xref: /openbsd/gnu/usr.bin/binutils/gdb/obsd-nat.c (revision 5af055cd)
1 /* Native-dependent code for OpenBSD.
2 
3    Copyright 2012 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 2 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, write to the Free Software
19    Foundation, Inc., 59 Temple Place - Suite 330,
20    Boston, MA 02111-1307, USA.  */
21 
22 #include "defs.h"
23 #include "gdbthread.h"
24 #include "inferior.h"
25 #include "target.h"
26 
27 #include "gdb_assert.h"
28 #include <sys/types.h>
29 #include <sys/ptrace.h>
30 #include <sys/wait.h>
31 
32 #include "obsd-nat.h"
33 
34 char *
35 obsd_pid_to_str (ptid_t ptid)
36 {
37   if (ptid_get_lwp (ptid) != 0)
38     {
39       static char buf[64];
40 
41       xsnprintf (buf, sizeof buf, "thread %ld", ptid_get_lwp (ptid));
42       return buf;
43     }
44 
45   return normal_pid_to_str (ptid);
46 }
47 
48 void
49 obsd_find_new_threads (void)
50 {
51   pid_t pid = ptid_get_pid (inferior_ptid);
52   struct ptrace_thread_state pts;
53 
54   if (ptrace(PT_GET_THREAD_FIRST, pid, (caddr_t)&pts, sizeof pts) == -1)
55     perror_with_name (("ptrace"));
56 
57   while (pts.pts_tid != -1)
58     {
59       ptid_t ptid = ptid_build (pid, pts.pts_tid, 0);
60 
61       if (!in_thread_list (ptid))
62 	{
63 	  /* HACK: Twiddle INFERIOR_PTID such that the initial thread
64 	     of a process isn't recognized as a new thread.  */
65 	  if (ptid_get_lwp (inferior_ptid) == 0)
66 	    inferior_ptid = ptid;
67 	  add_thread (ptid);
68 	}
69 
70       if (ptrace(PT_GET_THREAD_NEXT, pid, (caddr_t)&pts, sizeof pts) == -1)
71 	perror_with_name (("ptrace"));
72     }
73 }
74 
75 ptid_t
76 obsd_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
77 {
78   pid_t pid;
79   int status, save_errno;
80 
81   do
82     {
83       set_sigint_trap ();
84       set_sigio_trap ();
85 
86       do
87 	{
88 	  pid = waitpid (ptid_get_pid (ptid), &status, 0);
89 	  save_errno = errno;
90 	}
91       while (pid == -1 && errno == EINTR);
92 
93       clear_sigio_trap ();
94       clear_sigint_trap ();
95 
96       if (pid == -1)
97 	{
98 	  fprintf_unfiltered (gdb_stderr,
99 			      _("Child process unexpectedly missing: %s.\n"),
100 			      safe_strerror (save_errno));
101 
102 	  /* Claim it exited with unknown signal.  */
103 	  ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
104 	  ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
105 	  return minus_one_ptid;
106 	}
107 
108       /* Ignore terminated detached child processes.  */
109       if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid))
110 	pid = -1;
111     }
112   while (pid == -1);
113 
114   ptid = pid_to_ptid (pid);
115 
116   if (WIFSTOPPED (status))
117     {
118       ptrace_state_t pe;
119       pid_t fpid;
120 
121       if (ptrace (PT_GET_PROCESS_STATE, pid, (caddr_t)&pe, sizeof pe) == -1)
122 	perror_with_name (("ptrace"));
123 
124       switch (pe.pe_report_event)
125 	{
126 	case PTRACE_FORK:
127 	  ourstatus->kind = TARGET_WAITKIND_FORKED;
128 	  ourstatus->value.related_pid = pe.pe_other_pid;
129 
130 	  /* Make sure the other end of the fork is stopped too.  */
131 	  fpid = waitpid (pe.pe_other_pid, &status, 0);
132 	  if (fpid == -1)
133 	    perror_with_name (("waitpid"));
134 
135 	  if (ptrace (PT_GET_PROCESS_STATE, fpid,
136 		      (caddr_t)&pe, sizeof pe) == -1)
137 	    perror_with_name (("ptrace"));
138 
139 	  gdb_assert (pe.pe_report_event == PTRACE_FORK);
140 	  gdb_assert (pe.pe_other_pid == pid);
141 	  if (fpid == ptid_get_pid (inferior_ptid))
142 	    {
143 	      ourstatus->value.related_pid = pe.pe_other_pid;
144 	      return pid_to_ptid (fpid);
145 	    }
146 
147 	  return pid_to_ptid (pid);
148 	}
149 
150       ptid = ptid_build (pid, pe.pe_tid, 0);
151       if (!in_thread_list (ptid))
152 	{
153 	  /* HACK: Twiddle INFERIOR_PTID such that the initial thread
154 	     of a process isn't recognized as a new thread.  */
155 	  if (ptid_get_lwp (inferior_ptid) == 0)
156 	    inferior_ptid = ptid;
157 	  add_thread (ptid);
158 	}
159     }
160 
161   store_waitstatus (ourstatus, status);
162   return ptid;
163 }
164