1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2d879cb83SAl Viro #include <linux/export.h> 32f8b5444SChristoph Hellwig #include <linux/bvec.h> 4d879cb83SAl Viro #include <linux/uio.h> 5d879cb83SAl Viro #include <linux/pagemap.h> 6d879cb83SAl Viro #include <linux/slab.h> 7d879cb83SAl Viro #include <linux/vmalloc.h> 8241699cdSAl Viro #include <linux/splice.h> 9d879cb83SAl Viro #include <net/checksum.h> 10d05f4435SSagi Grimberg #include <linux/scatterlist.h> 11d0ef4c36SMarco Elver #include <linux/instrumented.h> 12d879cb83SAl Viro 13241699cdSAl Viro #define PIPE_PARANOIA /* for now */ 14241699cdSAl Viro 15d879cb83SAl Viro #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ 16d879cb83SAl Viro size_t left; \ 17d879cb83SAl Viro size_t wanted = n; \ 18d879cb83SAl Viro __p = i->iov; \ 19d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 20d879cb83SAl Viro if (likely(__v.iov_len)) { \ 21d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 22d879cb83SAl Viro left = (STEP); \ 23d879cb83SAl Viro __v.iov_len -= left; \ 24d879cb83SAl Viro skip += __v.iov_len; \ 25d879cb83SAl Viro n -= __v.iov_len; \ 26d879cb83SAl Viro } else { \ 27d879cb83SAl Viro left = 0; \ 28d879cb83SAl Viro } \ 29d879cb83SAl Viro while (unlikely(!left && n)) { \ 30d879cb83SAl Viro __p++; \ 31d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 32d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 33d879cb83SAl Viro continue; \ 34d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 35d879cb83SAl Viro left = (STEP); \ 36d879cb83SAl Viro __v.iov_len -= left; \ 37d879cb83SAl Viro skip = __v.iov_len; \ 38d879cb83SAl Viro n -= __v.iov_len; \ 39d879cb83SAl Viro } \ 40d879cb83SAl Viro n = wanted - n; \ 41d879cb83SAl Viro } 42d879cb83SAl Viro 43d879cb83SAl Viro #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ 44d879cb83SAl Viro size_t wanted = n; \ 45d879cb83SAl Viro __p = i->kvec; \ 46d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 47d879cb83SAl Viro if (likely(__v.iov_len)) { \ 48d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 49d879cb83SAl Viro (void)(STEP); \ 50d879cb83SAl Viro skip += __v.iov_len; \ 51d879cb83SAl Viro n -= __v.iov_len; \ 52d879cb83SAl Viro } \ 53d879cb83SAl Viro while (unlikely(n)) { \ 54d879cb83SAl Viro __p++; \ 55d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 56d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 57d879cb83SAl Viro continue; \ 58d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 59d879cb83SAl Viro (void)(STEP); \ 60d879cb83SAl Viro skip = __v.iov_len; \ 61d879cb83SAl Viro n -= __v.iov_len; \ 62d879cb83SAl Viro } \ 63d879cb83SAl Viro n = wanted; \ 64d879cb83SAl Viro } 65d879cb83SAl Viro 661bdc76aeSMing Lei #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ 671bdc76aeSMing Lei struct bvec_iter __start; \ 681bdc76aeSMing Lei __start.bi_size = n; \ 691bdc76aeSMing Lei __start.bi_bvec_done = skip; \ 701bdc76aeSMing Lei __start.bi_idx = 0; \ 711bdc76aeSMing Lei for_each_bvec(__v, i->bvec, __bi, __start) { \ 721bdc76aeSMing Lei if (!__v.bv_len) \ 73d879cb83SAl Viro continue; \ 74d879cb83SAl Viro (void)(STEP); \ 75d879cb83SAl Viro } \ 76d879cb83SAl Viro } 77d879cb83SAl Viro 78d879cb83SAl Viro #define iterate_all_kinds(i, n, v, I, B, K) { \ 7933844e66SAl Viro if (likely(n)) { \ 80d879cb83SAl Viro size_t skip = i->iov_offset; \ 81d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 82d879cb83SAl Viro struct bio_vec v; \ 831bdc76aeSMing Lei struct bvec_iter __bi; \ 841bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 85d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 86d879cb83SAl Viro const struct kvec *kvec; \ 87d879cb83SAl Viro struct kvec v; \ 88d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 899ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 90d879cb83SAl Viro } else { \ 91d879cb83SAl Viro const struct iovec *iov; \ 92d879cb83SAl Viro struct iovec v; \ 93d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 94d879cb83SAl Viro } \ 9533844e66SAl Viro } \ 96d879cb83SAl Viro } 97d879cb83SAl Viro 98d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 99dd254f5aSAl Viro if (unlikely(i->count < n)) \ 100dd254f5aSAl Viro n = i->count; \ 10119f18459SAl Viro if (i->count) { \ 102d879cb83SAl Viro size_t skip = i->iov_offset; \ 103d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 1041bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 105d879cb83SAl Viro struct bio_vec v; \ 1061bdc76aeSMing Lei struct bvec_iter __bi; \ 1071bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1081bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1091bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1101bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 111d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 112d879cb83SAl Viro const struct kvec *kvec; \ 113d879cb83SAl Viro struct kvec v; \ 114d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 115d879cb83SAl Viro if (skip == kvec->iov_len) { \ 116d879cb83SAl Viro kvec++; \ 117d879cb83SAl Viro skip = 0; \ 118d879cb83SAl Viro } \ 119d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 120d879cb83SAl Viro i->kvec = kvec; \ 1219ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 1229ea9ce04SDavid Howells skip += n; \ 123d879cb83SAl Viro } else { \ 124d879cb83SAl Viro const struct iovec *iov; \ 125d879cb83SAl Viro struct iovec v; \ 126d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 127d879cb83SAl Viro if (skip == iov->iov_len) { \ 128d879cb83SAl Viro iov++; \ 129d879cb83SAl Viro skip = 0; \ 130d879cb83SAl Viro } \ 131d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 132d879cb83SAl Viro i->iov = iov; \ 133d879cb83SAl Viro } \ 134d879cb83SAl Viro i->count -= n; \ 135d879cb83SAl Viro i->iov_offset = skip; \ 136dd254f5aSAl Viro } \ 137d879cb83SAl Viro } 138d879cb83SAl Viro 13909fc68dcSAl Viro static int copyout(void __user *to, const void *from, size_t n) 14009fc68dcSAl Viro { 14196d4f267SLinus Torvalds if (access_ok(to, n)) { 142d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 14309fc68dcSAl Viro n = raw_copy_to_user(to, from, n); 14409fc68dcSAl Viro } 14509fc68dcSAl Viro return n; 14609fc68dcSAl Viro } 14709fc68dcSAl Viro 14809fc68dcSAl Viro static int copyin(void *to, const void __user *from, size_t n) 14909fc68dcSAl Viro { 15096d4f267SLinus Torvalds if (access_ok(from, n)) { 151d0ef4c36SMarco Elver instrument_copy_from_user(to, from, n); 15209fc68dcSAl Viro n = raw_copy_from_user(to, from, n); 15309fc68dcSAl Viro } 15409fc68dcSAl Viro return n; 15509fc68dcSAl Viro } 15609fc68dcSAl Viro 157d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 158d879cb83SAl Viro struct iov_iter *i) 159d879cb83SAl Viro { 160d879cb83SAl Viro size_t skip, copy, left, wanted; 161d879cb83SAl Viro const struct iovec *iov; 162d879cb83SAl Viro char __user *buf; 163d879cb83SAl Viro void *kaddr, *from; 164d879cb83SAl Viro 165d879cb83SAl Viro if (unlikely(bytes > i->count)) 166d879cb83SAl Viro bytes = i->count; 167d879cb83SAl Viro 168d879cb83SAl Viro if (unlikely(!bytes)) 169d879cb83SAl Viro return 0; 170d879cb83SAl Viro 17109fc68dcSAl Viro might_fault(); 172d879cb83SAl Viro wanted = bytes; 173d879cb83SAl Viro iov = i->iov; 174d879cb83SAl Viro skip = i->iov_offset; 175d879cb83SAl Viro buf = iov->iov_base + skip; 176d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 177d879cb83SAl Viro 1783fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 179d879cb83SAl Viro kaddr = kmap_atomic(page); 180d879cb83SAl Viro from = kaddr + offset; 181d879cb83SAl Viro 182d879cb83SAl Viro /* first chunk, usually the only one */ 18309fc68dcSAl Viro left = copyout(buf, from, copy); 184d879cb83SAl Viro copy -= left; 185d879cb83SAl Viro skip += copy; 186d879cb83SAl Viro from += copy; 187d879cb83SAl Viro bytes -= copy; 188d879cb83SAl Viro 189d879cb83SAl Viro while (unlikely(!left && bytes)) { 190d879cb83SAl Viro iov++; 191d879cb83SAl Viro buf = iov->iov_base; 192d879cb83SAl Viro copy = min(bytes, iov->iov_len); 19309fc68dcSAl Viro left = copyout(buf, from, copy); 194d879cb83SAl Viro copy -= left; 195d879cb83SAl Viro skip = copy; 196d879cb83SAl Viro from += copy; 197d879cb83SAl Viro bytes -= copy; 198d879cb83SAl Viro } 199d879cb83SAl Viro if (likely(!bytes)) { 200d879cb83SAl Viro kunmap_atomic(kaddr); 201d879cb83SAl Viro goto done; 202d879cb83SAl Viro } 203d879cb83SAl Viro offset = from - kaddr; 204d879cb83SAl Viro buf += copy; 205d879cb83SAl Viro kunmap_atomic(kaddr); 206d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 207d879cb83SAl Viro } 208d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2093fa6c507SMikulas Patocka 210d879cb83SAl Viro kaddr = kmap(page); 211d879cb83SAl Viro from = kaddr + offset; 21209fc68dcSAl Viro left = copyout(buf, from, copy); 213d879cb83SAl Viro copy -= left; 214d879cb83SAl Viro skip += copy; 215d879cb83SAl Viro from += copy; 216d879cb83SAl Viro bytes -= copy; 217d879cb83SAl Viro while (unlikely(!left && bytes)) { 218d879cb83SAl Viro iov++; 219d879cb83SAl Viro buf = iov->iov_base; 220d879cb83SAl Viro copy = min(bytes, iov->iov_len); 22109fc68dcSAl Viro left = copyout(buf, from, copy); 222d879cb83SAl Viro copy -= left; 223d879cb83SAl Viro skip = copy; 224d879cb83SAl Viro from += copy; 225d879cb83SAl Viro bytes -= copy; 226d879cb83SAl Viro } 227d879cb83SAl Viro kunmap(page); 2283fa6c507SMikulas Patocka 229d879cb83SAl Viro done: 230d879cb83SAl Viro if (skip == iov->iov_len) { 231d879cb83SAl Viro iov++; 232d879cb83SAl Viro skip = 0; 233d879cb83SAl Viro } 234d879cb83SAl Viro i->count -= wanted - bytes; 235d879cb83SAl Viro i->nr_segs -= iov - i->iov; 236d879cb83SAl Viro i->iov = iov; 237d879cb83SAl Viro i->iov_offset = skip; 238d879cb83SAl Viro return wanted - bytes; 239d879cb83SAl Viro } 240d879cb83SAl Viro 241d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 242d879cb83SAl Viro struct iov_iter *i) 243d879cb83SAl Viro { 244d879cb83SAl Viro size_t skip, copy, left, wanted; 245d879cb83SAl Viro const struct iovec *iov; 246d879cb83SAl Viro char __user *buf; 247d879cb83SAl Viro void *kaddr, *to; 248d879cb83SAl Viro 249d879cb83SAl Viro if (unlikely(bytes > i->count)) 250d879cb83SAl Viro bytes = i->count; 251d879cb83SAl Viro 252d879cb83SAl Viro if (unlikely(!bytes)) 253d879cb83SAl Viro return 0; 254d879cb83SAl Viro 25509fc68dcSAl Viro might_fault(); 256d879cb83SAl Viro wanted = bytes; 257d879cb83SAl Viro iov = i->iov; 258d879cb83SAl Viro skip = i->iov_offset; 259d879cb83SAl Viro buf = iov->iov_base + skip; 260d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 261d879cb83SAl Viro 2623fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 263d879cb83SAl Viro kaddr = kmap_atomic(page); 264d879cb83SAl Viro to = kaddr + offset; 265d879cb83SAl Viro 266d879cb83SAl Viro /* first chunk, usually the only one */ 26709fc68dcSAl Viro left = copyin(to, buf, copy); 268d879cb83SAl Viro copy -= left; 269d879cb83SAl Viro skip += copy; 270d879cb83SAl Viro to += copy; 271d879cb83SAl Viro bytes -= copy; 272d879cb83SAl Viro 273d879cb83SAl Viro while (unlikely(!left && bytes)) { 274d879cb83SAl Viro iov++; 275d879cb83SAl Viro buf = iov->iov_base; 276d879cb83SAl Viro copy = min(bytes, iov->iov_len); 27709fc68dcSAl Viro left = copyin(to, buf, copy); 278d879cb83SAl Viro copy -= left; 279d879cb83SAl Viro skip = copy; 280d879cb83SAl Viro to += copy; 281d879cb83SAl Viro bytes -= copy; 282d879cb83SAl Viro } 283d879cb83SAl Viro if (likely(!bytes)) { 284d879cb83SAl Viro kunmap_atomic(kaddr); 285d879cb83SAl Viro goto done; 286d879cb83SAl Viro } 287d879cb83SAl Viro offset = to - kaddr; 288d879cb83SAl Viro buf += copy; 289d879cb83SAl Viro kunmap_atomic(kaddr); 290d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 291d879cb83SAl Viro } 292d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2933fa6c507SMikulas Patocka 294d879cb83SAl Viro kaddr = kmap(page); 295d879cb83SAl Viro to = kaddr + offset; 29609fc68dcSAl Viro left = copyin(to, buf, copy); 297d879cb83SAl Viro copy -= left; 298d879cb83SAl Viro skip += copy; 299d879cb83SAl Viro to += copy; 300d879cb83SAl Viro bytes -= copy; 301d879cb83SAl Viro while (unlikely(!left && bytes)) { 302d879cb83SAl Viro iov++; 303d879cb83SAl Viro buf = iov->iov_base; 304d879cb83SAl Viro copy = min(bytes, iov->iov_len); 30509fc68dcSAl Viro left = copyin(to, buf, copy); 306d879cb83SAl Viro copy -= left; 307d879cb83SAl Viro skip = copy; 308d879cb83SAl Viro to += copy; 309d879cb83SAl Viro bytes -= copy; 310d879cb83SAl Viro } 311d879cb83SAl Viro kunmap(page); 3123fa6c507SMikulas Patocka 313d879cb83SAl Viro done: 314d879cb83SAl Viro if (skip == iov->iov_len) { 315d879cb83SAl Viro iov++; 316d879cb83SAl Viro skip = 0; 317d879cb83SAl Viro } 318d879cb83SAl Viro i->count -= wanted - bytes; 319d879cb83SAl Viro i->nr_segs -= iov - i->iov; 320d879cb83SAl Viro i->iov = iov; 321d879cb83SAl Viro i->iov_offset = skip; 322d879cb83SAl Viro return wanted - bytes; 323d879cb83SAl Viro } 324d879cb83SAl Viro 325241699cdSAl Viro #ifdef PIPE_PARANOIA 326241699cdSAl Viro static bool sanity(const struct iov_iter *i) 327241699cdSAl Viro { 328241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 3298cefc107SDavid Howells unsigned int p_head = pipe->head; 3308cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3318cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3328cefc107SDavid Howells unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); 3338cefc107SDavid Howells unsigned int i_head = i->head; 3348cefc107SDavid Howells unsigned int idx; 3358cefc107SDavid Howells 336241699cdSAl Viro if (i->iov_offset) { 337241699cdSAl Viro struct pipe_buffer *p; 3388cefc107SDavid Howells if (unlikely(p_occupancy == 0)) 339241699cdSAl Viro goto Bad; // pipe must be non-empty 3408cefc107SDavid Howells if (unlikely(i_head != p_head - 1)) 341241699cdSAl Viro goto Bad; // must be at the last buffer... 342241699cdSAl Viro 3438cefc107SDavid Howells p = &pipe->bufs[i_head & p_mask]; 344241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 345241699cdSAl Viro goto Bad; // ... at the end of segment 346241699cdSAl Viro } else { 3478cefc107SDavid Howells if (i_head != p_head) 348241699cdSAl Viro goto Bad; // must be right after the last buffer 349241699cdSAl Viro } 350241699cdSAl Viro return true; 351241699cdSAl Viro Bad: 3528cefc107SDavid Howells printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); 3538cefc107SDavid Howells printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", 3548cefc107SDavid Howells p_head, p_tail, pipe->ring_size); 3558cefc107SDavid Howells for (idx = 0; idx < pipe->ring_size; idx++) 356241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 357241699cdSAl Viro pipe->bufs[idx].ops, 358241699cdSAl Viro pipe->bufs[idx].page, 359241699cdSAl Viro pipe->bufs[idx].offset, 360241699cdSAl Viro pipe->bufs[idx].len); 361241699cdSAl Viro WARN_ON(1); 362241699cdSAl Viro return false; 363241699cdSAl Viro } 364241699cdSAl Viro #else 365241699cdSAl Viro #define sanity(i) true 366241699cdSAl Viro #endif 367241699cdSAl Viro 368241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 369241699cdSAl Viro struct iov_iter *i) 370241699cdSAl Viro { 371241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 372241699cdSAl Viro struct pipe_buffer *buf; 3738cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3748cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3758cefc107SDavid Howells unsigned int i_head = i->head; 376241699cdSAl Viro size_t off; 377241699cdSAl Viro 378241699cdSAl Viro if (unlikely(bytes > i->count)) 379241699cdSAl Viro bytes = i->count; 380241699cdSAl Viro 381241699cdSAl Viro if (unlikely(!bytes)) 382241699cdSAl Viro return 0; 383241699cdSAl Viro 384241699cdSAl Viro if (!sanity(i)) 385241699cdSAl Viro return 0; 386241699cdSAl Viro 387241699cdSAl Viro off = i->iov_offset; 3888cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 389241699cdSAl Viro if (off) { 390241699cdSAl Viro if (offset == off && buf->page == page) { 391241699cdSAl Viro /* merge with the last one */ 392241699cdSAl Viro buf->len += bytes; 393241699cdSAl Viro i->iov_offset += bytes; 394241699cdSAl Viro goto out; 395241699cdSAl Viro } 3968cefc107SDavid Howells i_head++; 3978cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 398241699cdSAl Viro } 3996718b6f8SDavid Howells if (pipe_full(i_head, p_tail, pipe->max_usage)) 400241699cdSAl Viro return 0; 4018cefc107SDavid Howells 402241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 4038cefc107SDavid Howells get_page(page); 4048cefc107SDavid Howells buf->page = page; 405241699cdSAl Viro buf->offset = offset; 406241699cdSAl Viro buf->len = bytes; 4078cefc107SDavid Howells 4088cefc107SDavid Howells pipe->head = i_head + 1; 409241699cdSAl Viro i->iov_offset = offset + bytes; 4108cefc107SDavid Howells i->head = i_head; 411241699cdSAl Viro out: 412241699cdSAl Viro i->count -= bytes; 413241699cdSAl Viro return bytes; 414241699cdSAl Viro } 415241699cdSAl Viro 416d879cb83SAl Viro /* 417171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 418171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 419171a0203SAnton Altaparmakov * 420171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 421171a0203SAnton Altaparmakov * because it is an invalid address). 422171a0203SAnton Altaparmakov */ 423d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 424171a0203SAnton Altaparmakov { 425171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 426171a0203SAnton Altaparmakov const struct iovec *iov; 427171a0203SAnton Altaparmakov int err; 428171a0203SAnton Altaparmakov struct iovec v; 429171a0203SAnton Altaparmakov 430171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 431171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4324bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 433171a0203SAnton Altaparmakov if (unlikely(err)) 434171a0203SAnton Altaparmakov return err; 435171a0203SAnton Altaparmakov 0;})) 436171a0203SAnton Altaparmakov } 437171a0203SAnton Altaparmakov return 0; 438171a0203SAnton Altaparmakov } 439d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 440171a0203SAnton Altaparmakov 441aa563d7bSDavid Howells void iov_iter_init(struct iov_iter *i, unsigned int direction, 442d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 443d879cb83SAl Viro size_t count) 444d879cb83SAl Viro { 445aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 446aa563d7bSDavid Howells direction &= READ | WRITE; 447aa563d7bSDavid Howells 448d879cb83SAl Viro /* It will get better. Eventually... */ 449db68ce10SAl Viro if (uaccess_kernel()) { 450aa563d7bSDavid Howells i->type = ITER_KVEC | direction; 451d879cb83SAl Viro i->kvec = (struct kvec *)iov; 452d879cb83SAl Viro } else { 453aa563d7bSDavid Howells i->type = ITER_IOVEC | direction; 454d879cb83SAl Viro i->iov = iov; 455d879cb83SAl Viro } 456d879cb83SAl Viro i->nr_segs = nr_segs; 457d879cb83SAl Viro i->iov_offset = 0; 458d879cb83SAl Viro i->count = count; 459d879cb83SAl Viro } 460d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 461d879cb83SAl Viro 462d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 463d879cb83SAl Viro { 464d879cb83SAl Viro char *from = kmap_atomic(page); 465d879cb83SAl Viro memcpy(to, from + offset, len); 466d879cb83SAl Viro kunmap_atomic(from); 467d879cb83SAl Viro } 468d879cb83SAl Viro 46936f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 470d879cb83SAl Viro { 471d879cb83SAl Viro char *to = kmap_atomic(page); 472d879cb83SAl Viro memcpy(to + offset, from, len); 473d879cb83SAl Viro kunmap_atomic(to); 474d879cb83SAl Viro } 475d879cb83SAl Viro 476d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 477d879cb83SAl Viro { 478d879cb83SAl Viro char *addr = kmap_atomic(page); 479d879cb83SAl Viro memset(addr + offset, 0, len); 480d879cb83SAl Viro kunmap_atomic(addr); 481d879cb83SAl Viro } 482d879cb83SAl Viro 483241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 484241699cdSAl Viro { 485241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 486241699cdSAl Viro } 487241699cdSAl Viro 4888cefc107SDavid Howells static inline void data_start(const struct iov_iter *i, 4898cefc107SDavid Howells unsigned int *iter_headp, size_t *offp) 490241699cdSAl Viro { 4918cefc107SDavid Howells unsigned int p_mask = i->pipe->ring_size - 1; 4928cefc107SDavid Howells unsigned int iter_head = i->head; 493241699cdSAl Viro size_t off = i->iov_offset; 4948cefc107SDavid Howells 4958cefc107SDavid Howells if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || 4968cefc107SDavid Howells off == PAGE_SIZE)) { 4978cefc107SDavid Howells iter_head++; 498241699cdSAl Viro off = 0; 499241699cdSAl Viro } 5008cefc107SDavid Howells *iter_headp = iter_head; 501241699cdSAl Viro *offp = off; 502241699cdSAl Viro } 503241699cdSAl Viro 504241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 5058cefc107SDavid Howells int *iter_headp, size_t *offp) 506241699cdSAl Viro { 507241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5088cefc107SDavid Howells unsigned int p_tail = pipe->tail; 5098cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5108cefc107SDavid Howells unsigned int iter_head; 511241699cdSAl Viro size_t off; 512241699cdSAl Viro ssize_t left; 513241699cdSAl Viro 514241699cdSAl Viro if (unlikely(size > i->count)) 515241699cdSAl Viro size = i->count; 516241699cdSAl Viro if (unlikely(!size)) 517241699cdSAl Viro return 0; 518241699cdSAl Viro 519241699cdSAl Viro left = size; 5208cefc107SDavid Howells data_start(i, &iter_head, &off); 5218cefc107SDavid Howells *iter_headp = iter_head; 522241699cdSAl Viro *offp = off; 523241699cdSAl Viro if (off) { 524241699cdSAl Viro left -= PAGE_SIZE - off; 525241699cdSAl Viro if (left <= 0) { 5268cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len += size; 527241699cdSAl Viro return size; 528241699cdSAl Viro } 5298cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; 5308cefc107SDavid Howells iter_head++; 531241699cdSAl Viro } 5326718b6f8SDavid Howells while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { 5338cefc107SDavid Howells struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; 534241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 535241699cdSAl Viro if (!page) 536241699cdSAl Viro break; 5378cefc107SDavid Howells 5388cefc107SDavid Howells buf->ops = &default_pipe_buf_ops; 5398cefc107SDavid Howells buf->page = page; 5408cefc107SDavid Howells buf->offset = 0; 5418cefc107SDavid Howells buf->len = min_t(ssize_t, left, PAGE_SIZE); 5428cefc107SDavid Howells left -= buf->len; 5438cefc107SDavid Howells iter_head++; 5448cefc107SDavid Howells pipe->head = iter_head; 5458cefc107SDavid Howells 5468cefc107SDavid Howells if (left == 0) 547241699cdSAl Viro return size; 548241699cdSAl Viro } 549241699cdSAl Viro return size - left; 550241699cdSAl Viro } 551241699cdSAl Viro 552241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 553241699cdSAl Viro struct iov_iter *i) 554241699cdSAl Viro { 555241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5568cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5578cefc107SDavid Howells unsigned int i_head; 558241699cdSAl Viro size_t n, off; 559241699cdSAl Viro 560241699cdSAl Viro if (!sanity(i)) 561241699cdSAl Viro return 0; 562241699cdSAl Viro 5638cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 564241699cdSAl Viro if (unlikely(!n)) 565241699cdSAl Viro return 0; 5668cefc107SDavid Howells do { 567241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 5688cefc107SDavid Howells memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); 5698cefc107SDavid Howells i->head = i_head; 570241699cdSAl Viro i->iov_offset = off + chunk; 571241699cdSAl Viro n -= chunk; 572241699cdSAl Viro addr += chunk; 5738cefc107SDavid Howells off = 0; 5748cefc107SDavid Howells i_head++; 5758cefc107SDavid Howells } while (n); 576241699cdSAl Viro i->count -= bytes; 577241699cdSAl Viro return bytes; 578241699cdSAl Viro } 579241699cdSAl Viro 580f9152895SAl Viro static __wsum csum_and_memcpy(void *to, const void *from, size_t len, 581f9152895SAl Viro __wsum sum, size_t off) 582f9152895SAl Viro { 583f9152895SAl Viro __wsum next = csum_partial_copy_nocheck(from, to, len, 0); 584f9152895SAl Viro return csum_block_add(sum, next, off); 585f9152895SAl Viro } 586f9152895SAl Viro 58778e1f386SAl Viro static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 58878e1f386SAl Viro __wsum *csum, struct iov_iter *i) 58978e1f386SAl Viro { 59078e1f386SAl Viro struct pipe_inode_info *pipe = i->pipe; 5918cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5928cefc107SDavid Howells unsigned int i_head; 59378e1f386SAl Viro size_t n, r; 59478e1f386SAl Viro size_t off = 0; 595f9152895SAl Viro __wsum sum = *csum; 59678e1f386SAl Viro 59778e1f386SAl Viro if (!sanity(i)) 59878e1f386SAl Viro return 0; 59978e1f386SAl Viro 6008cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &r); 60178e1f386SAl Viro if (unlikely(!n)) 60278e1f386SAl Viro return 0; 6038cefc107SDavid Howells do { 60478e1f386SAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - r); 6058cefc107SDavid Howells char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); 606f9152895SAl Viro sum = csum_and_memcpy(p + r, addr, chunk, sum, off); 60778e1f386SAl Viro kunmap_atomic(p); 6088cefc107SDavid Howells i->head = i_head; 60978e1f386SAl Viro i->iov_offset = r + chunk; 61078e1f386SAl Viro n -= chunk; 61178e1f386SAl Viro off += chunk; 61278e1f386SAl Viro addr += chunk; 6138cefc107SDavid Howells r = 0; 6148cefc107SDavid Howells i_head++; 6158cefc107SDavid Howells } while (n); 61678e1f386SAl Viro i->count -= bytes; 61778e1f386SAl Viro *csum = sum; 61878e1f386SAl Viro return bytes; 61978e1f386SAl Viro } 62078e1f386SAl Viro 621aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 622d879cb83SAl Viro { 62336f7a8a4SAl Viro const char *from = addr; 62400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 625241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 62609fc68dcSAl Viro if (iter_is_iovec(i)) 62709fc68dcSAl Viro might_fault(); 628d879cb83SAl Viro iterate_and_advance(i, bytes, v, 62909fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 630d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 631d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 632d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 633d879cb83SAl Viro ) 634d879cb83SAl Viro 635d879cb83SAl Viro return bytes; 636d879cb83SAl Viro } 637aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 638d879cb83SAl Viro 6398780356eSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE 6408780356eSDan Williams static int copyout_mcsafe(void __user *to, const void *from, size_t n) 6418780356eSDan Williams { 64296d4f267SLinus Torvalds if (access_ok(to, n)) { 643d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 6448780356eSDan Williams n = copy_to_user_mcsafe((__force void *) to, from, n); 6458780356eSDan Williams } 6468780356eSDan Williams return n; 6478780356eSDan Williams } 6488780356eSDan Williams 6498780356eSDan Williams static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, 6508780356eSDan Williams const char *from, size_t len) 6518780356eSDan Williams { 6528780356eSDan Williams unsigned long ret; 6538780356eSDan Williams char *to; 6548780356eSDan Williams 6558780356eSDan Williams to = kmap_atomic(page); 6568780356eSDan Williams ret = memcpy_mcsafe(to + offset, from, len); 6578780356eSDan Williams kunmap_atomic(to); 6588780356eSDan Williams 6598780356eSDan Williams return ret; 6608780356eSDan Williams } 6618780356eSDan Williams 662ca146f6fSDan Williams static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, 663ca146f6fSDan Williams struct iov_iter *i) 664ca146f6fSDan Williams { 665ca146f6fSDan Williams struct pipe_inode_info *pipe = i->pipe; 6668cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 6678cefc107SDavid Howells unsigned int i_head; 668ca146f6fSDan Williams size_t n, off, xfer = 0; 669ca146f6fSDan Williams 670ca146f6fSDan Williams if (!sanity(i)) 671ca146f6fSDan Williams return 0; 672ca146f6fSDan Williams 6738cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 674ca146f6fSDan Williams if (unlikely(!n)) 675ca146f6fSDan Williams return 0; 6768cefc107SDavid Howells do { 677ca146f6fSDan Williams size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 678ca146f6fSDan Williams unsigned long rem; 679ca146f6fSDan Williams 6808cefc107SDavid Howells rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page, 6818cefc107SDavid Howells off, addr, chunk); 6828cefc107SDavid Howells i->head = i_head; 683ca146f6fSDan Williams i->iov_offset = off + chunk - rem; 684ca146f6fSDan Williams xfer += chunk - rem; 685ca146f6fSDan Williams if (rem) 686ca146f6fSDan Williams break; 687ca146f6fSDan Williams n -= chunk; 688ca146f6fSDan Williams addr += chunk; 6898cefc107SDavid Howells off = 0; 6908cefc107SDavid Howells i_head++; 6918cefc107SDavid Howells } while (n); 692ca146f6fSDan Williams i->count -= xfer; 693ca146f6fSDan Williams return xfer; 694ca146f6fSDan Williams } 695ca146f6fSDan Williams 696bf3eeb9bSDan Williams /** 697bf3eeb9bSDan Williams * _copy_to_iter_mcsafe - copy to user with source-read error exception handling 698bf3eeb9bSDan Williams * @addr: source kernel address 699bf3eeb9bSDan Williams * @bytes: total transfer length 700bf3eeb9bSDan Williams * @iter: destination iterator 701bf3eeb9bSDan Williams * 702bf3eeb9bSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 703bf3eeb9bSDan Williams * dax_copy_to_iter() for protecting read/write to persistent memory. 704bf3eeb9bSDan Williams * Unless / until an architecture can guarantee identical performance 705bf3eeb9bSDan Williams * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a 706bf3eeb9bSDan Williams * performance regression to switch more users to the mcsafe version. 707bf3eeb9bSDan Williams * 708bf3eeb9bSDan Williams * Otherwise, 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 * 720bf3eeb9bSDan Williams * See MCSAFE_TEST for self-test. 721bf3eeb9bSDan Williams */ 7228780356eSDan Williams size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) 7238780356eSDan Williams { 7248780356eSDan Williams const char *from = addr; 7258780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 7268780356eSDan Williams 72700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 728ca146f6fSDan Williams return copy_pipe_to_iter_mcsafe(addr, bytes, i); 7298780356eSDan Williams if (iter_is_iovec(i)) 7308780356eSDan Williams might_fault(); 7318780356eSDan Williams iterate_and_advance(i, bytes, v, 7328780356eSDan Williams copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 7338780356eSDan Williams ({ 7348780356eSDan Williams rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, 7358780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 7368780356eSDan Williams if (rem) { 7378780356eSDan Williams curr_addr = (unsigned long) from; 7388780356eSDan Williams bytes = curr_addr - s_addr - rem; 7398780356eSDan Williams return bytes; 7408780356eSDan Williams } 7418780356eSDan Williams }), 7428780356eSDan Williams ({ 7438780356eSDan Williams rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, 7448780356eSDan Williams v.iov_len); 7458780356eSDan Williams if (rem) { 7468780356eSDan Williams curr_addr = (unsigned long) from; 7478780356eSDan Williams bytes = curr_addr - s_addr - rem; 7488780356eSDan Williams return bytes; 7498780356eSDan Williams } 7508780356eSDan Williams }) 7518780356eSDan Williams ) 7528780356eSDan Williams 7538780356eSDan Williams return bytes; 7548780356eSDan Williams } 7558780356eSDan Williams EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); 7568780356eSDan Williams #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ 7578780356eSDan Williams 758aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 759d879cb83SAl Viro { 760d879cb83SAl Viro char *to = addr; 76100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 762241699cdSAl Viro WARN_ON(1); 763241699cdSAl Viro return 0; 764241699cdSAl Viro } 76509fc68dcSAl Viro if (iter_is_iovec(i)) 76609fc68dcSAl Viro might_fault(); 767d879cb83SAl Viro iterate_and_advance(i, bytes, v, 76809fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 769d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 770d879cb83SAl Viro v.bv_offset, v.bv_len), 771d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 772d879cb83SAl Viro ) 773d879cb83SAl Viro 774d879cb83SAl Viro return bytes; 775d879cb83SAl Viro } 776aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 777d879cb83SAl Viro 778aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 779cbbd26b8SAl Viro { 780cbbd26b8SAl Viro char *to = addr; 78100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 782cbbd26b8SAl Viro WARN_ON(1); 783cbbd26b8SAl Viro return false; 784cbbd26b8SAl Viro } 78533844e66SAl Viro if (unlikely(i->count < bytes)) 786cbbd26b8SAl Viro return false; 787cbbd26b8SAl Viro 78809fc68dcSAl Viro if (iter_is_iovec(i)) 78909fc68dcSAl Viro might_fault(); 790cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 79109fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 792cbbd26b8SAl Viro v.iov_base, v.iov_len)) 793cbbd26b8SAl Viro return false; 794cbbd26b8SAl Viro 0;}), 795cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 796cbbd26b8SAl Viro v.bv_offset, v.bv_len), 797cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 798cbbd26b8SAl Viro ) 799cbbd26b8SAl Viro 800cbbd26b8SAl Viro iov_iter_advance(i, bytes); 801cbbd26b8SAl Viro return true; 802cbbd26b8SAl Viro } 803aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 804cbbd26b8SAl Viro 805aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 806d879cb83SAl Viro { 807d879cb83SAl Viro char *to = addr; 80800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 809241699cdSAl Viro WARN_ON(1); 810241699cdSAl Viro return 0; 811241699cdSAl Viro } 812d879cb83SAl Viro iterate_and_advance(i, bytes, v, 8133f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 814d879cb83SAl Viro v.iov_base, v.iov_len), 815d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 816d879cb83SAl Viro v.bv_offset, v.bv_len), 817d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 818d879cb83SAl Viro ) 819d879cb83SAl Viro 820d879cb83SAl Viro return bytes; 821d879cb83SAl Viro } 822aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 823d879cb83SAl Viro 8240aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 825abd08d7dSDan Williams /** 826abd08d7dSDan Williams * _copy_from_iter_flushcache - write destination through cpu cache 827abd08d7dSDan Williams * @addr: destination kernel address 828abd08d7dSDan Williams * @bytes: total transfer length 829abd08d7dSDan Williams * @iter: source iterator 830abd08d7dSDan Williams * 831abd08d7dSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 832abd08d7dSDan Williams * dax_copy_from_iter() for ensuring that writes to persistent memory 833abd08d7dSDan Williams * are flushed through the CPU cache. It is differentiated from 834abd08d7dSDan Williams * _copy_from_iter_nocache() in that guarantees all data is flushed for 835abd08d7dSDan Williams * all iterator types. The _copy_from_iter_nocache() only attempts to 836abd08d7dSDan Williams * bypass the cache for the ITER_IOVEC case, and on some archs may use 837abd08d7dSDan Williams * instructions that strand dirty-data in the cache. 838abd08d7dSDan Williams */ 8396a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 8400aed55afSDan Williams { 8410aed55afSDan Williams char *to = addr; 84200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 8430aed55afSDan Williams WARN_ON(1); 8440aed55afSDan Williams return 0; 8450aed55afSDan Williams } 8460aed55afSDan Williams iterate_and_advance(i, bytes, v, 8470aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 8480aed55afSDan Williams v.iov_base, v.iov_len), 8490aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 8500aed55afSDan Williams v.bv_offset, v.bv_len), 8510aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 8520aed55afSDan Williams v.iov_len) 8530aed55afSDan Williams ) 8540aed55afSDan Williams 8550aed55afSDan Williams return bytes; 8560aed55afSDan Williams } 8576a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 8580aed55afSDan Williams #endif 8590aed55afSDan Williams 860aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 861cbbd26b8SAl Viro { 862cbbd26b8SAl Viro char *to = addr; 86300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 864cbbd26b8SAl Viro WARN_ON(1); 865cbbd26b8SAl Viro return false; 866cbbd26b8SAl Viro } 86733844e66SAl Viro if (unlikely(i->count < bytes)) 868cbbd26b8SAl Viro return false; 869cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 8703f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 871cbbd26b8SAl Viro v.iov_base, v.iov_len)) 872cbbd26b8SAl Viro return false; 873cbbd26b8SAl Viro 0;}), 874cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 875cbbd26b8SAl Viro v.bv_offset, v.bv_len), 876cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 877cbbd26b8SAl Viro ) 878cbbd26b8SAl Viro 879cbbd26b8SAl Viro iov_iter_advance(i, bytes); 880cbbd26b8SAl Viro return true; 881cbbd26b8SAl Viro } 882aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 883cbbd26b8SAl Viro 88472e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 88572e809edSAl Viro { 8866daef95bSEric Dumazet struct page *head; 8876daef95bSEric Dumazet size_t v = n + offset; 8886daef95bSEric Dumazet 8896daef95bSEric Dumazet /* 8906daef95bSEric Dumazet * The general case needs to access the page order in order 8916daef95bSEric Dumazet * to compute the page size. 8926daef95bSEric Dumazet * However, we mostly deal with order-0 pages and thus can 8936daef95bSEric Dumazet * avoid a possible cache line miss for requests that fit all 8946daef95bSEric Dumazet * page orders. 8956daef95bSEric Dumazet */ 8966daef95bSEric Dumazet if (n <= v && v <= PAGE_SIZE) 8976daef95bSEric Dumazet return true; 8986daef95bSEric Dumazet 8996daef95bSEric Dumazet head = compound_head(page); 9006daef95bSEric Dumazet v += (page - head) << PAGE_SHIFT; 901a90bcb86SPetar Penkov 902a50b854eSMatthew Wilcox (Oracle) if (likely(n <= v && v <= (page_size(head)))) 90372e809edSAl Viro return true; 90472e809edSAl Viro WARN_ON(1); 90572e809edSAl Viro return false; 90672e809edSAl Viro } 907d879cb83SAl Viro 908d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 909d879cb83SAl Viro struct iov_iter *i) 910d879cb83SAl Viro { 91172e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 91272e809edSAl Viro return 0; 913d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 914d879cb83SAl Viro void *kaddr = kmap_atomic(page); 915d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 916d879cb83SAl Viro kunmap_atomic(kaddr); 917d879cb83SAl Viro return wanted; 9189ea9ce04SDavid Howells } else if (unlikely(iov_iter_is_discard(i))) 9199ea9ce04SDavid Howells return bytes; 9209ea9ce04SDavid Howells else if (likely(!iov_iter_is_pipe(i))) 921d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 922241699cdSAl Viro else 923241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 924d879cb83SAl Viro } 925d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 926d879cb83SAl Viro 927d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 928d879cb83SAl Viro struct iov_iter *i) 929d879cb83SAl Viro { 93072e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 93172e809edSAl Viro return 0; 9329ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 933241699cdSAl Viro WARN_ON(1); 934241699cdSAl Viro return 0; 935241699cdSAl Viro } 936d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 937d879cb83SAl Viro void *kaddr = kmap_atomic(page); 938aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 939d879cb83SAl Viro kunmap_atomic(kaddr); 940d879cb83SAl Viro return wanted; 941d879cb83SAl Viro } else 942d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 943d879cb83SAl Viro } 944d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 945d879cb83SAl Viro 946241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 947241699cdSAl Viro { 948241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9498cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 9508cefc107SDavid Howells unsigned int i_head; 951241699cdSAl Viro size_t n, off; 952241699cdSAl Viro 953241699cdSAl Viro if (!sanity(i)) 954241699cdSAl Viro return 0; 955241699cdSAl Viro 9568cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 957241699cdSAl Viro if (unlikely(!n)) 958241699cdSAl Viro return 0; 959241699cdSAl Viro 9608cefc107SDavid Howells do { 961241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 9628cefc107SDavid Howells memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); 9638cefc107SDavid Howells i->head = i_head; 964241699cdSAl Viro i->iov_offset = off + chunk; 965241699cdSAl Viro n -= chunk; 9668cefc107SDavid Howells off = 0; 9678cefc107SDavid Howells i_head++; 9688cefc107SDavid Howells } while (n); 969241699cdSAl Viro i->count -= bytes; 970241699cdSAl Viro return bytes; 971241699cdSAl Viro } 972241699cdSAl Viro 973d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 974d879cb83SAl Viro { 97500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 976241699cdSAl Viro return pipe_zero(bytes, i); 977d879cb83SAl Viro iterate_and_advance(i, bytes, v, 97809fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 979d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 980d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 981d879cb83SAl Viro ) 982d879cb83SAl Viro 983d879cb83SAl Viro return bytes; 984d879cb83SAl Viro } 985d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 986d879cb83SAl Viro 987d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 988d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 989d879cb83SAl Viro { 990d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 99172e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 99272e809edSAl Viro kunmap_atomic(kaddr); 99372e809edSAl Viro return 0; 99472e809edSAl Viro } 9959ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 996241699cdSAl Viro kunmap_atomic(kaddr); 997241699cdSAl Viro WARN_ON(1); 998241699cdSAl Viro return 0; 999241699cdSAl Viro } 1000d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 100109fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 1002d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 1003d879cb83SAl Viro v.bv_offset, v.bv_len), 1004d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 1005d879cb83SAl Viro ) 1006d879cb83SAl Viro kunmap_atomic(kaddr); 1007d879cb83SAl Viro return bytes; 1008d879cb83SAl Viro } 1009d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 1010d879cb83SAl Viro 1011b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 1012241699cdSAl Viro { 1013241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 10148cefc107SDavid Howells unsigned int p_tail = pipe->tail; 10158cefc107SDavid Howells unsigned int p_head = pipe->head; 10168cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10178cefc107SDavid Howells 10188cefc107SDavid Howells if (!pipe_empty(p_head, p_tail)) { 10198cefc107SDavid Howells struct pipe_buffer *buf; 10208cefc107SDavid Howells unsigned int i_head = i->head; 1021b9dc6f65SAl Viro size_t off = i->iov_offset; 10228cefc107SDavid Howells 1023b9dc6f65SAl Viro if (off) { 10248cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 10258cefc107SDavid Howells buf->len = off - buf->offset; 10268cefc107SDavid Howells i_head++; 1027b9dc6f65SAl Viro } 10288cefc107SDavid Howells while (p_head != i_head) { 10298cefc107SDavid Howells p_head--; 10308cefc107SDavid Howells pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); 1031241699cdSAl Viro } 10328cefc107SDavid Howells 10338cefc107SDavid Howells pipe->head = p_head; 1034241699cdSAl Viro } 1035b9dc6f65SAl Viro } 1036b9dc6f65SAl Viro 1037b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 1038b9dc6f65SAl Viro { 1039b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 1040b9dc6f65SAl Viro if (unlikely(i->count < size)) 1041b9dc6f65SAl Viro size = i->count; 1042b9dc6f65SAl Viro if (size) { 1043b9dc6f65SAl Viro struct pipe_buffer *buf; 10448cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10458cefc107SDavid Howells unsigned int i_head = i->head; 1046b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 10478cefc107SDavid Howells 1048b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 10498cefc107SDavid Howells left += off - pipe->bufs[i_head & p_mask].offset; 1050b9dc6f65SAl Viro while (1) { 10518cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 1052b9dc6f65SAl Viro if (left <= buf->len) 1053b9dc6f65SAl Viro break; 1054b9dc6f65SAl Viro left -= buf->len; 10558cefc107SDavid Howells i_head++; 1056b9dc6f65SAl Viro } 10578cefc107SDavid Howells i->head = i_head; 1058b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 1059b9dc6f65SAl Viro } 1060b9dc6f65SAl Viro i->count -= size; 1061b9dc6f65SAl Viro /* ... and discard everything past that point */ 1062b9dc6f65SAl Viro pipe_truncate(i); 1063241699cdSAl Viro } 1064241699cdSAl Viro 1065d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 1066d879cb83SAl Viro { 106700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1068241699cdSAl Viro pipe_advance(i, size); 1069241699cdSAl Viro return; 1070241699cdSAl Viro } 10719ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) { 10729ea9ce04SDavid Howells i->count -= size; 10739ea9ce04SDavid Howells return; 10749ea9ce04SDavid Howells } 1075d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 1076d879cb83SAl Viro } 1077d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 1078d879cb83SAl Viro 107927c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 108027c0e374SAl Viro { 108127c0e374SAl Viro if (!unroll) 108227c0e374SAl Viro return; 10835b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 10845b47d59aSAl Viro return; 108527c0e374SAl Viro i->count += unroll; 108600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 108727c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 10888cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10898cefc107SDavid Howells unsigned int i_head = i->head; 109027c0e374SAl Viro size_t off = i->iov_offset; 109127c0e374SAl Viro while (1) { 10928cefc107SDavid Howells struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; 10938cefc107SDavid Howells size_t n = off - b->offset; 109427c0e374SAl Viro if (unroll < n) { 10954fa55cefSAl Viro off -= unroll; 109627c0e374SAl Viro break; 109727c0e374SAl Viro } 109827c0e374SAl Viro unroll -= n; 10998cefc107SDavid Howells if (!unroll && i_head == i->start_head) { 110027c0e374SAl Viro off = 0; 110127c0e374SAl Viro break; 110227c0e374SAl Viro } 11038cefc107SDavid Howells i_head--; 11048cefc107SDavid Howells b = &pipe->bufs[i_head & p_mask]; 11058cefc107SDavid Howells off = b->offset + b->len; 110627c0e374SAl Viro } 110727c0e374SAl Viro i->iov_offset = off; 11088cefc107SDavid Howells i->head = i_head; 110927c0e374SAl Viro pipe_truncate(i); 111027c0e374SAl Viro return; 111127c0e374SAl Viro } 11129ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11139ea9ce04SDavid Howells return; 111427c0e374SAl Viro if (unroll <= i->iov_offset) { 111527c0e374SAl Viro i->iov_offset -= unroll; 111627c0e374SAl Viro return; 111727c0e374SAl Viro } 111827c0e374SAl Viro unroll -= i->iov_offset; 111900e23707SDavid Howells if (iov_iter_is_bvec(i)) { 112027c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 112127c0e374SAl Viro while (1) { 112227c0e374SAl Viro size_t n = (--bvec)->bv_len; 112327c0e374SAl Viro i->nr_segs++; 112427c0e374SAl Viro if (unroll <= n) { 112527c0e374SAl Viro i->bvec = bvec; 112627c0e374SAl Viro i->iov_offset = n - unroll; 112727c0e374SAl Viro return; 112827c0e374SAl Viro } 112927c0e374SAl Viro unroll -= n; 113027c0e374SAl Viro } 113127c0e374SAl Viro } else { /* same logics for iovec and kvec */ 113227c0e374SAl Viro const struct iovec *iov = i->iov; 113327c0e374SAl Viro while (1) { 113427c0e374SAl Viro size_t n = (--iov)->iov_len; 113527c0e374SAl Viro i->nr_segs++; 113627c0e374SAl Viro if (unroll <= n) { 113727c0e374SAl Viro i->iov = iov; 113827c0e374SAl Viro i->iov_offset = n - unroll; 113927c0e374SAl Viro return; 114027c0e374SAl Viro } 114127c0e374SAl Viro unroll -= n; 114227c0e374SAl Viro } 114327c0e374SAl Viro } 114427c0e374SAl Viro } 114527c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 114627c0e374SAl Viro 1147d879cb83SAl Viro /* 1148d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1149d879cb83SAl Viro */ 1150d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1151d879cb83SAl Viro { 115200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1153241699cdSAl Viro return i->count; // it is a silly place, anyway 1154d879cb83SAl Viro if (i->nr_segs == 1) 1155d879cb83SAl Viro return i->count; 11569ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11579ea9ce04SDavid Howells return i->count; 115800e23707SDavid Howells else if (iov_iter_is_bvec(i)) 1159d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1160d879cb83SAl Viro else 1161d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1162d879cb83SAl Viro } 1163d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1164d879cb83SAl Viro 1165aa563d7bSDavid Howells void iov_iter_kvec(struct iov_iter *i, unsigned int direction, 1166d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1167d879cb83SAl Viro size_t count) 1168d879cb83SAl Viro { 1169aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1170aa563d7bSDavid Howells i->type = ITER_KVEC | (direction & (READ | WRITE)); 1171d879cb83SAl Viro i->kvec = kvec; 1172d879cb83SAl Viro i->nr_segs = nr_segs; 1173d879cb83SAl Viro i->iov_offset = 0; 1174d879cb83SAl Viro i->count = count; 1175d879cb83SAl Viro } 1176d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1177d879cb83SAl Viro 1178aa563d7bSDavid Howells void iov_iter_bvec(struct iov_iter *i, unsigned int direction, 1179d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1180d879cb83SAl Viro size_t count) 1181d879cb83SAl Viro { 1182aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1183aa563d7bSDavid Howells i->type = ITER_BVEC | (direction & (READ | WRITE)); 1184d879cb83SAl Viro i->bvec = bvec; 1185d879cb83SAl Viro i->nr_segs = nr_segs; 1186d879cb83SAl Viro i->iov_offset = 0; 1187d879cb83SAl Viro i->count = count; 1188d879cb83SAl Viro } 1189d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1190d879cb83SAl Viro 1191aa563d7bSDavid Howells void iov_iter_pipe(struct iov_iter *i, unsigned int direction, 1192241699cdSAl Viro struct pipe_inode_info *pipe, 1193241699cdSAl Viro size_t count) 1194241699cdSAl Viro { 1195aa563d7bSDavid Howells BUG_ON(direction != READ); 11968cefc107SDavid Howells WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); 1197aa563d7bSDavid Howells i->type = ITER_PIPE | READ; 1198241699cdSAl Viro i->pipe = pipe; 11998cefc107SDavid Howells i->head = pipe->head; 1200241699cdSAl Viro i->iov_offset = 0; 1201241699cdSAl Viro i->count = count; 12028cefc107SDavid Howells i->start_head = i->head; 1203241699cdSAl Viro } 1204241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1205241699cdSAl Viro 12069ea9ce04SDavid Howells /** 12079ea9ce04SDavid Howells * iov_iter_discard - Initialise an I/O iterator that discards data 12089ea9ce04SDavid Howells * @i: The iterator to initialise. 12099ea9ce04SDavid Howells * @direction: The direction of the transfer. 12109ea9ce04SDavid Howells * @count: The size of the I/O buffer in bytes. 12119ea9ce04SDavid Howells * 12129ea9ce04SDavid Howells * Set up an I/O iterator that just discards everything that's written to it. 12139ea9ce04SDavid Howells * It's only available as a READ iterator. 12149ea9ce04SDavid Howells */ 12159ea9ce04SDavid Howells void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) 12169ea9ce04SDavid Howells { 12179ea9ce04SDavid Howells BUG_ON(direction != READ); 12189ea9ce04SDavid Howells i->type = ITER_DISCARD | READ; 12199ea9ce04SDavid Howells i->count = count; 12209ea9ce04SDavid Howells i->iov_offset = 0; 12219ea9ce04SDavid Howells } 12229ea9ce04SDavid Howells EXPORT_SYMBOL(iov_iter_discard); 12239ea9ce04SDavid Howells 1224d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1225d879cb83SAl Viro { 1226d879cb83SAl Viro unsigned long res = 0; 1227d879cb83SAl Viro size_t size = i->count; 1228d879cb83SAl Viro 122900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1230e0ff126eSJan Kara unsigned int p_mask = i->pipe->ring_size - 1; 1231e0ff126eSJan Kara 12328cefc107SDavid Howells if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) 1233241699cdSAl Viro return size | i->iov_offset; 1234241699cdSAl Viro return size; 1235241699cdSAl Viro } 1236d879cb83SAl Viro iterate_all_kinds(i, size, v, 1237d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1238d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1239d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1240d879cb83SAl Viro ) 1241d879cb83SAl Viro return res; 1242d879cb83SAl Viro } 1243d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1244d879cb83SAl Viro 1245357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1246357f435dSAl Viro { 1247357f435dSAl Viro unsigned long res = 0; 1248357f435dSAl Viro size_t size = i->count; 1249357f435dSAl Viro 12509ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1251241699cdSAl Viro WARN_ON(1); 1252241699cdSAl Viro return ~0U; 1253241699cdSAl Viro } 1254241699cdSAl Viro 1255357f435dSAl Viro iterate_all_kinds(i, size, v, 1256357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1257357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1258357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1259357f435dSAl Viro (size != v.bv_len ? size : 0)), 1260357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1261357f435dSAl Viro (size != v.iov_len ? size : 0)) 1262357f435dSAl Viro ); 1263357f435dSAl Viro return res; 1264357f435dSAl Viro } 1265357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1266357f435dSAl Viro 1267e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1268241699cdSAl Viro size_t maxsize, 1269241699cdSAl Viro struct page **pages, 12708cefc107SDavid Howells int iter_head, 1271241699cdSAl Viro size_t *start) 1272241699cdSAl Viro { 1273241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 12748cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 12758cefc107SDavid Howells ssize_t n = push_pipe(i, maxsize, &iter_head, start); 1276241699cdSAl Viro if (!n) 1277241699cdSAl Viro return -EFAULT; 1278241699cdSAl Viro 1279241699cdSAl Viro maxsize = n; 1280241699cdSAl Viro n += *start; 12811689c73aSAl Viro while (n > 0) { 12828cefc107SDavid Howells get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); 12838cefc107SDavid Howells iter_head++; 1284241699cdSAl Viro n -= PAGE_SIZE; 1285241699cdSAl Viro } 1286241699cdSAl Viro 1287241699cdSAl Viro return maxsize; 1288241699cdSAl Viro } 1289241699cdSAl Viro 1290241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1291241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1292241699cdSAl Viro size_t *start) 1293241699cdSAl Viro { 12948cefc107SDavid Howells unsigned int iter_head, npages; 1295241699cdSAl Viro size_t capacity; 1296241699cdSAl Viro 129733844e66SAl Viro if (!maxsize) 129833844e66SAl Viro return 0; 129933844e66SAl Viro 1300241699cdSAl Viro if (!sanity(i)) 1301241699cdSAl Viro return -EFAULT; 1302241699cdSAl Viro 13038cefc107SDavid Howells data_start(i, &iter_head, start); 13048cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13058cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1306241699cdSAl Viro capacity = min(npages, maxpages) * PAGE_SIZE - *start; 1307241699cdSAl Viro 13088cefc107SDavid Howells return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); 1309241699cdSAl Viro } 1310241699cdSAl Viro 1311d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1312d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1313d879cb83SAl Viro size_t *start) 1314d879cb83SAl Viro { 1315d879cb83SAl Viro if (maxsize > i->count) 1316d879cb83SAl Viro maxsize = i->count; 1317d879cb83SAl Viro 131800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1319241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 13209ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 13219ea9ce04SDavid Howells return -EFAULT; 13229ea9ce04SDavid Howells 1323d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1324d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1325d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1326d879cb83SAl Viro int n; 1327d879cb83SAl Viro int res; 1328d879cb83SAl Viro 1329d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1330d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1331d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1332d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 133373b0140bSIra Weiny res = get_user_pages_fast(addr, n, 133473b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, 133573b0140bSIra Weiny pages); 1336d879cb83SAl Viro if (unlikely(res < 0)) 1337d879cb83SAl Viro return res; 1338d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1339d879cb83SAl Viro 0;}),({ 1340d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1341d879cb83SAl Viro *start = v.bv_offset; 1342d879cb83SAl Viro get_page(*pages = v.bv_page); 1343d879cb83SAl Viro return v.bv_len; 1344d879cb83SAl Viro }),({ 1345d879cb83SAl Viro return -EFAULT; 1346d879cb83SAl Viro }) 1347d879cb83SAl Viro ) 1348d879cb83SAl Viro return 0; 1349d879cb83SAl Viro } 1350d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1351d879cb83SAl Viro 1352d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1353d879cb83SAl Viro { 1354752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1355d879cb83SAl Viro } 1356d879cb83SAl Viro 1357241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1358241699cdSAl Viro struct page ***pages, size_t maxsize, 1359241699cdSAl Viro size_t *start) 1360241699cdSAl Viro { 1361241699cdSAl Viro struct page **p; 13628cefc107SDavid Howells unsigned int iter_head, npages; 1363d7760d63SIlya Dryomov ssize_t n; 1364241699cdSAl Viro 136533844e66SAl Viro if (!maxsize) 136633844e66SAl Viro return 0; 136733844e66SAl Viro 1368241699cdSAl Viro if (!sanity(i)) 1369241699cdSAl Viro return -EFAULT; 1370241699cdSAl Viro 13718cefc107SDavid Howells data_start(i, &iter_head, start); 13728cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13738cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1374241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1375241699cdSAl Viro if (maxsize > n) 1376241699cdSAl Viro maxsize = n; 1377241699cdSAl Viro else 1378241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1379241699cdSAl Viro p = get_pages_array(npages); 1380241699cdSAl Viro if (!p) 1381241699cdSAl Viro return -ENOMEM; 13828cefc107SDavid Howells n = __pipe_get_pages(i, maxsize, p, iter_head, start); 1383241699cdSAl Viro if (n > 0) 1384241699cdSAl Viro *pages = p; 1385241699cdSAl Viro else 1386241699cdSAl Viro kvfree(p); 1387241699cdSAl Viro return n; 1388241699cdSAl Viro } 1389241699cdSAl Viro 1390d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1391d879cb83SAl Viro struct page ***pages, size_t maxsize, 1392d879cb83SAl Viro size_t *start) 1393d879cb83SAl Viro { 1394d879cb83SAl Viro struct page **p; 1395d879cb83SAl Viro 1396d879cb83SAl Viro if (maxsize > i->count) 1397d879cb83SAl Viro maxsize = i->count; 1398d879cb83SAl Viro 139900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1400241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 14019ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 14029ea9ce04SDavid Howells return -EFAULT; 14039ea9ce04SDavid Howells 1404d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1405d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1406d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1407d879cb83SAl Viro int n; 1408d879cb83SAl Viro int res; 1409d879cb83SAl Viro 1410d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1411d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1412d879cb83SAl Viro p = get_pages_array(n); 1413d879cb83SAl Viro if (!p) 1414d879cb83SAl Viro return -ENOMEM; 141573b0140bSIra Weiny res = get_user_pages_fast(addr, n, 141673b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); 1417d879cb83SAl Viro if (unlikely(res < 0)) { 1418d879cb83SAl Viro kvfree(p); 1419d879cb83SAl Viro return res; 1420d879cb83SAl Viro } 1421d879cb83SAl Viro *pages = p; 1422d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1423d879cb83SAl Viro 0;}),({ 1424d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1425d879cb83SAl Viro *start = v.bv_offset; 1426d879cb83SAl Viro *pages = p = get_pages_array(1); 1427d879cb83SAl Viro if (!p) 1428d879cb83SAl Viro return -ENOMEM; 1429d879cb83SAl Viro get_page(*p = v.bv_page); 1430d879cb83SAl Viro return v.bv_len; 1431d879cb83SAl Viro }),({ 1432d879cb83SAl Viro return -EFAULT; 1433d879cb83SAl Viro }) 1434d879cb83SAl Viro ) 1435d879cb83SAl Viro return 0; 1436d879cb83SAl Viro } 1437d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1438d879cb83SAl Viro 1439d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1440d879cb83SAl Viro struct iov_iter *i) 1441d879cb83SAl Viro { 1442d879cb83SAl Viro char *to = addr; 1443d879cb83SAl Viro __wsum sum, next; 1444d879cb83SAl Viro size_t off = 0; 1445d879cb83SAl Viro sum = *csum; 14469ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1447241699cdSAl Viro WARN_ON(1); 1448241699cdSAl Viro return 0; 1449241699cdSAl Viro } 1450d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1451d879cb83SAl Viro int err = 0; 1452d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1453d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1454d879cb83SAl Viro v.iov_len, 0, &err); 1455d879cb83SAl Viro if (!err) { 1456d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1457d879cb83SAl Viro off += v.iov_len; 1458d879cb83SAl Viro } 1459d879cb83SAl Viro err ? v.iov_len : 0; 1460d879cb83SAl Viro }), ({ 1461d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1462f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1463f9152895SAl Viro p + v.bv_offset, v.bv_len, 1464f9152895SAl Viro sum, off); 1465d879cb83SAl Viro kunmap_atomic(p); 1466d879cb83SAl Viro off += v.bv_len; 1467d879cb83SAl Viro }),({ 1468f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1469f9152895SAl Viro v.iov_base, v.iov_len, 1470f9152895SAl Viro sum, off); 1471d879cb83SAl Viro off += v.iov_len; 1472d879cb83SAl Viro }) 1473d879cb83SAl Viro ) 1474d879cb83SAl Viro *csum = sum; 1475d879cb83SAl Viro return bytes; 1476d879cb83SAl Viro } 1477d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1478d879cb83SAl Viro 1479cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1480cbbd26b8SAl Viro struct iov_iter *i) 1481cbbd26b8SAl Viro { 1482cbbd26b8SAl Viro char *to = addr; 1483cbbd26b8SAl Viro __wsum sum, next; 1484cbbd26b8SAl Viro size_t off = 0; 1485cbbd26b8SAl Viro sum = *csum; 14869ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1487cbbd26b8SAl Viro WARN_ON(1); 1488cbbd26b8SAl Viro return false; 1489cbbd26b8SAl Viro } 1490cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1491cbbd26b8SAl Viro return false; 1492cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1493cbbd26b8SAl Viro int err = 0; 1494cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1495cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1496cbbd26b8SAl Viro v.iov_len, 0, &err); 1497cbbd26b8SAl Viro if (err) 1498cbbd26b8SAl Viro return false; 1499cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1500cbbd26b8SAl Viro off += v.iov_len; 1501cbbd26b8SAl Viro 0; 1502cbbd26b8SAl Viro }), ({ 1503cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1504f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1505f9152895SAl Viro p + v.bv_offset, v.bv_len, 1506f9152895SAl Viro sum, off); 1507cbbd26b8SAl Viro kunmap_atomic(p); 1508cbbd26b8SAl Viro off += v.bv_len; 1509cbbd26b8SAl Viro }),({ 1510f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1511f9152895SAl Viro v.iov_base, v.iov_len, 1512f9152895SAl Viro sum, off); 1513cbbd26b8SAl Viro off += v.iov_len; 1514cbbd26b8SAl Viro }) 1515cbbd26b8SAl Viro ) 1516cbbd26b8SAl Viro *csum = sum; 1517cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1518cbbd26b8SAl Viro return true; 1519cbbd26b8SAl Viro } 1520cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1521cbbd26b8SAl Viro 1522cb002d07SSagi Grimberg size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, 1523d879cb83SAl Viro struct iov_iter *i) 1524d879cb83SAl Viro { 152536f7a8a4SAl Viro const char *from = addr; 1526cb002d07SSagi Grimberg __wsum *csum = csump; 1527d879cb83SAl Viro __wsum sum, next; 1528d879cb83SAl Viro size_t off = 0; 152978e1f386SAl Viro 153078e1f386SAl Viro if (unlikely(iov_iter_is_pipe(i))) 153178e1f386SAl Viro return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); 153278e1f386SAl Viro 1533d879cb83SAl Viro sum = *csum; 153478e1f386SAl Viro if (unlikely(iov_iter_is_discard(i))) { 1535241699cdSAl Viro WARN_ON(1); /* for now */ 1536241699cdSAl Viro return 0; 1537241699cdSAl Viro } 1538d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1539d879cb83SAl Viro int err = 0; 1540d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1541d879cb83SAl Viro v.iov_base, 1542d879cb83SAl Viro v.iov_len, 0, &err); 1543d879cb83SAl Viro if (!err) { 1544d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1545d879cb83SAl Viro off += v.iov_len; 1546d879cb83SAl Viro } 1547d879cb83SAl Viro err ? v.iov_len : 0; 1548d879cb83SAl Viro }), ({ 1549d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1550f9152895SAl Viro sum = csum_and_memcpy(p + v.bv_offset, 1551f9152895SAl Viro (from += v.bv_len) - v.bv_len, 1552f9152895SAl Viro v.bv_len, sum, off); 1553d879cb83SAl Viro kunmap_atomic(p); 1554d879cb83SAl Viro off += v.bv_len; 1555d879cb83SAl Viro }),({ 1556f9152895SAl Viro sum = csum_and_memcpy(v.iov_base, 1557f9152895SAl Viro (from += v.iov_len) - v.iov_len, 1558f9152895SAl Viro v.iov_len, sum, off); 1559d879cb83SAl Viro off += v.iov_len; 1560d879cb83SAl Viro }) 1561d879cb83SAl Viro ) 1562d879cb83SAl Viro *csum = sum; 1563d879cb83SAl Viro return bytes; 1564d879cb83SAl Viro } 1565d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1566d879cb83SAl Viro 1567d05f4435SSagi Grimberg size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, 1568d05f4435SSagi Grimberg struct iov_iter *i) 1569d05f4435SSagi Grimberg { 157027fad74aSYueHaibing #ifdef CONFIG_CRYPTO 1571d05f4435SSagi Grimberg struct ahash_request *hash = hashp; 1572d05f4435SSagi Grimberg struct scatterlist sg; 1573d05f4435SSagi Grimberg size_t copied; 1574d05f4435SSagi Grimberg 1575d05f4435SSagi Grimberg copied = copy_to_iter(addr, bytes, i); 1576d05f4435SSagi Grimberg sg_init_one(&sg, addr, copied); 1577d05f4435SSagi Grimberg ahash_request_set_crypt(hash, &sg, NULL, copied); 1578d05f4435SSagi Grimberg crypto_ahash_update(hash); 1579d05f4435SSagi Grimberg return copied; 158027fad74aSYueHaibing #else 158127fad74aSYueHaibing return 0; 158227fad74aSYueHaibing #endif 1583d05f4435SSagi Grimberg } 1584d05f4435SSagi Grimberg EXPORT_SYMBOL(hash_and_copy_to_iter); 1585d05f4435SSagi Grimberg 1586d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1587d879cb83SAl Viro { 1588d879cb83SAl Viro size_t size = i->count; 1589d879cb83SAl Viro int npages = 0; 1590d879cb83SAl Viro 1591d879cb83SAl Viro if (!size) 1592d879cb83SAl Viro return 0; 15939ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 15949ea9ce04SDavid Howells return 0; 1595d879cb83SAl Viro 159600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1597241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 15988cefc107SDavid Howells unsigned int iter_head; 1599241699cdSAl Viro size_t off; 1600241699cdSAl Viro 1601241699cdSAl Viro if (!sanity(i)) 1602241699cdSAl Viro return 0; 1603241699cdSAl Viro 16048cefc107SDavid Howells data_start(i, &iter_head, &off); 1605241699cdSAl Viro /* some of this one + all after this one */ 16068cefc107SDavid Howells npages = pipe_space_for_user(iter_head, pipe->tail, pipe); 1607241699cdSAl Viro if (npages >= maxpages) 1608241699cdSAl Viro return maxpages; 1609241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1610d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1611d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1612d879cb83SAl Viro - p / PAGE_SIZE; 1613d879cb83SAl Viro if (npages >= maxpages) 1614d879cb83SAl Viro return maxpages; 1615d879cb83SAl Viro 0;}),({ 1616d879cb83SAl Viro npages++; 1617d879cb83SAl Viro if (npages >= maxpages) 1618d879cb83SAl Viro return maxpages; 1619d879cb83SAl Viro }),({ 1620d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1621d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1622d879cb83SAl Viro - p / PAGE_SIZE; 1623d879cb83SAl Viro if (npages >= maxpages) 1624d879cb83SAl Viro return maxpages; 1625d879cb83SAl Viro }) 1626d879cb83SAl Viro ) 1627d879cb83SAl Viro return npages; 1628d879cb83SAl Viro } 1629d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1630d879cb83SAl Viro 1631d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1632d879cb83SAl Viro { 1633d879cb83SAl Viro *new = *old; 163400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(new))) { 1635241699cdSAl Viro WARN_ON(1); 1636241699cdSAl Viro return NULL; 1637241699cdSAl Viro } 16389ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(new))) 16399ea9ce04SDavid Howells return NULL; 164000e23707SDavid Howells if (iov_iter_is_bvec(new)) 1641d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1642d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1643d879cb83SAl Viro flags); 1644d879cb83SAl Viro else 1645d879cb83SAl Viro /* iovec and kvec have identical layout */ 1646d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1647d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1648d879cb83SAl Viro flags); 1649d879cb83SAl Viro } 1650d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1651bc917be8SAl Viro 1652ffecee4fSVegard Nossum /** 1653ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1654ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1655ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1656ffecee4fSVegard Nossum * 1657ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1658ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1659ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1660ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1661ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1662ffecee4fSVegard Nossum * on-stack) kernel array. 1663ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1664ffecee4fSVegard Nossum * 1665ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1666ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1667ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1668ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1669ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1670ffecee4fSVegard Nossum * returns an error or not). 1671ffecee4fSVegard Nossum * 167287e5e6daSJens Axboe * Return: Negative error code on error, bytes imported on success 1673ffecee4fSVegard Nossum */ 167487e5e6daSJens Axboe ssize_t import_iovec(int type, const struct iovec __user * uvector, 1675bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1676bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1677bc917be8SAl Viro { 1678bc917be8SAl Viro ssize_t n; 1679bc917be8SAl Viro struct iovec *p; 1680bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1681bc917be8SAl Viro *iov, &p); 1682bc917be8SAl Viro if (n < 0) { 1683bc917be8SAl Viro if (p != *iov) 1684bc917be8SAl Viro kfree(p); 1685bc917be8SAl Viro *iov = NULL; 1686bc917be8SAl Viro return n; 1687bc917be8SAl Viro } 1688bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1689bc917be8SAl Viro *iov = p == *iov ? NULL : p; 169087e5e6daSJens Axboe return n; 1691bc917be8SAl Viro } 1692bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1693bc917be8SAl Viro 1694bc917be8SAl Viro #ifdef CONFIG_COMPAT 1695bc917be8SAl Viro #include <linux/compat.h> 1696bc917be8SAl Viro 169787e5e6daSJens Axboe ssize_t compat_import_iovec(int type, 169887e5e6daSJens Axboe const struct compat_iovec __user * uvector, 1699bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1700bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1701bc917be8SAl Viro { 1702bc917be8SAl Viro ssize_t n; 1703bc917be8SAl Viro struct iovec *p; 1704bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1705bc917be8SAl Viro *iov, &p); 1706bc917be8SAl Viro if (n < 0) { 1707bc917be8SAl Viro if (p != *iov) 1708bc917be8SAl Viro kfree(p); 1709bc917be8SAl Viro *iov = NULL; 1710bc917be8SAl Viro return n; 1711bc917be8SAl Viro } 1712bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1713bc917be8SAl Viro *iov = p == *iov ? NULL : p; 171487e5e6daSJens Axboe return n; 1715bc917be8SAl Viro } 171698aaaec4SArnd Bergmann EXPORT_SYMBOL(compat_import_iovec); 1717bc917be8SAl Viro #endif 1718bc917be8SAl Viro 1719bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1720bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1721bc917be8SAl Viro { 1722bc917be8SAl Viro if (len > MAX_RW_COUNT) 1723bc917be8SAl Viro len = MAX_RW_COUNT; 172496d4f267SLinus Torvalds if (unlikely(!access_ok(buf, len))) 1725bc917be8SAl Viro return -EFAULT; 1726bc917be8SAl Viro 1727bc917be8SAl Viro iov->iov_base = buf; 1728bc917be8SAl Viro iov->iov_len = len; 1729bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1730bc917be8SAl Viro return 0; 1731bc917be8SAl Viro } 1732e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 173309cf698aSAl Viro 173409cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 173509cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 173609cf698aSAl Viro void *context) 173709cf698aSAl Viro { 173809cf698aSAl Viro struct kvec w; 173909cf698aSAl Viro int err = -EINVAL; 174009cf698aSAl Viro if (!bytes) 174109cf698aSAl Viro return 0; 174209cf698aSAl Viro 174309cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 174409cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 174509cf698aSAl Viro w.iov_len = v.bv_len; 174609cf698aSAl Viro err = f(&w, context); 174709cf698aSAl Viro kunmap(v.bv_page); 174809cf698aSAl Viro err;}), ({ 174909cf698aSAl Viro w = v; 175009cf698aSAl Viro err = f(&w, context);}) 175109cf698aSAl Viro ) 175209cf698aSAl Viro return err; 175309cf698aSAl Viro } 175409cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1755