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 538aa28de27SAl 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 } 553aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 554d879cb83SAl Viro 555aa28de27SAl 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 } 572aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 573d879cb83SAl Viro 574aa28de27SAl 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 } 597aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 598cbbd26b8SAl Viro 599aa28de27SAl 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 } 616aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 617d879cb83SAl Viro 618aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 619cbbd26b8SAl Viro { 620cbbd26b8SAl Viro char *to = addr; 621cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 622cbbd26b8SAl Viro WARN_ON(1); 623cbbd26b8SAl Viro return false; 624cbbd26b8SAl Viro } 62533844e66SAl Viro if (unlikely(i->count < bytes)) 626cbbd26b8SAl Viro return false; 627cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 6283f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 629cbbd26b8SAl Viro v.iov_base, v.iov_len)) 630cbbd26b8SAl Viro return false; 631cbbd26b8SAl Viro 0;}), 632cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 633cbbd26b8SAl Viro v.bv_offset, v.bv_len), 634cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 635cbbd26b8SAl Viro ) 636cbbd26b8SAl Viro 637cbbd26b8SAl Viro iov_iter_advance(i, bytes); 638cbbd26b8SAl Viro return true; 639cbbd26b8SAl Viro } 640aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 641cbbd26b8SAl Viro 64272e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 64372e809edSAl Viro { 64472e809edSAl Viro size_t v = n + offset; 64572e809edSAl Viro if (likely(n <= v && v <= (PAGE_SIZE << compound_order(page)))) 64672e809edSAl Viro return true; 64772e809edSAl Viro WARN_ON(1); 64872e809edSAl Viro return false; 64972e809edSAl Viro } 65072e809edSAl Viro 651d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 652d879cb83SAl Viro struct iov_iter *i) 653d879cb83SAl Viro { 65472e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 65572e809edSAl Viro return 0; 656d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 657d879cb83SAl Viro void *kaddr = kmap_atomic(page); 658d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 659d879cb83SAl Viro kunmap_atomic(kaddr); 660d879cb83SAl Viro return wanted; 661241699cdSAl Viro } else if (likely(!(i->type & ITER_PIPE))) 662d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 663241699cdSAl Viro else 664241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 665d879cb83SAl Viro } 666d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 667d879cb83SAl Viro 668d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 669d879cb83SAl Viro struct iov_iter *i) 670d879cb83SAl Viro { 67172e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 67272e809edSAl Viro return 0; 673241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 674241699cdSAl Viro WARN_ON(1); 675241699cdSAl Viro return 0; 676241699cdSAl Viro } 677d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 678d879cb83SAl Viro void *kaddr = kmap_atomic(page); 679aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 680d879cb83SAl Viro kunmap_atomic(kaddr); 681d879cb83SAl Viro return wanted; 682d879cb83SAl Viro } else 683d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 684d879cb83SAl Viro } 685d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 686d879cb83SAl Viro 687241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 688241699cdSAl Viro { 689241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 690241699cdSAl Viro size_t n, off; 691241699cdSAl Viro int idx; 692241699cdSAl Viro 693241699cdSAl Viro if (!sanity(i)) 694241699cdSAl Viro return 0; 695241699cdSAl Viro 696241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 697241699cdSAl Viro if (unlikely(!n)) 698241699cdSAl Viro return 0; 699241699cdSAl Viro 700241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 701241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 702241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 703241699cdSAl Viro i->idx = idx; 704241699cdSAl Viro i->iov_offset = off + chunk; 705241699cdSAl Viro n -= chunk; 706241699cdSAl Viro } 707241699cdSAl Viro i->count -= bytes; 708241699cdSAl Viro return bytes; 709241699cdSAl Viro } 710241699cdSAl Viro 711d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 712d879cb83SAl Viro { 713241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 714241699cdSAl Viro return pipe_zero(bytes, i); 715d879cb83SAl Viro iterate_and_advance(i, bytes, v, 716d879cb83SAl Viro __clear_user(v.iov_base, v.iov_len), 717d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 718d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 719d879cb83SAl Viro ) 720d879cb83SAl Viro 721d879cb83SAl Viro return bytes; 722d879cb83SAl Viro } 723d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 724d879cb83SAl Viro 725d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 726d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 727d879cb83SAl Viro { 728d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 72972e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 73072e809edSAl Viro kunmap_atomic(kaddr); 73172e809edSAl Viro return 0; 73272e809edSAl Viro } 733241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 734241699cdSAl Viro kunmap_atomic(kaddr); 735241699cdSAl Viro WARN_ON(1); 736241699cdSAl Viro return 0; 737241699cdSAl Viro } 738d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 739d879cb83SAl Viro __copy_from_user_inatomic((p += v.iov_len) - v.iov_len, 740d879cb83SAl Viro v.iov_base, v.iov_len), 741d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 742d879cb83SAl Viro v.bv_offset, v.bv_len), 743d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 744d879cb83SAl Viro ) 745d879cb83SAl Viro kunmap_atomic(kaddr); 746d879cb83SAl Viro return bytes; 747d879cb83SAl Viro } 748d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 749d879cb83SAl Viro 750b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 751241699cdSAl Viro { 752241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 753241699cdSAl Viro if (pipe->nrbufs) { 754b9dc6f65SAl Viro size_t off = i->iov_offset; 755b9dc6f65SAl Viro int idx = i->idx; 756b9dc6f65SAl Viro int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); 757b9dc6f65SAl Viro if (off) { 758b9dc6f65SAl Viro pipe->bufs[idx].len = off - pipe->bufs[idx].offset; 759b9dc6f65SAl Viro idx = next_idx(idx, pipe); 760b9dc6f65SAl Viro nrbufs++; 761b9dc6f65SAl Viro } 762b9dc6f65SAl Viro while (pipe->nrbufs > nrbufs) { 763a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 764241699cdSAl Viro idx = next_idx(idx, pipe); 765241699cdSAl Viro pipe->nrbufs--; 766241699cdSAl Viro } 767241699cdSAl Viro } 768b9dc6f65SAl Viro } 769b9dc6f65SAl Viro 770b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 771b9dc6f65SAl Viro { 772b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 773b9dc6f65SAl Viro if (unlikely(i->count < size)) 774b9dc6f65SAl Viro size = i->count; 775b9dc6f65SAl Viro if (size) { 776b9dc6f65SAl Viro struct pipe_buffer *buf; 777b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 778b9dc6f65SAl Viro int idx = i->idx; 779b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 780b9dc6f65SAl Viro left += off - pipe->bufs[idx].offset; 781b9dc6f65SAl Viro while (1) { 782b9dc6f65SAl Viro buf = &pipe->bufs[idx]; 783b9dc6f65SAl Viro if (left <= buf->len) 784b9dc6f65SAl Viro break; 785b9dc6f65SAl Viro left -= buf->len; 786b9dc6f65SAl Viro idx = next_idx(idx, pipe); 787b9dc6f65SAl Viro } 788b9dc6f65SAl Viro i->idx = idx; 789b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 790b9dc6f65SAl Viro } 791b9dc6f65SAl Viro i->count -= size; 792b9dc6f65SAl Viro /* ... and discard everything past that point */ 793b9dc6f65SAl Viro pipe_truncate(i); 794241699cdSAl Viro } 795241699cdSAl Viro 796d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 797d879cb83SAl Viro { 798241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 799241699cdSAl Viro pipe_advance(i, size); 800241699cdSAl Viro return; 801241699cdSAl Viro } 802d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 803d879cb83SAl Viro } 804d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 805d879cb83SAl Viro 80627c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 80727c0e374SAl Viro { 80827c0e374SAl Viro if (!unroll) 80927c0e374SAl Viro return; 8105b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 8115b47d59aSAl Viro return; 81227c0e374SAl Viro i->count += unroll; 81327c0e374SAl Viro if (unlikely(i->type & ITER_PIPE)) { 81427c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 81527c0e374SAl Viro int idx = i->idx; 81627c0e374SAl Viro size_t off = i->iov_offset; 81727c0e374SAl Viro while (1) { 81827c0e374SAl Viro size_t n = off - pipe->bufs[idx].offset; 81927c0e374SAl Viro if (unroll < n) { 8204fa55cefSAl Viro off -= unroll; 82127c0e374SAl Viro break; 82227c0e374SAl Viro } 82327c0e374SAl Viro unroll -= n; 82427c0e374SAl Viro if (!unroll && idx == i->start_idx) { 82527c0e374SAl Viro off = 0; 82627c0e374SAl Viro break; 82727c0e374SAl Viro } 82827c0e374SAl Viro if (!idx--) 82927c0e374SAl Viro idx = pipe->buffers - 1; 83027c0e374SAl Viro off = pipe->bufs[idx].offset + pipe->bufs[idx].len; 83127c0e374SAl Viro } 83227c0e374SAl Viro i->iov_offset = off; 83327c0e374SAl Viro i->idx = idx; 83427c0e374SAl Viro pipe_truncate(i); 83527c0e374SAl Viro return; 83627c0e374SAl Viro } 83727c0e374SAl Viro if (unroll <= i->iov_offset) { 83827c0e374SAl Viro i->iov_offset -= unroll; 83927c0e374SAl Viro return; 84027c0e374SAl Viro } 84127c0e374SAl Viro unroll -= i->iov_offset; 84227c0e374SAl Viro if (i->type & ITER_BVEC) { 84327c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 84427c0e374SAl Viro while (1) { 84527c0e374SAl Viro size_t n = (--bvec)->bv_len; 84627c0e374SAl Viro i->nr_segs++; 84727c0e374SAl Viro if (unroll <= n) { 84827c0e374SAl Viro i->bvec = bvec; 84927c0e374SAl Viro i->iov_offset = n - unroll; 85027c0e374SAl Viro return; 85127c0e374SAl Viro } 85227c0e374SAl Viro unroll -= n; 85327c0e374SAl Viro } 85427c0e374SAl Viro } else { /* same logics for iovec and kvec */ 85527c0e374SAl Viro const struct iovec *iov = i->iov; 85627c0e374SAl Viro while (1) { 85727c0e374SAl Viro size_t n = (--iov)->iov_len; 85827c0e374SAl Viro i->nr_segs++; 85927c0e374SAl Viro if (unroll <= n) { 86027c0e374SAl Viro i->iov = iov; 86127c0e374SAl Viro i->iov_offset = n - unroll; 86227c0e374SAl Viro return; 86327c0e374SAl Viro } 86427c0e374SAl Viro unroll -= n; 86527c0e374SAl Viro } 86627c0e374SAl Viro } 86727c0e374SAl Viro } 86827c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 86927c0e374SAl Viro 870d879cb83SAl Viro /* 871d879cb83SAl Viro * Return the count of just the current iov_iter segment. 872d879cb83SAl Viro */ 873d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 874d879cb83SAl Viro { 875241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 876241699cdSAl Viro return i->count; // it is a silly place, anyway 877d879cb83SAl Viro if (i->nr_segs == 1) 878d879cb83SAl Viro return i->count; 879d879cb83SAl Viro else if (i->type & ITER_BVEC) 880d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 881d879cb83SAl Viro else 882d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 883d879cb83SAl Viro } 884d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 885d879cb83SAl Viro 886d879cb83SAl Viro void iov_iter_kvec(struct iov_iter *i, int direction, 887d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 888d879cb83SAl Viro size_t count) 889d879cb83SAl Viro { 890d879cb83SAl Viro BUG_ON(!(direction & ITER_KVEC)); 891d879cb83SAl Viro i->type = direction; 892d879cb83SAl Viro i->kvec = kvec; 893d879cb83SAl Viro i->nr_segs = nr_segs; 894d879cb83SAl Viro i->iov_offset = 0; 895d879cb83SAl Viro i->count = count; 896d879cb83SAl Viro } 897d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 898d879cb83SAl Viro 899d879cb83SAl Viro void iov_iter_bvec(struct iov_iter *i, int direction, 900d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 901d879cb83SAl Viro size_t count) 902d879cb83SAl Viro { 903d879cb83SAl Viro BUG_ON(!(direction & ITER_BVEC)); 904d879cb83SAl Viro i->type = direction; 905d879cb83SAl Viro i->bvec = bvec; 906d879cb83SAl Viro i->nr_segs = nr_segs; 907d879cb83SAl Viro i->iov_offset = 0; 908d879cb83SAl Viro i->count = count; 909d879cb83SAl Viro } 910d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 911d879cb83SAl Viro 912241699cdSAl Viro void iov_iter_pipe(struct iov_iter *i, int direction, 913241699cdSAl Viro struct pipe_inode_info *pipe, 914241699cdSAl Viro size_t count) 915241699cdSAl Viro { 916241699cdSAl Viro BUG_ON(direction != ITER_PIPE); 917b9dc6f65SAl Viro WARN_ON(pipe->nrbufs == pipe->buffers); 918241699cdSAl Viro i->type = direction; 919241699cdSAl Viro i->pipe = pipe; 920241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 921241699cdSAl Viro i->iov_offset = 0; 922241699cdSAl Viro i->count = count; 92327c0e374SAl Viro i->start_idx = i->idx; 924241699cdSAl Viro } 925241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 926241699cdSAl Viro 927d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 928d879cb83SAl Viro { 929d879cb83SAl Viro unsigned long res = 0; 930d879cb83SAl Viro size_t size = i->count; 931d879cb83SAl Viro 932241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 93333844e66SAl Viro if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 934241699cdSAl Viro return size | i->iov_offset; 935241699cdSAl Viro return size; 936241699cdSAl Viro } 937d879cb83SAl Viro iterate_all_kinds(i, size, v, 938d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 939d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 940d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 941d879cb83SAl Viro ) 942d879cb83SAl Viro return res; 943d879cb83SAl Viro } 944d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 945d879cb83SAl Viro 946357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 947357f435dSAl Viro { 948357f435dSAl Viro unsigned long res = 0; 949357f435dSAl Viro size_t size = i->count; 950357f435dSAl Viro 951241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 952241699cdSAl Viro WARN_ON(1); 953241699cdSAl Viro return ~0U; 954241699cdSAl Viro } 955241699cdSAl Viro 956357f435dSAl Viro iterate_all_kinds(i, size, v, 957357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 958357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 959357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 960357f435dSAl Viro (size != v.bv_len ? size : 0)), 961357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 962357f435dSAl Viro (size != v.iov_len ? size : 0)) 963357f435dSAl Viro ); 964357f435dSAl Viro return res; 965357f435dSAl Viro } 966357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 967357f435dSAl Viro 968241699cdSAl Viro static inline size_t __pipe_get_pages(struct iov_iter *i, 969241699cdSAl Viro size_t maxsize, 970241699cdSAl Viro struct page **pages, 971241699cdSAl Viro int idx, 972241699cdSAl Viro size_t *start) 973241699cdSAl Viro { 974241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 9751689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 976241699cdSAl Viro if (!n) 977241699cdSAl Viro return -EFAULT; 978241699cdSAl Viro 979241699cdSAl Viro maxsize = n; 980241699cdSAl Viro n += *start; 9811689c73aSAl Viro while (n > 0) { 982241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 983241699cdSAl Viro idx = next_idx(idx, pipe); 984241699cdSAl Viro n -= PAGE_SIZE; 985241699cdSAl Viro } 986241699cdSAl Viro 987241699cdSAl Viro return maxsize; 988241699cdSAl Viro } 989241699cdSAl Viro 990241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 991241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 992241699cdSAl Viro size_t *start) 993241699cdSAl Viro { 994241699cdSAl Viro unsigned npages; 995241699cdSAl Viro size_t capacity; 996241699cdSAl Viro int idx; 997241699cdSAl Viro 99833844e66SAl Viro if (!maxsize) 99933844e66SAl Viro return 0; 100033844e66SAl Viro 1001241699cdSAl Viro if (!sanity(i)) 1002241699cdSAl Viro return -EFAULT; 1003241699cdSAl Viro 1004241699cdSAl Viro data_start(i, &idx, start); 1005241699cdSAl Viro /* some of this one + all after this one */ 1006241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1007241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 1008241699cdSAl Viro 1009241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 1010241699cdSAl Viro } 1011241699cdSAl Viro 1012d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1013d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1014d879cb83SAl Viro size_t *start) 1015d879cb83SAl Viro { 1016d879cb83SAl Viro if (maxsize > i->count) 1017d879cb83SAl Viro maxsize = i->count; 1018d879cb83SAl Viro 1019241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1020241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 1021d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1022d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1023d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1024d879cb83SAl Viro int n; 1025d879cb83SAl Viro int res; 1026d879cb83SAl Viro 1027d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1028d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1029d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1030d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1031d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); 1032d879cb83SAl Viro if (unlikely(res < 0)) 1033d879cb83SAl Viro return res; 1034d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1035d879cb83SAl Viro 0;}),({ 1036d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1037d879cb83SAl Viro *start = v.bv_offset; 1038d879cb83SAl Viro get_page(*pages = v.bv_page); 1039d879cb83SAl Viro return v.bv_len; 1040d879cb83SAl Viro }),({ 1041d879cb83SAl Viro return -EFAULT; 1042d879cb83SAl Viro }) 1043d879cb83SAl Viro ) 1044d879cb83SAl Viro return 0; 1045d879cb83SAl Viro } 1046d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1047d879cb83SAl Viro 1048d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1049d879cb83SAl Viro { 1050752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1051d879cb83SAl Viro } 1052d879cb83SAl Viro 1053241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1054241699cdSAl Viro struct page ***pages, size_t maxsize, 1055241699cdSAl Viro size_t *start) 1056241699cdSAl Viro { 1057241699cdSAl Viro struct page **p; 1058241699cdSAl Viro size_t n; 1059241699cdSAl Viro int idx; 1060241699cdSAl Viro int npages; 1061241699cdSAl Viro 106233844e66SAl Viro if (!maxsize) 106333844e66SAl Viro return 0; 106433844e66SAl Viro 1065241699cdSAl Viro if (!sanity(i)) 1066241699cdSAl Viro return -EFAULT; 1067241699cdSAl Viro 1068241699cdSAl Viro data_start(i, &idx, start); 1069241699cdSAl Viro /* some of this one + all after this one */ 1070241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1071241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1072241699cdSAl Viro if (maxsize > n) 1073241699cdSAl Viro maxsize = n; 1074241699cdSAl Viro else 1075241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1076241699cdSAl Viro p = get_pages_array(npages); 1077241699cdSAl Viro if (!p) 1078241699cdSAl Viro return -ENOMEM; 1079241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 1080241699cdSAl Viro if (n > 0) 1081241699cdSAl Viro *pages = p; 1082241699cdSAl Viro else 1083241699cdSAl Viro kvfree(p); 1084241699cdSAl Viro return n; 1085241699cdSAl Viro } 1086241699cdSAl Viro 1087d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1088d879cb83SAl Viro struct page ***pages, size_t maxsize, 1089d879cb83SAl Viro size_t *start) 1090d879cb83SAl Viro { 1091d879cb83SAl Viro struct page **p; 1092d879cb83SAl Viro 1093d879cb83SAl Viro if (maxsize > i->count) 1094d879cb83SAl Viro maxsize = i->count; 1095d879cb83SAl Viro 1096241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1097241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 1098d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1099d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1100d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1101d879cb83SAl Viro int n; 1102d879cb83SAl Viro int res; 1103d879cb83SAl Viro 1104d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1105d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1106d879cb83SAl Viro p = get_pages_array(n); 1107d879cb83SAl Viro if (!p) 1108d879cb83SAl Viro return -ENOMEM; 1109d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); 1110d879cb83SAl Viro if (unlikely(res < 0)) { 1111d879cb83SAl Viro kvfree(p); 1112d879cb83SAl Viro return res; 1113d879cb83SAl Viro } 1114d879cb83SAl Viro *pages = p; 1115d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1116d879cb83SAl Viro 0;}),({ 1117d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1118d879cb83SAl Viro *start = v.bv_offset; 1119d879cb83SAl Viro *pages = p = get_pages_array(1); 1120d879cb83SAl Viro if (!p) 1121d879cb83SAl Viro return -ENOMEM; 1122d879cb83SAl Viro get_page(*p = v.bv_page); 1123d879cb83SAl Viro return v.bv_len; 1124d879cb83SAl Viro }),({ 1125d879cb83SAl Viro return -EFAULT; 1126d879cb83SAl Viro }) 1127d879cb83SAl Viro ) 1128d879cb83SAl Viro return 0; 1129d879cb83SAl Viro } 1130d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1131d879cb83SAl Viro 1132d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1133d879cb83SAl Viro struct iov_iter *i) 1134d879cb83SAl Viro { 1135d879cb83SAl Viro char *to = addr; 1136d879cb83SAl Viro __wsum sum, next; 1137d879cb83SAl Viro size_t off = 0; 1138d879cb83SAl Viro sum = *csum; 1139241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1140241699cdSAl Viro WARN_ON(1); 1141241699cdSAl Viro return 0; 1142241699cdSAl Viro } 1143d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1144d879cb83SAl Viro int err = 0; 1145d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1146d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1147d879cb83SAl Viro v.iov_len, 0, &err); 1148d879cb83SAl Viro if (!err) { 1149d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1150d879cb83SAl Viro off += v.iov_len; 1151d879cb83SAl Viro } 1152d879cb83SAl Viro err ? v.iov_len : 0; 1153d879cb83SAl Viro }), ({ 1154d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1155d879cb83SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1156d879cb83SAl Viro (to += v.bv_len) - v.bv_len, 1157d879cb83SAl Viro v.bv_len, 0); 1158d879cb83SAl Viro kunmap_atomic(p); 1159d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1160d879cb83SAl Viro off += v.bv_len; 1161d879cb83SAl Viro }),({ 1162d879cb83SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1163d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1164d879cb83SAl Viro v.iov_len, 0); 1165d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1166d879cb83SAl Viro off += v.iov_len; 1167d879cb83SAl Viro }) 1168d879cb83SAl Viro ) 1169d879cb83SAl Viro *csum = sum; 1170d879cb83SAl Viro return bytes; 1171d879cb83SAl Viro } 1172d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1173d879cb83SAl Viro 1174cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1175cbbd26b8SAl Viro struct iov_iter *i) 1176cbbd26b8SAl Viro { 1177cbbd26b8SAl Viro char *to = addr; 1178cbbd26b8SAl Viro __wsum sum, next; 1179cbbd26b8SAl Viro size_t off = 0; 1180cbbd26b8SAl Viro sum = *csum; 1181cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 1182cbbd26b8SAl Viro WARN_ON(1); 1183cbbd26b8SAl Viro return false; 1184cbbd26b8SAl Viro } 1185cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1186cbbd26b8SAl Viro return false; 1187cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1188cbbd26b8SAl Viro int err = 0; 1189cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1190cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1191cbbd26b8SAl Viro v.iov_len, 0, &err); 1192cbbd26b8SAl Viro if (err) 1193cbbd26b8SAl Viro return false; 1194cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1195cbbd26b8SAl Viro off += v.iov_len; 1196cbbd26b8SAl Viro 0; 1197cbbd26b8SAl Viro }), ({ 1198cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1199cbbd26b8SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1200cbbd26b8SAl Viro (to += v.bv_len) - v.bv_len, 1201cbbd26b8SAl Viro v.bv_len, 0); 1202cbbd26b8SAl Viro kunmap_atomic(p); 1203cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1204cbbd26b8SAl Viro off += v.bv_len; 1205cbbd26b8SAl Viro }),({ 1206cbbd26b8SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1207cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1208cbbd26b8SAl Viro v.iov_len, 0); 1209cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1210cbbd26b8SAl Viro off += v.iov_len; 1211cbbd26b8SAl Viro }) 1212cbbd26b8SAl Viro ) 1213cbbd26b8SAl Viro *csum = sum; 1214cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1215cbbd26b8SAl Viro return true; 1216cbbd26b8SAl Viro } 1217cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1218cbbd26b8SAl Viro 121936f7a8a4SAl Viro size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, 1220d879cb83SAl Viro struct iov_iter *i) 1221d879cb83SAl Viro { 122236f7a8a4SAl Viro const char *from = addr; 1223d879cb83SAl Viro __wsum sum, next; 1224d879cb83SAl Viro size_t off = 0; 1225d879cb83SAl Viro sum = *csum; 1226241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1227241699cdSAl Viro WARN_ON(1); /* for now */ 1228241699cdSAl Viro return 0; 1229241699cdSAl Viro } 1230d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1231d879cb83SAl Viro int err = 0; 1232d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1233d879cb83SAl Viro v.iov_base, 1234d879cb83SAl Viro v.iov_len, 0, &err); 1235d879cb83SAl Viro if (!err) { 1236d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1237d879cb83SAl Viro off += v.iov_len; 1238d879cb83SAl Viro } 1239d879cb83SAl Viro err ? v.iov_len : 0; 1240d879cb83SAl Viro }), ({ 1241d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1242d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, 1243d879cb83SAl Viro p + v.bv_offset, 1244d879cb83SAl Viro v.bv_len, 0); 1245d879cb83SAl Viro kunmap_atomic(p); 1246d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1247d879cb83SAl Viro off += v.bv_len; 1248d879cb83SAl Viro }),({ 1249d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, 1250d879cb83SAl Viro v.iov_base, 1251d879cb83SAl Viro v.iov_len, 0); 1252d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1253d879cb83SAl Viro off += v.iov_len; 1254d879cb83SAl Viro }) 1255d879cb83SAl Viro ) 1256d879cb83SAl Viro *csum = sum; 1257d879cb83SAl Viro return bytes; 1258d879cb83SAl Viro } 1259d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1260d879cb83SAl Viro 1261d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1262d879cb83SAl Viro { 1263d879cb83SAl Viro size_t size = i->count; 1264d879cb83SAl Viro int npages = 0; 1265d879cb83SAl Viro 1266d879cb83SAl Viro if (!size) 1267d879cb83SAl Viro return 0; 1268d879cb83SAl Viro 1269241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1270241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1271241699cdSAl Viro size_t off; 1272241699cdSAl Viro int idx; 1273241699cdSAl Viro 1274241699cdSAl Viro if (!sanity(i)) 1275241699cdSAl Viro return 0; 1276241699cdSAl Viro 1277241699cdSAl Viro data_start(i, &idx, &off); 1278241699cdSAl Viro /* some of this one + all after this one */ 1279241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1280241699cdSAl Viro if (npages >= maxpages) 1281241699cdSAl Viro return maxpages; 1282241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1283d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1284d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1285d879cb83SAl Viro - p / PAGE_SIZE; 1286d879cb83SAl Viro if (npages >= maxpages) 1287d879cb83SAl Viro return maxpages; 1288d879cb83SAl Viro 0;}),({ 1289d879cb83SAl Viro npages++; 1290d879cb83SAl Viro if (npages >= maxpages) 1291d879cb83SAl Viro return maxpages; 1292d879cb83SAl Viro }),({ 1293d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1294d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1295d879cb83SAl Viro - p / PAGE_SIZE; 1296d879cb83SAl Viro if (npages >= maxpages) 1297d879cb83SAl Viro return maxpages; 1298d879cb83SAl Viro }) 1299d879cb83SAl Viro ) 1300d879cb83SAl Viro return npages; 1301d879cb83SAl Viro } 1302d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1303d879cb83SAl Viro 1304d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1305d879cb83SAl Viro { 1306d879cb83SAl Viro *new = *old; 1307241699cdSAl Viro if (unlikely(new->type & ITER_PIPE)) { 1308241699cdSAl Viro WARN_ON(1); 1309241699cdSAl Viro return NULL; 1310241699cdSAl Viro } 1311d879cb83SAl Viro if (new->type & ITER_BVEC) 1312d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1313d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1314d879cb83SAl Viro flags); 1315d879cb83SAl Viro else 1316d879cb83SAl Viro /* iovec and kvec have identical layout */ 1317d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1318d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1319d879cb83SAl Viro flags); 1320d879cb83SAl Viro } 1321d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1322bc917be8SAl Viro 1323ffecee4fSVegard Nossum /** 1324ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1325ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1326ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1327ffecee4fSVegard Nossum * 1328ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1329ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1330ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1331ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1332ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1333ffecee4fSVegard Nossum * on-stack) kernel array. 1334ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1335ffecee4fSVegard Nossum * 1336ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1337ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1338ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1339ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1340ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1341ffecee4fSVegard Nossum * returns an error or not). 1342ffecee4fSVegard Nossum * 1343ffecee4fSVegard Nossum * Return: 0 on success or negative error code on error. 1344ffecee4fSVegard Nossum */ 1345bc917be8SAl Viro int import_iovec(int type, const struct iovec __user * uvector, 1346bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1347bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1348bc917be8SAl Viro { 1349bc917be8SAl Viro ssize_t n; 1350bc917be8SAl Viro struct iovec *p; 1351bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1352bc917be8SAl Viro *iov, &p); 1353bc917be8SAl Viro if (n < 0) { 1354bc917be8SAl Viro if (p != *iov) 1355bc917be8SAl Viro kfree(p); 1356bc917be8SAl Viro *iov = NULL; 1357bc917be8SAl Viro return n; 1358bc917be8SAl Viro } 1359bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1360bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1361bc917be8SAl Viro return 0; 1362bc917be8SAl Viro } 1363bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1364bc917be8SAl Viro 1365bc917be8SAl Viro #ifdef CONFIG_COMPAT 1366bc917be8SAl Viro #include <linux/compat.h> 1367bc917be8SAl Viro 1368bc917be8SAl Viro int compat_import_iovec(int type, const struct compat_iovec __user * uvector, 1369bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1370bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1371bc917be8SAl Viro { 1372bc917be8SAl Viro ssize_t n; 1373bc917be8SAl Viro struct iovec *p; 1374bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1375bc917be8SAl Viro *iov, &p); 1376bc917be8SAl Viro if (n < 0) { 1377bc917be8SAl Viro if (p != *iov) 1378bc917be8SAl Viro kfree(p); 1379bc917be8SAl Viro *iov = NULL; 1380bc917be8SAl Viro return n; 1381bc917be8SAl Viro } 1382bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1383bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1384bc917be8SAl Viro return 0; 1385bc917be8SAl Viro } 1386bc917be8SAl Viro #endif 1387bc917be8SAl Viro 1388bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1389bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1390bc917be8SAl Viro { 1391bc917be8SAl Viro if (len > MAX_RW_COUNT) 1392bc917be8SAl Viro len = MAX_RW_COUNT; 1393bc917be8SAl Viro if (unlikely(!access_ok(!rw, buf, len))) 1394bc917be8SAl Viro return -EFAULT; 1395bc917be8SAl Viro 1396bc917be8SAl Viro iov->iov_base = buf; 1397bc917be8SAl Viro iov->iov_len = len; 1398bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1399bc917be8SAl Viro return 0; 1400bc917be8SAl Viro } 1401e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 1402