1 /* 2 * Copyright (c) 2015 Dmitry V. Levin <ldv (at) altlinux.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifdef HAVE_CONFIG_H 29 # include "config.h" 30 #endif 31 #include <dlfcn.h> 32 #include <fcntl.h> 33 #include <unistd.h> 34 #include <sys/mman.h> 35 #include <sys/wait.h> 36 #include <sys/sendfile.h> 37 38 int main(void) 39 { 40 const unsigned long pagesize = sysconf(_SC_PAGESIZE); 41 42 #ifdef __s390__ 43 /* 44 * The si_addr field is unreliable: 45 * https://marc.info/?l=linux-s390&m=142515870124248&w=2 46 */ 47 return 77; 48 #endif 49 50 /* write instruction pointer length to the log */ 51 if (write(-1, NULL, 2 * sizeof(void *)) >= 0) 52 return 77; 53 54 /* just a noticeable line in the log */ 55 if (munmap(&main, 0) >= 0) 56 return 77; 57 58 int pid = fork(); 59 if (pid < 0) 60 return 77; 61 62 if (!pid) { 63 const unsigned long mask = ~(pagesize - 1); 64 unsigned long addr = (unsigned long) &main & mask; 65 unsigned long size = pagesize << 1; 66 67 #ifdef HAVE_DLADDR 68 Dl_info info; 69 if (dladdr(&main, &info)) { 70 const unsigned long base = 71 (unsigned long) info.dli_fbase & mask; 72 if (base < addr) { 73 size += addr - base; 74 addr = base; 75 } 76 } else 77 #endif 78 { 79 addr -= size; 80 size <<= 1; 81 } 82 83 /* SIGSEGV is expected */ 84 (void) munmap((void *) addr, size); 85 (void) munmap((void *) addr, size); 86 return 77; 87 } 88 89 int status; 90 if (wait(&status) != pid || 91 !WIFSIGNALED(status) || 92 WTERMSIG(status) != SIGSEGV) 93 return 77; 94 95 /* dump process map for debug purposes */ 96 close(0); 97 if (!open("/proc/self/maps", O_RDONLY)) 98 (void) sendfile(1, 0, NULL, pagesize); 99 100 return 0; 101 } 102
