
562 | size_t *start) |
563 | { | |
e5393fae AV |
564 | if (maxsize > i->count) |
565 | maxsize = i->count; | |
566 | ||
567 | if (!maxsize) | |
568 | return 0; | |
569 | ||
570 | iterate_all_kinds(i, maxsize, v, ({ | |
571 | unsigned long addr = (unsigned long)v.iov_base; | |
572 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
573 | int n; | |
574 | int res; | |
575 | ||
576 | if (len > maxpages * PAGE_SIZE) | |
577 | len = maxpages * PAGE_SIZE; | |
578 | addr &= ~(PAGE_SIZE - 1); | |
579 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
580 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); | |
581 | if (unlikely(res < 0)) | |
582 | return res; | |
583 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
584 | 0;}),({ | |
585 | /* can't be more than PAGE_SIZE */ | |
586 | *start = v.bv_offset; | |
587 | get_page(*pages = v.bv_page); | |
588 | return v.bv_len; | |
a280455f AV |
589 | }),({ |
590 | return -EFAULT; | |
e5393fae AV |
591 | }) |
592 | ) | |
593 | return 0; | |
62a8067a AV |
594 | } |
595 | EXPORT_SYMBOL(iov_iter_get_pages); | |
596 | ||
1b17f1f2 AV |
597 | static struct page **get_pages_array(size_t n) |
598 | { | |
599 | struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); | |
600 | if (!p) | |
601 | p = vmalloc(n * sizeof(struct page *)); | |
602 | return p; | |
603 | } | |
604 | ||
62a8067a AV |
605 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, |
606 | struct page ***pages, size_t maxsize, | |
607 | size_t *start) | |
608 | { | |
1b17f1f2 AV |
609 | struct page **p; |
610 | ||
611 | if (maxsize > i->count) | |
612 | maxsize = i->count; | |
613 | ||
614 | if (!maxsize) | |
615 | return 0; | |
616 | ||
617 | iterate_all_kinds(i, maxsize, v, ({ | |
618 | unsigned long addr = (unsigned long)v.iov_base; | |
619 | size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); | |
620 | int n; | |
621 | int res; | |
622 | ||
623 | addr &= ~(PAGE_SIZE - 1); | |
624 | n = DIV_ROUND_UP(len, PAGE_SIZE); | |
625 | p = get_pages_array(n); | |
626 | if (!p) | |
627 | return -ENOMEM; | |
628 | res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); | |
629 | if (unlikely(res < 0)) { | |
630 | kvfree(p); | |
631 | return res; | |
632 | } | |
633 | *pages = p; | |
634 | return (res == n ? len : res * PAGE_SIZE) - *start; | |
635 | 0;}),({ | |
636 | /* can't be more than PAGE_SIZE */ | |
637 | *start = v.bv_offset; | |
638 | *pages = p = get_pages_array(1); | |
639 | if (!p) | |
640 | return -ENOMEM; | |
641 | get_page(*p = v.bv_page); | |
642 | return v.bv_len; | |
a280455f AV |
643 | }),({ |
644 | return -EFAULT; | |
1b17f1f2 AV |
645 | }) |
646 | ) | |
647 | return 0; | |
62a8067a AV |
648 | } |
649 | EXPORT_SYMBOL(iov_iter_get_pages_alloc); | |
650 | ||
a604ec7e AV |
651 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, |
652 | struct iov_iter *i) | |
653 | { | |
654 | char *to = addr; | |
655 | __wsum sum, next; | |
656 | size_t off = 0; | |
a604ec7e AV |
657 | sum = *csum; |
658 | iterate_and_advance(i, bytes, v, ({ | |
659 | int err = 0; | |
660 | next = csum_and_copy_from_user(v.iov_base, | |
661 | (to += v.iov_len) - v.iov_len, | |
662 | v.iov_len, 0, &err); | |
663 | if (!err) { | |
664 | sum = csum_block_add(sum, next, off); | |
665 | off += v.iov_len; | |
666 | } | |
667 | err ? v.iov_len : 0; | |
668 | }), ({ | |
669 | char *p = kmap_atomic(v.bv_page); | |
670 | next = csum_partial_copy_nocheck(p + v.bv_offset, | |
671 | (to += v.bv_len) - v.bv_len, | |
672 | v.bv_len, 0); | |
673 | kunmap_atomic(p); | |
674 | sum = csum_block_add(sum, next, off); | |
675 | off += v.bv_len; | |
676 | }),({ | |
677 | next = csum_partial_copy_nocheck(v.iov_base, | |
678 | (to += v.iov_len) - v.iov_len, | |
679 | v.iov_len, 0); | |
680 | sum = csum_block_add(sum, next, off); | |
681 | off += v.iov_len; | |
682 | }) | |
683 | ) | |
684 | *csum = sum; | |
685 | return bytes; | |
686 | } | |
687 | EXPORT_SYMBOL(csum_and_copy_from_iter); | |
688 | ||
36f7a8a4 | 689 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, |
a604ec7e AV |
690 | struct iov_iter *i) |
691 | { | |
36f7a8a4 | 692 | const char *from = addr; |
a604ec7e AV |
693 | __wsum sum, next; |
694 | size_t off = 0; | |
a604ec7e AV |
695 | sum = *csum; |
696 | iterate_and_advance(i, bytes, v, ({ | |
697 | int err = 0; | |
698 | next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, | |
699 | v.iov_base, | |
700 | v.iov_len, 0, &err); | |
701 | if (!err) { | |
702 | sum = csum_block_add(sum, next, off); | |
703 | off += v.iov_len; | |
704 | } | |
705 | err ? v.iov_len : 0; | |
706 | }), ({ | |
707 | char *p = kmap_atomic(v.bv_page); | |
708 | next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, | |
709 | p + v.bv_offset, | |
710 | v.bv_len, 0); | |
711 | kunmap_atomic(p); | |
712 | sum = csum_block_add(sum, next, off); | |
713 | off += v.bv_len; | |
714 | }),({ | |
715 | next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, | |
716 | v.iov_base, | |
717 | v.iov_len, 0); | |
718 | sum = csum_block_add(sum, next, off); | |
719 | off += v.iov_len; | |
720 | }) | |
721 | ) | |
722 | *csum = sum; | |
723 | return bytes; | |
724 | } | |
725 | EXPORT_SYMBOL(csum_and_copy_to_iter); | |
726 | ||
62a8067a AV |
727 | int iov_iter_npages(const struct iov_iter *i, int maxpages) |
728 | { | |
e0f2dc40 AV |
729 | size_t size = i->count; |
730 | int npages = 0; | |
731 | ||
732 | if (!size) | |
733 | return 0; | |
734 | ||
735 | iterate_all_kinds(i, size, v, ({ | |
736 | unsigned long p = (unsigned long)v.iov_base; | |
737 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
738 | - p / PAGE_SIZE; | |
739 | if (npages >= maxpages) | |
740 | return maxpages; | |
741 | 0;}),({ | |
742 | npages++; | |
743 | if (npages >= maxpages) | |
744 | return maxpages; | |
a280455f AV |
745 | }),({ |
746 | unsigned long p = (unsigned long)v.iov_base; | |
747 | npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) | |
748 | - p / PAGE_SIZE; | |
749 | if (npages >= maxpages) | |
750 | return maxpages; | |
e0f2dc40 AV |
751 | }) |
752 | ) | |
753 | return npages; | |
62a8067a | 754 | } |
f67da30c | 755 | EXPORT_SYMBOL(iov_iter_npages); |
4b8164b9 AV |
756 | |
757 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) | |
758 | { | |
759 | *new = *old; | |
760 | if (new->type & ITER_BVEC) | |
761 | return new->bvec = kmemdup(new->bvec, | |
762 | new->nr_segs * sizeof(struct bio_vec), | |
763 | flags); | |
764 | else | |
765 | /* iovec and kvec have identical layout */ | |
766 | return new->iov = kmemdup(new->iov, | |
767 | new->nr_segs * sizeof(struct iovec), | |
768 | flags); | |
769 | } | |
770 | EXPORT_SYMBOL(dup_iter); | |
bc917be8 AV |
771 | |
772 | int import_iovec(int type, const struct iovec __user * uvector, | |
773 | unsigned nr_segs, unsigned fast_segs, | |
774 | struct iovec **iov, struct iov_iter *i) | |
775 | { | |
776 | ssize_t n; | |
777 | struct iovec *p; | |
778 | n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
779 | *iov, &p); | |
780 | if (n < 0) { | |
781 | if (p != *iov) | |
782 | kfree(p); | |
783 | *iov = NULL; | |
784 | return n; | |
785 | } | |
786 | iov_iter_init(i, type, p, nr_segs, n); | |
787 | *iov = p == *iov ? NULL : p; | |
788 | return 0; | |
789 | } | |
790 | EXPORT_SYMBOL(import_iovec); | |
791 | ||
792 | #ifdef CONFIG_COMPAT | |
793 | #include <linux/compat.h> | |
794 | ||
795 | int compat_import_iovec(int type, const struct compat_iovec __user * uvector, | |
796 | unsigned nr_segs, unsigned fast_segs, | |
797 | struct iovec **iov, struct iov_iter *i) | |
798 | { | |
799 | ssize_t n; | |
800 | struct iovec *p; | |
801 | n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, | |
802 | *iov, &p); | |
803 | if (n < 0) { | |
804 | if (p != *iov) | |
805 | kfree(p); | |
806 | *iov = NULL; | |
807 | return n; | |
808 | } | |
809 | iov_iter_init(i, type, p, nr_segs, n); | |
810 | *iov = p == *iov ? NULL : p; | |
811 | return 0; | |
812 | } | |
813 | #endif | |
814 | ||
815 | int import_single_range(int rw, void __user *buf, size_t len, | |
816 | struct iovec *iov, struct iov_iter *i) | |
817 | { | |
818 | if (len > MAX_RW_COUNT) | |
819 | len = MAX_RW_COUNT; | |
820 | if (unlikely(!access_ok(!rw, buf, len))) | |
821 | return -EFAULT; | |
822 | ||
823 | iov->iov_base = buf; | |
824 | iov->iov_len = len; | |
825 | iov_iter_init(i, rw, iov, 1, len); | |
826 | return 0; | |
827 | } | |
e1267585 | 828 | EXPORT_SYMBOL(import_single_range); |