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> 9d05f4435SSagi Grimberg #include <linux/scatterlist.h> 10d879cb83SAl Viro 11241699cdSAl Viro #define PIPE_PARANOIA /* for now */ 12241699cdSAl Viro 13d879cb83SAl Viro #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ 14d879cb83SAl Viro size_t left; \ 15d879cb83SAl Viro size_t wanted = n; \ 16d879cb83SAl Viro __p = i->iov; \ 17d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 18d879cb83SAl Viro if (likely(__v.iov_len)) { \ 19d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 20d879cb83SAl Viro left = (STEP); \ 21d879cb83SAl Viro __v.iov_len -= left; \ 22d879cb83SAl Viro skip += __v.iov_len; \ 23d879cb83SAl Viro n -= __v.iov_len; \ 24d879cb83SAl Viro } else { \ 25d879cb83SAl Viro left = 0; \ 26d879cb83SAl Viro } \ 27d879cb83SAl Viro while (unlikely(!left && n)) { \ 28d879cb83SAl Viro __p++; \ 29d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 30d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 31d879cb83SAl Viro continue; \ 32d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 33d879cb83SAl Viro left = (STEP); \ 34d879cb83SAl Viro __v.iov_len -= left; \ 35d879cb83SAl Viro skip = __v.iov_len; \ 36d879cb83SAl Viro n -= __v.iov_len; \ 37d879cb83SAl Viro } \ 38d879cb83SAl Viro n = wanted - n; \ 39d879cb83SAl Viro } 40d879cb83SAl Viro 41d879cb83SAl Viro #define iterate_kvec(i, n, __v, __p, skip, STEP) { \ 42d879cb83SAl Viro size_t wanted = n; \ 43d879cb83SAl Viro __p = i->kvec; \ 44d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len - skip); \ 45d879cb83SAl Viro if (likely(__v.iov_len)) { \ 46d879cb83SAl Viro __v.iov_base = __p->iov_base + skip; \ 47d879cb83SAl Viro (void)(STEP); \ 48d879cb83SAl Viro skip += __v.iov_len; \ 49d879cb83SAl Viro n -= __v.iov_len; \ 50d879cb83SAl Viro } \ 51d879cb83SAl Viro while (unlikely(n)) { \ 52d879cb83SAl Viro __p++; \ 53d879cb83SAl Viro __v.iov_len = min(n, __p->iov_len); \ 54d879cb83SAl Viro if (unlikely(!__v.iov_len)) \ 55d879cb83SAl Viro continue; \ 56d879cb83SAl Viro __v.iov_base = __p->iov_base; \ 57d879cb83SAl Viro (void)(STEP); \ 58d879cb83SAl Viro skip = __v.iov_len; \ 59d879cb83SAl Viro n -= __v.iov_len; \ 60d879cb83SAl Viro } \ 61d879cb83SAl Viro n = wanted; \ 62d879cb83SAl Viro } 63d879cb83SAl Viro 641bdc76aeSMing Lei #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ 651bdc76aeSMing Lei struct bvec_iter __start; \ 661bdc76aeSMing Lei __start.bi_size = n; \ 671bdc76aeSMing Lei __start.bi_bvec_done = skip; \ 681bdc76aeSMing Lei __start.bi_idx = 0; \ 691bdc76aeSMing Lei for_each_bvec(__v, i->bvec, __bi, __start) { \ 701bdc76aeSMing Lei if (!__v.bv_len) \ 71d879cb83SAl Viro continue; \ 72d879cb83SAl Viro (void)(STEP); \ 73d879cb83SAl Viro } \ 74d879cb83SAl Viro } 75d879cb83SAl Viro 76d879cb83SAl Viro #define iterate_all_kinds(i, n, v, I, B, K) { \ 7733844e66SAl Viro if (likely(n)) { \ 78d879cb83SAl Viro size_t skip = i->iov_offset; \ 79d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 80d879cb83SAl Viro struct bio_vec v; \ 811bdc76aeSMing Lei struct bvec_iter __bi; \ 821bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 83d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 84d879cb83SAl Viro const struct kvec *kvec; \ 85d879cb83SAl Viro struct kvec v; \ 86d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 879ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 88d879cb83SAl Viro } else { \ 89d879cb83SAl Viro const struct iovec *iov; \ 90d879cb83SAl Viro struct iovec v; \ 91d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 92d879cb83SAl Viro } \ 9333844e66SAl Viro } \ 94d879cb83SAl Viro } 95d879cb83SAl Viro 96d879cb83SAl Viro #define iterate_and_advance(i, n, v, I, B, K) { \ 97dd254f5aSAl Viro if (unlikely(i->count < n)) \ 98dd254f5aSAl Viro n = i->count; \ 9919f18459SAl Viro if (i->count) { \ 100d879cb83SAl Viro size_t skip = i->iov_offset; \ 101d879cb83SAl Viro if (unlikely(i->type & ITER_BVEC)) { \ 1021bdc76aeSMing Lei const struct bio_vec *bvec = i->bvec; \ 103d879cb83SAl Viro struct bio_vec v; \ 1041bdc76aeSMing Lei struct bvec_iter __bi; \ 1051bdc76aeSMing Lei iterate_bvec(i, n, v, __bi, skip, (B)) \ 1061bdc76aeSMing Lei i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ 1071bdc76aeSMing Lei i->nr_segs -= i->bvec - bvec; \ 1081bdc76aeSMing Lei skip = __bi.bi_bvec_done; \ 109d879cb83SAl Viro } else if (unlikely(i->type & ITER_KVEC)) { \ 110d879cb83SAl Viro const struct kvec *kvec; \ 111d879cb83SAl Viro struct kvec v; \ 112d879cb83SAl Viro iterate_kvec(i, n, v, kvec, skip, (K)) \ 113d879cb83SAl Viro if (skip == kvec->iov_len) { \ 114d879cb83SAl Viro kvec++; \ 115d879cb83SAl Viro skip = 0; \ 116d879cb83SAl Viro } \ 117d879cb83SAl Viro i->nr_segs -= kvec - i->kvec; \ 118d879cb83SAl Viro i->kvec = kvec; \ 1199ea9ce04SDavid Howells } else if (unlikely(i->type & ITER_DISCARD)) { \ 1209ea9ce04SDavid Howells skip += n; \ 121d879cb83SAl Viro } else { \ 122d879cb83SAl Viro const struct iovec *iov; \ 123d879cb83SAl Viro struct iovec v; \ 124d879cb83SAl Viro iterate_iovec(i, n, v, iov, skip, (I)) \ 125d879cb83SAl Viro if (skip == iov->iov_len) { \ 126d879cb83SAl Viro iov++; \ 127d879cb83SAl Viro skip = 0; \ 128d879cb83SAl Viro } \ 129d879cb83SAl Viro i->nr_segs -= iov - i->iov; \ 130d879cb83SAl Viro i->iov = iov; \ 131d879cb83SAl Viro } \ 132d879cb83SAl Viro i->count -= n; \ 133d879cb83SAl Viro i->iov_offset = skip; \ 134dd254f5aSAl Viro } \ 135d879cb83SAl Viro } 136d879cb83SAl Viro 13709fc68dcSAl Viro static int copyout(void __user *to, const void *from, size_t n) 13809fc68dcSAl Viro { 13996d4f267SLinus Torvalds if (access_ok(to, n)) { 14009fc68dcSAl Viro kasan_check_read(from, n); 14109fc68dcSAl Viro n = raw_copy_to_user(to, from, n); 14209fc68dcSAl Viro } 14309fc68dcSAl Viro return n; 14409fc68dcSAl Viro } 14509fc68dcSAl Viro 14609fc68dcSAl Viro static int copyin(void *to, const void __user *from, size_t n) 14709fc68dcSAl Viro { 14896d4f267SLinus Torvalds if (access_ok(from, n)) { 14909fc68dcSAl Viro kasan_check_write(to, n); 15009fc68dcSAl Viro n = raw_copy_from_user(to, from, n); 15109fc68dcSAl Viro } 15209fc68dcSAl Viro return n; 15309fc68dcSAl Viro } 15409fc68dcSAl Viro 155d879cb83SAl Viro static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, 156d879cb83SAl Viro struct iov_iter *i) 157d879cb83SAl Viro { 158d879cb83SAl Viro size_t skip, copy, left, wanted; 159d879cb83SAl Viro const struct iovec *iov; 160d879cb83SAl Viro char __user *buf; 161d879cb83SAl Viro void *kaddr, *from; 162d879cb83SAl Viro 163d879cb83SAl Viro if (unlikely(bytes > i->count)) 164d879cb83SAl Viro bytes = i->count; 165d879cb83SAl Viro 166d879cb83SAl Viro if (unlikely(!bytes)) 167d879cb83SAl Viro return 0; 168d879cb83SAl Viro 16909fc68dcSAl Viro might_fault(); 170d879cb83SAl Viro wanted = bytes; 171d879cb83SAl Viro iov = i->iov; 172d879cb83SAl Viro skip = i->iov_offset; 173d879cb83SAl Viro buf = iov->iov_base + skip; 174d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 175d879cb83SAl Viro 1763fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) { 177d879cb83SAl Viro kaddr = kmap_atomic(page); 178d879cb83SAl Viro from = kaddr + offset; 179d879cb83SAl Viro 180d879cb83SAl Viro /* first chunk, usually the only one */ 18109fc68dcSAl Viro left = copyout(buf, from, copy); 182d879cb83SAl Viro copy -= left; 183d879cb83SAl Viro skip += copy; 184d879cb83SAl Viro from += copy; 185d879cb83SAl Viro bytes -= copy; 186d879cb83SAl Viro 187d879cb83SAl Viro while (unlikely(!left && bytes)) { 188d879cb83SAl Viro iov++; 189d879cb83SAl Viro buf = iov->iov_base; 190d879cb83SAl Viro copy = min(bytes, iov->iov_len); 19109fc68dcSAl Viro left = copyout(buf, from, copy); 192d879cb83SAl Viro copy -= left; 193d879cb83SAl Viro skip = copy; 194d879cb83SAl Viro from += copy; 195d879cb83SAl Viro bytes -= copy; 196d879cb83SAl Viro } 197d879cb83SAl Viro if (likely(!bytes)) { 198d879cb83SAl Viro kunmap_atomic(kaddr); 199d879cb83SAl Viro goto done; 200d879cb83SAl Viro } 201d879cb83SAl Viro offset = from - kaddr; 202d879cb83SAl Viro buf += copy; 203d879cb83SAl Viro kunmap_atomic(kaddr); 204d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 205d879cb83SAl Viro } 206d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2073fa6c507SMikulas Patocka 208d879cb83SAl Viro kaddr = kmap(page); 209d879cb83SAl Viro from = kaddr + offset; 21009fc68dcSAl Viro left = copyout(buf, from, copy); 211d879cb83SAl Viro copy -= left; 212d879cb83SAl Viro skip += copy; 213d879cb83SAl Viro from += copy; 214d879cb83SAl Viro bytes -= copy; 215d879cb83SAl Viro while (unlikely(!left && bytes)) { 216d879cb83SAl Viro iov++; 217d879cb83SAl Viro buf = iov->iov_base; 218d879cb83SAl Viro copy = min(bytes, iov->iov_len); 21909fc68dcSAl Viro left = copyout(buf, from, copy); 220d879cb83SAl Viro copy -= left; 221d879cb83SAl Viro skip = copy; 222d879cb83SAl Viro from += copy; 223d879cb83SAl Viro bytes -= copy; 224d879cb83SAl Viro } 225d879cb83SAl Viro kunmap(page); 2263fa6c507SMikulas Patocka 227d879cb83SAl Viro done: 228d879cb83SAl Viro if (skip == iov->iov_len) { 229d879cb83SAl Viro iov++; 230d879cb83SAl Viro skip = 0; 231d879cb83SAl Viro } 232d879cb83SAl Viro i->count -= wanted - bytes; 233d879cb83SAl Viro i->nr_segs -= iov - i->iov; 234d879cb83SAl Viro i->iov = iov; 235d879cb83SAl Viro i->iov_offset = skip; 236d879cb83SAl Viro return wanted - bytes; 237d879cb83SAl Viro } 238d879cb83SAl Viro 239d879cb83SAl Viro static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes, 240d879cb83SAl Viro struct iov_iter *i) 241d879cb83SAl Viro { 242d879cb83SAl Viro size_t skip, copy, left, wanted; 243d879cb83SAl Viro const struct iovec *iov; 244d879cb83SAl Viro char __user *buf; 245d879cb83SAl Viro void *kaddr, *to; 246d879cb83SAl Viro 247d879cb83SAl Viro if (unlikely(bytes > i->count)) 248d879cb83SAl Viro bytes = i->count; 249d879cb83SAl Viro 250d879cb83SAl Viro if (unlikely(!bytes)) 251d879cb83SAl Viro return 0; 252d879cb83SAl Viro 25309fc68dcSAl Viro might_fault(); 254d879cb83SAl Viro wanted = bytes; 255d879cb83SAl Viro iov = i->iov; 256d879cb83SAl Viro skip = i->iov_offset; 257d879cb83SAl Viro buf = iov->iov_base + skip; 258d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 259d879cb83SAl Viro 2603fa6c507SMikulas Patocka if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) { 261d879cb83SAl Viro kaddr = kmap_atomic(page); 262d879cb83SAl Viro to = kaddr + offset; 263d879cb83SAl Viro 264d879cb83SAl Viro /* first chunk, usually the only one */ 26509fc68dcSAl Viro left = copyin(to, buf, copy); 266d879cb83SAl Viro copy -= left; 267d879cb83SAl Viro skip += copy; 268d879cb83SAl Viro to += copy; 269d879cb83SAl Viro bytes -= copy; 270d879cb83SAl Viro 271d879cb83SAl Viro while (unlikely(!left && bytes)) { 272d879cb83SAl Viro iov++; 273d879cb83SAl Viro buf = iov->iov_base; 274d879cb83SAl Viro copy = min(bytes, iov->iov_len); 27509fc68dcSAl Viro left = copyin(to, buf, copy); 276d879cb83SAl Viro copy -= left; 277d879cb83SAl Viro skip = copy; 278d879cb83SAl Viro to += copy; 279d879cb83SAl Viro bytes -= copy; 280d879cb83SAl Viro } 281d879cb83SAl Viro if (likely(!bytes)) { 282d879cb83SAl Viro kunmap_atomic(kaddr); 283d879cb83SAl Viro goto done; 284d879cb83SAl Viro } 285d879cb83SAl Viro offset = to - kaddr; 286d879cb83SAl Viro buf += copy; 287d879cb83SAl Viro kunmap_atomic(kaddr); 288d879cb83SAl Viro copy = min(bytes, iov->iov_len - skip); 289d879cb83SAl Viro } 290d879cb83SAl Viro /* Too bad - revert to non-atomic kmap */ 2913fa6c507SMikulas Patocka 292d879cb83SAl Viro kaddr = kmap(page); 293d879cb83SAl Viro to = kaddr + offset; 29409fc68dcSAl Viro left = copyin(to, buf, copy); 295d879cb83SAl Viro copy -= left; 296d879cb83SAl Viro skip += copy; 297d879cb83SAl Viro to += copy; 298d879cb83SAl Viro bytes -= copy; 299d879cb83SAl Viro while (unlikely(!left && bytes)) { 300d879cb83SAl Viro iov++; 301d879cb83SAl Viro buf = iov->iov_base; 302d879cb83SAl Viro copy = min(bytes, iov->iov_len); 30309fc68dcSAl Viro left = copyin(to, buf, copy); 304d879cb83SAl Viro copy -= left; 305d879cb83SAl Viro skip = copy; 306d879cb83SAl Viro to += copy; 307d879cb83SAl Viro bytes -= copy; 308d879cb83SAl Viro } 309d879cb83SAl Viro kunmap(page); 3103fa6c507SMikulas Patocka 311d879cb83SAl Viro done: 312d879cb83SAl Viro if (skip == iov->iov_len) { 313d879cb83SAl Viro iov++; 314d879cb83SAl Viro skip = 0; 315d879cb83SAl Viro } 316d879cb83SAl Viro i->count -= wanted - bytes; 317d879cb83SAl Viro i->nr_segs -= iov - i->iov; 318d879cb83SAl Viro i->iov = iov; 319d879cb83SAl Viro i->iov_offset = skip; 320d879cb83SAl Viro return wanted - bytes; 321d879cb83SAl Viro } 322d879cb83SAl Viro 323241699cdSAl Viro #ifdef PIPE_PARANOIA 324241699cdSAl Viro static bool sanity(const struct iov_iter *i) 325241699cdSAl Viro { 326241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 327241699cdSAl Viro int idx = i->idx; 328241699cdSAl Viro int next = pipe->curbuf + pipe->nrbufs; 329241699cdSAl Viro if (i->iov_offset) { 330241699cdSAl Viro struct pipe_buffer *p; 331241699cdSAl Viro if (unlikely(!pipe->nrbufs)) 332241699cdSAl Viro goto Bad; // pipe must be non-empty 333241699cdSAl Viro if (unlikely(idx != ((next - 1) & (pipe->buffers - 1)))) 334241699cdSAl Viro goto Bad; // must be at the last buffer... 335241699cdSAl Viro 336241699cdSAl Viro p = &pipe->bufs[idx]; 337241699cdSAl Viro if (unlikely(p->offset + p->len != i->iov_offset)) 338241699cdSAl Viro goto Bad; // ... at the end of segment 339241699cdSAl Viro } else { 340241699cdSAl Viro if (idx != (next & (pipe->buffers - 1))) 341241699cdSAl Viro goto Bad; // must be right after the last buffer 342241699cdSAl Viro } 343241699cdSAl Viro return true; 344241699cdSAl Viro Bad: 345241699cdSAl Viro printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset); 346241699cdSAl Viro printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n", 347241699cdSAl Viro pipe->curbuf, pipe->nrbufs, pipe->buffers); 348241699cdSAl Viro for (idx = 0; idx < pipe->buffers; idx++) 349241699cdSAl Viro printk(KERN_ERR "[%p %p %d %d]\n", 350241699cdSAl Viro pipe->bufs[idx].ops, 351241699cdSAl Viro pipe->bufs[idx].page, 352241699cdSAl Viro pipe->bufs[idx].offset, 353241699cdSAl Viro pipe->bufs[idx].len); 354241699cdSAl Viro WARN_ON(1); 355241699cdSAl Viro return false; 356241699cdSAl Viro } 357241699cdSAl Viro #else 358241699cdSAl Viro #define sanity(i) true 359241699cdSAl Viro #endif 360241699cdSAl Viro 361241699cdSAl Viro static inline int next_idx(int idx, struct pipe_inode_info *pipe) 362241699cdSAl Viro { 363241699cdSAl Viro return (idx + 1) & (pipe->buffers - 1); 364241699cdSAl Viro } 365241699cdSAl Viro 366241699cdSAl Viro static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, 367241699cdSAl Viro struct iov_iter *i) 368241699cdSAl Viro { 369241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 370241699cdSAl Viro struct pipe_buffer *buf; 371241699cdSAl Viro size_t off; 372241699cdSAl Viro int idx; 373241699cdSAl Viro 374241699cdSAl Viro if (unlikely(bytes > i->count)) 375241699cdSAl Viro bytes = i->count; 376241699cdSAl Viro 377241699cdSAl Viro if (unlikely(!bytes)) 378241699cdSAl Viro return 0; 379241699cdSAl Viro 380241699cdSAl Viro if (!sanity(i)) 381241699cdSAl Viro return 0; 382241699cdSAl Viro 383241699cdSAl Viro off = i->iov_offset; 384241699cdSAl Viro idx = i->idx; 385241699cdSAl Viro buf = &pipe->bufs[idx]; 386241699cdSAl Viro if (off) { 387241699cdSAl Viro if (offset == off && buf->page == page) { 388241699cdSAl Viro /* merge with the last one */ 389241699cdSAl Viro buf->len += bytes; 390241699cdSAl Viro i->iov_offset += bytes; 391241699cdSAl Viro goto out; 392241699cdSAl Viro } 393241699cdSAl Viro idx = next_idx(idx, pipe); 394241699cdSAl Viro buf = &pipe->bufs[idx]; 395241699cdSAl Viro } 396241699cdSAl Viro if (idx == pipe->curbuf && pipe->nrbufs) 397241699cdSAl Viro return 0; 398241699cdSAl Viro pipe->nrbufs++; 399241699cdSAl Viro buf->ops = &page_cache_pipe_buf_ops; 400241699cdSAl Viro get_page(buf->page = page); 401241699cdSAl Viro buf->offset = offset; 402241699cdSAl Viro buf->len = bytes; 403241699cdSAl Viro i->iov_offset = offset + bytes; 404241699cdSAl Viro i->idx = idx; 405241699cdSAl Viro out: 406241699cdSAl Viro i->count -= bytes; 407241699cdSAl Viro return bytes; 408241699cdSAl Viro } 409241699cdSAl Viro 410d879cb83SAl Viro /* 411171a0203SAnton Altaparmakov * Fault in one or more iovecs of the given iov_iter, to a maximum length of 412171a0203SAnton Altaparmakov * bytes. For each iovec, fault in each page that constitutes the iovec. 413171a0203SAnton Altaparmakov * 414171a0203SAnton Altaparmakov * Return 0 on success, or non-zero if the memory could not be accessed (i.e. 415171a0203SAnton Altaparmakov * because it is an invalid address). 416171a0203SAnton Altaparmakov */ 417d4690f1eSAl Viro int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) 418171a0203SAnton Altaparmakov { 419171a0203SAnton Altaparmakov size_t skip = i->iov_offset; 420171a0203SAnton Altaparmakov const struct iovec *iov; 421171a0203SAnton Altaparmakov int err; 422171a0203SAnton Altaparmakov struct iovec v; 423171a0203SAnton Altaparmakov 424171a0203SAnton Altaparmakov if (!(i->type & (ITER_BVEC|ITER_KVEC))) { 425171a0203SAnton Altaparmakov iterate_iovec(i, bytes, v, iov, skip, ({ 4264bce9f6eSAl Viro err = fault_in_pages_readable(v.iov_base, v.iov_len); 427171a0203SAnton Altaparmakov if (unlikely(err)) 428171a0203SAnton Altaparmakov return err; 429171a0203SAnton Altaparmakov 0;})) 430171a0203SAnton Altaparmakov } 431171a0203SAnton Altaparmakov return 0; 432171a0203SAnton Altaparmakov } 433d4690f1eSAl Viro EXPORT_SYMBOL(iov_iter_fault_in_readable); 434171a0203SAnton Altaparmakov 435aa563d7bSDavid Howells void iov_iter_init(struct iov_iter *i, unsigned int direction, 436d879cb83SAl Viro const struct iovec *iov, unsigned long nr_segs, 437d879cb83SAl Viro size_t count) 438d879cb83SAl Viro { 439aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 440aa563d7bSDavid Howells direction &= READ | WRITE; 441aa563d7bSDavid Howells 442d879cb83SAl Viro /* It will get better. Eventually... */ 443db68ce10SAl Viro if (uaccess_kernel()) { 444aa563d7bSDavid Howells i->type = ITER_KVEC | direction; 445d879cb83SAl Viro i->kvec = (struct kvec *)iov; 446d879cb83SAl Viro } else { 447aa563d7bSDavid Howells i->type = ITER_IOVEC | direction; 448d879cb83SAl Viro i->iov = iov; 449d879cb83SAl Viro } 450d879cb83SAl Viro i->nr_segs = nr_segs; 451d879cb83SAl Viro i->iov_offset = 0; 452d879cb83SAl Viro i->count = count; 453d879cb83SAl Viro } 454d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_init); 455d879cb83SAl Viro 456d879cb83SAl Viro static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) 457d879cb83SAl Viro { 458d879cb83SAl Viro char *from = kmap_atomic(page); 459d879cb83SAl Viro memcpy(to, from + offset, len); 460d879cb83SAl Viro kunmap_atomic(from); 461d879cb83SAl Viro } 462d879cb83SAl Viro 46336f7a8a4SAl Viro static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) 464d879cb83SAl Viro { 465d879cb83SAl Viro char *to = kmap_atomic(page); 466d879cb83SAl Viro memcpy(to + offset, from, len); 467d879cb83SAl Viro kunmap_atomic(to); 468d879cb83SAl Viro } 469d879cb83SAl Viro 470d879cb83SAl Viro static void memzero_page(struct page *page, size_t offset, size_t len) 471d879cb83SAl Viro { 472d879cb83SAl Viro char *addr = kmap_atomic(page); 473d879cb83SAl Viro memset(addr + offset, 0, len); 474d879cb83SAl Viro kunmap_atomic(addr); 475d879cb83SAl Viro } 476d879cb83SAl Viro 477241699cdSAl Viro static inline bool allocated(struct pipe_buffer *buf) 478241699cdSAl Viro { 479241699cdSAl Viro return buf->ops == &default_pipe_buf_ops; 480241699cdSAl Viro } 481241699cdSAl Viro 482241699cdSAl Viro static inline void data_start(const struct iov_iter *i, int *idxp, size_t *offp) 483241699cdSAl Viro { 484241699cdSAl Viro size_t off = i->iov_offset; 485241699cdSAl Viro int idx = i->idx; 486241699cdSAl Viro if (off && (!allocated(&i->pipe->bufs[idx]) || off == PAGE_SIZE)) { 487241699cdSAl Viro idx = next_idx(idx, i->pipe); 488241699cdSAl Viro off = 0; 489241699cdSAl Viro } 490241699cdSAl Viro *idxp = idx; 491241699cdSAl Viro *offp = off; 492241699cdSAl Viro } 493241699cdSAl Viro 494241699cdSAl Viro static size_t push_pipe(struct iov_iter *i, size_t size, 495241699cdSAl Viro int *idxp, size_t *offp) 496241699cdSAl Viro { 497241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 498241699cdSAl Viro size_t off; 499241699cdSAl Viro int idx; 500241699cdSAl Viro ssize_t left; 501241699cdSAl Viro 502241699cdSAl Viro if (unlikely(size > i->count)) 503241699cdSAl Viro size = i->count; 504241699cdSAl Viro if (unlikely(!size)) 505241699cdSAl Viro return 0; 506241699cdSAl Viro 507241699cdSAl Viro left = size; 508241699cdSAl Viro data_start(i, &idx, &off); 509241699cdSAl Viro *idxp = idx; 510241699cdSAl Viro *offp = off; 511241699cdSAl Viro if (off) { 512241699cdSAl Viro left -= PAGE_SIZE - off; 513241699cdSAl Viro if (left <= 0) { 514241699cdSAl Viro pipe->bufs[idx].len += size; 515241699cdSAl Viro return size; 516241699cdSAl Viro } 517241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 518241699cdSAl Viro idx = next_idx(idx, pipe); 519241699cdSAl Viro } 520241699cdSAl Viro while (idx != pipe->curbuf || !pipe->nrbufs) { 521241699cdSAl Viro struct page *page = alloc_page(GFP_USER); 522241699cdSAl Viro if (!page) 523241699cdSAl Viro break; 524241699cdSAl Viro pipe->nrbufs++; 525241699cdSAl Viro pipe->bufs[idx].ops = &default_pipe_buf_ops; 526241699cdSAl Viro pipe->bufs[idx].page = page; 527241699cdSAl Viro pipe->bufs[idx].offset = 0; 528241699cdSAl Viro if (left <= PAGE_SIZE) { 529241699cdSAl Viro pipe->bufs[idx].len = left; 530241699cdSAl Viro return size; 531241699cdSAl Viro } 532241699cdSAl Viro pipe->bufs[idx].len = PAGE_SIZE; 533241699cdSAl Viro left -= PAGE_SIZE; 534241699cdSAl Viro idx = next_idx(idx, pipe); 535241699cdSAl Viro } 536241699cdSAl Viro return size - left; 537241699cdSAl Viro } 538241699cdSAl Viro 539241699cdSAl Viro static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 540241699cdSAl Viro struct iov_iter *i) 541241699cdSAl Viro { 542241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 543241699cdSAl Viro size_t n, off; 544241699cdSAl Viro int idx; 545241699cdSAl Viro 546241699cdSAl Viro if (!sanity(i)) 547241699cdSAl Viro return 0; 548241699cdSAl Viro 549241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 550241699cdSAl Viro if (unlikely(!n)) 551241699cdSAl Viro return 0; 552241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 553241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 554241699cdSAl Viro memcpy_to_page(pipe->bufs[idx].page, off, addr, chunk); 555241699cdSAl Viro i->idx = idx; 556241699cdSAl Viro i->iov_offset = off + chunk; 557241699cdSAl Viro n -= chunk; 558241699cdSAl Viro addr += chunk; 559241699cdSAl Viro } 560241699cdSAl Viro i->count -= bytes; 561241699cdSAl Viro return bytes; 562241699cdSAl Viro } 563241699cdSAl Viro 564f9152895SAl Viro static __wsum csum_and_memcpy(void *to, const void *from, size_t len, 565f9152895SAl Viro __wsum sum, size_t off) 566f9152895SAl Viro { 567f9152895SAl Viro __wsum next = csum_partial_copy_nocheck(from, to, len, 0); 568f9152895SAl Viro return csum_block_add(sum, next, off); 569f9152895SAl Viro } 570f9152895SAl Viro 57178e1f386SAl Viro static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 57278e1f386SAl Viro __wsum *csum, struct iov_iter *i) 57378e1f386SAl Viro { 57478e1f386SAl Viro struct pipe_inode_info *pipe = i->pipe; 57578e1f386SAl Viro size_t n, r; 57678e1f386SAl Viro size_t off = 0; 577f9152895SAl Viro __wsum sum = *csum; 57878e1f386SAl Viro int idx; 57978e1f386SAl Viro 58078e1f386SAl Viro if (!sanity(i)) 58178e1f386SAl Viro return 0; 58278e1f386SAl Viro 58378e1f386SAl Viro bytes = n = push_pipe(i, bytes, &idx, &r); 58478e1f386SAl Viro if (unlikely(!n)) 58578e1f386SAl Viro return 0; 58678e1f386SAl Viro for ( ; n; idx = next_idx(idx, pipe), r = 0) { 58778e1f386SAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - r); 58878e1f386SAl Viro char *p = kmap_atomic(pipe->bufs[idx].page); 589f9152895SAl Viro sum = csum_and_memcpy(p + r, addr, chunk, sum, off); 59078e1f386SAl Viro kunmap_atomic(p); 59178e1f386SAl Viro i->idx = idx; 59278e1f386SAl Viro i->iov_offset = r + chunk; 59378e1f386SAl Viro n -= chunk; 59478e1f386SAl Viro off += chunk; 59578e1f386SAl Viro addr += chunk; 59678e1f386SAl Viro } 59778e1f386SAl Viro i->count -= bytes; 59878e1f386SAl Viro *csum = sum; 59978e1f386SAl Viro return bytes; 60078e1f386SAl Viro } 60178e1f386SAl Viro 602aa28de27SAl Viro size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) 603d879cb83SAl Viro { 60436f7a8a4SAl Viro const char *from = addr; 60500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 606241699cdSAl Viro return copy_pipe_to_iter(addr, bytes, i); 60709fc68dcSAl Viro if (iter_is_iovec(i)) 60809fc68dcSAl Viro might_fault(); 609d879cb83SAl Viro iterate_and_advance(i, bytes, v, 61009fc68dcSAl Viro copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 611d879cb83SAl Viro memcpy_to_page(v.bv_page, v.bv_offset, 612d879cb83SAl Viro (from += v.bv_len) - v.bv_len, v.bv_len), 613d879cb83SAl Viro memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) 614d879cb83SAl Viro ) 615d879cb83SAl Viro 616d879cb83SAl Viro return bytes; 617d879cb83SAl Viro } 618aa28de27SAl Viro EXPORT_SYMBOL(_copy_to_iter); 619d879cb83SAl Viro 6208780356eSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE 6218780356eSDan Williams static int copyout_mcsafe(void __user *to, const void *from, size_t n) 6228780356eSDan Williams { 62396d4f267SLinus Torvalds if (access_ok(to, n)) { 6248780356eSDan Williams kasan_check_read(from, n); 6258780356eSDan Williams n = copy_to_user_mcsafe((__force void *) to, from, n); 6268780356eSDan Williams } 6278780356eSDan Williams return n; 6288780356eSDan Williams } 6298780356eSDan Williams 6308780356eSDan Williams static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset, 6318780356eSDan Williams const char *from, size_t len) 6328780356eSDan Williams { 6338780356eSDan Williams unsigned long ret; 6348780356eSDan Williams char *to; 6358780356eSDan Williams 6368780356eSDan Williams to = kmap_atomic(page); 6378780356eSDan Williams ret = memcpy_mcsafe(to + offset, from, len); 6388780356eSDan Williams kunmap_atomic(to); 6398780356eSDan Williams 6408780356eSDan Williams return ret; 6418780356eSDan Williams } 6428780356eSDan Williams 643ca146f6fSDan Williams static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes, 644ca146f6fSDan Williams struct iov_iter *i) 645ca146f6fSDan Williams { 646ca146f6fSDan Williams struct pipe_inode_info *pipe = i->pipe; 647ca146f6fSDan Williams size_t n, off, xfer = 0; 648ca146f6fSDan Williams int idx; 649ca146f6fSDan Williams 650ca146f6fSDan Williams if (!sanity(i)) 651ca146f6fSDan Williams return 0; 652ca146f6fSDan Williams 653ca146f6fSDan Williams bytes = n = push_pipe(i, bytes, &idx, &off); 654ca146f6fSDan Williams if (unlikely(!n)) 655ca146f6fSDan Williams return 0; 656ca146f6fSDan Williams for ( ; n; idx = next_idx(idx, pipe), off = 0) { 657ca146f6fSDan Williams size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 658ca146f6fSDan Williams unsigned long rem; 659ca146f6fSDan Williams 660ca146f6fSDan Williams rem = memcpy_mcsafe_to_page(pipe->bufs[idx].page, off, addr, 661ca146f6fSDan Williams chunk); 662ca146f6fSDan Williams i->idx = idx; 663ca146f6fSDan Williams i->iov_offset = off + chunk - rem; 664ca146f6fSDan Williams xfer += chunk - rem; 665ca146f6fSDan Williams if (rem) 666ca146f6fSDan Williams break; 667ca146f6fSDan Williams n -= chunk; 668ca146f6fSDan Williams addr += chunk; 669ca146f6fSDan Williams } 670ca146f6fSDan Williams i->count -= xfer; 671ca146f6fSDan Williams return xfer; 672ca146f6fSDan Williams } 673ca146f6fSDan Williams 674bf3eeb9bSDan Williams /** 675bf3eeb9bSDan Williams * _copy_to_iter_mcsafe - copy to user with source-read error exception handling 676bf3eeb9bSDan Williams * @addr: source kernel address 677bf3eeb9bSDan Williams * @bytes: total transfer length 678bf3eeb9bSDan Williams * @iter: destination iterator 679bf3eeb9bSDan Williams * 680bf3eeb9bSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 681bf3eeb9bSDan Williams * dax_copy_to_iter() for protecting read/write to persistent memory. 682bf3eeb9bSDan Williams * Unless / until an architecture can guarantee identical performance 683bf3eeb9bSDan Williams * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a 684bf3eeb9bSDan Williams * performance regression to switch more users to the mcsafe version. 685bf3eeb9bSDan Williams * 686bf3eeb9bSDan Williams * Otherwise, the main differences between this and typical _copy_to_iter(). 687bf3eeb9bSDan Williams * 688bf3eeb9bSDan Williams * * Typical tail/residue handling after a fault retries the copy 689bf3eeb9bSDan Williams * byte-by-byte until the fault happens again. Re-triggering machine 690bf3eeb9bSDan Williams * checks is potentially fatal so the implementation uses source 691bf3eeb9bSDan Williams * alignment and poison alignment assumptions to avoid re-triggering 692bf3eeb9bSDan Williams * hardware exceptions. 693bf3eeb9bSDan Williams * 694bf3eeb9bSDan Williams * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies. 695bf3eeb9bSDan Williams * Compare to copy_to_iter() where only ITER_IOVEC attempts might return 696bf3eeb9bSDan Williams * a short copy. 697bf3eeb9bSDan Williams * 698bf3eeb9bSDan Williams * See MCSAFE_TEST for self-test. 699bf3eeb9bSDan Williams */ 7008780356eSDan Williams size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i) 7018780356eSDan Williams { 7028780356eSDan Williams const char *from = addr; 7038780356eSDan Williams unsigned long rem, curr_addr, s_addr = (unsigned long) addr; 7048780356eSDan Williams 70500e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 706ca146f6fSDan Williams return copy_pipe_to_iter_mcsafe(addr, bytes, i); 7078780356eSDan Williams if (iter_is_iovec(i)) 7088780356eSDan Williams might_fault(); 7098780356eSDan Williams iterate_and_advance(i, bytes, v, 7108780356eSDan Williams copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), 7118780356eSDan Williams ({ 7128780356eSDan Williams rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset, 7138780356eSDan Williams (from += v.bv_len) - v.bv_len, v.bv_len); 7148780356eSDan Williams if (rem) { 7158780356eSDan Williams curr_addr = (unsigned long) from; 7168780356eSDan Williams bytes = curr_addr - s_addr - rem; 7178780356eSDan Williams return bytes; 7188780356eSDan Williams } 7198780356eSDan Williams }), 7208780356eSDan Williams ({ 7218780356eSDan Williams rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, 7228780356eSDan Williams v.iov_len); 7238780356eSDan Williams if (rem) { 7248780356eSDan Williams curr_addr = (unsigned long) from; 7258780356eSDan Williams bytes = curr_addr - s_addr - rem; 7268780356eSDan Williams return bytes; 7278780356eSDan Williams } 7288780356eSDan Williams }) 7298780356eSDan Williams ) 7308780356eSDan Williams 7318780356eSDan Williams return bytes; 7328780356eSDan Williams } 7338780356eSDan Williams EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe); 7348780356eSDan Williams #endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */ 7358780356eSDan Williams 736aa28de27SAl Viro size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 737d879cb83SAl Viro { 738d879cb83SAl Viro char *to = addr; 73900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 740241699cdSAl Viro WARN_ON(1); 741241699cdSAl Viro return 0; 742241699cdSAl Viro } 74309fc68dcSAl Viro if (iter_is_iovec(i)) 74409fc68dcSAl Viro might_fault(); 745d879cb83SAl Viro iterate_and_advance(i, bytes, v, 74609fc68dcSAl Viro copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 747d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 748d879cb83SAl Viro v.bv_offset, v.bv_len), 749d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 750d879cb83SAl Viro ) 751d879cb83SAl Viro 752d879cb83SAl Viro return bytes; 753d879cb83SAl Viro } 754aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter); 755d879cb83SAl Viro 756aa28de27SAl Viro bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) 757cbbd26b8SAl Viro { 758cbbd26b8SAl Viro char *to = addr; 75900e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 760cbbd26b8SAl Viro WARN_ON(1); 761cbbd26b8SAl Viro return false; 762cbbd26b8SAl Viro } 76333844e66SAl Viro if (unlikely(i->count < bytes)) 764cbbd26b8SAl Viro return false; 765cbbd26b8SAl Viro 76609fc68dcSAl Viro if (iter_is_iovec(i)) 76709fc68dcSAl Viro might_fault(); 768cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 76909fc68dcSAl Viro if (copyin((to += v.iov_len) - v.iov_len, 770cbbd26b8SAl Viro v.iov_base, v.iov_len)) 771cbbd26b8SAl Viro return false; 772cbbd26b8SAl Viro 0;}), 773cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 774cbbd26b8SAl Viro v.bv_offset, v.bv_len), 775cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 776cbbd26b8SAl Viro ) 777cbbd26b8SAl Viro 778cbbd26b8SAl Viro iov_iter_advance(i, bytes); 779cbbd26b8SAl Viro return true; 780cbbd26b8SAl Viro } 781aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full); 782cbbd26b8SAl Viro 783aa28de27SAl Viro size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 784d879cb83SAl Viro { 785d879cb83SAl Viro char *to = addr; 78600e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 787241699cdSAl Viro WARN_ON(1); 788241699cdSAl Viro return 0; 789241699cdSAl Viro } 790d879cb83SAl Viro iterate_and_advance(i, bytes, v, 7913f763453SAl Viro __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 792d879cb83SAl Viro v.iov_base, v.iov_len), 793d879cb83SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 794d879cb83SAl Viro v.bv_offset, v.bv_len), 795d879cb83SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 796d879cb83SAl Viro ) 797d879cb83SAl Viro 798d879cb83SAl Viro return bytes; 799d879cb83SAl Viro } 800aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_nocache); 801d879cb83SAl Viro 8020aed55afSDan Williams #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE 803abd08d7dSDan Williams /** 804abd08d7dSDan Williams * _copy_from_iter_flushcache - write destination through cpu cache 805abd08d7dSDan Williams * @addr: destination kernel address 806abd08d7dSDan Williams * @bytes: total transfer length 807abd08d7dSDan Williams * @iter: source iterator 808abd08d7dSDan Williams * 809abd08d7dSDan Williams * The pmem driver arranges for filesystem-dax to use this facility via 810abd08d7dSDan Williams * dax_copy_from_iter() for ensuring that writes to persistent memory 811abd08d7dSDan Williams * are flushed through the CPU cache. It is differentiated from 812abd08d7dSDan Williams * _copy_from_iter_nocache() in that guarantees all data is flushed for 813abd08d7dSDan Williams * all iterator types. The _copy_from_iter_nocache() only attempts to 814abd08d7dSDan Williams * bypass the cache for the ITER_IOVEC case, and on some archs may use 815abd08d7dSDan Williams * instructions that strand dirty-data in the cache. 816abd08d7dSDan Williams */ 8176a37e940SLinus Torvalds size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 8180aed55afSDan Williams { 8190aed55afSDan Williams char *to = addr; 82000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 8210aed55afSDan Williams WARN_ON(1); 8220aed55afSDan Williams return 0; 8230aed55afSDan Williams } 8240aed55afSDan Williams iterate_and_advance(i, bytes, v, 8250aed55afSDan Williams __copy_from_user_flushcache((to += v.iov_len) - v.iov_len, 8260aed55afSDan Williams v.iov_base, v.iov_len), 8270aed55afSDan Williams memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page, 8280aed55afSDan Williams v.bv_offset, v.bv_len), 8290aed55afSDan Williams memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base, 8300aed55afSDan Williams v.iov_len) 8310aed55afSDan Williams ) 8320aed55afSDan Williams 8330aed55afSDan Williams return bytes; 8340aed55afSDan Williams } 8356a37e940SLinus Torvalds EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); 8360aed55afSDan Williams #endif 8370aed55afSDan Williams 838aa28de27SAl Viro bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) 839cbbd26b8SAl Viro { 840cbbd26b8SAl Viro char *to = addr; 84100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 842cbbd26b8SAl Viro WARN_ON(1); 843cbbd26b8SAl Viro return false; 844cbbd26b8SAl Viro } 84533844e66SAl Viro if (unlikely(i->count < bytes)) 846cbbd26b8SAl Viro return false; 847cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 8483f763453SAl Viro if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, 849cbbd26b8SAl Viro v.iov_base, v.iov_len)) 850cbbd26b8SAl Viro return false; 851cbbd26b8SAl Viro 0;}), 852cbbd26b8SAl Viro memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, 853cbbd26b8SAl Viro v.bv_offset, v.bv_len), 854cbbd26b8SAl Viro memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 855cbbd26b8SAl Viro ) 856cbbd26b8SAl Viro 857cbbd26b8SAl Viro iov_iter_advance(i, bytes); 858cbbd26b8SAl Viro return true; 859cbbd26b8SAl Viro } 860aa28de27SAl Viro EXPORT_SYMBOL(_copy_from_iter_full_nocache); 861cbbd26b8SAl Viro 86272e809edSAl Viro static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) 86372e809edSAl Viro { 8646daef95bSEric Dumazet struct page *head; 8656daef95bSEric Dumazet size_t v = n + offset; 8666daef95bSEric Dumazet 8676daef95bSEric Dumazet /* 8686daef95bSEric Dumazet * The general case needs to access the page order in order 8696daef95bSEric Dumazet * to compute the page size. 8706daef95bSEric Dumazet * However, we mostly deal with order-0 pages and thus can 8716daef95bSEric Dumazet * avoid a possible cache line miss for requests that fit all 8726daef95bSEric Dumazet * page orders. 8736daef95bSEric Dumazet */ 8746daef95bSEric Dumazet if (n <= v && v <= PAGE_SIZE) 8756daef95bSEric Dumazet return true; 8766daef95bSEric Dumazet 8776daef95bSEric Dumazet head = compound_head(page); 8786daef95bSEric Dumazet v += (page - head) << PAGE_SHIFT; 879a90bcb86SPetar Penkov 880a90bcb86SPetar Penkov if (likely(n <= v && v <= (PAGE_SIZE << compound_order(head)))) 88172e809edSAl Viro return true; 88272e809edSAl Viro WARN_ON(1); 88372e809edSAl Viro return false; 88472e809edSAl Viro } 885d879cb83SAl Viro 886d879cb83SAl Viro size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, 887d879cb83SAl Viro struct iov_iter *i) 888d879cb83SAl Viro { 88972e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 89072e809edSAl Viro return 0; 891d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 892d879cb83SAl Viro void *kaddr = kmap_atomic(page); 893d879cb83SAl Viro size_t wanted = copy_to_iter(kaddr + offset, bytes, i); 894d879cb83SAl Viro kunmap_atomic(kaddr); 895d879cb83SAl Viro return wanted; 8969ea9ce04SDavid Howells } else if (unlikely(iov_iter_is_discard(i))) 8979ea9ce04SDavid Howells return bytes; 8989ea9ce04SDavid Howells else if (likely(!iov_iter_is_pipe(i))) 899d879cb83SAl Viro return copy_page_to_iter_iovec(page, offset, bytes, i); 900241699cdSAl Viro else 901241699cdSAl Viro return copy_page_to_iter_pipe(page, offset, bytes, i); 902d879cb83SAl Viro } 903d879cb83SAl Viro EXPORT_SYMBOL(copy_page_to_iter); 904d879cb83SAl Viro 905d879cb83SAl Viro size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 906d879cb83SAl Viro struct iov_iter *i) 907d879cb83SAl Viro { 90872e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) 90972e809edSAl Viro return 0; 9109ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 911241699cdSAl Viro WARN_ON(1); 912241699cdSAl Viro return 0; 913241699cdSAl Viro } 914d879cb83SAl Viro if (i->type & (ITER_BVEC|ITER_KVEC)) { 915d879cb83SAl Viro void *kaddr = kmap_atomic(page); 916aa28de27SAl Viro size_t wanted = _copy_from_iter(kaddr + offset, bytes, i); 917d879cb83SAl Viro kunmap_atomic(kaddr); 918d879cb83SAl Viro return wanted; 919d879cb83SAl Viro } else 920d879cb83SAl Viro return copy_page_from_iter_iovec(page, offset, bytes, i); 921d879cb83SAl Viro } 922d879cb83SAl Viro EXPORT_SYMBOL(copy_page_from_iter); 923d879cb83SAl Viro 924241699cdSAl Viro static size_t pipe_zero(size_t bytes, struct iov_iter *i) 925241699cdSAl Viro { 926241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 927241699cdSAl Viro size_t n, off; 928241699cdSAl Viro int idx; 929241699cdSAl Viro 930241699cdSAl Viro if (!sanity(i)) 931241699cdSAl Viro return 0; 932241699cdSAl Viro 933241699cdSAl Viro bytes = n = push_pipe(i, bytes, &idx, &off); 934241699cdSAl Viro if (unlikely(!n)) 935241699cdSAl Viro return 0; 936241699cdSAl Viro 937241699cdSAl Viro for ( ; n; idx = next_idx(idx, pipe), off = 0) { 938241699cdSAl Viro size_t chunk = min_t(size_t, n, PAGE_SIZE - off); 939241699cdSAl Viro memzero_page(pipe->bufs[idx].page, off, chunk); 940241699cdSAl Viro i->idx = idx; 941241699cdSAl Viro i->iov_offset = off + chunk; 942241699cdSAl Viro n -= chunk; 943241699cdSAl Viro } 944241699cdSAl Viro i->count -= bytes; 945241699cdSAl Viro return bytes; 946241699cdSAl Viro } 947241699cdSAl Viro 948d879cb83SAl Viro size_t iov_iter_zero(size_t bytes, struct iov_iter *i) 949d879cb83SAl Viro { 95000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 951241699cdSAl Viro return pipe_zero(bytes, i); 952d879cb83SAl Viro iterate_and_advance(i, bytes, v, 95309fc68dcSAl Viro clear_user(v.iov_base, v.iov_len), 954d879cb83SAl Viro memzero_page(v.bv_page, v.bv_offset, v.bv_len), 955d879cb83SAl Viro memset(v.iov_base, 0, v.iov_len) 956d879cb83SAl Viro ) 957d879cb83SAl Viro 958d879cb83SAl Viro return bytes; 959d879cb83SAl Viro } 960d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_zero); 961d879cb83SAl Viro 962d879cb83SAl Viro size_t iov_iter_copy_from_user_atomic(struct page *page, 963d879cb83SAl Viro struct iov_iter *i, unsigned long offset, size_t bytes) 964d879cb83SAl Viro { 965d879cb83SAl Viro char *kaddr = kmap_atomic(page), *p = kaddr + offset; 96672e809edSAl Viro if (unlikely(!page_copy_sane(page, offset, bytes))) { 96772e809edSAl Viro kunmap_atomic(kaddr); 96872e809edSAl Viro return 0; 96972e809edSAl Viro } 9709ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 971241699cdSAl Viro kunmap_atomic(kaddr); 972241699cdSAl Viro WARN_ON(1); 973241699cdSAl Viro return 0; 974241699cdSAl Viro } 975d879cb83SAl Viro iterate_all_kinds(i, bytes, v, 97609fc68dcSAl Viro copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), 977d879cb83SAl Viro memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, 978d879cb83SAl Viro v.bv_offset, v.bv_len), 979d879cb83SAl Viro memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) 980d879cb83SAl Viro ) 981d879cb83SAl Viro kunmap_atomic(kaddr); 982d879cb83SAl Viro return bytes; 983d879cb83SAl Viro } 984d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); 985d879cb83SAl Viro 986b9dc6f65SAl Viro static inline void pipe_truncate(struct iov_iter *i) 987241699cdSAl Viro { 988241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 989241699cdSAl Viro if (pipe->nrbufs) { 990b9dc6f65SAl Viro size_t off = i->iov_offset; 991b9dc6f65SAl Viro int idx = i->idx; 992b9dc6f65SAl Viro int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1); 993b9dc6f65SAl Viro if (off) { 994b9dc6f65SAl Viro pipe->bufs[idx].len = off - pipe->bufs[idx].offset; 995b9dc6f65SAl Viro idx = next_idx(idx, pipe); 996b9dc6f65SAl Viro nrbufs++; 997b9dc6f65SAl Viro } 998b9dc6f65SAl Viro while (pipe->nrbufs > nrbufs) { 999a779638cSMiklos Szeredi pipe_buf_release(pipe, &pipe->bufs[idx]); 1000241699cdSAl Viro idx = next_idx(idx, pipe); 1001241699cdSAl Viro pipe->nrbufs--; 1002241699cdSAl Viro } 1003241699cdSAl Viro } 1004b9dc6f65SAl Viro } 1005b9dc6f65SAl Viro 1006b9dc6f65SAl Viro static void pipe_advance(struct iov_iter *i, size_t size) 1007b9dc6f65SAl Viro { 1008b9dc6f65SAl Viro struct pipe_inode_info *pipe = i->pipe; 1009b9dc6f65SAl Viro if (unlikely(i->count < size)) 1010b9dc6f65SAl Viro size = i->count; 1011b9dc6f65SAl Viro if (size) { 1012b9dc6f65SAl Viro struct pipe_buffer *buf; 1013b9dc6f65SAl Viro size_t off = i->iov_offset, left = size; 1014b9dc6f65SAl Viro int idx = i->idx; 1015b9dc6f65SAl Viro if (off) /* make it relative to the beginning of buffer */ 1016b9dc6f65SAl Viro left += off - pipe->bufs[idx].offset; 1017b9dc6f65SAl Viro while (1) { 1018b9dc6f65SAl Viro buf = &pipe->bufs[idx]; 1019b9dc6f65SAl Viro if (left <= buf->len) 1020b9dc6f65SAl Viro break; 1021b9dc6f65SAl Viro left -= buf->len; 1022b9dc6f65SAl Viro idx = next_idx(idx, pipe); 1023b9dc6f65SAl Viro } 1024b9dc6f65SAl Viro i->idx = idx; 1025b9dc6f65SAl Viro i->iov_offset = buf->offset + left; 1026b9dc6f65SAl Viro } 1027b9dc6f65SAl Viro i->count -= size; 1028b9dc6f65SAl Viro /* ... and discard everything past that point */ 1029b9dc6f65SAl Viro pipe_truncate(i); 1030241699cdSAl Viro } 1031241699cdSAl Viro 1032d879cb83SAl Viro void iov_iter_advance(struct iov_iter *i, size_t size) 1033d879cb83SAl Viro { 103400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1035241699cdSAl Viro pipe_advance(i, size); 1036241699cdSAl Viro return; 1037241699cdSAl Viro } 10389ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) { 10399ea9ce04SDavid Howells i->count -= size; 10409ea9ce04SDavid Howells return; 10419ea9ce04SDavid Howells } 1042d879cb83SAl Viro iterate_and_advance(i, size, v, 0, 0, 0) 1043d879cb83SAl Viro } 1044d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_advance); 1045d879cb83SAl Viro 104627c0e374SAl Viro void iov_iter_revert(struct iov_iter *i, size_t unroll) 104727c0e374SAl Viro { 104827c0e374SAl Viro if (!unroll) 104927c0e374SAl Viro return; 10505b47d59aSAl Viro if (WARN_ON(unroll > MAX_RW_COUNT)) 10515b47d59aSAl Viro return; 105227c0e374SAl Viro i->count += unroll; 105300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 105427c0e374SAl Viro struct pipe_inode_info *pipe = i->pipe; 105527c0e374SAl Viro int idx = i->idx; 105627c0e374SAl Viro size_t off = i->iov_offset; 105727c0e374SAl Viro while (1) { 105827c0e374SAl Viro size_t n = off - pipe->bufs[idx].offset; 105927c0e374SAl Viro if (unroll < n) { 10604fa55cefSAl Viro off -= unroll; 106127c0e374SAl Viro break; 106227c0e374SAl Viro } 106327c0e374SAl Viro unroll -= n; 106427c0e374SAl Viro if (!unroll && idx == i->start_idx) { 106527c0e374SAl Viro off = 0; 106627c0e374SAl Viro break; 106727c0e374SAl Viro } 106827c0e374SAl Viro if (!idx--) 106927c0e374SAl Viro idx = pipe->buffers - 1; 107027c0e374SAl Viro off = pipe->bufs[idx].offset + pipe->bufs[idx].len; 107127c0e374SAl Viro } 107227c0e374SAl Viro i->iov_offset = off; 107327c0e374SAl Viro i->idx = idx; 107427c0e374SAl Viro pipe_truncate(i); 107527c0e374SAl Viro return; 107627c0e374SAl Viro } 10779ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 10789ea9ce04SDavid Howells return; 107927c0e374SAl Viro if (unroll <= i->iov_offset) { 108027c0e374SAl Viro i->iov_offset -= unroll; 108127c0e374SAl Viro return; 108227c0e374SAl Viro } 108327c0e374SAl Viro unroll -= i->iov_offset; 108400e23707SDavid Howells if (iov_iter_is_bvec(i)) { 108527c0e374SAl Viro const struct bio_vec *bvec = i->bvec; 108627c0e374SAl Viro while (1) { 108727c0e374SAl Viro size_t n = (--bvec)->bv_len; 108827c0e374SAl Viro i->nr_segs++; 108927c0e374SAl Viro if (unroll <= n) { 109027c0e374SAl Viro i->bvec = bvec; 109127c0e374SAl Viro i->iov_offset = n - unroll; 109227c0e374SAl Viro return; 109327c0e374SAl Viro } 109427c0e374SAl Viro unroll -= n; 109527c0e374SAl Viro } 109627c0e374SAl Viro } else { /* same logics for iovec and kvec */ 109727c0e374SAl Viro const struct iovec *iov = i->iov; 109827c0e374SAl Viro while (1) { 109927c0e374SAl Viro size_t n = (--iov)->iov_len; 110027c0e374SAl Viro i->nr_segs++; 110127c0e374SAl Viro if (unroll <= n) { 110227c0e374SAl Viro i->iov = iov; 110327c0e374SAl Viro i->iov_offset = n - unroll; 110427c0e374SAl Viro return; 110527c0e374SAl Viro } 110627c0e374SAl Viro unroll -= n; 110727c0e374SAl Viro } 110827c0e374SAl Viro } 110927c0e374SAl Viro } 111027c0e374SAl Viro EXPORT_SYMBOL(iov_iter_revert); 111127c0e374SAl Viro 1112d879cb83SAl Viro /* 1113d879cb83SAl Viro * Return the count of just the current iov_iter segment. 1114d879cb83SAl Viro */ 1115d879cb83SAl Viro size_t iov_iter_single_seg_count(const struct iov_iter *i) 1116d879cb83SAl Viro { 111700e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1118241699cdSAl Viro return i->count; // it is a silly place, anyway 1119d879cb83SAl Viro if (i->nr_segs == 1) 1120d879cb83SAl Viro return i->count; 11219ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 11229ea9ce04SDavid Howells return i->count; 112300e23707SDavid Howells else if (iov_iter_is_bvec(i)) 1124d879cb83SAl Viro return min(i->count, i->bvec->bv_len - i->iov_offset); 1125d879cb83SAl Viro else 1126d879cb83SAl Viro return min(i->count, i->iov->iov_len - i->iov_offset); 1127d879cb83SAl Viro } 1128d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_single_seg_count); 1129d879cb83SAl Viro 1130aa563d7bSDavid Howells void iov_iter_kvec(struct iov_iter *i, unsigned int direction, 1131d879cb83SAl Viro const struct kvec *kvec, unsigned long nr_segs, 1132d879cb83SAl Viro size_t count) 1133d879cb83SAl Viro { 1134aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1135aa563d7bSDavid Howells i->type = ITER_KVEC | (direction & (READ | WRITE)); 1136d879cb83SAl Viro i->kvec = kvec; 1137d879cb83SAl Viro i->nr_segs = nr_segs; 1138d879cb83SAl Viro i->iov_offset = 0; 1139d879cb83SAl Viro i->count = count; 1140d879cb83SAl Viro } 1141d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_kvec); 1142d879cb83SAl Viro 1143aa563d7bSDavid Howells void iov_iter_bvec(struct iov_iter *i, unsigned int direction, 1144d879cb83SAl Viro const struct bio_vec *bvec, unsigned long nr_segs, 1145d879cb83SAl Viro size_t count) 1146d879cb83SAl Viro { 1147aa563d7bSDavid Howells WARN_ON(direction & ~(READ | WRITE)); 1148aa563d7bSDavid Howells i->type = ITER_BVEC | (direction & (READ | WRITE)); 1149d879cb83SAl Viro i->bvec = bvec; 1150d879cb83SAl Viro i->nr_segs = nr_segs; 1151d879cb83SAl Viro i->iov_offset = 0; 1152d879cb83SAl Viro i->count = count; 1153d879cb83SAl Viro } 1154d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_bvec); 1155d879cb83SAl Viro 1156aa563d7bSDavid Howells void iov_iter_pipe(struct iov_iter *i, unsigned int direction, 1157241699cdSAl Viro struct pipe_inode_info *pipe, 1158241699cdSAl Viro size_t count) 1159241699cdSAl Viro { 1160aa563d7bSDavid Howells BUG_ON(direction != READ); 1161b9dc6f65SAl Viro WARN_ON(pipe->nrbufs == pipe->buffers); 1162aa563d7bSDavid Howells i->type = ITER_PIPE | READ; 1163241699cdSAl Viro i->pipe = pipe; 1164241699cdSAl Viro i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); 1165241699cdSAl Viro i->iov_offset = 0; 1166241699cdSAl Viro i->count = count; 116727c0e374SAl Viro i->start_idx = i->idx; 1168241699cdSAl Viro } 1169241699cdSAl Viro EXPORT_SYMBOL(iov_iter_pipe); 1170241699cdSAl Viro 11719ea9ce04SDavid Howells /** 11729ea9ce04SDavid Howells * iov_iter_discard - Initialise an I/O iterator that discards data 11739ea9ce04SDavid Howells * @i: The iterator to initialise. 11749ea9ce04SDavid Howells * @direction: The direction of the transfer. 11759ea9ce04SDavid Howells * @count: The size of the I/O buffer in bytes. 11769ea9ce04SDavid Howells * 11779ea9ce04SDavid Howells * Set up an I/O iterator that just discards everything that's written to it. 11789ea9ce04SDavid Howells * It's only available as a READ iterator. 11799ea9ce04SDavid Howells */ 11809ea9ce04SDavid Howells void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) 11819ea9ce04SDavid Howells { 11829ea9ce04SDavid Howells BUG_ON(direction != READ); 11839ea9ce04SDavid Howells i->type = ITER_DISCARD | READ; 11849ea9ce04SDavid Howells i->count = count; 11859ea9ce04SDavid Howells i->iov_offset = 0; 11869ea9ce04SDavid Howells } 11879ea9ce04SDavid Howells EXPORT_SYMBOL(iov_iter_discard); 11889ea9ce04SDavid Howells 1189d879cb83SAl Viro unsigned long iov_iter_alignment(const struct iov_iter *i) 1190d879cb83SAl Viro { 1191d879cb83SAl Viro unsigned long res = 0; 1192d879cb83SAl Viro size_t size = i->count; 1193d879cb83SAl Viro 119400e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 119533844e66SAl Viro if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx])) 1196241699cdSAl Viro return size | i->iov_offset; 1197241699cdSAl Viro return size; 1198241699cdSAl Viro } 1199d879cb83SAl Viro iterate_all_kinds(i, size, v, 1200d879cb83SAl Viro (res |= (unsigned long)v.iov_base | v.iov_len, 0), 1201d879cb83SAl Viro res |= v.bv_offset | v.bv_len, 1202d879cb83SAl Viro res |= (unsigned long)v.iov_base | v.iov_len 1203d879cb83SAl Viro ) 1204d879cb83SAl Viro return res; 1205d879cb83SAl Viro } 1206d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_alignment); 1207d879cb83SAl Viro 1208357f435dSAl Viro unsigned long iov_iter_gap_alignment(const struct iov_iter *i) 1209357f435dSAl Viro { 1210357f435dSAl Viro unsigned long res = 0; 1211357f435dSAl Viro size_t size = i->count; 1212357f435dSAl Viro 12139ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1214241699cdSAl Viro WARN_ON(1); 1215241699cdSAl Viro return ~0U; 1216241699cdSAl Viro } 1217241699cdSAl Viro 1218357f435dSAl Viro iterate_all_kinds(i, size, v, 1219357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1220357f435dSAl Viro (size != v.iov_len ? size : 0), 0), 1221357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.bv_offset) | 1222357f435dSAl Viro (size != v.bv_len ? size : 0)), 1223357f435dSAl Viro (res |= (!res ? 0 : (unsigned long)v.iov_base) | 1224357f435dSAl Viro (size != v.iov_len ? size : 0)) 1225357f435dSAl Viro ); 1226357f435dSAl Viro return res; 1227357f435dSAl Viro } 1228357f435dSAl Viro EXPORT_SYMBOL(iov_iter_gap_alignment); 1229357f435dSAl Viro 1230e76b6312SIlya Dryomov static inline ssize_t __pipe_get_pages(struct iov_iter *i, 1231241699cdSAl Viro size_t maxsize, 1232241699cdSAl Viro struct page **pages, 1233241699cdSAl Viro int idx, 1234241699cdSAl Viro size_t *start) 1235241699cdSAl Viro { 1236241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 12371689c73aSAl Viro ssize_t n = push_pipe(i, maxsize, &idx, start); 1238241699cdSAl Viro if (!n) 1239241699cdSAl Viro return -EFAULT; 1240241699cdSAl Viro 1241241699cdSAl Viro maxsize = n; 1242241699cdSAl Viro n += *start; 12431689c73aSAl Viro while (n > 0) { 1244241699cdSAl Viro get_page(*pages++ = pipe->bufs[idx].page); 1245241699cdSAl Viro idx = next_idx(idx, pipe); 1246241699cdSAl Viro n -= PAGE_SIZE; 1247241699cdSAl Viro } 1248241699cdSAl Viro 1249241699cdSAl Viro return maxsize; 1250241699cdSAl Viro } 1251241699cdSAl Viro 1252241699cdSAl Viro static ssize_t pipe_get_pages(struct iov_iter *i, 1253241699cdSAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1254241699cdSAl Viro size_t *start) 1255241699cdSAl Viro { 1256241699cdSAl Viro unsigned npages; 1257241699cdSAl Viro size_t capacity; 1258241699cdSAl Viro int idx; 1259241699cdSAl Viro 126033844e66SAl Viro if (!maxsize) 126133844e66SAl Viro return 0; 126233844e66SAl Viro 1263241699cdSAl Viro if (!sanity(i)) 1264241699cdSAl Viro return -EFAULT; 1265241699cdSAl Viro 1266241699cdSAl Viro data_start(i, &idx, start); 1267241699cdSAl Viro /* some of this one + all after this one */ 1268241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1269241699cdSAl Viro capacity = min(npages,maxpages) * PAGE_SIZE - *start; 1270241699cdSAl Viro 1271241699cdSAl Viro return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start); 1272241699cdSAl Viro } 1273241699cdSAl Viro 1274d879cb83SAl Viro ssize_t iov_iter_get_pages(struct iov_iter *i, 1275d879cb83SAl Viro struct page **pages, size_t maxsize, unsigned maxpages, 1276d879cb83SAl Viro size_t *start) 1277d879cb83SAl Viro { 1278d879cb83SAl Viro if (maxsize > i->count) 1279d879cb83SAl Viro maxsize = i->count; 1280d879cb83SAl Viro 128100e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1282241699cdSAl Viro return pipe_get_pages(i, pages, maxsize, maxpages, start); 12839ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 12849ea9ce04SDavid Howells return -EFAULT; 12859ea9ce04SDavid Howells 1286d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1287d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1288d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1289d879cb83SAl Viro int n; 1290d879cb83SAl Viro int res; 1291d879cb83SAl Viro 1292d879cb83SAl Viro if (len > maxpages * PAGE_SIZE) 1293d879cb83SAl Viro len = maxpages * PAGE_SIZE; 1294d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1295d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 129673b0140bSIra Weiny res = get_user_pages_fast(addr, n, 129773b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, 129873b0140bSIra Weiny pages); 1299d879cb83SAl Viro if (unlikely(res < 0)) 1300d879cb83SAl Viro return res; 1301d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1302d879cb83SAl Viro 0;}),({ 1303d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1304d879cb83SAl Viro *start = v.bv_offset; 1305d879cb83SAl Viro get_page(*pages = v.bv_page); 1306d879cb83SAl Viro return v.bv_len; 1307d879cb83SAl Viro }),({ 1308d879cb83SAl Viro return -EFAULT; 1309d879cb83SAl Viro }) 1310d879cb83SAl Viro ) 1311d879cb83SAl Viro return 0; 1312d879cb83SAl Viro } 1313d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages); 1314d879cb83SAl Viro 1315d879cb83SAl Viro static struct page **get_pages_array(size_t n) 1316d879cb83SAl Viro { 1317752ade68SMichal Hocko return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); 1318d879cb83SAl Viro } 1319d879cb83SAl Viro 1320241699cdSAl Viro static ssize_t pipe_get_pages_alloc(struct iov_iter *i, 1321241699cdSAl Viro struct page ***pages, size_t maxsize, 1322241699cdSAl Viro size_t *start) 1323241699cdSAl Viro { 1324241699cdSAl Viro struct page **p; 1325d7760d63SIlya Dryomov ssize_t n; 1326241699cdSAl Viro int idx; 1327241699cdSAl Viro int npages; 1328241699cdSAl Viro 132933844e66SAl Viro if (!maxsize) 133033844e66SAl Viro return 0; 133133844e66SAl Viro 1332241699cdSAl Viro if (!sanity(i)) 1333241699cdSAl Viro return -EFAULT; 1334241699cdSAl Viro 1335241699cdSAl Viro data_start(i, &idx, start); 1336241699cdSAl Viro /* some of this one + all after this one */ 1337241699cdSAl Viro npages = ((i->pipe->curbuf - idx - 1) & (i->pipe->buffers - 1)) + 1; 1338241699cdSAl Viro n = npages * PAGE_SIZE - *start; 1339241699cdSAl Viro if (maxsize > n) 1340241699cdSAl Viro maxsize = n; 1341241699cdSAl Viro else 1342241699cdSAl Viro npages = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE); 1343241699cdSAl Viro p = get_pages_array(npages); 1344241699cdSAl Viro if (!p) 1345241699cdSAl Viro return -ENOMEM; 1346241699cdSAl Viro n = __pipe_get_pages(i, maxsize, p, idx, start); 1347241699cdSAl Viro if (n > 0) 1348241699cdSAl Viro *pages = p; 1349241699cdSAl Viro else 1350241699cdSAl Viro kvfree(p); 1351241699cdSAl Viro return n; 1352241699cdSAl Viro } 1353241699cdSAl Viro 1354d879cb83SAl Viro ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 1355d879cb83SAl Viro struct page ***pages, size_t maxsize, 1356d879cb83SAl Viro size_t *start) 1357d879cb83SAl Viro { 1358d879cb83SAl Viro struct page **p; 1359d879cb83SAl Viro 1360d879cb83SAl Viro if (maxsize > i->count) 1361d879cb83SAl Viro maxsize = i->count; 1362d879cb83SAl Viro 136300e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) 1364241699cdSAl Viro return pipe_get_pages_alloc(i, pages, maxsize, start); 13659ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 13669ea9ce04SDavid Howells return -EFAULT; 13679ea9ce04SDavid Howells 1368d879cb83SAl Viro iterate_all_kinds(i, maxsize, v, ({ 1369d879cb83SAl Viro unsigned long addr = (unsigned long)v.iov_base; 1370d879cb83SAl Viro size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); 1371d879cb83SAl Viro int n; 1372d879cb83SAl Viro int res; 1373d879cb83SAl Viro 1374d879cb83SAl Viro addr &= ~(PAGE_SIZE - 1); 1375d879cb83SAl Viro n = DIV_ROUND_UP(len, PAGE_SIZE); 1376d879cb83SAl Viro p = get_pages_array(n); 1377d879cb83SAl Viro if (!p) 1378d879cb83SAl Viro return -ENOMEM; 137973b0140bSIra Weiny res = get_user_pages_fast(addr, n, 138073b0140bSIra Weiny iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); 1381d879cb83SAl Viro if (unlikely(res < 0)) { 1382d879cb83SAl Viro kvfree(p); 1383d879cb83SAl Viro return res; 1384d879cb83SAl Viro } 1385d879cb83SAl Viro *pages = p; 1386d879cb83SAl Viro return (res == n ? len : res * PAGE_SIZE) - *start; 1387d879cb83SAl Viro 0;}),({ 1388d879cb83SAl Viro /* can't be more than PAGE_SIZE */ 1389d879cb83SAl Viro *start = v.bv_offset; 1390d879cb83SAl Viro *pages = p = get_pages_array(1); 1391d879cb83SAl Viro if (!p) 1392d879cb83SAl Viro return -ENOMEM; 1393d879cb83SAl Viro get_page(*p = v.bv_page); 1394d879cb83SAl Viro return v.bv_len; 1395d879cb83SAl Viro }),({ 1396d879cb83SAl Viro return -EFAULT; 1397d879cb83SAl Viro }) 1398d879cb83SAl Viro ) 1399d879cb83SAl Viro return 0; 1400d879cb83SAl Viro } 1401d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_get_pages_alloc); 1402d879cb83SAl Viro 1403d879cb83SAl Viro size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 1404d879cb83SAl Viro struct iov_iter *i) 1405d879cb83SAl Viro { 1406d879cb83SAl Viro char *to = addr; 1407d879cb83SAl Viro __wsum sum, next; 1408d879cb83SAl Viro size_t off = 0; 1409d879cb83SAl Viro sum = *csum; 14109ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1411241699cdSAl Viro WARN_ON(1); 1412241699cdSAl Viro return 0; 1413241699cdSAl Viro } 1414d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1415d879cb83SAl Viro int err = 0; 1416d879cb83SAl Viro next = csum_and_copy_from_user(v.iov_base, 1417d879cb83SAl Viro (to += v.iov_len) - v.iov_len, 1418d879cb83SAl Viro v.iov_len, 0, &err); 1419d879cb83SAl Viro if (!err) { 1420d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1421d879cb83SAl Viro off += v.iov_len; 1422d879cb83SAl Viro } 1423d879cb83SAl Viro err ? v.iov_len : 0; 1424d879cb83SAl Viro }), ({ 1425d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1426f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1427f9152895SAl Viro p + v.bv_offset, v.bv_len, 1428f9152895SAl Viro sum, off); 1429d879cb83SAl Viro kunmap_atomic(p); 1430d879cb83SAl Viro off += v.bv_len; 1431d879cb83SAl Viro }),({ 1432f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1433f9152895SAl Viro v.iov_base, v.iov_len, 1434f9152895SAl Viro sum, off); 1435d879cb83SAl Viro off += v.iov_len; 1436d879cb83SAl Viro }) 1437d879cb83SAl Viro ) 1438d879cb83SAl Viro *csum = sum; 1439d879cb83SAl Viro return bytes; 1440d879cb83SAl Viro } 1441d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter); 1442d879cb83SAl Viro 1443cbbd26b8SAl Viro bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 1444cbbd26b8SAl Viro struct iov_iter *i) 1445cbbd26b8SAl Viro { 1446cbbd26b8SAl Viro char *to = addr; 1447cbbd26b8SAl Viro __wsum sum, next; 1448cbbd26b8SAl Viro size_t off = 0; 1449cbbd26b8SAl Viro sum = *csum; 14509ea9ce04SDavid Howells if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { 1451cbbd26b8SAl Viro WARN_ON(1); 1452cbbd26b8SAl Viro return false; 1453cbbd26b8SAl Viro } 1454cbbd26b8SAl Viro if (unlikely(i->count < bytes)) 1455cbbd26b8SAl Viro return false; 1456cbbd26b8SAl Viro iterate_all_kinds(i, bytes, v, ({ 1457cbbd26b8SAl Viro int err = 0; 1458cbbd26b8SAl Viro next = csum_and_copy_from_user(v.iov_base, 1459cbbd26b8SAl Viro (to += v.iov_len) - v.iov_len, 1460cbbd26b8SAl Viro v.iov_len, 0, &err); 1461cbbd26b8SAl Viro if (err) 1462cbbd26b8SAl Viro return false; 1463cbbd26b8SAl Viro sum = csum_block_add(sum, next, off); 1464cbbd26b8SAl Viro off += v.iov_len; 1465cbbd26b8SAl Viro 0; 1466cbbd26b8SAl Viro }), ({ 1467cbbd26b8SAl Viro char *p = kmap_atomic(v.bv_page); 1468f9152895SAl Viro sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, 1469f9152895SAl Viro p + v.bv_offset, v.bv_len, 1470f9152895SAl Viro sum, off); 1471cbbd26b8SAl Viro kunmap_atomic(p); 1472cbbd26b8SAl Viro off += v.bv_len; 1473cbbd26b8SAl Viro }),({ 1474f9152895SAl Viro sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, 1475f9152895SAl Viro v.iov_base, v.iov_len, 1476f9152895SAl Viro sum, off); 1477cbbd26b8SAl Viro off += v.iov_len; 1478cbbd26b8SAl Viro }) 1479cbbd26b8SAl Viro ) 1480cbbd26b8SAl Viro *csum = sum; 1481cbbd26b8SAl Viro iov_iter_advance(i, bytes); 1482cbbd26b8SAl Viro return true; 1483cbbd26b8SAl Viro } 1484cbbd26b8SAl Viro EXPORT_SYMBOL(csum_and_copy_from_iter_full); 1485cbbd26b8SAl Viro 1486cb002d07SSagi Grimberg size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, 1487d879cb83SAl Viro struct iov_iter *i) 1488d879cb83SAl Viro { 148936f7a8a4SAl Viro const char *from = addr; 1490cb002d07SSagi Grimberg __wsum *csum = csump; 1491d879cb83SAl Viro __wsum sum, next; 1492d879cb83SAl Viro size_t off = 0; 149378e1f386SAl Viro 149478e1f386SAl Viro if (unlikely(iov_iter_is_pipe(i))) 149578e1f386SAl Viro return csum_and_copy_to_pipe_iter(addr, bytes, csum, i); 149678e1f386SAl Viro 1497d879cb83SAl Viro sum = *csum; 149878e1f386SAl Viro if (unlikely(iov_iter_is_discard(i))) { 1499241699cdSAl Viro WARN_ON(1); /* for now */ 1500241699cdSAl Viro return 0; 1501241699cdSAl Viro } 1502d879cb83SAl Viro iterate_and_advance(i, bytes, v, ({ 1503d879cb83SAl Viro int err = 0; 1504d879cb83SAl Viro next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, 1505d879cb83SAl Viro v.iov_base, 1506d879cb83SAl Viro v.iov_len, 0, &err); 1507d879cb83SAl Viro if (!err) { 1508d879cb83SAl Viro sum = csum_block_add(sum, next, off); 1509d879cb83SAl Viro off += v.iov_len; 1510d879cb83SAl Viro } 1511d879cb83SAl Viro err ? v.iov_len : 0; 1512d879cb83SAl Viro }), ({ 1513d879cb83SAl Viro char *p = kmap_atomic(v.bv_page); 1514f9152895SAl Viro sum = csum_and_memcpy(p + v.bv_offset, 1515f9152895SAl Viro (from += v.bv_len) - v.bv_len, 1516f9152895SAl Viro v.bv_len, sum, off); 1517d879cb83SAl Viro kunmap_atomic(p); 1518d879cb83SAl Viro off += v.bv_len; 1519d879cb83SAl Viro }),({ 1520f9152895SAl Viro sum = csum_and_memcpy(v.iov_base, 1521f9152895SAl Viro (from += v.iov_len) - v.iov_len, 1522f9152895SAl Viro v.iov_len, sum, off); 1523d879cb83SAl Viro off += v.iov_len; 1524d879cb83SAl Viro }) 1525d879cb83SAl Viro ) 1526d879cb83SAl Viro *csum = sum; 1527d879cb83SAl Viro return bytes; 1528d879cb83SAl Viro } 1529d879cb83SAl Viro EXPORT_SYMBOL(csum_and_copy_to_iter); 1530d879cb83SAl Viro 1531d05f4435SSagi Grimberg size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, 1532d05f4435SSagi Grimberg struct iov_iter *i) 1533d05f4435SSagi Grimberg { 153427fad74aSYueHaibing #ifdef CONFIG_CRYPTO 1535d05f4435SSagi Grimberg struct ahash_request *hash = hashp; 1536d05f4435SSagi Grimberg struct scatterlist sg; 1537d05f4435SSagi Grimberg size_t copied; 1538d05f4435SSagi Grimberg 1539d05f4435SSagi Grimberg copied = copy_to_iter(addr, bytes, i); 1540d05f4435SSagi Grimberg sg_init_one(&sg, addr, copied); 1541d05f4435SSagi Grimberg ahash_request_set_crypt(hash, &sg, NULL, copied); 1542d05f4435SSagi Grimberg crypto_ahash_update(hash); 1543d05f4435SSagi Grimberg return copied; 154427fad74aSYueHaibing #else 154527fad74aSYueHaibing return 0; 154627fad74aSYueHaibing #endif 1547d05f4435SSagi Grimberg } 1548d05f4435SSagi Grimberg EXPORT_SYMBOL(hash_and_copy_to_iter); 1549d05f4435SSagi Grimberg 1550d879cb83SAl Viro int iov_iter_npages(const struct iov_iter *i, int maxpages) 1551d879cb83SAl Viro { 1552d879cb83SAl Viro size_t size = i->count; 1553d879cb83SAl Viro int npages = 0; 1554d879cb83SAl Viro 1555d879cb83SAl Viro if (!size) 1556d879cb83SAl Viro return 0; 15579ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(i))) 15589ea9ce04SDavid Howells return 0; 1559d879cb83SAl Viro 156000e23707SDavid Howells if (unlikely(iov_iter_is_pipe(i))) { 1561241699cdSAl Viro struct pipe_inode_info *pipe = i->pipe; 1562241699cdSAl Viro size_t off; 1563241699cdSAl Viro int idx; 1564241699cdSAl Viro 1565241699cdSAl Viro if (!sanity(i)) 1566241699cdSAl Viro return 0; 1567241699cdSAl Viro 1568241699cdSAl Viro data_start(i, &idx, &off); 1569241699cdSAl Viro /* some of this one + all after this one */ 1570241699cdSAl Viro npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1; 1571241699cdSAl Viro if (npages >= maxpages) 1572241699cdSAl Viro return maxpages; 1573241699cdSAl Viro } else iterate_all_kinds(i, size, v, ({ 1574d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1575d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1576d879cb83SAl Viro - p / PAGE_SIZE; 1577d879cb83SAl Viro if (npages >= maxpages) 1578d879cb83SAl Viro return maxpages; 1579d879cb83SAl Viro 0;}),({ 1580d879cb83SAl Viro npages++; 1581d879cb83SAl Viro if (npages >= maxpages) 1582d879cb83SAl Viro return maxpages; 1583d879cb83SAl Viro }),({ 1584d879cb83SAl Viro unsigned long p = (unsigned long)v.iov_base; 1585d879cb83SAl Viro npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE) 1586d879cb83SAl Viro - p / PAGE_SIZE; 1587d879cb83SAl Viro if (npages >= maxpages) 1588d879cb83SAl Viro return maxpages; 1589d879cb83SAl Viro }) 1590d879cb83SAl Viro ) 1591d879cb83SAl Viro return npages; 1592d879cb83SAl Viro } 1593d879cb83SAl Viro EXPORT_SYMBOL(iov_iter_npages); 1594d879cb83SAl Viro 1595d879cb83SAl Viro const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) 1596d879cb83SAl Viro { 1597d879cb83SAl Viro *new = *old; 159800e23707SDavid Howells if (unlikely(iov_iter_is_pipe(new))) { 1599241699cdSAl Viro WARN_ON(1); 1600241699cdSAl Viro return NULL; 1601241699cdSAl Viro } 16029ea9ce04SDavid Howells if (unlikely(iov_iter_is_discard(new))) 16039ea9ce04SDavid Howells return NULL; 160400e23707SDavid Howells if (iov_iter_is_bvec(new)) 1605d879cb83SAl Viro return new->bvec = kmemdup(new->bvec, 1606d879cb83SAl Viro new->nr_segs * sizeof(struct bio_vec), 1607d879cb83SAl Viro flags); 1608d879cb83SAl Viro else 1609d879cb83SAl Viro /* iovec and kvec have identical layout */ 1610d879cb83SAl Viro return new->iov = kmemdup(new->iov, 1611d879cb83SAl Viro new->nr_segs * sizeof(struct iovec), 1612d879cb83SAl Viro flags); 1613d879cb83SAl Viro } 1614d879cb83SAl Viro EXPORT_SYMBOL(dup_iter); 1615bc917be8SAl Viro 1616ffecee4fSVegard Nossum /** 1617ffecee4fSVegard Nossum * import_iovec() - Copy an array of &struct iovec from userspace 1618ffecee4fSVegard Nossum * into the kernel, check that it is valid, and initialize a new 1619ffecee4fSVegard Nossum * &struct iov_iter iterator to access it. 1620ffecee4fSVegard Nossum * 1621ffecee4fSVegard Nossum * @type: One of %READ or %WRITE. 1622ffecee4fSVegard Nossum * @uvector: Pointer to the userspace array. 1623ffecee4fSVegard Nossum * @nr_segs: Number of elements in userspace array. 1624ffecee4fSVegard Nossum * @fast_segs: Number of elements in @iov. 1625ffecee4fSVegard Nossum * @iov: (input and output parameter) Pointer to pointer to (usually small 1626ffecee4fSVegard Nossum * on-stack) kernel array. 1627ffecee4fSVegard Nossum * @i: Pointer to iterator that will be initialized on success. 1628ffecee4fSVegard Nossum * 1629ffecee4fSVegard Nossum * If the array pointed to by *@iov is large enough to hold all @nr_segs, 1630ffecee4fSVegard Nossum * then this function places %NULL in *@iov on return. Otherwise, a new 1631ffecee4fSVegard Nossum * array will be allocated and the result placed in *@iov. This means that 1632ffecee4fSVegard Nossum * the caller may call kfree() on *@iov regardless of whether the small 1633ffecee4fSVegard Nossum * on-stack array was used or not (and regardless of whether this function 1634ffecee4fSVegard Nossum * returns an error or not). 1635ffecee4fSVegard Nossum * 1636ffecee4fSVegard Nossum * Return: 0 on success or negative error code on error. 1637ffecee4fSVegard Nossum */ 1638bc917be8SAl Viro int import_iovec(int type, const struct iovec __user * uvector, 1639bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1640bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1641bc917be8SAl Viro { 1642bc917be8SAl Viro ssize_t n; 1643bc917be8SAl Viro struct iovec *p; 1644bc917be8SAl Viro n = rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1645bc917be8SAl Viro *iov, &p); 1646bc917be8SAl Viro if (n < 0) { 1647bc917be8SAl Viro if (p != *iov) 1648bc917be8SAl Viro kfree(p); 1649bc917be8SAl Viro *iov = NULL; 1650bc917be8SAl Viro return n; 1651bc917be8SAl Viro } 1652bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1653bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1654bc917be8SAl Viro return 0; 1655bc917be8SAl Viro } 1656bc917be8SAl Viro EXPORT_SYMBOL(import_iovec); 1657bc917be8SAl Viro 1658bc917be8SAl Viro #ifdef CONFIG_COMPAT 1659bc917be8SAl Viro #include <linux/compat.h> 1660bc917be8SAl Viro 1661bc917be8SAl Viro int compat_import_iovec(int type, const struct compat_iovec __user * uvector, 1662bc917be8SAl Viro unsigned nr_segs, unsigned fast_segs, 1663bc917be8SAl Viro struct iovec **iov, struct iov_iter *i) 1664bc917be8SAl Viro { 1665bc917be8SAl Viro ssize_t n; 1666bc917be8SAl Viro struct iovec *p; 1667bc917be8SAl Viro n = compat_rw_copy_check_uvector(type, uvector, nr_segs, fast_segs, 1668bc917be8SAl Viro *iov, &p); 1669bc917be8SAl Viro if (n < 0) { 1670bc917be8SAl Viro if (p != *iov) 1671bc917be8SAl Viro kfree(p); 1672bc917be8SAl Viro *iov = NULL; 1673bc917be8SAl Viro return n; 1674bc917be8SAl Viro } 1675bc917be8SAl Viro iov_iter_init(i, type, p, nr_segs, n); 1676bc917be8SAl Viro *iov = p == *iov ? NULL : p; 1677bc917be8SAl Viro return 0; 1678bc917be8SAl Viro } 1679bc917be8SAl Viro #endif 1680bc917be8SAl Viro 1681bc917be8SAl Viro int import_single_range(int rw, void __user *buf, size_t len, 1682bc917be8SAl Viro struct iovec *iov, struct iov_iter *i) 1683bc917be8SAl Viro { 1684bc917be8SAl Viro if (len > MAX_RW_COUNT) 1685bc917be8SAl Viro len = MAX_RW_COUNT; 168696d4f267SLinus Torvalds if (unlikely(!access_ok(buf, len))) 1687bc917be8SAl Viro return -EFAULT; 1688bc917be8SAl Viro 1689bc917be8SAl Viro iov->iov_base = buf; 1690bc917be8SAl Viro iov->iov_len = len; 1691bc917be8SAl Viro iov_iter_init(i, rw, iov, 1, len); 1692bc917be8SAl Viro return 0; 1693bc917be8SAl Viro } 1694e1267585SAl Viro EXPORT_SYMBOL(import_single_range); 169509cf698aSAl Viro 169609cf698aSAl Viro int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, 169709cf698aSAl Viro int (*f)(struct kvec *vec, void *context), 169809cf698aSAl Viro void *context) 169909cf698aSAl Viro { 170009cf698aSAl Viro struct kvec w; 170109cf698aSAl Viro int err = -EINVAL; 170209cf698aSAl Viro if (!bytes) 170309cf698aSAl Viro return 0; 170409cf698aSAl Viro 170509cf698aSAl Viro iterate_all_kinds(i, bytes, v, -EINVAL, ({ 170609cf698aSAl Viro w.iov_base = kmap(v.bv_page) + v.bv_offset; 170709cf698aSAl Viro w.iov_len = v.bv_len; 170809cf698aSAl Viro err = f(&w, context); 170909cf698aSAl Viro kunmap(v.bv_page); 171009cf698aSAl Viro err;}), ({ 171109cf698aSAl Viro w = v; 171209cf698aSAl Viro err = f(&w, context);}) 171309cf698aSAl Viro ) 171409cf698aSAl Viro return err; 171509cf698aSAl Viro } 171609cf698aSAl Viro EXPORT_SYMBOL(iov_iter_for_each_range); 1717