1d879cb83SAl Viro #include <linux/export.h> 22f8b5444SChristoph Hellwig #include <linux/bvec.h> 3d879cb83SAl Viro #include <linux/uio.h> 4d879cb83SAl Viro #include <linux/pagemap.h> 5d879cb83SAl Viro #include <linux/slab.h> 6d879cb83SAl Viro #include <linux/vmalloc.h> 7241699cdSAl Viro #include <linux/splice.h> 8d879cb83SAl Viro #include <net/checksum.h> 9d879cb83SAl Viro 10241699cdSAl Viro #define PIPE_PARANOIA /* for now */ 11241699cdSAl Viro 12d879cb83SAl Viro #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ 13d879cb83SAl Viro size_t left; \ 14d879cb83SAl Viro size_t wanted = n; \ 15d879cb83SAl Viro __p = i->iov; \ 16d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 17d879cb83SAl Viro if (likely(__v.iov_len)) { \ 18d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 19d879cb83SAl Viro left = (STEP); \ 20d879cb83SAl Viro __v.iov_len -= left; \ 21d879cb83SAl Viro skip += __v.iov_len; \ 22d879cb83SAl Viro n -= __v.iov_len; \ 23d879cb83SAl Viro } else { \ 24d879cb83SAl Viro left = 0; \ 25d879cb83SAl Viro } \ 26d879cb83SAl Viro while (unlikely(!left && n)) { \ 27d879cb83SAl Viro __p++; \ 28d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 29d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 30d879cb83SAl Viro continue; \ 31d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 32d879cb83SAl Viro left = (STEP); \ 33d879cb83SAl Viro __v.iov_len -= left; \ 34d879cb83SAl Viro skip = __v.iov_len; \ 35d879cb83SAl Viro n -= __v.iov_len; \ 36d879cb83SAl Viro } \ 37d879cb83SAl Viro n = wanted - n; \ 38d879cb83SAl Viro } 39d879cb83SAl Viro 40d879cb83SAl Viro #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ 41d879cb83SAl Viro size_t wanted = n; \ 42d879cb83SAl Viro __p = i->kvec; \ 43d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 44d879cb83SAl Viro if (likely(__v.iov_len)) { \ 45d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 46d879cb83SAl Viro (void)(STEP); \ 47d879cb83SAl Viro skip += __v.iov_len; \ 48d879cb83SAl Viro n -= __v.iov_len; \ 49d879cb83SAl Viro } \ 50d879cb83SAl Viro while (unlikely(n)) { \ 51d879cb83SAl Viro __p++; \ 52d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 53d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 54d879cb83SAl Viro continue; \ 55d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 56d879cb83SAl Viro (void)(STEP); \ 57d879cb83SAl Viro skip = __v.iov_len; \ 58d879cb83SAl Viro n -= __v.iov_len; \ 59d879cb83SAl Viro } \ 60d879cb83SAl Viro n = wanted; \ 61d879cb83SAl Viro } 62d879cb83SAl Viro 631bdc76aeSMing Lei #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ 641bdc76aeSMing Lei struct bvec_iter __start; \ 651bdc76aeSMing Lei __start.bi_size = n; \ 661bdc76aeSMing Lei __start.bi_bvec_done = skip; \ 671bdc76aeSMing Lei __start.bi_idx = 0; \ 681bdc76aeSMing Lei for_each_bvec(__v, i->bvec, __bi, __start) { \ 691bdc76aeSMing Lei if (!__v.bv_len) \ 70d879cb83SAl Viro continue; \ 71d879cb83SAl Viro (void)(STEP); \ 72d879cb83SAl Viro } \ 73d879cb83SAl Viro } 74d879cb83SAl Viro 75d879cb83SAl Viro #define iterate_all_kinds(i, n, v, I, B, K) { \ 7633844e66SAl Viro if (likely(n)) { \ 77d879cb83SAl Viro size_t skip = i->iov_offset; \ 78d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 79d879cb83SAl Viro struct bio_vec v; \ 801bdc76aeSMing Lei struct bvec_iter __bi; \ 811bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 82d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 83d879cb83SAl Viro const struct kvec *kvec; \ 84d879cb83SAl Viro struct kvec v; \ 85d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 86d879cb83SAl Viro } else { \ 87d879cb83SAl Viro const struct iovec *iov; \ 88d879cb83SAl Viro struct iovec v; \ 89d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 90d879cb83SAl Viro } \ 9133844e66SAl Viro } \ 92d879cb83SAl Viro } 93d879cb83SAl Viro 94d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 95dd254f5aSAl Viro if (unlikely(i->count < n)) \ 96dd254f5aSAl Viro n = i->count; \ 9719f18459SAl Viro if (i->count) { \ 98d879cb83SAl Viro size_t skip = i->iov_offset; \ 99d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 1001bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 101d879cb83SAl Viro struct bio_vec v; \ 1021bdc76aeSMing Lei struct bvec_iter __bi; \ 1031bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1041bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1051bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1061bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 107d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 108d879cb83SAl Viro const struct kvec *kvec; \ 109d879cb83SAl Viro struct kvec v; \ 110d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 111d879cb83SAl Viro if (skip == kvec->iov_len) { \ 112d879cb83SAl Viro kvec++; \ 113d879cb83SAl Viro skip = 0; \ 114d879cb83SAl Viro } \ 115d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 116d879cb83SAl Viro i->kvec = kvec; \ 117d879cb83SAl Viro } else { \ 118d879cb83SAl Viro const struct iovec *iov; \ 119d879cb83SAl Viro struct iovec v; \ 120d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 121d879cb83SAl Viro if (skip == iov->iov_len) { \ 122d879cb83SAl Viro iov++; \ 123d879cb83SAl Viro skip = 0; \ 124d879cb83SAl Viro } \ 125d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 126d879cb83SAl Viro i->iov = iov; \ 127d879cb83SAl Viro } \ 128d879cb83SAl Viro i->count -= n; \ 129d879cb83SAl Viro i->iov_offset = skip; \ 130dd254f5aSAl Viro } \ 131d879cb83SAl Viro } 132d879cb83SAl Viro 13309fc68dcSAl Viro static int copyout(void __user *to, const void *from, size_t n) 13409fc68dcSAl Viro { 13509fc68dcSAl Viro if (access_ok(VERIFY_WRITE, to, n)) { 13609fc68dcSAl Viro kasan_check_read(from, n); 13709fc68dcSAl Viro n = raw_copy_to_user(to, from, n); 13809fc68dcSAl Viro } 13909fc68dcSAl Viro return n; 14009fc68dcSAl Viro } 14109fc68dcSAl Viro 14209fc68dcSAl Viro static int copyin(void *to, const void __user *from, size_t n) 14309fc68dcSAl Viro { 14409fc68dcSAl Viro if (access_ok(VERIFY_READ, from, n)) { 14509fc68dcSAl Viro kasan_check_write(to, n); 14609fc68dcSAl Viro n = raw_copy_from_user(to, from, n); 14709fc68dcSAl Viro } 14809fc68dcSAl Viro return n; 14909fc68dcSAl Viro } 15009fc68dcSAl Viro 151d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 152d879cb83SAl Viro struct iov_iter *i) 153d879cb83SAl Viro { 154d879cb83SAl Viro size_t skip, copy, left, wanted; 155d879cb83SAl Viro const struct iovec *iov; 156d879cb83SAl Viro char __user *buf; 157d879cb83SAl Viro void *kaddr, *from; 158d879cb83SAl Viro 159d879cb83SAl Viro if (unlikely(bytes > i->count)) 160d879cb83SAl Viro bytes = i->count; 161d879cb83SAl Viro 162d879cb83SAl Viro if (unlikely(!bytes)) 163d879cb83SAl Viro return 0; 164d879cb83SAl Viro 16509fc68dcSAl Viro might_fault(); 166d879cb83SAl Viro wanted = bytes; 167d879cb83SAl Viro iov = i->iov; 168d879cb83SAl Viro skip = i->iov_offset; 169d879cb83SAl Viro buf = iov->iov_base + skip; 170d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 171d879cb83SAl Viro 1723fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 173d879cb83SAl Viro kaddr = kmap_atomic(page); 174d879cb83SAl Viro from = kaddr + offset; 175d879cb83SAl Viro 176d879cb83SAl Viro /* first chunk, usually the only one */ 17709fc68dcSAl Viro left = copyout(buf, from, copy); 178d879cb83SAl Viro copy -= left; 179d879cb83SAl Viro skip += copy; 180d879cb83SAl Viro from += copy; 181d879cb83SAl Viro bytes -= copy; 182d879cb83SAl Viro 183d879cb83SAl Viro while (unlikely(!left && bytes)) { 184d879cb83SAl Viro iov++; 185d879cb83SAl Viro buf = iov->iov_base; 186d879cb83SAl Viro copy = min(bytes, iov->iov_len); 18709fc68dcSAl Viro left = copyout(buf, from, copy); 188d879cb83SAl Viro copy -= left; 189d879cb83SAl Viro skip = copy; 190d879cb83SAl Viro from += copy; 191d879cb83SAl Viro bytes -= copy; 192d879cb83SAl Viro } 193d879cb83SAl Viro if (likely(!bytes)) { 194d879cb83SAl Viro kunmap_atomic(kaddr); 195d879cb83SAl Viro goto done; 196d879cb83SAl Viro } 197d879cb83SAl Viro offset = from - kaddr; 198d879cb83SAl Viro buf += copy; 199d879cb83SAl Viro kunmap_atomic(kaddr); 200d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 201d879cb83SAl Viro } 202d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2033fa6c507SMikulas Patocka 204d879cb83SAl Viro kaddr = kmap(page); 205d879cb83SAl Viro from = kaddr + offset; 20609fc68dcSAl Viro left = copyout(buf, from, copy); 207d879cb83SAl Viro copy -= left; 208d879cb83SAl Viro skip += copy; 209d879cb83SAl Viro from += copy; 210d879cb83SAl Viro bytes -= copy; 211d879cb83SAl Viro while (unlikely(!left && bytes)) { 212d879cb83SAl Viro iov++; 213d879cb83SAl Viro buf = iov->iov_base; 214d879cb83SAl Viro copy = min(bytes, iov->iov_len); 21509fc68dcSAl Viro left = copyout(buf, from, copy); 216d879cb83SAl Viro copy -= left; 217d879cb83SAl Viro skip = copy; 218d879cb83SAl Viro from += copy; 219d879cb83SAl Viro bytes -= copy; 220d879cb83SAl Viro } 221d879cb83SAl Viro kunmap(page); 2223fa6c507SMikulas Patocka 223d879cb83SAl Viro done: 224d879cb83SAl Viro if (skip == iov->iov_len) { 225d879cb83SAl Viro iov++; 226d879cb83SAl Viro skip = 0; 227d879cb83SAl Viro } 228d879cb83SAl Viro i->count -= wanted - bytes; 229d879cb83SAl Viro i->nr_segs -= iov - i->iov; 230d879cb83SAl Viro i->iov = iov; 231d879cb83SAl Viro i->iov_offset = skip; 232d879cb83SAl Viro return wanted - bytes; 233d879cb83SAl Viro } 234d879cb83SAl Viro 235d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 236d879cb83SAl Viro struct iov_iter *i) 237d879cb83SAl Viro { 238d879cb83SAl Viro size_t skip, copy, left, wanted; 239d879cb83SAl Viro const struct iovec *iov; 240d879cb83SAl Viro char __user *buf; 241d879cb83SAl Viro void *kaddr, *to; 242d879cb83SAl Viro 243d879cb83SAl Viro if (unlikely(bytes > i->count)) 244d879cb83SAl Viro bytes = i->count; 245d879cb83SAl Viro 246d879cb83SAl Viro if (unlikely(!bytes)) 247d879cb83SAl Viro return 0; 248d879cb83SAl Viro 24909fc68dcSAl Viro might_fault(); 250d879cb83SAl Viro wanted = bytes; 251d879cb83SAl Viro iov = i->iov; 252d879cb83SAl Viro skip = i->iov_offset; 253d879cb83SAl Viro buf = iov->iov_base + skip; 254d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 255d879cb83SAl Viro 2563fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 257d879cb83SAl Viro kaddr = kmap_atomic(page); 258d879cb83SAl Viro to = kaddr + offset; 259d879cb83SAl Viro 260d879cb83SAl Viro /* first chunk, usually the only one */ 26109fc68dcSAl Viro left = copyin(to, buf, copy); 262d879cb83SAl Viro copy -= left; 263d879cb83SAl Viro skip += copy; 264d879cb83SAl Viro to += copy; 265d879cb83SAl Viro bytes -= copy; 266d879cb83SAl Viro 267d879cb83SAl Viro while (unlikely(!left && bytes)) { 268d879cb83SAl Viro iov++; 269d879cb83SAl Viro buf = iov->iov_base; 270d879cb83SAl Viro copy = min(bytes, iov->iov_len); 27109fc68dcSAl Viro left = copyin(to, buf, copy); 272d879cb83SAl Viro copy -= left; 273d879cb83SAl Viro skip = copy; 274d879cb83SAl Viro to += copy; 275d879cb83SAl Viro bytes -= copy; 276d879cb83SAl Viro } 277d879cb83SAl Viro if (likely(!bytes)) { 278d879cb83SAl Viro kunmap_atomic(kaddr); 279d879cb83SAl Viro goto done; 280d879cb83SAl Viro } 281d879cb83SAl Viro offset = to - kaddr; 282d879cb83SAl Viro buf += copy; 283d879cb83SAl Viro kunmap_atomic(kaddr); 284d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 285d879cb83SAl Viro } 286d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2873fa6c507SMikulas Patocka 288d879cb83SAl Viro kaddr = kmap(page); 289d879cb83SAl Viro to = kaddr + offset; 29009fc68dcSAl Viro left = copyin(to, buf, copy); 291d879cb83SAl Viro copy -= left; 292d879cb83SAl Viro skip += copy; 293d879cb83SAl Viro to += copy; 294d879cb83SAl Viro bytes -= copy; 295d879cb83SAl Viro while (unlikely(!left && bytes)) { 296d879cb83SAl Viro iov++; 297d879cb83SAl Viro buf = iov->iov_base; 298d879cb83SAl Viro copy = min(bytes, iov->iov_len); 29909fc68dcSAl Viro left = copyin(to, buf, copy); 300d879cb83SAl Viro copy -= left; 301d879cb83SAl Viro skip = copy; 302d879cb83SAl Viro to += copy; 303d879cb83SAl Viro bytes -= copy; 304d879cb83SAl Viro } 305d879cb83SAl Viro kunmap(page); 3063fa6c507SMikulas Patocka 307d879cb83SAl Viro done: 308d879cb83SAl Viro if (skip == iov->iov_len) { 309d879cb83SAl Viro iov++; 310d879cb83SAl Viro skip = 0; 311d879cb83SAl Viro } 312d879cb83SAl Viro i->count -= wanted - bytes; 313d879cb83SAl Viro i->nr_segs -= iov - i->iov; 314d879cb83SAl Viro i->iov = iov; 315d879cb83SAl Viro i->iov_offset = skip; 316d879cb83SAl Viro return wanted - bytes; 317d879cb83SAl Viro } 318d879cb83SAl Viro 319241699cdSAl Viro #ifdef PIPE_PARANOIA 320241699cdSAl Viro static bool sanity(const struct iov_iter *i) 321241699cdSAl Viro { 322241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 323241699cdSAl Viro int idx = i->idx; 324241699cdSAl Viro int next = pipe->curbuf + pipe->nrbufs; 325241699cdSAl Viro if (i->iov_offset) { 326241699cdSAl Viro struct pipe_buffer *p; 327241699cdSAl Viro if (unlikely(!pipe->nrbufs)) 328241699cdSAl Viro goto Bad; // pipe must be non-empty 329241699cdSAl Viro if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) 330241699cdSAl Viro goto Bad; // must be at the last buffer... 331241699cdSAl Viro 332241699cdSAl Viro p = &pipe->bufs[idx]; 333241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 334241699cdSAl Viro goto Bad; // ... at the end of segment 335241699cdSAl Viro } else { 336241699cdSAl Viro if (idx != (next & (pipe->buffers - 1))) 337241699cdSAl Viro goto Bad; // must be right after the last buffer 338241699cdSAl Viro } 339241699cdSAl Viro return true; 340241699cdSAl Viro Bad: 341241699cdSAl Viro printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); 342241699cdSAl Viro printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", 343241699cdSAl Viro pipe->curbuf, pipe->nrbufs, pipe->buffers); 344241699cdSAl Viro for (idx = 0; idx < pipe->buffers; idx++) 345241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 346241699cdSAl Viro pipe->bufs[idx].ops, 347241699cdSAl Viro pipe->bufs[idx].page, 348241699cdSAl Viro pipe->bufs[idx].offset, 349241699cdSAl Viro pipe->bufs[idx].len); 350241699cdSAl Viro WARN_ON(1); 351241699cdSAl Viro return false; 352241699cdSAl Viro } 353241699cdSAl Viro #else 354241699cdSAl Viro #define sanity(i) true 355241699cdSAl Viro #endif 356241699cdSAl Viro 357241699cdSAl Viro static inline int next_idx(int idx, struct pipe_inode_info *pipe) 358241699cdSAl Viro { 359241699cdSAl Viro return (idx + 1) & (pipe->buffers - 1); 360241699cdSAl Viro } 361241699cdSAl Viro 362241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 363241699cdSAl Viro struct iov_iter *i) 364241699cdSAl Viro { 365241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 366241699cdSAl Viro struct pipe_buffer *buf; 367241699cdSAl Viro size_t off; 368241699cdSAl Viro int idx; 369241699cdSAl Viro 370241699cdSAl Viro if (unlikely(bytes > i->count)) 371241699cdSAl Viro bytes = i->count; 372241699cdSAl Viro 373241699cdSAl Viro if (unlikely(!bytes)) 374241699cdSAl Viro return 0; 375241699cdSAl Viro 376241699cdSAl Viro if (!sanity(i)) 377241699cdSAl Viro return 0; 378241699cdSAl Viro 379241699cdSAl Viro off = i->iov_offset; 380241699cdSAl Viro idx = i->idx; 381241699cdSAl Viro buf = &pipe->bufs[idx]; 382241699cdSAl Viro if (off) { 383241699cdSAl Viro if (offset == off && buf->page == page) { 384241699cdSAl Viro /* merge with the last one */ 385241699cdSAl Viro buf->len += bytes; 386241699cdSAl Viro i->iov_offset += bytes; 387241699cdSAl Viro goto out; 388241699cdSAl Viro } 389241699cdSAl Viro idx = next_idx(idx, pipe); 390241699cdSAl Viro buf = &pipe->bufs[idx]; 391241699cdSAl Viro } 392241699cdSAl Viro if (idx == pipe->curbuf && pipe->nrbufs) 393241699cdSAl Viro return 0; 394241699cdSAl Viro pipe->nrbufs++; 395241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 396241699cdSAl Viro get_page(buf->page = page); 397241699cdSAl Viro buf->offset = offset; 398241699cdSAl Viro buf->len = bytes; 399241699cdSAl Viro i->iov_offset = offset + bytes; 400241699cdSAl Viro i->idx = idx; 401241699cdSAl Viro out: 402241699cdSAl Viro i->count -= bytes; 403241699cdSAl Viro return bytes; 404241699cdSAl Viro } 405241699cdSAl Viro 406d879cb83SAl Viro /* 407171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 408171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 409171a0203SAnton Altaparmakov * 410171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 411171a0203SAnton Altaparmakov * because it is an invalid address). 412171a0203SAnton Altaparmakov */ 413d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 414171a0203SAnton Altaparmakov { 415171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 416171a0203SAnton Altaparmakov const struct iovec *iov; 417171a0203SAnton Altaparmakov int err; 418171a0203SAnton Altaparmakov struct iovec v; 419171a0203SAnton Altaparmakov 420171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 421171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4224bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 423171a0203SAnton Altaparmakov if (unlikely(err)) 424171a0203SAnton Altaparmakov return err; 425171a0203SAnton Altaparmakov 0;})) 426171a0203SAnton Altaparmakov } 427171a0203SAnton Altaparmakov return 0; 428171a0203SAnton Altaparmakov } 429d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 430171a0203SAnton Altaparmakov 431d879cb83SAl Viro void iov_iter_init(struct iov_iter *i, int direction, 432d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 433d879cb83SAl Viro size_t count) 434d879cb83SAl Viro { 435d879cb83SAl Viro /* It will get better. Eventually... */ 436db68ce10SAl Viro if (uaccess_kernel()) { 437d879cb83SAl Viro direction |= ITER_KVEC; 438d879cb83SAl Viro i->type = direction; 439d879cb83SAl Viro i->kvec = (struct kvec *)iov; 440d879cb83SAl Viro } else { 441d879cb83SAl Viro i->type = direction; 442d879cb83SAl Viro i->iov = iov; 443d879cb83SAl Viro } 444d879cb83SAl Viro i->nr_segs = nr_segs; 445d879cb83SAl Viro i->iov_offset = 0; 446d879cb83SAl Viro i->count = count; 447d879cb83SAl Viro } 448d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 449d879cb83SAl Viro 450d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 451d879cb83SAl Viro { 452d879cb83SAl Viro char *from = kmap_atomic(page); 453d879cb83SAl Viro memcpy(to, from + offset, len); 454d879cb83SAl Viro kunmap_atomic(from); 455d879cb83SAl Viro } 456d879cb83SAl Viro 45736f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 458d879cb83SAl Viro { 459d879cb83SAl Viro char *to = kmap_atomic(page); 460d879cb83SAl Viro memcpy(to + offset, from, len); 461d879cb83SAl Viro kunmap_atomic(to); 462d879cb83SAl Viro } 463d879cb83SAl Viro 464d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 465d879cb83SAl Viro { 466d879cb83SAl Viro char *addr = kmap_atomic(page); 467d879cb83SAl Viro memset(addr + offset, 0, len); 468d879cb83SAl Viro kunmap_atomic(addr); 469d879cb83SAl Viro } 470d879cb83SAl Viro 471241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 472241699cdSAl Viro { 473241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 474241699cdSAl Viro } 475241699cdSAl Viro 476241699cdSAl Viro static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) 477241699cdSAl Viro { 478241699cdSAl Viro size_t off = i->iov_offset; 479241699cdSAl Viro int idx = i->idx; 480241699cdSAl Viro if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { 481241699cdSAl Viro idx = next_idx(idx, i->pipe); 482241699cdSAl Viro off = 0; 483241699cdSAl Viro } 484241699cdSAl Viro *idxp = idx; 485241699cdSAl Viro *offp = off; 486241699cdSAl Viro } 487241699cdSAl Viro 488241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 489241699cdSAl Viro int *idxp, size_t *offp) 490241699cdSAl Viro { 491241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 492241699cdSAl Viro size_t off; 493241699cdSAl Viro int idx; 494241699cdSAl Viro ssize_t left; 495241699cdSAl Viro 496241699cdSAl Viro if (unlikely(size > i->count)) 497241699cdSAl Viro size = i->count; 498241699cdSAl Viro if (unlikely(!size)) 499241699cdSAl Viro return 0; 500241699cdSAl Viro 501241699cdSAl Viro left = size; 502241699cdSAl Viro data_start(i, &idx, &off); 503241699cdSAl Viro *idxp = idx; 504241699cdSAl Viro *offp = off; 505241699cdSAl Viro if (off) { 506241699cdSAl Viro left -= PAGE_SIZE - off; 507241699cdSAl Viro if (left <= 0) { 508241699cdSAl Viro pipe->bufs[idx].len += size; 509241699cdSAl Viro return size; 510241699cdSAl Viro } 511241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 512241699cdSAl Viro idx = next_idx(idx, pipe); 513241699cdSAl Viro } 514241699cdSAl Viro while (idx != pipe->curbuf || !pipe->nrbufs) { 515241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 516241699cdSAl Viro if (!page) 517241699cdSAl Viro break; 518241699cdSAl Viro pipe->nrbufs++; 519241699cdSAl Viro pipe->bufs[idx].ops = &default_pipe_buf_ops; 520241699cdSAl Viro pipe->bufs[idx].page = page; 521241699cdSAl Viro pipe->bufs[idx].offset = 0; 522241699cdSAl Viro if (left <= PAGE_SIZE) { 523241699cdSAl Viro pipe->bufs[idx].len = left; 524241699cdSAl Viro return size; 525241699cdSAl Viro } 526241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 527241699cdSAl Viro left -= PAGE_SIZE; 528241699cdSAl Viro idx = next_idx(idx, pipe); 529241699cdSAl Viro } 530241699cdSAl Viro return size - left; 531241699cdSAl Viro } 532241699cdSAl Viro 533241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 534241699cdSAl Viro struct iov_iter *i) 535241699cdSAl Viro { 536241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 537241699cdSAl Viro size_t n, off; 538241699cdSAl Viro int idx; 539241699cdSAl Viro 540241699cdSAl Viro if (!sanity(i)) 541241699cdSAl Viro return 0; 542241699cdSAl Viro 543241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 544241699cdSAl Viro if (unlikely(!n)) 545241699cdSAl Viro return 0; 546241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 547241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 548241699cdSAl Viro memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); 549241699cdSAl Viro i->idx = idx; 550241699cdSAl Viro i->iov_offset = off + chunk; 551241699cdSAl Viro n -= chunk; 552241699cdSAl Viro addr += chunk; 553241699cdSAl Viro } 554241699cdSAl Viro i->count -= bytes; 555241699cdSAl Viro return bytes; 556241699cdSAl Viro } 557241699cdSAl Viro 558aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 559d879cb83SAl Viro { 56036f7a8a4SAl Viro const char *from = addr; 561241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 562241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 56309fc68dcSAl Viro if (iter_is_iovec(i)) 56409fc68dcSAl Viro might_fault(); 565d879cb83SAl Viro iterate_and_advance(i, bytes, v, 56609fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 567d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 568d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 569d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 570d879cb83SAl Viro ) 571d879cb83SAl Viro 572d879cb83SAl Viro return bytes; 573d879cb83SAl Viro } 574aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 575d879cb83SAl Viro 5768780356eSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE 5778780356eSDan Williams static int copyout_mcsafe(void __user *to, const void *from, size_t n) 5788780356eSDan Williams { 5798780356eSDan Williams if (access_ok(VERIFY_WRITE, to, n)) { 5808780356eSDan Williams kasan_check_read(from, n); 5818780356eSDan Williams n = copy_to_user_mcsafe((__force void *) to, from, n); 5828780356eSDan Williams } 5838780356eSDan Williams return n; 5848780356eSDan Williams } 5858780356eSDan Williams 5868780356eSDan Williams static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, 5878780356eSDan Williams const char *from, size_t len) 5888780356eSDan Williams { 5898780356eSDan Williams unsigned long ret; 5908780356eSDan Williams char *to; 5918780356eSDan Williams 5928780356eSDan Williams to = kmap_atomic(page); 5938780356eSDan Williams ret = memcpy_mcsafe(to + offset, from, len); 5948780356eSDan Williams kunmap_atomic(to); 5958780356eSDan Williams 5968780356eSDan Williams return ret; 5978780356eSDan Williams } 5988780356eSDan Williams 599bf3eeb9bSDan Williams /** 600bf3eeb9bSDan Williams * _copy_to_iter_mcsafe - copy to user with source-read error exception handling 601bf3eeb9bSDan Williams * @addr: source kernel address 602bf3eeb9bSDan Williams * @bytes: total transfer length 603bf3eeb9bSDan Williams * @iter: destination iterator 604bf3eeb9bSDan Williams * 605bf3eeb9bSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 606bf3eeb9bSDan Williams * dax_copy_to_iter() for protecting read/write to persistent memory. 607bf3eeb9bSDan Williams * Unless / until an architecture can guarantee identical performance 608bf3eeb9bSDan Williams * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a 609bf3eeb9bSDan Williams * performance regression to switch more users to the mcsafe version. 610bf3eeb9bSDan Williams * 611bf3eeb9bSDan Williams * Otherwise, the main differences between this and typical _copy_to_iter(). 612bf3eeb9bSDan Williams * 613bf3eeb9bSDan Williams * * Typical tail/residue handling after a fault retries the copy 614bf3eeb9bSDan Williams * byte-by-byte until the fault happens again. Re-triggering machine 615bf3eeb9bSDan Williams * checks is potentially fatal so the implementation uses source 616bf3eeb9bSDan Williams * alignment and poison alignment assumptions to avoid re-triggering 617bf3eeb9bSDan Williams * hardware exceptions. 618bf3eeb9bSDan Williams * 619bf3eeb9bSDan Williams * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. 620bf3eeb9bSDan Williams * Compare to copy_to_iter() where only ITER_IOVEC attempts might return 621bf3eeb9bSDan Williams * a short copy. 622bf3eeb9bSDan Williams * 623bf3eeb9bSDan Williams * See MCSAFE_TEST for self-test. 624bf3eeb9bSDan Williams */ 6258780356eSDan Williams size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) 6268780356eSDan Williams { 6278780356eSDan Williams const char *from = addr; 6288780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 6298780356eSDan Williams 6308780356eSDan Williams if (unlikely(i->type & ITER_PIPE)) { 6318780356eSDan Williams WARN_ON(1); 6328780356eSDan Williams return 0; 6338780356eSDan Williams } 6348780356eSDan Williams if (iter_is_iovec(i)) 6358780356eSDan Williams might_fault(); 6368780356eSDan Williams iterate_and_advance(i, bytes, v, 6378780356eSDan Williams copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 6388780356eSDan Williams ({ 6398780356eSDan Williams rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, 6408780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 6418780356eSDan Williams if (rem) { 6428780356eSDan Williams curr_addr = (unsigned long) from; 6438780356eSDan Williams bytes = curr_addr - s_addr - rem; 6448780356eSDan Williams return bytes; 6458780356eSDan Williams } 6468780356eSDan Williams }), 6478780356eSDan Williams ({ 6488780356eSDan Williams rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, 6498780356eSDan Williams v.iov_len); 6508780356eSDan Williams if (rem) { 6518780356eSDan Williams curr_addr = (unsigned long) from; 6528780356eSDan Williams bytes = curr_addr - s_addr - rem; 6538780356eSDan Williams return bytes; 6548780356eSDan Williams } 6558780356eSDan Williams }) 6568780356eSDan Williams ) 6578780356eSDan Williams 6588780356eSDan Williams return bytes; 6598780356eSDan Williams } 6608780356eSDan Williams EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); 6618780356eSDan Williams #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ 6628780356eSDan Williams 663aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 664d879cb83SAl Viro { 665d879cb83SAl Viro char *to = addr; 666241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 667241699cdSAl Viro WARN_ON(1); 668241699cdSAl Viro return 0; 669241699cdSAl Viro } 67009fc68dcSAl Viro if (iter_is_iovec(i)) 67109fc68dcSAl Viro might_fault(); 672d879cb83SAl Viro iterate_and_advance(i, bytes, v, 67309fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 674d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 675d879cb83SAl Viro v.bv_offset, v.bv_len), 676d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 677d879cb83SAl Viro ) 678d879cb83SAl Viro 679d879cb83SAl Viro return bytes; 680d879cb83SAl Viro } 681aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 682d879cb83SAl Viro 683aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 684cbbd26b8SAl Viro { 685cbbd26b8SAl Viro char *to = addr; 686cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 687cbbd26b8SAl Viro WARN_ON(1); 688cbbd26b8SAl Viro return false; 689cbbd26b8SAl Viro } 69033844e66SAl Viro if (unlikely(i->count < bytes)) 691cbbd26b8SAl Viro return false; 692cbbd26b8SAl Viro 69309fc68dcSAl Viro if (iter_is_iovec(i)) 69409fc68dcSAl Viro might_fault(); 695cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 69609fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 697cbbd26b8SAl Viro v.iov_base, v.iov_len)) 698cbbd26b8SAl Viro return false; 699cbbd26b8SAl Viro 0;}), 700cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 701cbbd26b8SAl Viro v.bv_offset, v.bv_len), 702cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 703cbbd26b8SAl Viro ) 704cbbd26b8SAl Viro 705cbbd26b8SAl Viro iov_iter_advance(i, bytes); 706cbbd26b8SAl Viro return true; 707cbbd26b8SAl Viro } 708aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 709cbbd26b8SAl Viro 710aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 711d879cb83SAl Viro { 712d879cb83SAl Viro char *to = addr; 713241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 714241699cdSAl Viro WARN_ON(1); 715241699cdSAl Viro return 0; 716241699cdSAl Viro } 717d879cb83SAl Viro iterate_and_advance(i, bytes, v, 7183f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 719d879cb83SAl Viro v.iov_base, v.iov_len), 720d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 721d879cb83SAl Viro v.bv_offset, v.bv_len), 722d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 723d879cb83SAl Viro ) 724d879cb83SAl Viro 725d879cb83SAl Viro return bytes; 726d879cb83SAl Viro } 727aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 728d879cb83SAl Viro 7290aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 7306a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 7310aed55afSDan Williams { 7320aed55afSDan Williams char *to = addr; 7330aed55afSDan Williams if (unlikely(i->type & ITER_PIPE)) { 7340aed55afSDan Williams WARN_ON(1); 7350aed55afSDan Williams return 0; 7360aed55afSDan Williams } 7370aed55afSDan Williams iterate_and_advance(i, bytes, v, 7380aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 7390aed55afSDan Williams v.iov_base, v.iov_len), 7400aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 7410aed55afSDan Williams v.bv_offset, v.bv_len), 7420aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 7430aed55afSDan Williams v.iov_len) 7440aed55afSDan Williams ) 7450aed55afSDan Williams 7460aed55afSDan Williams return bytes; 7470aed55afSDan Williams } 7486a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 7490aed55afSDan Williams #endif 7500aed55afSDan Williams 751aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 752cbbd26b8SAl Viro { 753cbbd26b8SAl Viro char *to = addr; 754cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 755cbbd26b8SAl Viro WARN_ON(1); 756cbbd26b8SAl Viro return false; 757cbbd26b8SAl Viro } 75833844e66SAl Viro if (unlikely(i->count < bytes)) 759cbbd26b8SAl Viro return false; 760cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 7613f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 762cbbd26b8SAl Viro v.iov_base, v.iov_len)) 763cbbd26b8SAl Viro return false; 764cbbd26b8SAl Viro 0;}), 765cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 766cbbd26b8SAl Viro v.bv_offset, v.bv_len), 767cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 768cbbd26b8SAl Viro ) 769cbbd26b8SAl Viro 770cbbd26b8SAl Viro iov_iter_advance(i, bytes); 771cbbd26b8SAl Viro return true; 772cbbd26b8SAl Viro } 773aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 774cbbd26b8SAl Viro 77572e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 77672e809edSAl Viro { 777a90bcb86SPetar Penkov struct page *head = compound_head(page); 778a90bcb86SPetar Penkov size_t v = n + offset + page_address(page) - page_address(head); 779a90bcb86SPetar Penkov 780a90bcb86SPetar Penkov if (likely(n <= v && v <= (PAGE_SIZE << compound_order(head)))) 78172e809edSAl Viro return true; 78272e809edSAl Viro WARN_ON(1); 78372e809edSAl Viro return false; 78472e809edSAl Viro } 785d879cb83SAl Viro 786d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 787d879cb83SAl Viro struct iov_iter *i) 788d879cb83SAl Viro { 78972e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 79072e809edSAl Viro return 0; 791d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 792d879cb83SAl Viro void *kaddr = kmap_atomic(page); 793d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 794d879cb83SAl Viro kunmap_atomic(kaddr); 795d879cb83SAl Viro return wanted; 796241699cdSAl Viro } else if (likely(!(i->type & ITER_PIPE))) 797d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 798241699cdSAl Viro else 799241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 800d879cb83SAl Viro } 801d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 802d879cb83SAl Viro 803d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 804d879cb83SAl Viro struct iov_iter *i) 805d879cb83SAl Viro { 80672e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 80772e809edSAl Viro return 0; 808241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 809241699cdSAl Viro WARN_ON(1); 810241699cdSAl Viro return 0; 811241699cdSAl Viro } 812d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 813d879cb83SAl Viro void *kaddr = kmap_atomic(page); 814aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 815d879cb83SAl Viro kunmap_atomic(kaddr); 816d879cb83SAl Viro return wanted; 817d879cb83SAl Viro } else 818d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 819d879cb83SAl Viro } 820d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 821d879cb83SAl Viro 822241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 823241699cdSAl Viro { 824241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 825241699cdSAl Viro size_t n, off; 826241699cdSAl Viro int idx; 827241699cdSAl Viro 828241699cdSAl Viro if (!sanity(i)) 829241699cdSAl Viro return 0; 830241699cdSAl Viro 831241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 832241699cdSAl Viro if (unlikely(!n)) 833241699cdSAl Viro return 0; 834241699cdSAl Viro 835241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 836241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 837241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 838241699cdSAl Viro i->idx = idx; 839241699cdSAl Viro i->iov_offset = off + chunk; 840241699cdSAl Viro n -= chunk; 841241699cdSAl Viro } 842241699cdSAl Viro i->count -= bytes; 843241699cdSAl Viro return bytes; 844241699cdSAl Viro } 845241699cdSAl Viro 846d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 847d879cb83SAl Viro { 848241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 849241699cdSAl Viro return pipe_zero(bytes, i); 850d879cb83SAl Viro iterate_and_advance(i, bytes, v, 85109fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 852d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 853d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 854d879cb83SAl Viro ) 855d879cb83SAl Viro 856d879cb83SAl Viro return bytes; 857d879cb83SAl Viro } 858d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 859d879cb83SAl Viro 860d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 861d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 862d879cb83SAl Viro { 863d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 86472e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 86572e809edSAl Viro kunmap_atomic(kaddr); 86672e809edSAl Viro return 0; 86772e809edSAl Viro } 868241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 869241699cdSAl Viro kunmap_atomic(kaddr); 870241699cdSAl Viro WARN_ON(1); 871241699cdSAl Viro return 0; 872241699cdSAl Viro } 873d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 87409fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 875d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 876d879cb83SAl Viro v.bv_offset, v.bv_len), 877d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 878d879cb83SAl Viro ) 879d879cb83SAl Viro kunmap_atomic(kaddr); 880d879cb83SAl Viro return bytes; 881d879cb83SAl Viro } 882d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 883d879cb83SAl Viro 884b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 885241699cdSAl Viro { 886241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 887241699cdSAl Viro if (pipe->nrbufs) { 888b9dc6f65SAl Viro size_t off = i->iov_offset; 889b9dc6f65SAl Viro int idx = i->idx; 890b9dc6f65SAl Viro int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); 891b9dc6f65SAl Viro if (off) { 892b9dc6f65SAl Viro pipe->bufs[idx].len = off - pipe->bufs[idx].offset; 893b9dc6f65SAl Viro idx = next_idx(idx, pipe); 894b9dc6f65SAl Viro nrbufs++; 895b9dc6f65SAl Viro } 896b9dc6f65SAl Viro while (pipe->nrbufs > nrbufs) { 897a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 898241699cdSAl Viro idx = next_idx(idx, pipe); 899241699cdSAl Viro pipe->nrbufs--; 900241699cdSAl Viro } 901241699cdSAl Viro } 902b9dc6f65SAl Viro } 903b9dc6f65SAl Viro 904b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 905b9dc6f65SAl Viro { 906b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 907b9dc6f65SAl Viro if (unlikely(i->count < size)) 908b9dc6f65SAl Viro size = i->count; 909b9dc6f65SAl Viro if (size) { 910b9dc6f65SAl Viro struct pipe_buffer *buf; 911b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 912b9dc6f65SAl Viro int idx = i->idx; 913b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 914b9dc6f65SAl Viro left += off - pipe->bufs[idx].offset; 915b9dc6f65SAl Viro while (1) { 916b9dc6f65SAl Viro buf = &pipe->bufs[idx]; 917b9dc6f65SAl Viro if (left <= buf->len) 918b9dc6f65SAl Viro break; 919b9dc6f65SAl Viro left -= buf->len; 920b9dc6f65SAl Viro idx = next_idx(idx, pipe); 921b9dc6f65SAl Viro } 922b9dc6f65SAl Viro i->idx = idx; 923b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 924b9dc6f65SAl Viro } 925b9dc6f65SAl Viro i->count -= size; 926b9dc6f65SAl Viro /* ... and discard everything past that point */ 927b9dc6f65SAl Viro pipe_truncate(i); 928241699cdSAl Viro } 929241699cdSAl Viro 930d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 931d879cb83SAl Viro { 932241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 933241699cdSAl Viro pipe_advance(i, size); 934241699cdSAl Viro return; 935241699cdSAl Viro } 936d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 937d879cb83SAl Viro } 938d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 939d879cb83SAl Viro 94027c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 94127c0e374SAl Viro { 94227c0e374SAl Viro if (!unroll) 94327c0e374SAl Viro return; 9445b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 9455b47d59aSAl Viro return; 94627c0e374SAl Viro i->count += unroll; 94727c0e374SAl Viro if (unlikely(i->type & ITER_PIPE)) { 94827c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 94927c0e374SAl Viro int idx = i->idx; 95027c0e374SAl Viro size_t off = i->iov_offset; 95127c0e374SAl Viro while (1) { 95227c0e374SAl Viro size_t n = off - pipe->bufs[idx].offset; 95327c0e374SAl Viro if (unroll < n) { 9544fa55cefSAl Viro off -= unroll; 95527c0e374SAl Viro break; 95627c0e374SAl Viro } 95727c0e374SAl Viro unroll -= n; 95827c0e374SAl Viro if (!unroll && idx == i->start_idx) { 95927c0e374SAl Viro off = 0; 96027c0e374SAl Viro break; 96127c0e374SAl Viro } 96227c0e374SAl Viro if (!idx--) 96327c0e374SAl Viro idx = pipe->buffers - 1; 96427c0e374SAl Viro off = pipe->bufs[idx].offset + pipe->bufs[idx].len; 96527c0e374SAl Viro } 96627c0e374SAl Viro i->iov_offset = off; 96727c0e374SAl Viro i->idx = idx; 96827c0e374SAl Viro pipe_truncate(i); 96927c0e374SAl Viro return; 97027c0e374SAl Viro } 97127c0e374SAl Viro if (unroll <= i->iov_offset) { 97227c0e374SAl Viro i->iov_offset -= unroll; 97327c0e374SAl Viro return; 97427c0e374SAl Viro } 97527c0e374SAl Viro unroll -= i->iov_offset; 97627c0e374SAl Viro if (i->type & ITER_BVEC) { 97727c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 97827c0e374SAl Viro while (1) { 97927c0e374SAl Viro size_t n = (--bvec)->bv_len; 98027c0e374SAl Viro i->nr_segs++; 98127c0e374SAl Viro if (unroll <= n) { 98227c0e374SAl Viro i->bvec = bvec; 98327c0e374SAl Viro i->iov_offset = n - unroll; 98427c0e374SAl Viro return; 98527c0e374SAl Viro } 98627c0e374SAl Viro unroll -= n; 98727c0e374SAl Viro } 98827c0e374SAl Viro } else { /* same logics for iovec and kvec */ 98927c0e374SAl Viro const struct iovec *iov = i->iov; 99027c0e374SAl Viro while (1) { 99127c0e374SAl Viro size_t n = (--iov)->iov_len; 99227c0e374SAl Viro i->nr_segs++; 99327c0e374SAl Viro if (unroll <= n) { 99427c0e374SAl Viro i->iov = iov; 99527c0e374SAl Viro i->iov_offset = n - unroll; 99627c0e374SAl Viro return; 99727c0e374SAl Viro } 99827c0e374SAl Viro unroll -= n; 99927c0e374SAl Viro } 100027c0e374SAl Viro } 100127c0e374SAl Viro } 100227c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 100327c0e374SAl Viro 1004d879cb83SAl Viro /* 1005d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1006d879cb83SAl Viro */ 1007d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1008d879cb83SAl Viro { 1009241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1010241699cdSAl Viro return i->count; // it is a silly place, anyway 1011d879cb83SAl Viro if (i->nr_segs == 1) 1012d879cb83SAl Viro return i->count; 1013d879cb83SAl Viro else if (i->type & ITER_BVEC) 1014d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1015d879cb83SAl Viro else 1016d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1017d879cb83SAl Viro } 1018d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1019d879cb83SAl Viro 1020d879cb83SAl Viro void iov_iter_kvec(struct iov_iter *i, int direction, 1021d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1022d879cb83SAl Viro size_t count) 1023d879cb83SAl Viro { 1024d879cb83SAl Viro BUG_ON(!(direction & ITER_KVEC)); 1025d879cb83SAl Viro i->type = direction; 1026d879cb83SAl Viro i->kvec = kvec; 1027d879cb83SAl Viro i->nr_segs = nr_segs; 1028d879cb83SAl Viro i->iov_offset = 0; 1029d879cb83SAl Viro i->count = count; 1030d879cb83SAl Viro } 1031d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1032d879cb83SAl Viro 1033d879cb83SAl Viro void iov_iter_bvec(struct iov_iter *i, int direction, 1034d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1035d879cb83SAl Viro size_t count) 1036d879cb83SAl Viro { 1037d879cb83SAl Viro BUG_ON(!(direction & ITER_BVEC)); 1038d879cb83SAl Viro i->type = direction; 1039d879cb83SAl Viro i->bvec = bvec; 1040d879cb83SAl Viro i->nr_segs = nr_segs; 1041d879cb83SAl Viro i->iov_offset = 0; 1042d879cb83SAl Viro i->count = count; 1043d879cb83SAl Viro } 1044d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1045d879cb83SAl Viro 1046241699cdSAl Viro void iov_iter_pipe(struct iov_iter *i, int direction, 1047241699cdSAl Viro struct pipe_inode_info *pipe, 1048241699cdSAl Viro size_t count) 1049241699cdSAl Viro { 1050241699cdSAl Viro BUG_ON(direction != ITER_PIPE); 1051b9dc6f65SAl Viro WARN_ON(pipe->nrbufs == pipe->buffers); 1052241699cdSAl Viro i->type = direction; 1053241699cdSAl Viro i->pipe = pipe; 1054241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 1055241699cdSAl Viro i->iov_offset = 0; 1056241699cdSAl Viro i->count = count; 105727c0e374SAl Viro i->start_idx = i->idx; 1058241699cdSAl Viro } 1059241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1060241699cdSAl Viro 1061d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1062d879cb83SAl Viro { 1063d879cb83SAl Viro unsigned long res = 0; 1064d879cb83SAl Viro size_t size = i->count; 1065d879cb83SAl Viro 1066241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 106733844e66SAl Viro if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 1068241699cdSAl Viro return size | i->iov_offset; 1069241699cdSAl Viro return size; 1070241699cdSAl Viro } 1071d879cb83SAl Viro iterate_all_kinds(i, size, v, 1072d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1073d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1074d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1075d879cb83SAl Viro ) 1076d879cb83SAl Viro return res; 1077d879cb83SAl Viro } 1078d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1079d879cb83SAl Viro 1080357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1081357f435dSAl Viro { 1082357f435dSAl Viro unsigned long res = 0; 1083357f435dSAl Viro size_t size = i->count; 1084357f435dSAl Viro 1085241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1086241699cdSAl Viro WARN_ON(1); 1087241699cdSAl Viro return ~0U; 1088241699cdSAl Viro } 1089241699cdSAl Viro 1090357f435dSAl Viro iterate_all_kinds(i, size, v, 1091357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1092357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1093357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1094357f435dSAl Viro (size != v.bv_len ? size : 0)), 1095357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1096357f435dSAl Viro (size != v.iov_len ? size : 0)) 1097357f435dSAl Viro ); 1098357f435dSAl Viro return res; 1099357f435dSAl Viro } 1100357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1101357f435dSAl Viro 1102e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1103241699cdSAl Viro size_t maxsize, 1104241699cdSAl Viro struct page **pages, 1105241699cdSAl Viro int idx, 1106241699cdSAl Viro size_t *start) 1107241699cdSAl Viro { 1108241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 11091689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 1110241699cdSAl Viro if (!n) 1111241699cdSAl Viro return -EFAULT; 1112241699cdSAl Viro 1113241699cdSAl Viro maxsize = n; 1114241699cdSAl Viro n += *start; 11151689c73aSAl Viro while (n > 0) { 1116241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 1117241699cdSAl Viro idx = next_idx(idx, pipe); 1118241699cdSAl Viro n -= PAGE_SIZE; 1119241699cdSAl Viro } 1120241699cdSAl Viro 1121241699cdSAl Viro return maxsize; 1122241699cdSAl Viro } 1123241699cdSAl Viro 1124241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1125241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1126241699cdSAl Viro size_t *start) 1127241699cdSAl Viro { 1128241699cdSAl Viro unsigned npages; 1129241699cdSAl Viro size_t capacity; 1130241699cdSAl Viro int idx; 1131241699cdSAl Viro 113233844e66SAl Viro if (!maxsize) 113333844e66SAl Viro return 0; 113433844e66SAl Viro 1135241699cdSAl Viro if (!sanity(i)) 1136241699cdSAl Viro return -EFAULT; 1137241699cdSAl Viro 1138241699cdSAl Viro data_start(i, &idx, start); 1139241699cdSAl Viro /* some of this one + all after this one */ 1140241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1141241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 1142241699cdSAl Viro 1143241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 1144241699cdSAl Viro } 1145241699cdSAl Viro 1146d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1147d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1148d879cb83SAl Viro size_t *start) 1149d879cb83SAl Viro { 1150d879cb83SAl Viro if (maxsize > i->count) 1151d879cb83SAl Viro maxsize = i->count; 1152d879cb83SAl Viro 1153241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1154241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 1155d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1156d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1157d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1158d879cb83SAl Viro int n; 1159d879cb83SAl Viro int res; 1160d879cb83SAl Viro 1161d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1162d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1163d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1164d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1165d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); 1166d879cb83SAl Viro if (unlikely(res < 0)) 1167d879cb83SAl Viro return res; 1168d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1169d879cb83SAl Viro 0;}),({ 1170d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1171d879cb83SAl Viro *start = v.bv_offset; 1172d879cb83SAl Viro get_page(*pages = v.bv_page); 1173d879cb83SAl Viro return v.bv_len; 1174d879cb83SAl Viro }),({ 1175d879cb83SAl Viro return -EFAULT; 1176d879cb83SAl Viro }) 1177d879cb83SAl Viro ) 1178d879cb83SAl Viro return 0; 1179d879cb83SAl Viro } 1180d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1181d879cb83SAl Viro 1182d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1183d879cb83SAl Viro { 1184752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1185d879cb83SAl Viro } 1186d879cb83SAl Viro 1187241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1188241699cdSAl Viro struct page ***pages, size_t maxsize, 1189241699cdSAl Viro size_t *start) 1190241699cdSAl Viro { 1191241699cdSAl Viro struct page **p; 1192d7760d63SIlya Dryomov ssize_t n; 1193241699cdSAl Viro int idx; 1194241699cdSAl Viro int npages; 1195241699cdSAl Viro 119633844e66SAl Viro if (!maxsize) 119733844e66SAl Viro return 0; 119833844e66SAl Viro 1199241699cdSAl Viro if (!sanity(i)) 1200241699cdSAl Viro return -EFAULT; 1201241699cdSAl Viro 1202241699cdSAl Viro data_start(i, &idx, start); 1203241699cdSAl Viro /* some of this one + all after this one */ 1204241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1205241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1206241699cdSAl Viro if (maxsize > n) 1207241699cdSAl Viro maxsize = n; 1208241699cdSAl Viro else 1209241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1210241699cdSAl Viro p = get_pages_array(npages); 1211241699cdSAl Viro if (!p) 1212241699cdSAl Viro return -ENOMEM; 1213241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 1214241699cdSAl Viro if (n > 0) 1215241699cdSAl Viro *pages = p; 1216241699cdSAl Viro else 1217241699cdSAl Viro kvfree(p); 1218241699cdSAl Viro return n; 1219241699cdSAl Viro } 1220241699cdSAl Viro 1221d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1222d879cb83SAl Viro struct page ***pages, size_t maxsize, 1223d879cb83SAl Viro size_t *start) 1224d879cb83SAl Viro { 1225d879cb83SAl Viro struct page **p; 1226d879cb83SAl Viro 1227d879cb83SAl Viro if (maxsize > i->count) 1228d879cb83SAl Viro maxsize = i->count; 1229d879cb83SAl Viro 1230241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) 1231241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 1232d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1233d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1234d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1235d879cb83SAl Viro int n; 1236d879cb83SAl Viro int res; 1237d879cb83SAl Viro 1238d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1239d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1240d879cb83SAl Viro p = get_pages_array(n); 1241d879cb83SAl Viro if (!p) 1242d879cb83SAl Viro return -ENOMEM; 1243d879cb83SAl Viro res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p); 1244d879cb83SAl Viro if (unlikely(res < 0)) { 1245d879cb83SAl Viro kvfree(p); 1246d879cb83SAl Viro return res; 1247d879cb83SAl Viro } 1248d879cb83SAl Viro *pages = p; 1249d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1250d879cb83SAl Viro 0;}),({ 1251d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1252d879cb83SAl Viro *start = v.bv_offset; 1253d879cb83SAl Viro *pages = p = get_pages_array(1); 1254d879cb83SAl Viro if (!p) 1255d879cb83SAl Viro return -ENOMEM; 1256d879cb83SAl Viro get_page(*p = v.bv_page); 1257d879cb83SAl Viro return v.bv_len; 1258d879cb83SAl Viro }),({ 1259d879cb83SAl Viro return -EFAULT; 1260d879cb83SAl Viro }) 1261d879cb83SAl Viro ) 1262d879cb83SAl Viro return 0; 1263d879cb83SAl Viro } 1264d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1265d879cb83SAl Viro 1266d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1267d879cb83SAl Viro struct iov_iter *i) 1268d879cb83SAl Viro { 1269d879cb83SAl Viro char *to = addr; 1270d879cb83SAl Viro __wsum sum, next; 1271d879cb83SAl Viro size_t off = 0; 1272d879cb83SAl Viro sum = *csum; 1273241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1274241699cdSAl Viro WARN_ON(1); 1275241699cdSAl Viro return 0; 1276241699cdSAl Viro } 1277d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1278d879cb83SAl Viro int err = 0; 1279d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1280d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1281d879cb83SAl Viro v.iov_len, 0, &err); 1282d879cb83SAl Viro if (!err) { 1283d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1284d879cb83SAl Viro off += v.iov_len; 1285d879cb83SAl Viro } 1286d879cb83SAl Viro err ? v.iov_len : 0; 1287d879cb83SAl Viro }), ({ 1288d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1289d879cb83SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1290d879cb83SAl Viro (to += v.bv_len) - v.bv_len, 1291d879cb83SAl Viro v.bv_len, 0); 1292d879cb83SAl Viro kunmap_atomic(p); 1293d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1294d879cb83SAl Viro off += v.bv_len; 1295d879cb83SAl Viro }),({ 1296d879cb83SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1297d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1298d879cb83SAl Viro v.iov_len, 0); 1299d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1300d879cb83SAl Viro off += v.iov_len; 1301d879cb83SAl Viro }) 1302d879cb83SAl Viro ) 1303d879cb83SAl Viro *csum = sum; 1304d879cb83SAl Viro return bytes; 1305d879cb83SAl Viro } 1306d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1307d879cb83SAl Viro 1308cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1309cbbd26b8SAl Viro struct iov_iter *i) 1310cbbd26b8SAl Viro { 1311cbbd26b8SAl Viro char *to = addr; 1312cbbd26b8SAl Viro __wsum sum, next; 1313cbbd26b8SAl Viro size_t off = 0; 1314cbbd26b8SAl Viro sum = *csum; 1315cbbd26b8SAl Viro if (unlikely(i->type & ITER_PIPE)) { 1316cbbd26b8SAl Viro WARN_ON(1); 1317cbbd26b8SAl Viro return false; 1318cbbd26b8SAl Viro } 1319cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1320cbbd26b8SAl Viro return false; 1321cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1322cbbd26b8SAl Viro int err = 0; 1323cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1324cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1325cbbd26b8SAl Viro v.iov_len, 0, &err); 1326cbbd26b8SAl Viro if (err) 1327cbbd26b8SAl Viro return false; 1328cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1329cbbd26b8SAl Viro off += v.iov_len; 1330cbbd26b8SAl Viro 0; 1331cbbd26b8SAl Viro }), ({ 1332cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1333cbbd26b8SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1334cbbd26b8SAl Viro (to += v.bv_len) - v.bv_len, 1335cbbd26b8SAl Viro v.bv_len, 0); 1336cbbd26b8SAl Viro kunmap_atomic(p); 1337cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1338cbbd26b8SAl Viro off += v.bv_len; 1339cbbd26b8SAl Viro }),({ 1340cbbd26b8SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1341cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1342cbbd26b8SAl Viro v.iov_len, 0); 1343cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1344cbbd26b8SAl Viro off += v.iov_len; 1345cbbd26b8SAl Viro }) 1346cbbd26b8SAl Viro ) 1347cbbd26b8SAl Viro *csum = sum; 1348cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1349cbbd26b8SAl Viro return true; 1350cbbd26b8SAl Viro } 1351cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1352cbbd26b8SAl Viro 135336f7a8a4SAl Viro size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, 1354d879cb83SAl Viro struct iov_iter *i) 1355d879cb83SAl Viro { 135636f7a8a4SAl Viro const char *from = addr; 1357d879cb83SAl Viro __wsum sum, next; 1358d879cb83SAl Viro size_t off = 0; 1359d879cb83SAl Viro sum = *csum; 1360241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1361241699cdSAl Viro WARN_ON(1); /* for now */ 1362241699cdSAl Viro return 0; 1363241699cdSAl Viro } 1364d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1365d879cb83SAl Viro int err = 0; 1366d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1367d879cb83SAl Viro v.iov_base, 1368d879cb83SAl Viro v.iov_len, 0, &err); 1369d879cb83SAl Viro if (!err) { 1370d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1371d879cb83SAl Viro off += v.iov_len; 1372d879cb83SAl Viro } 1373d879cb83SAl Viro err ? v.iov_len : 0; 1374d879cb83SAl Viro }), ({ 1375d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1376d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, 1377d879cb83SAl Viro p + v.bv_offset, 1378d879cb83SAl Viro v.bv_len, 0); 1379d879cb83SAl Viro kunmap_atomic(p); 1380d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1381d879cb83SAl Viro off += v.bv_len; 1382d879cb83SAl Viro }),({ 1383d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, 1384d879cb83SAl Viro v.iov_base, 1385d879cb83SAl Viro v.iov_len, 0); 1386d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1387d879cb83SAl Viro off += v.iov_len; 1388d879cb83SAl Viro }) 1389d879cb83SAl Viro ) 1390d879cb83SAl Viro *csum = sum; 1391d879cb83SAl Viro return bytes; 1392d879cb83SAl Viro } 1393d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1394d879cb83SAl Viro 1395d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1396d879cb83SAl Viro { 1397d879cb83SAl Viro size_t size = i->count; 1398d879cb83SAl Viro int npages = 0; 1399d879cb83SAl Viro 1400d879cb83SAl Viro if (!size) 1401d879cb83SAl Viro return 0; 1402d879cb83SAl Viro 1403241699cdSAl Viro if (unlikely(i->type & ITER_PIPE)) { 1404241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1405241699cdSAl Viro size_t off; 1406241699cdSAl Viro int idx; 1407241699cdSAl Viro 1408241699cdSAl Viro if (!sanity(i)) 1409241699cdSAl Viro return 0; 1410241699cdSAl Viro 1411241699cdSAl Viro data_start(i, &idx, &off); 1412241699cdSAl Viro /* some of this one + all after this one */ 1413241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1414241699cdSAl Viro if (npages >= maxpages) 1415241699cdSAl Viro return maxpages; 1416241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1417d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1418d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1419d879cb83SAl Viro - p / PAGE_SIZE; 1420d879cb83SAl Viro if (npages >= maxpages) 1421d879cb83SAl Viro return maxpages; 1422d879cb83SAl Viro 0;}),({ 1423d879cb83SAl Viro npages++; 1424d879cb83SAl Viro if (npages >= maxpages) 1425d879cb83SAl Viro return maxpages; 1426d879cb83SAl Viro }),({ 1427d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1428d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1429d879cb83SAl Viro - p / PAGE_SIZE; 1430d879cb83SAl Viro if (npages >= maxpages) 1431d879cb83SAl Viro return maxpages; 1432d879cb83SAl Viro }) 1433d879cb83SAl Viro ) 1434d879cb83SAl Viro return npages; 1435d879cb83SAl Viro } 1436d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1437d879cb83SAl Viro 1438d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1439d879cb83SAl Viro { 1440d879cb83SAl Viro *new = *old; 1441241699cdSAl Viro if (unlikely(new->type & ITER_PIPE)) { 1442241699cdSAl Viro WARN_ON(1); 1443241699cdSAl Viro return NULL; 1444241699cdSAl Viro } 1445d879cb83SAl Viro if (new->type & ITER_BVEC) 1446d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1447d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1448d879cb83SAl Viro flags); 1449d879cb83SAl Viro else 1450d879cb83SAl Viro /* iovec and kvec have identical layout */ 1451d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1452d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1453d879cb83SAl Viro flags); 1454d879cb83SAl Viro } 1455d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1456bc917be8SAl Viro 1457ffecee4fSVegard Nossum /** 1458ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1459ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1460ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1461ffecee4fSVegard Nossum * 1462ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1463ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1464ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1465ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1466ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1467ffecee4fSVegard Nossum * on-stack) kernel array. 1468ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1469ffecee4fSVegard Nossum * 1470ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1471ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1472ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1473ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1474ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1475ffecee4fSVegard Nossum * returns an error or not). 1476ffecee4fSVegard Nossum * 1477ffecee4fSVegard Nossum * Return: 0 on success or negative error code on error. 1478ffecee4fSVegard Nossum */ 1479bc917be8SAl Viro int import_iovec(int type, const struct iovec __user * uvector, 1480bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1481bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1482bc917be8SAl Viro { 1483bc917be8SAl Viro ssize_t n; 1484bc917be8SAl Viro struct iovec *p; 1485bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1486bc917be8SAl Viro *iov, &p); 1487bc917be8SAl Viro if (n < 0) { 1488bc917be8SAl Viro if (p != *iov) 1489bc917be8SAl Viro kfree(p); 1490bc917be8SAl Viro *iov = NULL; 1491bc917be8SAl Viro return n; 1492bc917be8SAl Viro } 1493bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1494bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1495bc917be8SAl Viro return 0; 1496bc917be8SAl Viro } 1497bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1498bc917be8SAl Viro 1499bc917be8SAl Viro #ifdef CONFIG_COMPAT 1500bc917be8SAl Viro #include <linux/compat.h> 1501bc917be8SAl Viro 1502bc917be8SAl Viro int compat_import_iovec(int type, const struct compat_iovec __user * uvector, 1503bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1504bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1505bc917be8SAl Viro { 1506bc917be8SAl Viro ssize_t n; 1507bc917be8SAl Viro struct iovec *p; 1508bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1509bc917be8SAl Viro *iov, &p); 1510bc917be8SAl Viro if (n < 0) { 1511bc917be8SAl Viro if (p != *iov) 1512bc917be8SAl Viro kfree(p); 1513bc917be8SAl Viro *iov = NULL; 1514bc917be8SAl Viro return n; 1515bc917be8SAl Viro } 1516bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1517bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1518bc917be8SAl Viro return 0; 1519bc917be8SAl Viro } 1520bc917be8SAl Viro #endif 1521bc917be8SAl Viro 1522bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1523bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1524bc917be8SAl Viro { 1525bc917be8SAl Viro if (len > MAX_RW_COUNT) 1526bc917be8SAl Viro len = MAX_RW_COUNT; 1527bc917be8SAl Viro if (unlikely(!access_ok(!rw, buf, len))) 1528bc917be8SAl Viro return -EFAULT; 1529bc917be8SAl Viro 1530bc917be8SAl Viro iov->iov_base = buf; 1531bc917be8SAl Viro iov->iov_len = len; 1532bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1533bc917be8SAl Viro return 0; 1534bc917be8SAl Viro } 1535e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 153609cf698aSAl Viro 153709cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 153809cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 153909cf698aSAl Viro void *context) 154009cf698aSAl Viro { 154109cf698aSAl Viro struct kvec w; 154209cf698aSAl Viro int err = -EINVAL; 154309cf698aSAl Viro if (!bytes) 154409cf698aSAl Viro return 0; 154509cf698aSAl Viro 154609cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 154709cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 154809cf698aSAl Viro w.iov_len = v.bv_len; 154909cf698aSAl Viro err = f(&w, context); 155009cf698aSAl Viro kunmap(v.bv_page); 155109cf698aSAl Viro err;}), ({ 155209cf698aSAl Viro w = v; 155309cf698aSAl Viro err = f(&w, context);}) 155409cf698aSAl Viro ) 155509cf698aSAl Viro return err; 155609cf698aSAl Viro } 155709cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1558