1/* Copyright 1992-2020 Free Software Foundation, Inc. 2 3 This file is part of GDB. 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18/* Simple little program that just generates a core dump from inside some 19 nested function calls. */ 20 21#include <stdio.h> 22#include <sys/types.h> 23#include <fcntl.h> 24#include <sys/mman.h> 25#include <signal.h> 26#include <stdlib.h> 27#include <unistd.h> 28#include <string.h> 29 30#ifndef __STDC__ 31#define const /**/ 32#endif 33 34#define MAPSIZE (8 * 1024) 35 36/* Don't make these automatic vars or we will have to walk back up the 37 stack to access them. */ 38 39char *buf1; 40char *buf2; 41char *buf2ro; 42char *buf3; 43 44int coremaker_data = 1; /* In Data section */ 45int coremaker_bss; /* In BSS section */ 46 47/* Place a chunk of memory before coremaker_ro to improve the chances 48 that coremaker_ro will end up on it's own page. See: 49 50 https://sourceware.org/pipermail/gdb-patches/2020-May/168168.html 51 https://sourceware.org/pipermail/gdb-patches/2020-May/168170.html */ 52const unsigned char filler_ro[MAPSIZE] = {1, 2, 3, 4, 5, 6, 7, 8}; 53const int coremaker_ro = 201; /* In Read-Only Data section */ 54 55/* Note that if the mapping fails for any reason, we set buf2 56 to -1 and the testsuite notices this and reports it as 57 a failure due to a mapping error. This way we don't have 58 to test for specific errors when running the core maker. */ 59 60void 61mmapdata () 62{ 63 int j, fd; 64 65 /* Allocate and initialize a buffer that will be used to write 66 the file that is later mapped in. */ 67 68 buf1 = (char *) malloc (MAPSIZE); 69 for (j = 0; j < MAPSIZE; ++j) 70 { 71 buf1[j] = j; 72 } 73 74 /* Write the file to map in */ 75 76 fd = open ("coremmap.data", O_CREAT | O_RDWR, 0666); 77 if (fd == -1) 78 { 79 perror ("coremmap.data open failed"); 80 buf2 = (char *) -1; 81 return; 82 } 83 write (fd, buf1, MAPSIZE); 84 85 /* Now map the file into our address space as buf2 */ 86 87 buf2 = (char *) mmap (0, MAPSIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); 88 if (buf2 == (char *) MAP_FAILED) 89 { 90 perror ("mmap failed"); 91 return; 92 } 93 94 /* Map in another copy, read-only. We won't write to this copy so it 95 will likely not end up in the core file. */ 96 buf2ro = (char *) mmap (0, MAPSIZE, PROT_READ, MAP_PRIVATE, fd, 0); 97 if (buf2ro == (char *) -1) 98 { 99 perror ("mmap failed"); 100 return; 101 } 102 103 /* Verify that the original data and the mapped data are identical. 104 If not, we'd rather fail now than when trying to access the mapped 105 data from the core file. */ 106 107 for (j = 0; j < MAPSIZE; ++j) 108 { 109 if (buf1[j] != buf2[j] || buf1[j] != buf2ro[j]) 110 { 111 fprintf (stderr, "mapped data is incorrect"); 112 buf2 = buf2ro = (char *) -1; 113 return; 114 } 115 } 116 /* Touch buf2 so kernel writes it out into 'core'. */ 117 buf2[0] = buf1[0]; 118 119 /* Create yet another region which is allocated, but not written to. */ 120 buf3 = mmap (NULL, MAPSIZE, PROT_READ | PROT_WRITE, 121 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); 122 if (buf3 == (char *) -1) 123 { 124 perror ("mmap failed"); 125 return; 126 } 127} 128 129void 130func2 () 131{ 132 int coremaker_local[5]; 133 int i; 134 135#ifdef SA_FULLDUMP 136 /* Force a corefile that includes the data section for AIX. */ 137 { 138 struct sigaction sa; 139 140 sigaction (SIGABRT, (struct sigaction *)0, &sa); 141 sa.sa_flags |= SA_FULLDUMP; 142 sigaction (SIGABRT, &sa, (struct sigaction *)0); 143 } 144#endif 145 146 /* Make sure that coremaker_local doesn't get optimized away. */ 147 for (i = 0; i < 5; i++) 148 coremaker_local[i] = i; 149 coremaker_bss = 0; 150 for (i = 0; i < 5; i++) 151 coremaker_bss += coremaker_local[i]; 152 coremaker_data = coremaker_ro + 1; 153 abort (); 154} 155 156void 157func1 () 158{ 159 func2 (); 160} 161 162int 163main (int argc, char **argv) 164{ 165 if (argc == 2 && strcmp (argv[1], "sleep") == 0) 166 { 167 sleep (60); 168 return 0; 169 } 170 mmapdata (); 171 func1 (); 172 return 0; 173} 174