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
;
79 set_libthread_db_search_path (char *ignored
, int from_tty
,
80 struct cmd_list_element
*c
)
82 if (*libthread_db_search_path
== '\0')
84 xfree (libthread_db_search_path
);
85 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
89 /* If non-zero, print details of libthread_db processing. */
91 static int libthread_db_debug
;
94 show_libthread_db_debug (struct ui_file
*file
, int from_tty
,
95 struct cmd_list_element
*c
, const char *value
)
97 fprintf_filtered (file
, _("libthread-db debugging is %s.\n"), value
);
100 /* If we're running on GNU/Linux, we must explicitly attach to any new
103 /* This module's target vector. */
104 static struct target_ops thread_db_ops
;
106 /* Non-zero if we have determined the signals used by the threads
108 static int thread_signals
;
109 static sigset_t thread_stop_set
;
110 static sigset_t thread_print_set
;
112 struct thread_db_info
114 struct thread_db_info
*next
;
116 /* Process id this object refers to. */
119 /* Handle from dlopen for libthread_db.so. */
122 /* Structure that identifies the child process for the
123 <proc_service.h> interface. */
124 struct ps_prochandle proc_handle
;
126 /* Connection to the libthread_db library. */
127 td_thragent_t
*thread_agent
;
129 /* True if we need to apply the workaround for glibc/BZ5983. When
130 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
131 list, nptl_db returns the parent's threads in addition to the new
132 (single) child thread. If this flag is set, we do extra work to
133 be able to ignore such stale entries. */
134 int need_stale_parent_threads_check
;
136 /* Location of the thread creation event breakpoint. The code at
137 this location in the child process will be called by the pthread
138 library whenever a new thread is created. By setting a special
139 breakpoint at this location, GDB can detect when a new thread is
140 created. We obtain this location via the td_ta_event_addr
142 CORE_ADDR td_create_bp_addr
;
144 /* Location of the thread death event breakpoint. */
145 CORE_ADDR td_death_bp_addr
;
147 /* Pointers to the libthread_db functions. */
149 td_err_e (*td_init_p
) (void);
151 td_err_e (*td_ta_new_p
) (struct ps_prochandle
* ps
,
153 td_err_e (*td_ta_map_id2thr_p
) (const td_thragent_t
*ta
, thread_t pt
,
154 td_thrhandle_t
*__th
);
155 td_err_e (*td_ta_map_lwp2thr_p
) (const td_thragent_t
*ta
,
156 lwpid_t lwpid
, td_thrhandle_t
*th
);
157 td_err_e (*td_ta_thr_iter_p
) (const td_thragent_t
*ta
,
158 td_thr_iter_f
*callback
, void *cbdata_p
,
159 td_thr_state_e state
, int ti_pri
,
160 sigset_t
*ti_sigmask_p
,
161 unsigned int ti_user_flags
);
162 td_err_e (*td_ta_event_addr_p
) (const td_thragent_t
*ta
,
163 td_event_e event
, td_notify_t
*ptr
);
164 td_err_e (*td_ta_set_event_p
) (const td_thragent_t
*ta
,
165 td_thr_events_t
*event
);
166 td_err_e (*td_ta_clear_event_p
) (const td_thragent_t
*ta
,
167 td_thr_events_t
*event
);
168 td_err_e (*td_ta_event_getmsg_p
) (const td_thragent_t
*ta
,
169 td_event_msg_t
*msg
);
171 td_err_e (*td_thr_validate_p
) (const td_thrhandle_t
*th
);
172 td_err_e (*td_thr_get_info_p
) (const td_thrhandle_t
*th
,
173 td_thrinfo_t
*infop
);
174 td_err_e (*td_thr_event_enable_p
) (const td_thrhandle_t
*th
,
177 td_err_e (*td_thr_tls_get_addr_p
) (const td_thrhandle_t
*th
,
178 psaddr_t map_address
,
179 size_t offset
, psaddr_t
*address
);
182 /* List of known processes using thread_db, and the required
184 struct thread_db_info
*thread_db_list
;
186 static void thread_db_find_new_threads_1 (ptid_t ptid
);
187 static void thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
);
189 /* Add the current inferior to the list of processes using libpthread.
190 Return a pointer to the newly allocated object that was added to
191 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
194 static struct thread_db_info
*
195 add_thread_db_info (void *handle
)
197 struct thread_db_info
*info
;
199 info
= xcalloc (1, sizeof (*info
));
200 info
->pid
= ptid_get_pid (inferior_ptid
);
201 info
->handle
= handle
;
203 /* The workaround works by reading from /proc/pid/status, so it is
204 disabled for core files. */
205 if (target_has_execution
)
206 info
->need_stale_parent_threads_check
= 1;
208 info
->next
= thread_db_list
;
209 thread_db_list
= info
;
214 /* Return the thread_db_info object representing the bookkeeping
215 related to process PID, if any; NULL otherwise. */
217 static struct thread_db_info
*
218 get_thread_db_info (int pid
)
220 struct thread_db_info
*info
;
222 for (info
= thread_db_list
; info
; info
= info
->next
)
223 if (pid
== info
->pid
)
229 /* When PID has exited or has been detached, we no longer want to keep
230 track of it as using libpthread. Call this function to discard
231 thread_db related info related to PID. Note that this closes
232 LIBTHREAD_DB_SO's dlopen'ed handle. */
235 delete_thread_db_info (int pid
)
237 struct thread_db_info
*info
, *info_prev
;
241 for (info
= thread_db_list
; info
; info_prev
= info
, info
= info
->next
)
242 if (pid
== info
->pid
)
248 if (info
->handle
!= NULL
)
249 dlclose (info
->handle
);
252 info_prev
->next
= info
->next
;
254 thread_db_list
= info
->next
;
259 /* Prototypes for local functions. */
260 static int attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
261 const td_thrinfo_t
*ti_p
);
262 static void detach_thread (ptid_t ptid
);
265 /* Use "struct private_thread_info" to cache thread state. This is
266 a substantial optimization. */
268 struct private_thread_info
270 /* Flag set when we see a TD_DEATH event for this thread. */
271 unsigned int dying
:1;
273 /* Cached thread state. */
280 thread_db_err_str (td_err_e err
)
287 return "generic 'call succeeded'";
289 return "generic error";
291 return "no thread to satisfy query";
293 return "no sync handle to satisfy query";
295 return "no LWP to satisfy query";
297 return "invalid process handle";
299 return "invalid thread handle";
301 return "invalid synchronization handle";
303 return "invalid thread agent";
305 return "invalid key";
307 return "no event message for getmsg";
309 return "FPU register set not available";
311 return "application not linked with libthread";
313 return "requested event is not supported";
315 return "capability not available";
317 return "debugger service failed";
319 return "operation not applicable to";
321 return "no thread-specific data for this thread";
323 return "malloc failed";
325 return "only part of register set was written/read";
327 return "X register set not available for this thread";
328 #ifdef THREAD_DB_HAS_TD_NOTALLOC
330 return "thread has not yet allocated TLS for given module";
332 #ifdef THREAD_DB_HAS_TD_VERSION
334 return "versions of libpthread and libthread_db do not match";
336 #ifdef THREAD_DB_HAS_TD_NOTLS
338 return "there is no TLS segment in the given module";
341 snprintf (buf
, sizeof (buf
), "unknown thread_db error '%d'", err
);
346 /* Return 1 if any threads have been registered. There may be none if
347 the threading library is not fully initialized yet. */
350 have_threads_callback (struct thread_info
*thread
, void *args
)
352 int pid
= * (int *) args
;
354 if (ptid_get_pid (thread
->ptid
) != pid
)
357 return thread
->private != NULL
;
361 have_threads (ptid_t ptid
)
363 int pid
= ptid_get_pid (ptid
);
365 return iterate_over_threads (have_threads_callback
, &pid
) != NULL
;
368 struct thread_get_info_inout
370 struct thread_info
*thread_info
;
371 struct thread_db_info
*thread_db_info
;
374 /* A callback function for td_ta_thr_iter, which we use to map all
377 THP is a handle to the current thread; if INFOP is not NULL, the
378 struct thread_info associated with this thread is returned in
381 If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
382 zero is returned to indicate success. */
385 thread_get_info_callback (const td_thrhandle_t
*thp
, void *argp
)
390 struct thread_get_info_inout
*inout
;
391 struct thread_db_info
*info
;
394 info
= inout
->thread_db_info
;
396 err
= info
->td_thr_get_info_p (thp
, &ti
);
398 error (_("thread_get_info_callback: cannot get thread info: %s"),
399 thread_db_err_str (err
));
401 /* Fill the cache. */
402 thread_ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
403 inout
->thread_info
= find_thread_ptid (thread_ptid
);
405 /* In the case of a zombie thread, don't continue. We don't want to
406 attach to it thinking it is a new thread. */
407 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
408 return TD_THR_ZOMBIE
;
410 if (inout
->thread_info
== NULL
)
412 /* New thread. Attach to it now (why wait?). */
413 if (!have_threads (thread_ptid
))
414 thread_db_find_new_threads_1 (thread_ptid
);
416 attach_thread (thread_ptid
, thp
, &ti
);
417 inout
->thread_info
= find_thread_ptid (thread_ptid
);
418 gdb_assert (inout
->thread_info
!= NULL
);
424 /* Convert between user-level thread ids and LWP ids. */
427 thread_from_lwp (ptid_t ptid
)
431 struct thread_db_info
*info
;
432 struct thread_get_info_inout io
= {0};
434 /* This ptid comes from linux-nat.c, which should always fill in the
436 gdb_assert (GET_LWP (ptid
) != 0);
438 info
= get_thread_db_info (GET_PID (ptid
));
440 /* Access an lwp we know is stopped. */
441 info
->proc_handle
.ptid
= ptid
;
442 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
444 error (_("Cannot find user-level thread for LWP %ld: %s"),
445 GET_LWP (ptid
), thread_db_err_str (err
));
447 /* Fetch the thread info. If we get back TD_THR_ZOMBIE, then the
448 event thread has already died. If another gdb interface has called
449 thread_alive() previously, the thread won't be found on the thread list
450 anymore. In that case, we don't want to process this ptid anymore
451 to avoid the possibility of later treating it as a newly
452 discovered thread id that we should add to the list. Thus,
453 we return a -1 ptid which is also how the thread list marks a
455 io
.thread_db_info
= info
;
456 io
.thread_info
= NULL
;
457 if (thread_get_info_callback (&th
, &io
) == TD_THR_ZOMBIE
458 && io
.thread_info
== NULL
)
459 return minus_one_ptid
;
461 gdb_assert (ptid_get_tid (ptid
) == 0);
466 /* Attach to lwp PTID, doing whatever else is required to have this
467 LWP under the debugger's control --- e.g., enabling event
468 reporting. Returns true on success. */
470 thread_db_attach_lwp (ptid_t ptid
)
475 struct thread_db_info
*info
;
477 info
= get_thread_db_info (GET_PID (ptid
));
482 /* This ptid comes from linux-nat.c, which should always fill in the
484 gdb_assert (GET_LWP (ptid
) != 0);
486 /* Access an lwp we know is stopped. */
487 info
->proc_handle
.ptid
= ptid
;
489 /* If we have only looked at the first thread before libpthread was
490 initialized, we may not know its thread ID yet. Make sure we do
491 before we add another thread to the list. */
492 if (!have_threads (ptid
))
493 thread_db_find_new_threads_1 (ptid
);
495 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
497 /* Cannot find user-level thread. */
500 err
= info
->td_thr_get_info_p (&th
, &ti
);
503 warning (_("Cannot get thread info: %s"), thread_db_err_str (err
));
507 attach_thread (ptid
, &th
, &ti
);
512 verbose_dlsym (void *handle
, const char *name
)
514 void *sym
= dlsym (handle
, name
);
516 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
522 enable_thread_event (int event
, CORE_ADDR
*bp
)
526 struct thread_db_info
*info
;
528 info
= get_thread_db_info (GET_PID (inferior_ptid
));
530 /* Access an lwp we know is stopped. */
531 info
->proc_handle
.ptid
= inferior_ptid
;
533 /* Get the breakpoint address for thread EVENT. */
534 err
= info
->td_ta_event_addr_p (info
->thread_agent
, event
, ¬ify
);
538 /* Set up the breakpoint. */
539 gdb_assert (exec_bfd
);
540 (*bp
) = (gdbarch_convert_from_func_ptr_addr
542 /* Do proper sign extension for the target. */
543 (bfd_get_sign_extend_vma (exec_bfd
) > 0
544 ? (CORE_ADDR
) (intptr_t) notify
.u
.bptaddr
545 : (CORE_ADDR
) (uintptr_t) notify
.u
.bptaddr
),
547 create_thread_event_breakpoint (target_gdbarch
, *bp
);
553 enable_thread_event_reporting (void)
555 td_thr_events_t events
;
557 #ifdef HAVE_GNU_LIBC_VERSION_H
558 const char *libc_version
;
559 int libc_major
, libc_minor
;
561 struct thread_db_info
*info
;
563 info
= get_thread_db_info (GET_PID (inferior_ptid
));
565 /* We cannot use the thread event reporting facility if these
566 functions aren't available. */
567 if (info
->td_ta_event_addr_p
== NULL
568 || info
->td_ta_set_event_p
== NULL
569 || info
->td_ta_event_getmsg_p
== NULL
570 || info
->td_thr_event_enable_p
== NULL
)
573 /* Set the process wide mask saying which events we're interested in. */
574 td_event_emptyset (&events
);
575 td_event_addset (&events
, TD_CREATE
);
577 #ifdef HAVE_GNU_LIBC_VERSION_H
578 /* The event reporting facility is broken for TD_DEATH events in
579 glibc 2.1.3, so don't enable it if we have glibc but a lower
581 libc_version
= gnu_get_libc_version ();
582 if (sscanf (libc_version
, "%d.%d", &libc_major
, &libc_minor
) == 2
583 && (libc_major
> 2 || (libc_major
== 2 && libc_minor
> 1)))
585 td_event_addset (&events
, TD_DEATH
);
587 err
= info
->td_ta_set_event_p (info
->thread_agent
, &events
);
590 warning (_("Unable to set global thread event mask: %s"),
591 thread_db_err_str (err
));
595 /* Delete previous thread event breakpoints, if any. */
596 remove_thread_event_breakpoints ();
597 info
->td_create_bp_addr
= 0;
598 info
->td_death_bp_addr
= 0;
600 /* Set up the thread creation event. */
601 err
= enable_thread_event (TD_CREATE
, &info
->td_create_bp_addr
);
604 warning (_("Unable to get location for thread creation breakpoint: %s"),
605 thread_db_err_str (err
));
609 /* Set up the thread death event. */
610 err
= enable_thread_event (TD_DEATH
, &info
->td_death_bp_addr
);
613 warning (_("Unable to get location for thread death breakpoint: %s"),
614 thread_db_err_str (err
));
619 /* Same as thread_db_find_new_threads_1, but silently ignore errors. */
622 thread_db_find_new_threads_silently (ptid_t ptid
)
624 volatile struct gdb_exception except
;
626 TRY_CATCH (except
, RETURN_MASK_ERROR
)
628 thread_db_find_new_threads_2 (ptid
, 1);
631 if (except
.reason
< 0 && libthread_db_debug
)
633 exception_fprintf (gdb_stderr
, except
,
634 "Warning: thread_db_find_new_threads_silently: ");
638 /* Lookup a library in which given symbol resides.
639 Note: this is looking in GDB process, not in the inferior.
640 Returns library name, or NULL. */
643 dladdr_to_soname (const void *addr
)
647 if (dladdr (addr
, &info
) != 0)
648 return info
.dli_fname
;
652 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
654 Failure could happen if libthread_db does not have symbols we expect,
655 or when it refuses to work with the current inferior (e.g. due to
656 version mismatch between libthread_db and libpthread). */
659 try_thread_db_load_1 (struct thread_db_info
*info
)
663 /* Initialize pointers to the dynamic library functions we will use.
664 Essential functions first. */
666 info
->td_init_p
= verbose_dlsym (info
->handle
, "td_init");
667 if (info
->td_init_p
== NULL
)
670 err
= info
->td_init_p ();
673 warning (_("Cannot initialize libthread_db: %s"),
674 thread_db_err_str (err
));
678 info
->td_ta_new_p
= verbose_dlsym (info
->handle
, "td_ta_new");
679 if (info
->td_ta_new_p
== NULL
)
682 /* Initialize the structure that identifies the child process. */
683 info
->proc_handle
.ptid
= inferior_ptid
;
685 /* Now attempt to open a connection to the thread library. */
686 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
689 if (libthread_db_debug
)
690 printf_unfiltered (_("td_ta_new failed: %s\n"),
691 thread_db_err_str (err
));
696 #ifdef THREAD_DB_HAS_TD_VERSION
699 /* The errors above are not unexpected and silently ignored:
700 they just mean we haven't found correct version of
704 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
709 info
->td_ta_map_id2thr_p
= verbose_dlsym (info
->handle
, "td_ta_map_id2thr");
710 if (info
->td_ta_map_id2thr_p
== NULL
)
713 info
->td_ta_map_lwp2thr_p
= verbose_dlsym (info
->handle
,
714 "td_ta_map_lwp2thr");
715 if (info
->td_ta_map_lwp2thr_p
== NULL
)
718 info
->td_ta_thr_iter_p
= verbose_dlsym (info
->handle
, "td_ta_thr_iter");
719 if (info
->td_ta_thr_iter_p
== NULL
)
722 info
->td_thr_validate_p
= verbose_dlsym (info
->handle
, "td_thr_validate");
723 if (info
->td_thr_validate_p
== NULL
)
726 info
->td_thr_get_info_p
= verbose_dlsym (info
->handle
, "td_thr_get_info");
727 if (info
->td_thr_get_info_p
== NULL
)
730 /* These are not essential. */
731 info
->td_ta_event_addr_p
= dlsym (info
->handle
, "td_ta_event_addr");
732 info
->td_ta_set_event_p
= dlsym (info
->handle
, "td_ta_set_event");
733 info
->td_ta_clear_event_p
= dlsym (info
->handle
, "td_ta_clear_event");
734 info
->td_ta_event_getmsg_p
= dlsym (info
->handle
, "td_ta_event_getmsg");
735 info
->td_thr_event_enable_p
= dlsym (info
->handle
, "td_thr_event_enable");
736 info
->td_thr_tls_get_addr_p
= dlsym (info
->handle
, "td_thr_tls_get_addr");
738 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
740 if (libthread_db_debug
|| *libthread_db_search_path
)
744 library
= dladdr_to_soname (*info
->td_ta_new_p
);
746 library
= LIBTHREAD_DB_SO
;
748 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
752 /* The thread library was detected. Activate the thread_db target
753 if this is the first process using it. */
754 if (thread_db_list
->next
== NULL
)
755 push_target (&thread_db_ops
);
757 /* Enable event reporting, but not when debugging a core file. */
758 if (target_has_execution
)
759 enable_thread_event_reporting ();
761 /* There appears to be a bug in glibc-2.3.6: calls to td_thr_get_info fail
762 with TD_ERR for statically linked executables if td_thr_get_info is
763 called before glibc has initialized itself. Silently ignore such
764 errors, and let gdb enumerate threads again later. */
765 thread_db_find_new_threads_silently (inferior_ptid
);
770 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
771 relative, or just LIBTHREAD_DB. */
774 try_thread_db_load (const char *library
)
777 struct thread_db_info
*info
;
779 if (libthread_db_debug
)
780 printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
782 handle
= dlopen (library
, RTLD_NOW
);
785 if (libthread_db_debug
)
786 printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
790 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
794 td_init
= dlsym (handle
, "td_init");
797 const char *const libpath
= dladdr_to_soname (td_init
);
800 printf_unfiltered (_("Host %s resolved to: %s.\n"),
805 info
= add_thread_db_info (handle
);
807 if (try_thread_db_load_1 (info
))
810 /* This library "refused" to work on current inferior. */
811 delete_thread_db_info (GET_PID (inferior_ptid
));
815 /* Handle $pdir in libthread-db-search-path.
816 Look for libthread_db in the directory of libpthread.
817 The result is true for success. */
820 try_thread_db_load_from_pdir (void)
825 if (libpthread_name_p (obj
->name
))
827 char path
[PATH_MAX
], *cp
;
829 gdb_assert (strlen (obj
->name
) < sizeof (path
));
830 strcpy (path
, obj
->name
);
831 cp
= strrchr (path
, '/');
835 warning (_("Expected absolute pathname for libpthread in the"
836 " inferior, but got %s."), path
);
838 else if (cp
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1 > path
+ sizeof (path
))
840 warning (_("Unexpected: path to libpthread in the inferior is"
841 " too long: %s"), path
);
845 strcpy (cp
+ 1, LIBTHREAD_DB_SO
);
846 if (try_thread_db_load (path
))
855 /* Handle $sdir in libthread-db-search-path.
856 Look for libthread_db in the system dirs, or wherever a plain
857 dlopen(file_without_path) will look.
858 The result is true for success. */
861 try_thread_db_load_from_sdir (void)
863 return try_thread_db_load (LIBTHREAD_DB_SO
);
866 /* Try to load libthread_db from directory DIR of length DIR_LEN.
867 The result is true for success. */
870 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
874 if (dir_len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1 > sizeof (path
))
876 char *cp
= xmalloc (dir_len
+ 1);
878 memcpy (cp
, dir
, dir_len
);
880 warning (_("libthread-db-search-path component too long,"
881 " ignored: %s."), cp
);
886 memcpy (path
, dir
, dir_len
);
888 strcpy (path
+ dir_len
+ 1, LIBTHREAD_DB_SO
);
889 return try_thread_db_load (path
);
892 /* Search libthread_db_search_path for libthread_db which "agrees"
893 to work on current inferior.
894 The result is true for success. */
897 thread_db_load_search (void)
899 const char *search_path
= libthread_db_search_path
;
904 const char *end
= strchr (search_path
, ':');
905 const char *this_dir
= search_path
;
910 this_dir_len
= end
- search_path
;
911 search_path
+= this_dir_len
+ 1;
915 this_dir_len
= strlen (this_dir
);
916 search_path
+= this_dir_len
;
919 if (this_dir_len
== sizeof ("$pdir") - 1
920 && strncmp (this_dir
, "$pdir", this_dir_len
) == 0)
922 if (try_thread_db_load_from_pdir ())
928 else if (this_dir_len
== sizeof ("$sdir") - 1
929 && strncmp (this_dir
, "$sdir", this_dir_len
) == 0)
931 if (try_thread_db_load_from_sdir ())
939 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
947 if (libthread_db_debug
)
948 printf_unfiltered (_("thread_db_load_search returning %d\n"), rc
);
952 /* Return non-zero if the inferior has a libpthread. */
955 has_libpthread (void)
960 if (libpthread_name_p (obj
->name
))
966 /* Attempt to load and initialize libthread_db.
967 Return 1 on success. */
970 thread_db_load (void)
972 struct thread_db_info
*info
;
974 info
= get_thread_db_info (GET_PID (inferior_ptid
));
979 /* Don't attempt to use thread_db on executables not running
981 if (!target_has_registers
)
984 /* Don't attempt to use thread_db for remote targets. */
985 if (!(target_can_run (¤t_target
) || core_bfd
))
988 if (thread_db_load_search ())
991 /* We couldn't find a libthread_db.
992 If the inferior has a libpthread warn the user. */
993 if (has_libpthread ())
995 warning (_("Unable to find libthread_db matching inferior's thread"
996 " library, thread debugging will not be available."));
1000 /* Either this executable isn't using libpthread at all, or it is
1001 statically linked. Since we can't easily distinguish these two cases,
1002 no warning is issued. */
1007 disable_thread_event_reporting (struct thread_db_info
*info
)
1009 if (info
->td_ta_clear_event_p
!= NULL
)
1011 td_thr_events_t events
;
1013 /* Set the process wide mask saying we aren't interested in any
1015 td_event_fillset (&events
);
1016 info
->td_ta_clear_event_p (info
->thread_agent
, &events
);
1019 info
->td_create_bp_addr
= 0;
1020 info
->td_death_bp_addr
= 0;
1024 check_thread_signals (void)
1026 if (!thread_signals
)
1031 lin_thread_get_thread_signals (&mask
);
1032 sigemptyset (&thread_stop_set
);
1033 sigemptyset (&thread_print_set
);
1035 for (i
= 1; i
< NSIG
; i
++)
1037 if (sigismember (&mask
, i
))
1039 if (signal_stop_update (target_signal_from_host (i
), 0))
1040 sigaddset (&thread_stop_set
, i
);
1041 if (signal_print_update (target_signal_from_host (i
), 0))
1042 sigaddset (&thread_print_set
, i
);
1049 /* Check whether thread_db is usable. This function is called when
1050 an inferior is created (or otherwise acquired, e.g. attached to)
1051 and when new shared libraries are loaded into a running process. */
1054 check_for_thread_db (void)
1056 /* Do nothing if we couldn't load libthread_db.so.1. */
1057 if (!thread_db_load ())
1062 thread_db_new_objfile (struct objfile
*objfile
)
1064 /* This observer must always be called with inferior_ptid set
1067 if (objfile
!= NULL
)
1068 check_for_thread_db ();
1071 /* Attach to a new thread. This function is called when we receive a
1072 TD_CREATE event or when we iterate over all threads and find one
1073 that wasn't already in our list. Returns true on success. */
1076 attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
1077 const td_thrinfo_t
*ti_p
)
1079 struct private_thread_info
*private;
1080 struct thread_info
*tp
= NULL
;
1082 struct thread_db_info
*info
;
1084 /* If we're being called after a TD_CREATE event, we may already
1085 know about this thread. There are two ways this can happen. We
1086 may have iterated over all threads between the thread creation
1087 and the TD_CREATE event, for instance when the user has issued
1088 the `info threads' command before the SIGTRAP for hitting the
1089 thread creation breakpoint was reported. Alternatively, the
1090 thread may have exited and a new one been created with the same
1091 thread ID. In the first case we don't need to do anything; in
1092 the second case we should discard information about the dead
1093 thread and attach to the new one. */
1094 if (in_thread_list (ptid
))
1096 tp
= find_thread_ptid (ptid
);
1097 gdb_assert (tp
!= NULL
);
1099 /* If tp->private is NULL, then GDB is already attached to this
1100 thread, but we do not know anything about it. We can learn
1101 about it here. This can only happen if we have some other
1102 way besides libthread_db to notice new threads (i.e.
1103 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
1104 exit, so this can not be a stale thread recreated with the
1106 if (tp
->private != NULL
)
1108 if (!tp
->private->dying
)
1111 delete_thread (ptid
);
1116 if (target_has_execution
)
1117 check_thread_signals ();
1119 if (ti_p
->ti_state
== TD_THR_UNKNOWN
|| ti_p
->ti_state
== TD_THR_ZOMBIE
)
1120 return 0; /* A zombie thread -- do not attach. */
1122 /* Under GNU/Linux, we have to attach to each and every thread. */
1123 if (target_has_execution
1125 && lin_lwp_attach_lwp (BUILD_LWP (ti_p
->ti_lid
, GET_PID (ptid
))) < 0)
1128 /* Construct the thread's private data. */
1129 private = xmalloc (sizeof (struct private_thread_info
));
1130 memset (private, 0, sizeof (struct private_thread_info
));
1132 /* A thread ID of zero may mean the thread library has not initialized
1133 yet. But we shouldn't even get here if that's the case. FIXME:
1134 if we change GDB to always have at least one thread in the thread
1135 list this will have to go somewhere else; maybe private == NULL
1136 until the thread_db target claims it. */
1137 gdb_assert (ti_p
->ti_tid
!= 0);
1138 private->th
= *th_p
;
1139 private->tid
= ti_p
->ti_tid
;
1141 /* Add the thread to GDB's thread list. */
1143 add_thread_with_info (ptid
, private);
1145 tp
->private = private;
1147 info
= get_thread_db_info (GET_PID (ptid
));
1149 /* Enable thread event reporting for this thread, except when
1150 debugging a core file. */
1151 if (target_has_execution
)
1153 err
= info
->td_thr_event_enable_p (th_p
, 1);
1155 error (_("Cannot enable thread event reporting for %s: %s"),
1156 target_pid_to_str (ptid
), thread_db_err_str (err
));
1163 detach_thread (ptid_t ptid
)
1165 struct thread_info
*thread_info
;
1167 /* Don't delete the thread now, because it still reports as active
1168 until it has executed a few instructions after the event
1169 breakpoint - if we deleted it now, "info threads" would cause us
1170 to re-attach to it. Just mark it as having had a TD_DEATH
1171 event. This means that we won't delete it from our thread list
1172 until we notice that it's dead (via prune_threads), or until
1173 something re-uses its thread ID. We'll report the thread exit
1174 when the underlying LWP dies. */
1175 thread_info
= find_thread_ptid (ptid
);
1176 gdb_assert (thread_info
!= NULL
&& thread_info
->private != NULL
);
1177 thread_info
->private->dying
= 1;
1181 thread_db_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1183 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1184 struct thread_db_info
*info
;
1186 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1190 if (target_has_execution
)
1192 disable_thread_event_reporting (info
);
1194 /* Delete the old thread event breakpoints. Note that
1195 unlike when mourning, we can remove them here because
1196 there's still a live inferior to poke at. In any case,
1197 GDB will not try to insert anything in the inferior when
1198 removing a breakpoint. */
1199 remove_thread_event_breakpoints ();
1202 delete_thread_db_info (GET_PID (inferior_ptid
));
1205 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
1207 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1209 /* If there are no more processes using libpthread, detach the
1210 thread_db target ops. */
1211 if (!thread_db_list
)
1212 unpush_target (&thread_db_ops
);
1215 /* Check if PID is currently stopped at the location of a thread event
1216 breakpoint location. If it is, read the event message and act upon
1220 check_event (ptid_t ptid
)
1222 struct regcache
*regcache
= get_thread_regcache (ptid
);
1223 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1229 struct thread_db_info
*info
;
1231 info
= get_thread_db_info (GET_PID (ptid
));
1233 /* Bail out early if we're not at a thread event breakpoint. */
1234 stop_pc
= regcache_read_pc (regcache
)
1235 - gdbarch_decr_pc_after_break (gdbarch
);
1236 if (stop_pc
!= info
->td_create_bp_addr
1237 && stop_pc
!= info
->td_death_bp_addr
)
1240 /* Access an lwp we know is stopped. */
1241 info
->proc_handle
.ptid
= ptid
;
1243 /* If we have only looked at the first thread before libpthread was
1244 initialized, we may not know its thread ID yet. Make sure we do
1245 before we add another thread to the list. */
1246 if (!have_threads (ptid
))
1247 thread_db_find_new_threads_1 (ptid
);
1249 /* If we are at a create breakpoint, we do not know what new lwp
1250 was created and cannot specifically locate the event message for it.
1251 We have to call td_ta_event_getmsg() to get
1252 the latest message. Since we have no way of correlating whether
1253 the event message we get back corresponds to our breakpoint, we must
1254 loop and read all event messages, processing them appropriately.
1255 This guarantees we will process the correct message before continuing
1256 from the breakpoint.
1258 Currently, death events are not enabled. If they are enabled,
1259 the death event can use the td_thr_event_getmsg() interface to
1260 get the message specifically for that lwp and avoid looping
1267 err
= info
->td_ta_event_getmsg_p (info
->thread_agent
, &msg
);
1270 if (err
== TD_NOMSG
)
1273 error (_("Cannot get thread event message: %s"),
1274 thread_db_err_str (err
));
1277 err
= info
->td_thr_get_info_p (msg
.th_p
, &ti
);
1279 error (_("Cannot get thread info: %s"), thread_db_err_str (err
));
1281 ptid
= ptid_build (GET_PID (ptid
), ti
.ti_lid
, 0);
1286 /* Call attach_thread whether or not we already know about a
1287 thread with this thread ID. */
1288 attach_thread (ptid
, msg
.th_p
, &ti
);
1294 if (!in_thread_list (ptid
))
1295 error (_("Spurious thread death event."));
1297 detach_thread (ptid
);
1302 error (_("Spurious thread event."));
1309 thread_db_wait (struct target_ops
*ops
,
1310 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1313 struct thread_db_info
*info
;
1314 struct target_ops
*beneath
= find_target_beneath (ops
);
1316 ptid
= beneath
->to_wait (beneath
, ptid
, ourstatus
, options
);
1318 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
1321 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
1322 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
1325 info
= get_thread_db_info (GET_PID (ptid
));
1327 /* If this process isn't using thread_db, we're done. */
1331 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1333 /* New image, it may or may not end up using thread_db. Assume
1334 not unless we find otherwise. */
1335 delete_thread_db_info (GET_PID (ptid
));
1336 if (!thread_db_list
)
1337 unpush_target (&thread_db_ops
);
1339 /* Thread event breakpoints are deleted by
1340 update_breakpoints_after_exec. */
1345 /* If we do not know about the main thread yet, this would be a good time to
1347 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
&& !have_threads (ptid
))
1348 thread_db_find_new_threads_1 (ptid
);
1350 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
1351 && ourstatus
->value
.sig
== TARGET_SIGNAL_TRAP
)
1352 /* Check for a thread event. */
1355 if (have_threads (ptid
))
1357 /* Change ptids back into the higher level PID + TID format. If
1358 the thread is dead and no longer on the thread list, we will
1359 get back a dead ptid. This can occur if the thread death
1360 event gets postponed by other simultaneous events. In such a
1361 case, we want to just ignore the event and continue on. */
1363 ptid
= thread_from_lwp (ptid
);
1364 if (GET_PID (ptid
) == -1)
1365 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1372 thread_db_mourn_inferior (struct target_ops
*ops
)
1374 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1376 delete_thread_db_info (GET_PID (inferior_ptid
));
1378 target_beneath
->to_mourn_inferior (target_beneath
);
1380 /* Delete the old thread event breakpoints. Do this after mourning
1381 the inferior, so that we don't try to uninsert them. */
1382 remove_thread_event_breakpoints ();
1384 /* Detach thread_db target ops. */
1385 if (!thread_db_list
)
1386 unpush_target (ops
);
1389 struct callback_data
1391 struct thread_db_info
*info
;
1396 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1401 struct thread_info
*tp
;
1402 struct callback_data
*cb_data
= data
;
1403 struct thread_db_info
*info
= cb_data
->info
;
1405 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1407 error (_("find_new_threads_callback: cannot get thread info: %s"),
1408 thread_db_err_str (err
));
1410 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
1411 return 0; /* A zombie -- ignore. */
1415 /* A thread ID of zero means that this is the main thread, but
1416 glibc has not yet initialized thread-local storage and the
1417 pthread library. We do not know what the thread's TID will
1418 be yet. Just enable event reporting and otherwise ignore
1421 /* In that case, we're not stopped in a fork syscall and don't
1422 need this glibc bug workaround. */
1423 info
->need_stale_parent_threads_check
= 0;
1425 if (target_has_execution
)
1427 err
= info
->td_thr_event_enable_p (th_p
, 1);
1429 error (_("Cannot enable thread event reporting for LWP %d: %s"),
1430 (int) ti
.ti_lid
, thread_db_err_str (err
));
1436 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1437 bit expensive, as it needs to open /proc/pid/status, so try to
1438 avoid doing the work if we know we don't have to. */
1439 if (info
->need_stale_parent_threads_check
)
1441 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1443 if (tgid
!= -1 && tgid
!= info
->pid
)
1447 ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
1448 tp
= find_thread_ptid (ptid
);
1449 if (tp
== NULL
|| tp
->private == NULL
)
1451 if (attach_thread (ptid
, th_p
, &ti
))
1452 cb_data
->new_threads
+= 1;
1454 /* Problem attaching this thread; perhaps it exited before we
1456 This could mean that the thread list inside glibc itself is in
1457 inconsistent state, and libthread_db could go on looping forever
1458 (observed with glibc-2.3.6). To prevent that, terminate
1459 iteration: thread_db_find_new_threads_2 will retry. */
1466 /* Helper for thread_db_find_new_threads_2.
1467 Returns number of new threads found. */
1470 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1473 volatile struct gdb_exception except
;
1474 struct callback_data data
;
1475 td_err_e err
= TD_ERR
;
1478 data
.new_threads
= 0;
1480 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1482 /* Iterate over all user-space threads to discover new threads. */
1483 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1484 find_new_threads_callback
,
1487 TD_THR_LOWEST_PRIORITY
,
1489 TD_THR_ANY_USER_FLAGS
);
1492 if (libthread_db_debug
)
1494 if (except
.reason
< 0)
1495 exception_fprintf (gdb_stderr
, except
,
1496 "Warning: find_new_threads_once: ");
1498 printf_filtered (_("Found %d new threads in iteration %d.\n"),
1499 data
.new_threads
, iteration
);
1505 return data
.new_threads
;
1508 /* Search for new threads, accessing memory through stopped thread
1509 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1510 searches in a row do not discover any new threads. */
1513 thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
)
1516 struct thread_db_info
*info
;
1517 int pid
= ptid_get_pid (ptid
);
1520 if (target_has_execution
)
1522 struct lwp_info
*lp
;
1524 /* In linux, we can only read memory through a stopped lwp. */
1526 if (lp
->stopped
&& ptid_get_pid (lp
->ptid
) == pid
)
1530 /* There is no stopped thread. Bail out. */
1534 info
= get_thread_db_info (GET_PID (ptid
));
1536 /* Access an lwp we know is stopped. */
1537 info
->proc_handle
.ptid
= ptid
;
1541 /* Require 4 successive iterations which do not find any new threads.
1542 The 4 is a heuristic: there is an inherent race here, and I have
1543 seen that 2 iterations in a row are not always sufficient to
1544 "capture" all threads. */
1545 for (i
= 0, loop
= 0; loop
< 4; ++i
, ++loop
)
1546 if (find_new_threads_once (info
, i
, NULL
) != 0)
1547 /* Found some new threads. Restart the loop from beginning. */
1552 find_new_threads_once (info
, 0, &err
);
1554 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1559 thread_db_find_new_threads_1 (ptid_t ptid
)
1561 thread_db_find_new_threads_2 (ptid
, 0);
1565 update_thread_core (struct lwp_info
*info
, void *closure
)
1567 info
->core
= linux_nat_core_of_thread_1 (info
->ptid
);
1572 thread_db_find_new_threads (struct target_ops
*ops
)
1574 struct thread_db_info
*info
;
1576 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1581 thread_db_find_new_threads_1 (inferior_ptid
);
1583 if (target_has_execution
)
1584 iterate_over_lwps (minus_one_ptid
/* iterate over all */,
1585 update_thread_core
, NULL
);
1589 thread_db_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
1591 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1592 struct target_ops
*beneath
;
1594 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1596 static char buf
[64];
1599 tid
= thread_info
->private->tid
;
1600 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1601 tid
, GET_LWP (ptid
));
1606 beneath
= find_target_beneath (ops
);
1607 if (beneath
->to_pid_to_str (beneath
, ptid
))
1608 return beneath
->to_pid_to_str (beneath
, ptid
);
1610 return normal_pid_to_str (ptid
);
1613 /* Return a string describing the state of the thread specified by
1617 thread_db_extra_thread_info (struct thread_info
*info
)
1619 if (info
->private == NULL
)
1622 if (info
->private->dying
)
1628 /* Get the address of the thread local variable in load module LM which
1629 is stored at OFFSET within the thread local storage for thread PTID. */
1632 thread_db_get_thread_local_address (struct target_ops
*ops
,
1637 struct thread_info
*thread_info
;
1638 struct target_ops
*beneath
;
1640 /* If we have not discovered any threads yet, check now. */
1641 if (!have_threads (ptid
))
1642 thread_db_find_new_threads_1 (ptid
);
1644 /* Find the matching thread. */
1645 thread_info
= find_thread_ptid (ptid
);
1647 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1651 struct thread_db_info
*info
;
1653 info
= get_thread_db_info (GET_PID (ptid
));
1655 /* glibc doesn't provide the needed interface. */
1656 if (!info
->td_thr_tls_get_addr_p
)
1657 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1658 _("No TLS library support"));
1660 /* Caller should have verified that lm != 0. */
1661 gdb_assert (lm
!= 0);
1663 /* Finally, get the address of the variable. */
1664 /* Note the cast through uintptr_t: this interface only works if
1665 a target address fits in a psaddr_t, which is a host pointer.
1666 So a 32-bit debugger can not access 64-bit TLS through this. */
1667 err
= info
->td_thr_tls_get_addr_p (&thread_info
->private->th
,
1668 (psaddr_t
)(uintptr_t) lm
,
1671 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1672 /* The memory hasn't been allocated, yet. */
1673 if (err
== TD_NOTALLOC
)
1674 /* Now, if libthread_db provided the initialization image's
1675 address, we *could* try to build a non-lvalue value from
1676 the initialization image. */
1677 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1678 _("TLS not allocated yet"));
1681 /* Something else went wrong. */
1683 throw_error (TLS_GENERIC_ERROR
,
1684 (("%s")), thread_db_err_str (err
));
1686 /* Cast assuming host == target. Joy. */
1687 /* Do proper sign extension for the target. */
1688 gdb_assert (exec_bfd
);
1689 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1690 ? (CORE_ADDR
) (intptr_t) address
1691 : (CORE_ADDR
) (uintptr_t) address
);
1694 beneath
= find_target_beneath (ops
);
1695 if (beneath
->to_get_thread_local_address
)
1696 return beneath
->to_get_thread_local_address (beneath
, ptid
, lm
, offset
);
1698 throw_error (TLS_GENERIC_ERROR
,
1699 _("TLS not supported on this target"));
1702 /* Callback routine used to find a thread based on the TID part of
1706 thread_db_find_thread_from_tid (struct thread_info
*thread
, void *data
)
1708 long *tid
= (long *) data
;
1710 if (thread
->private->tid
== *tid
)
1716 /* Implement the to_get_ada_task_ptid target method for this target. */
1719 thread_db_get_ada_task_ptid (long lwp
, long thread
)
1721 struct thread_info
*thread_info
;
1723 thread_db_find_new_threads_1 (inferior_ptid
);
1724 thread_info
= iterate_over_threads (thread_db_find_thread_from_tid
, &thread
);
1726 gdb_assert (thread_info
!= NULL
);
1728 return (thread_info
->ptid
);
1732 thread_db_resume (struct target_ops
*ops
,
1733 ptid_t ptid
, int step
, enum target_signal signo
)
1735 struct target_ops
*beneath
= find_target_beneath (ops
);
1736 struct thread_db_info
*info
;
1738 if (ptid_equal (ptid
, minus_one_ptid
))
1739 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1741 info
= get_thread_db_info (GET_PID (ptid
));
1743 /* This workaround is only needed for child fork lwps stopped in a
1744 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1745 workaround can be disabled. */
1747 info
->need_stale_parent_threads_check
= 0;
1749 beneath
->to_resume (beneath
, ptid
, step
, signo
);
1753 init_thread_db_ops (void)
1755 thread_db_ops
.to_shortname
= "multi-thread";
1756 thread_db_ops
.to_longname
= "multi-threaded child process.";
1757 thread_db_ops
.to_doc
= "Threads and pthreads support.";
1758 thread_db_ops
.to_detach
= thread_db_detach
;
1759 thread_db_ops
.to_wait
= thread_db_wait
;
1760 thread_db_ops
.to_resume
= thread_db_resume
;
1761 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
1762 thread_db_ops
.to_find_new_threads
= thread_db_find_new_threads
;
1763 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
1764 thread_db_ops
.to_stratum
= thread_stratum
;
1765 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
1766 thread_db_ops
.to_get_thread_local_address
1767 = thread_db_get_thread_local_address
;
1768 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
1769 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
1770 thread_db_ops
.to_magic
= OPS_MAGIC
;
1773 /* Provide a prototype to silence -Wmissing-prototypes. */
1774 extern initialize_file_ftype _initialize_thread_db
;
1777 _initialize_thread_db (void)
1779 init_thread_db_ops ();
1780 add_target (&thread_db_ops
);
1782 /* Defer loading of libthread_db.so until inferior is running.
1783 This allows gdb to load correct libthread_db for a given
1784 executable -- there could be mutiple versions of glibc,
1785 compiled with LinuxThreads or NPTL, and until there is
1786 a running inferior, we can't tell which libthread_db is
1787 the correct one to load. */
1789 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
1791 add_setshow_optional_filename_cmd ("libthread-db-search-path",
1793 &libthread_db_search_path
, _("\
1794 Set search path for libthread_db."), _("\
1795 Show the current search path or libthread_db."), _("\
1796 This path is used to search for libthread_db to be loaded into \
1798 Its value is a colon (':') separate list of directories to search.\n\
1799 Setting the search path to an empty list resets it to its default value."),
1800 set_libthread_db_search_path
,
1802 &setlist
, &showlist
);
1804 add_setshow_zinteger_cmd ("libthread-db", class_maintenance
,
1805 &libthread_db_debug
, _("\
1806 Set libthread-db debugging."), _("\
1807 Show libthread-db debugging."), _("\
1808 When non-zero, libthread-db debugging is enabled."),
1810 show_libthread_db_debug
,
1811 &setdebuglist
, &showdebuglist
);
1813 /* Add ourselves to objfile event chain. */
1814 observer_attach_new_objfile (thread_db_new_objfile
);