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 431aa563d7bSDavid Howells void iov_iter_init(struct iov_iter *i, unsigned int direction, 432d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 433d879cb83SAl Viro size_t count) 434d879cb83SAl Viro { 435aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 436aa563d7bSDavid Howells direction &= READ | WRITE; 437aa563d7bSDavid Howells 438d879cb83SAl Viro /* It will get better. Eventually... */ 439db68ce10SAl Viro if (uaccess_kernel()) { 440aa563d7bSDavid Howells i->type = ITER_KVEC | direction; 441d879cb83SAl Viro i->kvec = (struct kvec *)iov; 442d879cb83SAl Viro } else { 443aa563d7bSDavid Howells i->type = ITER_IOVEC | direction; 444d879cb83SAl Viro i->iov = iov; 445d879cb83SAl Viro } 446d879cb83SAl Viro i->nr_segs = nr_segs; 447d879cb83SAl Viro i->iov_offset = 0; 448d879cb83SAl Viro i->count = count; 449d879cb83SAl Viro } 450d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 451d879cb83SAl Viro 452d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 453d879cb83SAl Viro { 454d879cb83SAl Viro char *from = kmap_atomic(page); 455d879cb83SAl Viro memcpy(to, from + offset, len); 456d879cb83SAl Viro kunmap_atomic(from); 457d879cb83SAl Viro } 458d879cb83SAl Viro 45936f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 460d879cb83SAl Viro { 461d879cb83SAl Viro char *to = kmap_atomic(page); 462d879cb83SAl Viro memcpy(to + offset, from, len); 463d879cb83SAl Viro kunmap_atomic(to); 464d879cb83SAl Viro } 465d879cb83SAl Viro 466d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 467d879cb83SAl Viro { 468d879cb83SAl Viro char *addr = kmap_atomic(page); 469d879cb83SAl Viro memset(addr + offset, 0, len); 470d879cb83SAl Viro kunmap_atomic(addr); 471d879cb83SAl Viro } 472d879cb83SAl Viro 473241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 474241699cdSAl Viro { 475241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 476241699cdSAl Viro } 477241699cdSAl Viro 478241699cdSAl Viro static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) 479241699cdSAl Viro { 480241699cdSAl Viro size_t off = i->iov_offset; 481241699cdSAl Viro int idx = i->idx; 482241699cdSAl Viro if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { 483241699cdSAl Viro idx = next_idx(idx, i->pipe); 484241699cdSAl Viro off = 0; 485241699cdSAl Viro } 486241699cdSAl Viro *idxp = idx; 487241699cdSAl Viro *offp = off; 488241699cdSAl Viro } 489241699cdSAl Viro 490241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 491241699cdSAl Viro int *idxp, size_t *offp) 492241699cdSAl Viro { 493241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 494241699cdSAl Viro size_t off; 495241699cdSAl Viro int idx; 496241699cdSAl Viro ssize_t left; 497241699cdSAl Viro 498241699cdSAl Viro if (unlikely(size > i->count)) 499241699cdSAl Viro size = i->count; 500241699cdSAl Viro if (unlikely(!size)) 501241699cdSAl Viro return 0; 502241699cdSAl Viro 503241699cdSAl Viro left = size; 504241699cdSAl Viro data_start(i, &idx, &off); 505241699cdSAl Viro *idxp = idx; 506241699cdSAl Viro *offp = off; 507241699cdSAl Viro if (off) { 508241699cdSAl Viro left -= PAGE_SIZE - off; 509241699cdSAl Viro if (left <= 0) { 510241699cdSAl Viro pipe->bufs[idx].len += size; 511241699cdSAl Viro return size; 512241699cdSAl Viro } 513241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 514241699cdSAl Viro idx = next_idx(idx, pipe); 515241699cdSAl Viro } 516241699cdSAl Viro while (idx != pipe->curbuf || !pipe->nrbufs) { 517241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 518241699cdSAl Viro if (!page) 519241699cdSAl Viro break; 520241699cdSAl Viro pipe->nrbufs++; 521241699cdSAl Viro pipe->bufs[idx].ops = &default_pipe_buf_ops; 522241699cdSAl Viro pipe->bufs[idx].page = page; 523241699cdSAl Viro pipe->bufs[idx].offset = 0; 524241699cdSAl Viro if (left <= PAGE_SIZE) { 525241699cdSAl Viro pipe->bufs[idx].len = left; 526241699cdSAl Viro return size; 527241699cdSAl Viro } 528241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 529241699cdSAl Viro left -= PAGE_SIZE; 530241699cdSAl Viro idx = next_idx(idx, pipe); 531241699cdSAl Viro } 532241699cdSAl Viro return size - left; 533241699cdSAl Viro } 534241699cdSAl Viro 535241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 536241699cdSAl Viro struct iov_iter *i) 537241699cdSAl Viro { 538241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 539241699cdSAl Viro size_t n, off; 540241699cdSAl Viro int idx; 541241699cdSAl Viro 542241699cdSAl Viro if (!sanity(i)) 543241699cdSAl Viro return 0; 544241699cdSAl Viro 545241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 546241699cdSAl Viro if (unlikely(!n)) 547241699cdSAl Viro return 0; 548241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 549241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 550241699cdSAl Viro memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); 551241699cdSAl Viro i->idx = idx; 552241699cdSAl Viro i->iov_offset = off + chunk; 553241699cdSAl Viro n -= chunk; 554241699cdSAl Viro addr += chunk; 555241699cdSAl Viro } 556241699cdSAl Viro i->count -= bytes; 557241699cdSAl Viro return bytes; 558241699cdSAl Viro } 559241699cdSAl Viro 560aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 561d879cb83SAl Viro { 56236f7a8a4SAl Viro const char *from = addr; 56300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 564241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 56509fc68dcSAl Viro if (iter_is_iovec(i)) 56609fc68dcSAl Viro might_fault(); 567d879cb83SAl Viro iterate_and_advance(i, bytes, v, 56809fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 569d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 570d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 571d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 572d879cb83SAl Viro ) 573d879cb83SAl Viro 574d879cb83SAl Viro return bytes; 575d879cb83SAl Viro } 576aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 577d879cb83SAl Viro 5788780356eSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE 5798780356eSDan Williams static int copyout_mcsafe(void __user *to, const void *from, size_t n) 5808780356eSDan Williams { 5818780356eSDan Williams if (access_ok(VERIFY_WRITE, to, n)) { 5828780356eSDan Williams kasan_check_read(from, n); 5838780356eSDan Williams n = copy_to_user_mcsafe((__force void *) to, from, n); 5848780356eSDan Williams } 5858780356eSDan Williams return n; 5868780356eSDan Williams } 5878780356eSDan Williams 5888780356eSDan Williams static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, 5898780356eSDan Williams const char *from, size_t len) 5908780356eSDan Williams { 5918780356eSDan Williams unsigned long ret; 5928780356eSDan Williams char *to; 5938780356eSDan Williams 5948780356eSDan Williams to = kmap_atomic(page); 5958780356eSDan Williams ret = memcpy_mcsafe(to + offset, from, len); 5968780356eSDan Williams kunmap_atomic(to); 5978780356eSDan Williams 5988780356eSDan Williams return ret; 5998780356eSDan Williams } 6008780356eSDan Williams 601ca146f6fSDan Williams static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, 602ca146f6fSDan Williams struct iov_iter *i) 603ca146f6fSDan Williams { 604ca146f6fSDan Williams struct pipe_inode_info *pipe = i->pipe; 605ca146f6fSDan Williams size_t n, off, xfer = 0; 606ca146f6fSDan Williams int idx; 607ca146f6fSDan Williams 608ca146f6fSDan Williams if (!sanity(i)) 609ca146f6fSDan Williams return 0; 610ca146f6fSDan Williams 611ca146f6fSDan Williams bytes = n = push_pipe(i, bytes, &idx, &off); 612ca146f6fSDan Williams if (unlikely(!n)) 613ca146f6fSDan Williams return 0; 614ca146f6fSDan Williams for ( ; n; idx = next_idx(idx, pipe), off = 0) { 615ca146f6fSDan Williams size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 616ca146f6fSDan Williams unsigned long rem; 617ca146f6fSDan Williams 618ca146f6fSDan Williams rem = memcpy_mcsafe_to_page(pipe->bufs[idx].page, off, addr, 619ca146f6fSDan Williams chunk); 620ca146f6fSDan Williams i->idx = idx; 621ca146f6fSDan Williams i->iov_offset = off + chunk - rem; 622ca146f6fSDan Williams xfer += chunk - rem; 623ca146f6fSDan Williams if (rem) 624ca146f6fSDan Williams break; 625ca146f6fSDan Williams n -= chunk; 626ca146f6fSDan Williams addr += chunk; 627ca146f6fSDan Williams } 628ca146f6fSDan Williams i->count -= xfer; 629ca146f6fSDan Williams return xfer; 630ca146f6fSDan Williams } 631ca146f6fSDan Williams 632bf3eeb9bSDan Williams /** 633bf3eeb9bSDan Williams * _copy_to_iter_mcsafe - copy to user with source-read error exception handling 634bf3eeb9bSDan Williams * @addr: source kernel address 635bf3eeb9bSDan Williams * @bytes: total transfer length 636bf3eeb9bSDan Williams * @iter: destination iterator 637bf3eeb9bSDan Williams * 638bf3eeb9bSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 639bf3eeb9bSDan Williams * dax_copy_to_iter() for protecting read/write to persistent memory. 640bf3eeb9bSDan Williams * Unless / until an architecture can guarantee identical performance 641bf3eeb9bSDan Williams * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a 642bf3eeb9bSDan Williams * performance regression to switch more users to the mcsafe version. 643bf3eeb9bSDan Williams * 644bf3eeb9bSDan Williams * Otherwise, the main differences between this and typical _copy_to_iter(). 645bf3eeb9bSDan Williams * 646bf3eeb9bSDan Williams * * Typical tail/residue handling after a fault retries the copy 647bf3eeb9bSDan Williams * byte-by-byte until the fault happens again. Re-triggering machine 648bf3eeb9bSDan Williams * checks is potentially fatal so the implementation uses source 649bf3eeb9bSDan Williams * alignment and poison alignment assumptions to avoid re-triggering 650bf3eeb9bSDan Williams * hardware exceptions. 651bf3eeb9bSDan Williams * 652bf3eeb9bSDan Williams * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. 653bf3eeb9bSDan Williams * Compare to copy_to_iter() where only ITER_IOVEC attempts might return 654bf3eeb9bSDan Williams * a short copy. 655bf3eeb9bSDan Williams * 656bf3eeb9bSDan Williams * See MCSAFE_TEST for self-test. 657bf3eeb9bSDan Williams */ 6588780356eSDan Williams size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) 6598780356eSDan Williams { 6608780356eSDan Williams const char *from = addr; 6618780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 6628780356eSDan Williams 66300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 664ca146f6fSDan Williams return copy_pipe_to_iter_mcsafe(addr, bytes, i); 6658780356eSDan Williams if (iter_is_iovec(i)) 6668780356eSDan Williams might_fault(); 6678780356eSDan Williams iterate_and_advance(i, bytes, v, 6688780356eSDan Williams copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 6698780356eSDan Williams ({ 6708780356eSDan Williams rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, 6718780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 6728780356eSDan Williams if (rem) { 6738780356eSDan Williams curr_addr = (unsigned long) from; 6748780356eSDan Williams bytes = curr_addr - s_addr - rem; 6758780356eSDan Williams return bytes; 6768780356eSDan Williams } 6778780356eSDan Williams }), 6788780356eSDan Williams ({ 6798780356eSDan Williams rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, 6808780356eSDan Williams v.iov_len); 6818780356eSDan Williams if (rem) { 6828780356eSDan Williams curr_addr = (unsigned long) from; 6838780356eSDan Williams bytes = curr_addr - s_addr - rem; 6848780356eSDan Williams return bytes; 6858780356eSDan Williams } 6868780356eSDan Williams }) 6878780356eSDan Williams ) 6888780356eSDan Williams 6898780356eSDan Williams return bytes; 6908780356eSDan Williams } 6918780356eSDan Williams EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); 6928780356eSDan Williams #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ 6938780356eSDan Williams 694aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 695d879cb83SAl Viro { 696d879cb83SAl Viro char *to = addr; 69700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 698241699cdSAl Viro WARN_ON(1); 699241699cdSAl Viro return 0; 700241699cdSAl Viro } 70109fc68dcSAl Viro if (iter_is_iovec(i)) 70209fc68dcSAl Viro might_fault(); 703d879cb83SAl Viro iterate_and_advance(i, bytes, v, 70409fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 705d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 706d879cb83SAl Viro v.bv_offset, v.bv_len), 707d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 708d879cb83SAl Viro ) 709d879cb83SAl Viro 710d879cb83SAl Viro return bytes; 711d879cb83SAl Viro } 712aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 713d879cb83SAl Viro 714aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 715cbbd26b8SAl Viro { 716cbbd26b8SAl Viro char *to = addr; 71700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 718cbbd26b8SAl Viro WARN_ON(1); 719cbbd26b8SAl Viro return false; 720cbbd26b8SAl Viro } 72133844e66SAl Viro if (unlikely(i->count < bytes)) 722cbbd26b8SAl Viro return false; 723cbbd26b8SAl Viro 72409fc68dcSAl Viro if (iter_is_iovec(i)) 72509fc68dcSAl Viro might_fault(); 726cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 72709fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 728cbbd26b8SAl Viro v.iov_base, v.iov_len)) 729cbbd26b8SAl Viro return false; 730cbbd26b8SAl Viro 0;}), 731cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 732cbbd26b8SAl Viro v.bv_offset, v.bv_len), 733cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 734cbbd26b8SAl Viro ) 735cbbd26b8SAl Viro 736cbbd26b8SAl Viro iov_iter_advance(i, bytes); 737cbbd26b8SAl Viro return true; 738cbbd26b8SAl Viro } 739aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 740cbbd26b8SAl Viro 741aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 742d879cb83SAl Viro { 743d879cb83SAl Viro char *to = addr; 74400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 745241699cdSAl Viro WARN_ON(1); 746241699cdSAl Viro return 0; 747241699cdSAl Viro } 748d879cb83SAl Viro iterate_and_advance(i, bytes, v, 7493f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 750d879cb83SAl Viro v.iov_base, v.iov_len), 751d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 752d879cb83SAl Viro v.bv_offset, v.bv_len), 753d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 754d879cb83SAl Viro ) 755d879cb83SAl Viro 756d879cb83SAl Viro return bytes; 757d879cb83SAl Viro } 758aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 759d879cb83SAl Viro 7600aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 761abd08d7dSDan Williams /** 762abd08d7dSDan Williams * _copy_from_iter_flushcache - write destination through cpu cache 763abd08d7dSDan Williams * @addr: destination kernel address 764abd08d7dSDan Williams * @bytes: total transfer length 765abd08d7dSDan Williams * @iter: source iterator 766abd08d7dSDan Williams * 767abd08d7dSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 768abd08d7dSDan Williams * dax_copy_from_iter() for ensuring that writes to persistent memory 769abd08d7dSDan Williams * are flushed through the CPU cache. It is differentiated from 770abd08d7dSDan Williams * _copy_from_iter_nocache() in that guarantees all data is flushed for 771abd08d7dSDan Williams * all iterator types. The _copy_from_iter_nocache() only attempts to 772abd08d7dSDan Williams * bypass the cache for the ITER_IOVEC case, and on some archs may use 773abd08d7dSDan Williams * instructions that strand dirty-data in the cache. 774abd08d7dSDan Williams */ 7756a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 7760aed55afSDan Williams { 7770aed55afSDan Williams char *to = addr; 77800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 7790aed55afSDan Williams WARN_ON(1); 7800aed55afSDan Williams return 0; 7810aed55afSDan Williams } 7820aed55afSDan Williams iterate_and_advance(i, bytes, v, 7830aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 7840aed55afSDan Williams v.iov_base, v.iov_len), 7850aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 7860aed55afSDan Williams v.bv_offset, v.bv_len), 7870aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 7880aed55afSDan Williams v.iov_len) 7890aed55afSDan Williams ) 7900aed55afSDan Williams 7910aed55afSDan Williams return bytes; 7920aed55afSDan Williams } 7936a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 7940aed55afSDan Williams #endif 7950aed55afSDan Williams 796aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 797cbbd26b8SAl Viro { 798cbbd26b8SAl Viro char *to = addr; 79900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 800cbbd26b8SAl Viro WARN_ON(1); 801cbbd26b8SAl Viro return false; 802cbbd26b8SAl Viro } 80333844e66SAl Viro if (unlikely(i->count < bytes)) 804cbbd26b8SAl Viro return false; 805cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 8063f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 807cbbd26b8SAl Viro v.iov_base, v.iov_len)) 808cbbd26b8SAl Viro return false; 809cbbd26b8SAl Viro 0;}), 810cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 811cbbd26b8SAl Viro v.bv_offset, v.bv_len), 812cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 813cbbd26b8SAl Viro ) 814cbbd26b8SAl Viro 815cbbd26b8SAl Viro iov_iter_advance(i, bytes); 816cbbd26b8SAl Viro return true; 817cbbd26b8SAl Viro } 818aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 819cbbd26b8SAl Viro 82072e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 82172e809edSAl Viro { 822a90bcb86SPetar Penkov struct page *head = compound_head(page); 823a90bcb86SPetar Penkov size_t v = n + offset + page_address(page) - page_address(head); 824a90bcb86SPetar Penkov 825a90bcb86SPetar Penkov if (likely(n <= v && v <= (PAGE_SIZE << compound_order(head)))) 82672e809edSAl Viro return true; 82772e809edSAl Viro WARN_ON(1); 82872e809edSAl Viro return false; 82972e809edSAl Viro } 830d879cb83SAl Viro 831d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 832d879cb83SAl Viro struct iov_iter *i) 833d879cb83SAl Viro { 83472e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 83572e809edSAl Viro return 0; 836d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 837d879cb83SAl Viro void *kaddr = kmap_atomic(page); 838d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 839d879cb83SAl Viro kunmap_atomic(kaddr); 840d879cb83SAl Viro return wanted; 84100e23707SDavid Howells } else if (likely(!iov_iter_is_pipe(i))) 842d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 843241699cdSAl Viro else 844241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 845d879cb83SAl Viro } 846d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 847d879cb83SAl Viro 848d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 849d879cb83SAl Viro struct iov_iter *i) 850d879cb83SAl Viro { 85172e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 85272e809edSAl Viro return 0; 85300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 854241699cdSAl Viro WARN_ON(1); 855241699cdSAl Viro return 0; 856241699cdSAl Viro } 857d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 858d879cb83SAl Viro void *kaddr = kmap_atomic(page); 859aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 860d879cb83SAl Viro kunmap_atomic(kaddr); 861d879cb83SAl Viro return wanted; 862d879cb83SAl Viro } else 863d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 864d879cb83SAl Viro } 865d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 866d879cb83SAl Viro 867241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 868241699cdSAl Viro { 869241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 870241699cdSAl Viro size_t n, off; 871241699cdSAl Viro int idx; 872241699cdSAl Viro 873241699cdSAl Viro if (!sanity(i)) 874241699cdSAl Viro return 0; 875241699cdSAl Viro 876241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 877241699cdSAl Viro if (unlikely(!n)) 878241699cdSAl Viro return 0; 879241699cdSAl Viro 880241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 881241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 882241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 883241699cdSAl Viro i->idx = idx; 884241699cdSAl Viro i->iov_offset = off + chunk; 885241699cdSAl Viro n -= chunk; 886241699cdSAl Viro } 887241699cdSAl Viro i->count -= bytes; 888241699cdSAl Viro return bytes; 889241699cdSAl Viro } 890241699cdSAl Viro 891d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 892d879cb83SAl Viro { 89300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 894241699cdSAl Viro return pipe_zero(bytes, i); 895d879cb83SAl Viro iterate_and_advance(i, bytes, v, 89609fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 897d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 898d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 899d879cb83SAl Viro ) 900d879cb83SAl Viro 901d879cb83SAl Viro return bytes; 902d879cb83SAl Viro } 903d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 904d879cb83SAl Viro 905d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 906d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 907d879cb83SAl Viro { 908d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 90972e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 91072e809edSAl Viro kunmap_atomic(kaddr); 91172e809edSAl Viro return 0; 91272e809edSAl Viro } 91300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 914241699cdSAl Viro kunmap_atomic(kaddr); 915241699cdSAl Viro WARN_ON(1); 916241699cdSAl Viro return 0; 917241699cdSAl Viro } 918d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 91909fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 920d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 921d879cb83SAl Viro v.bv_offset, v.bv_len), 922d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 923d879cb83SAl Viro ) 924d879cb83SAl Viro kunmap_atomic(kaddr); 925d879cb83SAl Viro return bytes; 926d879cb83SAl Viro } 927d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 928d879cb83SAl Viro 929b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 930241699cdSAl Viro { 931241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 932241699cdSAl Viro if (pipe->nrbufs) { 933b9dc6f65SAl Viro size_t off = i->iov_offset; 934b9dc6f65SAl Viro int idx = i->idx; 935b9dc6f65SAl Viro int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); 936b9dc6f65SAl Viro if (off) { 937b9dc6f65SAl Viro pipe->bufs[idx].len = off - pipe->bufs[idx].offset; 938b9dc6f65SAl Viro idx = next_idx(idx, pipe); 939b9dc6f65SAl Viro nrbufs++; 940b9dc6f65SAl Viro } 941b9dc6f65SAl Viro while (pipe->nrbufs > nrbufs) { 942a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 943241699cdSAl Viro idx = next_idx(idx, pipe); 944241699cdSAl Viro pipe->nrbufs--; 945241699cdSAl Viro } 946241699cdSAl Viro } 947b9dc6f65SAl Viro } 948b9dc6f65SAl Viro 949b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 950b9dc6f65SAl Viro { 951b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 952b9dc6f65SAl Viro if (unlikely(i->count < size)) 953b9dc6f65SAl Viro size = i->count; 954b9dc6f65SAl Viro if (size) { 955b9dc6f65SAl Viro struct pipe_buffer *buf; 956b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 957b9dc6f65SAl Viro int idx = i->idx; 958b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 959b9dc6f65SAl Viro left += off - pipe->bufs[idx].offset; 960b9dc6f65SAl Viro while (1) { 961b9dc6f65SAl Viro buf = &pipe->bufs[idx]; 962b9dc6f65SAl Viro if (left <= buf->len) 963b9dc6f65SAl Viro break; 964b9dc6f65SAl Viro left -= buf->len; 965b9dc6f65SAl Viro idx = next_idx(idx, pipe); 966b9dc6f65SAl Viro } 967b9dc6f65SAl Viro i->idx = idx; 968b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 969b9dc6f65SAl Viro } 970b9dc6f65SAl Viro i->count -= size; 971b9dc6f65SAl Viro /* ... and discard everything past that point */ 972b9dc6f65SAl Viro pipe_truncate(i); 973241699cdSAl Viro } 974241699cdSAl Viro 975d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 976d879cb83SAl Viro { 97700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 978241699cdSAl Viro pipe_advance(i, size); 979241699cdSAl Viro return; 980241699cdSAl Viro } 981d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 982d879cb83SAl Viro } 983d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 984d879cb83SAl Viro 98527c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 98627c0e374SAl Viro { 98727c0e374SAl Viro if (!unroll) 98827c0e374SAl Viro return; 9895b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 9905b47d59aSAl Viro return; 99127c0e374SAl Viro i->count += unroll; 99200e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 99327c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 99427c0e374SAl Viro int idx = i->idx; 99527c0e374SAl Viro size_t off = i->iov_offset; 99627c0e374SAl Viro while (1) { 99727c0e374SAl Viro size_t n = off - pipe->bufs[idx].offset; 99827c0e374SAl Viro if (unroll < n) { 9994fa55cefSAl Viro off -= unroll; 100027c0e374SAl Viro break; 100127c0e374SAl Viro } 100227c0e374SAl Viro unroll -= n; 100327c0e374SAl Viro if (!unroll && idx == i->start_idx) { 100427c0e374SAl Viro off = 0; 100527c0e374SAl Viro break; 100627c0e374SAl Viro } 100727c0e374SAl Viro if (!idx--) 100827c0e374SAl Viro idx = pipe->buffers - 1; 100927c0e374SAl Viro off = pipe->bufs[idx].offset + pipe->bufs[idx].len; 101027c0e374SAl Viro } 101127c0e374SAl Viro i->iov_offset = off; 101227c0e374SAl Viro i->idx = idx; 101327c0e374SAl Viro pipe_truncate(i); 101427c0e374SAl Viro return; 101527c0e374SAl Viro } 101627c0e374SAl Viro if (unroll <= i->iov_offset) { 101727c0e374SAl Viro i->iov_offset -= unroll; 101827c0e374SAl Viro return; 101927c0e374SAl Viro } 102027c0e374SAl Viro unroll -= i->iov_offset; 102100e23707SDavid Howells if (iov_iter_is_bvec(i)) { 102227c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 102327c0e374SAl Viro while (1) { 102427c0e374SAl Viro size_t n = (--bvec)->bv_len; 102527c0e374SAl Viro i->nr_segs++; 102627c0e374SAl Viro if (unroll <= n) { 102727c0e374SAl Viro i->bvec = bvec; 102827c0e374SAl Viro i->iov_offset = n - unroll; 102927c0e374SAl Viro return; 103027c0e374SAl Viro } 103127c0e374SAl Viro unroll -= n; 103227c0e374SAl Viro } 103327c0e374SAl Viro } else { /* same logics for iovec and kvec */ 103427c0e374SAl Viro const struct iovec *iov = i->iov; 103527c0e374SAl Viro while (1) { 103627c0e374SAl Viro size_t n = (--iov)->iov_len; 103727c0e374SAl Viro i->nr_segs++; 103827c0e374SAl Viro if (unroll <= n) { 103927c0e374SAl Viro i->iov = iov; 104027c0e374SAl Viro i->iov_offset = n - unroll; 104127c0e374SAl Viro return; 104227c0e374SAl Viro } 104327c0e374SAl Viro unroll -= n; 104427c0e374SAl Viro } 104527c0e374SAl Viro } 104627c0e374SAl Viro } 104727c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 104827c0e374SAl Viro 1049d879cb83SAl Viro /* 1050d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1051d879cb83SAl Viro */ 1052d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1053d879cb83SAl Viro { 105400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1055241699cdSAl Viro return i->count; // it is a silly place, anyway 1056d879cb83SAl Viro if (i->nr_segs == 1) 1057d879cb83SAl Viro return i->count; 105800e23707SDavid Howells else if (iov_iter_is_bvec(i)) 1059d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1060d879cb83SAl Viro else 1061d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1062d879cb83SAl Viro } 1063d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1064d879cb83SAl Viro 1065aa563d7bSDavid Howells void iov_iter_kvec(struct iov_iter *i, unsigned int direction, 1066d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1067d879cb83SAl Viro size_t count) 1068d879cb83SAl Viro { 1069aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1070aa563d7bSDavid Howells i->type = ITER_KVEC | (direction & (READ | WRITE)); 1071d879cb83SAl Viro i->kvec = kvec; 1072d879cb83SAl Viro i->nr_segs = nr_segs; 1073d879cb83SAl Viro i->iov_offset = 0; 1074d879cb83SAl Viro i->count = count; 1075d879cb83SAl Viro } 1076d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1077d879cb83SAl Viro 1078aa563d7bSDavid Howells void iov_iter_bvec(struct iov_iter *i, unsigned int direction, 1079d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1080d879cb83SAl Viro size_t count) 1081d879cb83SAl Viro { 1082aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1083aa563d7bSDavid Howells i->type = ITER_BVEC | (direction & (READ | WRITE)); 1084d879cb83SAl Viro i->bvec = bvec; 1085d879cb83SAl Viro i->nr_segs = nr_segs; 1086d879cb83SAl Viro i->iov_offset = 0; 1087d879cb83SAl Viro i->count = count; 1088d879cb83SAl Viro } 1089d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1090d879cb83SAl Viro 1091aa563d7bSDavid Howells void iov_iter_pipe(struct iov_iter *i, unsigned int direction, 1092241699cdSAl Viro struct pipe_inode_info *pipe, 1093241699cdSAl Viro size_t count) 1094241699cdSAl Viro { 1095aa563d7bSDavid Howells BUG_ON(direction != READ); 1096b9dc6f65SAl Viro WARN_ON(pipe->nrbufs == pipe->buffers); 1097aa563d7bSDavid Howells i->type = ITER_PIPE | READ; 1098241699cdSAl Viro i->pipe = pipe; 1099241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 1100241699cdSAl Viro i->iov_offset = 0; 1101241699cdSAl Viro i->count = count; 110227c0e374SAl Viro i->start_idx = i->idx; 1103241699cdSAl Viro } 1104241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1105241699cdSAl Viro 1106d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1107d879cb83SAl Viro { 1108d879cb83SAl Viro unsigned long res = 0; 1109d879cb83SAl Viro size_t size = i->count; 1110d879cb83SAl Viro 111100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 111233844e66SAl Viro if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 1113241699cdSAl Viro return size | i->iov_offset; 1114241699cdSAl Viro return size; 1115241699cdSAl Viro } 1116d879cb83SAl Viro iterate_all_kinds(i, size, v, 1117d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1118d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1119d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1120d879cb83SAl Viro ) 1121d879cb83SAl Viro return res; 1122d879cb83SAl Viro } 1123d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1124d879cb83SAl Viro 1125357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1126357f435dSAl Viro { 1127357f435dSAl Viro unsigned long res = 0; 1128357f435dSAl Viro size_t size = i->count; 1129357f435dSAl Viro 113000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1131241699cdSAl Viro WARN_ON(1); 1132241699cdSAl Viro return ~0U; 1133241699cdSAl Viro } 1134241699cdSAl Viro 1135357f435dSAl Viro iterate_all_kinds(i, size, v, 1136357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1137357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1138357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1139357f435dSAl Viro (size != v.bv_len ? size : 0)), 1140357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1141357f435dSAl Viro (size != v.iov_len ? size : 0)) 1142357f435dSAl Viro ); 1143357f435dSAl Viro return res; 1144357f435dSAl Viro } 1145357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1146357f435dSAl Viro 1147e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1148241699cdSAl Viro size_t maxsize, 1149241699cdSAl Viro struct page **pages, 1150241699cdSAl Viro int idx, 1151241699cdSAl Viro size_t *start) 1152241699cdSAl Viro { 1153241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 11541689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 1155241699cdSAl Viro if (!n) 1156241699cdSAl Viro return -EFAULT; 1157241699cdSAl Viro 1158241699cdSAl Viro maxsize = n; 1159241699cdSAl Viro n += *start; 11601689c73aSAl Viro while (n > 0) { 1161241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 1162241699cdSAl Viro idx = next_idx(idx, pipe); 1163241699cdSAl Viro n -= PAGE_SIZE; 1164241699cdSAl Viro } 1165241699cdSAl Viro 1166241699cdSAl Viro return maxsize; 1167241699cdSAl Viro } 1168241699cdSAl Viro 1169241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1170241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1171241699cdSAl Viro size_t *start) 1172241699cdSAl Viro { 1173241699cdSAl Viro unsigned npages; 1174241699cdSAl Viro size_t capacity; 1175241699cdSAl Viro int idx; 1176241699cdSAl Viro 117733844e66SAl Viro if (!maxsize) 117833844e66SAl Viro return 0; 117933844e66SAl Viro 1180241699cdSAl Viro if (!sanity(i)) 1181241699cdSAl Viro return -EFAULT; 1182241699cdSAl Viro 1183241699cdSAl Viro data_start(i, &idx, start); 1184241699cdSAl Viro /* some of this one + all after this one */ 1185241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1186241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 1187241699cdSAl Viro 1188241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 1189241699cdSAl Viro } 1190241699cdSAl Viro 1191d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1192d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1193d879cb83SAl Viro size_t *start) 1194d879cb83SAl Viro { 1195d879cb83SAl Viro if (maxsize > i->count) 1196d879cb83SAl Viro maxsize = i->count; 1197d879cb83SAl Viro 119800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1199241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 1200d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1201d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1202d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1203d879cb83SAl Viro int n; 1204d879cb83SAl Viro int res; 1205d879cb83SAl Viro 1206d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1207d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1208d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1209d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 121000e23707SDavid Howells res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE, pages); 1211d879cb83SAl Viro if (unlikely(res < 0)) 1212d879cb83SAl Viro return res; 1213d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1214d879cb83SAl Viro 0;}),({ 1215d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1216d879cb83SAl Viro *start = v.bv_offset; 1217d879cb83SAl Viro get_page(*pages = v.bv_page); 1218d879cb83SAl Viro return v.bv_len; 1219d879cb83SAl Viro }),({ 1220d879cb83SAl Viro return -EFAULT; 1221d879cb83SAl Viro }) 1222d879cb83SAl Viro ) 1223d879cb83SAl Viro return 0; 1224d879cb83SAl Viro } 1225d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1226d879cb83SAl Viro 1227d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1228d879cb83SAl Viro { 1229752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1230d879cb83SAl Viro } 1231d879cb83SAl Viro 1232241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1233241699cdSAl Viro struct page ***pages, size_t maxsize, 1234241699cdSAl Viro size_t *start) 1235241699cdSAl Viro { 1236241699cdSAl Viro struct page **p; 1237d7760d63SIlya Dryomov ssize_t n; 1238241699cdSAl Viro int idx; 1239241699cdSAl Viro int npages; 1240241699cdSAl Viro 124133844e66SAl Viro if (!maxsize) 124233844e66SAl Viro return 0; 124333844e66SAl Viro 1244241699cdSAl Viro if (!sanity(i)) 1245241699cdSAl Viro return -EFAULT; 1246241699cdSAl Viro 1247241699cdSAl Viro data_start(i, &idx, start); 1248241699cdSAl Viro /* some of this one + all after this one */ 1249241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1250241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1251241699cdSAl Viro if (maxsize > n) 1252241699cdSAl Viro maxsize = n; 1253241699cdSAl Viro else 1254241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1255241699cdSAl Viro p = get_pages_array(npages); 1256241699cdSAl Viro if (!p) 1257241699cdSAl Viro return -ENOMEM; 1258241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 1259241699cdSAl Viro if (n > 0) 1260241699cdSAl Viro *pages = p; 1261241699cdSAl Viro else 1262241699cdSAl Viro kvfree(p); 1263241699cdSAl Viro return n; 1264241699cdSAl Viro } 1265241699cdSAl Viro 1266d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1267d879cb83SAl Viro struct page ***pages, size_t maxsize, 1268d879cb83SAl Viro size_t *start) 1269d879cb83SAl Viro { 1270d879cb83SAl Viro struct page **p; 1271d879cb83SAl Viro 1272d879cb83SAl Viro if (maxsize > i->count) 1273d879cb83SAl Viro maxsize = i->count; 1274d879cb83SAl Viro 127500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1276241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 1277d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1278d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1279d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1280d879cb83SAl Viro int n; 1281d879cb83SAl Viro int res; 1282d879cb83SAl Viro 1283d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1284d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1285d879cb83SAl Viro p = get_pages_array(n); 1286d879cb83SAl Viro if (!p) 1287d879cb83SAl Viro return -ENOMEM; 128800e23707SDavid Howells res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE, p); 1289d879cb83SAl Viro if (unlikely(res < 0)) { 1290d879cb83SAl Viro kvfree(p); 1291d879cb83SAl Viro return res; 1292d879cb83SAl Viro } 1293d879cb83SAl Viro *pages = p; 1294d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1295d879cb83SAl Viro 0;}),({ 1296d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1297d879cb83SAl Viro *start = v.bv_offset; 1298d879cb83SAl Viro *pages = p = get_pages_array(1); 1299d879cb83SAl Viro if (!p) 1300d879cb83SAl Viro return -ENOMEM; 1301d879cb83SAl Viro get_page(*p = v.bv_page); 1302d879cb83SAl Viro return v.bv_len; 1303d879cb83SAl Viro }),({ 1304d879cb83SAl Viro return -EFAULT; 1305d879cb83SAl Viro }) 1306d879cb83SAl Viro ) 1307d879cb83SAl Viro return 0; 1308d879cb83SAl Viro } 1309d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1310d879cb83SAl Viro 1311d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1312d879cb83SAl Viro struct iov_iter *i) 1313d879cb83SAl Viro { 1314d879cb83SAl Viro char *to = addr; 1315d879cb83SAl Viro __wsum sum, next; 1316d879cb83SAl Viro size_t off = 0; 1317d879cb83SAl Viro sum = *csum; 131800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1319241699cdSAl Viro WARN_ON(1); 1320241699cdSAl Viro return 0; 1321241699cdSAl Viro } 1322d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1323d879cb83SAl Viro int err = 0; 1324d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1325d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1326d879cb83SAl Viro v.iov_len, 0, &err); 1327d879cb83SAl Viro if (!err) { 1328d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1329d879cb83SAl Viro off += v.iov_len; 1330d879cb83SAl Viro } 1331d879cb83SAl Viro err ? v.iov_len : 0; 1332d879cb83SAl Viro }), ({ 1333d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1334d879cb83SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1335d879cb83SAl Viro (to += v.bv_len) - v.bv_len, 1336d879cb83SAl Viro v.bv_len, 0); 1337d879cb83SAl Viro kunmap_atomic(p); 1338d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1339d879cb83SAl Viro off += v.bv_len; 1340d879cb83SAl Viro }),({ 1341d879cb83SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1342d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1343d879cb83SAl Viro v.iov_len, 0); 1344d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1345d879cb83SAl Viro off += v.iov_len; 1346d879cb83SAl Viro }) 1347d879cb83SAl Viro ) 1348d879cb83SAl Viro *csum = sum; 1349d879cb83SAl Viro return bytes; 1350d879cb83SAl Viro } 1351d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1352d879cb83SAl Viro 1353cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1354cbbd26b8SAl Viro struct iov_iter *i) 1355cbbd26b8SAl Viro { 1356cbbd26b8SAl Viro char *to = addr; 1357cbbd26b8SAl Viro __wsum sum, next; 1358cbbd26b8SAl Viro size_t off = 0; 1359cbbd26b8SAl Viro sum = *csum; 136000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1361cbbd26b8SAl Viro WARN_ON(1); 1362cbbd26b8SAl Viro return false; 1363cbbd26b8SAl Viro } 1364cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1365cbbd26b8SAl Viro return false; 1366cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1367cbbd26b8SAl Viro int err = 0; 1368cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1369cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1370cbbd26b8SAl Viro v.iov_len, 0, &err); 1371cbbd26b8SAl Viro if (err) 1372cbbd26b8SAl Viro return false; 1373cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1374cbbd26b8SAl Viro off += v.iov_len; 1375cbbd26b8SAl Viro 0; 1376cbbd26b8SAl Viro }), ({ 1377cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1378cbbd26b8SAl Viro next = csum_partial_copy_nocheck(p + v.bv_offset, 1379cbbd26b8SAl Viro (to += v.bv_len) - v.bv_len, 1380cbbd26b8SAl Viro v.bv_len, 0); 1381cbbd26b8SAl Viro kunmap_atomic(p); 1382cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1383cbbd26b8SAl Viro off += v.bv_len; 1384cbbd26b8SAl Viro }),({ 1385cbbd26b8SAl Viro next = csum_partial_copy_nocheck(v.iov_base, 1386cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1387cbbd26b8SAl Viro v.iov_len, 0); 1388cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1389cbbd26b8SAl Viro off += v.iov_len; 1390cbbd26b8SAl Viro }) 1391cbbd26b8SAl Viro ) 1392cbbd26b8SAl Viro *csum = sum; 1393cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1394cbbd26b8SAl Viro return true; 1395cbbd26b8SAl Viro } 1396cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1397cbbd26b8SAl Viro 139836f7a8a4SAl Viro size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, 1399d879cb83SAl Viro struct iov_iter *i) 1400d879cb83SAl Viro { 140136f7a8a4SAl Viro const char *from = addr; 1402d879cb83SAl Viro __wsum sum, next; 1403d879cb83SAl Viro size_t off = 0; 1404d879cb83SAl Viro sum = *csum; 140500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1406241699cdSAl Viro WARN_ON(1); /* for now */ 1407241699cdSAl Viro return 0; 1408241699cdSAl Viro } 1409d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1410d879cb83SAl Viro int err = 0; 1411d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1412d879cb83SAl Viro v.iov_base, 1413d879cb83SAl Viro v.iov_len, 0, &err); 1414d879cb83SAl Viro if (!err) { 1415d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1416d879cb83SAl Viro off += v.iov_len; 1417d879cb83SAl Viro } 1418d879cb83SAl Viro err ? v.iov_len : 0; 1419d879cb83SAl Viro }), ({ 1420d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1421d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len, 1422d879cb83SAl Viro p + v.bv_offset, 1423d879cb83SAl Viro v.bv_len, 0); 1424d879cb83SAl Viro kunmap_atomic(p); 1425d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1426d879cb83SAl Viro off += v.bv_len; 1427d879cb83SAl Viro }),({ 1428d879cb83SAl Viro next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len, 1429d879cb83SAl Viro v.iov_base, 1430d879cb83SAl Viro v.iov_len, 0); 1431d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1432d879cb83SAl Viro off += v.iov_len; 1433d879cb83SAl Viro }) 1434d879cb83SAl Viro ) 1435d879cb83SAl Viro *csum = sum; 1436d879cb83SAl Viro return bytes; 1437d879cb83SAl Viro } 1438d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1439d879cb83SAl Viro 1440d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1441d879cb83SAl Viro { 1442d879cb83SAl Viro size_t size = i->count; 1443d879cb83SAl Viro int npages = 0; 1444d879cb83SAl Viro 1445d879cb83SAl Viro if (!size) 1446d879cb83SAl Viro return 0; 1447d879cb83SAl Viro 144800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1449241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1450241699cdSAl Viro size_t off; 1451241699cdSAl Viro int idx; 1452241699cdSAl Viro 1453241699cdSAl Viro if (!sanity(i)) 1454241699cdSAl Viro return 0; 1455241699cdSAl Viro 1456241699cdSAl Viro data_start(i, &idx, &off); 1457241699cdSAl Viro /* some of this one + all after this one */ 1458241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1459241699cdSAl Viro if (npages >= maxpages) 1460241699cdSAl Viro return maxpages; 1461241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1462d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1463d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1464d879cb83SAl Viro - p / PAGE_SIZE; 1465d879cb83SAl Viro if (npages >= maxpages) 1466d879cb83SAl Viro return maxpages; 1467d879cb83SAl Viro 0;}),({ 1468d879cb83SAl Viro npages++; 1469d879cb83SAl Viro if (npages >= maxpages) 1470d879cb83SAl Viro return maxpages; 1471d879cb83SAl Viro }),({ 1472d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1473d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1474d879cb83SAl Viro - p / PAGE_SIZE; 1475d879cb83SAl Viro if (npages >= maxpages) 1476d879cb83SAl Viro return maxpages; 1477d879cb83SAl Viro }) 1478d879cb83SAl Viro ) 1479d879cb83SAl Viro return npages; 1480d879cb83SAl Viro } 1481d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1482d879cb83SAl Viro 1483d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1484d879cb83SAl Viro { 1485d879cb83SAl Viro *new = *old; 148600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(new))) { 1487241699cdSAl Viro WARN_ON(1); 1488241699cdSAl Viro return NULL; 1489241699cdSAl Viro } 149000e23707SDavid Howells if (iov_iter_is_bvec(new)) 1491d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1492d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1493d879cb83SAl Viro flags); 1494d879cb83SAl Viro else 1495d879cb83SAl Viro /* iovec and kvec have identical layout */ 1496d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1497d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1498d879cb83SAl Viro flags); 1499d879cb83SAl Viro } 1500d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1501bc917be8SAl Viro 1502ffecee4fSVegard Nossum /** 1503ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1504ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1505ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1506ffecee4fSVegard Nossum * 1507ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1508ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1509ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1510ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1511ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1512ffecee4fSVegard Nossum * on-stack) kernel array. 1513ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1514ffecee4fSVegard Nossum * 1515ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1516ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1517ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1518ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1519ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1520ffecee4fSVegard Nossum * returns an error or not). 1521ffecee4fSVegard Nossum * 1522ffecee4fSVegard Nossum * Return: 0 on success or negative error code on error. 1523ffecee4fSVegard Nossum */ 1524bc917be8SAl Viro int import_iovec(int type, const struct iovec __user * uvector, 1525bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1526bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1527bc917be8SAl Viro { 1528bc917be8SAl Viro ssize_t n; 1529bc917be8SAl Viro struct iovec *p; 1530bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1531bc917be8SAl Viro *iov, &p); 1532bc917be8SAl Viro if (n < 0) { 1533bc917be8SAl Viro if (p != *iov) 1534bc917be8SAl Viro kfree(p); 1535bc917be8SAl Viro *iov = NULL; 1536bc917be8SAl Viro return n; 1537bc917be8SAl Viro } 1538bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1539bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1540bc917be8SAl Viro return 0; 1541bc917be8SAl Viro } 1542bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1543bc917be8SAl Viro 1544bc917be8SAl Viro #ifdef CONFIG_COMPAT 1545bc917be8SAl Viro #include <linux/compat.h> 1546bc917be8SAl Viro 1547bc917be8SAl Viro int compat_import_iovec(int type, const struct compat_iovec __user * uvector, 1548bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1549bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1550bc917be8SAl Viro { 1551bc917be8SAl Viro ssize_t n; 1552bc917be8SAl Viro struct iovec *p; 1553bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1554bc917be8SAl Viro *iov, &p); 1555bc917be8SAl Viro if (n < 0) { 1556bc917be8SAl Viro if (p != *iov) 1557bc917be8SAl Viro kfree(p); 1558bc917be8SAl Viro *iov = NULL; 1559bc917be8SAl Viro return n; 1560bc917be8SAl Viro } 1561bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1562bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1563bc917be8SAl Viro return 0; 1564bc917be8SAl Viro } 1565bc917be8SAl Viro #endif 1566bc917be8SAl Viro 1567bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1568bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1569bc917be8SAl Viro { 1570bc917be8SAl Viro if (len > MAX_RW_COUNT) 1571bc917be8SAl Viro len = MAX_RW_COUNT; 1572bc917be8SAl Viro if (unlikely(!access_ok(!rw, buf, len))) 1573bc917be8SAl Viro return -EFAULT; 1574bc917be8SAl Viro 1575bc917be8SAl Viro iov->iov_base = buf; 1576bc917be8SAl Viro iov->iov_len = len; 1577bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1578bc917be8SAl Viro return 0; 1579bc917be8SAl Viro } 1580e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 158109cf698aSAl Viro 158209cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 158309cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 158409cf698aSAl Viro void *context) 158509cf698aSAl Viro { 158609cf698aSAl Viro struct kvec w; 158709cf698aSAl Viro int err = -EINVAL; 158809cf698aSAl Viro if (!bytes) 158909cf698aSAl Viro return 0; 159009cf698aSAl Viro 159109cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 159209cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 159309cf698aSAl Viro w.iov_len = v.bv_len; 159409cf698aSAl Viro err = f(&w, context); 159509cf698aSAl Viro kunmap(v.bv_page); 159609cf698aSAl Viro err;}), ({ 159709cf698aSAl Viro w = v; 159809cf698aSAl Viro err = f(&w, context);}) 159909cf698aSAl Viro ) 160009cf698aSAl Viro return err; 160109cf698aSAl Viro } 160209cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1603