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> 10bfdc5970SChristoph Hellwig #include <linux/compat.h> 11d879cb83SAl Viro #include <net/checksum.h> 12d05f4435SSagi Grimberg #include <linux/scatterlist.h> 13d0ef4c36SMarco Elver #include <linux/instrumented.h> 14d879cb83SAl Viro 15241699cdSAl Viro #define PIPE_PARANOIA /* for now */ 16241699cdSAl Viro 17d879cb83SAl Viro #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ 18d879cb83SAl Viro size_t left; \ 19d879cb83SAl Viro size_t wanted = n; \ 20d879cb83SAl Viro __p = i->iov; \ 21d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 22d879cb83SAl Viro if (likely(__v.iov_len)) { \ 23d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 24d879cb83SAl Viro left = (STEP); \ 25d879cb83SAl Viro __v.iov_len -= left; \ 26d879cb83SAl Viro skip += __v.iov_len; \ 27d879cb83SAl Viro n -= __v.iov_len; \ 28d879cb83SAl Viro } else { \ 29d879cb83SAl Viro left = 0; \ 30d879cb83SAl Viro } \ 31d879cb83SAl Viro while (unlikely(!left && n)) { \ 32d879cb83SAl Viro __p++; \ 33d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 34d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 35d879cb83SAl Viro continue; \ 36d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 37d879cb83SAl Viro left = (STEP); \ 38d879cb83SAl Viro __v.iov_len -= left; \ 39d879cb83SAl Viro skip = __v.iov_len; \ 40d879cb83SAl Viro n -= __v.iov_len; \ 41d879cb83SAl Viro } \ 42d879cb83SAl Viro n = wanted - n; \ 43d879cb83SAl Viro } 44d879cb83SAl Viro 45d879cb83SAl Viro #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ 46d879cb83SAl Viro size_t wanted = n; \ 47d879cb83SAl Viro __p = i->kvec; \ 48d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 49d879cb83SAl Viro if (likely(__v.iov_len)) { \ 50d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 51d879cb83SAl Viro (void)(STEP); \ 52d879cb83SAl Viro skip += __v.iov_len; \ 53d879cb83SAl Viro n -= __v.iov_len; \ 54d879cb83SAl Viro } \ 55d879cb83SAl Viro while (unlikely(n)) { \ 56d879cb83SAl Viro __p++; \ 57d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 58d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 59d879cb83SAl Viro continue; \ 60d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 61d879cb83SAl Viro (void)(STEP); \ 62d879cb83SAl Viro skip = __v.iov_len; \ 63d879cb83SAl Viro n -= __v.iov_len; \ 64d879cb83SAl Viro } \ 65d879cb83SAl Viro n = wanted; \ 66d879cb83SAl Viro } 67d879cb83SAl Viro 681bdc76aeSMing Lei #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ 691bdc76aeSMing Lei struct bvec_iter __start; \ 701bdc76aeSMing Lei __start.bi_size = n; \ 711bdc76aeSMing Lei __start.bi_bvec_done = skip; \ 721bdc76aeSMing Lei __start.bi_idx = 0; \ 731bdc76aeSMing Lei for_each_bvec(__v, i->bvec, __bi, __start) { \ 741bdc76aeSMing Lei if (!__v.bv_len) \ 75d879cb83SAl Viro continue; \ 76d879cb83SAl Viro (void)(STEP); \ 77d879cb83SAl Viro } \ 78d879cb83SAl Viro } 79d879cb83SAl Viro 80d879cb83SAl Viro #define iterate_all_kinds(i, n, v, I, B, K) { \ 8133844e66SAl Viro if (likely(n)) { \ 82d879cb83SAl Viro size_t skip = i->iov_offset; \ 83d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 84d879cb83SAl Viro struct bio_vec v; \ 851bdc76aeSMing Lei struct bvec_iter __bi; \ 861bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 87d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 88d879cb83SAl Viro const struct kvec *kvec; \ 89d879cb83SAl Viro struct kvec v; \ 90d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 919ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 92d879cb83SAl Viro } else { \ 93d879cb83SAl Viro const struct iovec *iov; \ 94d879cb83SAl Viro struct iovec v; \ 95d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 96d879cb83SAl Viro } \ 9733844e66SAl Viro } \ 98d879cb83SAl Viro } 99d879cb83SAl Viro 100d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 101dd254f5aSAl Viro if (unlikely(i->count < n)) \ 102dd254f5aSAl Viro n = i->count; \ 10319f18459SAl Viro if (i->count) { \ 104d879cb83SAl Viro size_t skip = i->iov_offset; \ 105d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 1061bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 107d879cb83SAl Viro struct bio_vec v; \ 1081bdc76aeSMing Lei struct bvec_iter __bi; \ 1091bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1101bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1111bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1121bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 113d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 114d879cb83SAl Viro const struct kvec *kvec; \ 115d879cb83SAl Viro struct kvec v; \ 116d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 117d879cb83SAl Viro if (skip == kvec->iov_len) { \ 118d879cb83SAl Viro kvec++; \ 119d879cb83SAl Viro skip = 0; \ 120d879cb83SAl Viro } \ 121d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 122d879cb83SAl Viro i->kvec = kvec; \ 1239ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 1249ea9ce04SDavid Howells skip += n; \ 125d879cb83SAl Viro } else { \ 126d879cb83SAl Viro const struct iovec *iov; \ 127d879cb83SAl Viro struct iovec v; \ 128d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 129d879cb83SAl Viro if (skip == iov->iov_len) { \ 130d879cb83SAl Viro iov++; \ 131d879cb83SAl Viro skip = 0; \ 132d879cb83SAl Viro } \ 133d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 134d879cb83SAl Viro i->iov = iov; \ 135d879cb83SAl Viro } \ 136d879cb83SAl Viro i->count -= n; \ 137d879cb83SAl Viro i->iov_offset = skip; \ 138dd254f5aSAl Viro } \ 139d879cb83SAl Viro } 140d879cb83SAl Viro 14109fc68dcSAl Viro static int copyout(void __user *to, const void *from, size_t n) 14209fc68dcSAl Viro { 14396d4f267SLinus Torvalds if (access_ok(to, n)) { 144d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 14509fc68dcSAl Viro n = raw_copy_to_user(to, from, n); 14609fc68dcSAl Viro } 14709fc68dcSAl Viro return n; 14809fc68dcSAl Viro } 14909fc68dcSAl Viro 15009fc68dcSAl Viro static int copyin(void *to, const void __user *from, size_t n) 15109fc68dcSAl Viro { 15296d4f267SLinus Torvalds if (access_ok(from, n)) { 153d0ef4c36SMarco Elver instrument_copy_from_user(to, from, n); 15409fc68dcSAl Viro n = raw_copy_from_user(to, from, n); 15509fc68dcSAl Viro } 15609fc68dcSAl Viro return n; 15709fc68dcSAl Viro } 15809fc68dcSAl Viro 159d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 160d879cb83SAl Viro struct iov_iter *i) 161d879cb83SAl Viro { 162d879cb83SAl Viro size_t skip, copy, left, wanted; 163d879cb83SAl Viro const struct iovec *iov; 164d879cb83SAl Viro char __user *buf; 165d879cb83SAl Viro void *kaddr, *from; 166d879cb83SAl Viro 167d879cb83SAl Viro if (unlikely(bytes > i->count)) 168d879cb83SAl Viro bytes = i->count; 169d879cb83SAl Viro 170d879cb83SAl Viro if (unlikely(!bytes)) 171d879cb83SAl Viro return 0; 172d879cb83SAl Viro 17309fc68dcSAl Viro might_fault(); 174d879cb83SAl Viro wanted = bytes; 175d879cb83SAl Viro iov = i->iov; 176d879cb83SAl Viro skip = i->iov_offset; 177d879cb83SAl Viro buf = iov->iov_base + skip; 178d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 179d879cb83SAl Viro 1803fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 181d879cb83SAl Viro kaddr = kmap_atomic(page); 182d879cb83SAl Viro from = kaddr + offset; 183d879cb83SAl Viro 184d879cb83SAl Viro /* first chunk, usually the only one */ 18509fc68dcSAl Viro left = copyout(buf, from, copy); 186d879cb83SAl Viro copy -= left; 187d879cb83SAl Viro skip += copy; 188d879cb83SAl Viro from += copy; 189d879cb83SAl Viro bytes -= copy; 190d879cb83SAl Viro 191d879cb83SAl Viro while (unlikely(!left && bytes)) { 192d879cb83SAl Viro iov++; 193d879cb83SAl Viro buf = iov->iov_base; 194d879cb83SAl Viro copy = min(bytes, iov->iov_len); 19509fc68dcSAl Viro left = copyout(buf, from, copy); 196d879cb83SAl Viro copy -= left; 197d879cb83SAl Viro skip = copy; 198d879cb83SAl Viro from += copy; 199d879cb83SAl Viro bytes -= copy; 200d879cb83SAl Viro } 201d879cb83SAl Viro if (likely(!bytes)) { 202d879cb83SAl Viro kunmap_atomic(kaddr); 203d879cb83SAl Viro goto done; 204d879cb83SAl Viro } 205d879cb83SAl Viro offset = from - kaddr; 206d879cb83SAl Viro buf += copy; 207d879cb83SAl Viro kunmap_atomic(kaddr); 208d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 209d879cb83SAl Viro } 210d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2113fa6c507SMikulas Patocka 212d879cb83SAl Viro kaddr = kmap(page); 213d879cb83SAl Viro from = kaddr + offset; 21409fc68dcSAl Viro left = copyout(buf, from, copy); 215d879cb83SAl Viro copy -= left; 216d879cb83SAl Viro skip += copy; 217d879cb83SAl Viro from += copy; 218d879cb83SAl Viro bytes -= copy; 219d879cb83SAl Viro while (unlikely(!left && bytes)) { 220d879cb83SAl Viro iov++; 221d879cb83SAl Viro buf = iov->iov_base; 222d879cb83SAl Viro copy = min(bytes, iov->iov_len); 22309fc68dcSAl Viro left = copyout(buf, from, copy); 224d879cb83SAl Viro copy -= left; 225d879cb83SAl Viro skip = copy; 226d879cb83SAl Viro from += copy; 227d879cb83SAl Viro bytes -= copy; 228d879cb83SAl Viro } 229d879cb83SAl Viro kunmap(page); 2303fa6c507SMikulas Patocka 231d879cb83SAl Viro done: 232d879cb83SAl Viro if (skip == iov->iov_len) { 233d879cb83SAl Viro iov++; 234d879cb83SAl Viro skip = 0; 235d879cb83SAl Viro } 236d879cb83SAl Viro i->count -= wanted - bytes; 237d879cb83SAl Viro i->nr_segs -= iov - i->iov; 238d879cb83SAl Viro i->iov = iov; 239d879cb83SAl Viro i->iov_offset = skip; 240d879cb83SAl Viro return wanted - bytes; 241d879cb83SAl Viro } 242d879cb83SAl Viro 243d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 244d879cb83SAl Viro struct iov_iter *i) 245d879cb83SAl Viro { 246d879cb83SAl Viro size_t skip, copy, left, wanted; 247d879cb83SAl Viro const struct iovec *iov; 248d879cb83SAl Viro char __user *buf; 249d879cb83SAl Viro void *kaddr, *to; 250d879cb83SAl Viro 251d879cb83SAl Viro if (unlikely(bytes > i->count)) 252d879cb83SAl Viro bytes = i->count; 253d879cb83SAl Viro 254d879cb83SAl Viro if (unlikely(!bytes)) 255d879cb83SAl Viro return 0; 256d879cb83SAl Viro 25709fc68dcSAl Viro might_fault(); 258d879cb83SAl Viro wanted = bytes; 259d879cb83SAl Viro iov = i->iov; 260d879cb83SAl Viro skip = i->iov_offset; 261d879cb83SAl Viro buf = iov->iov_base + skip; 262d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 263d879cb83SAl Viro 2643fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 265d879cb83SAl Viro kaddr = kmap_atomic(page); 266d879cb83SAl Viro to = kaddr + offset; 267d879cb83SAl Viro 268d879cb83SAl Viro /* first chunk, usually the only one */ 26909fc68dcSAl Viro left = copyin(to, buf, copy); 270d879cb83SAl Viro copy -= left; 271d879cb83SAl Viro skip += copy; 272d879cb83SAl Viro to += copy; 273d879cb83SAl Viro bytes -= copy; 274d879cb83SAl Viro 275d879cb83SAl Viro while (unlikely(!left && bytes)) { 276d879cb83SAl Viro iov++; 277d879cb83SAl Viro buf = iov->iov_base; 278d879cb83SAl Viro copy = min(bytes, iov->iov_len); 27909fc68dcSAl Viro left = copyin(to, buf, copy); 280d879cb83SAl Viro copy -= left; 281d879cb83SAl Viro skip = copy; 282d879cb83SAl Viro to += copy; 283d879cb83SAl Viro bytes -= copy; 284d879cb83SAl Viro } 285d879cb83SAl Viro if (likely(!bytes)) { 286d879cb83SAl Viro kunmap_atomic(kaddr); 287d879cb83SAl Viro goto done; 288d879cb83SAl Viro } 289d879cb83SAl Viro offset = to - kaddr; 290d879cb83SAl Viro buf += copy; 291d879cb83SAl Viro kunmap_atomic(kaddr); 292d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 293d879cb83SAl Viro } 294d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2953fa6c507SMikulas Patocka 296d879cb83SAl Viro kaddr = kmap(page); 297d879cb83SAl Viro to = kaddr + offset; 29809fc68dcSAl Viro left = copyin(to, buf, copy); 299d879cb83SAl Viro copy -= left; 300d879cb83SAl Viro skip += copy; 301d879cb83SAl Viro to += copy; 302d879cb83SAl Viro bytes -= copy; 303d879cb83SAl Viro while (unlikely(!left && bytes)) { 304d879cb83SAl Viro iov++; 305d879cb83SAl Viro buf = iov->iov_base; 306d879cb83SAl Viro copy = min(bytes, iov->iov_len); 30709fc68dcSAl Viro left = copyin(to, buf, copy); 308d879cb83SAl Viro copy -= left; 309d879cb83SAl Viro skip = copy; 310d879cb83SAl Viro to += copy; 311d879cb83SAl Viro bytes -= copy; 312d879cb83SAl Viro } 313d879cb83SAl Viro kunmap(page); 3143fa6c507SMikulas Patocka 315d879cb83SAl Viro done: 316d879cb83SAl Viro if (skip == iov->iov_len) { 317d879cb83SAl Viro iov++; 318d879cb83SAl Viro skip = 0; 319d879cb83SAl Viro } 320d879cb83SAl Viro i->count -= wanted - bytes; 321d879cb83SAl Viro i->nr_segs -= iov - i->iov; 322d879cb83SAl Viro i->iov = iov; 323d879cb83SAl Viro i->iov_offset = skip; 324d879cb83SAl Viro return wanted - bytes; 325d879cb83SAl Viro } 326d879cb83SAl Viro 327241699cdSAl Viro #ifdef PIPE_PARANOIA 328241699cdSAl Viro static bool sanity(const struct iov_iter *i) 329241699cdSAl Viro { 330241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 3318cefc107SDavid Howells unsigned int p_head = pipe->head; 3328cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3338cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3348cefc107SDavid Howells unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); 3358cefc107SDavid Howells unsigned int i_head = i->head; 3368cefc107SDavid Howells unsigned int idx; 3378cefc107SDavid Howells 338241699cdSAl Viro if (i->iov_offset) { 339241699cdSAl Viro struct pipe_buffer *p; 3408cefc107SDavid Howells if (unlikely(p_occupancy == 0)) 341241699cdSAl Viro goto Bad; // pipe must be non-empty 3428cefc107SDavid Howells if (unlikely(i_head != p_head - 1)) 343241699cdSAl Viro goto Bad; // must be at the last buffer... 344241699cdSAl Viro 3458cefc107SDavid Howells p = &pipe->bufs[i_head & p_mask]; 346241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 347241699cdSAl Viro goto Bad; // ... at the end of segment 348241699cdSAl Viro } else { 3498cefc107SDavid Howells if (i_head != p_head) 350241699cdSAl Viro goto Bad; // must be right after the last buffer 351241699cdSAl Viro } 352241699cdSAl Viro return true; 353241699cdSAl Viro Bad: 3548cefc107SDavid Howells printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); 3558cefc107SDavid Howells printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", 3568cefc107SDavid Howells p_head, p_tail, pipe->ring_size); 3578cefc107SDavid Howells for (idx = 0; idx < pipe->ring_size; idx++) 358241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 359241699cdSAl Viro pipe->bufs[idx].ops, 360241699cdSAl Viro pipe->bufs[idx].page, 361241699cdSAl Viro pipe->bufs[idx].offset, 362241699cdSAl Viro pipe->bufs[idx].len); 363241699cdSAl Viro WARN_ON(1); 364241699cdSAl Viro return false; 365241699cdSAl Viro } 366241699cdSAl Viro #else 367241699cdSAl Viro #define sanity(i) true 368241699cdSAl Viro #endif 369241699cdSAl Viro 370241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 371241699cdSAl Viro struct iov_iter *i) 372241699cdSAl Viro { 373241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 374241699cdSAl Viro struct pipe_buffer *buf; 3758cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3768cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3778cefc107SDavid Howells unsigned int i_head = i->head; 378241699cdSAl Viro size_t off; 379241699cdSAl Viro 380241699cdSAl Viro if (unlikely(bytes > i->count)) 381241699cdSAl Viro bytes = i->count; 382241699cdSAl Viro 383241699cdSAl Viro if (unlikely(!bytes)) 384241699cdSAl Viro return 0; 385241699cdSAl Viro 386241699cdSAl Viro if (!sanity(i)) 387241699cdSAl Viro return 0; 388241699cdSAl Viro 389241699cdSAl Viro off = i->iov_offset; 3908cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 391241699cdSAl Viro if (off) { 392241699cdSAl Viro if (offset == off && buf->page == page) { 393241699cdSAl Viro /* merge with the last one */ 394241699cdSAl Viro buf->len += bytes; 395241699cdSAl Viro i->iov_offset += bytes; 396241699cdSAl Viro goto out; 397241699cdSAl Viro } 3988cefc107SDavid Howells i_head++; 3998cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 400241699cdSAl Viro } 4016718b6f8SDavid Howells if (pipe_full(i_head, p_tail, pipe->max_usage)) 402241699cdSAl Viro return 0; 4038cefc107SDavid Howells 404241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 4058cefc107SDavid Howells get_page(page); 4068cefc107SDavid Howells buf->page = page; 407241699cdSAl Viro buf->offset = offset; 408241699cdSAl Viro buf->len = bytes; 4098cefc107SDavid Howells 4108cefc107SDavid Howells pipe->head = i_head + 1; 411241699cdSAl Viro i->iov_offset = offset + bytes; 4128cefc107SDavid Howells i->head = i_head; 413241699cdSAl Viro out: 414241699cdSAl Viro i->count -= bytes; 415241699cdSAl Viro return bytes; 416241699cdSAl Viro } 417241699cdSAl Viro 418d879cb83SAl Viro /* 419171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 420171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 421171a0203SAnton Altaparmakov * 422171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 423171a0203SAnton Altaparmakov * because it is an invalid address). 424171a0203SAnton Altaparmakov */ 425d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 426171a0203SAnton Altaparmakov { 427171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 428171a0203SAnton Altaparmakov const struct iovec *iov; 429171a0203SAnton Altaparmakov int err; 430171a0203SAnton Altaparmakov struct iovec v; 431171a0203SAnton Altaparmakov 432171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 433171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4344bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 435171a0203SAnton Altaparmakov if (unlikely(err)) 436171a0203SAnton Altaparmakov return err; 437171a0203SAnton Altaparmakov 0;})) 438171a0203SAnton Altaparmakov } 439171a0203SAnton Altaparmakov return 0; 440171a0203SAnton Altaparmakov } 441d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 442171a0203SAnton Altaparmakov 443aa563d7bSDavid Howells void iov_iter_init(struct iov_iter *i, unsigned int direction, 444d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 445d879cb83SAl Viro size_t count) 446d879cb83SAl Viro { 447aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 448aa563d7bSDavid Howells direction &= READ | WRITE; 449aa563d7bSDavid Howells 450d879cb83SAl Viro /* It will get better. Eventually... */ 451db68ce10SAl Viro if (uaccess_kernel()) { 452aa563d7bSDavid Howells i->type = ITER_KVEC | direction; 453d879cb83SAl Viro i->kvec = (struct kvec *)iov; 454d879cb83SAl Viro } else { 455aa563d7bSDavid Howells i->type = ITER_IOVEC | direction; 456d879cb83SAl Viro i->iov = iov; 457d879cb83SAl Viro } 458d879cb83SAl Viro i->nr_segs = nr_segs; 459d879cb83SAl Viro i->iov_offset = 0; 460d879cb83SAl Viro i->count = count; 461d879cb83SAl Viro } 462d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 463d879cb83SAl Viro 464d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 465d879cb83SAl Viro { 466d879cb83SAl Viro char *from = kmap_atomic(page); 467d879cb83SAl Viro memcpy(to, from + offset, len); 468d879cb83SAl Viro kunmap_atomic(from); 469d879cb83SAl Viro } 470d879cb83SAl Viro 47136f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 472d879cb83SAl Viro { 473d879cb83SAl Viro char *to = kmap_atomic(page); 474d879cb83SAl Viro memcpy(to + offset, from, len); 475d879cb83SAl Viro kunmap_atomic(to); 476d879cb83SAl Viro } 477d879cb83SAl Viro 478d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 479d879cb83SAl Viro { 480d879cb83SAl Viro char *addr = kmap_atomic(page); 481d879cb83SAl Viro memset(addr + offset, 0, len); 482d879cb83SAl Viro kunmap_atomic(addr); 483d879cb83SAl Viro } 484d879cb83SAl Viro 485241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 486241699cdSAl Viro { 487241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 488241699cdSAl Viro } 489241699cdSAl Viro 4908cefc107SDavid Howells static inline void data_start(const struct iov_iter *i, 4918cefc107SDavid Howells unsigned int *iter_headp, size_t *offp) 492241699cdSAl Viro { 4938cefc107SDavid Howells unsigned int p_mask = i->pipe->ring_size - 1; 4948cefc107SDavid Howells unsigned int iter_head = i->head; 495241699cdSAl Viro size_t off = i->iov_offset; 4968cefc107SDavid Howells 4978cefc107SDavid Howells if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || 4988cefc107SDavid Howells off == PAGE_SIZE)) { 4998cefc107SDavid Howells iter_head++; 500241699cdSAl Viro off = 0; 501241699cdSAl Viro } 5028cefc107SDavid Howells *iter_headp = iter_head; 503241699cdSAl Viro *offp = off; 504241699cdSAl Viro } 505241699cdSAl Viro 506241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 5078cefc107SDavid Howells int *iter_headp, size_t *offp) 508241699cdSAl Viro { 509241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5108cefc107SDavid Howells unsigned int p_tail = pipe->tail; 5118cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5128cefc107SDavid Howells unsigned int iter_head; 513241699cdSAl Viro size_t off; 514241699cdSAl Viro ssize_t left; 515241699cdSAl Viro 516241699cdSAl Viro if (unlikely(size > i->count)) 517241699cdSAl Viro size = i->count; 518241699cdSAl Viro if (unlikely(!size)) 519241699cdSAl Viro return 0; 520241699cdSAl Viro 521241699cdSAl Viro left = size; 5228cefc107SDavid Howells data_start(i, &iter_head, &off); 5238cefc107SDavid Howells *iter_headp = iter_head; 524241699cdSAl Viro *offp = off; 525241699cdSAl Viro if (off) { 526241699cdSAl Viro left -= PAGE_SIZE - off; 527241699cdSAl Viro if (left <= 0) { 5288cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len += size; 529241699cdSAl Viro return size; 530241699cdSAl Viro } 5318cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; 5328cefc107SDavid Howells iter_head++; 533241699cdSAl Viro } 5346718b6f8SDavid Howells while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { 5358cefc107SDavid Howells struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; 536241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 537241699cdSAl Viro if (!page) 538241699cdSAl Viro break; 5398cefc107SDavid Howells 5408cefc107SDavid Howells buf->ops = &default_pipe_buf_ops; 5418cefc107SDavid Howells buf->page = page; 5428cefc107SDavid Howells buf->offset = 0; 5438cefc107SDavid Howells buf->len = min_t(ssize_t, left, PAGE_SIZE); 5448cefc107SDavid Howells left -= buf->len; 5458cefc107SDavid Howells iter_head++; 5468cefc107SDavid Howells pipe->head = iter_head; 5478cefc107SDavid Howells 5488cefc107SDavid Howells if (left == 0) 549241699cdSAl Viro return size; 550241699cdSAl Viro } 551241699cdSAl Viro return size - left; 552241699cdSAl Viro } 553241699cdSAl Viro 554241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 555241699cdSAl Viro struct iov_iter *i) 556241699cdSAl Viro { 557241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5588cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5598cefc107SDavid Howells unsigned int i_head; 560241699cdSAl Viro size_t n, off; 561241699cdSAl Viro 562241699cdSAl Viro if (!sanity(i)) 563241699cdSAl Viro return 0; 564241699cdSAl Viro 5658cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 566241699cdSAl Viro if (unlikely(!n)) 567241699cdSAl Viro return 0; 5688cefc107SDavid Howells do { 569241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 5708cefc107SDavid Howells memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); 5718cefc107SDavid Howells i->head = i_head; 572241699cdSAl Viro i->iov_offset = off + chunk; 573241699cdSAl Viro n -= chunk; 574241699cdSAl Viro addr += chunk; 5758cefc107SDavid Howells off = 0; 5768cefc107SDavid Howells i_head++; 5778cefc107SDavid Howells } while (n); 578241699cdSAl Viro i->count -= bytes; 579241699cdSAl Viro return bytes; 580241699cdSAl Viro } 581241699cdSAl Viro 582f9152895SAl Viro static __wsum csum_and_memcpy(void *to, const void *from, size_t len, 583f9152895SAl Viro __wsum sum, size_t off) 584f9152895SAl Viro { 585f9152895SAl Viro __wsum next = csum_partial_copy_nocheck(from, to, len, 0); 586f9152895SAl Viro return csum_block_add(sum, next, off); 587f9152895SAl Viro } 588f9152895SAl Viro 58978e1f386SAl Viro static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 59078e1f386SAl Viro __wsum *csum, struct iov_iter *i) 59178e1f386SAl Viro { 59278e1f386SAl Viro struct pipe_inode_info *pipe = i->pipe; 5938cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5948cefc107SDavid Howells unsigned int i_head; 59578e1f386SAl Viro size_t n, r; 59678e1f386SAl Viro size_t off = 0; 597f9152895SAl Viro __wsum sum = *csum; 59878e1f386SAl Viro 59978e1f386SAl Viro if (!sanity(i)) 60078e1f386SAl Viro return 0; 60178e1f386SAl Viro 6028cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &r); 60378e1f386SAl Viro if (unlikely(!n)) 60478e1f386SAl Viro return 0; 6058cefc107SDavid Howells do { 60678e1f386SAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - r); 6078cefc107SDavid Howells char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); 608f9152895SAl Viro sum = csum_and_memcpy(p + r, addr, chunk, sum, off); 60978e1f386SAl Viro kunmap_atomic(p); 6108cefc107SDavid Howells i->head = i_head; 61178e1f386SAl Viro i->iov_offset = r + chunk; 61278e1f386SAl Viro n -= chunk; 61378e1f386SAl Viro off += chunk; 61478e1f386SAl Viro addr += chunk; 6158cefc107SDavid Howells r = 0; 6168cefc107SDavid Howells i_head++; 6178cefc107SDavid Howells } while (n); 61878e1f386SAl Viro i->count -= bytes; 61978e1f386SAl Viro *csum = sum; 62078e1f386SAl Viro return bytes; 62178e1f386SAl Viro } 62278e1f386SAl Viro 623aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 624d879cb83SAl Viro { 62536f7a8a4SAl Viro const char *from = addr; 62600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 627241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 62809fc68dcSAl Viro if (iter_is_iovec(i)) 62909fc68dcSAl Viro might_fault(); 630d879cb83SAl Viro iterate_and_advance(i, bytes, v, 63109fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 632d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 633d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 634d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 635d879cb83SAl Viro ) 636d879cb83SAl Viro 637d879cb83SAl Viro return bytes; 638d879cb83SAl Viro } 639aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 640d879cb83SAl Viro 6418780356eSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE 6428780356eSDan Williams static int copyout_mcsafe(void __user *to, const void *from, size_t n) 6438780356eSDan Williams { 64496d4f267SLinus Torvalds if (access_ok(to, n)) { 645d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 6468780356eSDan Williams n = copy_to_user_mcsafe((__force void *) to, from, n); 6478780356eSDan Williams } 6488780356eSDan Williams return n; 6498780356eSDan Williams } 6508780356eSDan Williams 6518780356eSDan Williams static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, 6528780356eSDan Williams const char *from, size_t len) 6538780356eSDan Williams { 6548780356eSDan Williams unsigned long ret; 6558780356eSDan Williams char *to; 6568780356eSDan Williams 6578780356eSDan Williams to = kmap_atomic(page); 6588780356eSDan Williams ret = memcpy_mcsafe(to + offset, from, len); 6598780356eSDan Williams kunmap_atomic(to); 6608780356eSDan Williams 6618780356eSDan Williams return ret; 6628780356eSDan Williams } 6638780356eSDan Williams 664ca146f6fSDan Williams static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, 665ca146f6fSDan Williams struct iov_iter *i) 666ca146f6fSDan Williams { 667ca146f6fSDan Williams struct pipe_inode_info *pipe = i->pipe; 6688cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 6698cefc107SDavid Howells unsigned int i_head; 670ca146f6fSDan Williams size_t n, off, xfer = 0; 671ca146f6fSDan Williams 672ca146f6fSDan Williams if (!sanity(i)) 673ca146f6fSDan Williams return 0; 674ca146f6fSDan Williams 6758cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 676ca146f6fSDan Williams if (unlikely(!n)) 677ca146f6fSDan Williams return 0; 6788cefc107SDavid Howells do { 679ca146f6fSDan Williams size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 680ca146f6fSDan Williams unsigned long rem; 681ca146f6fSDan Williams 6828cefc107SDavid Howells rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page, 6838cefc107SDavid Howells off, addr, chunk); 6848cefc107SDavid Howells i->head = i_head; 685ca146f6fSDan Williams i->iov_offset = off + chunk - rem; 686ca146f6fSDan Williams xfer += chunk - rem; 687ca146f6fSDan Williams if (rem) 688ca146f6fSDan Williams break; 689ca146f6fSDan Williams n -= chunk; 690ca146f6fSDan Williams addr += chunk; 6918cefc107SDavid Howells off = 0; 6928cefc107SDavid Howells i_head++; 6938cefc107SDavid Howells } while (n); 694ca146f6fSDan Williams i->count -= xfer; 695ca146f6fSDan Williams return xfer; 696ca146f6fSDan Williams } 697ca146f6fSDan Williams 698bf3eeb9bSDan Williams /** 699bf3eeb9bSDan Williams * _copy_to_iter_mcsafe - copy to user with source-read error exception handling 700bf3eeb9bSDan Williams * @addr: source kernel address 701bf3eeb9bSDan Williams * @bytes: total transfer length 702bf3eeb9bSDan Williams * @iter: destination iterator 703bf3eeb9bSDan Williams * 704bf3eeb9bSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 705bf3eeb9bSDan Williams * dax_copy_to_iter() for protecting read/write to persistent memory. 706bf3eeb9bSDan Williams * Unless / until an architecture can guarantee identical performance 707bf3eeb9bSDan Williams * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a 708bf3eeb9bSDan Williams * performance regression to switch more users to the mcsafe version. 709bf3eeb9bSDan Williams * 710bf3eeb9bSDan Williams * Otherwise, the main differences between this and typical _copy_to_iter(). 711bf3eeb9bSDan Williams * 712bf3eeb9bSDan Williams * * Typical tail/residue handling after a fault retries the copy 713bf3eeb9bSDan Williams * byte-by-byte until the fault happens again. Re-triggering machine 714bf3eeb9bSDan Williams * checks is potentially fatal so the implementation uses source 715bf3eeb9bSDan Williams * alignment and poison alignment assumptions to avoid re-triggering 716bf3eeb9bSDan Williams * hardware exceptions. 717bf3eeb9bSDan Williams * 718bf3eeb9bSDan Williams * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. 719bf3eeb9bSDan Williams * Compare to copy_to_iter() where only ITER_IOVEC attempts might return 720bf3eeb9bSDan Williams * a short copy. 721bf3eeb9bSDan Williams * 722bf3eeb9bSDan Williams * See MCSAFE_TEST for self-test. 723bf3eeb9bSDan Williams */ 7248780356eSDan Williams size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) 7258780356eSDan Williams { 7268780356eSDan Williams const char *from = addr; 7278780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 7288780356eSDan Williams 72900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 730ca146f6fSDan Williams return copy_pipe_to_iter_mcsafe(addr, bytes, i); 7318780356eSDan Williams if (iter_is_iovec(i)) 7328780356eSDan Williams might_fault(); 7338780356eSDan Williams iterate_and_advance(i, bytes, v, 7348780356eSDan Williams copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 7358780356eSDan Williams ({ 7368780356eSDan Williams rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, 7378780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 7388780356eSDan Williams if (rem) { 7398780356eSDan Williams curr_addr = (unsigned long) from; 7408780356eSDan Williams bytes = curr_addr - s_addr - rem; 7418780356eSDan Williams return bytes; 7428780356eSDan Williams } 7438780356eSDan Williams }), 7448780356eSDan Williams ({ 7458780356eSDan Williams rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, 7468780356eSDan Williams v.iov_len); 7478780356eSDan Williams if (rem) { 7488780356eSDan Williams curr_addr = (unsigned long) from; 7498780356eSDan Williams bytes = curr_addr - s_addr - rem; 7508780356eSDan Williams return bytes; 7518780356eSDan Williams } 7528780356eSDan Williams }) 7538780356eSDan Williams ) 7548780356eSDan Williams 7558780356eSDan Williams return bytes; 7568780356eSDan Williams } 7578780356eSDan Williams EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); 7588780356eSDan Williams #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ 7598780356eSDan Williams 760aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 761d879cb83SAl Viro { 762d879cb83SAl Viro char *to = addr; 76300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 764241699cdSAl Viro WARN_ON(1); 765241699cdSAl Viro return 0; 766241699cdSAl Viro } 76709fc68dcSAl Viro if (iter_is_iovec(i)) 76809fc68dcSAl Viro might_fault(); 769d879cb83SAl Viro iterate_and_advance(i, bytes, v, 77009fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 771d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 772d879cb83SAl Viro v.bv_offset, v.bv_len), 773d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 774d879cb83SAl Viro ) 775d879cb83SAl Viro 776d879cb83SAl Viro return bytes; 777d879cb83SAl Viro } 778aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 779d879cb83SAl Viro 780aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 781cbbd26b8SAl Viro { 782cbbd26b8SAl Viro char *to = addr; 78300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 784cbbd26b8SAl Viro WARN_ON(1); 785cbbd26b8SAl Viro return false; 786cbbd26b8SAl Viro } 78733844e66SAl Viro if (unlikely(i->count < bytes)) 788cbbd26b8SAl Viro return false; 789cbbd26b8SAl Viro 79009fc68dcSAl Viro if (iter_is_iovec(i)) 79109fc68dcSAl Viro might_fault(); 792cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 79309fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 794cbbd26b8SAl Viro v.iov_base, v.iov_len)) 795cbbd26b8SAl Viro return false; 796cbbd26b8SAl Viro 0;}), 797cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 798cbbd26b8SAl Viro v.bv_offset, v.bv_len), 799cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 800cbbd26b8SAl Viro ) 801cbbd26b8SAl Viro 802cbbd26b8SAl Viro iov_iter_advance(i, bytes); 803cbbd26b8SAl Viro return true; 804cbbd26b8SAl Viro } 805aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 806cbbd26b8SAl Viro 807aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 808d879cb83SAl Viro { 809d879cb83SAl Viro char *to = addr; 81000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 811241699cdSAl Viro WARN_ON(1); 812241699cdSAl Viro return 0; 813241699cdSAl Viro } 814d879cb83SAl Viro iterate_and_advance(i, bytes, v, 8153f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 816d879cb83SAl Viro v.iov_base, v.iov_len), 817d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 818d879cb83SAl Viro v.bv_offset, v.bv_len), 819d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 820d879cb83SAl Viro ) 821d879cb83SAl Viro 822d879cb83SAl Viro return bytes; 823d879cb83SAl Viro } 824aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 825d879cb83SAl Viro 8260aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 827abd08d7dSDan Williams /** 828abd08d7dSDan Williams * _copy_from_iter_flushcache - write destination through cpu cache 829abd08d7dSDan Williams * @addr: destination kernel address 830abd08d7dSDan Williams * @bytes: total transfer length 831abd08d7dSDan Williams * @iter: source iterator 832abd08d7dSDan Williams * 833abd08d7dSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 834abd08d7dSDan Williams * dax_copy_from_iter() for ensuring that writes to persistent memory 835abd08d7dSDan Williams * are flushed through the CPU cache. It is differentiated from 836abd08d7dSDan Williams * _copy_from_iter_nocache() in that guarantees all data is flushed for 837abd08d7dSDan Williams * all iterator types. The _copy_from_iter_nocache() only attempts to 838abd08d7dSDan Williams * bypass the cache for the ITER_IOVEC case, and on some archs may use 839abd08d7dSDan Williams * instructions that strand dirty-data in the cache. 840abd08d7dSDan Williams */ 8416a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 8420aed55afSDan Williams { 8430aed55afSDan Williams char *to = addr; 84400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 8450aed55afSDan Williams WARN_ON(1); 8460aed55afSDan Williams return 0; 8470aed55afSDan Williams } 8480aed55afSDan Williams iterate_and_advance(i, bytes, v, 8490aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 8500aed55afSDan Williams v.iov_base, v.iov_len), 8510aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 8520aed55afSDan Williams v.bv_offset, v.bv_len), 8530aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 8540aed55afSDan Williams v.iov_len) 8550aed55afSDan Williams ) 8560aed55afSDan Williams 8570aed55afSDan Williams return bytes; 8580aed55afSDan Williams } 8596a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 8600aed55afSDan Williams #endif 8610aed55afSDan Williams 862aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 863cbbd26b8SAl Viro { 864cbbd26b8SAl Viro char *to = addr; 86500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 866cbbd26b8SAl Viro WARN_ON(1); 867cbbd26b8SAl Viro return false; 868cbbd26b8SAl Viro } 86933844e66SAl Viro if (unlikely(i->count < bytes)) 870cbbd26b8SAl Viro return false; 871cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 8723f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 873cbbd26b8SAl Viro v.iov_base, v.iov_len)) 874cbbd26b8SAl Viro return false; 875cbbd26b8SAl Viro 0;}), 876cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 877cbbd26b8SAl Viro v.bv_offset, v.bv_len), 878cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 879cbbd26b8SAl Viro ) 880cbbd26b8SAl Viro 881cbbd26b8SAl Viro iov_iter_advance(i, bytes); 882cbbd26b8SAl Viro return true; 883cbbd26b8SAl Viro } 884aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 885cbbd26b8SAl Viro 88672e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 88772e809edSAl Viro { 8886daef95bSEric Dumazet struct page *head; 8896daef95bSEric Dumazet size_t v = n + offset; 8906daef95bSEric Dumazet 8916daef95bSEric Dumazet /* 8926daef95bSEric Dumazet * The general case needs to access the page order in order 8936daef95bSEric Dumazet * to compute the page size. 8946daef95bSEric Dumazet * However, we mostly deal with order-0 pages and thus can 8956daef95bSEric Dumazet * avoid a possible cache line miss for requests that fit all 8966daef95bSEric Dumazet * page orders. 8976daef95bSEric Dumazet */ 8986daef95bSEric Dumazet if (n <= v && v <= PAGE_SIZE) 8996daef95bSEric Dumazet return true; 9006daef95bSEric Dumazet 9016daef95bSEric Dumazet head = compound_head(page); 9026daef95bSEric Dumazet v += (page - head) << PAGE_SHIFT; 903a90bcb86SPetar Penkov 904a50b854eSMatthew Wilcox (Oracle) if (likely(n <= v && v <= (page_size(head)))) 90572e809edSAl Viro return true; 90672e809edSAl Viro WARN_ON(1); 90772e809edSAl Viro return false; 90872e809edSAl Viro } 909d879cb83SAl Viro 910d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 911d879cb83SAl Viro struct iov_iter *i) 912d879cb83SAl Viro { 91372e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 91472e809edSAl Viro return 0; 915d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 916d879cb83SAl Viro void *kaddr = kmap_atomic(page); 917d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 918d879cb83SAl Viro kunmap_atomic(kaddr); 919d879cb83SAl Viro return wanted; 9209ea9ce04SDavid Howells } else if (unlikely(iov_iter_is_discard(i))) 9219ea9ce04SDavid Howells return bytes; 9229ea9ce04SDavid Howells else if (likely(!iov_iter_is_pipe(i))) 923d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 924241699cdSAl Viro else 925241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 926d879cb83SAl Viro } 927d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 928d879cb83SAl Viro 929d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 930d879cb83SAl Viro struct iov_iter *i) 931d879cb83SAl Viro { 93272e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 93372e809edSAl Viro return 0; 9349ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 935241699cdSAl Viro WARN_ON(1); 936241699cdSAl Viro return 0; 937241699cdSAl Viro } 938d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 939d879cb83SAl Viro void *kaddr = kmap_atomic(page); 940aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 941d879cb83SAl Viro kunmap_atomic(kaddr); 942d879cb83SAl Viro return wanted; 943d879cb83SAl Viro } else 944d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 945d879cb83SAl Viro } 946d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 947d879cb83SAl Viro 948241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 949241699cdSAl Viro { 950241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9518cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 9528cefc107SDavid Howells unsigned int i_head; 953241699cdSAl Viro size_t n, off; 954241699cdSAl Viro 955241699cdSAl Viro if (!sanity(i)) 956241699cdSAl Viro return 0; 957241699cdSAl Viro 9588cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 959241699cdSAl Viro if (unlikely(!n)) 960241699cdSAl Viro return 0; 961241699cdSAl Viro 9628cefc107SDavid Howells do { 963241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 9648cefc107SDavid Howells memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); 9658cefc107SDavid Howells i->head = i_head; 966241699cdSAl Viro i->iov_offset = off + chunk; 967241699cdSAl Viro n -= chunk; 9688cefc107SDavid Howells off = 0; 9698cefc107SDavid Howells i_head++; 9708cefc107SDavid Howells } while (n); 971241699cdSAl Viro i->count -= bytes; 972241699cdSAl Viro return bytes; 973241699cdSAl Viro } 974241699cdSAl Viro 975d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 976d879cb83SAl Viro { 97700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 978241699cdSAl Viro return pipe_zero(bytes, i); 979d879cb83SAl Viro iterate_and_advance(i, bytes, v, 98009fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 981d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 982d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 983d879cb83SAl Viro ) 984d879cb83SAl Viro 985d879cb83SAl Viro return bytes; 986d879cb83SAl Viro } 987d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 988d879cb83SAl Viro 989d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 990d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 991d879cb83SAl Viro { 992d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 99372e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 99472e809edSAl Viro kunmap_atomic(kaddr); 99572e809edSAl Viro return 0; 99672e809edSAl Viro } 9979ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 998241699cdSAl Viro kunmap_atomic(kaddr); 999241699cdSAl Viro WARN_ON(1); 1000241699cdSAl Viro return 0; 1001241699cdSAl Viro } 1002d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 100309fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 1004d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 1005d879cb83SAl Viro v.bv_offset, v.bv_len), 1006d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 1007d879cb83SAl Viro ) 1008d879cb83SAl Viro kunmap_atomic(kaddr); 1009d879cb83SAl Viro return bytes; 1010d879cb83SAl Viro } 1011d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 1012d879cb83SAl Viro 1013b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 1014241699cdSAl Viro { 1015241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 10168cefc107SDavid Howells unsigned int p_tail = pipe->tail; 10178cefc107SDavid Howells unsigned int p_head = pipe->head; 10188cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10198cefc107SDavid Howells 10208cefc107SDavid Howells if (!pipe_empty(p_head, p_tail)) { 10218cefc107SDavid Howells struct pipe_buffer *buf; 10228cefc107SDavid Howells unsigned int i_head = i->head; 1023b9dc6f65SAl Viro size_t off = i->iov_offset; 10248cefc107SDavid Howells 1025b9dc6f65SAl Viro if (off) { 10268cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 10278cefc107SDavid Howells buf->len = off - buf->offset; 10288cefc107SDavid Howells i_head++; 1029b9dc6f65SAl Viro } 10308cefc107SDavid Howells while (p_head != i_head) { 10318cefc107SDavid Howells p_head--; 10328cefc107SDavid Howells pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); 1033241699cdSAl Viro } 10348cefc107SDavid Howells 10358cefc107SDavid Howells pipe->head = p_head; 1036241699cdSAl Viro } 1037b9dc6f65SAl Viro } 1038b9dc6f65SAl Viro 1039b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 1040b9dc6f65SAl Viro { 1041b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 1042b9dc6f65SAl Viro if (unlikely(i->count < size)) 1043b9dc6f65SAl Viro size = i->count; 1044b9dc6f65SAl Viro if (size) { 1045b9dc6f65SAl Viro struct pipe_buffer *buf; 10468cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10478cefc107SDavid Howells unsigned int i_head = i->head; 1048b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 10498cefc107SDavid Howells 1050b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 10518cefc107SDavid Howells left += off - pipe->bufs[i_head & p_mask].offset; 1052b9dc6f65SAl Viro while (1) { 10538cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 1054b9dc6f65SAl Viro if (left <= buf->len) 1055b9dc6f65SAl Viro break; 1056b9dc6f65SAl Viro left -= buf->len; 10578cefc107SDavid Howells i_head++; 1058b9dc6f65SAl Viro } 10598cefc107SDavid Howells i->head = i_head; 1060b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 1061b9dc6f65SAl Viro } 1062b9dc6f65SAl Viro i->count -= size; 1063b9dc6f65SAl Viro /* ... and discard everything past that point */ 1064b9dc6f65SAl Viro pipe_truncate(i); 1065241699cdSAl Viro } 1066241699cdSAl Viro 1067d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 1068d879cb83SAl Viro { 106900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1070241699cdSAl Viro pipe_advance(i, size); 1071241699cdSAl Viro return; 1072241699cdSAl Viro } 10739ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) { 10749ea9ce04SDavid Howells i->count -= size; 10759ea9ce04SDavid Howells return; 10769ea9ce04SDavid Howells } 1077d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 1078d879cb83SAl Viro } 1079d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 1080d879cb83SAl Viro 108127c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 108227c0e374SAl Viro { 108327c0e374SAl Viro if (!unroll) 108427c0e374SAl Viro return; 10855b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 10865b47d59aSAl Viro return; 108727c0e374SAl Viro i->count += unroll; 108800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 108927c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 10908cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10918cefc107SDavid Howells unsigned int i_head = i->head; 109227c0e374SAl Viro size_t off = i->iov_offset; 109327c0e374SAl Viro while (1) { 10948cefc107SDavid Howells struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; 10958cefc107SDavid Howells size_t n = off - b->offset; 109627c0e374SAl Viro if (unroll < n) { 10974fa55cefSAl Viro off -= unroll; 109827c0e374SAl Viro break; 109927c0e374SAl Viro } 110027c0e374SAl Viro unroll -= n; 11018cefc107SDavid Howells if (!unroll && i_head == i->start_head) { 110227c0e374SAl Viro off = 0; 110327c0e374SAl Viro break; 110427c0e374SAl Viro } 11058cefc107SDavid Howells i_head--; 11068cefc107SDavid Howells b = &pipe->bufs[i_head & p_mask]; 11078cefc107SDavid Howells off = b->offset + b->len; 110827c0e374SAl Viro } 110927c0e374SAl Viro i->iov_offset = off; 11108cefc107SDavid Howells i->head = i_head; 111127c0e374SAl Viro pipe_truncate(i); 111227c0e374SAl Viro return; 111327c0e374SAl Viro } 11149ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11159ea9ce04SDavid Howells return; 111627c0e374SAl Viro if (unroll <= i->iov_offset) { 111727c0e374SAl Viro i->iov_offset -= unroll; 111827c0e374SAl Viro return; 111927c0e374SAl Viro } 112027c0e374SAl Viro unroll -= i->iov_offset; 112100e23707SDavid Howells if (iov_iter_is_bvec(i)) { 112227c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 112327c0e374SAl Viro while (1) { 112427c0e374SAl Viro size_t n = (--bvec)->bv_len; 112527c0e374SAl Viro i->nr_segs++; 112627c0e374SAl Viro if (unroll <= n) { 112727c0e374SAl Viro i->bvec = bvec; 112827c0e374SAl Viro i->iov_offset = n - unroll; 112927c0e374SAl Viro return; 113027c0e374SAl Viro } 113127c0e374SAl Viro unroll -= n; 113227c0e374SAl Viro } 113327c0e374SAl Viro } else { /* same logics for iovec and kvec */ 113427c0e374SAl Viro const struct iovec *iov = i->iov; 113527c0e374SAl Viro while (1) { 113627c0e374SAl Viro size_t n = (--iov)->iov_len; 113727c0e374SAl Viro i->nr_segs++; 113827c0e374SAl Viro if (unroll <= n) { 113927c0e374SAl Viro i->iov = iov; 114027c0e374SAl Viro i->iov_offset = n - unroll; 114127c0e374SAl Viro return; 114227c0e374SAl Viro } 114327c0e374SAl Viro unroll -= n; 114427c0e374SAl Viro } 114527c0e374SAl Viro } 114627c0e374SAl Viro } 114727c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 114827c0e374SAl Viro 1149d879cb83SAl Viro /* 1150d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1151d879cb83SAl Viro */ 1152d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1153d879cb83SAl Viro { 115400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1155241699cdSAl Viro return i->count; // it is a silly place, anyway 1156d879cb83SAl Viro if (i->nr_segs == 1) 1157d879cb83SAl Viro return i->count; 11589ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11599ea9ce04SDavid Howells return i->count; 116000e23707SDavid Howells else if (iov_iter_is_bvec(i)) 1161d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1162d879cb83SAl Viro else 1163d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1164d879cb83SAl Viro } 1165d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1166d879cb83SAl Viro 1167aa563d7bSDavid Howells void iov_iter_kvec(struct iov_iter *i, unsigned int direction, 1168d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1169d879cb83SAl Viro size_t count) 1170d879cb83SAl Viro { 1171aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1172aa563d7bSDavid Howells i->type = ITER_KVEC | (direction & (READ | WRITE)); 1173d879cb83SAl Viro i->kvec = kvec; 1174d879cb83SAl Viro i->nr_segs = nr_segs; 1175d879cb83SAl Viro i->iov_offset = 0; 1176d879cb83SAl Viro i->count = count; 1177d879cb83SAl Viro } 1178d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1179d879cb83SAl Viro 1180aa563d7bSDavid Howells void iov_iter_bvec(struct iov_iter *i, unsigned int direction, 1181d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1182d879cb83SAl Viro size_t count) 1183d879cb83SAl Viro { 1184aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1185aa563d7bSDavid Howells i->type = ITER_BVEC | (direction & (READ | WRITE)); 1186d879cb83SAl Viro i->bvec = bvec; 1187d879cb83SAl Viro i->nr_segs = nr_segs; 1188d879cb83SAl Viro i->iov_offset = 0; 1189d879cb83SAl Viro i->count = count; 1190d879cb83SAl Viro } 1191d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1192d879cb83SAl Viro 1193aa563d7bSDavid Howells void iov_iter_pipe(struct iov_iter *i, unsigned int direction, 1194241699cdSAl Viro struct pipe_inode_info *pipe, 1195241699cdSAl Viro size_t count) 1196241699cdSAl Viro { 1197aa563d7bSDavid Howells BUG_ON(direction != READ); 11988cefc107SDavid Howells WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); 1199aa563d7bSDavid Howells i->type = ITER_PIPE | READ; 1200241699cdSAl Viro i->pipe = pipe; 12018cefc107SDavid Howells i->head = pipe->head; 1202241699cdSAl Viro i->iov_offset = 0; 1203241699cdSAl Viro i->count = count; 12048cefc107SDavid Howells i->start_head = i->head; 1205241699cdSAl Viro } 1206241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1207241699cdSAl Viro 12089ea9ce04SDavid Howells /** 12099ea9ce04SDavid Howells * iov_iter_discard - Initialise an I/O iterator that discards data 12109ea9ce04SDavid Howells * @i: The iterator to initialise. 12119ea9ce04SDavid Howells * @direction: The direction of the transfer. 12129ea9ce04SDavid Howells * @count: The size of the I/O buffer in bytes. 12139ea9ce04SDavid Howells * 12149ea9ce04SDavid Howells * Set up an I/O iterator that just discards everything that's written to it. 12159ea9ce04SDavid Howells * It's only available as a READ iterator. 12169ea9ce04SDavid Howells */ 12179ea9ce04SDavid Howells void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) 12189ea9ce04SDavid Howells { 12199ea9ce04SDavid Howells BUG_ON(direction != READ); 12209ea9ce04SDavid Howells i->type = ITER_DISCARD | READ; 12219ea9ce04SDavid Howells i->count = count; 12229ea9ce04SDavid Howells i->iov_offset = 0; 12239ea9ce04SDavid Howells } 12249ea9ce04SDavid Howells EXPORT_SYMBOL(iov_iter_discard); 12259ea9ce04SDavid Howells 1226d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1227d879cb83SAl Viro { 1228d879cb83SAl Viro unsigned long res = 0; 1229d879cb83SAl Viro size_t size = i->count; 1230d879cb83SAl Viro 123100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1232e0ff126eSJan Kara unsigned int p_mask = i->pipe->ring_size - 1; 1233e0ff126eSJan Kara 12348cefc107SDavid Howells if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) 1235241699cdSAl Viro return size | i->iov_offset; 1236241699cdSAl Viro return size; 1237241699cdSAl Viro } 1238d879cb83SAl Viro iterate_all_kinds(i, size, v, 1239d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1240d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1241d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1242d879cb83SAl Viro ) 1243d879cb83SAl Viro return res; 1244d879cb83SAl Viro } 1245d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1246d879cb83SAl Viro 1247357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1248357f435dSAl Viro { 1249357f435dSAl Viro unsigned long res = 0; 1250357f435dSAl Viro size_t size = i->count; 1251357f435dSAl Viro 12529ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1253241699cdSAl Viro WARN_ON(1); 1254241699cdSAl Viro return ~0U; 1255241699cdSAl Viro } 1256241699cdSAl Viro 1257357f435dSAl Viro iterate_all_kinds(i, size, v, 1258357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1259357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1260357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1261357f435dSAl Viro (size != v.bv_len ? size : 0)), 1262357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1263357f435dSAl Viro (size != v.iov_len ? size : 0)) 1264357f435dSAl Viro ); 1265357f435dSAl Viro return res; 1266357f435dSAl Viro } 1267357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1268357f435dSAl Viro 1269e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1270241699cdSAl Viro size_t maxsize, 1271241699cdSAl Viro struct page **pages, 12728cefc107SDavid Howells int iter_head, 1273241699cdSAl Viro size_t *start) 1274241699cdSAl Viro { 1275241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 12768cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 12778cefc107SDavid Howells ssize_t n = push_pipe(i, maxsize, &iter_head, start); 1278241699cdSAl Viro if (!n) 1279241699cdSAl Viro return -EFAULT; 1280241699cdSAl Viro 1281241699cdSAl Viro maxsize = n; 1282241699cdSAl Viro n += *start; 12831689c73aSAl Viro while (n > 0) { 12848cefc107SDavid Howells get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); 12858cefc107SDavid Howells iter_head++; 1286241699cdSAl Viro n -= PAGE_SIZE; 1287241699cdSAl Viro } 1288241699cdSAl Viro 1289241699cdSAl Viro return maxsize; 1290241699cdSAl Viro } 1291241699cdSAl Viro 1292241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1293241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1294241699cdSAl Viro size_t *start) 1295241699cdSAl Viro { 12968cefc107SDavid Howells unsigned int iter_head, npages; 1297241699cdSAl Viro size_t capacity; 1298241699cdSAl Viro 129933844e66SAl Viro if (!maxsize) 130033844e66SAl Viro return 0; 130133844e66SAl Viro 1302241699cdSAl Viro if (!sanity(i)) 1303241699cdSAl Viro return -EFAULT; 1304241699cdSAl Viro 13058cefc107SDavid Howells data_start(i, &iter_head, start); 13068cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13078cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1308241699cdSAl Viro capacity = min(npages, maxpages) * PAGE_SIZE - *start; 1309241699cdSAl Viro 13108cefc107SDavid Howells return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); 1311241699cdSAl Viro } 1312241699cdSAl Viro 1313d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1314d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1315d879cb83SAl Viro size_t *start) 1316d879cb83SAl Viro { 1317d879cb83SAl Viro if (maxsize > i->count) 1318d879cb83SAl Viro maxsize = i->count; 1319d879cb83SAl Viro 132000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1321241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 13229ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 13239ea9ce04SDavid Howells return -EFAULT; 13249ea9ce04SDavid Howells 1325d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1326d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1327d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1328d879cb83SAl Viro int n; 1329d879cb83SAl Viro int res; 1330d879cb83SAl Viro 1331d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1332d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1333d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1334d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 133573b0140bSIra Weiny res = get_user_pages_fast(addr, n, 133673b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, 133773b0140bSIra Weiny pages); 1338d879cb83SAl Viro if (unlikely(res < 0)) 1339d879cb83SAl Viro return res; 1340d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1341d879cb83SAl Viro 0;}),({ 1342d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1343d879cb83SAl Viro *start = v.bv_offset; 1344d879cb83SAl Viro get_page(*pages = v.bv_page); 1345d879cb83SAl Viro return v.bv_len; 1346d879cb83SAl Viro }),({ 1347d879cb83SAl Viro return -EFAULT; 1348d879cb83SAl Viro }) 1349d879cb83SAl Viro ) 1350d879cb83SAl Viro return 0; 1351d879cb83SAl Viro } 1352d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1353d879cb83SAl Viro 1354d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1355d879cb83SAl Viro { 1356752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1357d879cb83SAl Viro } 1358d879cb83SAl Viro 1359241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1360241699cdSAl Viro struct page ***pages, size_t maxsize, 1361241699cdSAl Viro size_t *start) 1362241699cdSAl Viro { 1363241699cdSAl Viro struct page **p; 13648cefc107SDavid Howells unsigned int iter_head, npages; 1365d7760d63SIlya Dryomov ssize_t n; 1366241699cdSAl Viro 136733844e66SAl Viro if (!maxsize) 136833844e66SAl Viro return 0; 136933844e66SAl Viro 1370241699cdSAl Viro if (!sanity(i)) 1371241699cdSAl Viro return -EFAULT; 1372241699cdSAl Viro 13738cefc107SDavid Howells data_start(i, &iter_head, start); 13748cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13758cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1376241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1377241699cdSAl Viro if (maxsize > n) 1378241699cdSAl Viro maxsize = n; 1379241699cdSAl Viro else 1380241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1381241699cdSAl Viro p = get_pages_array(npages); 1382241699cdSAl Viro if (!p) 1383241699cdSAl Viro return -ENOMEM; 13848cefc107SDavid Howells n = __pipe_get_pages(i, maxsize, p, iter_head, start); 1385241699cdSAl Viro if (n > 0) 1386241699cdSAl Viro *pages = p; 1387241699cdSAl Viro else 1388241699cdSAl Viro kvfree(p); 1389241699cdSAl Viro return n; 1390241699cdSAl Viro } 1391241699cdSAl Viro 1392d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1393d879cb83SAl Viro struct page ***pages, size_t maxsize, 1394d879cb83SAl Viro size_t *start) 1395d879cb83SAl Viro { 1396d879cb83SAl Viro struct page **p; 1397d879cb83SAl Viro 1398d879cb83SAl Viro if (maxsize > i->count) 1399d879cb83SAl Viro maxsize = i->count; 1400d879cb83SAl Viro 140100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1402241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 14039ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 14049ea9ce04SDavid Howells return -EFAULT; 14059ea9ce04SDavid Howells 1406d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1407d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1408d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1409d879cb83SAl Viro int n; 1410d879cb83SAl Viro int res; 1411d879cb83SAl Viro 1412d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1413d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1414d879cb83SAl Viro p = get_pages_array(n); 1415d879cb83SAl Viro if (!p) 1416d879cb83SAl Viro return -ENOMEM; 141773b0140bSIra Weiny res = get_user_pages_fast(addr, n, 141873b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); 1419d879cb83SAl Viro if (unlikely(res < 0)) { 1420d879cb83SAl Viro kvfree(p); 1421d879cb83SAl Viro return res; 1422d879cb83SAl Viro } 1423d879cb83SAl Viro *pages = p; 1424d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1425d879cb83SAl Viro 0;}),({ 1426d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1427d879cb83SAl Viro *start = v.bv_offset; 1428d879cb83SAl Viro *pages = p = get_pages_array(1); 1429d879cb83SAl Viro if (!p) 1430d879cb83SAl Viro return -ENOMEM; 1431d879cb83SAl Viro get_page(*p = v.bv_page); 1432d879cb83SAl Viro return v.bv_len; 1433d879cb83SAl Viro }),({ 1434d879cb83SAl Viro return -EFAULT; 1435d879cb83SAl Viro }) 1436d879cb83SAl Viro ) 1437d879cb83SAl Viro return 0; 1438d879cb83SAl Viro } 1439d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1440d879cb83SAl Viro 1441d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1442d879cb83SAl Viro struct iov_iter *i) 1443d879cb83SAl Viro { 1444d879cb83SAl Viro char *to = addr; 1445d879cb83SAl Viro __wsum sum, next; 1446d879cb83SAl Viro size_t off = 0; 1447d879cb83SAl Viro sum = *csum; 14489ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1449241699cdSAl Viro WARN_ON(1); 1450241699cdSAl Viro return 0; 1451241699cdSAl Viro } 1452d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1453d879cb83SAl Viro int err = 0; 1454d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1455d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1456d879cb83SAl Viro v.iov_len, 0, &err); 1457d879cb83SAl Viro if (!err) { 1458d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1459d879cb83SAl Viro off += v.iov_len; 1460d879cb83SAl Viro } 1461d879cb83SAl Viro err ? v.iov_len : 0; 1462d879cb83SAl Viro }), ({ 1463d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1464f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1465f9152895SAl Viro p + v.bv_offset, v.bv_len, 1466f9152895SAl Viro sum, off); 1467d879cb83SAl Viro kunmap_atomic(p); 1468d879cb83SAl Viro off += v.bv_len; 1469d879cb83SAl Viro }),({ 1470f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1471f9152895SAl Viro v.iov_base, v.iov_len, 1472f9152895SAl Viro sum, off); 1473d879cb83SAl Viro off += v.iov_len; 1474d879cb83SAl Viro }) 1475d879cb83SAl Viro ) 1476d879cb83SAl Viro *csum = sum; 1477d879cb83SAl Viro return bytes; 1478d879cb83SAl Viro } 1479d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1480d879cb83SAl Viro 1481cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1482cbbd26b8SAl Viro struct iov_iter *i) 1483cbbd26b8SAl Viro { 1484cbbd26b8SAl Viro char *to = addr; 1485cbbd26b8SAl Viro __wsum sum, next; 1486cbbd26b8SAl Viro size_t off = 0; 1487cbbd26b8SAl Viro sum = *csum; 14889ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1489cbbd26b8SAl Viro WARN_ON(1); 1490cbbd26b8SAl Viro return false; 1491cbbd26b8SAl Viro } 1492cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1493cbbd26b8SAl Viro return false; 1494cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1495cbbd26b8SAl Viro int err = 0; 1496cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1497cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1498cbbd26b8SAl Viro v.iov_len, 0, &err); 1499cbbd26b8SAl Viro if (err) 1500cbbd26b8SAl Viro return false; 1501cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1502cbbd26b8SAl Viro off += v.iov_len; 1503cbbd26b8SAl Viro 0; 1504cbbd26b8SAl Viro }), ({ 1505cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1506f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1507f9152895SAl Viro p + v.bv_offset, v.bv_len, 1508f9152895SAl Viro sum, off); 1509cbbd26b8SAl Viro kunmap_atomic(p); 1510cbbd26b8SAl Viro off += v.bv_len; 1511cbbd26b8SAl Viro }),({ 1512f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1513f9152895SAl Viro v.iov_base, v.iov_len, 1514f9152895SAl Viro sum, off); 1515cbbd26b8SAl Viro off += v.iov_len; 1516cbbd26b8SAl Viro }) 1517cbbd26b8SAl Viro ) 1518cbbd26b8SAl Viro *csum = sum; 1519cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1520cbbd26b8SAl Viro return true; 1521cbbd26b8SAl Viro } 1522cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1523cbbd26b8SAl Viro 1524cb002d07SSagi Grimberg size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, 1525d879cb83SAl Viro struct iov_iter *i) 1526d879cb83SAl Viro { 152736f7a8a4SAl Viro const char *from = addr; 1528cb002d07SSagi Grimberg __wsum *csum = csump; 1529d879cb83SAl Viro __wsum sum, next; 1530d879cb83SAl Viro size_t off = 0; 153178e1f386SAl Viro 153278e1f386SAl Viro if (unlikely(iov_iter_is_pipe(i))) 153378e1f386SAl Viro return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); 153478e1f386SAl Viro 1535d879cb83SAl Viro sum = *csum; 153678e1f386SAl Viro if (unlikely(iov_iter_is_discard(i))) { 1537241699cdSAl Viro WARN_ON(1); /* for now */ 1538241699cdSAl Viro return 0; 1539241699cdSAl Viro } 1540d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1541d879cb83SAl Viro int err = 0; 1542d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1543d879cb83SAl Viro v.iov_base, 1544d879cb83SAl Viro v.iov_len, 0, &err); 1545d879cb83SAl Viro if (!err) { 1546d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1547d879cb83SAl Viro off += v.iov_len; 1548d879cb83SAl Viro } 1549d879cb83SAl Viro err ? v.iov_len : 0; 1550d879cb83SAl Viro }), ({ 1551d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1552f9152895SAl Viro sum = csum_and_memcpy(p + v.bv_offset, 1553f9152895SAl Viro (from += v.bv_len) - v.bv_len, 1554f9152895SAl Viro v.bv_len, sum, off); 1555d879cb83SAl Viro kunmap_atomic(p); 1556d879cb83SAl Viro off += v.bv_len; 1557d879cb83SAl Viro }),({ 1558f9152895SAl Viro sum = csum_and_memcpy(v.iov_base, 1559f9152895SAl Viro (from += v.iov_len) - v.iov_len, 1560f9152895SAl Viro v.iov_len, sum, off); 1561d879cb83SAl Viro off += v.iov_len; 1562d879cb83SAl Viro }) 1563d879cb83SAl Viro ) 1564d879cb83SAl Viro *csum = sum; 1565d879cb83SAl Viro return bytes; 1566d879cb83SAl Viro } 1567d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1568d879cb83SAl Viro 1569d05f4435SSagi Grimberg size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, 1570d05f4435SSagi Grimberg struct iov_iter *i) 1571d05f4435SSagi Grimberg { 15727999096fSHerbert Xu #ifdef CONFIG_CRYPTO_HASH 1573d05f4435SSagi Grimberg struct ahash_request *hash = hashp; 1574d05f4435SSagi Grimberg struct scatterlist sg; 1575d05f4435SSagi Grimberg size_t copied; 1576d05f4435SSagi Grimberg 1577d05f4435SSagi Grimberg copied = copy_to_iter(addr, bytes, i); 1578d05f4435SSagi Grimberg sg_init_one(&sg, addr, copied); 1579d05f4435SSagi Grimberg ahash_request_set_crypt(hash, &sg, NULL, copied); 1580d05f4435SSagi Grimberg crypto_ahash_update(hash); 1581d05f4435SSagi Grimberg return copied; 158227fad74aSYueHaibing #else 158327fad74aSYueHaibing return 0; 158427fad74aSYueHaibing #endif 1585d05f4435SSagi Grimberg } 1586d05f4435SSagi Grimberg EXPORT_SYMBOL(hash_and_copy_to_iter); 1587d05f4435SSagi Grimberg 1588d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1589d879cb83SAl Viro { 1590d879cb83SAl Viro size_t size = i->count; 1591d879cb83SAl Viro int npages = 0; 1592d879cb83SAl Viro 1593d879cb83SAl Viro if (!size) 1594d879cb83SAl Viro return 0; 15959ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 15969ea9ce04SDavid Howells return 0; 1597d879cb83SAl Viro 159800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1599241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 16008cefc107SDavid Howells unsigned int iter_head; 1601241699cdSAl Viro size_t off; 1602241699cdSAl Viro 1603241699cdSAl Viro if (!sanity(i)) 1604241699cdSAl Viro return 0; 1605241699cdSAl Viro 16068cefc107SDavid Howells data_start(i, &iter_head, &off); 1607241699cdSAl Viro /* some of this one + all after this one */ 16088cefc107SDavid Howells npages = pipe_space_for_user(iter_head, pipe->tail, pipe); 1609241699cdSAl Viro if (npages >= maxpages) 1610241699cdSAl Viro return maxpages; 1611241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1612d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1613d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1614d879cb83SAl Viro - p / PAGE_SIZE; 1615d879cb83SAl Viro if (npages >= maxpages) 1616d879cb83SAl Viro return maxpages; 1617d879cb83SAl Viro 0;}),({ 1618d879cb83SAl Viro npages++; 1619d879cb83SAl Viro if (npages >= maxpages) 1620d879cb83SAl Viro return maxpages; 1621d879cb83SAl Viro }),({ 1622d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1623d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1624d879cb83SAl Viro - p / PAGE_SIZE; 1625d879cb83SAl Viro if (npages >= maxpages) 1626d879cb83SAl Viro return maxpages; 1627d879cb83SAl Viro }) 1628d879cb83SAl Viro ) 1629d879cb83SAl Viro return npages; 1630d879cb83SAl Viro } 1631d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1632d879cb83SAl Viro 1633d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1634d879cb83SAl Viro { 1635d879cb83SAl Viro *new = *old; 163600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(new))) { 1637241699cdSAl Viro WARN_ON(1); 1638241699cdSAl Viro return NULL; 1639241699cdSAl Viro } 16409ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(new))) 16419ea9ce04SDavid Howells return NULL; 164200e23707SDavid Howells if (iov_iter_is_bvec(new)) 1643d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1644d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1645d879cb83SAl Viro flags); 1646d879cb83SAl Viro else 1647d879cb83SAl Viro /* iovec and kvec have identical layout */ 1648d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1649d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1650d879cb83SAl Viro flags); 1651d879cb83SAl Viro } 1652d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1653bc917be8SAl Viro 1654bfdc5970SChristoph Hellwig static int copy_compat_iovec_from_user(struct iovec *iov, 1655bfdc5970SChristoph Hellwig const struct iovec __user *uvec, unsigned long nr_segs) 1656bfdc5970SChristoph Hellwig { 1657bfdc5970SChristoph Hellwig const struct compat_iovec __user *uiov = 1658bfdc5970SChristoph Hellwig (const struct compat_iovec __user *)uvec; 1659bfdc5970SChristoph Hellwig int ret = -EFAULT, i; 1660bfdc5970SChristoph Hellwig 1661bfdc5970SChristoph Hellwig if (!user_access_begin(uvec, nr_segs * sizeof(*uvec))) 1662bfdc5970SChristoph Hellwig return -EFAULT; 1663bfdc5970SChristoph Hellwig 1664bfdc5970SChristoph Hellwig for (i = 0; i < nr_segs; i++) { 1665bfdc5970SChristoph Hellwig compat_uptr_t buf; 1666bfdc5970SChristoph Hellwig compat_ssize_t len; 1667bfdc5970SChristoph Hellwig 1668bfdc5970SChristoph Hellwig unsafe_get_user(len, &uiov[i].iov_len, uaccess_end); 1669bfdc5970SChristoph Hellwig unsafe_get_user(buf, &uiov[i].iov_base, uaccess_end); 1670bfdc5970SChristoph Hellwig 1671bfdc5970SChristoph Hellwig /* check for compat_size_t not fitting in compat_ssize_t .. */ 1672bfdc5970SChristoph Hellwig if (len < 0) { 1673bfdc5970SChristoph Hellwig ret = -EINVAL; 1674bfdc5970SChristoph Hellwig goto uaccess_end; 1675bfdc5970SChristoph Hellwig } 1676bfdc5970SChristoph Hellwig iov[i].iov_base = compat_ptr(buf); 1677bfdc5970SChristoph Hellwig iov[i].iov_len = len; 1678bfdc5970SChristoph Hellwig } 1679bfdc5970SChristoph Hellwig 1680bfdc5970SChristoph Hellwig ret = 0; 1681bfdc5970SChristoph Hellwig uaccess_end: 1682bfdc5970SChristoph Hellwig user_access_end(); 1683bfdc5970SChristoph Hellwig return ret; 1684bfdc5970SChristoph Hellwig } 1685bfdc5970SChristoph Hellwig 1686bfdc5970SChristoph Hellwig static int copy_iovec_from_user(struct iovec *iov, 1687bfdc5970SChristoph Hellwig const struct iovec __user *uvec, unsigned long nr_segs) 1688fb041b59SDavid Laight { 1689fb041b59SDavid Laight unsigned long seg; 1690bfdc5970SChristoph Hellwig 1691bfdc5970SChristoph Hellwig if (copy_from_user(iov, uvec, nr_segs * sizeof(*uvec))) 1692bfdc5970SChristoph Hellwig return -EFAULT; 1693bfdc5970SChristoph Hellwig for (seg = 0; seg < nr_segs; seg++) { 1694bfdc5970SChristoph Hellwig if ((ssize_t)iov[seg].iov_len < 0) 1695bfdc5970SChristoph Hellwig return -EINVAL; 1696bfdc5970SChristoph Hellwig } 1697bfdc5970SChristoph Hellwig 1698bfdc5970SChristoph Hellwig return 0; 1699bfdc5970SChristoph Hellwig } 1700bfdc5970SChristoph Hellwig 1701bfdc5970SChristoph Hellwig struct iovec *iovec_from_user(const struct iovec __user *uvec, 1702bfdc5970SChristoph Hellwig unsigned long nr_segs, unsigned long fast_segs, 1703bfdc5970SChristoph Hellwig struct iovec *fast_iov, bool compat) 1704bfdc5970SChristoph Hellwig { 1705bfdc5970SChristoph Hellwig struct iovec *iov = fast_iov; 1706bfdc5970SChristoph Hellwig int ret; 1707fb041b59SDavid Laight 1708fb041b59SDavid Laight /* 1709bfdc5970SChristoph Hellwig * SuS says "The readv() function *may* fail if the iovcnt argument was 1710bfdc5970SChristoph Hellwig * less than or equal to 0, or greater than {IOV_MAX}. Linux has 1711fb041b59SDavid Laight * traditionally returned zero for zero segments, so... 1712fb041b59SDavid Laight */ 1713bfdc5970SChristoph Hellwig if (nr_segs == 0) 1714bfdc5970SChristoph Hellwig return iov; 1715bfdc5970SChristoph Hellwig if (nr_segs > UIO_MAXIOV) 1716bfdc5970SChristoph Hellwig return ERR_PTR(-EINVAL); 1717fb041b59SDavid Laight if (nr_segs > fast_segs) { 1718fb041b59SDavid Laight iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); 1719bfdc5970SChristoph Hellwig if (!iov) 1720bfdc5970SChristoph Hellwig return ERR_PTR(-ENOMEM); 1721fb041b59SDavid Laight } 1722bfdc5970SChristoph Hellwig 1723bfdc5970SChristoph Hellwig if (compat) 1724bfdc5970SChristoph Hellwig ret = copy_compat_iovec_from_user(iov, uvec, nr_segs); 1725bfdc5970SChristoph Hellwig else 1726bfdc5970SChristoph Hellwig ret = copy_iovec_from_user(iov, uvec, nr_segs); 1727bfdc5970SChristoph Hellwig if (ret) { 1728bfdc5970SChristoph Hellwig if (iov != fast_iov) 1729bfdc5970SChristoph Hellwig kfree(iov); 1730bfdc5970SChristoph Hellwig return ERR_PTR(ret); 1731fb041b59SDavid Laight } 1732bfdc5970SChristoph Hellwig 1733bfdc5970SChristoph Hellwig return iov; 1734bfdc5970SChristoph Hellwig } 1735bfdc5970SChristoph Hellwig 1736bfdc5970SChristoph Hellwig ssize_t __import_iovec(int type, const struct iovec __user *uvec, 1737bfdc5970SChristoph Hellwig unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, 1738bfdc5970SChristoph Hellwig struct iov_iter *i, bool compat) 1739bfdc5970SChristoph Hellwig { 1740bfdc5970SChristoph Hellwig ssize_t total_len = 0; 1741bfdc5970SChristoph Hellwig unsigned long seg; 1742bfdc5970SChristoph Hellwig struct iovec *iov; 1743bfdc5970SChristoph Hellwig 1744bfdc5970SChristoph Hellwig iov = iovec_from_user(uvec, nr_segs, fast_segs, *iovp, compat); 1745bfdc5970SChristoph Hellwig if (IS_ERR(iov)) { 1746bfdc5970SChristoph Hellwig *iovp = NULL; 1747bfdc5970SChristoph Hellwig return PTR_ERR(iov); 1748fb041b59SDavid Laight } 1749fb041b59SDavid Laight 1750fb041b59SDavid Laight /* 1751bfdc5970SChristoph Hellwig * According to the Single Unix Specification we should return EINVAL if 1752bfdc5970SChristoph Hellwig * an element length is < 0 when cast to ssize_t or if the total length 1753bfdc5970SChristoph Hellwig * would overflow the ssize_t return value of the system call. 1754fb041b59SDavid Laight * 1755fb041b59SDavid Laight * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the 1756fb041b59SDavid Laight * overflow case. 1757fb041b59SDavid Laight */ 1758fb041b59SDavid Laight for (seg = 0; seg < nr_segs; seg++) { 1759fb041b59SDavid Laight ssize_t len = (ssize_t)iov[seg].iov_len; 1760fb041b59SDavid Laight 1761bfdc5970SChristoph Hellwig if (!access_ok(iov[seg].iov_base, len)) { 1762bfdc5970SChristoph Hellwig if (iov != *iovp) 1763bfdc5970SChristoph Hellwig kfree(iov); 1764bfdc5970SChristoph Hellwig *iovp = NULL; 1765bfdc5970SChristoph Hellwig return -EFAULT; 1766fb041b59SDavid Laight } 1767bfdc5970SChristoph Hellwig 1768bfdc5970SChristoph Hellwig if (len > MAX_RW_COUNT - total_len) { 1769bfdc5970SChristoph Hellwig len = MAX_RW_COUNT - total_len; 1770fb041b59SDavid Laight iov[seg].iov_len = len; 1771fb041b59SDavid Laight } 1772bfdc5970SChristoph Hellwig total_len += len; 1773fb041b59SDavid Laight } 1774bfdc5970SChristoph Hellwig 1775bfdc5970SChristoph Hellwig iov_iter_init(i, type, iov, nr_segs, total_len); 1776bfdc5970SChristoph Hellwig if (iov == *iovp) 1777bfdc5970SChristoph Hellwig *iovp = NULL; 1778bfdc5970SChristoph Hellwig else 1779bfdc5970SChristoph Hellwig *iovp = iov; 1780bfdc5970SChristoph Hellwig return total_len; 1781fb041b59SDavid Laight } 1782fb041b59SDavid Laight 1783fb041b59SDavid Laight /** 1784ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1785ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1786ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1787ffecee4fSVegard Nossum * 1788ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1789bfdc5970SChristoph Hellwig * @uvec: Pointer to the userspace array. 1790ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1791ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1792bfdc5970SChristoph Hellwig * @iovp: (input and output parameter) Pointer to pointer to (usually small 1793ffecee4fSVegard Nossum * on-stack) kernel array. 1794ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1795ffecee4fSVegard Nossum * 1796ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1797ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1798ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1799ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1800ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1801ffecee4fSVegard Nossum * returns an error or not). 1802ffecee4fSVegard Nossum * 180387e5e6daSJens Axboe * Return: Negative error code on error, bytes imported on success 1804ffecee4fSVegard Nossum */ 1805bfdc5970SChristoph Hellwig ssize_t import_iovec(int type, const struct iovec __user *uvec, 1806bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1807bfdc5970SChristoph Hellwig struct iovec **iovp, struct iov_iter *i) 1808bc917be8SAl Viro { 180989cd35c5SChristoph Hellwig return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i, 181089cd35c5SChristoph Hellwig in_compat_syscall()); 1811bc917be8SAl Viro } 1812bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1813bc917be8SAl Viro 1814bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1815bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1816bc917be8SAl Viro { 1817bc917be8SAl Viro if (len > MAX_RW_COUNT) 1818bc917be8SAl Viro len = MAX_RW_COUNT; 181996d4f267SLinus Torvalds if (unlikely(!access_ok(buf, len))) 1820bc917be8SAl Viro return -EFAULT; 1821bc917be8SAl Viro 1822bc917be8SAl Viro iov->iov_base = buf; 1823bc917be8SAl Viro iov->iov_len = len; 1824bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1825bc917be8SAl Viro return 0; 1826bc917be8SAl Viro } 1827e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 182809cf698aSAl Viro 182909cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 183009cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 183109cf698aSAl Viro void *context) 183209cf698aSAl Viro { 183309cf698aSAl Viro struct kvec w; 183409cf698aSAl Viro int err = -EINVAL; 183509cf698aSAl Viro if (!bytes) 183609cf698aSAl Viro return 0; 183709cf698aSAl Viro 183809cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 183909cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 184009cf698aSAl Viro w.iov_len = v.bv_len; 184109cf698aSAl Viro err = f(&w, context); 184209cf698aSAl Viro kunmap(v.bv_page); 184309cf698aSAl Viro err;}), ({ 184409cf698aSAl Viro w = v; 184509cf698aSAl Viro err = f(&w, context);}) 184609cf698aSAl Viro ) 184709cf698aSAl Viro return err; 184809cf698aSAl Viro } 184909cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1850