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