1/* Test case for forgotten hw-watchpoints after fork()-off of a process.
2
3   Copyright 2012-2023 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
19
20#include "watchpoint-fork.h"
21
22#include <string.h>
23#include <errno.h>
24#include <unistd.h>
25#include <assert.h>
26#include <signal.h>
27#include <stdio.h>
28
29/* `pid_t' may not be available.  */
30
31static volatile int usr1_got;
32
33static void
34handler_usr1 (int signo)
35{
36  usr1_got++;
37}
38
39void
40forkoff (int nr)
41{
42  int child, save_parent = getpid ();
43  int i;
44  struct sigaction act, oldact;
45#ifdef THREAD
46  void *thread_result;
47#endif
48
49  memset (&act, 0, sizeof act);
50  act.sa_flags = SA_RESTART;
51  act.sa_handler = handler_usr1;
52  sigemptyset (&act.sa_mask);
53  i = sigaction (SIGUSR1, &act, &oldact);
54  assert (i == 0);
55
56  child = fork ();
57  switch (child)
58    {
59    case -1:
60      assert (0);
61    default:
62#if DEBUG
63      printf ("parent%d: %d\n", nr, (int) child);
64#endif
65
66      /* Sleep for a while to possibly get incorrectly ATTACH_THREADed by GDB
67	 tracing the child fork with no longer valid thread/lwp entries of the
68	 parent.  */
69
70      i = sleep (2);
71      assert (i == 0);
72
73      /* We must not get caught here (against a forgotten breakpoint).  */
74
75      var++;
76      marker ();
77
78#ifdef THREAD
79      /* And neither got caught our thread.  */
80
81      step = 99;
82      i = pthread_join (thread, &thread_result);
83      assert (i == 0);
84      assert (thread_result == (void *) 99UL);
85#endif
86
87      /* Be sure our child knows we did not get caught above.  */
88
89      i = kill (child, SIGUSR1);
90      assert (i == 0);
91
92      /* Sleep for a while to check GDB's `info threads' no longer tracks us in
93	 the child fork.  */
94
95      i = sleep (2);
96      assert (i == 0);
97
98      _exit (0);
99    case 0:
100#if DEBUG
101      printf ("child%d: %d\n", nr, (int) getpid ());
102#endif
103
104      /* Let the parent signal us about its success.  Be careful of races.  */
105
106      for (;;)
107	{
108	  /* Parent either died (and USR1_GOT is zero) or it succeeded.  */
109	  if (getppid () != save_parent)
110	    break;
111	  if (kill (getppid (), 0) != 0)
112	    break;
113	  /* Parent succeeded?  */
114	  if (usr1_got)
115	    break;
116
117#ifdef THREAD
118	  i = pthread_yield ();
119	  assert (i == 0);
120#endif
121	}
122      assert (usr1_got);
123
124      /* We must get caught here (against a false watchpoint removal).  */
125
126      marker ();
127    }
128
129  i = sigaction (SIGUSR1, &oldact, NULL);
130  assert (i == 0);
131}
132