1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "gdb_assert.h"
25 #include "gdb_proc_service.h"
26 #include "gdb_thread_db.h"
29 #include "exceptions.h"
30 #include "gdbthread.h"
36 #include "solib-svr4.h"
39 #include "linux-nat.h"
43 #ifdef HAVE_GNU_LIBC_VERSION_H
44 #include <gnu/libc-version.h>
47 #ifndef LIBTHREAD_DB_SO
48 #define LIBTHREAD_DB_SO "libthread_db.so.1"
51 /* GNU/Linux libthread_db support.
53 libthread_db is a library, provided along with libpthread.so, which
54 exposes the internals of the thread library to a debugger. It
55 allows GDB to find existing threads, new threads as they are
56 created, thread IDs (usually, the result of pthread_self), and
57 thread-local variables.
59 The libthread_db interface originates on Solaris, where it is
60 both more powerful and more complicated. This implementation
61 only works for LinuxThreads and NPTL, the two glibc threading
62 libraries. It assumes that each thread is permanently assigned
63 to a single light-weight process (LWP).
65 libthread_db-specific information is stored in the "private" field
66 of struct thread_info. When the field is NULL we do not yet have
67 information about the new thread; this could be temporary (created,
68 but the thread library's data structures do not reflect it yet)
69 or permanent (created using clone instead of pthread_create).
71 Process IDs managed by linux-thread-db.c match those used by
72 linux-nat.c: a common PID for all processes, an LWP ID for each
73 thread, and no TID. We save the TID in private. Keeping it out
74 of the ptid_t prevents thread IDs changing when libpthread is
75 loaded or unloaded. */
77 /* If we're running on GNU/Linux, we must explicitly attach to any new
80 /* This module's target vector. */
81 static struct target_ops thread_db_ops
;
83 /* The target vector that we call for things this module can't handle. */
84 static struct target_ops
*target_beneath
;
86 /* Non-zero if we're using this module's target vector. */
87 static int using_thread_db
;
89 /* Non-zero if we have determined the signals used by the threads
91 static int thread_signals
;
92 static sigset_t thread_stop_set
;
93 static sigset_t thread_print_set
;
95 /* Structure that identifies the child process for the
96 <proc_service.h> interface. */
97 static struct ps_prochandle proc_handle
;
99 /* Connection to the libthread_db library. */
100 static td_thragent_t
*thread_agent
;
102 /* Pointers to the libthread_db functions. */
104 static td_err_e (*td_init_p
) (void);
106 static td_err_e (*td_ta_new_p
) (struct ps_prochandle
* ps
,
108 static td_err_e (*td_ta_map_id2thr_p
) (const td_thragent_t
*ta
, thread_t pt
,
109 td_thrhandle_t
*__th
);
110 static td_err_e (*td_ta_map_lwp2thr_p
) (const td_thragent_t
*ta
,
111 lwpid_t lwpid
, td_thrhandle_t
*th
);
112 static td_err_e (*td_ta_thr_iter_p
) (const td_thragent_t
*ta
,
113 td_thr_iter_f
*callback
, void *cbdata_p
,
114 td_thr_state_e state
, int ti_pri
,
115 sigset_t
*ti_sigmask_p
,
116 unsigned int ti_user_flags
);
117 static td_err_e (*td_ta_event_addr_p
) (const td_thragent_t
*ta
,
118 td_event_e event
, td_notify_t
*ptr
);
119 static td_err_e (*td_ta_set_event_p
) (const td_thragent_t
*ta
,
120 td_thr_events_t
*event
);
121 static td_err_e (*td_ta_event_getmsg_p
) (const td_thragent_t
*ta
,
122 td_event_msg_t
*msg
);
124 static td_err_e (*td_thr_validate_p
) (const td_thrhandle_t
*th
);
125 static td_err_e (*td_thr_get_info_p
) (const td_thrhandle_t
*th
,
126 td_thrinfo_t
*infop
);
127 static td_err_e (*td_thr_event_enable_p
) (const td_thrhandle_t
*th
,
130 static td_err_e (*td_thr_tls_get_addr_p
) (const td_thrhandle_t
*th
,
132 size_t offset
, void **address
);
134 /* Location of the thread creation event breakpoint. The code at this
135 location in the child process will be called by the pthread library
136 whenever a new thread is created. By setting a special breakpoint
137 at this location, GDB can detect when a new thread is created. We
138 obtain this location via the td_ta_event_addr call. */
139 static CORE_ADDR td_create_bp_addr
;
141 /* Location of the thread death event breakpoint. */
142 static CORE_ADDR td_death_bp_addr
;
144 /* Prototypes for local functions. */
145 static void thread_db_find_new_threads (void);
146 static void attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
147 const td_thrinfo_t
*ti_p
);
148 static void detach_thread (ptid_t ptid
);
151 /* Use "struct private_thread_info" to cache thread state. This is
152 a substantial optimization. */
154 struct private_thread_info
156 /* Flag set when we see a TD_DEATH event for this thread. */
157 unsigned int dying
:1;
159 /* Cached thread state. */
166 thread_db_err_str (td_err_e err
)
173 return "generic 'call succeeded'";
175 return "generic error";
177 return "no thread to satisfy query";
179 return "no sync handle to satisfy query";
181 return "no LWP to satisfy query";
183 return "invalid process handle";
185 return "invalid thread handle";
187 return "invalid synchronization handle";
189 return "invalid thread agent";
191 return "invalid key";
193 return "no event message for getmsg";
195 return "FPU register set not available";
197 return "application not linked with libthread";
199 return "requested event is not supported";
201 return "capability not available";
203 return "debugger service failed";
205 return "operation not applicable to";
207 return "no thread-specific data for this thread";
209 return "malloc failed";
211 return "only part of register set was written/read";
213 return "X register set not available for this thread";
214 #ifdef THREAD_DB_HAS_TD_NOTALLOC
216 return "thread has not yet allocated TLS for given module";
218 #ifdef THREAD_DB_HAS_TD_VERSION
220 return "versions of libpthread and libthread_db do not match";
222 #ifdef THREAD_DB_HAS_TD_NOTLS
224 return "there is no TLS segment in the given module";
227 snprintf (buf
, sizeof (buf
), "unknown thread_db error '%d'", err
);
232 /* Return 1 if any threads have been registered. There may be none if
233 the threading library is not fully initialized yet. */
236 have_threads_callback (struct thread_info
*thread
, void *dummy
)
238 return thread
->private != NULL
;
244 return iterate_over_threads (have_threads_callback
, NULL
) != NULL
;
247 /* A callback function for td_ta_thr_iter, which we use to map all
250 THP is a handle to the current thread; if INFOP is not NULL, the
251 struct thread_info associated with this thread is returned in
254 If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
255 zero is returned to indicate success. */
258 thread_get_info_callback (const td_thrhandle_t
*thp
, void *infop
)
262 struct thread_info
*thread_info
;
265 err
= td_thr_get_info_p (thp
, &ti
);
267 error (_("thread_get_info_callback: cannot get thread info: %s"),
268 thread_db_err_str (err
));
270 /* Fill the cache. */
271 thread_ptid
= ptid_build (GET_PID (inferior_ptid
), ti
.ti_lid
, 0);
272 thread_info
= find_thread_pid (thread_ptid
);
274 /* In the case of a zombie thread, don't continue. We don't want to
275 attach to it thinking it is a new thread. */
276 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
279 *(struct thread_info
**) infop
= thread_info
;
280 return TD_THR_ZOMBIE
;
283 if (thread_info
== NULL
)
285 /* New thread. Attach to it now (why wait?). */
286 if (!have_threads ())
287 thread_db_find_new_threads ();
289 attach_thread (thread_ptid
, thp
, &ti
);
290 thread_info
= find_thread_pid (thread_ptid
);
291 gdb_assert (thread_info
!= NULL
);
295 *(struct thread_info
**) infop
= thread_info
;
300 /* Convert between user-level thread ids and LWP ids. */
303 thread_from_lwp (ptid_t ptid
)
307 struct thread_info
*thread_info
;
310 /* This ptid comes from linux-nat.c, which should always fill in the
312 gdb_assert (GET_LWP (ptid
) != 0);
314 /* Access an lwp we know is stopped. */
315 proc_handle
.pid
= GET_LWP (ptid
);
316 err
= td_ta_map_lwp2thr_p (thread_agent
, GET_LWP (ptid
), &th
);
318 error (_("Cannot find user-level thread for LWP %ld: %s"),
319 GET_LWP (ptid
), thread_db_err_str (err
));
323 /* Fetch the thread info. If we get back TD_THR_ZOMBIE, then the
324 event thread has already died. If another gdb interface has called
325 thread_alive() previously, the thread won't be found on the thread list
326 anymore. In that case, we don't want to process this ptid anymore
327 to avoid the possibility of later treating it as a newly
328 discovered thread id that we should add to the list. Thus,
329 we return a -1 ptid which is also how the thread list marks a
331 if (thread_get_info_callback (&th
, &thread_info
) == TD_THR_ZOMBIE
332 && thread_info
== NULL
)
333 return pid_to_ptid (-1);
335 gdb_assert (ptid_get_tid (ptid
) == 0);
340 /* Attach to lwp PTID, doing whatever else is required to have this
341 LWP under the debugger's control --- e.g., enabling event
342 reporting. Returns true on success. */
344 thread_db_attach_lwp (ptid_t ptid
)
350 if (!using_thread_db
)
353 /* This ptid comes from linux-nat.c, which should always fill in the
355 gdb_assert (GET_LWP (ptid
) != 0);
357 /* Access an lwp we know is stopped. */
358 proc_handle
.pid
= GET_LWP (ptid
);
360 /* If we have only looked at the first thread before libpthread was
361 initialized, we may not know its thread ID yet. Make sure we do
362 before we add another thread to the list. */
363 if (!have_threads ())
364 thread_db_find_new_threads ();
366 err
= td_ta_map_lwp2thr_p (thread_agent
, GET_LWP (ptid
), &th
);
368 /* Cannot find user-level thread. */
371 err
= td_thr_get_info_p (&th
, &ti
);
374 warning (_("Cannot get thread info: %s"), thread_db_err_str (err
));
378 attach_thread (ptid
, &th
, &ti
);
383 thread_db_init (struct target_ops
*target
)
385 target_beneath
= target
;
389 verbose_dlsym (void *handle
, const char *name
)
391 void *sym
= dlsym (handle
, name
);
393 warning (_("Symbol \"%s\" not found in libthread_db: %s"), name
, dlerror ());
398 thread_db_load (void)
403 handle
= dlopen (LIBTHREAD_DB_SO
, RTLD_NOW
);
406 fprintf_filtered (gdb_stderr
, "\n\ndlopen failed on '%s' - %s\n",
407 LIBTHREAD_DB_SO
, dlerror ());
408 fprintf_filtered (gdb_stderr
,
409 "GDB will not be able to debug pthreads.\n\n");
413 /* Initialize pointers to the dynamic library functions we will use.
414 Essential functions first. */
416 td_init_p
= verbose_dlsym (handle
, "td_init");
417 if (td_init_p
== NULL
)
420 td_ta_new_p
= verbose_dlsym (handle
, "td_ta_new");
421 if (td_ta_new_p
== NULL
)
424 td_ta_map_id2thr_p
= verbose_dlsym (handle
, "td_ta_map_id2thr");
425 if (td_ta_map_id2thr_p
== NULL
)
428 td_ta_map_lwp2thr_p
= verbose_dlsym (handle
, "td_ta_map_lwp2thr");
429 if (td_ta_map_lwp2thr_p
== NULL
)
432 td_ta_thr_iter_p
= verbose_dlsym (handle
, "td_ta_thr_iter");
433 if (td_ta_thr_iter_p
== NULL
)
436 td_thr_validate_p
= verbose_dlsym (handle
, "td_thr_validate");
437 if (td_thr_validate_p
== NULL
)
440 td_thr_get_info_p
= verbose_dlsym (handle
, "td_thr_get_info");
441 if (td_thr_get_info_p
== NULL
)
444 /* Initialize the library. */
448 warning (_("Cannot initialize libthread_db: %s"), thread_db_err_str (err
));
452 /* These are not essential. */
453 td_ta_event_addr_p
= dlsym (handle
, "td_ta_event_addr");
454 td_ta_set_event_p
= dlsym (handle
, "td_ta_set_event");
455 td_ta_event_getmsg_p
= dlsym (handle
, "td_ta_event_getmsg");
456 td_thr_event_enable_p
= dlsym (handle
, "td_thr_event_enable");
457 td_thr_tls_get_addr_p
= dlsym (handle
, "td_thr_tls_get_addr");
463 enable_thread_event (td_thragent_t
*thread_agent
, int event
, CORE_ADDR
*bp
)
468 /* Access an lwp we know is stopped. */
469 proc_handle
.pid
= GET_LWP (inferior_ptid
);
471 /* Get the breakpoint address for thread EVENT. */
472 err
= td_ta_event_addr_p (thread_agent
, event
, ¬ify
);
476 /* Set up the breakpoint. */
477 gdb_assert (exec_bfd
);
478 (*bp
) = (gdbarch_convert_from_func_ptr_addr
480 /* Do proper sign extension for the target. */
481 (bfd_get_sign_extend_vma (exec_bfd
) > 0
482 ? (CORE_ADDR
) (intptr_t) notify
.u
.bptaddr
483 : (CORE_ADDR
) (uintptr_t) notify
.u
.bptaddr
),
485 create_thread_event_breakpoint ((*bp
));
491 enable_thread_event_reporting (void)
493 td_thr_events_t events
;
496 #ifdef HAVE_GNU_LIBC_VERSION_H
497 const char *libc_version
;
498 int libc_major
, libc_minor
;
501 /* We cannot use the thread event reporting facility if these
502 functions aren't available. */
503 if (td_ta_event_addr_p
== NULL
|| td_ta_set_event_p
== NULL
504 || td_ta_event_getmsg_p
== NULL
|| td_thr_event_enable_p
== NULL
)
507 /* Set the process wide mask saying which events we're interested in. */
508 td_event_emptyset (&events
);
509 td_event_addset (&events
, TD_CREATE
);
511 #ifdef HAVE_GNU_LIBC_VERSION_H
512 /* The event reporting facility is broken for TD_DEATH events in
513 glibc 2.1.3, so don't enable it if we have glibc but a lower
515 libc_version
= gnu_get_libc_version ();
516 if (sscanf (libc_version
, "%d.%d", &libc_major
, &libc_minor
) == 2
517 && (libc_major
> 2 || (libc_major
== 2 && libc_minor
> 1)))
519 td_event_addset (&events
, TD_DEATH
);
521 err
= td_ta_set_event_p (thread_agent
, &events
);
524 warning (_("Unable to set global thread event mask: %s"),
525 thread_db_err_str (err
));
529 /* Delete previous thread event breakpoints, if any. */
530 remove_thread_event_breakpoints ();
531 td_create_bp_addr
= 0;
532 td_death_bp_addr
= 0;
534 /* Set up the thread creation event. */
535 err
= enable_thread_event (thread_agent
, TD_CREATE
, &td_create_bp_addr
);
538 warning (_("Unable to get location for thread creation breakpoint: %s"),
539 thread_db_err_str (err
));
543 /* Set up the thread death event. */
544 err
= enable_thread_event (thread_agent
, TD_DEATH
, &td_death_bp_addr
);
547 warning (_("Unable to get location for thread death breakpoint: %s"),
548 thread_db_err_str (err
));
554 disable_thread_event_reporting (void)
556 td_thr_events_t events
;
558 /* Set the process wide mask saying we aren't interested in any
560 td_event_emptyset (&events
);
561 td_ta_set_event_p (thread_agent
, &events
);
563 /* Delete thread event breakpoints, if any. */
564 remove_thread_event_breakpoints ();
565 td_create_bp_addr
= 0;
566 td_death_bp_addr
= 0;
570 check_thread_signals (void)
572 #ifdef GET_THREAD_SIGNALS
578 GET_THREAD_SIGNALS (&mask
);
579 sigemptyset (&thread_stop_set
);
580 sigemptyset (&thread_print_set
);
582 for (i
= 1; i
< NSIG
; i
++)
584 if (sigismember (&mask
, i
))
586 if (signal_stop_update (target_signal_from_host (i
), 0))
587 sigaddset (&thread_stop_set
, i
);
588 if (signal_print_update (target_signal_from_host (i
), 0))
589 sigaddset (&thread_print_set
, i
);
597 /* Check whether thread_db is usable. This function is called when
598 an inferior is created (or otherwise acquired, e.g. attached to)
599 and when new shared libraries are loaded into a running process. */
602 check_for_thread_db (void)
605 static int already_loaded
;
607 /* Do nothing if we couldn't load libthread_db.so.1. */
608 if (td_ta_new_p
== NULL
)
611 /* First time through, report that libthread_db was successfuly
612 loaded. Can't print this in in thread_db_load as, at that stage,
613 the interpreter and it's console haven't started. */
618 const char *library
= NULL
;
619 if (dladdr ((*td_ta_new_p
), &info
) != 0)
620 library
= info
.dli_fname
;
625 /* Paranoid - don't let a NULL path slip through. */
626 library
= LIBTHREAD_DB_SO
;
629 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
635 /* Nothing to do. The thread library was already detected and the
636 target vector was already activated. */
639 /* Don't attempt to use thread_db on targets which can not run
640 (executables not running yet, core files) for now. */
641 if (!target_has_execution
)
644 /* Don't attempt to use thread_db for remote targets. */
645 if (!target_can_run (¤t_target
))
648 /* Initialize the structure that identifies the child process. */
649 proc_handle
.pid
= GET_PID (inferior_ptid
);
651 /* Now attempt to open a connection to the thread library. */
652 err
= td_ta_new_p (&proc_handle
, &thread_agent
);
656 /* No thread library was detected. */
660 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
662 /* The thread library was detected. Activate the thread_db target. */
663 push_target (&thread_db_ops
);
666 enable_thread_event_reporting ();
667 thread_db_find_new_threads ();
671 warning (_("Cannot initialize thread debugging library: %s"),
672 thread_db_err_str (err
));
678 thread_db_new_objfile (struct objfile
*objfile
)
681 check_for_thread_db ();
684 /* Attach to a new thread. This function is called when we receive a
685 TD_CREATE event or when we iterate over all threads and find one
686 that wasn't already in our list. */
689 attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
690 const td_thrinfo_t
*ti_p
)
692 struct private_thread_info
*private;
693 struct thread_info
*tp
= NULL
;
696 /* If we're being called after a TD_CREATE event, we may already
697 know about this thread. There are two ways this can happen. We
698 may have iterated over all threads between the thread creation
699 and the TD_CREATE event, for instance when the user has issued
700 the `info threads' command before the SIGTRAP for hitting the
701 thread creation breakpoint was reported. Alternatively, the
702 thread may have exited and a new one been created with the same
703 thread ID. In the first case we don't need to do anything; in
704 the second case we should discard information about the dead
705 thread and attach to the new one. */
706 if (in_thread_list (ptid
))
708 tp
= find_thread_pid (ptid
);
709 gdb_assert (tp
!= NULL
);
711 /* If tp->private is NULL, then GDB is already attached to this
712 thread, but we do not know anything about it. We can learn
713 about it here. This can only happen if we have some other
714 way besides libthread_db to notice new threads (i.e.
715 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
716 exit, so this can not be a stale thread recreated with the
718 if (tp
->private != NULL
)
720 if (!tp
->private->dying
)
723 delete_thread (ptid
);
728 check_thread_signals ();
730 if (ti_p
->ti_state
== TD_THR_UNKNOWN
|| ti_p
->ti_state
== TD_THR_ZOMBIE
)
731 return; /* A zombie thread -- do not attach. */
733 /* Under GNU/Linux, we have to attach to each and every thread. */
735 && lin_lwp_attach_lwp (BUILD_LWP (ti_p
->ti_lid
, GET_PID (ptid
))) < 0)
738 /* Construct the thread's private data. */
739 private = xmalloc (sizeof (struct private_thread_info
));
740 memset (private, 0, sizeof (struct private_thread_info
));
742 /* A thread ID of zero may mean the thread library has not initialized
743 yet. But we shouldn't even get here if that's the case. FIXME:
744 if we change GDB to always have at least one thread in the thread
745 list this will have to go somewhere else; maybe private == NULL
746 until the thread_db target claims it. */
747 gdb_assert (ti_p
->ti_tid
!= 0);
749 private->tid
= ti_p
->ti_tid
;
751 /* Add the thread to GDB's thread list. */
753 tp
= add_thread_with_info (ptid
, private);
755 tp
->private = private;
757 /* Enable thread event reporting for this thread. */
758 err
= td_thr_event_enable_p (th_p
, 1);
760 error (_("Cannot enable thread event reporting for %s: %s"),
761 target_pid_to_str (ptid
), thread_db_err_str (err
));
765 detach_thread (ptid_t ptid
)
767 struct thread_info
*thread_info
;
769 /* Don't delete the thread now, because it still reports as active
770 until it has executed a few instructions after the event
771 breakpoint - if we deleted it now, "info threads" would cause us
772 to re-attach to it. Just mark it as having had a TD_DEATH
773 event. This means that we won't delete it from our thread list
774 until we notice that it's dead (via prune_threads), or until
775 something re-uses its thread ID. We'll report the thread exit
776 when the underlying LWP dies. */
777 thread_info
= find_thread_pid (ptid
);
778 gdb_assert (thread_info
!= NULL
&& thread_info
->private != NULL
);
779 thread_info
->private->dying
= 1;
783 thread_db_detach (struct target_ops
*ops
, char *args
, int from_tty
)
785 disable_thread_event_reporting ();
787 /* Forget about the child's process ID. We shouldn't need it
791 /* Detach thread_db target ops. */
792 unpush_target (&thread_db_ops
);
795 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
798 /* Check if PID is currently stopped at the location of a thread event
799 breakpoint location. If it is, read the event message and act upon
803 check_event (ptid_t ptid
)
805 struct regcache
*regcache
= get_thread_regcache (ptid
);
806 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
813 /* Bail out early if we're not at a thread event breakpoint. */
814 stop_pc
= regcache_read_pc (regcache
)
815 - gdbarch_decr_pc_after_break (gdbarch
);
816 if (stop_pc
!= td_create_bp_addr
&& stop_pc
!= td_death_bp_addr
)
819 /* Access an lwp we know is stopped. */
820 proc_handle
.pid
= GET_LWP (ptid
);
822 /* If we have only looked at the first thread before libpthread was
823 initialized, we may not know its thread ID yet. Make sure we do
824 before we add another thread to the list. */
825 if (!have_threads ())
826 thread_db_find_new_threads ();
828 /* If we are at a create breakpoint, we do not know what new lwp
829 was created and cannot specifically locate the event message for it.
830 We have to call td_ta_event_getmsg() to get
831 the latest message. Since we have no way of correlating whether
832 the event message we get back corresponds to our breakpoint, we must
833 loop and read all event messages, processing them appropriately.
834 This guarantees we will process the correct message before continuing
837 Currently, death events are not enabled. If they are enabled,
838 the death event can use the td_thr_event_getmsg() interface to
839 get the message specifically for that lwp and avoid looping
846 err
= td_ta_event_getmsg_p (thread_agent
, &msg
);
852 error (_("Cannot get thread event message: %s"),
853 thread_db_err_str (err
));
856 err
= td_thr_get_info_p (msg
.th_p
, &ti
);
858 error (_("Cannot get thread info: %s"), thread_db_err_str (err
));
860 ptid
= ptid_build (GET_PID (ptid
), ti
.ti_lid
, 0);
865 /* Call attach_thread whether or not we already know about a
866 thread with this thread ID. */
867 attach_thread (ptid
, msg
.th_p
, &ti
);
873 if (!in_thread_list (ptid
))
874 error (_("Spurious thread death event."));
876 detach_thread (ptid
);
881 error (_("Spurious thread event."));
888 thread_db_wait (ptid_t ptid
, struct target_waitstatus
*ourstatus
)
890 ptid
= target_beneath
->to_wait (ptid
, ourstatus
);
892 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
895 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
896 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
899 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
901 remove_thread_event_breakpoints ();
902 unpush_target (&thread_db_ops
);
908 /* If we do not know about the main thread yet, this would be a good time to
910 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
&& !have_threads ())
911 thread_db_find_new_threads ();
913 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
914 && ourstatus
->value
.sig
== TARGET_SIGNAL_TRAP
)
915 /* Check for a thread event. */
920 /* Change ptids back into the higher level PID + TID format. If
921 the thread is dead and no longer on the thread list, we will
922 get back a dead ptid. This can occur if the thread death
923 event gets postponed by other simultaneous events. In such a
924 case, we want to just ignore the event and continue on. */
926 ptid
= thread_from_lwp (ptid
);
927 if (GET_PID (ptid
) == -1)
928 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
935 thread_db_mourn_inferior (struct target_ops
*ops
)
937 /* Forget about the child's process ID. We shouldn't need it
941 target_beneath
->to_mourn_inferior (target_beneath
);
943 /* Delete the old thread event breakpoints. Do this after mourning
944 the inferior, so that we don't try to uninsert them. */
945 remove_thread_event_breakpoints ();
947 /* Detach thread_db target ops. */
953 thread_db_can_async_p (void)
955 return target_beneath
->to_can_async_p ();
959 thread_db_is_async_p (void)
961 return target_beneath
->to_is_async_p ();
965 thread_db_async (void (*callback
) (enum inferior_event_type event_type
,
966 void *context
), void *context
)
968 return target_beneath
->to_async (callback
, context
);
972 thread_db_async_mask (int mask
)
974 return target_beneath
->to_async_mask (mask
);
978 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
983 struct thread_info
*tp
;
985 err
= td_thr_get_info_p (th_p
, &ti
);
987 error (_("find_new_threads_callback: cannot get thread info: %s"),
988 thread_db_err_str (err
));
990 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
991 return 0; /* A zombie -- ignore. */
993 ptid
= ptid_build (GET_PID (inferior_ptid
), ti
.ti_lid
, 0);
997 /* A thread ID of zero means that this is the main thread, but
998 glibc has not yet initialized thread-local storage and the
999 pthread library. We do not know what the thread's TID will
1000 be yet. Just enable event reporting and otherwise ignore
1003 err
= td_thr_event_enable_p (th_p
, 1);
1005 error (_("Cannot enable thread event reporting for %s: %s"),
1006 target_pid_to_str (ptid
), thread_db_err_str (err
));
1011 tp
= find_thread_pid (ptid
);
1012 if (tp
== NULL
|| tp
->private == NULL
)
1013 attach_thread (ptid
, th_p
, &ti
);
1018 /* Search for new threads, accessing memory through stopped thread
1022 thread_db_find_new_threads (void)
1025 struct lwp_info
*lp
;
1028 /* In linux, we can only read memory through a stopped lwp. */
1034 /* There is no stopped thread. Bail out. */
1037 /* Access an lwp we know is stopped. */
1038 proc_handle
.pid
= GET_LWP (ptid
);
1039 /* Iterate over all user-space threads to discover new threads. */
1040 err
= td_ta_thr_iter_p (thread_agent
, find_new_threads_callback
, NULL
,
1041 TD_THR_ANY_STATE
, TD_THR_LOWEST_PRIORITY
,
1042 TD_SIGNO_MASK
, TD_THR_ANY_USER_FLAGS
);
1044 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1048 thread_db_pid_to_str (ptid_t ptid
)
1050 struct thread_info
*thread_info
= find_thread_pid (ptid
);
1052 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1054 static char buf
[64];
1057 tid
= thread_info
->private->tid
;
1058 thread_info
= find_thread_pid (ptid
);
1059 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1060 tid
, GET_LWP (ptid
));
1065 if (target_beneath
->to_pid_to_str (ptid
))
1066 return target_beneath
->to_pid_to_str (ptid
);
1068 return normal_pid_to_str (ptid
);
1071 /* Return a string describing the state of the thread specified by
1075 thread_db_extra_thread_info (struct thread_info
*info
)
1077 if (info
->private == NULL
)
1080 if (info
->private->dying
)
1086 /* Get the address of the thread local variable in load module LM which
1087 is stored at OFFSET within the thread local storage for thread PTID. */
1090 thread_db_get_thread_local_address (ptid_t ptid
,
1094 struct thread_info
*thread_info
;
1096 /* If we have not discovered any threads yet, check now. */
1097 if (!have_threads ())
1098 thread_db_find_new_threads ();
1100 /* Find the matching thread. */
1101 thread_info
= find_thread_pid (ptid
);
1103 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1108 /* glibc doesn't provide the needed interface. */
1109 if (!td_thr_tls_get_addr_p
)
1110 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1111 _("No TLS library support"));
1113 /* Caller should have verified that lm != 0. */
1114 gdb_assert (lm
!= 0);
1116 /* Finally, get the address of the variable. */
1117 err
= td_thr_tls_get_addr_p (&thread_info
->private->th
,
1118 (void *)(size_t) lm
,
1121 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1122 /* The memory hasn't been allocated, yet. */
1123 if (err
== TD_NOTALLOC
)
1124 /* Now, if libthread_db provided the initialization image's
1125 address, we *could* try to build a non-lvalue value from
1126 the initialization image. */
1127 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1128 _("TLS not allocated yet"));
1131 /* Something else went wrong. */
1133 throw_error (TLS_GENERIC_ERROR
,
1134 (("%s")), thread_db_err_str (err
));
1136 /* Cast assuming host == target. Joy. */
1137 /* Do proper sign extension for the target. */
1138 gdb_assert (exec_bfd
);
1139 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1140 ? (CORE_ADDR
) (intptr_t) address
1141 : (CORE_ADDR
) (uintptr_t) address
);
1144 if (target_beneath
->to_get_thread_local_address
)
1145 return target_beneath
->to_get_thread_local_address (ptid
, lm
, offset
);
1147 throw_error (TLS_GENERIC_ERROR
,
1148 _("TLS not supported on this target"));
1151 /* Callback routine used to find a thread based on the TID part of
1155 thread_db_find_thread_from_tid (struct thread_info
*thread
, void *data
)
1157 long *tid
= (long *) data
;
1159 if (thread
->private->tid
== *tid
)
1165 /* Implement the to_get_ada_task_ptid target method for this target. */
1168 thread_db_get_ada_task_ptid (long lwp
, long thread
)
1170 struct thread_info
*thread_info
;
1172 thread_db_find_new_threads ();
1173 thread_info
= iterate_over_threads (thread_db_find_thread_from_tid
, &thread
);
1175 gdb_assert (thread_info
!= NULL
);
1177 return (thread_info
->ptid
);
1181 init_thread_db_ops (void)
1183 thread_db_ops
.to_shortname
= "multi-thread";
1184 thread_db_ops
.to_longname
= "multi-threaded child process.";
1185 thread_db_ops
.to_doc
= "Threads and pthreads support.";
1186 thread_db_ops
.to_detach
= thread_db_detach
;
1187 thread_db_ops
.to_wait
= thread_db_wait
;
1188 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
1189 thread_db_ops
.to_find_new_threads
= thread_db_find_new_threads
;
1190 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
1191 thread_db_ops
.to_stratum
= thread_stratum
;
1192 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
1193 thread_db_ops
.to_get_thread_local_address
1194 = thread_db_get_thread_local_address
;
1195 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
1196 thread_db_ops
.to_can_async_p
= thread_db_can_async_p
;
1197 thread_db_ops
.to_is_async_p
= thread_db_is_async_p
;
1198 thread_db_ops
.to_async
= thread_db_async
;
1199 thread_db_ops
.to_async_mask
= thread_db_async_mask
;
1200 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
1201 thread_db_ops
.to_magic
= OPS_MAGIC
;
1205 _initialize_thread_db (void)
1207 /* Only initialize the module if we can load libthread_db. */
1208 if (thread_db_load ())
1210 init_thread_db_ops ();
1211 add_target (&thread_db_ops
);
1213 /* Add ourselves to objfile event chain. */
1214 observer_attach_new_objfile (thread_db_new_objfile
);