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 133d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 134d879cb83SAl Viro struct iov_iter *i) 135d879cb83SAl Viro { 136d879cb83SAl Viro size_t skip, copy, left, wanted; 137d879cb83SAl Viro const struct iovec *iov; 138d879cb83SAl Viro char __user *buf; 139d879cb83SAl Viro void *kaddr, *from; 140d879cb83SAl Viro 141d879cb83SAl Viro if (unlikely(bytes > i->count)) 142d879cb83SAl Viro bytes = i->count; 143d879cb83SAl Viro 144d879cb83SAl Viro if (unlikely(!bytes)) 145d879cb83SAl Viro return 0; 146d879cb83SAl Viro 147d879cb83SAl Viro wanted = bytes; 148d879cb83SAl Viro iov = i->iov; 149d879cb83SAl Viro skip = i->iov_offset; 150d879cb83SAl Viro buf = iov->iov_base + skip; 151d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 152d879cb83SAl Viro 1533fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 154d879cb83SAl Viro kaddr = kmap_atomic(page); 155d879cb83SAl Viro from = kaddr + offset; 156d879cb83SAl Viro 157d879cb83SAl Viro /* first chunk, usually the only one */ 158d879cb83SAl Viro left = __copy_to_user_inatomic(buf, from, copy); 159d879cb83SAl Viro copy -= left; 160d879cb83SAl Viro skip += copy; 161d879cb83SAl Viro from += copy; 162d879cb83SAl Viro bytes -= copy; 163d879cb83SAl Viro 164d879cb83SAl Viro while (unlikely(!left && bytes)) { 165d879cb83SAl Viro iov++; 166d879cb83SAl Viro buf = iov->iov_base; 167d879cb83SAl Viro copy = min(bytes, iov->iov_len); 168d879cb83SAl Viro left = __copy_to_user_inatomic(buf, from, copy); 169d879cb83SAl Viro copy -= left; 170d879cb83SAl Viro skip = copy; 171d879cb83SAl Viro from += copy; 172d879cb83SAl Viro bytes -= copy; 173d879cb83SAl Viro } 174d879cb83SAl Viro if (likely(!bytes)) { 175d879cb83SAl Viro kunmap_atomic(kaddr); 176d879cb83SAl Viro goto done; 177d879cb83SAl Viro } 178d879cb83SAl Viro offset = from - kaddr; 179d879cb83SAl Viro buf += copy; 180d879cb83SAl Viro kunmap_atomic(kaddr); 181d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 182d879cb83SAl Viro } 183d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 1843fa6c507SMikulas Patocka 185d879cb83SAl Viro kaddr = kmap(page); 186d879cb83SAl Viro from = kaddr + offset; 187d879cb83SAl Viro left = __copy_to_user(buf, from, copy); 188d879cb83SAl Viro copy -= left; 189d879cb83SAl Viro skip += copy; 190d879cb83SAl Viro from += copy; 191d879cb83SAl Viro bytes -= copy; 192d879cb83SAl Viro while (unlikely(!left && bytes)) { 193d879cb83SAl Viro iov++; 194d879cb83SAl Viro buf = iov->iov_base; 195d879cb83SAl Viro copy = min(bytes, iov->iov_len); 196d879cb83SAl Viro left = __copy_to_user(buf, from, copy); 197d879cb83SAl Viro copy -= left; 198d879cb83SAl Viro skip = copy; 199d879cb83SAl Viro from += copy; 200d879cb83SAl Viro bytes -= copy; 201d879cb83SAl Viro } 202d879cb83SAl Viro kunmap(page); 2033fa6c507SMikulas Patocka 204d879cb83SAl Viro done: 205d879cb83SAl Viro if (skip == iov->iov_len) { 206d879cb83SAl Viro iov++; 207d879cb83SAl Viro skip = 0; 208d879cb83SAl Viro } 209d879cb83SAl Viro i->count -= wanted - bytes; 210d879cb83SAl Viro i->nr_segs -= iov - i->iov; 211d879cb83SAl Viro i->iov = iov; 212d879cb83SAl Viro i->iov_offset = skip; 213d879cb83SAl Viro return wanted - bytes; 214d879cb83SAl Viro } 215d879cb83SAl Viro 216d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 217d879cb83SAl Viro struct iov_iter *i) 218d879cb83SAl Viro { 219d879cb83SAl Viro size_t skip, copy, left, wanted; 220d879cb83SAl Viro const struct iovec *iov; 221d879cb83SAl Viro char __user *buf; 222d879cb83SAl Viro void *kaddr, *to; 223d879cb83SAl Viro 224d879cb83SAl Viro if (unlikely(bytes > i->count)) 225d879cb83SAl Viro bytes = i->count; 226d879cb83SAl Viro 227d879cb83SAl Viro if (unlikely(!bytes)) 228d879cb83SAl Viro return 0; 229d879cb83SAl Viro 230d879cb83SAl Viro wanted = bytes; 231d879cb83SAl Viro iov = i->iov; 232d879cb83SAl Viro skip = i->iov_offset; 233d879cb83SAl Viro buf = iov->iov_base + skip; 234d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 235d879cb83SAl Viro 2363fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 237d879cb83SAl Viro kaddr = kmap_atomic(page); 238d879cb83SAl Viro to = kaddr + offset; 239d879cb83SAl Viro 240d879cb83SAl Viro /* first chunk, usually the only one */ 241d879cb83SAl Viro left = __copy_from_user_inatomic(to, buf, copy); 242d879cb83SAl Viro copy -= left; 243d879cb83SAl Viro skip += copy; 244d879cb83SAl Viro to += copy; 245d879cb83SAl Viro bytes -= copy; 246d879cb83SAl Viro 247d879cb83SAl Viro while (unlikely(!left && bytes)) { 248d879cb83SAl Viro iov++; 249d879cb83SAl Viro buf = iov->iov_base; 250d879cb83SAl Viro copy = min(bytes, iov->iov_len); 251d879cb83SAl Viro left = __copy_from_user_inatomic(to, buf, copy); 252d879cb83SAl Viro copy -= left; 253d879cb83SAl Viro skip = copy; 254d879cb83SAl Viro to += copy; 255d879cb83SAl Viro bytes -= copy; 256d879cb83SAl Viro } 257d879cb83SAl Viro if (likely(!bytes)) { 258d879cb83SAl Viro kunmap_atomic(kaddr); 259d879cb83SAl Viro goto done; 260d879cb83SAl Viro } 261d879cb83SAl Viro offset = to - kaddr; 262d879cb83SAl Viro buf += copy; 263d879cb83SAl Viro kunmap_atomic(kaddr); 264d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 265d879cb83SAl Viro } 266d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2673fa6c507SMikulas Patocka 268d879cb83SAl Viro kaddr = kmap(page); 269d879cb83SAl Viro to = kaddr + offset; 270d879cb83SAl Viro left = __copy_from_user(to, buf, copy); 271d879cb83SAl Viro copy -= left; 272d879cb83SAl Viro skip += copy; 273d879cb83SAl Viro to += copy; 274d879cb83SAl Viro bytes -= copy; 275d879cb83SAl Viro while (unlikely(!left && bytes)) { 276d879cb83SAl Viro iov++; 277d879cb83SAl Viro buf = iov->iov_base; 278d879cb83SAl Viro copy = min(bytes, iov->iov_len); 279d879cb83SAl Viro left = __copy_from_user(to, buf, copy); 280d879cb83SAl Viro copy -= left; 281d879cb83SAl Viro skip = copy; 282d879cb83SAl Viro to += copy; 283d879cb83SAl Viro bytes -= copy; 284d879cb83SAl Viro } 285d879cb83SAl Viro kunmap(page); 2863fa6c507SMikulas Patocka 287d879cb83SAl Viro done: 288d879cb83SAl Viro if (skip == iov->iov_len) { 289d879cb83SAl Viro iov++; 290d879cb83SAl Viro skip = 0; 291d879cb83SAl Viro } 292d879cb83SAl Viro i->count -= wanted - bytes; 293d879cb83SAl Viro i->nr_segs -= iov - i->iov; 294d879cb83SAl Viro i->iov = iov; 295d879cb83SAl Viro i->iov_offset = skip; 296d879cb83SAl Viro return wanted - bytes; 297d879cb83SAl Viro } 298d879cb83SAl Viro 299241699cdSAl Viro #ifdef PIPE_PARANOIA 300241699cdSAl Viro static bool sanity(const struct iov_iter *i) 301241699cdSAl Viro { 302241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 303241699cdSAl Viro int idx = i->idx; 304241699cdSAl Viro int next = pipe->curbuf + pipe->nrbufs; 305241699cdSAl Viro if (i->iov_offset) { 306241699cdSAl Viro struct pipe_buffer *p; 307241699cdSAl Viro if (unlikely(!pipe->nrbufs)) 308241699cdSAl Viro goto Bad; // pipe must be non-empty 309241699cdSAl Viro if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) 310241699cdSAl Viro goto Bad; // must be at the last buffer... 311241699cdSAl Viro 312241699cdSAl Viro p = &pipe->bufs[idx]; 313241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 314241699cdSAl Viro goto Bad; // ... at the end of segment 315241699cdSAl Viro } else { 316241699cdSAl Viro if (idx != (next & (pipe->buffers - 1))) 317241699cdSAl Viro goto Bad; // must be right after the last buffer 318241699cdSAl Viro } 319241699cdSAl Viro return true; 320241699cdSAl Viro Bad: 321241699cdSAl Viro printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); 322241699cdSAl Viro printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", 323241699cdSAl Viro pipe->curbuf, pipe->nrbufs, pipe->buffers); 324241699cdSAl Viro for (idx = 0; idx < pipe->buffers; idx++) 325241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 326241699cdSAl Viro pipe->bufs[idx].ops, 327241699cdSAl Viro pipe->bufs[idx].page, 328241699cdSAl Viro pipe->bufs[idx].offset, 329241699cdSAl Viro pipe->bufs[idx].len); 330241699cdSAl Viro WARN_ON(1); 331241699cdSAl Viro return false; 332241699cdSAl Viro } 333241699cdSAl Viro #else 334241699cdSAl Viro #define sanity(i) true 335241699cdSAl Viro #endif 336241699cdSAl Viro 337241699cdSAl Viro static inline int next_idx(int idx, struct pipe_inode_info *pipe) 338241699cdSAl Viro { 339241699cdSAl Viro return (idx + 1) & (pipe->buffers - 1); 340241699cdSAl Viro } 341241699cdSAl Viro 342241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 343241699cdSAl Viro struct iov_iter *i) 344241699cdSAl Viro { 345241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 346241699cdSAl Viro struct pipe_buffer *buf; 347241699cdSAl Viro size_t off; 348241699cdSAl Viro int idx; 349241699cdSAl Viro 350241699cdSAl Viro if (unlikely(bytes > i->count)) 351241699cdSAl Viro bytes = i->count; 352241699cdSAl Viro 353241699cdSAl Viro if (unlikely(!bytes)) 354241699cdSAl Viro return 0; 355241699cdSAl Viro 356241699cdSAl Viro if (!sanity(i)) 357241699cdSAl Viro return 0; 358241699cdSAl Viro 359241699cdSAl Viro off = i->iov_offset; 360241699cdSAl Viro idx = i->idx; 361241699cdSAl Viro buf = &pipe->bufs[idx]; 362241699cdSAl Viro if (off) { 363241699cdSAl Viro if (offset == off && buf->page == page) { 364241699cdSAl Viro /* merge with the last one */ 365241699cdSAl Viro buf->len += bytes; 366241699cdSAl Viro i->iov_offset += bytes; 367241699cdSAl Viro goto out; 368241699cdSAl Viro } 369241699cdSAl Viro idx = next_idx(idx, pipe); 370241699cdSAl Viro buf = &pipe->bufs[idx]; 371241699cdSAl Viro } 372241699cdSAl Viro if (idx == pipe->curbuf && pipe->nrbufs) 373241699cdSAl Viro return 0; 374241699cdSAl Viro pipe->nrbufs++; 375241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 376241699cdSAl Viro get_page(buf->page = page); 377241699cdSAl Viro buf->offset = offset; 378241699cdSAl Viro buf->len = bytes; 379241699cdSAl Viro i->iov_offset = offset + bytes; 380241699cdSAl Viro i->idx = idx; 381241699cdSAl Viro out: 382241699cdSAl Viro i->count -= bytes; 383241699cdSAl Viro return bytes; 384241699cdSAl Viro } 385241699cdSAl Viro 386d879cb83SAl Viro /* 387171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 388171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 389171a0203SAnton Altaparmakov * 390171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 391171a0203SAnton Altaparmakov * because it is an invalid address). 392171a0203SAnton Altaparmakov */ 393d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 394171a0203SAnton Altaparmakov { 395171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 396171a0203SAnton Altaparmakov const struct iovec *iov; 397171a0203SAnton Altaparmakov int err; 398171a0203SAnton Altaparmakov struct iovec v; 399171a0203SAnton Altaparmakov 400171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 401171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4024bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 403171a0203SAnton Altaparmakov if (unlikely(err)) 404171a0203SAnton Altaparmakov return err; 405171a0203SAnton Altaparmakov 0;})) 406171a0203SAnton Altaparmakov } 407171a0203SAnton Altaparmakov return 0; 408171a0203SAnton Altaparmakov } 409d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 410171a0203SAnton Altaparmakov 411d879cb83SAl Viro void iov_iter_init(struct iov_iter *i, int direction, 412d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 413d879cb83SAl Viro size_t count) 414d879cb83SAl Viro { 415d879cb83SAl Viro /* It will get better. Eventually... */ 416d879cb83SAl Viro if (segment_eq(get_fs(), KERNEL_DS)) { 417d879cb83SAl Viro direction |= ITER_KVEC; 418d879cb83SAl Viro i->type = direction; 419d879cb83SAl Viro i->kvec = (struct kvec *)iov; 420d879cb83SAl Viro } else { 421d879cb83SAl Viro i->type = direction; 422d879cb83SAl Viro i->iov = iov; 423d879cb83SAl Viro } 424d879cb83SAl Viro i->nr_segs = nr_segs; 425d879cb83SAl Viro i->iov_offset = 0; 426d879cb83SAl Viro i->count = count; 427d879cb83SAl Viro } 428d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 429d879cb83SAl Viro 430d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 431d879cb83SAl Viro { 432d879cb83SAl Viro char *from = kmap_atomic(page); 433d879cb83SAl Viro memcpy(to, from + offset, len); 434d879cb83SAl Viro kunmap_atomic(from); 435d879cb83SAl Viro } 436d879cb83SAl Viro 43736f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 438d879cb83SAl Viro { 439d879cb83SAl Viro char *to = kmap_atomic(page); 440d879cb83SAl Viro memcpy(to + offset, from, len); 441d879cb83SAl Viro kunmap_atomic(to); 442d879cb83SAl Viro } 443d879cb83SAl Viro 444d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 445d879cb83SAl Viro { 446d879cb83SAl Viro char *addr = kmap_atomic(page); 447d879cb83SAl Viro memset(addr + offset, 0, len); 448d879cb83SAl Viro kunmap_atomic(addr); 449d879cb83SAl Viro } 450d879cb83SAl Viro 451241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 452241699cdSAl Viro { 453241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 454241699cdSAl Viro } 455241699cdSAl Viro 456241699cdSAl Viro static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) 457241699cdSAl Viro { 458241699cdSAl Viro size_t off = i->iov_offset; 459241699cdSAl Viro int idx = i->idx; 460241699cdSAl Viro if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { 461241699cdSAl Viro idx = next_idx(idx, i->pipe); 462241699cdSAl Viro off = 0; 463241699cdSAl Viro } 464241699cdSAl Viro *idxp = idx; 465241699cdSAl Viro *offp = off; 466241699cdSAl Viro } 467241699cdSAl Viro 468241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 469241699cdSAl Viro int *idxp, size_t *offp) 470241699cdSAl Viro { 471241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 472241699cdSAl Viro size_t off; 473241699cdSAl Viro int idx; 474241699cdSAl Viro ssize_t left; 475241699cdSAl Viro 476241699cdSAl Viro if (unlikely(size > i->count)) 477241699cdSAl Viro size = i->count; 478241699cdSAl Viro if (unlikely(!size)) 479241699cdSAl Viro return 0; 480241699cdSAl Viro 481241699cdSAl Viro left = size; 482241699cdSAl Viro data_start(i, &idx, &off); 483241699cdSAl Viro *idxp = idx; 484241699cdSAl Viro *offp = off; 485241699cdSAl Viro if (off) { 486241699cdSAl Viro left -= PAGE_SIZE - off; 487241699cdSAl Viro if (left <= 0) { 488241699cdSAl Viro pipe->bufs[idx].len += size; 489241699cdSAl Viro return size; 490241699cdSAl Viro } 491241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 492241699cdSAl Viro idx = next_idx(idx, pipe); 493241699cdSAl Viro } 494241699cdSAl Viro while (idx != pipe->curbuf || !pipe->nrbufs) { 495241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 496241699cdSAl Viro if (!page) 497241699cdSAl Viro break; 498241699cdSAl Viro pipe->nrbufs++; 499241699cdSAl Viro pipe->bufs[idx].ops = &default_pipe_buf_ops; 500241699cdSAl Viro pipe->bufs[idx].page = page; 501241699cdSAl Viro pipe->bufs[idx].offset = 0; 502241699cdSAl Viro if (left <= PAGE_SIZE) { 503241699cdSAl Viro pipe->bufs[idx].len = left; 504241699cdSAl Viro return size; 505241699cdSAl Viro } 506241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 507241699cdSAl Viro left -= PAGE_SIZE; 508241699cdSAl Viro idx = next_idx(idx, pipe); 509241699cdSAl Viro } 510241699cdSAl Viro return size - left; 511241699cdSAl Viro } 512241699cdSAl Viro 513241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 514241699cdSAl Viro struct iov_iter *i) 515241699cdSAl Viro { 516241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 517241699cdSAl Viro size_t n, off; 518241699cdSAl Viro int idx; 519241699cdSAl Viro 520241699cdSAl Viro if (!sanity(i)) 521241699cdSAl Viro return 0; 522241699cdSAl Viro 523241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 524241699cdSAl Viro if (unlikely(!n)) 525241699cdSAl Viro return 0; 526241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 527241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 528241699cdSAl Viro memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); 529241699cdSAl Viro i->idx = idx; 530241699cdSAl Viro i->iov_offset = off + chunk; 531241699cdSAl Viro n -= chunk; 532241699cdSAl Viro addr += chunk; 533241699cdSAl Viro } 534241699cdSAl Viro i->count -= bytes; 535241699cdSAl Viro return bytes; 536241699cdSAl Viro } 537241699cdSAl Viro 53836f7a8a4SAl Viro size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 539d879cb83SAl Viro { 54036f7a8a4SAl Viro const char *from = addr; 541241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 542241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 543d879cb83SAl Viro iterate_and_advance(i, bytes, v, 544d879cb83SAl Viro __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, 545d879cb83SAl Viro v.iov_len), 546d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 547d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 548d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 549d879cb83SAl Viro ) 550d879cb83SAl Viro 551d879cb83SAl Viro return bytes; 552d879cb83SAl Viro } 553d879cb83SAl Viro EXPORT_SYMBOL(copy_to_iter); 554d879cb83SAl Viro 555d879cb83SAl Viro size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 556d879cb83SAl Viro { 557d879cb83SAl Viro char *to = addr; 558241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 559241699cdSAl Viro WARN_ON(1); 560241699cdSAl Viro return 0; 561241699cdSAl Viro } 562d879cb83SAl Viro iterate_and_advance(i, bytes, v, 563d879cb83SAl Viro __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, 564d879cb83SAl Viro v.iov_len), 565d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 566d879cb83SAl Viro v.bv_offset, v.bv_len), 567d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 568d879cb83SAl Viro ) 569d879cb83SAl Viro 570d879cb83SAl Viro return bytes; 571d879cb83SAl Viro } 572d879cb83SAl Viro EXPORT_SYMBOL(copy_from_iter); 573d879cb83SAl Viro 574cbbd26b8SAl Viro bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 575cbbd26b8SAl Viro { 576cbbd26b8SAl Viro char *to = addr; 577cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 578cbbd26b8SAl Viro WARN_ON(1); 579cbbd26b8SAl Viro return false; 580cbbd26b8SAl Viro } 58133844e66SAl Viro if (unlikely(i->count < bytes)) 582cbbd26b8SAl Viro return false; 583cbbd26b8SAl Viro 584cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 585cbbd26b8SAl Viro if (__copy_from_user((to += v.iov_len) - v.iov_len, 586cbbd26b8SAl Viro v.iov_base, v.iov_len)) 587cbbd26b8SAl Viro return false; 588cbbd26b8SAl Viro 0;}), 589cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 590cbbd26b8SAl Viro v.bv_offset, v.bv_len), 591cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 592cbbd26b8SAl Viro ) 593cbbd26b8SAl Viro 594cbbd26b8SAl Viro iov_iter_advance(i, bytes); 595cbbd26b8SAl Viro return true; 596cbbd26b8SAl Viro } 597cbbd26b8SAl Viro EXPORT_SYMBOL(copy_from_iter_full); 598cbbd26b8SAl Viro 599d879cb83SAl Viro size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 600d879cb83SAl Viro { 601d879cb83SAl Viro char *to = addr; 602241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 603241699cdSAl Viro WARN_ON(1); 604241699cdSAl Viro return 0; 605241699cdSAl Viro } 606d879cb83SAl Viro iterate_and_advance(i, bytes, v, 607d879cb83SAl Viro __copy_from_user_nocache((to += v.iov_len) - v.iov_len, 608d879cb83SAl Viro v.iov_base, v.iov_len), 609d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 610d879cb83SAl Viro v.bv_offset, v.bv_len), 611d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 612d879cb83SAl Viro ) 613d879cb83SAl Viro 614d879cb83SAl Viro return bytes; 615d879cb83SAl Viro } 616d879cb83SAl Viro EXPORT_SYMBOL(copy_from_iter_nocache); 617d879cb83SAl Viro 618cbbd26b8SAl Viro bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 619cbbd26b8SAl Viro { 620cbbd26b8SAl Viro char *to = addr; 621cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 622cbbd26b8SAl Viro WARN_ON(1); 623cbbd26b8SAl Viro return false; 624cbbd26b8SAl Viro } 62533844e66SAl Viro if (unlikely(i->count < bytes)) 626cbbd26b8SAl Viro return false; 627cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 628cbbd26b8SAl Viro if (__copy_from_user_nocache((to += v.iov_len) - v.iov_len, 629cbbd26b8SAl Viro v.iov_base, v.iov_len)) 630cbbd26b8SAl Viro return false; 631cbbd26b8SAl Viro 0;}), 632cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 633cbbd26b8SAl Viro v.bv_offset, v.bv_len), 634cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 635cbbd26b8SAl Viro ) 636cbbd26b8SAl Viro 637cbbd26b8SAl Viro iov_iter_advance(i, bytes); 638cbbd26b8SAl Viro return true; 639cbbd26b8SAl Viro } 640cbbd26b8SAl Viro EXPORT_SYMBOL(copy_from_iter_full_nocache); 641cbbd26b8SAl Viro 642d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 643d879cb83SAl Viro struct iov_iter *i) 644d879cb83SAl Viro { 645d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 646d879cb83SAl Viro void *kaddr = kmap_atomic(page); 647d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 648d879cb83SAl Viro kunmap_atomic(kaddr); 649d879cb83SAl Viro return wanted; 650241699cdSAl Viro } else if (likely(!(i->type & ITER_PIPE))) 651d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 652241699cdSAl Viro else 653241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 654d879cb83SAl Viro } 655d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 656d879cb83SAl Viro 657d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 658d879cb83SAl Viro struct iov_iter *i) 659d879cb83SAl Viro { 660241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 661241699cdSAl Viro WARN_ON(1); 662241699cdSAl Viro return 0; 663241699cdSAl Viro } 664d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 665d879cb83SAl Viro void *kaddr = kmap_atomic(page); 666d879cb83SAl Viro size_t wanted = copy_from_iter(kaddr + offset, bytes, i); 667d879cb83SAl Viro kunmap_atomic(kaddr); 668d879cb83SAl Viro return wanted; 669d879cb83SAl Viro } else 670d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 671d879cb83SAl Viro } 672d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 673d879cb83SAl Viro 674241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 675241699cdSAl Viro { 676241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 677241699cdSAl Viro size_t n, off; 678241699cdSAl Viro int idx; 679241699cdSAl Viro 680241699cdSAl Viro if (!sanity(i)) 681241699cdSAl Viro return 0; 682241699cdSAl Viro 683241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 684241699cdSAl Viro if (unlikely(!n)) 685241699cdSAl Viro return 0; 686241699cdSAl Viro 687241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 688241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 689241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 690241699cdSAl Viro i->idx = idx; 691241699cdSAl Viro i->iov_offset = off + chunk; 692241699cdSAl Viro n -= chunk; 693241699cdSAl Viro } 694241699cdSAl Viro i->count -= bytes; 695241699cdSAl Viro return bytes; 696241699cdSAl Viro } 697241699cdSAl Viro 698d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 699d879cb83SAl Viro { 700241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 701241699cdSAl Viro return pipe_zero(bytes, i); 702d879cb83SAl Viro iterate_and_advance(i, bytes, v, 703d879cb83SAl Viro __clear_user(v.iov_base, v.iov_len), 704d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 705d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 706d879cb83SAl Viro ) 707d879cb83SAl Viro 708d879cb83SAl Viro return bytes; 709d879cb83SAl Viro } 710d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 711d879cb83SAl Viro 712d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 713d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 714d879cb83SAl Viro { 715d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 716241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 717241699cdSAl Viro kunmap_atomic(kaddr); 718241699cdSAl Viro WARN_ON(1); 719241699cdSAl Viro return 0; 720241699cdSAl Viro } 721d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 722d879cb83SAl Viro __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, 723d879cb83SAl Viro v.iov_base, v.iov_len), 724d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 725d879cb83SAl Viro v.bv_offset, v.bv_len), 726d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 727d879cb83SAl Viro ) 728d879cb83SAl Viro kunmap_atomic(kaddr); 729d879cb83SAl Viro return bytes; 730d879cb83SAl Viro } 731d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 732d879cb83SAl Viro 733b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 734241699cdSAl Viro { 735241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 736241699cdSAl Viro if (pipe->nrbufs) { 737b9dc6f65SAl Viro size_t off = i->iov_offset; 738b9dc6f65SAl Viro int idx = i->idx; 739b9dc6f65SAl Viro int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); 740b9dc6f65SAl Viro if (off) { 741b9dc6f65SAl Viro pipe->bufs[idx].len = off - pipe->bufs[idx].offset; 742b9dc6f65SAl Viro idx = next_idx(idx, pipe); 743b9dc6f65SAl Viro nrbufs++; 744b9dc6f65SAl Viro } 745b9dc6f65SAl Viro while (pipe->nrbufs > nrbufs) { 746a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 747241699cdSAl Viro idx = next_idx(idx, pipe); 748241699cdSAl Viro pipe->nrbufs--; 749241699cdSAl Viro } 750241699cdSAl Viro } 751b9dc6f65SAl Viro } 752b9dc6f65SAl Viro 753b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 754b9dc6f65SAl Viro { 755b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 756b9dc6f65SAl Viro if (unlikely(i->count < size)) 757b9dc6f65SAl Viro size = i->count; 758b9dc6f65SAl Viro if (size) { 759b9dc6f65SAl Viro struct pipe_buffer *buf; 760b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 761b9dc6f65SAl Viro int idx = i->idx; 762b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 763b9dc6f65SAl Viro left += off - pipe->bufs[idx].offset; 764b9dc6f65SAl Viro while (1) { 765b9dc6f65SAl Viro buf = &pipe->bufs[idx]; 766b9dc6f65SAl Viro if (left <= buf->len) 767b9dc6f65SAl Viro break; 768b9dc6f65SAl Viro left -= buf->len; 769b9dc6f65SAl Viro idx = next_idx(idx, pipe); 770b9dc6f65SAl Viro } 771b9dc6f65SAl Viro i->idx = idx; 772b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 773b9dc6f65SAl Viro } 774b9dc6f65SAl Viro i->count -= size; 775b9dc6f65SAl Viro /* ... and discard everything past that point */ 776b9dc6f65SAl Viro pipe_truncate(i); 777241699cdSAl Viro } 778241699cdSAl Viro 779d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 780d879cb83SAl Viro { 781241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 782241699cdSAl Viro pipe_advance(i, size); 783241699cdSAl Viro return; 784241699cdSAl Viro } 785d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 786d879cb83SAl Viro } 787d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 788d879cb83SAl Viro 78927c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 79027c0e374SAl Viro { 79127c0e374SAl Viro if (!unroll) 79227c0e374SAl Viro return; 79327c0e374SAl Viro i->count += unroll; 79427c0e374SAl Viro if (unlikely(i->type & ITER_PIPE)) { 79527c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 79627c0e374SAl Viro int idx = i->idx; 79727c0e374SAl Viro size_t off = i->iov_offset; 79827c0e374SAl Viro while (1) { 79927c0e374SAl Viro size_t n = off - pipe->bufs[idx].offset; 80027c0e374SAl Viro if (unroll < n) { 80127c0e374SAl Viro off -= (n - unroll); 80227c0e374SAl Viro break; 80327c0e374SAl Viro } 80427c0e374SAl Viro unroll -= n; 80527c0e374SAl Viro if (!unroll && idx == i->start_idx) { 80627c0e374SAl Viro off = 0; 80727c0e374SAl Viro break; 80827c0e374SAl Viro } 80927c0e374SAl Viro if (!idx--) 81027c0e374SAl Viro idx = pipe->buffers - 1; 81127c0e374SAl Viro off = pipe->bufs[idx].offset + pipe->bufs[idx].len; 81227c0e374SAl Viro } 81327c0e374SAl Viro i->iov_offset = off; 81427c0e374SAl Viro i->idx = idx; 81527c0e374SAl Viro pipe_truncate(i); 81627c0e374SAl Viro return; 81727c0e374SAl Viro } 81827c0e374SAl Viro if (unroll <= i->iov_offset) { 81927c0e374SAl Viro i->iov_offset -= unroll; 82027c0e374SAl Viro return; 82127c0e374SAl Viro } 82227c0e374SAl Viro unroll -= i->iov_offset; 82327c0e374SAl Viro if (i->type & ITER_BVEC) { 82427c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 82527c0e374SAl Viro while (1) { 82627c0e374SAl Viro size_t n = (--bvec)->bv_len; 82727c0e374SAl Viro i->nr_segs++; 82827c0e374SAl Viro if (unroll <= n) { 82927c0e374SAl Viro i->bvec = bvec; 83027c0e374SAl Viro i->iov_offset = n - unroll; 83127c0e374SAl Viro return; 83227c0e374SAl Viro } 83327c0e374SAl Viro unroll -= n; 83427c0e374SAl Viro } 83527c0e374SAl Viro } else { /* same logics for iovec and kvec */ 83627c0e374SAl Viro const struct iovec *iov = i->iov; 83727c0e374SAl Viro while (1) { 83827c0e374SAl Viro size_t n = (--iov)->iov_len; 83927c0e374SAl Viro i->nr_segs++; 84027c0e374SAl Viro if (unroll <= n) { 84127c0e374SAl Viro i->iov = iov; 84227c0e374SAl Viro i->iov_offset = n - unroll; 84327c0e374SAl Viro return; 84427c0e374SAl Viro } 84527c0e374SAl Viro unroll -= n; 84627c0e374SAl Viro } 84727c0e374SAl Viro } 84827c0e374SAl Viro } 84927c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 85027c0e374SAl Viro 851d879cb83SAl Viro /* 852d879cb83SAl Viro * Return the count of just the current iov_iter segment. 853d879cb83SAl Viro */ 854d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 855d879cb83SAl Viro { 856241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 857241699cdSAl Viro return i->count; // it is a silly place, anyway 858d879cb83SAl Viro if (i->nr_segs == 1) 859d879cb83SAl Viro return i->count; 860d879cb83SAl Viro else if (i->type & ITER_BVEC) 861d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 862d879cb83SAl Viro else 863d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 864d879cb83SAl Viro } 865d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 866d879cb83SAl Viro 867d879cb83SAl Viro void iov_iter_kvec(struct iov_iter *i, int direction, 868d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 869d879cb83SAl Viro size_t count) 870d879cb83SAl Viro { 871d879cb83SAl Viro BUG_ON(!(direction & ITER_KVEC)); 872d879cb83SAl Viro i->type = direction; 873d879cb83SAl Viro i->kvec = kvec; 874d879cb83SAl Viro i->nr_segs = nr_segs; 875d879cb83SAl Viro i->iov_offset = 0; 876d879cb83SAl Viro i->count = count; 877d879cb83SAl Viro } 878d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 879d879cb83SAl Viro 880d879cb83SAl Viro void iov_iter_bvec(struct iov_iter *i, int direction, 881d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 882d879cb83SAl Viro size_t count) 883d879cb83SAl Viro { 884d879cb83SAl Viro BUG_ON(!(direction & ITER_BVEC)); 885d879cb83SAl Viro i->type = direction; 886d879cb83SAl Viro i->bvec = bvec; 887d879cb83SAl Viro i->nr_segs = nr_segs; 888d879cb83SAl Viro i->iov_offset = 0; 889d879cb83SAl Viro i->count = count; 890d879cb83SAl Viro } 891d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 892d879cb83SAl Viro 893241699cdSAl Viro void iov_iter_pipe(struct iov_iter *i, int direction, 894241699cdSAl Viro struct pipe_inode_info *pipe, 895241699cdSAl Viro size_t count) 896241699cdSAl Viro { 897241699cdSAl Viro BUG_ON(direction != ITER_PIPE); 898b9dc6f65SAl Viro WARN_ON(pipe->nrbufs == pipe->buffers); 899241699cdSAl Viro i->type = direction; 900241699cdSAl Viro i->pipe = pipe; 901241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 902241699cdSAl Viro i->iov_offset = 0; 903241699cdSAl Viro i->count = count; 90427c0e374SAl Viro i->start_idx = i->idx; 905241699cdSAl Viro } 906241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 907241699cdSAl Viro 908d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 909d879cb83SAl Viro { 910d879cb83SAl Viro unsigned long res = 0; 911d879cb83SAl Viro size_t size = i->count; 912d879cb83SAl Viro 913241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 91433844e66SAl Viro if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 915241699cdSAl Viro return size | i->iov_offset; 916241699cdSAl Viro return size; 917241699cdSAl Viro } 918d879cb83SAl Viro iterate_all_kinds(i, size, v, 919d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 920d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 921d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 922d879cb83SAl Viro ) 923d879cb83SAl Viro return res; 924d879cb83SAl Viro } 925d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 926d879cb83SAl Viro 927357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 928357f435dSAl Viro { 929357f435dSAl Viro unsigned long res = 0; 930357f435dSAl Viro size_t size = i->count; 931357f435dSAl Viro 932241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 933241699cdSAl Viro WARN_ON(1); 934241699cdSAl Viro return ~0U; 935241699cdSAl Viro } 936241699cdSAl Viro 937357f435dSAl Viro iterate_all_kinds(i, size, v, 938357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 939357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 940357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 941357f435dSAl Viro (size != v.bv_len ? size : 0)), 942357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 943357f435dSAl Viro (size != v.iov_len ? size : 0)) 944357f435dSAl Viro ); 945357f435dSAl Viro return res; 946357f435dSAl Viro } 947357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 948357f435dSAl Viro 949241699cdSAl Viro static inline size_t __pipe_get_pages(struct iov_iter *i, 950241699cdSAl Viro size_t maxsize, 951241699cdSAl Viro struct page **pages, 952241699cdSAl Viro int idx, 953241699cdSAl Viro size_t *start) 954241699cdSAl Viro { 955241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9561689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 957241699cdSAl Viro if (!n) 958241699cdSAl Viro return -EFAULT; 959241699cdSAl Viro 960241699cdSAl Viro maxsize = n; 961241699cdSAl Viro n += *start; 9621689c73aSAl Viro while (n > 0) { 963241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 964241699cdSAl Viro idx = next_idx(idx, pipe); 965241699cdSAl Viro n -= PAGE_SIZE; 966241699cdSAl Viro } 967241699cdSAl Viro 968241699cdSAl Viro return maxsize; 969241699cdSAl Viro } 970241699cdSAl Viro 971241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 972241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 973241699cdSAl Viro size_t *start) 974241699cdSAl Viro { 975241699cdSAl Viro unsigned npages; 976241699cdSAl Viro size_t capacity; 977241699cdSAl Viro int idx; 978241699cdSAl Viro 97933844e66SAl Viro if (!maxsize) 98033844e66SAl Viro return 0; 98133844e66SAl Viro 982241699cdSAl Viro if (!sanity(i)) 983241699cdSAl Viro return -EFAULT; 984241699cdSAl Viro 985241699cdSAl Viro data_start(i, &idx, start); 986241699cdSAl Viro /* some of this one + all after this one */ 987241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 988241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 989241699cdSAl Viro 990241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 991241699cdSAl Viro } 992241699cdSAl Viro 993d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 994d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 995d879cb83SAl Viro size_t *start) 996d879cb83SAl Viro { 997d879cb83SAl Viro if (maxsize > i->count) 998d879cb83SAl Viro maxsize = i->count; 999d879cb83SAl Viro 1000241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1001241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 1002d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1003d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1004d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1005d879cb83SAl Viro int n; 1006d879cb83SAl Viro int res; 1007d879cb83SAl Viro 1008d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1009d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1010d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1011d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1012d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); 1013d879cb83SAl Viro if (unlikely(res < 0)) 1014d879cb83SAl Viro return res; 1015d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1016d879cb83SAl Viro 0;}),({ 1017d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1018d879cb83SAl Viro *start = v.bv_offset; 1019d879cb83SAl Viro get_page(*pages = v.bv_page); 1020d879cb83SAl Viro return v.bv_len; 1021d879cb83SAl Viro }),({ 1022d879cb83SAl Viro return -EFAULT; 1023d879cb83SAl Viro }) 1024d879cb83SAl Viro ) 1025d879cb83SAl Viro return 0; 1026d879cb83SAl Viro } 1027d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1028d879cb83SAl Viro 1029d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1030d879cb83SAl Viro { 1031d879cb83SAl Viro struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); 1032d879cb83SAl Viro if (!p) 1033d879cb83SAl Viro p = vmalloc(n * sizeof(struct page *)); 1034d879cb83SAl Viro return p; 1035d879cb83SAl Viro } 1036d879cb83SAl Viro 1037241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1038241699cdSAl Viro struct page ***pages, size_t maxsize, 1039241699cdSAl Viro size_t *start) 1040241699cdSAl Viro { 1041241699cdSAl Viro struct page **p; 1042241699cdSAl Viro size_t n; 1043241699cdSAl Viro int idx; 1044241699cdSAl Viro int npages; 1045241699cdSAl Viro 104633844e66SAl Viro if (!maxsize) 104733844e66SAl Viro return 0; 104833844e66SAl Viro 1049241699cdSAl Viro if (!sanity(i)) 1050241699cdSAl Viro return -EFAULT; 1051241699cdSAl Viro 1052241699cdSAl Viro data_start(i, &idx, start); 1053241699cdSAl Viro /* some of this one + all after this one */ 1054241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1055241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1056241699cdSAl Viro if (maxsize > n) 1057241699cdSAl Viro maxsize = n; 1058241699cdSAl Viro else 1059241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1060241699cdSAl Viro p = get_pages_array(npages); 1061241699cdSAl Viro if (!p) 1062241699cdSAl Viro return -ENOMEM; 1063241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 1064241699cdSAl Viro if (n > 0) 1065241699cdSAl Viro *pages = p; 1066241699cdSAl Viro else 1067241699cdSAl Viro kvfree(p); 1068241699cdSAl Viro return n; 1069241699cdSAl Viro } 1070241699cdSAl Viro 1071d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1072d879cb83SAl Viro struct page ***pages, size_t maxsize, 1073d879cb83SAl Viro size_t *start) 1074d879cb83SAl Viro { 1075d879cb83SAl Viro struct page **p; 1076d879cb83SAl Viro 1077d879cb83SAl Viro if (maxsize > i->count) 1078d879cb83SAl Viro maxsize = i->count; 1079d879cb83SAl Viro 1080241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1081241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 1082d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1083d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1084d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1085d879cb83SAl Viro int n; 1086d879cb83SAl Viro int res; 1087d879cb83SAl Viro 1088d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1089d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1090d879cb83SAl Viro p = get_pages_array(n); 1091d879cb83SAl Viro if (!p) 1092d879cb83SAl Viro return -ENOMEM; 1093d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); 1094d879cb83SAl Viro if (unlikely(res < 0)) { 1095d879cb83SAl Viro kvfree(p); 1096d879cb83SAl Viro return res; 1097d879cb83SAl Viro } 1098d879cb83SAl Viro *pages = p; 1099d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1100d879cb83SAl Viro 0;}),({ 1101d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1102d879cb83SAl Viro *start = v.bv_offset; 1103d879cb83SAl Viro *pages = p = get_pages_array(1); 1104d879cb83SAl Viro if (!p) 1105d879cb83SAl Viro return -ENOMEM; 1106d879cb83SAl Viro get_page(*p = v.bv_page); 1107d879cb83SAl Viro return v.bv_len; 1108d879cb83SAl Viro }),({ 1109d879cb83SAl Viro return -EFAULT; 1110d879cb83SAl Viro }) 1111d879cb83SAl Viro ) 1112d879cb83SAl Viro return 0; 1113d879cb83SAl Viro } 1114d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1115d879cb83SAl Viro 1116d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1117d879cb83SAl Viro struct iov_iter *i) 1118d879cb83SAl Viro { 1119d879cb83SAl Viro char *to = addr; 1120d879cb83SAl Viro __wsum sum, next; 1121d879cb83SAl Viro size_t off = 0; 1122d879cb83SAl Viro sum = *csum; 1123241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1124241699cdSAl Viro WARN_ON(1); 1125241699cdSAl Viro return 0; 1126241699cdSAl Viro } 1127d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1128d879cb83SAl Viro int err = 0; 1129d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1130d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1131d879cb83SAl Viro v.iov_len, 0, &err); 1132d879cb83SAl Viro if (!err) { 1133d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1134d879cb83SAl Viro off += v.iov_len; 1135d879cb83SAl Viro } 1136d879cb83SAl Viro err ? v.iov_len : 0; 1137d879cb83SAl Viro }), ({ 1138d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1139d879cb83SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1140d879cb83SAl Viro (to += v.bv_len) - v.bv_len, 1141d879cb83SAl Viro v.bv_len, 0); 1142d879cb83SAl Viro kunmap_atomic(p); 1143d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1144d879cb83SAl Viro off += v.bv_len; 1145d879cb83SAl Viro }),({ 1146d879cb83SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1147d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1148d879cb83SAl Viro v.iov_len, 0); 1149d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1150d879cb83SAl Viro off += v.iov_len; 1151d879cb83SAl Viro }) 1152d879cb83SAl Viro ) 1153d879cb83SAl Viro *csum = sum; 1154d879cb83SAl Viro return bytes; 1155d879cb83SAl Viro } 1156d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1157d879cb83SAl Viro 1158cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1159cbbd26b8SAl Viro struct iov_iter *i) 1160cbbd26b8SAl Viro { 1161cbbd26b8SAl Viro char *to = addr; 1162cbbd26b8SAl Viro __wsum sum, next; 1163cbbd26b8SAl Viro size_t off = 0; 1164cbbd26b8SAl Viro sum = *csum; 1165cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 1166cbbd26b8SAl Viro WARN_ON(1); 1167cbbd26b8SAl Viro return false; 1168cbbd26b8SAl Viro } 1169cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1170cbbd26b8SAl Viro return false; 1171cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1172cbbd26b8SAl Viro int err = 0; 1173cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1174cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1175cbbd26b8SAl Viro v.iov_len, 0, &err); 1176cbbd26b8SAl Viro if (err) 1177cbbd26b8SAl Viro return false; 1178cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1179cbbd26b8SAl Viro off += v.iov_len; 1180cbbd26b8SAl Viro 0; 1181cbbd26b8SAl Viro }), ({ 1182cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1183cbbd26b8SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1184cbbd26b8SAl Viro (to += v.bv_len) - v.bv_len, 1185cbbd26b8SAl Viro v.bv_len, 0); 1186cbbd26b8SAl Viro kunmap_atomic(p); 1187cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1188cbbd26b8SAl Viro off += v.bv_len; 1189cbbd26b8SAl Viro }),({ 1190cbbd26b8SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1191cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1192cbbd26b8SAl Viro v.iov_len, 0); 1193cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1194cbbd26b8SAl Viro off += v.iov_len; 1195cbbd26b8SAl Viro }) 1196cbbd26b8SAl Viro ) 1197cbbd26b8SAl Viro *csum = sum; 1198cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1199cbbd26b8SAl Viro return true; 1200cbbd26b8SAl Viro } 1201cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1202cbbd26b8SAl Viro 120336f7a8a4SAl Viro size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, 1204d879cb83SAl Viro struct iov_iter *i) 1205d879cb83SAl Viro { 120636f7a8a4SAl Viro const char *from = addr; 1207d879cb83SAl Viro __wsum sum, next; 1208d879cb83SAl Viro size_t off = 0; 1209d879cb83SAl Viro sum = *csum; 1210241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1211241699cdSAl Viro WARN_ON(1); /* for now */ 1212241699cdSAl Viro return 0; 1213241699cdSAl Viro } 1214d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1215d879cb83SAl Viro int err = 0; 1216d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1217d879cb83SAl Viro v.iov_base, 1218d879cb83SAl Viro v.iov_len, 0, &err); 1219d879cb83SAl Viro if (!err) { 1220d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1221d879cb83SAl Viro off += v.iov_len; 1222d879cb83SAl Viro } 1223d879cb83SAl Viro err ? v.iov_len : 0; 1224d879cb83SAl Viro }), ({ 1225d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1226d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, 1227d879cb83SAl Viro p + v.bv_offset, 1228d879cb83SAl Viro v.bv_len, 0); 1229d879cb83SAl Viro kunmap_atomic(p); 1230d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1231d879cb83SAl Viro off += v.bv_len; 1232d879cb83SAl Viro }),({ 1233d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, 1234d879cb83SAl Viro v.iov_base, 1235d879cb83SAl Viro v.iov_len, 0); 1236d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1237d879cb83SAl Viro off += v.iov_len; 1238d879cb83SAl Viro }) 1239d879cb83SAl Viro ) 1240d879cb83SAl Viro *csum = sum; 1241d879cb83SAl Viro return bytes; 1242d879cb83SAl Viro } 1243d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1244d879cb83SAl Viro 1245d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1246d879cb83SAl Viro { 1247d879cb83SAl Viro size_t size = i->count; 1248d879cb83SAl Viro int npages = 0; 1249d879cb83SAl Viro 1250d879cb83SAl Viro if (!size) 1251d879cb83SAl Viro return 0; 1252d879cb83SAl Viro 1253241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1254241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1255241699cdSAl Viro size_t off; 1256241699cdSAl Viro int idx; 1257241699cdSAl Viro 1258241699cdSAl Viro if (!sanity(i)) 1259241699cdSAl Viro return 0; 1260241699cdSAl Viro 1261241699cdSAl Viro data_start(i, &idx, &off); 1262241699cdSAl Viro /* some of this one + all after this one */ 1263241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1264241699cdSAl Viro if (npages >= maxpages) 1265241699cdSAl Viro return maxpages; 1266241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1267d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1268d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1269d879cb83SAl Viro - p / PAGE_SIZE; 1270d879cb83SAl Viro if (npages >= maxpages) 1271d879cb83SAl Viro return maxpages; 1272d879cb83SAl Viro 0;}),({ 1273d879cb83SAl Viro npages++; 1274d879cb83SAl Viro if (npages >= maxpages) 1275d879cb83SAl Viro return maxpages; 1276d879cb83SAl Viro }),({ 1277d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1278d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1279d879cb83SAl Viro - p / PAGE_SIZE; 1280d879cb83SAl Viro if (npages >= maxpages) 1281d879cb83SAl Viro return maxpages; 1282d879cb83SAl Viro }) 1283d879cb83SAl Viro ) 1284d879cb83SAl Viro return npages; 1285d879cb83SAl Viro } 1286d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1287d879cb83SAl Viro 1288d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1289d879cb83SAl Viro { 1290d879cb83SAl Viro *new = *old; 1291241699cdSAl Viro if (unlikely(new->type & ITER_PIPE)) { 1292241699cdSAl Viro WARN_ON(1); 1293241699cdSAl Viro return NULL; 1294241699cdSAl Viro } 1295d879cb83SAl Viro if (new->type & ITER_BVEC) 1296d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1297d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1298d879cb83SAl Viro flags); 1299d879cb83SAl Viro else 1300d879cb83SAl Viro /* iovec and kvec have identical layout */ 1301d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1302d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1303d879cb83SAl Viro flags); 1304d879cb83SAl Viro } 1305d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1306bc917be8SAl Viro 1307ffecee4fSVegard Nossum /** 1308ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1309ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1310ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1311ffecee4fSVegard Nossum * 1312ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1313ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1314ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1315ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1316ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1317ffecee4fSVegard Nossum * on-stack) kernel array. 1318ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1319ffecee4fSVegard Nossum * 1320ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1321ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1322ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1323ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1324ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1325ffecee4fSVegard Nossum * returns an error or not). 1326ffecee4fSVegard Nossum * 1327ffecee4fSVegard Nossum * Return: 0 on success or negative error code on error. 1328ffecee4fSVegard Nossum */ 1329bc917be8SAl Viro int import_iovec(int type, const struct iovec __user * uvector, 1330bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1331bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1332bc917be8SAl Viro { 1333bc917be8SAl Viro ssize_t n; 1334bc917be8SAl Viro struct iovec *p; 1335bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1336bc917be8SAl Viro *iov, &p); 1337bc917be8SAl Viro if (n < 0) { 1338bc917be8SAl Viro if (p != *iov) 1339bc917be8SAl Viro kfree(p); 1340bc917be8SAl Viro *iov = NULL; 1341bc917be8SAl Viro return n; 1342bc917be8SAl Viro } 1343bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1344bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1345bc917be8SAl Viro return 0; 1346bc917be8SAl Viro } 1347bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1348bc917be8SAl Viro 1349bc917be8SAl Viro #ifdef CONFIG_COMPAT 1350bc917be8SAl Viro #include <linux/compat.h> 1351bc917be8SAl Viro 1352bc917be8SAl Viro int compat_import_iovec(int type, const struct compat_iovec __user * uvector, 1353bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1354bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1355bc917be8SAl Viro { 1356bc917be8SAl Viro ssize_t n; 1357bc917be8SAl Viro struct iovec *p; 1358bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1359bc917be8SAl Viro *iov, &p); 1360bc917be8SAl Viro if (n < 0) { 1361bc917be8SAl Viro if (p != *iov) 1362bc917be8SAl Viro kfree(p); 1363bc917be8SAl Viro *iov = NULL; 1364bc917be8SAl Viro return n; 1365bc917be8SAl Viro } 1366bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1367bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1368bc917be8SAl Viro return 0; 1369bc917be8SAl Viro } 1370bc917be8SAl Viro #endif 1371bc917be8SAl Viro 1372bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1373bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1374bc917be8SAl Viro { 1375bc917be8SAl Viro if (len > MAX_RW_COUNT) 1376bc917be8SAl Viro len = MAX_RW_COUNT; 1377bc917be8SAl Viro if (unlikely(!access_ok(!rw, buf, len))) 1378bc917be8SAl Viro return -EFAULT; 1379bc917be8SAl Viro 1380bc917be8SAl Viro iov->iov_base = buf; 1381bc917be8SAl Viro iov->iov_len = len; 1382bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1383bc917be8SAl Viro return 0; 1384bc917be8SAl Viro } 1385e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 1386