1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 27999096fSHerbert Xu #include <crypto/hash.h> 3d879cb83SAl Viro #include <linux/export.h> 42f8b5444SChristoph Hellwig #include <linux/bvec.h> 5d879cb83SAl Viro #include <linux/uio.h> 6d879cb83SAl Viro #include <linux/pagemap.h> 7d879cb83SAl Viro #include <linux/slab.h> 8d879cb83SAl Viro #include <linux/vmalloc.h> 9241699cdSAl Viro #include <linux/splice.h> 10d879cb83SAl Viro #include <net/checksum.h> 11d05f4435SSagi Grimberg #include <linux/scatterlist.h> 12d0ef4c36SMarco Elver #include <linux/instrumented.h> 13d879cb83SAl Viro 14241699cdSAl Viro #define PIPE_PARANOIA /* for now */ 15241699cdSAl Viro 16d879cb83SAl Viro #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ 17d879cb83SAl Viro size_t left; \ 18d879cb83SAl Viro size_t wanted = n; \ 19d879cb83SAl Viro __p = i->iov; \ 20d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 21d879cb83SAl Viro if (likely(__v.iov_len)) { \ 22d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 23d879cb83SAl Viro left = (STEP); \ 24d879cb83SAl Viro __v.iov_len -= left; \ 25d879cb83SAl Viro skip += __v.iov_len; \ 26d879cb83SAl Viro n -= __v.iov_len; \ 27d879cb83SAl Viro } else { \ 28d879cb83SAl Viro left = 0; \ 29d879cb83SAl Viro } \ 30d879cb83SAl Viro while (unlikely(!left && n)) { \ 31d879cb83SAl Viro __p++; \ 32d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 33d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 34d879cb83SAl Viro continue; \ 35d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 36d879cb83SAl Viro left = (STEP); \ 37d879cb83SAl Viro __v.iov_len -= left; \ 38d879cb83SAl Viro skip = __v.iov_len; \ 39d879cb83SAl Viro n -= __v.iov_len; \ 40d879cb83SAl Viro } \ 41d879cb83SAl Viro n = wanted - n; \ 42d879cb83SAl Viro } 43d879cb83SAl Viro 44d879cb83SAl Viro #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ 45d879cb83SAl Viro size_t wanted = n; \ 46d879cb83SAl Viro __p = i->kvec; \ 47d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 48d879cb83SAl Viro if (likely(__v.iov_len)) { \ 49d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 50d879cb83SAl Viro (void)(STEP); \ 51d879cb83SAl Viro skip += __v.iov_len; \ 52d879cb83SAl Viro n -= __v.iov_len; \ 53d879cb83SAl Viro } \ 54d879cb83SAl Viro while (unlikely(n)) { \ 55d879cb83SAl Viro __p++; \ 56d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 57d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 58d879cb83SAl Viro continue; \ 59d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 60d879cb83SAl Viro (void)(STEP); \ 61d879cb83SAl Viro skip = __v.iov_len; \ 62d879cb83SAl Viro n -= __v.iov_len; \ 63d879cb83SAl Viro } \ 64d879cb83SAl Viro n = wanted; \ 65d879cb83SAl Viro } 66d879cb83SAl Viro 671bdc76aeSMing Lei #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ 681bdc76aeSMing Lei struct bvec_iter __start; \ 691bdc76aeSMing Lei __start.bi_size = n; \ 701bdc76aeSMing Lei __start.bi_bvec_done = skip; \ 711bdc76aeSMing Lei __start.bi_idx = 0; \ 721bdc76aeSMing Lei for_each_bvec(__v, i->bvec, __bi, __start) { \ 731bdc76aeSMing Lei if (!__v.bv_len) \ 74d879cb83SAl Viro continue; \ 75d879cb83SAl Viro (void)(STEP); \ 76d879cb83SAl Viro } \ 77d879cb83SAl Viro } 78d879cb83SAl Viro 79d879cb83SAl Viro #define iterate_all_kinds(i, n, v, I, B, K) { \ 8033844e66SAl Viro if (likely(n)) { \ 81d879cb83SAl Viro size_t skip = i->iov_offset; \ 82d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 83d879cb83SAl Viro struct bio_vec v; \ 841bdc76aeSMing Lei struct bvec_iter __bi; \ 851bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 86d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 87d879cb83SAl Viro const struct kvec *kvec; \ 88d879cb83SAl Viro struct kvec v; \ 89d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 909ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 91d879cb83SAl Viro } else { \ 92d879cb83SAl Viro const struct iovec *iov; \ 93d879cb83SAl Viro struct iovec v; \ 94d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 95d879cb83SAl Viro } \ 9633844e66SAl Viro } \ 97d879cb83SAl Viro } 98d879cb83SAl Viro 99d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 100dd254f5aSAl Viro if (unlikely(i->count < n)) \ 101dd254f5aSAl Viro n = i->count; \ 10219f18459SAl Viro if (i->count) { \ 103d879cb83SAl Viro size_t skip = i->iov_offset; \ 104d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 1051bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 106d879cb83SAl Viro struct bio_vec v; \ 1071bdc76aeSMing Lei struct bvec_iter __bi; \ 1081bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1091bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1101bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1111bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 112d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 113d879cb83SAl Viro const struct kvec *kvec; \ 114d879cb83SAl Viro struct kvec v; \ 115d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 116d879cb83SAl Viro if (skip == kvec->iov_len) { \ 117d879cb83SAl Viro kvec++; \ 118d879cb83SAl Viro skip = 0; \ 119d879cb83SAl Viro } \ 120d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 121d879cb83SAl Viro i->kvec = kvec; \ 1229ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 1239ea9ce04SDavid Howells skip += n; \ 124d879cb83SAl Viro } else { \ 125d879cb83SAl Viro const struct iovec *iov; \ 126d879cb83SAl Viro struct iovec v; \ 127d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 128d879cb83SAl Viro if (skip == iov->iov_len) { \ 129d879cb83SAl Viro iov++; \ 130d879cb83SAl Viro skip = 0; \ 131d879cb83SAl Viro } \ 132d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 133d879cb83SAl Viro i->iov = iov; \ 134d879cb83SAl Viro } \ 135d879cb83SAl Viro i->count -= n; \ 136d879cb83SAl Viro i->iov_offset = skip; \ 137dd254f5aSAl Viro } \ 138d879cb83SAl Viro } 139d879cb83SAl Viro 14009fc68dcSAl Viro static int copyout(void __user *to, const void *from, size_t n) 14109fc68dcSAl Viro { 14296d4f267SLinus Torvalds if (access_ok(to, n)) { 143d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 14409fc68dcSAl Viro n = raw_copy_to_user(to, from, n); 14509fc68dcSAl Viro } 14609fc68dcSAl Viro return n; 14709fc68dcSAl Viro } 14809fc68dcSAl Viro 14909fc68dcSAl Viro static int copyin(void *to, const void __user *from, size_t n) 15009fc68dcSAl Viro { 15196d4f267SLinus Torvalds if (access_ok(from, n)) { 152d0ef4c36SMarco Elver instrument_copy_from_user(to, from, n); 15309fc68dcSAl Viro n = raw_copy_from_user(to, from, n); 15409fc68dcSAl Viro } 15509fc68dcSAl Viro return n; 15609fc68dcSAl Viro } 15709fc68dcSAl Viro 158d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 159d879cb83SAl Viro struct iov_iter *i) 160d879cb83SAl Viro { 161d879cb83SAl Viro size_t skip, copy, left, wanted; 162d879cb83SAl Viro const struct iovec *iov; 163d879cb83SAl Viro char __user *buf; 164d879cb83SAl Viro void *kaddr, *from; 165d879cb83SAl Viro 166d879cb83SAl Viro if (unlikely(bytes > i->count)) 167d879cb83SAl Viro bytes = i->count; 168d879cb83SAl Viro 169d879cb83SAl Viro if (unlikely(!bytes)) 170d879cb83SAl Viro return 0; 171d879cb83SAl Viro 17209fc68dcSAl Viro might_fault(); 173d879cb83SAl Viro wanted = bytes; 174d879cb83SAl Viro iov = i->iov; 175d879cb83SAl Viro skip = i->iov_offset; 176d879cb83SAl Viro buf = iov->iov_base + skip; 177d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 178d879cb83SAl Viro 1793fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 180d879cb83SAl Viro kaddr = kmap_atomic(page); 181d879cb83SAl Viro from = kaddr + offset; 182d879cb83SAl Viro 183d879cb83SAl Viro /* first chunk, usually the only one */ 18409fc68dcSAl Viro left = copyout(buf, from, copy); 185d879cb83SAl Viro copy -= left; 186d879cb83SAl Viro skip += copy; 187d879cb83SAl Viro from += copy; 188d879cb83SAl Viro bytes -= copy; 189d879cb83SAl Viro 190d879cb83SAl Viro while (unlikely(!left && bytes)) { 191d879cb83SAl Viro iov++; 192d879cb83SAl Viro buf = iov->iov_base; 193d879cb83SAl Viro copy = min(bytes, iov->iov_len); 19409fc68dcSAl Viro left = copyout(buf, from, copy); 195d879cb83SAl Viro copy -= left; 196d879cb83SAl Viro skip = copy; 197d879cb83SAl Viro from += copy; 198d879cb83SAl Viro bytes -= copy; 199d879cb83SAl Viro } 200d879cb83SAl Viro if (likely(!bytes)) { 201d879cb83SAl Viro kunmap_atomic(kaddr); 202d879cb83SAl Viro goto done; 203d879cb83SAl Viro } 204d879cb83SAl Viro offset = from - kaddr; 205d879cb83SAl Viro buf += copy; 206d879cb83SAl Viro kunmap_atomic(kaddr); 207d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 208d879cb83SAl Viro } 209d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2103fa6c507SMikulas Patocka 211d879cb83SAl Viro kaddr = kmap(page); 212d879cb83SAl Viro from = kaddr + offset; 21309fc68dcSAl Viro left = copyout(buf, from, copy); 214d879cb83SAl Viro copy -= left; 215d879cb83SAl Viro skip += copy; 216d879cb83SAl Viro from += copy; 217d879cb83SAl Viro bytes -= copy; 218d879cb83SAl Viro while (unlikely(!left && bytes)) { 219d879cb83SAl Viro iov++; 220d879cb83SAl Viro buf = iov->iov_base; 221d879cb83SAl Viro copy = min(bytes, iov->iov_len); 22209fc68dcSAl Viro left = copyout(buf, from, copy); 223d879cb83SAl Viro copy -= left; 224d879cb83SAl Viro skip = copy; 225d879cb83SAl Viro from += copy; 226d879cb83SAl Viro bytes -= copy; 227d879cb83SAl Viro } 228d879cb83SAl Viro kunmap(page); 2293fa6c507SMikulas Patocka 230d879cb83SAl Viro done: 231d879cb83SAl Viro if (skip == iov->iov_len) { 232d879cb83SAl Viro iov++; 233d879cb83SAl Viro skip = 0; 234d879cb83SAl Viro } 235d879cb83SAl Viro i->count -= wanted - bytes; 236d879cb83SAl Viro i->nr_segs -= iov - i->iov; 237d879cb83SAl Viro i->iov = iov; 238d879cb83SAl Viro i->iov_offset = skip; 239d879cb83SAl Viro return wanted - bytes; 240d879cb83SAl Viro } 241d879cb83SAl Viro 242d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 243d879cb83SAl Viro struct iov_iter *i) 244d879cb83SAl Viro { 245d879cb83SAl Viro size_t skip, copy, left, wanted; 246d879cb83SAl Viro const struct iovec *iov; 247d879cb83SAl Viro char __user *buf; 248d879cb83SAl Viro void *kaddr, *to; 249d879cb83SAl Viro 250d879cb83SAl Viro if (unlikely(bytes > i->count)) 251d879cb83SAl Viro bytes = i->count; 252d879cb83SAl Viro 253d879cb83SAl Viro if (unlikely(!bytes)) 254d879cb83SAl Viro return 0; 255d879cb83SAl Viro 25609fc68dcSAl Viro might_fault(); 257d879cb83SAl Viro wanted = bytes; 258d879cb83SAl Viro iov = i->iov; 259d879cb83SAl Viro skip = i->iov_offset; 260d879cb83SAl Viro buf = iov->iov_base + skip; 261d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 262d879cb83SAl Viro 2633fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 264d879cb83SAl Viro kaddr = kmap_atomic(page); 265d879cb83SAl Viro to = kaddr + offset; 266d879cb83SAl Viro 267d879cb83SAl Viro /* first chunk, usually the only one */ 26809fc68dcSAl Viro left = copyin(to, buf, copy); 269d879cb83SAl Viro copy -= left; 270d879cb83SAl Viro skip += copy; 271d879cb83SAl Viro to += copy; 272d879cb83SAl Viro bytes -= copy; 273d879cb83SAl Viro 274d879cb83SAl Viro while (unlikely(!left && bytes)) { 275d879cb83SAl Viro iov++; 276d879cb83SAl Viro buf = iov->iov_base; 277d879cb83SAl Viro copy = min(bytes, iov->iov_len); 27809fc68dcSAl Viro left = copyin(to, buf, copy); 279d879cb83SAl Viro copy -= left; 280d879cb83SAl Viro skip = copy; 281d879cb83SAl Viro to += copy; 282d879cb83SAl Viro bytes -= copy; 283d879cb83SAl Viro } 284d879cb83SAl Viro if (likely(!bytes)) { 285d879cb83SAl Viro kunmap_atomic(kaddr); 286d879cb83SAl Viro goto done; 287d879cb83SAl Viro } 288d879cb83SAl Viro offset = to - kaddr; 289d879cb83SAl Viro buf += copy; 290d879cb83SAl Viro kunmap_atomic(kaddr); 291d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 292d879cb83SAl Viro } 293d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2943fa6c507SMikulas Patocka 295d879cb83SAl Viro kaddr = kmap(page); 296d879cb83SAl Viro to = kaddr + offset; 29709fc68dcSAl Viro left = copyin(to, buf, copy); 298d879cb83SAl Viro copy -= left; 299d879cb83SAl Viro skip += copy; 300d879cb83SAl Viro to += copy; 301d879cb83SAl Viro bytes -= copy; 302d879cb83SAl Viro while (unlikely(!left && bytes)) { 303d879cb83SAl Viro iov++; 304d879cb83SAl Viro buf = iov->iov_base; 305d879cb83SAl Viro copy = min(bytes, iov->iov_len); 30609fc68dcSAl Viro left = copyin(to, buf, copy); 307d879cb83SAl Viro copy -= left; 308d879cb83SAl Viro skip = copy; 309d879cb83SAl Viro to += copy; 310d879cb83SAl Viro bytes -= copy; 311d879cb83SAl Viro } 312d879cb83SAl Viro kunmap(page); 3133fa6c507SMikulas Patocka 314d879cb83SAl Viro done: 315d879cb83SAl Viro if (skip == iov->iov_len) { 316d879cb83SAl Viro iov++; 317d879cb83SAl Viro skip = 0; 318d879cb83SAl Viro } 319d879cb83SAl Viro i->count -= wanted - bytes; 320d879cb83SAl Viro i->nr_segs -= iov - i->iov; 321d879cb83SAl Viro i->iov = iov; 322d879cb83SAl Viro i->iov_offset = skip; 323d879cb83SAl Viro return wanted - bytes; 324d879cb83SAl Viro } 325d879cb83SAl Viro 326241699cdSAl Viro #ifdef PIPE_PARANOIA 327241699cdSAl Viro static bool sanity(const struct iov_iter *i) 328241699cdSAl Viro { 329241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 3308cefc107SDavid Howells unsigned int p_head = pipe->head; 3318cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3328cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3338cefc107SDavid Howells unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); 3348cefc107SDavid Howells unsigned int i_head = i->head; 3358cefc107SDavid Howells unsigned int idx; 3368cefc107SDavid Howells 337241699cdSAl Viro if (i->iov_offset) { 338241699cdSAl Viro struct pipe_buffer *p; 3398cefc107SDavid Howells if (unlikely(p_occupancy == 0)) 340241699cdSAl Viro goto Bad; // pipe must be non-empty 3418cefc107SDavid Howells if (unlikely(i_head != p_head - 1)) 342241699cdSAl Viro goto Bad; // must be at the last buffer... 343241699cdSAl Viro 3448cefc107SDavid Howells p = &pipe->bufs[i_head & p_mask]; 345241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 346241699cdSAl Viro goto Bad; // ... at the end of segment 347241699cdSAl Viro } else { 3488cefc107SDavid Howells if (i_head != p_head) 349241699cdSAl Viro goto Bad; // must be right after the last buffer 350241699cdSAl Viro } 351241699cdSAl Viro return true; 352241699cdSAl Viro Bad: 3538cefc107SDavid Howells printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); 3548cefc107SDavid Howells printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", 3558cefc107SDavid Howells p_head, p_tail, pipe->ring_size); 3568cefc107SDavid Howells for (idx = 0; idx < pipe->ring_size; idx++) 357241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 358241699cdSAl Viro pipe->bufs[idx].ops, 359241699cdSAl Viro pipe->bufs[idx].page, 360241699cdSAl Viro pipe->bufs[idx].offset, 361241699cdSAl Viro pipe->bufs[idx].len); 362241699cdSAl Viro WARN_ON(1); 363241699cdSAl Viro return false; 364241699cdSAl Viro } 365241699cdSAl Viro #else 366241699cdSAl Viro #define sanity(i) true 367241699cdSAl Viro #endif 368241699cdSAl Viro 369241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 370241699cdSAl Viro struct iov_iter *i) 371241699cdSAl Viro { 372241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 373241699cdSAl Viro struct pipe_buffer *buf; 3748cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3758cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3768cefc107SDavid Howells unsigned int i_head = i->head; 377241699cdSAl Viro size_t off; 378241699cdSAl Viro 379241699cdSAl Viro if (unlikely(bytes > i->count)) 380241699cdSAl Viro bytes = i->count; 381241699cdSAl Viro 382241699cdSAl Viro if (unlikely(!bytes)) 383241699cdSAl Viro return 0; 384241699cdSAl Viro 385241699cdSAl Viro if (!sanity(i)) 386241699cdSAl Viro return 0; 387241699cdSAl Viro 388241699cdSAl Viro off = i->iov_offset; 3898cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 390241699cdSAl Viro if (off) { 391241699cdSAl Viro if (offset == off && buf->page == page) { 392241699cdSAl Viro /* merge with the last one */ 393241699cdSAl Viro buf->len += bytes; 394241699cdSAl Viro i->iov_offset += bytes; 395241699cdSAl Viro goto out; 396241699cdSAl Viro } 3978cefc107SDavid Howells i_head++; 3988cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 399241699cdSAl Viro } 4006718b6f8SDavid Howells if (pipe_full(i_head, p_tail, pipe->max_usage)) 401241699cdSAl Viro return 0; 4028cefc107SDavid Howells 403241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 4048cefc107SDavid Howells get_page(page); 4058cefc107SDavid Howells buf->page = page; 406241699cdSAl Viro buf->offset = offset; 407241699cdSAl Viro buf->len = bytes; 4088cefc107SDavid Howells 4098cefc107SDavid Howells pipe->head = i_head + 1; 410241699cdSAl Viro i->iov_offset = offset + bytes; 4118cefc107SDavid Howells i->head = i_head; 412241699cdSAl Viro out: 413241699cdSAl Viro i->count -= bytes; 414241699cdSAl Viro return bytes; 415241699cdSAl Viro } 416241699cdSAl Viro 417d879cb83SAl Viro /* 418171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 419171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 420171a0203SAnton Altaparmakov * 421171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 422171a0203SAnton Altaparmakov * because it is an invalid address). 423171a0203SAnton Altaparmakov */ 424d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 425171a0203SAnton Altaparmakov { 426171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 427171a0203SAnton Altaparmakov const struct iovec *iov; 428171a0203SAnton Altaparmakov int err; 429171a0203SAnton Altaparmakov struct iovec v; 430171a0203SAnton Altaparmakov 431171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 432171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4334bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 434171a0203SAnton Altaparmakov if (unlikely(err)) 435171a0203SAnton Altaparmakov return err; 436171a0203SAnton Altaparmakov 0;})) 437171a0203SAnton Altaparmakov } 438171a0203SAnton Altaparmakov return 0; 439171a0203SAnton Altaparmakov } 440d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 441171a0203SAnton Altaparmakov 442aa563d7bSDavid Howells void iov_iter_init(struct iov_iter *i, unsigned int direction, 443d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 444d879cb83SAl Viro size_t count) 445d879cb83SAl Viro { 446aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 447aa563d7bSDavid Howells direction &= READ | WRITE; 448aa563d7bSDavid Howells 449d879cb83SAl Viro /* It will get better. Eventually... */ 450db68ce10SAl Viro if (uaccess_kernel()) { 451aa563d7bSDavid Howells i->type = ITER_KVEC | direction; 452d879cb83SAl Viro i->kvec = (struct kvec *)iov; 453d879cb83SAl Viro } else { 454aa563d7bSDavid Howells i->type = ITER_IOVEC | direction; 455d879cb83SAl Viro i->iov = iov; 456d879cb83SAl Viro } 457d879cb83SAl Viro i->nr_segs = nr_segs; 458d879cb83SAl Viro i->iov_offset = 0; 459d879cb83SAl Viro i->count = count; 460d879cb83SAl Viro } 461d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 462d879cb83SAl Viro 463d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 464d879cb83SAl Viro { 465d879cb83SAl Viro char *from = kmap_atomic(page); 466d879cb83SAl Viro memcpy(to, from + offset, len); 467d879cb83SAl Viro kunmap_atomic(from); 468d879cb83SAl Viro } 469d879cb83SAl Viro 47036f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 471d879cb83SAl Viro { 472d879cb83SAl Viro char *to = kmap_atomic(page); 473d879cb83SAl Viro memcpy(to + offset, from, len); 474d879cb83SAl Viro kunmap_atomic(to); 475d879cb83SAl Viro } 476d879cb83SAl Viro 477d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 478d879cb83SAl Viro { 479d879cb83SAl Viro char *addr = kmap_atomic(page); 480d879cb83SAl Viro memset(addr + offset, 0, len); 481d879cb83SAl Viro kunmap_atomic(addr); 482d879cb83SAl Viro } 483d879cb83SAl Viro 484241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 485241699cdSAl Viro { 486241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 487241699cdSAl Viro } 488241699cdSAl Viro 4898cefc107SDavid Howells static inline void data_start(const struct iov_iter *i, 4908cefc107SDavid Howells unsigned int *iter_headp, size_t *offp) 491241699cdSAl Viro { 4928cefc107SDavid Howells unsigned int p_mask = i->pipe->ring_size - 1; 4938cefc107SDavid Howells unsigned int iter_head = i->head; 494241699cdSAl Viro size_t off = i->iov_offset; 4958cefc107SDavid Howells 4968cefc107SDavid Howells if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || 4978cefc107SDavid Howells off == PAGE_SIZE)) { 4988cefc107SDavid Howells iter_head++; 499241699cdSAl Viro off = 0; 500241699cdSAl Viro } 5018cefc107SDavid Howells *iter_headp = iter_head; 502241699cdSAl Viro *offp = off; 503241699cdSAl Viro } 504241699cdSAl Viro 505241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 5068cefc107SDavid Howells int *iter_headp, size_t *offp) 507241699cdSAl Viro { 508241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5098cefc107SDavid Howells unsigned int p_tail = pipe->tail; 5108cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5118cefc107SDavid Howells unsigned int iter_head; 512241699cdSAl Viro size_t off; 513241699cdSAl Viro ssize_t left; 514241699cdSAl Viro 515241699cdSAl Viro if (unlikely(size > i->count)) 516241699cdSAl Viro size = i->count; 517241699cdSAl Viro if (unlikely(!size)) 518241699cdSAl Viro return 0; 519241699cdSAl Viro 520241699cdSAl Viro left = size; 5218cefc107SDavid Howells data_start(i, &iter_head, &off); 5228cefc107SDavid Howells *iter_headp = iter_head; 523241699cdSAl Viro *offp = off; 524241699cdSAl Viro if (off) { 525241699cdSAl Viro left -= PAGE_SIZE - off; 526241699cdSAl Viro if (left <= 0) { 5278cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len += size; 528241699cdSAl Viro return size; 529241699cdSAl Viro } 5308cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; 5318cefc107SDavid Howells iter_head++; 532241699cdSAl Viro } 5336718b6f8SDavid Howells while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { 5348cefc107SDavid Howells struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; 535241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 536241699cdSAl Viro if (!page) 537241699cdSAl Viro break; 5388cefc107SDavid Howells 5398cefc107SDavid Howells buf->ops = &default_pipe_buf_ops; 5408cefc107SDavid Howells buf->page = page; 5418cefc107SDavid Howells buf->offset = 0; 5428cefc107SDavid Howells buf->len = min_t(ssize_t, left, PAGE_SIZE); 5438cefc107SDavid Howells left -= buf->len; 5448cefc107SDavid Howells iter_head++; 5458cefc107SDavid Howells pipe->head = iter_head; 5468cefc107SDavid Howells 5478cefc107SDavid Howells if (left == 0) 548241699cdSAl Viro return size; 549241699cdSAl Viro } 550241699cdSAl Viro return size - left; 551241699cdSAl Viro } 552241699cdSAl Viro 553241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 554241699cdSAl Viro struct iov_iter *i) 555241699cdSAl Viro { 556241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5578cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5588cefc107SDavid Howells unsigned int i_head; 559241699cdSAl Viro size_t n, off; 560241699cdSAl Viro 561241699cdSAl Viro if (!sanity(i)) 562241699cdSAl Viro return 0; 563241699cdSAl Viro 5648cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 565241699cdSAl Viro if (unlikely(!n)) 566241699cdSAl Viro return 0; 5678cefc107SDavid Howells do { 568241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 5698cefc107SDavid Howells memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); 5708cefc107SDavid Howells i->head = i_head; 571241699cdSAl Viro i->iov_offset = off + chunk; 572241699cdSAl Viro n -= chunk; 573241699cdSAl Viro addr += chunk; 5748cefc107SDavid Howells off = 0; 5758cefc107SDavid Howells i_head++; 5768cefc107SDavid Howells } while (n); 577241699cdSAl Viro i->count -= bytes; 578241699cdSAl Viro return bytes; 579241699cdSAl Viro } 580241699cdSAl Viro 581f9152895SAl Viro static __wsum csum_and_memcpy(void *to, const void *from, size_t len, 582f9152895SAl Viro __wsum sum, size_t off) 583f9152895SAl Viro { 584f9152895SAl Viro __wsum next = csum_partial_copy_nocheck(from, to, len, 0); 585f9152895SAl Viro return csum_block_add(sum, next, off); 586f9152895SAl Viro } 587f9152895SAl Viro 58878e1f386SAl Viro static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 58978e1f386SAl Viro __wsum *csum, struct iov_iter *i) 59078e1f386SAl Viro { 59178e1f386SAl Viro struct pipe_inode_info *pipe = i->pipe; 5928cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5938cefc107SDavid Howells unsigned int i_head; 59478e1f386SAl Viro size_t n, r; 59578e1f386SAl Viro size_t off = 0; 596f9152895SAl Viro __wsum sum = *csum; 59778e1f386SAl Viro 59878e1f386SAl Viro if (!sanity(i)) 59978e1f386SAl Viro return 0; 60078e1f386SAl Viro 6018cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &r); 60278e1f386SAl Viro if (unlikely(!n)) 60378e1f386SAl Viro return 0; 6048cefc107SDavid Howells do { 60578e1f386SAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - r); 6068cefc107SDavid Howells char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); 607f9152895SAl Viro sum = csum_and_memcpy(p + r, addr, chunk, sum, off); 60878e1f386SAl Viro kunmap_atomic(p); 6098cefc107SDavid Howells i->head = i_head; 61078e1f386SAl Viro i->iov_offset = r + chunk; 61178e1f386SAl Viro n -= chunk; 61278e1f386SAl Viro off += chunk; 61378e1f386SAl Viro addr += chunk; 6148cefc107SDavid Howells r = 0; 6158cefc107SDavid Howells i_head++; 6168cefc107SDavid Howells } while (n); 61778e1f386SAl Viro i->count -= bytes; 61878e1f386SAl Viro *csum = sum; 61978e1f386SAl Viro return bytes; 62078e1f386SAl Viro } 62178e1f386SAl Viro 622aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 623d879cb83SAl Viro { 62436f7a8a4SAl Viro const char *from = addr; 62500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 626241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 62709fc68dcSAl Viro if (iter_is_iovec(i)) 62809fc68dcSAl Viro might_fault(); 629d879cb83SAl Viro iterate_and_advance(i, bytes, v, 63009fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 631d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 632d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 633d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 634d879cb83SAl Viro ) 635d879cb83SAl Viro 636d879cb83SAl Viro return bytes; 637d879cb83SAl Viro } 638aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 639d879cb83SAl Viro 6408780356eSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE 6418780356eSDan Williams static int copyout_mcsafe(void __user *to, const void *from, size_t n) 6428780356eSDan Williams { 64396d4f267SLinus Torvalds if (access_ok(to, n)) { 644d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 6458780356eSDan Williams n = copy_to_user_mcsafe((__force void *) to, from, n); 6468780356eSDan Williams } 6478780356eSDan Williams return n; 6488780356eSDan Williams } 6498780356eSDan Williams 6508780356eSDan Williams static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, 6518780356eSDan Williams const char *from, size_t len) 6528780356eSDan Williams { 6538780356eSDan Williams unsigned long ret; 6548780356eSDan Williams char *to; 6558780356eSDan Williams 6568780356eSDan Williams to = kmap_atomic(page); 6578780356eSDan Williams ret = memcpy_mcsafe(to + offset, from, len); 6588780356eSDan Williams kunmap_atomic(to); 6598780356eSDan Williams 6608780356eSDan Williams return ret; 6618780356eSDan Williams } 6628780356eSDan Williams 663ca146f6fSDan Williams static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, 664ca146f6fSDan Williams struct iov_iter *i) 665ca146f6fSDan Williams { 666ca146f6fSDan Williams struct pipe_inode_info *pipe = i->pipe; 6678cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 6688cefc107SDavid Howells unsigned int i_head; 669ca146f6fSDan Williams size_t n, off, xfer = 0; 670ca146f6fSDan Williams 671ca146f6fSDan Williams if (!sanity(i)) 672ca146f6fSDan Williams return 0; 673ca146f6fSDan Williams 6748cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 675ca146f6fSDan Williams if (unlikely(!n)) 676ca146f6fSDan Williams return 0; 6778cefc107SDavid Howells do { 678ca146f6fSDan Williams size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 679ca146f6fSDan Williams unsigned long rem; 680ca146f6fSDan Williams 6818cefc107SDavid Howells rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page, 6828cefc107SDavid Howells off, addr, chunk); 6838cefc107SDavid Howells i->head = i_head; 684ca146f6fSDan Williams i->iov_offset = off + chunk - rem; 685ca146f6fSDan Williams xfer += chunk - rem; 686ca146f6fSDan Williams if (rem) 687ca146f6fSDan Williams break; 688ca146f6fSDan Williams n -= chunk; 689ca146f6fSDan Williams addr += chunk; 6908cefc107SDavid Howells off = 0; 6918cefc107SDavid Howells i_head++; 6928cefc107SDavid Howells } while (n); 693ca146f6fSDan Williams i->count -= xfer; 694ca146f6fSDan Williams return xfer; 695ca146f6fSDan Williams } 696ca146f6fSDan Williams 697bf3eeb9bSDan Williams /** 698bf3eeb9bSDan Williams * _copy_to_iter_mcsafe - copy to user with source-read error exception handling 699bf3eeb9bSDan Williams * @addr: source kernel address 700bf3eeb9bSDan Williams * @bytes: total transfer length 701bf3eeb9bSDan Williams * @iter: destination iterator 702bf3eeb9bSDan Williams * 703bf3eeb9bSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 704bf3eeb9bSDan Williams * dax_copy_to_iter() for protecting read/write to persistent memory. 705bf3eeb9bSDan Williams * Unless / until an architecture can guarantee identical performance 706bf3eeb9bSDan Williams * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a 707bf3eeb9bSDan Williams * performance regression to switch more users to the mcsafe version. 708bf3eeb9bSDan Williams * 709bf3eeb9bSDan Williams * Otherwise, the main differences between this and typical _copy_to_iter(). 710bf3eeb9bSDan Williams * 711bf3eeb9bSDan Williams * * Typical tail/residue handling after a fault retries the copy 712bf3eeb9bSDan Williams * byte-by-byte until the fault happens again. Re-triggering machine 713bf3eeb9bSDan Williams * checks is potentially fatal so the implementation uses source 714bf3eeb9bSDan Williams * alignment and poison alignment assumptions to avoid re-triggering 715bf3eeb9bSDan Williams * hardware exceptions. 716bf3eeb9bSDan Williams * 717bf3eeb9bSDan Williams * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. 718bf3eeb9bSDan Williams * Compare to copy_to_iter() where only ITER_IOVEC attempts might return 719bf3eeb9bSDan Williams * a short copy. 720bf3eeb9bSDan Williams * 721bf3eeb9bSDan Williams * See MCSAFE_TEST for self-test. 722bf3eeb9bSDan Williams */ 7238780356eSDan Williams size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) 7248780356eSDan Williams { 7258780356eSDan Williams const char *from = addr; 7268780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 7278780356eSDan Williams 72800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 729ca146f6fSDan Williams return copy_pipe_to_iter_mcsafe(addr, bytes, i); 7308780356eSDan Williams if (iter_is_iovec(i)) 7318780356eSDan Williams might_fault(); 7328780356eSDan Williams iterate_and_advance(i, bytes, v, 7338780356eSDan Williams copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 7348780356eSDan Williams ({ 7358780356eSDan Williams rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, 7368780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 7378780356eSDan Williams if (rem) { 7388780356eSDan Williams curr_addr = (unsigned long) from; 7398780356eSDan Williams bytes = curr_addr - s_addr - rem; 7408780356eSDan Williams return bytes; 7418780356eSDan Williams } 7428780356eSDan Williams }), 7438780356eSDan Williams ({ 7448780356eSDan Williams rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, 7458780356eSDan Williams v.iov_len); 7468780356eSDan Williams if (rem) { 7478780356eSDan Williams curr_addr = (unsigned long) from; 7488780356eSDan Williams bytes = curr_addr - s_addr - rem; 7498780356eSDan Williams return bytes; 7508780356eSDan Williams } 7518780356eSDan Williams }) 7528780356eSDan Williams ) 7538780356eSDan Williams 7548780356eSDan Williams return bytes; 7558780356eSDan Williams } 7568780356eSDan Williams EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); 7578780356eSDan Williams #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ 7588780356eSDan Williams 759aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 760d879cb83SAl Viro { 761d879cb83SAl Viro char *to = addr; 76200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 763241699cdSAl Viro WARN_ON(1); 764241699cdSAl Viro return 0; 765241699cdSAl Viro } 76609fc68dcSAl Viro if (iter_is_iovec(i)) 76709fc68dcSAl Viro might_fault(); 768d879cb83SAl Viro iterate_and_advance(i, bytes, v, 76909fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 770d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 771d879cb83SAl Viro v.bv_offset, v.bv_len), 772d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 773d879cb83SAl Viro ) 774d879cb83SAl Viro 775d879cb83SAl Viro return bytes; 776d879cb83SAl Viro } 777aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 778d879cb83SAl Viro 779aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 780cbbd26b8SAl Viro { 781cbbd26b8SAl Viro char *to = addr; 78200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 783cbbd26b8SAl Viro WARN_ON(1); 784cbbd26b8SAl Viro return false; 785cbbd26b8SAl Viro } 78633844e66SAl Viro if (unlikely(i->count < bytes)) 787cbbd26b8SAl Viro return false; 788cbbd26b8SAl Viro 78909fc68dcSAl Viro if (iter_is_iovec(i)) 79009fc68dcSAl Viro might_fault(); 791cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 79209fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 793cbbd26b8SAl Viro v.iov_base, v.iov_len)) 794cbbd26b8SAl Viro return false; 795cbbd26b8SAl Viro 0;}), 796cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 797cbbd26b8SAl Viro v.bv_offset, v.bv_len), 798cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 799cbbd26b8SAl Viro ) 800cbbd26b8SAl Viro 801cbbd26b8SAl Viro iov_iter_advance(i, bytes); 802cbbd26b8SAl Viro return true; 803cbbd26b8SAl Viro } 804aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 805cbbd26b8SAl Viro 806aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 807d879cb83SAl Viro { 808d879cb83SAl Viro char *to = addr; 80900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 810241699cdSAl Viro WARN_ON(1); 811241699cdSAl Viro return 0; 812241699cdSAl Viro } 813d879cb83SAl Viro iterate_and_advance(i, bytes, v, 8143f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 815d879cb83SAl Viro v.iov_base, v.iov_len), 816d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 817d879cb83SAl Viro v.bv_offset, v.bv_len), 818d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 819d879cb83SAl Viro ) 820d879cb83SAl Viro 821d879cb83SAl Viro return bytes; 822d879cb83SAl Viro } 823aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 824d879cb83SAl Viro 8250aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 826abd08d7dSDan Williams /** 827abd08d7dSDan Williams * _copy_from_iter_flushcache - write destination through cpu cache 828abd08d7dSDan Williams * @addr: destination kernel address 829abd08d7dSDan Williams * @bytes: total transfer length 830abd08d7dSDan Williams * @iter: source iterator 831abd08d7dSDan Williams * 832abd08d7dSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 833abd08d7dSDan Williams * dax_copy_from_iter() for ensuring that writes to persistent memory 834abd08d7dSDan Williams * are flushed through the CPU cache. It is differentiated from 835abd08d7dSDan Williams * _copy_from_iter_nocache() in that guarantees all data is flushed for 836abd08d7dSDan Williams * all iterator types. The _copy_from_iter_nocache() only attempts to 837abd08d7dSDan Williams * bypass the cache for the ITER_IOVEC case, and on some archs may use 838abd08d7dSDan Williams * instructions that strand dirty-data in the cache. 839abd08d7dSDan Williams */ 8406a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 8410aed55afSDan Williams { 8420aed55afSDan Williams char *to = addr; 84300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 8440aed55afSDan Williams WARN_ON(1); 8450aed55afSDan Williams return 0; 8460aed55afSDan Williams } 8470aed55afSDan Williams iterate_and_advance(i, bytes, v, 8480aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 8490aed55afSDan Williams v.iov_base, v.iov_len), 8500aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 8510aed55afSDan Williams v.bv_offset, v.bv_len), 8520aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 8530aed55afSDan Williams v.iov_len) 8540aed55afSDan Williams ) 8550aed55afSDan Williams 8560aed55afSDan Williams return bytes; 8570aed55afSDan Williams } 8586a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 8590aed55afSDan Williams #endif 8600aed55afSDan Williams 861aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 862cbbd26b8SAl Viro { 863cbbd26b8SAl Viro char *to = addr; 86400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 865cbbd26b8SAl Viro WARN_ON(1); 866cbbd26b8SAl Viro return false; 867cbbd26b8SAl Viro } 86833844e66SAl Viro if (unlikely(i->count < bytes)) 869cbbd26b8SAl Viro return false; 870cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 8713f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 872cbbd26b8SAl Viro v.iov_base, v.iov_len)) 873cbbd26b8SAl Viro return false; 874cbbd26b8SAl Viro 0;}), 875cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 876cbbd26b8SAl Viro v.bv_offset, v.bv_len), 877cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 878cbbd26b8SAl Viro ) 879cbbd26b8SAl Viro 880cbbd26b8SAl Viro iov_iter_advance(i, bytes); 881cbbd26b8SAl Viro return true; 882cbbd26b8SAl Viro } 883aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 884cbbd26b8SAl Viro 88572e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 88672e809edSAl Viro { 8876daef95bSEric Dumazet struct page *head; 8886daef95bSEric Dumazet size_t v = n + offset; 8896daef95bSEric Dumazet 8906daef95bSEric Dumazet /* 8916daef95bSEric Dumazet * The general case needs to access the page order in order 8926daef95bSEric Dumazet * to compute the page size. 8936daef95bSEric Dumazet * However, we mostly deal with order-0 pages and thus can 8946daef95bSEric Dumazet * avoid a possible cache line miss for requests that fit all 8956daef95bSEric Dumazet * page orders. 8966daef95bSEric Dumazet */ 8976daef95bSEric Dumazet if (n <= v && v <= PAGE_SIZE) 8986daef95bSEric Dumazet return true; 8996daef95bSEric Dumazet 9006daef95bSEric Dumazet head = compound_head(page); 9016daef95bSEric Dumazet v += (page - head) << PAGE_SHIFT; 902a90bcb86SPetar Penkov 903a50b854eSMatthew Wilcox (Oracle) if (likely(n <= v && v <= (page_size(head)))) 90472e809edSAl Viro return true; 90572e809edSAl Viro WARN_ON(1); 90672e809edSAl Viro return false; 90772e809edSAl Viro } 908d879cb83SAl Viro 909d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 910d879cb83SAl Viro struct iov_iter *i) 911d879cb83SAl Viro { 91272e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 91372e809edSAl Viro return 0; 914d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 915d879cb83SAl Viro void *kaddr = kmap_atomic(page); 916d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 917d879cb83SAl Viro kunmap_atomic(kaddr); 918d879cb83SAl Viro return wanted; 9199ea9ce04SDavid Howells } else if (unlikely(iov_iter_is_discard(i))) 9209ea9ce04SDavid Howells return bytes; 9219ea9ce04SDavid Howells else if (likely(!iov_iter_is_pipe(i))) 922d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 923241699cdSAl Viro else 924241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 925d879cb83SAl Viro } 926d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 927d879cb83SAl Viro 928d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 929d879cb83SAl Viro struct iov_iter *i) 930d879cb83SAl Viro { 93172e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 93272e809edSAl Viro return 0; 9339ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 934241699cdSAl Viro WARN_ON(1); 935241699cdSAl Viro return 0; 936241699cdSAl Viro } 937d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 938d879cb83SAl Viro void *kaddr = kmap_atomic(page); 939aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 940d879cb83SAl Viro kunmap_atomic(kaddr); 941d879cb83SAl Viro return wanted; 942d879cb83SAl Viro } else 943d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 944d879cb83SAl Viro } 945d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 946d879cb83SAl Viro 947241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 948241699cdSAl Viro { 949241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9508cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 9518cefc107SDavid Howells unsigned int i_head; 952241699cdSAl Viro size_t n, off; 953241699cdSAl Viro 954241699cdSAl Viro if (!sanity(i)) 955241699cdSAl Viro return 0; 956241699cdSAl Viro 9578cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 958241699cdSAl Viro if (unlikely(!n)) 959241699cdSAl Viro return 0; 960241699cdSAl Viro 9618cefc107SDavid Howells do { 962241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 9638cefc107SDavid Howells memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); 9648cefc107SDavid Howells i->head = i_head; 965241699cdSAl Viro i->iov_offset = off + chunk; 966241699cdSAl Viro n -= chunk; 9678cefc107SDavid Howells off = 0; 9688cefc107SDavid Howells i_head++; 9698cefc107SDavid Howells } while (n); 970241699cdSAl Viro i->count -= bytes; 971241699cdSAl Viro return bytes; 972241699cdSAl Viro } 973241699cdSAl Viro 974d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 975d879cb83SAl Viro { 97600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 977241699cdSAl Viro return pipe_zero(bytes, i); 978d879cb83SAl Viro iterate_and_advance(i, bytes, v, 97909fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 980d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 981d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 982d879cb83SAl Viro ) 983d879cb83SAl Viro 984d879cb83SAl Viro return bytes; 985d879cb83SAl Viro } 986d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 987d879cb83SAl Viro 988d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 989d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 990d879cb83SAl Viro { 991d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 99272e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 99372e809edSAl Viro kunmap_atomic(kaddr); 99472e809edSAl Viro return 0; 99572e809edSAl Viro } 9969ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 997241699cdSAl Viro kunmap_atomic(kaddr); 998241699cdSAl Viro WARN_ON(1); 999241699cdSAl Viro return 0; 1000241699cdSAl Viro } 1001d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 100209fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 1003d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 1004d879cb83SAl Viro v.bv_offset, v.bv_len), 1005d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 1006d879cb83SAl Viro ) 1007d879cb83SAl Viro kunmap_atomic(kaddr); 1008d879cb83SAl Viro return bytes; 1009d879cb83SAl Viro } 1010d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 1011d879cb83SAl Viro 1012b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 1013241699cdSAl Viro { 1014241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 10158cefc107SDavid Howells unsigned int p_tail = pipe->tail; 10168cefc107SDavid Howells unsigned int p_head = pipe->head; 10178cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10188cefc107SDavid Howells 10198cefc107SDavid Howells if (!pipe_empty(p_head, p_tail)) { 10208cefc107SDavid Howells struct pipe_buffer *buf; 10218cefc107SDavid Howells unsigned int i_head = i->head; 1022b9dc6f65SAl Viro size_t off = i->iov_offset; 10238cefc107SDavid Howells 1024b9dc6f65SAl Viro if (off) { 10258cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 10268cefc107SDavid Howells buf->len = off - buf->offset; 10278cefc107SDavid Howells i_head++; 1028b9dc6f65SAl Viro } 10298cefc107SDavid Howells while (p_head != i_head) { 10308cefc107SDavid Howells p_head--; 10318cefc107SDavid Howells pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); 1032241699cdSAl Viro } 10338cefc107SDavid Howells 10348cefc107SDavid Howells pipe->head = p_head; 1035241699cdSAl Viro } 1036b9dc6f65SAl Viro } 1037b9dc6f65SAl Viro 1038b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 1039b9dc6f65SAl Viro { 1040b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 1041b9dc6f65SAl Viro if (unlikely(i->count < size)) 1042b9dc6f65SAl Viro size = i->count; 1043b9dc6f65SAl Viro if (size) { 1044b9dc6f65SAl Viro struct pipe_buffer *buf; 10458cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10468cefc107SDavid Howells unsigned int i_head = i->head; 1047b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 10488cefc107SDavid Howells 1049b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 10508cefc107SDavid Howells left += off - pipe->bufs[i_head & p_mask].offset; 1051b9dc6f65SAl Viro while (1) { 10528cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 1053b9dc6f65SAl Viro if (left <= buf->len) 1054b9dc6f65SAl Viro break; 1055b9dc6f65SAl Viro left -= buf->len; 10568cefc107SDavid Howells i_head++; 1057b9dc6f65SAl Viro } 10588cefc107SDavid Howells i->head = i_head; 1059b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 1060b9dc6f65SAl Viro } 1061b9dc6f65SAl Viro i->count -= size; 1062b9dc6f65SAl Viro /* ... and discard everything past that point */ 1063b9dc6f65SAl Viro pipe_truncate(i); 1064241699cdSAl Viro } 1065241699cdSAl Viro 1066d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 1067d879cb83SAl Viro { 106800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1069241699cdSAl Viro pipe_advance(i, size); 1070241699cdSAl Viro return; 1071241699cdSAl Viro } 10729ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) { 10739ea9ce04SDavid Howells i->count -= size; 10749ea9ce04SDavid Howells return; 10759ea9ce04SDavid Howells } 1076d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 1077d879cb83SAl Viro } 1078d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 1079d879cb83SAl Viro 108027c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 108127c0e374SAl Viro { 108227c0e374SAl Viro if (!unroll) 108327c0e374SAl Viro return; 10845b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 10855b47d59aSAl Viro return; 108627c0e374SAl Viro i->count += unroll; 108700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 108827c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 10898cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10908cefc107SDavid Howells unsigned int i_head = i->head; 109127c0e374SAl Viro size_t off = i->iov_offset; 109227c0e374SAl Viro while (1) { 10938cefc107SDavid Howells struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; 10948cefc107SDavid Howells size_t n = off - b->offset; 109527c0e374SAl Viro if (unroll < n) { 10964fa55cefSAl Viro off -= unroll; 109727c0e374SAl Viro break; 109827c0e374SAl Viro } 109927c0e374SAl Viro unroll -= n; 11008cefc107SDavid Howells if (!unroll && i_head == i->start_head) { 110127c0e374SAl Viro off = 0; 110227c0e374SAl Viro break; 110327c0e374SAl Viro } 11048cefc107SDavid Howells i_head--; 11058cefc107SDavid Howells b = &pipe->bufs[i_head & p_mask]; 11068cefc107SDavid Howells off = b->offset + b->len; 110727c0e374SAl Viro } 110827c0e374SAl Viro i->iov_offset = off; 11098cefc107SDavid Howells i->head = i_head; 111027c0e374SAl Viro pipe_truncate(i); 111127c0e374SAl Viro return; 111227c0e374SAl Viro } 11139ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11149ea9ce04SDavid Howells return; 111527c0e374SAl Viro if (unroll <= i->iov_offset) { 111627c0e374SAl Viro i->iov_offset -= unroll; 111727c0e374SAl Viro return; 111827c0e374SAl Viro } 111927c0e374SAl Viro unroll -= i->iov_offset; 112000e23707SDavid Howells if (iov_iter_is_bvec(i)) { 112127c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 112227c0e374SAl Viro while (1) { 112327c0e374SAl Viro size_t n = (--bvec)->bv_len; 112427c0e374SAl Viro i->nr_segs++; 112527c0e374SAl Viro if (unroll <= n) { 112627c0e374SAl Viro i->bvec = bvec; 112727c0e374SAl Viro i->iov_offset = n - unroll; 112827c0e374SAl Viro return; 112927c0e374SAl Viro } 113027c0e374SAl Viro unroll -= n; 113127c0e374SAl Viro } 113227c0e374SAl Viro } else { /* same logics for iovec and kvec */ 113327c0e374SAl Viro const struct iovec *iov = i->iov; 113427c0e374SAl Viro while (1) { 113527c0e374SAl Viro size_t n = (--iov)->iov_len; 113627c0e374SAl Viro i->nr_segs++; 113727c0e374SAl Viro if (unroll <= n) { 113827c0e374SAl Viro i->iov = iov; 113927c0e374SAl Viro i->iov_offset = n - unroll; 114027c0e374SAl Viro return; 114127c0e374SAl Viro } 114227c0e374SAl Viro unroll -= n; 114327c0e374SAl Viro } 114427c0e374SAl Viro } 114527c0e374SAl Viro } 114627c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 114727c0e374SAl Viro 1148d879cb83SAl Viro /* 1149d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1150d879cb83SAl Viro */ 1151d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1152d879cb83SAl Viro { 115300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1154241699cdSAl Viro return i->count; // it is a silly place, anyway 1155d879cb83SAl Viro if (i->nr_segs == 1) 1156d879cb83SAl Viro return i->count; 11579ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11589ea9ce04SDavid Howells return i->count; 115900e23707SDavid Howells else if (iov_iter_is_bvec(i)) 1160d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1161d879cb83SAl Viro else 1162d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1163d879cb83SAl Viro } 1164d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1165d879cb83SAl Viro 1166aa563d7bSDavid Howells void iov_iter_kvec(struct iov_iter *i, unsigned int direction, 1167d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1168d879cb83SAl Viro size_t count) 1169d879cb83SAl Viro { 1170aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1171aa563d7bSDavid Howells i->type = ITER_KVEC | (direction & (READ | WRITE)); 1172d879cb83SAl Viro i->kvec = kvec; 1173d879cb83SAl Viro i->nr_segs = nr_segs; 1174d879cb83SAl Viro i->iov_offset = 0; 1175d879cb83SAl Viro i->count = count; 1176d879cb83SAl Viro } 1177d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1178d879cb83SAl Viro 1179aa563d7bSDavid Howells void iov_iter_bvec(struct iov_iter *i, unsigned int direction, 1180d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1181d879cb83SAl Viro size_t count) 1182d879cb83SAl Viro { 1183aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1184aa563d7bSDavid Howells i->type = ITER_BVEC | (direction & (READ | WRITE)); 1185d879cb83SAl Viro i->bvec = bvec; 1186d879cb83SAl Viro i->nr_segs = nr_segs; 1187d879cb83SAl Viro i->iov_offset = 0; 1188d879cb83SAl Viro i->count = count; 1189d879cb83SAl Viro } 1190d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1191d879cb83SAl Viro 1192aa563d7bSDavid Howells void iov_iter_pipe(struct iov_iter *i, unsigned int direction, 1193241699cdSAl Viro struct pipe_inode_info *pipe, 1194241699cdSAl Viro size_t count) 1195241699cdSAl Viro { 1196aa563d7bSDavid Howells BUG_ON(direction != READ); 11978cefc107SDavid Howells WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); 1198aa563d7bSDavid Howells i->type = ITER_PIPE | READ; 1199241699cdSAl Viro i->pipe = pipe; 12008cefc107SDavid Howells i->head = pipe->head; 1201241699cdSAl Viro i->iov_offset = 0; 1202241699cdSAl Viro i->count = count; 12038cefc107SDavid Howells i->start_head = i->head; 1204241699cdSAl Viro } 1205241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1206241699cdSAl Viro 12079ea9ce04SDavid Howells /** 12089ea9ce04SDavid Howells * iov_iter_discard - Initialise an I/O iterator that discards data 12099ea9ce04SDavid Howells * @i: The iterator to initialise. 12109ea9ce04SDavid Howells * @direction: The direction of the transfer. 12119ea9ce04SDavid Howells * @count: The size of the I/O buffer in bytes. 12129ea9ce04SDavid Howells * 12139ea9ce04SDavid Howells * Set up an I/O iterator that just discards everything that's written to it. 12149ea9ce04SDavid Howells * It's only available as a READ iterator. 12159ea9ce04SDavid Howells */ 12169ea9ce04SDavid Howells void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) 12179ea9ce04SDavid Howells { 12189ea9ce04SDavid Howells BUG_ON(direction != READ); 12199ea9ce04SDavid Howells i->type = ITER_DISCARD | READ; 12209ea9ce04SDavid Howells i->count = count; 12219ea9ce04SDavid Howells i->iov_offset = 0; 12229ea9ce04SDavid Howells } 12239ea9ce04SDavid Howells EXPORT_SYMBOL(iov_iter_discard); 12249ea9ce04SDavid Howells 1225d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1226d879cb83SAl Viro { 1227d879cb83SAl Viro unsigned long res = 0; 1228d879cb83SAl Viro size_t size = i->count; 1229d879cb83SAl Viro 123000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1231e0ff126eSJan Kara unsigned int p_mask = i->pipe->ring_size - 1; 1232e0ff126eSJan Kara 12338cefc107SDavid Howells if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) 1234241699cdSAl Viro return size | i->iov_offset; 1235241699cdSAl Viro return size; 1236241699cdSAl Viro } 1237d879cb83SAl Viro iterate_all_kinds(i, size, v, 1238d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1239d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1240d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1241d879cb83SAl Viro ) 1242d879cb83SAl Viro return res; 1243d879cb83SAl Viro } 1244d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1245d879cb83SAl Viro 1246357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1247357f435dSAl Viro { 1248357f435dSAl Viro unsigned long res = 0; 1249357f435dSAl Viro size_t size = i->count; 1250357f435dSAl Viro 12519ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1252241699cdSAl Viro WARN_ON(1); 1253241699cdSAl Viro return ~0U; 1254241699cdSAl Viro } 1255241699cdSAl Viro 1256357f435dSAl Viro iterate_all_kinds(i, size, v, 1257357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1258357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1259357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1260357f435dSAl Viro (size != v.bv_len ? size : 0)), 1261357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1262357f435dSAl Viro (size != v.iov_len ? size : 0)) 1263357f435dSAl Viro ); 1264357f435dSAl Viro return res; 1265357f435dSAl Viro } 1266357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1267357f435dSAl Viro 1268e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1269241699cdSAl Viro size_t maxsize, 1270241699cdSAl Viro struct page **pages, 12718cefc107SDavid Howells int iter_head, 1272241699cdSAl Viro size_t *start) 1273241699cdSAl Viro { 1274241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 12758cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 12768cefc107SDavid Howells ssize_t n = push_pipe(i, maxsize, &iter_head, start); 1277241699cdSAl Viro if (!n) 1278241699cdSAl Viro return -EFAULT; 1279241699cdSAl Viro 1280241699cdSAl Viro maxsize = n; 1281241699cdSAl Viro n += *start; 12821689c73aSAl Viro while (n > 0) { 12838cefc107SDavid Howells get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); 12848cefc107SDavid Howells iter_head++; 1285241699cdSAl Viro n -= PAGE_SIZE; 1286241699cdSAl Viro } 1287241699cdSAl Viro 1288241699cdSAl Viro return maxsize; 1289241699cdSAl Viro } 1290241699cdSAl Viro 1291241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1292241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1293241699cdSAl Viro size_t *start) 1294241699cdSAl Viro { 12958cefc107SDavid Howells unsigned int iter_head, npages; 1296241699cdSAl Viro size_t capacity; 1297241699cdSAl Viro 129833844e66SAl Viro if (!maxsize) 129933844e66SAl Viro return 0; 130033844e66SAl Viro 1301241699cdSAl Viro if (!sanity(i)) 1302241699cdSAl Viro return -EFAULT; 1303241699cdSAl Viro 13048cefc107SDavid Howells data_start(i, &iter_head, start); 13058cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13068cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1307241699cdSAl Viro capacity = min(npages, maxpages) * PAGE_SIZE - *start; 1308241699cdSAl Viro 13098cefc107SDavid Howells return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); 1310241699cdSAl Viro } 1311241699cdSAl Viro 1312d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1313d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1314d879cb83SAl Viro size_t *start) 1315d879cb83SAl Viro { 1316d879cb83SAl Viro if (maxsize > i->count) 1317d879cb83SAl Viro maxsize = i->count; 1318d879cb83SAl Viro 131900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1320241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 13219ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 13229ea9ce04SDavid Howells return -EFAULT; 13239ea9ce04SDavid Howells 1324d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1325d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1326d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1327d879cb83SAl Viro int n; 1328d879cb83SAl Viro int res; 1329d879cb83SAl Viro 1330d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1331d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1332d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1333d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 133473b0140bSIra Weiny res = get_user_pages_fast(addr, n, 133573b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, 133673b0140bSIra Weiny pages); 1337d879cb83SAl Viro if (unlikely(res < 0)) 1338d879cb83SAl Viro return res; 1339d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1340d879cb83SAl Viro 0;}),({ 1341d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1342d879cb83SAl Viro *start = v.bv_offset; 1343d879cb83SAl Viro get_page(*pages = v.bv_page); 1344d879cb83SAl Viro return v.bv_len; 1345d879cb83SAl Viro }),({ 1346d879cb83SAl Viro return -EFAULT; 1347d879cb83SAl Viro }) 1348d879cb83SAl Viro ) 1349d879cb83SAl Viro return 0; 1350d879cb83SAl Viro } 1351d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1352d879cb83SAl Viro 1353d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1354d879cb83SAl Viro { 1355752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1356d879cb83SAl Viro } 1357d879cb83SAl Viro 1358241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1359241699cdSAl Viro struct page ***pages, size_t maxsize, 1360241699cdSAl Viro size_t *start) 1361241699cdSAl Viro { 1362241699cdSAl Viro struct page **p; 13638cefc107SDavid Howells unsigned int iter_head, npages; 1364d7760d63SIlya Dryomov ssize_t n; 1365241699cdSAl Viro 136633844e66SAl Viro if (!maxsize) 136733844e66SAl Viro return 0; 136833844e66SAl Viro 1369241699cdSAl Viro if (!sanity(i)) 1370241699cdSAl Viro return -EFAULT; 1371241699cdSAl Viro 13728cefc107SDavid Howells data_start(i, &iter_head, start); 13738cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13748cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1375241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1376241699cdSAl Viro if (maxsize > n) 1377241699cdSAl Viro maxsize = n; 1378241699cdSAl Viro else 1379241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1380241699cdSAl Viro p = get_pages_array(npages); 1381241699cdSAl Viro if (!p) 1382241699cdSAl Viro return -ENOMEM; 13838cefc107SDavid Howells n = __pipe_get_pages(i, maxsize, p, iter_head, start); 1384241699cdSAl Viro if (n > 0) 1385241699cdSAl Viro *pages = p; 1386241699cdSAl Viro else 1387241699cdSAl Viro kvfree(p); 1388241699cdSAl Viro return n; 1389241699cdSAl Viro } 1390241699cdSAl Viro 1391d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1392d879cb83SAl Viro struct page ***pages, size_t maxsize, 1393d879cb83SAl Viro size_t *start) 1394d879cb83SAl Viro { 1395d879cb83SAl Viro struct page **p; 1396d879cb83SAl Viro 1397d879cb83SAl Viro if (maxsize > i->count) 1398d879cb83SAl Viro maxsize = i->count; 1399d879cb83SAl Viro 140000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1401241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 14029ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 14039ea9ce04SDavid Howells return -EFAULT; 14049ea9ce04SDavid Howells 1405d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1406d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1407d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1408d879cb83SAl Viro int n; 1409d879cb83SAl Viro int res; 1410d879cb83SAl Viro 1411d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1412d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1413d879cb83SAl Viro p = get_pages_array(n); 1414d879cb83SAl Viro if (!p) 1415d879cb83SAl Viro return -ENOMEM; 141673b0140bSIra Weiny res = get_user_pages_fast(addr, n, 141773b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); 1418d879cb83SAl Viro if (unlikely(res < 0)) { 1419d879cb83SAl Viro kvfree(p); 1420d879cb83SAl Viro return res; 1421d879cb83SAl Viro } 1422d879cb83SAl Viro *pages = p; 1423d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1424d879cb83SAl Viro 0;}),({ 1425d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1426d879cb83SAl Viro *start = v.bv_offset; 1427d879cb83SAl Viro *pages = p = get_pages_array(1); 1428d879cb83SAl Viro if (!p) 1429d879cb83SAl Viro return -ENOMEM; 1430d879cb83SAl Viro get_page(*p = v.bv_page); 1431d879cb83SAl Viro return v.bv_len; 1432d879cb83SAl Viro }),({ 1433d879cb83SAl Viro return -EFAULT; 1434d879cb83SAl Viro }) 1435d879cb83SAl Viro ) 1436d879cb83SAl Viro return 0; 1437d879cb83SAl Viro } 1438d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1439d879cb83SAl Viro 1440d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1441d879cb83SAl Viro struct iov_iter *i) 1442d879cb83SAl Viro { 1443d879cb83SAl Viro char *to = addr; 1444d879cb83SAl Viro __wsum sum, next; 1445d879cb83SAl Viro size_t off = 0; 1446d879cb83SAl Viro sum = *csum; 14479ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1448241699cdSAl Viro WARN_ON(1); 1449241699cdSAl Viro return 0; 1450241699cdSAl Viro } 1451d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1452d879cb83SAl Viro int err = 0; 1453d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1454d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1455d879cb83SAl Viro v.iov_len, 0, &err); 1456d879cb83SAl Viro if (!err) { 1457d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1458d879cb83SAl Viro off += v.iov_len; 1459d879cb83SAl Viro } 1460d879cb83SAl Viro err ? v.iov_len : 0; 1461d879cb83SAl Viro }), ({ 1462d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1463f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1464f9152895SAl Viro p + v.bv_offset, v.bv_len, 1465f9152895SAl Viro sum, off); 1466d879cb83SAl Viro kunmap_atomic(p); 1467d879cb83SAl Viro off += v.bv_len; 1468d879cb83SAl Viro }),({ 1469f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1470f9152895SAl Viro v.iov_base, v.iov_len, 1471f9152895SAl Viro sum, off); 1472d879cb83SAl Viro off += v.iov_len; 1473d879cb83SAl Viro }) 1474d879cb83SAl Viro ) 1475d879cb83SAl Viro *csum = sum; 1476d879cb83SAl Viro return bytes; 1477d879cb83SAl Viro } 1478d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1479d879cb83SAl Viro 1480cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1481cbbd26b8SAl Viro struct iov_iter *i) 1482cbbd26b8SAl Viro { 1483cbbd26b8SAl Viro char *to = addr; 1484cbbd26b8SAl Viro __wsum sum, next; 1485cbbd26b8SAl Viro size_t off = 0; 1486cbbd26b8SAl Viro sum = *csum; 14879ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1488cbbd26b8SAl Viro WARN_ON(1); 1489cbbd26b8SAl Viro return false; 1490cbbd26b8SAl Viro } 1491cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1492cbbd26b8SAl Viro return false; 1493cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1494cbbd26b8SAl Viro int err = 0; 1495cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1496cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1497cbbd26b8SAl Viro v.iov_len, 0, &err); 1498cbbd26b8SAl Viro if (err) 1499cbbd26b8SAl Viro return false; 1500cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1501cbbd26b8SAl Viro off += v.iov_len; 1502cbbd26b8SAl Viro 0; 1503cbbd26b8SAl Viro }), ({ 1504cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1505f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1506f9152895SAl Viro p + v.bv_offset, v.bv_len, 1507f9152895SAl Viro sum, off); 1508cbbd26b8SAl Viro kunmap_atomic(p); 1509cbbd26b8SAl Viro off += v.bv_len; 1510cbbd26b8SAl Viro }),({ 1511f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1512f9152895SAl Viro v.iov_base, v.iov_len, 1513f9152895SAl Viro sum, off); 1514cbbd26b8SAl Viro off += v.iov_len; 1515cbbd26b8SAl Viro }) 1516cbbd26b8SAl Viro ) 1517cbbd26b8SAl Viro *csum = sum; 1518cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1519cbbd26b8SAl Viro return true; 1520cbbd26b8SAl Viro } 1521cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1522cbbd26b8SAl Viro 1523cb002d07SSagi Grimberg size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, 1524d879cb83SAl Viro struct iov_iter *i) 1525d879cb83SAl Viro { 152636f7a8a4SAl Viro const char *from = addr; 1527cb002d07SSagi Grimberg __wsum *csum = csump; 1528d879cb83SAl Viro __wsum sum, next; 1529d879cb83SAl Viro size_t off = 0; 153078e1f386SAl Viro 153178e1f386SAl Viro if (unlikely(iov_iter_is_pipe(i))) 153278e1f386SAl Viro return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); 153378e1f386SAl Viro 1534d879cb83SAl Viro sum = *csum; 153578e1f386SAl Viro if (unlikely(iov_iter_is_discard(i))) { 1536241699cdSAl Viro WARN_ON(1); /* for now */ 1537241699cdSAl Viro return 0; 1538241699cdSAl Viro } 1539d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1540d879cb83SAl Viro int err = 0; 1541d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1542d879cb83SAl Viro v.iov_base, 1543d879cb83SAl Viro v.iov_len, 0, &err); 1544d879cb83SAl Viro if (!err) { 1545d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1546d879cb83SAl Viro off += v.iov_len; 1547d879cb83SAl Viro } 1548d879cb83SAl Viro err ? v.iov_len : 0; 1549d879cb83SAl Viro }), ({ 1550d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1551f9152895SAl Viro sum = csum_and_memcpy(p + v.bv_offset, 1552f9152895SAl Viro (from += v.bv_len) - v.bv_len, 1553f9152895SAl Viro v.bv_len, sum, off); 1554d879cb83SAl Viro kunmap_atomic(p); 1555d879cb83SAl Viro off += v.bv_len; 1556d879cb83SAl Viro }),({ 1557f9152895SAl Viro sum = csum_and_memcpy(v.iov_base, 1558f9152895SAl Viro (from += v.iov_len) - v.iov_len, 1559f9152895SAl Viro v.iov_len, sum, off); 1560d879cb83SAl Viro off += v.iov_len; 1561d879cb83SAl Viro }) 1562d879cb83SAl Viro ) 1563d879cb83SAl Viro *csum = sum; 1564d879cb83SAl Viro return bytes; 1565d879cb83SAl Viro } 1566d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1567d879cb83SAl Viro 1568d05f4435SSagi Grimberg size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, 1569d05f4435SSagi Grimberg struct iov_iter *i) 1570d05f4435SSagi Grimberg { 15717999096fSHerbert Xu #ifdef CONFIG_CRYPTO_HASH 1572d05f4435SSagi Grimberg struct ahash_request *hash = hashp; 1573d05f4435SSagi Grimberg struct scatterlist sg; 1574d05f4435SSagi Grimberg size_t copied; 1575d05f4435SSagi Grimberg 1576d05f4435SSagi Grimberg copied = copy_to_iter(addr, bytes, i); 1577d05f4435SSagi Grimberg sg_init_one(&sg, addr, copied); 1578d05f4435SSagi Grimberg ahash_request_set_crypt(hash, &sg, NULL, copied); 1579d05f4435SSagi Grimberg crypto_ahash_update(hash); 1580d05f4435SSagi Grimberg return copied; 158127fad74aSYueHaibing #else 158227fad74aSYueHaibing return 0; 158327fad74aSYueHaibing #endif 1584d05f4435SSagi Grimberg } 1585d05f4435SSagi Grimberg EXPORT_SYMBOL(hash_and_copy_to_iter); 1586d05f4435SSagi Grimberg 1587d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1588d879cb83SAl Viro { 1589d879cb83SAl Viro size_t size = i->count; 1590d879cb83SAl Viro int npages = 0; 1591d879cb83SAl Viro 1592d879cb83SAl Viro if (!size) 1593d879cb83SAl Viro return 0; 15949ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 15959ea9ce04SDavid Howells return 0; 1596d879cb83SAl Viro 159700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1598241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 15998cefc107SDavid Howells unsigned int iter_head; 1600241699cdSAl Viro size_t off; 1601241699cdSAl Viro 1602241699cdSAl Viro if (!sanity(i)) 1603241699cdSAl Viro return 0; 1604241699cdSAl Viro 16058cefc107SDavid Howells data_start(i, &iter_head, &off); 1606241699cdSAl Viro /* some of this one + all after this one */ 16078cefc107SDavid Howells npages = pipe_space_for_user(iter_head, pipe->tail, pipe); 1608241699cdSAl Viro if (npages >= maxpages) 1609241699cdSAl Viro return maxpages; 1610241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1611d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1612d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1613d879cb83SAl Viro - p / PAGE_SIZE; 1614d879cb83SAl Viro if (npages >= maxpages) 1615d879cb83SAl Viro return maxpages; 1616d879cb83SAl Viro 0;}),({ 1617d879cb83SAl Viro npages++; 1618d879cb83SAl Viro if (npages >= maxpages) 1619d879cb83SAl Viro return maxpages; 1620d879cb83SAl Viro }),({ 1621d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1622d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1623d879cb83SAl Viro - p / PAGE_SIZE; 1624d879cb83SAl Viro if (npages >= maxpages) 1625d879cb83SAl Viro return maxpages; 1626d879cb83SAl Viro }) 1627d879cb83SAl Viro ) 1628d879cb83SAl Viro return npages; 1629d879cb83SAl Viro } 1630d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1631d879cb83SAl Viro 1632d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1633d879cb83SAl Viro { 1634d879cb83SAl Viro *new = *old; 163500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(new))) { 1636241699cdSAl Viro WARN_ON(1); 1637241699cdSAl Viro return NULL; 1638241699cdSAl Viro } 16399ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(new))) 16409ea9ce04SDavid Howells return NULL; 164100e23707SDavid Howells if (iov_iter_is_bvec(new)) 1642d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1643d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1644d879cb83SAl Viro flags); 1645d879cb83SAl Viro else 1646d879cb83SAl Viro /* iovec and kvec have identical layout */ 1647d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1648d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1649d879cb83SAl Viro flags); 1650d879cb83SAl Viro } 1651d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1652bc917be8SAl Viro 1653ffecee4fSVegard Nossum /** 1654fb041b59SDavid Laight * rw_copy_check_uvector() - Copy an array of &struct iovec from userspace 1655fb041b59SDavid Laight * into the kernel and check that it is valid. 1656fb041b59SDavid Laight * 1657fb041b59SDavid Laight * @type: One of %CHECK_IOVEC_ONLY, %READ, or %WRITE. 1658fb041b59SDavid Laight * @uvector: Pointer to the userspace array. 1659fb041b59SDavid Laight * @nr_segs: Number of elements in userspace array. 1660fb041b59SDavid Laight * @fast_segs: Number of elements in @fast_pointer. 1661fb041b59SDavid Laight * @fast_pointer: Pointer to (usually small on-stack) kernel array. 1662fb041b59SDavid Laight * @ret_pointer: (output parameter) Pointer to a variable that will point to 1663fb041b59SDavid Laight * either @fast_pointer, a newly allocated kernel array, or NULL, 1664fb041b59SDavid Laight * depending on which array was used. 1665fb041b59SDavid Laight * 1666fb041b59SDavid Laight * This function copies an array of &struct iovec of @nr_segs from 1667fb041b59SDavid Laight * userspace into the kernel and checks that each element is valid (e.g. 1668fb041b59SDavid Laight * it does not point to a kernel address or cause overflow by being too 1669fb041b59SDavid Laight * large, etc.). 1670fb041b59SDavid Laight * 1671fb041b59SDavid Laight * As an optimization, the caller may provide a pointer to a small 1672fb041b59SDavid Laight * on-stack array in @fast_pointer, typically %UIO_FASTIOV elements long 1673fb041b59SDavid Laight * (the size of this array, or 0 if unused, should be given in @fast_segs). 1674fb041b59SDavid Laight * 1675fb041b59SDavid Laight * @ret_pointer will always point to the array that was used, so the 1676fb041b59SDavid Laight * caller must take care not to call kfree() on it e.g. in case the 1677fb041b59SDavid Laight * @fast_pointer array was used and it was allocated on the stack. 1678fb041b59SDavid Laight * 1679fb041b59SDavid Laight * Return: The total number of bytes covered by the iovec array on success 1680fb041b59SDavid Laight * or a negative error code on error. 1681fb041b59SDavid Laight */ 1682fb041b59SDavid Laight ssize_t rw_copy_check_uvector(int type, const struct iovec __user *uvector, 1683fb041b59SDavid Laight unsigned long nr_segs, unsigned long fast_segs, 1684fb041b59SDavid Laight struct iovec *fast_pointer, struct iovec **ret_pointer) 1685fb041b59SDavid Laight { 1686fb041b59SDavid Laight unsigned long seg; 1687fb041b59SDavid Laight ssize_t ret; 1688fb041b59SDavid Laight struct iovec *iov = fast_pointer; 1689fb041b59SDavid Laight 1690fb041b59SDavid Laight /* 1691fb041b59SDavid Laight * SuS says "The readv() function *may* fail if the iovcnt argument 1692fb041b59SDavid Laight * was less than or equal to 0, or greater than {IOV_MAX}. Linux has 1693fb041b59SDavid Laight * traditionally returned zero for zero segments, so... 1694fb041b59SDavid Laight */ 1695fb041b59SDavid Laight if (nr_segs == 0) { 1696fb041b59SDavid Laight ret = 0; 1697fb041b59SDavid Laight goto out; 1698fb041b59SDavid Laight } 1699fb041b59SDavid Laight 1700fb041b59SDavid Laight /* 1701fb041b59SDavid Laight * First get the "struct iovec" from user memory and 1702fb041b59SDavid Laight * verify all the pointers 1703fb041b59SDavid Laight */ 1704fb041b59SDavid Laight if (nr_segs > UIO_MAXIOV) { 1705fb041b59SDavid Laight ret = -EINVAL; 1706fb041b59SDavid Laight goto out; 1707fb041b59SDavid Laight } 1708fb041b59SDavid Laight if (nr_segs > fast_segs) { 1709fb041b59SDavid Laight iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); 1710fb041b59SDavid Laight if (iov == NULL) { 1711fb041b59SDavid Laight ret = -ENOMEM; 1712fb041b59SDavid Laight goto out; 1713fb041b59SDavid Laight } 1714fb041b59SDavid Laight } 1715fb041b59SDavid Laight if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { 1716fb041b59SDavid Laight ret = -EFAULT; 1717fb041b59SDavid Laight goto out; 1718fb041b59SDavid Laight } 1719fb041b59SDavid Laight 1720fb041b59SDavid Laight /* 1721fb041b59SDavid Laight * According to the Single Unix Specification we should return EINVAL 1722fb041b59SDavid Laight * if an element length is < 0 when cast to ssize_t or if the 1723fb041b59SDavid Laight * total length would overflow the ssize_t return value of the 1724fb041b59SDavid Laight * system call. 1725fb041b59SDavid Laight * 1726fb041b59SDavid Laight * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the 1727fb041b59SDavid Laight * overflow case. 1728fb041b59SDavid Laight */ 1729fb041b59SDavid Laight ret = 0; 1730fb041b59SDavid Laight for (seg = 0; seg < nr_segs; seg++) { 1731fb041b59SDavid Laight void __user *buf = iov[seg].iov_base; 1732fb041b59SDavid Laight ssize_t len = (ssize_t)iov[seg].iov_len; 1733fb041b59SDavid Laight 1734fb041b59SDavid Laight /* see if we we're about to use an invalid len or if 1735fb041b59SDavid Laight * it's about to overflow ssize_t */ 1736fb041b59SDavid Laight if (len < 0) { 1737fb041b59SDavid Laight ret = -EINVAL; 1738fb041b59SDavid Laight goto out; 1739fb041b59SDavid Laight } 1740fb041b59SDavid Laight if (type >= 0 1741fb041b59SDavid Laight && unlikely(!access_ok(buf, len))) { 1742fb041b59SDavid Laight ret = -EFAULT; 1743fb041b59SDavid Laight goto out; 1744fb041b59SDavid Laight } 1745fb041b59SDavid Laight if (len > MAX_RW_COUNT - ret) { 1746fb041b59SDavid Laight len = MAX_RW_COUNT - ret; 1747fb041b59SDavid Laight iov[seg].iov_len = len; 1748fb041b59SDavid Laight } 1749fb041b59SDavid Laight ret += len; 1750fb041b59SDavid Laight } 1751fb041b59SDavid Laight out: 1752fb041b59SDavid Laight *ret_pointer = iov; 1753fb041b59SDavid Laight return ret; 1754fb041b59SDavid Laight } 1755fb041b59SDavid Laight 1756fb041b59SDavid Laight /** 1757ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1758ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1759ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1760ffecee4fSVegard Nossum * 1761ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1762ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1763ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1764ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1765ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1766ffecee4fSVegard Nossum * on-stack) kernel array. 1767ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1768ffecee4fSVegard Nossum * 1769ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1770ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1771ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1772ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1773ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1774ffecee4fSVegard Nossum * returns an error or not). 1775ffecee4fSVegard Nossum * 177687e5e6daSJens Axboe * Return: Negative error code on error, bytes imported on success 1777ffecee4fSVegard Nossum */ 177887e5e6daSJens Axboe ssize_t import_iovec(int type, const struct iovec __user * uvector, 1779bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1780bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1781bc917be8SAl Viro { 1782bc917be8SAl Viro ssize_t n; 1783bc917be8SAl Viro struct iovec *p; 1784bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1785bc917be8SAl Viro *iov, &p); 1786bc917be8SAl Viro if (n < 0) { 1787bc917be8SAl Viro if (p != *iov) 1788bc917be8SAl Viro kfree(p); 1789bc917be8SAl Viro *iov = NULL; 1790bc917be8SAl Viro return n; 1791bc917be8SAl Viro } 1792bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1793bc917be8SAl Viro *iov = p == *iov ? NULL : p; 179487e5e6daSJens Axboe return n; 1795bc917be8SAl Viro } 1796bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1797bc917be8SAl Viro 1798bc917be8SAl Viro #ifdef CONFIG_COMPAT 1799bc917be8SAl Viro #include <linux/compat.h> 1800bc917be8SAl Viro 1801fb041b59SDavid Laight ssize_t compat_rw_copy_check_uvector(int type, 1802fb041b59SDavid Laight const struct compat_iovec __user *uvector, 1803fb041b59SDavid Laight unsigned long nr_segs, unsigned long fast_segs, 1804fb041b59SDavid Laight struct iovec *fast_pointer, struct iovec **ret_pointer) 1805fb041b59SDavid Laight { 1806fb041b59SDavid Laight compat_ssize_t tot_len; 1807fb041b59SDavid Laight struct iovec *iov = *ret_pointer = fast_pointer; 1808fb041b59SDavid Laight ssize_t ret = 0; 1809fb041b59SDavid Laight int seg; 1810fb041b59SDavid Laight 1811fb041b59SDavid Laight /* 1812fb041b59SDavid Laight * SuS says "The readv() function *may* fail if the iovcnt argument 1813fb041b59SDavid Laight * was less than or equal to 0, or greater than {IOV_MAX}. Linux has 1814fb041b59SDavid Laight * traditionally returned zero for zero segments, so... 1815fb041b59SDavid Laight */ 1816fb041b59SDavid Laight if (nr_segs == 0) 1817fb041b59SDavid Laight goto out; 1818fb041b59SDavid Laight 1819fb041b59SDavid Laight ret = -EINVAL; 1820fb041b59SDavid Laight if (nr_segs > UIO_MAXIOV) 1821fb041b59SDavid Laight goto out; 1822fb041b59SDavid Laight if (nr_segs > fast_segs) { 1823fb041b59SDavid Laight ret = -ENOMEM; 1824fb041b59SDavid Laight iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); 1825fb041b59SDavid Laight if (iov == NULL) 1826fb041b59SDavid Laight goto out; 1827fb041b59SDavid Laight } 1828fb041b59SDavid Laight *ret_pointer = iov; 1829fb041b59SDavid Laight 1830fb041b59SDavid Laight ret = -EFAULT; 1831fb041b59SDavid Laight if (!access_ok(uvector, nr_segs*sizeof(*uvector))) 1832fb041b59SDavid Laight goto out; 1833fb041b59SDavid Laight 1834fb041b59SDavid Laight /* 1835fb041b59SDavid Laight * Single unix specification: 1836fb041b59SDavid Laight * We should -EINVAL if an element length is not >= 0 and fitting an 1837fb041b59SDavid Laight * ssize_t. 1838fb041b59SDavid Laight * 1839fb041b59SDavid Laight * In Linux, the total length is limited to MAX_RW_COUNT, there is 1840fb041b59SDavid Laight * no overflow possibility. 1841fb041b59SDavid Laight */ 1842fb041b59SDavid Laight tot_len = 0; 1843fb041b59SDavid Laight ret = -EINVAL; 1844fb041b59SDavid Laight for (seg = 0; seg < nr_segs; seg++) { 1845fb041b59SDavid Laight compat_uptr_t buf; 1846fb041b59SDavid Laight compat_ssize_t len; 1847fb041b59SDavid Laight 1848fb041b59SDavid Laight if (__get_user(len, &uvector->iov_len) || 1849fb041b59SDavid Laight __get_user(buf, &uvector->iov_base)) { 1850fb041b59SDavid Laight ret = -EFAULT; 1851fb041b59SDavid Laight goto out; 1852fb041b59SDavid Laight } 1853fb041b59SDavid Laight if (len < 0) /* size_t not fitting in compat_ssize_t .. */ 1854fb041b59SDavid Laight goto out; 1855fb041b59SDavid Laight if (type >= 0 && 1856fb041b59SDavid Laight !access_ok(compat_ptr(buf), len)) { 1857fb041b59SDavid Laight ret = -EFAULT; 1858fb041b59SDavid Laight goto out; 1859fb041b59SDavid Laight } 1860fb041b59SDavid Laight if (len > MAX_RW_COUNT - tot_len) 1861fb041b59SDavid Laight len = MAX_RW_COUNT - tot_len; 1862fb041b59SDavid Laight tot_len += len; 1863fb041b59SDavid Laight iov->iov_base = compat_ptr(buf); 1864fb041b59SDavid Laight iov->iov_len = (compat_size_t) len; 1865fb041b59SDavid Laight uvector++; 1866fb041b59SDavid Laight iov++; 1867fb041b59SDavid Laight } 1868fb041b59SDavid Laight ret = tot_len; 1869fb041b59SDavid Laight 1870fb041b59SDavid Laight out: 1871fb041b59SDavid Laight return ret; 1872fb041b59SDavid Laight } 1873fb041b59SDavid Laight 187487e5e6daSJens Axboe ssize_t compat_import_iovec(int type, 187587e5e6daSJens Axboe const struct compat_iovec __user * uvector, 1876bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1877bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1878bc917be8SAl Viro { 1879bc917be8SAl Viro ssize_t n; 1880bc917be8SAl Viro struct iovec *p; 1881bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1882bc917be8SAl Viro *iov, &p); 1883bc917be8SAl Viro if (n < 0) { 1884bc917be8SAl Viro if (p != *iov) 1885bc917be8SAl Viro kfree(p); 1886bc917be8SAl Viro *iov = NULL; 1887bc917be8SAl Viro return n; 1888bc917be8SAl Viro } 1889bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1890bc917be8SAl Viro *iov = p == *iov ? NULL : p; 189187e5e6daSJens Axboe return n; 1892bc917be8SAl Viro } 189398aaaec4SArnd Bergmann EXPORT_SYMBOL(compat_import_iovec); 1894bc917be8SAl Viro #endif 1895bc917be8SAl Viro 1896bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1897bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1898bc917be8SAl Viro { 1899bc917be8SAl Viro if (len > MAX_RW_COUNT) 1900bc917be8SAl Viro len = MAX_RW_COUNT; 190196d4f267SLinus Torvalds if (unlikely(!access_ok(buf, len))) 1902bc917be8SAl Viro return -EFAULT; 1903bc917be8SAl Viro 1904bc917be8SAl Viro iov->iov_base = buf; 1905bc917be8SAl Viro iov->iov_len = len; 1906bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1907bc917be8SAl Viro return 0; 1908bc917be8SAl Viro } 1909e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 191009cf698aSAl Viro 191109cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 191209cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 191309cf698aSAl Viro void *context) 191409cf698aSAl Viro { 191509cf698aSAl Viro struct kvec w; 191609cf698aSAl Viro int err = -EINVAL; 191709cf698aSAl Viro if (!bytes) 191809cf698aSAl Viro return 0; 191909cf698aSAl Viro 192009cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 192109cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 192209cf698aSAl Viro w.iov_len = v.bv_len; 192309cf698aSAl Viro err = f(&w, context); 192409cf698aSAl Viro kunmap(v.bv_page); 192509cf698aSAl Viro err;}), ({ 192609cf698aSAl Viro w = v; 192709cf698aSAl Viro err = f(&w, context);}) 192809cf698aSAl Viro ) 192909cf698aSAl Viro return err; 193009cf698aSAl Viro } 193109cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1932