1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
4 2010, 2011 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"
30 #include "exceptions.h"
32 #include "gdbthread.h"
39 #include "solib-svr4.h"
42 #include "linux-nat.h"
46 #ifdef HAVE_GNU_LIBC_VERSION_H
47 #include <gnu/libc-version.h>
50 /* GNU/Linux libthread_db support.
52 libthread_db is a library, provided along with libpthread.so, which
53 exposes the internals of the thread library to a debugger. It
54 allows GDB to find existing threads, new threads as they are
55 created, thread IDs (usually, the result of pthread_self), and
56 thread-local variables.
58 The libthread_db interface originates on Solaris, where it is
59 both more powerful and more complicated. This implementation
60 only works for LinuxThreads and NPTL, the two glibc threading
61 libraries. It assumes that each thread is permanently assigned
62 to a single light-weight process (LWP).
64 libthread_db-specific information is stored in the "private" field
65 of struct thread_info. When the field is NULL we do not yet have
66 information about the new thread; this could be temporary (created,
67 but the thread library's data structures do not reflect it yet)
68 or permanent (created using clone instead of pthread_create).
70 Process IDs managed by linux-thread-db.c match those used by
71 linux-nat.c: a common PID for all processes, an LWP ID for each
72 thread, and no TID. We save the TID in private. Keeping it out
73 of the ptid_t prevents thread IDs changing when libpthread is
74 loaded or unloaded. */
76 static char *libthread_db_search_path
;
78 /* If non-zero, print details of libthread_db processing. */
80 static int libthread_db_debug
;
83 show_libthread_db_debug (struct ui_file
*file
, int from_tty
,
84 struct cmd_list_element
*c
, const char *value
)
86 fprintf_filtered (file
, _("libthread-db debugging is %s.\n"), value
);
90 /* If we're running on GNU/Linux, we must explicitly attach to any new
93 /* This module's target vector. */
94 static struct target_ops thread_db_ops
;
96 /* Non-zero if we have determined the signals used by the threads
98 static int thread_signals
;
99 static sigset_t thread_stop_set
;
100 static sigset_t thread_print_set
;
102 struct thread_db_info
104 struct thread_db_info
*next
;
106 /* Process id this object refers to. */
109 /* Handle from dlopen for libthread_db.so. */
112 /* Structure that identifies the child process for the
113 <proc_service.h> interface. */
114 struct ps_prochandle proc_handle
;
116 /* Connection to the libthread_db library. */
117 td_thragent_t
*thread_agent
;
119 /* True if we need to apply the workaround for glibc/BZ5983. When
120 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
121 list, nptl_db returns the parent's threads in addition to the new
122 (single) child thread. If this flag is set, we do extra work to
123 be able to ignore such stale entries. */
124 int need_stale_parent_threads_check
;
126 /* Location of the thread creation event breakpoint. The code at
127 this location in the child process will be called by the pthread
128 library whenever a new thread is created. By setting a special
129 breakpoint at this location, GDB can detect when a new thread is
130 created. We obtain this location via the td_ta_event_addr
132 CORE_ADDR td_create_bp_addr
;
134 /* Location of the thread death event breakpoint. */
135 CORE_ADDR td_death_bp_addr
;
137 /* Pointers to the libthread_db functions. */
139 td_err_e (*td_init_p
) (void);
141 td_err_e (*td_ta_new_p
) (struct ps_prochandle
* ps
,
143 td_err_e (*td_ta_map_id2thr_p
) (const td_thragent_t
*ta
, thread_t pt
,
144 td_thrhandle_t
*__th
);
145 td_err_e (*td_ta_map_lwp2thr_p
) (const td_thragent_t
*ta
,
146 lwpid_t lwpid
, td_thrhandle_t
*th
);
147 td_err_e (*td_ta_thr_iter_p
) (const td_thragent_t
*ta
,
148 td_thr_iter_f
*callback
, void *cbdata_p
,
149 td_thr_state_e state
, int ti_pri
,
150 sigset_t
*ti_sigmask_p
,
151 unsigned int ti_user_flags
);
152 td_err_e (*td_ta_event_addr_p
) (const td_thragent_t
*ta
,
153 td_event_e event
, td_notify_t
*ptr
);
154 td_err_e (*td_ta_set_event_p
) (const td_thragent_t
*ta
,
155 td_thr_events_t
*event
);
156 td_err_e (*td_ta_clear_event_p
) (const td_thragent_t
*ta
,
157 td_thr_events_t
*event
);
158 td_err_e (*td_ta_event_getmsg_p
) (const td_thragent_t
*ta
,
159 td_event_msg_t
*msg
);
161 td_err_e (*td_thr_validate_p
) (const td_thrhandle_t
*th
);
162 td_err_e (*td_thr_get_info_p
) (const td_thrhandle_t
*th
,
163 td_thrinfo_t
*infop
);
164 td_err_e (*td_thr_event_enable_p
) (const td_thrhandle_t
*th
,
167 td_err_e (*td_thr_tls_get_addr_p
) (const td_thrhandle_t
*th
,
168 psaddr_t map_address
,
169 size_t offset
, psaddr_t
*address
);
172 /* List of known processes using thread_db, and the required
174 struct thread_db_info
*thread_db_list
;
176 static void thread_db_find_new_threads_1 (ptid_t ptid
);
177 static void thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
);
179 /* Add the current inferior to the list of processes using libpthread.
180 Return a pointer to the newly allocated object that was added to
181 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
184 static struct thread_db_info
*
185 add_thread_db_info (void *handle
)
187 struct thread_db_info
*info
;
189 info
= xcalloc (1, sizeof (*info
));
190 info
->pid
= ptid_get_pid (inferior_ptid
);
191 info
->handle
= handle
;
193 /* The workaround works by reading from /proc/pid/status, so it is
194 disabled for core files. */
195 if (target_has_execution
)
196 info
->need_stale_parent_threads_check
= 1;
198 info
->next
= thread_db_list
;
199 thread_db_list
= info
;
204 /* Return the thread_db_info object representing the bookkeeping
205 related to process PID, if any; NULL otherwise. */
207 static struct thread_db_info
*
208 get_thread_db_info (int pid
)
210 struct thread_db_info
*info
;
212 for (info
= thread_db_list
; info
; info
= info
->next
)
213 if (pid
== info
->pid
)
219 /* When PID has exited or has been detached, we no longer want to keep
220 track of it as using libpthread. Call this function to discard
221 thread_db related info related to PID. Note that this closes
222 LIBTHREAD_DB_SO's dlopen'ed handle. */
225 delete_thread_db_info (int pid
)
227 struct thread_db_info
*info
, *info_prev
;
231 for (info
= thread_db_list
; info
; info_prev
= info
, info
= info
->next
)
232 if (pid
== info
->pid
)
238 if (info
->handle
!= NULL
)
239 dlclose (info
->handle
);
242 info_prev
->next
= info
->next
;
244 thread_db_list
= info
->next
;
249 /* Prototypes for local functions. */
250 static int attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
251 const td_thrinfo_t
*ti_p
);
252 static void detach_thread (ptid_t ptid
);
255 /* Use "struct private_thread_info" to cache thread state. This is
256 a substantial optimization. */
258 struct private_thread_info
260 /* Flag set when we see a TD_DEATH event for this thread. */
261 unsigned int dying
:1;
263 /* Cached thread state. */
270 thread_db_err_str (td_err_e err
)
277 return "generic 'call succeeded'";
279 return "generic error";
281 return "no thread to satisfy query";
283 return "no sync handle to satisfy query";
285 return "no LWP to satisfy query";
287 return "invalid process handle";
289 return "invalid thread handle";
291 return "invalid synchronization handle";
293 return "invalid thread agent";
295 return "invalid key";
297 return "no event message for getmsg";
299 return "FPU register set not available";
301 return "application not linked with libthread";
303 return "requested event is not supported";
305 return "capability not available";
307 return "debugger service failed";
309 return "operation not applicable to";
311 return "no thread-specific data for this thread";
313 return "malloc failed";
315 return "only part of register set was written/read";
317 return "X register set not available for this thread";
318 #ifdef THREAD_DB_HAS_TD_NOTALLOC
320 return "thread has not yet allocated TLS for given module";
322 #ifdef THREAD_DB_HAS_TD_VERSION
324 return "versions of libpthread and libthread_db do not match";
326 #ifdef THREAD_DB_HAS_TD_NOTLS
328 return "there is no TLS segment in the given module";
331 snprintf (buf
, sizeof (buf
), "unknown thread_db error '%d'", err
);
336 /* Return 1 if any threads have been registered. There may be none if
337 the threading library is not fully initialized yet. */
340 have_threads_callback (struct thread_info
*thread
, void *args
)
342 int pid
= * (int *) args
;
344 if (ptid_get_pid (thread
->ptid
) != pid
)
347 return thread
->private != NULL
;
351 have_threads (ptid_t ptid
)
353 int pid
= ptid_get_pid (ptid
);
355 return iterate_over_threads (have_threads_callback
, &pid
) != NULL
;
358 struct thread_get_info_inout
360 struct thread_info
*thread_info
;
361 struct thread_db_info
*thread_db_info
;
364 /* A callback function for td_ta_thr_iter, which we use to map all
367 THP is a handle to the current thread; if INFOP is not NULL, the
368 struct thread_info associated with this thread is returned in
371 If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
372 zero is returned to indicate success. */
375 thread_get_info_callback (const td_thrhandle_t
*thp
, void *argp
)
380 struct thread_get_info_inout
*inout
;
381 struct thread_db_info
*info
;
384 info
= inout
->thread_db_info
;
386 err
= info
->td_thr_get_info_p (thp
, &ti
);
388 error (_("thread_get_info_callback: cannot get thread info: %s"),
389 thread_db_err_str (err
));
391 /* Fill the cache. */
392 thread_ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
393 inout
->thread_info
= find_thread_ptid (thread_ptid
);
395 /* In the case of a zombie thread, don't continue. We don't want to
396 attach to it thinking it is a new thread. */
397 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
398 return TD_THR_ZOMBIE
;
400 if (inout
->thread_info
== NULL
)
402 /* New thread. Attach to it now (why wait?). */
403 if (!have_threads (thread_ptid
))
404 thread_db_find_new_threads_1 (thread_ptid
);
406 attach_thread (thread_ptid
, thp
, &ti
);
407 inout
->thread_info
= find_thread_ptid (thread_ptid
);
408 gdb_assert (inout
->thread_info
!= NULL
);
414 /* Convert between user-level thread ids and LWP ids. */
417 thread_from_lwp (ptid_t ptid
)
421 struct thread_db_info
*info
;
422 struct thread_get_info_inout io
= {0};
424 /* This ptid comes from linux-nat.c, which should always fill in the
426 gdb_assert (GET_LWP (ptid
) != 0);
428 info
= get_thread_db_info (GET_PID (ptid
));
430 /* Access an lwp we know is stopped. */
431 info
->proc_handle
.ptid
= ptid
;
432 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
434 error (_("Cannot find user-level thread for LWP %ld: %s"),
435 GET_LWP (ptid
), thread_db_err_str (err
));
437 /* Fetch the thread info. If we get back TD_THR_ZOMBIE, then the
438 event thread has already died. If another gdb interface has called
439 thread_alive() previously, the thread won't be found on the thread list
440 anymore. In that case, we don't want to process this ptid anymore
441 to avoid the possibility of later treating it as a newly
442 discovered thread id that we should add to the list. Thus,
443 we return a -1 ptid which is also how the thread list marks a
445 io
.thread_db_info
= info
;
446 io
.thread_info
= NULL
;
447 if (thread_get_info_callback (&th
, &io
) == TD_THR_ZOMBIE
448 && io
.thread_info
== NULL
)
449 return minus_one_ptid
;
451 gdb_assert (ptid_get_tid (ptid
) == 0);
456 /* Attach to lwp PTID, doing whatever else is required to have this
457 LWP under the debugger's control --- e.g., enabling event
458 reporting. Returns true on success. */
460 thread_db_attach_lwp (ptid_t ptid
)
465 struct thread_db_info
*info
;
467 info
= get_thread_db_info (GET_PID (ptid
));
472 /* This ptid comes from linux-nat.c, which should always fill in the
474 gdb_assert (GET_LWP (ptid
) != 0);
476 /* Access an lwp we know is stopped. */
477 info
->proc_handle
.ptid
= ptid
;
479 /* If we have only looked at the first thread before libpthread was
480 initialized, we may not know its thread ID yet. Make sure we do
481 before we add another thread to the list. */
482 if (!have_threads (ptid
))
483 thread_db_find_new_threads_1 (ptid
);
485 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
487 /* Cannot find user-level thread. */
490 err
= info
->td_thr_get_info_p (&th
, &ti
);
493 warning (_("Cannot get thread info: %s"), thread_db_err_str (err
));
497 attach_thread (ptid
, &th
, &ti
);
502 verbose_dlsym (void *handle
, const char *name
)
504 void *sym
= dlsym (handle
, name
);
506 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
512 enable_thread_event (int event
, CORE_ADDR
*bp
)
516 struct thread_db_info
*info
;
518 info
= get_thread_db_info (GET_PID (inferior_ptid
));
520 /* Access an lwp we know is stopped. */
521 info
->proc_handle
.ptid
= inferior_ptid
;
523 /* Get the breakpoint address for thread EVENT. */
524 err
= info
->td_ta_event_addr_p (info
->thread_agent
, event
, ¬ify
);
528 /* Set up the breakpoint. */
529 gdb_assert (exec_bfd
);
530 (*bp
) = (gdbarch_convert_from_func_ptr_addr
532 /* Do proper sign extension for the target. */
533 (bfd_get_sign_extend_vma (exec_bfd
) > 0
534 ? (CORE_ADDR
) (intptr_t) notify
.u
.bptaddr
535 : (CORE_ADDR
) (uintptr_t) notify
.u
.bptaddr
),
537 create_thread_event_breakpoint (target_gdbarch
, *bp
);
543 enable_thread_event_reporting (void)
545 td_thr_events_t events
;
547 #ifdef HAVE_GNU_LIBC_VERSION_H
548 const char *libc_version
;
549 int libc_major
, libc_minor
;
551 struct thread_db_info
*info
;
553 info
= get_thread_db_info (GET_PID (inferior_ptid
));
555 /* We cannot use the thread event reporting facility if these
556 functions aren't available. */
557 if (info
->td_ta_event_addr_p
== NULL
558 || info
->td_ta_set_event_p
== NULL
559 || info
->td_ta_event_getmsg_p
== NULL
560 || info
->td_thr_event_enable_p
== NULL
)
563 /* Set the process wide mask saying which events we're interested in. */
564 td_event_emptyset (&events
);
565 td_event_addset (&events
, TD_CREATE
);
567 #ifdef HAVE_GNU_LIBC_VERSION_H
568 /* The event reporting facility is broken for TD_DEATH events in
569 glibc 2.1.3, so don't enable it if we have glibc but a lower
571 libc_version
= gnu_get_libc_version ();
572 if (sscanf (libc_version
, "%d.%d", &libc_major
, &libc_minor
) == 2
573 && (libc_major
> 2 || (libc_major
== 2 && libc_minor
> 1)))
575 td_event_addset (&events
, TD_DEATH
);
577 err
= info
->td_ta_set_event_p (info
->thread_agent
, &events
);
580 warning (_("Unable to set global thread event mask: %s"),
581 thread_db_err_str (err
));
585 /* Delete previous thread event breakpoints, if any. */
586 remove_thread_event_breakpoints ();
587 info
->td_create_bp_addr
= 0;
588 info
->td_death_bp_addr
= 0;
590 /* Set up the thread creation event. */
591 err
= enable_thread_event (TD_CREATE
, &info
->td_create_bp_addr
);
594 warning (_("Unable to get location for thread creation breakpoint: %s"),
595 thread_db_err_str (err
));
599 /* Set up the thread death event. */
600 err
= enable_thread_event (TD_DEATH
, &info
->td_death_bp_addr
);
603 warning (_("Unable to get location for thread death breakpoint: %s"),
604 thread_db_err_str (err
));
609 /* Same as thread_db_find_new_threads_1, but silently ignore errors. */
612 thread_db_find_new_threads_silently (ptid_t ptid
)
614 volatile struct gdb_exception except
;
616 TRY_CATCH (except
, RETURN_MASK_ERROR
)
618 thread_db_find_new_threads_2 (ptid
, 1);
621 if (except
.reason
< 0 && libthread_db_debug
)
623 exception_fprintf (gdb_stderr
, except
,
624 "Warning: thread_db_find_new_threads_silently: ");
628 /* Lookup a library in which given symbol resides.
629 Note: this is looking in GDB process, not in the inferior.
630 Returns library name, or NULL. */
633 dladdr_to_soname (const void *addr
)
637 if (dladdr (addr
, &info
) != 0)
638 return info
.dli_fname
;
642 /* Attempt to initialize dlopen()ed libthread_db, described by HANDLE.
644 Failure could happen if libthread_db does not have symbols we expect,
645 or when it refuses to work with the current inferior (e.g. due to
646 version mismatch between libthread_db and libpthread). */
649 try_thread_db_load_1 (struct thread_db_info
*info
)
653 /* Initialize pointers to the dynamic library functions we will use.
654 Essential functions first. */
656 info
->td_init_p
= verbose_dlsym (info
->handle
, "td_init");
657 if (info
->td_init_p
== NULL
)
660 err
= info
->td_init_p ();
663 warning (_("Cannot initialize libthread_db: %s"),
664 thread_db_err_str (err
));
668 info
->td_ta_new_p
= verbose_dlsym (info
->handle
, "td_ta_new");
669 if (info
->td_ta_new_p
== NULL
)
672 /* Initialize the structure that identifies the child process. */
673 info
->proc_handle
.ptid
= inferior_ptid
;
675 /* Now attempt to open a connection to the thread library. */
676 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
679 if (libthread_db_debug
)
680 printf_unfiltered (_("td_ta_new failed: %s\n"),
681 thread_db_err_str (err
));
686 #ifdef THREAD_DB_HAS_TD_VERSION
689 /* The errors above are not unexpected and silently ignored:
690 they just mean we haven't found correct version of
694 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
699 info
->td_ta_map_id2thr_p
= verbose_dlsym (info
->handle
, "td_ta_map_id2thr");
700 if (info
->td_ta_map_id2thr_p
== NULL
)
703 info
->td_ta_map_lwp2thr_p
= verbose_dlsym (info
->handle
,
704 "td_ta_map_lwp2thr");
705 if (info
->td_ta_map_lwp2thr_p
== NULL
)
708 info
->td_ta_thr_iter_p
= verbose_dlsym (info
->handle
, "td_ta_thr_iter");
709 if (info
->td_ta_thr_iter_p
== NULL
)
712 info
->td_thr_validate_p
= verbose_dlsym (info
->handle
, "td_thr_validate");
713 if (info
->td_thr_validate_p
== NULL
)
716 info
->td_thr_get_info_p
= verbose_dlsym (info
->handle
, "td_thr_get_info");
717 if (info
->td_thr_get_info_p
== NULL
)
720 /* These are not essential. */
721 info
->td_ta_event_addr_p
= dlsym (info
->handle
, "td_ta_event_addr");
722 info
->td_ta_set_event_p
= dlsym (info
->handle
, "td_ta_set_event");
723 info
->td_ta_clear_event_p
= dlsym (info
->handle
, "td_ta_clear_event");
724 info
->td_ta_event_getmsg_p
= dlsym (info
->handle
, "td_ta_event_getmsg");
725 info
->td_thr_event_enable_p
= dlsym (info
->handle
, "td_thr_event_enable");
726 info
->td_thr_tls_get_addr_p
= dlsym (info
->handle
, "td_thr_tls_get_addr");
728 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
730 if (libthread_db_debug
|| *libthread_db_search_path
)
734 library
= dladdr_to_soname (*info
->td_ta_new_p
);
736 library
= LIBTHREAD_DB_SO
;
738 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
742 /* The thread library was detected. Activate the thread_db target
743 if this is the first process using it. */
744 if (thread_db_list
->next
== NULL
)
745 push_target (&thread_db_ops
);
747 /* Enable event reporting, but not when debugging a core file. */
748 if (target_has_execution
)
749 enable_thread_event_reporting ();
751 /* There appears to be a bug in glibc-2.3.6: calls to td_thr_get_info fail
752 with TD_ERR for statically linked executables if td_thr_get_info is
753 called before glibc has initialized itself. Silently ignore such
754 errors, and let gdb enumerate threads again later. */
755 thread_db_find_new_threads_silently (inferior_ptid
);
760 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
761 relative, or just LIBTHREAD_DB. */
764 try_thread_db_load (const char *library
)
767 struct thread_db_info
*info
;
769 if (libthread_db_debug
)
770 printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
772 handle
= dlopen (library
, RTLD_NOW
);
775 if (libthread_db_debug
)
776 printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
780 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
784 td_init
= dlsym (handle
, "td_init");
787 const char *const libpath
= dladdr_to_soname (td_init
);
790 printf_unfiltered (_("Host %s resolved to: %s.\n"),
795 info
= add_thread_db_info (handle
);
797 if (try_thread_db_load_1 (info
))
800 /* This library "refused" to work on current inferior. */
801 delete_thread_db_info (GET_PID (inferior_ptid
));
806 /* Search libthread_db_search_path for libthread_db which "agrees"
807 to work on current inferior. */
810 thread_db_load_search (void)
813 const char *search_path
= libthread_db_search_path
;
818 const char *end
= strchr (search_path
, ':');
822 size_t len
= end
- search_path
;
824 if (len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1 > sizeof (path
))
826 char *cp
= xmalloc (len
+ 1);
828 memcpy (cp
, search_path
, len
);
830 warning (_("libthread_db_search_path component too long,"
831 " ignored: %s."), cp
);
833 search_path
+= len
+ 1;
836 memcpy (path
, search_path
, len
);
838 search_path
+= len
+ 1;
842 size_t len
= strlen (search_path
);
844 if (len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1 > sizeof (path
))
846 warning (_("libthread_db_search_path component too long,"
847 " ignored: %s."), search_path
);
850 memcpy (path
, search_path
, len
+ 1);
854 strcat (path
, LIBTHREAD_DB_SO
);
855 if (try_thread_db_load (path
))
862 rc
= try_thread_db_load (LIBTHREAD_DB_SO
);
866 /* Attempt to load and initialize libthread_db.
871 thread_db_load (void)
874 struct thread_db_info
*info
;
876 info
= get_thread_db_info (GET_PID (inferior_ptid
));
881 /* Don't attempt to use thread_db on executables not running
883 if (!target_has_registers
)
886 /* Don't attempt to use thread_db for remote targets. */
887 if (!(target_can_run (¤t_target
) || core_bfd
))
890 if (thread_db_load_search ())
893 /* None of the libthread_db's on our search path, not the system default
894 ones worked. If the executable is dynamically linked against
895 libpthread, try loading libthread_db from the same directory. */
898 if (libpthread_name_p (obj
->name
))
900 char path
[PATH_MAX
], *cp
;
902 gdb_assert (strlen (obj
->name
) < sizeof (path
));
903 strcpy (path
, obj
->name
);
904 cp
= strrchr (path
, '/');
908 warning (_("Expected absolute pathname for libpthread in the"
909 " inferior, but got %s."), path
);
911 else if (cp
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1 > path
+ sizeof (path
))
913 warning (_("Unexpected: path to libpthread in the inferior is"
914 " too long: %s"), path
);
918 strcpy (cp
+ 1, LIBTHREAD_DB_SO
);
919 if (try_thread_db_load (path
))
922 warning (_("Unable to find libthread_db matching inferior's thread"
923 " library, thread debugging will not be available."));
926 /* Either this executable isn't using libpthread at all, or it is
927 statically linked. Since we can't easily distinguish these two cases,
928 no warning is issued. */
933 disable_thread_event_reporting (struct thread_db_info
*info
)
935 if (info
->td_ta_clear_event_p
!= NULL
)
937 td_thr_events_t events
;
939 /* Set the process wide mask saying we aren't interested in any
941 td_event_fillset (&events
);
942 info
->td_ta_clear_event_p (info
->thread_agent
, &events
);
945 info
->td_create_bp_addr
= 0;
946 info
->td_death_bp_addr
= 0;
950 check_thread_signals (void)
957 lin_thread_get_thread_signals (&mask
);
958 sigemptyset (&thread_stop_set
);
959 sigemptyset (&thread_print_set
);
961 for (i
= 1; i
< NSIG
; i
++)
963 if (sigismember (&mask
, i
))
965 if (signal_stop_update (target_signal_from_host (i
), 0))
966 sigaddset (&thread_stop_set
, i
);
967 if (signal_print_update (target_signal_from_host (i
), 0))
968 sigaddset (&thread_print_set
, i
);
975 /* Check whether thread_db is usable. This function is called when
976 an inferior is created (or otherwise acquired, e.g. attached to)
977 and when new shared libraries are loaded into a running process. */
980 check_for_thread_db (void)
982 /* Do nothing if we couldn't load libthread_db.so.1. */
983 if (!thread_db_load ())
988 thread_db_new_objfile (struct objfile
*objfile
)
990 /* This observer must always be called with inferior_ptid set
994 check_for_thread_db ();
997 /* Attach to a new thread. This function is called when we receive a
998 TD_CREATE event or when we iterate over all threads and find one
999 that wasn't already in our list. Returns true on success. */
1002 attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
1003 const td_thrinfo_t
*ti_p
)
1005 struct private_thread_info
*private;
1006 struct thread_info
*tp
= NULL
;
1008 struct thread_db_info
*info
;
1010 /* If we're being called after a TD_CREATE event, we may already
1011 know about this thread. There are two ways this can happen. We
1012 may have iterated over all threads between the thread creation
1013 and the TD_CREATE event, for instance when the user has issued
1014 the `info threads' command before the SIGTRAP for hitting the
1015 thread creation breakpoint was reported. Alternatively, the
1016 thread may have exited and a new one been created with the same
1017 thread ID. In the first case we don't need to do anything; in
1018 the second case we should discard information about the dead
1019 thread and attach to the new one. */
1020 if (in_thread_list (ptid
))
1022 tp
= find_thread_ptid (ptid
);
1023 gdb_assert (tp
!= NULL
);
1025 /* If tp->private is NULL, then GDB is already attached to this
1026 thread, but we do not know anything about it. We can learn
1027 about it here. This can only happen if we have some other
1028 way besides libthread_db to notice new threads (i.e.
1029 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
1030 exit, so this can not be a stale thread recreated with the
1032 if (tp
->private != NULL
)
1034 if (!tp
->private->dying
)
1037 delete_thread (ptid
);
1042 if (target_has_execution
)
1043 check_thread_signals ();
1045 if (ti_p
->ti_state
== TD_THR_UNKNOWN
|| ti_p
->ti_state
== TD_THR_ZOMBIE
)
1046 return 0; /* A zombie thread -- do not attach. */
1048 /* Under GNU/Linux, we have to attach to each and every thread. */
1049 if (target_has_execution
1051 && lin_lwp_attach_lwp (BUILD_LWP (ti_p
->ti_lid
, GET_PID (ptid
))) < 0)
1054 /* Construct the thread's private data. */
1055 private = xmalloc (sizeof (struct private_thread_info
));
1056 memset (private, 0, sizeof (struct private_thread_info
));
1058 /* A thread ID of zero may mean the thread library has not initialized
1059 yet. But we shouldn't even get here if that's the case. FIXME:
1060 if we change GDB to always have at least one thread in the thread
1061 list this will have to go somewhere else; maybe private == NULL
1062 until the thread_db target claims it. */
1063 gdb_assert (ti_p
->ti_tid
!= 0);
1064 private->th
= *th_p
;
1065 private->tid
= ti_p
->ti_tid
;
1067 /* Add the thread to GDB's thread list. */
1069 tp
= add_thread_with_info (ptid
, private);
1071 tp
->private = private;
1073 info
= get_thread_db_info (GET_PID (ptid
));
1075 /* Enable thread event reporting for this thread, except when
1076 debugging a core file. */
1077 if (target_has_execution
)
1079 err
= info
->td_thr_event_enable_p (th_p
, 1);
1081 error (_("Cannot enable thread event reporting for %s: %s"),
1082 target_pid_to_str (ptid
), thread_db_err_str (err
));
1089 detach_thread (ptid_t ptid
)
1091 struct thread_info
*thread_info
;
1093 /* Don't delete the thread now, because it still reports as active
1094 until it has executed a few instructions after the event
1095 breakpoint - if we deleted it now, "info threads" would cause us
1096 to re-attach to it. Just mark it as having had a TD_DEATH
1097 event. This means that we won't delete it from our thread list
1098 until we notice that it's dead (via prune_threads), or until
1099 something re-uses its thread ID. We'll report the thread exit
1100 when the underlying LWP dies. */
1101 thread_info
= find_thread_ptid (ptid
);
1102 gdb_assert (thread_info
!= NULL
&& thread_info
->private != NULL
);
1103 thread_info
->private->dying
= 1;
1107 thread_db_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1109 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1110 struct thread_db_info
*info
;
1112 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1116 if (target_has_execution
)
1118 disable_thread_event_reporting (info
);
1120 /* Delete the old thread event breakpoints. Note that
1121 unlike when mourning, we can remove them here because
1122 there's still a live inferior to poke at. In any case,
1123 GDB will not try to insert anything in the inferior when
1124 removing a breakpoint. */
1125 remove_thread_event_breakpoints ();
1128 delete_thread_db_info (GET_PID (inferior_ptid
));
1131 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
1133 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1135 /* If there are no more processes using libpthread, detach the
1136 thread_db target ops. */
1137 if (!thread_db_list
)
1138 unpush_target (&thread_db_ops
);
1141 /* Check if PID is currently stopped at the location of a thread event
1142 breakpoint location. If it is, read the event message and act upon
1146 check_event (ptid_t ptid
)
1148 struct regcache
*regcache
= get_thread_regcache (ptid
);
1149 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1155 struct thread_db_info
*info
;
1157 info
= get_thread_db_info (GET_PID (ptid
));
1159 /* Bail out early if we're not at a thread event breakpoint. */
1160 stop_pc
= regcache_read_pc (regcache
)
1161 - gdbarch_decr_pc_after_break (gdbarch
);
1162 if (stop_pc
!= info
->td_create_bp_addr
1163 && stop_pc
!= info
->td_death_bp_addr
)
1166 /* Access an lwp we know is stopped. */
1167 info
->proc_handle
.ptid
= ptid
;
1169 /* If we have only looked at the first thread before libpthread was
1170 initialized, we may not know its thread ID yet. Make sure we do
1171 before we add another thread to the list. */
1172 if (!have_threads (ptid
))
1173 thread_db_find_new_threads_1 (ptid
);
1175 /* If we are at a create breakpoint, we do not know what new lwp
1176 was created and cannot specifically locate the event message for it.
1177 We have to call td_ta_event_getmsg() to get
1178 the latest message. Since we have no way of correlating whether
1179 the event message we get back corresponds to our breakpoint, we must
1180 loop and read all event messages, processing them appropriately.
1181 This guarantees we will process the correct message before continuing
1182 from the breakpoint.
1184 Currently, death events are not enabled. If they are enabled,
1185 the death event can use the td_thr_event_getmsg() interface to
1186 get the message specifically for that lwp and avoid looping
1193 err
= info
->td_ta_event_getmsg_p (info
->thread_agent
, &msg
);
1196 if (err
== TD_NOMSG
)
1199 error (_("Cannot get thread event message: %s"),
1200 thread_db_err_str (err
));
1203 err
= info
->td_thr_get_info_p (msg
.th_p
, &ti
);
1205 error (_("Cannot get thread info: %s"), thread_db_err_str (err
));
1207 ptid
= ptid_build (GET_PID (ptid
), ti
.ti_lid
, 0);
1212 /* Call attach_thread whether or not we already know about a
1213 thread with this thread ID. */
1214 attach_thread (ptid
, msg
.th_p
, &ti
);
1220 if (!in_thread_list (ptid
))
1221 error (_("Spurious thread death event."));
1223 detach_thread (ptid
);
1228 error (_("Spurious thread event."));
1235 thread_db_wait (struct target_ops
*ops
,
1236 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1239 struct thread_db_info
*info
;
1240 struct target_ops
*beneath
= find_target_beneath (ops
);
1242 ptid
= beneath
->to_wait (beneath
, ptid
, ourstatus
, options
);
1244 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
1247 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
1248 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
1251 info
= get_thread_db_info (GET_PID (ptid
));
1253 /* If this process isn't using thread_db, we're done. */
1257 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1259 /* New image, it may or may not end up using thread_db. Assume
1260 not unless we find otherwise. */
1261 delete_thread_db_info (GET_PID (ptid
));
1262 if (!thread_db_list
)
1263 unpush_target (&thread_db_ops
);
1265 /* Thread event breakpoints are deleted by
1266 update_breakpoints_after_exec. */
1271 /* If we do not know about the main thread yet, this would be a good time to
1273 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
&& !have_threads (ptid
))
1274 thread_db_find_new_threads_1 (ptid
);
1276 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
1277 && ourstatus
->value
.sig
== TARGET_SIGNAL_TRAP
)
1278 /* Check for a thread event. */
1281 if (have_threads (ptid
))
1283 /* Change ptids back into the higher level PID + TID format. If
1284 the thread is dead and no longer on the thread list, we will
1285 get back a dead ptid. This can occur if the thread death
1286 event gets postponed by other simultaneous events. In such a
1287 case, we want to just ignore the event and continue on. */
1289 ptid
= thread_from_lwp (ptid
);
1290 if (GET_PID (ptid
) == -1)
1291 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1298 thread_db_mourn_inferior (struct target_ops
*ops
)
1300 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1302 delete_thread_db_info (GET_PID (inferior_ptid
));
1304 target_beneath
->to_mourn_inferior (target_beneath
);
1306 /* Delete the old thread event breakpoints. Do this after mourning
1307 the inferior, so that we don't try to uninsert them. */
1308 remove_thread_event_breakpoints ();
1310 /* Detach thread_db target ops. */
1311 if (!thread_db_list
)
1312 unpush_target (ops
);
1315 struct callback_data
1317 struct thread_db_info
*info
;
1322 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1327 struct thread_info
*tp
;
1328 struct callback_data
*cb_data
= data
;
1329 struct thread_db_info
*info
= cb_data
->info
;
1331 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1333 error (_("find_new_threads_callback: cannot get thread info: %s"),
1334 thread_db_err_str (err
));
1336 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
1337 return 0; /* A zombie -- ignore. */
1339 if (ti
.ti_tid
== 0 && target_has_execution
)
1341 /* A thread ID of zero means that this is the main thread, but
1342 glibc has not yet initialized thread-local storage and the
1343 pthread library. We do not know what the thread's TID will
1344 be yet. Just enable event reporting and otherwise ignore
1347 /* In that case, we're not stopped in a fork syscall and don't
1348 need this glibc bug workaround. */
1349 info
->need_stale_parent_threads_check
= 0;
1351 err
= info
->td_thr_event_enable_p (th_p
, 1);
1353 error (_("Cannot enable thread event reporting for LWP %d: %s"),
1354 (int) ti
.ti_lid
, thread_db_err_str (err
));
1359 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1360 bit expensive, as it needs to open /proc/pid/status, so try to
1361 avoid doing the work if we know we don't have to. */
1362 if (info
->need_stale_parent_threads_check
)
1364 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1366 if (tgid
!= -1 && tgid
!= info
->pid
)
1370 ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
1371 tp
= find_thread_ptid (ptid
);
1372 if (tp
== NULL
|| tp
->private == NULL
)
1374 if (attach_thread (ptid
, th_p
, &ti
))
1375 cb_data
->new_threads
+= 1;
1377 /* Problem attaching this thread; perhaps it exited before we
1379 This could mean that the thread list inside glibc itself is in
1380 inconsistent state, and libthread_db could go on looping forever
1381 (observed with glibc-2.3.6). To prevent that, terminate
1382 iteration: thread_db_find_new_threads_2 will retry. */
1389 /* Helper for thread_db_find_new_threads_2.
1390 Returns number of new threads found. */
1393 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1396 volatile struct gdb_exception except
;
1397 struct callback_data data
;
1398 td_err_e err
= TD_ERR
;
1401 data
.new_threads
= 0;
1403 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1405 /* Iterate over all user-space threads to discover new threads. */
1406 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1407 find_new_threads_callback
,
1410 TD_THR_LOWEST_PRIORITY
,
1412 TD_THR_ANY_USER_FLAGS
);
1415 if (libthread_db_debug
)
1417 if (except
.reason
< 0)
1418 exception_fprintf (gdb_stderr
, except
,
1419 "Warning: find_new_threads_once: ");
1421 printf_filtered (_("Found %d new threads in iteration %d.\n"),
1422 data
.new_threads
, iteration
);
1428 return data
.new_threads
;
1431 /* Search for new threads, accessing memory through stopped thread
1432 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1433 searches in a row do not discover any new threads. */
1436 thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
)
1439 struct thread_db_info
*info
;
1440 int pid
= ptid_get_pid (ptid
);
1443 if (target_has_execution
)
1445 struct lwp_info
*lp
;
1447 /* In linux, we can only read memory through a stopped lwp. */
1449 if (lp
->stopped
&& ptid_get_pid (lp
->ptid
) == pid
)
1453 /* There is no stopped thread. Bail out. */
1457 info
= get_thread_db_info (GET_PID (ptid
));
1459 /* Access an lwp we know is stopped. */
1460 info
->proc_handle
.ptid
= ptid
;
1464 /* Require 4 successive iterations which do not find any new threads.
1465 The 4 is a heuristic: there is an inherent race here, and I have
1466 seen that 2 iterations in a row are not always sufficient to
1467 "capture" all threads. */
1468 for (i
= 0, loop
= 0; loop
< 4; ++i
, ++loop
)
1469 if (find_new_threads_once (info
, i
, NULL
) != 0)
1470 /* Found some new threads. Restart the loop from beginning. */
1475 find_new_threads_once (info
, 0, &err
);
1477 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1482 thread_db_find_new_threads_1 (ptid_t ptid
)
1484 thread_db_find_new_threads_2 (ptid
, 0);
1488 update_thread_core (struct lwp_info
*info
, void *closure
)
1490 info
->core
= linux_nat_core_of_thread_1 (info
->ptid
);
1495 thread_db_find_new_threads (struct target_ops
*ops
)
1497 struct thread_db_info
*info
;
1499 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1504 thread_db_find_new_threads_1 (inferior_ptid
);
1506 if (target_has_execution
)
1507 iterate_over_lwps (minus_one_ptid
/* iterate over all */,
1508 update_thread_core
, NULL
);
1512 thread_db_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
1514 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1515 struct target_ops
*beneath
;
1517 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1519 static char buf
[64];
1522 tid
= thread_info
->private->tid
;
1523 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1524 tid
, GET_LWP (ptid
));
1529 beneath
= find_target_beneath (ops
);
1530 if (beneath
->to_pid_to_str (beneath
, ptid
))
1531 return beneath
->to_pid_to_str (beneath
, ptid
);
1533 return normal_pid_to_str (ptid
);
1536 /* Return a string describing the state of the thread specified by
1540 thread_db_extra_thread_info (struct thread_info
*info
)
1542 if (info
->private == NULL
)
1545 if (info
->private->dying
)
1551 /* Get the address of the thread local variable in load module LM which
1552 is stored at OFFSET within the thread local storage for thread PTID. */
1555 thread_db_get_thread_local_address (struct target_ops
*ops
,
1560 struct thread_info
*thread_info
;
1561 struct target_ops
*beneath
;
1563 /* If we have not discovered any threads yet, check now. */
1564 if (!have_threads (ptid
))
1565 thread_db_find_new_threads_1 (ptid
);
1567 /* Find the matching thread. */
1568 thread_info
= find_thread_ptid (ptid
);
1570 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1574 struct thread_db_info
*info
;
1576 info
= get_thread_db_info (GET_PID (ptid
));
1578 /* glibc doesn't provide the needed interface. */
1579 if (!info
->td_thr_tls_get_addr_p
)
1580 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1581 _("No TLS library support"));
1583 /* Caller should have verified that lm != 0. */
1584 gdb_assert (lm
!= 0);
1586 /* Finally, get the address of the variable. */
1587 /* Note the cast through uintptr_t: this interface only works if
1588 a target address fits in a psaddr_t, which is a host pointer.
1589 So a 32-bit debugger can not access 64-bit TLS through this. */
1590 err
= info
->td_thr_tls_get_addr_p (&thread_info
->private->th
,
1591 (psaddr_t
)(uintptr_t) lm
,
1594 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1595 /* The memory hasn't been allocated, yet. */
1596 if (err
== TD_NOTALLOC
)
1597 /* Now, if libthread_db provided the initialization image's
1598 address, we *could* try to build a non-lvalue value from
1599 the initialization image. */
1600 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1601 _("TLS not allocated yet"));
1604 /* Something else went wrong. */
1606 throw_error (TLS_GENERIC_ERROR
,
1607 (("%s")), thread_db_err_str (err
));
1609 /* Cast assuming host == target. Joy. */
1610 /* Do proper sign extension for the target. */
1611 gdb_assert (exec_bfd
);
1612 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1613 ? (CORE_ADDR
) (intptr_t) address
1614 : (CORE_ADDR
) (uintptr_t) address
);
1617 beneath
= find_target_beneath (ops
);
1618 if (beneath
->to_get_thread_local_address
)
1619 return beneath
->to_get_thread_local_address (beneath
, ptid
, lm
, offset
);
1621 throw_error (TLS_GENERIC_ERROR
,
1622 _("TLS not supported on this target"));
1625 /* Callback routine used to find a thread based on the TID part of
1629 thread_db_find_thread_from_tid (struct thread_info
*thread
, void *data
)
1631 long *tid
= (long *) data
;
1633 if (thread
->private->tid
== *tid
)
1639 /* Implement the to_get_ada_task_ptid target method for this target. */
1642 thread_db_get_ada_task_ptid (long lwp
, long thread
)
1644 struct thread_info
*thread_info
;
1646 thread_db_find_new_threads_1 (inferior_ptid
);
1647 thread_info
= iterate_over_threads (thread_db_find_thread_from_tid
, &thread
);
1649 gdb_assert (thread_info
!= NULL
);
1651 return (thread_info
->ptid
);
1655 thread_db_resume (struct target_ops
*ops
,
1656 ptid_t ptid
, int step
, enum target_signal signo
)
1658 struct target_ops
*beneath
= find_target_beneath (ops
);
1659 struct thread_db_info
*info
;
1661 if (ptid_equal (ptid
, minus_one_ptid
))
1662 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1664 info
= get_thread_db_info (GET_PID (ptid
));
1666 /* This workaround is only needed for child fork lwps stopped in a
1667 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1668 workaround can be disabled. */
1670 info
->need_stale_parent_threads_check
= 0;
1672 beneath
->to_resume (beneath
, ptid
, step
, signo
);
1676 init_thread_db_ops (void)
1678 thread_db_ops
.to_shortname
= "multi-thread";
1679 thread_db_ops
.to_longname
= "multi-threaded child process.";
1680 thread_db_ops
.to_doc
= "Threads and pthreads support.";
1681 thread_db_ops
.to_detach
= thread_db_detach
;
1682 thread_db_ops
.to_wait
= thread_db_wait
;
1683 thread_db_ops
.to_resume
= thread_db_resume
;
1684 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
1685 thread_db_ops
.to_find_new_threads
= thread_db_find_new_threads
;
1686 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
1687 thread_db_ops
.to_stratum
= thread_stratum
;
1688 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
1689 thread_db_ops
.to_get_thread_local_address
1690 = thread_db_get_thread_local_address
;
1691 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
1692 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
1693 thread_db_ops
.to_magic
= OPS_MAGIC
;
1696 /* Provide a prototype to silence -Wmissing-prototypes. */
1697 extern initialize_file_ftype _initialize_thread_db
;
1700 _initialize_thread_db (void)
1702 init_thread_db_ops ();
1703 add_target (&thread_db_ops
);
1705 /* Defer loading of libthread_db.so until inferior is running.
1706 This allows gdb to load correct libthread_db for a given
1707 executable -- there could be mutiple versions of glibc,
1708 compiled with LinuxThreads or NPTL, and until there is
1709 a running inferior, we can't tell which libthread_db is
1710 the correct one to load. */
1712 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
1714 add_setshow_optional_filename_cmd ("libthread-db-search-path",
1716 &libthread_db_search_path
, _("\
1717 Set search path for libthread_db."), _("\
1718 Show the current search path or libthread_db."), _("\
1719 This path is used to search for libthread_db to be loaded into \
1723 &setlist
, &showlist
);
1725 add_setshow_zinteger_cmd ("libthread-db", class_maintenance
,
1726 &libthread_db_debug
, _("\
1727 Set libthread-db debugging."), _("\
1728 Show libthread-db debugging."), _("\
1729 When non-zero, libthread-db debugging is enabled."),
1731 show_libthread_db_debug
,
1732 &setdebuglist
, &showdebuglist
);
1734 /* Add ourselves to objfile event chain. */
1735 observer_attach_new_objfile (thread_db_new_objfile
);