[RFC] Patch to add kernel threads support for FreeBSD 6.1

[Fred Fish <fnf at specifix dot com>]

This patch adds support for kernel threads on FreeBSD 6.1.  There are
obviously some rough edges still, and I'd appreciate feedback from
people with FreeBSD experience and also experience with thread support
in gdb.

One thing that currently is broken according to the gdb testsuite
thread tests is thread local storage.

-Fred


2006-12-18  Fred Fish  <fnf@specifix.com>

	* Makefile.in (fbsd-threads.o): New target.
	* fbsd-threads.c: New file from FreeBSD 6.1, with tweaks.
	* i386bsd-nat.c: Add supply_gregset, supply_fpregset, fill_gregset,
	and fill_fpregset.
	* i386fbsd-nat.c (_initialize_i386fbsd_nat): Call thread_db_init
	with current target to save it as target_beneath.
	* inf-child.c:  Add global variable child_suppress_run.
	(inf_child_can_run): Return !child_suppress_run instead of 1.
	* config/i386/fbsd.mh (NATDEPFILES): Add fbsd-threads.o
	(LOADLIBES): Add -rdynamic.


Index: Makefile.in
===================================================================
RCS file: /services/cvs/cvsroot/latest/gdb/gdb/Makefile.in,v
retrieving revision 1.1.1.35.2.5
diff -u -p -r1.1.1.35.2.5 Makefile.in
--- Makefile.in	19 Jan 2007 05:21:06 -0000	1.1.1.35.2.5
+++ Makefile.in	7 Feb 2007 00:12:16 -0000
@@ -1989,6 +1989,13 @@ expprint.o: expprint.c $(defs_h) $(symta
 fbsd-nat.o: fbsd-nat.c $(defs_h) $(gdbcore_h) $(inferior_h) $(regcache_h) \
 	$(regset_h) $(gdb_assert_h) $(gdb_string_h) $(elf_bfd_h) \
 	$(fbsd_nat_h)
+fbsd-threads.o: $(defs_h) $(gdbthread_h) $(value_h) $(symtab_h) \
+	$(inferior_h) $(solib_h) $(gdb_assert_h) $(bfdlink_h) $(objfiles_h) \
+	$(dcache_h) $(target_h) $(memattr_h) $(symfile_h) $(regcache_h) \
+	$(command_h) $(ui_out_h) $(gdbcmd_h) $(gregset_h) $(solib_svr4_h) \
+	$(i387_tdep_h) $(gdb_obstack_h) $(gdb_events_h) $(expression_h) \
+	$(hashtab_h) $(gdbtypes_h) $(doublest_h) $(gdbcore_h) $(elf_external_h) \
+	$(elf_internal_h) $(elf_common_h) $(symcat_h) $(ui_file_h)
 f-exp.o: f-exp.c $(defs_h) $(gdb_string_h) $(expression_h) $(value_h) \
 	$(parser_defs_h) $(language_h) $(f_lang_h) $(bfd_h) $(symfile_h) \
 	$(objfiles_h) $(block_h)
Index: fbsd-threads.c
===================================================================
RCS file: fbsd-threads.c
diff -N fbsd-threads.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ fbsd-threads.c	7 Feb 2007 00:12:16 -0000
@@ -0,0 +1,1638 @@
+/* $FreeBSD: src/gnu/usr.bin/gdb/libgdb/fbsd-threads.c,v 1.13.2.1 2006/02/16 02:40:56 davidxu Exp $ */
+/* FreeBSD libthread_db assisted debugging support.
+   Copyright 1999, 2000, 2001 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 <dlfcn.h>
+#include <sys/types.h>
+#include <sys/ptrace.h>
+
+#include "proc_service.h"
+#include "thread_db.h"
+
+#include "defs.h"
+#include "bfd.h"
+#include "elf-bfd.h"
+#include "gdb_assert.h"
+#include "gdbcore.h"
+#include "gdbthread.h"
+#include "inferior.h"
+#include "objfiles.h"
+#include "regcache.h"
+#include "solib.h"
+#include "symfile.h"
+#include "symtab.h"
+#include "target.h"
+#include "gdbcmd.h"
+#include "solib-svr4.h"
+#include "gregset.h"
+#include "i387-tdep.h"
+
+#define LIBTHREAD_DB_SO "libthread_db.so"
+
+struct ps_prochandle
+{
+  pid_t pid;
+};
+
+extern int child_suppress_run;
+
+/* The target vector that we call for things this module can't handle.  */
+static struct target_ops *target_beneath;
+
+/* This module's target vectors.  */
+static struct target_ops fbsd_thread_ops;
+static struct target_ops fbsd_core_ops;
+
+/* Saved copy of orignal core_ops. */
+static struct target_ops orig_core_ops;
+extern struct target_ops core_ops;
+
+/* Pointer to the next function on the objfile event chain.  */
+static void (*target_new_objfile_chain) (struct objfile *objfile);
+
+/* Non-zero if there is a thread module */
+static int fbsd_thread_present;
+
+/* Non-zero if we're using this module's target vector.  */
+static int fbsd_thread_active;
+
+/* Non-zero if core_open is called */
+static int fbsd_thread_core = 0;
+
+/* Non-zero if we have to keep this module's target vector active
+   across re-runs.  */
+static int keep_thread_db;
+
+/* Structure that identifies the child process for the
+   <proc_service.h> interface.  */
+static struct ps_prochandle proc_handle;
+
+/* Connection to the libthread_db library.  */
+static td_thragent_t *thread_agent;
+
+/* The last thread we are single stepping */
+static ptid_t last_single_step_thread;
+
+/* Pointers to the libthread_db functions.  */
+
+static td_err_e (*td_init_p) (void);
+
+static td_err_e (*td_ta_new_p) (struct ps_prochandle *ps, td_thragent_t **ta);
+static td_err_e (*td_ta_delete_p) (td_thragent_t *);
+static td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt,
+				       td_thrhandle_t *__th);
+static td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta, lwpid_t lwpid,
+					td_thrhandle_t *th);
+static td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
+				     td_thr_iter_f *callback,
+				     void *cbdata_p, td_thr_state_e state,
+				     int ti_pri, sigset_t *ti_sigmask_p,
+				     unsigned int ti_user_flags);
+static td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
+				       td_event_e event, td_notify_t *ptr);
+static td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
+				      td_thr_events_t *event);
+static td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
+					 td_event_msg_t *msg);
+static td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
+				      td_thrinfo_t *infop);
+#ifdef PT_GETXMMREGS
+static td_err_e (*td_thr_getxmmregs_p) (const td_thrhandle_t *th,
+					char *regset);
+#endif
+static td_err_e (*td_thr_getfpregs_p) (const td_thrhandle_t *th,
+				       prfpregset_t *regset);
+static td_err_e (*td_thr_getgregs_p) (const td_thrhandle_t *th,
+				      prgregset_t gregs);
+#ifdef PT_GETXMMREGS
+static td_err_e (*td_thr_setxmmregs_p) (const td_thrhandle_t *th,
+					const char *fpregs);
+#endif
+static td_err_e (*td_thr_setfpregs_p) (const td_thrhandle_t *th,
+				       const prfpregset_t *fpregs);
+static td_err_e (*td_thr_setgregs_p) (const td_thrhandle_t *th,
+				      prgregset_t gregs);
+static td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th, int event);
+
+static td_err_e (*td_thr_sstep_p) (td_thrhandle_t *th, int step);
+
+static td_err_e (*td_ta_tsd_iter_p) (const td_thragent_t *ta,
+				 td_key_iter_f *func, void *data);
+static td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
+                                          void *map_address,
+                                          size_t offset, void **address);
+static td_err_e (*td_thr_dbsuspend_p) (const td_thrhandle_t *);
+static td_err_e (*td_thr_dbresume_p) (const td_thrhandle_t *);
+
+static CORE_ADDR td_create_bp_addr;
+
+/* Location of the thread death event breakpoint.  */
+static CORE_ADDR td_death_bp_addr;
+
+/* Prototypes for local functions.  */
+static void fbsd_thread_find_new_threads (void);
+static int fbsd_thread_alive (ptid_t ptid);
+static void attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
+               const td_thrinfo_t *ti_p, int verbose);
+static void fbsd_thread_detach (char *args, int from_tty);
+
+/* Building process ids.  */
+
+#define GET_PID(ptid)		ptid_get_pid (ptid)
+#define GET_LWP(ptid)		ptid_get_lwp (ptid)
+#define GET_THREAD(ptid)	ptid_get_tid (ptid)
+
+#define IS_LWP(ptid)		(GET_LWP (ptid) != 0)
+#define IS_THREAD(ptid)		(GET_THREAD (ptid) != 0)
+
+#define BUILD_LWP(lwp, pid)	ptid_build (pid, lwp, 0)
+#define BUILD_THREAD(tid, pid)	ptid_build (pid, 0, tid)
+
+static char *
+thread_db_err_str (td_err_e err)
+{
+  static char buf[64];
+
+  switch (err)
+    {
+    case TD_OK:
+      return "generic 'call succeeded'";
+    case TD_ERR:
+      return "generic error";
+    case TD_NOTHR:
+      return "no thread to satisfy query";
+    case TD_NOSV:
+      return "no sync handle to satisfy query";
+    case TD_NOLWP:
+      return "no LWP to satisfy query";
+    case TD_BADPH:
+      return "invalid process handle";
+    case TD_BADTH:
+      return "invalid thread handle";
+    case TD_BADSH:
+      return "invalid synchronization handle";
+    case TD_BADTA:
+      return "invalid thread agent";
+    case TD_BADKEY:
+      return "invalid key";
+    case TD_NOMSG:
+      return "no event message for getmsg";
+    case TD_NOFPREGS:
+      return "FPU register set not available";
+    case TD_NOLIBTHREAD:
+      return "application not linked with libthread";
+    case TD_NOEVENT:
+      return "requested event is not supported";
+    case TD_NOCAPAB:
+      return "capability not available";
+    case TD_DBERR:
+      return "debugger service failed";
+    case TD_NOAPLIC:
+      return "operation not applicable to";
+    case TD_NOTSD:
+      return "no thread-specific data for this thread";
+    case TD_MALLOC:
+      return "malloc failed";
+    case TD_PARTIALREG:
+      return "only part of register set was written/read";
+    case TD_NOXREGS:
+      return "X register set not available for this thread";
+    default:
+      snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
+      return buf;
+    }
+}
+
+static char *
+thread_db_state_str (td_thr_state_e state)
+{
+  static char buf[64];
+
+  switch (state)
+    {
+    case TD_THR_STOPPED:
+      return "stopped by debugger";
+    case TD_THR_RUN:
+      return "runnable";
+    case TD_THR_ACTIVE:
+      return "active";
+    case TD_THR_ZOMBIE:
+      return "zombie";
+    case TD_THR_SLEEP:
+      return "sleeping";
+    case TD_THR_STOPPED_ASLEEP:
+      return "stopped by debugger AND blocked";
+    default:
+      snprintf (buf, sizeof (buf), "unknown thread_db state %d", state);
+      return buf;
+    }
+}
+
+/* Convert LWP to user-level thread id. */
+static ptid_t
+thread_from_lwp (ptid_t ptid, td_thrhandle_t *th, td_thrinfo_t *ti)
+{
+  td_err_e err;
+ 
+  gdb_assert (IS_LWP (ptid));
+
+  if (fbsd_thread_active)
+    {
+      err = td_ta_map_lwp2thr_p (thread_agent, GET_LWP (ptid), th);
+      if (err == TD_OK)
+        {
+          err = td_thr_get_info_p (th, ti);
+          if (err != TD_OK)
+            error ("Cannot get thread info: %s", thread_db_err_str (err));
+          return BUILD_THREAD (ti->ti_tid, GET_PID (ptid));
+        }
+    }
+
+  /* the LWP is not mapped to user thread */  
+  return BUILD_LWP (GET_LWP (ptid), GET_PID (ptid));
+}
+
+static void
+fbsd_core_get_first_lwp (bfd *abfd, asection *asect, void *obj)
+{
+  if (strncmp (bfd_section_name (abfd, asect), ".reg/", 5) != 0)
+    return;
+
+  if (*(lwpid_t *)obj != 0)
+    return;
+
+  *(lwpid_t *)obj = atoi (bfd_section_name (abfd, asect) + 5);
+}
+
+static long
+get_current_lwp (int pid)
+{
+  struct ptrace_lwpinfo pl;
+  lwpid_t lwpid;
+
+  if (!target_has_execution)
+    {
+      lwpid = 0;
+      bfd_map_over_sections (core_bfd, fbsd_core_get_first_lwp, &lwpid);
+      return lwpid;
+    }
+  if (ptrace (PT_LWPINFO, pid, (caddr_t)&pl, sizeof(pl)))
+    perror_with_name("PT_LWPINFO");
+
+  return (long)pl.pl_lwpid;
+}
+
+static void
+get_current_thread ()
+{
+  td_thrhandle_t th;
+  td_thrinfo_t ti;
+  long lwp;
+  ptid_t tmp, ptid;
+
+  lwp = get_current_lwp (proc_handle.pid);
+  tmp = BUILD_LWP (lwp, proc_handle.pid);
+  ptid = thread_from_lwp (tmp, &th, &ti);
+  if (!in_thread_list (ptid))
+    {
+      attach_thread (ptid, &th, &ti, 1);
+    }
+  inferior_ptid = ptid;
+}
+
+static td_err_e
+enable_thread_event (td_thragent_t *thread_agent, int event, CORE_ADDR *bp)
+{
+  td_notify_t notify;
+  td_err_e err;
+
+  /* Get the breakpoint address for thread EVENT.  */
+  err = td_ta_event_addr_p (thread_agent, event, &notify);
+  if (err != TD_OK)
+    return err;
+
+  /* Set up the breakpoint.  */
+  (*bp) = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
+            extract_typed_address((const gdb_byte *)&notify.u.bptaddr, builtin_type_void_func_ptr),
+            &current_target);
+  create_thread_event_breakpoint ((*bp));
+
+  return TD_OK;
+}
+
+static void
+enable_thread_event_reporting (void)
+{
+  td_thr_events_t events;
+  td_notify_t notify;
+  td_err_e err;
+
+  /* We cannot use the thread event reporting facility if these
+     functions aren't available.  */
+  if (td_ta_event_addr_p == NULL || td_ta_set_event_p == NULL
+      || td_ta_event_getmsg_p == NULL || td_thr_event_enable_p == NULL)
+    return;
+
+  /* Set the process wide mask saying which events we're interested in.  */
+  td_event_emptyset (&events);
+  td_event_addset (&events, TD_CREATE);
+  td_event_addset (&events, TD_DEATH);
+
+  err = td_ta_set_event_p (thread_agent, &events);
+  if (err != TD_OK)
+    {
+      warning ("Unable to set global thread event mask: %s",
+	       thread_db_err_str (err));
+      return;
+    }
+
+  /* Delete previous thread event breakpoints, if any.  */
+  remove_thread_event_breakpoints ();
+  td_create_bp_addr = 0;
+  td_death_bp_addr = 0;
+
+  /* Set up the thread creation event.  */
+  err = enable_thread_event (thread_agent, TD_CREATE, &td_create_bp_addr);
+  if (err != TD_OK)
+    {
+      warning ("Unable to get location for thread creation breakpoint: %s",
+	       thread_db_err_str (err));
+      return;
+    }
+
+  /* Set up the thread death event.  */
+  err = enable_thread_event (thread_agent, TD_DEATH, &td_death_bp_addr);
+  if (err != TD_OK)
+    {
+      warning ("Unable to get location for thread death breakpoint: %s",
+	       thread_db_err_str (err));
+      return;
+    }
+}
+
+static void
+disable_thread_event_reporting (void)
+{
+  td_thr_events_t events;
+
+  /* Set the process wide mask saying we aren't interested in any
+     events anymore.  */
+  td_event_emptyset (&events);
+  td_ta_set_event_p (thread_agent, &events);
+
+  /* Delete thread event breakpoints, if any.  */
+  remove_thread_event_breakpoints ();
+  td_create_bp_addr = 0;
+  td_death_bp_addr = 0;
+}
+
+static void
+fbsd_thread_activate (void)
+{
+  fbsd_thread_active = 1;
+  init_thread_list();
+  if (fbsd_thread_core == 0)
+    enable_thread_event_reporting ();
+  fbsd_thread_find_new_threads ();
+  get_current_thread ();
+}
+
+static void
+fbsd_thread_deactivate (void)
+{
+  if (fbsd_thread_core == 0)
+    disable_thread_event_reporting();
+  td_ta_delete_p (thread_agent);
+
+  inferior_ptid = pid_to_ptid (proc_handle.pid);
+  proc_handle.pid = 0;
+  fbsd_thread_active = 0;
+  fbsd_thread_present = 0;
+  init_thread_list ();
+}
+
+static void
+fbsd_thread_new_objfile (struct objfile *objfile)
+{
+  td_err_e err;
+
+  if (objfile == NULL)
+    {
+      /* All symbols have been discarded.  If the thread_db target is
+         active, deactivate it now.  */
+      if (fbsd_thread_active)
+        {
+          gdb_assert (proc_handle.pid == 0);
+          fbsd_thread_active = 0;
+        }
+
+      goto quit;
+    }
+
+  if (!child_suppress_run)
+    goto quit;
+
+  /* Nothing to do.  The thread library was already detected and the
+     target vector was already activated.  */
+  if (fbsd_thread_active)
+    goto quit;
+
+  /* Initialize the structure that identifies the child process.  Note
+     that at this point there is no guarantee that we actually have a
+     child process.  */
+  proc_handle.pid = GET_PID (inferior_ptid);
+  
+  /* Now attempt to open a connection to the thread library.  */
+  err = td_ta_new_p (&proc_handle, &thread_agent);
+  switch (err)
+    {
+    case TD_NOLIBTHREAD:
+      /* No thread library was detected.  */
+      break;
+
+    case TD_OK:
+      /* The thread library was detected.  Activate the thread_db target.  */
+      fbsd_thread_present = 1;
+
+      /* We can only poke around if there actually is a child process.
+         If there is no child process alive, postpone the steps below
+         until one has been created.  */
+      if (fbsd_thread_core == 0 && proc_handle.pid != 0)
+        {
+          push_target(&fbsd_thread_ops);
+          fbsd_thread_activate();
+        }
+      else
+        {
+          td_ta_delete_p(thread_agent);
+          thread_agent = NULL;
+        }
+      break;
+
+    default:
+      warning ("Cannot initialize thread debugging library: %s",
+               thread_db_err_str (err));
+      break;
+    }
+
+ quit:
+  if (target_new_objfile_chain)
+    target_new_objfile_chain (objfile);
+}
+
+static void
+fbsd_thread_attach (char *args, int from_tty)
+{
+  fbsd_thread_core = 0;
+
+  target_beneath->to_attach (args, from_tty);
+
+  /* Must get symbols from solibs before libthread_db can run! */
+  solib_add (NULL, from_tty, (struct target_ops *) 0, auto_solib_add);
+
+  if (fbsd_thread_present && !fbsd_thread_active)
+    push_target(&fbsd_thread_ops);
+}
+
+static void
+fbsd_thread_post_attach (int pid)
+{
+  target_beneath->to_post_attach (pid);
+
+  if (fbsd_thread_present && !fbsd_thread_active)
+    {
+      proc_handle.pid = GET_PID (inferior_ptid);
+      fbsd_thread_activate ();
+    }
+}
+
+static void
+fbsd_thread_detach (char *args, int from_tty)
+{
+  fbsd_thread_deactivate ();
+  unpush_target (&fbsd_thread_ops);
+
+  /* Clear gdb solib information and symbol file
+     cache, so that after detach and re-attach, new_objfile
+     hook will be called */
+
+  clear_solib();
+  symbol_file_clear(0);
+  proc_handle.pid = 0;
+  target_beneath->to_detach (args, from_tty);
+}
+
+static int
+suspend_thread_callback (const td_thrhandle_t *th_p, void *data)
+{
+  int err = td_thr_dbsuspend_p (th_p);
+  if (err != 0)
+	fprintf_filtered(gdb_stderr, "%s %s\n", __func__, thread_db_err_str (err));
+  return (err);
+}
+
+static int
+resume_thread_callback (const td_thrhandle_t *th_p, void *data)
+{
+  int err = td_thr_dbresume_p (th_p);
+  if (err != 0)
+	fprintf_filtered(gdb_stderr, "%s %s\n", __func__, thread_db_err_str (err));
+  return (err);
+}
+
+static void
+fbsd_thread_resume (ptid_t ptid, int step, enum target_signal signo)
+{
+  td_thrhandle_t th;
+  td_thrinfo_t ti;
+  ptid_t work_ptid;
+  int resume_all, ret;
+  long lwp, thvalid = 0;
+
+  if (!fbsd_thread_active)
+    {
+      target_beneath->to_resume (ptid, step, signo);
+      return;
+    }
+
+  if (GET_PID(ptid) != -1 && step != 0)
+    {
+      resume_all = 0;
+      work_ptid = ptid;
+    }
+  else
+    {
+      resume_all = 1;
+      work_ptid = inferior_ptid;
+    }
+
+  lwp = GET_LWP (work_ptid);
+  if (lwp == 0)
+    {
+      /* check user thread */
+      ret = td_ta_map_id2thr_p (thread_agent, GET_THREAD(work_ptid), &th);
+      if (ret)
+        error (_("Cannot find thread: %s"),thread_db_err_str (ret));
+
+      /* For M:N thread, we need to tell UTS to set/unset single step
+         flag at context switch time, the flag will be written into
+         thread mailbox. This becauses some architecture may not have
+         machine single step flag in ucontext, so we put the flag in mailbox,
+         when the thread switches back, kse_switchin restores the single step
+         state.  */
+      ret = td_thr_sstep_p (&th, step);
+      if (ret)
+        error (_("Cannot set/unset single step flag: %s"),thread_db_err_str (ret));
+      ret = td_thr_get_info_p (&th, &ti);
+      if (ret)
+        error (_("Cannot get thread info: %s"),thread_db_err_str (ret));
+      thvalid = 1;
+      lwp = ti.ti_lid;
+    }
+
+  if (lwp)
+    {
+      int req = step ? PT_SETSTEP : PT_CLEARSTEP;
+      if (ptrace (req, (pid_t) lwp, (caddr_t) 1, target_signal_to_host(signo)))
+        perror_with_name ("PT_SETSTEP/PT_CLEARSTEP");
+    }
+
+  if (!ptid_equal (last_single_step_thread, null_ptid))
+    {
+       ret = td_ta_thr_iter_p (thread_agent, resume_thread_callback, NULL,
+          TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
+          TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
+      if (ret != TD_OK)
+        error ("resume error: %s", thread_db_err_str (ret));
+    }
+
+  if (!resume_all)
+    {
+      ret = td_ta_thr_iter_p (thread_agent, suspend_thread_callback, NULL,
+          TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
+          TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
+      if (ret != TD_OK)
+        error ("suspend error: %s", thread_db_err_str (ret));
+      last_single_step_thread = work_ptid;
+    }
+  else
+    last_single_step_thread = null_ptid;
+
+  if (thvalid)
+    {
+      ret = td_thr_dbresume_p (&th);
+      if (ret != TD_OK)
+        error ("resume error: %s", thread_db_err_str (ret));
+    }
+  else
+    {
+      /* it is not necessary, put it here for completness */
+      ret = ptrace(PT_RESUME, lwp, 0, 0);
+    }
+
+  /* now continue the process, suspended thread wont run */
+  if (ptrace (PT_CONTINUE, proc_handle.pid , (caddr_t)1,
+	      target_signal_to_host(signo)))
+    perror_with_name ("PT_CONTINUE");
+}
+
+static void
+attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
+               const td_thrinfo_t *ti_p, int verbose)
+{
+  td_err_e err;
+
+  /* Add the thread to GDB's thread list.  */
+  if (!in_thread_list (ptid)) {
+    add_thread (ptid);
+    if (verbose)
+      printf_unfiltered ("[New %s]\n", target_pid_to_str (ptid));
+  }
+
+  if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
+    return;                     /* A zombie thread -- do not attach.  */
+
+  if (! IS_THREAD(ptid))
+    return;
+  if (fbsd_thread_core != 0)
+    return;
+  /* Enable thread event reporting for this thread. */
+  err = td_thr_event_enable_p (th_p, 1);
+  if (err != TD_OK)
+    error ("Cannot enable thread event reporting for %s: %s",
+           target_pid_to_str (ptid), thread_db_err_str (err));
+}
+
+static void
+detach_thread (ptid_t ptid, int verbose)
+{
+  if (verbose)
+    printf_unfiltered ("[%s exited]\n", target_pid_to_str (ptid));
+}
+
+static void
+check_event (ptid_t ptid)
+{
+  td_event_msg_t msg;
+  td_thrinfo_t ti;
+  td_err_e err;
+  CORE_ADDR stop_pc;
+  int loop = 0;
+
+  /* Bail out early if we're not at a thread event breakpoint.  */
+  stop_pc = read_pc_pid (ptid) - DECR_PC_AFTER_BREAK;
+  if (stop_pc != td_create_bp_addr && stop_pc != td_death_bp_addr)
+    return;
+  loop = 1;
+
+  do
+    {
+      err = td_ta_event_getmsg_p (thread_agent, &msg);
+      if (err != TD_OK)
+        {
+	  if (err == TD_NOMSG)
+	    return;
+          error ("Cannot get thread event message: %s",
+		 thread_db_err_str (err));
+        }
+      err = td_thr_get_info_p (msg.th_p, &ti);
+      if (err != TD_OK)
+        error ("Cannot get thread info: %s", thread_db_err_str (err));
+      ptid = BUILD_THREAD (ti.ti_tid, GET_PID (ptid));
+      switch (msg.event)
+        {
+        case TD_CREATE:
+          /* We may already know about this thread, for instance when the
+             user has issued the `info threads' command before the SIGTRAP
+             for hitting the thread creation breakpoint was reported.  */
+          attach_thread (ptid, msg.th_p, &ti, 1);
+          break;
+       case TD_DEATH:
+         if (!in_thread_list (ptid))
+           error ("Spurious thread death event.");
+         detach_thread (ptid, 1);
+         break;
+       default:
+          error ("Spurious thread event.");
+       }
+    }
+  while (loop);
+}
+
+static ptid_t
+fbsd_thread_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
+{
+  ptid_t ret;
+  long lwp;
+  CORE_ADDR stop_pc;
+  td_thrhandle_t th;
+  td_thrinfo_t ti;
+
+  ret = target_beneath->to_wait (ptid, ourstatus);
+  if (GET_PID(ret) >= 0 && ourstatus->kind == TARGET_WAITKIND_STOPPED)
+    {
+      lwp = get_current_lwp (GET_PID(ret));
+      ret = thread_from_lwp (BUILD_LWP(lwp, GET_PID(ret)),
+         &th, &ti);
+      if (!in_thread_list(ret)) {
+        /*
+         * We have to enable event reporting for initial thread
+         * which was not mapped before.
+	 */
+        attach_thread(ret, &th, &ti, 1);
+      }
+      if (ourstatus->value.sig == TARGET_SIGNAL_TRAP)
+        check_event(ret);
+      /* this is a hack, if an event won't cause gdb to stop, for example,
+         SIGARLM, gdb resumes the process immediatly without setting
+         inferior_ptid to the new thread returned here, this is a bug
+         because inferior_ptid may already not exist there, and passing
+         a none existing thread to fbsd_thread_resume causes error. */
+      if (!fbsd_thread_alive (inferior_ptid))
+        {
+          delete_thread (inferior_ptid);
+          inferior_ptid = ret;
+        }
+    }
+
+  return (ret);
+}
+
+static LONGEST
+fbsd_thread_xfer_partial (struct target_ops *ops, enum target_object object,
+			  const char *annex, gdb_byte *readbuf,
+			  const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
+{
+  struct cleanup *old_chain = save_inferior_ptid ();
+  LONGEST xfer;
+
+#if 0
+  if (is_thread (inferior_ptid))
+    {
+      /* FIXME: This seems to be necessary to make sure breakpoints
+         are removed.  */
+      if (!target_thread_alive (inferior_ptid))
+	inferior_ptid = pid_to_ptid (GET_PID (inferior_ptid));
+      else
+	inferior_ptid = lwp_from_thread (inferior_ptid);
+    }
+#endif
+
+  xfer = target_beneath->to_xfer_partial (ops, object, annex,
+					  readbuf, writebuf, offset, len);
+
+  do_cleanups (old_chain);
+  return xfer;
+}
+
+static void
+fbsd_lwp_fetch_registers (int regno)
+{
+  gregset_t gregs;
+  fpregset_t fpregs;
+  lwpid_t lwp;
+#ifdef PT_GETXMMREGS
+  char xmmregs[512];
+#endif
+
+  if (!target_has_execution)
+    {
+      orig_core_ops.to_fetch_registers (-1);
+      return;
+    }
+
+  /* XXX: We've replaced the pid with the lwpid for GDB's benefit. */
+  lwp = GET_PID (inferior_ptid);
+
+  if (ptrace (PT_GETREGS, lwp, (caddr_t) &gregs, 0) == -1)
+    error ("Cannot get lwp %d registers: %s\n", lwp, safe_strerror (errno));
+  supply_gregset (&gregs);
+  
+#ifdef PT_GETXMMREGS
+  if (ptrace (PT_GETXMMREGS, lwp, xmmregs, 0) == 0)
+    {
+      i387_supply_fxsave (current_regcache, -1, xmmregs);
+    }
+  else
+    {
+#endif
+      if (ptrace (PT_GETFPREGS, lwp, (caddr_t) &fpregs, 0) == -1)
+	error ("Cannot get lwp %d registers: %s\n ", lwp, safe_strerror (errno));
+      supply_fpregset (&fpregs);
+#ifdef PT_GETXMMREGS
+    }
+#endif
+}
+
+static void
+fbsd_thread_fetch_registers (int regno)
+{
+  prgregset_t gregset;
+  prfpregset_t fpregset;
+  td_thrhandle_t th;
+  td_err_e err;
+#ifdef PT_GETXMMREGS
+  char xmmregs[512];
+#endif
+
+  if (!IS_THREAD (inferior_ptid))
+    {
+      fbsd_lwp_fetch_registers (regno);
+      return;
+    }
+
+  err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (inferior_ptid), &th);
+  if (err != TD_OK)
+    error ("Cannot find thread %d: Thread ID=%ld, %s",
+           pid_to_thread_id (inferior_ptid),           
+           GET_THREAD (inferior_ptid), thread_db_err_str (err));
+
+  err = td_thr_getgregs_p (&th, gregset);
+  if (err != TD_OK)
+    error ("Cannot fetch general-purpose registers for thread %d: Thread ID=%ld, %s",
+           pid_to_thread_id (inferior_ptid),
+           GET_THREAD (inferior_ptid), thread_db_err_str (err));
+#ifdef PT_GETXMMREGS
+  err = td_thr_getxmmregs_p (&th, xmmregs);
+  if (err == TD_OK)
+    {
+      i387_supply_fxsave (current_regcache, -1, xmmregs);
+    }
+  else
+    {
+#endif
+      err = td_thr_getfpregs_p (&th, &fpregset);
+      if (err != TD_OK)
+	error ("Cannot get floating-point registers for thread %d: Thread ID=%ld, %s",
+	       pid_to_thread_id (inferior_ptid),
+	       GET_THREAD (inferior_ptid), thread_db_err_str (err));
+      supply_fpregset (&fpregset);
+#ifdef PT_GETXMMREGS
+    }
+#endif
+
+  supply_gregset (gregset);
+}
+
+static void
+fbsd_lwp_store_registers (int regno)
+{
+  gregset_t gregs;
+  fpregset_t fpregs;
+  lwpid_t lwp;
+#ifdef PT_GETXMMREGS
+  char xmmregs[512];
+#endif
+
+  /* FIXME, is it possible ? */
+  if (!IS_LWP (inferior_ptid))
+    {
+      target_beneath->to_store_registers (regno);
+      return ;
+    }
+
+  lwp = GET_LWP (inferior_ptid);
+  if (regno != -1)
+    if (ptrace (PT_GETREGS, lwp, (caddr_t) &gregs, 0) == -1)
+      error ("Cannot get lwp %d registers: %s\n", lwp, safe_strerror (errno));
+
+  fill_gregset (&gregs, regno);
+  if (ptrace (PT_SETREGS, lwp, (caddr_t) &gregs, 0) == -1)
+      error ("Cannot set lwp %d registers: %s\n", lwp, safe_strerror (errno));
+
+#ifdef PT_GETXMMREGS
+  if (regno != -1)
+    if (ptrace (PT_GETXMMREGS, lwp, xmmregs, 0) == -1)
+      goto noxmm;
+
+  i387_fill_fxsave (xmmregs, regno);
+  if (ptrace (PT_SETXMMREGS, lwp, xmmregs, 0) == -1)
+    goto noxmm;
+
+  return;
+
+noxmm:
+#endif
+
+  if (regno != -1)
+    if (ptrace (PT_GETFPREGS, lwp, (caddr_t) &fpregs, 0) == -1)
+      error ("Cannot get lwp %d float registers: %s\n", lwp,
+             safe_strerror (errno));
+
+  fill_fpregset (&fpregs, regno);
+  if (ptrace (PT_SETFPREGS, lwp, (caddr_t) &fpregs, 0) == -1)
+     error ("Cannot set lwp %d float registers: %s\n", lwp,
+            safe_strerror (errno));
+}
+
+static void
+fbsd_thread_store_registers (int regno)
+{
+  prgregset_t gregset;
+  prfpregset_t fpregset;
+  td_thrhandle_t th;
+  td_err_e err;
+#ifdef PT_GETXMMREGS
+  char xmmregs[512];
+#endif
+
+  if (!IS_THREAD (inferior_ptid))
+    {
+      fbsd_lwp_store_registers (regno);
+      return;
+    }
+
+  err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (inferior_ptid), &th);
+  if (err != TD_OK)
+    error ("Cannot find thread %d: Thread ID=%ld, %s",
+           pid_to_thread_id (inferior_ptid),
+           GET_THREAD (inferior_ptid),
+           thread_db_err_str (err));
+
+  if (regno != -1)
+    {
+      char old_value[MAX_REGISTER_SIZE];
+
+      regcache_raw_collect (current_regcache, regno, old_value);
+      err = td_thr_getgregs_p (&th, gregset);
+      if (err != TD_OK)
+        error ("%s: td_thr_getgregs %s", __func__, thread_db_err_str (err));
+      err = td_thr_getfpregs_p (&th, &fpregset);
+      if (err != TD_OK)
+        error ("%s: td_thr_getfpgregs %s", __func__, thread_db_err_str (err));
+      regcache_raw_supply (current_regcache, regno, old_value);
+    }
+
+  fill_gregset (gregset, regno);
+  fill_fpregset (&fpregset, regno);
+#ifdef PT_GETXMMREGS
+  i387_fill_fxsave (xmmregs, regno);
+#endif
+
+  err = td_thr_setgregs_p (&th, gregset);
+  if (err != TD_OK)
+    error ("Cannot store general-purpose registers for thread %d: Thread ID=%ld, %s",
+           pid_to_thread_id (inferior_ptid), GET_THREAD (inferior_ptid),
+           thread_db_err_str (err));
+
+#ifdef PT_GETXMMREGS
+  err = td_thr_setxmmregs_p (&th, xmmregs);
+  if (err == TD_OK)
+    return;
+#endif
+
+  err = td_thr_setfpregs_p (&th, &fpregset);
+  if (err != TD_OK)
+    error ("Cannot store floating-point registers for thread %d: Thread ID=%ld, %s",
+           pid_to_thread_id (inferior_ptid), GET_THREAD (inferior_ptid),
+           thread_db_err_str (err));
+}
+
+static void
+fbsd_thread_kill (void)
+{
+  target_beneath->to_kill();
+}
+
+static int
+fbsd_thread_can_run (void)
+{
+  return child_suppress_run;
+}
+
+static void
+fbsd_thread_create_inferior (char *exec_file, char *allargs, char **env, int from_tty)
+{
+  if (fbsd_thread_present && !fbsd_thread_active)
+    push_target(&fbsd_thread_ops);
+
+  target_beneath->to_create_inferior (exec_file, allargs, env, from_tty);
+}
+
+static void
+fbsd_thread_post_startup_inferior (ptid_t ptid)
+{
+  if (fbsd_thread_present && !fbsd_thread_active)
+    {
+      /* The child process is now the actual multi-threaded
+         program.  Snatch its process ID... */
+      proc_handle.pid = GET_PID (ptid);
+      td_ta_new_p (&proc_handle, &thread_agent);
+      fbsd_thread_activate();
+    }
+}
+
+static void
+fbsd_thread_mourn_inferior (void)
+{
+  if (fbsd_thread_active)
+    fbsd_thread_deactivate ();
+
+  unpush_target (&fbsd_thread_ops);
+
+  target_beneath->to_mourn_inferior ();
+}
+
+static void
+fbsd_core_check_lwp (bfd *abfd, asection *asect, void *obj)
+{
+  lwpid_t lwp;
+
+  if (strncmp (bfd_section_name (abfd, asect), ".reg/", 5) != 0)
+    return;
+
+  /* already found */
+  if (*(lwpid_t *)obj == 0)
+    return;
+
+  lwp = atoi (bfd_section_name (abfd, asect) + 5);
+  if (*(lwpid_t *)obj == lwp)
+    *(lwpid_t *)obj = 0;
+}
+
+static int
+fbsd_thread_alive (ptid_t ptid)
+{
+  td_thrhandle_t th;
+  td_thrinfo_t ti;
+  td_err_e err;
+  gregset_t gregs;
+  lwpid_t lwp;
+
+  if (IS_THREAD (ptid))
+    {
+      err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (ptid), &th);
+      if (err != TD_OK)
+        return 0;
+
+      err = td_thr_get_info_p (&th, &ti);
+      if (err != TD_OK)
+        return 0;
+
+      /* A zombie thread. */
+      if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
+        return 0;
+
+      return 1;
+    }
+  else if (GET_LWP (ptid) == 0)
+    {
+      /* we sometimes are called with lwp == 0 */
+      return 1;
+    }
+
+  if (fbsd_thread_active)
+    {
+      err = td_ta_map_lwp2thr_p (thread_agent, GET_LWP (ptid), &th);
+
+      /*
+       * if the lwp was already mapped to user thread, don't use it
+       * directly, please use user thread id instead.
+       */
+      if (err == TD_OK)
+        return 0;
+    }
+
+  if (!target_has_execution)
+    {
+      lwp = GET_LWP (ptid);
+      bfd_map_over_sections (core_bfd, fbsd_core_check_lwp, &lwp);
+      return (lwp == 0); 
+    }
+
+  /* check lwp in kernel */
+  return ptrace (PT_GETREGS, GET_LWP (ptid), (caddr_t)&gregs, 0) == 0;
+}
+
+static void
+fbsd_thread_files_info (struct target_ops *ignore)
+{
+  target_beneath->to_files_info (ignore);
+}
+
+static int
+find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
+{
+  td_thrinfo_t ti;
+  td_err_e err;
+  ptid_t ptid;
+
+  err = td_thr_get_info_p (th_p, &ti);
+  if (err != TD_OK)
+    error ("Cannot get thread info: %s", thread_db_err_str (err));
+
+  /* Ignore zombie */
+  if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
+    return 0;
+
+  ptid = BUILD_THREAD (ti.ti_tid, proc_handle.pid);
+  attach_thread (ptid, th_p, &ti, 1);
+  return 0;
+}
+
+static void
+fbsd_thread_find_new_threads (void)
+{
+  td_err_e err;
+
+  if (!fbsd_thread_active)
+    return;
+
+  /* Iterate over all user-space threads to discover new threads. */
+  err = td_ta_thr_iter_p (thread_agent, find_new_threads_callback, NULL,
+          TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
+          TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
+  if (err != TD_OK)
+    error ("Cannot find new threads: %s", thread_db_err_str (err));
+}
+
+static char *
+fbsd_thread_pid_to_str (ptid_t ptid)
+{
+  static char buf[64];
+
+  if (IS_THREAD (ptid))
+    {
+      td_thrhandle_t th;
+      td_thrinfo_t ti;
+      td_err_e err;
+
+      err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (ptid), &th);
+      if (err != TD_OK)
+        error ("Cannot find thread, Thread ID=%ld, %s",
+                GET_THREAD (ptid), thread_db_err_str (err));
+
+      err = td_thr_get_info_p (&th, &ti);
+      if (err != TD_OK)
+        error ("Cannot get thread info, Thread ID=%ld, %s",
+               GET_THREAD (ptid), thread_db_err_str (err));
+
+      if (ti.ti_lid != 0)
+        {
+          snprintf (buf, sizeof (buf), "Thread %p (LWP %d)",
+                    th.th_thread, ti.ti_lid);
+        }
+      else
+        {
+          snprintf (buf, sizeof (buf), "Thread %p (%s)",
+                    th.th_thread, thread_db_state_str (ti.ti_state));
+        }
+
+      return buf;
+    }
+  else if (IS_LWP (ptid))
+    {
+      snprintf (buf, sizeof (buf), "LWP %d", (int) GET_LWP (ptid));
+      return buf;
+    }
+  return normal_pid_to_str (ptid);
+}
+
+CORE_ADDR
+fbsd_thread_get_local_address(ptid_t ptid, CORE_ADDR lm, CORE_ADDR offset)
+{
+  td_thrhandle_t th;
+  void *address;
+  void *lm2;
+  int ret;
+
+  if (IS_THREAD (ptid))
+    {
+      if (!td_thr_tls_get_addr_p)
+        error ("Cannot find thread-local interface in thread_db library.");
+
+      ret = td_ta_map_id2thr_p (thread_agent, GET_THREAD(ptid), &th);
+
+      /* get the address of the variable. */
+      store_typed_address((gdb_byte *)&lm2, builtin_type_void_data_ptr, lm);
+      ret = td_thr_tls_get_addr_p (&th, lm2, offset, &address);
+
+      if (ret != TD_OK)
+        {
+	  error ("Cannot find thread-local storage for thread %ld: %s",
+		 (long) GET_THREAD (ptid), thread_db_err_str (ret));
+        }
+
+      /* Cast assuming host == target. */
+      return extract_typed_address((const gdb_byte *)&address, builtin_type_void_data_ptr);
+    }
+  return (0);
+}
+
+static int
+tsd_cb (thread_key_t key, void (*destructor)(void *), void *ignore)
+{
+  struct minimal_symbol *ms;
+  char *name;
+
+  ms = lookup_minimal_symbol_by_pc (
+	extract_typed_address((const gdb_byte *)&destructor, builtin_type_void_func_ptr));
+  if (!ms)
+    name = "???";
+  else
+    name = DEPRECATED_SYMBOL_NAME (ms);
+
+  printf_filtered ("Destructor %p <%s>\n", destructor, name);
+  return 0;
+}
+
+static void
+fbsd_thread_tsd_cmd (char *exp, int from_tty)
+{
+  if (fbsd_thread_active)
+    td_ta_tsd_iter_p (thread_agent, tsd_cb, NULL);
+}
+
+static int
+ignore (CORE_ADDR addr, char *contents)
+{
+  return 0;
+}
+
+static void
+fbsd_core_open (char *filename, int from_tty)
+{
+  int err;
+
+  fbsd_thread_core = 1;
+
+  orig_core_ops.to_open (filename, from_tty);
+
+  if (fbsd_thread_present)
+    {
+      err = td_ta_new_p (&proc_handle, &thread_agent);
+      if (err == TD_OK)
+        {
+          proc_handle.pid = elf_tdata (core_bfd)->core_pid;
+          fbsd_thread_activate ();
+        }
+      else
+        error ("fbsd_core_open: td_ta_new: %s", thread_db_err_str (err));
+    }
+}
+
+static void
+fbsd_core_close (int quitting)
+{
+  orig_core_ops.to_close (quitting);
+}
+
+static void
+fbsd_core_detach (char *args, int from_tty)
+{
+  if (fbsd_thread_active)
+    fbsd_thread_deactivate ();
+  unpush_target (&fbsd_thread_ops);
+  orig_core_ops.to_detach (args, from_tty);
+ 
+  /* Clear gdb solib information and symbol file
+     cache, so that after detach and re-attach, new_objfile
+     hook will be called */
+  clear_solib();
+  symbol_file_clear(0);
+}
+
+static void
+fbsd_core_files_info (struct target_ops *ignore)
+{
+  orig_core_ops.to_files_info (ignore);
+}
+
+static void
+init_fbsd_core_ops (void)
+{
+  fbsd_core_ops.to_shortname = "FreeBSD-core";
+  fbsd_core_ops.to_longname = "FreeBSD core thread.";
+  fbsd_core_ops.to_doc = "FreeBSD threads support for core files.";
+  fbsd_core_ops.to_open = fbsd_core_open;
+  fbsd_core_ops.to_close = fbsd_core_close;
+  fbsd_core_ops.to_attach = 0;
+  fbsd_core_ops.to_post_attach = 0;
+  fbsd_core_ops.to_detach = fbsd_core_detach;
+  /* fbsd_core_ops.to_resume  = 0; */
+  /* fbsd_core_ops.to_wait  = 0;  */
+  fbsd_core_ops.to_fetch_registers = fbsd_thread_fetch_registers;
+  /* fbsd_core_ops.to_store_registers  = 0; */
+  /* fbsd_core_ops.to_prepare_to_store  = 0; */
+  fbsd_core_ops.to_xfer_partial = fbsd_thread_xfer_partial;
+  fbsd_core_ops.to_files_info = fbsd_core_files_info;
+  fbsd_core_ops.to_insert_breakpoint = ignore;
+  fbsd_core_ops.to_remove_breakpoint = ignore;
+  /* fbsd_core_ops.to_lookup_symbol  = 0; */
+  fbsd_core_ops.to_create_inferior = fbsd_thread_create_inferior;
+  fbsd_core_ops.to_stratum = core_stratum;
+  fbsd_core_ops.to_has_all_memory = 0;
+  fbsd_core_ops.to_has_memory = 1;
+  fbsd_core_ops.to_has_stack = 1;
+  fbsd_core_ops.to_has_registers = 1;
+  fbsd_core_ops.to_has_execution = 0;
+  fbsd_core_ops.to_has_thread_control = tc_none;
+  fbsd_core_ops.to_thread_alive = fbsd_thread_alive;
+  fbsd_core_ops.to_pid_to_str = fbsd_thread_pid_to_str;
+  fbsd_core_ops.to_find_new_threads = fbsd_thread_find_new_threads;
+  fbsd_core_ops.to_sections = 0;
+  fbsd_core_ops.to_sections_end = 0;
+  fbsd_core_ops.to_magic = OPS_MAGIC;
+}
+
+static void
+init_fbsd_thread_ops (void)
+{
+  fbsd_thread_ops.to_shortname = "freebsd-threads";
+  fbsd_thread_ops.to_longname = "FreeBSD multithreaded child process.";
+  fbsd_thread_ops.to_doc = "FreeBSD threads support.";
+  fbsd_thread_ops.to_attach = fbsd_thread_attach;
+  fbsd_thread_ops.to_detach = fbsd_thread_detach;
+  fbsd_thread_ops.to_post_attach = fbsd_thread_post_attach;
+  fbsd_thread_ops.to_resume = fbsd_thread_resume;
+  fbsd_thread_ops.to_wait = fbsd_thread_wait;
+  fbsd_thread_ops.to_fetch_registers = fbsd_thread_fetch_registers;
+  fbsd_thread_ops.to_store_registers = fbsd_thread_store_registers;
+  fbsd_thread_ops.to_xfer_partial = fbsd_thread_xfer_partial;
+  fbsd_thread_ops.to_files_info = fbsd_thread_files_info;
+  fbsd_thread_ops.to_kill = fbsd_thread_kill;
+  fbsd_thread_ops.to_create_inferior = fbsd_thread_create_inferior;
+  fbsd_thread_ops.to_post_startup_inferior = fbsd_thread_post_startup_inferior;
+  fbsd_thread_ops.to_mourn_inferior = fbsd_thread_mourn_inferior;
+  fbsd_thread_ops.to_can_run = fbsd_thread_can_run;
+  fbsd_thread_ops.to_thread_alive = fbsd_thread_alive;
+  fbsd_thread_ops.to_find_new_threads = fbsd_thread_find_new_threads;
+  fbsd_thread_ops.to_pid_to_str = fbsd_thread_pid_to_str;
+  fbsd_thread_ops.to_stratum = thread_stratum;
+  fbsd_thread_ops.to_has_thread_control = tc_none;
+  fbsd_thread_ops.to_has_all_memory = 1;
+  fbsd_thread_ops.to_has_memory = 1;
+  fbsd_thread_ops.to_has_stack = 1;
+  fbsd_thread_ops.to_has_registers = 1;
+  fbsd_thread_ops.to_has_execution = 1;
+  fbsd_thread_ops.to_insert_breakpoint = memory_insert_breakpoint;
+  fbsd_thread_ops.to_remove_breakpoint = memory_remove_breakpoint;
+  fbsd_thread_ops.to_get_thread_local_address = fbsd_thread_get_local_address;
+  fbsd_thread_ops.to_magic = OPS_MAGIC;
+}
+
+static int
+thread_db_load (void)
+{
+  void *handle;
+  td_err_e err;
+
+  handle = dlopen (LIBTHREAD_DB_SO, RTLD_NOW);
+  if (handle == NULL)
+      return 0;
+
+#define resolve(X)			\
+ if (!(X##_p = dlsym (handle, #X)))	\
+   return 0;
+
+  resolve(td_init);
+  resolve(td_ta_new);
+  resolve(td_ta_delete);
+  resolve(td_ta_map_id2thr);
+  resolve(td_ta_map_lwp2thr);
+  resolve(td_ta_thr_iter);
+  resolve(td_thr_get_info);
+#ifdef PT_GETXMMREGS
+  resolve(td_thr_getxmmregs);
+#endif
+  resolve(td_thr_getfpregs);
+  resolve(td_thr_getgregs);
+#ifdef PT_GETXMMREGS
+  resolve(td_thr_setxmmregs);
+#endif
+  resolve(td_thr_setfpregs);
+  resolve(td_thr_setgregs);
+  resolve(td_thr_sstep);
+  resolve(td_ta_tsd_iter);
+  resolve(td_thr_dbsuspend);
+  resolve(td_thr_dbresume);
+  resolve(td_thr_tls_get_addr);
+
+  /* Initialize the library.  */
+  err = td_init_p ();
+  if (err != TD_OK)
+    {
+      warning ("Cannot initialize libthread_db: %s", thread_db_err_str (err));
+      return 0;
+    }
+
+  /* These are not essential.  */
+  td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr");
+  td_ta_set_event_p = dlsym (handle, "td_ta_set_event");
+  td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg");
+  td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable");
+  td_thr_tls_get_addr_p = dlsym (handle, "td_thr_tls_get_addr");
+  
+  return 1;
+}
+
+void
+thread_db_init (struct target_ops *target)
+{
+  target_beneath = target;
+}
+
+/* we suppress the call to add_target of core_ops in corelow because
+   if there are two targets in the stratum core_stratum, find_core_target
+   won't know which one to return.  see corelow.c for an additonal
+   comment on coreops_suppress_target. */
+
+int coreops_suppress_target = 1;
+
+void
+_initialize_thread_db (void)
+{
+  init_fbsd_thread_ops ();
+  init_fbsd_core_ops ();
+
+  if (thread_db_load ())
+    {
+      add_target (&fbsd_thread_ops);
+
+      /* "thread tsd" command */
+      add_cmd ("tsd", class_run, fbsd_thread_tsd_cmd,
+            "Show the thread-specific data keys and destructors "
+            "for the process.\n",
+           &thread_cmd_list);
+
+      memcpy (&orig_core_ops, &core_ops, sizeof (struct target_ops));
+      memcpy (&core_ops, &fbsd_core_ops, sizeof (struct target_ops));
+      add_target (&core_ops);
+
+      /* Add ourselves to objfile event chain. */
+      target_new_objfile_chain = deprecated_target_new_objfile_hook;
+      deprecated_target_new_objfile_hook = fbsd_thread_new_objfile;
+
+      child_suppress_run = 1;
+    }
+  else
+    {
+      fprintf_unfiltered (gdb_stderr,
+        "[GDB will not be able to debug user-mode threads: %s]\n", dlerror());
+     
+      /* allow the user to debug non-threaded core files */
+      add_target (&core_ops);
+    }
+}
+
+/* proc service functions */
+void
+ps_plog (const char *fmt, ...)
+{
+  va_list args;
+
+  va_start (args, fmt);
+  vfprintf_filtered (gdb_stderr, fmt, args);
+  va_end (args);
+}
+
+ps_err_e
+ps_pglobal_lookup (struct ps_prochandle *ph, const char *obj,
+   const char *name, psaddr_t *sym_addr)
+{
+  struct minimal_symbol *ms;
+  CORE_ADDR addr;
+
+  ms = lookup_minimal_symbol (name, NULL, NULL);
+  if (ms == NULL)
+    return PS_NOSYM;
+
+  addr = SYMBOL_VALUE_ADDRESS (ms);
+  store_typed_address((gdb_byte *)sym_addr, builtin_type_void_data_ptr, addr);
+  return PS_OK;
+}
+
+ps_err_e
+ps_pread (struct ps_prochandle *ph, psaddr_t addr, void *buf, size_t len)
+{
+  int err = target_read_memory (
+    extract_typed_address((const gdb_byte *)&addr, builtin_type_void_data_ptr), buf, len);
+  return (err == 0 ? PS_OK : PS_ERR);
+}
+
+ps_err_e
+ps_pwrite (struct ps_prochandle *ph, psaddr_t addr, const void *buf,
+            size_t len)
+{
+  int err = target_write_memory (
+    extract_typed_address((const gdb_byte *)&addr, builtin_type_void_data_ptr), (void *)buf, len);
+  return (err == 0 ? PS_OK : PS_ERR);
+}
+
+ps_err_e
+ps_lgetregs (struct ps_prochandle *ph, lwpid_t lwpid, prgregset_t gregset)
+{
+  struct cleanup *old_chain;
+
+  old_chain = save_inferior_ptid ();
+
+  /* XXX: Target operation isn't lwp aware: replace pid with lwp */
+  inferior_ptid = BUILD_LWP (0, lwpid);
+
+  target_fetch_registers (-1);
+  fill_gregset (gregset, -1);
+  do_cleanups (old_chain);
+  return PS_OK;
+}
+
+ps_err_e
+ps_lsetregs (struct ps_prochandle *ph, lwpid_t lwpid, const prgregset_t gregset)
+{
+  struct cleanup *old_chain;
+
+  old_chain = save_inferior_ptid ();
+  inferior_ptid = BUILD_LWP (lwpid, PIDGET (inferior_ptid));
+  supply_gregset (gregset);
+  target_store_registers (-1);
+  do_cleanups (old_chain);
+  return PS_OK;
+}
+
+ps_err_e
+ps_lgetfpregs (struct ps_prochandle *ph, lwpid_t lwpid, prfpregset_t *fpregset)
+{
+  struct cleanup *old_chain;
+
+  old_chain = save_inferior_ptid ();
+  inferior_ptid = BUILD_LWP (lwpid, PIDGET (inferior_ptid));
+  target_fetch_registers (-1);
+  fill_fpregset (fpregset, -1);
+  do_cleanups (old_chain);
+  return PS_OK;
+}
+
+ps_err_e
+ps_lsetfpregs (struct ps_prochandle *ph, lwpid_t lwpid,
+               const prfpregset_t *fpregset)
+{
+  struct cleanup *old_chain;
+
+  old_chain = save_inferior_ptid ();
+  inferior_ptid = BUILD_LWP (lwpid, PIDGET (inferior_ptid));
+  supply_fpregset (fpregset);
+  target_store_registers (-1);
+  do_cleanups (old_chain);
+  return PS_OK;
+}
+
+#ifdef PT_GETXMMREGS
+ps_err_e
+ps_lgetxmmregs (struct ps_prochandle *ph, lwpid_t lwpid, char *xmmregs)
+{
+  struct cleanup *old_chain;
+
+  old_chain = save_inferior_ptid ();
+  inferior_ptid = BUILD_LWP (lwpid, PIDGET (inferior_ptid));
+  target_fetch_registers (-1);
+  i387_fill_fxsave (xmmregs, -1);
+  do_cleanups (old_chain);
+  return PS_OK;
+}
+
+ps_err_e
+ps_lsetxmmregs (struct ps_prochandle *ph, lwpid_t lwpid,
+		const char *xmmregs)
+{
+  struct cleanup *old_chain;
+
+  old_chain = save_inferior_ptid ();
+  inferior_ptid = BUILD_LWP (lwpid, PIDGET (inferior_ptid));
+  i387_supply_fxsave (current_regcache, -1, xmmregs);
+  target_store_registers (-1);
+  do_cleanups (old_chain);
+  return PS_OK;
+}
+#endif
+
+ps_err_e
+ps_lstop(struct ps_prochandle *ph, lwpid_t lwpid)
+{
+  if (ptrace (PT_SUSPEND, lwpid, 0, 0) == -1)
+    return PS_ERR;
+  return PS_OK;  
+}
+
+ps_err_e
+ps_lcontinue(struct ps_prochandle *ph, lwpid_t lwpid)
+{
+  if (ptrace (PT_RESUME, lwpid, 0, 0) == -1)
+    return PS_ERR;
+  return PS_OK;   
+}
Index: i386bsd-nat.c
===================================================================
RCS file: /services/cvs/cvsroot/latest/gdb/gdb/i386bsd-nat.c,v
retrieving revision 1.1.1.2.4.1
diff -u -p -r1.1.1.2.4.1 i386bsd-nat.c
--- i386bsd-nat.c	19 Jan 2007 05:21:41 -0000	1.1.1.2.4.1
+++ i386bsd-nat.c	7 Feb 2007 00:12:16 -0000
@@ -105,6 +105,21 @@ i386bsd_supply_gregset (struct regcache 
     }
 }
 
+void
+supply_gregset (void *gregsetp)	  /* FIXME: arg type */
+{
+  i386bsd_supply_gregset (current_regcache, (const void *) gregsetp);
+}
+
+/* Fill GDB's register array with the floating-point register values in
+   *FPREGSETP.  */
+
+void 
+supply_fpregset (void *fpregsetp)
+{
+  i387_supply_fsave (current_regcache, -1, fpregsetp);
+}
+
 /* Collect register REGNUM from REGCACHE and store its contents in
    GREGS.  If REGNUM is -1, collect and store all appropriate
    registers.  */
@@ -128,6 +143,22 @@ i386bsd_collect_gregset (const struct re
     }
 }
 
+void
+fill_gregset (void *gregsetp, int regno)
+{
+  i386bsd_collect_gregset (current_regcache, (const void *) gregsetp, regno);
+}
+
+/* Fill register REGNO (if it is a floating-point register) in
+   *FPREGSETP with the value in GDB's register array.  If REGNO is -1,
+   do this for all registers.  */
+
+void
+fill_fpregset (void *fpregsetp, int regno)
+{
+  i387_fill_fsave ((char *) fpregsetp, regno);
+}
+ 
 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
    for all registers (including the floating point registers).  */
 
Index: i386fbsd-nat.c
===================================================================
RCS file: /services/cvs/cvsroot/latest/gdb/gdb/i386fbsd-nat.c,v
retrieving revision 1.1.1.2.4.1
diff -u -p -r1.1.1.2.4.1 i386fbsd-nat.c
--- i386fbsd-nat.c	19 Jan 2007 05:21:41 -0000	1.1.1.2.4.1
+++ i386fbsd-nat.c	7 Feb 2007 00:12:16 -0000
@@ -131,6 +131,10 @@ _initialize_i386fbsd_nat (void)
   t->to_make_corefile_notes = fbsd_make_corefile_notes;
   add_target (t);
 
+  /* TODO: Eliminate this and have libthread_db use
+     find_target_beneath.  */
+  thread_db_init (t);
+
   /* Support debugging kernel virtual memory images.  */
   bsd_kvm_add_target (i386fbsd_supply_pcb);
 
Index: inf-child.c
===================================================================
RCS file: /services/cvs/cvsroot/latest/gdb/gdb/inf-child.c,v
retrieving revision 1.1.1.2.4.1
diff -u -p -r1.1.1.2.4.1 inf-child.c
--- inf-child.c	19 Jan 2007 05:21:43 -0000	1.1.1.2.4.1
+++ inf-child.c	7 Feb 2007 00:12:16 -0000
@@ -29,6 +29,11 @@
 #include "inferior.h"
 #include "gdb_string.h"
 
+int child_suppress_run = 0;	/* Non-zero if inf-child should pretend not to
+				   be a runnable target.  Used by targets
+				   that can sit atop inftarg, such as FreeBSD
+				   thread support.  */
+
 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
    for all registers.  */
 
@@ -154,7 +159,7 @@ inf_child_reported_exec_events_per_exec_
 static int
 inf_child_can_run (void)
 {
-  return 1;
+  return !child_suppress_run;
 }
 
 static struct symtab_and_line *
Index: config/i386/fbsd.mh
===================================================================
RCS file: /services/cvs/cvsroot/latest/gdb/gdb/config/i386/fbsd.mh,v
retrieving revision 1.1.1.1
diff -u -p -r1.1.1.1 fbsd.mh
--- config/i386/fbsd.mh	8 Oct 2005 19:36:19 -0000	1.1.1.1
+++ config/i386/fbsd.mh	7 Feb 2007 00:12:16 -0000
@@ -1,7 +1,9 @@
 # Host: FreeBSD/i386
 NATDEPFILES= fork-child.o inf-ptrace.o \
 	fbsd-nat.o i386-nat.o i386bsd-nat.o i386fbsd-nat.o \
-	gcore.o bsd-kvm.o
+	gcore.o bsd-kvm.o fbsd-threads.o
 NAT_FILE= nm-fbsd.h
 
-LOADLIBES= -lkvm
+# The dynamically loaded libthread_db needs access to symbols in the
+# gdb executable.
+LOADLIBES= -lkvm -rdynamic