1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999-2016 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_proc_service.h"
23 #include "nat/gdb_thread_db.h"
28 #include "gdbthread.h"
36 #include "solib-svr4.h"
39 #include "linux-nat.h"
40 #include "nat/linux-procfs.h"
41 #include "nat/linux-ptrace.h"
42 #include "nat/linux-osdata.h"
43 #include "auto-load.h"
44 #include "cli/cli-utils.h"
47 #include "nat/linux-namespaces.h"
49 /* GNU/Linux libthread_db support.
51 libthread_db is a library, provided along with libpthread.so, which
52 exposes the internals of the thread library to a debugger. It
53 allows GDB to find existing threads, new threads as they are
54 created, thread IDs (usually, the result of pthread_self), and
55 thread-local variables.
57 The libthread_db interface originates on Solaris, where it is both
58 more powerful and more complicated. This implementation only works
59 for NPTL, the glibc threading library. It assumes that each thread
60 is permanently assigned to a single light-weight process (LWP). At
61 some point it also supported the older LinuxThreads library, but it
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 /* Pointers to the libthread_db functions. */
157 td_init_ftype
*td_init_p
;
158 td_ta_new_ftype
*td_ta_new_p
;
159 td_ta_map_lwp2thr_ftype
*td_ta_map_lwp2thr_p
;
160 td_ta_thr_iter_ftype
*td_ta_thr_iter_p
;
161 td_thr_validate_ftype
*td_thr_validate_p
;
162 td_thr_get_info_ftype
*td_thr_get_info_p
;
163 td_thr_tls_get_addr_ftype
*td_thr_tls_get_addr_p
;
164 td_thr_tlsbase_ftype
*td_thr_tlsbase_p
;
167 /* List of known processes using thread_db, and the required
169 struct thread_db_info
*thread_db_list
;
171 static void thread_db_find_new_threads_1 (ptid_t ptid
);
172 static void thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
);
174 static void check_thread_signals (void);
176 static struct thread_info
*record_thread
177 (struct thread_db_info
*info
, struct thread_info
*tp
,
178 ptid_t ptid
, const td_thrhandle_t
*th_p
, const td_thrinfo_t
*ti_p
);
180 /* Add the current inferior to the list of processes using libpthread.
181 Return a pointer to the newly allocated object that was added to
182 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
185 static struct thread_db_info
*
186 add_thread_db_info (void *handle
)
188 struct thread_db_info
*info
= XCNEW (struct thread_db_info
);
190 info
->pid
= ptid_get_pid (inferior_ptid
);
191 info
->handle
= handle
;
193 /* The workaround works by reading from /proc/pid/status, so it is
194 disabled for core files. */
195 if (target_has_execution
)
196 info
->need_stale_parent_threads_check
= 1;
198 info
->next
= thread_db_list
;
199 thread_db_list
= info
;
204 /* Return the thread_db_info object representing the bookkeeping
205 related to process PID, if any; NULL otherwise. */
207 static struct thread_db_info
*
208 get_thread_db_info (int pid
)
210 struct thread_db_info
*info
;
212 for (info
= thread_db_list
; info
; info
= info
->next
)
213 if (pid
== info
->pid
)
219 /* When PID has exited or has been detached, we no longer want to keep
220 track of it as using libpthread. Call this function to discard
221 thread_db related info related to PID. Note that this closes
222 LIBTHREAD_DB_SO's dlopen'ed handle. */
225 delete_thread_db_info (int pid
)
227 struct thread_db_info
*info
, *info_prev
;
231 for (info
= thread_db_list
; info
; info_prev
= info
, info
= info
->next
)
232 if (pid
== info
->pid
)
238 if (info
->handle
!= NULL
)
239 dlclose (info
->handle
);
241 xfree (info
->filename
);
244 info_prev
->next
= info
->next
;
246 thread_db_list
= info
->next
;
251 /* Use "struct private_thread_info" to cache thread state. This is
252 a substantial optimization. */
254 struct private_thread_info
256 /* Flag set when we see a TD_DEATH event for this thread. */
257 unsigned int dying
:1;
259 /* Cached thread state. */
266 thread_db_err_str (td_err_e err
)
273 return "generic 'call succeeded'";
275 return "generic error";
277 return "no thread to satisfy query";
279 return "no sync handle to satisfy query";
281 return "no LWP to satisfy query";
283 return "invalid process handle";
285 return "invalid thread handle";
287 return "invalid synchronization handle";
289 return "invalid thread agent";
291 return "invalid key";
293 return "no event message for getmsg";
295 return "FPU register set not available";
297 return "application not linked with libthread";
299 return "requested event is not supported";
301 return "capability not available";
303 return "debugger service failed";
305 return "operation not applicable to";
307 return "no thread-specific data for this thread";
309 return "malloc failed";
311 return "only part of register set was written/read";
313 return "X register set not available for this thread";
314 #ifdef THREAD_DB_HAS_TD_NOTALLOC
316 return "thread has not yet allocated TLS for given module";
318 #ifdef THREAD_DB_HAS_TD_VERSION
320 return "versions of libpthread and libthread_db do not match";
322 #ifdef THREAD_DB_HAS_TD_NOTLS
324 return "there is no TLS segment in the given module";
327 snprintf (buf
, sizeof (buf
), "unknown thread_db error '%d'", err
);
332 /* Fetch the user-level thread id of PTID. */
334 static struct thread_info
*
335 thread_from_lwp (ptid_t ptid
)
340 struct thread_db_info
*info
;
341 struct thread_info
*tp
;
343 /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
346 /* This ptid comes from linux-nat.c, which should always fill in the
348 gdb_assert (ptid_get_lwp (ptid
) != 0);
350 info
= get_thread_db_info (ptid_get_pid (ptid
));
352 /* Access an lwp we know is stopped. */
353 info
->proc_handle
.ptid
= ptid
;
354 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, ptid_get_lwp (ptid
),
357 error (_("Cannot find user-level thread for LWP %ld: %s"),
358 ptid_get_lwp (ptid
), thread_db_err_str (err
));
360 err
= info
->td_thr_get_info_p (&th
, &ti
);
362 error (_("thread_get_info_callback: cannot get thread info: %s"),
363 thread_db_err_str (err
));
365 /* Fill the cache. */
366 tp
= find_thread_ptid (ptid
);
367 return record_thread (info
, tp
, ptid
, &th
, &ti
);
371 /* See linux-nat.h. */
374 thread_db_notice_clone (ptid_t parent
, ptid_t child
)
379 struct thread_db_info
*info
;
381 info
= get_thread_db_info (ptid_get_pid (child
));
386 thread_from_lwp (child
);
388 /* If we do not know about the main thread yet, this would be a good
390 thread_from_lwp (parent
);
395 verbose_dlsym (void *handle
, const char *name
)
397 void *sym
= dlsym (handle
, name
);
399 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
404 /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
405 return 1 if this version is lower (and not equal) to
406 VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
409 inferior_has_bug (const char *ver_symbol
, int ver_major_min
, int ver_minor_min
)
411 struct bound_minimal_symbol version_msym
;
412 CORE_ADDR version_addr
;
414 int err
, got
, retval
= 0;
416 version_msym
= lookup_minimal_symbol (ver_symbol
, NULL
, NULL
);
417 if (version_msym
.minsym
== NULL
)
420 version_addr
= BMSYMBOL_VALUE_ADDRESS (version_msym
);
421 got
= target_read_string (version_addr
, &version
, 32, &err
);
422 if (err
== 0 && memchr (version
, 0, got
) == &version
[got
-1])
426 retval
= (sscanf (version
, "%d.%d", &major
, &minor
) == 2
427 && (major
< ver_major_min
428 || (major
== ver_major_min
&& minor
< ver_minor_min
)));
435 /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
438 Return 1 if the caller should abort libthread_db initialization. Return 0
442 thread_db_find_new_threads_silently (ptid_t ptid
)
447 thread_db_find_new_threads_2 (ptid
, 1);
450 CATCH (except
, RETURN_MASK_ERROR
)
452 if (libthread_db_debug
)
453 exception_fprintf (gdb_stdlog
, except
,
454 "Warning: thread_db_find_new_threads_silently: ");
456 /* There is a bug fixed between nptl 2.6.1 and 2.7 by
457 commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
458 where calls to td_thr_get_info fail with TD_ERR for statically linked
459 executables if td_thr_get_info is called before glibc has initialized
462 If the nptl bug is NOT present in the inferior and still thread_db
463 reports an error return 1. It means the inferior has corrupted thread
464 list and GDB should fall back only to LWPs.
466 If the nptl bug is present in the inferior return 0 to silently ignore
467 such errors, and let gdb enumerate threads again later. In such case
468 GDB cannot properly display LWPs if the inferior thread list is
469 corrupted. For core files it does not apply, no 'later enumeration'
472 if (!target_has_execution
|| !inferior_has_bug ("nptl_version", 2, 7))
474 exception_fprintf (gdb_stderr
, except
,
475 _("Warning: couldn't activate thread debugging "
476 "using libthread_db: "));
485 /* Lookup a library in which given symbol resides.
486 Note: this is looking in GDB process, not in the inferior.
487 Returns library name, or NULL. */
490 dladdr_to_soname (const void *addr
)
494 if (dladdr (addr
, &info
) != 0)
495 return info
.dli_fname
;
499 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
501 Failure could happen if libthread_db does not have symbols we expect,
502 or when it refuses to work with the current inferior (e.g. due to
503 version mismatch between libthread_db and libpthread). */
506 try_thread_db_load_1 (struct thread_db_info
*info
)
510 /* Initialize pointers to the dynamic library functions we will use.
511 Essential functions first. */
513 #define TDB_VERBOSE_DLSYM(info, func) \
514 info->func ## _p = (func ## _ftype *) verbose_dlsym (info->handle, #func)
516 #define TDB_DLSYM(info, func) \
517 info->func ## _p = (func ## _ftype *) dlsym (info->handle, #func)
526 CHK (TDB_VERBOSE_DLSYM (info
, td_init
));
528 err
= info
->td_init_p ();
531 warning (_("Cannot initialize libthread_db: %s"),
532 thread_db_err_str (err
));
536 CHK (TDB_VERBOSE_DLSYM (info
, td_ta_new
));
538 /* Initialize the structure that identifies the child process. */
539 info
->proc_handle
.ptid
= inferior_ptid
;
541 /* Now attempt to open a connection to the thread library. */
542 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
545 if (libthread_db_debug
)
546 fprintf_unfiltered (gdb_stdlog
, _("td_ta_new failed: %s\n"),
547 thread_db_err_str (err
));
552 #ifdef THREAD_DB_HAS_TD_VERSION
555 /* The errors above are not unexpected and silently ignored:
556 they just mean we haven't found correct version of
560 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
565 /* These are essential. */
566 CHK (TDB_VERBOSE_DLSYM (info
, td_ta_map_lwp2thr
));
567 CHK (TDB_VERBOSE_DLSYM (info
, td_thr_validate
));
568 CHK (TDB_VERBOSE_DLSYM (info
, td_thr_get_info
));
570 /* These are not essential. */
571 TDB_DLSYM (info
, td_thr_tls_get_addr
);
572 TDB_DLSYM (info
, td_thr_tlsbase
);
574 /* It's best to avoid td_ta_thr_iter if possible. That walks data
575 structures in the inferior's address space that may be corrupted,
576 or, if the target is running, may change while we walk them. If
577 there's execution (and /proc is mounted), then we're already
578 attached to all LWPs. Use thread_from_lwp, which uses
579 td_ta_map_lwp2thr instead, which does not walk the thread list.
581 td_ta_map_lwp2thr uses ps_get_thread_area, but we can't use that
582 currently on core targets, as it uses ptrace directly. */
583 if (target_has_execution
584 && linux_proc_task_list_dir_exists (ptid_get_pid (inferior_ptid
)))
585 info
->td_ta_thr_iter_p
= NULL
;
587 CHK (TDB_VERBOSE_DLSYM (info
, td_ta_thr_iter
));
589 #undef TDB_VERBOSE_DLSYM
593 if (info
->td_ta_thr_iter_p
== NULL
)
596 int pid
= ptid_get_pid (inferior_ptid
);
598 linux_stop_and_wait_all_lwps ();
601 if (ptid_get_pid (lp
->ptid
) == pid
)
602 thread_from_lwp (lp
->ptid
);
604 linux_unstop_all_lwps ();
606 else if (thread_db_find_new_threads_silently (inferior_ptid
) != 0)
608 /* Even if libthread_db initializes, if the thread list is
609 corrupted, we'd not manage to list any threads. Better reject this
610 thread_db, and fall back to at least listing LWPs. */
614 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
616 if (*libthread_db_search_path
|| libthread_db_debug
)
618 struct ui_file
*file
;
621 library
= dladdr_to_soname ((const void *) *info
->td_ta_new_p
);
623 library
= LIBTHREAD_DB_SO
;
625 /* If we'd print this to gdb_stdout when debug output is
626 disabled, still print it to gdb_stdout if debug output is
627 enabled. User visible output should not depend on debug
629 file
= *libthread_db_search_path
!= '\0' ? gdb_stdout
: gdb_stdlog
;
630 fprintf_unfiltered (file
, _("Using host libthread_db library \"%s\".\n"),
634 /* The thread library was detected. Activate the thread_db target
635 if this is the first process using it. */
636 if (thread_db_list
->next
== NULL
)
637 push_target (&thread_db_ops
);
642 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
643 relative, or just LIBTHREAD_DB. */
646 try_thread_db_load (const char *library
, int check_auto_load_safe
)
649 struct thread_db_info
*info
;
651 if (libthread_db_debug
)
652 fprintf_unfiltered (gdb_stdlog
,
653 _("Trying host libthread_db library: %s.\n"),
656 if (check_auto_load_safe
)
658 if (access (library
, R_OK
) != 0)
660 /* Do not print warnings by file_is_auto_load_safe if the library does
661 not exist at this place. */
662 if (libthread_db_debug
)
663 fprintf_unfiltered (gdb_stdlog
, _("open failed: %s.\n"),
664 safe_strerror (errno
));
668 if (!file_is_auto_load_safe (library
, _("auto-load: Loading libthread-db "
669 "library \"%s\" from explicit "
675 handle
= dlopen (library
, RTLD_NOW
);
678 if (libthread_db_debug
)
679 fprintf_unfiltered (gdb_stdlog
, _("dlopen failed: %s.\n"), dlerror ());
683 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
687 td_init
= dlsym (handle
, "td_init");
690 const char *const libpath
= dladdr_to_soname (td_init
);
693 fprintf_unfiltered (gdb_stdlog
, _("Host %s resolved to: %s.\n"),
698 info
= add_thread_db_info (handle
);
700 /* Do not save system library name, that one is always trusted. */
701 if (strchr (library
, '/') != NULL
)
702 info
->filename
= gdb_realpath (library
);
704 if (try_thread_db_load_1 (info
))
707 /* This library "refused" to work on current inferior. */
708 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
712 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
713 Try loading libthread_db in directory(OBJ)/SUBDIR.
714 SUBDIR may be NULL. It may also be something like "../lib64".
715 The result is true for success. */
718 try_thread_db_load_from_pdir_1 (struct objfile
*obj
, const char *subdir
)
720 struct cleanup
*cleanup
;
723 const char *obj_name
= objfile_name (obj
);
726 if (obj_name
[0] != '/')
728 warning (_("Expected absolute pathname for libpthread in the"
729 " inferior, but got %s."), obj_name
);
733 alloc_len
= (strlen (obj_name
)
734 + (subdir
? strlen (subdir
) + 1 : 0)
735 + 1 + strlen (LIBTHREAD_DB_SO
) + 1);
736 path
= (char *) xmalloc (alloc_len
);
737 cleanup
= make_cleanup (xfree
, path
);
739 strcpy (path
, obj_name
);
740 cp
= strrchr (path
, '/');
741 /* This should at minimum hit the first character. */
742 gdb_assert (cp
!= NULL
);
749 strcat (cp
, LIBTHREAD_DB_SO
);
751 result
= try_thread_db_load (path
, 1);
753 do_cleanups (cleanup
);
757 /* Handle $pdir in libthread-db-search-path.
758 Look for libthread_db in directory(libpthread)/SUBDIR.
759 SUBDIR may be NULL. It may also be something like "../lib64".
760 The result is true for success. */
763 try_thread_db_load_from_pdir (const char *subdir
)
767 if (!auto_load_thread_db
)
771 if (libpthread_name_p (objfile_name (obj
)))
773 if (try_thread_db_load_from_pdir_1 (obj
, subdir
))
776 /* We may have found the separate-debug-info version of
777 libpthread, and it may live in a directory without a matching
779 if (obj
->separate_debug_objfile_backlink
!= NULL
)
780 return try_thread_db_load_from_pdir_1 (obj
->separate_debug_objfile_backlink
,
789 /* Handle $sdir in libthread-db-search-path.
790 Look for libthread_db in the system dirs, or wherever a plain
791 dlopen(file_without_path) will look.
792 The result is true for success. */
795 try_thread_db_load_from_sdir (void)
797 return try_thread_db_load (LIBTHREAD_DB_SO
, 0);
800 /* Try to load libthread_db from directory DIR of length DIR_LEN.
801 The result is true for success. */
804 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
806 struct cleanup
*cleanup
;
810 if (!auto_load_thread_db
)
813 path
= (char *) xmalloc (dir_len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1);
814 cleanup
= make_cleanup (xfree
, path
);
816 memcpy (path
, dir
, dir_len
);
818 strcpy (path
+ dir_len
+ 1, LIBTHREAD_DB_SO
);
820 result
= try_thread_db_load (path
, 1);
822 do_cleanups (cleanup
);
826 /* Search libthread_db_search_path for libthread_db which "agrees"
827 to work on current inferior.
828 The result is true for success. */
831 thread_db_load_search (void)
833 VEC (char_ptr
) *dir_vec
;
834 struct cleanup
*cleanups
;
838 dir_vec
= dirnames_to_char_ptr_vec (libthread_db_search_path
);
839 cleanups
= make_cleanup_free_char_ptr_vec (dir_vec
);
841 for (i
= 0; VEC_iterate (char_ptr
, dir_vec
, i
, this_dir
); ++i
)
843 const int pdir_len
= sizeof ("$pdir") - 1;
846 this_dir_len
= strlen (this_dir
);
848 if (strncmp (this_dir
, "$pdir", pdir_len
) == 0
849 && (this_dir
[pdir_len
] == '\0'
850 || this_dir
[pdir_len
] == '/'))
853 struct cleanup
*free_subdir_cleanup
854 = make_cleanup (null_cleanup
, NULL
);
856 if (this_dir
[pdir_len
] == '/')
858 subdir
= (char *) xmalloc (strlen (this_dir
));
859 make_cleanup (xfree
, subdir
);
860 strcpy (subdir
, this_dir
+ pdir_len
+ 1);
862 rc
= try_thread_db_load_from_pdir (subdir
);
863 do_cleanups (free_subdir_cleanup
);
867 else if (strcmp (this_dir
, "$sdir") == 0)
869 if (try_thread_db_load_from_sdir ())
877 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
885 do_cleanups (cleanups
);
886 if (libthread_db_debug
)
887 fprintf_unfiltered (gdb_stdlog
,
888 _("thread_db_load_search returning %d\n"), rc
);
892 /* Return non-zero if the inferior has a libpthread. */
895 has_libpthread (void)
900 if (libpthread_name_p (objfile_name (obj
)))
906 /* Attempt to load and initialize libthread_db.
907 Return 1 on success. */
910 thread_db_load (void)
912 struct thread_db_info
*info
;
914 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
919 /* Don't attempt to use thread_db on executables not running
921 if (!target_has_registers
)
924 /* Don't attempt to use thread_db for remote targets. */
925 if (!(target_can_run (¤t_target
) || core_bfd
))
928 if (thread_db_load_search ())
931 /* We couldn't find a libthread_db.
932 If the inferior has a libpthread warn the user. */
933 if (has_libpthread ())
935 warning (_("Unable to find libthread_db matching inferior's thread"
936 " library, thread debugging will not be available."));
940 /* Either this executable isn't using libpthread at all, or it is
941 statically linked. Since we can't easily distinguish these two cases,
942 no warning is issued. */
947 check_thread_signals (void)
954 lin_thread_get_thread_signals (&mask
);
955 sigemptyset (&thread_stop_set
);
956 sigemptyset (&thread_print_set
);
958 for (i
= 1; i
< NSIG
; i
++)
960 if (sigismember (&mask
, i
))
962 if (signal_stop_update (gdb_signal_from_host (i
), 0))
963 sigaddset (&thread_stop_set
, i
);
964 if (signal_print_update (gdb_signal_from_host (i
), 0))
965 sigaddset (&thread_print_set
, i
);
972 /* Check whether thread_db is usable. This function is called when
973 an inferior is created (or otherwise acquired, e.g. attached to)
974 and when new shared libraries are loaded into a running process. */
977 check_for_thread_db (void)
979 /* Do nothing if we couldn't load libthread_db.so.1. */
980 if (!thread_db_load ())
984 /* This function is called via the new_objfile observer. */
987 thread_db_new_objfile (struct objfile
*objfile
)
989 /* This observer must always be called with inferior_ptid set
993 /* libpthread with separate debug info has its debug info file already
994 loaded (and notified without successful thread_db initialization)
995 the time observer_notify_new_objfile is called for the library itself.
996 Static executables have their separate debug info loaded already
997 before the inferior has started. */
998 && objfile
->separate_debug_objfile_backlink
== NULL
999 /* Only check for thread_db if we loaded libpthread,
1000 or if this is the main symbol file.
1001 We need to check OBJF_MAINLINE to handle the case of debugging
1002 a statically linked executable AND the symbol file is specified AFTER
1003 the exec file is loaded (e.g., gdb -c core ; file foo).
1004 For dynamically linked executables, libpthread can be near the end
1005 of the list of shared libraries to load, and in an app of several
1006 thousand shared libraries, this can otherwise be painful. */
1007 && ((objfile
->flags
& OBJF_MAINLINE
) != 0
1008 || libpthread_name_p (objfile_name (objfile
))))
1009 check_for_thread_db ();
1013 check_pid_namespace_match (void)
1015 /* Check is only relevant for local targets targets. */
1016 if (target_can_run (¤t_target
))
1018 /* If the child is in a different PID namespace, its idea of its
1019 PID will differ from our idea of its PID. When we scan the
1020 child's thread list, we'll mistakenly think it has no threads
1021 since the thread PID fields won't match the PID we give to
1023 if (!linux_ns_same (ptid_get_pid (inferior_ptid
), LINUX_NS_PID
))
1025 warning (_ ("Target and debugger are in different PID "
1026 "namespaces; thread lists and other data are "
1027 "likely unreliable. "
1028 "Connect to gdbserver inside the container."));
1033 /* This function is called via the inferior_created observer.
1034 This handles the case of debugging statically linked executables. */
1037 thread_db_inferior_created (struct target_ops
*target
, int from_tty
)
1039 check_pid_namespace_match ();
1040 check_for_thread_db ();
1043 /* Update the thread's state (what's displayed in "info threads"),
1044 from libthread_db thread state information. */
1047 update_thread_state (struct private_thread_info
*priv
,
1048 const td_thrinfo_t
*ti_p
)
1050 priv
->dying
= (ti_p
->ti_state
== TD_THR_UNKNOWN
1051 || ti_p
->ti_state
== TD_THR_ZOMBIE
);
1054 /* Record a new thread in GDB's thread list. Creates the thread's
1055 private info. If TP is NULL or TP is marked as having exited,
1056 creates a new thread. Otherwise, uses TP. */
1058 static struct thread_info
*
1059 record_thread (struct thread_db_info
*info
,
1060 struct thread_info
*tp
,
1061 ptid_t ptid
, const td_thrhandle_t
*th_p
,
1062 const td_thrinfo_t
*ti_p
)
1065 struct private_thread_info
*priv
;
1066 int new_thread
= (tp
== NULL
);
1068 /* A thread ID of zero may mean the thread library has not
1069 initialized yet. Leave private == NULL until the thread library
1071 if (ti_p
->ti_tid
== 0)
1074 /* Construct the thread's private data. */
1075 priv
= XCNEW (struct private_thread_info
);
1078 priv
->tid
= ti_p
->ti_tid
;
1079 update_thread_state (priv
, ti_p
);
1081 /* Add the thread to GDB's thread list. If we already know about a
1082 thread with this PTID, but it's marked exited, then the kernel
1083 reused the tid of an old thread. */
1084 if (tp
== NULL
|| tp
->state
== THREAD_EXITED
)
1085 tp
= add_thread_with_info (ptid
, priv
);
1089 if (target_has_execution
)
1090 check_thread_signals ();
1096 thread_db_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1098 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1099 struct thread_db_info
*info
;
1101 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1104 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
1106 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
1108 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1110 /* If there are no more processes using libpthread, detach the
1111 thread_db target ops. */
1112 if (!thread_db_list
)
1113 unpush_target (&thread_db_ops
);
1117 thread_db_wait (struct target_ops
*ops
,
1118 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1121 struct thread_db_info
*info
;
1122 struct target_ops
*beneath
= find_target_beneath (ops
);
1124 ptid
= beneath
->to_wait (beneath
, ptid
, ourstatus
, options
);
1126 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
1129 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
1130 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
1133 info
= get_thread_db_info (ptid_get_pid (ptid
));
1135 /* If this process isn't using thread_db, we're done. */
1139 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1141 /* New image, it may or may not end up using thread_db. Assume
1142 not unless we find otherwise. */
1143 delete_thread_db_info (ptid_get_pid (ptid
));
1144 if (!thread_db_list
)
1145 unpush_target (&thread_db_ops
);
1150 /* Fill in the thread's user-level thread id and status. */
1151 thread_from_lwp (ptid
);
1157 thread_db_mourn_inferior (struct target_ops
*ops
)
1159 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1161 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
1163 target_beneath
->to_mourn_inferior (target_beneath
);
1165 /* Detach thread_db target ops. */
1166 if (!thread_db_list
)
1167 unpush_target (ops
);
1170 struct callback_data
1172 struct thread_db_info
*info
;
1177 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1182 struct thread_info
*tp
;
1183 struct callback_data
*cb_data
= (struct callback_data
*) data
;
1184 struct thread_db_info
*info
= cb_data
->info
;
1186 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1188 error (_("find_new_threads_callback: cannot get thread info: %s"),
1189 thread_db_err_str (err
));
1191 if (ti
.ti_lid
== -1)
1193 /* A thread with kernel thread ID -1 is either a thread that
1194 exited and was joined, or a thread that is being created but
1195 hasn't started yet, and that is reusing the tcb/stack of a
1196 thread that previously exited and was joined. (glibc marks
1197 terminated and joined threads with kernel thread ID -1. See
1199 if (libthread_db_debug
)
1200 fprintf_unfiltered (gdb_stdlog
,
1201 "thread_db: skipping exited and "
1202 "joined thread (0x%lx)\n",
1203 (unsigned long) ti
.ti_tid
);
1209 /* A thread ID of zero means that this is the main thread, but
1210 glibc has not yet initialized thread-local storage and the
1211 pthread library. We do not know what the thread's TID will
1214 /* In that case, we're not stopped in a fork syscall and don't
1215 need this glibc bug workaround. */
1216 info
->need_stale_parent_threads_check
= 0;
1221 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1222 bit expensive, as it needs to open /proc/pid/status, so try to
1223 avoid doing the work if we know we don't have to. */
1224 if (info
->need_stale_parent_threads_check
)
1226 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1228 if (tgid
!= -1 && tgid
!= info
->pid
)
1232 ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
1233 tp
= find_thread_ptid (ptid
);
1234 if (tp
== NULL
|| tp
->priv
== NULL
)
1235 record_thread (info
, tp
, ptid
, th_p
, &ti
);
1240 /* Helper for thread_db_find_new_threads_2.
1241 Returns number of new threads found. */
1244 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1247 struct callback_data data
;
1248 td_err_e err
= TD_ERR
;
1251 data
.new_threads
= 0;
1253 /* See comment in thread_db_update_thread_list. */
1254 gdb_assert (info
->td_ta_thr_iter_p
!= NULL
);
1258 /* Iterate over all user-space threads to discover new threads. */
1259 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1260 find_new_threads_callback
,
1263 TD_THR_LOWEST_PRIORITY
,
1265 TD_THR_ANY_USER_FLAGS
);
1267 CATCH (except
, RETURN_MASK_ERROR
)
1269 if (libthread_db_debug
)
1271 exception_fprintf (gdb_stdlog
, except
,
1272 "Warning: find_new_threads_once: ");
1277 if (libthread_db_debug
)
1279 fprintf_unfiltered (gdb_stdlog
,
1280 _("Found %d new threads in iteration %d.\n"),
1281 data
.new_threads
, iteration
);
1287 return data
.new_threads
;
1290 /* Search for new threads, accessing memory through stopped thread
1291 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1292 searches in a row do not discover any new threads. */
1295 thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
)
1297 td_err_e err
= TD_OK
;
1298 struct thread_db_info
*info
;
1301 info
= get_thread_db_info (ptid_get_pid (ptid
));
1303 /* Access an lwp we know is stopped. */
1304 info
->proc_handle
.ptid
= ptid
;
1308 /* Require 4 successive iterations which do not find any new threads.
1309 The 4 is a heuristic: there is an inherent race here, and I have
1310 seen that 2 iterations in a row are not always sufficient to
1311 "capture" all threads. */
1312 for (i
= 0, loop
= 0; loop
< 4 && err
== TD_OK
; ++i
, ++loop
)
1313 if (find_new_threads_once (info
, i
, &err
) != 0)
1315 /* Found some new threads. Restart the loop from beginning. */
1320 find_new_threads_once (info
, 0, &err
);
1323 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1327 thread_db_find_new_threads_1 (ptid_t ptid
)
1329 thread_db_find_new_threads_2 (ptid
, 0);
1332 /* Implement the to_update_thread_list target method for this
1336 thread_db_update_thread_list (struct target_ops
*ops
)
1338 struct thread_db_info
*info
;
1339 struct inferior
*inf
;
1345 struct thread_info
*thread
;
1350 info
= get_thread_db_info (inf
->pid
);
1354 thread
= any_live_thread_of_process (inf
->pid
);
1355 if (thread
== NULL
|| thread
->executing
)
1358 /* It's best to avoid td_ta_thr_iter if possible. That walks
1359 data structures in the inferior's address space that may be
1360 corrupted, or, if the target is running, the list may change
1361 while we walk it. In the latter case, it's possible that a
1362 thread exits just at the exact time that causes GDB to get
1363 stuck in an infinite loop. To avoid pausing all threads
1364 whenever the core wants to refresh the thread list, we
1365 instead use thread_from_lwp immediately when we see an LWP
1366 stop. That uses thread_db entry points that do not walk
1367 libpthread's thread list, so should be safe, as well as more
1369 if (target_has_execution_1 (thread
->ptid
))
1372 thread_db_find_new_threads_1 (thread
->ptid
);
1375 /* Give the beneath target a chance to do extra processing. */
1376 ops
->beneath
->to_update_thread_list (ops
->beneath
);
1380 thread_db_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
1382 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1383 struct target_ops
*beneath
;
1385 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
1387 static char buf
[64];
1390 tid
= thread_info
->priv
->tid
;
1391 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1392 (unsigned long) tid
, ptid_get_lwp (ptid
));
1397 beneath
= find_target_beneath (ops
);
1398 return beneath
->to_pid_to_str (beneath
, ptid
);
1401 /* Return a string describing the state of the thread specified by
1405 thread_db_extra_thread_info (struct target_ops
*self
,
1406 struct thread_info
*info
)
1408 if (info
->priv
== NULL
)
1411 if (info
->priv
->dying
)
1417 /* Get the address of the thread local variable in load module LM which
1418 is stored at OFFSET within the thread local storage for thread PTID. */
1421 thread_db_get_thread_local_address (struct target_ops
*ops
,
1426 struct thread_info
*thread_info
;
1427 struct target_ops
*beneath
;
1429 /* Find the matching thread. */
1430 thread_info
= find_thread_ptid (ptid
);
1432 /* We may not have discovered the thread yet. */
1433 if (thread_info
!= NULL
&& thread_info
->priv
== NULL
)
1434 thread_info
= thread_from_lwp (ptid
);
1436 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
1440 struct thread_db_info
*info
;
1442 info
= get_thread_db_info (ptid_get_pid (ptid
));
1444 /* Finally, get the address of the variable. */
1447 /* glibc doesn't provide the needed interface. */
1448 if (!info
->td_thr_tls_get_addr_p
)
1449 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1450 _("No TLS library support"));
1452 /* Note the cast through uintptr_t: this interface only works if
1453 a target address fits in a psaddr_t, which is a host pointer.
1454 So a 32-bit debugger can not access 64-bit TLS through this. */
1455 err
= info
->td_thr_tls_get_addr_p (&thread_info
->priv
->th
,
1456 (psaddr_t
)(uintptr_t) lm
,
1461 /* If glibc doesn't provide the needed interface throw an error
1462 that LM is zero - normally cases it should not be. */
1463 if (!info
->td_thr_tlsbase_p
)
1464 throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR
,
1465 _("TLS load module not found"));
1467 /* This code path handles the case of -static -pthread executables:
1468 https://sourceware.org/ml/libc-help/2014-03/msg00024.html
1469 For older GNU libc r_debug.r_map is NULL. For GNU libc after
1470 PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
1471 The constant number 1 depends on GNU __libc_setup_tls
1472 initialization of l_tls_modid to 1. */
1473 err
= info
->td_thr_tlsbase_p (&thread_info
->priv
->th
,
1475 address
= (char *) address
+ offset
;
1478 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1479 /* The memory hasn't been allocated, yet. */
1480 if (err
== TD_NOTALLOC
)
1481 /* Now, if libthread_db provided the initialization image's
1482 address, we *could* try to build a non-lvalue value from
1483 the initialization image. */
1484 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1485 _("TLS not allocated yet"));
1488 /* Something else went wrong. */
1490 throw_error (TLS_GENERIC_ERROR
,
1491 (("%s")), thread_db_err_str (err
));
1493 /* Cast assuming host == target. Joy. */
1494 /* Do proper sign extension for the target. */
1495 gdb_assert (exec_bfd
);
1496 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1497 ? (CORE_ADDR
) (intptr_t) address
1498 : (CORE_ADDR
) (uintptr_t) address
);
1501 beneath
= find_target_beneath (ops
);
1502 return beneath
->to_get_thread_local_address (beneath
, ptid
, lm
, offset
);
1505 /* Implement the to_get_ada_task_ptid target method for this target. */
1508 thread_db_get_ada_task_ptid (struct target_ops
*self
, long lwp
, long thread
)
1510 /* NPTL uses a 1:1 model, so the LWP id suffices. */
1511 return ptid_build (ptid_get_pid (inferior_ptid
), lwp
, 0);
1515 thread_db_resume (struct target_ops
*ops
,
1516 ptid_t ptid
, int step
, enum gdb_signal signo
)
1518 struct target_ops
*beneath
= find_target_beneath (ops
);
1519 struct thread_db_info
*info
;
1521 if (ptid_equal (ptid
, minus_one_ptid
))
1522 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1524 info
= get_thread_db_info (ptid_get_pid (ptid
));
1526 /* This workaround is only needed for child fork lwps stopped in a
1527 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1528 workaround can be disabled. */
1530 info
->need_stale_parent_threads_check
= 0;
1532 beneath
->to_resume (beneath
, ptid
, step
, signo
);
1535 /* qsort helper function for info_auto_load_libthread_db, sort the
1536 thread_db_info pointers primarily by their FILENAME and secondarily by their
1537 PID, both in ascending order. */
1540 info_auto_load_libthread_db_compare (const void *ap
, const void *bp
)
1542 struct thread_db_info
*a
= *(struct thread_db_info
**) ap
;
1543 struct thread_db_info
*b
= *(struct thread_db_info
**) bp
;
1546 retval
= strcmp (a
->filename
, b
->filename
);
1550 return (a
->pid
> b
->pid
) - (a
->pid
- b
->pid
);
1553 /* Implement 'info auto-load libthread-db'. */
1556 info_auto_load_libthread_db (char *args
, int from_tty
)
1558 struct ui_out
*uiout
= current_uiout
;
1559 const char *cs
= args
? args
: "";
1560 struct thread_db_info
*info
, **array
;
1561 unsigned info_count
, unique_filenames
;
1562 size_t max_filename_len
, max_pids_len
, pids_len
;
1563 struct cleanup
*back_to
;
1567 cs
= skip_spaces_const (cs
);
1569 error (_("'info auto-load libthread-db' does not accept any parameters"));
1572 for (info
= thread_db_list
; info
; info
= info
->next
)
1573 if (info
->filename
!= NULL
)
1576 array
= XNEWVEC (struct thread_db_info
*, info_count
);
1577 back_to
= make_cleanup (xfree
, array
);
1580 for (info
= thread_db_list
; info
; info
= info
->next
)
1581 if (info
->filename
!= NULL
)
1582 array
[info_count
++] = info
;
1584 /* Sort ARRAY by filenames and PIDs. */
1586 qsort (array
, info_count
, sizeof (*array
),
1587 info_auto_load_libthread_db_compare
);
1589 /* Calculate the number of unique filenames (rows) and the maximum string
1590 length of PIDs list for the unique filenames (columns). */
1592 unique_filenames
= 0;
1593 max_filename_len
= 0;
1596 for (i
= 0; i
< info_count
; i
++)
1598 int pid
= array
[i
]->pid
;
1599 size_t this_pid_len
;
1601 for (this_pid_len
= 0; pid
!= 0; pid
/= 10)
1604 if (i
== 0 || strcmp (array
[i
- 1]->filename
, array
[i
]->filename
) != 0)
1607 max_filename_len
= max (max_filename_len
,
1608 strlen (array
[i
]->filename
));
1612 pids_len
-= strlen (", ");
1613 max_pids_len
= max (max_pids_len
, pids_len
);
1617 pids_len
+= this_pid_len
+ strlen (", ");
1621 pids_len
-= strlen (", ");
1622 max_pids_len
= max (max_pids_len
, pids_len
);
1625 /* Table header shifted right by preceding "libthread-db: " would not match
1627 if (info_count
> 0 && args
== auto_load_info_scripts_pattern_nl
)
1628 ui_out_text (uiout
, "\n");
1630 make_cleanup_ui_out_table_begin_end (uiout
, 2, unique_filenames
,
1631 "LinuxThreadDbTable");
1633 ui_out_table_header (uiout
, max_filename_len
, ui_left
, "filename",
1635 ui_out_table_header (uiout
, pids_len
, ui_left
, "PIDs", "Pids");
1636 ui_out_table_body (uiout
);
1638 pids
= (char *) xmalloc (max_pids_len
+ 1);
1639 make_cleanup (xfree
, pids
);
1641 /* Note I is incremented inside the cycle, not at its end. */
1642 for (i
= 0; i
< info_count
;)
1644 struct cleanup
*chain
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
1648 ui_out_field_string (uiout
, "filename", info
->filename
);
1651 while (i
< info_count
&& strcmp (info
->filename
, array
[i
]->filename
) == 0)
1653 if (pids_end
!= pids
)
1658 pids_end
+= xsnprintf (pids_end
, &pids
[max_pids_len
+ 1] - pids_end
,
1659 "%u", array
[i
]->pid
);
1660 gdb_assert (pids_end
< &pids
[max_pids_len
+ 1]);
1666 ui_out_field_string (uiout
, "pids", pids
);
1668 ui_out_text (uiout
, "\n");
1669 do_cleanups (chain
);
1672 do_cleanups (back_to
);
1674 if (info_count
== 0)
1675 ui_out_message (uiout
, 0, _("No auto-loaded libthread-db.\n"));
1679 init_thread_db_ops (void)
1681 thread_db_ops
.to_shortname
= "multi-thread";
1682 thread_db_ops
.to_longname
= "multi-threaded child process.";
1683 thread_db_ops
.to_doc
= "Threads and pthreads support.";
1684 thread_db_ops
.to_detach
= thread_db_detach
;
1685 thread_db_ops
.to_wait
= thread_db_wait
;
1686 thread_db_ops
.to_resume
= thread_db_resume
;
1687 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
1688 thread_db_ops
.to_update_thread_list
= thread_db_update_thread_list
;
1689 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
1690 thread_db_ops
.to_stratum
= thread_stratum
;
1691 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
1692 thread_db_ops
.to_get_thread_local_address
1693 = thread_db_get_thread_local_address
;
1694 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
1695 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
1696 thread_db_ops
.to_magic
= OPS_MAGIC
;
1698 complete_target_initialization (&thread_db_ops
);
1701 /* Provide a prototype to silence -Wmissing-prototypes. */
1702 extern initialize_file_ftype _initialize_thread_db
;
1705 _initialize_thread_db (void)
1707 init_thread_db_ops ();
1709 /* Defer loading of libthread_db.so until inferior is running.
1710 This allows gdb to load correct libthread_db for a given
1711 executable -- there could be multiple versions of glibc,
1712 and until there is a running inferior, we can't tell which
1713 libthread_db is the correct one to load. */
1715 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
1717 add_setshow_optional_filename_cmd ("libthread-db-search-path",
1719 &libthread_db_search_path
, _("\
1720 Set search path for libthread_db."), _("\
1721 Show the current search path or libthread_db."), _("\
1722 This path is used to search for libthread_db to be loaded into \
1724 Its value is a colon (':') separate list of directories to search.\n\
1725 Setting the search path to an empty list resets it to its default value."),
1726 set_libthread_db_search_path
,
1728 &setlist
, &showlist
);
1730 add_setshow_zuinteger_cmd ("libthread-db", class_maintenance
,
1731 &libthread_db_debug
, _("\
1732 Set libthread-db debugging."), _("\
1733 Show libthread-db debugging."), _("\
1734 When non-zero, libthread-db debugging is enabled."),
1736 show_libthread_db_debug
,
1737 &setdebuglist
, &showdebuglist
);
1739 add_setshow_boolean_cmd ("libthread-db", class_support
,
1740 &auto_load_thread_db
, _("\
1741 Enable or disable auto-loading of inferior specific libthread_db."), _("\
1742 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
1743 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
1744 locations to load libthread_db compatible with the inferior.\n\
1745 Standard system libthread_db still gets loaded even with this option off.\n\
1746 This options has security implications for untrusted inferiors."),
1747 NULL
, show_auto_load_thread_db
,
1748 auto_load_set_cmdlist_get (),
1749 auto_load_show_cmdlist_get ());
1751 add_cmd ("libthread-db", class_info
, info_auto_load_libthread_db
,
1752 _("Print the list of loaded inferior specific libthread_db.\n\
1753 Usage: info auto-load libthread-db"),
1754 auto_load_info_cmdlist_get ());
1756 /* Add ourselves to objfile event chain. */
1757 observer_attach_new_objfile (thread_db_new_objfile
);
1759 /* Add ourselves to inferior_created event chain.
1760 This is needed to handle debugging statically linked programs where
1761 the new_objfile observer won't get called for libpthread. */
1762 observer_attach_inferior_created (thread_db_inferior_created
);