1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2d879cb83SAl Viro #include <linux/export.h> 32f8b5444SChristoph Hellwig #include <linux/bvec.h> 4d879cb83SAl Viro #include <linux/uio.h> 5d879cb83SAl Viro #include <linux/pagemap.h> 6d879cb83SAl Viro #include <linux/slab.h> 7d879cb83SAl Viro #include <linux/vmalloc.h> 8241699cdSAl Viro #include <linux/splice.h> 9d879cb83SAl Viro #include <net/checksum.h> 10d05f4435SSagi Grimberg #include <linux/scatterlist.h> 11d879cb83SAl Viro 12241699cdSAl Viro #define PIPE_PARANOIA /* for now */ 13241699cdSAl Viro 14d879cb83SAl Viro #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ 15d879cb83SAl Viro size_t left; \ 16d879cb83SAl Viro size_t wanted = n; \ 17d879cb83SAl Viro __p = i->iov; \ 18d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 19d879cb83SAl Viro if (likely(__v.iov_len)) { \ 20d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 21d879cb83SAl Viro left = (STEP); \ 22d879cb83SAl Viro __v.iov_len -= left; \ 23d879cb83SAl Viro skip += __v.iov_len; \ 24d879cb83SAl Viro n -= __v.iov_len; \ 25d879cb83SAl Viro } else { \ 26d879cb83SAl Viro left = 0; \ 27d879cb83SAl Viro } \ 28d879cb83SAl Viro while (unlikely(!left && n)) { \ 29d879cb83SAl Viro __p++; \ 30d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 31d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 32d879cb83SAl Viro continue; \ 33d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 34d879cb83SAl Viro left = (STEP); \ 35d879cb83SAl Viro __v.iov_len -= left; \ 36d879cb83SAl Viro skip = __v.iov_len; \ 37d879cb83SAl Viro n -= __v.iov_len; \ 38d879cb83SAl Viro } \ 39d879cb83SAl Viro n = wanted - n; \ 40d879cb83SAl Viro } 41d879cb83SAl Viro 42d879cb83SAl Viro #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ 43d879cb83SAl Viro size_t wanted = n; \ 44d879cb83SAl Viro __p = i->kvec; \ 45d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 46d879cb83SAl Viro if (likely(__v.iov_len)) { \ 47d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 48d879cb83SAl Viro (void)(STEP); \ 49d879cb83SAl Viro skip += __v.iov_len; \ 50d879cb83SAl Viro n -= __v.iov_len; \ 51d879cb83SAl Viro } \ 52d879cb83SAl Viro while (unlikely(n)) { \ 53d879cb83SAl Viro __p++; \ 54d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 55d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 56d879cb83SAl Viro continue; \ 57d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 58d879cb83SAl Viro (void)(STEP); \ 59d879cb83SAl Viro skip = __v.iov_len; \ 60d879cb83SAl Viro n -= __v.iov_len; \ 61d879cb83SAl Viro } \ 62d879cb83SAl Viro n = wanted; \ 63d879cb83SAl Viro } 64d879cb83SAl Viro 651bdc76aeSMing Lei #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ 661bdc76aeSMing Lei struct bvec_iter __start; \ 671bdc76aeSMing Lei __start.bi_size = n; \ 681bdc76aeSMing Lei __start.bi_bvec_done = skip; \ 691bdc76aeSMing Lei __start.bi_idx = 0; \ 701bdc76aeSMing Lei for_each_bvec(__v, i->bvec, __bi, __start) { \ 711bdc76aeSMing Lei if (!__v.bv_len) \ 72d879cb83SAl Viro continue; \ 73d879cb83SAl Viro (void)(STEP); \ 74d879cb83SAl Viro } \ 75d879cb83SAl Viro } 76d879cb83SAl Viro 77d879cb83SAl Viro #define iterate_all_kinds(i, n, v, I, B, K) { \ 7833844e66SAl Viro if (likely(n)) { \ 79d879cb83SAl Viro size_t skip = i->iov_offset; \ 80d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 81d879cb83SAl Viro struct bio_vec v; \ 821bdc76aeSMing Lei struct bvec_iter __bi; \ 831bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 84d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 85d879cb83SAl Viro const struct kvec *kvec; \ 86d879cb83SAl Viro struct kvec v; \ 87d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 889ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 89d879cb83SAl Viro } else { \ 90d879cb83SAl Viro const struct iovec *iov; \ 91d879cb83SAl Viro struct iovec v; \ 92d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 93d879cb83SAl Viro } \ 9433844e66SAl Viro } \ 95d879cb83SAl Viro } 96d879cb83SAl Viro 97d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 98dd254f5aSAl Viro if (unlikely(i->count < n)) \ 99dd254f5aSAl Viro n = i->count; \ 10019f18459SAl Viro if (i->count) { \ 101d879cb83SAl Viro size_t skip = i->iov_offset; \ 102d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 1031bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 104d879cb83SAl Viro struct bio_vec v; \ 1051bdc76aeSMing Lei struct bvec_iter __bi; \ 1061bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1071bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1081bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1091bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 110d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 111d879cb83SAl Viro const struct kvec *kvec; \ 112d879cb83SAl Viro struct kvec v; \ 113d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 114d879cb83SAl Viro if (skip == kvec->iov_len) { \ 115d879cb83SAl Viro kvec++; \ 116d879cb83SAl Viro skip = 0; \ 117d879cb83SAl Viro } \ 118d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 119d879cb83SAl Viro i->kvec = kvec; \ 1209ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 1219ea9ce04SDavid Howells skip += n; \ 122d879cb83SAl Viro } else { \ 123d879cb83SAl Viro const struct iovec *iov; \ 124d879cb83SAl Viro struct iovec v; \ 125d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 126d879cb83SAl Viro if (skip == iov->iov_len) { \ 127d879cb83SAl Viro iov++; \ 128d879cb83SAl Viro skip = 0; \ 129d879cb83SAl Viro } \ 130d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 131d879cb83SAl Viro i->iov = iov; \ 132d879cb83SAl Viro } \ 133d879cb83SAl Viro i->count -= n; \ 134d879cb83SAl Viro i->iov_offset = skip; \ 135dd254f5aSAl Viro } \ 136d879cb83SAl Viro } 137d879cb83SAl Viro 13809fc68dcSAl Viro static int copyout(void __user *to, const void *from, size_t n) 13909fc68dcSAl Viro { 14096d4f267SLinus Torvalds if (access_ok(to, n)) { 14109fc68dcSAl Viro kasan_check_read(from, n); 14209fc68dcSAl Viro n = raw_copy_to_user(to, from, n); 14309fc68dcSAl Viro } 14409fc68dcSAl Viro return n; 14509fc68dcSAl Viro } 14609fc68dcSAl Viro 14709fc68dcSAl Viro static int copyin(void *to, const void __user *from, size_t n) 14809fc68dcSAl Viro { 14996d4f267SLinus Torvalds if (access_ok(from, n)) { 15009fc68dcSAl Viro kasan_check_write(to, n); 15109fc68dcSAl Viro n = raw_copy_from_user(to, from, n); 15209fc68dcSAl Viro } 15309fc68dcSAl Viro return n; 15409fc68dcSAl Viro } 15509fc68dcSAl Viro 156d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 157d879cb83SAl Viro struct iov_iter *i) 158d879cb83SAl Viro { 159d879cb83SAl Viro size_t skip, copy, left, wanted; 160d879cb83SAl Viro const struct iovec *iov; 161d879cb83SAl Viro char __user *buf; 162d879cb83SAl Viro void *kaddr, *from; 163d879cb83SAl Viro 164d879cb83SAl Viro if (unlikely(bytes > i->count)) 165d879cb83SAl Viro bytes = i->count; 166d879cb83SAl Viro 167d879cb83SAl Viro if (unlikely(!bytes)) 168d879cb83SAl Viro return 0; 169d879cb83SAl Viro 17009fc68dcSAl Viro might_fault(); 171d879cb83SAl Viro wanted = bytes; 172d879cb83SAl Viro iov = i->iov; 173d879cb83SAl Viro skip = i->iov_offset; 174d879cb83SAl Viro buf = iov->iov_base + skip; 175d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 176d879cb83SAl Viro 1773fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 178d879cb83SAl Viro kaddr = kmap_atomic(page); 179d879cb83SAl Viro from = kaddr + offset; 180d879cb83SAl Viro 181d879cb83SAl Viro /* first chunk, usually the only one */ 18209fc68dcSAl Viro left = copyout(buf, from, copy); 183d879cb83SAl Viro copy -= left; 184d879cb83SAl Viro skip += copy; 185d879cb83SAl Viro from += copy; 186d879cb83SAl Viro bytes -= copy; 187d879cb83SAl Viro 188d879cb83SAl Viro while (unlikely(!left && bytes)) { 189d879cb83SAl Viro iov++; 190d879cb83SAl Viro buf = iov->iov_base; 191d879cb83SAl Viro copy = min(bytes, iov->iov_len); 19209fc68dcSAl Viro left = copyout(buf, from, copy); 193d879cb83SAl Viro copy -= left; 194d879cb83SAl Viro skip = copy; 195d879cb83SAl Viro from += copy; 196d879cb83SAl Viro bytes -= copy; 197d879cb83SAl Viro } 198d879cb83SAl Viro if (likely(!bytes)) { 199d879cb83SAl Viro kunmap_atomic(kaddr); 200d879cb83SAl Viro goto done; 201d879cb83SAl Viro } 202d879cb83SAl Viro offset = from - kaddr; 203d879cb83SAl Viro buf += copy; 204d879cb83SAl Viro kunmap_atomic(kaddr); 205d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 206d879cb83SAl Viro } 207d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2083fa6c507SMikulas Patocka 209d879cb83SAl Viro kaddr = kmap(page); 210d879cb83SAl Viro from = kaddr + offset; 21109fc68dcSAl Viro left = copyout(buf, from, copy); 212d879cb83SAl Viro copy -= left; 213d879cb83SAl Viro skip += copy; 214d879cb83SAl Viro from += copy; 215d879cb83SAl Viro bytes -= copy; 216d879cb83SAl Viro while (unlikely(!left && bytes)) { 217d879cb83SAl Viro iov++; 218d879cb83SAl Viro buf = iov->iov_base; 219d879cb83SAl Viro copy = min(bytes, iov->iov_len); 22009fc68dcSAl Viro left = copyout(buf, from, copy); 221d879cb83SAl Viro copy -= left; 222d879cb83SAl Viro skip = copy; 223d879cb83SAl Viro from += copy; 224d879cb83SAl Viro bytes -= copy; 225d879cb83SAl Viro } 226d879cb83SAl Viro kunmap(page); 2273fa6c507SMikulas Patocka 228d879cb83SAl Viro done: 229d879cb83SAl Viro if (skip == iov->iov_len) { 230d879cb83SAl Viro iov++; 231d879cb83SAl Viro skip = 0; 232d879cb83SAl Viro } 233d879cb83SAl Viro i->count -= wanted - bytes; 234d879cb83SAl Viro i->nr_segs -= iov - i->iov; 235d879cb83SAl Viro i->iov = iov; 236d879cb83SAl Viro i->iov_offset = skip; 237d879cb83SAl Viro return wanted - bytes; 238d879cb83SAl Viro } 239d879cb83SAl Viro 240d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 241d879cb83SAl Viro struct iov_iter *i) 242d879cb83SAl Viro { 243d879cb83SAl Viro size_t skip, copy, left, wanted; 244d879cb83SAl Viro const struct iovec *iov; 245d879cb83SAl Viro char __user *buf; 246d879cb83SAl Viro void *kaddr, *to; 247d879cb83SAl Viro 248d879cb83SAl Viro if (unlikely(bytes > i->count)) 249d879cb83SAl Viro bytes = i->count; 250d879cb83SAl Viro 251d879cb83SAl Viro if (unlikely(!bytes)) 252d879cb83SAl Viro return 0; 253d879cb83SAl Viro 25409fc68dcSAl Viro might_fault(); 255d879cb83SAl Viro wanted = bytes; 256d879cb83SAl Viro iov = i->iov; 257d879cb83SAl Viro skip = i->iov_offset; 258d879cb83SAl Viro buf = iov->iov_base + skip; 259d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 260d879cb83SAl Viro 2613fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 262d879cb83SAl Viro kaddr = kmap_atomic(page); 263d879cb83SAl Viro to = kaddr + offset; 264d879cb83SAl Viro 265d879cb83SAl Viro /* first chunk, usually the only one */ 26609fc68dcSAl Viro left = copyin(to, buf, copy); 267d879cb83SAl Viro copy -= left; 268d879cb83SAl Viro skip += copy; 269d879cb83SAl Viro to += copy; 270d879cb83SAl Viro bytes -= copy; 271d879cb83SAl Viro 272d879cb83SAl Viro while (unlikely(!left && bytes)) { 273d879cb83SAl Viro iov++; 274d879cb83SAl Viro buf = iov->iov_base; 275d879cb83SAl Viro copy = min(bytes, iov->iov_len); 27609fc68dcSAl Viro left = copyin(to, buf, copy); 277d879cb83SAl Viro copy -= left; 278d879cb83SAl Viro skip = copy; 279d879cb83SAl Viro to += copy; 280d879cb83SAl Viro bytes -= copy; 281d879cb83SAl Viro } 282d879cb83SAl Viro if (likely(!bytes)) { 283d879cb83SAl Viro kunmap_atomic(kaddr); 284d879cb83SAl Viro goto done; 285d879cb83SAl Viro } 286d879cb83SAl Viro offset = to - kaddr; 287d879cb83SAl Viro buf += copy; 288d879cb83SAl Viro kunmap_atomic(kaddr); 289d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 290d879cb83SAl Viro } 291d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2923fa6c507SMikulas Patocka 293d879cb83SAl Viro kaddr = kmap(page); 294d879cb83SAl Viro to = kaddr + offset; 29509fc68dcSAl Viro left = copyin(to, buf, copy); 296d879cb83SAl Viro copy -= left; 297d879cb83SAl Viro skip += copy; 298d879cb83SAl Viro to += copy; 299d879cb83SAl Viro bytes -= copy; 300d879cb83SAl Viro while (unlikely(!left && bytes)) { 301d879cb83SAl Viro iov++; 302d879cb83SAl Viro buf = iov->iov_base; 303d879cb83SAl Viro copy = min(bytes, iov->iov_len); 30409fc68dcSAl Viro left = copyin(to, buf, copy); 305d879cb83SAl Viro copy -= left; 306d879cb83SAl Viro skip = copy; 307d879cb83SAl Viro to += copy; 308d879cb83SAl Viro bytes -= copy; 309d879cb83SAl Viro } 310d879cb83SAl Viro kunmap(page); 3113fa6c507SMikulas Patocka 312d879cb83SAl Viro done: 313d879cb83SAl Viro if (skip == iov->iov_len) { 314d879cb83SAl Viro iov++; 315d879cb83SAl Viro skip = 0; 316d879cb83SAl Viro } 317d879cb83SAl Viro i->count -= wanted - bytes; 318d879cb83SAl Viro i->nr_segs -= iov - i->iov; 319d879cb83SAl Viro i->iov = iov; 320d879cb83SAl Viro i->iov_offset = skip; 321d879cb83SAl Viro return wanted - bytes; 322d879cb83SAl Viro } 323d879cb83SAl Viro 324241699cdSAl Viro #ifdef PIPE_PARANOIA 325241699cdSAl Viro static bool sanity(const struct iov_iter *i) 326241699cdSAl Viro { 327241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 328241699cdSAl Viro int idx = i->idx; 329241699cdSAl Viro int next = pipe->curbuf + pipe->nrbufs; 330241699cdSAl Viro if (i->iov_offset) { 331241699cdSAl Viro struct pipe_buffer *p; 332241699cdSAl Viro if (unlikely(!pipe->nrbufs)) 333241699cdSAl Viro goto Bad; // pipe must be non-empty 334241699cdSAl Viro if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) 335241699cdSAl Viro goto Bad; // must be at the last buffer... 336241699cdSAl Viro 337241699cdSAl Viro p = &pipe->bufs[idx]; 338241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 339241699cdSAl Viro goto Bad; // ... at the end of segment 340241699cdSAl Viro } else { 341241699cdSAl Viro if (idx != (next & (pipe->buffers - 1))) 342241699cdSAl Viro goto Bad; // must be right after the last buffer 343241699cdSAl Viro } 344241699cdSAl Viro return true; 345241699cdSAl Viro Bad: 346241699cdSAl Viro printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); 347241699cdSAl Viro printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", 348241699cdSAl Viro pipe->curbuf, pipe->nrbufs, pipe->buffers); 349241699cdSAl Viro for (idx = 0; idx < pipe->buffers; idx++) 350241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 351241699cdSAl Viro pipe->bufs[idx].ops, 352241699cdSAl Viro pipe->bufs[idx].page, 353241699cdSAl Viro pipe->bufs[idx].offset, 354241699cdSAl Viro pipe->bufs[idx].len); 355241699cdSAl Viro WARN_ON(1); 356241699cdSAl Viro return false; 357241699cdSAl Viro } 358241699cdSAl Viro #else 359241699cdSAl Viro #define sanity(i) true 360241699cdSAl Viro #endif 361241699cdSAl Viro 362241699cdSAl Viro static inline int next_idx(int idx, struct pipe_inode_info *pipe) 363241699cdSAl Viro { 364241699cdSAl Viro return (idx + 1) & (pipe->buffers - 1); 365241699cdSAl Viro } 366241699cdSAl Viro 367241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 368241699cdSAl Viro struct iov_iter *i) 369241699cdSAl Viro { 370241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 371241699cdSAl Viro struct pipe_buffer *buf; 372241699cdSAl Viro size_t off; 373241699cdSAl Viro int idx; 374241699cdSAl Viro 375241699cdSAl Viro if (unlikely(bytes > i->count)) 376241699cdSAl Viro bytes = i->count; 377241699cdSAl Viro 378241699cdSAl Viro if (unlikely(!bytes)) 379241699cdSAl Viro return 0; 380241699cdSAl Viro 381241699cdSAl Viro if (!sanity(i)) 382241699cdSAl Viro return 0; 383241699cdSAl Viro 384241699cdSAl Viro off = i->iov_offset; 385241699cdSAl Viro idx = i->idx; 386241699cdSAl Viro buf = &pipe->bufs[idx]; 387241699cdSAl Viro if (off) { 388241699cdSAl Viro if (offset == off && buf->page == page) { 389241699cdSAl Viro /* merge with the last one */ 390241699cdSAl Viro buf->len += bytes; 391241699cdSAl Viro i->iov_offset += bytes; 392241699cdSAl Viro goto out; 393241699cdSAl Viro } 394241699cdSAl Viro idx = next_idx(idx, pipe); 395241699cdSAl Viro buf = &pipe->bufs[idx]; 396241699cdSAl Viro } 397241699cdSAl Viro if (idx == pipe->curbuf && pipe->nrbufs) 398241699cdSAl Viro return 0; 399241699cdSAl Viro pipe->nrbufs++; 400241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 401241699cdSAl Viro get_page(buf->page = page); 402241699cdSAl Viro buf->offset = offset; 403241699cdSAl Viro buf->len = bytes; 404241699cdSAl Viro i->iov_offset = offset + bytes; 405241699cdSAl Viro i->idx = idx; 406241699cdSAl Viro out: 407241699cdSAl Viro i->count -= bytes; 408241699cdSAl Viro return bytes; 409241699cdSAl Viro } 410241699cdSAl Viro 411d879cb83SAl Viro /* 412171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 413171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 414171a0203SAnton Altaparmakov * 415171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 416171a0203SAnton Altaparmakov * because it is an invalid address). 417171a0203SAnton Altaparmakov */ 418d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 419171a0203SAnton Altaparmakov { 420171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 421171a0203SAnton Altaparmakov const struct iovec *iov; 422171a0203SAnton Altaparmakov int err; 423171a0203SAnton Altaparmakov struct iovec v; 424171a0203SAnton Altaparmakov 425171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 426171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4274bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 428171a0203SAnton Altaparmakov if (unlikely(err)) 429171a0203SAnton Altaparmakov return err; 430171a0203SAnton Altaparmakov 0;})) 431171a0203SAnton Altaparmakov } 432171a0203SAnton Altaparmakov return 0; 433171a0203SAnton Altaparmakov } 434d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 435171a0203SAnton Altaparmakov 436aa563d7bSDavid Howells void iov_iter_init(struct iov_iter *i, unsigned int direction, 437d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 438d879cb83SAl Viro size_t count) 439d879cb83SAl Viro { 440aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 441aa563d7bSDavid Howells direction &= READ | WRITE; 442aa563d7bSDavid Howells 443d879cb83SAl Viro /* It will get better. Eventually... */ 444db68ce10SAl Viro if (uaccess_kernel()) { 445aa563d7bSDavid Howells i->type = ITER_KVEC | direction; 446d879cb83SAl Viro i->kvec = (struct kvec *)iov; 447d879cb83SAl Viro } else { 448aa563d7bSDavid Howells i->type = ITER_IOVEC | direction; 449d879cb83SAl Viro i->iov = iov; 450d879cb83SAl Viro } 451d879cb83SAl Viro i->nr_segs = nr_segs; 452d879cb83SAl Viro i->iov_offset = 0; 453d879cb83SAl Viro i->count = count; 454d879cb83SAl Viro } 455d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 456d879cb83SAl Viro 457d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 458d879cb83SAl Viro { 459d879cb83SAl Viro char *from = kmap_atomic(page); 460d879cb83SAl Viro memcpy(to, from + offset, len); 461d879cb83SAl Viro kunmap_atomic(from); 462d879cb83SAl Viro } 463d879cb83SAl Viro 46436f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 465d879cb83SAl Viro { 466d879cb83SAl Viro char *to = kmap_atomic(page); 467d879cb83SAl Viro memcpy(to + offset, from, len); 468d879cb83SAl Viro kunmap_atomic(to); 469d879cb83SAl Viro } 470d879cb83SAl Viro 471d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 472d879cb83SAl Viro { 473d879cb83SAl Viro char *addr = kmap_atomic(page); 474d879cb83SAl Viro memset(addr + offset, 0, len); 475d879cb83SAl Viro kunmap_atomic(addr); 476d879cb83SAl Viro } 477d879cb83SAl Viro 478241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 479241699cdSAl Viro { 480241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 481241699cdSAl Viro } 482241699cdSAl Viro 483241699cdSAl Viro static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) 484241699cdSAl Viro { 485241699cdSAl Viro size_t off = i->iov_offset; 486241699cdSAl Viro int idx = i->idx; 487241699cdSAl Viro if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { 488241699cdSAl Viro idx = next_idx(idx, i->pipe); 489241699cdSAl Viro off = 0; 490241699cdSAl Viro } 491241699cdSAl Viro *idxp = idx; 492241699cdSAl Viro *offp = off; 493241699cdSAl Viro } 494241699cdSAl Viro 495241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 496241699cdSAl Viro int *idxp, size_t *offp) 497241699cdSAl Viro { 498241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 499241699cdSAl Viro size_t off; 500241699cdSAl Viro int idx; 501241699cdSAl Viro ssize_t left; 502241699cdSAl Viro 503241699cdSAl Viro if (unlikely(size > i->count)) 504241699cdSAl Viro size = i->count; 505241699cdSAl Viro if (unlikely(!size)) 506241699cdSAl Viro return 0; 507241699cdSAl Viro 508241699cdSAl Viro left = size; 509241699cdSAl Viro data_start(i, &idx, &off); 510241699cdSAl Viro *idxp = idx; 511241699cdSAl Viro *offp = off; 512241699cdSAl Viro if (off) { 513241699cdSAl Viro left -= PAGE_SIZE - off; 514241699cdSAl Viro if (left <= 0) { 515241699cdSAl Viro pipe->bufs[idx].len += size; 516241699cdSAl Viro return size; 517241699cdSAl Viro } 518241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 519241699cdSAl Viro idx = next_idx(idx, pipe); 520241699cdSAl Viro } 521241699cdSAl Viro while (idx != pipe->curbuf || !pipe->nrbufs) { 522241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 523241699cdSAl Viro if (!page) 524241699cdSAl Viro break; 525241699cdSAl Viro pipe->nrbufs++; 526241699cdSAl Viro pipe->bufs[idx].ops = &default_pipe_buf_ops; 527241699cdSAl Viro pipe->bufs[idx].page = page; 528241699cdSAl Viro pipe->bufs[idx].offset = 0; 529241699cdSAl Viro if (left <= PAGE_SIZE) { 530241699cdSAl Viro pipe->bufs[idx].len = left; 531241699cdSAl Viro return size; 532241699cdSAl Viro } 533241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 534241699cdSAl Viro left -= PAGE_SIZE; 535241699cdSAl Viro idx = next_idx(idx, pipe); 536241699cdSAl Viro } 537241699cdSAl Viro return size - left; 538241699cdSAl Viro } 539241699cdSAl Viro 540241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 541241699cdSAl Viro struct iov_iter *i) 542241699cdSAl Viro { 543241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 544241699cdSAl Viro size_t n, off; 545241699cdSAl Viro int idx; 546241699cdSAl Viro 547241699cdSAl Viro if (!sanity(i)) 548241699cdSAl Viro return 0; 549241699cdSAl Viro 550241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 551241699cdSAl Viro if (unlikely(!n)) 552241699cdSAl Viro return 0; 553241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 554241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 555241699cdSAl Viro memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); 556241699cdSAl Viro i->idx = idx; 557241699cdSAl Viro i->iov_offset = off + chunk; 558241699cdSAl Viro n -= chunk; 559241699cdSAl Viro addr += chunk; 560241699cdSAl Viro } 561241699cdSAl Viro i->count -= bytes; 562241699cdSAl Viro return bytes; 563241699cdSAl Viro } 564241699cdSAl Viro 565f9152895SAl Viro static __wsum csum_and_memcpy(void *to, const void *from, size_t len, 566f9152895SAl Viro __wsum sum, size_t off) 567f9152895SAl Viro { 568f9152895SAl Viro __wsum next = csum_partial_copy_nocheck(from, to, len, 0); 569f9152895SAl Viro return csum_block_add(sum, next, off); 570f9152895SAl Viro } 571f9152895SAl Viro 57278e1f386SAl Viro static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 57378e1f386SAl Viro __wsum *csum, struct iov_iter *i) 57478e1f386SAl Viro { 57578e1f386SAl Viro struct pipe_inode_info *pipe = i->pipe; 57678e1f386SAl Viro size_t n, r; 57778e1f386SAl Viro size_t off = 0; 578f9152895SAl Viro __wsum sum = *csum; 57978e1f386SAl Viro int idx; 58078e1f386SAl Viro 58178e1f386SAl Viro if (!sanity(i)) 58278e1f386SAl Viro return 0; 58378e1f386SAl Viro 58478e1f386SAl Viro bytes = n = push_pipe(i, bytes, &idx, &r); 58578e1f386SAl Viro if (unlikely(!n)) 58678e1f386SAl Viro return 0; 58778e1f386SAl Viro for ( ; n; idx = next_idx(idx, pipe), r = 0) { 58878e1f386SAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - r); 58978e1f386SAl Viro char *p = kmap_atomic(pipe->bufs[idx].page); 590f9152895SAl Viro sum = csum_and_memcpy(p + r, addr, chunk, sum, off); 59178e1f386SAl Viro kunmap_atomic(p); 59278e1f386SAl Viro i->idx = idx; 59378e1f386SAl Viro i->iov_offset = r + chunk; 59478e1f386SAl Viro n -= chunk; 59578e1f386SAl Viro off += chunk; 59678e1f386SAl Viro addr += chunk; 59778e1f386SAl Viro } 59878e1f386SAl Viro i->count -= bytes; 59978e1f386SAl Viro *csum = sum; 60078e1f386SAl Viro return bytes; 60178e1f386SAl Viro } 60278e1f386SAl Viro 603aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 604d879cb83SAl Viro { 60536f7a8a4SAl Viro const char *from = addr; 60600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 607241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 60809fc68dcSAl Viro if (iter_is_iovec(i)) 60909fc68dcSAl Viro might_fault(); 610d879cb83SAl Viro iterate_and_advance(i, bytes, v, 61109fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 612d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 613d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 614d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 615d879cb83SAl Viro ) 616d879cb83SAl Viro 617d879cb83SAl Viro return bytes; 618d879cb83SAl Viro } 619aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 620d879cb83SAl Viro 6218780356eSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE 6228780356eSDan Williams static int copyout_mcsafe(void __user *to, const void *from, size_t n) 6238780356eSDan Williams { 62496d4f267SLinus Torvalds if (access_ok(to, n)) { 6258780356eSDan Williams kasan_check_read(from, n); 6268780356eSDan Williams n = copy_to_user_mcsafe((__force void *) to, from, n); 6278780356eSDan Williams } 6288780356eSDan Williams return n; 6298780356eSDan Williams } 6308780356eSDan Williams 6318780356eSDan Williams static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, 6328780356eSDan Williams const char *from, size_t len) 6338780356eSDan Williams { 6348780356eSDan Williams unsigned long ret; 6358780356eSDan Williams char *to; 6368780356eSDan Williams 6378780356eSDan Williams to = kmap_atomic(page); 6388780356eSDan Williams ret = memcpy_mcsafe(to + offset, from, len); 6398780356eSDan Williams kunmap_atomic(to); 6408780356eSDan Williams 6418780356eSDan Williams return ret; 6428780356eSDan Williams } 6438780356eSDan Williams 644ca146f6fSDan Williams static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, 645ca146f6fSDan Williams struct iov_iter *i) 646ca146f6fSDan Williams { 647ca146f6fSDan Williams struct pipe_inode_info *pipe = i->pipe; 648ca146f6fSDan Williams size_t n, off, xfer = 0; 649ca146f6fSDan Williams int idx; 650ca146f6fSDan Williams 651ca146f6fSDan Williams if (!sanity(i)) 652ca146f6fSDan Williams return 0; 653ca146f6fSDan Williams 654ca146f6fSDan Williams bytes = n = push_pipe(i, bytes, &idx, &off); 655ca146f6fSDan Williams if (unlikely(!n)) 656ca146f6fSDan Williams return 0; 657ca146f6fSDan Williams for ( ; n; idx = next_idx(idx, pipe), off = 0) { 658ca146f6fSDan Williams size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 659ca146f6fSDan Williams unsigned long rem; 660ca146f6fSDan Williams 661ca146f6fSDan Williams rem = memcpy_mcsafe_to_page(pipe->bufs[idx].page, off, addr, 662ca146f6fSDan Williams chunk); 663ca146f6fSDan Williams i->idx = idx; 664ca146f6fSDan Williams i->iov_offset = off + chunk - rem; 665ca146f6fSDan Williams xfer += chunk - rem; 666ca146f6fSDan Williams if (rem) 667ca146f6fSDan Williams break; 668ca146f6fSDan Williams n -= chunk; 669ca146f6fSDan Williams addr += chunk; 670ca146f6fSDan Williams } 671ca146f6fSDan Williams i->count -= xfer; 672ca146f6fSDan Williams return xfer; 673ca146f6fSDan Williams } 674ca146f6fSDan Williams 675bf3eeb9bSDan Williams /** 676bf3eeb9bSDan Williams * _copy_to_iter_mcsafe - copy to user with source-read error exception handling 677bf3eeb9bSDan Williams * @addr: source kernel address 678bf3eeb9bSDan Williams * @bytes: total transfer length 679bf3eeb9bSDan Williams * @iter: destination iterator 680bf3eeb9bSDan Williams * 681bf3eeb9bSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 682bf3eeb9bSDan Williams * dax_copy_to_iter() for protecting read/write to persistent memory. 683bf3eeb9bSDan Williams * Unless / until an architecture can guarantee identical performance 684bf3eeb9bSDan Williams * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a 685bf3eeb9bSDan Williams * performance regression to switch more users to the mcsafe version. 686bf3eeb9bSDan Williams * 687bf3eeb9bSDan Williams * Otherwise, the main differences between this and typical _copy_to_iter(). 688bf3eeb9bSDan Williams * 689bf3eeb9bSDan Williams * * Typical tail/residue handling after a fault retries the copy 690bf3eeb9bSDan Williams * byte-by-byte until the fault happens again. Re-triggering machine 691bf3eeb9bSDan Williams * checks is potentially fatal so the implementation uses source 692bf3eeb9bSDan Williams * alignment and poison alignment assumptions to avoid re-triggering 693bf3eeb9bSDan Williams * hardware exceptions. 694bf3eeb9bSDan Williams * 695bf3eeb9bSDan Williams * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. 696bf3eeb9bSDan Williams * Compare to copy_to_iter() where only ITER_IOVEC attempts might return 697bf3eeb9bSDan Williams * a short copy. 698bf3eeb9bSDan Williams * 699bf3eeb9bSDan Williams * See MCSAFE_TEST for self-test. 700bf3eeb9bSDan Williams */ 7018780356eSDan Williams size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) 7028780356eSDan Williams { 7038780356eSDan Williams const char *from = addr; 7048780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 7058780356eSDan Williams 70600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 707ca146f6fSDan Williams return copy_pipe_to_iter_mcsafe(addr, bytes, i); 7088780356eSDan Williams if (iter_is_iovec(i)) 7098780356eSDan Williams might_fault(); 7108780356eSDan Williams iterate_and_advance(i, bytes, v, 7118780356eSDan Williams copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 7128780356eSDan Williams ({ 7138780356eSDan Williams rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, 7148780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 7158780356eSDan Williams if (rem) { 7168780356eSDan Williams curr_addr = (unsigned long) from; 7178780356eSDan Williams bytes = curr_addr - s_addr - rem; 7188780356eSDan Williams return bytes; 7198780356eSDan Williams } 7208780356eSDan Williams }), 7218780356eSDan Williams ({ 7228780356eSDan Williams rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, 7238780356eSDan Williams v.iov_len); 7248780356eSDan Williams if (rem) { 7258780356eSDan Williams curr_addr = (unsigned long) from; 7268780356eSDan Williams bytes = curr_addr - s_addr - rem; 7278780356eSDan Williams return bytes; 7288780356eSDan Williams } 7298780356eSDan Williams }) 7308780356eSDan Williams ) 7318780356eSDan Williams 7328780356eSDan Williams return bytes; 7338780356eSDan Williams } 7348780356eSDan Williams EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); 7358780356eSDan Williams #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ 7368780356eSDan Williams 737aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 738d879cb83SAl Viro { 739d879cb83SAl Viro char *to = addr; 74000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 741241699cdSAl Viro WARN_ON(1); 742241699cdSAl Viro return 0; 743241699cdSAl Viro } 74409fc68dcSAl Viro if (iter_is_iovec(i)) 74509fc68dcSAl Viro might_fault(); 746d879cb83SAl Viro iterate_and_advance(i, bytes, v, 74709fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 748d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 749d879cb83SAl Viro v.bv_offset, v.bv_len), 750d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 751d879cb83SAl Viro ) 752d879cb83SAl Viro 753d879cb83SAl Viro return bytes; 754d879cb83SAl Viro } 755aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 756d879cb83SAl Viro 757aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 758cbbd26b8SAl Viro { 759cbbd26b8SAl Viro char *to = addr; 76000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 761cbbd26b8SAl Viro WARN_ON(1); 762cbbd26b8SAl Viro return false; 763cbbd26b8SAl Viro } 76433844e66SAl Viro if (unlikely(i->count < bytes)) 765cbbd26b8SAl Viro return false; 766cbbd26b8SAl Viro 76709fc68dcSAl Viro if (iter_is_iovec(i)) 76809fc68dcSAl Viro might_fault(); 769cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 77009fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 771cbbd26b8SAl Viro v.iov_base, v.iov_len)) 772cbbd26b8SAl Viro return false; 773cbbd26b8SAl Viro 0;}), 774cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 775cbbd26b8SAl Viro v.bv_offset, v.bv_len), 776cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 777cbbd26b8SAl Viro ) 778cbbd26b8SAl Viro 779cbbd26b8SAl Viro iov_iter_advance(i, bytes); 780cbbd26b8SAl Viro return true; 781cbbd26b8SAl Viro } 782aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 783cbbd26b8SAl Viro 784aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 785d879cb83SAl Viro { 786d879cb83SAl Viro char *to = addr; 78700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 788241699cdSAl Viro WARN_ON(1); 789241699cdSAl Viro return 0; 790241699cdSAl Viro } 791d879cb83SAl Viro iterate_and_advance(i, bytes, v, 7923f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 793d879cb83SAl Viro v.iov_base, v.iov_len), 794d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 795d879cb83SAl Viro v.bv_offset, v.bv_len), 796d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 797d879cb83SAl Viro ) 798d879cb83SAl Viro 799d879cb83SAl Viro return bytes; 800d879cb83SAl Viro } 801aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 802d879cb83SAl Viro 8030aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 804abd08d7dSDan Williams /** 805abd08d7dSDan Williams * _copy_from_iter_flushcache - write destination through cpu cache 806abd08d7dSDan Williams * @addr: destination kernel address 807abd08d7dSDan Williams * @bytes: total transfer length 808abd08d7dSDan Williams * @iter: source iterator 809abd08d7dSDan Williams * 810abd08d7dSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 811abd08d7dSDan Williams * dax_copy_from_iter() for ensuring that writes to persistent memory 812abd08d7dSDan Williams * are flushed through the CPU cache. It is differentiated from 813abd08d7dSDan Williams * _copy_from_iter_nocache() in that guarantees all data is flushed for 814abd08d7dSDan Williams * all iterator types. The _copy_from_iter_nocache() only attempts to 815abd08d7dSDan Williams * bypass the cache for the ITER_IOVEC case, and on some archs may use 816abd08d7dSDan Williams * instructions that strand dirty-data in the cache. 817abd08d7dSDan Williams */ 8186a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 8190aed55afSDan Williams { 8200aed55afSDan Williams char *to = addr; 82100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 8220aed55afSDan Williams WARN_ON(1); 8230aed55afSDan Williams return 0; 8240aed55afSDan Williams } 8250aed55afSDan Williams iterate_and_advance(i, bytes, v, 8260aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 8270aed55afSDan Williams v.iov_base, v.iov_len), 8280aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 8290aed55afSDan Williams v.bv_offset, v.bv_len), 8300aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 8310aed55afSDan Williams v.iov_len) 8320aed55afSDan Williams ) 8330aed55afSDan Williams 8340aed55afSDan Williams return bytes; 8350aed55afSDan Williams } 8366a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 8370aed55afSDan Williams #endif 8380aed55afSDan Williams 839aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 840cbbd26b8SAl Viro { 841cbbd26b8SAl Viro char *to = addr; 84200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 843cbbd26b8SAl Viro WARN_ON(1); 844cbbd26b8SAl Viro return false; 845cbbd26b8SAl Viro } 84633844e66SAl Viro if (unlikely(i->count < bytes)) 847cbbd26b8SAl Viro return false; 848cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 8493f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 850cbbd26b8SAl Viro v.iov_base, v.iov_len)) 851cbbd26b8SAl Viro return false; 852cbbd26b8SAl Viro 0;}), 853cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 854cbbd26b8SAl Viro v.bv_offset, v.bv_len), 855cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 856cbbd26b8SAl Viro ) 857cbbd26b8SAl Viro 858cbbd26b8SAl Viro iov_iter_advance(i, bytes); 859cbbd26b8SAl Viro return true; 860cbbd26b8SAl Viro } 861aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 862cbbd26b8SAl Viro 86372e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 86472e809edSAl Viro { 8656daef95bSEric Dumazet struct page *head; 8666daef95bSEric Dumazet size_t v = n + offset; 8676daef95bSEric Dumazet 8686daef95bSEric Dumazet /* 8696daef95bSEric Dumazet * The general case needs to access the page order in order 8706daef95bSEric Dumazet * to compute the page size. 8716daef95bSEric Dumazet * However, we mostly deal with order-0 pages and thus can 8726daef95bSEric Dumazet * avoid a possible cache line miss for requests that fit all 8736daef95bSEric Dumazet * page orders. 8746daef95bSEric Dumazet */ 8756daef95bSEric Dumazet if (n <= v && v <= PAGE_SIZE) 8766daef95bSEric Dumazet return true; 8776daef95bSEric Dumazet 8786daef95bSEric Dumazet head = compound_head(page); 8796daef95bSEric Dumazet v += (page - head) << PAGE_SHIFT; 880a90bcb86SPetar Penkov 881a90bcb86SPetar Penkov if (likely(n <= v && v <= (PAGE_SIZE << compound_order(head)))) 88272e809edSAl Viro return true; 88372e809edSAl Viro WARN_ON(1); 88472e809edSAl Viro return false; 88572e809edSAl Viro } 886d879cb83SAl Viro 887d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 888d879cb83SAl Viro struct iov_iter *i) 889d879cb83SAl Viro { 89072e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 89172e809edSAl Viro return 0; 892d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 893d879cb83SAl Viro void *kaddr = kmap_atomic(page); 894d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 895d879cb83SAl Viro kunmap_atomic(kaddr); 896d879cb83SAl Viro return wanted; 8979ea9ce04SDavid Howells } else if (unlikely(iov_iter_is_discard(i))) 8989ea9ce04SDavid Howells return bytes; 8999ea9ce04SDavid Howells else if (likely(!iov_iter_is_pipe(i))) 900d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 901241699cdSAl Viro else 902241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 903d879cb83SAl Viro } 904d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 905d879cb83SAl Viro 906d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 907d879cb83SAl Viro struct iov_iter *i) 908d879cb83SAl Viro { 90972e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 91072e809edSAl Viro return 0; 9119ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 912241699cdSAl Viro WARN_ON(1); 913241699cdSAl Viro return 0; 914241699cdSAl Viro } 915d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 916d879cb83SAl Viro void *kaddr = kmap_atomic(page); 917aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 918d879cb83SAl Viro kunmap_atomic(kaddr); 919d879cb83SAl Viro return wanted; 920d879cb83SAl Viro } else 921d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 922d879cb83SAl Viro } 923d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 924d879cb83SAl Viro 925241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 926241699cdSAl Viro { 927241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 928241699cdSAl Viro size_t n, off; 929241699cdSAl Viro int idx; 930241699cdSAl Viro 931241699cdSAl Viro if (!sanity(i)) 932241699cdSAl Viro return 0; 933241699cdSAl Viro 934241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 935241699cdSAl Viro if (unlikely(!n)) 936241699cdSAl Viro return 0; 937241699cdSAl Viro 938241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 939241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 940241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 941241699cdSAl Viro i->idx = idx; 942241699cdSAl Viro i->iov_offset = off + chunk; 943241699cdSAl Viro n -= chunk; 944241699cdSAl Viro } 945241699cdSAl Viro i->count -= bytes; 946241699cdSAl Viro return bytes; 947241699cdSAl Viro } 948241699cdSAl Viro 949d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 950d879cb83SAl Viro { 95100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 952241699cdSAl Viro return pipe_zero(bytes, i); 953d879cb83SAl Viro iterate_and_advance(i, bytes, v, 95409fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 955d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 956d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 957d879cb83SAl Viro ) 958d879cb83SAl Viro 959d879cb83SAl Viro return bytes; 960d879cb83SAl Viro } 961d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 962d879cb83SAl Viro 963d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 964d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 965d879cb83SAl Viro { 966d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 96772e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 96872e809edSAl Viro kunmap_atomic(kaddr); 96972e809edSAl Viro return 0; 97072e809edSAl Viro } 9719ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 972241699cdSAl Viro kunmap_atomic(kaddr); 973241699cdSAl Viro WARN_ON(1); 974241699cdSAl Viro return 0; 975241699cdSAl Viro } 976d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 97709fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 978d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 979d879cb83SAl Viro v.bv_offset, v.bv_len), 980d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 981d879cb83SAl Viro ) 982d879cb83SAl Viro kunmap_atomic(kaddr); 983d879cb83SAl Viro return bytes; 984d879cb83SAl Viro } 985d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 986d879cb83SAl Viro 987b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 988241699cdSAl Viro { 989241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 990241699cdSAl Viro if (pipe->nrbufs) { 991b9dc6f65SAl Viro size_t off = i->iov_offset; 992b9dc6f65SAl Viro int idx = i->idx; 993b9dc6f65SAl Viro int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); 994b9dc6f65SAl Viro if (off) { 995b9dc6f65SAl Viro pipe->bufs[idx].len = off - pipe->bufs[idx].offset; 996b9dc6f65SAl Viro idx = next_idx(idx, pipe); 997b9dc6f65SAl Viro nrbufs++; 998b9dc6f65SAl Viro } 999b9dc6f65SAl Viro while (pipe->nrbufs > nrbufs) { 1000a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 1001241699cdSAl Viro idx = next_idx(idx, pipe); 1002241699cdSAl Viro pipe->nrbufs--; 1003241699cdSAl Viro } 1004241699cdSAl Viro } 1005b9dc6f65SAl Viro } 1006b9dc6f65SAl Viro 1007b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 1008b9dc6f65SAl Viro { 1009b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 1010b9dc6f65SAl Viro if (unlikely(i->count < size)) 1011b9dc6f65SAl Viro size = i->count; 1012b9dc6f65SAl Viro if (size) { 1013b9dc6f65SAl Viro struct pipe_buffer *buf; 1014b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 1015b9dc6f65SAl Viro int idx = i->idx; 1016b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 1017b9dc6f65SAl Viro left += off - pipe->bufs[idx].offset; 1018b9dc6f65SAl Viro while (1) { 1019b9dc6f65SAl Viro buf = &pipe->bufs[idx]; 1020b9dc6f65SAl Viro if (left <= buf->len) 1021b9dc6f65SAl Viro break; 1022b9dc6f65SAl Viro left -= buf->len; 1023b9dc6f65SAl Viro idx = next_idx(idx, pipe); 1024b9dc6f65SAl Viro } 1025b9dc6f65SAl Viro i->idx = idx; 1026b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 1027b9dc6f65SAl Viro } 1028b9dc6f65SAl Viro i->count -= size; 1029b9dc6f65SAl Viro /* ... and discard everything past that point */ 1030b9dc6f65SAl Viro pipe_truncate(i); 1031241699cdSAl Viro } 1032241699cdSAl Viro 1033d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 1034d879cb83SAl Viro { 103500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1036241699cdSAl Viro pipe_advance(i, size); 1037241699cdSAl Viro return; 1038241699cdSAl Viro } 10399ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) { 10409ea9ce04SDavid Howells i->count -= size; 10419ea9ce04SDavid Howells return; 10429ea9ce04SDavid Howells } 1043d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 1044d879cb83SAl Viro } 1045d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 1046d879cb83SAl Viro 104727c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 104827c0e374SAl Viro { 104927c0e374SAl Viro if (!unroll) 105027c0e374SAl Viro return; 10515b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 10525b47d59aSAl Viro return; 105327c0e374SAl Viro i->count += unroll; 105400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 105527c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 105627c0e374SAl Viro int idx = i->idx; 105727c0e374SAl Viro size_t off = i->iov_offset; 105827c0e374SAl Viro while (1) { 105927c0e374SAl Viro size_t n = off - pipe->bufs[idx].offset; 106027c0e374SAl Viro if (unroll < n) { 10614fa55cefSAl Viro off -= unroll; 106227c0e374SAl Viro break; 106327c0e374SAl Viro } 106427c0e374SAl Viro unroll -= n; 106527c0e374SAl Viro if (!unroll && idx == i->start_idx) { 106627c0e374SAl Viro off = 0; 106727c0e374SAl Viro break; 106827c0e374SAl Viro } 106927c0e374SAl Viro if (!idx--) 107027c0e374SAl Viro idx = pipe->buffers - 1; 107127c0e374SAl Viro off = pipe->bufs[idx].offset + pipe->bufs[idx].len; 107227c0e374SAl Viro } 107327c0e374SAl Viro i->iov_offset = off; 107427c0e374SAl Viro i->idx = idx; 107527c0e374SAl Viro pipe_truncate(i); 107627c0e374SAl Viro return; 107727c0e374SAl Viro } 10789ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 10799ea9ce04SDavid Howells return; 108027c0e374SAl Viro if (unroll <= i->iov_offset) { 108127c0e374SAl Viro i->iov_offset -= unroll; 108227c0e374SAl Viro return; 108327c0e374SAl Viro } 108427c0e374SAl Viro unroll -= i->iov_offset; 108500e23707SDavid Howells if (iov_iter_is_bvec(i)) { 108627c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 108727c0e374SAl Viro while (1) { 108827c0e374SAl Viro size_t n = (--bvec)->bv_len; 108927c0e374SAl Viro i->nr_segs++; 109027c0e374SAl Viro if (unroll <= n) { 109127c0e374SAl Viro i->bvec = bvec; 109227c0e374SAl Viro i->iov_offset = n - unroll; 109327c0e374SAl Viro return; 109427c0e374SAl Viro } 109527c0e374SAl Viro unroll -= n; 109627c0e374SAl Viro } 109727c0e374SAl Viro } else { /* same logics for iovec and kvec */ 109827c0e374SAl Viro const struct iovec *iov = i->iov; 109927c0e374SAl Viro while (1) { 110027c0e374SAl Viro size_t n = (--iov)->iov_len; 110127c0e374SAl Viro i->nr_segs++; 110227c0e374SAl Viro if (unroll <= n) { 110327c0e374SAl Viro i->iov = iov; 110427c0e374SAl Viro i->iov_offset = n - unroll; 110527c0e374SAl Viro return; 110627c0e374SAl Viro } 110727c0e374SAl Viro unroll -= n; 110827c0e374SAl Viro } 110927c0e374SAl Viro } 111027c0e374SAl Viro } 111127c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 111227c0e374SAl Viro 1113d879cb83SAl Viro /* 1114d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1115d879cb83SAl Viro */ 1116d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1117d879cb83SAl Viro { 111800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1119241699cdSAl Viro return i->count; // it is a silly place, anyway 1120d879cb83SAl Viro if (i->nr_segs == 1) 1121d879cb83SAl Viro return i->count; 11229ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11239ea9ce04SDavid Howells return i->count; 112400e23707SDavid Howells else if (iov_iter_is_bvec(i)) 1125d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1126d879cb83SAl Viro else 1127d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1128d879cb83SAl Viro } 1129d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1130d879cb83SAl Viro 1131aa563d7bSDavid Howells void iov_iter_kvec(struct iov_iter *i, unsigned int direction, 1132d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1133d879cb83SAl Viro size_t count) 1134d879cb83SAl Viro { 1135aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1136aa563d7bSDavid Howells i->type = ITER_KVEC | (direction & (READ | WRITE)); 1137d879cb83SAl Viro i->kvec = kvec; 1138d879cb83SAl Viro i->nr_segs = nr_segs; 1139d879cb83SAl Viro i->iov_offset = 0; 1140d879cb83SAl Viro i->count = count; 1141d879cb83SAl Viro } 1142d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1143d879cb83SAl Viro 1144aa563d7bSDavid Howells void iov_iter_bvec(struct iov_iter *i, unsigned int direction, 1145d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1146d879cb83SAl Viro size_t count) 1147d879cb83SAl Viro { 1148aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1149aa563d7bSDavid Howells i->type = ITER_BVEC | (direction & (READ | WRITE)); 1150d879cb83SAl Viro i->bvec = bvec; 1151d879cb83SAl Viro i->nr_segs = nr_segs; 1152d879cb83SAl Viro i->iov_offset = 0; 1153d879cb83SAl Viro i->count = count; 1154d879cb83SAl Viro } 1155d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1156d879cb83SAl Viro 1157aa563d7bSDavid Howells void iov_iter_pipe(struct iov_iter *i, unsigned int direction, 1158241699cdSAl Viro struct pipe_inode_info *pipe, 1159241699cdSAl Viro size_t count) 1160241699cdSAl Viro { 1161aa563d7bSDavid Howells BUG_ON(direction != READ); 1162b9dc6f65SAl Viro WARN_ON(pipe->nrbufs == pipe->buffers); 1163aa563d7bSDavid Howells i->type = ITER_PIPE | READ; 1164241699cdSAl Viro i->pipe = pipe; 1165241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 1166241699cdSAl Viro i->iov_offset = 0; 1167241699cdSAl Viro i->count = count; 116827c0e374SAl Viro i->start_idx = i->idx; 1169241699cdSAl Viro } 1170241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1171241699cdSAl Viro 11729ea9ce04SDavid Howells /** 11739ea9ce04SDavid Howells * iov_iter_discard - Initialise an I/O iterator that discards data 11749ea9ce04SDavid Howells * @i: The iterator to initialise. 11759ea9ce04SDavid Howells * @direction: The direction of the transfer. 11769ea9ce04SDavid Howells * @count: The size of the I/O buffer in bytes. 11779ea9ce04SDavid Howells * 11789ea9ce04SDavid Howells * Set up an I/O iterator that just discards everything that's written to it. 11799ea9ce04SDavid Howells * It's only available as a READ iterator. 11809ea9ce04SDavid Howells */ 11819ea9ce04SDavid Howells void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) 11829ea9ce04SDavid Howells { 11839ea9ce04SDavid Howells BUG_ON(direction != READ); 11849ea9ce04SDavid Howells i->type = ITER_DISCARD | READ; 11859ea9ce04SDavid Howells i->count = count; 11869ea9ce04SDavid Howells i->iov_offset = 0; 11879ea9ce04SDavid Howells } 11889ea9ce04SDavid Howells EXPORT_SYMBOL(iov_iter_discard); 11899ea9ce04SDavid Howells 1190d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1191d879cb83SAl Viro { 1192d879cb83SAl Viro unsigned long res = 0; 1193d879cb83SAl Viro size_t size = i->count; 1194d879cb83SAl Viro 119500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 119633844e66SAl Viro if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 1197241699cdSAl Viro return size | i->iov_offset; 1198241699cdSAl Viro return size; 1199241699cdSAl Viro } 1200d879cb83SAl Viro iterate_all_kinds(i, size, v, 1201d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1202d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1203d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1204d879cb83SAl Viro ) 1205d879cb83SAl Viro return res; 1206d879cb83SAl Viro } 1207d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1208d879cb83SAl Viro 1209357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1210357f435dSAl Viro { 1211357f435dSAl Viro unsigned long res = 0; 1212357f435dSAl Viro size_t size = i->count; 1213357f435dSAl Viro 12149ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1215241699cdSAl Viro WARN_ON(1); 1216241699cdSAl Viro return ~0U; 1217241699cdSAl Viro } 1218241699cdSAl Viro 1219357f435dSAl Viro iterate_all_kinds(i, size, v, 1220357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1221357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1222357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1223357f435dSAl Viro (size != v.bv_len ? size : 0)), 1224357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1225357f435dSAl Viro (size != v.iov_len ? size : 0)) 1226357f435dSAl Viro ); 1227357f435dSAl Viro return res; 1228357f435dSAl Viro } 1229357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1230357f435dSAl Viro 1231e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1232241699cdSAl Viro size_t maxsize, 1233241699cdSAl Viro struct page **pages, 1234241699cdSAl Viro int idx, 1235241699cdSAl Viro size_t *start) 1236241699cdSAl Viro { 1237241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 12381689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 1239241699cdSAl Viro if (!n) 1240241699cdSAl Viro return -EFAULT; 1241241699cdSAl Viro 1242241699cdSAl Viro maxsize = n; 1243241699cdSAl Viro n += *start; 12441689c73aSAl Viro while (n > 0) { 1245241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 1246241699cdSAl Viro idx = next_idx(idx, pipe); 1247241699cdSAl Viro n -= PAGE_SIZE; 1248241699cdSAl Viro } 1249241699cdSAl Viro 1250241699cdSAl Viro return maxsize; 1251241699cdSAl Viro } 1252241699cdSAl Viro 1253241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1254241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1255241699cdSAl Viro size_t *start) 1256241699cdSAl Viro { 1257241699cdSAl Viro unsigned npages; 1258241699cdSAl Viro size_t capacity; 1259241699cdSAl Viro int idx; 1260241699cdSAl Viro 126133844e66SAl Viro if (!maxsize) 126233844e66SAl Viro return 0; 126333844e66SAl Viro 1264241699cdSAl Viro if (!sanity(i)) 1265241699cdSAl Viro return -EFAULT; 1266241699cdSAl Viro 1267241699cdSAl Viro data_start(i, &idx, start); 1268241699cdSAl Viro /* some of this one + all after this one */ 1269241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1270241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 1271241699cdSAl Viro 1272241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 1273241699cdSAl Viro } 1274241699cdSAl Viro 1275d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1276d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1277d879cb83SAl Viro size_t *start) 1278d879cb83SAl Viro { 1279d879cb83SAl Viro if (maxsize > i->count) 1280d879cb83SAl Viro maxsize = i->count; 1281d879cb83SAl Viro 128200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1283241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 12849ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 12859ea9ce04SDavid Howells return -EFAULT; 12869ea9ce04SDavid Howells 1287d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1288d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1289d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1290d879cb83SAl Viro int n; 1291d879cb83SAl Viro int res; 1292d879cb83SAl Viro 1293d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1294d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1295d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1296d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 129773b0140bSIra Weiny res = get_user_pages_fast(addr, n, 129873b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, 129973b0140bSIra Weiny pages); 1300d879cb83SAl Viro if (unlikely(res < 0)) 1301d879cb83SAl Viro return res; 1302d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1303d879cb83SAl Viro 0;}),({ 1304d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1305d879cb83SAl Viro *start = v.bv_offset; 1306d879cb83SAl Viro get_page(*pages = v.bv_page); 1307d879cb83SAl Viro return v.bv_len; 1308d879cb83SAl Viro }),({ 1309d879cb83SAl Viro return -EFAULT; 1310d879cb83SAl Viro }) 1311d879cb83SAl Viro ) 1312d879cb83SAl Viro return 0; 1313d879cb83SAl Viro } 1314d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1315d879cb83SAl Viro 1316d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1317d879cb83SAl Viro { 1318752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1319d879cb83SAl Viro } 1320d879cb83SAl Viro 1321241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1322241699cdSAl Viro struct page ***pages, size_t maxsize, 1323241699cdSAl Viro size_t *start) 1324241699cdSAl Viro { 1325241699cdSAl Viro struct page **p; 1326d7760d63SIlya Dryomov ssize_t n; 1327241699cdSAl Viro int idx; 1328241699cdSAl Viro int npages; 1329241699cdSAl Viro 133033844e66SAl Viro if (!maxsize) 133133844e66SAl Viro return 0; 133233844e66SAl Viro 1333241699cdSAl Viro if (!sanity(i)) 1334241699cdSAl Viro return -EFAULT; 1335241699cdSAl Viro 1336241699cdSAl Viro data_start(i, &idx, start); 1337241699cdSAl Viro /* some of this one + all after this one */ 1338241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1339241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1340241699cdSAl Viro if (maxsize > n) 1341241699cdSAl Viro maxsize = n; 1342241699cdSAl Viro else 1343241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1344241699cdSAl Viro p = get_pages_array(npages); 1345241699cdSAl Viro if (!p) 1346241699cdSAl Viro return -ENOMEM; 1347241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 1348241699cdSAl Viro if (n > 0) 1349241699cdSAl Viro *pages = p; 1350241699cdSAl Viro else 1351241699cdSAl Viro kvfree(p); 1352241699cdSAl Viro return n; 1353241699cdSAl Viro } 1354241699cdSAl Viro 1355d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1356d879cb83SAl Viro struct page ***pages, size_t maxsize, 1357d879cb83SAl Viro size_t *start) 1358d879cb83SAl Viro { 1359d879cb83SAl Viro struct page **p; 1360d879cb83SAl Viro 1361d879cb83SAl Viro if (maxsize > i->count) 1362d879cb83SAl Viro maxsize = i->count; 1363d879cb83SAl Viro 136400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1365241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 13669ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 13679ea9ce04SDavid Howells return -EFAULT; 13689ea9ce04SDavid Howells 1369d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1370d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1371d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1372d879cb83SAl Viro int n; 1373d879cb83SAl Viro int res; 1374d879cb83SAl Viro 1375d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1376d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1377d879cb83SAl Viro p = get_pages_array(n); 1378d879cb83SAl Viro if (!p) 1379d879cb83SAl Viro return -ENOMEM; 138073b0140bSIra Weiny res = get_user_pages_fast(addr, n, 138173b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); 1382d879cb83SAl Viro if (unlikely(res < 0)) { 1383d879cb83SAl Viro kvfree(p); 1384d879cb83SAl Viro return res; 1385d879cb83SAl Viro } 1386d879cb83SAl Viro *pages = p; 1387d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1388d879cb83SAl Viro 0;}),({ 1389d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1390d879cb83SAl Viro *start = v.bv_offset; 1391d879cb83SAl Viro *pages = p = get_pages_array(1); 1392d879cb83SAl Viro if (!p) 1393d879cb83SAl Viro return -ENOMEM; 1394d879cb83SAl Viro get_page(*p = v.bv_page); 1395d879cb83SAl Viro return v.bv_len; 1396d879cb83SAl Viro }),({ 1397d879cb83SAl Viro return -EFAULT; 1398d879cb83SAl Viro }) 1399d879cb83SAl Viro ) 1400d879cb83SAl Viro return 0; 1401d879cb83SAl Viro } 1402d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1403d879cb83SAl Viro 1404d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1405d879cb83SAl Viro struct iov_iter *i) 1406d879cb83SAl Viro { 1407d879cb83SAl Viro char *to = addr; 1408d879cb83SAl Viro __wsum sum, next; 1409d879cb83SAl Viro size_t off = 0; 1410d879cb83SAl Viro sum = *csum; 14119ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1412241699cdSAl Viro WARN_ON(1); 1413241699cdSAl Viro return 0; 1414241699cdSAl Viro } 1415d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1416d879cb83SAl Viro int err = 0; 1417d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1418d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1419d879cb83SAl Viro v.iov_len, 0, &err); 1420d879cb83SAl Viro if (!err) { 1421d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1422d879cb83SAl Viro off += v.iov_len; 1423d879cb83SAl Viro } 1424d879cb83SAl Viro err ? v.iov_len : 0; 1425d879cb83SAl Viro }), ({ 1426d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1427f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1428f9152895SAl Viro p + v.bv_offset, v.bv_len, 1429f9152895SAl Viro sum, off); 1430d879cb83SAl Viro kunmap_atomic(p); 1431d879cb83SAl Viro off += v.bv_len; 1432d879cb83SAl Viro }),({ 1433f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1434f9152895SAl Viro v.iov_base, v.iov_len, 1435f9152895SAl Viro sum, off); 1436d879cb83SAl Viro off += v.iov_len; 1437d879cb83SAl Viro }) 1438d879cb83SAl Viro ) 1439d879cb83SAl Viro *csum = sum; 1440d879cb83SAl Viro return bytes; 1441d879cb83SAl Viro } 1442d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1443d879cb83SAl Viro 1444cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1445cbbd26b8SAl Viro struct iov_iter *i) 1446cbbd26b8SAl Viro { 1447cbbd26b8SAl Viro char *to = addr; 1448cbbd26b8SAl Viro __wsum sum, next; 1449cbbd26b8SAl Viro size_t off = 0; 1450cbbd26b8SAl Viro sum = *csum; 14519ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1452cbbd26b8SAl Viro WARN_ON(1); 1453cbbd26b8SAl Viro return false; 1454cbbd26b8SAl Viro } 1455cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1456cbbd26b8SAl Viro return false; 1457cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1458cbbd26b8SAl Viro int err = 0; 1459cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1460cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1461cbbd26b8SAl Viro v.iov_len, 0, &err); 1462cbbd26b8SAl Viro if (err) 1463cbbd26b8SAl Viro return false; 1464cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1465cbbd26b8SAl Viro off += v.iov_len; 1466cbbd26b8SAl Viro 0; 1467cbbd26b8SAl Viro }), ({ 1468cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1469f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1470f9152895SAl Viro p + v.bv_offset, v.bv_len, 1471f9152895SAl Viro sum, off); 1472cbbd26b8SAl Viro kunmap_atomic(p); 1473cbbd26b8SAl Viro off += v.bv_len; 1474cbbd26b8SAl Viro }),({ 1475f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1476f9152895SAl Viro v.iov_base, v.iov_len, 1477f9152895SAl Viro sum, off); 1478cbbd26b8SAl Viro off += v.iov_len; 1479cbbd26b8SAl Viro }) 1480cbbd26b8SAl Viro ) 1481cbbd26b8SAl Viro *csum = sum; 1482cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1483cbbd26b8SAl Viro return true; 1484cbbd26b8SAl Viro } 1485cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1486cbbd26b8SAl Viro 1487cb002d07SSagi Grimberg size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, 1488d879cb83SAl Viro struct iov_iter *i) 1489d879cb83SAl Viro { 149036f7a8a4SAl Viro const char *from = addr; 1491cb002d07SSagi Grimberg __wsum *csum = csump; 1492d879cb83SAl Viro __wsum sum, next; 1493d879cb83SAl Viro size_t off = 0; 149478e1f386SAl Viro 149578e1f386SAl Viro if (unlikely(iov_iter_is_pipe(i))) 149678e1f386SAl Viro return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); 149778e1f386SAl Viro 1498d879cb83SAl Viro sum = *csum; 149978e1f386SAl Viro if (unlikely(iov_iter_is_discard(i))) { 1500241699cdSAl Viro WARN_ON(1); /* for now */ 1501241699cdSAl Viro return 0; 1502241699cdSAl Viro } 1503d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1504d879cb83SAl Viro int err = 0; 1505d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1506d879cb83SAl Viro v.iov_base, 1507d879cb83SAl Viro v.iov_len, 0, &err); 1508d879cb83SAl Viro if (!err) { 1509d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1510d879cb83SAl Viro off += v.iov_len; 1511d879cb83SAl Viro } 1512d879cb83SAl Viro err ? v.iov_len : 0; 1513d879cb83SAl Viro }), ({ 1514d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1515f9152895SAl Viro sum = csum_and_memcpy(p + v.bv_offset, 1516f9152895SAl Viro (from += v.bv_len) - v.bv_len, 1517f9152895SAl Viro v.bv_len, sum, off); 1518d879cb83SAl Viro kunmap_atomic(p); 1519d879cb83SAl Viro off += v.bv_len; 1520d879cb83SAl Viro }),({ 1521f9152895SAl Viro sum = csum_and_memcpy(v.iov_base, 1522f9152895SAl Viro (from += v.iov_len) - v.iov_len, 1523f9152895SAl Viro v.iov_len, sum, off); 1524d879cb83SAl Viro off += v.iov_len; 1525d879cb83SAl Viro }) 1526d879cb83SAl Viro ) 1527d879cb83SAl Viro *csum = sum; 1528d879cb83SAl Viro return bytes; 1529d879cb83SAl Viro } 1530d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1531d879cb83SAl Viro 1532d05f4435SSagi Grimberg size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, 1533d05f4435SSagi Grimberg struct iov_iter *i) 1534d05f4435SSagi Grimberg { 153527fad74aSYueHaibing #ifdef CONFIG_CRYPTO 1536d05f4435SSagi Grimberg struct ahash_request *hash = hashp; 1537d05f4435SSagi Grimberg struct scatterlist sg; 1538d05f4435SSagi Grimberg size_t copied; 1539d05f4435SSagi Grimberg 1540d05f4435SSagi Grimberg copied = copy_to_iter(addr, bytes, i); 1541d05f4435SSagi Grimberg sg_init_one(&sg, addr, copied); 1542d05f4435SSagi Grimberg ahash_request_set_crypt(hash, &sg, NULL, copied); 1543d05f4435SSagi Grimberg crypto_ahash_update(hash); 1544d05f4435SSagi Grimberg return copied; 154527fad74aSYueHaibing #else 154627fad74aSYueHaibing return 0; 154727fad74aSYueHaibing #endif 1548d05f4435SSagi Grimberg } 1549d05f4435SSagi Grimberg EXPORT_SYMBOL(hash_and_copy_to_iter); 1550d05f4435SSagi Grimberg 1551d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1552d879cb83SAl Viro { 1553d879cb83SAl Viro size_t size = i->count; 1554d879cb83SAl Viro int npages = 0; 1555d879cb83SAl Viro 1556d879cb83SAl Viro if (!size) 1557d879cb83SAl Viro return 0; 15589ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 15599ea9ce04SDavid Howells return 0; 1560d879cb83SAl Viro 156100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1562241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1563241699cdSAl Viro size_t off; 1564241699cdSAl Viro int idx; 1565241699cdSAl Viro 1566241699cdSAl Viro if (!sanity(i)) 1567241699cdSAl Viro return 0; 1568241699cdSAl Viro 1569241699cdSAl Viro data_start(i, &idx, &off); 1570241699cdSAl Viro /* some of this one + all after this one */ 1571241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1572241699cdSAl Viro if (npages >= maxpages) 1573241699cdSAl Viro return maxpages; 1574241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1575d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1576d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1577d879cb83SAl Viro - p / PAGE_SIZE; 1578d879cb83SAl Viro if (npages >= maxpages) 1579d879cb83SAl Viro return maxpages; 1580d879cb83SAl Viro 0;}),({ 1581d879cb83SAl Viro npages++; 1582d879cb83SAl Viro if (npages >= maxpages) 1583d879cb83SAl Viro return maxpages; 1584d879cb83SAl Viro }),({ 1585d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1586d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1587d879cb83SAl Viro - p / PAGE_SIZE; 1588d879cb83SAl Viro if (npages >= maxpages) 1589d879cb83SAl Viro return maxpages; 1590d879cb83SAl Viro }) 1591d879cb83SAl Viro ) 1592d879cb83SAl Viro return npages; 1593d879cb83SAl Viro } 1594d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1595d879cb83SAl Viro 1596d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1597d879cb83SAl Viro { 1598d879cb83SAl Viro *new = *old; 159900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(new))) { 1600241699cdSAl Viro WARN_ON(1); 1601241699cdSAl Viro return NULL; 1602241699cdSAl Viro } 16039ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(new))) 16049ea9ce04SDavid Howells return NULL; 160500e23707SDavid Howells if (iov_iter_is_bvec(new)) 1606d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1607d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1608d879cb83SAl Viro flags); 1609d879cb83SAl Viro else 1610d879cb83SAl Viro /* iovec and kvec have identical layout */ 1611d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1612d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1613d879cb83SAl Viro flags); 1614d879cb83SAl Viro } 1615d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1616bc917be8SAl Viro 1617ffecee4fSVegard Nossum /** 1618ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1619ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1620ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1621ffecee4fSVegard Nossum * 1622ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1623ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1624ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1625ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1626ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1627ffecee4fSVegard Nossum * on-stack) kernel array. 1628ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1629ffecee4fSVegard Nossum * 1630ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1631ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1632ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1633ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1634ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1635ffecee4fSVegard Nossum * returns an error or not). 1636ffecee4fSVegard Nossum * 163787e5e6daSJens Axboe * Return: Negative error code on error, bytes imported on success 1638ffecee4fSVegard Nossum */ 163987e5e6daSJens Axboe ssize_t import_iovec(int type, const struct iovec __user * uvector, 1640bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1641bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1642bc917be8SAl Viro { 1643bc917be8SAl Viro ssize_t n; 1644bc917be8SAl Viro struct iovec *p; 1645bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1646bc917be8SAl Viro *iov, &p); 1647bc917be8SAl Viro if (n < 0) { 1648bc917be8SAl Viro if (p != *iov) 1649bc917be8SAl Viro kfree(p); 1650bc917be8SAl Viro *iov = NULL; 1651bc917be8SAl Viro return n; 1652bc917be8SAl Viro } 1653bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1654bc917be8SAl Viro *iov = p == *iov ? NULL : p; 165587e5e6daSJens Axboe return n; 1656bc917be8SAl Viro } 1657bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1658bc917be8SAl Viro 1659bc917be8SAl Viro #ifdef CONFIG_COMPAT 1660bc917be8SAl Viro #include <linux/compat.h> 1661bc917be8SAl Viro 166287e5e6daSJens Axboe ssize_t compat_import_iovec(int type, 166387e5e6daSJens Axboe const struct compat_iovec __user * uvector, 1664bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1665bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1666bc917be8SAl Viro { 1667bc917be8SAl Viro ssize_t n; 1668bc917be8SAl Viro struct iovec *p; 1669bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1670bc917be8SAl Viro *iov, &p); 1671bc917be8SAl Viro if (n < 0) { 1672bc917be8SAl Viro if (p != *iov) 1673bc917be8SAl Viro kfree(p); 1674bc917be8SAl Viro *iov = NULL; 1675bc917be8SAl Viro return n; 1676bc917be8SAl Viro } 1677bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1678bc917be8SAl Viro *iov = p == *iov ? NULL : p; 167987e5e6daSJens Axboe return n; 1680bc917be8SAl Viro } 1681bc917be8SAl Viro #endif 1682bc917be8SAl Viro 1683bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1684bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1685bc917be8SAl Viro { 1686bc917be8SAl Viro if (len > MAX_RW_COUNT) 1687bc917be8SAl Viro len = MAX_RW_COUNT; 168896d4f267SLinus Torvalds if (unlikely(!access_ok(buf, len))) 1689bc917be8SAl Viro return -EFAULT; 1690bc917be8SAl Viro 1691bc917be8SAl Viro iov->iov_base = buf; 1692bc917be8SAl Viro iov->iov_len = len; 1693bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1694bc917be8SAl Viro return 0; 1695bc917be8SAl Viro } 1696e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 169709cf698aSAl Viro 169809cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 169909cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 170009cf698aSAl Viro void *context) 170109cf698aSAl Viro { 170209cf698aSAl Viro struct kvec w; 170309cf698aSAl Viro int err = -EINVAL; 170409cf698aSAl Viro if (!bytes) 170509cf698aSAl Viro return 0; 170609cf698aSAl Viro 170709cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 170809cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 170909cf698aSAl Viro w.iov_len = v.bv_len; 171009cf698aSAl Viro err = f(&w, context); 171109cf698aSAl Viro kunmap(v.bv_page); 171209cf698aSAl Viro err;}), ({ 171309cf698aSAl Viro w = v; 171409cf698aSAl Viro err = f(&w, context);}) 171509cf698aSAl Viro ) 171609cf698aSAl Viro return err; 171709cf698aSAl Viro } 171809cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1719