1 /* 2 * Copyright (c) 2011 Artur Grabowski <art@openbsd.org> 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17 18 #include <sys/types.h> 19 #include <sys/mman.h> 20 #include <err.h> 21 #include <stdlib.h> 22 #include <stdio.h> 23 #include <string.h> 24 #include <unistd.h> 25 #include <errno.h> 26 27 /* 28 * Test a corner case writing to a file from an mmap region from that file 29 * should fail. 30 */ 31 int 32 main(int argc, char **argv) 33 { 34 char name[20] = "/tmp/fluff.XXXXXX"; 35 char *buf; 36 size_t ps; 37 int fd; 38 39 ps = getpagesize(); 40 41 if ((fd = mkstemp(name)) == -1) 42 err(1, "mkstemp"); 43 44 if (unlink(name) == -1) 45 err(1, "unlink"); 46 47 buf = mmap(NULL, ps, PROT_READ, MAP_FILE|MAP_SHARED, fd, 0); 48 if (buf == MAP_FAILED) 49 err(1, "mmap"); 50 51 if (pwrite(fd, buf, ps, 0) == ps) 52 errx(1, "write to self succeeded"); 53 54 if (errno != EFAULT) 55 err(1, "unexpected errno"); 56 57 return (0); 58 } 59