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; 3288cefc107SDavid Howells unsigned int p_head = pipe->head; 3298cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3308cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3318cefc107SDavid Howells unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); 3328cefc107SDavid Howells unsigned int i_head = i->head; 3338cefc107SDavid Howells unsigned int idx; 3348cefc107SDavid Howells 335241699cdSAl Viro if (i->iov_offset) { 336241699cdSAl Viro struct pipe_buffer *p; 3378cefc107SDavid Howells if (unlikely(p_occupancy == 0)) 338241699cdSAl Viro goto Bad; // pipe must be non-empty 3398cefc107SDavid Howells if (unlikely(i_head != p_head - 1)) 340241699cdSAl Viro goto Bad; // must be at the last buffer... 341241699cdSAl Viro 3428cefc107SDavid Howells p = &pipe->bufs[i_head & p_mask]; 343241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 344241699cdSAl Viro goto Bad; // ... at the end of segment 345241699cdSAl Viro } else { 3468cefc107SDavid Howells if (i_head != p_head) 347241699cdSAl Viro goto Bad; // must be right after the last buffer 348241699cdSAl Viro } 349241699cdSAl Viro return true; 350241699cdSAl Viro Bad: 3518cefc107SDavid Howells printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); 3528cefc107SDavid Howells printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", 3538cefc107SDavid Howells p_head, p_tail, pipe->ring_size); 3548cefc107SDavid Howells for (idx = 0; idx < pipe->ring_size; idx++) 355241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 356241699cdSAl Viro pipe->bufs[idx].ops, 357241699cdSAl Viro pipe->bufs[idx].page, 358241699cdSAl Viro pipe->bufs[idx].offset, 359241699cdSAl Viro pipe->bufs[idx].len); 360241699cdSAl Viro WARN_ON(1); 361241699cdSAl Viro return false; 362241699cdSAl Viro } 363241699cdSAl Viro #else 364241699cdSAl Viro #define sanity(i) true 365241699cdSAl Viro #endif 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; 3728cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3738cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3748cefc107SDavid Howells unsigned int i_head = i->head; 375241699cdSAl Viro size_t off; 376241699cdSAl Viro 377241699cdSAl Viro if (unlikely(bytes > i->count)) 378241699cdSAl Viro bytes = i->count; 379241699cdSAl Viro 380241699cdSAl Viro if (unlikely(!bytes)) 381241699cdSAl Viro return 0; 382241699cdSAl Viro 383241699cdSAl Viro if (!sanity(i)) 384241699cdSAl Viro return 0; 385241699cdSAl Viro 386241699cdSAl Viro off = i->iov_offset; 3878cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 388241699cdSAl Viro if (off) { 389241699cdSAl Viro if (offset == off && buf->page == page) { 390241699cdSAl Viro /* merge with the last one */ 391241699cdSAl Viro buf->len += bytes; 392241699cdSAl Viro i->iov_offset += bytes; 393241699cdSAl Viro goto out; 394241699cdSAl Viro } 3958cefc107SDavid Howells i_head++; 3968cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 397241699cdSAl Viro } 3986718b6f8SDavid Howells if (pipe_full(i_head, p_tail, pipe->max_usage)) 399241699cdSAl Viro return 0; 4008cefc107SDavid Howells 401241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 4028cefc107SDavid Howells get_page(page); 4038cefc107SDavid Howells buf->page = page; 404241699cdSAl Viro buf->offset = offset; 405241699cdSAl Viro buf->len = bytes; 4068cefc107SDavid Howells 4078cefc107SDavid Howells pipe->head = i_head + 1; 408241699cdSAl Viro i->iov_offset = offset + bytes; 4098cefc107SDavid Howells i->head = i_head; 410241699cdSAl Viro out: 411241699cdSAl Viro i->count -= bytes; 412241699cdSAl Viro return bytes; 413241699cdSAl Viro } 414241699cdSAl Viro 415d879cb83SAl Viro /* 416171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 417171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 418171a0203SAnton Altaparmakov * 419171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 420171a0203SAnton Altaparmakov * because it is an invalid address). 421171a0203SAnton Altaparmakov */ 422d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 423171a0203SAnton Altaparmakov { 424171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 425171a0203SAnton Altaparmakov const struct iovec *iov; 426171a0203SAnton Altaparmakov int err; 427171a0203SAnton Altaparmakov struct iovec v; 428171a0203SAnton Altaparmakov 429171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 430171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4314bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 432171a0203SAnton Altaparmakov if (unlikely(err)) 433171a0203SAnton Altaparmakov return err; 434171a0203SAnton Altaparmakov 0;})) 435171a0203SAnton Altaparmakov } 436171a0203SAnton Altaparmakov return 0; 437171a0203SAnton Altaparmakov } 438d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 439171a0203SAnton Altaparmakov 440aa563d7bSDavid Howells void iov_iter_init(struct iov_iter *i, unsigned int direction, 441d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 442d879cb83SAl Viro size_t count) 443d879cb83SAl Viro { 444aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 445aa563d7bSDavid Howells direction &= READ | WRITE; 446aa563d7bSDavid Howells 447d879cb83SAl Viro /* It will get better. Eventually... */ 448db68ce10SAl Viro if (uaccess_kernel()) { 449aa563d7bSDavid Howells i->type = ITER_KVEC | direction; 450d879cb83SAl Viro i->kvec = (struct kvec *)iov; 451d879cb83SAl Viro } else { 452aa563d7bSDavid Howells i->type = ITER_IOVEC | direction; 453d879cb83SAl Viro i->iov = iov; 454d879cb83SAl Viro } 455d879cb83SAl Viro i->nr_segs = nr_segs; 456d879cb83SAl Viro i->iov_offset = 0; 457d879cb83SAl Viro i->count = count; 458d879cb83SAl Viro } 459d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 460d879cb83SAl Viro 461d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 462d879cb83SAl Viro { 463d879cb83SAl Viro char *from = kmap_atomic(page); 464d879cb83SAl Viro memcpy(to, from + offset, len); 465d879cb83SAl Viro kunmap_atomic(from); 466d879cb83SAl Viro } 467d879cb83SAl Viro 46836f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 469d879cb83SAl Viro { 470d879cb83SAl Viro char *to = kmap_atomic(page); 471d879cb83SAl Viro memcpy(to + offset, from, len); 472d879cb83SAl Viro kunmap_atomic(to); 473d879cb83SAl Viro } 474d879cb83SAl Viro 475d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 476d879cb83SAl Viro { 477d879cb83SAl Viro char *addr = kmap_atomic(page); 478d879cb83SAl Viro memset(addr + offset, 0, len); 479d879cb83SAl Viro kunmap_atomic(addr); 480d879cb83SAl Viro } 481d879cb83SAl Viro 482241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 483241699cdSAl Viro { 484241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 485241699cdSAl Viro } 486241699cdSAl Viro 4878cefc107SDavid Howells static inline void data_start(const struct iov_iter *i, 4888cefc107SDavid Howells unsigned int *iter_headp, size_t *offp) 489241699cdSAl Viro { 4908cefc107SDavid Howells unsigned int p_mask = i->pipe->ring_size - 1; 4918cefc107SDavid Howells unsigned int iter_head = i->head; 492241699cdSAl Viro size_t off = i->iov_offset; 4938cefc107SDavid Howells 4948cefc107SDavid Howells if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || 4958cefc107SDavid Howells off == PAGE_SIZE)) { 4968cefc107SDavid Howells iter_head++; 497241699cdSAl Viro off = 0; 498241699cdSAl Viro } 4998cefc107SDavid Howells *iter_headp = iter_head; 500241699cdSAl Viro *offp = off; 501241699cdSAl Viro } 502241699cdSAl Viro 503241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 5048cefc107SDavid Howells int *iter_headp, size_t *offp) 505241699cdSAl Viro { 506241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5078cefc107SDavid Howells unsigned int p_tail = pipe->tail; 5088cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5098cefc107SDavid Howells unsigned int iter_head; 510241699cdSAl Viro size_t off; 511241699cdSAl Viro ssize_t left; 512241699cdSAl Viro 513241699cdSAl Viro if (unlikely(size > i->count)) 514241699cdSAl Viro size = i->count; 515241699cdSAl Viro if (unlikely(!size)) 516241699cdSAl Viro return 0; 517241699cdSAl Viro 518241699cdSAl Viro left = size; 5198cefc107SDavid Howells data_start(i, &iter_head, &off); 5208cefc107SDavid Howells *iter_headp = iter_head; 521241699cdSAl Viro *offp = off; 522241699cdSAl Viro if (off) { 523241699cdSAl Viro left -= PAGE_SIZE - off; 524241699cdSAl Viro if (left <= 0) { 5258cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len += size; 526241699cdSAl Viro return size; 527241699cdSAl Viro } 5288cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; 5298cefc107SDavid Howells iter_head++; 530241699cdSAl Viro } 5316718b6f8SDavid Howells while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { 5328cefc107SDavid Howells struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; 533241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 534241699cdSAl Viro if (!page) 535241699cdSAl Viro break; 5368cefc107SDavid Howells 5378cefc107SDavid Howells buf->ops = &default_pipe_buf_ops; 5388cefc107SDavid Howells buf->page = page; 5398cefc107SDavid Howells buf->offset = 0; 5408cefc107SDavid Howells buf->len = min_t(ssize_t, left, PAGE_SIZE); 5418cefc107SDavid Howells left -= buf->len; 5428cefc107SDavid Howells iter_head++; 5438cefc107SDavid Howells pipe->head = iter_head; 5448cefc107SDavid Howells 5458cefc107SDavid Howells if (left == 0) 546241699cdSAl Viro return size; 547241699cdSAl Viro } 548241699cdSAl Viro return size - left; 549241699cdSAl Viro } 550241699cdSAl Viro 551241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 552241699cdSAl Viro struct iov_iter *i) 553241699cdSAl Viro { 554241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5558cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5568cefc107SDavid Howells unsigned int i_head; 557241699cdSAl Viro size_t n, off; 558241699cdSAl Viro 559241699cdSAl Viro if (!sanity(i)) 560241699cdSAl Viro return 0; 561241699cdSAl Viro 5628cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 563241699cdSAl Viro if (unlikely(!n)) 564241699cdSAl Viro return 0; 5658cefc107SDavid Howells do { 566241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 5678cefc107SDavid Howells memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); 5688cefc107SDavid Howells i->head = i_head; 569241699cdSAl Viro i->iov_offset = off + chunk; 570241699cdSAl Viro n -= chunk; 571241699cdSAl Viro addr += chunk; 5728cefc107SDavid Howells off = 0; 5738cefc107SDavid Howells i_head++; 5748cefc107SDavid Howells } while (n); 575241699cdSAl Viro i->count -= bytes; 576241699cdSAl Viro return bytes; 577241699cdSAl Viro } 578241699cdSAl Viro 579f9152895SAl Viro static __wsum csum_and_memcpy(void *to, const void *from, size_t len, 580f9152895SAl Viro __wsum sum, size_t off) 581f9152895SAl Viro { 582f9152895SAl Viro __wsum next = csum_partial_copy_nocheck(from, to, len, 0); 583f9152895SAl Viro return csum_block_add(sum, next, off); 584f9152895SAl Viro } 585f9152895SAl Viro 58678e1f386SAl Viro static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 58778e1f386SAl Viro __wsum *csum, struct iov_iter *i) 58878e1f386SAl Viro { 58978e1f386SAl Viro struct pipe_inode_info *pipe = i->pipe; 5908cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5918cefc107SDavid Howells unsigned int i_head; 59278e1f386SAl Viro size_t n, r; 59378e1f386SAl Viro size_t off = 0; 594f9152895SAl Viro __wsum sum = *csum; 59578e1f386SAl Viro 59678e1f386SAl Viro if (!sanity(i)) 59778e1f386SAl Viro return 0; 59878e1f386SAl Viro 5998cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &r); 60078e1f386SAl Viro if (unlikely(!n)) 60178e1f386SAl Viro return 0; 6028cefc107SDavid Howells do { 60378e1f386SAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - r); 6048cefc107SDavid Howells char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); 605f9152895SAl Viro sum = csum_and_memcpy(p + r, addr, chunk, sum, off); 60678e1f386SAl Viro kunmap_atomic(p); 6078cefc107SDavid Howells i->head = i_head; 60878e1f386SAl Viro i->iov_offset = r + chunk; 60978e1f386SAl Viro n -= chunk; 61078e1f386SAl Viro off += chunk; 61178e1f386SAl Viro addr += chunk; 6128cefc107SDavid Howells r = 0; 6138cefc107SDavid Howells i_head++; 6148cefc107SDavid Howells } while (n); 61578e1f386SAl Viro i->count -= bytes; 61678e1f386SAl Viro *csum = sum; 61778e1f386SAl Viro return bytes; 61878e1f386SAl Viro } 61978e1f386SAl Viro 620aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 621d879cb83SAl Viro { 62236f7a8a4SAl Viro const char *from = addr; 62300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 624241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 62509fc68dcSAl Viro if (iter_is_iovec(i)) 62609fc68dcSAl Viro might_fault(); 627d879cb83SAl Viro iterate_and_advance(i, bytes, v, 62809fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 629d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 630d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 631d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 632d879cb83SAl Viro ) 633d879cb83SAl Viro 634d879cb83SAl Viro return bytes; 635d879cb83SAl Viro } 636aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 637d879cb83SAl Viro 6388780356eSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE 6398780356eSDan Williams static int copyout_mcsafe(void __user *to, const void *from, size_t n) 6408780356eSDan Williams { 64196d4f267SLinus Torvalds if (access_ok(to, n)) { 6428780356eSDan Williams kasan_check_read(from, n); 6438780356eSDan Williams n = copy_to_user_mcsafe((__force void *) to, from, n); 6448780356eSDan Williams } 6458780356eSDan Williams return n; 6468780356eSDan Williams } 6478780356eSDan Williams 6488780356eSDan Williams static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, 6498780356eSDan Williams const char *from, size_t len) 6508780356eSDan Williams { 6518780356eSDan Williams unsigned long ret; 6528780356eSDan Williams char *to; 6538780356eSDan Williams 6548780356eSDan Williams to = kmap_atomic(page); 6558780356eSDan Williams ret = memcpy_mcsafe(to + offset, from, len); 6568780356eSDan Williams kunmap_atomic(to); 6578780356eSDan Williams 6588780356eSDan Williams return ret; 6598780356eSDan Williams } 6608780356eSDan Williams 661ca146f6fSDan Williams static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, 662ca146f6fSDan Williams struct iov_iter *i) 663ca146f6fSDan Williams { 664ca146f6fSDan Williams struct pipe_inode_info *pipe = i->pipe; 6658cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 6668cefc107SDavid Howells unsigned int i_head; 667ca146f6fSDan Williams size_t n, off, xfer = 0; 668ca146f6fSDan Williams 669ca146f6fSDan Williams if (!sanity(i)) 670ca146f6fSDan Williams return 0; 671ca146f6fSDan Williams 6728cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 673ca146f6fSDan Williams if (unlikely(!n)) 674ca146f6fSDan Williams return 0; 6758cefc107SDavid Howells do { 676ca146f6fSDan Williams size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 677ca146f6fSDan Williams unsigned long rem; 678ca146f6fSDan Williams 6798cefc107SDavid Howells rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page, 6808cefc107SDavid Howells off, addr, chunk); 6818cefc107SDavid Howells i->head = i_head; 682ca146f6fSDan Williams i->iov_offset = off + chunk - rem; 683ca146f6fSDan Williams xfer += chunk - rem; 684ca146f6fSDan Williams if (rem) 685ca146f6fSDan Williams break; 686ca146f6fSDan Williams n -= chunk; 687ca146f6fSDan Williams addr += chunk; 6888cefc107SDavid Howells off = 0; 6898cefc107SDavid Howells i_head++; 6908cefc107SDavid Howells } while (n); 691ca146f6fSDan Williams i->count -= xfer; 692ca146f6fSDan Williams return xfer; 693ca146f6fSDan Williams } 694ca146f6fSDan Williams 695bf3eeb9bSDan Williams /** 696bf3eeb9bSDan Williams * _copy_to_iter_mcsafe - copy to user with source-read error exception handling 697bf3eeb9bSDan Williams * @addr: source kernel address 698bf3eeb9bSDan Williams * @bytes: total transfer length 699bf3eeb9bSDan Williams * @iter: destination iterator 700bf3eeb9bSDan Williams * 701bf3eeb9bSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 702bf3eeb9bSDan Williams * dax_copy_to_iter() for protecting read/write to persistent memory. 703bf3eeb9bSDan Williams * Unless / until an architecture can guarantee identical performance 704bf3eeb9bSDan Williams * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a 705bf3eeb9bSDan Williams * performance regression to switch more users to the mcsafe version. 706bf3eeb9bSDan Williams * 707bf3eeb9bSDan Williams * Otherwise, the main differences between this and typical _copy_to_iter(). 708bf3eeb9bSDan Williams * 709bf3eeb9bSDan Williams * * Typical tail/residue handling after a fault retries the copy 710bf3eeb9bSDan Williams * byte-by-byte until the fault happens again. Re-triggering machine 711bf3eeb9bSDan Williams * checks is potentially fatal so the implementation uses source 712bf3eeb9bSDan Williams * alignment and poison alignment assumptions to avoid re-triggering 713bf3eeb9bSDan Williams * hardware exceptions. 714bf3eeb9bSDan Williams * 715bf3eeb9bSDan Williams * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. 716bf3eeb9bSDan Williams * Compare to copy_to_iter() where only ITER_IOVEC attempts might return 717bf3eeb9bSDan Williams * a short copy. 718bf3eeb9bSDan Williams * 719bf3eeb9bSDan Williams * See MCSAFE_TEST for self-test. 720bf3eeb9bSDan Williams */ 7218780356eSDan Williams size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) 7228780356eSDan Williams { 7238780356eSDan Williams const char *from = addr; 7248780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 7258780356eSDan Williams 72600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 727ca146f6fSDan Williams return copy_pipe_to_iter_mcsafe(addr, bytes, i); 7288780356eSDan Williams if (iter_is_iovec(i)) 7298780356eSDan Williams might_fault(); 7308780356eSDan Williams iterate_and_advance(i, bytes, v, 7318780356eSDan Williams copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 7328780356eSDan Williams ({ 7338780356eSDan Williams rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, 7348780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 7358780356eSDan Williams if (rem) { 7368780356eSDan Williams curr_addr = (unsigned long) from; 7378780356eSDan Williams bytes = curr_addr - s_addr - rem; 7388780356eSDan Williams return bytes; 7398780356eSDan Williams } 7408780356eSDan Williams }), 7418780356eSDan Williams ({ 7428780356eSDan Williams rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, 7438780356eSDan Williams v.iov_len); 7448780356eSDan Williams if (rem) { 7458780356eSDan Williams curr_addr = (unsigned long) from; 7468780356eSDan Williams bytes = curr_addr - s_addr - rem; 7478780356eSDan Williams return bytes; 7488780356eSDan Williams } 7498780356eSDan Williams }) 7508780356eSDan Williams ) 7518780356eSDan Williams 7528780356eSDan Williams return bytes; 7538780356eSDan Williams } 7548780356eSDan Williams EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); 7558780356eSDan Williams #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ 7568780356eSDan Williams 757aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 758d879cb83SAl Viro { 759d879cb83SAl Viro char *to = addr; 76000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 761241699cdSAl Viro WARN_ON(1); 762241699cdSAl Viro return 0; 763241699cdSAl Viro } 76409fc68dcSAl Viro if (iter_is_iovec(i)) 76509fc68dcSAl Viro might_fault(); 766d879cb83SAl Viro iterate_and_advance(i, bytes, v, 76709fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 768d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 769d879cb83SAl Viro v.bv_offset, v.bv_len), 770d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 771d879cb83SAl Viro ) 772d879cb83SAl Viro 773d879cb83SAl Viro return bytes; 774d879cb83SAl Viro } 775aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 776d879cb83SAl Viro 777aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 778cbbd26b8SAl Viro { 779cbbd26b8SAl Viro char *to = addr; 78000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 781cbbd26b8SAl Viro WARN_ON(1); 782cbbd26b8SAl Viro return false; 783cbbd26b8SAl Viro } 78433844e66SAl Viro if (unlikely(i->count < bytes)) 785cbbd26b8SAl Viro return false; 786cbbd26b8SAl Viro 78709fc68dcSAl Viro if (iter_is_iovec(i)) 78809fc68dcSAl Viro might_fault(); 789cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 79009fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 791cbbd26b8SAl Viro v.iov_base, v.iov_len)) 792cbbd26b8SAl Viro return false; 793cbbd26b8SAl Viro 0;}), 794cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 795cbbd26b8SAl Viro v.bv_offset, v.bv_len), 796cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 797cbbd26b8SAl Viro ) 798cbbd26b8SAl Viro 799cbbd26b8SAl Viro iov_iter_advance(i, bytes); 800cbbd26b8SAl Viro return true; 801cbbd26b8SAl Viro } 802aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 803cbbd26b8SAl Viro 804aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 805d879cb83SAl Viro { 806d879cb83SAl Viro char *to = addr; 80700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 808241699cdSAl Viro WARN_ON(1); 809241699cdSAl Viro return 0; 810241699cdSAl Viro } 811d879cb83SAl Viro iterate_and_advance(i, bytes, v, 8123f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 813d879cb83SAl Viro v.iov_base, v.iov_len), 814d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 815d879cb83SAl Viro v.bv_offset, v.bv_len), 816d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 817d879cb83SAl Viro ) 818d879cb83SAl Viro 819d879cb83SAl Viro return bytes; 820d879cb83SAl Viro } 821aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 822d879cb83SAl Viro 8230aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 824abd08d7dSDan Williams /** 825abd08d7dSDan Williams * _copy_from_iter_flushcache - write destination through cpu cache 826abd08d7dSDan Williams * @addr: destination kernel address 827abd08d7dSDan Williams * @bytes: total transfer length 828abd08d7dSDan Williams * @iter: source iterator 829abd08d7dSDan Williams * 830abd08d7dSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 831abd08d7dSDan Williams * dax_copy_from_iter() for ensuring that writes to persistent memory 832abd08d7dSDan Williams * are flushed through the CPU cache. It is differentiated from 833abd08d7dSDan Williams * _copy_from_iter_nocache() in that guarantees all data is flushed for 834abd08d7dSDan Williams * all iterator types. The _copy_from_iter_nocache() only attempts to 835abd08d7dSDan Williams * bypass the cache for the ITER_IOVEC case, and on some archs may use 836abd08d7dSDan Williams * instructions that strand dirty-data in the cache. 837abd08d7dSDan Williams */ 8386a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 8390aed55afSDan Williams { 8400aed55afSDan Williams char *to = addr; 84100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 8420aed55afSDan Williams WARN_ON(1); 8430aed55afSDan Williams return 0; 8440aed55afSDan Williams } 8450aed55afSDan Williams iterate_and_advance(i, bytes, v, 8460aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 8470aed55afSDan Williams v.iov_base, v.iov_len), 8480aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 8490aed55afSDan Williams v.bv_offset, v.bv_len), 8500aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 8510aed55afSDan Williams v.iov_len) 8520aed55afSDan Williams ) 8530aed55afSDan Williams 8540aed55afSDan Williams return bytes; 8550aed55afSDan Williams } 8566a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 8570aed55afSDan Williams #endif 8580aed55afSDan Williams 859aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 860cbbd26b8SAl Viro { 861cbbd26b8SAl Viro char *to = addr; 86200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 863cbbd26b8SAl Viro WARN_ON(1); 864cbbd26b8SAl Viro return false; 865cbbd26b8SAl Viro } 86633844e66SAl Viro if (unlikely(i->count < bytes)) 867cbbd26b8SAl Viro return false; 868cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 8693f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 870cbbd26b8SAl Viro v.iov_base, v.iov_len)) 871cbbd26b8SAl Viro return false; 872cbbd26b8SAl Viro 0;}), 873cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 874cbbd26b8SAl Viro v.bv_offset, v.bv_len), 875cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 876cbbd26b8SAl Viro ) 877cbbd26b8SAl Viro 878cbbd26b8SAl Viro iov_iter_advance(i, bytes); 879cbbd26b8SAl Viro return true; 880cbbd26b8SAl Viro } 881aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 882cbbd26b8SAl Viro 88372e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 88472e809edSAl Viro { 8856daef95bSEric Dumazet struct page *head; 8866daef95bSEric Dumazet size_t v = n + offset; 8876daef95bSEric Dumazet 8886daef95bSEric Dumazet /* 8896daef95bSEric Dumazet * The general case needs to access the page order in order 8906daef95bSEric Dumazet * to compute the page size. 8916daef95bSEric Dumazet * However, we mostly deal with order-0 pages and thus can 8926daef95bSEric Dumazet * avoid a possible cache line miss for requests that fit all 8936daef95bSEric Dumazet * page orders. 8946daef95bSEric Dumazet */ 8956daef95bSEric Dumazet if (n <= v && v <= PAGE_SIZE) 8966daef95bSEric Dumazet return true; 8976daef95bSEric Dumazet 8986daef95bSEric Dumazet head = compound_head(page); 8996daef95bSEric Dumazet v += (page - head) << PAGE_SHIFT; 900a90bcb86SPetar Penkov 901a50b854eSMatthew Wilcox (Oracle) if (likely(n <= v && v <= (page_size(head)))) 90272e809edSAl Viro return true; 90372e809edSAl Viro WARN_ON(1); 90472e809edSAl Viro return false; 90572e809edSAl Viro } 906d879cb83SAl Viro 907d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 908d879cb83SAl Viro struct iov_iter *i) 909d879cb83SAl Viro { 91072e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 91172e809edSAl Viro return 0; 912d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 913d879cb83SAl Viro void *kaddr = kmap_atomic(page); 914d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 915d879cb83SAl Viro kunmap_atomic(kaddr); 916d879cb83SAl Viro return wanted; 9179ea9ce04SDavid Howells } else if (unlikely(iov_iter_is_discard(i))) 9189ea9ce04SDavid Howells return bytes; 9199ea9ce04SDavid Howells else if (likely(!iov_iter_is_pipe(i))) 920d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 921241699cdSAl Viro else 922241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 923d879cb83SAl Viro } 924d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 925d879cb83SAl Viro 926d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 927d879cb83SAl Viro struct iov_iter *i) 928d879cb83SAl Viro { 92972e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 93072e809edSAl Viro return 0; 9319ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 932241699cdSAl Viro WARN_ON(1); 933241699cdSAl Viro return 0; 934241699cdSAl Viro } 935d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 936d879cb83SAl Viro void *kaddr = kmap_atomic(page); 937aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 938d879cb83SAl Viro kunmap_atomic(kaddr); 939d879cb83SAl Viro return wanted; 940d879cb83SAl Viro } else 941d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 942d879cb83SAl Viro } 943d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 944d879cb83SAl Viro 945241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 946241699cdSAl Viro { 947241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9488cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 9498cefc107SDavid Howells unsigned int i_head; 950241699cdSAl Viro size_t n, off; 951241699cdSAl Viro 952241699cdSAl Viro if (!sanity(i)) 953241699cdSAl Viro return 0; 954241699cdSAl Viro 9558cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 956241699cdSAl Viro if (unlikely(!n)) 957241699cdSAl Viro return 0; 958241699cdSAl Viro 9598cefc107SDavid Howells do { 960241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 9618cefc107SDavid Howells memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); 9628cefc107SDavid Howells i->head = i_head; 963241699cdSAl Viro i->iov_offset = off + chunk; 964241699cdSAl Viro n -= chunk; 9658cefc107SDavid Howells off = 0; 9668cefc107SDavid Howells i_head++; 9678cefc107SDavid Howells } while (n); 968241699cdSAl Viro i->count -= bytes; 969241699cdSAl Viro return bytes; 970241699cdSAl Viro } 971241699cdSAl Viro 972d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 973d879cb83SAl Viro { 97400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 975241699cdSAl Viro return pipe_zero(bytes, i); 976d879cb83SAl Viro iterate_and_advance(i, bytes, v, 97709fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 978d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 979d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 980d879cb83SAl Viro ) 981d879cb83SAl Viro 982d879cb83SAl Viro return bytes; 983d879cb83SAl Viro } 984d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 985d879cb83SAl Viro 986d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 987d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 988d879cb83SAl Viro { 989d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 99072e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 99172e809edSAl Viro kunmap_atomic(kaddr); 99272e809edSAl Viro return 0; 99372e809edSAl Viro } 9949ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 995241699cdSAl Viro kunmap_atomic(kaddr); 996241699cdSAl Viro WARN_ON(1); 997241699cdSAl Viro return 0; 998241699cdSAl Viro } 999d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 100009fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 1001d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 1002d879cb83SAl Viro v.bv_offset, v.bv_len), 1003d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 1004d879cb83SAl Viro ) 1005d879cb83SAl Viro kunmap_atomic(kaddr); 1006d879cb83SAl Viro return bytes; 1007d879cb83SAl Viro } 1008d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 1009d879cb83SAl Viro 1010b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 1011241699cdSAl Viro { 1012241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 10138cefc107SDavid Howells unsigned int p_tail = pipe->tail; 10148cefc107SDavid Howells unsigned int p_head = pipe->head; 10158cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10168cefc107SDavid Howells 10178cefc107SDavid Howells if (!pipe_empty(p_head, p_tail)) { 10188cefc107SDavid Howells struct pipe_buffer *buf; 10198cefc107SDavid Howells unsigned int i_head = i->head; 1020b9dc6f65SAl Viro size_t off = i->iov_offset; 10218cefc107SDavid Howells 1022b9dc6f65SAl Viro if (off) { 10238cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 10248cefc107SDavid Howells buf->len = off - buf->offset; 10258cefc107SDavid Howells i_head++; 1026b9dc6f65SAl Viro } 10278cefc107SDavid Howells while (p_head != i_head) { 10288cefc107SDavid Howells p_head--; 10298cefc107SDavid Howells pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); 1030241699cdSAl Viro } 10318cefc107SDavid Howells 10328cefc107SDavid Howells pipe->head = p_head; 1033241699cdSAl Viro } 1034b9dc6f65SAl Viro } 1035b9dc6f65SAl Viro 1036b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 1037b9dc6f65SAl Viro { 1038b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 1039b9dc6f65SAl Viro if (unlikely(i->count < size)) 1040b9dc6f65SAl Viro size = i->count; 1041b9dc6f65SAl Viro if (size) { 1042b9dc6f65SAl Viro struct pipe_buffer *buf; 10438cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10448cefc107SDavid Howells unsigned int i_head = i->head; 1045b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 10468cefc107SDavid Howells 1047b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 10488cefc107SDavid Howells left += off - pipe->bufs[i_head & p_mask].offset; 1049b9dc6f65SAl Viro while (1) { 10508cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 1051b9dc6f65SAl Viro if (left <= buf->len) 1052b9dc6f65SAl Viro break; 1053b9dc6f65SAl Viro left -= buf->len; 10548cefc107SDavid Howells i_head++; 1055b9dc6f65SAl Viro } 10568cefc107SDavid Howells i->head = i_head; 1057b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 1058b9dc6f65SAl Viro } 1059b9dc6f65SAl Viro i->count -= size; 1060b9dc6f65SAl Viro /* ... and discard everything past that point */ 1061b9dc6f65SAl Viro pipe_truncate(i); 1062241699cdSAl Viro } 1063241699cdSAl Viro 1064d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 1065d879cb83SAl Viro { 106600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1067241699cdSAl Viro pipe_advance(i, size); 1068241699cdSAl Viro return; 1069241699cdSAl Viro } 10709ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) { 10719ea9ce04SDavid Howells i->count -= size; 10729ea9ce04SDavid Howells return; 10739ea9ce04SDavid Howells } 1074d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 1075d879cb83SAl Viro } 1076d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 1077d879cb83SAl Viro 107827c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 107927c0e374SAl Viro { 108027c0e374SAl Viro if (!unroll) 108127c0e374SAl Viro return; 10825b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 10835b47d59aSAl Viro return; 108427c0e374SAl Viro i->count += unroll; 108500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 108627c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 10878cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10888cefc107SDavid Howells unsigned int i_head = i->head; 108927c0e374SAl Viro size_t off = i->iov_offset; 109027c0e374SAl Viro while (1) { 10918cefc107SDavid Howells struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; 10928cefc107SDavid Howells size_t n = off - b->offset; 109327c0e374SAl Viro if (unroll < n) { 10944fa55cefSAl Viro off -= unroll; 109527c0e374SAl Viro break; 109627c0e374SAl Viro } 109727c0e374SAl Viro unroll -= n; 10988cefc107SDavid Howells if (!unroll && i_head == i->start_head) { 109927c0e374SAl Viro off = 0; 110027c0e374SAl Viro break; 110127c0e374SAl Viro } 11028cefc107SDavid Howells i_head--; 11038cefc107SDavid Howells b = &pipe->bufs[i_head & p_mask]; 11048cefc107SDavid Howells off = b->offset + b->len; 110527c0e374SAl Viro } 110627c0e374SAl Viro i->iov_offset = off; 11078cefc107SDavid Howells i->head = i_head; 110827c0e374SAl Viro pipe_truncate(i); 110927c0e374SAl Viro return; 111027c0e374SAl Viro } 11119ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11129ea9ce04SDavid Howells return; 111327c0e374SAl Viro if (unroll <= i->iov_offset) { 111427c0e374SAl Viro i->iov_offset -= unroll; 111527c0e374SAl Viro return; 111627c0e374SAl Viro } 111727c0e374SAl Viro unroll -= i->iov_offset; 111800e23707SDavid Howells if (iov_iter_is_bvec(i)) { 111927c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 112027c0e374SAl Viro while (1) { 112127c0e374SAl Viro size_t n = (--bvec)->bv_len; 112227c0e374SAl Viro i->nr_segs++; 112327c0e374SAl Viro if (unroll <= n) { 112427c0e374SAl Viro i->bvec = bvec; 112527c0e374SAl Viro i->iov_offset = n - unroll; 112627c0e374SAl Viro return; 112727c0e374SAl Viro } 112827c0e374SAl Viro unroll -= n; 112927c0e374SAl Viro } 113027c0e374SAl Viro } else { /* same logics for iovec and kvec */ 113127c0e374SAl Viro const struct iovec *iov = i->iov; 113227c0e374SAl Viro while (1) { 113327c0e374SAl Viro size_t n = (--iov)->iov_len; 113427c0e374SAl Viro i->nr_segs++; 113527c0e374SAl Viro if (unroll <= n) { 113627c0e374SAl Viro i->iov = iov; 113727c0e374SAl Viro i->iov_offset = n - unroll; 113827c0e374SAl Viro return; 113927c0e374SAl Viro } 114027c0e374SAl Viro unroll -= n; 114127c0e374SAl Viro } 114227c0e374SAl Viro } 114327c0e374SAl Viro } 114427c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 114527c0e374SAl Viro 1146d879cb83SAl Viro /* 1147d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1148d879cb83SAl Viro */ 1149d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1150d879cb83SAl Viro { 115100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1152241699cdSAl Viro return i->count; // it is a silly place, anyway 1153d879cb83SAl Viro if (i->nr_segs == 1) 1154d879cb83SAl Viro return i->count; 11559ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11569ea9ce04SDavid Howells return i->count; 115700e23707SDavid Howells else if (iov_iter_is_bvec(i)) 1158d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1159d879cb83SAl Viro else 1160d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1161d879cb83SAl Viro } 1162d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1163d879cb83SAl Viro 1164aa563d7bSDavid Howells void iov_iter_kvec(struct iov_iter *i, unsigned int direction, 1165d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1166d879cb83SAl Viro size_t count) 1167d879cb83SAl Viro { 1168aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1169aa563d7bSDavid Howells i->type = ITER_KVEC | (direction & (READ | WRITE)); 1170d879cb83SAl Viro i->kvec = kvec; 1171d879cb83SAl Viro i->nr_segs = nr_segs; 1172d879cb83SAl Viro i->iov_offset = 0; 1173d879cb83SAl Viro i->count = count; 1174d879cb83SAl Viro } 1175d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1176d879cb83SAl Viro 1177aa563d7bSDavid Howells void iov_iter_bvec(struct iov_iter *i, unsigned int direction, 1178d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1179d879cb83SAl Viro size_t count) 1180d879cb83SAl Viro { 1181aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1182aa563d7bSDavid Howells i->type = ITER_BVEC | (direction & (READ | WRITE)); 1183d879cb83SAl Viro i->bvec = bvec; 1184d879cb83SAl Viro i->nr_segs = nr_segs; 1185d879cb83SAl Viro i->iov_offset = 0; 1186d879cb83SAl Viro i->count = count; 1187d879cb83SAl Viro } 1188d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1189d879cb83SAl Viro 1190aa563d7bSDavid Howells void iov_iter_pipe(struct iov_iter *i, unsigned int direction, 1191241699cdSAl Viro struct pipe_inode_info *pipe, 1192241699cdSAl Viro size_t count) 1193241699cdSAl Viro { 1194aa563d7bSDavid Howells BUG_ON(direction != READ); 11958cefc107SDavid Howells WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); 1196aa563d7bSDavid Howells i->type = ITER_PIPE | READ; 1197241699cdSAl Viro i->pipe = pipe; 11988cefc107SDavid Howells i->head = pipe->head; 1199241699cdSAl Viro i->iov_offset = 0; 1200241699cdSAl Viro i->count = count; 12018cefc107SDavid Howells i->start_head = i->head; 1202241699cdSAl Viro } 1203241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1204241699cdSAl Viro 12059ea9ce04SDavid Howells /** 12069ea9ce04SDavid Howells * iov_iter_discard - Initialise an I/O iterator that discards data 12079ea9ce04SDavid Howells * @i: The iterator to initialise. 12089ea9ce04SDavid Howells * @direction: The direction of the transfer. 12099ea9ce04SDavid Howells * @count: The size of the I/O buffer in bytes. 12109ea9ce04SDavid Howells * 12119ea9ce04SDavid Howells * Set up an I/O iterator that just discards everything that's written to it. 12129ea9ce04SDavid Howells * It's only available as a READ iterator. 12139ea9ce04SDavid Howells */ 12149ea9ce04SDavid Howells void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) 12159ea9ce04SDavid Howells { 12169ea9ce04SDavid Howells BUG_ON(direction != READ); 12179ea9ce04SDavid Howells i->type = ITER_DISCARD | READ; 12189ea9ce04SDavid Howells i->count = count; 12199ea9ce04SDavid Howells i->iov_offset = 0; 12209ea9ce04SDavid Howells } 12219ea9ce04SDavid Howells EXPORT_SYMBOL(iov_iter_discard); 12229ea9ce04SDavid Howells 1223d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1224d879cb83SAl Viro { 12258cefc107SDavid Howells unsigned int p_mask = i->pipe->ring_size - 1; 1226d879cb83SAl Viro unsigned long res = 0; 1227d879cb83SAl Viro size_t size = i->count; 1228d879cb83SAl Viro 122900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 12308cefc107SDavid Howells if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) 1231241699cdSAl Viro return size | i->iov_offset; 1232241699cdSAl Viro return size; 1233241699cdSAl Viro } 1234d879cb83SAl Viro iterate_all_kinds(i, size, v, 1235d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1236d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1237d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1238d879cb83SAl Viro ) 1239d879cb83SAl Viro return res; 1240d879cb83SAl Viro } 1241d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1242d879cb83SAl Viro 1243357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1244357f435dSAl Viro { 1245357f435dSAl Viro unsigned long res = 0; 1246357f435dSAl Viro size_t size = i->count; 1247357f435dSAl Viro 12489ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1249241699cdSAl Viro WARN_ON(1); 1250241699cdSAl Viro return ~0U; 1251241699cdSAl Viro } 1252241699cdSAl Viro 1253357f435dSAl Viro iterate_all_kinds(i, size, v, 1254357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1255357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1256357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1257357f435dSAl Viro (size != v.bv_len ? size : 0)), 1258357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1259357f435dSAl Viro (size != v.iov_len ? size : 0)) 1260357f435dSAl Viro ); 1261357f435dSAl Viro return res; 1262357f435dSAl Viro } 1263357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1264357f435dSAl Viro 1265e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1266241699cdSAl Viro size_t maxsize, 1267241699cdSAl Viro struct page **pages, 12688cefc107SDavid Howells int iter_head, 1269241699cdSAl Viro size_t *start) 1270241699cdSAl Viro { 1271241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 12728cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 12738cefc107SDavid Howells ssize_t n = push_pipe(i, maxsize, &iter_head, start); 1274241699cdSAl Viro if (!n) 1275241699cdSAl Viro return -EFAULT; 1276241699cdSAl Viro 1277241699cdSAl Viro maxsize = n; 1278241699cdSAl Viro n += *start; 12791689c73aSAl Viro while (n > 0) { 12808cefc107SDavid Howells get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); 12818cefc107SDavid Howells iter_head++; 1282241699cdSAl Viro n -= PAGE_SIZE; 1283241699cdSAl Viro } 1284241699cdSAl Viro 1285241699cdSAl Viro return maxsize; 1286241699cdSAl Viro } 1287241699cdSAl Viro 1288241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1289241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1290241699cdSAl Viro size_t *start) 1291241699cdSAl Viro { 12928cefc107SDavid Howells unsigned int iter_head, npages; 1293241699cdSAl Viro size_t capacity; 1294241699cdSAl Viro 129533844e66SAl Viro if (!maxsize) 129633844e66SAl Viro return 0; 129733844e66SAl Viro 1298241699cdSAl Viro if (!sanity(i)) 1299241699cdSAl Viro return -EFAULT; 1300241699cdSAl Viro 13018cefc107SDavid Howells data_start(i, &iter_head, start); 13028cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13038cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1304241699cdSAl Viro capacity = min(npages, maxpages) * PAGE_SIZE - *start; 1305241699cdSAl Viro 13068cefc107SDavid Howells return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); 1307241699cdSAl Viro } 1308241699cdSAl Viro 1309d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1310d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1311d879cb83SAl Viro size_t *start) 1312d879cb83SAl Viro { 1313d879cb83SAl Viro if (maxsize > i->count) 1314d879cb83SAl Viro maxsize = i->count; 1315d879cb83SAl Viro 131600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1317241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 13189ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 13199ea9ce04SDavid Howells return -EFAULT; 13209ea9ce04SDavid Howells 1321d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1322d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1323d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1324d879cb83SAl Viro int n; 1325d879cb83SAl Viro int res; 1326d879cb83SAl Viro 1327d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1328d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1329d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1330d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 133173b0140bSIra Weiny res = get_user_pages_fast(addr, n, 133273b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, 133373b0140bSIra Weiny pages); 1334d879cb83SAl Viro if (unlikely(res < 0)) 1335d879cb83SAl Viro return res; 1336d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1337d879cb83SAl Viro 0;}),({ 1338d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1339d879cb83SAl Viro *start = v.bv_offset; 1340d879cb83SAl Viro get_page(*pages = v.bv_page); 1341d879cb83SAl Viro return v.bv_len; 1342d879cb83SAl Viro }),({ 1343d879cb83SAl Viro return -EFAULT; 1344d879cb83SAl Viro }) 1345d879cb83SAl Viro ) 1346d879cb83SAl Viro return 0; 1347d879cb83SAl Viro } 1348d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1349d879cb83SAl Viro 1350d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1351d879cb83SAl Viro { 1352752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1353d879cb83SAl Viro } 1354d879cb83SAl Viro 1355241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1356241699cdSAl Viro struct page ***pages, size_t maxsize, 1357241699cdSAl Viro size_t *start) 1358241699cdSAl Viro { 1359241699cdSAl Viro struct page **p; 13608cefc107SDavid Howells unsigned int iter_head, npages; 1361d7760d63SIlya Dryomov ssize_t n; 1362241699cdSAl Viro 136333844e66SAl Viro if (!maxsize) 136433844e66SAl Viro return 0; 136533844e66SAl Viro 1366241699cdSAl Viro if (!sanity(i)) 1367241699cdSAl Viro return -EFAULT; 1368241699cdSAl Viro 13698cefc107SDavid Howells data_start(i, &iter_head, start); 13708cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13718cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1372241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1373241699cdSAl Viro if (maxsize > n) 1374241699cdSAl Viro maxsize = n; 1375241699cdSAl Viro else 1376241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1377241699cdSAl Viro p = get_pages_array(npages); 1378241699cdSAl Viro if (!p) 1379241699cdSAl Viro return -ENOMEM; 13808cefc107SDavid Howells n = __pipe_get_pages(i, maxsize, p, iter_head, start); 1381241699cdSAl Viro if (n > 0) 1382241699cdSAl Viro *pages = p; 1383241699cdSAl Viro else 1384241699cdSAl Viro kvfree(p); 1385241699cdSAl Viro return n; 1386241699cdSAl Viro } 1387241699cdSAl Viro 1388d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1389d879cb83SAl Viro struct page ***pages, size_t maxsize, 1390d879cb83SAl Viro size_t *start) 1391d879cb83SAl Viro { 1392d879cb83SAl Viro struct page **p; 1393d879cb83SAl Viro 1394d879cb83SAl Viro if (maxsize > i->count) 1395d879cb83SAl Viro maxsize = i->count; 1396d879cb83SAl Viro 139700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1398241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 13999ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 14009ea9ce04SDavid Howells return -EFAULT; 14019ea9ce04SDavid Howells 1402d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1403d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1404d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1405d879cb83SAl Viro int n; 1406d879cb83SAl Viro int res; 1407d879cb83SAl Viro 1408d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1409d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1410d879cb83SAl Viro p = get_pages_array(n); 1411d879cb83SAl Viro if (!p) 1412d879cb83SAl Viro return -ENOMEM; 141373b0140bSIra Weiny res = get_user_pages_fast(addr, n, 141473b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); 1415d879cb83SAl Viro if (unlikely(res < 0)) { 1416d879cb83SAl Viro kvfree(p); 1417d879cb83SAl Viro return res; 1418d879cb83SAl Viro } 1419d879cb83SAl Viro *pages = p; 1420d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1421d879cb83SAl Viro 0;}),({ 1422d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1423d879cb83SAl Viro *start = v.bv_offset; 1424d879cb83SAl Viro *pages = p = get_pages_array(1); 1425d879cb83SAl Viro if (!p) 1426d879cb83SAl Viro return -ENOMEM; 1427d879cb83SAl Viro get_page(*p = v.bv_page); 1428d879cb83SAl Viro return v.bv_len; 1429d879cb83SAl Viro }),({ 1430d879cb83SAl Viro return -EFAULT; 1431d879cb83SAl Viro }) 1432d879cb83SAl Viro ) 1433d879cb83SAl Viro return 0; 1434d879cb83SAl Viro } 1435d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1436d879cb83SAl Viro 1437d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1438d879cb83SAl Viro struct iov_iter *i) 1439d879cb83SAl Viro { 1440d879cb83SAl Viro char *to = addr; 1441d879cb83SAl Viro __wsum sum, next; 1442d879cb83SAl Viro size_t off = 0; 1443d879cb83SAl Viro sum = *csum; 14449ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1445241699cdSAl Viro WARN_ON(1); 1446241699cdSAl Viro return 0; 1447241699cdSAl Viro } 1448d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1449d879cb83SAl Viro int err = 0; 1450d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1451d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1452d879cb83SAl Viro v.iov_len, 0, &err); 1453d879cb83SAl Viro if (!err) { 1454d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1455d879cb83SAl Viro off += v.iov_len; 1456d879cb83SAl Viro } 1457d879cb83SAl Viro err ? v.iov_len : 0; 1458d879cb83SAl Viro }), ({ 1459d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1460f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1461f9152895SAl Viro p + v.bv_offset, v.bv_len, 1462f9152895SAl Viro sum, off); 1463d879cb83SAl Viro kunmap_atomic(p); 1464d879cb83SAl Viro off += v.bv_len; 1465d879cb83SAl Viro }),({ 1466f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1467f9152895SAl Viro v.iov_base, v.iov_len, 1468f9152895SAl Viro sum, off); 1469d879cb83SAl Viro off += v.iov_len; 1470d879cb83SAl Viro }) 1471d879cb83SAl Viro ) 1472d879cb83SAl Viro *csum = sum; 1473d879cb83SAl Viro return bytes; 1474d879cb83SAl Viro } 1475d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1476d879cb83SAl Viro 1477cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1478cbbd26b8SAl Viro struct iov_iter *i) 1479cbbd26b8SAl Viro { 1480cbbd26b8SAl Viro char *to = addr; 1481cbbd26b8SAl Viro __wsum sum, next; 1482cbbd26b8SAl Viro size_t off = 0; 1483cbbd26b8SAl Viro sum = *csum; 14849ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1485cbbd26b8SAl Viro WARN_ON(1); 1486cbbd26b8SAl Viro return false; 1487cbbd26b8SAl Viro } 1488cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1489cbbd26b8SAl Viro return false; 1490cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1491cbbd26b8SAl Viro int err = 0; 1492cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1493cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1494cbbd26b8SAl Viro v.iov_len, 0, &err); 1495cbbd26b8SAl Viro if (err) 1496cbbd26b8SAl Viro return false; 1497cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1498cbbd26b8SAl Viro off += v.iov_len; 1499cbbd26b8SAl Viro 0; 1500cbbd26b8SAl Viro }), ({ 1501cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1502f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1503f9152895SAl Viro p + v.bv_offset, v.bv_len, 1504f9152895SAl Viro sum, off); 1505cbbd26b8SAl Viro kunmap_atomic(p); 1506cbbd26b8SAl Viro off += v.bv_len; 1507cbbd26b8SAl Viro }),({ 1508f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1509f9152895SAl Viro v.iov_base, v.iov_len, 1510f9152895SAl Viro sum, off); 1511cbbd26b8SAl Viro off += v.iov_len; 1512cbbd26b8SAl Viro }) 1513cbbd26b8SAl Viro ) 1514cbbd26b8SAl Viro *csum = sum; 1515cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1516cbbd26b8SAl Viro return true; 1517cbbd26b8SAl Viro } 1518cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1519cbbd26b8SAl Viro 1520cb002d07SSagi Grimberg size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, 1521d879cb83SAl Viro struct iov_iter *i) 1522d879cb83SAl Viro { 152336f7a8a4SAl Viro const char *from = addr; 1524cb002d07SSagi Grimberg __wsum *csum = csump; 1525d879cb83SAl Viro __wsum sum, next; 1526d879cb83SAl Viro size_t off = 0; 152778e1f386SAl Viro 152878e1f386SAl Viro if (unlikely(iov_iter_is_pipe(i))) 152978e1f386SAl Viro return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); 153078e1f386SAl Viro 1531d879cb83SAl Viro sum = *csum; 153278e1f386SAl Viro if (unlikely(iov_iter_is_discard(i))) { 1533241699cdSAl Viro WARN_ON(1); /* for now */ 1534241699cdSAl Viro return 0; 1535241699cdSAl Viro } 1536d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1537d879cb83SAl Viro int err = 0; 1538d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1539d879cb83SAl Viro v.iov_base, 1540d879cb83SAl Viro v.iov_len, 0, &err); 1541d879cb83SAl Viro if (!err) { 1542d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1543d879cb83SAl Viro off += v.iov_len; 1544d879cb83SAl Viro } 1545d879cb83SAl Viro err ? v.iov_len : 0; 1546d879cb83SAl Viro }), ({ 1547d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1548f9152895SAl Viro sum = csum_and_memcpy(p + v.bv_offset, 1549f9152895SAl Viro (from += v.bv_len) - v.bv_len, 1550f9152895SAl Viro v.bv_len, sum, off); 1551d879cb83SAl Viro kunmap_atomic(p); 1552d879cb83SAl Viro off += v.bv_len; 1553d879cb83SAl Viro }),({ 1554f9152895SAl Viro sum = csum_and_memcpy(v.iov_base, 1555f9152895SAl Viro (from += v.iov_len) - v.iov_len, 1556f9152895SAl Viro v.iov_len, sum, off); 1557d879cb83SAl Viro off += v.iov_len; 1558d879cb83SAl Viro }) 1559d879cb83SAl Viro ) 1560d879cb83SAl Viro *csum = sum; 1561d879cb83SAl Viro return bytes; 1562d879cb83SAl Viro } 1563d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1564d879cb83SAl Viro 1565d05f4435SSagi Grimberg size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, 1566d05f4435SSagi Grimberg struct iov_iter *i) 1567d05f4435SSagi Grimberg { 156827fad74aSYueHaibing #ifdef CONFIG_CRYPTO 1569d05f4435SSagi Grimberg struct ahash_request *hash = hashp; 1570d05f4435SSagi Grimberg struct scatterlist sg; 1571d05f4435SSagi Grimberg size_t copied; 1572d05f4435SSagi Grimberg 1573d05f4435SSagi Grimberg copied = copy_to_iter(addr, bytes, i); 1574d05f4435SSagi Grimberg sg_init_one(&sg, addr, copied); 1575d05f4435SSagi Grimberg ahash_request_set_crypt(hash, &sg, NULL, copied); 1576d05f4435SSagi Grimberg crypto_ahash_update(hash); 1577d05f4435SSagi Grimberg return copied; 157827fad74aSYueHaibing #else 157927fad74aSYueHaibing return 0; 158027fad74aSYueHaibing #endif 1581d05f4435SSagi Grimberg } 1582d05f4435SSagi Grimberg EXPORT_SYMBOL(hash_and_copy_to_iter); 1583d05f4435SSagi Grimberg 1584d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1585d879cb83SAl Viro { 1586d879cb83SAl Viro size_t size = i->count; 1587d879cb83SAl Viro int npages = 0; 1588d879cb83SAl Viro 1589d879cb83SAl Viro if (!size) 1590d879cb83SAl Viro return 0; 15919ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 15929ea9ce04SDavid Howells return 0; 1593d879cb83SAl Viro 159400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1595241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 15968cefc107SDavid Howells unsigned int iter_head; 1597241699cdSAl Viro size_t off; 1598241699cdSAl Viro 1599241699cdSAl Viro if (!sanity(i)) 1600241699cdSAl Viro return 0; 1601241699cdSAl Viro 16028cefc107SDavid Howells data_start(i, &iter_head, &off); 1603241699cdSAl Viro /* some of this one + all after this one */ 16048cefc107SDavid Howells npages = pipe_space_for_user(iter_head, pipe->tail, pipe); 1605241699cdSAl Viro if (npages >= maxpages) 1606241699cdSAl Viro return maxpages; 1607241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1608d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1609d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1610d879cb83SAl Viro - p / PAGE_SIZE; 1611d879cb83SAl Viro if (npages >= maxpages) 1612d879cb83SAl Viro return maxpages; 1613d879cb83SAl Viro 0;}),({ 1614d879cb83SAl Viro npages++; 1615d879cb83SAl Viro if (npages >= maxpages) 1616d879cb83SAl Viro return maxpages; 1617d879cb83SAl Viro }),({ 1618d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1619d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1620d879cb83SAl Viro - p / PAGE_SIZE; 1621d879cb83SAl Viro if (npages >= maxpages) 1622d879cb83SAl Viro return maxpages; 1623d879cb83SAl Viro }) 1624d879cb83SAl Viro ) 1625d879cb83SAl Viro return npages; 1626d879cb83SAl Viro } 1627d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1628d879cb83SAl Viro 1629d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1630d879cb83SAl Viro { 1631d879cb83SAl Viro *new = *old; 163200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(new))) { 1633241699cdSAl Viro WARN_ON(1); 1634241699cdSAl Viro return NULL; 1635241699cdSAl Viro } 16369ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(new))) 16379ea9ce04SDavid Howells return NULL; 163800e23707SDavid Howells if (iov_iter_is_bvec(new)) 1639d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1640d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1641d879cb83SAl Viro flags); 1642d879cb83SAl Viro else 1643d879cb83SAl Viro /* iovec and kvec have identical layout */ 1644d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1645d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1646d879cb83SAl Viro flags); 1647d879cb83SAl Viro } 1648d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1649bc917be8SAl Viro 1650ffecee4fSVegard Nossum /** 1651ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1652ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1653ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1654ffecee4fSVegard Nossum * 1655ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1656ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1657ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1658ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1659ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1660ffecee4fSVegard Nossum * on-stack) kernel array. 1661ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1662ffecee4fSVegard Nossum * 1663ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1664ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1665ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1666ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1667ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1668ffecee4fSVegard Nossum * returns an error or not). 1669ffecee4fSVegard Nossum * 167087e5e6daSJens Axboe * Return: Negative error code on error, bytes imported on success 1671ffecee4fSVegard Nossum */ 167287e5e6daSJens Axboe ssize_t import_iovec(int type, const struct iovec __user * uvector, 1673bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1674bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1675bc917be8SAl Viro { 1676bc917be8SAl Viro ssize_t n; 1677bc917be8SAl Viro struct iovec *p; 1678bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1679bc917be8SAl Viro *iov, &p); 1680bc917be8SAl Viro if (n < 0) { 1681bc917be8SAl Viro if (p != *iov) 1682bc917be8SAl Viro kfree(p); 1683bc917be8SAl Viro *iov = NULL; 1684bc917be8SAl Viro return n; 1685bc917be8SAl Viro } 1686bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1687bc917be8SAl Viro *iov = p == *iov ? NULL : p; 168887e5e6daSJens Axboe return n; 1689bc917be8SAl Viro } 1690bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1691bc917be8SAl Viro 1692bc917be8SAl Viro #ifdef CONFIG_COMPAT 1693bc917be8SAl Viro #include <linux/compat.h> 1694bc917be8SAl Viro 169587e5e6daSJens Axboe ssize_t compat_import_iovec(int type, 169687e5e6daSJens Axboe const struct compat_iovec __user * uvector, 1697bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1698bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1699bc917be8SAl Viro { 1700bc917be8SAl Viro ssize_t n; 1701bc917be8SAl Viro struct iovec *p; 1702bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1703bc917be8SAl Viro *iov, &p); 1704bc917be8SAl Viro if (n < 0) { 1705bc917be8SAl Viro if (p != *iov) 1706bc917be8SAl Viro kfree(p); 1707bc917be8SAl Viro *iov = NULL; 1708bc917be8SAl Viro return n; 1709bc917be8SAl Viro } 1710bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1711bc917be8SAl Viro *iov = p == *iov ? NULL : p; 171287e5e6daSJens Axboe return n; 1713bc917be8SAl Viro } 1714bc917be8SAl Viro #endif 1715bc917be8SAl Viro 1716bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1717bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1718bc917be8SAl Viro { 1719bc917be8SAl Viro if (len > MAX_RW_COUNT) 1720bc917be8SAl Viro len = MAX_RW_COUNT; 172196d4f267SLinus Torvalds if (unlikely(!access_ok(buf, len))) 1722bc917be8SAl Viro return -EFAULT; 1723bc917be8SAl Viro 1724bc917be8SAl Viro iov->iov_base = buf; 1725bc917be8SAl Viro iov->iov_len = len; 1726bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1727bc917be8SAl Viro return 0; 1728bc917be8SAl Viro } 1729e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 173009cf698aSAl Viro 173109cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 173209cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 173309cf698aSAl Viro void *context) 173409cf698aSAl Viro { 173509cf698aSAl Viro struct kvec w; 173609cf698aSAl Viro int err = -EINVAL; 173709cf698aSAl Viro if (!bytes) 173809cf698aSAl Viro return 0; 173909cf698aSAl Viro 174009cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 174109cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 174209cf698aSAl Viro w.iov_len = v.bv_len; 174309cf698aSAl Viro err = f(&w, context); 174409cf698aSAl Viro kunmap(v.bv_page); 174509cf698aSAl Viro err;}), ({ 174609cf698aSAl Viro w = v; 174709cf698aSAl Viro err = f(&w, context);}) 174809cf698aSAl Viro ) 174909cf698aSAl Viro return err; 175009cf698aSAl Viro } 175109cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1752