| /* |
| * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org> |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include <string.h> |
| #include <unistd.h> |
| #include <sys/mman.h> |
| |
| int |
| main(void) |
| { |
| const size_t page_len = sysconf(_SC_PAGESIZE); |
| const size_t tail_len = 257; |
| |
| if (tail_len >= page_len) |
| return 77; |
| |
| void *p = mmap(NULL, page_len * 2, PROT_READ | PROT_WRITE, |
| MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| if (p == MAP_FAILED || mprotect(p + page_len, page_len, PROT_NONE)) |
| return 77; |
| |
| memset(p, 0, page_len); |
| char *addr = p + page_len - tail_len; |
| memset(addr, '/', tail_len - 1); |
| if (chdir(addr)) |
| return 77; |
| |
| return 0; |
| } |