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... */ 416db68ce10SAl Viro if (uaccess_kernel()) { 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, 6073f763453SAl Viro __copy_from_user_inatomic_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 6180aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 6190aed55afSDan Williams size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 6200aed55afSDan Williams { 6210aed55afSDan Williams char *to = addr; 6220aed55afSDan Williams if (unlikely(i->type & ITER_PIPE)) { 6230aed55afSDan Williams WARN_ON(1); 6240aed55afSDan Williams return 0; 6250aed55afSDan Williams } 6260aed55afSDan Williams iterate_and_advance(i, bytes, v, 6270aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 6280aed55afSDan Williams v.iov_base, v.iov_len), 6290aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 6300aed55afSDan Williams v.bv_offset, v.bv_len), 6310aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 6320aed55afSDan Williams v.iov_len) 6330aed55afSDan Williams ) 6340aed55afSDan Williams 6350aed55afSDan Williams return bytes; 6360aed55afSDan Williams } 6370aed55afSDan Williams EXPORT_SYMBOL_GPL(copy_from_iter_flushcache); 6380aed55afSDan Williams #endif 6390aed55afSDan Williams 640cbbd26b8SAl Viro bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 641cbbd26b8SAl Viro { 642cbbd26b8SAl Viro char *to = addr; 643cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 644cbbd26b8SAl Viro WARN_ON(1); 645cbbd26b8SAl Viro return false; 646cbbd26b8SAl Viro } 64733844e66SAl Viro if (unlikely(i->count < bytes)) 648cbbd26b8SAl Viro return false; 649cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 6503f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 651cbbd26b8SAl Viro v.iov_base, v.iov_len)) 652cbbd26b8SAl Viro return false; 653cbbd26b8SAl Viro 0;}), 654cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 655cbbd26b8SAl Viro v.bv_offset, v.bv_len), 656cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 657cbbd26b8SAl Viro ) 658cbbd26b8SAl Viro 659cbbd26b8SAl Viro iov_iter_advance(i, bytes); 660cbbd26b8SAl Viro return true; 661cbbd26b8SAl Viro } 662cbbd26b8SAl Viro EXPORT_SYMBOL(copy_from_iter_full_nocache); 663cbbd26b8SAl Viro 664d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 665d879cb83SAl Viro struct iov_iter *i) 666d879cb83SAl Viro { 667d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 668d879cb83SAl Viro void *kaddr = kmap_atomic(page); 669d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 670d879cb83SAl Viro kunmap_atomic(kaddr); 671d879cb83SAl Viro return wanted; 672241699cdSAl Viro } else if (likely(!(i->type & ITER_PIPE))) 673d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 674241699cdSAl Viro else 675241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 676d879cb83SAl Viro } 677d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 678d879cb83SAl Viro 679d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 680d879cb83SAl Viro struct iov_iter *i) 681d879cb83SAl Viro { 682241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 683241699cdSAl Viro WARN_ON(1); 684241699cdSAl Viro return 0; 685241699cdSAl Viro } 686d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 687d879cb83SAl Viro void *kaddr = kmap_atomic(page); 688d879cb83SAl Viro size_t wanted = copy_from_iter(kaddr + offset, bytes, i); 689d879cb83SAl Viro kunmap_atomic(kaddr); 690d879cb83SAl Viro return wanted; 691d879cb83SAl Viro } else 692d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 693d879cb83SAl Viro } 694d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 695d879cb83SAl Viro 696241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 697241699cdSAl Viro { 698241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 699241699cdSAl Viro size_t n, off; 700241699cdSAl Viro int idx; 701241699cdSAl Viro 702241699cdSAl Viro if (!sanity(i)) 703241699cdSAl Viro return 0; 704241699cdSAl Viro 705241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 706241699cdSAl Viro if (unlikely(!n)) 707241699cdSAl Viro return 0; 708241699cdSAl Viro 709241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 710241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 711241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 712241699cdSAl Viro i->idx = idx; 713241699cdSAl Viro i->iov_offset = off + chunk; 714241699cdSAl Viro n -= chunk; 715241699cdSAl Viro } 716241699cdSAl Viro i->count -= bytes; 717241699cdSAl Viro return bytes; 718241699cdSAl Viro } 719241699cdSAl Viro 720d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 721d879cb83SAl Viro { 722241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 723241699cdSAl Viro return pipe_zero(bytes, i); 724d879cb83SAl Viro iterate_and_advance(i, bytes, v, 725d879cb83SAl Viro __clear_user(v.iov_base, v.iov_len), 726d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 727d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 728d879cb83SAl Viro ) 729d879cb83SAl Viro 730d879cb83SAl Viro return bytes; 731d879cb83SAl Viro } 732d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 733d879cb83SAl Viro 734d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 735d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 736d879cb83SAl Viro { 737d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 738241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 739241699cdSAl Viro kunmap_atomic(kaddr); 740241699cdSAl Viro WARN_ON(1); 741241699cdSAl Viro return 0; 742241699cdSAl Viro } 743d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 744d879cb83SAl Viro __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, 745d879cb83SAl Viro v.iov_base, v.iov_len), 746d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 747d879cb83SAl Viro v.bv_offset, v.bv_len), 748d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 749d879cb83SAl Viro ) 750d879cb83SAl Viro kunmap_atomic(kaddr); 751d879cb83SAl Viro return bytes; 752d879cb83SAl Viro } 753d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 754d879cb83SAl Viro 755b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 756241699cdSAl Viro { 757241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 758241699cdSAl Viro if (pipe->nrbufs) { 759b9dc6f65SAl Viro size_t off = i->iov_offset; 760b9dc6f65SAl Viro int idx = i->idx; 761b9dc6f65SAl Viro int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); 762b9dc6f65SAl Viro if (off) { 763b9dc6f65SAl Viro pipe->bufs[idx].len = off - pipe->bufs[idx].offset; 764b9dc6f65SAl Viro idx = next_idx(idx, pipe); 765b9dc6f65SAl Viro nrbufs++; 766b9dc6f65SAl Viro } 767b9dc6f65SAl Viro while (pipe->nrbufs > nrbufs) { 768a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 769241699cdSAl Viro idx = next_idx(idx, pipe); 770241699cdSAl Viro pipe->nrbufs--; 771241699cdSAl Viro } 772241699cdSAl Viro } 773b9dc6f65SAl Viro } 774b9dc6f65SAl Viro 775b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 776b9dc6f65SAl Viro { 777b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 778b9dc6f65SAl Viro if (unlikely(i->count < size)) 779b9dc6f65SAl Viro size = i->count; 780b9dc6f65SAl Viro if (size) { 781b9dc6f65SAl Viro struct pipe_buffer *buf; 782b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 783b9dc6f65SAl Viro int idx = i->idx; 784b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 785b9dc6f65SAl Viro left += off - pipe->bufs[idx].offset; 786b9dc6f65SAl Viro while (1) { 787b9dc6f65SAl Viro buf = &pipe->bufs[idx]; 788b9dc6f65SAl Viro if (left <= buf->len) 789b9dc6f65SAl Viro break; 790b9dc6f65SAl Viro left -= buf->len; 791b9dc6f65SAl Viro idx = next_idx(idx, pipe); 792b9dc6f65SAl Viro } 793b9dc6f65SAl Viro i->idx = idx; 794b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 795b9dc6f65SAl Viro } 796b9dc6f65SAl Viro i->count -= size; 797b9dc6f65SAl Viro /* ... and discard everything past that point */ 798b9dc6f65SAl Viro pipe_truncate(i); 799241699cdSAl Viro } 800241699cdSAl Viro 801d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 802d879cb83SAl Viro { 803241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 804241699cdSAl Viro pipe_advance(i, size); 805241699cdSAl Viro return; 806241699cdSAl Viro } 807d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 808d879cb83SAl Viro } 809d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 810d879cb83SAl Viro 81127c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 81227c0e374SAl Viro { 81327c0e374SAl Viro if (!unroll) 81427c0e374SAl Viro return; 8155b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 8165b47d59aSAl Viro return; 81727c0e374SAl Viro i->count += unroll; 81827c0e374SAl Viro if (unlikely(i->type & ITER_PIPE)) { 81927c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 82027c0e374SAl Viro int idx = i->idx; 82127c0e374SAl Viro size_t off = i->iov_offset; 82227c0e374SAl Viro while (1) { 82327c0e374SAl Viro size_t n = off - pipe->bufs[idx].offset; 82427c0e374SAl Viro if (unroll < n) { 8254fa55cefSAl Viro off -= unroll; 82627c0e374SAl Viro break; 82727c0e374SAl Viro } 82827c0e374SAl Viro unroll -= n; 82927c0e374SAl Viro if (!unroll && idx == i->start_idx) { 83027c0e374SAl Viro off = 0; 83127c0e374SAl Viro break; 83227c0e374SAl Viro } 83327c0e374SAl Viro if (!idx--) 83427c0e374SAl Viro idx = pipe->buffers - 1; 83527c0e374SAl Viro off = pipe->bufs[idx].offset + pipe->bufs[idx].len; 83627c0e374SAl Viro } 83727c0e374SAl Viro i->iov_offset = off; 83827c0e374SAl Viro i->idx = idx; 83927c0e374SAl Viro pipe_truncate(i); 84027c0e374SAl Viro return; 84127c0e374SAl Viro } 84227c0e374SAl Viro if (unroll <= i->iov_offset) { 84327c0e374SAl Viro i->iov_offset -= unroll; 84427c0e374SAl Viro return; 84527c0e374SAl Viro } 84627c0e374SAl Viro unroll -= i->iov_offset; 84727c0e374SAl Viro if (i->type & ITER_BVEC) { 84827c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 84927c0e374SAl Viro while (1) { 85027c0e374SAl Viro size_t n = (--bvec)->bv_len; 85127c0e374SAl Viro i->nr_segs++; 85227c0e374SAl Viro if (unroll <= n) { 85327c0e374SAl Viro i->bvec = bvec; 85427c0e374SAl Viro i->iov_offset = n - unroll; 85527c0e374SAl Viro return; 85627c0e374SAl Viro } 85727c0e374SAl Viro unroll -= n; 85827c0e374SAl Viro } 85927c0e374SAl Viro } else { /* same logics for iovec and kvec */ 86027c0e374SAl Viro const struct iovec *iov = i->iov; 86127c0e374SAl Viro while (1) { 86227c0e374SAl Viro size_t n = (--iov)->iov_len; 86327c0e374SAl Viro i->nr_segs++; 86427c0e374SAl Viro if (unroll <= n) { 86527c0e374SAl Viro i->iov = iov; 86627c0e374SAl Viro i->iov_offset = n - unroll; 86727c0e374SAl Viro return; 86827c0e374SAl Viro } 86927c0e374SAl Viro unroll -= n; 87027c0e374SAl Viro } 87127c0e374SAl Viro } 87227c0e374SAl Viro } 87327c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 87427c0e374SAl Viro 875d879cb83SAl Viro /* 876d879cb83SAl Viro * Return the count of just the current iov_iter segment. 877d879cb83SAl Viro */ 878d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 879d879cb83SAl Viro { 880241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 881241699cdSAl Viro return i->count; // it is a silly place, anyway 882d879cb83SAl Viro if (i->nr_segs == 1) 883d879cb83SAl Viro return i->count; 884d879cb83SAl Viro else if (i->type & ITER_BVEC) 885d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 886d879cb83SAl Viro else 887d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 888d879cb83SAl Viro } 889d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 890d879cb83SAl Viro 891d879cb83SAl Viro void iov_iter_kvec(struct iov_iter *i, int direction, 892d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 893d879cb83SAl Viro size_t count) 894d879cb83SAl Viro { 895d879cb83SAl Viro BUG_ON(!(direction & ITER_KVEC)); 896d879cb83SAl Viro i->type = direction; 897d879cb83SAl Viro i->kvec = kvec; 898d879cb83SAl Viro i->nr_segs = nr_segs; 899d879cb83SAl Viro i->iov_offset = 0; 900d879cb83SAl Viro i->count = count; 901d879cb83SAl Viro } 902d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 903d879cb83SAl Viro 904d879cb83SAl Viro void iov_iter_bvec(struct iov_iter *i, int direction, 905d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 906d879cb83SAl Viro size_t count) 907d879cb83SAl Viro { 908d879cb83SAl Viro BUG_ON(!(direction & ITER_BVEC)); 909d879cb83SAl Viro i->type = direction; 910d879cb83SAl Viro i->bvec = bvec; 911d879cb83SAl Viro i->nr_segs = nr_segs; 912d879cb83SAl Viro i->iov_offset = 0; 913d879cb83SAl Viro i->count = count; 914d879cb83SAl Viro } 915d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 916d879cb83SAl Viro 917241699cdSAl Viro void iov_iter_pipe(struct iov_iter *i, int direction, 918241699cdSAl Viro struct pipe_inode_info *pipe, 919241699cdSAl Viro size_t count) 920241699cdSAl Viro { 921241699cdSAl Viro BUG_ON(direction != ITER_PIPE); 922b9dc6f65SAl Viro WARN_ON(pipe->nrbufs == pipe->buffers); 923241699cdSAl Viro i->type = direction; 924241699cdSAl Viro i->pipe = pipe; 925241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 926241699cdSAl Viro i->iov_offset = 0; 927241699cdSAl Viro i->count = count; 92827c0e374SAl Viro i->start_idx = i->idx; 929241699cdSAl Viro } 930241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 931241699cdSAl Viro 932d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 933d879cb83SAl Viro { 934d879cb83SAl Viro unsigned long res = 0; 935d879cb83SAl Viro size_t size = i->count; 936d879cb83SAl Viro 937241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 93833844e66SAl Viro if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 939241699cdSAl Viro return size | i->iov_offset; 940241699cdSAl Viro return size; 941241699cdSAl Viro } 942d879cb83SAl Viro iterate_all_kinds(i, size, v, 943d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 944d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 945d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 946d879cb83SAl Viro ) 947d879cb83SAl Viro return res; 948d879cb83SAl Viro } 949d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 950d879cb83SAl Viro 951357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 952357f435dSAl Viro { 953357f435dSAl Viro unsigned long res = 0; 954357f435dSAl Viro size_t size = i->count; 955357f435dSAl Viro 956241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 957241699cdSAl Viro WARN_ON(1); 958241699cdSAl Viro return ~0U; 959241699cdSAl Viro } 960241699cdSAl Viro 961357f435dSAl Viro iterate_all_kinds(i, size, v, 962357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 963357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 964357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 965357f435dSAl Viro (size != v.bv_len ? size : 0)), 966357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 967357f435dSAl Viro (size != v.iov_len ? size : 0)) 968357f435dSAl Viro ); 969357f435dSAl Viro return res; 970357f435dSAl Viro } 971357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 972357f435dSAl Viro 973241699cdSAl Viro static inline size_t __pipe_get_pages(struct iov_iter *i, 974241699cdSAl Viro size_t maxsize, 975241699cdSAl Viro struct page **pages, 976241699cdSAl Viro int idx, 977241699cdSAl Viro size_t *start) 978241699cdSAl Viro { 979241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9801689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 981241699cdSAl Viro if (!n) 982241699cdSAl Viro return -EFAULT; 983241699cdSAl Viro 984241699cdSAl Viro maxsize = n; 985241699cdSAl Viro n += *start; 9861689c73aSAl Viro while (n > 0) { 987241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 988241699cdSAl Viro idx = next_idx(idx, pipe); 989241699cdSAl Viro n -= PAGE_SIZE; 990241699cdSAl Viro } 991241699cdSAl Viro 992241699cdSAl Viro return maxsize; 993241699cdSAl Viro } 994241699cdSAl Viro 995241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 996241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 997241699cdSAl Viro size_t *start) 998241699cdSAl Viro { 999241699cdSAl Viro unsigned npages; 1000241699cdSAl Viro size_t capacity; 1001241699cdSAl Viro int idx; 1002241699cdSAl Viro 100333844e66SAl Viro if (!maxsize) 100433844e66SAl Viro return 0; 100533844e66SAl Viro 1006241699cdSAl Viro if (!sanity(i)) 1007241699cdSAl Viro return -EFAULT; 1008241699cdSAl Viro 1009241699cdSAl Viro data_start(i, &idx, start); 1010241699cdSAl Viro /* some of this one + all after this one */ 1011241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1012241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 1013241699cdSAl Viro 1014241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 1015241699cdSAl Viro } 1016241699cdSAl Viro 1017d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1018d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1019d879cb83SAl Viro size_t *start) 1020d879cb83SAl Viro { 1021d879cb83SAl Viro if (maxsize > i->count) 1022d879cb83SAl Viro maxsize = i->count; 1023d879cb83SAl Viro 1024241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1025241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 1026d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1027d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1028d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1029d879cb83SAl Viro int n; 1030d879cb83SAl Viro int res; 1031d879cb83SAl Viro 1032d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1033d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1034d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1035d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1036d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); 1037d879cb83SAl Viro if (unlikely(res < 0)) 1038d879cb83SAl Viro return res; 1039d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1040d879cb83SAl Viro 0;}),({ 1041d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1042d879cb83SAl Viro *start = v.bv_offset; 1043d879cb83SAl Viro get_page(*pages = v.bv_page); 1044d879cb83SAl Viro return v.bv_len; 1045d879cb83SAl Viro }),({ 1046d879cb83SAl Viro return -EFAULT; 1047d879cb83SAl Viro }) 1048d879cb83SAl Viro ) 1049d879cb83SAl Viro return 0; 1050d879cb83SAl Viro } 1051d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1052d879cb83SAl Viro 1053d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1054d879cb83SAl Viro { 1055752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1056d879cb83SAl Viro } 1057d879cb83SAl Viro 1058241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1059241699cdSAl Viro struct page ***pages, size_t maxsize, 1060241699cdSAl Viro size_t *start) 1061241699cdSAl Viro { 1062241699cdSAl Viro struct page **p; 1063241699cdSAl Viro size_t n; 1064241699cdSAl Viro int idx; 1065241699cdSAl Viro int npages; 1066241699cdSAl Viro 106733844e66SAl Viro if (!maxsize) 106833844e66SAl Viro return 0; 106933844e66SAl Viro 1070241699cdSAl Viro if (!sanity(i)) 1071241699cdSAl Viro return -EFAULT; 1072241699cdSAl Viro 1073241699cdSAl Viro data_start(i, &idx, start); 1074241699cdSAl Viro /* some of this one + all after this one */ 1075241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1076241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1077241699cdSAl Viro if (maxsize > n) 1078241699cdSAl Viro maxsize = n; 1079241699cdSAl Viro else 1080241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1081241699cdSAl Viro p = get_pages_array(npages); 1082241699cdSAl Viro if (!p) 1083241699cdSAl Viro return -ENOMEM; 1084241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 1085241699cdSAl Viro if (n > 0) 1086241699cdSAl Viro *pages = p; 1087241699cdSAl Viro else 1088241699cdSAl Viro kvfree(p); 1089241699cdSAl Viro return n; 1090241699cdSAl Viro } 1091241699cdSAl Viro 1092d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1093d879cb83SAl Viro struct page ***pages, size_t maxsize, 1094d879cb83SAl Viro size_t *start) 1095d879cb83SAl Viro { 1096d879cb83SAl Viro struct page **p; 1097d879cb83SAl Viro 1098d879cb83SAl Viro if (maxsize > i->count) 1099d879cb83SAl Viro maxsize = i->count; 1100d879cb83SAl Viro 1101241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1102241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 1103d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1104d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1105d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1106d879cb83SAl Viro int n; 1107d879cb83SAl Viro int res; 1108d879cb83SAl Viro 1109d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1110d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1111d879cb83SAl Viro p = get_pages_array(n); 1112d879cb83SAl Viro if (!p) 1113d879cb83SAl Viro return -ENOMEM; 1114d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); 1115d879cb83SAl Viro if (unlikely(res < 0)) { 1116d879cb83SAl Viro kvfree(p); 1117d879cb83SAl Viro return res; 1118d879cb83SAl Viro } 1119d879cb83SAl Viro *pages = p; 1120d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1121d879cb83SAl Viro 0;}),({ 1122d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1123d879cb83SAl Viro *start = v.bv_offset; 1124d879cb83SAl Viro *pages = p = get_pages_array(1); 1125d879cb83SAl Viro if (!p) 1126d879cb83SAl Viro return -ENOMEM; 1127d879cb83SAl Viro get_page(*p = v.bv_page); 1128d879cb83SAl Viro return v.bv_len; 1129d879cb83SAl Viro }),({ 1130d879cb83SAl Viro return -EFAULT; 1131d879cb83SAl Viro }) 1132d879cb83SAl Viro ) 1133d879cb83SAl Viro return 0; 1134d879cb83SAl Viro } 1135d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1136d879cb83SAl Viro 1137d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1138d879cb83SAl Viro struct iov_iter *i) 1139d879cb83SAl Viro { 1140d879cb83SAl Viro char *to = addr; 1141d879cb83SAl Viro __wsum sum, next; 1142d879cb83SAl Viro size_t off = 0; 1143d879cb83SAl Viro sum = *csum; 1144241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1145241699cdSAl Viro WARN_ON(1); 1146241699cdSAl Viro return 0; 1147241699cdSAl Viro } 1148d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1149d879cb83SAl Viro int err = 0; 1150d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1151d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1152d879cb83SAl Viro v.iov_len, 0, &err); 1153d879cb83SAl Viro if (!err) { 1154d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1155d879cb83SAl Viro off += v.iov_len; 1156d879cb83SAl Viro } 1157d879cb83SAl Viro err ? v.iov_len : 0; 1158d879cb83SAl Viro }), ({ 1159d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1160d879cb83SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1161d879cb83SAl Viro (to += v.bv_len) - v.bv_len, 1162d879cb83SAl Viro v.bv_len, 0); 1163d879cb83SAl Viro kunmap_atomic(p); 1164d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1165d879cb83SAl Viro off += v.bv_len; 1166d879cb83SAl Viro }),({ 1167d879cb83SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1168d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1169d879cb83SAl Viro v.iov_len, 0); 1170d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1171d879cb83SAl Viro off += v.iov_len; 1172d879cb83SAl Viro }) 1173d879cb83SAl Viro ) 1174d879cb83SAl Viro *csum = sum; 1175d879cb83SAl Viro return bytes; 1176d879cb83SAl Viro } 1177d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1178d879cb83SAl Viro 1179cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1180cbbd26b8SAl Viro struct iov_iter *i) 1181cbbd26b8SAl Viro { 1182cbbd26b8SAl Viro char *to = addr; 1183cbbd26b8SAl Viro __wsum sum, next; 1184cbbd26b8SAl Viro size_t off = 0; 1185cbbd26b8SAl Viro sum = *csum; 1186cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 1187cbbd26b8SAl Viro WARN_ON(1); 1188cbbd26b8SAl Viro return false; 1189cbbd26b8SAl Viro } 1190cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1191cbbd26b8SAl Viro return false; 1192cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1193cbbd26b8SAl Viro int err = 0; 1194cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1195cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1196cbbd26b8SAl Viro v.iov_len, 0, &err); 1197cbbd26b8SAl Viro if (err) 1198cbbd26b8SAl Viro return false; 1199cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1200cbbd26b8SAl Viro off += v.iov_len; 1201cbbd26b8SAl Viro 0; 1202cbbd26b8SAl Viro }), ({ 1203cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1204cbbd26b8SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1205cbbd26b8SAl Viro (to += v.bv_len) - v.bv_len, 1206cbbd26b8SAl Viro v.bv_len, 0); 1207cbbd26b8SAl Viro kunmap_atomic(p); 1208cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1209cbbd26b8SAl Viro off += v.bv_len; 1210cbbd26b8SAl Viro }),({ 1211cbbd26b8SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1212cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1213cbbd26b8SAl Viro v.iov_len, 0); 1214cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1215cbbd26b8SAl Viro off += v.iov_len; 1216cbbd26b8SAl Viro }) 1217cbbd26b8SAl Viro ) 1218cbbd26b8SAl Viro *csum = sum; 1219cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1220cbbd26b8SAl Viro return true; 1221cbbd26b8SAl Viro } 1222cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1223cbbd26b8SAl Viro 122436f7a8a4SAl Viro size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, 1225d879cb83SAl Viro struct iov_iter *i) 1226d879cb83SAl Viro { 122736f7a8a4SAl Viro const char *from = addr; 1228d879cb83SAl Viro __wsum sum, next; 1229d879cb83SAl Viro size_t off = 0; 1230d879cb83SAl Viro sum = *csum; 1231241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1232241699cdSAl Viro WARN_ON(1); /* for now */ 1233241699cdSAl Viro return 0; 1234241699cdSAl Viro } 1235d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1236d879cb83SAl Viro int err = 0; 1237d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1238d879cb83SAl Viro v.iov_base, 1239d879cb83SAl Viro v.iov_len, 0, &err); 1240d879cb83SAl Viro if (!err) { 1241d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1242d879cb83SAl Viro off += v.iov_len; 1243d879cb83SAl Viro } 1244d879cb83SAl Viro err ? v.iov_len : 0; 1245d879cb83SAl Viro }), ({ 1246d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1247d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, 1248d879cb83SAl Viro p + v.bv_offset, 1249d879cb83SAl Viro v.bv_len, 0); 1250d879cb83SAl Viro kunmap_atomic(p); 1251d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1252d879cb83SAl Viro off += v.bv_len; 1253d879cb83SAl Viro }),({ 1254d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, 1255d879cb83SAl Viro v.iov_base, 1256d879cb83SAl Viro v.iov_len, 0); 1257d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1258d879cb83SAl Viro off += v.iov_len; 1259d879cb83SAl Viro }) 1260d879cb83SAl Viro ) 1261d879cb83SAl Viro *csum = sum; 1262d879cb83SAl Viro return bytes; 1263d879cb83SAl Viro } 1264d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1265d879cb83SAl Viro 1266d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1267d879cb83SAl Viro { 1268d879cb83SAl Viro size_t size = i->count; 1269d879cb83SAl Viro int npages = 0; 1270d879cb83SAl Viro 1271d879cb83SAl Viro if (!size) 1272d879cb83SAl Viro return 0; 1273d879cb83SAl Viro 1274241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1275241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1276241699cdSAl Viro size_t off; 1277241699cdSAl Viro int idx; 1278241699cdSAl Viro 1279241699cdSAl Viro if (!sanity(i)) 1280241699cdSAl Viro return 0; 1281241699cdSAl Viro 1282241699cdSAl Viro data_start(i, &idx, &off); 1283241699cdSAl Viro /* some of this one + all after this one */ 1284241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1285241699cdSAl Viro if (npages >= maxpages) 1286241699cdSAl Viro return maxpages; 1287241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1288d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1289d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1290d879cb83SAl Viro - p / PAGE_SIZE; 1291d879cb83SAl Viro if (npages >= maxpages) 1292d879cb83SAl Viro return maxpages; 1293d879cb83SAl Viro 0;}),({ 1294d879cb83SAl Viro npages++; 1295d879cb83SAl Viro if (npages >= maxpages) 1296d879cb83SAl Viro return maxpages; 1297d879cb83SAl Viro }),({ 1298d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1299d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1300d879cb83SAl Viro - p / PAGE_SIZE; 1301d879cb83SAl Viro if (npages >= maxpages) 1302d879cb83SAl Viro return maxpages; 1303d879cb83SAl Viro }) 1304d879cb83SAl Viro ) 1305d879cb83SAl Viro return npages; 1306d879cb83SAl Viro } 1307d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1308d879cb83SAl Viro 1309d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1310d879cb83SAl Viro { 1311d879cb83SAl Viro *new = *old; 1312241699cdSAl Viro if (unlikely(new->type & ITER_PIPE)) { 1313241699cdSAl Viro WARN_ON(1); 1314241699cdSAl Viro return NULL; 1315241699cdSAl Viro } 1316d879cb83SAl Viro if (new->type & ITER_BVEC) 1317d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1318d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1319d879cb83SAl Viro flags); 1320d879cb83SAl Viro else 1321d879cb83SAl Viro /* iovec and kvec have identical layout */ 1322d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1323d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1324d879cb83SAl Viro flags); 1325d879cb83SAl Viro } 1326d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1327bc917be8SAl Viro 1328ffecee4fSVegard Nossum /** 1329ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1330ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1331ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1332ffecee4fSVegard Nossum * 1333ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1334ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1335ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1336ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1337ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1338ffecee4fSVegard Nossum * on-stack) kernel array. 1339ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1340ffecee4fSVegard Nossum * 1341ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1342ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1343ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1344ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1345ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1346ffecee4fSVegard Nossum * returns an error or not). 1347ffecee4fSVegard Nossum * 1348ffecee4fSVegard Nossum * Return: 0 on success or negative error code on error. 1349ffecee4fSVegard Nossum */ 1350bc917be8SAl Viro int import_iovec(int type, const struct iovec __user * uvector, 1351bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1352bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1353bc917be8SAl Viro { 1354bc917be8SAl Viro ssize_t n; 1355bc917be8SAl Viro struct iovec *p; 1356bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1357bc917be8SAl Viro *iov, &p); 1358bc917be8SAl Viro if (n < 0) { 1359bc917be8SAl Viro if (p != *iov) 1360bc917be8SAl Viro kfree(p); 1361bc917be8SAl Viro *iov = NULL; 1362bc917be8SAl Viro return n; 1363bc917be8SAl Viro } 1364bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1365bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1366bc917be8SAl Viro return 0; 1367bc917be8SAl Viro } 1368bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1369bc917be8SAl Viro 1370bc917be8SAl Viro #ifdef CONFIG_COMPAT 1371bc917be8SAl Viro #include <linux/compat.h> 1372bc917be8SAl Viro 1373bc917be8SAl Viro int compat_import_iovec(int type, const struct compat_iovec __user * uvector, 1374bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1375bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1376bc917be8SAl Viro { 1377bc917be8SAl Viro ssize_t n; 1378bc917be8SAl Viro struct iovec *p; 1379bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1380bc917be8SAl Viro *iov, &p); 1381bc917be8SAl Viro if (n < 0) { 1382bc917be8SAl Viro if (p != *iov) 1383bc917be8SAl Viro kfree(p); 1384bc917be8SAl Viro *iov = NULL; 1385bc917be8SAl Viro return n; 1386bc917be8SAl Viro } 1387bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1388bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1389bc917be8SAl Viro return 0; 1390bc917be8SAl Viro } 1391bc917be8SAl Viro #endif 1392bc917be8SAl Viro 1393bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1394bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1395bc917be8SAl Viro { 1396bc917be8SAl Viro if (len > MAX_RW_COUNT) 1397bc917be8SAl Viro len = MAX_RW_COUNT; 1398bc917be8SAl Viro if (unlikely(!access_ok(!rw, buf, len))) 1399bc917be8SAl Viro return -EFAULT; 1400bc917be8SAl Viro 1401bc917be8SAl Viro iov->iov_base = buf; 1402bc917be8SAl Viro iov->iov_len = len; 1403bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1404bc917be8SAl Viro return 0; 1405bc917be8SAl Viro } 1406e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 1407