1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999-2013 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"
45 #include "cli/cli-utils.h"
50 /* GNU/Linux libthread_db support.
52 libthread_db is a library, provided along with libpthread.so, which
53 exposes the internals of the thread library to a debugger. It
54 allows GDB to find existing threads, new threads as they are
55 created, thread IDs (usually, the result of pthread_self), and
56 thread-local variables.
58 The libthread_db interface originates on Solaris, where it is
59 both more powerful and more complicated. This implementation
60 only works for LinuxThreads and NPTL, the two glibc threading
61 libraries. It assumes that each thread is permanently assigned
62 to a single light-weight process (LWP).
64 libthread_db-specific information is stored in the "private" field
65 of struct thread_info. When the field is NULL we do not yet have
66 information about the new thread; this could be temporary (created,
67 but the thread library's data structures do not reflect it yet)
68 or permanent (created using clone instead of pthread_create).
70 Process IDs managed by linux-thread-db.c match those used by
71 linux-nat.c: a common PID for all processes, an LWP ID for each
72 thread, and no TID. We save the TID in private. Keeping it out
73 of the ptid_t prevents thread IDs changing when libpthread is
74 loaded or unloaded. */
76 static char *libthread_db_search_path
;
78 /* Set to non-zero if thread_db auto-loading is enabled
79 by the "set auto-load libthread-db" command. */
80 static int auto_load_thread_db
= 1;
82 /* "show" command for the auto_load_thread_db configuration variable. */
85 show_auto_load_thread_db (struct ui_file
*file
, int from_tty
,
86 struct cmd_list_element
*c
, const char *value
)
88 fprintf_filtered (file
, _("Auto-loading of inferior specific libthread_db "
94 set_libthread_db_search_path (char *ignored
, int from_tty
,
95 struct cmd_list_element
*c
)
97 if (*libthread_db_search_path
== '\0')
99 xfree (libthread_db_search_path
);
100 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
104 /* If non-zero, print details of libthread_db processing. */
106 static unsigned int libthread_db_debug
;
109 show_libthread_db_debug (struct ui_file
*file
, int from_tty
,
110 struct cmd_list_element
*c
, const char *value
)
112 fprintf_filtered (file
, _("libthread-db debugging is %s.\n"), value
);
115 /* If we're running on GNU/Linux, we must explicitly attach to any new
118 /* This module's target vector. */
119 static struct target_ops thread_db_ops
;
121 /* Non-zero if we have determined the signals used by the threads
123 static int thread_signals
;
124 static sigset_t thread_stop_set
;
125 static sigset_t thread_print_set
;
127 struct thread_db_info
129 struct thread_db_info
*next
;
131 /* Process id this object refers to. */
134 /* Handle from dlopen for libthread_db.so. */
137 /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
138 HANDLE. It may be NULL for system library. */
141 /* Structure that identifies the child process for the
142 <proc_service.h> interface. */
143 struct ps_prochandle proc_handle
;
145 /* Connection to the libthread_db library. */
146 td_thragent_t
*thread_agent
;
148 /* True if we need to apply the workaround for glibc/BZ5983. When
149 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
150 list, nptl_db returns the parent's threads in addition to the new
151 (single) child thread. If this flag is set, we do extra work to
152 be able to ignore such stale entries. */
153 int need_stale_parent_threads_check
;
155 /* Location of the thread creation event breakpoint. The code at
156 this location in the child process will be called by the pthread
157 library whenever a new thread is created. By setting a special
158 breakpoint at this location, GDB can detect when a new thread is
159 created. We obtain this location via the td_ta_event_addr
161 CORE_ADDR td_create_bp_addr
;
163 /* Location of the thread death event breakpoint. */
164 CORE_ADDR td_death_bp_addr
;
166 /* Pointers to the libthread_db functions. */
168 td_err_e (*td_init_p
) (void);
170 td_err_e (*td_ta_new_p
) (struct ps_prochandle
* ps
,
172 td_err_e (*td_ta_map_id2thr_p
) (const td_thragent_t
*ta
, thread_t pt
,
173 td_thrhandle_t
*__th
);
174 td_err_e (*td_ta_map_lwp2thr_p
) (const td_thragent_t
*ta
,
175 lwpid_t lwpid
, td_thrhandle_t
*th
);
176 td_err_e (*td_ta_thr_iter_p
) (const td_thragent_t
*ta
,
177 td_thr_iter_f
*callback
, void *cbdata_p
,
178 td_thr_state_e state
, int ti_pri
,
179 sigset_t
*ti_sigmask_p
,
180 unsigned int ti_user_flags
);
181 td_err_e (*td_ta_event_addr_p
) (const td_thragent_t
*ta
,
182 td_event_e event
, td_notify_t
*ptr
);
183 td_err_e (*td_ta_set_event_p
) (const td_thragent_t
*ta
,
184 td_thr_events_t
*event
);
185 td_err_e (*td_ta_clear_event_p
) (const td_thragent_t
*ta
,
186 td_thr_events_t
*event
);
187 td_err_e (*td_ta_event_getmsg_p
) (const td_thragent_t
*ta
,
188 td_event_msg_t
*msg
);
190 td_err_e (*td_thr_validate_p
) (const td_thrhandle_t
*th
);
191 td_err_e (*td_thr_get_info_p
) (const td_thrhandle_t
*th
,
192 td_thrinfo_t
*infop
);
193 td_err_e (*td_thr_event_enable_p
) (const td_thrhandle_t
*th
,
196 td_err_e (*td_thr_tls_get_addr_p
) (const td_thrhandle_t
*th
,
197 psaddr_t map_address
,
198 size_t offset
, psaddr_t
*address
);
201 /* List of known processes using thread_db, and the required
203 struct thread_db_info
*thread_db_list
;
205 static void thread_db_find_new_threads_1 (ptid_t ptid
);
206 static void thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
);
208 /* Add the current inferior to the list of processes using libpthread.
209 Return a pointer to the newly allocated object that was added to
210 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
213 static struct thread_db_info
*
214 add_thread_db_info (void *handle
)
216 struct thread_db_info
*info
;
218 info
= xcalloc (1, sizeof (*info
));
219 info
->pid
= ptid_get_pid (inferior_ptid
);
220 info
->handle
= handle
;
222 /* The workaround works by reading from /proc/pid/status, so it is
223 disabled for core files. */
224 if (target_has_execution
)
225 info
->need_stale_parent_threads_check
= 1;
227 info
->next
= thread_db_list
;
228 thread_db_list
= info
;
233 /* Return the thread_db_info object representing the bookkeeping
234 related to process PID, if any; NULL otherwise. */
236 static struct thread_db_info
*
237 get_thread_db_info (int pid
)
239 struct thread_db_info
*info
;
241 for (info
= thread_db_list
; info
; info
= info
->next
)
242 if (pid
== info
->pid
)
248 /* When PID has exited or has been detached, we no longer want to keep
249 track of it as using libpthread. Call this function to discard
250 thread_db related info related to PID. Note that this closes
251 LIBTHREAD_DB_SO's dlopen'ed handle. */
254 delete_thread_db_info (int pid
)
256 struct thread_db_info
*info
, *info_prev
;
260 for (info
= thread_db_list
; info
; info_prev
= info
, info
= info
->next
)
261 if (pid
== info
->pid
)
267 if (info
->handle
!= NULL
)
268 dlclose (info
->handle
);
270 xfree (info
->filename
);
273 info_prev
->next
= info
->next
;
275 thread_db_list
= info
->next
;
280 /* Prototypes for local functions. */
281 static int attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
282 const td_thrinfo_t
*ti_p
);
283 static void detach_thread (ptid_t ptid
);
286 /* Use "struct private_thread_info" to cache thread state. This is
287 a substantial optimization. */
289 struct private_thread_info
291 /* Flag set when we see a TD_DEATH event for this thread. */
292 unsigned int dying
:1;
294 /* Cached thread state. */
301 thread_db_err_str (td_err_e err
)
308 return "generic 'call succeeded'";
310 return "generic error";
312 return "no thread to satisfy query";
314 return "no sync handle to satisfy query";
316 return "no LWP to satisfy query";
318 return "invalid process handle";
320 return "invalid thread handle";
322 return "invalid synchronization handle";
324 return "invalid thread agent";
326 return "invalid key";
328 return "no event message for getmsg";
330 return "FPU register set not available";
332 return "application not linked with libthread";
334 return "requested event is not supported";
336 return "capability not available";
338 return "debugger service failed";
340 return "operation not applicable to";
342 return "no thread-specific data for this thread";
344 return "malloc failed";
346 return "only part of register set was written/read";
348 return "X register set not available for this thread";
349 #ifdef THREAD_DB_HAS_TD_NOTALLOC
351 return "thread has not yet allocated TLS for given module";
353 #ifdef THREAD_DB_HAS_TD_VERSION
355 return "versions of libpthread and libthread_db do not match";
357 #ifdef THREAD_DB_HAS_TD_NOTLS
359 return "there is no TLS segment in the given module";
362 snprintf (buf
, sizeof (buf
), "unknown thread_db error '%d'", err
);
367 /* Return 1 if any threads have been registered. There may be none if
368 the threading library is not fully initialized yet. */
371 have_threads_callback (struct thread_info
*thread
, void *args
)
373 int pid
= * (int *) args
;
375 if (ptid_get_pid (thread
->ptid
) != pid
)
378 return thread
->private != NULL
;
382 have_threads (ptid_t ptid
)
384 int pid
= ptid_get_pid (ptid
);
386 return iterate_over_threads (have_threads_callback
, &pid
) != NULL
;
389 struct thread_get_info_inout
391 struct thread_info
*thread_info
;
392 struct thread_db_info
*thread_db_info
;
395 /* A callback function for td_ta_thr_iter, which we use to map all
398 THP is a handle to the current thread; if INFOP is not NULL, the
399 struct thread_info associated with this thread is returned in
402 If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
403 zero is returned to indicate success. */
406 thread_get_info_callback (const td_thrhandle_t
*thp
, void *argp
)
411 struct thread_get_info_inout
*inout
;
412 struct thread_db_info
*info
;
415 info
= inout
->thread_db_info
;
417 err
= info
->td_thr_get_info_p (thp
, &ti
);
419 error (_("thread_get_info_callback: cannot get thread info: %s"),
420 thread_db_err_str (err
));
422 /* Fill the cache. */
423 thread_ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
424 inout
->thread_info
= find_thread_ptid (thread_ptid
);
426 if (inout
->thread_info
== NULL
)
428 /* New thread. Attach to it now (why wait?). */
429 if (!have_threads (thread_ptid
))
430 thread_db_find_new_threads_1 (thread_ptid
);
432 attach_thread (thread_ptid
, thp
, &ti
);
433 inout
->thread_info
= find_thread_ptid (thread_ptid
);
434 gdb_assert (inout
->thread_info
!= NULL
);
440 /* Fetch the user-level thread id of PTID. */
443 thread_from_lwp (ptid_t ptid
)
447 struct thread_db_info
*info
;
448 struct thread_get_info_inout io
= {0};
450 /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
453 /* This ptid comes from linux-nat.c, which should always fill in the
455 gdb_assert (GET_LWP (ptid
) != 0);
457 info
= get_thread_db_info (GET_PID (ptid
));
459 /* Access an lwp we know is stopped. */
460 info
->proc_handle
.ptid
= ptid
;
461 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
463 error (_("Cannot find user-level thread for LWP %ld: %s"),
464 GET_LWP (ptid
), thread_db_err_str (err
));
466 /* Long-winded way of fetching the thread info. */
467 io
.thread_db_info
= info
;
468 io
.thread_info
= NULL
;
469 thread_get_info_callback (&th
, &io
);
473 /* Attach to lwp PTID, doing whatever else is required to have this
474 LWP under the debugger's control --- e.g., enabling event
475 reporting. Returns true on success. */
477 thread_db_attach_lwp (ptid_t ptid
)
482 struct thread_db_info
*info
;
484 info
= get_thread_db_info (GET_PID (ptid
));
489 /* This ptid comes from linux-nat.c, which should always fill in the
491 gdb_assert (GET_LWP (ptid
) != 0);
493 /* Access an lwp we know is stopped. */
494 info
->proc_handle
.ptid
= ptid
;
496 /* If we have only looked at the first thread before libpthread was
497 initialized, we may not know its thread ID yet. Make sure we do
498 before we add another thread to the list. */
499 if (!have_threads (ptid
))
500 thread_db_find_new_threads_1 (ptid
);
502 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
504 /* Cannot find user-level thread. */
507 err
= info
->td_thr_get_info_p (&th
, &ti
);
510 warning (_("Cannot get thread info: %s"), thread_db_err_str (err
));
514 attach_thread (ptid
, &th
, &ti
);
519 verbose_dlsym (void *handle
, const char *name
)
521 void *sym
= dlsym (handle
, name
);
523 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
529 enable_thread_event (int event
, CORE_ADDR
*bp
)
533 struct thread_db_info
*info
;
535 info
= get_thread_db_info (GET_PID (inferior_ptid
));
537 /* Access an lwp we know is stopped. */
538 info
->proc_handle
.ptid
= inferior_ptid
;
540 /* Get the breakpoint address for thread EVENT. */
541 err
= info
->td_ta_event_addr_p (info
->thread_agent
, event
, ¬ify
);
545 /* Set up the breakpoint. */
546 gdb_assert (exec_bfd
);
547 (*bp
) = (gdbarch_convert_from_func_ptr_addr
549 /* Do proper sign extension for the target. */
550 (bfd_get_sign_extend_vma (exec_bfd
) > 0
551 ? (CORE_ADDR
) (intptr_t) notify
.u
.bptaddr
552 : (CORE_ADDR
) (uintptr_t) notify
.u
.bptaddr
),
554 create_thread_event_breakpoint (target_gdbarch (), *bp
);
559 /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
560 return 1 if this version is lower (and not equal) to
561 VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
564 inferior_has_bug (const char *ver_symbol
, int ver_major_min
, int ver_minor_min
)
566 struct minimal_symbol
*version_msym
;
567 CORE_ADDR version_addr
;
569 int err
, got
, retval
= 0;
571 version_msym
= lookup_minimal_symbol (ver_symbol
, NULL
, NULL
);
572 if (version_msym
== NULL
)
575 version_addr
= SYMBOL_VALUE_ADDRESS (version_msym
);
576 got
= target_read_string (version_addr
, &version
, 32, &err
);
577 if (err
== 0 && memchr (version
, 0, got
) == &version
[got
-1])
581 retval
= (sscanf (version
, "%d.%d", &major
, &minor
) == 2
582 && (major
< ver_major_min
583 || (major
== ver_major_min
&& minor
< ver_minor_min
)));
591 enable_thread_event_reporting (void)
593 td_thr_events_t events
;
595 struct thread_db_info
*info
;
597 info
= get_thread_db_info (GET_PID (inferior_ptid
));
599 /* We cannot use the thread event reporting facility if these
600 functions aren't available. */
601 if (info
->td_ta_event_addr_p
== NULL
602 || info
->td_ta_set_event_p
== NULL
603 || info
->td_ta_event_getmsg_p
== NULL
604 || info
->td_thr_event_enable_p
== NULL
)
607 /* Set the process wide mask saying which events we're interested in. */
608 td_event_emptyset (&events
);
609 td_event_addset (&events
, TD_CREATE
);
611 /* There is a bug fixed between linuxthreads 2.1.3 and 2.2 by
612 commit 2e4581e4fba917f1779cd0a010a45698586c190a
613 * manager.c (pthread_exited): Correctly report event as TD_REAP
614 instead of TD_DEATH. Fix comments.
615 where event reporting facility is broken for TD_DEATH events,
616 so don't enable it if we have glibc but a lower version. */
617 if (!inferior_has_bug ("__linuxthreads_version", 2, 2))
618 td_event_addset (&events
, TD_DEATH
);
620 err
= info
->td_ta_set_event_p (info
->thread_agent
, &events
);
623 warning (_("Unable to set global thread event mask: %s"),
624 thread_db_err_str (err
));
628 /* Delete previous thread event breakpoints, if any. */
629 remove_thread_event_breakpoints ();
630 info
->td_create_bp_addr
= 0;
631 info
->td_death_bp_addr
= 0;
633 /* Set up the thread creation event. */
634 err
= enable_thread_event (TD_CREATE
, &info
->td_create_bp_addr
);
637 warning (_("Unable to get location for thread creation breakpoint: %s"),
638 thread_db_err_str (err
));
642 /* Set up the thread death event. */
643 err
= enable_thread_event (TD_DEATH
, &info
->td_death_bp_addr
);
646 warning (_("Unable to get location for thread death breakpoint: %s"),
647 thread_db_err_str (err
));
652 /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
655 Return 1 if the caller should abort libthread_db initialization. Return 0
659 thread_db_find_new_threads_silently (ptid_t ptid
)
661 volatile struct gdb_exception except
;
663 TRY_CATCH (except
, RETURN_MASK_ERROR
)
665 thread_db_find_new_threads_2 (ptid
, 1);
668 if (except
.reason
< 0)
670 if (libthread_db_debug
)
671 exception_fprintf (gdb_stderr
, except
,
672 "Warning: thread_db_find_new_threads_silently: ");
674 /* There is a bug fixed between nptl 2.6.1 and 2.7 by
675 commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
676 where calls to td_thr_get_info fail with TD_ERR for statically linked
677 executables if td_thr_get_info is called before glibc has initialized
680 If the nptl bug is NOT present in the inferior and still thread_db
681 reports an error return 1. It means the inferior has corrupted thread
682 list and GDB should fall back only to LWPs.
684 If the nptl bug is present in the inferior return 0 to silently ignore
685 such errors, and let gdb enumerate threads again later. In such case
686 GDB cannot properly display LWPs if the inferior thread list is
687 corrupted. For core files it does not apply, no 'later enumeration'
690 if (!target_has_execution
|| !inferior_has_bug ("nptl_version", 2, 7))
692 exception_fprintf (gdb_stderr
, except
,
693 _("Warning: couldn't activate thread debugging "
694 "using libthread_db: "));
701 /* Lookup a library in which given symbol resides.
702 Note: this is looking in GDB process, not in the inferior.
703 Returns library name, or NULL. */
706 dladdr_to_soname (const void *addr
)
710 if (dladdr (addr
, &info
) != 0)
711 return info
.dli_fname
;
715 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
717 Failure could happen if libthread_db does not have symbols we expect,
718 or when it refuses to work with the current inferior (e.g. due to
719 version mismatch between libthread_db and libpthread). */
722 try_thread_db_load_1 (struct thread_db_info
*info
)
726 /* Initialize pointers to the dynamic library functions we will use.
727 Essential functions first. */
729 info
->td_init_p
= verbose_dlsym (info
->handle
, "td_init");
730 if (info
->td_init_p
== NULL
)
733 err
= info
->td_init_p ();
736 warning (_("Cannot initialize libthread_db: %s"),
737 thread_db_err_str (err
));
741 info
->td_ta_new_p
= verbose_dlsym (info
->handle
, "td_ta_new");
742 if (info
->td_ta_new_p
== NULL
)
745 /* Initialize the structure that identifies the child process. */
746 info
->proc_handle
.ptid
= inferior_ptid
;
748 /* Now attempt to open a connection to the thread library. */
749 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
752 if (libthread_db_debug
)
753 printf_unfiltered (_("td_ta_new failed: %s\n"),
754 thread_db_err_str (err
));
759 #ifdef THREAD_DB_HAS_TD_VERSION
762 /* The errors above are not unexpected and silently ignored:
763 they just mean we haven't found correct version of
767 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
772 info
->td_ta_map_id2thr_p
= verbose_dlsym (info
->handle
, "td_ta_map_id2thr");
773 if (info
->td_ta_map_id2thr_p
== NULL
)
776 info
->td_ta_map_lwp2thr_p
= verbose_dlsym (info
->handle
,
777 "td_ta_map_lwp2thr");
778 if (info
->td_ta_map_lwp2thr_p
== NULL
)
781 info
->td_ta_thr_iter_p
= verbose_dlsym (info
->handle
, "td_ta_thr_iter");
782 if (info
->td_ta_thr_iter_p
== NULL
)
785 info
->td_thr_validate_p
= verbose_dlsym (info
->handle
, "td_thr_validate");
786 if (info
->td_thr_validate_p
== NULL
)
789 info
->td_thr_get_info_p
= verbose_dlsym (info
->handle
, "td_thr_get_info");
790 if (info
->td_thr_get_info_p
== NULL
)
793 /* These are not essential. */
794 info
->td_ta_event_addr_p
= dlsym (info
->handle
, "td_ta_event_addr");
795 info
->td_ta_set_event_p
= dlsym (info
->handle
, "td_ta_set_event");
796 info
->td_ta_clear_event_p
= dlsym (info
->handle
, "td_ta_clear_event");
797 info
->td_ta_event_getmsg_p
= dlsym (info
->handle
, "td_ta_event_getmsg");
798 info
->td_thr_event_enable_p
= dlsym (info
->handle
, "td_thr_event_enable");
799 info
->td_thr_tls_get_addr_p
= dlsym (info
->handle
, "td_thr_tls_get_addr");
801 if (thread_db_find_new_threads_silently (inferior_ptid
) != 0)
803 /* Even if libthread_db initializes, if the thread list is
804 corrupted, we'd not manage to list any threads. Better reject this
805 thread_db, and fall back to at least listing LWPs. */
809 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
811 if (libthread_db_debug
|| *libthread_db_search_path
)
815 library
= dladdr_to_soname (*info
->td_ta_new_p
);
817 library
= LIBTHREAD_DB_SO
;
819 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
823 /* The thread library was detected. Activate the thread_db target
824 if this is the first process using it. */
825 if (thread_db_list
->next
== NULL
)
826 push_target (&thread_db_ops
);
828 /* Enable event reporting, but not when debugging a core file. */
829 if (target_has_execution
)
830 enable_thread_event_reporting ();
835 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
836 relative, or just LIBTHREAD_DB. */
839 try_thread_db_load (const char *library
)
842 struct thread_db_info
*info
;
844 if (libthread_db_debug
)
845 printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
847 handle
= dlopen (library
, RTLD_NOW
);
850 if (libthread_db_debug
)
851 printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
855 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
859 td_init
= dlsym (handle
, "td_init");
862 const char *const libpath
= dladdr_to_soname (td_init
);
865 printf_unfiltered (_("Host %s resolved to: %s.\n"),
870 info
= add_thread_db_info (handle
);
872 /* Do not save system library name, that one is always trusted. */
873 if (strchr (library
, '/') != NULL
)
874 info
->filename
= gdb_realpath (library
);
876 if (try_thread_db_load_1 (info
))
879 /* This library "refused" to work on current inferior. */
880 delete_thread_db_info (GET_PID (inferior_ptid
));
884 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
885 Try loading libthread_db in directory(OBJ)/SUBDIR.
886 SUBDIR may be NULL. It may also be something like "../lib64".
887 The result is true for success. */
890 try_thread_db_load_from_pdir_1 (struct objfile
*obj
, const char *subdir
)
892 struct cleanup
*cleanup
;
895 const char *obj_name
= objfile_name (obj
);
897 if (obj_name
[0] != '/')
899 warning (_("Expected absolute pathname for libpthread in the"
900 " inferior, but got %s."), obj_name
);
904 path
= xmalloc (strlen (obj_name
) + (subdir
? strlen (subdir
) + 1 : 0)
905 + 1 + strlen (LIBTHREAD_DB_SO
) + 1);
906 cleanup
= make_cleanup (xfree
, path
);
908 strcpy (path
, obj_name
);
909 cp
= strrchr (path
, '/');
910 /* This should at minimum hit the first character. */
911 gdb_assert (cp
!= NULL
);
918 strcat (cp
, LIBTHREAD_DB_SO
);
920 if (!file_is_auto_load_safe (path
, _("auto-load: Loading libthread-db "
921 "library \"%s\" from $pdir.\n"),
925 result
= try_thread_db_load (path
);
927 do_cleanups (cleanup
);
931 /* Handle $pdir in libthread-db-search-path.
932 Look for libthread_db in directory(libpthread)/SUBDIR.
933 SUBDIR may be NULL. It may also be something like "../lib64".
934 The result is true for success. */
937 try_thread_db_load_from_pdir (const char *subdir
)
941 if (!auto_load_thread_db
)
945 if (libpthread_name_p (objfile_name (obj
)))
947 if (try_thread_db_load_from_pdir_1 (obj
, subdir
))
950 /* We may have found the separate-debug-info version of
951 libpthread, and it may live in a directory without a matching
953 if (obj
->separate_debug_objfile_backlink
!= NULL
)
954 return try_thread_db_load_from_pdir_1 (obj
->separate_debug_objfile_backlink
,
963 /* Handle $sdir in libthread-db-search-path.
964 Look for libthread_db in the system dirs, or wherever a plain
965 dlopen(file_without_path) will look.
966 The result is true for success. */
969 try_thread_db_load_from_sdir (void)
971 return try_thread_db_load (LIBTHREAD_DB_SO
);
974 /* Try to load libthread_db from directory DIR of length DIR_LEN.
975 The result is true for success. */
978 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
980 struct cleanup
*cleanup
;
984 if (!auto_load_thread_db
)
987 path
= xmalloc (dir_len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1);
988 cleanup
= make_cleanup (xfree
, path
);
990 memcpy (path
, dir
, dir_len
);
992 strcpy (path
+ dir_len
+ 1, LIBTHREAD_DB_SO
);
994 if (!file_is_auto_load_safe (path
, _("auto-load: Loading libthread-db "
995 "library \"%s\" from explicit "
1000 result
= try_thread_db_load (path
);
1002 do_cleanups (cleanup
);
1006 /* Search libthread_db_search_path for libthread_db which "agrees"
1007 to work on current inferior.
1008 The result is true for success. */
1011 thread_db_load_search (void)
1013 VEC (char_ptr
) *dir_vec
;
1014 struct cleanup
*cleanups
;
1018 dir_vec
= dirnames_to_char_ptr_vec (libthread_db_search_path
);
1019 cleanups
= make_cleanup_free_char_ptr_vec (dir_vec
);
1021 for (i
= 0; VEC_iterate (char_ptr
, dir_vec
, i
, this_dir
); ++i
)
1023 const int pdir_len
= sizeof ("$pdir") - 1;
1024 size_t this_dir_len
;
1026 this_dir_len
= strlen (this_dir
);
1028 if (strncmp (this_dir
, "$pdir", pdir_len
) == 0
1029 && (this_dir
[pdir_len
] == '\0'
1030 || this_dir
[pdir_len
] == '/'))
1032 char *subdir
= NULL
;
1033 struct cleanup
*free_subdir_cleanup
1034 = make_cleanup (null_cleanup
, NULL
);
1036 if (this_dir
[pdir_len
] == '/')
1038 subdir
= xmalloc (strlen (this_dir
));
1039 make_cleanup (xfree
, subdir
);
1040 strcpy (subdir
, this_dir
+ pdir_len
+ 1);
1042 rc
= try_thread_db_load_from_pdir (subdir
);
1043 do_cleanups (free_subdir_cleanup
);
1047 else if (strcmp (this_dir
, "$sdir") == 0)
1049 if (try_thread_db_load_from_sdir ())
1057 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
1065 do_cleanups (cleanups
);
1066 if (libthread_db_debug
)
1067 printf_unfiltered (_("thread_db_load_search returning %d\n"), rc
);
1071 /* Return non-zero if the inferior has a libpthread. */
1074 has_libpthread (void)
1076 struct objfile
*obj
;
1079 if (libpthread_name_p (objfile_name (obj
)))
1085 /* Attempt to load and initialize libthread_db.
1086 Return 1 on success. */
1089 thread_db_load (void)
1091 struct thread_db_info
*info
;
1093 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1098 /* Don't attempt to use thread_db on executables not running
1100 if (!target_has_registers
)
1103 /* Don't attempt to use thread_db for remote targets. */
1104 if (!(target_can_run (¤t_target
) || core_bfd
))
1107 if (thread_db_load_search ())
1110 /* We couldn't find a libthread_db.
1111 If the inferior has a libpthread warn the user. */
1112 if (has_libpthread ())
1114 warning (_("Unable to find libthread_db matching inferior's thread"
1115 " library, thread debugging will not be available."));
1119 /* Either this executable isn't using libpthread at all, or it is
1120 statically linked. Since we can't easily distinguish these two cases,
1121 no warning is issued. */
1126 disable_thread_event_reporting (struct thread_db_info
*info
)
1128 if (info
->td_ta_clear_event_p
!= NULL
)
1130 td_thr_events_t events
;
1132 /* Set the process wide mask saying we aren't interested in any
1134 td_event_fillset (&events
);
1135 info
->td_ta_clear_event_p (info
->thread_agent
, &events
);
1138 info
->td_create_bp_addr
= 0;
1139 info
->td_death_bp_addr
= 0;
1143 check_thread_signals (void)
1145 if (!thread_signals
)
1150 lin_thread_get_thread_signals (&mask
);
1151 sigemptyset (&thread_stop_set
);
1152 sigemptyset (&thread_print_set
);
1154 for (i
= 1; i
< NSIG
; i
++)
1156 if (sigismember (&mask
, i
))
1158 if (signal_stop_update (gdb_signal_from_host (i
), 0))
1159 sigaddset (&thread_stop_set
, i
);
1160 if (signal_print_update (gdb_signal_from_host (i
), 0))
1161 sigaddset (&thread_print_set
, i
);
1168 /* Check whether thread_db is usable. This function is called when
1169 an inferior is created (or otherwise acquired, e.g. attached to)
1170 and when new shared libraries are loaded into a running process. */
1173 check_for_thread_db (void)
1175 /* Do nothing if we couldn't load libthread_db.so.1. */
1176 if (!thread_db_load ())
1180 /* This function is called via the new_objfile observer. */
1183 thread_db_new_objfile (struct objfile
*objfile
)
1185 /* This observer must always be called with inferior_ptid set
1189 /* libpthread with separate debug info has its debug info file already
1190 loaded (and notified without successful thread_db initialization)
1191 the time observer_notify_new_objfile is called for the library itself.
1192 Static executables have their separate debug info loaded already
1193 before the inferior has started. */
1194 && objfile
->separate_debug_objfile_backlink
== NULL
1195 /* Only check for thread_db if we loaded libpthread,
1196 or if this is the main symbol file.
1197 We need to check OBJF_MAINLINE to handle the case of debugging
1198 a statically linked executable AND the symbol file is specified AFTER
1199 the exec file is loaded (e.g., gdb -c core ; file foo).
1200 For dynamically linked executables, libpthread can be near the end
1201 of the list of shared libraries to load, and in an app of several
1202 thousand shared libraries, this can otherwise be painful. */
1203 && ((objfile
->flags
& OBJF_MAINLINE
) != 0
1204 || libpthread_name_p (objfile_name (objfile
))))
1205 check_for_thread_db ();
1208 /* This function is called via the inferior_created observer.
1209 This handles the case of debugging statically linked executables. */
1212 thread_db_inferior_created (struct target_ops
*target
, int from_tty
)
1214 check_for_thread_db ();
1217 /* Attach to a new thread. This function is called when we receive a
1218 TD_CREATE event or when we iterate over all threads and find one
1219 that wasn't already in our list. Returns true on success. */
1222 attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
1223 const td_thrinfo_t
*ti_p
)
1225 struct private_thread_info
*private;
1226 struct thread_info
*tp
;
1228 struct thread_db_info
*info
;
1230 /* If we're being called after a TD_CREATE event, we may already
1231 know about this thread. There are two ways this can happen. We
1232 may have iterated over all threads between the thread creation
1233 and the TD_CREATE event, for instance when the user has issued
1234 the `info threads' command before the SIGTRAP for hitting the
1235 thread creation breakpoint was reported. Alternatively, the
1236 thread may have exited and a new one been created with the same
1237 thread ID. In the first case we don't need to do anything; in
1238 the second case we should discard information about the dead
1239 thread and attach to the new one. */
1240 tp
= find_thread_ptid (ptid
);
1243 /* If tp->private is NULL, then GDB is already attached to this
1244 thread, but we do not know anything about it. We can learn
1245 about it here. This can only happen if we have some other
1246 way besides libthread_db to notice new threads (i.e.
1247 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
1248 exit, so this can not be a stale thread recreated with the
1250 if (tp
->private != NULL
)
1252 if (!tp
->private->dying
)
1255 delete_thread (ptid
);
1260 if (target_has_execution
)
1261 check_thread_signals ();
1263 /* Under GNU/Linux, we have to attach to each and every thread. */
1264 if (target_has_execution
1269 res
= lin_lwp_attach_lwp (BUILD_LWP (ti_p
->ti_lid
, GET_PID (ptid
)));
1272 /* Error, stop iterating. */
1277 /* Pretend this thread doesn't exist yet, and keep
1282 /* Otherwise, we sucessfully attached to the thread. */
1285 /* Construct the thread's private data. */
1286 private = xmalloc (sizeof (struct private_thread_info
));
1287 memset (private, 0, sizeof (struct private_thread_info
));
1289 /* A thread ID of zero may mean the thread library has not initialized
1290 yet. But we shouldn't even get here if that's the case. FIXME:
1291 if we change GDB to always have at least one thread in the thread
1292 list this will have to go somewhere else; maybe private == NULL
1293 until the thread_db target claims it. */
1294 gdb_assert (ti_p
->ti_tid
!= 0);
1295 private->th
= *th_p
;
1296 private->tid
= ti_p
->ti_tid
;
1297 if (ti_p
->ti_state
== TD_THR_UNKNOWN
|| ti_p
->ti_state
== TD_THR_ZOMBIE
)
1300 /* Add the thread to GDB's thread list. */
1302 add_thread_with_info (ptid
, private);
1304 tp
->private = private;
1306 info
= get_thread_db_info (GET_PID (ptid
));
1308 /* Enable thread event reporting for this thread, except when
1309 debugging a core file. */
1310 if (target_has_execution
)
1312 err
= info
->td_thr_event_enable_p (th_p
, 1);
1314 error (_("Cannot enable thread event reporting for %s: %s"),
1315 target_pid_to_str (ptid
), thread_db_err_str (err
));
1322 detach_thread (ptid_t ptid
)
1324 struct thread_info
*thread_info
;
1326 /* Don't delete the thread now, because it still reports as active
1327 until it has executed a few instructions after the event
1328 breakpoint - if we deleted it now, "info threads" would cause us
1329 to re-attach to it. Just mark it as having had a TD_DEATH
1330 event. This means that we won't delete it from our thread list
1331 until we notice that it's dead (via prune_threads), or until
1332 something re-uses its thread ID. We'll report the thread exit
1333 when the underlying LWP dies. */
1334 thread_info
= find_thread_ptid (ptid
);
1335 gdb_assert (thread_info
!= NULL
&& thread_info
->private != NULL
);
1336 thread_info
->private->dying
= 1;
1340 thread_db_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1342 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1343 struct thread_db_info
*info
;
1345 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1349 if (target_has_execution
)
1351 disable_thread_event_reporting (info
);
1353 /* Delete the old thread event breakpoints. Note that
1354 unlike when mourning, we can remove them here because
1355 there's still a live inferior to poke at. In any case,
1356 GDB will not try to insert anything in the inferior when
1357 removing a breakpoint. */
1358 remove_thread_event_breakpoints ();
1361 delete_thread_db_info (GET_PID (inferior_ptid
));
1364 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
1366 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1368 /* If there are no more processes using libpthread, detach the
1369 thread_db target ops. */
1370 if (!thread_db_list
)
1371 unpush_target (&thread_db_ops
);
1374 /* Check if PID is currently stopped at the location of a thread event
1375 breakpoint location. If it is, read the event message and act upon
1379 check_event (ptid_t ptid
)
1381 struct regcache
*regcache
= get_thread_regcache (ptid
);
1382 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1388 struct thread_db_info
*info
;
1390 info
= get_thread_db_info (GET_PID (ptid
));
1392 /* Bail out early if we're not at a thread event breakpoint. */
1393 stop_pc
= regcache_read_pc (regcache
)
1394 - gdbarch_decr_pc_after_break (gdbarch
);
1395 if (stop_pc
!= info
->td_create_bp_addr
1396 && stop_pc
!= info
->td_death_bp_addr
)
1399 /* Access an lwp we know is stopped. */
1400 info
->proc_handle
.ptid
= ptid
;
1402 /* If we have only looked at the first thread before libpthread was
1403 initialized, we may not know its thread ID yet. Make sure we do
1404 before we add another thread to the list. */
1405 if (!have_threads (ptid
))
1406 thread_db_find_new_threads_1 (ptid
);
1408 /* If we are at a create breakpoint, we do not know what new lwp
1409 was created and cannot specifically locate the event message for it.
1410 We have to call td_ta_event_getmsg() to get
1411 the latest message. Since we have no way of correlating whether
1412 the event message we get back corresponds to our breakpoint, we must
1413 loop and read all event messages, processing them appropriately.
1414 This guarantees we will process the correct message before continuing
1415 from the breakpoint.
1417 Currently, death events are not enabled. If they are enabled,
1418 the death event can use the td_thr_event_getmsg() interface to
1419 get the message specifically for that lwp and avoid looping
1426 err
= info
->td_ta_event_getmsg_p (info
->thread_agent
, &msg
);
1429 if (err
== TD_NOMSG
)
1432 error (_("Cannot get thread event message: %s"),
1433 thread_db_err_str (err
));
1436 err
= info
->td_thr_get_info_p (msg
.th_p
, &ti
);
1438 error (_("Cannot get thread info: %s"), thread_db_err_str (err
));
1440 ptid
= ptid_build (GET_PID (ptid
), ti
.ti_lid
, 0);
1445 /* Call attach_thread whether or not we already know about a
1446 thread with this thread ID. */
1447 attach_thread (ptid
, msg
.th_p
, &ti
);
1453 if (!in_thread_list (ptid
))
1454 error (_("Spurious thread death event."));
1456 detach_thread (ptid
);
1461 error (_("Spurious thread event."));
1468 thread_db_wait (struct target_ops
*ops
,
1469 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1472 struct thread_db_info
*info
;
1473 struct target_ops
*beneath
= find_target_beneath (ops
);
1475 ptid
= beneath
->to_wait (beneath
, ptid
, ourstatus
, options
);
1477 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
1480 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
1481 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
1484 info
= get_thread_db_info (GET_PID (ptid
));
1486 /* If this process isn't using thread_db, we're done. */
1490 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1492 /* New image, it may or may not end up using thread_db. Assume
1493 not unless we find otherwise. */
1494 delete_thread_db_info (GET_PID (ptid
));
1495 if (!thread_db_list
)
1496 unpush_target (&thread_db_ops
);
1498 /* Thread event breakpoints are deleted by
1499 update_breakpoints_after_exec. */
1504 /* If we do not know about the main thread yet, this would be a good time to
1506 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
&& !have_threads (ptid
))
1507 thread_db_find_new_threads_1 (ptid
);
1509 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
1510 && ourstatus
->value
.sig
== GDB_SIGNAL_TRAP
)
1511 /* Check for a thread event. */
1514 if (have_threads (ptid
))
1516 /* Fill in the thread's user-level thread id. */
1517 thread_from_lwp (ptid
);
1524 thread_db_mourn_inferior (struct target_ops
*ops
)
1526 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1528 delete_thread_db_info (GET_PID (inferior_ptid
));
1530 target_beneath
->to_mourn_inferior (target_beneath
);
1532 /* Delete the old thread event breakpoints. Do this after mourning
1533 the inferior, so that we don't try to uninsert them. */
1534 remove_thread_event_breakpoints ();
1536 /* Detach thread_db target ops. */
1537 if (!thread_db_list
)
1538 unpush_target (ops
);
1541 struct callback_data
1543 struct thread_db_info
*info
;
1548 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1553 struct thread_info
*tp
;
1554 struct callback_data
*cb_data
= data
;
1555 struct thread_db_info
*info
= cb_data
->info
;
1557 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1559 error (_("find_new_threads_callback: cannot get thread info: %s"),
1560 thread_db_err_str (err
));
1564 /* A thread ID of zero means that this is the main thread, but
1565 glibc has not yet initialized thread-local storage and the
1566 pthread library. We do not know what the thread's TID will
1567 be yet. Just enable event reporting and otherwise ignore
1570 /* In that case, we're not stopped in a fork syscall and don't
1571 need this glibc bug workaround. */
1572 info
->need_stale_parent_threads_check
= 0;
1574 if (target_has_execution
)
1576 err
= info
->td_thr_event_enable_p (th_p
, 1);
1578 error (_("Cannot enable thread event reporting for LWP %d: %s"),
1579 (int) ti
.ti_lid
, thread_db_err_str (err
));
1585 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1586 bit expensive, as it needs to open /proc/pid/status, so try to
1587 avoid doing the work if we know we don't have to. */
1588 if (info
->need_stale_parent_threads_check
)
1590 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1592 if (tgid
!= -1 && tgid
!= info
->pid
)
1596 ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
1597 tp
= find_thread_ptid (ptid
);
1598 if (tp
== NULL
|| tp
->private == NULL
)
1600 if (attach_thread (ptid
, th_p
, &ti
))
1601 cb_data
->new_threads
+= 1;
1603 /* Problem attaching this thread; perhaps it exited before we
1605 This could mean that the thread list inside glibc itself is in
1606 inconsistent state, and libthread_db could go on looping forever
1607 (observed with glibc-2.3.6). To prevent that, terminate
1608 iteration: thread_db_find_new_threads_2 will retry. */
1615 /* Helper for thread_db_find_new_threads_2.
1616 Returns number of new threads found. */
1619 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1622 volatile struct gdb_exception except
;
1623 struct callback_data data
;
1624 td_err_e err
= TD_ERR
;
1627 data
.new_threads
= 0;
1629 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1631 /* Iterate over all user-space threads to discover new threads. */
1632 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1633 find_new_threads_callback
,
1636 TD_THR_LOWEST_PRIORITY
,
1638 TD_THR_ANY_USER_FLAGS
);
1641 if (libthread_db_debug
)
1643 if (except
.reason
< 0)
1644 exception_fprintf (gdb_stderr
, except
,
1645 "Warning: find_new_threads_once: ");
1647 printf_filtered (_("Found %d new threads in iteration %d.\n"),
1648 data
.new_threads
, iteration
);
1654 return data
.new_threads
;
1657 /* Search for new threads, accessing memory through stopped thread
1658 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1659 searches in a row do not discover any new threads. */
1662 thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
)
1664 td_err_e err
= TD_OK
;
1665 struct thread_db_info
*info
;
1668 info
= get_thread_db_info (GET_PID (ptid
));
1670 /* Access an lwp we know is stopped. */
1671 info
->proc_handle
.ptid
= ptid
;
1675 /* Require 4 successive iterations which do not find any new threads.
1676 The 4 is a heuristic: there is an inherent race here, and I have
1677 seen that 2 iterations in a row are not always sufficient to
1678 "capture" all threads. */
1679 for (i
= 0, loop
= 0; loop
< 4 && err
== TD_OK
; ++i
, ++loop
)
1680 if (find_new_threads_once (info
, i
, &err
) != 0)
1682 /* Found some new threads. Restart the loop from beginning. */
1687 find_new_threads_once (info
, 0, &err
);
1690 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1694 thread_db_find_new_threads_1 (ptid_t ptid
)
1696 thread_db_find_new_threads_2 (ptid
, 0);
1700 update_thread_core (struct lwp_info
*info
, void *closure
)
1702 info
->core
= linux_common_core_of_thread (info
->ptid
);
1707 thread_db_find_new_threads (struct target_ops
*ops
)
1709 struct thread_db_info
*info
;
1710 struct inferior
*inf
;
1714 struct thread_info
*thread
;
1719 info
= get_thread_db_info (inf
->pid
);
1723 thread
= any_live_thread_of_process (inf
->pid
);
1724 if (thread
== NULL
|| thread
->executing
)
1727 thread_db_find_new_threads_1 (thread
->ptid
);
1730 if (target_has_execution
)
1731 iterate_over_lwps (minus_one_ptid
/* iterate over all */,
1732 update_thread_core
, NULL
);
1736 thread_db_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
1738 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1739 struct target_ops
*beneath
;
1741 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1743 static char buf
[64];
1746 tid
= thread_info
->private->tid
;
1747 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1748 tid
, GET_LWP (ptid
));
1753 beneath
= find_target_beneath (ops
);
1754 if (beneath
->to_pid_to_str (beneath
, ptid
))
1755 return beneath
->to_pid_to_str (beneath
, ptid
);
1757 return normal_pid_to_str (ptid
);
1760 /* Return a string describing the state of the thread specified by
1764 thread_db_extra_thread_info (struct thread_info
*info
)
1766 if (info
->private == NULL
)
1769 if (info
->private->dying
)
1775 /* Get the address of the thread local variable in load module LM which
1776 is stored at OFFSET within the thread local storage for thread PTID. */
1779 thread_db_get_thread_local_address (struct target_ops
*ops
,
1784 struct thread_info
*thread_info
;
1785 struct target_ops
*beneath
;
1787 /* If we have not discovered any threads yet, check now. */
1788 if (!have_threads (ptid
))
1789 thread_db_find_new_threads_1 (ptid
);
1791 /* Find the matching thread. */
1792 thread_info
= find_thread_ptid (ptid
);
1794 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1798 struct thread_db_info
*info
;
1800 info
= get_thread_db_info (GET_PID (ptid
));
1802 /* glibc doesn't provide the needed interface. */
1803 if (!info
->td_thr_tls_get_addr_p
)
1804 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1805 _("No TLS library support"));
1807 /* Caller should have verified that lm != 0. */
1808 gdb_assert (lm
!= 0);
1810 /* Finally, get the address of the variable. */
1811 /* Note the cast through uintptr_t: this interface only works if
1812 a target address fits in a psaddr_t, which is a host pointer.
1813 So a 32-bit debugger can not access 64-bit TLS through this. */
1814 err
= info
->td_thr_tls_get_addr_p (&thread_info
->private->th
,
1815 (psaddr_t
)(uintptr_t) lm
,
1818 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1819 /* The memory hasn't been allocated, yet. */
1820 if (err
== TD_NOTALLOC
)
1821 /* Now, if libthread_db provided the initialization image's
1822 address, we *could* try to build a non-lvalue value from
1823 the initialization image. */
1824 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1825 _("TLS not allocated yet"));
1828 /* Something else went wrong. */
1830 throw_error (TLS_GENERIC_ERROR
,
1831 (("%s")), thread_db_err_str (err
));
1833 /* Cast assuming host == target. Joy. */
1834 /* Do proper sign extension for the target. */
1835 gdb_assert (exec_bfd
);
1836 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1837 ? (CORE_ADDR
) (intptr_t) address
1838 : (CORE_ADDR
) (uintptr_t) address
);
1841 beneath
= find_target_beneath (ops
);
1842 if (beneath
->to_get_thread_local_address
)
1843 return beneath
->to_get_thread_local_address (beneath
, ptid
, lm
, offset
);
1845 throw_error (TLS_GENERIC_ERROR
,
1846 _("TLS not supported on this target"));
1849 /* Callback routine used to find a thread based on the TID part of
1853 thread_db_find_thread_from_tid (struct thread_info
*thread
, void *data
)
1855 long *tid
= (long *) data
;
1857 if (thread
->private->tid
== *tid
)
1863 /* Implement the to_get_ada_task_ptid target method for this target. */
1866 thread_db_get_ada_task_ptid (long lwp
, long thread
)
1868 struct thread_info
*thread_info
;
1870 thread_db_find_new_threads_1 (inferior_ptid
);
1871 thread_info
= iterate_over_threads (thread_db_find_thread_from_tid
, &thread
);
1873 gdb_assert (thread_info
!= NULL
);
1875 return (thread_info
->ptid
);
1879 thread_db_resume (struct target_ops
*ops
,
1880 ptid_t ptid
, int step
, enum gdb_signal signo
)
1882 struct target_ops
*beneath
= find_target_beneath (ops
);
1883 struct thread_db_info
*info
;
1885 if (ptid_equal (ptid
, minus_one_ptid
))
1886 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1888 info
= get_thread_db_info (GET_PID (ptid
));
1890 /* This workaround is only needed for child fork lwps stopped in a
1891 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1892 workaround can be disabled. */
1894 info
->need_stale_parent_threads_check
= 0;
1896 beneath
->to_resume (beneath
, ptid
, step
, signo
);
1899 /* qsort helper function for info_auto_load_libthread_db, sort the
1900 thread_db_info pointers primarily by their FILENAME and secondarily by their
1901 PID, both in ascending order. */
1904 info_auto_load_libthread_db_compare (const void *ap
, const void *bp
)
1906 struct thread_db_info
*a
= *(struct thread_db_info
**) ap
;
1907 struct thread_db_info
*b
= *(struct thread_db_info
**) bp
;
1910 retval
= strcmp (a
->filename
, b
->filename
);
1914 return (a
->pid
> b
->pid
) - (a
->pid
- b
->pid
);
1917 /* Implement 'info auto-load libthread-db'. */
1920 info_auto_load_libthread_db (char *args
, int from_tty
)
1922 struct ui_out
*uiout
= current_uiout
;
1923 const char *cs
= args
? args
: "";
1924 struct thread_db_info
*info
, **array
;
1925 unsigned info_count
, unique_filenames
;
1926 size_t max_filename_len
, max_pids_len
, pids_len
;
1927 struct cleanup
*back_to
;
1931 cs
= skip_spaces_const (cs
);
1933 error (_("'info auto-load libthread-db' does not accept any parameters"));
1936 for (info
= thread_db_list
; info
; info
= info
->next
)
1937 if (info
->filename
!= NULL
)
1940 array
= xmalloc (sizeof (*array
) * info_count
);
1941 back_to
= make_cleanup (xfree
, array
);
1944 for (info
= thread_db_list
; info
; info
= info
->next
)
1945 if (info
->filename
!= NULL
)
1946 array
[info_count
++] = info
;
1948 /* Sort ARRAY by filenames and PIDs. */
1950 qsort (array
, info_count
, sizeof (*array
),
1951 info_auto_load_libthread_db_compare
);
1953 /* Calculate the number of unique filenames (rows) and the maximum string
1954 length of PIDs list for the unique filenames (columns). */
1956 unique_filenames
= 0;
1957 max_filename_len
= 0;
1960 for (i
= 0; i
< info_count
; i
++)
1962 int pid
= array
[i
]->pid
;
1963 size_t this_pid_len
;
1965 for (this_pid_len
= 0; pid
!= 0; pid
/= 10)
1968 if (i
== 0 || strcmp (array
[i
- 1]->filename
, array
[i
]->filename
) != 0)
1971 max_filename_len
= max (max_filename_len
,
1972 strlen (array
[i
]->filename
));
1976 pids_len
-= strlen (", ");
1977 max_pids_len
= max (max_pids_len
, pids_len
);
1981 pids_len
+= this_pid_len
+ strlen (", ");
1985 pids_len
-= strlen (", ");
1986 max_pids_len
= max (max_pids_len
, pids_len
);
1989 /* Table header shifted right by preceding "libthread-db: " would not match
1991 if (info_count
> 0 && args
== auto_load_info_scripts_pattern_nl
)
1992 ui_out_text (uiout
, "\n");
1994 make_cleanup_ui_out_table_begin_end (uiout
, 2, unique_filenames
,
1995 "LinuxThreadDbTable");
1997 ui_out_table_header (uiout
, max_filename_len
, ui_left
, "filename",
1999 ui_out_table_header (uiout
, pids_len
, ui_left
, "PIDs", "Pids");
2000 ui_out_table_body (uiout
);
2002 pids
= xmalloc (max_pids_len
+ 1);
2003 make_cleanup (xfree
, pids
);
2005 /* Note I is incremented inside the cycle, not at its end. */
2006 for (i
= 0; i
< info_count
;)
2008 struct cleanup
*chain
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
2012 ui_out_field_string (uiout
, "filename", info
->filename
);
2015 while (i
< info_count
&& strcmp (info
->filename
, array
[i
]->filename
) == 0)
2017 if (pids_end
!= pids
)
2022 pids_end
+= xsnprintf (pids_end
, &pids
[max_pids_len
+ 1] - pids_end
,
2023 "%u", array
[i
]->pid
);
2024 gdb_assert (pids_end
< &pids
[max_pids_len
+ 1]);
2030 ui_out_field_string (uiout
, "pids", pids
);
2032 ui_out_text (uiout
, "\n");
2033 do_cleanups (chain
);
2036 do_cleanups (back_to
);
2038 if (info_count
== 0)
2039 ui_out_message (uiout
, 0, _("No auto-loaded libthread-db.\n"));
2043 init_thread_db_ops (void)
2045 thread_db_ops
.to_shortname
= "multi-thread";
2046 thread_db_ops
.to_longname
= "multi-threaded child process.";
2047 thread_db_ops
.to_doc
= "Threads and pthreads support.";
2048 thread_db_ops
.to_detach
= thread_db_detach
;
2049 thread_db_ops
.to_wait
= thread_db_wait
;
2050 thread_db_ops
.to_resume
= thread_db_resume
;
2051 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
2052 thread_db_ops
.to_find_new_threads
= thread_db_find_new_threads
;
2053 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
2054 thread_db_ops
.to_stratum
= thread_stratum
;
2055 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
2056 thread_db_ops
.to_get_thread_local_address
2057 = thread_db_get_thread_local_address
;
2058 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
2059 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
2060 thread_db_ops
.to_magic
= OPS_MAGIC
;
2062 complete_target_initialization (&thread_db_ops
);
2065 /* Provide a prototype to silence -Wmissing-prototypes. */
2066 extern initialize_file_ftype _initialize_thread_db
;
2069 _initialize_thread_db (void)
2071 init_thread_db_ops ();
2073 /* Defer loading of libthread_db.so until inferior is running.
2074 This allows gdb to load correct libthread_db for a given
2075 executable -- there could be mutiple versions of glibc,
2076 compiled with LinuxThreads or NPTL, and until there is
2077 a running inferior, we can't tell which libthread_db is
2078 the correct one to load. */
2080 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
2082 add_setshow_optional_filename_cmd ("libthread-db-search-path",
2084 &libthread_db_search_path
, _("\
2085 Set search path for libthread_db."), _("\
2086 Show the current search path or libthread_db."), _("\
2087 This path is used to search for libthread_db to be loaded into \
2089 Its value is a colon (':') separate list of directories to search.\n\
2090 Setting the search path to an empty list resets it to its default value."),
2091 set_libthread_db_search_path
,
2093 &setlist
, &showlist
);
2095 add_setshow_zuinteger_cmd ("libthread-db", class_maintenance
,
2096 &libthread_db_debug
, _("\
2097 Set libthread-db debugging."), _("\
2098 Show libthread-db debugging."), _("\
2099 When non-zero, libthread-db debugging is enabled."),
2101 show_libthread_db_debug
,
2102 &setdebuglist
, &showdebuglist
);
2104 add_setshow_boolean_cmd ("libthread-db", class_support
,
2105 &auto_load_thread_db
, _("\
2106 Enable or disable auto-loading of inferior specific libthread_db."), _("\
2107 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
2108 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
2109 locations to load libthread_db compatible with the inferior.\n\
2110 Standard system libthread_db still gets loaded even with this option off.\n\
2111 This options has security implications for untrusted inferiors."),
2112 NULL
, show_auto_load_thread_db
,
2113 auto_load_set_cmdlist_get (),
2114 auto_load_show_cmdlist_get ());
2116 add_cmd ("libthread-db", class_info
, info_auto_load_libthread_db
,
2117 _("Print the list of loaded inferior specific libthread_db.\n\
2118 Usage: info auto-load libthread-db"),
2119 auto_load_info_cmdlist_get ());
2121 /* Add ourselves to objfile event chain. */
2122 observer_attach_new_objfile (thread_db_new_objfile
);
2124 /* Add ourselves to inferior_created event chain.
2125 This is needed to handle debugging statically linked programs where
2126 the new_objfile observer won't get called for libpthread. */
2127 observer_attach_inferior_created (thread_db_inferior_created
);