* Makefile.in (linux-nat.o): Add rule.

	* linux-nat.c: New file.
	* config/nm-linux.h (CHILD_INSERT_FORK_CATCHPOINT): Define.
	(CHILD_INSERT_VFORK_CATCHPOINT): Define.
	(CHILD_INSERT_EXEC_CATCHPOINT): Define.
	* config/alpha/alpha-linux.mh (NATDEPFILES): Add linux-nat.o.
	* config/arm/linux.mh (NATDEPFILES): Likewise.
	* config/i386/linux.mh (NATDEPFILES): Likewise.
	* config/i386/x86-64linux.mh (NATDEPFILES): Likewise.
	* config/ia64/linux.mh (NATDEPFILES): Likewise.
	* config/m68k/linux.mh (NATDEPFILES): Likewise.
	* config/mips/linux.mh (NATDEPFILES): Likewise.
	* config/powerpc/linux.mh (NATDEPFILES): Likewise.
	* config/s390/s390.mh (NATDEPFILES): Likewise.
	* config/sparc/linux.mh (NATDEPFILES): Likewise.

1 files changed, 176 insertions, 0 deletions

diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
new file mode 100644
index 00000000000..046544d1d3c
--- /dev/null
+++ b/gdb/linux-nat.c
@@ -0,0 +1,176 @@
+/* GNU/Linux native-dependent code common to multiple platforms.
+   Copyright (C) 2003 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include "defs.h"
+#include "inferior.h"
+#include "target.h"
+
+#include "gdb_wait.h"
+#include <sys/ptrace.h>
+
+/* If the system headers did not provide the constants, hard-code the normal
+   values.  */
+#ifndef PTRACE_EVENT_FORK
+
+#define PTRACE_SETOPTIONS	0x4200
+#define PTRACE_GETEVENTMSG	0x4201
+
+/* options set using PTRACE_SETOPTIONS */
+#define PTRACE_O_TRACESYSGOOD	0x00000001
+#define PTRACE_O_TRACEFORK	0x00000002
+#define PTRACE_O_TRACEVFORK	0x00000004
+#define PTRACE_O_TRACECLONE	0x00000008
+#define PTRACE_O_TRACEEXEC	0x00000010
+
+/* Wait extended result codes for the above trace options.  */
+#define PTRACE_EVENT_FORK	1
+#define PTRACE_EVENT_VFORK	2
+#define PTRACE_EVENT_CLONE	3
+#define PTRACE_EVENT_EXEC	4
+
+#endif /* PTRACE_EVENT_FORK */
+
+/* We can't always assume that this flag is available, but all systems
+   with the ptrace event handlers also have __WALL, so it's safe to use
+   here.  */
+#ifndef __WALL
+#define __WALL          0x40000000 /* Wait for any child.  */
+#endif
+
+/* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
+   can not be used, 1 if it can.  */
+
+static int linux_supports_tracefork_flag = -1;
+
+
+/* A helper function for linux_test_for_tracefork, called after fork ().  */
+
+static void
+linux_tracefork_child (void)
+{
+  int ret;
+
+  ptrace (PTRACE_TRACEME, 0, 0, 0);
+  kill (getpid (), SIGSTOP);
+  fork ();
+  exit (0);
+}
+
+/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.  We
+   create a child process, attach to it, use PTRACE_SETOPTIONS to enable
+   fork tracing, and let it fork.  If the process exits, we assume that
+   we can't use TRACEFORK; if we get the fork notification, and we can
+   extract the new child's PID, then we assume that we can.  */
+
+static void
+linux_test_for_tracefork (void)
+{
+  int child_pid, ret, status;
+  long second_pid;
+
+  child_pid = fork ();
+  if (child_pid == -1)
+    perror_with_name ("linux_test_for_tracefork: fork");
+
+  if (child_pid == 0)
+    linux_tracefork_child ();
+
+  ret = waitpid (child_pid, &status, 0);
+  if (ret == -1)
+    perror_with_name ("linux_test_for_tracefork: waitpid");
+  else if (ret != child_pid)
+    error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret);
+  if (! WIFSTOPPED (status))
+    error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
+
+  linux_supports_tracefork_flag = 0;
+
+  ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
+  if (ret != 0)
+    {
+      ptrace (PTRACE_KILL, child_pid, 0, 0);
+      waitpid (child_pid, &status, 0);
+      return;
+    }
+
+  ptrace (PTRACE_CONT, child_pid, 0, 0);
+  ret = waitpid (child_pid, &status, 0);
+  if (ret == child_pid && WIFSTOPPED (status)
+      && status >> 16 == PTRACE_EVENT_FORK)
+    {
+      second_pid = 0;
+      ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
+      if (ret == 0 && second_pid != 0)
+	{
+	  int second_status;
+
+	  linux_supports_tracefork_flag = 1;
+	  waitpid (second_pid, &second_status, 0);
+	  ptrace (PTRACE_DETACH, second_pid, 0, 0);
+	}
+    }
+
+  if (WIFSTOPPED (status))
+    {
+      ptrace (PTRACE_DETACH, child_pid, 0, 0);
+      waitpid (child_pid, &status, 0);
+    }
+}
+
+/* Return non-zero iff we have tracefork functionality available.
+   This function also sets linux_supports_tracefork_flag.  */
+
+static int
+linux_supports_tracefork (void)
+{
+  if (linux_supports_tracefork_flag == -1)
+    linux_test_for_tracefork ();
+  return linux_supports_tracefork_flag;
+}
+
+
+int
+child_insert_fork_catchpoint (int pid)
+{
+  if (linux_supports_tracefork ())
+    error ("Fork catchpoints have not been implemented yet.");
+  else
+    error ("Your system does not support fork catchpoints.");
+}
+
+int
+child_insert_vfork_catchpoint (int pid)
+{
+  if (linux_supports_tracefork ())
+    error ("Vfork catchpoints have not been implemented yet.");
+  else
+    error ("Your system does not support vfork catchpoints.");
+}
+
+int
+child_insert_exec_catchpoint (int pid)
+{
+  if (linux_supports_tracefork ())
+    error ("Exec catchpoints have not been implemented yet.");
+  else
+    error ("Your system does not support exec catchpoints.");
+}
+
+