1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999-2001, 2003-2012 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "gdb_assert.h"
24 #include "gdb_proc_service.h"
25 #include "gdb_thread_db.h"
29 #include "exceptions.h"
31 #include "gdbthread.h"
38 #include "solib-svr4.h"
41 #include "linux-nat.h"
42 #include "linux-procfs.h"
43 #include "linux-osdata.h"
44 #include "auto-load.h"
49 #ifdef HAVE_GNU_LIBC_VERSION_H
50 #include <gnu/libc-version.h>
53 /* GNU/Linux libthread_db support.
55 libthread_db is a library, provided along with libpthread.so, which
56 exposes the internals of the thread library to a debugger. It
57 allows GDB to find existing threads, new threads as they are
58 created, thread IDs (usually, the result of pthread_self), and
59 thread-local variables.
61 The libthread_db interface originates on Solaris, where it is
62 both more powerful and more complicated. This implementation
63 only works for LinuxThreads and NPTL, the two glibc threading
64 libraries. It assumes that each thread is permanently assigned
65 to a single light-weight process (LWP).
67 libthread_db-specific information is stored in the "private" field
68 of struct thread_info. When the field is NULL we do not yet have
69 information about the new thread; this could be temporary (created,
70 but the thread library's data structures do not reflect it yet)
71 or permanent (created using clone instead of pthread_create).
73 Process IDs managed by linux-thread-db.c match those used by
74 linux-nat.c: a common PID for all processes, an LWP ID for each
75 thread, and no TID. We save the TID in private. Keeping it out
76 of the ptid_t prevents thread IDs changing when libpthread is
77 loaded or unloaded. */
79 static char *libthread_db_search_path
;
81 /* Set to non-zero if thread_db auto-loading is enabled
82 by the "set auto-load libthread-db" command. */
83 static int auto_load_thread_db
= 1;
85 /* "show" command for the auto_load_thread_db configuration variable. */
88 show_auto_load_thread_db (struct ui_file
*file
, int from_tty
,
89 struct cmd_list_element
*c
, const char *value
)
91 fprintf_filtered (file
, _("Auto-loading of inferior specific libthread_db "
97 set_libthread_db_search_path (char *ignored
, int from_tty
,
98 struct cmd_list_element
*c
)
100 if (*libthread_db_search_path
== '\0')
102 xfree (libthread_db_search_path
);
103 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
107 /* If non-zero, print details of libthread_db processing. */
109 static int libthread_db_debug
;
112 show_libthread_db_debug (struct ui_file
*file
, int from_tty
,
113 struct cmd_list_element
*c
, const char *value
)
115 fprintf_filtered (file
, _("libthread-db debugging is %s.\n"), value
);
118 /* If we're running on GNU/Linux, we must explicitly attach to any new
121 /* This module's target vector. */
122 static struct target_ops thread_db_ops
;
124 /* Non-zero if we have determined the signals used by the threads
126 static int thread_signals
;
127 static sigset_t thread_stop_set
;
128 static sigset_t thread_print_set
;
130 struct thread_db_info
132 struct thread_db_info
*next
;
134 /* Process id this object refers to. */
137 /* Handle from dlopen for libthread_db.so. */
140 /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
141 HANDLE. It may be NULL for system library. */
144 /* Structure that identifies the child process for the
145 <proc_service.h> interface. */
146 struct ps_prochandle proc_handle
;
148 /* Connection to the libthread_db library. */
149 td_thragent_t
*thread_agent
;
151 /* True if we need to apply the workaround for glibc/BZ5983. When
152 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
153 list, nptl_db returns the parent's threads in addition to the new
154 (single) child thread. If this flag is set, we do extra work to
155 be able to ignore such stale entries. */
156 int need_stale_parent_threads_check
;
158 /* Location of the thread creation event breakpoint. The code at
159 this location in the child process will be called by the pthread
160 library whenever a new thread is created. By setting a special
161 breakpoint at this location, GDB can detect when a new thread is
162 created. We obtain this location via the td_ta_event_addr
164 CORE_ADDR td_create_bp_addr
;
166 /* Location of the thread death event breakpoint. */
167 CORE_ADDR td_death_bp_addr
;
169 /* Pointers to the libthread_db functions. */
171 td_err_e (*td_init_p
) (void);
173 td_err_e (*td_ta_new_p
) (struct ps_prochandle
* ps
,
175 td_err_e (*td_ta_map_id2thr_p
) (const td_thragent_t
*ta
, thread_t pt
,
176 td_thrhandle_t
*__th
);
177 td_err_e (*td_ta_map_lwp2thr_p
) (const td_thragent_t
*ta
,
178 lwpid_t lwpid
, td_thrhandle_t
*th
);
179 td_err_e (*td_ta_thr_iter_p
) (const td_thragent_t
*ta
,
180 td_thr_iter_f
*callback
, void *cbdata_p
,
181 td_thr_state_e state
, int ti_pri
,
182 sigset_t
*ti_sigmask_p
,
183 unsigned int ti_user_flags
);
184 td_err_e (*td_ta_event_addr_p
) (const td_thragent_t
*ta
,
185 td_event_e event
, td_notify_t
*ptr
);
186 td_err_e (*td_ta_set_event_p
) (const td_thragent_t
*ta
,
187 td_thr_events_t
*event
);
188 td_err_e (*td_ta_clear_event_p
) (const td_thragent_t
*ta
,
189 td_thr_events_t
*event
);
190 td_err_e (*td_ta_event_getmsg_p
) (const td_thragent_t
*ta
,
191 td_event_msg_t
*msg
);
193 td_err_e (*td_thr_validate_p
) (const td_thrhandle_t
*th
);
194 td_err_e (*td_thr_get_info_p
) (const td_thrhandle_t
*th
,
195 td_thrinfo_t
*infop
);
196 td_err_e (*td_thr_event_enable_p
) (const td_thrhandle_t
*th
,
199 td_err_e (*td_thr_tls_get_addr_p
) (const td_thrhandle_t
*th
,
200 psaddr_t map_address
,
201 size_t offset
, psaddr_t
*address
);
204 /* List of known processes using thread_db, and the required
206 struct thread_db_info
*thread_db_list
;
208 static void thread_db_find_new_threads_1 (ptid_t ptid
);
209 static void thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
);
211 /* Add the current inferior to the list of processes using libpthread.
212 Return a pointer to the newly allocated object that was added to
213 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
216 static struct thread_db_info
*
217 add_thread_db_info (void *handle
)
219 struct thread_db_info
*info
;
221 info
= xcalloc (1, sizeof (*info
));
222 info
->pid
= ptid_get_pid (inferior_ptid
);
223 info
->handle
= handle
;
225 /* The workaround works by reading from /proc/pid/status, so it is
226 disabled for core files. */
227 if (target_has_execution
)
228 info
->need_stale_parent_threads_check
= 1;
230 info
->next
= thread_db_list
;
231 thread_db_list
= info
;
236 /* Return the thread_db_info object representing the bookkeeping
237 related to process PID, if any; NULL otherwise. */
239 static struct thread_db_info
*
240 get_thread_db_info (int pid
)
242 struct thread_db_info
*info
;
244 for (info
= thread_db_list
; info
; info
= info
->next
)
245 if (pid
== info
->pid
)
251 /* When PID has exited or has been detached, we no longer want to keep
252 track of it as using libpthread. Call this function to discard
253 thread_db related info related to PID. Note that this closes
254 LIBTHREAD_DB_SO's dlopen'ed handle. */
257 delete_thread_db_info (int pid
)
259 struct thread_db_info
*info
, *info_prev
;
263 for (info
= thread_db_list
; info
; info_prev
= info
, info
= info
->next
)
264 if (pid
== info
->pid
)
270 if (info
->handle
!= NULL
)
271 dlclose (info
->handle
);
273 xfree (info
->filename
);
276 info_prev
->next
= info
->next
;
278 thread_db_list
= info
->next
;
283 /* Prototypes for local functions. */
284 static int attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
285 const td_thrinfo_t
*ti_p
);
286 static void detach_thread (ptid_t ptid
);
289 /* Use "struct private_thread_info" to cache thread state. This is
290 a substantial optimization. */
292 struct private_thread_info
294 /* Flag set when we see a TD_DEATH event for this thread. */
295 unsigned int dying
:1;
297 /* Cached thread state. */
304 thread_db_err_str (td_err_e err
)
311 return "generic 'call succeeded'";
313 return "generic error";
315 return "no thread to satisfy query";
317 return "no sync handle to satisfy query";
319 return "no LWP to satisfy query";
321 return "invalid process handle";
323 return "invalid thread handle";
325 return "invalid synchronization handle";
327 return "invalid thread agent";
329 return "invalid key";
331 return "no event message for getmsg";
333 return "FPU register set not available";
335 return "application not linked with libthread";
337 return "requested event is not supported";
339 return "capability not available";
341 return "debugger service failed";
343 return "operation not applicable to";
345 return "no thread-specific data for this thread";
347 return "malloc failed";
349 return "only part of register set was written/read";
351 return "X register set not available for this thread";
352 #ifdef THREAD_DB_HAS_TD_NOTALLOC
354 return "thread has not yet allocated TLS for given module";
356 #ifdef THREAD_DB_HAS_TD_VERSION
358 return "versions of libpthread and libthread_db do not match";
360 #ifdef THREAD_DB_HAS_TD_NOTLS
362 return "there is no TLS segment in the given module";
365 snprintf (buf
, sizeof (buf
), "unknown thread_db error '%d'", err
);
370 /* Return 1 if any threads have been registered. There may be none if
371 the threading library is not fully initialized yet. */
374 have_threads_callback (struct thread_info
*thread
, void *args
)
376 int pid
= * (int *) args
;
378 if (ptid_get_pid (thread
->ptid
) != pid
)
381 return thread
->private != NULL
;
385 have_threads (ptid_t ptid
)
387 int pid
= ptid_get_pid (ptid
);
389 return iterate_over_threads (have_threads_callback
, &pid
) != NULL
;
392 struct thread_get_info_inout
394 struct thread_info
*thread_info
;
395 struct thread_db_info
*thread_db_info
;
398 /* A callback function for td_ta_thr_iter, which we use to map all
401 THP is a handle to the current thread; if INFOP is not NULL, the
402 struct thread_info associated with this thread is returned in
405 If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
406 zero is returned to indicate success. */
409 thread_get_info_callback (const td_thrhandle_t
*thp
, void *argp
)
414 struct thread_get_info_inout
*inout
;
415 struct thread_db_info
*info
;
418 info
= inout
->thread_db_info
;
420 err
= info
->td_thr_get_info_p (thp
, &ti
);
422 error (_("thread_get_info_callback: cannot get thread info: %s"),
423 thread_db_err_str (err
));
425 /* Fill the cache. */
426 thread_ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
427 inout
->thread_info
= find_thread_ptid (thread_ptid
);
429 /* In the case of a zombie thread, don't continue. We don't want to
430 attach to it thinking it is a new thread. */
431 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
432 return TD_THR_ZOMBIE
;
434 if (inout
->thread_info
== NULL
)
436 /* New thread. Attach to it now (why wait?). */
437 if (!have_threads (thread_ptid
))
438 thread_db_find_new_threads_1 (thread_ptid
);
440 attach_thread (thread_ptid
, thp
, &ti
);
441 inout
->thread_info
= find_thread_ptid (thread_ptid
);
442 gdb_assert (inout
->thread_info
!= NULL
);
448 /* Convert between user-level thread ids and LWP ids. */
451 thread_from_lwp (ptid_t ptid
)
455 struct thread_db_info
*info
;
456 struct thread_get_info_inout io
= {0};
458 /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
461 /* This ptid comes from linux-nat.c, which should always fill in the
463 gdb_assert (GET_LWP (ptid
) != 0);
465 info
= get_thread_db_info (GET_PID (ptid
));
467 /* Access an lwp we know is stopped. */
468 info
->proc_handle
.ptid
= ptid
;
469 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
471 error (_("Cannot find user-level thread for LWP %ld: %s"),
472 GET_LWP (ptid
), thread_db_err_str (err
));
474 /* Fetch the thread info. If we get back TD_THR_ZOMBIE, then the
475 event thread has already died. If another gdb interface has called
476 thread_alive() previously, the thread won't be found on the thread list
477 anymore. In that case, we don't want to process this ptid anymore
478 to avoid the possibility of later treating it as a newly
479 discovered thread id that we should add to the list. Thus,
480 we return a -1 ptid which is also how the thread list marks a
482 io
.thread_db_info
= info
;
483 io
.thread_info
= NULL
;
484 if (thread_get_info_callback (&th
, &io
) == TD_THR_ZOMBIE
485 && io
.thread_info
== NULL
)
486 return minus_one_ptid
;
488 gdb_assert (ptid_get_tid (ptid
) == 0);
493 /* Attach to lwp PTID, doing whatever else is required to have this
494 LWP under the debugger's control --- e.g., enabling event
495 reporting. Returns true on success. */
497 thread_db_attach_lwp (ptid_t ptid
)
502 struct thread_db_info
*info
;
504 info
= get_thread_db_info (GET_PID (ptid
));
509 /* This ptid comes from linux-nat.c, which should always fill in the
511 gdb_assert (GET_LWP (ptid
) != 0);
513 /* Access an lwp we know is stopped. */
514 info
->proc_handle
.ptid
= ptid
;
516 /* If we have only looked at the first thread before libpthread was
517 initialized, we may not know its thread ID yet. Make sure we do
518 before we add another thread to the list. */
519 if (!have_threads (ptid
))
520 thread_db_find_new_threads_1 (ptid
);
522 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
524 /* Cannot find user-level thread. */
527 err
= info
->td_thr_get_info_p (&th
, &ti
);
530 warning (_("Cannot get thread info: %s"), thread_db_err_str (err
));
534 attach_thread (ptid
, &th
, &ti
);
539 verbose_dlsym (void *handle
, const char *name
)
541 void *sym
= dlsym (handle
, name
);
543 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
549 enable_thread_event (int event
, CORE_ADDR
*bp
)
553 struct thread_db_info
*info
;
555 info
= get_thread_db_info (GET_PID (inferior_ptid
));
557 /* Access an lwp we know is stopped. */
558 info
->proc_handle
.ptid
= inferior_ptid
;
560 /* Get the breakpoint address for thread EVENT. */
561 err
= info
->td_ta_event_addr_p (info
->thread_agent
, event
, ¬ify
);
565 /* Set up the breakpoint. */
566 gdb_assert (exec_bfd
);
567 (*bp
) = (gdbarch_convert_from_func_ptr_addr
569 /* Do proper sign extension for the target. */
570 (bfd_get_sign_extend_vma (exec_bfd
) > 0
571 ? (CORE_ADDR
) (intptr_t) notify
.u
.bptaddr
572 : (CORE_ADDR
) (uintptr_t) notify
.u
.bptaddr
),
574 create_thread_event_breakpoint (target_gdbarch
, *bp
);
580 enable_thread_event_reporting (void)
582 td_thr_events_t events
;
584 #ifdef HAVE_GNU_LIBC_VERSION_H
585 const char *libc_version
;
586 int libc_major
, libc_minor
;
588 struct thread_db_info
*info
;
590 info
= get_thread_db_info (GET_PID (inferior_ptid
));
592 /* We cannot use the thread event reporting facility if these
593 functions aren't available. */
594 if (info
->td_ta_event_addr_p
== NULL
595 || info
->td_ta_set_event_p
== NULL
596 || info
->td_ta_event_getmsg_p
== NULL
597 || info
->td_thr_event_enable_p
== NULL
)
600 /* Set the process wide mask saying which events we're interested in. */
601 td_event_emptyset (&events
);
602 td_event_addset (&events
, TD_CREATE
);
604 #ifdef HAVE_GNU_LIBC_VERSION_H
605 /* The event reporting facility is broken for TD_DEATH events in
606 glibc 2.1.3, so don't enable it if we have glibc but a lower
608 libc_version
= gnu_get_libc_version ();
609 if (sscanf (libc_version
, "%d.%d", &libc_major
, &libc_minor
) == 2
610 && (libc_major
> 2 || (libc_major
== 2 && libc_minor
> 1)))
612 td_event_addset (&events
, TD_DEATH
);
614 err
= info
->td_ta_set_event_p (info
->thread_agent
, &events
);
617 warning (_("Unable to set global thread event mask: %s"),
618 thread_db_err_str (err
));
622 /* Delete previous thread event breakpoints, if any. */
623 remove_thread_event_breakpoints ();
624 info
->td_create_bp_addr
= 0;
625 info
->td_death_bp_addr
= 0;
627 /* Set up the thread creation event. */
628 err
= enable_thread_event (TD_CREATE
, &info
->td_create_bp_addr
);
631 warning (_("Unable to get location for thread creation breakpoint: %s"),
632 thread_db_err_str (err
));
636 /* Set up the thread death event. */
637 err
= enable_thread_event (TD_DEATH
, &info
->td_death_bp_addr
);
640 warning (_("Unable to get location for thread death breakpoint: %s"),
641 thread_db_err_str (err
));
646 /* Same as thread_db_find_new_threads_1, but silently ignore errors. */
649 thread_db_find_new_threads_silently (ptid_t ptid
)
651 volatile struct gdb_exception except
;
653 TRY_CATCH (except
, RETURN_MASK_ERROR
)
655 thread_db_find_new_threads_2 (ptid
, 1);
658 if (except
.reason
< 0 && libthread_db_debug
)
660 exception_fprintf (gdb_stderr
, except
,
661 "Warning: thread_db_find_new_threads_silently: ");
665 /* Lookup a library in which given symbol resides.
666 Note: this is looking in GDB process, not in the inferior.
667 Returns library name, or NULL. */
670 dladdr_to_soname (const void *addr
)
674 if (dladdr (addr
, &info
) != 0)
675 return info
.dli_fname
;
679 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
681 Failure could happen if libthread_db does not have symbols we expect,
682 or when it refuses to work with the current inferior (e.g. due to
683 version mismatch between libthread_db and libpthread). */
686 try_thread_db_load_1 (struct thread_db_info
*info
)
690 /* Initialize pointers to the dynamic library functions we will use.
691 Essential functions first. */
693 info
->td_init_p
= verbose_dlsym (info
->handle
, "td_init");
694 if (info
->td_init_p
== NULL
)
697 err
= info
->td_init_p ();
700 warning (_("Cannot initialize libthread_db: %s"),
701 thread_db_err_str (err
));
705 info
->td_ta_new_p
= verbose_dlsym (info
->handle
, "td_ta_new");
706 if (info
->td_ta_new_p
== NULL
)
709 /* Initialize the structure that identifies the child process. */
710 info
->proc_handle
.ptid
= inferior_ptid
;
712 /* Now attempt to open a connection to the thread library. */
713 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
716 if (libthread_db_debug
)
717 printf_unfiltered (_("td_ta_new failed: %s\n"),
718 thread_db_err_str (err
));
723 #ifdef THREAD_DB_HAS_TD_VERSION
726 /* The errors above are not unexpected and silently ignored:
727 they just mean we haven't found correct version of
731 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
736 info
->td_ta_map_id2thr_p
= verbose_dlsym (info
->handle
, "td_ta_map_id2thr");
737 if (info
->td_ta_map_id2thr_p
== NULL
)
740 info
->td_ta_map_lwp2thr_p
= verbose_dlsym (info
->handle
,
741 "td_ta_map_lwp2thr");
742 if (info
->td_ta_map_lwp2thr_p
== NULL
)
745 info
->td_ta_thr_iter_p
= verbose_dlsym (info
->handle
, "td_ta_thr_iter");
746 if (info
->td_ta_thr_iter_p
== NULL
)
749 info
->td_thr_validate_p
= verbose_dlsym (info
->handle
, "td_thr_validate");
750 if (info
->td_thr_validate_p
== NULL
)
753 info
->td_thr_get_info_p
= verbose_dlsym (info
->handle
, "td_thr_get_info");
754 if (info
->td_thr_get_info_p
== NULL
)
757 /* These are not essential. */
758 info
->td_ta_event_addr_p
= dlsym (info
->handle
, "td_ta_event_addr");
759 info
->td_ta_set_event_p
= dlsym (info
->handle
, "td_ta_set_event");
760 info
->td_ta_clear_event_p
= dlsym (info
->handle
, "td_ta_clear_event");
761 info
->td_ta_event_getmsg_p
= dlsym (info
->handle
, "td_ta_event_getmsg");
762 info
->td_thr_event_enable_p
= dlsym (info
->handle
, "td_thr_event_enable");
763 info
->td_thr_tls_get_addr_p
= dlsym (info
->handle
, "td_thr_tls_get_addr");
765 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
767 if (libthread_db_debug
|| *libthread_db_search_path
)
771 library
= dladdr_to_soname (*info
->td_ta_new_p
);
773 library
= LIBTHREAD_DB_SO
;
775 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
779 /* The thread library was detected. Activate the thread_db target
780 if this is the first process using it. */
781 if (thread_db_list
->next
== NULL
)
782 push_target (&thread_db_ops
);
784 /* Enable event reporting, but not when debugging a core file. */
785 if (target_has_execution
)
786 enable_thread_event_reporting ();
788 /* There appears to be a bug in glibc-2.3.6: calls to td_thr_get_info fail
789 with TD_ERR for statically linked executables if td_thr_get_info is
790 called before glibc has initialized itself. Silently ignore such
791 errors, and let gdb enumerate threads again later. */
792 thread_db_find_new_threads_silently (inferior_ptid
);
797 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
798 relative, or just LIBTHREAD_DB. */
801 try_thread_db_load (const char *library
)
804 struct thread_db_info
*info
;
806 if (libthread_db_debug
)
807 printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
809 handle
= dlopen (library
, RTLD_NOW
);
812 if (libthread_db_debug
)
813 printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
817 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
821 td_init
= dlsym (handle
, "td_init");
824 const char *const libpath
= dladdr_to_soname (td_init
);
827 printf_unfiltered (_("Host %s resolved to: %s.\n"),
832 info
= add_thread_db_info (handle
);
834 /* Do not save system library name, that one is always trusted. */
835 if (strchr (library
, '/') != NULL
)
836 info
->filename
= gdb_realpath (library
);
838 if (try_thread_db_load_1 (info
))
841 /* This library "refused" to work on current inferior. */
842 delete_thread_db_info (GET_PID (inferior_ptid
));
846 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
847 Try loading libthread_db from the same directory as OBJ.
848 The result is true for success. */
851 try_thread_db_load_from_pdir_1 (struct objfile
*obj
)
853 struct cleanup
*cleanup
;
857 if (obj
->name
[0] != '/')
859 warning (_("Expected absolute pathname for libpthread in the"
860 " inferior, but got %s."), obj
->name
);
864 path
= xmalloc (strlen (obj
->name
) + 1 + strlen (LIBTHREAD_DB_SO
) + 1);
865 cleanup
= make_cleanup (xfree
, path
);
867 strcpy (path
, obj
->name
);
868 cp
= strrchr (path
, '/');
869 /* This should at minimum hit the first character. */
870 gdb_assert (cp
!= NULL
);
871 strcpy (cp
+ 1, LIBTHREAD_DB_SO
);
873 if (!file_is_auto_load_safe (path
, _("auto-load: Loading libthread-db "
874 "library \"%s\" from $pdir.\n"),
878 result
= try_thread_db_load (path
);
880 do_cleanups (cleanup
);
884 /* Handle $pdir in libthread-db-search-path.
885 Look for libthread_db in the directory of libpthread.
886 The result is true for success. */
889 try_thread_db_load_from_pdir (void)
893 if (!auto_load_thread_db
)
897 if (libpthread_name_p (obj
->name
))
899 if (try_thread_db_load_from_pdir_1 (obj
))
902 /* We may have found the separate-debug-info version of
903 libpthread, and it may live in a directory without a matching
905 if (obj
->separate_debug_objfile_backlink
!= NULL
)
906 return try_thread_db_load_from_pdir_1 (obj
->separate_debug_objfile_backlink
);
914 /* Handle $sdir in libthread-db-search-path.
915 Look for libthread_db in the system dirs, or wherever a plain
916 dlopen(file_without_path) will look.
917 The result is true for success. */
920 try_thread_db_load_from_sdir (void)
922 return try_thread_db_load (LIBTHREAD_DB_SO
);
925 /* Try to load libthread_db from directory DIR of length DIR_LEN.
926 The result is true for success. */
929 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
931 struct cleanup
*cleanup
;
935 if (!auto_load_thread_db
)
938 path
= xmalloc (dir_len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1);
939 cleanup
= make_cleanup (xfree
, path
);
941 memcpy (path
, dir
, dir_len
);
943 strcpy (path
+ dir_len
+ 1, LIBTHREAD_DB_SO
);
945 if (!file_is_auto_load_safe (path
, _("auto-load: Loading libthread-db "
946 "library \"%s\" from explicit "
951 result
= try_thread_db_load (path
);
953 do_cleanups (cleanup
);
957 /* Search libthread_db_search_path for libthread_db which "agrees"
958 to work on current inferior.
959 The result is true for success. */
962 thread_db_load_search (void)
964 const char *search_path
= libthread_db_search_path
;
969 const char *end
= strchr (search_path
, ':');
970 const char *this_dir
= search_path
;
975 this_dir_len
= end
- search_path
;
976 search_path
+= this_dir_len
+ 1;
980 this_dir_len
= strlen (this_dir
);
981 search_path
+= this_dir_len
;
984 if (this_dir_len
== sizeof ("$pdir") - 1
985 && strncmp (this_dir
, "$pdir", this_dir_len
) == 0)
987 if (try_thread_db_load_from_pdir ())
993 else if (this_dir_len
== sizeof ("$sdir") - 1
994 && strncmp (this_dir
, "$sdir", this_dir_len
) == 0)
996 if (try_thread_db_load_from_sdir ())
1004 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
1012 if (libthread_db_debug
)
1013 printf_unfiltered (_("thread_db_load_search returning %d\n"), rc
);
1017 /* Return non-zero if the inferior has a libpthread. */
1020 has_libpthread (void)
1022 struct objfile
*obj
;
1025 if (libpthread_name_p (obj
->name
))
1031 /* Attempt to load and initialize libthread_db.
1032 Return 1 on success. */
1035 thread_db_load (void)
1037 struct thread_db_info
*info
;
1039 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1044 /* Don't attempt to use thread_db on executables not running
1046 if (!target_has_registers
)
1049 /* Don't attempt to use thread_db for remote targets. */
1050 if (!(target_can_run (¤t_target
) || core_bfd
))
1053 if (thread_db_load_search ())
1056 /* We couldn't find a libthread_db.
1057 If the inferior has a libpthread warn the user. */
1058 if (has_libpthread ())
1060 warning (_("Unable to find libthread_db matching inferior's thread"
1061 " library, thread debugging will not be available."));
1065 /* Either this executable isn't using libpthread at all, or it is
1066 statically linked. Since we can't easily distinguish these two cases,
1067 no warning is issued. */
1072 disable_thread_event_reporting (struct thread_db_info
*info
)
1074 if (info
->td_ta_clear_event_p
!= NULL
)
1076 td_thr_events_t events
;
1078 /* Set the process wide mask saying we aren't interested in any
1080 td_event_fillset (&events
);
1081 info
->td_ta_clear_event_p (info
->thread_agent
, &events
);
1084 info
->td_create_bp_addr
= 0;
1085 info
->td_death_bp_addr
= 0;
1089 check_thread_signals (void)
1091 if (!thread_signals
)
1096 lin_thread_get_thread_signals (&mask
);
1097 sigemptyset (&thread_stop_set
);
1098 sigemptyset (&thread_print_set
);
1100 for (i
= 1; i
< NSIG
; i
++)
1102 if (sigismember (&mask
, i
))
1104 if (signal_stop_update (gdb_signal_from_host (i
), 0))
1105 sigaddset (&thread_stop_set
, i
);
1106 if (signal_print_update (gdb_signal_from_host (i
), 0))
1107 sigaddset (&thread_print_set
, i
);
1114 /* Check whether thread_db is usable. This function is called when
1115 an inferior is created (or otherwise acquired, e.g. attached to)
1116 and when new shared libraries are loaded into a running process. */
1119 check_for_thread_db (void)
1121 /* Do nothing if we couldn't load libthread_db.so.1. */
1122 if (!thread_db_load ())
1126 /* This function is called via the new_objfile observer. */
1129 thread_db_new_objfile (struct objfile
*objfile
)
1131 /* This observer must always be called with inferior_ptid set
1135 /* Only check for thread_db if we loaded libpthread,
1136 or if this is the main symbol file.
1137 We need to check OBJF_MAINLINE to handle the case of debugging
1138 a statically linked executable AND the symbol file is specified AFTER
1139 the exec file is loaded (e.g., gdb -c core ; file foo).
1140 For dynamically linked executables, libpthread can be near the end
1141 of the list of shared libraries to load, and in an app of several
1142 thousand shared libraries, this can otherwise be painful. */
1143 && ((objfile
->flags
& OBJF_MAINLINE
) != 0
1144 || libpthread_name_p (objfile
->name
)))
1145 check_for_thread_db ();
1148 /* This function is called via the inferior_created observer.
1149 This handles the case of debugging statically linked executables. */
1152 thread_db_inferior_created (struct target_ops
*target
, int from_tty
)
1154 check_for_thread_db ();
1157 /* Attach to a new thread. This function is called when we receive a
1158 TD_CREATE event or when we iterate over all threads and find one
1159 that wasn't already in our list. Returns true on success. */
1162 attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
1163 const td_thrinfo_t
*ti_p
)
1165 struct private_thread_info
*private;
1166 struct thread_info
*tp
;
1168 struct thread_db_info
*info
;
1170 /* If we're being called after a TD_CREATE event, we may already
1171 know about this thread. There are two ways this can happen. We
1172 may have iterated over all threads between the thread creation
1173 and the TD_CREATE event, for instance when the user has issued
1174 the `info threads' command before the SIGTRAP for hitting the
1175 thread creation breakpoint was reported. Alternatively, the
1176 thread may have exited and a new one been created with the same
1177 thread ID. In the first case we don't need to do anything; in
1178 the second case we should discard information about the dead
1179 thread and attach to the new one. */
1180 tp
= find_thread_ptid (ptid
);
1183 /* If tp->private is NULL, then GDB is already attached to this
1184 thread, but we do not know anything about it. We can learn
1185 about it here. This can only happen if we have some other
1186 way besides libthread_db to notice new threads (i.e.
1187 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
1188 exit, so this can not be a stale thread recreated with the
1190 if (tp
->private != NULL
)
1192 if (!tp
->private->dying
)
1195 delete_thread (ptid
);
1200 if (target_has_execution
)
1201 check_thread_signals ();
1203 if (ti_p
->ti_state
== TD_THR_UNKNOWN
|| ti_p
->ti_state
== TD_THR_ZOMBIE
)
1204 return 0; /* A zombie thread -- do not attach. */
1206 /* Under GNU/Linux, we have to attach to each and every thread. */
1207 if (target_has_execution
1212 res
= lin_lwp_attach_lwp (BUILD_LWP (ti_p
->ti_lid
, GET_PID (ptid
)));
1215 /* Error, stop iterating. */
1220 /* Pretend this thread doesn't exist yet, and keep
1225 /* Otherwise, we sucessfully attached to the thread. */
1228 /* Construct the thread's private data. */
1229 private = xmalloc (sizeof (struct private_thread_info
));
1230 memset (private, 0, sizeof (struct private_thread_info
));
1232 /* A thread ID of zero may mean the thread library has not initialized
1233 yet. But we shouldn't even get here if that's the case. FIXME:
1234 if we change GDB to always have at least one thread in the thread
1235 list this will have to go somewhere else; maybe private == NULL
1236 until the thread_db target claims it. */
1237 gdb_assert (ti_p
->ti_tid
!= 0);
1238 private->th
= *th_p
;
1239 private->tid
= ti_p
->ti_tid
;
1241 /* Add the thread to GDB's thread list. */
1243 add_thread_with_info (ptid
, private);
1245 tp
->private = private;
1247 info
= get_thread_db_info (GET_PID (ptid
));
1249 /* Enable thread event reporting for this thread, except when
1250 debugging a core file. */
1251 if (target_has_execution
)
1253 err
= info
->td_thr_event_enable_p (th_p
, 1);
1255 error (_("Cannot enable thread event reporting for %s: %s"),
1256 target_pid_to_str (ptid
), thread_db_err_str (err
));
1263 detach_thread (ptid_t ptid
)
1265 struct thread_info
*thread_info
;
1267 /* Don't delete the thread now, because it still reports as active
1268 until it has executed a few instructions after the event
1269 breakpoint - if we deleted it now, "info threads" would cause us
1270 to re-attach to it. Just mark it as having had a TD_DEATH
1271 event. This means that we won't delete it from our thread list
1272 until we notice that it's dead (via prune_threads), or until
1273 something re-uses its thread ID. We'll report the thread exit
1274 when the underlying LWP dies. */
1275 thread_info
= find_thread_ptid (ptid
);
1276 gdb_assert (thread_info
!= NULL
&& thread_info
->private != NULL
);
1277 thread_info
->private->dying
= 1;
1281 thread_db_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1283 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1284 struct thread_db_info
*info
;
1286 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1290 if (target_has_execution
)
1292 disable_thread_event_reporting (info
);
1294 /* Delete the old thread event breakpoints. Note that
1295 unlike when mourning, we can remove them here because
1296 there's still a live inferior to poke at. In any case,
1297 GDB will not try to insert anything in the inferior when
1298 removing a breakpoint. */
1299 remove_thread_event_breakpoints ();
1302 delete_thread_db_info (GET_PID (inferior_ptid
));
1305 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
1307 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1309 /* If there are no more processes using libpthread, detach the
1310 thread_db target ops. */
1311 if (!thread_db_list
)
1312 unpush_target (&thread_db_ops
);
1315 /* Check if PID is currently stopped at the location of a thread event
1316 breakpoint location. If it is, read the event message and act upon
1320 check_event (ptid_t ptid
)
1322 struct regcache
*regcache
= get_thread_regcache (ptid
);
1323 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1329 struct thread_db_info
*info
;
1331 info
= get_thread_db_info (GET_PID (ptid
));
1333 /* Bail out early if we're not at a thread event breakpoint. */
1334 stop_pc
= regcache_read_pc (regcache
)
1335 - gdbarch_decr_pc_after_break (gdbarch
);
1336 if (stop_pc
!= info
->td_create_bp_addr
1337 && stop_pc
!= info
->td_death_bp_addr
)
1340 /* Access an lwp we know is stopped. */
1341 info
->proc_handle
.ptid
= ptid
;
1343 /* If we have only looked at the first thread before libpthread was
1344 initialized, we may not know its thread ID yet. Make sure we do
1345 before we add another thread to the list. */
1346 if (!have_threads (ptid
))
1347 thread_db_find_new_threads_1 (ptid
);
1349 /* If we are at a create breakpoint, we do not know what new lwp
1350 was created and cannot specifically locate the event message for it.
1351 We have to call td_ta_event_getmsg() to get
1352 the latest message. Since we have no way of correlating whether
1353 the event message we get back corresponds to our breakpoint, we must
1354 loop and read all event messages, processing them appropriately.
1355 This guarantees we will process the correct message before continuing
1356 from the breakpoint.
1358 Currently, death events are not enabled. If they are enabled,
1359 the death event can use the td_thr_event_getmsg() interface to
1360 get the message specifically for that lwp and avoid looping
1367 err
= info
->td_ta_event_getmsg_p (info
->thread_agent
, &msg
);
1370 if (err
== TD_NOMSG
)
1373 error (_("Cannot get thread event message: %s"),
1374 thread_db_err_str (err
));
1377 err
= info
->td_thr_get_info_p (msg
.th_p
, &ti
);
1379 error (_("Cannot get thread info: %s"), thread_db_err_str (err
));
1381 ptid
= ptid_build (GET_PID (ptid
), ti
.ti_lid
, 0);
1386 /* Call attach_thread whether or not we already know about a
1387 thread with this thread ID. */
1388 attach_thread (ptid
, msg
.th_p
, &ti
);
1394 if (!in_thread_list (ptid
))
1395 error (_("Spurious thread death event."));
1397 detach_thread (ptid
);
1402 error (_("Spurious thread event."));
1409 thread_db_wait (struct target_ops
*ops
,
1410 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1413 struct thread_db_info
*info
;
1414 struct target_ops
*beneath
= find_target_beneath (ops
);
1416 ptid
= beneath
->to_wait (beneath
, ptid
, ourstatus
, options
);
1418 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
1421 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
1422 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
1425 info
= get_thread_db_info (GET_PID (ptid
));
1427 /* If this process isn't using thread_db, we're done. */
1431 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1433 /* New image, it may or may not end up using thread_db. Assume
1434 not unless we find otherwise. */
1435 delete_thread_db_info (GET_PID (ptid
));
1436 if (!thread_db_list
)
1437 unpush_target (&thread_db_ops
);
1439 /* Thread event breakpoints are deleted by
1440 update_breakpoints_after_exec. */
1445 /* If we do not know about the main thread yet, this would be a good time to
1447 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
&& !have_threads (ptid
))
1448 thread_db_find_new_threads_1 (ptid
);
1450 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
1451 && ourstatus
->value
.sig
== GDB_SIGNAL_TRAP
)
1452 /* Check for a thread event. */
1455 if (have_threads (ptid
))
1457 /* Change ptids back into the higher level PID + TID format. If
1458 the thread is dead and no longer on the thread list, we will
1459 get back a dead ptid. This can occur if the thread death
1460 event gets postponed by other simultaneous events. In such a
1461 case, we want to just ignore the event and continue on. */
1463 ptid
= thread_from_lwp (ptid
);
1464 if (GET_PID (ptid
) == -1)
1465 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1472 thread_db_mourn_inferior (struct target_ops
*ops
)
1474 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1476 delete_thread_db_info (GET_PID (inferior_ptid
));
1478 target_beneath
->to_mourn_inferior (target_beneath
);
1480 /* Delete the old thread event breakpoints. Do this after mourning
1481 the inferior, so that we don't try to uninsert them. */
1482 remove_thread_event_breakpoints ();
1484 /* Detach thread_db target ops. */
1485 if (!thread_db_list
)
1486 unpush_target (ops
);
1489 struct callback_data
1491 struct thread_db_info
*info
;
1496 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1501 struct thread_info
*tp
;
1502 struct callback_data
*cb_data
= data
;
1503 struct thread_db_info
*info
= cb_data
->info
;
1505 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1507 error (_("find_new_threads_callback: cannot get thread info: %s"),
1508 thread_db_err_str (err
));
1510 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
1511 return 0; /* A zombie -- ignore. */
1515 /* A thread ID of zero means that this is the main thread, but
1516 glibc has not yet initialized thread-local storage and the
1517 pthread library. We do not know what the thread's TID will
1518 be yet. Just enable event reporting and otherwise ignore
1521 /* In that case, we're not stopped in a fork syscall and don't
1522 need this glibc bug workaround. */
1523 info
->need_stale_parent_threads_check
= 0;
1525 if (target_has_execution
)
1527 err
= info
->td_thr_event_enable_p (th_p
, 1);
1529 error (_("Cannot enable thread event reporting for LWP %d: %s"),
1530 (int) ti
.ti_lid
, thread_db_err_str (err
));
1536 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1537 bit expensive, as it needs to open /proc/pid/status, so try to
1538 avoid doing the work if we know we don't have to. */
1539 if (info
->need_stale_parent_threads_check
)
1541 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1543 if (tgid
!= -1 && tgid
!= info
->pid
)
1547 ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
1548 tp
= find_thread_ptid (ptid
);
1549 if (tp
== NULL
|| tp
->private == NULL
)
1551 if (attach_thread (ptid
, th_p
, &ti
))
1552 cb_data
->new_threads
+= 1;
1554 /* Problem attaching this thread; perhaps it exited before we
1556 This could mean that the thread list inside glibc itself is in
1557 inconsistent state, and libthread_db could go on looping forever
1558 (observed with glibc-2.3.6). To prevent that, terminate
1559 iteration: thread_db_find_new_threads_2 will retry. */
1566 /* Helper for thread_db_find_new_threads_2.
1567 Returns number of new threads found. */
1570 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1573 volatile struct gdb_exception except
;
1574 struct callback_data data
;
1575 td_err_e err
= TD_ERR
;
1578 data
.new_threads
= 0;
1580 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1582 /* Iterate over all user-space threads to discover new threads. */
1583 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1584 find_new_threads_callback
,
1587 TD_THR_LOWEST_PRIORITY
,
1589 TD_THR_ANY_USER_FLAGS
);
1592 if (libthread_db_debug
)
1594 if (except
.reason
< 0)
1595 exception_fprintf (gdb_stderr
, except
,
1596 "Warning: find_new_threads_once: ");
1598 printf_filtered (_("Found %d new threads in iteration %d.\n"),
1599 data
.new_threads
, iteration
);
1605 return data
.new_threads
;
1608 /* Search for new threads, accessing memory through stopped thread
1609 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1610 searches in a row do not discover any new threads. */
1613 thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
)
1616 struct thread_db_info
*info
;
1617 int pid
= ptid_get_pid (ptid
);
1620 info
= get_thread_db_info (GET_PID (ptid
));
1622 /* Access an lwp we know is stopped. */
1623 info
->proc_handle
.ptid
= ptid
;
1627 /* Require 4 successive iterations which do not find any new threads.
1628 The 4 is a heuristic: there is an inherent race here, and I have
1629 seen that 2 iterations in a row are not always sufficient to
1630 "capture" all threads. */
1631 for (i
= 0, loop
= 0; loop
< 4; ++i
, ++loop
)
1632 if (find_new_threads_once (info
, i
, NULL
) != 0)
1633 /* Found some new threads. Restart the loop from beginning. */
1638 find_new_threads_once (info
, 0, &err
);
1640 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1645 thread_db_find_new_threads_1 (ptid_t ptid
)
1647 thread_db_find_new_threads_2 (ptid
, 0);
1651 update_thread_core (struct lwp_info
*info
, void *closure
)
1653 info
->core
= linux_common_core_of_thread (info
->ptid
);
1658 thread_db_find_new_threads (struct target_ops
*ops
)
1660 struct thread_db_info
*info
;
1661 struct inferior
*inf
;
1665 struct thread_info
*thread
;
1670 info
= get_thread_db_info (inf
->pid
);
1674 thread
= any_live_thread_of_process (inf
->pid
);
1675 if (thread
== NULL
|| thread
->executing
)
1678 thread_db_find_new_threads_1 (thread
->ptid
);
1681 if (target_has_execution
)
1682 iterate_over_lwps (minus_one_ptid
/* iterate over all */,
1683 update_thread_core
, NULL
);
1687 thread_db_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
1689 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1690 struct target_ops
*beneath
;
1692 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1694 static char buf
[64];
1697 tid
= thread_info
->private->tid
;
1698 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1699 tid
, GET_LWP (ptid
));
1704 beneath
= find_target_beneath (ops
);
1705 if (beneath
->to_pid_to_str (beneath
, ptid
))
1706 return beneath
->to_pid_to_str (beneath
, ptid
);
1708 return normal_pid_to_str (ptid
);
1711 /* Return a string describing the state of the thread specified by
1715 thread_db_extra_thread_info (struct thread_info
*info
)
1717 if (info
->private == NULL
)
1720 if (info
->private->dying
)
1726 /* Get the address of the thread local variable in load module LM which
1727 is stored at OFFSET within the thread local storage for thread PTID. */
1730 thread_db_get_thread_local_address (struct target_ops
*ops
,
1735 struct thread_info
*thread_info
;
1736 struct target_ops
*beneath
;
1738 /* If we have not discovered any threads yet, check now. */
1739 if (!have_threads (ptid
))
1740 thread_db_find_new_threads_1 (ptid
);
1742 /* Find the matching thread. */
1743 thread_info
= find_thread_ptid (ptid
);
1745 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1749 struct thread_db_info
*info
;
1751 info
= get_thread_db_info (GET_PID (ptid
));
1753 /* glibc doesn't provide the needed interface. */
1754 if (!info
->td_thr_tls_get_addr_p
)
1755 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1756 _("No TLS library support"));
1758 /* Caller should have verified that lm != 0. */
1759 gdb_assert (lm
!= 0);
1761 /* Finally, get the address of the variable. */
1762 /* Note the cast through uintptr_t: this interface only works if
1763 a target address fits in a psaddr_t, which is a host pointer.
1764 So a 32-bit debugger can not access 64-bit TLS through this. */
1765 err
= info
->td_thr_tls_get_addr_p (&thread_info
->private->th
,
1766 (psaddr_t
)(uintptr_t) lm
,
1769 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1770 /* The memory hasn't been allocated, yet. */
1771 if (err
== TD_NOTALLOC
)
1772 /* Now, if libthread_db provided the initialization image's
1773 address, we *could* try to build a non-lvalue value from
1774 the initialization image. */
1775 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1776 _("TLS not allocated yet"));
1779 /* Something else went wrong. */
1781 throw_error (TLS_GENERIC_ERROR
,
1782 (("%s")), thread_db_err_str (err
));
1784 /* Cast assuming host == target. Joy. */
1785 /* Do proper sign extension for the target. */
1786 gdb_assert (exec_bfd
);
1787 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1788 ? (CORE_ADDR
) (intptr_t) address
1789 : (CORE_ADDR
) (uintptr_t) address
);
1792 beneath
= find_target_beneath (ops
);
1793 if (beneath
->to_get_thread_local_address
)
1794 return beneath
->to_get_thread_local_address (beneath
, ptid
, lm
, offset
);
1796 throw_error (TLS_GENERIC_ERROR
,
1797 _("TLS not supported on this target"));
1800 /* Callback routine used to find a thread based on the TID part of
1804 thread_db_find_thread_from_tid (struct thread_info
*thread
, void *data
)
1806 long *tid
= (long *) data
;
1808 if (thread
->private->tid
== *tid
)
1814 /* Implement the to_get_ada_task_ptid target method for this target. */
1817 thread_db_get_ada_task_ptid (long lwp
, long thread
)
1819 struct thread_info
*thread_info
;
1821 thread_db_find_new_threads_1 (inferior_ptid
);
1822 thread_info
= iterate_over_threads (thread_db_find_thread_from_tid
, &thread
);
1824 gdb_assert (thread_info
!= NULL
);
1826 return (thread_info
->ptid
);
1830 thread_db_resume (struct target_ops
*ops
,
1831 ptid_t ptid
, int step
, enum gdb_signal signo
)
1833 struct target_ops
*beneath
= find_target_beneath (ops
);
1834 struct thread_db_info
*info
;
1836 if (ptid_equal (ptid
, minus_one_ptid
))
1837 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1839 info
= get_thread_db_info (GET_PID (ptid
));
1841 /* This workaround is only needed for child fork lwps stopped in a
1842 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1843 workaround can be disabled. */
1845 info
->need_stale_parent_threads_check
= 0;
1847 beneath
->to_resume (beneath
, ptid
, step
, signo
);
1850 /* qsort helper function for info_auto_load_libthread_db, sort the
1851 thread_db_info pointers primarily by their FILENAME and secondarily by their
1852 PID, both in ascending order. */
1855 info_auto_load_libthread_db_compare (const void *ap
, const void *bp
)
1857 struct thread_db_info
*a
= *(struct thread_db_info
**) ap
;
1858 struct thread_db_info
*b
= *(struct thread_db_info
**) bp
;
1861 retval
= strcmp (a
->filename
, b
->filename
);
1865 return (a
->pid
> b
->pid
) - (a
->pid
- b
->pid
);
1868 /* Implement 'info auto-load libthread-db'. */
1871 info_auto_load_libthread_db (char *args
, int from_tty
)
1873 struct ui_out
*uiout
= current_uiout
;
1874 const char *cs
= args
? args
: "";
1875 struct thread_db_info
*info
, **array
;
1876 unsigned info_count
, unique_filenames
;
1877 size_t max_filename_len
, max_pids_len
, pids_len
;
1878 struct cleanup
*back_to
;
1882 while (isspace (*cs
))
1885 error (_("'info auto-load libthread-db' does not accept any parameters"));
1888 for (info
= thread_db_list
; info
; info
= info
->next
)
1889 if (info
->filename
!= NULL
)
1892 array
= xmalloc (sizeof (*array
) * info_count
);
1893 back_to
= make_cleanup (xfree
, array
);
1896 for (info
= thread_db_list
; info
; info
= info
->next
)
1897 if (info
->filename
!= NULL
)
1898 array
[info_count
++] = info
;
1900 /* Sort ARRAY by filenames and PIDs. */
1902 qsort (array
, info_count
, sizeof (*array
),
1903 info_auto_load_libthread_db_compare
);
1905 /* Calculate the number of unique filenames (rows) and the maximum string
1906 length of PIDs list for the unique filenames (columns). */
1908 unique_filenames
= 0;
1909 max_filename_len
= 0;
1912 for (i
= 0; i
< info_count
; i
++)
1914 int pid
= array
[i
]->pid
;
1915 size_t this_pid_len
;
1917 for (this_pid_len
= 0; pid
!= 0; pid
/= 10)
1920 if (i
== 0 || strcmp (array
[i
- 1]->filename
, array
[i
]->filename
) != 0)
1923 max_filename_len
= max (max_filename_len
,
1924 strlen (array
[i
]->filename
));
1928 pids_len
-= strlen (", ");
1929 max_pids_len
= max (max_pids_len
, pids_len
);
1933 pids_len
+= this_pid_len
+ strlen (", ");
1937 pids_len
-= strlen (", ");
1938 max_pids_len
= max (max_pids_len
, pids_len
);
1941 /* Table header shifted right by preceding "libthread-db: " would not match
1943 if (info_count
> 0 && args
== auto_load_info_scripts_pattern_nl
)
1944 ui_out_text (uiout
, "\n");
1946 make_cleanup_ui_out_table_begin_end (uiout
, 2, unique_filenames
,
1947 "LinuxThreadDbTable");
1949 ui_out_table_header (uiout
, max_filename_len
, ui_left
, "filename",
1951 ui_out_table_header (uiout
, pids_len
, ui_left
, "PIDs", "Pids");
1952 ui_out_table_body (uiout
);
1954 pids
= xmalloc (max_pids_len
+ 1);
1955 make_cleanup (xfree
, pids
);
1957 /* Note I is incremented inside the cycle, not at its end. */
1958 for (i
= 0; i
< info_count
;)
1960 struct cleanup
*chain
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
1964 ui_out_field_string (uiout
, "filename", info
->filename
);
1967 while (i
< info_count
&& strcmp (info
->filename
, array
[i
]->filename
) == 0)
1969 if (pids_end
!= pids
)
1974 pids_end
+= xsnprintf (pids_end
, &pids
[max_pids_len
+ 1] - pids_end
,
1975 "%u", array
[i
]->pid
);
1976 gdb_assert (pids_end
< &pids
[max_pids_len
+ 1]);
1982 ui_out_field_string (uiout
, "pids", pids
);
1984 ui_out_text (uiout
, "\n");
1985 do_cleanups (chain
);
1988 do_cleanups (back_to
);
1990 if (info_count
== 0)
1991 ui_out_message (uiout
, 0, _("No auto-loaded libthread-db.\n"));
1995 init_thread_db_ops (void)
1997 thread_db_ops
.to_shortname
= "multi-thread";
1998 thread_db_ops
.to_longname
= "multi-threaded child process.";
1999 thread_db_ops
.to_doc
= "Threads and pthreads support.";
2000 thread_db_ops
.to_detach
= thread_db_detach
;
2001 thread_db_ops
.to_wait
= thread_db_wait
;
2002 thread_db_ops
.to_resume
= thread_db_resume
;
2003 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
2004 thread_db_ops
.to_find_new_threads
= thread_db_find_new_threads
;
2005 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
2006 thread_db_ops
.to_stratum
= thread_stratum
;
2007 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
2008 thread_db_ops
.to_get_thread_local_address
2009 = thread_db_get_thread_local_address
;
2010 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
2011 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
2012 thread_db_ops
.to_magic
= OPS_MAGIC
;
2015 /* Provide a prototype to silence -Wmissing-prototypes. */
2016 extern initialize_file_ftype _initialize_thread_db
;
2019 _initialize_thread_db (void)
2021 init_thread_db_ops ();
2022 add_target (&thread_db_ops
);
2024 /* Defer loading of libthread_db.so until inferior is running.
2025 This allows gdb to load correct libthread_db for a given
2026 executable -- there could be mutiple versions of glibc,
2027 compiled with LinuxThreads or NPTL, and until there is
2028 a running inferior, we can't tell which libthread_db is
2029 the correct one to load. */
2031 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
2033 add_setshow_optional_filename_cmd ("libthread-db-search-path",
2035 &libthread_db_search_path
, _("\
2036 Set search path for libthread_db."), _("\
2037 Show the current search path or libthread_db."), _("\
2038 This path is used to search for libthread_db to be loaded into \
2040 Its value is a colon (':') separate list of directories to search.\n\
2041 Setting the search path to an empty list resets it to its default value."),
2042 set_libthread_db_search_path
,
2044 &setlist
, &showlist
);
2046 add_setshow_zinteger_cmd ("libthread-db", class_maintenance
,
2047 &libthread_db_debug
, _("\
2048 Set libthread-db debugging."), _("\
2049 Show libthread-db debugging."), _("\
2050 When non-zero, libthread-db debugging is enabled."),
2052 show_libthread_db_debug
,
2053 &setdebuglist
, &showdebuglist
);
2055 add_setshow_boolean_cmd ("libthread-db", class_support
,
2056 &auto_load_thread_db
, _("\
2057 Enable or disable auto-loading of inferior specific libthread_db."), _("\
2058 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
2059 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
2060 locations to load libthread_db compatible with the inferior.\n\
2061 Standard system libthread_db still gets loaded even with this option off.\n\
2062 This options has security implications for untrusted inferiors."),
2063 NULL
, show_auto_load_thread_db
,
2064 auto_load_set_cmdlist_get (),
2065 auto_load_show_cmdlist_get ());
2067 add_cmd ("libthread-db", class_info
, info_auto_load_libthread_db
,
2068 _("Print the list of loaded inferior specific libthread_db.\n\
2069 Usage: info auto-load libthread-db"),
2070 auto_load_info_cmdlist_get ());
2072 /* Add ourselves to objfile event chain. */
2073 observer_attach_new_objfile (thread_db_new_objfile
);
2075 /* Add ourselves to inferior_created event chain.
2076 This is needed to handle debugging statically linked programs where
2077 the new_objfile observer won't get called for libpthread. */
2078 observer_attach_inferior_created (thread_db_inferior_created
);