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) { \ 76d879cb83SAl Viro size_t skip = i->iov_offset; \ 77d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 78d879cb83SAl Viro struct bio_vec v; \ 791bdc76aeSMing Lei struct bvec_iter __bi; \ 801bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 81d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 82d879cb83SAl Viro const struct kvec *kvec; \ 83d879cb83SAl Viro struct kvec v; \ 84d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 85d879cb83SAl Viro } else { \ 86d879cb83SAl Viro const struct iovec *iov; \ 87d879cb83SAl Viro struct iovec v; \ 88d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 89d879cb83SAl Viro } \ 90d879cb83SAl Viro } 91d879cb83SAl Viro 92d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 93dd254f5aSAl Viro if (unlikely(i->count < n)) \ 94dd254f5aSAl Viro n = i->count; \ 9519f18459SAl Viro if (i->count) { \ 96d879cb83SAl Viro size_t skip = i->iov_offset; \ 97d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 981bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 99d879cb83SAl Viro struct bio_vec v; \ 1001bdc76aeSMing Lei struct bvec_iter __bi; \ 1011bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1021bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1031bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1041bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 105d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 106d879cb83SAl Viro const struct kvec *kvec; \ 107d879cb83SAl Viro struct kvec v; \ 108d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 109d879cb83SAl Viro if (skip == kvec->iov_len) { \ 110d879cb83SAl Viro kvec++; \ 111d879cb83SAl Viro skip = 0; \ 112d879cb83SAl Viro } \ 113d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 114d879cb83SAl Viro i->kvec = kvec; \ 115d879cb83SAl Viro } else { \ 116d879cb83SAl Viro const struct iovec *iov; \ 117d879cb83SAl Viro struct iovec v; \ 118d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 119d879cb83SAl Viro if (skip == iov->iov_len) { \ 120d879cb83SAl Viro iov++; \ 121d879cb83SAl Viro skip = 0; \ 122d879cb83SAl Viro } \ 123d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 124d879cb83SAl Viro i->iov = iov; \ 125d879cb83SAl Viro } \ 126d879cb83SAl Viro i->count -= n; \ 127d879cb83SAl Viro i->iov_offset = skip; \ 128dd254f5aSAl Viro } \ 129d879cb83SAl Viro } 130d879cb83SAl Viro 131d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 132d879cb83SAl Viro struct iov_iter *i) 133d879cb83SAl Viro { 134d879cb83SAl Viro size_t skip, copy, left, wanted; 135d879cb83SAl Viro const struct iovec *iov; 136d879cb83SAl Viro char __user *buf; 137d879cb83SAl Viro void *kaddr, *from; 138d879cb83SAl Viro 139d879cb83SAl Viro if (unlikely(bytes > i->count)) 140d879cb83SAl Viro bytes = i->count; 141d879cb83SAl Viro 142d879cb83SAl Viro if (unlikely(!bytes)) 143d879cb83SAl Viro return 0; 144d879cb83SAl Viro 145d879cb83SAl Viro wanted = bytes; 146d879cb83SAl Viro iov = i->iov; 147d879cb83SAl Viro skip = i->iov_offset; 148d879cb83SAl Viro buf = iov->iov_base + skip; 149d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 150d879cb83SAl Viro 1513fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 152d879cb83SAl Viro kaddr = kmap_atomic(page); 153d879cb83SAl Viro from = kaddr + offset; 154d879cb83SAl Viro 155d879cb83SAl Viro /* first chunk, usually the only one */ 156d879cb83SAl Viro left = __copy_to_user_inatomic(buf, from, copy); 157d879cb83SAl Viro copy -= left; 158d879cb83SAl Viro skip += copy; 159d879cb83SAl Viro from += copy; 160d879cb83SAl Viro bytes -= copy; 161d879cb83SAl Viro 162d879cb83SAl Viro while (unlikely(!left && bytes)) { 163d879cb83SAl Viro iov++; 164d879cb83SAl Viro buf = iov->iov_base; 165d879cb83SAl Viro copy = min(bytes, iov->iov_len); 166d879cb83SAl Viro left = __copy_to_user_inatomic(buf, from, copy); 167d879cb83SAl Viro copy -= left; 168d879cb83SAl Viro skip = copy; 169d879cb83SAl Viro from += copy; 170d879cb83SAl Viro bytes -= copy; 171d879cb83SAl Viro } 172d879cb83SAl Viro if (likely(!bytes)) { 173d879cb83SAl Viro kunmap_atomic(kaddr); 174d879cb83SAl Viro goto done; 175d879cb83SAl Viro } 176d879cb83SAl Viro offset = from - kaddr; 177d879cb83SAl Viro buf += copy; 178d879cb83SAl Viro kunmap_atomic(kaddr); 179d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 180d879cb83SAl Viro } 181d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 1823fa6c507SMikulas Patocka 183d879cb83SAl Viro kaddr = kmap(page); 184d879cb83SAl Viro from = kaddr + offset; 185d879cb83SAl Viro left = __copy_to_user(buf, from, copy); 186d879cb83SAl Viro copy -= left; 187d879cb83SAl Viro skip += copy; 188d879cb83SAl Viro from += copy; 189d879cb83SAl Viro bytes -= copy; 190d879cb83SAl Viro while (unlikely(!left && bytes)) { 191d879cb83SAl Viro iov++; 192d879cb83SAl Viro buf = iov->iov_base; 193d879cb83SAl Viro copy = min(bytes, iov->iov_len); 194d879cb83SAl Viro left = __copy_to_user(buf, from, copy); 195d879cb83SAl Viro copy -= left; 196d879cb83SAl Viro skip = copy; 197d879cb83SAl Viro from += copy; 198d879cb83SAl Viro bytes -= copy; 199d879cb83SAl Viro } 200d879cb83SAl Viro kunmap(page); 2013fa6c507SMikulas Patocka 202d879cb83SAl Viro done: 203d879cb83SAl Viro if (skip == iov->iov_len) { 204d879cb83SAl Viro iov++; 205d879cb83SAl Viro skip = 0; 206d879cb83SAl Viro } 207d879cb83SAl Viro i->count -= wanted - bytes; 208d879cb83SAl Viro i->nr_segs -= iov - i->iov; 209d879cb83SAl Viro i->iov = iov; 210d879cb83SAl Viro i->iov_offset = skip; 211d879cb83SAl Viro return wanted - bytes; 212d879cb83SAl Viro } 213d879cb83SAl Viro 214d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 215d879cb83SAl Viro struct iov_iter *i) 216d879cb83SAl Viro { 217d879cb83SAl Viro size_t skip, copy, left, wanted; 218d879cb83SAl Viro const struct iovec *iov; 219d879cb83SAl Viro char __user *buf; 220d879cb83SAl Viro void *kaddr, *to; 221d879cb83SAl Viro 222d879cb83SAl Viro if (unlikely(bytes > i->count)) 223d879cb83SAl Viro bytes = i->count; 224d879cb83SAl Viro 225d879cb83SAl Viro if (unlikely(!bytes)) 226d879cb83SAl Viro return 0; 227d879cb83SAl Viro 228d879cb83SAl Viro wanted = bytes; 229d879cb83SAl Viro iov = i->iov; 230d879cb83SAl Viro skip = i->iov_offset; 231d879cb83SAl Viro buf = iov->iov_base + skip; 232d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 233d879cb83SAl Viro 2343fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 235d879cb83SAl Viro kaddr = kmap_atomic(page); 236d879cb83SAl Viro to = kaddr + offset; 237d879cb83SAl Viro 238d879cb83SAl Viro /* first chunk, usually the only one */ 239d879cb83SAl Viro left = __copy_from_user_inatomic(to, buf, copy); 240d879cb83SAl Viro copy -= left; 241d879cb83SAl Viro skip += copy; 242d879cb83SAl Viro to += copy; 243d879cb83SAl Viro bytes -= copy; 244d879cb83SAl Viro 245d879cb83SAl Viro while (unlikely(!left && bytes)) { 246d879cb83SAl Viro iov++; 247d879cb83SAl Viro buf = iov->iov_base; 248d879cb83SAl Viro copy = min(bytes, iov->iov_len); 249d879cb83SAl Viro left = __copy_from_user_inatomic(to, buf, copy); 250d879cb83SAl Viro copy -= left; 251d879cb83SAl Viro skip = copy; 252d879cb83SAl Viro to += copy; 253d879cb83SAl Viro bytes -= copy; 254d879cb83SAl Viro } 255d879cb83SAl Viro if (likely(!bytes)) { 256d879cb83SAl Viro kunmap_atomic(kaddr); 257d879cb83SAl Viro goto done; 258d879cb83SAl Viro } 259d879cb83SAl Viro offset = to - kaddr; 260d879cb83SAl Viro buf += copy; 261d879cb83SAl Viro kunmap_atomic(kaddr); 262d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 263d879cb83SAl Viro } 264d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2653fa6c507SMikulas Patocka 266d879cb83SAl Viro kaddr = kmap(page); 267d879cb83SAl Viro to = kaddr + offset; 268d879cb83SAl Viro left = __copy_from_user(to, buf, copy); 269d879cb83SAl Viro copy -= left; 270d879cb83SAl Viro skip += copy; 271d879cb83SAl Viro to += copy; 272d879cb83SAl Viro bytes -= copy; 273d879cb83SAl Viro while (unlikely(!left && bytes)) { 274d879cb83SAl Viro iov++; 275d879cb83SAl Viro buf = iov->iov_base; 276d879cb83SAl Viro copy = min(bytes, iov->iov_len); 277d879cb83SAl Viro left = __copy_from_user(to, buf, copy); 278d879cb83SAl Viro copy -= left; 279d879cb83SAl Viro skip = copy; 280d879cb83SAl Viro to += copy; 281d879cb83SAl Viro bytes -= copy; 282d879cb83SAl Viro } 283d879cb83SAl Viro kunmap(page); 2843fa6c507SMikulas Patocka 285d879cb83SAl Viro done: 286d879cb83SAl Viro if (skip == iov->iov_len) { 287d879cb83SAl Viro iov++; 288d879cb83SAl Viro skip = 0; 289d879cb83SAl Viro } 290d879cb83SAl Viro i->count -= wanted - bytes; 291d879cb83SAl Viro i->nr_segs -= iov - i->iov; 292d879cb83SAl Viro i->iov = iov; 293d879cb83SAl Viro i->iov_offset = skip; 294d879cb83SAl Viro return wanted - bytes; 295d879cb83SAl Viro } 296d879cb83SAl Viro 297241699cdSAl Viro #ifdef PIPE_PARANOIA 298241699cdSAl Viro static bool sanity(const struct iov_iter *i) 299241699cdSAl Viro { 300241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 301241699cdSAl Viro int idx = i->idx; 302241699cdSAl Viro int next = pipe->curbuf + pipe->nrbufs; 303241699cdSAl Viro if (i->iov_offset) { 304241699cdSAl Viro struct pipe_buffer *p; 305241699cdSAl Viro if (unlikely(!pipe->nrbufs)) 306241699cdSAl Viro goto Bad; // pipe must be non-empty 307241699cdSAl Viro if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) 308241699cdSAl Viro goto Bad; // must be at the last buffer... 309241699cdSAl Viro 310241699cdSAl Viro p = &pipe->bufs[idx]; 311241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 312241699cdSAl Viro goto Bad; // ... at the end of segment 313241699cdSAl Viro } else { 314241699cdSAl Viro if (idx != (next & (pipe->buffers - 1))) 315241699cdSAl Viro goto Bad; // must be right after the last buffer 316241699cdSAl Viro } 317241699cdSAl Viro return true; 318241699cdSAl Viro Bad: 319241699cdSAl Viro printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); 320241699cdSAl Viro printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", 321241699cdSAl Viro pipe->curbuf, pipe->nrbufs, pipe->buffers); 322241699cdSAl Viro for (idx = 0; idx < pipe->buffers; idx++) 323241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 324241699cdSAl Viro pipe->bufs[idx].ops, 325241699cdSAl Viro pipe->bufs[idx].page, 326241699cdSAl Viro pipe->bufs[idx].offset, 327241699cdSAl Viro pipe->bufs[idx].len); 328241699cdSAl Viro WARN_ON(1); 329241699cdSAl Viro return false; 330241699cdSAl Viro } 331241699cdSAl Viro #else 332241699cdSAl Viro #define sanity(i) true 333241699cdSAl Viro #endif 334241699cdSAl Viro 335241699cdSAl Viro static inline int next_idx(int idx, struct pipe_inode_info *pipe) 336241699cdSAl Viro { 337241699cdSAl Viro return (idx + 1) & (pipe->buffers - 1); 338241699cdSAl Viro } 339241699cdSAl Viro 340241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 341241699cdSAl Viro struct iov_iter *i) 342241699cdSAl Viro { 343241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 344241699cdSAl Viro struct pipe_buffer *buf; 345241699cdSAl Viro size_t off; 346241699cdSAl Viro int idx; 347241699cdSAl Viro 348241699cdSAl Viro if (unlikely(bytes > i->count)) 349241699cdSAl Viro bytes = i->count; 350241699cdSAl Viro 351241699cdSAl Viro if (unlikely(!bytes)) 352241699cdSAl Viro return 0; 353241699cdSAl Viro 354241699cdSAl Viro if (!sanity(i)) 355241699cdSAl Viro return 0; 356241699cdSAl Viro 357241699cdSAl Viro off = i->iov_offset; 358241699cdSAl Viro idx = i->idx; 359241699cdSAl Viro buf = &pipe->bufs[idx]; 360241699cdSAl Viro if (off) { 361241699cdSAl Viro if (offset == off && buf->page == page) { 362241699cdSAl Viro /* merge with the last one */ 363241699cdSAl Viro buf->len += bytes; 364241699cdSAl Viro i->iov_offset += bytes; 365241699cdSAl Viro goto out; 366241699cdSAl Viro } 367241699cdSAl Viro idx = next_idx(idx, pipe); 368241699cdSAl Viro buf = &pipe->bufs[idx]; 369241699cdSAl Viro } 370241699cdSAl Viro if (idx == pipe->curbuf && pipe->nrbufs) 371241699cdSAl Viro return 0; 372241699cdSAl Viro pipe->nrbufs++; 373241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 374241699cdSAl Viro get_page(buf->page = page); 375241699cdSAl Viro buf->offset = offset; 376241699cdSAl Viro buf->len = bytes; 377241699cdSAl Viro i->iov_offset = offset + bytes; 378241699cdSAl Viro i->idx = idx; 379241699cdSAl Viro out: 380241699cdSAl Viro i->count -= bytes; 381241699cdSAl Viro return bytes; 382241699cdSAl Viro } 383241699cdSAl Viro 384d879cb83SAl Viro /* 385171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 386171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 387171a0203SAnton Altaparmakov * 388171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 389171a0203SAnton Altaparmakov * because it is an invalid address). 390171a0203SAnton Altaparmakov */ 391d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 392171a0203SAnton Altaparmakov { 393171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 394171a0203SAnton Altaparmakov const struct iovec *iov; 395171a0203SAnton Altaparmakov int err; 396171a0203SAnton Altaparmakov struct iovec v; 397171a0203SAnton Altaparmakov 398171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 399171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4004bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 401171a0203SAnton Altaparmakov if (unlikely(err)) 402171a0203SAnton Altaparmakov return err; 403171a0203SAnton Altaparmakov 0;})) 404171a0203SAnton Altaparmakov } 405171a0203SAnton Altaparmakov return 0; 406171a0203SAnton Altaparmakov } 407d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 408171a0203SAnton Altaparmakov 409d879cb83SAl Viro void iov_iter_init(struct iov_iter *i, int direction, 410d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 411d879cb83SAl Viro size_t count) 412d879cb83SAl Viro { 413d879cb83SAl Viro /* It will get better. Eventually... */ 414d879cb83SAl Viro if (segment_eq(get_fs(), KERNEL_DS)) { 415d879cb83SAl Viro direction |= ITER_KVEC; 416d879cb83SAl Viro i->type = direction; 417d879cb83SAl Viro i->kvec = (struct kvec *)iov; 418d879cb83SAl Viro } else { 419d879cb83SAl Viro i->type = direction; 420d879cb83SAl Viro i->iov = iov; 421d879cb83SAl Viro } 422d879cb83SAl Viro i->nr_segs = nr_segs; 423d879cb83SAl Viro i->iov_offset = 0; 424d879cb83SAl Viro i->count = count; 425d879cb83SAl Viro } 426d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 427d879cb83SAl Viro 428d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 429d879cb83SAl Viro { 430d879cb83SAl Viro char *from = kmap_atomic(page); 431d879cb83SAl Viro memcpy(to, from + offset, len); 432d879cb83SAl Viro kunmap_atomic(from); 433d879cb83SAl Viro } 434d879cb83SAl Viro 43536f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 436d879cb83SAl Viro { 437d879cb83SAl Viro char *to = kmap_atomic(page); 438d879cb83SAl Viro memcpy(to + offset, from, len); 439d879cb83SAl Viro kunmap_atomic(to); 440d879cb83SAl Viro } 441d879cb83SAl Viro 442d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 443d879cb83SAl Viro { 444d879cb83SAl Viro char *addr = kmap_atomic(page); 445d879cb83SAl Viro memset(addr + offset, 0, len); 446d879cb83SAl Viro kunmap_atomic(addr); 447d879cb83SAl Viro } 448d879cb83SAl Viro 449241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 450241699cdSAl Viro { 451241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 452241699cdSAl Viro } 453241699cdSAl Viro 454241699cdSAl Viro static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) 455241699cdSAl Viro { 456241699cdSAl Viro size_t off = i->iov_offset; 457241699cdSAl Viro int idx = i->idx; 458241699cdSAl Viro if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { 459241699cdSAl Viro idx = next_idx(idx, i->pipe); 460241699cdSAl Viro off = 0; 461241699cdSAl Viro } 462241699cdSAl Viro *idxp = idx; 463241699cdSAl Viro *offp = off; 464241699cdSAl Viro } 465241699cdSAl Viro 466241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 467241699cdSAl Viro int *idxp, size_t *offp) 468241699cdSAl Viro { 469241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 470241699cdSAl Viro size_t off; 471241699cdSAl Viro int idx; 472241699cdSAl Viro ssize_t left; 473241699cdSAl Viro 474241699cdSAl Viro if (unlikely(size > i->count)) 475241699cdSAl Viro size = i->count; 476241699cdSAl Viro if (unlikely(!size)) 477241699cdSAl Viro return 0; 478241699cdSAl Viro 479241699cdSAl Viro left = size; 480241699cdSAl Viro data_start(i, &idx, &off); 481241699cdSAl Viro *idxp = idx; 482241699cdSAl Viro *offp = off; 483241699cdSAl Viro if (off) { 484241699cdSAl Viro left -= PAGE_SIZE - off; 485241699cdSAl Viro if (left <= 0) { 486241699cdSAl Viro pipe->bufs[idx].len += size; 487241699cdSAl Viro return size; 488241699cdSAl Viro } 489241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 490241699cdSAl Viro idx = next_idx(idx, pipe); 491241699cdSAl Viro } 492241699cdSAl Viro while (idx != pipe->curbuf || !pipe->nrbufs) { 493241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 494241699cdSAl Viro if (!page) 495241699cdSAl Viro break; 496241699cdSAl Viro pipe->nrbufs++; 497241699cdSAl Viro pipe->bufs[idx].ops = &default_pipe_buf_ops; 498241699cdSAl Viro pipe->bufs[idx].page = page; 499241699cdSAl Viro pipe->bufs[idx].offset = 0; 500241699cdSAl Viro if (left <= PAGE_SIZE) { 501241699cdSAl Viro pipe->bufs[idx].len = left; 502241699cdSAl Viro return size; 503241699cdSAl Viro } 504241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 505241699cdSAl Viro left -= PAGE_SIZE; 506241699cdSAl Viro idx = next_idx(idx, pipe); 507241699cdSAl Viro } 508241699cdSAl Viro return size - left; 509241699cdSAl Viro } 510241699cdSAl Viro 511241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 512241699cdSAl Viro struct iov_iter *i) 513241699cdSAl Viro { 514241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 515241699cdSAl Viro size_t n, off; 516241699cdSAl Viro int idx; 517241699cdSAl Viro 518241699cdSAl Viro if (!sanity(i)) 519241699cdSAl Viro return 0; 520241699cdSAl Viro 521241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 522241699cdSAl Viro if (unlikely(!n)) 523241699cdSAl Viro return 0; 524241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 525241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 526241699cdSAl Viro memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); 527241699cdSAl Viro i->idx = idx; 528241699cdSAl Viro i->iov_offset = off + chunk; 529241699cdSAl Viro n -= chunk; 530241699cdSAl Viro addr += chunk; 531241699cdSAl Viro } 532241699cdSAl Viro i->count -= bytes; 533241699cdSAl Viro return bytes; 534241699cdSAl Viro } 535241699cdSAl Viro 53636f7a8a4SAl Viro size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 537d879cb83SAl Viro { 53836f7a8a4SAl Viro const char *from = addr; 539241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 540241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 541d879cb83SAl Viro iterate_and_advance(i, bytes, v, 542d879cb83SAl Viro __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len, 543d879cb83SAl Viro v.iov_len), 544d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 545d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 546d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 547d879cb83SAl Viro ) 548d879cb83SAl Viro 549d879cb83SAl Viro return bytes; 550d879cb83SAl Viro } 551d879cb83SAl Viro EXPORT_SYMBOL(copy_to_iter); 552d879cb83SAl Viro 553d879cb83SAl Viro size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 554d879cb83SAl Viro { 555d879cb83SAl Viro char *to = addr; 556241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 557241699cdSAl Viro WARN_ON(1); 558241699cdSAl Viro return 0; 559241699cdSAl Viro } 560d879cb83SAl Viro iterate_and_advance(i, bytes, v, 561d879cb83SAl Viro __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, 562d879cb83SAl Viro v.iov_len), 563d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 564d879cb83SAl Viro v.bv_offset, v.bv_len), 565d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 566d879cb83SAl Viro ) 567d879cb83SAl Viro 568d879cb83SAl Viro return bytes; 569d879cb83SAl Viro } 570d879cb83SAl Viro EXPORT_SYMBOL(copy_from_iter); 571d879cb83SAl Viro 572d879cb83SAl Viro size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 573d879cb83SAl Viro { 574d879cb83SAl Viro char *to = addr; 575241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 576241699cdSAl Viro WARN_ON(1); 577241699cdSAl Viro return 0; 578241699cdSAl Viro } 579d879cb83SAl Viro iterate_and_advance(i, bytes, v, 580d879cb83SAl Viro __copy_from_user_nocache((to += v.iov_len) - v.iov_len, 581d879cb83SAl Viro v.iov_base, v.iov_len), 582d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 583d879cb83SAl Viro v.bv_offset, v.bv_len), 584d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 585d879cb83SAl Viro ) 586d879cb83SAl Viro 587d879cb83SAl Viro return bytes; 588d879cb83SAl Viro } 589d879cb83SAl Viro EXPORT_SYMBOL(copy_from_iter_nocache); 590d879cb83SAl Viro 591d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 592d879cb83SAl Viro struct iov_iter *i) 593d879cb83SAl Viro { 594d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 595d879cb83SAl Viro void *kaddr = kmap_atomic(page); 596d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 597d879cb83SAl Viro kunmap_atomic(kaddr); 598d879cb83SAl Viro return wanted; 599241699cdSAl Viro } else if (likely(!(i->type & ITER_PIPE))) 600d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 601241699cdSAl Viro else 602241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 603d879cb83SAl Viro } 604d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 605d879cb83SAl Viro 606d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 607d879cb83SAl Viro struct iov_iter *i) 608d879cb83SAl Viro { 609241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 610241699cdSAl Viro WARN_ON(1); 611241699cdSAl Viro return 0; 612241699cdSAl Viro } 613d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 614d879cb83SAl Viro void *kaddr = kmap_atomic(page); 615d879cb83SAl Viro size_t wanted = copy_from_iter(kaddr + offset, bytes, i); 616d879cb83SAl Viro kunmap_atomic(kaddr); 617d879cb83SAl Viro return wanted; 618d879cb83SAl Viro } else 619d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 620d879cb83SAl Viro } 621d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 622d879cb83SAl Viro 623241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 624241699cdSAl Viro { 625241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 626241699cdSAl Viro size_t n, off; 627241699cdSAl Viro int idx; 628241699cdSAl Viro 629241699cdSAl Viro if (!sanity(i)) 630241699cdSAl Viro return 0; 631241699cdSAl Viro 632241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 633241699cdSAl Viro if (unlikely(!n)) 634241699cdSAl Viro return 0; 635241699cdSAl Viro 636241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 637241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 638241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 639241699cdSAl Viro i->idx = idx; 640241699cdSAl Viro i->iov_offset = off + chunk; 641241699cdSAl Viro n -= chunk; 642241699cdSAl Viro } 643241699cdSAl Viro i->count -= bytes; 644241699cdSAl Viro return bytes; 645241699cdSAl Viro } 646241699cdSAl Viro 647d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 648d879cb83SAl Viro { 649241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 650241699cdSAl Viro return pipe_zero(bytes, i); 651d879cb83SAl Viro iterate_and_advance(i, bytes, v, 652d879cb83SAl Viro __clear_user(v.iov_base, v.iov_len), 653d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 654d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 655d879cb83SAl Viro ) 656d879cb83SAl Viro 657d879cb83SAl Viro return bytes; 658d879cb83SAl Viro } 659d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 660d879cb83SAl Viro 661d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 662d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 663d879cb83SAl Viro { 664d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 665241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 666241699cdSAl Viro kunmap_atomic(kaddr); 667241699cdSAl Viro WARN_ON(1); 668241699cdSAl Viro return 0; 669241699cdSAl Viro } 670d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 671d879cb83SAl Viro __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, 672d879cb83SAl Viro v.iov_base, v.iov_len), 673d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 674d879cb83SAl Viro v.bv_offset, v.bv_len), 675d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 676d879cb83SAl Viro ) 677d879cb83SAl Viro kunmap_atomic(kaddr); 678d879cb83SAl Viro return bytes; 679d879cb83SAl Viro } 680d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 681d879cb83SAl Viro 682241699cdSAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 683241699cdSAl Viro { 684241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 685241699cdSAl Viro struct pipe_buffer *buf; 686241699cdSAl Viro int idx = i->idx; 687241699cdSAl Viro size_t off = i->iov_offset; 688241699cdSAl Viro 689241699cdSAl Viro if (unlikely(i->count < size)) 690241699cdSAl Viro size = i->count; 691241699cdSAl Viro 692241699cdSAl Viro if (size) { 693241699cdSAl Viro if (off) /* make it relative to the beginning of buffer */ 694241699cdSAl Viro size += off - pipe->bufs[idx].offset; 695241699cdSAl Viro while (1) { 696241699cdSAl Viro buf = &pipe->bufs[idx]; 697241699cdSAl Viro if (size <= buf->len) 698241699cdSAl Viro break; 699241699cdSAl Viro size -= buf->len; 700241699cdSAl Viro idx = next_idx(idx, pipe); 701241699cdSAl Viro } 702241699cdSAl Viro buf->len = size; 703241699cdSAl Viro i->idx = idx; 704241699cdSAl Viro off = i->iov_offset = buf->offset + size; 705241699cdSAl Viro } 706241699cdSAl Viro if (off) 707241699cdSAl Viro idx = next_idx(idx, pipe); 708241699cdSAl Viro if (pipe->nrbufs) { 709241699cdSAl Viro int unused = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 710241699cdSAl Viro /* [curbuf,unused) is in use. Free [idx,unused) */ 711241699cdSAl Viro while (idx != unused) { 712a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 713241699cdSAl Viro idx = next_idx(idx, pipe); 714241699cdSAl Viro pipe->nrbufs--; 715241699cdSAl Viro } 716241699cdSAl Viro } 717241699cdSAl Viro } 718241699cdSAl Viro 719d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 720d879cb83SAl Viro { 721241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 722241699cdSAl Viro pipe_advance(i, size); 723241699cdSAl Viro return; 724241699cdSAl Viro } 725d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 726d879cb83SAl Viro } 727d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 728d879cb83SAl Viro 729d879cb83SAl Viro /* 730d879cb83SAl Viro * Return the count of just the current iov_iter segment. 731d879cb83SAl Viro */ 732d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 733d879cb83SAl Viro { 734241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 735241699cdSAl Viro return i->count; // it is a silly place, anyway 736d879cb83SAl Viro if (i->nr_segs == 1) 737d879cb83SAl Viro return i->count; 738d879cb83SAl Viro else if (i->type & ITER_BVEC) 739d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 740d879cb83SAl Viro else 741d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 742d879cb83SAl Viro } 743d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 744d879cb83SAl Viro 745d879cb83SAl Viro void iov_iter_kvec(struct iov_iter *i, int direction, 746d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 747d879cb83SAl Viro size_t count) 748d879cb83SAl Viro { 749d879cb83SAl Viro BUG_ON(!(direction & ITER_KVEC)); 750d879cb83SAl Viro i->type = direction; 751d879cb83SAl Viro i->kvec = kvec; 752d879cb83SAl Viro i->nr_segs = nr_segs; 753d879cb83SAl Viro i->iov_offset = 0; 754d879cb83SAl Viro i->count = count; 755d879cb83SAl Viro } 756d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 757d879cb83SAl Viro 758d879cb83SAl Viro void iov_iter_bvec(struct iov_iter *i, int direction, 759d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 760d879cb83SAl Viro size_t count) 761d879cb83SAl Viro { 762d879cb83SAl Viro BUG_ON(!(direction & ITER_BVEC)); 763d879cb83SAl Viro i->type = direction; 764d879cb83SAl Viro i->bvec = bvec; 765d879cb83SAl Viro i->nr_segs = nr_segs; 766d879cb83SAl Viro i->iov_offset = 0; 767d879cb83SAl Viro i->count = count; 768d879cb83SAl Viro } 769d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 770d879cb83SAl Viro 771241699cdSAl Viro void iov_iter_pipe(struct iov_iter *i, int direction, 772241699cdSAl Viro struct pipe_inode_info *pipe, 773241699cdSAl Viro size_t count) 774241699cdSAl Viro { 775241699cdSAl Viro BUG_ON(direction != ITER_PIPE); 776241699cdSAl Viro i->type = direction; 777241699cdSAl Viro i->pipe = pipe; 778241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 779241699cdSAl Viro i->iov_offset = 0; 780241699cdSAl Viro i->count = count; 781241699cdSAl Viro } 782241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 783241699cdSAl Viro 784d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 785d879cb83SAl Viro { 786d879cb83SAl Viro unsigned long res = 0; 787d879cb83SAl Viro size_t size = i->count; 788d879cb83SAl Viro 789d879cb83SAl Viro if (!size) 790d879cb83SAl Viro return 0; 791d879cb83SAl Viro 792241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 793241699cdSAl Viro if (i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 794241699cdSAl Viro return size | i->iov_offset; 795241699cdSAl Viro return size; 796241699cdSAl Viro } 797d879cb83SAl Viro iterate_all_kinds(i, size, v, 798d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 799d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 800d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 801d879cb83SAl Viro ) 802d879cb83SAl Viro return res; 803d879cb83SAl Viro } 804d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 805d879cb83SAl Viro 806357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 807357f435dSAl Viro { 808357f435dSAl Viro unsigned long res = 0; 809357f435dSAl Viro size_t size = i->count; 810357f435dSAl Viro if (!size) 811357f435dSAl Viro return 0; 812357f435dSAl Viro 813241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 814241699cdSAl Viro WARN_ON(1); 815241699cdSAl Viro return ~0U; 816241699cdSAl Viro } 817241699cdSAl Viro 818357f435dSAl Viro iterate_all_kinds(i, size, v, 819357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 820357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 821357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 822357f435dSAl Viro (size != v.bv_len ? size : 0)), 823357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 824357f435dSAl Viro (size != v.iov_len ? size : 0)) 825357f435dSAl Viro ); 826357f435dSAl Viro return res; 827357f435dSAl Viro } 828357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 829357f435dSAl Viro 830241699cdSAl Viro static inline size_t __pipe_get_pages(struct iov_iter *i, 831241699cdSAl Viro size_t maxsize, 832241699cdSAl Viro struct page **pages, 833241699cdSAl Viro int idx, 834241699cdSAl Viro size_t *start) 835241699cdSAl Viro { 836241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 8371689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 838241699cdSAl Viro if (!n) 839241699cdSAl Viro return -EFAULT; 840241699cdSAl Viro 841241699cdSAl Viro maxsize = n; 842241699cdSAl Viro n += *start; 8431689c73aSAl Viro while (n > 0) { 844241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 845241699cdSAl Viro idx = next_idx(idx, pipe); 846241699cdSAl Viro n -= PAGE_SIZE; 847241699cdSAl Viro } 848241699cdSAl Viro 849241699cdSAl Viro return maxsize; 850241699cdSAl Viro } 851241699cdSAl Viro 852241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 853241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 854241699cdSAl Viro size_t *start) 855241699cdSAl Viro { 856241699cdSAl Viro unsigned npages; 857241699cdSAl Viro size_t capacity; 858241699cdSAl Viro int idx; 859241699cdSAl Viro 860241699cdSAl Viro if (!sanity(i)) 861241699cdSAl Viro return -EFAULT; 862241699cdSAl Viro 863241699cdSAl Viro data_start(i, &idx, start); 864241699cdSAl Viro /* some of this one + all after this one */ 865241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 866241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 867241699cdSAl Viro 868241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 869241699cdSAl Viro } 870241699cdSAl Viro 871d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 872d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 873d879cb83SAl Viro size_t *start) 874d879cb83SAl Viro { 875d879cb83SAl Viro if (maxsize > i->count) 876d879cb83SAl Viro maxsize = i->count; 877d879cb83SAl Viro 878d879cb83SAl Viro if (!maxsize) 879d879cb83SAl Viro return 0; 880d879cb83SAl Viro 881241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 882241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 883d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 884d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 885d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 886d879cb83SAl Viro int n; 887d879cb83SAl Viro int res; 888d879cb83SAl Viro 889d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 890d879cb83SAl Viro len = maxpages * PAGE_SIZE; 891d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 892d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 893d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); 894d879cb83SAl Viro if (unlikely(res < 0)) 895d879cb83SAl Viro return res; 896d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 897d879cb83SAl Viro 0;}),({ 898d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 899d879cb83SAl Viro *start = v.bv_offset; 900d879cb83SAl Viro get_page(*pages = v.bv_page); 901d879cb83SAl Viro return v.bv_len; 902d879cb83SAl Viro }),({ 903d879cb83SAl Viro return -EFAULT; 904d879cb83SAl Viro }) 905d879cb83SAl Viro ) 906d879cb83SAl Viro return 0; 907d879cb83SAl Viro } 908d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 909d879cb83SAl Viro 910d879cb83SAl Viro static struct page **get_pages_array(size_t n) 911d879cb83SAl Viro { 912d879cb83SAl Viro struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL); 913d879cb83SAl Viro if (!p) 914d879cb83SAl Viro p = vmalloc(n * sizeof(struct page *)); 915d879cb83SAl Viro return p; 916d879cb83SAl Viro } 917d879cb83SAl Viro 918241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 919241699cdSAl Viro struct page ***pages, size_t maxsize, 920241699cdSAl Viro size_t *start) 921241699cdSAl Viro { 922241699cdSAl Viro struct page **p; 923241699cdSAl Viro size_t n; 924241699cdSAl Viro int idx; 925241699cdSAl Viro int npages; 926241699cdSAl Viro 927241699cdSAl Viro if (!sanity(i)) 928241699cdSAl Viro return -EFAULT; 929241699cdSAl Viro 930241699cdSAl Viro data_start(i, &idx, start); 931241699cdSAl Viro /* some of this one + all after this one */ 932241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 933241699cdSAl Viro n = npages * PAGE_SIZE - *start; 934241699cdSAl Viro if (maxsize > n) 935241699cdSAl Viro maxsize = n; 936241699cdSAl Viro else 937241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 938241699cdSAl Viro p = get_pages_array(npages); 939241699cdSAl Viro if (!p) 940241699cdSAl Viro return -ENOMEM; 941241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 942241699cdSAl Viro if (n > 0) 943241699cdSAl Viro *pages = p; 944241699cdSAl Viro else 945241699cdSAl Viro kvfree(p); 946241699cdSAl Viro return n; 947241699cdSAl Viro } 948241699cdSAl Viro 949d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 950d879cb83SAl Viro struct page ***pages, size_t maxsize, 951d879cb83SAl Viro size_t *start) 952d879cb83SAl Viro { 953d879cb83SAl Viro struct page **p; 954d879cb83SAl Viro 955d879cb83SAl Viro if (maxsize > i->count) 956d879cb83SAl Viro maxsize = i->count; 957d879cb83SAl Viro 958d879cb83SAl Viro if (!maxsize) 959d879cb83SAl Viro return 0; 960d879cb83SAl Viro 961241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 962241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 963d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 964d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 965d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 966d879cb83SAl Viro int n; 967d879cb83SAl Viro int res; 968d879cb83SAl Viro 969d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 970d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 971d879cb83SAl Viro p = get_pages_array(n); 972d879cb83SAl Viro if (!p) 973d879cb83SAl Viro return -ENOMEM; 974d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); 975d879cb83SAl Viro if (unlikely(res < 0)) { 976d879cb83SAl Viro kvfree(p); 977d879cb83SAl Viro return res; 978d879cb83SAl Viro } 979d879cb83SAl Viro *pages = p; 980d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 981d879cb83SAl Viro 0;}),({ 982d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 983d879cb83SAl Viro *start = v.bv_offset; 984d879cb83SAl Viro *pages = p = get_pages_array(1); 985d879cb83SAl Viro if (!p) 986d879cb83SAl Viro return -ENOMEM; 987d879cb83SAl Viro get_page(*p = v.bv_page); 988d879cb83SAl Viro return v.bv_len; 989d879cb83SAl Viro }),({ 990d879cb83SAl Viro return -EFAULT; 991d879cb83SAl Viro }) 992d879cb83SAl Viro ) 993d879cb83SAl Viro return 0; 994d879cb83SAl Viro } 995d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 996d879cb83SAl Viro 997d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 998d879cb83SAl Viro struct iov_iter *i) 999d879cb83SAl Viro { 1000d879cb83SAl Viro char *to = addr; 1001d879cb83SAl Viro __wsum sum, next; 1002d879cb83SAl Viro size_t off = 0; 1003d879cb83SAl Viro sum = *csum; 1004241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1005241699cdSAl Viro WARN_ON(1); 1006241699cdSAl Viro return 0; 1007241699cdSAl Viro } 1008d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1009d879cb83SAl Viro int err = 0; 1010d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1011d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1012d879cb83SAl Viro v.iov_len, 0, &err); 1013d879cb83SAl Viro if (!err) { 1014d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1015d879cb83SAl Viro off += v.iov_len; 1016d879cb83SAl Viro } 1017d879cb83SAl Viro err ? v.iov_len : 0; 1018d879cb83SAl Viro }), ({ 1019d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1020d879cb83SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1021d879cb83SAl Viro (to += v.bv_len) - v.bv_len, 1022d879cb83SAl Viro v.bv_len, 0); 1023d879cb83SAl Viro kunmap_atomic(p); 1024d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1025d879cb83SAl Viro off += v.bv_len; 1026d879cb83SAl Viro }),({ 1027d879cb83SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1028d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1029d879cb83SAl Viro v.iov_len, 0); 1030d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1031d879cb83SAl Viro off += v.iov_len; 1032d879cb83SAl Viro }) 1033d879cb83SAl Viro ) 1034d879cb83SAl Viro *csum = sum; 1035d879cb83SAl Viro return bytes; 1036d879cb83SAl Viro } 1037d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1038d879cb83SAl Viro 103936f7a8a4SAl Viro size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, 1040d879cb83SAl Viro struct iov_iter *i) 1041d879cb83SAl Viro { 104236f7a8a4SAl Viro const char *from = addr; 1043d879cb83SAl Viro __wsum sum, next; 1044d879cb83SAl Viro size_t off = 0; 1045d879cb83SAl Viro sum = *csum; 1046241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1047241699cdSAl Viro WARN_ON(1); /* for now */ 1048241699cdSAl Viro return 0; 1049241699cdSAl Viro } 1050d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1051d879cb83SAl Viro int err = 0; 1052d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1053d879cb83SAl Viro v.iov_base, 1054d879cb83SAl Viro v.iov_len, 0, &err); 1055d879cb83SAl Viro if (!err) { 1056d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1057d879cb83SAl Viro off += v.iov_len; 1058d879cb83SAl Viro } 1059d879cb83SAl Viro err ? v.iov_len : 0; 1060d879cb83SAl Viro }), ({ 1061d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1062d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, 1063d879cb83SAl Viro p + v.bv_offset, 1064d879cb83SAl Viro v.bv_len, 0); 1065d879cb83SAl Viro kunmap_atomic(p); 1066d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1067d879cb83SAl Viro off += v.bv_len; 1068d879cb83SAl Viro }),({ 1069d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, 1070d879cb83SAl Viro v.iov_base, 1071d879cb83SAl Viro v.iov_len, 0); 1072d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1073d879cb83SAl Viro off += v.iov_len; 1074d879cb83SAl Viro }) 1075d879cb83SAl Viro ) 1076d879cb83SAl Viro *csum = sum; 1077d879cb83SAl Viro return bytes; 1078d879cb83SAl Viro } 1079d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1080d879cb83SAl Viro 1081d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1082d879cb83SAl Viro { 1083d879cb83SAl Viro size_t size = i->count; 1084d879cb83SAl Viro int npages = 0; 1085d879cb83SAl Viro 1086d879cb83SAl Viro if (!size) 1087d879cb83SAl Viro return 0; 1088d879cb83SAl Viro 1089241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1090241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1091241699cdSAl Viro size_t off; 1092241699cdSAl Viro int idx; 1093241699cdSAl Viro 1094241699cdSAl Viro if (!sanity(i)) 1095241699cdSAl Viro return 0; 1096241699cdSAl Viro 1097241699cdSAl Viro data_start(i, &idx, &off); 1098241699cdSAl Viro /* some of this one + all after this one */ 1099241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1100241699cdSAl Viro if (npages >= maxpages) 1101241699cdSAl Viro return maxpages; 1102241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1103d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1104d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1105d879cb83SAl Viro - p / PAGE_SIZE; 1106d879cb83SAl Viro if (npages >= maxpages) 1107d879cb83SAl Viro return maxpages; 1108d879cb83SAl Viro 0;}),({ 1109d879cb83SAl Viro npages++; 1110d879cb83SAl Viro if (npages >= maxpages) 1111d879cb83SAl Viro return maxpages; 1112d879cb83SAl Viro }),({ 1113d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1114d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1115d879cb83SAl Viro - p / PAGE_SIZE; 1116d879cb83SAl Viro if (npages >= maxpages) 1117d879cb83SAl Viro return maxpages; 1118d879cb83SAl Viro }) 1119d879cb83SAl Viro ) 1120d879cb83SAl Viro return npages; 1121d879cb83SAl Viro } 1122d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1123d879cb83SAl Viro 1124d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1125d879cb83SAl Viro { 1126d879cb83SAl Viro *new = *old; 1127241699cdSAl Viro if (unlikely(new->type & ITER_PIPE)) { 1128241699cdSAl Viro WARN_ON(1); 1129241699cdSAl Viro return NULL; 1130241699cdSAl Viro } 1131d879cb83SAl Viro if (new->type & ITER_BVEC) 1132d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1133d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1134d879cb83SAl Viro flags); 1135d879cb83SAl Viro else 1136d879cb83SAl Viro /* iovec and kvec have identical layout */ 1137d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1138d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1139d879cb83SAl Viro flags); 1140d879cb83SAl Viro } 1141d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1142bc917be8SAl Viro 1143ffecee4fSVegard Nossum /** 1144ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1145ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1146ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1147ffecee4fSVegard Nossum * 1148ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1149ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1150ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1151ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1152ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1153ffecee4fSVegard Nossum * on-stack) kernel array. 1154ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1155ffecee4fSVegard Nossum * 1156ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1157ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1158ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1159ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1160ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1161ffecee4fSVegard Nossum * returns an error or not). 1162ffecee4fSVegard Nossum * 1163ffecee4fSVegard Nossum * Return: 0 on success or negative error code on error. 1164ffecee4fSVegard Nossum */ 1165bc917be8SAl Viro int import_iovec(int type, const struct iovec __user * uvector, 1166bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1167bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1168bc917be8SAl Viro { 1169bc917be8SAl Viro ssize_t n; 1170bc917be8SAl Viro struct iovec *p; 1171bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1172bc917be8SAl Viro *iov, &p); 1173bc917be8SAl Viro if (n < 0) { 1174bc917be8SAl Viro if (p != *iov) 1175bc917be8SAl Viro kfree(p); 1176bc917be8SAl Viro *iov = NULL; 1177bc917be8SAl Viro return n; 1178bc917be8SAl Viro } 1179bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1180bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1181bc917be8SAl Viro return 0; 1182bc917be8SAl Viro } 1183bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1184bc917be8SAl Viro 1185bc917be8SAl Viro #ifdef CONFIG_COMPAT 1186bc917be8SAl Viro #include <linux/compat.h> 1187bc917be8SAl Viro 1188bc917be8SAl Viro int compat_import_iovec(int type, const struct compat_iovec __user * uvector, 1189bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1190bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1191bc917be8SAl Viro { 1192bc917be8SAl Viro ssize_t n; 1193bc917be8SAl Viro struct iovec *p; 1194bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1195bc917be8SAl Viro *iov, &p); 1196bc917be8SAl Viro if (n < 0) { 1197bc917be8SAl Viro if (p != *iov) 1198bc917be8SAl Viro kfree(p); 1199bc917be8SAl Viro *iov = NULL; 1200bc917be8SAl Viro return n; 1201bc917be8SAl Viro } 1202bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1203bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1204bc917be8SAl Viro return 0; 1205bc917be8SAl Viro } 1206bc917be8SAl Viro #endif 1207bc917be8SAl Viro 1208bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1209bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1210bc917be8SAl Viro { 1211bc917be8SAl Viro if (len > MAX_RW_COUNT) 1212bc917be8SAl Viro len = MAX_RW_COUNT; 1213bc917be8SAl Viro if (unlikely(!access_ok(!rw, buf, len))) 1214bc917be8SAl Viro return -EFAULT; 1215bc917be8SAl Viro 1216bc917be8SAl Viro iov->iov_base = buf; 1217bc917be8SAl Viro iov->iov_len = len; 1218bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1219bc917be8SAl Viro return 0; 1220bc917be8SAl Viro } 1221e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 1222