1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 27999096fSHerbert Xu #include <crypto/hash.h> 3d879cb83SAl Viro #include <linux/export.h> 42f8b5444SChristoph Hellwig #include <linux/bvec.h> 5d879cb83SAl Viro #include <linux/uio.h> 6d879cb83SAl Viro #include <linux/pagemap.h> 7d879cb83SAl Viro #include <linux/slab.h> 8d879cb83SAl Viro #include <linux/vmalloc.h> 9241699cdSAl Viro #include <linux/splice.h> 10d879cb83SAl Viro #include <net/checksum.h> 11d05f4435SSagi Grimberg #include <linux/scatterlist.h> 12d0ef4c36SMarco Elver #include <linux/instrumented.h> 13d879cb83SAl Viro 14241699cdSAl Viro #define PIPE_PARANOIA /* for now */ 15241699cdSAl Viro 16d879cb83SAl Viro #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ 17d879cb83SAl Viro size_t left; \ 18d879cb83SAl Viro size_t wanted = n; \ 19d879cb83SAl Viro __p = i->iov; \ 20d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 21d879cb83SAl Viro if (likely(__v.iov_len)) { \ 22d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 23d879cb83SAl Viro left = (STEP); \ 24d879cb83SAl Viro __v.iov_len -= left; \ 25d879cb83SAl Viro skip += __v.iov_len; \ 26d879cb83SAl Viro n -= __v.iov_len; \ 27d879cb83SAl Viro } else { \ 28d879cb83SAl Viro left = 0; \ 29d879cb83SAl Viro } \ 30d879cb83SAl Viro while (unlikely(!left && n)) { \ 31d879cb83SAl Viro __p++; \ 32d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 33d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 34d879cb83SAl Viro continue; \ 35d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 36d879cb83SAl Viro left = (STEP); \ 37d879cb83SAl Viro __v.iov_len -= left; \ 38d879cb83SAl Viro skip = __v.iov_len; \ 39d879cb83SAl Viro n -= __v.iov_len; \ 40d879cb83SAl Viro } \ 41d879cb83SAl Viro n = wanted - n; \ 42d879cb83SAl Viro } 43d879cb83SAl Viro 44d879cb83SAl Viro #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ 45d879cb83SAl Viro size_t wanted = n; \ 46d879cb83SAl Viro __p = i->kvec; \ 47d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 48d879cb83SAl Viro if (likely(__v.iov_len)) { \ 49d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 50d879cb83SAl Viro (void)(STEP); \ 51d879cb83SAl Viro skip += __v.iov_len; \ 52d879cb83SAl Viro n -= __v.iov_len; \ 53d879cb83SAl Viro } \ 54d879cb83SAl Viro while (unlikely(n)) { \ 55d879cb83SAl Viro __p++; \ 56d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 57d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 58d879cb83SAl Viro continue; \ 59d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 60d879cb83SAl Viro (void)(STEP); \ 61d879cb83SAl Viro skip = __v.iov_len; \ 62d879cb83SAl Viro n -= __v.iov_len; \ 63d879cb83SAl Viro } \ 64d879cb83SAl Viro n = wanted; \ 65d879cb83SAl Viro } 66d879cb83SAl Viro 671bdc76aeSMing Lei #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ 681bdc76aeSMing Lei struct bvec_iter __start; \ 691bdc76aeSMing Lei __start.bi_size = n; \ 701bdc76aeSMing Lei __start.bi_bvec_done = skip; \ 711bdc76aeSMing Lei __start.bi_idx = 0; \ 721bdc76aeSMing Lei for_each_bvec(__v, i->bvec, __bi, __start) { \ 731bdc76aeSMing Lei if (!__v.bv_len) \ 74d879cb83SAl Viro continue; \ 75d879cb83SAl Viro (void)(STEP); \ 76d879cb83SAl Viro } \ 77d879cb83SAl Viro } 78d879cb83SAl Viro 79d879cb83SAl Viro #define iterate_all_kinds(i, n, v, I, B, K) { \ 8033844e66SAl Viro if (likely(n)) { \ 81d879cb83SAl Viro size_t skip = i->iov_offset; \ 82d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 83d879cb83SAl Viro struct bio_vec v; \ 841bdc76aeSMing Lei struct bvec_iter __bi; \ 851bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 86d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 87d879cb83SAl Viro const struct kvec *kvec; \ 88d879cb83SAl Viro struct kvec v; \ 89d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 909ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 91d879cb83SAl Viro } else { \ 92d879cb83SAl Viro const struct iovec *iov; \ 93d879cb83SAl Viro struct iovec v; \ 94d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 95d879cb83SAl Viro } \ 9633844e66SAl Viro } \ 97d879cb83SAl Viro } 98d879cb83SAl Viro 99d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 100dd254f5aSAl Viro if (unlikely(i->count < n)) \ 101dd254f5aSAl Viro n = i->count; \ 10219f18459SAl Viro if (i->count) { \ 103d879cb83SAl Viro size_t skip = i->iov_offset; \ 104d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 1051bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 106d879cb83SAl Viro struct bio_vec v; \ 1071bdc76aeSMing Lei struct bvec_iter __bi; \ 1081bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1091bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1101bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1111bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 112d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 113d879cb83SAl Viro const struct kvec *kvec; \ 114d879cb83SAl Viro struct kvec v; \ 115d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 116d879cb83SAl Viro if (skip == kvec->iov_len) { \ 117d879cb83SAl Viro kvec++; \ 118d879cb83SAl Viro skip = 0; \ 119d879cb83SAl Viro } \ 120d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 121d879cb83SAl Viro i->kvec = kvec; \ 1229ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 1239ea9ce04SDavid Howells skip += n; \ 124d879cb83SAl Viro } else { \ 125d879cb83SAl Viro const struct iovec *iov; \ 126d879cb83SAl Viro struct iovec v; \ 127d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 128d879cb83SAl Viro if (skip == iov->iov_len) { \ 129d879cb83SAl Viro iov++; \ 130d879cb83SAl Viro skip = 0; \ 131d879cb83SAl Viro } \ 132d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 133d879cb83SAl Viro i->iov = iov; \ 134d879cb83SAl Viro } \ 135d879cb83SAl Viro i->count -= n; \ 136d879cb83SAl Viro i->iov_offset = skip; \ 137dd254f5aSAl Viro } \ 138d879cb83SAl Viro } 139d879cb83SAl Viro 14009fc68dcSAl Viro static int copyout(void __user *to, const void *from, size_t n) 14109fc68dcSAl Viro { 14296d4f267SLinus Torvalds if (access_ok(to, n)) { 143d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 14409fc68dcSAl Viro n = raw_copy_to_user(to, from, n); 14509fc68dcSAl Viro } 14609fc68dcSAl Viro return n; 14709fc68dcSAl Viro } 14809fc68dcSAl Viro 14909fc68dcSAl Viro static int copyin(void *to, const void __user *from, size_t n) 15009fc68dcSAl Viro { 15196d4f267SLinus Torvalds if (access_ok(from, n)) { 152d0ef4c36SMarco Elver instrument_copy_from_user(to, from, n); 15309fc68dcSAl Viro n = raw_copy_from_user(to, from, n); 15409fc68dcSAl Viro } 15509fc68dcSAl Viro return n; 15609fc68dcSAl Viro } 15709fc68dcSAl Viro 158d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 159d879cb83SAl Viro struct iov_iter *i) 160d879cb83SAl Viro { 161d879cb83SAl Viro size_t skip, copy, left, wanted; 162d879cb83SAl Viro const struct iovec *iov; 163d879cb83SAl Viro char __user *buf; 164d879cb83SAl Viro void *kaddr, *from; 165d879cb83SAl Viro 166d879cb83SAl Viro if (unlikely(bytes > i->count)) 167d879cb83SAl Viro bytes = i->count; 168d879cb83SAl Viro 169d879cb83SAl Viro if (unlikely(!bytes)) 170d879cb83SAl Viro return 0; 171d879cb83SAl Viro 17209fc68dcSAl Viro might_fault(); 173d879cb83SAl Viro wanted = bytes; 174d879cb83SAl Viro iov = i->iov; 175d879cb83SAl Viro skip = i->iov_offset; 176d879cb83SAl Viro buf = iov->iov_base + skip; 177d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 178d879cb83SAl Viro 1793fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 180d879cb83SAl Viro kaddr = kmap_atomic(page); 181d879cb83SAl Viro from = kaddr + offset; 182d879cb83SAl Viro 183d879cb83SAl Viro /* first chunk, usually the only one */ 18409fc68dcSAl Viro left = copyout(buf, from, copy); 185d879cb83SAl Viro copy -= left; 186d879cb83SAl Viro skip += copy; 187d879cb83SAl Viro from += copy; 188d879cb83SAl Viro bytes -= copy; 189d879cb83SAl Viro 190d879cb83SAl Viro while (unlikely(!left && bytes)) { 191d879cb83SAl Viro iov++; 192d879cb83SAl Viro buf = iov->iov_base; 193d879cb83SAl Viro copy = min(bytes, iov->iov_len); 19409fc68dcSAl Viro left = copyout(buf, from, copy); 195d879cb83SAl Viro copy -= left; 196d879cb83SAl Viro skip = copy; 197d879cb83SAl Viro from += copy; 198d879cb83SAl Viro bytes -= copy; 199d879cb83SAl Viro } 200d879cb83SAl Viro if (likely(!bytes)) { 201d879cb83SAl Viro kunmap_atomic(kaddr); 202d879cb83SAl Viro goto done; 203d879cb83SAl Viro } 204d879cb83SAl Viro offset = from - kaddr; 205d879cb83SAl Viro buf += copy; 206d879cb83SAl Viro kunmap_atomic(kaddr); 207d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 208d879cb83SAl Viro } 209d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2103fa6c507SMikulas Patocka 211d879cb83SAl Viro kaddr = kmap(page); 212d879cb83SAl Viro from = kaddr + offset; 21309fc68dcSAl Viro left = copyout(buf, from, copy); 214d879cb83SAl Viro copy -= left; 215d879cb83SAl Viro skip += copy; 216d879cb83SAl Viro from += copy; 217d879cb83SAl Viro bytes -= copy; 218d879cb83SAl Viro while (unlikely(!left && bytes)) { 219d879cb83SAl Viro iov++; 220d879cb83SAl Viro buf = iov->iov_base; 221d879cb83SAl Viro copy = min(bytes, iov->iov_len); 22209fc68dcSAl Viro left = copyout(buf, from, copy); 223d879cb83SAl Viro copy -= left; 224d879cb83SAl Viro skip = copy; 225d879cb83SAl Viro from += copy; 226d879cb83SAl Viro bytes -= copy; 227d879cb83SAl Viro } 228d879cb83SAl Viro kunmap(page); 2293fa6c507SMikulas Patocka 230d879cb83SAl Viro done: 231d879cb83SAl Viro if (skip == iov->iov_len) { 232d879cb83SAl Viro iov++; 233d879cb83SAl Viro skip = 0; 234d879cb83SAl Viro } 235d879cb83SAl Viro i->count -= wanted - bytes; 236d879cb83SAl Viro i->nr_segs -= iov - i->iov; 237d879cb83SAl Viro i->iov = iov; 238d879cb83SAl Viro i->iov_offset = skip; 239d879cb83SAl Viro return wanted - bytes; 240d879cb83SAl Viro } 241d879cb83SAl Viro 242d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 243d879cb83SAl Viro struct iov_iter *i) 244d879cb83SAl Viro { 245d879cb83SAl Viro size_t skip, copy, left, wanted; 246d879cb83SAl Viro const struct iovec *iov; 247d879cb83SAl Viro char __user *buf; 248d879cb83SAl Viro void *kaddr, *to; 249d879cb83SAl Viro 250d879cb83SAl Viro if (unlikely(bytes > i->count)) 251d879cb83SAl Viro bytes = i->count; 252d879cb83SAl Viro 253d879cb83SAl Viro if (unlikely(!bytes)) 254d879cb83SAl Viro return 0; 255d879cb83SAl Viro 25609fc68dcSAl Viro might_fault(); 257d879cb83SAl Viro wanted = bytes; 258d879cb83SAl Viro iov = i->iov; 259d879cb83SAl Viro skip = i->iov_offset; 260d879cb83SAl Viro buf = iov->iov_base + skip; 261d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 262d879cb83SAl Viro 2633fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 264d879cb83SAl Viro kaddr = kmap_atomic(page); 265d879cb83SAl Viro to = kaddr + offset; 266d879cb83SAl Viro 267d879cb83SAl Viro /* first chunk, usually the only one */ 26809fc68dcSAl Viro left = copyin(to, buf, copy); 269d879cb83SAl Viro copy -= left; 270d879cb83SAl Viro skip += copy; 271d879cb83SAl Viro to += copy; 272d879cb83SAl Viro bytes -= copy; 273d879cb83SAl Viro 274d879cb83SAl Viro while (unlikely(!left && bytes)) { 275d879cb83SAl Viro iov++; 276d879cb83SAl Viro buf = iov->iov_base; 277d879cb83SAl Viro copy = min(bytes, iov->iov_len); 27809fc68dcSAl Viro left = copyin(to, buf, copy); 279d879cb83SAl Viro copy -= left; 280d879cb83SAl Viro skip = copy; 281d879cb83SAl Viro to += copy; 282d879cb83SAl Viro bytes -= copy; 283d879cb83SAl Viro } 284d879cb83SAl Viro if (likely(!bytes)) { 285d879cb83SAl Viro kunmap_atomic(kaddr); 286d879cb83SAl Viro goto done; 287d879cb83SAl Viro } 288d879cb83SAl Viro offset = to - kaddr; 289d879cb83SAl Viro buf += copy; 290d879cb83SAl Viro kunmap_atomic(kaddr); 291d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 292d879cb83SAl Viro } 293d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2943fa6c507SMikulas Patocka 295d879cb83SAl Viro kaddr = kmap(page); 296d879cb83SAl Viro to = kaddr + offset; 29709fc68dcSAl Viro left = copyin(to, buf, copy); 298d879cb83SAl Viro copy -= left; 299d879cb83SAl Viro skip += copy; 300d879cb83SAl Viro to += copy; 301d879cb83SAl Viro bytes -= copy; 302d879cb83SAl Viro while (unlikely(!left && bytes)) { 303d879cb83SAl Viro iov++; 304d879cb83SAl Viro buf = iov->iov_base; 305d879cb83SAl Viro copy = min(bytes, iov->iov_len); 30609fc68dcSAl Viro left = copyin(to, buf, copy); 307d879cb83SAl Viro copy -= left; 308d879cb83SAl Viro skip = copy; 309d879cb83SAl Viro to += copy; 310d879cb83SAl Viro bytes -= copy; 311d879cb83SAl Viro } 312d879cb83SAl Viro kunmap(page); 3133fa6c507SMikulas Patocka 314d879cb83SAl Viro done: 315d879cb83SAl Viro if (skip == iov->iov_len) { 316d879cb83SAl Viro iov++; 317d879cb83SAl Viro skip = 0; 318d879cb83SAl Viro } 319d879cb83SAl Viro i->count -= wanted - bytes; 320d879cb83SAl Viro i->nr_segs -= iov - i->iov; 321d879cb83SAl Viro i->iov = iov; 322d879cb83SAl Viro i->iov_offset = skip; 323d879cb83SAl Viro return wanted - bytes; 324d879cb83SAl Viro } 325d879cb83SAl Viro 326241699cdSAl Viro #ifdef PIPE_PARANOIA 327241699cdSAl Viro static bool sanity(const struct iov_iter *i) 328241699cdSAl Viro { 329241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 3308cefc107SDavid Howells unsigned int p_head = pipe->head; 3318cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3328cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3338cefc107SDavid Howells unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); 3348cefc107SDavid Howells unsigned int i_head = i->head; 3358cefc107SDavid Howells unsigned int idx; 3368cefc107SDavid Howells 337241699cdSAl Viro if (i->iov_offset) { 338241699cdSAl Viro struct pipe_buffer *p; 3398cefc107SDavid Howells if (unlikely(p_occupancy == 0)) 340241699cdSAl Viro goto Bad; // pipe must be non-empty 3418cefc107SDavid Howells if (unlikely(i_head != p_head - 1)) 342241699cdSAl Viro goto Bad; // must be at the last buffer... 343241699cdSAl Viro 3448cefc107SDavid Howells p = &pipe->bufs[i_head & p_mask]; 345241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 346241699cdSAl Viro goto Bad; // ... at the end of segment 347241699cdSAl Viro } else { 3488cefc107SDavid Howells if (i_head != p_head) 349241699cdSAl Viro goto Bad; // must be right after the last buffer 350241699cdSAl Viro } 351241699cdSAl Viro return true; 352241699cdSAl Viro Bad: 3538cefc107SDavid Howells printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); 3548cefc107SDavid Howells printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", 3558cefc107SDavid Howells p_head, p_tail, pipe->ring_size); 3568cefc107SDavid Howells for (idx = 0; idx < pipe->ring_size; idx++) 357241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 358241699cdSAl Viro pipe->bufs[idx].ops, 359241699cdSAl Viro pipe->bufs[idx].page, 360241699cdSAl Viro pipe->bufs[idx].offset, 361241699cdSAl Viro pipe->bufs[idx].len); 362241699cdSAl Viro WARN_ON(1); 363241699cdSAl Viro return false; 364241699cdSAl Viro } 365241699cdSAl Viro #else 366241699cdSAl Viro #define sanity(i) true 367241699cdSAl Viro #endif 368241699cdSAl Viro 369241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 370241699cdSAl Viro struct iov_iter *i) 371241699cdSAl Viro { 372241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 373241699cdSAl Viro struct pipe_buffer *buf; 3748cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3758cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3768cefc107SDavid Howells unsigned int i_head = i->head; 377241699cdSAl Viro size_t off; 378241699cdSAl Viro 379241699cdSAl Viro if (unlikely(bytes > i->count)) 380241699cdSAl Viro bytes = i->count; 381241699cdSAl Viro 382241699cdSAl Viro if (unlikely(!bytes)) 383241699cdSAl Viro return 0; 384241699cdSAl Viro 385241699cdSAl Viro if (!sanity(i)) 386241699cdSAl Viro return 0; 387241699cdSAl Viro 388241699cdSAl Viro off = i->iov_offset; 3898cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 390241699cdSAl Viro if (off) { 391241699cdSAl Viro if (offset == off && buf->page == page) { 392241699cdSAl Viro /* merge with the last one */ 393241699cdSAl Viro buf->len += bytes; 394241699cdSAl Viro i->iov_offset += bytes; 395241699cdSAl Viro goto out; 396241699cdSAl Viro } 3978cefc107SDavid Howells i_head++; 3988cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 399241699cdSAl Viro } 4006718b6f8SDavid Howells if (pipe_full(i_head, p_tail, pipe->max_usage)) 401241699cdSAl Viro return 0; 4028cefc107SDavid Howells 403241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 4048cefc107SDavid Howells get_page(page); 4058cefc107SDavid Howells buf->page = page; 406241699cdSAl Viro buf->offset = offset; 407241699cdSAl Viro buf->len = bytes; 4088cefc107SDavid Howells 4098cefc107SDavid Howells pipe->head = i_head + 1; 410241699cdSAl Viro i->iov_offset = offset + bytes; 4118cefc107SDavid Howells i->head = i_head; 412241699cdSAl Viro out: 413241699cdSAl Viro i->count -= bytes; 414241699cdSAl Viro return bytes; 415241699cdSAl Viro } 416241699cdSAl Viro 417d879cb83SAl Viro /* 418171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 419171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 420171a0203SAnton Altaparmakov * 421171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 422171a0203SAnton Altaparmakov * because it is an invalid address). 423171a0203SAnton Altaparmakov */ 424d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 425171a0203SAnton Altaparmakov { 426171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 427171a0203SAnton Altaparmakov const struct iovec *iov; 428171a0203SAnton Altaparmakov int err; 429171a0203SAnton Altaparmakov struct iovec v; 430171a0203SAnton Altaparmakov 431171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 432171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4334bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 434171a0203SAnton Altaparmakov if (unlikely(err)) 435171a0203SAnton Altaparmakov return err; 436171a0203SAnton Altaparmakov 0;})) 437171a0203SAnton Altaparmakov } 438171a0203SAnton Altaparmakov return 0; 439171a0203SAnton Altaparmakov } 440d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 441171a0203SAnton Altaparmakov 442aa563d7bSDavid Howells void iov_iter_init(struct iov_iter *i, unsigned int direction, 443d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 444d879cb83SAl Viro size_t count) 445d879cb83SAl Viro { 446aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 447aa563d7bSDavid Howells direction &= READ | WRITE; 448aa563d7bSDavid Howells 449d879cb83SAl Viro /* It will get better. Eventually... */ 450db68ce10SAl Viro if (uaccess_kernel()) { 451aa563d7bSDavid Howells i->type = ITER_KVEC | direction; 452d879cb83SAl Viro i->kvec = (struct kvec *)iov; 453d879cb83SAl Viro } else { 454aa563d7bSDavid Howells i->type = ITER_IOVEC | direction; 455d879cb83SAl Viro i->iov = iov; 456d879cb83SAl Viro } 457d879cb83SAl Viro i->nr_segs = nr_segs; 458d879cb83SAl Viro i->iov_offset = 0; 459d879cb83SAl Viro i->count = count; 460d879cb83SAl Viro } 461d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 462d879cb83SAl Viro 463d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 464d879cb83SAl Viro { 465d879cb83SAl Viro char *from = kmap_atomic(page); 466d879cb83SAl Viro memcpy(to, from + offset, len); 467d879cb83SAl Viro kunmap_atomic(from); 468d879cb83SAl Viro } 469d879cb83SAl Viro 47036f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 471d879cb83SAl Viro { 472d879cb83SAl Viro char *to = kmap_atomic(page); 473d879cb83SAl Viro memcpy(to + offset, from, len); 474d879cb83SAl Viro kunmap_atomic(to); 475d879cb83SAl Viro } 476d879cb83SAl Viro 477d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 478d879cb83SAl Viro { 479d879cb83SAl Viro char *addr = kmap_atomic(page); 480d879cb83SAl Viro memset(addr + offset, 0, len); 481d879cb83SAl Viro kunmap_atomic(addr); 482d879cb83SAl Viro } 483d879cb83SAl Viro 484241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 485241699cdSAl Viro { 486241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 487241699cdSAl Viro } 488241699cdSAl Viro 4898cefc107SDavid Howells static inline void data_start(const struct iov_iter *i, 4908cefc107SDavid Howells unsigned int *iter_headp, size_t *offp) 491241699cdSAl Viro { 4928cefc107SDavid Howells unsigned int p_mask = i->pipe->ring_size - 1; 4938cefc107SDavid Howells unsigned int iter_head = i->head; 494241699cdSAl Viro size_t off = i->iov_offset; 4958cefc107SDavid Howells 4968cefc107SDavid Howells if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || 4978cefc107SDavid Howells off == PAGE_SIZE)) { 4988cefc107SDavid Howells iter_head++; 499241699cdSAl Viro off = 0; 500241699cdSAl Viro } 5018cefc107SDavid Howells *iter_headp = iter_head; 502241699cdSAl Viro *offp = off; 503241699cdSAl Viro } 504241699cdSAl Viro 505241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 5068cefc107SDavid Howells int *iter_headp, size_t *offp) 507241699cdSAl Viro { 508241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5098cefc107SDavid Howells unsigned int p_tail = pipe->tail; 5108cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5118cefc107SDavid Howells unsigned int iter_head; 512241699cdSAl Viro size_t off; 513241699cdSAl Viro ssize_t left; 514241699cdSAl Viro 515241699cdSAl Viro if (unlikely(size > i->count)) 516241699cdSAl Viro size = i->count; 517241699cdSAl Viro if (unlikely(!size)) 518241699cdSAl Viro return 0; 519241699cdSAl Viro 520241699cdSAl Viro left = size; 5218cefc107SDavid Howells data_start(i, &iter_head, &off); 5228cefc107SDavid Howells *iter_headp = iter_head; 523241699cdSAl Viro *offp = off; 524241699cdSAl Viro if (off) { 525241699cdSAl Viro left -= PAGE_SIZE - off; 526241699cdSAl Viro if (left <= 0) { 5278cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len += size; 528241699cdSAl Viro return size; 529241699cdSAl Viro } 5308cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; 5318cefc107SDavid Howells iter_head++; 532241699cdSAl Viro } 5336718b6f8SDavid Howells while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { 5348cefc107SDavid Howells struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; 535241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 536241699cdSAl Viro if (!page) 537241699cdSAl Viro break; 5388cefc107SDavid Howells 5398cefc107SDavid Howells buf->ops = &default_pipe_buf_ops; 5408cefc107SDavid Howells buf->page = page; 5418cefc107SDavid Howells buf->offset = 0; 5428cefc107SDavid Howells buf->len = min_t(ssize_t, left, PAGE_SIZE); 5438cefc107SDavid Howells left -= buf->len; 5448cefc107SDavid Howells iter_head++; 5458cefc107SDavid Howells pipe->head = iter_head; 5468cefc107SDavid Howells 5478cefc107SDavid Howells if (left == 0) 548241699cdSAl Viro return size; 549241699cdSAl Viro } 550241699cdSAl Viro return size - left; 551241699cdSAl Viro } 552241699cdSAl Viro 553241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 554241699cdSAl Viro struct iov_iter *i) 555241699cdSAl Viro { 556241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5578cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5588cefc107SDavid Howells unsigned int i_head; 559241699cdSAl Viro size_t n, off; 560241699cdSAl Viro 561241699cdSAl Viro if (!sanity(i)) 562241699cdSAl Viro return 0; 563241699cdSAl Viro 5648cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 565241699cdSAl Viro if (unlikely(!n)) 566241699cdSAl Viro return 0; 5678cefc107SDavid Howells do { 568241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 5698cefc107SDavid Howells memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); 5708cefc107SDavid Howells i->head = i_head; 571241699cdSAl Viro i->iov_offset = off + chunk; 572241699cdSAl Viro n -= chunk; 573241699cdSAl Viro addr += chunk; 5748cefc107SDavid Howells off = 0; 5758cefc107SDavid Howells i_head++; 5768cefc107SDavid Howells } while (n); 577241699cdSAl Viro i->count -= bytes; 578241699cdSAl Viro return bytes; 579241699cdSAl Viro } 580241699cdSAl Viro 581f9152895SAl Viro static __wsum csum_and_memcpy(void *to, const void *from, size_t len, 582f9152895SAl Viro __wsum sum, size_t off) 583f9152895SAl Viro { 584f9152895SAl Viro __wsum next = csum_partial_copy_nocheck(from, to, len, 0); 585f9152895SAl Viro return csum_block_add(sum, next, off); 586f9152895SAl Viro } 587f9152895SAl Viro 58878e1f386SAl Viro static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 58978e1f386SAl Viro __wsum *csum, struct iov_iter *i) 59078e1f386SAl Viro { 59178e1f386SAl Viro struct pipe_inode_info *pipe = i->pipe; 5928cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5938cefc107SDavid Howells unsigned int i_head; 59478e1f386SAl Viro size_t n, r; 59578e1f386SAl Viro size_t off = 0; 596f9152895SAl Viro __wsum sum = *csum; 59778e1f386SAl Viro 59878e1f386SAl Viro if (!sanity(i)) 59978e1f386SAl Viro return 0; 60078e1f386SAl Viro 6018cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &r); 60278e1f386SAl Viro if (unlikely(!n)) 60378e1f386SAl Viro return 0; 6048cefc107SDavid Howells do { 60578e1f386SAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - r); 6068cefc107SDavid Howells char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); 607f9152895SAl Viro sum = csum_and_memcpy(p + r, addr, chunk, sum, off); 60878e1f386SAl Viro kunmap_atomic(p); 6098cefc107SDavid Howells i->head = i_head; 61078e1f386SAl Viro i->iov_offset = r + chunk; 61178e1f386SAl Viro n -= chunk; 61278e1f386SAl Viro off += chunk; 61378e1f386SAl Viro addr += chunk; 6148cefc107SDavid Howells r = 0; 6158cefc107SDavid Howells i_head++; 6168cefc107SDavid Howells } while (n); 61778e1f386SAl Viro i->count -= bytes; 61878e1f386SAl Viro *csum = sum; 61978e1f386SAl Viro return bytes; 62078e1f386SAl Viro } 62178e1f386SAl Viro 622aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 623d879cb83SAl Viro { 62436f7a8a4SAl Viro const char *from = addr; 62500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 626241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 62709fc68dcSAl Viro if (iter_is_iovec(i)) 62809fc68dcSAl Viro might_fault(); 629d879cb83SAl Viro iterate_and_advance(i, bytes, v, 63009fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 631d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 632d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 633d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 634d879cb83SAl Viro ) 635d879cb83SAl Viro 636d879cb83SAl Viro return bytes; 637d879cb83SAl Viro } 638aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 639d879cb83SAl Viro 640ec6347bbSDan Williams #ifdef CONFIG_ARCH_HAS_COPY_MC 641ec6347bbSDan Williams static int copyout_mc(void __user *to, const void *from, size_t n) 6428780356eSDan Williams { 64396d4f267SLinus Torvalds if (access_ok(to, n)) { 644d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 645ec6347bbSDan Williams n = copy_mc_to_user((__force void *) to, from, n); 6468780356eSDan Williams } 6478780356eSDan Williams return n; 6488780356eSDan Williams } 6498780356eSDan Williams 650ec6347bbSDan Williams static unsigned long copy_mc_to_page(struct page *page, size_t offset, 6518780356eSDan Williams const char *from, size_t len) 6528780356eSDan Williams { 6538780356eSDan Williams unsigned long ret; 6548780356eSDan Williams char *to; 6558780356eSDan Williams 6568780356eSDan Williams to = kmap_atomic(page); 657ec6347bbSDan Williams ret = copy_mc_to_kernel(to + offset, from, len); 6588780356eSDan Williams kunmap_atomic(to); 6598780356eSDan Williams 6608780356eSDan Williams return ret; 6618780356eSDan Williams } 6628780356eSDan Williams 663ec6347bbSDan Williams static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes, 664ca146f6fSDan Williams struct iov_iter *i) 665ca146f6fSDan Williams { 666ca146f6fSDan Williams struct pipe_inode_info *pipe = i->pipe; 6678cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 6688cefc107SDavid Howells unsigned int i_head; 669ca146f6fSDan Williams size_t n, off, xfer = 0; 670ca146f6fSDan Williams 671ca146f6fSDan Williams if (!sanity(i)) 672ca146f6fSDan Williams return 0; 673ca146f6fSDan Williams 6748cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 675ca146f6fSDan Williams if (unlikely(!n)) 676ca146f6fSDan Williams return 0; 6778cefc107SDavid Howells do { 678ca146f6fSDan Williams size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 679ca146f6fSDan Williams unsigned long rem; 680ca146f6fSDan Williams 681ec6347bbSDan Williams rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page, 6828cefc107SDavid Howells off, addr, chunk); 6838cefc107SDavid Howells i->head = i_head; 684ca146f6fSDan Williams i->iov_offset = off + chunk - rem; 685ca146f6fSDan Williams xfer += chunk - rem; 686ca146f6fSDan Williams if (rem) 687ca146f6fSDan Williams break; 688ca146f6fSDan Williams n -= chunk; 689ca146f6fSDan Williams addr += chunk; 6908cefc107SDavid Howells off = 0; 6918cefc107SDavid Howells i_head++; 6928cefc107SDavid Howells } while (n); 693ca146f6fSDan Williams i->count -= xfer; 694ca146f6fSDan Williams return xfer; 695ca146f6fSDan Williams } 696ca146f6fSDan Williams 697bf3eeb9bSDan Williams /** 698ec6347bbSDan Williams * _copy_mc_to_iter - copy to iter with source memory error exception handling 699bf3eeb9bSDan Williams * @addr: source kernel address 700bf3eeb9bSDan Williams * @bytes: total transfer length 701bf3eeb9bSDan Williams * @iter: destination iterator 702bf3eeb9bSDan Williams * 703ec6347bbSDan Williams * The pmem driver deploys this for the dax operation 704ec6347bbSDan Williams * (dax_copy_to_iter()) for dax reads (bypass page-cache and the 705ec6347bbSDan Williams * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes 706ec6347bbSDan Williams * successfully copied. 707bf3eeb9bSDan Williams * 708ec6347bbSDan Williams * The main differences between this and typical _copy_to_iter(). 709bf3eeb9bSDan Williams * 710bf3eeb9bSDan Williams * * Typical tail/residue handling after a fault retries the copy 711bf3eeb9bSDan Williams * byte-by-byte until the fault happens again. Re-triggering machine 712bf3eeb9bSDan Williams * checks is potentially fatal so the implementation uses source 713bf3eeb9bSDan Williams * alignment and poison alignment assumptions to avoid re-triggering 714bf3eeb9bSDan Williams * hardware exceptions. 715bf3eeb9bSDan Williams * 716bf3eeb9bSDan Williams * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. 717bf3eeb9bSDan Williams * Compare to copy_to_iter() where only ITER_IOVEC attempts might return 718bf3eeb9bSDan Williams * a short copy. 719bf3eeb9bSDan Williams */ 720ec6347bbSDan Williams size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 7218780356eSDan Williams { 7228780356eSDan Williams const char *from = addr; 7238780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 7248780356eSDan Williams 72500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 726ec6347bbSDan Williams return copy_mc_pipe_to_iter(addr, bytes, i); 7278780356eSDan Williams if (iter_is_iovec(i)) 7288780356eSDan Williams might_fault(); 7298780356eSDan Williams iterate_and_advance(i, bytes, v, 730ec6347bbSDan Williams copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len, 731ec6347bbSDan Williams v.iov_len), 7328780356eSDan Williams ({ 733ec6347bbSDan Williams rem = copy_mc_to_page(v.bv_page, v.bv_offset, 7348780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 7358780356eSDan Williams if (rem) { 7368780356eSDan Williams curr_addr = (unsigned long) from; 7378780356eSDan Williams bytes = curr_addr - s_addr - rem; 7388780356eSDan Williams return bytes; 7398780356eSDan Williams } 7408780356eSDan Williams }), 7418780356eSDan Williams ({ 742ec6347bbSDan Williams rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len) 743ec6347bbSDan Williams - v.iov_len, v.iov_len); 7448780356eSDan Williams if (rem) { 7458780356eSDan Williams curr_addr = (unsigned long) from; 7468780356eSDan Williams bytes = curr_addr - s_addr - rem; 7478780356eSDan Williams return bytes; 7488780356eSDan Williams } 7498780356eSDan Williams }) 7508780356eSDan Williams ) 7518780356eSDan Williams 7528780356eSDan Williams return bytes; 7538780356eSDan Williams } 754ec6347bbSDan Williams EXPORT_SYMBOL_GPL(_copy_mc_to_iter); 755ec6347bbSDan Williams #endif /* CONFIG_ARCH_HAS_COPY_MC */ 7568780356eSDan Williams 757aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 758d879cb83SAl Viro { 759d879cb83SAl Viro char *to = addr; 76000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 761241699cdSAl Viro WARN_ON(1); 762241699cdSAl Viro return 0; 763241699cdSAl Viro } 76409fc68dcSAl Viro if (iter_is_iovec(i)) 76509fc68dcSAl Viro might_fault(); 766d879cb83SAl Viro iterate_and_advance(i, bytes, v, 76709fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 768d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 769d879cb83SAl Viro v.bv_offset, v.bv_len), 770d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 771d879cb83SAl Viro ) 772d879cb83SAl Viro 773d879cb83SAl Viro return bytes; 774d879cb83SAl Viro } 775aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 776d879cb83SAl Viro 777aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 778cbbd26b8SAl Viro { 779cbbd26b8SAl Viro char *to = addr; 78000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 781cbbd26b8SAl Viro WARN_ON(1); 782cbbd26b8SAl Viro return false; 783cbbd26b8SAl Viro } 78433844e66SAl Viro if (unlikely(i->count < bytes)) 785cbbd26b8SAl Viro return false; 786cbbd26b8SAl Viro 78709fc68dcSAl Viro if (iter_is_iovec(i)) 78809fc68dcSAl Viro might_fault(); 789cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 79009fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 791cbbd26b8SAl Viro v.iov_base, v.iov_len)) 792cbbd26b8SAl Viro return false; 793cbbd26b8SAl Viro 0;}), 794cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 795cbbd26b8SAl Viro v.bv_offset, v.bv_len), 796cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 797cbbd26b8SAl Viro ) 798cbbd26b8SAl Viro 799cbbd26b8SAl Viro iov_iter_advance(i, bytes); 800cbbd26b8SAl Viro return true; 801cbbd26b8SAl Viro } 802aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 803cbbd26b8SAl Viro 804aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 805d879cb83SAl Viro { 806d879cb83SAl Viro char *to = addr; 80700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 808241699cdSAl Viro WARN_ON(1); 809241699cdSAl Viro return 0; 810241699cdSAl Viro } 811d879cb83SAl Viro iterate_and_advance(i, bytes, v, 8123f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 813d879cb83SAl Viro v.iov_base, v.iov_len), 814d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 815d879cb83SAl Viro v.bv_offset, v.bv_len), 816d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 817d879cb83SAl Viro ) 818d879cb83SAl Viro 819d879cb83SAl Viro return bytes; 820d879cb83SAl Viro } 821aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 822d879cb83SAl Viro 8230aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 824abd08d7dSDan Williams /** 825abd08d7dSDan Williams * _copy_from_iter_flushcache - write destination through cpu cache 826abd08d7dSDan Williams * @addr: destination kernel address 827abd08d7dSDan Williams * @bytes: total transfer length 828abd08d7dSDan Williams * @iter: source iterator 829abd08d7dSDan Williams * 830abd08d7dSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 831abd08d7dSDan Williams * dax_copy_from_iter() for ensuring that writes to persistent memory 832abd08d7dSDan Williams * are flushed through the CPU cache. It is differentiated from 833abd08d7dSDan Williams * _copy_from_iter_nocache() in that guarantees all data is flushed for 834abd08d7dSDan Williams * all iterator types. The _copy_from_iter_nocache() only attempts to 835abd08d7dSDan Williams * bypass the cache for the ITER_IOVEC case, and on some archs may use 836abd08d7dSDan Williams * instructions that strand dirty-data in the cache. 837abd08d7dSDan Williams */ 8386a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 8390aed55afSDan Williams { 8400aed55afSDan Williams char *to = addr; 84100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 8420aed55afSDan Williams WARN_ON(1); 8430aed55afSDan Williams return 0; 8440aed55afSDan Williams } 8450aed55afSDan Williams iterate_and_advance(i, bytes, v, 8460aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 8470aed55afSDan Williams v.iov_base, v.iov_len), 8480aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 8490aed55afSDan Williams v.bv_offset, v.bv_len), 8500aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 8510aed55afSDan Williams v.iov_len) 8520aed55afSDan Williams ) 8530aed55afSDan Williams 8540aed55afSDan Williams return bytes; 8550aed55afSDan Williams } 8566a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 8570aed55afSDan Williams #endif 8580aed55afSDan Williams 859aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 860cbbd26b8SAl Viro { 861cbbd26b8SAl Viro char *to = addr; 86200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 863cbbd26b8SAl Viro WARN_ON(1); 864cbbd26b8SAl Viro return false; 865cbbd26b8SAl Viro } 86633844e66SAl Viro if (unlikely(i->count < bytes)) 867cbbd26b8SAl Viro return false; 868cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 8693f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 870cbbd26b8SAl Viro v.iov_base, v.iov_len)) 871cbbd26b8SAl Viro return false; 872cbbd26b8SAl Viro 0;}), 873cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 874cbbd26b8SAl Viro v.bv_offset, v.bv_len), 875cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 876cbbd26b8SAl Viro ) 877cbbd26b8SAl Viro 878cbbd26b8SAl Viro iov_iter_advance(i, bytes); 879cbbd26b8SAl Viro return true; 880cbbd26b8SAl Viro } 881aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 882cbbd26b8SAl Viro 88372e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 88472e809edSAl Viro { 8856daef95bSEric Dumazet struct page *head; 8866daef95bSEric Dumazet size_t v = n + offset; 8876daef95bSEric Dumazet 8886daef95bSEric Dumazet /* 8896daef95bSEric Dumazet * The general case needs to access the page order in order 8906daef95bSEric Dumazet * to compute the page size. 8916daef95bSEric Dumazet * However, we mostly deal with order-0 pages and thus can 8926daef95bSEric Dumazet * avoid a possible cache line miss for requests that fit all 8936daef95bSEric Dumazet * page orders. 8946daef95bSEric Dumazet */ 8956daef95bSEric Dumazet if (n <= v && v <= PAGE_SIZE) 8966daef95bSEric Dumazet return true; 8976daef95bSEric Dumazet 8986daef95bSEric Dumazet head = compound_head(page); 8996daef95bSEric Dumazet v += (page - head) << PAGE_SHIFT; 900a90bcb86SPetar Penkov 901a50b854eSMatthew Wilcox (Oracle) if (likely(n <= v && v <= (page_size(head)))) 90272e809edSAl Viro return true; 90372e809edSAl Viro WARN_ON(1); 90472e809edSAl Viro return false; 90572e809edSAl Viro } 906d879cb83SAl Viro 907d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 908d879cb83SAl Viro struct iov_iter *i) 909d879cb83SAl Viro { 91072e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 91172e809edSAl Viro return 0; 912d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 913d879cb83SAl Viro void *kaddr = kmap_atomic(page); 914d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 915d879cb83SAl Viro kunmap_atomic(kaddr); 916d879cb83SAl Viro return wanted; 9179ea9ce04SDavid Howells } else if (unlikely(iov_iter_is_discard(i))) 9189ea9ce04SDavid Howells return bytes; 9199ea9ce04SDavid Howells else if (likely(!iov_iter_is_pipe(i))) 920d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 921241699cdSAl Viro else 922241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 923d879cb83SAl Viro } 924d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 925d879cb83SAl Viro 926d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 927d879cb83SAl Viro struct iov_iter *i) 928d879cb83SAl Viro { 92972e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 93072e809edSAl Viro return 0; 9319ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 932241699cdSAl Viro WARN_ON(1); 933241699cdSAl Viro return 0; 934241699cdSAl Viro } 935d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 936d879cb83SAl Viro void *kaddr = kmap_atomic(page); 937aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 938d879cb83SAl Viro kunmap_atomic(kaddr); 939d879cb83SAl Viro return wanted; 940d879cb83SAl Viro } else 941d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 942d879cb83SAl Viro } 943d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 944d879cb83SAl Viro 945241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 946241699cdSAl Viro { 947241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9488cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 9498cefc107SDavid Howells unsigned int i_head; 950241699cdSAl Viro size_t n, off; 951241699cdSAl Viro 952241699cdSAl Viro if (!sanity(i)) 953241699cdSAl Viro return 0; 954241699cdSAl Viro 9558cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 956241699cdSAl Viro if (unlikely(!n)) 957241699cdSAl Viro return 0; 958241699cdSAl Viro 9598cefc107SDavid Howells do { 960241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 9618cefc107SDavid Howells memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); 9628cefc107SDavid Howells i->head = i_head; 963241699cdSAl Viro i->iov_offset = off + chunk; 964241699cdSAl Viro n -= chunk; 9658cefc107SDavid Howells off = 0; 9668cefc107SDavid Howells i_head++; 9678cefc107SDavid Howells } while (n); 968241699cdSAl Viro i->count -= bytes; 969241699cdSAl Viro return bytes; 970241699cdSAl Viro } 971241699cdSAl Viro 972d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 973d879cb83SAl Viro { 97400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 975241699cdSAl Viro return pipe_zero(bytes, i); 976d879cb83SAl Viro iterate_and_advance(i, bytes, v, 97709fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 978d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 979d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 980d879cb83SAl Viro ) 981d879cb83SAl Viro 982d879cb83SAl Viro return bytes; 983d879cb83SAl Viro } 984d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 985d879cb83SAl Viro 986d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 987d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 988d879cb83SAl Viro { 989d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 99072e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 99172e809edSAl Viro kunmap_atomic(kaddr); 99272e809edSAl Viro return 0; 99372e809edSAl Viro } 9949ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 995241699cdSAl Viro kunmap_atomic(kaddr); 996241699cdSAl Viro WARN_ON(1); 997241699cdSAl Viro return 0; 998241699cdSAl Viro } 999d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 100009fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 1001d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 1002d879cb83SAl Viro v.bv_offset, v.bv_len), 1003d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 1004d879cb83SAl Viro ) 1005d879cb83SAl Viro kunmap_atomic(kaddr); 1006d879cb83SAl Viro return bytes; 1007d879cb83SAl Viro } 1008d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 1009d879cb83SAl Viro 1010b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 1011241699cdSAl Viro { 1012241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 10138cefc107SDavid Howells unsigned int p_tail = pipe->tail; 10148cefc107SDavid Howells unsigned int p_head = pipe->head; 10158cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10168cefc107SDavid Howells 10178cefc107SDavid Howells if (!pipe_empty(p_head, p_tail)) { 10188cefc107SDavid Howells struct pipe_buffer *buf; 10198cefc107SDavid Howells unsigned int i_head = i->head; 1020b9dc6f65SAl Viro size_t off = i->iov_offset; 10218cefc107SDavid Howells 1022b9dc6f65SAl Viro if (off) { 10238cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 10248cefc107SDavid Howells buf->len = off - buf->offset; 10258cefc107SDavid Howells i_head++; 1026b9dc6f65SAl Viro } 10278cefc107SDavid Howells while (p_head != i_head) { 10288cefc107SDavid Howells p_head--; 10298cefc107SDavid Howells pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); 1030241699cdSAl Viro } 10318cefc107SDavid Howells 10328cefc107SDavid Howells pipe->head = p_head; 1033241699cdSAl Viro } 1034b9dc6f65SAl Viro } 1035b9dc6f65SAl Viro 1036b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 1037b9dc6f65SAl Viro { 1038b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 1039b9dc6f65SAl Viro if (unlikely(i->count < size)) 1040b9dc6f65SAl Viro size = i->count; 1041b9dc6f65SAl Viro if (size) { 1042b9dc6f65SAl Viro struct pipe_buffer *buf; 10438cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10448cefc107SDavid Howells unsigned int i_head = i->head; 1045b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 10468cefc107SDavid Howells 1047b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 10488cefc107SDavid Howells left += off - pipe->bufs[i_head & p_mask].offset; 1049b9dc6f65SAl Viro while (1) { 10508cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 1051b9dc6f65SAl Viro if (left <= buf->len) 1052b9dc6f65SAl Viro break; 1053b9dc6f65SAl Viro left -= buf->len; 10548cefc107SDavid Howells i_head++; 1055b9dc6f65SAl Viro } 10568cefc107SDavid Howells i->head = i_head; 1057b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 1058b9dc6f65SAl Viro } 1059b9dc6f65SAl Viro i->count -= size; 1060b9dc6f65SAl Viro /* ... and discard everything past that point */ 1061b9dc6f65SAl Viro pipe_truncate(i); 1062241699cdSAl Viro } 1063241699cdSAl Viro 1064d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 1065d879cb83SAl Viro { 106600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1067241699cdSAl Viro pipe_advance(i, size); 1068241699cdSAl Viro return; 1069241699cdSAl Viro } 10709ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) { 10719ea9ce04SDavid Howells i->count -= size; 10729ea9ce04SDavid Howells return; 10739ea9ce04SDavid Howells } 1074d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 1075d879cb83SAl Viro } 1076d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 1077d879cb83SAl Viro 107827c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 107927c0e374SAl Viro { 108027c0e374SAl Viro if (!unroll) 108127c0e374SAl Viro return; 10825b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 10835b47d59aSAl Viro return; 108427c0e374SAl Viro i->count += unroll; 108500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 108627c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 10878cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10888cefc107SDavid Howells unsigned int i_head = i->head; 108927c0e374SAl Viro size_t off = i->iov_offset; 109027c0e374SAl Viro while (1) { 10918cefc107SDavid Howells struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; 10928cefc107SDavid Howells size_t n = off - b->offset; 109327c0e374SAl Viro if (unroll < n) { 10944fa55cefSAl Viro off -= unroll; 109527c0e374SAl Viro break; 109627c0e374SAl Viro } 109727c0e374SAl Viro unroll -= n; 10988cefc107SDavid Howells if (!unroll && i_head == i->start_head) { 109927c0e374SAl Viro off = 0; 110027c0e374SAl Viro break; 110127c0e374SAl Viro } 11028cefc107SDavid Howells i_head--; 11038cefc107SDavid Howells b = &pipe->bufs[i_head & p_mask]; 11048cefc107SDavid Howells off = b->offset + b->len; 110527c0e374SAl Viro } 110627c0e374SAl Viro i->iov_offset = off; 11078cefc107SDavid Howells i->head = i_head; 110827c0e374SAl Viro pipe_truncate(i); 110927c0e374SAl Viro return; 111027c0e374SAl Viro } 11119ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11129ea9ce04SDavid Howells return; 111327c0e374SAl Viro if (unroll <= i->iov_offset) { 111427c0e374SAl Viro i->iov_offset -= unroll; 111527c0e374SAl Viro return; 111627c0e374SAl Viro } 111727c0e374SAl Viro unroll -= i->iov_offset; 111800e23707SDavid Howells if (iov_iter_is_bvec(i)) { 111927c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 112027c0e374SAl Viro while (1) { 112127c0e374SAl Viro size_t n = (--bvec)->bv_len; 112227c0e374SAl Viro i->nr_segs++; 112327c0e374SAl Viro if (unroll <= n) { 112427c0e374SAl Viro i->bvec = bvec; 112527c0e374SAl Viro i->iov_offset = n - unroll; 112627c0e374SAl Viro return; 112727c0e374SAl Viro } 112827c0e374SAl Viro unroll -= n; 112927c0e374SAl Viro } 113027c0e374SAl Viro } else { /* same logics for iovec and kvec */ 113127c0e374SAl Viro const struct iovec *iov = i->iov; 113227c0e374SAl Viro while (1) { 113327c0e374SAl Viro size_t n = (--iov)->iov_len; 113427c0e374SAl Viro i->nr_segs++; 113527c0e374SAl Viro if (unroll <= n) { 113627c0e374SAl Viro i->iov = iov; 113727c0e374SAl Viro i->iov_offset = n - unroll; 113827c0e374SAl Viro return; 113927c0e374SAl Viro } 114027c0e374SAl Viro unroll -= n; 114127c0e374SAl Viro } 114227c0e374SAl Viro } 114327c0e374SAl Viro } 114427c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 114527c0e374SAl Viro 1146d879cb83SAl Viro /* 1147d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1148d879cb83SAl Viro */ 1149d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1150d879cb83SAl Viro { 115100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1152241699cdSAl Viro return i->count; // it is a silly place, anyway 1153d879cb83SAl Viro if (i->nr_segs == 1) 1154d879cb83SAl Viro return i->count; 11559ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11569ea9ce04SDavid Howells return i->count; 115700e23707SDavid Howells else if (iov_iter_is_bvec(i)) 1158d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1159d879cb83SAl Viro else 1160d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1161d879cb83SAl Viro } 1162d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1163d879cb83SAl Viro 1164aa563d7bSDavid Howells void iov_iter_kvec(struct iov_iter *i, unsigned int direction, 1165d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1166d879cb83SAl Viro size_t count) 1167d879cb83SAl Viro { 1168aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1169aa563d7bSDavid Howells i->type = ITER_KVEC | (direction & (READ | WRITE)); 1170d879cb83SAl Viro i->kvec = kvec; 1171d879cb83SAl Viro i->nr_segs = nr_segs; 1172d879cb83SAl Viro i->iov_offset = 0; 1173d879cb83SAl Viro i->count = count; 1174d879cb83SAl Viro } 1175d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1176d879cb83SAl Viro 1177aa563d7bSDavid Howells void iov_iter_bvec(struct iov_iter *i, unsigned int direction, 1178d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1179d879cb83SAl Viro size_t count) 1180d879cb83SAl Viro { 1181aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1182aa563d7bSDavid Howells i->type = ITER_BVEC | (direction & (READ | WRITE)); 1183d879cb83SAl Viro i->bvec = bvec; 1184d879cb83SAl Viro i->nr_segs = nr_segs; 1185d879cb83SAl Viro i->iov_offset = 0; 1186d879cb83SAl Viro i->count = count; 1187d879cb83SAl Viro } 1188d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1189d879cb83SAl Viro 1190aa563d7bSDavid Howells void iov_iter_pipe(struct iov_iter *i, unsigned int direction, 1191241699cdSAl Viro struct pipe_inode_info *pipe, 1192241699cdSAl Viro size_t count) 1193241699cdSAl Viro { 1194aa563d7bSDavid Howells BUG_ON(direction != READ); 11958cefc107SDavid Howells WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); 1196aa563d7bSDavid Howells i->type = ITER_PIPE | READ; 1197241699cdSAl Viro i->pipe = pipe; 11988cefc107SDavid Howells i->head = pipe->head; 1199241699cdSAl Viro i->iov_offset = 0; 1200241699cdSAl Viro i->count = count; 12018cefc107SDavid Howells i->start_head = i->head; 1202241699cdSAl Viro } 1203241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1204241699cdSAl Viro 12059ea9ce04SDavid Howells /** 12069ea9ce04SDavid Howells * iov_iter_discard - Initialise an I/O iterator that discards data 12079ea9ce04SDavid Howells * @i: The iterator to initialise. 12089ea9ce04SDavid Howells * @direction: The direction of the transfer. 12099ea9ce04SDavid Howells * @count: The size of the I/O buffer in bytes. 12109ea9ce04SDavid Howells * 12119ea9ce04SDavid Howells * Set up an I/O iterator that just discards everything that's written to it. 12129ea9ce04SDavid Howells * It's only available as a READ iterator. 12139ea9ce04SDavid Howells */ 12149ea9ce04SDavid Howells void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) 12159ea9ce04SDavid Howells { 12169ea9ce04SDavid Howells BUG_ON(direction != READ); 12179ea9ce04SDavid Howells i->type = ITER_DISCARD | READ; 12189ea9ce04SDavid Howells i->count = count; 12199ea9ce04SDavid Howells i->iov_offset = 0; 12209ea9ce04SDavid Howells } 12219ea9ce04SDavid Howells EXPORT_SYMBOL(iov_iter_discard); 12229ea9ce04SDavid Howells 1223d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1224d879cb83SAl Viro { 1225d879cb83SAl Viro unsigned long res = 0; 1226d879cb83SAl Viro size_t size = i->count; 1227d879cb83SAl Viro 122800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1229e0ff126eSJan Kara unsigned int p_mask = i->pipe->ring_size - 1; 1230e0ff126eSJan Kara 12318cefc107SDavid Howells if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) 1232241699cdSAl Viro return size | i->iov_offset; 1233241699cdSAl Viro return size; 1234241699cdSAl Viro } 1235d879cb83SAl Viro iterate_all_kinds(i, size, v, 1236d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1237d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1238d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1239d879cb83SAl Viro ) 1240d879cb83SAl Viro return res; 1241d879cb83SAl Viro } 1242d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1243d879cb83SAl Viro 1244357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1245357f435dSAl Viro { 1246357f435dSAl Viro unsigned long res = 0; 1247357f435dSAl Viro size_t size = i->count; 1248357f435dSAl Viro 12499ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1250241699cdSAl Viro WARN_ON(1); 1251241699cdSAl Viro return ~0U; 1252241699cdSAl Viro } 1253241699cdSAl Viro 1254357f435dSAl Viro iterate_all_kinds(i, size, v, 1255357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1256357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1257357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1258357f435dSAl Viro (size != v.bv_len ? size : 0)), 1259357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1260357f435dSAl Viro (size != v.iov_len ? size : 0)) 1261357f435dSAl Viro ); 1262357f435dSAl Viro return res; 1263357f435dSAl Viro } 1264357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1265357f435dSAl Viro 1266e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1267241699cdSAl Viro size_t maxsize, 1268241699cdSAl Viro struct page **pages, 12698cefc107SDavid Howells int iter_head, 1270241699cdSAl Viro size_t *start) 1271241699cdSAl Viro { 1272241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 12738cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 12748cefc107SDavid Howells ssize_t n = push_pipe(i, maxsize, &iter_head, start); 1275241699cdSAl Viro if (!n) 1276241699cdSAl Viro return -EFAULT; 1277241699cdSAl Viro 1278241699cdSAl Viro maxsize = n; 1279241699cdSAl Viro n += *start; 12801689c73aSAl Viro while (n > 0) { 12818cefc107SDavid Howells get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); 12828cefc107SDavid Howells iter_head++; 1283241699cdSAl Viro n -= PAGE_SIZE; 1284241699cdSAl Viro } 1285241699cdSAl Viro 1286241699cdSAl Viro return maxsize; 1287241699cdSAl Viro } 1288241699cdSAl Viro 1289241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1290241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1291241699cdSAl Viro size_t *start) 1292241699cdSAl Viro { 12938cefc107SDavid Howells unsigned int iter_head, npages; 1294241699cdSAl Viro size_t capacity; 1295241699cdSAl Viro 129633844e66SAl Viro if (!maxsize) 129733844e66SAl Viro return 0; 129833844e66SAl Viro 1299241699cdSAl Viro if (!sanity(i)) 1300241699cdSAl Viro return -EFAULT; 1301241699cdSAl Viro 13028cefc107SDavid Howells data_start(i, &iter_head, start); 13038cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13048cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1305241699cdSAl Viro capacity = min(npages, maxpages) * PAGE_SIZE - *start; 1306241699cdSAl Viro 13078cefc107SDavid Howells return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); 1308241699cdSAl Viro } 1309241699cdSAl Viro 1310d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1311d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1312d879cb83SAl Viro size_t *start) 1313d879cb83SAl Viro { 1314d879cb83SAl Viro if (maxsize > i->count) 1315d879cb83SAl Viro maxsize = i->count; 1316d879cb83SAl Viro 131700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1318241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 13199ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 13209ea9ce04SDavid Howells return -EFAULT; 13219ea9ce04SDavid Howells 1322d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1323d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1324d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1325d879cb83SAl Viro int n; 1326d879cb83SAl Viro int res; 1327d879cb83SAl Viro 1328d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1329d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1330d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1331d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 133273b0140bSIra Weiny res = get_user_pages_fast(addr, n, 133373b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, 133473b0140bSIra Weiny pages); 1335d879cb83SAl Viro if (unlikely(res < 0)) 1336d879cb83SAl Viro return res; 1337d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1338d879cb83SAl Viro 0;}),({ 1339d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1340d879cb83SAl Viro *start = v.bv_offset; 1341d879cb83SAl Viro get_page(*pages = v.bv_page); 1342d879cb83SAl Viro return v.bv_len; 1343d879cb83SAl Viro }),({ 1344d879cb83SAl Viro return -EFAULT; 1345d879cb83SAl Viro }) 1346d879cb83SAl Viro ) 1347d879cb83SAl Viro return 0; 1348d879cb83SAl Viro } 1349d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1350d879cb83SAl Viro 1351d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1352d879cb83SAl Viro { 1353752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1354d879cb83SAl Viro } 1355d879cb83SAl Viro 1356241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1357241699cdSAl Viro struct page ***pages, size_t maxsize, 1358241699cdSAl Viro size_t *start) 1359241699cdSAl Viro { 1360241699cdSAl Viro struct page **p; 13618cefc107SDavid Howells unsigned int iter_head, npages; 1362d7760d63SIlya Dryomov ssize_t n; 1363241699cdSAl Viro 136433844e66SAl Viro if (!maxsize) 136533844e66SAl Viro return 0; 136633844e66SAl Viro 1367241699cdSAl Viro if (!sanity(i)) 1368241699cdSAl Viro return -EFAULT; 1369241699cdSAl Viro 13708cefc107SDavid Howells data_start(i, &iter_head, start); 13718cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13728cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1373241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1374241699cdSAl Viro if (maxsize > n) 1375241699cdSAl Viro maxsize = n; 1376241699cdSAl Viro else 1377241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1378241699cdSAl Viro p = get_pages_array(npages); 1379241699cdSAl Viro if (!p) 1380241699cdSAl Viro return -ENOMEM; 13818cefc107SDavid Howells n = __pipe_get_pages(i, maxsize, p, iter_head, start); 1382241699cdSAl Viro if (n > 0) 1383241699cdSAl Viro *pages = p; 1384241699cdSAl Viro else 1385241699cdSAl Viro kvfree(p); 1386241699cdSAl Viro return n; 1387241699cdSAl Viro } 1388241699cdSAl Viro 1389d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1390d879cb83SAl Viro struct page ***pages, size_t maxsize, 1391d879cb83SAl Viro size_t *start) 1392d879cb83SAl Viro { 1393d879cb83SAl Viro struct page **p; 1394d879cb83SAl Viro 1395d879cb83SAl Viro if (maxsize > i->count) 1396d879cb83SAl Viro maxsize = i->count; 1397d879cb83SAl Viro 139800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1399241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 14009ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 14019ea9ce04SDavid Howells return -EFAULT; 14029ea9ce04SDavid Howells 1403d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1404d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1405d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1406d879cb83SAl Viro int n; 1407d879cb83SAl Viro int res; 1408d879cb83SAl Viro 1409d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1410d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1411d879cb83SAl Viro p = get_pages_array(n); 1412d879cb83SAl Viro if (!p) 1413d879cb83SAl Viro return -ENOMEM; 141473b0140bSIra Weiny res = get_user_pages_fast(addr, n, 141573b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); 1416d879cb83SAl Viro if (unlikely(res < 0)) { 1417d879cb83SAl Viro kvfree(p); 1418d879cb83SAl Viro return res; 1419d879cb83SAl Viro } 1420d879cb83SAl Viro *pages = p; 1421d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1422d879cb83SAl Viro 0;}),({ 1423d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1424d879cb83SAl Viro *start = v.bv_offset; 1425d879cb83SAl Viro *pages = p = get_pages_array(1); 1426d879cb83SAl Viro if (!p) 1427d879cb83SAl Viro return -ENOMEM; 1428d879cb83SAl Viro get_page(*p = v.bv_page); 1429d879cb83SAl Viro return v.bv_len; 1430d879cb83SAl Viro }),({ 1431d879cb83SAl Viro return -EFAULT; 1432d879cb83SAl Viro }) 1433d879cb83SAl Viro ) 1434d879cb83SAl Viro return 0; 1435d879cb83SAl Viro } 1436d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1437d879cb83SAl Viro 1438d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1439d879cb83SAl Viro struct iov_iter *i) 1440d879cb83SAl Viro { 1441d879cb83SAl Viro char *to = addr; 1442d879cb83SAl Viro __wsum sum, next; 1443d879cb83SAl Viro size_t off = 0; 1444d879cb83SAl Viro sum = *csum; 14459ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1446241699cdSAl Viro WARN_ON(1); 1447241699cdSAl Viro return 0; 1448241699cdSAl Viro } 1449d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1450d879cb83SAl Viro int err = 0; 1451d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1452d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1453d879cb83SAl Viro v.iov_len, 0, &err); 1454d879cb83SAl Viro if (!err) { 1455d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1456d879cb83SAl Viro off += v.iov_len; 1457d879cb83SAl Viro } 1458d879cb83SAl Viro err ? v.iov_len : 0; 1459d879cb83SAl Viro }), ({ 1460d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1461f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1462f9152895SAl Viro p + v.bv_offset, v.bv_len, 1463f9152895SAl Viro sum, off); 1464d879cb83SAl Viro kunmap_atomic(p); 1465d879cb83SAl Viro off += v.bv_len; 1466d879cb83SAl Viro }),({ 1467f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1468f9152895SAl Viro v.iov_base, v.iov_len, 1469f9152895SAl Viro sum, off); 1470d879cb83SAl Viro off += v.iov_len; 1471d879cb83SAl Viro }) 1472d879cb83SAl Viro ) 1473d879cb83SAl Viro *csum = sum; 1474d879cb83SAl Viro return bytes; 1475d879cb83SAl Viro } 1476d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1477d879cb83SAl Viro 1478cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1479cbbd26b8SAl Viro struct iov_iter *i) 1480cbbd26b8SAl Viro { 1481cbbd26b8SAl Viro char *to = addr; 1482cbbd26b8SAl Viro __wsum sum, next; 1483cbbd26b8SAl Viro size_t off = 0; 1484cbbd26b8SAl Viro sum = *csum; 14859ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1486cbbd26b8SAl Viro WARN_ON(1); 1487cbbd26b8SAl Viro return false; 1488cbbd26b8SAl Viro } 1489cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1490cbbd26b8SAl Viro return false; 1491cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1492cbbd26b8SAl Viro int err = 0; 1493cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1494cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1495cbbd26b8SAl Viro v.iov_len, 0, &err); 1496cbbd26b8SAl Viro if (err) 1497cbbd26b8SAl Viro return false; 1498cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1499cbbd26b8SAl Viro off += v.iov_len; 1500cbbd26b8SAl Viro 0; 1501cbbd26b8SAl Viro }), ({ 1502cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1503f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1504f9152895SAl Viro p + v.bv_offset, v.bv_len, 1505f9152895SAl Viro sum, off); 1506cbbd26b8SAl Viro kunmap_atomic(p); 1507cbbd26b8SAl Viro off += v.bv_len; 1508cbbd26b8SAl Viro }),({ 1509f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1510f9152895SAl Viro v.iov_base, v.iov_len, 1511f9152895SAl Viro sum, off); 1512cbbd26b8SAl Viro off += v.iov_len; 1513cbbd26b8SAl Viro }) 1514cbbd26b8SAl Viro ) 1515cbbd26b8SAl Viro *csum = sum; 1516cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1517cbbd26b8SAl Viro return true; 1518cbbd26b8SAl Viro } 1519cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1520cbbd26b8SAl Viro 1521cb002d07SSagi Grimberg size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, 1522d879cb83SAl Viro struct iov_iter *i) 1523d879cb83SAl Viro { 152436f7a8a4SAl Viro const char *from = addr; 1525cb002d07SSagi Grimberg __wsum *csum = csump; 1526d879cb83SAl Viro __wsum sum, next; 1527d879cb83SAl Viro size_t off = 0; 152878e1f386SAl Viro 152978e1f386SAl Viro if (unlikely(iov_iter_is_pipe(i))) 153078e1f386SAl Viro return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); 153178e1f386SAl Viro 1532d879cb83SAl Viro sum = *csum; 153378e1f386SAl Viro if (unlikely(iov_iter_is_discard(i))) { 1534241699cdSAl Viro WARN_ON(1); /* for now */ 1535241699cdSAl Viro return 0; 1536241699cdSAl Viro } 1537d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1538d879cb83SAl Viro int err = 0; 1539d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1540d879cb83SAl Viro v.iov_base, 1541d879cb83SAl Viro v.iov_len, 0, &err); 1542d879cb83SAl Viro if (!err) { 1543d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1544d879cb83SAl Viro off += v.iov_len; 1545d879cb83SAl Viro } 1546d879cb83SAl Viro err ? v.iov_len : 0; 1547d879cb83SAl Viro }), ({ 1548d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1549f9152895SAl Viro sum = csum_and_memcpy(p + v.bv_offset, 1550f9152895SAl Viro (from += v.bv_len) - v.bv_len, 1551f9152895SAl Viro v.bv_len, sum, off); 1552d879cb83SAl Viro kunmap_atomic(p); 1553d879cb83SAl Viro off += v.bv_len; 1554d879cb83SAl Viro }),({ 1555f9152895SAl Viro sum = csum_and_memcpy(v.iov_base, 1556f9152895SAl Viro (from += v.iov_len) - v.iov_len, 1557f9152895SAl Viro v.iov_len, sum, off); 1558d879cb83SAl Viro off += v.iov_len; 1559d879cb83SAl Viro }) 1560d879cb83SAl Viro ) 1561d879cb83SAl Viro *csum = sum; 1562d879cb83SAl Viro return bytes; 1563d879cb83SAl Viro } 1564d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1565d879cb83SAl Viro 1566d05f4435SSagi Grimberg size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, 1567d05f4435SSagi Grimberg struct iov_iter *i) 1568d05f4435SSagi Grimberg { 15697999096fSHerbert Xu #ifdef CONFIG_CRYPTO_HASH 1570d05f4435SSagi Grimberg struct ahash_request *hash = hashp; 1571d05f4435SSagi Grimberg struct scatterlist sg; 1572d05f4435SSagi Grimberg size_t copied; 1573d05f4435SSagi Grimberg 1574d05f4435SSagi Grimberg copied = copy_to_iter(addr, bytes, i); 1575d05f4435SSagi Grimberg sg_init_one(&sg, addr, copied); 1576d05f4435SSagi Grimberg ahash_request_set_crypt(hash, &sg, NULL, copied); 1577d05f4435SSagi Grimberg crypto_ahash_update(hash); 1578d05f4435SSagi Grimberg return copied; 157927fad74aSYueHaibing #else 158027fad74aSYueHaibing return 0; 158127fad74aSYueHaibing #endif 1582d05f4435SSagi Grimberg } 1583d05f4435SSagi Grimberg EXPORT_SYMBOL(hash_and_copy_to_iter); 1584d05f4435SSagi Grimberg 1585d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1586d879cb83SAl Viro { 1587d879cb83SAl Viro size_t size = i->count; 1588d879cb83SAl Viro int npages = 0; 1589d879cb83SAl Viro 1590d879cb83SAl Viro if (!size) 1591d879cb83SAl Viro return 0; 15929ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 15939ea9ce04SDavid Howells return 0; 1594d879cb83SAl Viro 159500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1596241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 15978cefc107SDavid Howells unsigned int iter_head; 1598241699cdSAl Viro size_t off; 1599241699cdSAl Viro 1600241699cdSAl Viro if (!sanity(i)) 1601241699cdSAl Viro return 0; 1602241699cdSAl Viro 16038cefc107SDavid Howells data_start(i, &iter_head, &off); 1604241699cdSAl Viro /* some of this one + all after this one */ 16058cefc107SDavid Howells npages = pipe_space_for_user(iter_head, pipe->tail, pipe); 1606241699cdSAl Viro if (npages >= maxpages) 1607241699cdSAl Viro return maxpages; 1608241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1609d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1610d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1611d879cb83SAl Viro - p / PAGE_SIZE; 1612d879cb83SAl Viro if (npages >= maxpages) 1613d879cb83SAl Viro return maxpages; 1614d879cb83SAl Viro 0;}),({ 1615d879cb83SAl Viro npages++; 1616d879cb83SAl Viro if (npages >= maxpages) 1617d879cb83SAl Viro return maxpages; 1618d879cb83SAl Viro }),({ 1619d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1620d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1621d879cb83SAl Viro - p / PAGE_SIZE; 1622d879cb83SAl Viro if (npages >= maxpages) 1623d879cb83SAl Viro return maxpages; 1624d879cb83SAl Viro }) 1625d879cb83SAl Viro ) 1626d879cb83SAl Viro return npages; 1627d879cb83SAl Viro } 1628d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1629d879cb83SAl Viro 1630d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1631d879cb83SAl Viro { 1632d879cb83SAl Viro *new = *old; 163300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(new))) { 1634241699cdSAl Viro WARN_ON(1); 1635241699cdSAl Viro return NULL; 1636241699cdSAl Viro } 16379ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(new))) 16389ea9ce04SDavid Howells return NULL; 163900e23707SDavid Howells if (iov_iter_is_bvec(new)) 1640d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1641d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1642d879cb83SAl Viro flags); 1643d879cb83SAl Viro else 1644d879cb83SAl Viro /* iovec and kvec have identical layout */ 1645d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1646d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1647d879cb83SAl Viro flags); 1648d879cb83SAl Viro } 1649d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1650bc917be8SAl Viro 1651ffecee4fSVegard Nossum /** 1652ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1653ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1654ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1655ffecee4fSVegard Nossum * 1656ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1657ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1658ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1659ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1660ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1661ffecee4fSVegard Nossum * on-stack) kernel array. 1662ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1663ffecee4fSVegard Nossum * 1664ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1665ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1666ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1667ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1668ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1669ffecee4fSVegard Nossum * returns an error or not). 1670ffecee4fSVegard Nossum * 167187e5e6daSJens Axboe * Return: Negative error code on error, bytes imported on success 1672ffecee4fSVegard Nossum */ 167387e5e6daSJens Axboe ssize_t import_iovec(int type, const struct iovec __user * uvector, 1674bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1675bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1676bc917be8SAl Viro { 1677bc917be8SAl Viro ssize_t n; 1678bc917be8SAl Viro struct iovec *p; 1679bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1680bc917be8SAl Viro *iov, &p); 1681bc917be8SAl Viro if (n < 0) { 1682bc917be8SAl Viro if (p != *iov) 1683bc917be8SAl Viro kfree(p); 1684bc917be8SAl Viro *iov = NULL; 1685bc917be8SAl Viro return n; 1686bc917be8SAl Viro } 1687bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1688bc917be8SAl Viro *iov = p == *iov ? NULL : p; 168987e5e6daSJens Axboe return n; 1690bc917be8SAl Viro } 1691bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1692bc917be8SAl Viro 1693bc917be8SAl Viro #ifdef CONFIG_COMPAT 1694bc917be8SAl Viro #include <linux/compat.h> 1695bc917be8SAl Viro 169687e5e6daSJens Axboe ssize_t compat_import_iovec(int type, 169787e5e6daSJens Axboe const struct compat_iovec __user * uvector, 1698bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1699bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1700bc917be8SAl Viro { 1701bc917be8SAl Viro ssize_t n; 1702bc917be8SAl Viro struct iovec *p; 1703bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1704bc917be8SAl Viro *iov, &p); 1705bc917be8SAl Viro if (n < 0) { 1706bc917be8SAl Viro if (p != *iov) 1707bc917be8SAl Viro kfree(p); 1708bc917be8SAl Viro *iov = NULL; 1709bc917be8SAl Viro return n; 1710bc917be8SAl Viro } 1711bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1712bc917be8SAl Viro *iov = p == *iov ? NULL : p; 171387e5e6daSJens Axboe return n; 1714bc917be8SAl Viro } 171598aaaec4SArnd Bergmann EXPORT_SYMBOL(compat_import_iovec); 1716bc917be8SAl Viro #endif 1717bc917be8SAl Viro 1718bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1719bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1720bc917be8SAl Viro { 1721bc917be8SAl Viro if (len > MAX_RW_COUNT) 1722bc917be8SAl Viro len = MAX_RW_COUNT; 172396d4f267SLinus Torvalds if (unlikely(!access_ok(buf, len))) 1724bc917be8SAl Viro return -EFAULT; 1725bc917be8SAl Viro 1726bc917be8SAl Viro iov->iov_base = buf; 1727bc917be8SAl Viro iov->iov_len = len; 1728bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1729bc917be8SAl Viro return 0; 1730bc917be8SAl Viro } 1731e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 173209cf698aSAl Viro 173309cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 173409cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 173509cf698aSAl Viro void *context) 173609cf698aSAl Viro { 173709cf698aSAl Viro struct kvec w; 173809cf698aSAl Viro int err = -EINVAL; 173909cf698aSAl Viro if (!bytes) 174009cf698aSAl Viro return 0; 174109cf698aSAl Viro 174209cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 174309cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 174409cf698aSAl Viro w.iov_len = v.bv_len; 174509cf698aSAl Viro err = f(&w, context); 174609cf698aSAl Viro kunmap(v.bv_page); 174709cf698aSAl Viro err;}), ({ 174809cf698aSAl Viro w = v; 174909cf698aSAl Viro err = f(&w, context);}) 175009cf698aSAl Viro ) 175109cf698aSAl Viro return err; 175209cf698aSAl Viro } 175309cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1754