--- /dev/null
+/* 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;
+
+\f
+/* 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;
+}
+
+\f
+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.");
+}
+
+
projects / deliverable / binutils-gdb.git / commitdiff
