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 6420aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 6436a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 6440aed55afSDan Williams { 6450aed55afSDan Williams char *to = addr; 6460aed55afSDan Williams if (unlikely(i->type & ITER_PIPE)) { 6470aed55afSDan Williams WARN_ON(1); 6480aed55afSDan Williams return 0; 6490aed55afSDan Williams } 6500aed55afSDan Williams iterate_and_advance(i, bytes, v, 6510aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 6520aed55afSDan Williams v.iov_base, v.iov_len), 6530aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 6540aed55afSDan Williams v.bv_offset, v.bv_len), 6550aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 6560aed55afSDan Williams v.iov_len) 6570aed55afSDan Williams ) 6580aed55afSDan Williams 6590aed55afSDan Williams return bytes; 6600aed55afSDan Williams } 6616a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 6620aed55afSDan Williams #endif 6630aed55afSDan Williams 664aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 665cbbd26b8SAl Viro { 666cbbd26b8SAl Viro char *to = addr; 667cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 668cbbd26b8SAl Viro WARN_ON(1); 669cbbd26b8SAl Viro return false; 670cbbd26b8SAl Viro } 67133844e66SAl Viro if (unlikely(i->count < bytes)) 672cbbd26b8SAl Viro return false; 673cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 6743f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 675cbbd26b8SAl Viro v.iov_base, v.iov_len)) 676cbbd26b8SAl Viro return false; 677cbbd26b8SAl Viro 0;}), 678cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 679cbbd26b8SAl Viro v.bv_offset, v.bv_len), 680cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 681cbbd26b8SAl Viro ) 682cbbd26b8SAl Viro 683cbbd26b8SAl Viro iov_iter_advance(i, bytes); 684cbbd26b8SAl Viro return true; 685cbbd26b8SAl Viro } 686aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 687cbbd26b8SAl Viro 68872e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 68972e809edSAl Viro { 69072e809edSAl Viro size_t v = n + offset; 69172e809edSAl Viro if (likely(n <= v && v <= (PAGE_SIZE << compound_order(page)))) 69272e809edSAl Viro return true; 69372e809edSAl Viro WARN_ON(1); 69472e809edSAl Viro return false; 69572e809edSAl Viro } 696d879cb83SAl Viro 697d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 698d879cb83SAl Viro struct iov_iter *i) 699d879cb83SAl Viro { 70072e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 70172e809edSAl Viro return 0; 702d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 703d879cb83SAl Viro void *kaddr = kmap_atomic(page); 704d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 705d879cb83SAl Viro kunmap_atomic(kaddr); 706d879cb83SAl Viro return wanted; 707241699cdSAl Viro } else if (likely(!(i->type & ITER_PIPE))) 708d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 709241699cdSAl Viro else 710241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 711d879cb83SAl Viro } 712d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 713d879cb83SAl Viro 714d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 715d879cb83SAl Viro struct iov_iter *i) 716d879cb83SAl Viro { 71772e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 71872e809edSAl Viro return 0; 719241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 720241699cdSAl Viro WARN_ON(1); 721241699cdSAl Viro return 0; 722241699cdSAl Viro } 723d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 724d879cb83SAl Viro void *kaddr = kmap_atomic(page); 725aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 726d879cb83SAl Viro kunmap_atomic(kaddr); 727d879cb83SAl Viro return wanted; 728d879cb83SAl Viro } else 729d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 730d879cb83SAl Viro } 731d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 732d879cb83SAl Viro 733241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 734241699cdSAl Viro { 735241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 736241699cdSAl Viro size_t n, off; 737241699cdSAl Viro int idx; 738241699cdSAl Viro 739241699cdSAl Viro if (!sanity(i)) 740241699cdSAl Viro return 0; 741241699cdSAl Viro 742241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 743241699cdSAl Viro if (unlikely(!n)) 744241699cdSAl Viro return 0; 745241699cdSAl Viro 746241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 747241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 748241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 749241699cdSAl Viro i->idx = idx; 750241699cdSAl Viro i->iov_offset = off + chunk; 751241699cdSAl Viro n -= chunk; 752241699cdSAl Viro } 753241699cdSAl Viro i->count -= bytes; 754241699cdSAl Viro return bytes; 755241699cdSAl Viro } 756241699cdSAl Viro 757d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 758d879cb83SAl Viro { 759241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 760241699cdSAl Viro return pipe_zero(bytes, i); 761d879cb83SAl Viro iterate_and_advance(i, bytes, v, 76209fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 763d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 764d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 765d879cb83SAl Viro ) 766d879cb83SAl Viro 767d879cb83SAl Viro return bytes; 768d879cb83SAl Viro } 769d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 770d879cb83SAl Viro 771d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 772d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 773d879cb83SAl Viro { 774d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 77572e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 77672e809edSAl Viro kunmap_atomic(kaddr); 77772e809edSAl Viro return 0; 77872e809edSAl Viro } 779241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 780241699cdSAl Viro kunmap_atomic(kaddr); 781241699cdSAl Viro WARN_ON(1); 782241699cdSAl Viro return 0; 783241699cdSAl Viro } 784d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 78509fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 786d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 787d879cb83SAl Viro v.bv_offset, v.bv_len), 788d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 789d879cb83SAl Viro ) 790d879cb83SAl Viro kunmap_atomic(kaddr); 791d879cb83SAl Viro return bytes; 792d879cb83SAl Viro } 793d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 794d879cb83SAl Viro 795b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 796241699cdSAl Viro { 797241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 798241699cdSAl Viro if (pipe->nrbufs) { 799b9dc6f65SAl Viro size_t off = i->iov_offset; 800b9dc6f65SAl Viro int idx = i->idx; 801b9dc6f65SAl Viro int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); 802b9dc6f65SAl Viro if (off) { 803b9dc6f65SAl Viro pipe->bufs[idx].len = off - pipe->bufs[idx].offset; 804b9dc6f65SAl Viro idx = next_idx(idx, pipe); 805b9dc6f65SAl Viro nrbufs++; 806b9dc6f65SAl Viro } 807b9dc6f65SAl Viro while (pipe->nrbufs > nrbufs) { 808a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 809241699cdSAl Viro idx = next_idx(idx, pipe); 810241699cdSAl Viro pipe->nrbufs--; 811241699cdSAl Viro } 812241699cdSAl Viro } 813b9dc6f65SAl Viro } 814b9dc6f65SAl Viro 815b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 816b9dc6f65SAl Viro { 817b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 818b9dc6f65SAl Viro if (unlikely(i->count < size)) 819b9dc6f65SAl Viro size = i->count; 820b9dc6f65SAl Viro if (size) { 821b9dc6f65SAl Viro struct pipe_buffer *buf; 822b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 823b9dc6f65SAl Viro int idx = i->idx; 824b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 825b9dc6f65SAl Viro left += off - pipe->bufs[idx].offset; 826b9dc6f65SAl Viro while (1) { 827b9dc6f65SAl Viro buf = &pipe->bufs[idx]; 828b9dc6f65SAl Viro if (left <= buf->len) 829b9dc6f65SAl Viro break; 830b9dc6f65SAl Viro left -= buf->len; 831b9dc6f65SAl Viro idx = next_idx(idx, pipe); 832b9dc6f65SAl Viro } 833b9dc6f65SAl Viro i->idx = idx; 834b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 835b9dc6f65SAl Viro } 836b9dc6f65SAl Viro i->count -= size; 837b9dc6f65SAl Viro /* ... and discard everything past that point */ 838b9dc6f65SAl Viro pipe_truncate(i); 839241699cdSAl Viro } 840241699cdSAl Viro 841d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 842d879cb83SAl Viro { 843241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 844241699cdSAl Viro pipe_advance(i, size); 845241699cdSAl Viro return; 846241699cdSAl Viro } 847d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 848d879cb83SAl Viro } 849d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 850d879cb83SAl Viro 85127c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 85227c0e374SAl Viro { 85327c0e374SAl Viro if (!unroll) 85427c0e374SAl Viro return; 8555b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 8565b47d59aSAl Viro return; 85727c0e374SAl Viro i->count += unroll; 85827c0e374SAl Viro if (unlikely(i->type & ITER_PIPE)) { 85927c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 86027c0e374SAl Viro int idx = i->idx; 86127c0e374SAl Viro size_t off = i->iov_offset; 86227c0e374SAl Viro while (1) { 86327c0e374SAl Viro size_t n = off - pipe->bufs[idx].offset; 86427c0e374SAl Viro if (unroll < n) { 8654fa55cefSAl Viro off -= unroll; 86627c0e374SAl Viro break; 86727c0e374SAl Viro } 86827c0e374SAl Viro unroll -= n; 86927c0e374SAl Viro if (!unroll && idx == i->start_idx) { 87027c0e374SAl Viro off = 0; 87127c0e374SAl Viro break; 87227c0e374SAl Viro } 87327c0e374SAl Viro if (!idx--) 87427c0e374SAl Viro idx = pipe->buffers - 1; 87527c0e374SAl Viro off = pipe->bufs[idx].offset + pipe->bufs[idx].len; 87627c0e374SAl Viro } 87727c0e374SAl Viro i->iov_offset = off; 87827c0e374SAl Viro i->idx = idx; 87927c0e374SAl Viro pipe_truncate(i); 88027c0e374SAl Viro return; 88127c0e374SAl Viro } 88227c0e374SAl Viro if (unroll <= i->iov_offset) { 88327c0e374SAl Viro i->iov_offset -= unroll; 88427c0e374SAl Viro return; 88527c0e374SAl Viro } 88627c0e374SAl Viro unroll -= i->iov_offset; 88727c0e374SAl Viro if (i->type & ITER_BVEC) { 88827c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 88927c0e374SAl Viro while (1) { 89027c0e374SAl Viro size_t n = (--bvec)->bv_len; 89127c0e374SAl Viro i->nr_segs++; 89227c0e374SAl Viro if (unroll <= n) { 89327c0e374SAl Viro i->bvec = bvec; 89427c0e374SAl Viro i->iov_offset = n - unroll; 89527c0e374SAl Viro return; 89627c0e374SAl Viro } 89727c0e374SAl Viro unroll -= n; 89827c0e374SAl Viro } 89927c0e374SAl Viro } else { /* same logics for iovec and kvec */ 90027c0e374SAl Viro const struct iovec *iov = i->iov; 90127c0e374SAl Viro while (1) { 90227c0e374SAl Viro size_t n = (--iov)->iov_len; 90327c0e374SAl Viro i->nr_segs++; 90427c0e374SAl Viro if (unroll <= n) { 90527c0e374SAl Viro i->iov = iov; 90627c0e374SAl Viro i->iov_offset = n - unroll; 90727c0e374SAl Viro return; 90827c0e374SAl Viro } 90927c0e374SAl Viro unroll -= n; 91027c0e374SAl Viro } 91127c0e374SAl Viro } 91227c0e374SAl Viro } 91327c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 91427c0e374SAl Viro 915d879cb83SAl Viro /* 916d879cb83SAl Viro * Return the count of just the current iov_iter segment. 917d879cb83SAl Viro */ 918d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 919d879cb83SAl Viro { 920241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 921241699cdSAl Viro return i->count; // it is a silly place, anyway 922d879cb83SAl Viro if (i->nr_segs == 1) 923d879cb83SAl Viro return i->count; 924d879cb83SAl Viro else if (i->type & ITER_BVEC) 925d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 926d879cb83SAl Viro else 927d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 928d879cb83SAl Viro } 929d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 930d879cb83SAl Viro 931d879cb83SAl Viro void iov_iter_kvec(struct iov_iter *i, int direction, 932d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 933d879cb83SAl Viro size_t count) 934d879cb83SAl Viro { 935d879cb83SAl Viro BUG_ON(!(direction & ITER_KVEC)); 936d879cb83SAl Viro i->type = direction; 937d879cb83SAl Viro i->kvec = kvec; 938d879cb83SAl Viro i->nr_segs = nr_segs; 939d879cb83SAl Viro i->iov_offset = 0; 940d879cb83SAl Viro i->count = count; 941d879cb83SAl Viro } 942d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 943d879cb83SAl Viro 944d879cb83SAl Viro void iov_iter_bvec(struct iov_iter *i, int direction, 945d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 946d879cb83SAl Viro size_t count) 947d879cb83SAl Viro { 948d879cb83SAl Viro BUG_ON(!(direction & ITER_BVEC)); 949d879cb83SAl Viro i->type = direction; 950d879cb83SAl Viro i->bvec = bvec; 951d879cb83SAl Viro i->nr_segs = nr_segs; 952d879cb83SAl Viro i->iov_offset = 0; 953d879cb83SAl Viro i->count = count; 954d879cb83SAl Viro } 955d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 956d879cb83SAl Viro 957241699cdSAl Viro void iov_iter_pipe(struct iov_iter *i, int direction, 958241699cdSAl Viro struct pipe_inode_info *pipe, 959241699cdSAl Viro size_t count) 960241699cdSAl Viro { 961241699cdSAl Viro BUG_ON(direction != ITER_PIPE); 962b9dc6f65SAl Viro WARN_ON(pipe->nrbufs == pipe->buffers); 963241699cdSAl Viro i->type = direction; 964241699cdSAl Viro i->pipe = pipe; 965241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 966241699cdSAl Viro i->iov_offset = 0; 967241699cdSAl Viro i->count = count; 96827c0e374SAl Viro i->start_idx = i->idx; 969241699cdSAl Viro } 970241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 971241699cdSAl Viro 972d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 973d879cb83SAl Viro { 974d879cb83SAl Viro unsigned long res = 0; 975d879cb83SAl Viro size_t size = i->count; 976d879cb83SAl Viro 977241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 97833844e66SAl Viro if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 979241699cdSAl Viro return size | i->iov_offset; 980241699cdSAl Viro return size; 981241699cdSAl Viro } 982d879cb83SAl Viro iterate_all_kinds(i, size, v, 983d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 984d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 985d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 986d879cb83SAl Viro ) 987d879cb83SAl Viro return res; 988d879cb83SAl Viro } 989d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 990d879cb83SAl Viro 991357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 992357f435dSAl Viro { 993357f435dSAl Viro unsigned long res = 0; 994357f435dSAl Viro size_t size = i->count; 995357f435dSAl Viro 996241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 997241699cdSAl Viro WARN_ON(1); 998241699cdSAl Viro return ~0U; 999241699cdSAl Viro } 1000241699cdSAl Viro 1001357f435dSAl Viro iterate_all_kinds(i, size, v, 1002357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1003357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1004357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1005357f435dSAl Viro (size != v.bv_len ? size : 0)), 1006357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1007357f435dSAl Viro (size != v.iov_len ? size : 0)) 1008357f435dSAl Viro ); 1009357f435dSAl Viro return res; 1010357f435dSAl Viro } 1011357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1012357f435dSAl Viro 1013241699cdSAl Viro static inline size_t __pipe_get_pages(struct iov_iter *i, 1014241699cdSAl Viro size_t maxsize, 1015241699cdSAl Viro struct page **pages, 1016241699cdSAl Viro int idx, 1017241699cdSAl Viro size_t *start) 1018241699cdSAl Viro { 1019241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 10201689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 1021241699cdSAl Viro if (!n) 1022241699cdSAl Viro return -EFAULT; 1023241699cdSAl Viro 1024241699cdSAl Viro maxsize = n; 1025241699cdSAl Viro n += *start; 10261689c73aSAl Viro while (n > 0) { 1027241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 1028241699cdSAl Viro idx = next_idx(idx, pipe); 1029241699cdSAl Viro n -= PAGE_SIZE; 1030241699cdSAl Viro } 1031241699cdSAl Viro 1032241699cdSAl Viro return maxsize; 1033241699cdSAl Viro } 1034241699cdSAl Viro 1035241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1036241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1037241699cdSAl Viro size_t *start) 1038241699cdSAl Viro { 1039241699cdSAl Viro unsigned npages; 1040241699cdSAl Viro size_t capacity; 1041241699cdSAl Viro int idx; 1042241699cdSAl Viro 104333844e66SAl Viro if (!maxsize) 104433844e66SAl Viro return 0; 104533844e66SAl Viro 1046241699cdSAl Viro if (!sanity(i)) 1047241699cdSAl Viro return -EFAULT; 1048241699cdSAl Viro 1049241699cdSAl Viro data_start(i, &idx, start); 1050241699cdSAl Viro /* some of this one + all after this one */ 1051241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1052241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 1053241699cdSAl Viro 1054241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 1055241699cdSAl Viro } 1056241699cdSAl Viro 1057d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1058d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1059d879cb83SAl Viro size_t *start) 1060d879cb83SAl Viro { 1061d879cb83SAl Viro if (maxsize > i->count) 1062d879cb83SAl Viro maxsize = i->count; 1063d879cb83SAl Viro 1064241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1065241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 1066d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1067d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1068d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1069d879cb83SAl Viro int n; 1070d879cb83SAl Viro int res; 1071d879cb83SAl Viro 1072d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1073d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1074d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1075d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1076d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); 1077d879cb83SAl Viro if (unlikely(res < 0)) 1078d879cb83SAl Viro return res; 1079d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1080d879cb83SAl Viro 0;}),({ 1081d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1082d879cb83SAl Viro *start = v.bv_offset; 1083d879cb83SAl Viro get_page(*pages = v.bv_page); 1084d879cb83SAl Viro return v.bv_len; 1085d879cb83SAl Viro }),({ 1086d879cb83SAl Viro return -EFAULT; 1087d879cb83SAl Viro }) 1088d879cb83SAl Viro ) 1089d879cb83SAl Viro return 0; 1090d879cb83SAl Viro } 1091d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1092d879cb83SAl Viro 1093d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1094d879cb83SAl Viro { 1095752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1096d879cb83SAl Viro } 1097d879cb83SAl Viro 1098241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1099241699cdSAl Viro struct page ***pages, size_t maxsize, 1100241699cdSAl Viro size_t *start) 1101241699cdSAl Viro { 1102241699cdSAl Viro struct page **p; 1103241699cdSAl Viro size_t n; 1104241699cdSAl Viro int idx; 1105241699cdSAl Viro int npages; 1106241699cdSAl Viro 110733844e66SAl Viro if (!maxsize) 110833844e66SAl Viro return 0; 110933844e66SAl Viro 1110241699cdSAl Viro if (!sanity(i)) 1111241699cdSAl Viro return -EFAULT; 1112241699cdSAl Viro 1113241699cdSAl Viro data_start(i, &idx, start); 1114241699cdSAl Viro /* some of this one + all after this one */ 1115241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1116241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1117241699cdSAl Viro if (maxsize > n) 1118241699cdSAl Viro maxsize = n; 1119241699cdSAl Viro else 1120241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1121241699cdSAl Viro p = get_pages_array(npages); 1122241699cdSAl Viro if (!p) 1123241699cdSAl Viro return -ENOMEM; 1124241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 1125241699cdSAl Viro if (n > 0) 1126241699cdSAl Viro *pages = p; 1127241699cdSAl Viro else 1128241699cdSAl Viro kvfree(p); 1129241699cdSAl Viro return n; 1130241699cdSAl Viro } 1131241699cdSAl Viro 1132d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1133d879cb83SAl Viro struct page ***pages, size_t maxsize, 1134d879cb83SAl Viro size_t *start) 1135d879cb83SAl Viro { 1136d879cb83SAl Viro struct page **p; 1137d879cb83SAl Viro 1138d879cb83SAl Viro if (maxsize > i->count) 1139d879cb83SAl Viro maxsize = i->count; 1140d879cb83SAl Viro 1141241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1142241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 1143d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1144d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1145d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1146d879cb83SAl Viro int n; 1147d879cb83SAl Viro int res; 1148d879cb83SAl Viro 1149d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1150d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1151d879cb83SAl Viro p = get_pages_array(n); 1152d879cb83SAl Viro if (!p) 1153d879cb83SAl Viro return -ENOMEM; 1154d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); 1155d879cb83SAl Viro if (unlikely(res < 0)) { 1156d879cb83SAl Viro kvfree(p); 1157d879cb83SAl Viro return res; 1158d879cb83SAl Viro } 1159d879cb83SAl Viro *pages = p; 1160d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1161d879cb83SAl Viro 0;}),({ 1162d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1163d879cb83SAl Viro *start = v.bv_offset; 1164d879cb83SAl Viro *pages = p = get_pages_array(1); 1165d879cb83SAl Viro if (!p) 1166d879cb83SAl Viro return -ENOMEM; 1167d879cb83SAl Viro get_page(*p = v.bv_page); 1168d879cb83SAl Viro return v.bv_len; 1169d879cb83SAl Viro }),({ 1170d879cb83SAl Viro return -EFAULT; 1171d879cb83SAl Viro }) 1172d879cb83SAl Viro ) 1173d879cb83SAl Viro return 0; 1174d879cb83SAl Viro } 1175d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1176d879cb83SAl Viro 1177d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1178d879cb83SAl Viro struct iov_iter *i) 1179d879cb83SAl Viro { 1180d879cb83SAl Viro char *to = addr; 1181d879cb83SAl Viro __wsum sum, next; 1182d879cb83SAl Viro size_t off = 0; 1183d879cb83SAl Viro sum = *csum; 1184241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1185241699cdSAl Viro WARN_ON(1); 1186241699cdSAl Viro return 0; 1187241699cdSAl Viro } 1188d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1189d879cb83SAl Viro int err = 0; 1190d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1191d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1192d879cb83SAl Viro v.iov_len, 0, &err); 1193d879cb83SAl Viro if (!err) { 1194d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1195d879cb83SAl Viro off += v.iov_len; 1196d879cb83SAl Viro } 1197d879cb83SAl Viro err ? v.iov_len : 0; 1198d879cb83SAl Viro }), ({ 1199d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1200d879cb83SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1201d879cb83SAl Viro (to += v.bv_len) - v.bv_len, 1202d879cb83SAl Viro v.bv_len, 0); 1203d879cb83SAl Viro kunmap_atomic(p); 1204d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1205d879cb83SAl Viro off += v.bv_len; 1206d879cb83SAl Viro }),({ 1207d879cb83SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1208d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1209d879cb83SAl Viro v.iov_len, 0); 1210d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1211d879cb83SAl Viro off += v.iov_len; 1212d879cb83SAl Viro }) 1213d879cb83SAl Viro ) 1214d879cb83SAl Viro *csum = sum; 1215d879cb83SAl Viro return bytes; 1216d879cb83SAl Viro } 1217d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1218d879cb83SAl Viro 1219cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1220cbbd26b8SAl Viro struct iov_iter *i) 1221cbbd26b8SAl Viro { 1222cbbd26b8SAl Viro char *to = addr; 1223cbbd26b8SAl Viro __wsum sum, next; 1224cbbd26b8SAl Viro size_t off = 0; 1225cbbd26b8SAl Viro sum = *csum; 1226cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 1227cbbd26b8SAl Viro WARN_ON(1); 1228cbbd26b8SAl Viro return false; 1229cbbd26b8SAl Viro } 1230cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1231cbbd26b8SAl Viro return false; 1232cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1233cbbd26b8SAl Viro int err = 0; 1234cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1235cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1236cbbd26b8SAl Viro v.iov_len, 0, &err); 1237cbbd26b8SAl Viro if (err) 1238cbbd26b8SAl Viro return false; 1239cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1240cbbd26b8SAl Viro off += v.iov_len; 1241cbbd26b8SAl Viro 0; 1242cbbd26b8SAl Viro }), ({ 1243cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1244cbbd26b8SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1245cbbd26b8SAl Viro (to += v.bv_len) - v.bv_len, 1246cbbd26b8SAl Viro v.bv_len, 0); 1247cbbd26b8SAl Viro kunmap_atomic(p); 1248cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1249cbbd26b8SAl Viro off += v.bv_len; 1250cbbd26b8SAl Viro }),({ 1251cbbd26b8SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1252cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1253cbbd26b8SAl Viro v.iov_len, 0); 1254cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1255cbbd26b8SAl Viro off += v.iov_len; 1256cbbd26b8SAl Viro }) 1257cbbd26b8SAl Viro ) 1258cbbd26b8SAl Viro *csum = sum; 1259cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1260cbbd26b8SAl Viro return true; 1261cbbd26b8SAl Viro } 1262cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1263cbbd26b8SAl Viro 126436f7a8a4SAl Viro size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, 1265d879cb83SAl Viro struct iov_iter *i) 1266d879cb83SAl Viro { 126736f7a8a4SAl Viro const char *from = addr; 1268d879cb83SAl Viro __wsum sum, next; 1269d879cb83SAl Viro size_t off = 0; 1270d879cb83SAl Viro sum = *csum; 1271241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1272241699cdSAl Viro WARN_ON(1); /* for now */ 1273241699cdSAl Viro return 0; 1274241699cdSAl Viro } 1275d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1276d879cb83SAl Viro int err = 0; 1277d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1278d879cb83SAl Viro v.iov_base, 1279d879cb83SAl Viro v.iov_len, 0, &err); 1280d879cb83SAl Viro if (!err) { 1281d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1282d879cb83SAl Viro off += v.iov_len; 1283d879cb83SAl Viro } 1284d879cb83SAl Viro err ? v.iov_len : 0; 1285d879cb83SAl Viro }), ({ 1286d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1287d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, 1288d879cb83SAl Viro p + v.bv_offset, 1289d879cb83SAl Viro v.bv_len, 0); 1290d879cb83SAl Viro kunmap_atomic(p); 1291d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1292d879cb83SAl Viro off += v.bv_len; 1293d879cb83SAl Viro }),({ 1294d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, 1295d879cb83SAl Viro v.iov_base, 1296d879cb83SAl Viro v.iov_len, 0); 1297d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1298d879cb83SAl Viro off += v.iov_len; 1299d879cb83SAl Viro }) 1300d879cb83SAl Viro ) 1301d879cb83SAl Viro *csum = sum; 1302d879cb83SAl Viro return bytes; 1303d879cb83SAl Viro } 1304d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1305d879cb83SAl Viro 1306d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1307d879cb83SAl Viro { 1308d879cb83SAl Viro size_t size = i->count; 1309d879cb83SAl Viro int npages = 0; 1310d879cb83SAl Viro 1311d879cb83SAl Viro if (!size) 1312d879cb83SAl Viro return 0; 1313d879cb83SAl Viro 1314241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1315241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1316241699cdSAl Viro size_t off; 1317241699cdSAl Viro int idx; 1318241699cdSAl Viro 1319241699cdSAl Viro if (!sanity(i)) 1320241699cdSAl Viro return 0; 1321241699cdSAl Viro 1322241699cdSAl Viro data_start(i, &idx, &off); 1323241699cdSAl Viro /* some of this one + all after this one */ 1324241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1325241699cdSAl Viro if (npages >= maxpages) 1326241699cdSAl Viro return maxpages; 1327241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1328d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1329d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1330d879cb83SAl Viro - p / PAGE_SIZE; 1331d879cb83SAl Viro if (npages >= maxpages) 1332d879cb83SAl Viro return maxpages; 1333d879cb83SAl Viro 0;}),({ 1334d879cb83SAl Viro npages++; 1335d879cb83SAl Viro if (npages >= maxpages) 1336d879cb83SAl Viro return maxpages; 1337d879cb83SAl Viro }),({ 1338d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1339d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1340d879cb83SAl Viro - p / PAGE_SIZE; 1341d879cb83SAl Viro if (npages >= maxpages) 1342d879cb83SAl Viro return maxpages; 1343d879cb83SAl Viro }) 1344d879cb83SAl Viro ) 1345d879cb83SAl Viro return npages; 1346d879cb83SAl Viro } 1347d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1348d879cb83SAl Viro 1349d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1350d879cb83SAl Viro { 1351d879cb83SAl Viro *new = *old; 1352241699cdSAl Viro if (unlikely(new->type & ITER_PIPE)) { 1353241699cdSAl Viro WARN_ON(1); 1354241699cdSAl Viro return NULL; 1355241699cdSAl Viro } 1356d879cb83SAl Viro if (new->type & ITER_BVEC) 1357d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1358d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1359d879cb83SAl Viro flags); 1360d879cb83SAl Viro else 1361d879cb83SAl Viro /* iovec and kvec have identical layout */ 1362d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1363d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1364d879cb83SAl Viro flags); 1365d879cb83SAl Viro } 1366d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1367bc917be8SAl Viro 1368ffecee4fSVegard Nossum /** 1369ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1370ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1371ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1372ffecee4fSVegard Nossum * 1373ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1374ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1375ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1376ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1377ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1378ffecee4fSVegard Nossum * on-stack) kernel array. 1379ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1380ffecee4fSVegard Nossum * 1381ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1382ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1383ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1384ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1385ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1386ffecee4fSVegard Nossum * returns an error or not). 1387ffecee4fSVegard Nossum * 1388ffecee4fSVegard Nossum * Return: 0 on success or negative error code on error. 1389ffecee4fSVegard Nossum */ 1390bc917be8SAl Viro int import_iovec(int type, const struct iovec __user * uvector, 1391bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1392bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1393bc917be8SAl Viro { 1394bc917be8SAl Viro ssize_t n; 1395bc917be8SAl Viro struct iovec *p; 1396bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1397bc917be8SAl Viro *iov, &p); 1398bc917be8SAl Viro if (n < 0) { 1399bc917be8SAl Viro if (p != *iov) 1400bc917be8SAl Viro kfree(p); 1401bc917be8SAl Viro *iov = NULL; 1402bc917be8SAl Viro return n; 1403bc917be8SAl Viro } 1404bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1405bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1406bc917be8SAl Viro return 0; 1407bc917be8SAl Viro } 1408bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1409bc917be8SAl Viro 1410bc917be8SAl Viro #ifdef CONFIG_COMPAT 1411bc917be8SAl Viro #include <linux/compat.h> 1412bc917be8SAl Viro 1413bc917be8SAl Viro int compat_import_iovec(int type, const struct compat_iovec __user * uvector, 1414bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1415bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1416bc917be8SAl Viro { 1417bc917be8SAl Viro ssize_t n; 1418bc917be8SAl Viro struct iovec *p; 1419bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1420bc917be8SAl Viro *iov, &p); 1421bc917be8SAl Viro if (n < 0) { 1422bc917be8SAl Viro if (p != *iov) 1423bc917be8SAl Viro kfree(p); 1424bc917be8SAl Viro *iov = NULL; 1425bc917be8SAl Viro return n; 1426bc917be8SAl Viro } 1427bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1428bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1429bc917be8SAl Viro return 0; 1430bc917be8SAl Viro } 1431bc917be8SAl Viro #endif 1432bc917be8SAl Viro 1433bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1434bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1435bc917be8SAl Viro { 1436bc917be8SAl Viro if (len > MAX_RW_COUNT) 1437bc917be8SAl Viro len = MAX_RW_COUNT; 1438bc917be8SAl Viro if (unlikely(!access_ok(!rw, buf, len))) 1439bc917be8SAl Viro return -EFAULT; 1440bc917be8SAl Viro 1441bc917be8SAl Viro iov->iov_base = buf; 1442bc917be8SAl Viro iov->iov_len = len; 1443bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1444bc917be8SAl Viro return 0; 1445bc917be8SAl Viro } 1446e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 1447