2004-09-12 Andrew Cagney <cagney@gnu.org>

	* ppcnbsd-nat.c: Include "inf-ptrace.h".
	(ppcnbsd_fetch_inferior_registers): Rename fetch_inferior_registers.
	(ppcnbsd_store_inferior_registers): Rename store_inferior_registers.
	(_initialize_ppcnbsd_nat): Create and add a NetBSD/PPC ptrace
	target.
	* config/powerpc/nbsd.mh (NATDEPFILES): Replace and inftarg.o with
	inf-ptrace.o and inf-child.o.
	* inf-ptrace.h, inf-ptrace.c, inf-child.h, inf-child.c: New files.
	* Makefile.in: Update dependencies.

8 files changed, 1020 insertions, 6 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 6b46034764a..759dd8f8d65 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,15 @@
+2004-09-12  Andrew Cagney  <cagney@gnu.org>
+
+	* ppcnbsd-nat.c: Include "inf-ptrace.h".
+	(ppcnbsd_fetch_inferior_registers): Rename fetch_inferior_registers.
+	(ppcnbsd_store_inferior_registers): Rename store_inferior_registers.
+	(_initialize_ppcnbsd_nat): Create and add a NetBSD/PPC ptrace
+	target.
+	* config/powerpc/nbsd.mh (NATDEPFILES): Replace and inftarg.o with
+	inf-ptrace.o and inf-child.o.
+	* inf-ptrace.h, inf-ptrace.c, inf-child.h, inf-child.c: New files.
+	* Makefile.in: Update dependencies.
+	
 2004-09-11  Andrew Cagney  <cagney@gnu.org>
 
 	* language.c (hex_string, hex_string_custom): Move from here ...
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 99932d7fc40..cf29fade1cd 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -703,9 +703,11 @@ i386_tdep_h = i386-tdep.h
 i387_tdep_h = i387-tdep.h
 ia64_tdep_h = ia64-tdep.h
 infcall_h = infcall.h
+inf_child_h = inf-child.h
 inferior_h = inferior.h $(breakpoint_h) $(target_h) $(frame_h)
 inf_loop_h = inf-loop.h
 inflow_h = inflow.h $(terminal_h)
+inf_ptrace_h = inf-ptrace.h
 infttrace_h = infttrace.h
 interps_h = interps.h
 jv_lang_h = jv-lang.h
@@ -2038,6 +2040,8 @@ infcall.o: infcall.c $(defs_h) $(breakpoint_h) $(target_h) $(regcache_h) \
 	$(inferior_h) $(gdb_assert_h) $(block_h) $(gdbcore_h) $(language_h) \
 	$(objfiles_h) $(gdbcmd_h) $(command_h) $(gdb_string_h) $(infcall_h) \
 	$(dummy_frame_h)
+inf-child.o: inf-child.c $(defs_h) $(regcache_h) $(memattr_h) $(symtab_h) \
+	$(target_h) $(inferior_h)
 infcmd.o: infcmd.c $(defs_h) $(gdb_string_h) $(symtab_h) $(gdbtypes_h) \
 	$(frame_h) $(inferior_h) $(environ_h) $(value_h) $(gdbcmd_h) \
 	$(symfile_h) $(gdbcore_h) $(target_h) $(language_h) $(symfile_h) \
@@ -2049,6 +2053,9 @@ inf-loop.o: inf-loop.c $(defs_h) $(inferior_h) $(target_h) $(event_loop_h) \
 inflow.o: inflow.c $(defs_h) $(frame_h) $(inferior_h) $(command_h) \
 	$(serial_h) $(terminal_h) $(target_h) $(gdbthread_h) $(gdb_string_h) \
 	$(inflow_h)
+inf-ptrace.o: inf-ptrace.c $(defs_h) $(observer_h) $(gdb_ptrace_h) \
+	$(inflow_h) $(inferior_h) $(regcache_h) $(command_h) $(gdbcore_h) \
+	$(inf_child_h) $(gdbcmd_h)
 infptrace.o: infptrace.c $(defs_h) $(command_h) $(frame_h) $(gdbcore_h) \
 	$(inferior_h) $(regcache_h) $(target_h) $(gdb_assert_h) \
 	$(gdb_wait_h) $(gdb_string_h) $(gdb_dirent_h) $(gdb_ptrace_h)
@@ -2284,7 +2291,7 @@ ppc-linux-tdep.o: ppc-linux-tdep.c $(defs_h) $(frame_h) $(inferior_h) \
 	$(solib_svr4_h) $(ppc_tdep_h) $(trad_frame_h) $(frame_unwind_h)
 ppcnbsd-nat.o: ppcnbsd-nat.c $(defs_h) $(inferior_h) $(gdb_assert_h) \
 	$(gdbcore_h) $(regcache_h) $(bsd_kvm_h) $(ppc_tdep_h) \
-	$(ppcnbsd_tdep_h)
+	$(ppcnbsd_tdep_h) $(inf_ptrace_h)
 ppcnbsd-tdep.o: ppcnbsd-tdep.c $(defs_h) $(gdbcore_h) $(regcache_h) \
 	$(target_h) $(breakpoint_h) $(value_h) $(osabi_h) $(ppc_tdep_h) \
 	$(ppcnbsd_tdep_h) $(nbsd_tdep_h) $(tramp_frame_h) $(trad_frame_h) \
diff --git a/gdb/config/powerpc/nbsd.mh b/gdb/config/powerpc/nbsd.mh
index 6a5ce92e43e..4e7388bf962 100644
--- a/gdb/config/powerpc/nbsd.mh
+++ b/gdb/config/powerpc/nbsd.mh
@@ -1,5 +1,5 @@
 # Host: PowerPC, running NetBSD
-NATDEPFILES= fork-child.o infptrace.o inftarg.o ppcnbsd-nat.o bsd-kvm.o
+NATDEPFILES= fork-child.o inf-child.o inf-ptrace.o infptrace.o ppcnbsd-nat.o bsd-kvm.o
 NAT_FILE= config/nm-nbsd.h
 
 LOADLIBES= -lkvm
diff --git a/gdb/inf-child.c b/gdb/inf-child.c
new file mode 100644
index 00000000000..f729611173a
--- /dev/null
+++ b/gdb/inf-child.c
@@ -0,0 +1,241 @@
+/* Default child (native) target interface, for GDB when running under
+   Unix.
+
+   Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+   1998, 1999, 2000, 2001, 2002, 2004 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 "regcache.h"
+#include "memattr.h"
+#include "symtab.h"
+#include "target.h"
+#include "inferior.h"
+
+/* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
+   for all registers.  */
+
+static void
+inf_child_fetch_inferior_registers (int regnum)
+{
+  if (regnum == -1)
+    {
+      for (regnum = 0; regnum < NUM_REGS; regnum++)
+	regcache_raw_supply (current_regcache, regnum, NULL);
+    }
+  else
+    regcache_raw_supply (current_regcache, regnum, NULL);
+}
+
+/* Store register REGNUM back into the inferior.  If REGNUM is -1, do
+   this for all registers (including the floating point registers).  */
+
+static void
+inf_child_store_inferior_registers (int regnum)
+{
+}
+
+void
+inf_child_post_wait (ptid_t ptid, int wait_status)
+{
+  /* This version of Unix doesn't require a meaningful "post wait"
+     operation.
+   */
+}
+
+static void
+inf_child_post_attach (int pid)
+{
+  /* This version of Unix doesn't require a meaningful "post attach"
+     operation by a debugger.  */
+}
+
+/* Get ready to modify the registers array.  On machines which store
+   individual registers, this doesn't need to do anything.  On
+   machines which store all the registers in one fell swoop, this
+   makes sure that registers contains all the registers from the
+   program being debugged.  */
+
+static void
+inf_child_prepare_to_store (void)
+{
+}
+
+static void
+inf_child_open (char *arg, int from_tty)
+{
+  error ("Use the \"run\" command to start a Unix child process.");
+}
+
+static void
+inf_child_post_startup_inferior (ptid_t ptid)
+{
+  /* This version of Unix doesn't require a meaningful "post startup
+     inferior" operation by a debugger.  */
+}
+
+static void
+inf_child_acknowledge_created_inferior (int pid)
+{
+  /* This version of Unix doesn't require a meaningful "acknowledge
+     created inferior" operation by a debugger.  */
+}
+
+static int
+inf_child_insert_fork_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of fork
+     events.  */
+  return 0;
+}
+
+static int
+inf_child_remove_fork_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of fork
+     events.  */
+  return 0;
+}
+
+static int
+inf_child_insert_vfork_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of vfork
+     events.  */
+  return 0;
+}
+
+static int
+inf_child_remove_vfork_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of vfork
+     events.  */
+  return 0;
+}
+
+static int
+inf_child_follow_fork (int follow_child)
+{
+  /* This version of Unix doesn't support following fork or vfork
+     events.  */
+  return 0;
+}
+
+static int
+inf_child_insert_exec_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of exec
+     events.  */
+  return 0;
+}
+
+static int
+inf_child_remove_exec_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of exec
+     events.  */
+  return 0;
+}
+
+static int
+inf_child_reported_exec_events_per_exec_call (void)
+{
+  /* This version of Unix doesn't support notification of exec
+     events.  */
+  return 1;
+}
+
+static int
+inf_child_can_run (void)
+{
+  return 1;
+}
+
+static struct symtab_and_line *
+inf_child_enable_exception_callback (enum exception_event_kind kind,
+				     int enable)
+{
+  return (struct symtab_and_line *) NULL;
+}
+
+static struct exception_event_record *
+inf_child_get_current_exception_event (void)
+{
+  return (struct exception_event_record *) NULL;
+}
+
+static char *
+inf_child_pid_to_exec_file (int pid)
+{
+  /* This version of Unix doesn't support translation of a process ID
+     to the filename of the executable file.  */
+  return NULL;
+}
+
+static char *
+inf_child_core_file_to_sym_file (char *core)
+{
+  /* The target stratum for a running executable need not support this
+     operation.  */
+  return NULL;
+}
+
+struct target_ops *
+inf_child_target (void)
+{
+  struct target_ops *t = XZALLOC (struct target_ops);
+  t->to_shortname = "child";
+  t->to_longname = "Unix child process";
+  t->to_doc = "Unix child process (started by the \"run\" command).";
+  t->to_open = inf_child_open;
+  t->to_post_attach = inf_child_post_attach;
+  t->to_post_wait = inf_child_post_wait;
+  t->to_prepare_to_store = inf_child_prepare_to_store;
+  t->to_insert_breakpoint = memory_insert_breakpoint;
+  t->to_remove_breakpoint = memory_remove_breakpoint;
+  t->to_terminal_init = terminal_init_inferior;
+  t->to_terminal_inferior = terminal_inferior;
+  t->to_terminal_ours_for_output = terminal_ours_for_output;
+  t->to_terminal_save_ours = terminal_save_ours;
+  t->to_terminal_ours = terminal_ours;
+  t->to_terminal_info = child_terminal_info;
+  t->to_post_startup_inferior = inf_child_post_startup_inferior;
+  t->to_acknowledge_created_inferior = inf_child_acknowledge_created_inferior;
+  t->to_insert_fork_catchpoint = inf_child_insert_fork_catchpoint;
+  t->to_remove_fork_catchpoint = inf_child_remove_fork_catchpoint;
+  t->to_insert_vfork_catchpoint = inf_child_insert_vfork_catchpoint;
+  t->to_remove_vfork_catchpoint = inf_child_remove_vfork_catchpoint;
+  t->to_follow_fork = inf_child_follow_fork;
+  t->to_insert_exec_catchpoint = inf_child_insert_exec_catchpoint;
+  t->to_remove_exec_catchpoint = inf_child_remove_exec_catchpoint;
+  t->to_reported_exec_events_per_exec_call =
+    inf_child_reported_exec_events_per_exec_call;
+  t->to_can_run = inf_child_can_run;
+  t->to_enable_exception_callback = inf_child_enable_exception_callback;
+  t->to_get_current_exception_event = inf_child_get_current_exception_event;
+  t->to_pid_to_exec_file = inf_child_pid_to_exec_file;
+  t->to_stratum = process_stratum;
+  t->to_has_all_memory = 1;
+  t->to_has_memory = 1;
+  t->to_has_stack = 1;
+  t->to_has_registers = 1;
+  t->to_has_execution = 1;
+  t->to_magic = OPS_MAGIC;
+  return t;
+}
diff --git a/gdb/inf-child.h b/gdb/inf-child.h
new file mode 100644
index 00000000000..5b6edec1052
--- /dev/null
+++ b/gdb/inf-child.h
@@ -0,0 +1,30 @@
+/* Low level Unix child interface, for GDB when running under Unix.
+
+   Copyright 2004 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.  */
+
+#ifndef INF_CHILD_H
+#define INF_CHILD_H
+
+/* Create a prototype child target.  The client can override it with
+   local methods.  */
+
+extern struct target_ops *inf_child_target (void);
+
+#endif
diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c
new file mode 100644
index 00000000000..f79f7863ba6
--- /dev/null
+++ b/gdb/inf-ptrace.c
@@ -0,0 +1,685 @@
+/* Low level Unix child interface to ptrace, for GDB when running under Unix.
+
+   Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
+   1998, 1999, 2000, 2001, 2002, 2004 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 "observer.h"
+#include "gdb_ptrace.h"
+#include "inflow.h"
+#include "inferior.h"
+#include "regcache.h"
+#include "command.h"
+#include "gdbcore.h"
+#include "inf-child.h"
+#include "gdbcmd.h"
+
+#include <sys/wait.h>
+#include <signal.h>
+
+/* HACK: Save the ptrace ops returned by ptrace_target.  */
+static struct target_ops *ptrace_ops_hack;
+
+static void
+inf_ptrace_kill_inferior (void)
+{
+  int status;
+  int pid = PIDGET (inferior_ptid);
+
+  if (pid == 0)
+    return;
+
+  /* This once used to call "kill" to kill the inferior just in case
+     the inferior was still running.  As others have noted in the past
+     (kingdon) there shouldn't be any way to get here if the inferior
+     is still running -- else there's a major problem elsewere in gdb
+     and it needs to be fixed.
+
+     The kill call causes problems under hpux10, so it's been removed;
+     if this causes problems we'll deal with them as they arise.  */
+  call_ptrace (PT_KILL, pid, (PTRACE_TYPE_ARG3) 0, 0);
+  ptrace_wait (null_ptid, &status);
+  target_mourn_inferior ();
+}
+
+/* Resume execution of the inferior process.  If STEP is nonzero,
+   single-step it.  If SIGNAL is nonzero, give it that signal.  */
+
+static void
+inf_ptrace_resume (ptid_t ptid, int step, enum target_signal signal)
+{
+  int request = PT_CONTINUE;
+  int pid = PIDGET (ptid);
+
+  if (pid == -1)
+    /* Resume all threads.  */
+    /* I think this only gets used in the non-threaded case, where
+       "resume all threads" and "resume inferior_ptid" are the
+       same.  */
+    pid = PIDGET (inferior_ptid);
+
+  if (step)
+    {
+      /* If this system does not support PT_STEP, a higher level
+         function will have called single_step() to transmute the step
+         request into a continue request (by setting breakpoints on
+         all possible successor instructions), so we don't have to
+         worry about that here.  */
+      request = PT_STEP;
+    }
+
+  /* An address of (PTRACE_TYPE_ARG3)1 tells ptrace to continue from
+     where it was.  If GDB wanted it to start some other way, we have
+     already written a new PC value to the child.  */
+  errno = 0;
+  ptrace (request, pid, (PTRACE_TYPE_ARG3) 1, target_signal_to_host (signal));
+  if (errno != 0)
+    perror_with_name ("ptrace");
+}
+
+/* Set an upper limit on alloca.  */
+#define GDB_MAX_ALLOCA 0x1000
+
+/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
+   in the NEW_SUN_PTRACE case.  It ought to be straightforward.  But
+   it appears that writing did not write the data that I specified.  I
+   cannot understand where it got the data that it actually did
+   write.  */
+
+/* Copy LEN bytes to or from inferior's memory starting at MEMADDR to
+   debugger memory starting at MYADDR.  Copy to inferior if WRITE is
+   nonzero.  TARGET is ignored.
+
+   Returns the length copied, which is either the LEN argument or
+   zero.  This xfer function does not do partial moves, since
+   ptrace_ops_hack doesn't allow memory operations to cross below us in the
+   target stack anyway.  */
+
+int
+inf_ptrace_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
+			struct mem_attrib *attrib, struct target_ops *target)
+{
+  int i;
+  /* Round starting address down to longword boundary.  */
+  CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_TYPE_RET);
+  /* Round ending address up; get number of longwords that makes.  */
+  int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
+	       / sizeof (PTRACE_TYPE_RET));
+  int alloc = count * sizeof (PTRACE_TYPE_RET);
+  PTRACE_TYPE_RET *buffer;
+  struct cleanup *old_chain = NULL;
+
+#ifdef PT_IO
+  /* OpenBSD 3.1, NetBSD 1.6 and FreeBSD 5.0 have a new PT_IO request
+     that promises to be much more efficient in reading and writing
+     data in the traced process's address space.  */
+
+  {
+    struct ptrace_io_desc piod;
+
+    /* NOTE: We assume that there are no distinct address spaces for
+       instruction and data.  */
+    piod.piod_op = write ? PIOD_WRITE_D : PIOD_READ_D;
+    piod.piod_offs = (void *) memaddr;
+    piod.piod_addr = myaddr;
+    piod.piod_len = len;
+
+    if (ptrace (PT_IO, PIDGET (inferior_ptid), (caddr_t) & piod, 0) == -1)
+      {
+	/* If the PT_IO request is somehow not supported, fallback on
+	   using PT_WRITE_D/PT_READ_D.  Otherwise we will return zero
+	   to indicate failure.  */
+	if (errno != EINVAL)
+	  return 0;
+      }
+    else
+      {
+	/* Return the actual number of bytes read or written.  */
+	return piod.piod_len;
+      }
+  }
+#endif
+
+  /* Allocate buffer of that many longwords.  */
+  if (len < GDB_MAX_ALLOCA)
+    {
+      buffer = (PTRACE_TYPE_RET *) alloca (alloc);
+    }
+  else
+    {
+      buffer = (PTRACE_TYPE_RET *) xmalloc (alloc);
+      old_chain = make_cleanup (xfree, buffer);
+    }
+
+  if (write)
+    {
+      /* Fill start and end extra bytes of buffer with existing memory
+         data.  */
+      if (addr != memaddr || len < (int) sizeof (PTRACE_TYPE_RET))
+	{
+	  /* Need part of initial word -- fetch it.  */
+	  buffer[0] = ptrace (PT_READ_I, PIDGET (inferior_ptid),
+			      (PTRACE_TYPE_ARG3) addr, 0);
+	}
+
+      if (count > 1)		/* FIXME, avoid if even boundary.  */
+	{
+	  buffer[count - 1] =
+	    ptrace (PT_READ_I, PIDGET (inferior_ptid),
+		    ((PTRACE_TYPE_ARG3)
+		     (addr + (count - 1) * sizeof (PTRACE_TYPE_RET))), 0);
+	}
+
+      /* Copy data to be written over corresponding part of buffer.  */
+      memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
+	      myaddr, len);
+
+      /* Write the entire buffer.  */
+      for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
+	{
+	  errno = 0;
+	  ptrace (PT_WRITE_D, PIDGET (inferior_ptid),
+		  (PTRACE_TYPE_ARG3) addr, buffer[i]);
+	  if (errno)
+	    {
+	      /* Using the appropriate one (I or D) is necessary for
+	         Gould NP1, at least.  */
+	      errno = 0;
+	      ptrace (PT_WRITE_I, PIDGET (inferior_ptid),
+		      (PTRACE_TYPE_ARG3) addr, buffer[i]);
+	    }
+	  if (errno)
+	    return 0;
+	}
+    }
+  else
+    {
+      /* Read all the longwords.  */
+      for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
+	{
+	  errno = 0;
+	  buffer[i] = ptrace (PT_READ_I, PIDGET (inferior_ptid),
+			      (PTRACE_TYPE_ARG3) addr, 0);
+	  if (errno)
+	    return 0;
+	  QUIT;
+	}
+
+      /* Copy appropriate bytes out of the buffer.  */
+      memcpy (myaddr,
+	      (char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
+	      len);
+    }
+
+  if (old_chain != NULL)
+    do_cleanups (old_chain);
+  return len;
+}
+
+/* Wait for child to do something.  Return pid of child, or -1 in case
+   of error; store status through argument pointer OURSTATUS.  */
+
+static ptid_t
+inf_ptrace_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
+{
+  int save_errno;
+  int status;
+  char *execd_pathname = NULL;
+  int exit_status;
+  int related_pid;
+  int syscall_id;
+  enum target_waitkind kind;
+  int pid;
+
+  do
+    {
+      set_sigint_trap ();	/* Causes SIGINT to be passed on to the
+				   attached process. */
+      set_sigio_trap ();
+
+      pid = ptrace_wait (inferior_ptid, &status);
+
+      save_errno = errno;
+
+      clear_sigio_trap ();
+
+      clear_sigint_trap ();
+
+      if (pid == -1)
+	{
+	  if (save_errno == EINTR)
+	    continue;
+
+	  fprintf_unfiltered (gdb_stderr,
+			      "Child process unexpectedly missing: %s.\n",
+			      safe_strerror (save_errno));
+
+	  /* Claim it exited with unknown signal.  */
+	  ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
+	  ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
+	  return pid_to_ptid (-1);
+	}
+
+      /* Did it exit?
+       */
+      if (target_has_exited (pid, status, &exit_status))
+	{
+	  /* ??rehrauer: For now, ignore this. */
+	  continue;
+	}
+
+      if (!target_thread_alive (pid_to_ptid (pid)))
+	{
+	  ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
+	  return pid_to_ptid (pid);
+	}
+    }
+  while (pid != PIDGET (inferior_ptid));	/* Some other child died or stopped */
+
+  store_waitstatus (ourstatus, status);
+  return pid_to_ptid (pid);
+}
+
+void
+inf_ptrace_post_wait (ptid_t ptid, int wait_status)
+{
+  /* This version of Unix doesn't require a meaningful "post wait"
+     operation.
+   */
+}
+
+/* Check to see if the given thread is alive.
+
+   FIXME: Is kill() ever the right way to do this?  I doubt it, but
+   for now we're going to try and be compatable with the old thread
+   code.  */
+
+static int
+inf_ptrace_thread_alive (ptid_t ptid)
+{
+  pid_t pid = PIDGET (ptid);
+
+  return (kill (pid, 0) != -1);
+}
+
+/* Attach to process PID, then initialize for debugging it.  */
+
+static void
+inf_ptrace_attach (char *args, int from_tty)
+{
+  char *exec_file;
+  int pid;
+  char *dummy;
+
+  if (!args)
+    error_no_arg ("process-id to attach");
+
+  dummy = args;
+  pid = strtol (args, &dummy, 0);
+  /* Some targets don't set errno on errors, grrr! */
+  if ((pid == 0) && (args == dummy))
+    error ("Illegal process-id: %s\n", args);
+
+  if (pid == getpid ())		/* Trying to masturbate? */
+    error ("I refuse to debug myself!");
+
+  if (from_tty)
+    {
+      exec_file = (char *) get_exec_file (0);
+
+      if (exec_file)
+	printf_unfiltered ("Attaching to program: %s, %s\n", exec_file,
+			   target_pid_to_str (pid_to_ptid (pid)));
+      else
+	printf_unfiltered ("Attaching to %s\n",
+			   target_pid_to_str (pid_to_ptid (pid)));
+
+      gdb_flush (gdb_stdout);
+    }
+
+  attach (pid);
+
+  inferior_ptid = pid_to_ptid (pid);
+  push_target (ptrace_ops_hack);
+}
+
+static void
+inf_ptrace_post_attach (int pid)
+{
+  /* This version of Unix doesn't require a meaningful "post attach"
+     operation by a debugger.  */
+}
+
+/* Take a program previously attached to and detaches it.  The program
+   resumes execution and will no longer stop on signals, etc.  We'd
+   better not have left any breakpoints in the program or it'll die
+   when it hits one.  For this to work, it may be necessary for the
+   process to have been previously attached.  It *might* work if the
+   program was started via the normal ptrace (PTRACE_TRACEME).  */
+
+static void
+inf_ptrace_detach (char *args, int from_tty)
+{
+  int siggnal = 0;
+  int pid = PIDGET (inferior_ptid);
+
+  if (from_tty)
+    {
+      char *exec_file = get_exec_file (0);
+      if (exec_file == 0)
+	exec_file = "";
+      printf_unfiltered ("Detaching from program: %s, %s\n", exec_file,
+			 target_pid_to_str (pid_to_ptid (pid)));
+      gdb_flush (gdb_stdout);
+    }
+  if (args)
+    siggnal = atoi (args);
+
+  detach (siggnal);
+
+  inferior_ptid = null_ptid;
+  unpush_target (ptrace_ops_hack);
+}
+
+/* Get ready to modify the registers array.  On machines which store
+   individual registers, this doesn't need to do anything.  On
+   machines which store all the registers in one fell swoop, this
+   makes sure that registers contains all the registers from the
+   program being debugged.  */
+
+static void
+inf_ptrace_prepare_to_store (void)
+{
+}
+
+/* Print status information about what we're accessing.  */
+
+static void
+inf_ptrace_files_info (struct target_ops *ignore)
+{
+  printf_unfiltered ("\tUsing the running image of %s %s.\n",
+		     attach_flag ? "attached" : "child",
+		     target_pid_to_str (inferior_ptid));
+}
+
+static void
+inf_ptrace_open (char *arg, int from_tty)
+{
+  error ("Use the \"run\" command to start a Unix child process.");
+}
+
+/* Stub function which causes the inferior that runs it, to be ptrace-able
+   by its parent process.  */
+
+static void
+inf_ptrace_me (void)
+{
+  /* "Trace me, Dr. Memory!" */
+  call_ptrace (0, 0, (PTRACE_TYPE_ARG3) 0, 0);
+}
+
+/* Stub function which causes the GDB that runs it, to start ptrace-ing
+   the child process.  */
+
+static void
+inf_ptrace_him (int pid)
+{
+  push_target (ptrace_ops_hack);
+
+  /* On some targets, there must be some explicit synchronization
+     between the parent and child processes after the debugger
+     forks, and before the child execs the debuggee program.  This
+     call basically gives permission for the child to exec.
+   */
+
+  target_acknowledge_created_inferior (pid);
+
+  /* START_INFERIOR_TRAPS_EXPECTED is defined in inferior.h,
+   * and will be 1 or 2 depending on whether we're starting
+   * without or with a shell.
+   */
+  startup_inferior (START_INFERIOR_TRAPS_EXPECTED);
+
+  /* On some targets, there must be some explicit actions taken after
+     the inferior has been started up.
+   */
+  target_post_startup_inferior (pid_to_ptid (pid));
+}
+
+/* Start an inferior Unix child process and sets inferior_ptid to its
+   pid.  EXEC_FILE is the file to run.  ALLARGS is a string containing
+   the arguments to the program.  ENV is the environment vector to
+   pass.  Errors reported with error().  */
+
+static void
+inf_ptrace_create_inferior (char *exec_file, char *allargs, char **env,
+			    int from_tty)
+{
+  fork_inferior (exec_file, allargs, env, inf_ptrace_me, inf_ptrace_him,
+		 NULL, NULL);
+  /* We are at the first instruction we care about.  */
+  observer_notify_inferior_created (&current_target, from_tty);
+  /* Pedal to the metal... */
+  proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0);
+}
+
+static void
+inf_ptrace_post_startup_inferior (ptid_t ptid)
+{
+  /* This version of Unix doesn't require a meaningful "post startup inferior"
+     operation by a debugger.
+   */
+}
+
+static void
+inf_ptrace_acknowledge_created_inferior (int pid)
+{
+  /* This version of Unix doesn't require a meaningful "acknowledge created inferior"
+     operation by a debugger.
+   */
+}
+
+static int
+inf_ptrace_insert_fork_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of fork events.  */
+  return 0;
+}
+
+static int
+inf_ptrace_remove_fork_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of fork events.  */
+  return 0;
+}
+
+static int
+inf_ptrace_insert_vfork_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of vfork events.  */
+  return 0;
+}
+
+static int
+inf_ptrace_remove_vfork_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of vfork events.  */
+  return 0;
+}
+
+static int
+inf_ptrace_follow_fork (int follow_child)
+{
+  /* This version of Unix doesn't support following fork or vfork events.  */
+  return 0;
+}
+
+static int
+inf_ptrace_insert_exec_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of exec events.  */
+  return 0;
+}
+
+static int
+inf_ptrace_remove_exec_catchpoint (int pid)
+{
+  /* This version of Unix doesn't support notification of exec events.  */
+  return 0;
+}
+
+static int
+inf_ptrace_reported_exec_events_per_exec_call (void)
+{
+  /* This version of Unix doesn't support notification of exec events.
+   */
+  return 1;
+}
+
+static int
+inf_ptrace_has_exited (int pid, int wait_status, int *exit_status)
+{
+  if (WIFEXITED (wait_status))
+    {
+      *exit_status = WEXITSTATUS (wait_status);
+      return 1;
+    }
+
+  if (WIFSIGNALED (wait_status))
+    {
+      *exit_status = 0;		/* ?? Don't know what else to say here. */
+      return 1;
+    }
+
+  /* ?? Do we really need to consult the event state, too?  Assume the
+     wait_state alone suffices.
+   */
+  return 0;
+}
+
+static void
+inf_ptrace_mourn_inferior (void)
+{
+  unpush_target (ptrace_ops_hack);
+  generic_mourn_inferior ();
+}
+
+static int
+inf_ptrace_can_run (void)
+{
+  return 1;
+}
+
+/* Send a SIGINT to the process group.  This acts just like the user
+   typed a ^C on the controlling terminal.
+
+   XXX - This may not be correct for all systems.  Some may want to
+   use killpg() instead of kill (-pgrp). */
+
+static void
+inf_ptrace_stop (void)
+{
+  kill (-inferior_process_group, SIGINT);
+}
+
+/* Perform a partial transfer to/from the specified object.  For
+   memory transfers, fall back to the old memory xfer functions.  */
+
+static LONGEST
+inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
+			 const char *annex, void *readbuf,
+			 const void *writebuf, ULONGEST offset, LONGEST len)
+{
+  switch (object)
+    {
+    case TARGET_OBJECT_MEMORY:
+      if (readbuf)
+	return inf_ptrace_xfer_memory (offset, readbuf, len, 0 /*write */ ,
+				       NULL, ops);
+      if (writebuf)
+	return inf_ptrace_xfer_memory (offset, readbuf, len, 1 /*write */ ,
+				       NULL, ops);
+      return -1;
+
+    case TARGET_OBJECT_UNWIND_TABLE:
+      return -1;
+
+    case TARGET_OBJECT_AUXV:
+      return -1;
+
+    case TARGET_OBJECT_WCOOKIE:
+      return -1;
+
+    default:
+      return -1;
+    }
+}
+
+static char *
+inf_ptrace_pid_to_str (ptid_t ptid)
+{
+  return normal_pid_to_str (ptid);
+}
+
+struct target_ops *
+inf_ptrace_target (void)
+{
+  struct target_ops *t = inf_child_target ();
+  t->to_open = inf_ptrace_open;
+  t->to_attach = inf_ptrace_attach;
+  t->to_post_attach = inf_ptrace_post_attach;
+  t->to_detach = inf_ptrace_detach;
+  t->to_resume = inf_ptrace_resume;
+  t->to_wait = inf_ptrace_wait;
+  t->to_post_wait = inf_ptrace_post_wait;
+  t->to_prepare_to_store = inf_ptrace_prepare_to_store;
+  t->to_xfer_memory = inf_ptrace_xfer_memory;
+  t->to_xfer_partial = inf_ptrace_xfer_partial;
+  t->to_files_info = inf_ptrace_files_info;
+  t->to_kill = inf_ptrace_kill_inferior;
+  t->to_create_inferior = inf_ptrace_create_inferior;
+  t->to_post_startup_inferior = inf_ptrace_post_startup_inferior;
+  t->to_acknowledge_created_inferior =
+    inf_ptrace_acknowledge_created_inferior;
+  t->to_insert_fork_catchpoint = inf_ptrace_insert_fork_catchpoint;
+  t->to_remove_fork_catchpoint = inf_ptrace_remove_fork_catchpoint;
+  t->to_insert_vfork_catchpoint = inf_ptrace_insert_vfork_catchpoint;
+  t->to_remove_vfork_catchpoint = inf_ptrace_remove_vfork_catchpoint;
+  t->to_follow_fork = inf_ptrace_follow_fork;
+  t->to_insert_exec_catchpoint = inf_ptrace_insert_exec_catchpoint;
+  t->to_remove_exec_catchpoint = inf_ptrace_remove_exec_catchpoint;
+  t->to_reported_exec_events_per_exec_call =
+    inf_ptrace_reported_exec_events_per_exec_call;
+  t->to_has_exited = inf_ptrace_has_exited;
+  t->to_mourn_inferior = inf_ptrace_mourn_inferior;
+  t->to_can_run = inf_ptrace_can_run;
+  t->to_thread_alive = inf_ptrace_thread_alive;
+  t->to_pid_to_str = inf_ptrace_pid_to_str;
+  t->to_stop = inf_ptrace_stop;
+  t->to_stratum = process_stratum;
+  t->to_has_all_memory = 1;
+  t->to_has_memory = 1;
+  t->to_has_stack = 1;
+  t->to_has_registers = 1;
+  t->to_has_execution = 1;
+  t->to_magic = OPS_MAGIC;
+  ptrace_ops_hack = t;
+  return t;
+}
diff --git a/gdb/inf-ptrace.h b/gdb/inf-ptrace.h
new file mode 100644
index 00000000000..e9ceae3c963
--- /dev/null
+++ b/gdb/inf-ptrace.h
@@ -0,0 +1,31 @@
+/* Low level Unix child interface to ptrace, for GDB when running
+   under Unix.
+
+   Copyright 2004 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.  */
+
+#ifndef INF_PTRACE_H
+#define INF_PTRACE_H
+
+/* Create a prototype ptrace target.  The client can override it with
+   local methods.  */
+
+extern struct target_ops *inf_ptrace_target (void);
+
+#endif
diff --git a/gdb/ppcnbsd-nat.c b/gdb/ppcnbsd-nat.c
index 7fd84c0423b..6fa55d6bc01 100644
--- a/gdb/ppcnbsd-nat.c
+++ b/gdb/ppcnbsd-nat.c
@@ -35,6 +35,8 @@
 #include "ppc-tdep.h"
 #include "ppcnbsd-tdep.h"
 
+#include "inf-ptrace.h"
+
 /* Returns true if PT_GETREGS fetches this register.  */
 static int
 getregs_supplies (int regno)
@@ -73,8 +75,8 @@ getfpregs_supplies (int regno)
 	  || regno == tdep->ppc_fpscr_regnum);
 }
 
-void
-fetch_inferior_registers (int regno)
+static void
+ppcnbsd_fetch_inferior_registers (int regno)
 {
   if (regno == -1 || getregs_supplies (regno))
     {
@@ -103,8 +105,8 @@ fetch_inferior_registers (int regno)
     }
 }
 
-void
-store_inferior_registers (int regno)
+static void
+ppcnbsd_store_inferior_registers (int regno)
 {
   if (regno == -1 || getregs_supplies (regno))
     {
@@ -177,6 +179,12 @@ void _initialize_ppcnbsd_nat (void);
 void
 _initialize_ppcnbsd_nat (void)
 {
+  struct target_ops *t;
   /* Support debugging kernel virtual memory images.  */
   bsd_kvm_add_target (ppcnbsd_supply_pcb);
+  /* Add in local overrides.  */
+  t = inf_ptrace_target ();
+  t->to_fetch_registers = ppcnbsd_fetch_inferior_registers;
+  t->to_store_registers = ppcnbsd_store_inferior_registers;
+  add_target (t);
 }