1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 27999096fSHerbert Xu #include <crypto/hash.h> 3d879cb83SAl Viro #include <linux/export.h> 42f8b5444SChristoph Hellwig #include <linux/bvec.h> 54d0e9df5SAlbert van der Linde #include <linux/fault-inject-usercopy.h> 6d879cb83SAl Viro #include <linux/uio.h> 7d879cb83SAl Viro #include <linux/pagemap.h> 8d879cb83SAl Viro #include <linux/slab.h> 9d879cb83SAl Viro #include <linux/vmalloc.h> 10241699cdSAl Viro #include <linux/splice.h> 11bfdc5970SChristoph Hellwig #include <linux/compat.h> 12d879cb83SAl Viro #include <net/checksum.h> 13d05f4435SSagi Grimberg #include <linux/scatterlist.h> 14d0ef4c36SMarco Elver #include <linux/instrumented.h> 15d879cb83SAl Viro 16241699cdSAl Viro #define PIPE_PARANOIA /* for now */ 17241699cdSAl Viro 18d879cb83SAl Viro #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ 19d879cb83SAl Viro size_t left; \ 20d879cb83SAl Viro size_t wanted = n; \ 21d879cb83SAl Viro __p = i->iov; \ 22d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 23d879cb83SAl Viro if (likely(__v.iov_len)) { \ 24d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 25d879cb83SAl Viro left = (STEP); \ 26d879cb83SAl Viro __v.iov_len -= left; \ 27d879cb83SAl Viro skip += __v.iov_len; \ 28d879cb83SAl Viro n -= __v.iov_len; \ 29d879cb83SAl Viro } else { \ 30d879cb83SAl Viro left = 0; \ 31d879cb83SAl Viro } \ 32d879cb83SAl Viro while (unlikely(!left && n)) { \ 33d879cb83SAl Viro __p++; \ 34d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 35d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 36d879cb83SAl Viro continue; \ 37d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 38d879cb83SAl Viro left = (STEP); \ 39d879cb83SAl Viro __v.iov_len -= left; \ 40d879cb83SAl Viro skip = __v.iov_len; \ 41d879cb83SAl Viro n -= __v.iov_len; \ 42d879cb83SAl Viro } \ 43d879cb83SAl Viro n = wanted - n; \ 44d879cb83SAl Viro } 45d879cb83SAl Viro 46d879cb83SAl Viro #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ 47d879cb83SAl Viro size_t wanted = n; \ 48d879cb83SAl Viro __p = i->kvec; \ 49d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 50d879cb83SAl Viro if (likely(__v.iov_len)) { \ 51d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 52d879cb83SAl Viro (void)(STEP); \ 53d879cb83SAl Viro skip += __v.iov_len; \ 54d879cb83SAl Viro n -= __v.iov_len; \ 55d879cb83SAl Viro } \ 56d879cb83SAl Viro while (unlikely(n)) { \ 57d879cb83SAl Viro __p++; \ 58d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 59d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 60d879cb83SAl Viro continue; \ 61d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 62d879cb83SAl Viro (void)(STEP); \ 63d879cb83SAl Viro skip = __v.iov_len; \ 64d879cb83SAl Viro n -= __v.iov_len; \ 65d879cb83SAl Viro } \ 66d879cb83SAl Viro n = wanted; \ 67d879cb83SAl Viro } 68d879cb83SAl Viro 691bdc76aeSMing Lei #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ 701bdc76aeSMing Lei struct bvec_iter __start; \ 711bdc76aeSMing Lei __start.bi_size = n; \ 721bdc76aeSMing Lei __start.bi_bvec_done = skip; \ 731bdc76aeSMing Lei __start.bi_idx = 0; \ 741bdc76aeSMing Lei for_each_bvec(__v, i->bvec, __bi, __start) { \ 751bdc76aeSMing Lei if (!__v.bv_len) \ 76d879cb83SAl Viro continue; \ 77d879cb83SAl Viro (void)(STEP); \ 78d879cb83SAl Viro } \ 79d879cb83SAl Viro } 80d879cb83SAl Viro 81d879cb83SAl Viro #define iterate_all_kinds(i, n, v, I, B, K) { \ 8233844e66SAl Viro if (likely(n)) { \ 83d879cb83SAl Viro size_t skip = i->iov_offset; \ 84d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 85d879cb83SAl Viro struct bio_vec v; \ 861bdc76aeSMing Lei struct bvec_iter __bi; \ 871bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 88d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 89d879cb83SAl Viro const struct kvec *kvec; \ 90d879cb83SAl Viro struct kvec v; \ 91d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 929ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 93d879cb83SAl Viro } else { \ 94d879cb83SAl Viro const struct iovec *iov; \ 95d879cb83SAl Viro struct iovec v; \ 96d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 97d879cb83SAl Viro } \ 9833844e66SAl Viro } \ 99d879cb83SAl Viro } 100d879cb83SAl Viro 101d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 102dd254f5aSAl Viro if (unlikely(i->count < n)) \ 103dd254f5aSAl Viro n = i->count; \ 10419f18459SAl Viro if (i->count) { \ 105d879cb83SAl Viro size_t skip = i->iov_offset; \ 106d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 1071bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 108d879cb83SAl Viro struct bio_vec v; \ 1091bdc76aeSMing Lei struct bvec_iter __bi; \ 1101bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1111bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1121bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1131bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 114d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 115d879cb83SAl Viro const struct kvec *kvec; \ 116d879cb83SAl Viro struct kvec v; \ 117d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 118d879cb83SAl Viro if (skip == kvec->iov_len) { \ 119d879cb83SAl Viro kvec++; \ 120d879cb83SAl Viro skip = 0; \ 121d879cb83SAl Viro } \ 122d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 123d879cb83SAl Viro i->kvec = kvec; \ 1249ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 1259ea9ce04SDavid Howells skip += n; \ 126d879cb83SAl Viro } else { \ 127d879cb83SAl Viro const struct iovec *iov; \ 128d879cb83SAl Viro struct iovec v; \ 129d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 130d879cb83SAl Viro if (skip == iov->iov_len) { \ 131d879cb83SAl Viro iov++; \ 132d879cb83SAl Viro skip = 0; \ 133d879cb83SAl Viro } \ 134d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 135d879cb83SAl Viro i->iov = iov; \ 136d879cb83SAl Viro } \ 137d879cb83SAl Viro i->count -= n; \ 138d879cb83SAl Viro i->iov_offset = skip; \ 139dd254f5aSAl Viro } \ 140d879cb83SAl Viro } 141d879cb83SAl Viro 14209fc68dcSAl Viro static int copyout(void __user *to, const void *from, size_t n) 14309fc68dcSAl Viro { 1444d0e9df5SAlbert van der Linde if (should_fail_usercopy()) 1454d0e9df5SAlbert van der Linde return n; 14696d4f267SLinus Torvalds if (access_ok(to, n)) { 147d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 14809fc68dcSAl Viro n = raw_copy_to_user(to, from, n); 14909fc68dcSAl Viro } 15009fc68dcSAl Viro return n; 15109fc68dcSAl Viro } 15209fc68dcSAl Viro 15309fc68dcSAl Viro static int copyin(void *to, const void __user *from, size_t n) 15409fc68dcSAl Viro { 1554d0e9df5SAlbert van der Linde if (should_fail_usercopy()) 1564d0e9df5SAlbert van der Linde return n; 15796d4f267SLinus Torvalds if (access_ok(from, n)) { 158d0ef4c36SMarco Elver instrument_copy_from_user(to, from, n); 15909fc68dcSAl Viro n = raw_copy_from_user(to, from, n); 16009fc68dcSAl Viro } 16109fc68dcSAl Viro return n; 16209fc68dcSAl Viro } 16309fc68dcSAl Viro 164d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 165d879cb83SAl Viro struct iov_iter *i) 166d879cb83SAl Viro { 167d879cb83SAl Viro size_t skip, copy, left, wanted; 168d879cb83SAl Viro const struct iovec *iov; 169d879cb83SAl Viro char __user *buf; 170d879cb83SAl Viro void *kaddr, *from; 171d879cb83SAl Viro 172d879cb83SAl Viro if (unlikely(bytes > i->count)) 173d879cb83SAl Viro bytes = i->count; 174d879cb83SAl Viro 175d879cb83SAl Viro if (unlikely(!bytes)) 176d879cb83SAl Viro return 0; 177d879cb83SAl Viro 17809fc68dcSAl Viro might_fault(); 179d879cb83SAl Viro wanted = bytes; 180d879cb83SAl Viro iov = i->iov; 181d879cb83SAl Viro skip = i->iov_offset; 182d879cb83SAl Viro buf = iov->iov_base + skip; 183d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 184d879cb83SAl Viro 1853fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 186d879cb83SAl Viro kaddr = kmap_atomic(page); 187d879cb83SAl Viro from = kaddr + offset; 188d879cb83SAl Viro 189d879cb83SAl Viro /* first chunk, usually the only one */ 19009fc68dcSAl Viro left = copyout(buf, from, copy); 191d879cb83SAl Viro copy -= left; 192d879cb83SAl Viro skip += copy; 193d879cb83SAl Viro from += copy; 194d879cb83SAl Viro bytes -= copy; 195d879cb83SAl Viro 196d879cb83SAl Viro while (unlikely(!left && bytes)) { 197d879cb83SAl Viro iov++; 198d879cb83SAl Viro buf = iov->iov_base; 199d879cb83SAl Viro copy = min(bytes, iov->iov_len); 20009fc68dcSAl Viro left = copyout(buf, from, copy); 201d879cb83SAl Viro copy -= left; 202d879cb83SAl Viro skip = copy; 203d879cb83SAl Viro from += copy; 204d879cb83SAl Viro bytes -= copy; 205d879cb83SAl Viro } 206d879cb83SAl Viro if (likely(!bytes)) { 207d879cb83SAl Viro kunmap_atomic(kaddr); 208d879cb83SAl Viro goto done; 209d879cb83SAl Viro } 210d879cb83SAl Viro offset = from - kaddr; 211d879cb83SAl Viro buf += copy; 212d879cb83SAl Viro kunmap_atomic(kaddr); 213d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 214d879cb83SAl Viro } 215d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2163fa6c507SMikulas Patocka 217d879cb83SAl Viro kaddr = kmap(page); 218d879cb83SAl Viro from = kaddr + offset; 21909fc68dcSAl Viro left = copyout(buf, from, copy); 220d879cb83SAl Viro copy -= left; 221d879cb83SAl Viro skip += copy; 222d879cb83SAl Viro from += copy; 223d879cb83SAl Viro bytes -= copy; 224d879cb83SAl Viro while (unlikely(!left && bytes)) { 225d879cb83SAl Viro iov++; 226d879cb83SAl Viro buf = iov->iov_base; 227d879cb83SAl Viro copy = min(bytes, iov->iov_len); 22809fc68dcSAl Viro left = copyout(buf, from, copy); 229d879cb83SAl Viro copy -= left; 230d879cb83SAl Viro skip = copy; 231d879cb83SAl Viro from += copy; 232d879cb83SAl Viro bytes -= copy; 233d879cb83SAl Viro } 234d879cb83SAl Viro kunmap(page); 2353fa6c507SMikulas Patocka 236d879cb83SAl Viro done: 237d879cb83SAl Viro if (skip == iov->iov_len) { 238d879cb83SAl Viro iov++; 239d879cb83SAl Viro skip = 0; 240d879cb83SAl Viro } 241d879cb83SAl Viro i->count -= wanted - bytes; 242d879cb83SAl Viro i->nr_segs -= iov - i->iov; 243d879cb83SAl Viro i->iov = iov; 244d879cb83SAl Viro i->iov_offset = skip; 245d879cb83SAl Viro return wanted - bytes; 246d879cb83SAl Viro } 247d879cb83SAl Viro 248d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 249d879cb83SAl Viro struct iov_iter *i) 250d879cb83SAl Viro { 251d879cb83SAl Viro size_t skip, copy, left, wanted; 252d879cb83SAl Viro const struct iovec *iov; 253d879cb83SAl Viro char __user *buf; 254d879cb83SAl Viro void *kaddr, *to; 255d879cb83SAl Viro 256d879cb83SAl Viro if (unlikely(bytes > i->count)) 257d879cb83SAl Viro bytes = i->count; 258d879cb83SAl Viro 259d879cb83SAl Viro if (unlikely(!bytes)) 260d879cb83SAl Viro return 0; 261d879cb83SAl Viro 26209fc68dcSAl Viro might_fault(); 263d879cb83SAl Viro wanted = bytes; 264d879cb83SAl Viro iov = i->iov; 265d879cb83SAl Viro skip = i->iov_offset; 266d879cb83SAl Viro buf = iov->iov_base + skip; 267d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 268d879cb83SAl Viro 2693fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 270d879cb83SAl Viro kaddr = kmap_atomic(page); 271d879cb83SAl Viro to = kaddr + offset; 272d879cb83SAl Viro 273d879cb83SAl Viro /* first chunk, usually the only one */ 27409fc68dcSAl Viro left = copyin(to, buf, copy); 275d879cb83SAl Viro copy -= left; 276d879cb83SAl Viro skip += copy; 277d879cb83SAl Viro to += copy; 278d879cb83SAl Viro bytes -= copy; 279d879cb83SAl Viro 280d879cb83SAl Viro while (unlikely(!left && bytes)) { 281d879cb83SAl Viro iov++; 282d879cb83SAl Viro buf = iov->iov_base; 283d879cb83SAl Viro copy = min(bytes, iov->iov_len); 28409fc68dcSAl Viro left = copyin(to, buf, copy); 285d879cb83SAl Viro copy -= left; 286d879cb83SAl Viro skip = copy; 287d879cb83SAl Viro to += copy; 288d879cb83SAl Viro bytes -= copy; 289d879cb83SAl Viro } 290d879cb83SAl Viro if (likely(!bytes)) { 291d879cb83SAl Viro kunmap_atomic(kaddr); 292d879cb83SAl Viro goto done; 293d879cb83SAl Viro } 294d879cb83SAl Viro offset = to - kaddr; 295d879cb83SAl Viro buf += copy; 296d879cb83SAl Viro kunmap_atomic(kaddr); 297d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 298d879cb83SAl Viro } 299d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 3003fa6c507SMikulas Patocka 301d879cb83SAl Viro kaddr = kmap(page); 302d879cb83SAl Viro to = kaddr + offset; 30309fc68dcSAl Viro left = copyin(to, buf, copy); 304d879cb83SAl Viro copy -= left; 305d879cb83SAl Viro skip += copy; 306d879cb83SAl Viro to += copy; 307d879cb83SAl Viro bytes -= copy; 308d879cb83SAl Viro while (unlikely(!left && bytes)) { 309d879cb83SAl Viro iov++; 310d879cb83SAl Viro buf = iov->iov_base; 311d879cb83SAl Viro copy = min(bytes, iov->iov_len); 31209fc68dcSAl Viro left = copyin(to, buf, copy); 313d879cb83SAl Viro copy -= left; 314d879cb83SAl Viro skip = copy; 315d879cb83SAl Viro to += copy; 316d879cb83SAl Viro bytes -= copy; 317d879cb83SAl Viro } 318d879cb83SAl Viro kunmap(page); 3193fa6c507SMikulas Patocka 320d879cb83SAl Viro done: 321d879cb83SAl Viro if (skip == iov->iov_len) { 322d879cb83SAl Viro iov++; 323d879cb83SAl Viro skip = 0; 324d879cb83SAl Viro } 325d879cb83SAl Viro i->count -= wanted - bytes; 326d879cb83SAl Viro i->nr_segs -= iov - i->iov; 327d879cb83SAl Viro i->iov = iov; 328d879cb83SAl Viro i->iov_offset = skip; 329d879cb83SAl Viro return wanted - bytes; 330d879cb83SAl Viro } 331d879cb83SAl Viro 332241699cdSAl Viro #ifdef PIPE_PARANOIA 333241699cdSAl Viro static bool sanity(const struct iov_iter *i) 334241699cdSAl Viro { 335241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 3368cefc107SDavid Howells unsigned int p_head = pipe->head; 3378cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3388cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3398cefc107SDavid Howells unsigned int p_occupancy = pipe_occupancy(p_head, p_tail); 3408cefc107SDavid Howells unsigned int i_head = i->head; 3418cefc107SDavid Howells unsigned int idx; 3428cefc107SDavid Howells 343241699cdSAl Viro if (i->iov_offset) { 344241699cdSAl Viro struct pipe_buffer *p; 3458cefc107SDavid Howells if (unlikely(p_occupancy == 0)) 346241699cdSAl Viro goto Bad; // pipe must be non-empty 3478cefc107SDavid Howells if (unlikely(i_head != p_head - 1)) 348241699cdSAl Viro goto Bad; // must be at the last buffer... 349241699cdSAl Viro 3508cefc107SDavid Howells p = &pipe->bufs[i_head & p_mask]; 351241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 352241699cdSAl Viro goto Bad; // ... at the end of segment 353241699cdSAl Viro } else { 3548cefc107SDavid Howells if (i_head != p_head) 355241699cdSAl Viro goto Bad; // must be right after the last buffer 356241699cdSAl Viro } 357241699cdSAl Viro return true; 358241699cdSAl Viro Bad: 3598cefc107SDavid Howells printk(KERN_ERR "idx = %d, offset = %zd\n", i_head, i->iov_offset); 3608cefc107SDavid Howells printk(KERN_ERR "head = %d, tail = %d, buffers = %d\n", 3618cefc107SDavid Howells p_head, p_tail, pipe->ring_size); 3628cefc107SDavid Howells for (idx = 0; idx < pipe->ring_size; idx++) 363241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 364241699cdSAl Viro pipe->bufs[idx].ops, 365241699cdSAl Viro pipe->bufs[idx].page, 366241699cdSAl Viro pipe->bufs[idx].offset, 367241699cdSAl Viro pipe->bufs[idx].len); 368241699cdSAl Viro WARN_ON(1); 369241699cdSAl Viro return false; 370241699cdSAl Viro } 371241699cdSAl Viro #else 372241699cdSAl Viro #define sanity(i) true 373241699cdSAl Viro #endif 374241699cdSAl Viro 375241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 376241699cdSAl Viro struct iov_iter *i) 377241699cdSAl Viro { 378241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 379241699cdSAl Viro struct pipe_buffer *buf; 3808cefc107SDavid Howells unsigned int p_tail = pipe->tail; 3818cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 3828cefc107SDavid Howells unsigned int i_head = i->head; 383241699cdSAl Viro size_t off; 384241699cdSAl Viro 385241699cdSAl Viro if (unlikely(bytes > i->count)) 386241699cdSAl Viro bytes = i->count; 387241699cdSAl Viro 388241699cdSAl Viro if (unlikely(!bytes)) 389241699cdSAl Viro return 0; 390241699cdSAl Viro 391241699cdSAl Viro if (!sanity(i)) 392241699cdSAl Viro return 0; 393241699cdSAl Viro 394241699cdSAl Viro off = i->iov_offset; 3958cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 396241699cdSAl Viro if (off) { 397241699cdSAl Viro if (offset == off && buf->page == page) { 398241699cdSAl Viro /* merge with the last one */ 399241699cdSAl Viro buf->len += bytes; 400241699cdSAl Viro i->iov_offset += bytes; 401241699cdSAl Viro goto out; 402241699cdSAl Viro } 4038cefc107SDavid Howells i_head++; 4048cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 405241699cdSAl Viro } 4066718b6f8SDavid Howells if (pipe_full(i_head, p_tail, pipe->max_usage)) 407241699cdSAl Viro return 0; 4088cefc107SDavid Howells 409241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 4108cefc107SDavid Howells get_page(page); 4118cefc107SDavid Howells buf->page = page; 412241699cdSAl Viro buf->offset = offset; 413241699cdSAl Viro buf->len = bytes; 4148cefc107SDavid Howells 4158cefc107SDavid Howells pipe->head = i_head + 1; 416241699cdSAl Viro i->iov_offset = offset + bytes; 4178cefc107SDavid Howells i->head = i_head; 418241699cdSAl Viro out: 419241699cdSAl Viro i->count -= bytes; 420241699cdSAl Viro return bytes; 421241699cdSAl Viro } 422241699cdSAl Viro 423d879cb83SAl Viro /* 424171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 425171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 426171a0203SAnton Altaparmakov * 427171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 428171a0203SAnton Altaparmakov * because it is an invalid address). 429171a0203SAnton Altaparmakov */ 430d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 431171a0203SAnton Altaparmakov { 432171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 433171a0203SAnton Altaparmakov const struct iovec *iov; 434171a0203SAnton Altaparmakov int err; 435171a0203SAnton Altaparmakov struct iovec v; 436171a0203SAnton Altaparmakov 437171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 438171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4394bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 440171a0203SAnton Altaparmakov if (unlikely(err)) 441171a0203SAnton Altaparmakov return err; 442171a0203SAnton Altaparmakov 0;})) 443171a0203SAnton Altaparmakov } 444171a0203SAnton Altaparmakov return 0; 445171a0203SAnton Altaparmakov } 446d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 447171a0203SAnton Altaparmakov 448aa563d7bSDavid Howells void iov_iter_init(struct iov_iter *i, unsigned int direction, 449d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 450d879cb83SAl Viro size_t count) 451d879cb83SAl Viro { 452aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 453aa563d7bSDavid Howells direction &= READ | WRITE; 454aa563d7bSDavid Howells 455d879cb83SAl Viro /* It will get better. Eventually... */ 456db68ce10SAl Viro if (uaccess_kernel()) { 457aa563d7bSDavid Howells i->type = ITER_KVEC | direction; 458d879cb83SAl Viro i->kvec = (struct kvec *)iov; 459d879cb83SAl Viro } else { 460aa563d7bSDavid Howells i->type = ITER_IOVEC | direction; 461d879cb83SAl Viro i->iov = iov; 462d879cb83SAl Viro } 463d879cb83SAl Viro i->nr_segs = nr_segs; 464d879cb83SAl Viro i->iov_offset = 0; 465d879cb83SAl Viro i->count = count; 466d879cb83SAl Viro } 467d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 468d879cb83SAl Viro 469d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 470d879cb83SAl Viro { 471d879cb83SAl Viro char *from = kmap_atomic(page); 472d879cb83SAl Viro memcpy(to, from + offset, len); 473d879cb83SAl Viro kunmap_atomic(from); 474d879cb83SAl Viro } 475d879cb83SAl Viro 47636f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 477d879cb83SAl Viro { 478d879cb83SAl Viro char *to = kmap_atomic(page); 479d879cb83SAl Viro memcpy(to + offset, from, len); 480d879cb83SAl Viro kunmap_atomic(to); 481d879cb83SAl Viro } 482d879cb83SAl Viro 483d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 484d879cb83SAl Viro { 485d879cb83SAl Viro char *addr = kmap_atomic(page); 486d879cb83SAl Viro memset(addr + offset, 0, len); 487d879cb83SAl Viro kunmap_atomic(addr); 488d879cb83SAl Viro } 489d879cb83SAl Viro 490241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 491241699cdSAl Viro { 492241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 493241699cdSAl Viro } 494241699cdSAl Viro 4958cefc107SDavid Howells static inline void data_start(const struct iov_iter *i, 4968cefc107SDavid Howells unsigned int *iter_headp, size_t *offp) 497241699cdSAl Viro { 4988cefc107SDavid Howells unsigned int p_mask = i->pipe->ring_size - 1; 4998cefc107SDavid Howells unsigned int iter_head = i->head; 500241699cdSAl Viro size_t off = i->iov_offset; 5018cefc107SDavid Howells 5028cefc107SDavid Howells if (off && (!allocated(&i->pipe->bufs[iter_head & p_mask]) || 5038cefc107SDavid Howells off == PAGE_SIZE)) { 5048cefc107SDavid Howells iter_head++; 505241699cdSAl Viro off = 0; 506241699cdSAl Viro } 5078cefc107SDavid Howells *iter_headp = iter_head; 508241699cdSAl Viro *offp = off; 509241699cdSAl Viro } 510241699cdSAl Viro 511241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 5128cefc107SDavid Howells int *iter_headp, size_t *offp) 513241699cdSAl Viro { 514241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5158cefc107SDavid Howells unsigned int p_tail = pipe->tail; 5168cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5178cefc107SDavid Howells unsigned int iter_head; 518241699cdSAl Viro size_t off; 519241699cdSAl Viro ssize_t left; 520241699cdSAl Viro 521241699cdSAl Viro if (unlikely(size > i->count)) 522241699cdSAl Viro size = i->count; 523241699cdSAl Viro if (unlikely(!size)) 524241699cdSAl Viro return 0; 525241699cdSAl Viro 526241699cdSAl Viro left = size; 5278cefc107SDavid Howells data_start(i, &iter_head, &off); 5288cefc107SDavid Howells *iter_headp = iter_head; 529241699cdSAl Viro *offp = off; 530241699cdSAl Viro if (off) { 531241699cdSAl Viro left -= PAGE_SIZE - off; 532241699cdSAl Viro if (left <= 0) { 5338cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len += size; 534241699cdSAl Viro return size; 535241699cdSAl Viro } 5368cefc107SDavid Howells pipe->bufs[iter_head & p_mask].len = PAGE_SIZE; 5378cefc107SDavid Howells iter_head++; 538241699cdSAl Viro } 5396718b6f8SDavid Howells while (!pipe_full(iter_head, p_tail, pipe->max_usage)) { 5408cefc107SDavid Howells struct pipe_buffer *buf = &pipe->bufs[iter_head & p_mask]; 541241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 542241699cdSAl Viro if (!page) 543241699cdSAl Viro break; 5448cefc107SDavid Howells 5458cefc107SDavid Howells buf->ops = &default_pipe_buf_ops; 5468cefc107SDavid Howells buf->page = page; 5478cefc107SDavid Howells buf->offset = 0; 5488cefc107SDavid Howells buf->len = min_t(ssize_t, left, PAGE_SIZE); 5498cefc107SDavid Howells left -= buf->len; 5508cefc107SDavid Howells iter_head++; 5518cefc107SDavid Howells pipe->head = iter_head; 5528cefc107SDavid Howells 5538cefc107SDavid Howells if (left == 0) 554241699cdSAl Viro return size; 555241699cdSAl Viro } 556241699cdSAl Viro return size - left; 557241699cdSAl Viro } 558241699cdSAl Viro 559241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 560241699cdSAl Viro struct iov_iter *i) 561241699cdSAl Viro { 562241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 5638cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 5648cefc107SDavid Howells unsigned int i_head; 565241699cdSAl Viro size_t n, off; 566241699cdSAl Viro 567241699cdSAl Viro if (!sanity(i)) 568241699cdSAl Viro return 0; 569241699cdSAl Viro 5708cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 571241699cdSAl Viro if (unlikely(!n)) 572241699cdSAl Viro return 0; 5738cefc107SDavid Howells do { 574241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 5758cefc107SDavid Howells memcpy_to_page(pipe->bufs[i_head & p_mask].page, off, addr, chunk); 5768cefc107SDavid Howells i->head = i_head; 577241699cdSAl Viro i->iov_offset = off + chunk; 578241699cdSAl Viro n -= chunk; 579241699cdSAl Viro addr += chunk; 5808cefc107SDavid Howells off = 0; 5818cefc107SDavid Howells i_head++; 5828cefc107SDavid Howells } while (n); 583241699cdSAl Viro i->count -= bytes; 584241699cdSAl Viro return bytes; 585241699cdSAl Viro } 586241699cdSAl Viro 587f9152895SAl Viro static __wsum csum_and_memcpy(void *to, const void *from, size_t len, 588f9152895SAl Viro __wsum sum, size_t off) 589f9152895SAl Viro { 590cc44c17bSAl Viro __wsum next = csum_partial_copy_nocheck(from, to, len); 591f9152895SAl Viro return csum_block_add(sum, next, off); 592f9152895SAl Viro } 593f9152895SAl Viro 59478e1f386SAl Viro static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 595*52cbd23aSWillem de Bruijn struct csum_state *csstate, 596*52cbd23aSWillem de Bruijn struct iov_iter *i) 59778e1f386SAl Viro { 59878e1f386SAl Viro struct pipe_inode_info *pipe = i->pipe; 5998cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 600*52cbd23aSWillem de Bruijn __wsum sum = csstate->csum; 601*52cbd23aSWillem de Bruijn size_t off = csstate->off; 6028cefc107SDavid Howells unsigned int i_head; 60378e1f386SAl Viro size_t n, r; 60478e1f386SAl Viro 60578e1f386SAl Viro if (!sanity(i)) 60678e1f386SAl Viro return 0; 60778e1f386SAl Viro 6088cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &r); 60978e1f386SAl Viro if (unlikely(!n)) 61078e1f386SAl Viro return 0; 6118cefc107SDavid Howells do { 61278e1f386SAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - r); 6138cefc107SDavid Howells char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); 614f9152895SAl Viro sum = csum_and_memcpy(p + r, addr, chunk, sum, off); 61578e1f386SAl Viro kunmap_atomic(p); 6168cefc107SDavid Howells i->head = i_head; 61778e1f386SAl Viro i->iov_offset = r + chunk; 61878e1f386SAl Viro n -= chunk; 61978e1f386SAl Viro off += chunk; 62078e1f386SAl Viro addr += chunk; 6218cefc107SDavid Howells r = 0; 6228cefc107SDavid Howells i_head++; 6238cefc107SDavid Howells } while (n); 62478e1f386SAl Viro i->count -= bytes; 625*52cbd23aSWillem de Bruijn csstate->csum = sum; 626*52cbd23aSWillem de Bruijn csstate->off = off; 62778e1f386SAl Viro return bytes; 62878e1f386SAl Viro } 62978e1f386SAl Viro 630aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 631d879cb83SAl Viro { 63236f7a8a4SAl Viro const char *from = addr; 63300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 634241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 63509fc68dcSAl Viro if (iter_is_iovec(i)) 63609fc68dcSAl Viro might_fault(); 637d879cb83SAl Viro iterate_and_advance(i, bytes, v, 63809fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 639d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 640d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 641d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 642d879cb83SAl Viro ) 643d879cb83SAl Viro 644d879cb83SAl Viro return bytes; 645d879cb83SAl Viro } 646aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 647d879cb83SAl Viro 648ec6347bbSDan Williams #ifdef CONFIG_ARCH_HAS_COPY_MC 649ec6347bbSDan Williams static int copyout_mc(void __user *to, const void *from, size_t n) 6508780356eSDan Williams { 65196d4f267SLinus Torvalds if (access_ok(to, n)) { 652d0ef4c36SMarco Elver instrument_copy_to_user(to, from, n); 653ec6347bbSDan Williams n = copy_mc_to_user((__force void *) to, from, n); 6548780356eSDan Williams } 6558780356eSDan Williams return n; 6568780356eSDan Williams } 6578780356eSDan Williams 658ec6347bbSDan Williams static unsigned long copy_mc_to_page(struct page *page, size_t offset, 6598780356eSDan Williams const char *from, size_t len) 6608780356eSDan Williams { 6618780356eSDan Williams unsigned long ret; 6628780356eSDan Williams char *to; 6638780356eSDan Williams 6648780356eSDan Williams to = kmap_atomic(page); 665ec6347bbSDan Williams ret = copy_mc_to_kernel(to + offset, from, len); 6668780356eSDan Williams kunmap_atomic(to); 6678780356eSDan Williams 6688780356eSDan Williams return ret; 6698780356eSDan Williams } 6708780356eSDan Williams 671ec6347bbSDan Williams static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes, 672ca146f6fSDan Williams struct iov_iter *i) 673ca146f6fSDan Williams { 674ca146f6fSDan Williams struct pipe_inode_info *pipe = i->pipe; 6758cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 6768cefc107SDavid Howells unsigned int i_head; 677ca146f6fSDan Williams size_t n, off, xfer = 0; 678ca146f6fSDan Williams 679ca146f6fSDan Williams if (!sanity(i)) 680ca146f6fSDan Williams return 0; 681ca146f6fSDan Williams 6828cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 683ca146f6fSDan Williams if (unlikely(!n)) 684ca146f6fSDan Williams return 0; 6858cefc107SDavid Howells do { 686ca146f6fSDan Williams size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 687ca146f6fSDan Williams unsigned long rem; 688ca146f6fSDan Williams 689ec6347bbSDan Williams rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page, 6908cefc107SDavid Howells off, addr, chunk); 6918cefc107SDavid Howells i->head = i_head; 692ca146f6fSDan Williams i->iov_offset = off + chunk - rem; 693ca146f6fSDan Williams xfer += chunk - rem; 694ca146f6fSDan Williams if (rem) 695ca146f6fSDan Williams break; 696ca146f6fSDan Williams n -= chunk; 697ca146f6fSDan Williams addr += chunk; 6988cefc107SDavid Howells off = 0; 6998cefc107SDavid Howells i_head++; 7008cefc107SDavid Howells } while (n); 701ca146f6fSDan Williams i->count -= xfer; 702ca146f6fSDan Williams return xfer; 703ca146f6fSDan Williams } 704ca146f6fSDan Williams 705bf3eeb9bSDan Williams /** 706ec6347bbSDan Williams * _copy_mc_to_iter - copy to iter with source memory error exception handling 707bf3eeb9bSDan Williams * @addr: source kernel address 708bf3eeb9bSDan Williams * @bytes: total transfer length 709bf3eeb9bSDan Williams * @iter: destination iterator 710bf3eeb9bSDan Williams * 711ec6347bbSDan Williams * The pmem driver deploys this for the dax operation 712ec6347bbSDan Williams * (dax_copy_to_iter()) for dax reads (bypass page-cache and the 713ec6347bbSDan Williams * block-layer). Upon #MC read(2) aborts and returns EIO or the bytes 714ec6347bbSDan Williams * successfully copied. 715bf3eeb9bSDan Williams * 716ec6347bbSDan Williams * The main differences between this and typical _copy_to_iter(). 717bf3eeb9bSDan Williams * 718bf3eeb9bSDan Williams * * Typical tail/residue handling after a fault retries the copy 719bf3eeb9bSDan Williams * byte-by-byte until the fault happens again. Re-triggering machine 720bf3eeb9bSDan Williams * checks is potentially fatal so the implementation uses source 721bf3eeb9bSDan Williams * alignment and poison alignment assumptions to avoid re-triggering 722bf3eeb9bSDan Williams * hardware exceptions. 723bf3eeb9bSDan Williams * 724bf3eeb9bSDan Williams * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. 725bf3eeb9bSDan Williams * Compare to copy_to_iter() where only ITER_IOVEC attempts might return 726bf3eeb9bSDan Williams * a short copy. 727bf3eeb9bSDan Williams */ 728ec6347bbSDan Williams size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 7298780356eSDan Williams { 7308780356eSDan Williams const char *from = addr; 7318780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 7328780356eSDan Williams 73300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 734ec6347bbSDan Williams return copy_mc_pipe_to_iter(addr, bytes, i); 7358780356eSDan Williams if (iter_is_iovec(i)) 7368780356eSDan Williams might_fault(); 7378780356eSDan Williams iterate_and_advance(i, bytes, v, 738ec6347bbSDan Williams copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len, 739ec6347bbSDan Williams v.iov_len), 7408780356eSDan Williams ({ 741ec6347bbSDan Williams rem = copy_mc_to_page(v.bv_page, v.bv_offset, 7428780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 7438780356eSDan Williams if (rem) { 7448780356eSDan Williams curr_addr = (unsigned long) from; 7458780356eSDan Williams bytes = curr_addr - s_addr - rem; 7468780356eSDan Williams return bytes; 7478780356eSDan Williams } 7488780356eSDan Williams }), 7498780356eSDan Williams ({ 750ec6347bbSDan Williams rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len) 751ec6347bbSDan Williams - v.iov_len, v.iov_len); 7528780356eSDan Williams if (rem) { 7538780356eSDan Williams curr_addr = (unsigned long) from; 7548780356eSDan Williams bytes = curr_addr - s_addr - rem; 7558780356eSDan Williams return bytes; 7568780356eSDan Williams } 7578780356eSDan Williams }) 7588780356eSDan Williams ) 7598780356eSDan Williams 7608780356eSDan Williams return bytes; 7618780356eSDan Williams } 762ec6347bbSDan Williams EXPORT_SYMBOL_GPL(_copy_mc_to_iter); 763ec6347bbSDan Williams #endif /* CONFIG_ARCH_HAS_COPY_MC */ 7648780356eSDan Williams 765aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 766d879cb83SAl Viro { 767d879cb83SAl Viro char *to = addr; 76800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 769241699cdSAl Viro WARN_ON(1); 770241699cdSAl Viro return 0; 771241699cdSAl Viro } 77209fc68dcSAl Viro if (iter_is_iovec(i)) 77309fc68dcSAl Viro might_fault(); 774d879cb83SAl Viro iterate_and_advance(i, bytes, v, 77509fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 776d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 777d879cb83SAl Viro v.bv_offset, v.bv_len), 778d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 779d879cb83SAl Viro ) 780d879cb83SAl Viro 781d879cb83SAl Viro return bytes; 782d879cb83SAl Viro } 783aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 784d879cb83SAl Viro 785aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 786cbbd26b8SAl Viro { 787cbbd26b8SAl Viro char *to = addr; 78800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 789cbbd26b8SAl Viro WARN_ON(1); 790cbbd26b8SAl Viro return false; 791cbbd26b8SAl Viro } 79233844e66SAl Viro if (unlikely(i->count < bytes)) 793cbbd26b8SAl Viro return false; 794cbbd26b8SAl Viro 79509fc68dcSAl Viro if (iter_is_iovec(i)) 79609fc68dcSAl Viro might_fault(); 797cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 79809fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 799cbbd26b8SAl Viro v.iov_base, v.iov_len)) 800cbbd26b8SAl Viro return false; 801cbbd26b8SAl Viro 0;}), 802cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 803cbbd26b8SAl Viro v.bv_offset, v.bv_len), 804cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 805cbbd26b8SAl Viro ) 806cbbd26b8SAl Viro 807cbbd26b8SAl Viro iov_iter_advance(i, bytes); 808cbbd26b8SAl Viro return true; 809cbbd26b8SAl Viro } 810aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 811cbbd26b8SAl Viro 812aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 813d879cb83SAl Viro { 814d879cb83SAl Viro char *to = addr; 81500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 816241699cdSAl Viro WARN_ON(1); 817241699cdSAl Viro return 0; 818241699cdSAl Viro } 819d879cb83SAl Viro iterate_and_advance(i, bytes, v, 8203f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 821d879cb83SAl Viro v.iov_base, v.iov_len), 822d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 823d879cb83SAl Viro v.bv_offset, v.bv_len), 824d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 825d879cb83SAl Viro ) 826d879cb83SAl Viro 827d879cb83SAl Viro return bytes; 828d879cb83SAl Viro } 829aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 830d879cb83SAl Viro 8310aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 832abd08d7dSDan Williams /** 833abd08d7dSDan Williams * _copy_from_iter_flushcache - write destination through cpu cache 834abd08d7dSDan Williams * @addr: destination kernel address 835abd08d7dSDan Williams * @bytes: total transfer length 836abd08d7dSDan Williams * @iter: source iterator 837abd08d7dSDan Williams * 838abd08d7dSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 839abd08d7dSDan Williams * dax_copy_from_iter() for ensuring that writes to persistent memory 840abd08d7dSDan Williams * are flushed through the CPU cache. It is differentiated from 841abd08d7dSDan Williams * _copy_from_iter_nocache() in that guarantees all data is flushed for 842abd08d7dSDan Williams * all iterator types. The _copy_from_iter_nocache() only attempts to 843abd08d7dSDan Williams * bypass the cache for the ITER_IOVEC case, and on some archs may use 844abd08d7dSDan Williams * instructions that strand dirty-data in the cache. 845abd08d7dSDan Williams */ 8466a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 8470aed55afSDan Williams { 8480aed55afSDan Williams char *to = addr; 84900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 8500aed55afSDan Williams WARN_ON(1); 8510aed55afSDan Williams return 0; 8520aed55afSDan Williams } 8530aed55afSDan Williams iterate_and_advance(i, bytes, v, 8540aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 8550aed55afSDan Williams v.iov_base, v.iov_len), 8560aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 8570aed55afSDan Williams v.bv_offset, v.bv_len), 8580aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 8590aed55afSDan Williams v.iov_len) 8600aed55afSDan Williams ) 8610aed55afSDan Williams 8620aed55afSDan Williams return bytes; 8630aed55afSDan Williams } 8646a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 8650aed55afSDan Williams #endif 8660aed55afSDan Williams 867aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 868cbbd26b8SAl Viro { 869cbbd26b8SAl Viro char *to = addr; 87000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 871cbbd26b8SAl Viro WARN_ON(1); 872cbbd26b8SAl Viro return false; 873cbbd26b8SAl Viro } 87433844e66SAl Viro if (unlikely(i->count < bytes)) 875cbbd26b8SAl Viro return false; 876cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 8773f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 878cbbd26b8SAl Viro v.iov_base, v.iov_len)) 879cbbd26b8SAl Viro return false; 880cbbd26b8SAl Viro 0;}), 881cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 882cbbd26b8SAl Viro v.bv_offset, v.bv_len), 883cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 884cbbd26b8SAl Viro ) 885cbbd26b8SAl Viro 886cbbd26b8SAl Viro iov_iter_advance(i, bytes); 887cbbd26b8SAl Viro return true; 888cbbd26b8SAl Viro } 889aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 890cbbd26b8SAl Viro 89172e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 89272e809edSAl Viro { 8936daef95bSEric Dumazet struct page *head; 8946daef95bSEric Dumazet size_t v = n + offset; 8956daef95bSEric Dumazet 8966daef95bSEric Dumazet /* 8976daef95bSEric Dumazet * The general case needs to access the page order in order 8986daef95bSEric Dumazet * to compute the page size. 8996daef95bSEric Dumazet * However, we mostly deal with order-0 pages and thus can 9006daef95bSEric Dumazet * avoid a possible cache line miss for requests that fit all 9016daef95bSEric Dumazet * page orders. 9026daef95bSEric Dumazet */ 9036daef95bSEric Dumazet if (n <= v && v <= PAGE_SIZE) 9046daef95bSEric Dumazet return true; 9056daef95bSEric Dumazet 9066daef95bSEric Dumazet head = compound_head(page); 9076daef95bSEric Dumazet v += (page - head) << PAGE_SHIFT; 908a90bcb86SPetar Penkov 909a50b854eSMatthew Wilcox (Oracle) if (likely(n <= v && v <= (page_size(head)))) 91072e809edSAl Viro return true; 91172e809edSAl Viro WARN_ON(1); 91272e809edSAl Viro return false; 91372e809edSAl Viro } 914d879cb83SAl Viro 915d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 916d879cb83SAl Viro struct iov_iter *i) 917d879cb83SAl Viro { 91872e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 91972e809edSAl Viro return 0; 920d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 921d879cb83SAl Viro void *kaddr = kmap_atomic(page); 922d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 923d879cb83SAl Viro kunmap_atomic(kaddr); 924d879cb83SAl Viro return wanted; 9259ea9ce04SDavid Howells } else if (unlikely(iov_iter_is_discard(i))) 9269ea9ce04SDavid Howells return bytes; 9279ea9ce04SDavid Howells else if (likely(!iov_iter_is_pipe(i))) 928d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 929241699cdSAl Viro else 930241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 931d879cb83SAl Viro } 932d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 933d879cb83SAl Viro 934d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 935d879cb83SAl Viro struct iov_iter *i) 936d879cb83SAl Viro { 93772e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 93872e809edSAl Viro return 0; 9399ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 940241699cdSAl Viro WARN_ON(1); 941241699cdSAl Viro return 0; 942241699cdSAl Viro } 943d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 944d879cb83SAl Viro void *kaddr = kmap_atomic(page); 945aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 946d879cb83SAl Viro kunmap_atomic(kaddr); 947d879cb83SAl Viro return wanted; 948d879cb83SAl Viro } else 949d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 950d879cb83SAl Viro } 951d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 952d879cb83SAl Viro 953241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 954241699cdSAl Viro { 955241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9568cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 9578cefc107SDavid Howells unsigned int i_head; 958241699cdSAl Viro size_t n, off; 959241699cdSAl Viro 960241699cdSAl Viro if (!sanity(i)) 961241699cdSAl Viro return 0; 962241699cdSAl Viro 9638cefc107SDavid Howells bytes = n = push_pipe(i, bytes, &i_head, &off); 964241699cdSAl Viro if (unlikely(!n)) 965241699cdSAl Viro return 0; 966241699cdSAl Viro 9678cefc107SDavid Howells do { 968241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 9698cefc107SDavid Howells memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk); 9708cefc107SDavid Howells i->head = i_head; 971241699cdSAl Viro i->iov_offset = off + chunk; 972241699cdSAl Viro n -= chunk; 9738cefc107SDavid Howells off = 0; 9748cefc107SDavid Howells i_head++; 9758cefc107SDavid Howells } while (n); 976241699cdSAl Viro i->count -= bytes; 977241699cdSAl Viro return bytes; 978241699cdSAl Viro } 979241699cdSAl Viro 980d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 981d879cb83SAl Viro { 98200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 983241699cdSAl Viro return pipe_zero(bytes, i); 984d879cb83SAl Viro iterate_and_advance(i, bytes, v, 98509fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 986d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 987d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 988d879cb83SAl Viro ) 989d879cb83SAl Viro 990d879cb83SAl Viro return bytes; 991d879cb83SAl Viro } 992d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 993d879cb83SAl Viro 994d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 995d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 996d879cb83SAl Viro { 997d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 99872e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 99972e809edSAl Viro kunmap_atomic(kaddr); 100072e809edSAl Viro return 0; 100172e809edSAl Viro } 10029ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1003241699cdSAl Viro kunmap_atomic(kaddr); 1004241699cdSAl Viro WARN_ON(1); 1005241699cdSAl Viro return 0; 1006241699cdSAl Viro } 1007d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 100809fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 1009d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 1010d879cb83SAl Viro v.bv_offset, v.bv_len), 1011d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 1012d879cb83SAl Viro ) 1013d879cb83SAl Viro kunmap_atomic(kaddr); 1014d879cb83SAl Viro return bytes; 1015d879cb83SAl Viro } 1016d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 1017d879cb83SAl Viro 1018b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 1019241699cdSAl Viro { 1020241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 10218cefc107SDavid Howells unsigned int p_tail = pipe->tail; 10228cefc107SDavid Howells unsigned int p_head = pipe->head; 10238cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10248cefc107SDavid Howells 10258cefc107SDavid Howells if (!pipe_empty(p_head, p_tail)) { 10268cefc107SDavid Howells struct pipe_buffer *buf; 10278cefc107SDavid Howells unsigned int i_head = i->head; 1028b9dc6f65SAl Viro size_t off = i->iov_offset; 10298cefc107SDavid Howells 1030b9dc6f65SAl Viro if (off) { 10318cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 10328cefc107SDavid Howells buf->len = off - buf->offset; 10338cefc107SDavid Howells i_head++; 1034b9dc6f65SAl Viro } 10358cefc107SDavid Howells while (p_head != i_head) { 10368cefc107SDavid Howells p_head--; 10378cefc107SDavid Howells pipe_buf_release(pipe, &pipe->bufs[p_head & p_mask]); 1038241699cdSAl Viro } 10398cefc107SDavid Howells 10408cefc107SDavid Howells pipe->head = p_head; 1041241699cdSAl Viro } 1042b9dc6f65SAl Viro } 1043b9dc6f65SAl Viro 1044b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 1045b9dc6f65SAl Viro { 1046b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 1047b9dc6f65SAl Viro if (unlikely(i->count < size)) 1048b9dc6f65SAl Viro size = i->count; 1049b9dc6f65SAl Viro if (size) { 1050b9dc6f65SAl Viro struct pipe_buffer *buf; 10518cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10528cefc107SDavid Howells unsigned int i_head = i->head; 1053b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 10548cefc107SDavid Howells 1055b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 10568cefc107SDavid Howells left += off - pipe->bufs[i_head & p_mask].offset; 1057b9dc6f65SAl Viro while (1) { 10588cefc107SDavid Howells buf = &pipe->bufs[i_head & p_mask]; 1059b9dc6f65SAl Viro if (left <= buf->len) 1060b9dc6f65SAl Viro break; 1061b9dc6f65SAl Viro left -= buf->len; 10628cefc107SDavid Howells i_head++; 1063b9dc6f65SAl Viro } 10648cefc107SDavid Howells i->head = i_head; 1065b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 1066b9dc6f65SAl Viro } 1067b9dc6f65SAl Viro i->count -= size; 1068b9dc6f65SAl Viro /* ... and discard everything past that point */ 1069b9dc6f65SAl Viro pipe_truncate(i); 1070241699cdSAl Viro } 1071241699cdSAl Viro 1072d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 1073d879cb83SAl Viro { 107400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1075241699cdSAl Viro pipe_advance(i, size); 1076241699cdSAl Viro return; 1077241699cdSAl Viro } 10789ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) { 10799ea9ce04SDavid Howells i->count -= size; 10809ea9ce04SDavid Howells return; 10819ea9ce04SDavid Howells } 1082d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 1083d879cb83SAl Viro } 1084d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 1085d879cb83SAl Viro 108627c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 108727c0e374SAl Viro { 108827c0e374SAl Viro if (!unroll) 108927c0e374SAl Viro return; 10905b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 10915b47d59aSAl Viro return; 109227c0e374SAl Viro i->count += unroll; 109300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 109427c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 10958cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 10968cefc107SDavid Howells unsigned int i_head = i->head; 109727c0e374SAl Viro size_t off = i->iov_offset; 109827c0e374SAl Viro while (1) { 10998cefc107SDavid Howells struct pipe_buffer *b = &pipe->bufs[i_head & p_mask]; 11008cefc107SDavid Howells size_t n = off - b->offset; 110127c0e374SAl Viro if (unroll < n) { 11024fa55cefSAl Viro off -= unroll; 110327c0e374SAl Viro break; 110427c0e374SAl Viro } 110527c0e374SAl Viro unroll -= n; 11068cefc107SDavid Howells if (!unroll && i_head == i->start_head) { 110727c0e374SAl Viro off = 0; 110827c0e374SAl Viro break; 110927c0e374SAl Viro } 11108cefc107SDavid Howells i_head--; 11118cefc107SDavid Howells b = &pipe->bufs[i_head & p_mask]; 11128cefc107SDavid Howells off = b->offset + b->len; 111327c0e374SAl Viro } 111427c0e374SAl Viro i->iov_offset = off; 11158cefc107SDavid Howells i->head = i_head; 111627c0e374SAl Viro pipe_truncate(i); 111727c0e374SAl Viro return; 111827c0e374SAl Viro } 11199ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11209ea9ce04SDavid Howells return; 112127c0e374SAl Viro if (unroll <= i->iov_offset) { 112227c0e374SAl Viro i->iov_offset -= unroll; 112327c0e374SAl Viro return; 112427c0e374SAl Viro } 112527c0e374SAl Viro unroll -= i->iov_offset; 112600e23707SDavid Howells if (iov_iter_is_bvec(i)) { 112727c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 112827c0e374SAl Viro while (1) { 112927c0e374SAl Viro size_t n = (--bvec)->bv_len; 113027c0e374SAl Viro i->nr_segs++; 113127c0e374SAl Viro if (unroll <= n) { 113227c0e374SAl Viro i->bvec = bvec; 113327c0e374SAl Viro i->iov_offset = n - unroll; 113427c0e374SAl Viro return; 113527c0e374SAl Viro } 113627c0e374SAl Viro unroll -= n; 113727c0e374SAl Viro } 113827c0e374SAl Viro } else { /* same logics for iovec and kvec */ 113927c0e374SAl Viro const struct iovec *iov = i->iov; 114027c0e374SAl Viro while (1) { 114127c0e374SAl Viro size_t n = (--iov)->iov_len; 114227c0e374SAl Viro i->nr_segs++; 114327c0e374SAl Viro if (unroll <= n) { 114427c0e374SAl Viro i->iov = iov; 114527c0e374SAl Viro i->iov_offset = n - unroll; 114627c0e374SAl Viro return; 114727c0e374SAl Viro } 114827c0e374SAl Viro unroll -= n; 114927c0e374SAl Viro } 115027c0e374SAl Viro } 115127c0e374SAl Viro } 115227c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 115327c0e374SAl Viro 1154d879cb83SAl Viro /* 1155d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1156d879cb83SAl Viro */ 1157d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1158d879cb83SAl Viro { 115900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1160241699cdSAl Viro return i->count; // it is a silly place, anyway 1161d879cb83SAl Viro if (i->nr_segs == 1) 1162d879cb83SAl Viro return i->count; 11639ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11649ea9ce04SDavid Howells return i->count; 116500e23707SDavid Howells else if (iov_iter_is_bvec(i)) 1166d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1167d879cb83SAl Viro else 1168d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1169d879cb83SAl Viro } 1170d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1171d879cb83SAl Viro 1172aa563d7bSDavid Howells void iov_iter_kvec(struct iov_iter *i, unsigned int direction, 1173d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1174d879cb83SAl Viro size_t count) 1175d879cb83SAl Viro { 1176aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1177aa563d7bSDavid Howells i->type = ITER_KVEC | (direction & (READ | WRITE)); 1178d879cb83SAl Viro i->kvec = kvec; 1179d879cb83SAl Viro i->nr_segs = nr_segs; 1180d879cb83SAl Viro i->iov_offset = 0; 1181d879cb83SAl Viro i->count = count; 1182d879cb83SAl Viro } 1183d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1184d879cb83SAl Viro 1185aa563d7bSDavid Howells void iov_iter_bvec(struct iov_iter *i, unsigned int direction, 1186d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1187d879cb83SAl Viro size_t count) 1188d879cb83SAl Viro { 1189aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1190aa563d7bSDavid Howells i->type = ITER_BVEC | (direction & (READ | WRITE)); 1191d879cb83SAl Viro i->bvec = bvec; 1192d879cb83SAl Viro i->nr_segs = nr_segs; 1193d879cb83SAl Viro i->iov_offset = 0; 1194d879cb83SAl Viro i->count = count; 1195d879cb83SAl Viro } 1196d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1197d879cb83SAl Viro 1198aa563d7bSDavid Howells void iov_iter_pipe(struct iov_iter *i, unsigned int direction, 1199241699cdSAl Viro struct pipe_inode_info *pipe, 1200241699cdSAl Viro size_t count) 1201241699cdSAl Viro { 1202aa563d7bSDavid Howells BUG_ON(direction != READ); 12038cefc107SDavid Howells WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); 1204aa563d7bSDavid Howells i->type = ITER_PIPE | READ; 1205241699cdSAl Viro i->pipe = pipe; 12068cefc107SDavid Howells i->head = pipe->head; 1207241699cdSAl Viro i->iov_offset = 0; 1208241699cdSAl Viro i->count = count; 12098cefc107SDavid Howells i->start_head = i->head; 1210241699cdSAl Viro } 1211241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1212241699cdSAl Viro 12139ea9ce04SDavid Howells /** 12149ea9ce04SDavid Howells * iov_iter_discard - Initialise an I/O iterator that discards data 12159ea9ce04SDavid Howells * @i: The iterator to initialise. 12169ea9ce04SDavid Howells * @direction: The direction of the transfer. 12179ea9ce04SDavid Howells * @count: The size of the I/O buffer in bytes. 12189ea9ce04SDavid Howells * 12199ea9ce04SDavid Howells * Set up an I/O iterator that just discards everything that's written to it. 12209ea9ce04SDavid Howells * It's only available as a READ iterator. 12219ea9ce04SDavid Howells */ 12229ea9ce04SDavid Howells void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) 12239ea9ce04SDavid Howells { 12249ea9ce04SDavid Howells BUG_ON(direction != READ); 12259ea9ce04SDavid Howells i->type = ITER_DISCARD | READ; 12269ea9ce04SDavid Howells i->count = count; 12279ea9ce04SDavid Howells i->iov_offset = 0; 12289ea9ce04SDavid Howells } 12299ea9ce04SDavid Howells EXPORT_SYMBOL(iov_iter_discard); 12309ea9ce04SDavid Howells 1231d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1232d879cb83SAl Viro { 1233d879cb83SAl Viro unsigned long res = 0; 1234d879cb83SAl Viro size_t size = i->count; 1235d879cb83SAl Viro 123600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1237e0ff126eSJan Kara unsigned int p_mask = i->pipe->ring_size - 1; 1238e0ff126eSJan Kara 12398cefc107SDavid Howells if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask])) 1240241699cdSAl Viro return size | i->iov_offset; 1241241699cdSAl Viro return size; 1242241699cdSAl Viro } 1243d879cb83SAl Viro iterate_all_kinds(i, size, v, 1244d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1245d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1246d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1247d879cb83SAl Viro ) 1248d879cb83SAl Viro return res; 1249d879cb83SAl Viro } 1250d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1251d879cb83SAl Viro 1252357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1253357f435dSAl Viro { 1254357f435dSAl Viro unsigned long res = 0; 1255357f435dSAl Viro size_t size = i->count; 1256357f435dSAl Viro 12579ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1258241699cdSAl Viro WARN_ON(1); 1259241699cdSAl Viro return ~0U; 1260241699cdSAl Viro } 1261241699cdSAl Viro 1262357f435dSAl Viro iterate_all_kinds(i, size, v, 1263357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1264357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1265357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1266357f435dSAl Viro (size != v.bv_len ? size : 0)), 1267357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1268357f435dSAl Viro (size != v.iov_len ? size : 0)) 1269357f435dSAl Viro ); 1270357f435dSAl Viro return res; 1271357f435dSAl Viro } 1272357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1273357f435dSAl Viro 1274e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1275241699cdSAl Viro size_t maxsize, 1276241699cdSAl Viro struct page **pages, 12778cefc107SDavid Howells int iter_head, 1278241699cdSAl Viro size_t *start) 1279241699cdSAl Viro { 1280241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 12818cefc107SDavid Howells unsigned int p_mask = pipe->ring_size - 1; 12828cefc107SDavid Howells ssize_t n = push_pipe(i, maxsize, &iter_head, start); 1283241699cdSAl Viro if (!n) 1284241699cdSAl Viro return -EFAULT; 1285241699cdSAl Viro 1286241699cdSAl Viro maxsize = n; 1287241699cdSAl Viro n += *start; 12881689c73aSAl Viro while (n > 0) { 12898cefc107SDavid Howells get_page(*pages++ = pipe->bufs[iter_head & p_mask].page); 12908cefc107SDavid Howells iter_head++; 1291241699cdSAl Viro n -= PAGE_SIZE; 1292241699cdSAl Viro } 1293241699cdSAl Viro 1294241699cdSAl Viro return maxsize; 1295241699cdSAl Viro } 1296241699cdSAl Viro 1297241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1298241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1299241699cdSAl Viro size_t *start) 1300241699cdSAl Viro { 13018cefc107SDavid Howells unsigned int iter_head, npages; 1302241699cdSAl Viro size_t capacity; 1303241699cdSAl Viro 130433844e66SAl Viro if (!maxsize) 130533844e66SAl Viro return 0; 130633844e66SAl Viro 1307241699cdSAl Viro if (!sanity(i)) 1308241699cdSAl Viro return -EFAULT; 1309241699cdSAl Viro 13108cefc107SDavid Howells data_start(i, &iter_head, start); 13118cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13128cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1313241699cdSAl Viro capacity = min(npages, maxpages) * PAGE_SIZE - *start; 1314241699cdSAl Viro 13158cefc107SDavid Howells return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); 1316241699cdSAl Viro } 1317241699cdSAl Viro 1318d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1319d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1320d879cb83SAl Viro size_t *start) 1321d879cb83SAl Viro { 1322d879cb83SAl Viro if (maxsize > i->count) 1323d879cb83SAl Viro maxsize = i->count; 1324d879cb83SAl Viro 132500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1326241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 13279ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 13289ea9ce04SDavid Howells return -EFAULT; 13299ea9ce04SDavid Howells 1330d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1331d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1332d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1333d879cb83SAl Viro int n; 1334d879cb83SAl Viro int res; 1335d879cb83SAl Viro 1336d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1337d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1338d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1339d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 134073b0140bSIra Weiny res = get_user_pages_fast(addr, n, 134173b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, 134273b0140bSIra Weiny pages); 1343d879cb83SAl Viro if (unlikely(res < 0)) 1344d879cb83SAl Viro return res; 1345d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1346d879cb83SAl Viro 0;}),({ 1347d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1348d879cb83SAl Viro *start = v.bv_offset; 1349d879cb83SAl Viro get_page(*pages = v.bv_page); 1350d879cb83SAl Viro return v.bv_len; 1351d879cb83SAl Viro }),({ 1352d879cb83SAl Viro return -EFAULT; 1353d879cb83SAl Viro }) 1354d879cb83SAl Viro ) 1355d879cb83SAl Viro return 0; 1356d879cb83SAl Viro } 1357d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1358d879cb83SAl Viro 1359d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1360d879cb83SAl Viro { 1361752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1362d879cb83SAl Viro } 1363d879cb83SAl Viro 1364241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1365241699cdSAl Viro struct page ***pages, size_t maxsize, 1366241699cdSAl Viro size_t *start) 1367241699cdSAl Viro { 1368241699cdSAl Viro struct page **p; 13698cefc107SDavid Howells unsigned int iter_head, npages; 1370d7760d63SIlya Dryomov ssize_t n; 1371241699cdSAl Viro 137233844e66SAl Viro if (!maxsize) 137333844e66SAl Viro return 0; 137433844e66SAl Viro 1375241699cdSAl Viro if (!sanity(i)) 1376241699cdSAl Viro return -EFAULT; 1377241699cdSAl Viro 13788cefc107SDavid Howells data_start(i, &iter_head, start); 13798cefc107SDavid Howells /* Amount of free space: some of this one + all after this one */ 13808cefc107SDavid Howells npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe); 1381241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1382241699cdSAl Viro if (maxsize > n) 1383241699cdSAl Viro maxsize = n; 1384241699cdSAl Viro else 1385241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1386241699cdSAl Viro p = get_pages_array(npages); 1387241699cdSAl Viro if (!p) 1388241699cdSAl Viro return -ENOMEM; 13898cefc107SDavid Howells n = __pipe_get_pages(i, maxsize, p, iter_head, start); 1390241699cdSAl Viro if (n > 0) 1391241699cdSAl Viro *pages = p; 1392241699cdSAl Viro else 1393241699cdSAl Viro kvfree(p); 1394241699cdSAl Viro return n; 1395241699cdSAl Viro } 1396241699cdSAl Viro 1397d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1398d879cb83SAl Viro struct page ***pages, size_t maxsize, 1399d879cb83SAl Viro size_t *start) 1400d879cb83SAl Viro { 1401d879cb83SAl Viro struct page **p; 1402d879cb83SAl Viro 1403d879cb83SAl Viro if (maxsize > i->count) 1404d879cb83SAl Viro maxsize = i->count; 1405d879cb83SAl Viro 140600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1407241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 14089ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 14099ea9ce04SDavid Howells return -EFAULT; 14109ea9ce04SDavid Howells 1411d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1412d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1413d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1414d879cb83SAl Viro int n; 1415d879cb83SAl Viro int res; 1416d879cb83SAl Viro 1417d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1418d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1419d879cb83SAl Viro p = get_pages_array(n); 1420d879cb83SAl Viro if (!p) 1421d879cb83SAl Viro return -ENOMEM; 142273b0140bSIra Weiny res = get_user_pages_fast(addr, n, 142373b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); 1424d879cb83SAl Viro if (unlikely(res < 0)) { 1425d879cb83SAl Viro kvfree(p); 1426d879cb83SAl Viro return res; 1427d879cb83SAl Viro } 1428d879cb83SAl Viro *pages = p; 1429d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1430d879cb83SAl Viro 0;}),({ 1431d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1432d879cb83SAl Viro *start = v.bv_offset; 1433d879cb83SAl Viro *pages = p = get_pages_array(1); 1434d879cb83SAl Viro if (!p) 1435d879cb83SAl Viro return -ENOMEM; 1436d879cb83SAl Viro get_page(*p = v.bv_page); 1437d879cb83SAl Viro return v.bv_len; 1438d879cb83SAl Viro }),({ 1439d879cb83SAl Viro return -EFAULT; 1440d879cb83SAl Viro }) 1441d879cb83SAl Viro ) 1442d879cb83SAl Viro return 0; 1443d879cb83SAl Viro } 1444d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1445d879cb83SAl Viro 1446d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1447d879cb83SAl Viro struct iov_iter *i) 1448d879cb83SAl Viro { 1449d879cb83SAl Viro char *to = addr; 1450d879cb83SAl Viro __wsum sum, next; 1451d879cb83SAl Viro size_t off = 0; 1452d879cb83SAl Viro sum = *csum; 14539ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1454241699cdSAl Viro WARN_ON(1); 1455241699cdSAl Viro return 0; 1456241699cdSAl Viro } 1457d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1458d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1459d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1460c693cc46SAl Viro v.iov_len); 1461c693cc46SAl Viro if (next) { 1462d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1463d879cb83SAl Viro off += v.iov_len; 1464d879cb83SAl Viro } 1465c693cc46SAl Viro next ? 0 : v.iov_len; 1466d879cb83SAl Viro }), ({ 1467d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1468f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1469f9152895SAl Viro p + v.bv_offset, v.bv_len, 1470f9152895SAl Viro sum, off); 1471d879cb83SAl Viro kunmap_atomic(p); 1472d879cb83SAl Viro off += v.bv_len; 1473d879cb83SAl Viro }),({ 1474f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1475f9152895SAl Viro v.iov_base, v.iov_len, 1476f9152895SAl Viro sum, off); 1477d879cb83SAl Viro off += v.iov_len; 1478d879cb83SAl Viro }) 1479d879cb83SAl Viro ) 1480d879cb83SAl Viro *csum = sum; 1481d879cb83SAl Viro return bytes; 1482d879cb83SAl Viro } 1483d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1484d879cb83SAl Viro 1485cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1486cbbd26b8SAl Viro struct iov_iter *i) 1487cbbd26b8SAl Viro { 1488cbbd26b8SAl Viro char *to = addr; 1489cbbd26b8SAl Viro __wsum sum, next; 1490cbbd26b8SAl Viro size_t off = 0; 1491cbbd26b8SAl Viro sum = *csum; 14929ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1493cbbd26b8SAl Viro WARN_ON(1); 1494cbbd26b8SAl Viro return false; 1495cbbd26b8SAl Viro } 1496cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1497cbbd26b8SAl Viro return false; 1498cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1499cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1500cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1501c693cc46SAl Viro v.iov_len); 1502c693cc46SAl Viro if (!next) 1503cbbd26b8SAl Viro return false; 1504cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1505cbbd26b8SAl Viro off += v.iov_len; 1506cbbd26b8SAl Viro 0; 1507cbbd26b8SAl Viro }), ({ 1508cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1509f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1510f9152895SAl Viro p + v.bv_offset, v.bv_len, 1511f9152895SAl Viro sum, off); 1512cbbd26b8SAl Viro kunmap_atomic(p); 1513cbbd26b8SAl Viro off += v.bv_len; 1514cbbd26b8SAl Viro }),({ 1515f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1516f9152895SAl Viro v.iov_base, v.iov_len, 1517f9152895SAl Viro sum, off); 1518cbbd26b8SAl Viro off += v.iov_len; 1519cbbd26b8SAl Viro }) 1520cbbd26b8SAl Viro ) 1521cbbd26b8SAl Viro *csum = sum; 1522cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1523cbbd26b8SAl Viro return true; 1524cbbd26b8SAl Viro } 1525cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1526cbbd26b8SAl Viro 1527*52cbd23aSWillem de Bruijn size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, 1528d879cb83SAl Viro struct iov_iter *i) 1529d879cb83SAl Viro { 1530*52cbd23aSWillem de Bruijn struct csum_state *csstate = _csstate; 153136f7a8a4SAl Viro const char *from = addr; 1532d879cb83SAl Viro __wsum sum, next; 1533*52cbd23aSWillem de Bruijn size_t off; 153478e1f386SAl Viro 153578e1f386SAl Viro if (unlikely(iov_iter_is_pipe(i))) 1536*52cbd23aSWillem de Bruijn return csum_and_copy_to_pipe_iter(addr, bytes, _csstate, i); 153778e1f386SAl Viro 1538*52cbd23aSWillem de Bruijn sum = csstate->csum; 1539*52cbd23aSWillem de Bruijn off = csstate->off; 154078e1f386SAl Viro if (unlikely(iov_iter_is_discard(i))) { 1541241699cdSAl Viro WARN_ON(1); /* for now */ 1542241699cdSAl Viro return 0; 1543241699cdSAl Viro } 1544d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1545d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1546d879cb83SAl Viro v.iov_base, 1547c693cc46SAl Viro v.iov_len); 1548c693cc46SAl Viro if (next) { 1549d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1550d879cb83SAl Viro off += v.iov_len; 1551d879cb83SAl Viro } 1552c693cc46SAl Viro next ? 0 : v.iov_len; 1553d879cb83SAl Viro }), ({ 1554d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1555f9152895SAl Viro sum = csum_and_memcpy(p + v.bv_offset, 1556f9152895SAl Viro (from += v.bv_len) - v.bv_len, 1557f9152895SAl Viro v.bv_len, sum, off); 1558d879cb83SAl Viro kunmap_atomic(p); 1559d879cb83SAl Viro off += v.bv_len; 1560d879cb83SAl Viro }),({ 1561f9152895SAl Viro sum = csum_and_memcpy(v.iov_base, 1562f9152895SAl Viro (from += v.iov_len) - v.iov_len, 1563f9152895SAl Viro v.iov_len, sum, off); 1564d879cb83SAl Viro off += v.iov_len; 1565d879cb83SAl Viro }) 1566d879cb83SAl Viro ) 1567*52cbd23aSWillem de Bruijn csstate->csum = sum; 1568*52cbd23aSWillem de Bruijn csstate->off = off; 1569d879cb83SAl Viro return bytes; 1570d879cb83SAl Viro } 1571d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1572d879cb83SAl Viro 1573d05f4435SSagi Grimberg size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, 1574d05f4435SSagi Grimberg struct iov_iter *i) 1575d05f4435SSagi Grimberg { 15767999096fSHerbert Xu #ifdef CONFIG_CRYPTO_HASH 1577d05f4435SSagi Grimberg struct ahash_request *hash = hashp; 1578d05f4435SSagi Grimberg struct scatterlist sg; 1579d05f4435SSagi Grimberg size_t copied; 1580d05f4435SSagi Grimberg 1581d05f4435SSagi Grimberg copied = copy_to_iter(addr, bytes, i); 1582d05f4435SSagi Grimberg sg_init_one(&sg, addr, copied); 1583d05f4435SSagi Grimberg ahash_request_set_crypt(hash, &sg, NULL, copied); 1584d05f4435SSagi Grimberg crypto_ahash_update(hash); 1585d05f4435SSagi Grimberg return copied; 158627fad74aSYueHaibing #else 158727fad74aSYueHaibing return 0; 158827fad74aSYueHaibing #endif 1589d05f4435SSagi Grimberg } 1590d05f4435SSagi Grimberg EXPORT_SYMBOL(hash_and_copy_to_iter); 1591d05f4435SSagi Grimberg 1592d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1593d879cb83SAl Viro { 1594d879cb83SAl Viro size_t size = i->count; 1595d879cb83SAl Viro int npages = 0; 1596d879cb83SAl Viro 1597d879cb83SAl Viro if (!size) 1598d879cb83SAl Viro return 0; 15999ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 16009ea9ce04SDavid Howells return 0; 1601d879cb83SAl Viro 160200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1603241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 16048cefc107SDavid Howells unsigned int iter_head; 1605241699cdSAl Viro size_t off; 1606241699cdSAl Viro 1607241699cdSAl Viro if (!sanity(i)) 1608241699cdSAl Viro return 0; 1609241699cdSAl Viro 16108cefc107SDavid Howells data_start(i, &iter_head, &off); 1611241699cdSAl Viro /* some of this one + all after this one */ 16128cefc107SDavid Howells npages = pipe_space_for_user(iter_head, pipe->tail, pipe); 1613241699cdSAl Viro if (npages >= maxpages) 1614241699cdSAl Viro return maxpages; 1615241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1616d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1617d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1618d879cb83SAl Viro - p / PAGE_SIZE; 1619d879cb83SAl Viro if (npages >= maxpages) 1620d879cb83SAl Viro return maxpages; 1621d879cb83SAl Viro 0;}),({ 1622d879cb83SAl Viro npages++; 1623d879cb83SAl Viro if (npages >= maxpages) 1624d879cb83SAl Viro return maxpages; 1625d879cb83SAl Viro }),({ 1626d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1627d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1628d879cb83SAl Viro - p / PAGE_SIZE; 1629d879cb83SAl Viro if (npages >= maxpages) 1630d879cb83SAl Viro return maxpages; 1631d879cb83SAl Viro }) 1632d879cb83SAl Viro ) 1633d879cb83SAl Viro return npages; 1634d879cb83SAl Viro } 1635d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1636d879cb83SAl Viro 1637d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1638d879cb83SAl Viro { 1639d879cb83SAl Viro *new = *old; 164000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(new))) { 1641241699cdSAl Viro WARN_ON(1); 1642241699cdSAl Viro return NULL; 1643241699cdSAl Viro } 16449ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(new))) 16459ea9ce04SDavid Howells return NULL; 164600e23707SDavid Howells if (iov_iter_is_bvec(new)) 1647d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1648d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1649d879cb83SAl Viro flags); 1650d879cb83SAl Viro else 1651d879cb83SAl Viro /* iovec and kvec have identical layout */ 1652d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1653d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1654d879cb83SAl Viro flags); 1655d879cb83SAl Viro } 1656d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1657bc917be8SAl Viro 1658bfdc5970SChristoph Hellwig static int copy_compat_iovec_from_user(struct iovec *iov, 1659bfdc5970SChristoph Hellwig const struct iovec __user *uvec, unsigned long nr_segs) 1660bfdc5970SChristoph Hellwig { 1661bfdc5970SChristoph Hellwig const struct compat_iovec __user *uiov = 1662bfdc5970SChristoph Hellwig (const struct compat_iovec __user *)uvec; 1663bfdc5970SChristoph Hellwig int ret = -EFAULT, i; 1664bfdc5970SChristoph Hellwig 1665a959a978SChristoph Hellwig if (!user_access_begin(uiov, nr_segs * sizeof(*uiov))) 1666bfdc5970SChristoph Hellwig return -EFAULT; 1667bfdc5970SChristoph Hellwig 1668bfdc5970SChristoph Hellwig for (i = 0; i < nr_segs; i++) { 1669bfdc5970SChristoph Hellwig compat_uptr_t buf; 1670bfdc5970SChristoph Hellwig compat_ssize_t len; 1671bfdc5970SChristoph Hellwig 1672bfdc5970SChristoph Hellwig unsafe_get_user(len, &uiov[i].iov_len, uaccess_end); 1673bfdc5970SChristoph Hellwig unsafe_get_user(buf, &uiov[i].iov_base, uaccess_end); 1674bfdc5970SChristoph Hellwig 1675bfdc5970SChristoph Hellwig /* check for compat_size_t not fitting in compat_ssize_t .. */ 1676bfdc5970SChristoph Hellwig if (len < 0) { 1677bfdc5970SChristoph Hellwig ret = -EINVAL; 1678bfdc5970SChristoph Hellwig goto uaccess_end; 1679bfdc5970SChristoph Hellwig } 1680bfdc5970SChristoph Hellwig iov[i].iov_base = compat_ptr(buf); 1681bfdc5970SChristoph Hellwig iov[i].iov_len = len; 1682bfdc5970SChristoph Hellwig } 1683bfdc5970SChristoph Hellwig 1684bfdc5970SChristoph Hellwig ret = 0; 1685bfdc5970SChristoph Hellwig uaccess_end: 1686bfdc5970SChristoph Hellwig user_access_end(); 1687bfdc5970SChristoph Hellwig return ret; 1688bfdc5970SChristoph Hellwig } 1689bfdc5970SChristoph Hellwig 1690bfdc5970SChristoph Hellwig static int copy_iovec_from_user(struct iovec *iov, 1691bfdc5970SChristoph Hellwig const struct iovec __user *uvec, unsigned long nr_segs) 1692fb041b59SDavid Laight { 1693fb041b59SDavid Laight unsigned long seg; 1694bfdc5970SChristoph Hellwig 1695bfdc5970SChristoph Hellwig if (copy_from_user(iov, uvec, nr_segs * sizeof(*uvec))) 1696bfdc5970SChristoph Hellwig return -EFAULT; 1697bfdc5970SChristoph Hellwig for (seg = 0; seg < nr_segs; seg++) { 1698bfdc5970SChristoph Hellwig if ((ssize_t)iov[seg].iov_len < 0) 1699bfdc5970SChristoph Hellwig return -EINVAL; 1700bfdc5970SChristoph Hellwig } 1701bfdc5970SChristoph Hellwig 1702bfdc5970SChristoph Hellwig return 0; 1703bfdc5970SChristoph Hellwig } 1704bfdc5970SChristoph Hellwig 1705bfdc5970SChristoph Hellwig struct iovec *iovec_from_user(const struct iovec __user *uvec, 1706bfdc5970SChristoph Hellwig unsigned long nr_segs, unsigned long fast_segs, 1707bfdc5970SChristoph Hellwig struct iovec *fast_iov, bool compat) 1708bfdc5970SChristoph Hellwig { 1709bfdc5970SChristoph Hellwig struct iovec *iov = fast_iov; 1710bfdc5970SChristoph Hellwig int ret; 1711fb041b59SDavid Laight 1712fb041b59SDavid Laight /* 1713bfdc5970SChristoph Hellwig * SuS says "The readv() function *may* fail if the iovcnt argument was 1714bfdc5970SChristoph Hellwig * less than or equal to 0, or greater than {IOV_MAX}. Linux has 1715fb041b59SDavid Laight * traditionally returned zero for zero segments, so... 1716fb041b59SDavid Laight */ 1717bfdc5970SChristoph Hellwig if (nr_segs == 0) 1718bfdc5970SChristoph Hellwig return iov; 1719bfdc5970SChristoph Hellwig if (nr_segs > UIO_MAXIOV) 1720bfdc5970SChristoph Hellwig return ERR_PTR(-EINVAL); 1721fb041b59SDavid Laight if (nr_segs > fast_segs) { 1722fb041b59SDavid Laight iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL); 1723bfdc5970SChristoph Hellwig if (!iov) 1724bfdc5970SChristoph Hellwig return ERR_PTR(-ENOMEM); 1725fb041b59SDavid Laight } 1726bfdc5970SChristoph Hellwig 1727bfdc5970SChristoph Hellwig if (compat) 1728bfdc5970SChristoph Hellwig ret = copy_compat_iovec_from_user(iov, uvec, nr_segs); 1729bfdc5970SChristoph Hellwig else 1730bfdc5970SChristoph Hellwig ret = copy_iovec_from_user(iov, uvec, nr_segs); 1731bfdc5970SChristoph Hellwig if (ret) { 1732bfdc5970SChristoph Hellwig if (iov != fast_iov) 1733bfdc5970SChristoph Hellwig kfree(iov); 1734bfdc5970SChristoph Hellwig return ERR_PTR(ret); 1735fb041b59SDavid Laight } 1736bfdc5970SChristoph Hellwig 1737bfdc5970SChristoph Hellwig return iov; 1738bfdc5970SChristoph Hellwig } 1739bfdc5970SChristoph Hellwig 1740bfdc5970SChristoph Hellwig ssize_t __import_iovec(int type, const struct iovec __user *uvec, 1741bfdc5970SChristoph Hellwig unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, 1742bfdc5970SChristoph Hellwig struct iov_iter *i, bool compat) 1743bfdc5970SChristoph Hellwig { 1744bfdc5970SChristoph Hellwig ssize_t total_len = 0; 1745bfdc5970SChristoph Hellwig unsigned long seg; 1746bfdc5970SChristoph Hellwig struct iovec *iov; 1747bfdc5970SChristoph Hellwig 1748bfdc5970SChristoph Hellwig iov = iovec_from_user(uvec, nr_segs, fast_segs, *iovp, compat); 1749bfdc5970SChristoph Hellwig if (IS_ERR(iov)) { 1750bfdc5970SChristoph Hellwig *iovp = NULL; 1751bfdc5970SChristoph Hellwig return PTR_ERR(iov); 1752fb041b59SDavid Laight } 1753fb041b59SDavid Laight 1754fb041b59SDavid Laight /* 1755bfdc5970SChristoph Hellwig * According to the Single Unix Specification we should return EINVAL if 1756bfdc5970SChristoph Hellwig * an element length is < 0 when cast to ssize_t or if the total length 1757bfdc5970SChristoph Hellwig * would overflow the ssize_t return value of the system call. 1758fb041b59SDavid Laight * 1759fb041b59SDavid Laight * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the 1760fb041b59SDavid Laight * overflow case. 1761fb041b59SDavid Laight */ 1762fb041b59SDavid Laight for (seg = 0; seg < nr_segs; seg++) { 1763fb041b59SDavid Laight ssize_t len = (ssize_t)iov[seg].iov_len; 1764fb041b59SDavid Laight 1765bfdc5970SChristoph Hellwig if (!access_ok(iov[seg].iov_base, len)) { 1766bfdc5970SChristoph Hellwig if (iov != *iovp) 1767bfdc5970SChristoph Hellwig kfree(iov); 1768bfdc5970SChristoph Hellwig *iovp = NULL; 1769bfdc5970SChristoph Hellwig return -EFAULT; 1770fb041b59SDavid Laight } 1771bfdc5970SChristoph Hellwig 1772bfdc5970SChristoph Hellwig if (len > MAX_RW_COUNT - total_len) { 1773bfdc5970SChristoph Hellwig len = MAX_RW_COUNT - total_len; 1774fb041b59SDavid Laight iov[seg].iov_len = len; 1775fb041b59SDavid Laight } 1776bfdc5970SChristoph Hellwig total_len += len; 1777fb041b59SDavid Laight } 1778bfdc5970SChristoph Hellwig 1779bfdc5970SChristoph Hellwig iov_iter_init(i, type, iov, nr_segs, total_len); 1780bfdc5970SChristoph Hellwig if (iov == *iovp) 1781bfdc5970SChristoph Hellwig *iovp = NULL; 1782bfdc5970SChristoph Hellwig else 1783bfdc5970SChristoph Hellwig *iovp = iov; 1784bfdc5970SChristoph Hellwig return total_len; 1785fb041b59SDavid Laight } 1786fb041b59SDavid Laight 1787ffecee4fSVegard Nossum /** 1788ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1789ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1790ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1791ffecee4fSVegard Nossum * 1792ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1793bfdc5970SChristoph Hellwig * @uvec: Pointer to the userspace array. 1794ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1795ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1796bfdc5970SChristoph Hellwig * @iovp: (input and output parameter) Pointer to pointer to (usually small 1797ffecee4fSVegard Nossum * on-stack) kernel array. 1798ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1799ffecee4fSVegard Nossum * 1800ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1801ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1802ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1803ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1804ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1805ffecee4fSVegard Nossum * returns an error or not). 1806ffecee4fSVegard Nossum * 180787e5e6daSJens Axboe * Return: Negative error code on error, bytes imported on success 1808ffecee4fSVegard Nossum */ 1809bfdc5970SChristoph Hellwig ssize_t import_iovec(int type, const struct iovec __user *uvec, 1810bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1811bfdc5970SChristoph Hellwig struct iovec **iovp, struct iov_iter *i) 1812bc917be8SAl Viro { 181389cd35c5SChristoph Hellwig return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i, 181489cd35c5SChristoph Hellwig in_compat_syscall()); 1815bc917be8SAl Viro } 1816bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1817bc917be8SAl Viro 1818bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1819bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1820bc917be8SAl Viro { 1821bc917be8SAl Viro if (len > MAX_RW_COUNT) 1822bc917be8SAl Viro len = MAX_RW_COUNT; 182396d4f267SLinus Torvalds if (unlikely(!access_ok(buf, len))) 1824bc917be8SAl Viro return -EFAULT; 1825bc917be8SAl Viro 1826bc917be8SAl Viro iov->iov_base = buf; 1827bc917be8SAl Viro iov->iov_len = len; 1828bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1829bc917be8SAl Viro return 0; 1830bc917be8SAl Viro } 1831e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 183209cf698aSAl Viro 183309cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 183409cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 183509cf698aSAl Viro void *context) 183609cf698aSAl Viro { 183709cf698aSAl Viro struct kvec w; 183809cf698aSAl Viro int err = -EINVAL; 183909cf698aSAl Viro if (!bytes) 184009cf698aSAl Viro return 0; 184109cf698aSAl Viro 184209cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 184309cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 184409cf698aSAl Viro w.iov_len = v.bv_len; 184509cf698aSAl Viro err = f(&w, context); 184609cf698aSAl Viro kunmap(v.bv_page); 184709cf698aSAl Viro err;}), ({ 184809cf698aSAl Viro w = v; 184909cf698aSAl Viro err = f(&w, context);}) 185009cf698aSAl Viro ) 185109cf698aSAl Viro return err; 185209cf698aSAl Viro } 185309cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1854