1d879cb83SAl Viro #include <linux/export.h> 22f8b5444SChristoph Hellwig #include <linux/bvec.h> 3d879cb83SAl Viro #include <linux/uio.h> 4d879cb83SAl Viro #include <linux/pagemap.h> 5d879cb83SAl Viro #include <linux/slab.h> 6d879cb83SAl Viro #include <linux/vmalloc.h> 7241699cdSAl Viro #include <linux/splice.h> 8d879cb83SAl Viro #include <net/checksum.h> 9d879cb83SAl Viro 10241699cdSAl Viro #define PIPE_PARANOIA /* for now */ 11241699cdSAl Viro 12d879cb83SAl Viro #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ 13d879cb83SAl Viro size_t left; \ 14d879cb83SAl Viro size_t wanted = n; \ 15d879cb83SAl Viro __p = i->iov; \ 16d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 17d879cb83SAl Viro if (likely(__v.iov_len)) { \ 18d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 19d879cb83SAl Viro left = (STEP); \ 20d879cb83SAl Viro __v.iov_len -= left; \ 21d879cb83SAl Viro skip += __v.iov_len; \ 22d879cb83SAl Viro n -= __v.iov_len; \ 23d879cb83SAl Viro } else { \ 24d879cb83SAl Viro left = 0; \ 25d879cb83SAl Viro } \ 26d879cb83SAl Viro while (unlikely(!left && n)) { \ 27d879cb83SAl Viro __p++; \ 28d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 29d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 30d879cb83SAl Viro continue; \ 31d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 32d879cb83SAl Viro left = (STEP); \ 33d879cb83SAl Viro __v.iov_len -= left; \ 34d879cb83SAl Viro skip = __v.iov_len; \ 35d879cb83SAl Viro n -= __v.iov_len; \ 36d879cb83SAl Viro } \ 37d879cb83SAl Viro n = wanted - n; \ 38d879cb83SAl Viro } 39d879cb83SAl Viro 40d879cb83SAl Viro #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ 41d879cb83SAl Viro size_t wanted = n; \ 42d879cb83SAl Viro __p = i->kvec; \ 43d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 44d879cb83SAl Viro if (likely(__v.iov_len)) { \ 45d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 46d879cb83SAl Viro (void)(STEP); \ 47d879cb83SAl Viro skip += __v.iov_len; \ 48d879cb83SAl Viro n -= __v.iov_len; \ 49d879cb83SAl Viro } \ 50d879cb83SAl Viro while (unlikely(n)) { \ 51d879cb83SAl Viro __p++; \ 52d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 53d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 54d879cb83SAl Viro continue; \ 55d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 56d879cb83SAl Viro (void)(STEP); \ 57d879cb83SAl Viro skip = __v.iov_len; \ 58d879cb83SAl Viro n -= __v.iov_len; \ 59d879cb83SAl Viro } \ 60d879cb83SAl Viro n = wanted; \ 61d879cb83SAl Viro } 62d879cb83SAl Viro 631bdc76aeSMing Lei #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ 641bdc76aeSMing Lei struct bvec_iter __start; \ 651bdc76aeSMing Lei __start.bi_size = n; \ 661bdc76aeSMing Lei __start.bi_bvec_done = skip; \ 671bdc76aeSMing Lei __start.bi_idx = 0; \ 681bdc76aeSMing Lei for_each_bvec(__v, i->bvec, __bi, __start) { \ 691bdc76aeSMing Lei if (!__v.bv_len) \ 70d879cb83SAl Viro continue; \ 71d879cb83SAl Viro (void)(STEP); \ 72d879cb83SAl Viro } \ 73d879cb83SAl Viro } 74d879cb83SAl Viro 75d879cb83SAl Viro #define iterate_all_kinds(i, n, v, I, B, K) { \ 7633844e66SAl Viro if (likely(n)) { \ 77d879cb83SAl Viro size_t skip = i->iov_offset; \ 78d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 79d879cb83SAl Viro struct bio_vec v; \ 801bdc76aeSMing Lei struct bvec_iter __bi; \ 811bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 82d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 83d879cb83SAl Viro const struct kvec *kvec; \ 84d879cb83SAl Viro struct kvec v; \ 85d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 86d879cb83SAl Viro } else { \ 87d879cb83SAl Viro const struct iovec *iov; \ 88d879cb83SAl Viro struct iovec v; \ 89d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 90d879cb83SAl Viro } \ 9133844e66SAl Viro } \ 92d879cb83SAl Viro } 93d879cb83SAl Viro 94d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 95dd254f5aSAl Viro if (unlikely(i->count < n)) \ 96dd254f5aSAl Viro n = i->count; \ 9719f18459SAl Viro if (i->count) { \ 98d879cb83SAl Viro size_t skip = i->iov_offset; \ 99d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 1001bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 101d879cb83SAl Viro struct bio_vec v; \ 1021bdc76aeSMing Lei struct bvec_iter __bi; \ 1031bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1041bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1051bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1061bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 107d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 108d879cb83SAl Viro const struct kvec *kvec; \ 109d879cb83SAl Viro struct kvec v; \ 110d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 111d879cb83SAl Viro if (skip == kvec->iov_len) { \ 112d879cb83SAl Viro kvec++; \ 113d879cb83SAl Viro skip = 0; \ 114d879cb83SAl Viro } \ 115d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 116d879cb83SAl Viro i->kvec = kvec; \ 117d879cb83SAl Viro } else { \ 118d879cb83SAl Viro const struct iovec *iov; \ 119d879cb83SAl Viro struct iovec v; \ 120d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 121d879cb83SAl Viro if (skip == iov->iov_len) { \ 122d879cb83SAl Viro iov++; \ 123d879cb83SAl Viro skip = 0; \ 124d879cb83SAl Viro } \ 125d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 126d879cb83SAl Viro i->iov = iov; \ 127d879cb83SAl Viro } \ 128d879cb83SAl Viro i->count -= n; \ 129d879cb83SAl Viro i->iov_offset = skip; \ 130dd254f5aSAl Viro } \ 131d879cb83SAl Viro } 132d879cb83SAl Viro 13309fc68dcSAl Viro static int copyout(void __user *to, const void *from, size_t n) 13409fc68dcSAl Viro { 13509fc68dcSAl Viro if (access_ok(VERIFY_WRITE, to, n)) { 13609fc68dcSAl Viro kasan_check_read(from, n); 13709fc68dcSAl Viro n = raw_copy_to_user(to, from, n); 13809fc68dcSAl Viro } 13909fc68dcSAl Viro return n; 14009fc68dcSAl Viro } 14109fc68dcSAl Viro 14209fc68dcSAl Viro static int copyin(void *to, const void __user *from, size_t n) 14309fc68dcSAl Viro { 14409fc68dcSAl Viro if (access_ok(VERIFY_READ, from, n)) { 14509fc68dcSAl Viro kasan_check_write(to, n); 14609fc68dcSAl Viro n = raw_copy_from_user(to, from, n); 14709fc68dcSAl Viro } 14809fc68dcSAl Viro return n; 14909fc68dcSAl Viro } 15009fc68dcSAl Viro 151d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 152d879cb83SAl Viro struct iov_iter *i) 153d879cb83SAl Viro { 154d879cb83SAl Viro size_t skip, copy, left, wanted; 155d879cb83SAl Viro const struct iovec *iov; 156d879cb83SAl Viro char __user *buf; 157d879cb83SAl Viro void *kaddr, *from; 158d879cb83SAl Viro 159d879cb83SAl Viro if (unlikely(bytes > i->count)) 160d879cb83SAl Viro bytes = i->count; 161d879cb83SAl Viro 162d879cb83SAl Viro if (unlikely(!bytes)) 163d879cb83SAl Viro return 0; 164d879cb83SAl Viro 16509fc68dcSAl Viro might_fault(); 166d879cb83SAl Viro wanted = bytes; 167d879cb83SAl Viro iov = i->iov; 168d879cb83SAl Viro skip = i->iov_offset; 169d879cb83SAl Viro buf = iov->iov_base + skip; 170d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 171d879cb83SAl Viro 1723fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 173d879cb83SAl Viro kaddr = kmap_atomic(page); 174d879cb83SAl Viro from = kaddr + offset; 175d879cb83SAl Viro 176d879cb83SAl Viro /* first chunk, usually the only one */ 17709fc68dcSAl Viro left = copyout(buf, from, copy); 178d879cb83SAl Viro copy -= left; 179d879cb83SAl Viro skip += copy; 180d879cb83SAl Viro from += copy; 181d879cb83SAl Viro bytes -= copy; 182d879cb83SAl Viro 183d879cb83SAl Viro while (unlikely(!left && bytes)) { 184d879cb83SAl Viro iov++; 185d879cb83SAl Viro buf = iov->iov_base; 186d879cb83SAl Viro copy = min(bytes, iov->iov_len); 18709fc68dcSAl Viro left = copyout(buf, from, copy); 188d879cb83SAl Viro copy -= left; 189d879cb83SAl Viro skip = copy; 190d879cb83SAl Viro from += copy; 191d879cb83SAl Viro bytes -= copy; 192d879cb83SAl Viro } 193d879cb83SAl Viro if (likely(!bytes)) { 194d879cb83SAl Viro kunmap_atomic(kaddr); 195d879cb83SAl Viro goto done; 196d879cb83SAl Viro } 197d879cb83SAl Viro offset = from - kaddr; 198d879cb83SAl Viro buf += copy; 199d879cb83SAl Viro kunmap_atomic(kaddr); 200d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 201d879cb83SAl Viro } 202d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2033fa6c507SMikulas Patocka 204d879cb83SAl Viro kaddr = kmap(page); 205d879cb83SAl Viro from = kaddr + offset; 20609fc68dcSAl Viro left = copyout(buf, from, copy); 207d879cb83SAl Viro copy -= left; 208d879cb83SAl Viro skip += copy; 209d879cb83SAl Viro from += copy; 210d879cb83SAl Viro bytes -= copy; 211d879cb83SAl Viro while (unlikely(!left && bytes)) { 212d879cb83SAl Viro iov++; 213d879cb83SAl Viro buf = iov->iov_base; 214d879cb83SAl Viro copy = min(bytes, iov->iov_len); 21509fc68dcSAl Viro left = copyout(buf, from, copy); 216d879cb83SAl Viro copy -= left; 217d879cb83SAl Viro skip = copy; 218d879cb83SAl Viro from += copy; 219d879cb83SAl Viro bytes -= copy; 220d879cb83SAl Viro } 221d879cb83SAl Viro kunmap(page); 2223fa6c507SMikulas Patocka 223d879cb83SAl Viro done: 224d879cb83SAl Viro if (skip == iov->iov_len) { 225d879cb83SAl Viro iov++; 226d879cb83SAl Viro skip = 0; 227d879cb83SAl Viro } 228d879cb83SAl Viro i->count -= wanted - bytes; 229d879cb83SAl Viro i->nr_segs -= iov - i->iov; 230d879cb83SAl Viro i->iov = iov; 231d879cb83SAl Viro i->iov_offset = skip; 232d879cb83SAl Viro return wanted - bytes; 233d879cb83SAl Viro } 234d879cb83SAl Viro 235d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 236d879cb83SAl Viro struct iov_iter *i) 237d879cb83SAl Viro { 238d879cb83SAl Viro size_t skip, copy, left, wanted; 239d879cb83SAl Viro const struct iovec *iov; 240d879cb83SAl Viro char __user *buf; 241d879cb83SAl Viro void *kaddr, *to; 242d879cb83SAl Viro 243d879cb83SAl Viro if (unlikely(bytes > i->count)) 244d879cb83SAl Viro bytes = i->count; 245d879cb83SAl Viro 246d879cb83SAl Viro if (unlikely(!bytes)) 247d879cb83SAl Viro return 0; 248d879cb83SAl Viro 24909fc68dcSAl Viro might_fault(); 250d879cb83SAl Viro wanted = bytes; 251d879cb83SAl Viro iov = i->iov; 252d879cb83SAl Viro skip = i->iov_offset; 253d879cb83SAl Viro buf = iov->iov_base + skip; 254d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 255d879cb83SAl Viro 2563fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 257d879cb83SAl Viro kaddr = kmap_atomic(page); 258d879cb83SAl Viro to = kaddr + offset; 259d879cb83SAl Viro 260d879cb83SAl Viro /* first chunk, usually the only one */ 26109fc68dcSAl Viro left = copyin(to, buf, copy); 262d879cb83SAl Viro copy -= left; 263d879cb83SAl Viro skip += copy; 264d879cb83SAl Viro to += copy; 265d879cb83SAl Viro bytes -= copy; 266d879cb83SAl Viro 267d879cb83SAl Viro while (unlikely(!left && bytes)) { 268d879cb83SAl Viro iov++; 269d879cb83SAl Viro buf = iov->iov_base; 270d879cb83SAl Viro copy = min(bytes, iov->iov_len); 27109fc68dcSAl Viro left = copyin(to, buf, copy); 272d879cb83SAl Viro copy -= left; 273d879cb83SAl Viro skip = copy; 274d879cb83SAl Viro to += copy; 275d879cb83SAl Viro bytes -= copy; 276d879cb83SAl Viro } 277d879cb83SAl Viro if (likely(!bytes)) { 278d879cb83SAl Viro kunmap_atomic(kaddr); 279d879cb83SAl Viro goto done; 280d879cb83SAl Viro } 281d879cb83SAl Viro offset = to - kaddr; 282d879cb83SAl Viro buf += copy; 283d879cb83SAl Viro kunmap_atomic(kaddr); 284d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 285d879cb83SAl Viro } 286d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2873fa6c507SMikulas Patocka 288d879cb83SAl Viro kaddr = kmap(page); 289d879cb83SAl Viro to = kaddr + offset; 29009fc68dcSAl Viro left = copyin(to, buf, copy); 291d879cb83SAl Viro copy -= left; 292d879cb83SAl Viro skip += copy; 293d879cb83SAl Viro to += copy; 294d879cb83SAl Viro bytes -= copy; 295d879cb83SAl Viro while (unlikely(!left && bytes)) { 296d879cb83SAl Viro iov++; 297d879cb83SAl Viro buf = iov->iov_base; 298d879cb83SAl Viro copy = min(bytes, iov->iov_len); 29909fc68dcSAl Viro left = copyin(to, buf, copy); 300d879cb83SAl Viro copy -= left; 301d879cb83SAl Viro skip = copy; 302d879cb83SAl Viro to += copy; 303d879cb83SAl Viro bytes -= copy; 304d879cb83SAl Viro } 305d879cb83SAl Viro kunmap(page); 3063fa6c507SMikulas Patocka 307d879cb83SAl Viro done: 308d879cb83SAl Viro if (skip == iov->iov_len) { 309d879cb83SAl Viro iov++; 310d879cb83SAl Viro skip = 0; 311d879cb83SAl Viro } 312d879cb83SAl Viro i->count -= wanted - bytes; 313d879cb83SAl Viro i->nr_segs -= iov - i->iov; 314d879cb83SAl Viro i->iov = iov; 315d879cb83SAl Viro i->iov_offset = skip; 316d879cb83SAl Viro return wanted - bytes; 317d879cb83SAl Viro } 318d879cb83SAl Viro 319241699cdSAl Viro #ifdef PIPE_PARANOIA 320241699cdSAl Viro static bool sanity(const struct iov_iter *i) 321241699cdSAl Viro { 322241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 323241699cdSAl Viro int idx = i->idx; 324241699cdSAl Viro int next = pipe->curbuf + pipe->nrbufs; 325241699cdSAl Viro if (i->iov_offset) { 326241699cdSAl Viro struct pipe_buffer *p; 327241699cdSAl Viro if (unlikely(!pipe->nrbufs)) 328241699cdSAl Viro goto Bad; // pipe must be non-empty 329241699cdSAl Viro if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) 330241699cdSAl Viro goto Bad; // must be at the last buffer... 331241699cdSAl Viro 332241699cdSAl Viro p = &pipe->bufs[idx]; 333241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 334241699cdSAl Viro goto Bad; // ... at the end of segment 335241699cdSAl Viro } else { 336241699cdSAl Viro if (idx != (next & (pipe->buffers - 1))) 337241699cdSAl Viro goto Bad; // must be right after the last buffer 338241699cdSAl Viro } 339241699cdSAl Viro return true; 340241699cdSAl Viro Bad: 341241699cdSAl Viro printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); 342241699cdSAl Viro printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", 343241699cdSAl Viro pipe->curbuf, pipe->nrbufs, pipe->buffers); 344241699cdSAl Viro for (idx = 0; idx < pipe->buffers; idx++) 345241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 346241699cdSAl Viro pipe->bufs[idx].ops, 347241699cdSAl Viro pipe->bufs[idx].page, 348241699cdSAl Viro pipe->bufs[idx].offset, 349241699cdSAl Viro pipe->bufs[idx].len); 350241699cdSAl Viro WARN_ON(1); 351241699cdSAl Viro return false; 352241699cdSAl Viro } 353241699cdSAl Viro #else 354241699cdSAl Viro #define sanity(i) true 355241699cdSAl Viro #endif 356241699cdSAl Viro 357241699cdSAl Viro static inline int next_idx(int idx, struct pipe_inode_info *pipe) 358241699cdSAl Viro { 359241699cdSAl Viro return (idx + 1) & (pipe->buffers - 1); 360241699cdSAl Viro } 361241699cdSAl Viro 362241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 363241699cdSAl Viro struct iov_iter *i) 364241699cdSAl Viro { 365241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 366241699cdSAl Viro struct pipe_buffer *buf; 367241699cdSAl Viro size_t off; 368241699cdSAl Viro int idx; 369241699cdSAl Viro 370241699cdSAl Viro if (unlikely(bytes > i->count)) 371241699cdSAl Viro bytes = i->count; 372241699cdSAl Viro 373241699cdSAl Viro if (unlikely(!bytes)) 374241699cdSAl Viro return 0; 375241699cdSAl Viro 376241699cdSAl Viro if (!sanity(i)) 377241699cdSAl Viro return 0; 378241699cdSAl Viro 379241699cdSAl Viro off = i->iov_offset; 380241699cdSAl Viro idx = i->idx; 381241699cdSAl Viro buf = &pipe->bufs[idx]; 382241699cdSAl Viro if (off) { 383241699cdSAl Viro if (offset == off && buf->page == page) { 384241699cdSAl Viro /* merge with the last one */ 385241699cdSAl Viro buf->len += bytes; 386241699cdSAl Viro i->iov_offset += bytes; 387241699cdSAl Viro goto out; 388241699cdSAl Viro } 389241699cdSAl Viro idx = next_idx(idx, pipe); 390241699cdSAl Viro buf = &pipe->bufs[idx]; 391241699cdSAl Viro } 392241699cdSAl Viro if (idx == pipe->curbuf && pipe->nrbufs) 393241699cdSAl Viro return 0; 394241699cdSAl Viro pipe->nrbufs++; 395241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 396241699cdSAl Viro get_page(buf->page = page); 397241699cdSAl Viro buf->offset = offset; 398241699cdSAl Viro buf->len = bytes; 399241699cdSAl Viro i->iov_offset = offset + bytes; 400241699cdSAl Viro i->idx = idx; 401241699cdSAl Viro out: 402241699cdSAl Viro i->count -= bytes; 403241699cdSAl Viro return bytes; 404241699cdSAl Viro } 405241699cdSAl Viro 406d879cb83SAl Viro /* 407171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 408171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 409171a0203SAnton Altaparmakov * 410171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 411171a0203SAnton Altaparmakov * because it is an invalid address). 412171a0203SAnton Altaparmakov */ 413d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 414171a0203SAnton Altaparmakov { 415171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 416171a0203SAnton Altaparmakov const struct iovec *iov; 417171a0203SAnton Altaparmakov int err; 418171a0203SAnton Altaparmakov struct iovec v; 419171a0203SAnton Altaparmakov 420171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 421171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4224bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 423171a0203SAnton Altaparmakov if (unlikely(err)) 424171a0203SAnton Altaparmakov return err; 425171a0203SAnton Altaparmakov 0;})) 426171a0203SAnton Altaparmakov } 427171a0203SAnton Altaparmakov return 0; 428171a0203SAnton Altaparmakov } 429d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 430171a0203SAnton Altaparmakov 431d879cb83SAl Viro void iov_iter_init(struct iov_iter *i, int direction, 432d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 433d879cb83SAl Viro size_t count) 434d879cb83SAl Viro { 435d879cb83SAl Viro /* It will get better. Eventually... */ 436db68ce10SAl Viro if (uaccess_kernel()) { 437d879cb83SAl Viro direction |= ITER_KVEC; 438d879cb83SAl Viro i->type = direction; 439d879cb83SAl Viro i->kvec = (struct kvec *)iov; 440d879cb83SAl Viro } else { 441d879cb83SAl Viro i->type = direction; 442d879cb83SAl Viro i->iov = iov; 443d879cb83SAl Viro } 444d879cb83SAl Viro i->nr_segs = nr_segs; 445d879cb83SAl Viro i->iov_offset = 0; 446d879cb83SAl Viro i->count = count; 447d879cb83SAl Viro } 448d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 449d879cb83SAl Viro 450d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 451d879cb83SAl Viro { 452d879cb83SAl Viro char *from = kmap_atomic(page); 453d879cb83SAl Viro memcpy(to, from + offset, len); 454d879cb83SAl Viro kunmap_atomic(from); 455d879cb83SAl Viro } 456d879cb83SAl Viro 45736f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 458d879cb83SAl Viro { 459d879cb83SAl Viro char *to = kmap_atomic(page); 460d879cb83SAl Viro memcpy(to + offset, from, len); 461d879cb83SAl Viro kunmap_atomic(to); 462d879cb83SAl Viro } 463d879cb83SAl Viro 464d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 465d879cb83SAl Viro { 466d879cb83SAl Viro char *addr = kmap_atomic(page); 467d879cb83SAl Viro memset(addr + offset, 0, len); 468d879cb83SAl Viro kunmap_atomic(addr); 469d879cb83SAl Viro } 470d879cb83SAl Viro 471241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 472241699cdSAl Viro { 473241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 474241699cdSAl Viro } 475241699cdSAl Viro 476241699cdSAl Viro static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) 477241699cdSAl Viro { 478241699cdSAl Viro size_t off = i->iov_offset; 479241699cdSAl Viro int idx = i->idx; 480241699cdSAl Viro if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { 481241699cdSAl Viro idx = next_idx(idx, i->pipe); 482241699cdSAl Viro off = 0; 483241699cdSAl Viro } 484241699cdSAl Viro *idxp = idx; 485241699cdSAl Viro *offp = off; 486241699cdSAl Viro } 487241699cdSAl Viro 488241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 489241699cdSAl Viro int *idxp, size_t *offp) 490241699cdSAl Viro { 491241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 492241699cdSAl Viro size_t off; 493241699cdSAl Viro int idx; 494241699cdSAl Viro ssize_t left; 495241699cdSAl Viro 496241699cdSAl Viro if (unlikely(size > i->count)) 497241699cdSAl Viro size = i->count; 498241699cdSAl Viro if (unlikely(!size)) 499241699cdSAl Viro return 0; 500241699cdSAl Viro 501241699cdSAl Viro left = size; 502241699cdSAl Viro data_start(i, &idx, &off); 503241699cdSAl Viro *idxp = idx; 504241699cdSAl Viro *offp = off; 505241699cdSAl Viro if (off) { 506241699cdSAl Viro left -= PAGE_SIZE - off; 507241699cdSAl Viro if (left <= 0) { 508241699cdSAl Viro pipe->bufs[idx].len += size; 509241699cdSAl Viro return size; 510241699cdSAl Viro } 511241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 512241699cdSAl Viro idx = next_idx(idx, pipe); 513241699cdSAl Viro } 514241699cdSAl Viro while (idx != pipe->curbuf || !pipe->nrbufs) { 515241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 516241699cdSAl Viro if (!page) 517241699cdSAl Viro break; 518241699cdSAl Viro pipe->nrbufs++; 519241699cdSAl Viro pipe->bufs[idx].ops = &default_pipe_buf_ops; 520241699cdSAl Viro pipe->bufs[idx].page = page; 521241699cdSAl Viro pipe->bufs[idx].offset = 0; 522241699cdSAl Viro if (left <= PAGE_SIZE) { 523241699cdSAl Viro pipe->bufs[idx].len = left; 524241699cdSAl Viro return size; 525241699cdSAl Viro } 526241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 527241699cdSAl Viro left -= PAGE_SIZE; 528241699cdSAl Viro idx = next_idx(idx, pipe); 529241699cdSAl Viro } 530241699cdSAl Viro return size - left; 531241699cdSAl Viro } 532241699cdSAl Viro 533241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 534241699cdSAl Viro struct iov_iter *i) 535241699cdSAl Viro { 536241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 537241699cdSAl Viro size_t n, off; 538241699cdSAl Viro int idx; 539241699cdSAl Viro 540241699cdSAl Viro if (!sanity(i)) 541241699cdSAl Viro return 0; 542241699cdSAl Viro 543241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 544241699cdSAl Viro if (unlikely(!n)) 545241699cdSAl Viro return 0; 546241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 547241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 548241699cdSAl Viro memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); 549241699cdSAl Viro i->idx = idx; 550241699cdSAl Viro i->iov_offset = off + chunk; 551241699cdSAl Viro n -= chunk; 552241699cdSAl Viro addr += chunk; 553241699cdSAl Viro } 554241699cdSAl Viro i->count -= bytes; 555241699cdSAl Viro return bytes; 556241699cdSAl Viro } 557241699cdSAl Viro 558aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 559d879cb83SAl Viro { 56036f7a8a4SAl Viro const char *from = addr; 561241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 562241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 56309fc68dcSAl Viro if (iter_is_iovec(i)) 56409fc68dcSAl Viro might_fault(); 565d879cb83SAl Viro iterate_and_advance(i, bytes, v, 56609fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 567d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 568d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 569d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 570d879cb83SAl Viro ) 571d879cb83SAl Viro 572d879cb83SAl Viro return bytes; 573d879cb83SAl Viro } 574aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 575d879cb83SAl Viro 576aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 577d879cb83SAl Viro { 578d879cb83SAl Viro char *to = addr; 579241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 580241699cdSAl Viro WARN_ON(1); 581241699cdSAl Viro return 0; 582241699cdSAl Viro } 58309fc68dcSAl Viro if (iter_is_iovec(i)) 58409fc68dcSAl Viro might_fault(); 585d879cb83SAl Viro iterate_and_advance(i, bytes, v, 58609fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 587d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 588d879cb83SAl Viro v.bv_offset, v.bv_len), 589d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 590d879cb83SAl Viro ) 591d879cb83SAl Viro 592d879cb83SAl Viro return bytes; 593d879cb83SAl Viro } 594aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 595d879cb83SAl Viro 596aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 597cbbd26b8SAl Viro { 598cbbd26b8SAl Viro char *to = addr; 599cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 600cbbd26b8SAl Viro WARN_ON(1); 601cbbd26b8SAl Viro return false; 602cbbd26b8SAl Viro } 60333844e66SAl Viro if (unlikely(i->count < bytes)) 604cbbd26b8SAl Viro return false; 605cbbd26b8SAl Viro 60609fc68dcSAl Viro if (iter_is_iovec(i)) 60709fc68dcSAl Viro might_fault(); 608cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 60909fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 610cbbd26b8SAl Viro v.iov_base, v.iov_len)) 611cbbd26b8SAl Viro return false; 612cbbd26b8SAl Viro 0;}), 613cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 614cbbd26b8SAl Viro v.bv_offset, v.bv_len), 615cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 616cbbd26b8SAl Viro ) 617cbbd26b8SAl Viro 618cbbd26b8SAl Viro iov_iter_advance(i, bytes); 619cbbd26b8SAl Viro return true; 620cbbd26b8SAl Viro } 621aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 622cbbd26b8SAl Viro 623aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 624d879cb83SAl Viro { 625d879cb83SAl Viro char *to = addr; 626241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 627241699cdSAl Viro WARN_ON(1); 628241699cdSAl Viro return 0; 629241699cdSAl Viro } 630d879cb83SAl Viro iterate_and_advance(i, bytes, v, 6313f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 632d879cb83SAl Viro v.iov_base, v.iov_len), 633d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 634d879cb83SAl Viro v.bv_offset, v.bv_len), 635d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 636d879cb83SAl Viro ) 637d879cb83SAl Viro 638d879cb83SAl Viro return bytes; 639d879cb83SAl Viro } 640aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 641d879cb83SAl Viro 642aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 643cbbd26b8SAl Viro { 644cbbd26b8SAl Viro char *to = addr; 645cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 646cbbd26b8SAl Viro WARN_ON(1); 647cbbd26b8SAl Viro return false; 648cbbd26b8SAl Viro } 64933844e66SAl Viro if (unlikely(i->count < bytes)) 650cbbd26b8SAl Viro return false; 651cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 6523f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 653cbbd26b8SAl Viro v.iov_base, v.iov_len)) 654cbbd26b8SAl Viro return false; 655cbbd26b8SAl Viro 0;}), 656cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 657cbbd26b8SAl Viro v.bv_offset, v.bv_len), 658cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 659cbbd26b8SAl Viro ) 660cbbd26b8SAl Viro 661cbbd26b8SAl Viro iov_iter_advance(i, bytes); 662cbbd26b8SAl Viro return true; 663cbbd26b8SAl Viro } 664aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 665cbbd26b8SAl Viro 66672e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 66772e809edSAl Viro { 66872e809edSAl Viro size_t v = n + offset; 66972e809edSAl Viro if (likely(n <= v && v <= (PAGE_SIZE << compound_order(page)))) 67072e809edSAl Viro return true; 67172e809edSAl Viro WARN_ON(1); 67272e809edSAl Viro return false; 67372e809edSAl Viro } 67472e809edSAl Viro 675d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 676d879cb83SAl Viro struct iov_iter *i) 677d879cb83SAl Viro { 67872e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 67972e809edSAl Viro return 0; 680d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 681d879cb83SAl Viro void *kaddr = kmap_atomic(page); 682d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 683d879cb83SAl Viro kunmap_atomic(kaddr); 684d879cb83SAl Viro return wanted; 685241699cdSAl Viro } else if (likely(!(i->type & ITER_PIPE))) 686d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 687241699cdSAl Viro else 688241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 689d879cb83SAl Viro } 690d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 691d879cb83SAl Viro 692d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 693d879cb83SAl Viro struct iov_iter *i) 694d879cb83SAl Viro { 69572e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 69672e809edSAl Viro return 0; 697241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 698241699cdSAl Viro WARN_ON(1); 699241699cdSAl Viro return 0; 700241699cdSAl Viro } 701d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 702d879cb83SAl Viro void *kaddr = kmap_atomic(page); 703aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 704d879cb83SAl Viro kunmap_atomic(kaddr); 705d879cb83SAl Viro return wanted; 706d879cb83SAl Viro } else 707d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 708d879cb83SAl Viro } 709d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 710d879cb83SAl Viro 711241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 712241699cdSAl Viro { 713241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 714241699cdSAl Viro size_t n, off; 715241699cdSAl Viro int idx; 716241699cdSAl Viro 717241699cdSAl Viro if (!sanity(i)) 718241699cdSAl Viro return 0; 719241699cdSAl Viro 720241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 721241699cdSAl Viro if (unlikely(!n)) 722241699cdSAl Viro return 0; 723241699cdSAl Viro 724241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 725241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 726241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 727241699cdSAl Viro i->idx = idx; 728241699cdSAl Viro i->iov_offset = off + chunk; 729241699cdSAl Viro n -= chunk; 730241699cdSAl Viro } 731241699cdSAl Viro i->count -= bytes; 732241699cdSAl Viro return bytes; 733241699cdSAl Viro } 734241699cdSAl Viro 735d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 736d879cb83SAl Viro { 737241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 738241699cdSAl Viro return pipe_zero(bytes, i); 739d879cb83SAl Viro iterate_and_advance(i, bytes, v, 74009fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 741d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 742d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 743d879cb83SAl Viro ) 744d879cb83SAl Viro 745d879cb83SAl Viro return bytes; 746d879cb83SAl Viro } 747d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 748d879cb83SAl Viro 749d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 750d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 751d879cb83SAl Viro { 752d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 75372e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 75472e809edSAl Viro kunmap_atomic(kaddr); 75572e809edSAl Viro return 0; 75672e809edSAl Viro } 757241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 758241699cdSAl Viro kunmap_atomic(kaddr); 759241699cdSAl Viro WARN_ON(1); 760241699cdSAl Viro return 0; 761241699cdSAl Viro } 762d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 76309fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 764d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 765d879cb83SAl Viro v.bv_offset, v.bv_len), 766d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 767d879cb83SAl Viro ) 768d879cb83SAl Viro kunmap_atomic(kaddr); 769d879cb83SAl Viro return bytes; 770d879cb83SAl Viro } 771d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 772d879cb83SAl Viro 773b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 774241699cdSAl Viro { 775241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 776241699cdSAl Viro if (pipe->nrbufs) { 777b9dc6f65SAl Viro size_t off = i->iov_offset; 778b9dc6f65SAl Viro int idx = i->idx; 779b9dc6f65SAl Viro int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); 780b9dc6f65SAl Viro if (off) { 781b9dc6f65SAl Viro pipe->bufs[idx].len = off - pipe->bufs[idx].offset; 782b9dc6f65SAl Viro idx = next_idx(idx, pipe); 783b9dc6f65SAl Viro nrbufs++; 784b9dc6f65SAl Viro } 785b9dc6f65SAl Viro while (pipe->nrbufs > nrbufs) { 786a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 787241699cdSAl Viro idx = next_idx(idx, pipe); 788241699cdSAl Viro pipe->nrbufs--; 789241699cdSAl Viro } 790241699cdSAl Viro } 791b9dc6f65SAl Viro } 792b9dc6f65SAl Viro 793b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 794b9dc6f65SAl Viro { 795b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 796b9dc6f65SAl Viro if (unlikely(i->count < size)) 797b9dc6f65SAl Viro size = i->count; 798b9dc6f65SAl Viro if (size) { 799b9dc6f65SAl Viro struct pipe_buffer *buf; 800b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 801b9dc6f65SAl Viro int idx = i->idx; 802b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 803b9dc6f65SAl Viro left += off - pipe->bufs[idx].offset; 804b9dc6f65SAl Viro while (1) { 805b9dc6f65SAl Viro buf = &pipe->bufs[idx]; 806b9dc6f65SAl Viro if (left <= buf->len) 807b9dc6f65SAl Viro break; 808b9dc6f65SAl Viro left -= buf->len; 809b9dc6f65SAl Viro idx = next_idx(idx, pipe); 810b9dc6f65SAl Viro } 811b9dc6f65SAl Viro i->idx = idx; 812b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 813b9dc6f65SAl Viro } 814b9dc6f65SAl Viro i->count -= size; 815b9dc6f65SAl Viro /* ... and discard everything past that point */ 816b9dc6f65SAl Viro pipe_truncate(i); 817241699cdSAl Viro } 818241699cdSAl Viro 819d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 820d879cb83SAl Viro { 821241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 822241699cdSAl Viro pipe_advance(i, size); 823241699cdSAl Viro return; 824241699cdSAl Viro } 825d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 826d879cb83SAl Viro } 827d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 828d879cb83SAl Viro 82927c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 83027c0e374SAl Viro { 83127c0e374SAl Viro if (!unroll) 83227c0e374SAl Viro return; 8335b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 8345b47d59aSAl Viro return; 83527c0e374SAl Viro i->count += unroll; 83627c0e374SAl Viro if (unlikely(i->type & ITER_PIPE)) { 83727c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 83827c0e374SAl Viro int idx = i->idx; 83927c0e374SAl Viro size_t off = i->iov_offset; 84027c0e374SAl Viro while (1) { 84127c0e374SAl Viro size_t n = off - pipe->bufs[idx].offset; 84227c0e374SAl Viro if (unroll < n) { 8434fa55cefSAl Viro off -= unroll; 84427c0e374SAl Viro break; 84527c0e374SAl Viro } 84627c0e374SAl Viro unroll -= n; 84727c0e374SAl Viro if (!unroll && idx == i->start_idx) { 84827c0e374SAl Viro off = 0; 84927c0e374SAl Viro break; 85027c0e374SAl Viro } 85127c0e374SAl Viro if (!idx--) 85227c0e374SAl Viro idx = pipe->buffers - 1; 85327c0e374SAl Viro off = pipe->bufs[idx].offset + pipe->bufs[idx].len; 85427c0e374SAl Viro } 85527c0e374SAl Viro i->iov_offset = off; 85627c0e374SAl Viro i->idx = idx; 85727c0e374SAl Viro pipe_truncate(i); 85827c0e374SAl Viro return; 85927c0e374SAl Viro } 86027c0e374SAl Viro if (unroll <= i->iov_offset) { 86127c0e374SAl Viro i->iov_offset -= unroll; 86227c0e374SAl Viro return; 86327c0e374SAl Viro } 86427c0e374SAl Viro unroll -= i->iov_offset; 86527c0e374SAl Viro if (i->type & ITER_BVEC) { 86627c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 86727c0e374SAl Viro while (1) { 86827c0e374SAl Viro size_t n = (--bvec)->bv_len; 86927c0e374SAl Viro i->nr_segs++; 87027c0e374SAl Viro if (unroll <= n) { 87127c0e374SAl Viro i->bvec = bvec; 87227c0e374SAl Viro i->iov_offset = n - unroll; 87327c0e374SAl Viro return; 87427c0e374SAl Viro } 87527c0e374SAl Viro unroll -= n; 87627c0e374SAl Viro } 87727c0e374SAl Viro } else { /* same logics for iovec and kvec */ 87827c0e374SAl Viro const struct iovec *iov = i->iov; 87927c0e374SAl Viro while (1) { 88027c0e374SAl Viro size_t n = (--iov)->iov_len; 88127c0e374SAl Viro i->nr_segs++; 88227c0e374SAl Viro if (unroll <= n) { 88327c0e374SAl Viro i->iov = iov; 88427c0e374SAl Viro i->iov_offset = n - unroll; 88527c0e374SAl Viro return; 88627c0e374SAl Viro } 88727c0e374SAl Viro unroll -= n; 88827c0e374SAl Viro } 88927c0e374SAl Viro } 89027c0e374SAl Viro } 89127c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 89227c0e374SAl Viro 893d879cb83SAl Viro /* 894d879cb83SAl Viro * Return the count of just the current iov_iter segment. 895d879cb83SAl Viro */ 896d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 897d879cb83SAl Viro { 898241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 899241699cdSAl Viro return i->count; // it is a silly place, anyway 900d879cb83SAl Viro if (i->nr_segs == 1) 901d879cb83SAl Viro return i->count; 902d879cb83SAl Viro else if (i->type & ITER_BVEC) 903d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 904d879cb83SAl Viro else 905d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 906d879cb83SAl Viro } 907d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 908d879cb83SAl Viro 909d879cb83SAl Viro void iov_iter_kvec(struct iov_iter *i, int direction, 910d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 911d879cb83SAl Viro size_t count) 912d879cb83SAl Viro { 913d879cb83SAl Viro BUG_ON(!(direction & ITER_KVEC)); 914d879cb83SAl Viro i->type = direction; 915d879cb83SAl Viro i->kvec = kvec; 916d879cb83SAl Viro i->nr_segs = nr_segs; 917d879cb83SAl Viro i->iov_offset = 0; 918d879cb83SAl Viro i->count = count; 919d879cb83SAl Viro } 920d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 921d879cb83SAl Viro 922d879cb83SAl Viro void iov_iter_bvec(struct iov_iter *i, int direction, 923d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 924d879cb83SAl Viro size_t count) 925d879cb83SAl Viro { 926d879cb83SAl Viro BUG_ON(!(direction & ITER_BVEC)); 927d879cb83SAl Viro i->type = direction; 928d879cb83SAl Viro i->bvec = bvec; 929d879cb83SAl Viro i->nr_segs = nr_segs; 930d879cb83SAl Viro i->iov_offset = 0; 931d879cb83SAl Viro i->count = count; 932d879cb83SAl Viro } 933d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 934d879cb83SAl Viro 935241699cdSAl Viro void iov_iter_pipe(struct iov_iter *i, int direction, 936241699cdSAl Viro struct pipe_inode_info *pipe, 937241699cdSAl Viro size_t count) 938241699cdSAl Viro { 939241699cdSAl Viro BUG_ON(direction != ITER_PIPE); 940b9dc6f65SAl Viro WARN_ON(pipe->nrbufs == pipe->buffers); 941241699cdSAl Viro i->type = direction; 942241699cdSAl Viro i->pipe = pipe; 943241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 944241699cdSAl Viro i->iov_offset = 0; 945241699cdSAl Viro i->count = count; 94627c0e374SAl Viro i->start_idx = i->idx; 947241699cdSAl Viro } 948241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 949241699cdSAl Viro 950d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 951d879cb83SAl Viro { 952d879cb83SAl Viro unsigned long res = 0; 953d879cb83SAl Viro size_t size = i->count; 954d879cb83SAl Viro 955241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 95633844e66SAl Viro if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 957241699cdSAl Viro return size | i->iov_offset; 958241699cdSAl Viro return size; 959241699cdSAl Viro } 960d879cb83SAl Viro iterate_all_kinds(i, size, v, 961d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 962d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 963d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 964d879cb83SAl Viro ) 965d879cb83SAl Viro return res; 966d879cb83SAl Viro } 967d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 968d879cb83SAl Viro 969357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 970357f435dSAl Viro { 971357f435dSAl Viro unsigned long res = 0; 972357f435dSAl Viro size_t size = i->count; 973357f435dSAl Viro 974241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 975241699cdSAl Viro WARN_ON(1); 976241699cdSAl Viro return ~0U; 977241699cdSAl Viro } 978241699cdSAl Viro 979357f435dSAl Viro iterate_all_kinds(i, size, v, 980357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 981357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 982357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 983357f435dSAl Viro (size != v.bv_len ? size : 0)), 984357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 985357f435dSAl Viro (size != v.iov_len ? size : 0)) 986357f435dSAl Viro ); 987357f435dSAl Viro return res; 988357f435dSAl Viro } 989357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 990357f435dSAl Viro 991241699cdSAl Viro static inline size_t __pipe_get_pages(struct iov_iter *i, 992241699cdSAl Viro size_t maxsize, 993241699cdSAl Viro struct page **pages, 994241699cdSAl Viro int idx, 995241699cdSAl Viro size_t *start) 996241699cdSAl Viro { 997241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9981689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 999241699cdSAl Viro if (!n) 1000241699cdSAl Viro return -EFAULT; 1001241699cdSAl Viro 1002241699cdSAl Viro maxsize = n; 1003241699cdSAl Viro n += *start; 10041689c73aSAl Viro while (n > 0) { 1005241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 1006241699cdSAl Viro idx = next_idx(idx, pipe); 1007241699cdSAl Viro n -= PAGE_SIZE; 1008241699cdSAl Viro } 1009241699cdSAl Viro 1010241699cdSAl Viro return maxsize; 1011241699cdSAl Viro } 1012241699cdSAl Viro 1013241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1014241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1015241699cdSAl Viro size_t *start) 1016241699cdSAl Viro { 1017241699cdSAl Viro unsigned npages; 1018241699cdSAl Viro size_t capacity; 1019241699cdSAl Viro int idx; 1020241699cdSAl Viro 102133844e66SAl Viro if (!maxsize) 102233844e66SAl Viro return 0; 102333844e66SAl Viro 1024241699cdSAl Viro if (!sanity(i)) 1025241699cdSAl Viro return -EFAULT; 1026241699cdSAl Viro 1027241699cdSAl Viro data_start(i, &idx, start); 1028241699cdSAl Viro /* some of this one + all after this one */ 1029241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1030241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 1031241699cdSAl Viro 1032241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 1033241699cdSAl Viro } 1034241699cdSAl Viro 1035d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1036d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1037d879cb83SAl Viro size_t *start) 1038d879cb83SAl Viro { 1039d879cb83SAl Viro if (maxsize > i->count) 1040d879cb83SAl Viro maxsize = i->count; 1041d879cb83SAl Viro 1042241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1043241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 1044d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1045d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1046d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1047d879cb83SAl Viro int n; 1048d879cb83SAl Viro int res; 1049d879cb83SAl Viro 1050d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1051d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1052d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1053d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1054d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); 1055d879cb83SAl Viro if (unlikely(res < 0)) 1056d879cb83SAl Viro return res; 1057d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1058d879cb83SAl Viro 0;}),({ 1059d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1060d879cb83SAl Viro *start = v.bv_offset; 1061d879cb83SAl Viro get_page(*pages = v.bv_page); 1062d879cb83SAl Viro return v.bv_len; 1063d879cb83SAl Viro }),({ 1064d879cb83SAl Viro return -EFAULT; 1065d879cb83SAl Viro }) 1066d879cb83SAl Viro ) 1067d879cb83SAl Viro return 0; 1068d879cb83SAl Viro } 1069d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1070d879cb83SAl Viro 1071d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1072d879cb83SAl Viro { 1073752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1074d879cb83SAl Viro } 1075d879cb83SAl Viro 1076241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1077241699cdSAl Viro struct page ***pages, size_t maxsize, 1078241699cdSAl Viro size_t *start) 1079241699cdSAl Viro { 1080241699cdSAl Viro struct page **p; 1081241699cdSAl Viro size_t n; 1082241699cdSAl Viro int idx; 1083241699cdSAl Viro int npages; 1084241699cdSAl Viro 108533844e66SAl Viro if (!maxsize) 108633844e66SAl Viro return 0; 108733844e66SAl Viro 1088241699cdSAl Viro if (!sanity(i)) 1089241699cdSAl Viro return -EFAULT; 1090241699cdSAl Viro 1091241699cdSAl Viro data_start(i, &idx, start); 1092241699cdSAl Viro /* some of this one + all after this one */ 1093241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1094241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1095241699cdSAl Viro if (maxsize > n) 1096241699cdSAl Viro maxsize = n; 1097241699cdSAl Viro else 1098241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1099241699cdSAl Viro p = get_pages_array(npages); 1100241699cdSAl Viro if (!p) 1101241699cdSAl Viro return -ENOMEM; 1102241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 1103241699cdSAl Viro if (n > 0) 1104241699cdSAl Viro *pages = p; 1105241699cdSAl Viro else 1106241699cdSAl Viro kvfree(p); 1107241699cdSAl Viro return n; 1108241699cdSAl Viro } 1109241699cdSAl Viro 1110d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1111d879cb83SAl Viro struct page ***pages, size_t maxsize, 1112d879cb83SAl Viro size_t *start) 1113d879cb83SAl Viro { 1114d879cb83SAl Viro struct page **p; 1115d879cb83SAl Viro 1116d879cb83SAl Viro if (maxsize > i->count) 1117d879cb83SAl Viro maxsize = i->count; 1118d879cb83SAl Viro 1119241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1120241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 1121d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1122d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1123d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1124d879cb83SAl Viro int n; 1125d879cb83SAl Viro int res; 1126d879cb83SAl Viro 1127d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1128d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1129d879cb83SAl Viro p = get_pages_array(n); 1130d879cb83SAl Viro if (!p) 1131d879cb83SAl Viro return -ENOMEM; 1132d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); 1133d879cb83SAl Viro if (unlikely(res < 0)) { 1134d879cb83SAl Viro kvfree(p); 1135d879cb83SAl Viro return res; 1136d879cb83SAl Viro } 1137d879cb83SAl Viro *pages = p; 1138d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1139d879cb83SAl Viro 0;}),({ 1140d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1141d879cb83SAl Viro *start = v.bv_offset; 1142d879cb83SAl Viro *pages = p = get_pages_array(1); 1143d879cb83SAl Viro if (!p) 1144d879cb83SAl Viro return -ENOMEM; 1145d879cb83SAl Viro get_page(*p = v.bv_page); 1146d879cb83SAl Viro return v.bv_len; 1147d879cb83SAl Viro }),({ 1148d879cb83SAl Viro return -EFAULT; 1149d879cb83SAl Viro }) 1150d879cb83SAl Viro ) 1151d879cb83SAl Viro return 0; 1152d879cb83SAl Viro } 1153d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1154d879cb83SAl Viro 1155d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1156d879cb83SAl Viro struct iov_iter *i) 1157d879cb83SAl Viro { 1158d879cb83SAl Viro char *to = addr; 1159d879cb83SAl Viro __wsum sum, next; 1160d879cb83SAl Viro size_t off = 0; 1161d879cb83SAl Viro sum = *csum; 1162241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1163241699cdSAl Viro WARN_ON(1); 1164241699cdSAl Viro return 0; 1165241699cdSAl Viro } 1166d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1167d879cb83SAl Viro int err = 0; 1168d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1169d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1170d879cb83SAl Viro v.iov_len, 0, &err); 1171d879cb83SAl Viro if (!err) { 1172d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1173d879cb83SAl Viro off += v.iov_len; 1174d879cb83SAl Viro } 1175d879cb83SAl Viro err ? v.iov_len : 0; 1176d879cb83SAl Viro }), ({ 1177d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1178d879cb83SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1179d879cb83SAl Viro (to += v.bv_len) - v.bv_len, 1180d879cb83SAl Viro v.bv_len, 0); 1181d879cb83SAl Viro kunmap_atomic(p); 1182d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1183d879cb83SAl Viro off += v.bv_len; 1184d879cb83SAl Viro }),({ 1185d879cb83SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1186d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1187d879cb83SAl Viro v.iov_len, 0); 1188d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1189d879cb83SAl Viro off += v.iov_len; 1190d879cb83SAl Viro }) 1191d879cb83SAl Viro ) 1192d879cb83SAl Viro *csum = sum; 1193d879cb83SAl Viro return bytes; 1194d879cb83SAl Viro } 1195d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1196d879cb83SAl Viro 1197cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1198cbbd26b8SAl Viro struct iov_iter *i) 1199cbbd26b8SAl Viro { 1200cbbd26b8SAl Viro char *to = addr; 1201cbbd26b8SAl Viro __wsum sum, next; 1202cbbd26b8SAl Viro size_t off = 0; 1203cbbd26b8SAl Viro sum = *csum; 1204cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 1205cbbd26b8SAl Viro WARN_ON(1); 1206cbbd26b8SAl Viro return false; 1207cbbd26b8SAl Viro } 1208cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1209cbbd26b8SAl Viro return false; 1210cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1211cbbd26b8SAl Viro int err = 0; 1212cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1213cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1214cbbd26b8SAl Viro v.iov_len, 0, &err); 1215cbbd26b8SAl Viro if (err) 1216cbbd26b8SAl Viro return false; 1217cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1218cbbd26b8SAl Viro off += v.iov_len; 1219cbbd26b8SAl Viro 0; 1220cbbd26b8SAl Viro }), ({ 1221cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1222cbbd26b8SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1223cbbd26b8SAl Viro (to += v.bv_len) - v.bv_len, 1224cbbd26b8SAl Viro v.bv_len, 0); 1225cbbd26b8SAl Viro kunmap_atomic(p); 1226cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1227cbbd26b8SAl Viro off += v.bv_len; 1228cbbd26b8SAl Viro }),({ 1229cbbd26b8SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1230cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1231cbbd26b8SAl Viro v.iov_len, 0); 1232cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1233cbbd26b8SAl Viro off += v.iov_len; 1234cbbd26b8SAl Viro }) 1235cbbd26b8SAl Viro ) 1236cbbd26b8SAl Viro *csum = sum; 1237cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1238cbbd26b8SAl Viro return true; 1239cbbd26b8SAl Viro } 1240cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1241cbbd26b8SAl Viro 124236f7a8a4SAl Viro size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, 1243d879cb83SAl Viro struct iov_iter *i) 1244d879cb83SAl Viro { 124536f7a8a4SAl Viro const char *from = addr; 1246d879cb83SAl Viro __wsum sum, next; 1247d879cb83SAl Viro size_t off = 0; 1248d879cb83SAl Viro sum = *csum; 1249241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1250241699cdSAl Viro WARN_ON(1); /* for now */ 1251241699cdSAl Viro return 0; 1252241699cdSAl Viro } 1253d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1254d879cb83SAl Viro int err = 0; 1255d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1256d879cb83SAl Viro v.iov_base, 1257d879cb83SAl Viro v.iov_len, 0, &err); 1258d879cb83SAl Viro if (!err) { 1259d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1260d879cb83SAl Viro off += v.iov_len; 1261d879cb83SAl Viro } 1262d879cb83SAl Viro err ? v.iov_len : 0; 1263d879cb83SAl Viro }), ({ 1264d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1265d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, 1266d879cb83SAl Viro p + v.bv_offset, 1267d879cb83SAl Viro v.bv_len, 0); 1268d879cb83SAl Viro kunmap_atomic(p); 1269d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1270d879cb83SAl Viro off += v.bv_len; 1271d879cb83SAl Viro }),({ 1272d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, 1273d879cb83SAl Viro v.iov_base, 1274d879cb83SAl Viro v.iov_len, 0); 1275d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1276d879cb83SAl Viro off += v.iov_len; 1277d879cb83SAl Viro }) 1278d879cb83SAl Viro ) 1279d879cb83SAl Viro *csum = sum; 1280d879cb83SAl Viro return bytes; 1281d879cb83SAl Viro } 1282d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1283d879cb83SAl Viro 1284d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1285d879cb83SAl Viro { 1286d879cb83SAl Viro size_t size = i->count; 1287d879cb83SAl Viro int npages = 0; 1288d879cb83SAl Viro 1289d879cb83SAl Viro if (!size) 1290d879cb83SAl Viro return 0; 1291d879cb83SAl Viro 1292241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1293241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1294241699cdSAl Viro size_t off; 1295241699cdSAl Viro int idx; 1296241699cdSAl Viro 1297241699cdSAl Viro if (!sanity(i)) 1298241699cdSAl Viro return 0; 1299241699cdSAl Viro 1300241699cdSAl Viro data_start(i, &idx, &off); 1301241699cdSAl Viro /* some of this one + all after this one */ 1302241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1303241699cdSAl Viro if (npages >= maxpages) 1304241699cdSAl Viro return maxpages; 1305241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1306d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1307d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1308d879cb83SAl Viro - p / PAGE_SIZE; 1309d879cb83SAl Viro if (npages >= maxpages) 1310d879cb83SAl Viro return maxpages; 1311d879cb83SAl Viro 0;}),({ 1312d879cb83SAl Viro npages++; 1313d879cb83SAl Viro if (npages >= maxpages) 1314d879cb83SAl Viro return maxpages; 1315d879cb83SAl Viro }),({ 1316d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1317d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1318d879cb83SAl Viro - p / PAGE_SIZE; 1319d879cb83SAl Viro if (npages >= maxpages) 1320d879cb83SAl Viro return maxpages; 1321d879cb83SAl Viro }) 1322d879cb83SAl Viro ) 1323d879cb83SAl Viro return npages; 1324d879cb83SAl Viro } 1325d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1326d879cb83SAl Viro 1327d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1328d879cb83SAl Viro { 1329d879cb83SAl Viro *new = *old; 1330241699cdSAl Viro if (unlikely(new->type & ITER_PIPE)) { 1331241699cdSAl Viro WARN_ON(1); 1332241699cdSAl Viro return NULL; 1333241699cdSAl Viro } 1334d879cb83SAl Viro if (new->type & ITER_BVEC) 1335d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1336d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1337d879cb83SAl Viro flags); 1338d879cb83SAl Viro else 1339d879cb83SAl Viro /* iovec and kvec have identical layout */ 1340d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1341d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1342d879cb83SAl Viro flags); 1343d879cb83SAl Viro } 1344d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1345bc917be8SAl Viro 1346ffecee4fSVegard Nossum /** 1347ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1348ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1349ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1350ffecee4fSVegard Nossum * 1351ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1352ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1353ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1354ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1355ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1356ffecee4fSVegard Nossum * on-stack) kernel array. 1357ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1358ffecee4fSVegard Nossum * 1359ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1360ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1361ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1362ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1363ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1364ffecee4fSVegard Nossum * returns an error or not). 1365ffecee4fSVegard Nossum * 1366ffecee4fSVegard Nossum * Return: 0 on success or negative error code on error. 1367ffecee4fSVegard Nossum */ 1368bc917be8SAl Viro int import_iovec(int type, const struct iovec __user * uvector, 1369bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1370bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1371bc917be8SAl Viro { 1372bc917be8SAl Viro ssize_t n; 1373bc917be8SAl Viro struct iovec *p; 1374bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1375bc917be8SAl Viro *iov, &p); 1376bc917be8SAl Viro if (n < 0) { 1377bc917be8SAl Viro if (p != *iov) 1378bc917be8SAl Viro kfree(p); 1379bc917be8SAl Viro *iov = NULL; 1380bc917be8SAl Viro return n; 1381bc917be8SAl Viro } 1382bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1383bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1384bc917be8SAl Viro return 0; 1385bc917be8SAl Viro } 1386bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1387bc917be8SAl Viro 1388bc917be8SAl Viro #ifdef CONFIG_COMPAT 1389bc917be8SAl Viro #include <linux/compat.h> 1390bc917be8SAl Viro 1391bc917be8SAl Viro int compat_import_iovec(int type, const struct compat_iovec __user * uvector, 1392bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1393bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1394bc917be8SAl Viro { 1395bc917be8SAl Viro ssize_t n; 1396bc917be8SAl Viro struct iovec *p; 1397bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1398bc917be8SAl Viro *iov, &p); 1399bc917be8SAl Viro if (n < 0) { 1400bc917be8SAl Viro if (p != *iov) 1401bc917be8SAl Viro kfree(p); 1402bc917be8SAl Viro *iov = NULL; 1403bc917be8SAl Viro return n; 1404bc917be8SAl Viro } 1405bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1406bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1407bc917be8SAl Viro return 0; 1408bc917be8SAl Viro } 1409bc917be8SAl Viro #endif 1410bc917be8SAl Viro 1411bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1412bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1413bc917be8SAl Viro { 1414bc917be8SAl Viro if (len > MAX_RW_COUNT) 1415bc917be8SAl Viro len = MAX_RW_COUNT; 1416bc917be8SAl Viro if (unlikely(!access_ok(!rw, buf, len))) 1417bc917be8SAl Viro return -EFAULT; 1418bc917be8SAl Viro 1419bc917be8SAl Viro iov->iov_base = buf; 1420bc917be8SAl Viro iov->iov_len = len; 1421bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1422bc917be8SAl Viro return 0; 1423bc917be8SAl Viro } 1424e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 1425