1/* This testcase is part of GDB, the GNU debugger.
2
3   Copyright 1996-2020 Free Software Foundation, Inc.
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#include <signal.h>
19#include <setjmp.h>
20#include <stdlib.h>
21#include <string.h>
22
23enum tests {
24  code_entry_point, code_descriptor, data_read, data_write
25};
26
27static volatile enum tests test;
28
29/* Some basic types and zero buffers.  */
30
31typedef long data_t;
32typedef long code_t (void);
33data_t *volatile data;
34code_t *volatile code;
35/* "desc" is intentionally initialized to a data object.  This is
36   needed to test function descriptors on arches like ia64.  */
37data_t zero[10];
38code_t *volatile desc = (code_t *) (void *) zero;
39
40sigjmp_buf env;
41
42extern void
43keeper (int sig)
44{
45  siglongjmp (env, 0);
46}
47
48extern long
49bowler (void)
50{
51  switch (test)
52    {
53    case data_read:
54      /* Try to read address zero.  */
55      return (*data);
56    case data_write:
57      /* Try to write (the assignment) to address zero.  */
58      return (*data) = 1;
59    case code_entry_point:
60      /* For typical architectures, call a function at address
61	 zero.  */
62      return (*code) ();
63    case code_descriptor:
64      /* For atypical architectures that use function descriptors,
65	 call a function descriptor, the code field of which is zero
66	 (which has the effect of jumping to address zero).  */
67      return (*desc) ();
68    }
69}
70
71int
72main ()
73{
74  static volatile int i;
75
76  struct sigaction act;
77  memset (&act, 0, sizeof act);
78  act.sa_handler = keeper;
79  sigaction (SIGSEGV, &act, NULL);
80  sigaction (SIGBUS, &act, NULL);
81
82  for (i = 0; i < 10; i++)
83    {
84      sigsetjmp (env, 1);
85      bowler ();
86    }
87}
88