1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999-2015 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_ta_thr_iter
));
568 CHK (TDB_VERBOSE_DLSYM (info
, td_thr_validate
));
569 CHK (TDB_VERBOSE_DLSYM (info
, td_thr_get_info
));
571 /* These are not essential. */
572 TDB_DLSYM (info
, td_thr_tls_get_addr
);
573 TDB_DLSYM (info
, td_thr_tlsbase
);
575 #undef TDB_VERBOSE_DLSYM
579 /* It's best to avoid td_ta_thr_iter if possible. That walks data
580 structures in the inferior's address space that may be corrupted,
581 or, if the target is running, may change while we walk them. If
582 there's execution (and /proc is mounted), then we're already
583 attached to all LWPs. Use thread_from_lwp, which uses
584 td_ta_map_lwp2thr instead, which does not walk the thread list.
586 td_ta_map_lwp2thr uses ps_get_thread_area, but we can't use that
587 currently on core targets, as it uses ptrace directly. */
588 if (target_has_execution
589 && linux_proc_task_list_dir_exists (ptid_get_pid (inferior_ptid
)))
592 int pid
= ptid_get_pid (inferior_ptid
);
594 linux_stop_and_wait_all_lwps ();
597 if (ptid_get_pid (lp
->ptid
) == pid
)
598 thread_from_lwp (lp
->ptid
);
600 linux_unstop_all_lwps ();
602 else if (thread_db_find_new_threads_silently (inferior_ptid
) != 0)
604 /* Even if libthread_db initializes, if the thread list is
605 corrupted, we'd not manage to list any threads. Better reject this
606 thread_db, and fall back to at least listing LWPs. */
610 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
612 if (*libthread_db_search_path
|| libthread_db_debug
)
614 struct ui_file
*file
;
617 library
= dladdr_to_soname ((const void *) *info
->td_ta_new_p
);
619 library
= LIBTHREAD_DB_SO
;
621 /* If we'd print this to gdb_stdout when debug output is
622 disabled, still print it to gdb_stdout if debug output is
623 enabled. User visible output should not depend on debug
625 file
= *libthread_db_search_path
!= '\0' ? gdb_stdout
: gdb_stdlog
;
626 fprintf_unfiltered (file
, _("Using host libthread_db library \"%s\".\n"),
630 /* The thread library was detected. Activate the thread_db target
631 if this is the first process using it. */
632 if (thread_db_list
->next
== NULL
)
633 push_target (&thread_db_ops
);
638 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
639 relative, or just LIBTHREAD_DB. */
642 try_thread_db_load (const char *library
, int check_auto_load_safe
)
645 struct thread_db_info
*info
;
647 if (libthread_db_debug
)
648 fprintf_unfiltered (gdb_stdlog
,
649 _("Trying host libthread_db library: %s.\n"),
652 if (check_auto_load_safe
)
654 if (access (library
, R_OK
) != 0)
656 /* Do not print warnings by file_is_auto_load_safe if the library does
657 not exist at this place. */
658 if (libthread_db_debug
)
659 fprintf_unfiltered (gdb_stdlog
, _("open failed: %s.\n"),
660 safe_strerror (errno
));
664 if (!file_is_auto_load_safe (library
, _("auto-load: Loading libthread-db "
665 "library \"%s\" from explicit "
671 handle
= dlopen (library
, RTLD_NOW
);
674 if (libthread_db_debug
)
675 fprintf_unfiltered (gdb_stdlog
, _("dlopen failed: %s.\n"), dlerror ());
679 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
683 td_init
= dlsym (handle
, "td_init");
686 const char *const libpath
= dladdr_to_soname (td_init
);
689 fprintf_unfiltered (gdb_stdlog
, _("Host %s resolved to: %s.\n"),
694 info
= add_thread_db_info (handle
);
696 /* Do not save system library name, that one is always trusted. */
697 if (strchr (library
, '/') != NULL
)
698 info
->filename
= gdb_realpath (library
);
700 if (try_thread_db_load_1 (info
))
703 /* This library "refused" to work on current inferior. */
704 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
708 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
709 Try loading libthread_db in directory(OBJ)/SUBDIR.
710 SUBDIR may be NULL. It may also be something like "../lib64".
711 The result is true for success. */
714 try_thread_db_load_from_pdir_1 (struct objfile
*obj
, const char *subdir
)
716 struct cleanup
*cleanup
;
719 const char *obj_name
= objfile_name (obj
);
722 if (obj_name
[0] != '/')
724 warning (_("Expected absolute pathname for libpthread in the"
725 " inferior, but got %s."), obj_name
);
729 alloc_len
= (strlen (obj_name
)
730 + (subdir
? strlen (subdir
) + 1 : 0)
731 + 1 + strlen (LIBTHREAD_DB_SO
) + 1);
732 path
= (char *) xmalloc (alloc_len
);
733 cleanup
= make_cleanup (xfree
, path
);
735 strcpy (path
, obj_name
);
736 cp
= strrchr (path
, '/');
737 /* This should at minimum hit the first character. */
738 gdb_assert (cp
!= NULL
);
745 strcat (cp
, LIBTHREAD_DB_SO
);
747 result
= try_thread_db_load (path
, 1);
749 do_cleanups (cleanup
);
753 /* Handle $pdir in libthread-db-search-path.
754 Look for libthread_db in directory(libpthread)/SUBDIR.
755 SUBDIR may be NULL. It may also be something like "../lib64".
756 The result is true for success. */
759 try_thread_db_load_from_pdir (const char *subdir
)
763 if (!auto_load_thread_db
)
767 if (libpthread_name_p (objfile_name (obj
)))
769 if (try_thread_db_load_from_pdir_1 (obj
, subdir
))
772 /* We may have found the separate-debug-info version of
773 libpthread, and it may live in a directory without a matching
775 if (obj
->separate_debug_objfile_backlink
!= NULL
)
776 return try_thread_db_load_from_pdir_1 (obj
->separate_debug_objfile_backlink
,
785 /* Handle $sdir in libthread-db-search-path.
786 Look for libthread_db in the system dirs, or wherever a plain
787 dlopen(file_without_path) will look.
788 The result is true for success. */
791 try_thread_db_load_from_sdir (void)
793 return try_thread_db_load (LIBTHREAD_DB_SO
, 0);
796 /* Try to load libthread_db from directory DIR of length DIR_LEN.
797 The result is true for success. */
800 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
802 struct cleanup
*cleanup
;
806 if (!auto_load_thread_db
)
809 path
= (char *) xmalloc (dir_len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1);
810 cleanup
= make_cleanup (xfree
, path
);
812 memcpy (path
, dir
, dir_len
);
814 strcpy (path
+ dir_len
+ 1, LIBTHREAD_DB_SO
);
816 result
= try_thread_db_load (path
, 1);
818 do_cleanups (cleanup
);
822 /* Search libthread_db_search_path for libthread_db which "agrees"
823 to work on current inferior.
824 The result is true for success. */
827 thread_db_load_search (void)
829 VEC (char_ptr
) *dir_vec
;
830 struct cleanup
*cleanups
;
834 dir_vec
= dirnames_to_char_ptr_vec (libthread_db_search_path
);
835 cleanups
= make_cleanup_free_char_ptr_vec (dir_vec
);
837 for (i
= 0; VEC_iterate (char_ptr
, dir_vec
, i
, this_dir
); ++i
)
839 const int pdir_len
= sizeof ("$pdir") - 1;
842 this_dir_len
= strlen (this_dir
);
844 if (strncmp (this_dir
, "$pdir", pdir_len
) == 0
845 && (this_dir
[pdir_len
] == '\0'
846 || this_dir
[pdir_len
] == '/'))
849 struct cleanup
*free_subdir_cleanup
850 = make_cleanup (null_cleanup
, NULL
);
852 if (this_dir
[pdir_len
] == '/')
854 subdir
= (char *) xmalloc (strlen (this_dir
));
855 make_cleanup (xfree
, subdir
);
856 strcpy (subdir
, this_dir
+ pdir_len
+ 1);
858 rc
= try_thread_db_load_from_pdir (subdir
);
859 do_cleanups (free_subdir_cleanup
);
863 else if (strcmp (this_dir
, "$sdir") == 0)
865 if (try_thread_db_load_from_sdir ())
873 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
881 do_cleanups (cleanups
);
882 if (libthread_db_debug
)
883 fprintf_unfiltered (gdb_stdlog
,
884 _("thread_db_load_search returning %d\n"), rc
);
888 /* Return non-zero if the inferior has a libpthread. */
891 has_libpthread (void)
896 if (libpthread_name_p (objfile_name (obj
)))
902 /* Attempt to load and initialize libthread_db.
903 Return 1 on success. */
906 thread_db_load (void)
908 struct thread_db_info
*info
;
910 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
915 /* Don't attempt to use thread_db on executables not running
917 if (!target_has_registers
)
920 /* Don't attempt to use thread_db for remote targets. */
921 if (!(target_can_run (¤t_target
) || core_bfd
))
924 if (thread_db_load_search ())
927 /* We couldn't find a libthread_db.
928 If the inferior has a libpthread warn the user. */
929 if (has_libpthread ())
931 warning (_("Unable to find libthread_db matching inferior's thread"
932 " library, thread debugging will not be available."));
936 /* Either this executable isn't using libpthread at all, or it is
937 statically linked. Since we can't easily distinguish these two cases,
938 no warning is issued. */
943 check_thread_signals (void)
950 lin_thread_get_thread_signals (&mask
);
951 sigemptyset (&thread_stop_set
);
952 sigemptyset (&thread_print_set
);
954 for (i
= 1; i
< NSIG
; i
++)
956 if (sigismember (&mask
, i
))
958 if (signal_stop_update (gdb_signal_from_host (i
), 0))
959 sigaddset (&thread_stop_set
, i
);
960 if (signal_print_update (gdb_signal_from_host (i
), 0))
961 sigaddset (&thread_print_set
, i
);
968 /* Check whether thread_db is usable. This function is called when
969 an inferior is created (or otherwise acquired, e.g. attached to)
970 and when new shared libraries are loaded into a running process. */
973 check_for_thread_db (void)
975 /* Do nothing if we couldn't load libthread_db.so.1. */
976 if (!thread_db_load ())
980 /* This function is called via the new_objfile observer. */
983 thread_db_new_objfile (struct objfile
*objfile
)
985 /* This observer must always be called with inferior_ptid set
989 /* libpthread with separate debug info has its debug info file already
990 loaded (and notified without successful thread_db initialization)
991 the time observer_notify_new_objfile is called for the library itself.
992 Static executables have their separate debug info loaded already
993 before the inferior has started. */
994 && objfile
->separate_debug_objfile_backlink
== NULL
995 /* Only check for thread_db if we loaded libpthread,
996 or if this is the main symbol file.
997 We need to check OBJF_MAINLINE to handle the case of debugging
998 a statically linked executable AND the symbol file is specified AFTER
999 the exec file is loaded (e.g., gdb -c core ; file foo).
1000 For dynamically linked executables, libpthread can be near the end
1001 of the list of shared libraries to load, and in an app of several
1002 thousand shared libraries, this can otherwise be painful. */
1003 && ((objfile
->flags
& OBJF_MAINLINE
) != 0
1004 || libpthread_name_p (objfile_name (objfile
))))
1005 check_for_thread_db ();
1009 check_pid_namespace_match (void)
1011 /* Check is only relevant for local targets targets. */
1012 if (target_can_run (¤t_target
))
1014 /* If the child is in a different PID namespace, its idea of its
1015 PID will differ from our idea of its PID. When we scan the
1016 child's thread list, we'll mistakenly think it has no threads
1017 since the thread PID fields won't match the PID we give to
1019 if (!linux_ns_same (ptid_get_pid (inferior_ptid
), LINUX_NS_PID
))
1021 warning (_ ("Target and debugger are in different PID "
1022 "namespaces; thread lists and other data are "
1023 "likely unreliable"));
1028 /* This function is called via the inferior_created observer.
1029 This handles the case of debugging statically linked executables. */
1032 thread_db_inferior_created (struct target_ops
*target
, int from_tty
)
1034 check_pid_namespace_match ();
1035 check_for_thread_db ();
1038 /* Update the thread's state (what's displayed in "info threads"),
1039 from libthread_db thread state information. */
1042 update_thread_state (struct private_thread_info
*priv
,
1043 const td_thrinfo_t
*ti_p
)
1045 priv
->dying
= (ti_p
->ti_state
== TD_THR_UNKNOWN
1046 || ti_p
->ti_state
== TD_THR_ZOMBIE
);
1049 /* Record a new thread in GDB's thread list. Creates the thread's
1050 private info. If TP is NULL or TP is marked as having exited,
1051 creates a new thread. Otherwise, uses TP. */
1053 static struct thread_info
*
1054 record_thread (struct thread_db_info
*info
,
1055 struct thread_info
*tp
,
1056 ptid_t ptid
, const td_thrhandle_t
*th_p
,
1057 const td_thrinfo_t
*ti_p
)
1060 struct private_thread_info
*priv
;
1061 int new_thread
= (tp
== NULL
);
1063 /* A thread ID of zero may mean the thread library has not
1064 initialized yet. Leave private == NULL until the thread library
1066 if (ti_p
->ti_tid
== 0)
1069 /* Construct the thread's private data. */
1070 priv
= XCNEW (struct private_thread_info
);
1073 priv
->tid
= ti_p
->ti_tid
;
1074 update_thread_state (priv
, ti_p
);
1076 /* Add the thread to GDB's thread list. If we already know about a
1077 thread with this PTID, but it's marked exited, then the kernel
1078 reused the tid of an old thread. */
1079 if (tp
== NULL
|| tp
->state
== THREAD_EXITED
)
1080 tp
= add_thread_with_info (ptid
, priv
);
1084 if (target_has_execution
)
1085 check_thread_signals ();
1091 thread_db_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1093 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1094 struct thread_db_info
*info
;
1096 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1099 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
1101 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
1103 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1105 /* If there are no more processes using libpthread, detach the
1106 thread_db target ops. */
1107 if (!thread_db_list
)
1108 unpush_target (&thread_db_ops
);
1112 thread_db_wait (struct target_ops
*ops
,
1113 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1116 struct thread_db_info
*info
;
1117 struct target_ops
*beneath
= find_target_beneath (ops
);
1119 ptid
= beneath
->to_wait (beneath
, ptid
, ourstatus
, options
);
1121 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
1124 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
1125 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
1128 info
= get_thread_db_info (ptid_get_pid (ptid
));
1130 /* If this process isn't using thread_db, we're done. */
1134 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1136 /* New image, it may or may not end up using thread_db. Assume
1137 not unless we find otherwise. */
1138 delete_thread_db_info (ptid_get_pid (ptid
));
1139 if (!thread_db_list
)
1140 unpush_target (&thread_db_ops
);
1145 /* Fill in the thread's user-level thread id and status. */
1146 thread_from_lwp (ptid
);
1152 thread_db_mourn_inferior (struct target_ops
*ops
)
1154 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1156 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
1158 target_beneath
->to_mourn_inferior (target_beneath
);
1160 /* Detach thread_db target ops. */
1161 if (!thread_db_list
)
1162 unpush_target (ops
);
1165 struct callback_data
1167 struct thread_db_info
*info
;
1172 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1177 struct thread_info
*tp
;
1178 struct callback_data
*cb_data
= (struct callback_data
*) data
;
1179 struct thread_db_info
*info
= cb_data
->info
;
1181 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1183 error (_("find_new_threads_callback: cannot get thread info: %s"),
1184 thread_db_err_str (err
));
1186 if (ti
.ti_lid
== -1)
1188 /* A thread with kernel thread ID -1 is either a thread that
1189 exited and was joined, or a thread that is being created but
1190 hasn't started yet, and that is reusing the tcb/stack of a
1191 thread that previously exited and was joined. (glibc marks
1192 terminated and joined threads with kernel thread ID -1. See
1194 if (libthread_db_debug
)
1195 fprintf_unfiltered (gdb_stdlog
,
1196 "thread_db: skipping exited and "
1197 "joined thread (0x%lx)\n",
1198 (unsigned long) ti
.ti_tid
);
1204 /* A thread ID of zero means that this is the main thread, but
1205 glibc has not yet initialized thread-local storage and the
1206 pthread library. We do not know what the thread's TID will
1209 /* In that case, we're not stopped in a fork syscall and don't
1210 need this glibc bug workaround. */
1211 info
->need_stale_parent_threads_check
= 0;
1216 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1217 bit expensive, as it needs to open /proc/pid/status, so try to
1218 avoid doing the work if we know we don't have to. */
1219 if (info
->need_stale_parent_threads_check
)
1221 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1223 if (tgid
!= -1 && tgid
!= info
->pid
)
1227 ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
1228 tp
= find_thread_ptid (ptid
);
1229 if (tp
== NULL
|| tp
->priv
== NULL
)
1230 record_thread (info
, tp
, ptid
, th_p
, &ti
);
1235 /* Helper for thread_db_find_new_threads_2.
1236 Returns number of new threads found. */
1239 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1242 struct callback_data data
;
1243 td_err_e err
= TD_ERR
;
1246 data
.new_threads
= 0;
1248 /* See comment in thread_db_update_thread_list. */
1249 gdb_assert (!target_has_execution
);
1253 /* Iterate over all user-space threads to discover new threads. */
1254 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1255 find_new_threads_callback
,
1258 TD_THR_LOWEST_PRIORITY
,
1260 TD_THR_ANY_USER_FLAGS
);
1262 CATCH (except
, RETURN_MASK_ERROR
)
1264 if (libthread_db_debug
)
1266 exception_fprintf (gdb_stdlog
, except
,
1267 "Warning: find_new_threads_once: ");
1272 if (libthread_db_debug
)
1274 fprintf_unfiltered (gdb_stdlog
,
1275 _("Found %d new threads in iteration %d.\n"),
1276 data
.new_threads
, iteration
);
1282 return data
.new_threads
;
1285 /* Search for new threads, accessing memory through stopped thread
1286 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1287 searches in a row do not discover any new threads. */
1290 thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
)
1292 td_err_e err
= TD_OK
;
1293 struct thread_db_info
*info
;
1296 info
= get_thread_db_info (ptid_get_pid (ptid
));
1298 /* Access an lwp we know is stopped. */
1299 info
->proc_handle
.ptid
= ptid
;
1303 /* Require 4 successive iterations which do not find any new threads.
1304 The 4 is a heuristic: there is an inherent race here, and I have
1305 seen that 2 iterations in a row are not always sufficient to
1306 "capture" all threads. */
1307 for (i
= 0, loop
= 0; loop
< 4 && err
== TD_OK
; ++i
, ++loop
)
1308 if (find_new_threads_once (info
, i
, &err
) != 0)
1310 /* Found some new threads. Restart the loop from beginning. */
1315 find_new_threads_once (info
, 0, &err
);
1318 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1322 thread_db_find_new_threads_1 (ptid_t ptid
)
1324 thread_db_find_new_threads_2 (ptid
, 0);
1328 update_thread_core (struct lwp_info
*info
, void *closure
)
1330 info
->core
= linux_common_core_of_thread (info
->ptid
);
1334 /* Update the thread list using td_ta_thr_iter. */
1337 thread_db_update_thread_list_td_ta_thr_iter (struct target_ops
*ops
)
1339 struct thread_db_info
*info
;
1340 struct inferior
*inf
;
1346 struct thread_info
*thread
;
1351 info
= get_thread_db_info (inf
->pid
);
1355 thread
= any_live_thread_of_process (inf
->pid
);
1356 if (thread
== NULL
|| thread
->executing
)
1359 thread_db_find_new_threads_1 (thread
->ptid
);
1363 /* Implement the to_update_thread_list target method for this
1367 thread_db_update_thread_list (struct target_ops
*ops
)
1369 /* It's best to avoid td_ta_thr_iter if possible. That walks data
1370 structures in the inferior's address space that may be corrupted,
1371 or, if the target is running, the list may change while we walk
1372 it. In the latter case, it's possible that a thread exits just
1373 at the exact time that causes GDB to get stuck in an infinite
1374 loop. To avoid pausing all threads whenever the core wants to
1375 refresh the thread list, use thread_from_lwp immediately when we
1376 see an LWP stop. That uses thread_db entry points that do not
1377 walk libpthread's thread list, so should be safe, as well as
1379 if (target_has_execution
)
1380 ops
->beneath
->to_update_thread_list (ops
->beneath
);
1382 thread_db_update_thread_list_td_ta_thr_iter (ops
);
1384 if (target_has_execution
)
1385 iterate_over_lwps (minus_one_ptid
/* iterate over all */,
1386 update_thread_core
, NULL
);
1390 thread_db_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
1392 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1393 struct target_ops
*beneath
;
1395 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
1397 static char buf
[64];
1400 tid
= thread_info
->priv
->tid
;
1401 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1402 (unsigned long) tid
, ptid_get_lwp (ptid
));
1407 beneath
= find_target_beneath (ops
);
1408 return beneath
->to_pid_to_str (beneath
, ptid
);
1411 /* Return a string describing the state of the thread specified by
1415 thread_db_extra_thread_info (struct target_ops
*self
,
1416 struct thread_info
*info
)
1418 if (info
->priv
== NULL
)
1421 if (info
->priv
->dying
)
1427 /* Get the address of the thread local variable in load module LM which
1428 is stored at OFFSET within the thread local storage for thread PTID. */
1431 thread_db_get_thread_local_address (struct target_ops
*ops
,
1436 struct thread_info
*thread_info
;
1437 struct target_ops
*beneath
;
1439 /* Find the matching thread. */
1440 thread_info
= find_thread_ptid (ptid
);
1442 /* We may not have discovered the thread yet. */
1443 if (thread_info
!= NULL
&& thread_info
->priv
== NULL
)
1444 thread_info
= thread_from_lwp (ptid
);
1446 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
1450 struct thread_db_info
*info
;
1452 info
= get_thread_db_info (ptid_get_pid (ptid
));
1454 /* Finally, get the address of the variable. */
1457 /* glibc doesn't provide the needed interface. */
1458 if (!info
->td_thr_tls_get_addr_p
)
1459 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1460 _("No TLS library support"));
1462 /* Note the cast through uintptr_t: this interface only works if
1463 a target address fits in a psaddr_t, which is a host pointer.
1464 So a 32-bit debugger can not access 64-bit TLS through this. */
1465 err
= info
->td_thr_tls_get_addr_p (&thread_info
->priv
->th
,
1466 (psaddr_t
)(uintptr_t) lm
,
1471 /* If glibc doesn't provide the needed interface throw an error
1472 that LM is zero - normally cases it should not be. */
1473 if (!info
->td_thr_tlsbase_p
)
1474 throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR
,
1475 _("TLS load module not found"));
1477 /* This code path handles the case of -static -pthread executables:
1478 https://sourceware.org/ml/libc-help/2014-03/msg00024.html
1479 For older GNU libc r_debug.r_map is NULL. For GNU libc after
1480 PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
1481 The constant number 1 depends on GNU __libc_setup_tls
1482 initialization of l_tls_modid to 1. */
1483 err
= info
->td_thr_tlsbase_p (&thread_info
->priv
->th
,
1485 address
= (char *) address
+ offset
;
1488 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1489 /* The memory hasn't been allocated, yet. */
1490 if (err
== TD_NOTALLOC
)
1491 /* Now, if libthread_db provided the initialization image's
1492 address, we *could* try to build a non-lvalue value from
1493 the initialization image. */
1494 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1495 _("TLS not allocated yet"));
1498 /* Something else went wrong. */
1500 throw_error (TLS_GENERIC_ERROR
,
1501 (("%s")), thread_db_err_str (err
));
1503 /* Cast assuming host == target. Joy. */
1504 /* Do proper sign extension for the target. */
1505 gdb_assert (exec_bfd
);
1506 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1507 ? (CORE_ADDR
) (intptr_t) address
1508 : (CORE_ADDR
) (uintptr_t) address
);
1511 beneath
= find_target_beneath (ops
);
1512 return beneath
->to_get_thread_local_address (beneath
, ptid
, lm
, offset
);
1515 /* Implement the to_get_ada_task_ptid target method for this target. */
1518 thread_db_get_ada_task_ptid (struct target_ops
*self
, long lwp
, long thread
)
1520 /* NPTL uses a 1:1 model, so the LWP id suffices. */
1521 return ptid_build (ptid_get_pid (inferior_ptid
), lwp
, 0);
1525 thread_db_resume (struct target_ops
*ops
,
1526 ptid_t ptid
, int step
, enum gdb_signal signo
)
1528 struct target_ops
*beneath
= find_target_beneath (ops
);
1529 struct thread_db_info
*info
;
1531 if (ptid_equal (ptid
, minus_one_ptid
))
1532 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1534 info
= get_thread_db_info (ptid_get_pid (ptid
));
1536 /* This workaround is only needed for child fork lwps stopped in a
1537 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1538 workaround can be disabled. */
1540 info
->need_stale_parent_threads_check
= 0;
1542 beneath
->to_resume (beneath
, ptid
, step
, signo
);
1545 /* qsort helper function for info_auto_load_libthread_db, sort the
1546 thread_db_info pointers primarily by their FILENAME and secondarily by their
1547 PID, both in ascending order. */
1550 info_auto_load_libthread_db_compare (const void *ap
, const void *bp
)
1552 struct thread_db_info
*a
= *(struct thread_db_info
**) ap
;
1553 struct thread_db_info
*b
= *(struct thread_db_info
**) bp
;
1556 retval
= strcmp (a
->filename
, b
->filename
);
1560 return (a
->pid
> b
->pid
) - (a
->pid
- b
->pid
);
1563 /* Implement 'info auto-load libthread-db'. */
1566 info_auto_load_libthread_db (char *args
, int from_tty
)
1568 struct ui_out
*uiout
= current_uiout
;
1569 const char *cs
= args
? args
: "";
1570 struct thread_db_info
*info
, **array
;
1571 unsigned info_count
, unique_filenames
;
1572 size_t max_filename_len
, max_pids_len
, pids_len
;
1573 struct cleanup
*back_to
;
1577 cs
= skip_spaces_const (cs
);
1579 error (_("'info auto-load libthread-db' does not accept any parameters"));
1582 for (info
= thread_db_list
; info
; info
= info
->next
)
1583 if (info
->filename
!= NULL
)
1586 array
= XNEWVEC (struct thread_db_info
*, info_count
);
1587 back_to
= make_cleanup (xfree
, array
);
1590 for (info
= thread_db_list
; info
; info
= info
->next
)
1591 if (info
->filename
!= NULL
)
1592 array
[info_count
++] = info
;
1594 /* Sort ARRAY by filenames and PIDs. */
1596 qsort (array
, info_count
, sizeof (*array
),
1597 info_auto_load_libthread_db_compare
);
1599 /* Calculate the number of unique filenames (rows) and the maximum string
1600 length of PIDs list for the unique filenames (columns). */
1602 unique_filenames
= 0;
1603 max_filename_len
= 0;
1606 for (i
= 0; i
< info_count
; i
++)
1608 int pid
= array
[i
]->pid
;
1609 size_t this_pid_len
;
1611 for (this_pid_len
= 0; pid
!= 0; pid
/= 10)
1614 if (i
== 0 || strcmp (array
[i
- 1]->filename
, array
[i
]->filename
) != 0)
1617 max_filename_len
= max (max_filename_len
,
1618 strlen (array
[i
]->filename
));
1622 pids_len
-= strlen (", ");
1623 max_pids_len
= max (max_pids_len
, pids_len
);
1627 pids_len
+= this_pid_len
+ strlen (", ");
1631 pids_len
-= strlen (", ");
1632 max_pids_len
= max (max_pids_len
, pids_len
);
1635 /* Table header shifted right by preceding "libthread-db: " would not match
1637 if (info_count
> 0 && args
== auto_load_info_scripts_pattern_nl
)
1638 ui_out_text (uiout
, "\n");
1640 make_cleanup_ui_out_table_begin_end (uiout
, 2, unique_filenames
,
1641 "LinuxThreadDbTable");
1643 ui_out_table_header (uiout
, max_filename_len
, ui_left
, "filename",
1645 ui_out_table_header (uiout
, pids_len
, ui_left
, "PIDs", "Pids");
1646 ui_out_table_body (uiout
);
1648 pids
= (char *) xmalloc (max_pids_len
+ 1);
1649 make_cleanup (xfree
, pids
);
1651 /* Note I is incremented inside the cycle, not at its end. */
1652 for (i
= 0; i
< info_count
;)
1654 struct cleanup
*chain
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
1658 ui_out_field_string (uiout
, "filename", info
->filename
);
1661 while (i
< info_count
&& strcmp (info
->filename
, array
[i
]->filename
) == 0)
1663 if (pids_end
!= pids
)
1668 pids_end
+= xsnprintf (pids_end
, &pids
[max_pids_len
+ 1] - pids_end
,
1669 "%u", array
[i
]->pid
);
1670 gdb_assert (pids_end
< &pids
[max_pids_len
+ 1]);
1676 ui_out_field_string (uiout
, "pids", pids
);
1678 ui_out_text (uiout
, "\n");
1679 do_cleanups (chain
);
1682 do_cleanups (back_to
);
1684 if (info_count
== 0)
1685 ui_out_message (uiout
, 0, _("No auto-loaded libthread-db.\n"));
1689 init_thread_db_ops (void)
1691 thread_db_ops
.to_shortname
= "multi-thread";
1692 thread_db_ops
.to_longname
= "multi-threaded child process.";
1693 thread_db_ops
.to_doc
= "Threads and pthreads support.";
1694 thread_db_ops
.to_detach
= thread_db_detach
;
1695 thread_db_ops
.to_wait
= thread_db_wait
;
1696 thread_db_ops
.to_resume
= thread_db_resume
;
1697 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
1698 thread_db_ops
.to_update_thread_list
= thread_db_update_thread_list
;
1699 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
1700 thread_db_ops
.to_stratum
= thread_stratum
;
1701 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
1702 thread_db_ops
.to_get_thread_local_address
1703 = thread_db_get_thread_local_address
;
1704 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
1705 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
1706 thread_db_ops
.to_magic
= OPS_MAGIC
;
1708 complete_target_initialization (&thread_db_ops
);
1711 /* Provide a prototype to silence -Wmissing-prototypes. */
1712 extern initialize_file_ftype _initialize_thread_db
;
1715 _initialize_thread_db (void)
1717 init_thread_db_ops ();
1719 /* Defer loading of libthread_db.so until inferior is running.
1720 This allows gdb to load correct libthread_db for a given
1721 executable -- there could be multiple versions of glibc,
1722 and until there is a running inferior, we can't tell which
1723 libthread_db is the correct one to load. */
1725 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
1727 add_setshow_optional_filename_cmd ("libthread-db-search-path",
1729 &libthread_db_search_path
, _("\
1730 Set search path for libthread_db."), _("\
1731 Show the current search path or libthread_db."), _("\
1732 This path is used to search for libthread_db to be loaded into \
1734 Its value is a colon (':') separate list of directories to search.\n\
1735 Setting the search path to an empty list resets it to its default value."),
1736 set_libthread_db_search_path
,
1738 &setlist
, &showlist
);
1740 add_setshow_zuinteger_cmd ("libthread-db", class_maintenance
,
1741 &libthread_db_debug
, _("\
1742 Set libthread-db debugging."), _("\
1743 Show libthread-db debugging."), _("\
1744 When non-zero, libthread-db debugging is enabled."),
1746 show_libthread_db_debug
,
1747 &setdebuglist
, &showdebuglist
);
1749 add_setshow_boolean_cmd ("libthread-db", class_support
,
1750 &auto_load_thread_db
, _("\
1751 Enable or disable auto-loading of inferior specific libthread_db."), _("\
1752 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
1753 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
1754 locations to load libthread_db compatible with the inferior.\n\
1755 Standard system libthread_db still gets loaded even with this option off.\n\
1756 This options has security implications for untrusted inferiors."),
1757 NULL
, show_auto_load_thread_db
,
1758 auto_load_set_cmdlist_get (),
1759 auto_load_show_cmdlist_get ());
1761 add_cmd ("libthread-db", class_info
, info_auto_load_libthread_db
,
1762 _("Print the list of loaded inferior specific libthread_db.\n\
1763 Usage: info auto-load libthread-db"),
1764 auto_load_info_cmdlist_get ());
1766 /* Add ourselves to objfile event chain. */
1767 observer_attach_new_objfile (thread_db_new_objfile
);
1769 /* Add ourselves to inferior_created event chain.
1770 This is needed to handle debugging statically linked programs where
1771 the new_objfile observer won't get called for libpthread. */
1772 observer_attach_inferior_created (thread_db_inferior_created
);