1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999-2014 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-osdata.h"
42 #include "auto-load.h"
43 #include "cli/cli-utils.h"
48 /* GNU/Linux libthread_db support.
50 libthread_db is a library, provided along with libpthread.so, which
51 exposes the internals of the thread library to a debugger. It
52 allows GDB to find existing threads, new threads as they are
53 created, thread IDs (usually, the result of pthread_self), and
54 thread-local variables.
56 The libthread_db interface originates on Solaris, where it is
57 both more powerful and more complicated. This implementation
58 only works for LinuxThreads and NPTL, the two glibc threading
59 libraries. It assumes that each thread is permanently assigned
60 to a single light-weight process (LWP).
62 libthread_db-specific information is stored in the "private" field
63 of struct thread_info. When the field is NULL we do not yet have
64 information about the new thread; this could be temporary (created,
65 but the thread library's data structures do not reflect it yet)
66 or permanent (created using clone instead of pthread_create).
68 Process IDs managed by linux-thread-db.c match those used by
69 linux-nat.c: a common PID for all processes, an LWP ID for each
70 thread, and no TID. We save the TID in private. Keeping it out
71 of the ptid_t prevents thread IDs changing when libpthread is
72 loaded or unloaded. */
74 static char *libthread_db_search_path
;
76 /* Set to non-zero if thread_db auto-loading is enabled
77 by the "set auto-load libthread-db" command. */
78 static int auto_load_thread_db
= 1;
80 /* "show" command for the auto_load_thread_db configuration variable. */
83 show_auto_load_thread_db (struct ui_file
*file
, int from_tty
,
84 struct cmd_list_element
*c
, const char *value
)
86 fprintf_filtered (file
, _("Auto-loading of inferior specific libthread_db "
92 set_libthread_db_search_path (char *ignored
, int from_tty
,
93 struct cmd_list_element
*c
)
95 if (*libthread_db_search_path
== '\0')
97 xfree (libthread_db_search_path
);
98 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
102 /* If non-zero, print details of libthread_db processing. */
104 static unsigned int libthread_db_debug
;
107 show_libthread_db_debug (struct ui_file
*file
, int from_tty
,
108 struct cmd_list_element
*c
, const char *value
)
110 fprintf_filtered (file
, _("libthread-db debugging is %s.\n"), value
);
113 /* If we're running on GNU/Linux, we must explicitly attach to any new
116 /* This module's target vector. */
117 static struct target_ops thread_db_ops
;
119 /* Non-zero if we have determined the signals used by the threads
121 static int thread_signals
;
122 static sigset_t thread_stop_set
;
123 static sigset_t thread_print_set
;
125 struct thread_db_info
127 struct thread_db_info
*next
;
129 /* Process id this object refers to. */
132 /* Handle from dlopen for libthread_db.so. */
135 /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
136 HANDLE. It may be NULL for system library. */
139 /* Structure that identifies the child process for the
140 <proc_service.h> interface. */
141 struct ps_prochandle proc_handle
;
143 /* Connection to the libthread_db library. */
144 td_thragent_t
*thread_agent
;
146 /* True if we need to apply the workaround for glibc/BZ5983. When
147 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
148 list, nptl_db returns the parent's threads in addition to the new
149 (single) child thread. If this flag is set, we do extra work to
150 be able to ignore such stale entries. */
151 int need_stale_parent_threads_check
;
153 /* Location of the thread creation event breakpoint. The code at
154 this location in the child process will be called by the pthread
155 library whenever a new thread is created. By setting a special
156 breakpoint at this location, GDB can detect when a new thread is
157 created. We obtain this location via the td_ta_event_addr
159 CORE_ADDR td_create_bp_addr
;
161 /* Location of the thread death event breakpoint. */
162 CORE_ADDR td_death_bp_addr
;
164 /* Pointers to the libthread_db functions. */
166 td_err_e (*td_init_p
) (void);
168 td_err_e (*td_ta_new_p
) (struct ps_prochandle
* ps
,
170 td_err_e (*td_ta_map_id2thr_p
) (const td_thragent_t
*ta
, thread_t pt
,
171 td_thrhandle_t
*__th
);
172 td_err_e (*td_ta_map_lwp2thr_p
) (const td_thragent_t
*ta
,
173 lwpid_t lwpid
, td_thrhandle_t
*th
);
174 td_err_e (*td_ta_thr_iter_p
) (const td_thragent_t
*ta
,
175 td_thr_iter_f
*callback
, void *cbdata_p
,
176 td_thr_state_e state
, int ti_pri
,
177 sigset_t
*ti_sigmask_p
,
178 unsigned int ti_user_flags
);
179 td_err_e (*td_ta_event_addr_p
) (const td_thragent_t
*ta
,
180 td_event_e event
, td_notify_t
*ptr
);
181 td_err_e (*td_ta_set_event_p
) (const td_thragent_t
*ta
,
182 td_thr_events_t
*event
);
183 td_err_e (*td_ta_clear_event_p
) (const td_thragent_t
*ta
,
184 td_thr_events_t
*event
);
185 td_err_e (*td_ta_event_getmsg_p
) (const td_thragent_t
*ta
,
186 td_event_msg_t
*msg
);
188 td_err_e (*td_thr_validate_p
) (const td_thrhandle_t
*th
);
189 td_err_e (*td_thr_get_info_p
) (const td_thrhandle_t
*th
,
190 td_thrinfo_t
*infop
);
191 td_err_e (*td_thr_event_enable_p
) (const td_thrhandle_t
*th
,
194 td_err_e (*td_thr_tls_get_addr_p
) (const td_thrhandle_t
*th
,
195 psaddr_t map_address
,
196 size_t offset
, psaddr_t
*address
);
197 td_err_e (*td_thr_tlsbase_p
) (const td_thrhandle_t
*th
,
198 unsigned long int modid
,
202 /* List of known processes using thread_db, and the required
204 struct thread_db_info
*thread_db_list
;
206 static void thread_db_find_new_threads_1 (ptid_t ptid
);
207 static void thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
);
209 /* Add the current inferior to the list of processes using libpthread.
210 Return a pointer to the newly allocated object that was added to
211 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
214 static struct thread_db_info
*
215 add_thread_db_info (void *handle
)
217 struct thread_db_info
*info
;
219 info
= xcalloc (1, sizeof (*info
));
220 info
->pid
= ptid_get_pid (inferior_ptid
);
221 info
->handle
= handle
;
223 /* The workaround works by reading from /proc/pid/status, so it is
224 disabled for core files. */
225 if (target_has_execution
)
226 info
->need_stale_parent_threads_check
= 1;
228 info
->next
= thread_db_list
;
229 thread_db_list
= info
;
234 /* Return the thread_db_info object representing the bookkeeping
235 related to process PID, if any; NULL otherwise. */
237 static struct thread_db_info
*
238 get_thread_db_info (int pid
)
240 struct thread_db_info
*info
;
242 for (info
= thread_db_list
; info
; info
= info
->next
)
243 if (pid
== info
->pid
)
249 /* When PID has exited or has been detached, we no longer want to keep
250 track of it as using libpthread. Call this function to discard
251 thread_db related info related to PID. Note that this closes
252 LIBTHREAD_DB_SO's dlopen'ed handle. */
255 delete_thread_db_info (int pid
)
257 struct thread_db_info
*info
, *info_prev
;
261 for (info
= thread_db_list
; info
; info_prev
= info
, info
= info
->next
)
262 if (pid
== info
->pid
)
268 if (info
->handle
!= NULL
)
269 dlclose (info
->handle
);
271 xfree (info
->filename
);
274 info_prev
->next
= info
->next
;
276 thread_db_list
= info
->next
;
281 /* Prototypes for local functions. */
282 static int attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
283 const td_thrinfo_t
*ti_p
);
284 static void detach_thread (ptid_t ptid
);
287 /* Use "struct private_thread_info" to cache thread state. This is
288 a substantial optimization. */
290 struct private_thread_info
292 /* Flag set when we see a TD_DEATH event for this thread. */
293 unsigned int dying
:1;
295 /* Cached thread state. */
302 thread_db_err_str (td_err_e err
)
309 return "generic 'call succeeded'";
311 return "generic error";
313 return "no thread to satisfy query";
315 return "no sync handle to satisfy query";
317 return "no LWP to satisfy query";
319 return "invalid process handle";
321 return "invalid thread handle";
323 return "invalid synchronization handle";
325 return "invalid thread agent";
327 return "invalid key";
329 return "no event message for getmsg";
331 return "FPU register set not available";
333 return "application not linked with libthread";
335 return "requested event is not supported";
337 return "capability not available";
339 return "debugger service failed";
341 return "operation not applicable to";
343 return "no thread-specific data for this thread";
345 return "malloc failed";
347 return "only part of register set was written/read";
349 return "X register set not available for this thread";
350 #ifdef THREAD_DB_HAS_TD_NOTALLOC
352 return "thread has not yet allocated TLS for given module";
354 #ifdef THREAD_DB_HAS_TD_VERSION
356 return "versions of libpthread and libthread_db do not match";
358 #ifdef THREAD_DB_HAS_TD_NOTLS
360 return "there is no TLS segment in the given module";
363 snprintf (buf
, sizeof (buf
), "unknown thread_db error '%d'", err
);
368 /* Return 1 if any threads have been registered. There may be none if
369 the threading library is not fully initialized yet. */
372 have_threads_callback (struct thread_info
*thread
, void *args
)
374 int pid
= * (int *) args
;
376 if (ptid_get_pid (thread
->ptid
) != pid
)
379 return thread
->private != NULL
;
383 have_threads (ptid_t ptid
)
385 int pid
= ptid_get_pid (ptid
);
387 return iterate_over_threads (have_threads_callback
, &pid
) != NULL
;
390 struct thread_get_info_inout
392 struct thread_info
*thread_info
;
393 struct thread_db_info
*thread_db_info
;
396 /* A callback function for td_ta_thr_iter, which we use to map all
399 THP is a handle to the current thread; if INFOP is not NULL, the
400 struct thread_info associated with this thread is returned in
403 If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
404 zero is returned to indicate success. */
407 thread_get_info_callback (const td_thrhandle_t
*thp
, void *argp
)
412 struct thread_get_info_inout
*inout
;
413 struct thread_db_info
*info
;
416 info
= inout
->thread_db_info
;
418 err
= info
->td_thr_get_info_p (thp
, &ti
);
420 error (_("thread_get_info_callback: cannot get thread info: %s"),
421 thread_db_err_str (err
));
423 /* Fill the cache. */
424 thread_ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
425 inout
->thread_info
= find_thread_ptid (thread_ptid
);
427 if (inout
->thread_info
== NULL
)
429 /* New thread. Attach to it now (why wait?). */
430 if (!have_threads (thread_ptid
))
431 thread_db_find_new_threads_1 (thread_ptid
);
433 attach_thread (thread_ptid
, thp
, &ti
);
434 inout
->thread_info
= find_thread_ptid (thread_ptid
);
435 gdb_assert (inout
->thread_info
!= NULL
);
441 /* Fetch the user-level thread id of PTID. */
444 thread_from_lwp (ptid_t ptid
)
448 struct thread_db_info
*info
;
449 struct thread_get_info_inout io
= {0};
451 /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
454 /* This ptid comes from linux-nat.c, which should always fill in the
456 gdb_assert (ptid_get_lwp (ptid
) != 0);
458 info
= get_thread_db_info (ptid_get_pid (ptid
));
460 /* Access an lwp we know is stopped. */
461 info
->proc_handle
.ptid
= ptid
;
462 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, ptid_get_lwp (ptid
),
465 error (_("Cannot find user-level thread for LWP %ld: %s"),
466 ptid_get_lwp (ptid
), thread_db_err_str (err
));
468 /* Long-winded way of fetching the thread info. */
469 io
.thread_db_info
= info
;
470 io
.thread_info
= NULL
;
471 thread_get_info_callback (&th
, &io
);
475 /* Attach to lwp PTID, doing whatever else is required to have this
476 LWP under the debugger's control --- e.g., enabling event
477 reporting. Returns true on success. */
479 thread_db_attach_lwp (ptid_t ptid
)
484 struct thread_db_info
*info
;
486 info
= get_thread_db_info (ptid_get_pid (ptid
));
491 /* This ptid comes from linux-nat.c, which should always fill in the
493 gdb_assert (ptid_get_lwp (ptid
) != 0);
495 /* Access an lwp we know is stopped. */
496 info
->proc_handle
.ptid
= ptid
;
498 /* If we have only looked at the first thread before libpthread was
499 initialized, we may not know its thread ID yet. Make sure we do
500 before we add another thread to the list. */
501 if (!have_threads (ptid
))
502 thread_db_find_new_threads_1 (ptid
);
504 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, ptid_get_lwp (ptid
),
507 /* Cannot find user-level thread. */
510 err
= info
->td_thr_get_info_p (&th
, &ti
);
513 warning (_("Cannot get thread info: %s"), thread_db_err_str (err
));
517 attach_thread (ptid
, &th
, &ti
);
522 verbose_dlsym (void *handle
, const char *name
)
524 void *sym
= dlsym (handle
, name
);
526 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
532 enable_thread_event (int event
, CORE_ADDR
*bp
)
536 struct thread_db_info
*info
;
538 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
540 /* Access an lwp we know is stopped. */
541 info
->proc_handle
.ptid
= inferior_ptid
;
543 /* Get the breakpoint address for thread EVENT. */
544 err
= info
->td_ta_event_addr_p (info
->thread_agent
, event
, ¬ify
);
548 /* Set up the breakpoint. */
549 gdb_assert (exec_bfd
);
550 (*bp
) = (gdbarch_convert_from_func_ptr_addr
552 /* Do proper sign extension for the target. */
553 (bfd_get_sign_extend_vma (exec_bfd
) > 0
554 ? (CORE_ADDR
) (intptr_t) notify
.u
.bptaddr
555 : (CORE_ADDR
) (uintptr_t) notify
.u
.bptaddr
),
557 create_thread_event_breakpoint (target_gdbarch (), *bp
);
562 /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
563 return 1 if this version is lower (and not equal) to
564 VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
567 inferior_has_bug (const char *ver_symbol
, int ver_major_min
, int ver_minor_min
)
569 struct bound_minimal_symbol version_msym
;
570 CORE_ADDR version_addr
;
572 int err
, got
, retval
= 0;
574 version_msym
= lookup_minimal_symbol (ver_symbol
, NULL
, NULL
);
575 if (version_msym
.minsym
== NULL
)
578 version_addr
= BMSYMBOL_VALUE_ADDRESS (version_msym
);
579 got
= target_read_string (version_addr
, &version
, 32, &err
);
580 if (err
== 0 && memchr (version
, 0, got
) == &version
[got
-1])
584 retval
= (sscanf (version
, "%d.%d", &major
, &minor
) == 2
585 && (major
< ver_major_min
586 || (major
== ver_major_min
&& minor
< ver_minor_min
)));
594 enable_thread_event_reporting (void)
596 td_thr_events_t events
;
598 struct thread_db_info
*info
;
600 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
602 /* We cannot use the thread event reporting facility if these
603 functions aren't available. */
604 if (info
->td_ta_event_addr_p
== NULL
605 || info
->td_ta_set_event_p
== NULL
606 || info
->td_ta_event_getmsg_p
== NULL
607 || info
->td_thr_event_enable_p
== NULL
)
610 /* Set the process wide mask saying which events we're interested in. */
611 td_event_emptyset (&events
);
612 td_event_addset (&events
, TD_CREATE
);
614 /* There is a bug fixed between linuxthreads 2.1.3 and 2.2 by
615 commit 2e4581e4fba917f1779cd0a010a45698586c190a
616 * manager.c (pthread_exited): Correctly report event as TD_REAP
617 instead of TD_DEATH. Fix comments.
618 where event reporting facility is broken for TD_DEATH events,
619 so don't enable it if we have glibc but a lower version. */
620 if (!inferior_has_bug ("__linuxthreads_version", 2, 2))
621 td_event_addset (&events
, TD_DEATH
);
623 err
= info
->td_ta_set_event_p (info
->thread_agent
, &events
);
626 warning (_("Unable to set global thread event mask: %s"),
627 thread_db_err_str (err
));
631 /* Delete previous thread event breakpoints, if any. */
632 remove_thread_event_breakpoints ();
633 info
->td_create_bp_addr
= 0;
634 info
->td_death_bp_addr
= 0;
636 /* Set up the thread creation event. */
637 err
= enable_thread_event (TD_CREATE
, &info
->td_create_bp_addr
);
640 warning (_("Unable to get location for thread creation breakpoint: %s"),
641 thread_db_err_str (err
));
645 /* Set up the thread death event. */
646 err
= enable_thread_event (TD_DEATH
, &info
->td_death_bp_addr
);
649 warning (_("Unable to get location for thread death breakpoint: %s"),
650 thread_db_err_str (err
));
655 /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
658 Return 1 if the caller should abort libthread_db initialization. Return 0
662 thread_db_find_new_threads_silently (ptid_t ptid
)
664 volatile struct gdb_exception except
;
666 TRY_CATCH (except
, RETURN_MASK_ERROR
)
668 thread_db_find_new_threads_2 (ptid
, 1);
671 if (except
.reason
< 0)
673 if (libthread_db_debug
)
674 exception_fprintf (gdb_stderr
, except
,
675 "Warning: thread_db_find_new_threads_silently: ");
677 /* There is a bug fixed between nptl 2.6.1 and 2.7 by
678 commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
679 where calls to td_thr_get_info fail with TD_ERR for statically linked
680 executables if td_thr_get_info is called before glibc has initialized
683 If the nptl bug is NOT present in the inferior and still thread_db
684 reports an error return 1. It means the inferior has corrupted thread
685 list and GDB should fall back only to LWPs.
687 If the nptl bug is present in the inferior return 0 to silently ignore
688 such errors, and let gdb enumerate threads again later. In such case
689 GDB cannot properly display LWPs if the inferior thread list is
690 corrupted. For core files it does not apply, no 'later enumeration'
693 if (!target_has_execution
|| !inferior_has_bug ("nptl_version", 2, 7))
695 exception_fprintf (gdb_stderr
, except
,
696 _("Warning: couldn't activate thread debugging "
697 "using libthread_db: "));
704 /* Lookup a library in which given symbol resides.
705 Note: this is looking in GDB process, not in the inferior.
706 Returns library name, or NULL. */
709 dladdr_to_soname (const void *addr
)
713 if (dladdr (addr
, &info
) != 0)
714 return info
.dli_fname
;
718 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
720 Failure could happen if libthread_db does not have symbols we expect,
721 or when it refuses to work with the current inferior (e.g. due to
722 version mismatch between libthread_db and libpthread). */
725 try_thread_db_load_1 (struct thread_db_info
*info
)
729 /* Initialize pointers to the dynamic library functions we will use.
730 Essential functions first. */
732 info
->td_init_p
= verbose_dlsym (info
->handle
, "td_init");
733 if (info
->td_init_p
== NULL
)
736 err
= info
->td_init_p ();
739 warning (_("Cannot initialize libthread_db: %s"),
740 thread_db_err_str (err
));
744 info
->td_ta_new_p
= verbose_dlsym (info
->handle
, "td_ta_new");
745 if (info
->td_ta_new_p
== NULL
)
748 /* Initialize the structure that identifies the child process. */
749 info
->proc_handle
.ptid
= inferior_ptid
;
751 /* Now attempt to open a connection to the thread library. */
752 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
755 if (libthread_db_debug
)
756 printf_unfiltered (_("td_ta_new failed: %s\n"),
757 thread_db_err_str (err
));
762 #ifdef THREAD_DB_HAS_TD_VERSION
765 /* The errors above are not unexpected and silently ignored:
766 they just mean we haven't found correct version of
770 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
775 info
->td_ta_map_id2thr_p
= verbose_dlsym (info
->handle
, "td_ta_map_id2thr");
776 if (info
->td_ta_map_id2thr_p
== NULL
)
779 info
->td_ta_map_lwp2thr_p
= verbose_dlsym (info
->handle
,
780 "td_ta_map_lwp2thr");
781 if (info
->td_ta_map_lwp2thr_p
== NULL
)
784 info
->td_ta_thr_iter_p
= verbose_dlsym (info
->handle
, "td_ta_thr_iter");
785 if (info
->td_ta_thr_iter_p
== NULL
)
788 info
->td_thr_validate_p
= verbose_dlsym (info
->handle
, "td_thr_validate");
789 if (info
->td_thr_validate_p
== NULL
)
792 info
->td_thr_get_info_p
= verbose_dlsym (info
->handle
, "td_thr_get_info");
793 if (info
->td_thr_get_info_p
== NULL
)
796 /* These are not essential. */
797 info
->td_ta_event_addr_p
= dlsym (info
->handle
, "td_ta_event_addr");
798 info
->td_ta_set_event_p
= dlsym (info
->handle
, "td_ta_set_event");
799 info
->td_ta_clear_event_p
= dlsym (info
->handle
, "td_ta_clear_event");
800 info
->td_ta_event_getmsg_p
= dlsym (info
->handle
, "td_ta_event_getmsg");
801 info
->td_thr_event_enable_p
= dlsym (info
->handle
, "td_thr_event_enable");
802 info
->td_thr_tls_get_addr_p
= dlsym (info
->handle
, "td_thr_tls_get_addr");
803 info
->td_thr_tlsbase_p
= dlsym (info
->handle
, "td_thr_tlsbase");
805 if (thread_db_find_new_threads_silently (inferior_ptid
) != 0)
807 /* Even if libthread_db initializes, if the thread list is
808 corrupted, we'd not manage to list any threads. Better reject this
809 thread_db, and fall back to at least listing LWPs. */
813 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
815 if (libthread_db_debug
|| *libthread_db_search_path
)
819 library
= dladdr_to_soname (*info
->td_ta_new_p
);
821 library
= LIBTHREAD_DB_SO
;
823 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
827 /* The thread library was detected. Activate the thread_db target
828 if this is the first process using it. */
829 if (thread_db_list
->next
== NULL
)
830 push_target (&thread_db_ops
);
832 /* Enable event reporting, but not when debugging a core file. */
833 if (target_has_execution
)
834 enable_thread_event_reporting ();
839 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
840 relative, or just LIBTHREAD_DB. */
843 try_thread_db_load (const char *library
, int check_auto_load_safe
)
846 struct thread_db_info
*info
;
848 if (libthread_db_debug
)
849 printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
852 if (check_auto_load_safe
)
854 if (access (library
, R_OK
) != 0)
856 /* Do not print warnings by file_is_auto_load_safe if the library does
857 not exist at this place. */
858 if (libthread_db_debug
)
859 printf_unfiltered (_("open failed: %s.\n"), safe_strerror (errno
));
863 if (!file_is_auto_load_safe (library
, _("auto-load: Loading libthread-db "
864 "library \"%s\" from explicit "
870 handle
= dlopen (library
, RTLD_NOW
);
873 if (libthread_db_debug
)
874 printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
878 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
882 td_init
= dlsym (handle
, "td_init");
885 const char *const libpath
= dladdr_to_soname (td_init
);
888 printf_unfiltered (_("Host %s resolved to: %s.\n"),
893 info
= add_thread_db_info (handle
);
895 /* Do not save system library name, that one is always trusted. */
896 if (strchr (library
, '/') != NULL
)
897 info
->filename
= gdb_realpath (library
);
899 if (try_thread_db_load_1 (info
))
902 /* This library "refused" to work on current inferior. */
903 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
907 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
908 Try loading libthread_db in directory(OBJ)/SUBDIR.
909 SUBDIR may be NULL. It may also be something like "../lib64".
910 The result is true for success. */
913 try_thread_db_load_from_pdir_1 (struct objfile
*obj
, const char *subdir
)
915 struct cleanup
*cleanup
;
918 const char *obj_name
= objfile_name (obj
);
920 if (obj_name
[0] != '/')
922 warning (_("Expected absolute pathname for libpthread in the"
923 " inferior, but got %s."), obj_name
);
927 path
= xmalloc (strlen (obj_name
) + (subdir
? strlen (subdir
) + 1 : 0)
928 + 1 + strlen (LIBTHREAD_DB_SO
) + 1);
929 cleanup
= make_cleanup (xfree
, path
);
931 strcpy (path
, obj_name
);
932 cp
= strrchr (path
, '/');
933 /* This should at minimum hit the first character. */
934 gdb_assert (cp
!= NULL
);
941 strcat (cp
, LIBTHREAD_DB_SO
);
943 result
= try_thread_db_load (path
, 1);
945 do_cleanups (cleanup
);
949 /* Handle $pdir in libthread-db-search-path.
950 Look for libthread_db in directory(libpthread)/SUBDIR.
951 SUBDIR may be NULL. It may also be something like "../lib64".
952 The result is true for success. */
955 try_thread_db_load_from_pdir (const char *subdir
)
959 if (!auto_load_thread_db
)
963 if (libpthread_name_p (objfile_name (obj
)))
965 if (try_thread_db_load_from_pdir_1 (obj
, subdir
))
968 /* We may have found the separate-debug-info version of
969 libpthread, and it may live in a directory without a matching
971 if (obj
->separate_debug_objfile_backlink
!= NULL
)
972 return try_thread_db_load_from_pdir_1 (obj
->separate_debug_objfile_backlink
,
981 /* Handle $sdir in libthread-db-search-path.
982 Look for libthread_db in the system dirs, or wherever a plain
983 dlopen(file_without_path) will look.
984 The result is true for success. */
987 try_thread_db_load_from_sdir (void)
989 return try_thread_db_load (LIBTHREAD_DB_SO
, 0);
992 /* Try to load libthread_db from directory DIR of length DIR_LEN.
993 The result is true for success. */
996 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
998 struct cleanup
*cleanup
;
1002 if (!auto_load_thread_db
)
1005 path
= xmalloc (dir_len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1);
1006 cleanup
= make_cleanup (xfree
, path
);
1008 memcpy (path
, dir
, dir_len
);
1009 path
[dir_len
] = '/';
1010 strcpy (path
+ dir_len
+ 1, LIBTHREAD_DB_SO
);
1012 result
= try_thread_db_load (path
, 1);
1014 do_cleanups (cleanup
);
1018 /* Search libthread_db_search_path for libthread_db which "agrees"
1019 to work on current inferior.
1020 The result is true for success. */
1023 thread_db_load_search (void)
1025 VEC (char_ptr
) *dir_vec
;
1026 struct cleanup
*cleanups
;
1030 dir_vec
= dirnames_to_char_ptr_vec (libthread_db_search_path
);
1031 cleanups
= make_cleanup_free_char_ptr_vec (dir_vec
);
1033 for (i
= 0; VEC_iterate (char_ptr
, dir_vec
, i
, this_dir
); ++i
)
1035 const int pdir_len
= sizeof ("$pdir") - 1;
1036 size_t this_dir_len
;
1038 this_dir_len
= strlen (this_dir
);
1040 if (strncmp (this_dir
, "$pdir", pdir_len
) == 0
1041 && (this_dir
[pdir_len
] == '\0'
1042 || this_dir
[pdir_len
] == '/'))
1044 char *subdir
= NULL
;
1045 struct cleanup
*free_subdir_cleanup
1046 = make_cleanup (null_cleanup
, NULL
);
1048 if (this_dir
[pdir_len
] == '/')
1050 subdir
= xmalloc (strlen (this_dir
));
1051 make_cleanup (xfree
, subdir
);
1052 strcpy (subdir
, this_dir
+ pdir_len
+ 1);
1054 rc
= try_thread_db_load_from_pdir (subdir
);
1055 do_cleanups (free_subdir_cleanup
);
1059 else if (strcmp (this_dir
, "$sdir") == 0)
1061 if (try_thread_db_load_from_sdir ())
1069 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
1077 do_cleanups (cleanups
);
1078 if (libthread_db_debug
)
1079 printf_unfiltered (_("thread_db_load_search returning %d\n"), rc
);
1083 /* Return non-zero if the inferior has a libpthread. */
1086 has_libpthread (void)
1088 struct objfile
*obj
;
1091 if (libpthread_name_p (objfile_name (obj
)))
1097 /* Attempt to load and initialize libthread_db.
1098 Return 1 on success. */
1101 thread_db_load (void)
1103 struct thread_db_info
*info
;
1105 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1110 /* Don't attempt to use thread_db on executables not running
1112 if (!target_has_registers
)
1115 /* Don't attempt to use thread_db for remote targets. */
1116 if (!(target_can_run (¤t_target
) || core_bfd
))
1119 if (thread_db_load_search ())
1122 /* We couldn't find a libthread_db.
1123 If the inferior has a libpthread warn the user. */
1124 if (has_libpthread ())
1126 warning (_("Unable to find libthread_db matching inferior's thread"
1127 " library, thread debugging will not be available."));
1131 /* Either this executable isn't using libpthread at all, or it is
1132 statically linked. Since we can't easily distinguish these two cases,
1133 no warning is issued. */
1138 disable_thread_event_reporting (struct thread_db_info
*info
)
1140 if (info
->td_ta_clear_event_p
!= NULL
)
1142 td_thr_events_t events
;
1144 /* Set the process wide mask saying we aren't interested in any
1146 td_event_fillset (&events
);
1147 info
->td_ta_clear_event_p (info
->thread_agent
, &events
);
1150 info
->td_create_bp_addr
= 0;
1151 info
->td_death_bp_addr
= 0;
1155 check_thread_signals (void)
1157 if (!thread_signals
)
1162 lin_thread_get_thread_signals (&mask
);
1163 sigemptyset (&thread_stop_set
);
1164 sigemptyset (&thread_print_set
);
1166 for (i
= 1; i
< NSIG
; i
++)
1168 if (sigismember (&mask
, i
))
1170 if (signal_stop_update (gdb_signal_from_host (i
), 0))
1171 sigaddset (&thread_stop_set
, i
);
1172 if (signal_print_update (gdb_signal_from_host (i
), 0))
1173 sigaddset (&thread_print_set
, i
);
1180 /* Check whether thread_db is usable. This function is called when
1181 an inferior is created (or otherwise acquired, e.g. attached to)
1182 and when new shared libraries are loaded into a running process. */
1185 check_for_thread_db (void)
1187 /* Do nothing if we couldn't load libthread_db.so.1. */
1188 if (!thread_db_load ())
1192 /* This function is called via the new_objfile observer. */
1195 thread_db_new_objfile (struct objfile
*objfile
)
1197 /* This observer must always be called with inferior_ptid set
1201 /* libpthread with separate debug info has its debug info file already
1202 loaded (and notified without successful thread_db initialization)
1203 the time observer_notify_new_objfile is called for the library itself.
1204 Static executables have their separate debug info loaded already
1205 before the inferior has started. */
1206 && objfile
->separate_debug_objfile_backlink
== NULL
1207 /* Only check for thread_db if we loaded libpthread,
1208 or if this is the main symbol file.
1209 We need to check OBJF_MAINLINE to handle the case of debugging
1210 a statically linked executable AND the symbol file is specified AFTER
1211 the exec file is loaded (e.g., gdb -c core ; file foo).
1212 For dynamically linked executables, libpthread can be near the end
1213 of the list of shared libraries to load, and in an app of several
1214 thousand shared libraries, this can otherwise be painful. */
1215 && ((objfile
->flags
& OBJF_MAINLINE
) != 0
1216 || libpthread_name_p (objfile_name (objfile
))))
1217 check_for_thread_db ();
1220 /* This function is called via the inferior_created observer.
1221 This handles the case of debugging statically linked executables. */
1224 thread_db_inferior_created (struct target_ops
*target
, int from_tty
)
1226 check_for_thread_db ();
1229 /* Attach to a new thread. This function is called when we receive a
1230 TD_CREATE event or when we iterate over all threads and find one
1231 that wasn't already in our list. Returns true on success. */
1234 attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
1235 const td_thrinfo_t
*ti_p
)
1237 struct private_thread_info
*private;
1238 struct thread_info
*tp
;
1240 struct thread_db_info
*info
;
1242 /* If we're being called after a TD_CREATE event, we may already
1243 know about this thread. There are two ways this can happen. We
1244 may have iterated over all threads between the thread creation
1245 and the TD_CREATE event, for instance when the user has issued
1246 the `info threads' command before the SIGTRAP for hitting the
1247 thread creation breakpoint was reported. Alternatively, the
1248 thread may have exited and a new one been created with the same
1249 thread ID. In the first case we don't need to do anything; in
1250 the second case we should discard information about the dead
1251 thread and attach to the new one. */
1252 tp
= find_thread_ptid (ptid
);
1255 /* If tp->private is NULL, then GDB is already attached to this
1256 thread, but we do not know anything about it. We can learn
1257 about it here. This can only happen if we have some other
1258 way besides libthread_db to notice new threads (i.e.
1259 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
1260 exit, so this can not be a stale thread recreated with the
1262 if (tp
->private != NULL
)
1264 if (!tp
->private->dying
)
1267 delete_thread (ptid
);
1272 if (target_has_execution
)
1273 check_thread_signals ();
1275 /* Under GNU/Linux, we have to attach to each and every thread. */
1276 if (target_has_execution
1281 res
= lin_lwp_attach_lwp (ptid_build (ptid_get_pid (ptid
),
1285 /* Error, stop iterating. */
1290 /* Pretend this thread doesn't exist yet, and keep
1295 /* Otherwise, we sucessfully attached to the thread. */
1298 /* Construct the thread's private data. */
1299 private = xmalloc (sizeof (struct private_thread_info
));
1300 memset (private, 0, sizeof (struct private_thread_info
));
1302 /* A thread ID of zero may mean the thread library has not initialized
1303 yet. But we shouldn't even get here if that's the case. FIXME:
1304 if we change GDB to always have at least one thread in the thread
1305 list this will have to go somewhere else; maybe private == NULL
1306 until the thread_db target claims it. */
1307 gdb_assert (ti_p
->ti_tid
!= 0);
1308 private->th
= *th_p
;
1309 private->tid
= ti_p
->ti_tid
;
1310 if (ti_p
->ti_state
== TD_THR_UNKNOWN
|| ti_p
->ti_state
== TD_THR_ZOMBIE
)
1313 /* Add the thread to GDB's thread list. */
1315 add_thread_with_info (ptid
, private);
1317 tp
->private = private;
1319 info
= get_thread_db_info (ptid_get_pid (ptid
));
1321 /* Enable thread event reporting for this thread, except when
1322 debugging a core file. */
1323 if (target_has_execution
)
1325 err
= info
->td_thr_event_enable_p (th_p
, 1);
1327 error (_("Cannot enable thread event reporting for %s: %s"),
1328 target_pid_to_str (ptid
), thread_db_err_str (err
));
1335 detach_thread (ptid_t ptid
)
1337 struct thread_info
*thread_info
;
1339 /* Don't delete the thread now, because it still reports as active
1340 until it has executed a few instructions after the event
1341 breakpoint - if we deleted it now, "info threads" would cause us
1342 to re-attach to it. Just mark it as having had a TD_DEATH
1343 event. This means that we won't delete it from our thread list
1344 until we notice that it's dead (via prune_threads), or until
1345 something re-uses its thread ID. We'll report the thread exit
1346 when the underlying LWP dies. */
1347 thread_info
= find_thread_ptid (ptid
);
1348 gdb_assert (thread_info
!= NULL
&& thread_info
->private != NULL
);
1349 thread_info
->private->dying
= 1;
1353 thread_db_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1355 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1356 struct thread_db_info
*info
;
1358 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1362 if (target_has_execution
)
1364 disable_thread_event_reporting (info
);
1366 /* Delete the old thread event breakpoints. Note that
1367 unlike when mourning, we can remove them here because
1368 there's still a live inferior to poke at. In any case,
1369 GDB will not try to insert anything in the inferior when
1370 removing a breakpoint. */
1371 remove_thread_event_breakpoints ();
1374 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
1377 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
1379 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1381 /* If there are no more processes using libpthread, detach the
1382 thread_db target ops. */
1383 if (!thread_db_list
)
1384 unpush_target (&thread_db_ops
);
1387 /* Check if PID is currently stopped at the location of a thread event
1388 breakpoint location. If it is, read the event message and act upon
1392 check_event (ptid_t ptid
)
1394 struct regcache
*regcache
= get_thread_regcache (ptid
);
1395 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1401 struct thread_db_info
*info
;
1403 info
= get_thread_db_info (ptid_get_pid (ptid
));
1405 /* Bail out early if we're not at a thread event breakpoint. */
1406 stop_pc
= regcache_read_pc (regcache
)
1407 - target_decr_pc_after_break (gdbarch
);
1408 if (stop_pc
!= info
->td_create_bp_addr
1409 && stop_pc
!= info
->td_death_bp_addr
)
1412 /* Access an lwp we know is stopped. */
1413 info
->proc_handle
.ptid
= ptid
;
1415 /* If we have only looked at the first thread before libpthread was
1416 initialized, we may not know its thread ID yet. Make sure we do
1417 before we add another thread to the list. */
1418 if (!have_threads (ptid
))
1419 thread_db_find_new_threads_1 (ptid
);
1421 /* If we are at a create breakpoint, we do not know what new lwp
1422 was created and cannot specifically locate the event message for it.
1423 We have to call td_ta_event_getmsg() to get
1424 the latest message. Since we have no way of correlating whether
1425 the event message we get back corresponds to our breakpoint, we must
1426 loop and read all event messages, processing them appropriately.
1427 This guarantees we will process the correct message before continuing
1428 from the breakpoint.
1430 Currently, death events are not enabled. If they are enabled,
1431 the death event can use the td_thr_event_getmsg() interface to
1432 get the message specifically for that lwp and avoid looping
1439 err
= info
->td_ta_event_getmsg_p (info
->thread_agent
, &msg
);
1442 if (err
== TD_NOMSG
)
1445 error (_("Cannot get thread event message: %s"),
1446 thread_db_err_str (err
));
1449 err
= info
->td_thr_get_info_p (msg
.th_p
, &ti
);
1451 error (_("Cannot get thread info: %s"), thread_db_err_str (err
));
1453 ptid
= ptid_build (ptid_get_pid (ptid
), ti
.ti_lid
, 0);
1458 /* Call attach_thread whether or not we already know about a
1459 thread with this thread ID. */
1460 attach_thread (ptid
, msg
.th_p
, &ti
);
1466 if (!in_thread_list (ptid
))
1467 error (_("Spurious thread death event."));
1469 detach_thread (ptid
);
1474 error (_("Spurious thread event."));
1481 thread_db_wait (struct target_ops
*ops
,
1482 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1485 struct thread_db_info
*info
;
1486 struct target_ops
*beneath
= find_target_beneath (ops
);
1488 ptid
= beneath
->to_wait (beneath
, ptid
, ourstatus
, options
);
1490 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
1493 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
1494 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
1497 info
= get_thread_db_info (ptid_get_pid (ptid
));
1499 /* If this process isn't using thread_db, we're done. */
1503 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1505 /* New image, it may or may not end up using thread_db. Assume
1506 not unless we find otherwise. */
1507 delete_thread_db_info (ptid_get_pid (ptid
));
1508 if (!thread_db_list
)
1509 unpush_target (&thread_db_ops
);
1511 /* Thread event breakpoints are deleted by
1512 update_breakpoints_after_exec. */
1517 /* If we do not know about the main thread yet, this would be a good time to
1519 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
&& !have_threads (ptid
))
1520 thread_db_find_new_threads_1 (ptid
);
1522 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
1523 && ourstatus
->value
.sig
== GDB_SIGNAL_TRAP
)
1524 /* Check for a thread event. */
1527 if (have_threads (ptid
))
1529 /* Fill in the thread's user-level thread id. */
1530 thread_from_lwp (ptid
);
1537 thread_db_mourn_inferior (struct target_ops
*ops
)
1539 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1541 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
1543 target_beneath
->to_mourn_inferior (target_beneath
);
1545 /* Delete the old thread event breakpoints. Do this after mourning
1546 the inferior, so that we don't try to uninsert them. */
1547 remove_thread_event_breakpoints ();
1549 /* Detach thread_db target ops. */
1550 if (!thread_db_list
)
1551 unpush_target (ops
);
1554 struct callback_data
1556 struct thread_db_info
*info
;
1561 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1566 struct thread_info
*tp
;
1567 struct callback_data
*cb_data
= data
;
1568 struct thread_db_info
*info
= cb_data
->info
;
1570 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1572 error (_("find_new_threads_callback: cannot get thread info: %s"),
1573 thread_db_err_str (err
));
1577 /* A thread ID of zero means that this is the main thread, but
1578 glibc has not yet initialized thread-local storage and the
1579 pthread library. We do not know what the thread's TID will
1580 be yet. Just enable event reporting and otherwise ignore
1583 /* In that case, we're not stopped in a fork syscall and don't
1584 need this glibc bug workaround. */
1585 info
->need_stale_parent_threads_check
= 0;
1587 if (target_has_execution
)
1589 err
= info
->td_thr_event_enable_p (th_p
, 1);
1591 error (_("Cannot enable thread event reporting for LWP %d: %s"),
1592 (int) ti
.ti_lid
, thread_db_err_str (err
));
1598 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1599 bit expensive, as it needs to open /proc/pid/status, so try to
1600 avoid doing the work if we know we don't have to. */
1601 if (info
->need_stale_parent_threads_check
)
1603 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1605 if (tgid
!= -1 && tgid
!= info
->pid
)
1609 ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
1610 tp
= find_thread_ptid (ptid
);
1611 if (tp
== NULL
|| tp
->private == NULL
)
1613 if (attach_thread (ptid
, th_p
, &ti
))
1614 cb_data
->new_threads
+= 1;
1616 /* Problem attaching this thread; perhaps it exited before we
1618 This could mean that the thread list inside glibc itself is in
1619 inconsistent state, and libthread_db could go on looping forever
1620 (observed with glibc-2.3.6). To prevent that, terminate
1621 iteration: thread_db_find_new_threads_2 will retry. */
1628 /* Helper for thread_db_find_new_threads_2.
1629 Returns number of new threads found. */
1632 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1635 volatile struct gdb_exception except
;
1636 struct callback_data data
;
1637 td_err_e err
= TD_ERR
;
1640 data
.new_threads
= 0;
1642 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1644 /* Iterate over all user-space threads to discover new threads. */
1645 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1646 find_new_threads_callback
,
1649 TD_THR_LOWEST_PRIORITY
,
1651 TD_THR_ANY_USER_FLAGS
);
1654 if (libthread_db_debug
)
1656 if (except
.reason
< 0)
1657 exception_fprintf (gdb_stderr
, except
,
1658 "Warning: find_new_threads_once: ");
1660 printf_filtered (_("Found %d new threads in iteration %d.\n"),
1661 data
.new_threads
, iteration
);
1667 return data
.new_threads
;
1670 /* Search for new threads, accessing memory through stopped thread
1671 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1672 searches in a row do not discover any new threads. */
1675 thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
)
1677 td_err_e err
= TD_OK
;
1678 struct thread_db_info
*info
;
1681 info
= get_thread_db_info (ptid_get_pid (ptid
));
1683 /* Access an lwp we know is stopped. */
1684 info
->proc_handle
.ptid
= ptid
;
1688 /* Require 4 successive iterations which do not find any new threads.
1689 The 4 is a heuristic: there is an inherent race here, and I have
1690 seen that 2 iterations in a row are not always sufficient to
1691 "capture" all threads. */
1692 for (i
= 0, loop
= 0; loop
< 4 && err
== TD_OK
; ++i
, ++loop
)
1693 if (find_new_threads_once (info
, i
, &err
) != 0)
1695 /* Found some new threads. Restart the loop from beginning. */
1700 find_new_threads_once (info
, 0, &err
);
1703 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1707 thread_db_find_new_threads_1 (ptid_t ptid
)
1709 thread_db_find_new_threads_2 (ptid
, 0);
1713 update_thread_core (struct lwp_info
*info
, void *closure
)
1715 info
->core
= linux_common_core_of_thread (info
->ptid
);
1720 thread_db_update_thread_list (struct target_ops
*ops
)
1722 struct thread_db_info
*info
;
1723 struct inferior
*inf
;
1729 struct thread_info
*thread
;
1734 info
= get_thread_db_info (inf
->pid
);
1738 thread
= any_live_thread_of_process (inf
->pid
);
1739 if (thread
== NULL
|| thread
->executing
)
1742 thread_db_find_new_threads_1 (thread
->ptid
);
1745 if (target_has_execution
)
1746 iterate_over_lwps (minus_one_ptid
/* iterate over all */,
1747 update_thread_core
, NULL
);
1751 thread_db_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
1753 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1754 struct target_ops
*beneath
;
1756 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1758 static char buf
[64];
1761 tid
= thread_info
->private->tid
;
1762 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1763 tid
, ptid_get_lwp (ptid
));
1768 beneath
= find_target_beneath (ops
);
1769 return beneath
->to_pid_to_str (beneath
, ptid
);
1772 /* Return a string describing the state of the thread specified by
1776 thread_db_extra_thread_info (struct target_ops
*self
,
1777 struct thread_info
*info
)
1779 if (info
->private == NULL
)
1782 if (info
->private->dying
)
1788 /* Get the address of the thread local variable in load module LM which
1789 is stored at OFFSET within the thread local storage for thread PTID. */
1792 thread_db_get_thread_local_address (struct target_ops
*ops
,
1797 struct thread_info
*thread_info
;
1798 struct target_ops
*beneath
;
1800 /* If we have not discovered any threads yet, check now. */
1801 if (!have_threads (ptid
))
1802 thread_db_find_new_threads_1 (ptid
);
1804 /* Find the matching thread. */
1805 thread_info
= find_thread_ptid (ptid
);
1807 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1811 struct thread_db_info
*info
;
1813 info
= get_thread_db_info (ptid_get_pid (ptid
));
1815 /* Finally, get the address of the variable. */
1818 /* glibc doesn't provide the needed interface. */
1819 if (!info
->td_thr_tls_get_addr_p
)
1820 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1821 _("No TLS library support"));
1823 /* Note the cast through uintptr_t: this interface only works if
1824 a target address fits in a psaddr_t, which is a host pointer.
1825 So a 32-bit debugger can not access 64-bit TLS through this. */
1826 err
= info
->td_thr_tls_get_addr_p (&thread_info
->private->th
,
1827 (psaddr_t
)(uintptr_t) lm
,
1832 /* If glibc doesn't provide the needed interface throw an error
1833 that LM is zero - normally cases it should not be. */
1834 if (!info
->td_thr_tlsbase_p
)
1835 throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR
,
1836 _("TLS load module not found"));
1838 /* This code path handles the case of -static -pthread executables:
1839 https://sourceware.org/ml/libc-help/2014-03/msg00024.html
1840 For older GNU libc r_debug.r_map is NULL. For GNU libc after
1841 PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
1842 The constant number 1 depends on GNU __libc_setup_tls
1843 initialization of l_tls_modid to 1. */
1844 err
= info
->td_thr_tlsbase_p (&thread_info
->private->th
,
1846 address
= (char *) address
+ offset
;
1849 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1850 /* The memory hasn't been allocated, yet. */
1851 if (err
== TD_NOTALLOC
)
1852 /* Now, if libthread_db provided the initialization image's
1853 address, we *could* try to build a non-lvalue value from
1854 the initialization image. */
1855 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1856 _("TLS not allocated yet"));
1859 /* Something else went wrong. */
1861 throw_error (TLS_GENERIC_ERROR
,
1862 (("%s")), thread_db_err_str (err
));
1864 /* Cast assuming host == target. Joy. */
1865 /* Do proper sign extension for the target. */
1866 gdb_assert (exec_bfd
);
1867 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1868 ? (CORE_ADDR
) (intptr_t) address
1869 : (CORE_ADDR
) (uintptr_t) address
);
1872 beneath
= find_target_beneath (ops
);
1873 return beneath
->to_get_thread_local_address (beneath
, ptid
, lm
, offset
);
1876 /* Callback routine used to find a thread based on the TID part of
1880 thread_db_find_thread_from_tid (struct thread_info
*thread
, void *data
)
1882 long *tid
= (long *) data
;
1884 if (thread
->private->tid
== *tid
)
1890 /* Implement the to_get_ada_task_ptid target method for this target. */
1893 thread_db_get_ada_task_ptid (struct target_ops
*self
, long lwp
, long thread
)
1895 struct thread_info
*thread_info
;
1897 thread_db_find_new_threads_1 (inferior_ptid
);
1898 thread_info
= iterate_over_threads (thread_db_find_thread_from_tid
, &thread
);
1900 gdb_assert (thread_info
!= NULL
);
1902 return (thread_info
->ptid
);
1906 thread_db_resume (struct target_ops
*ops
,
1907 ptid_t ptid
, int step
, enum gdb_signal signo
)
1909 struct target_ops
*beneath
= find_target_beneath (ops
);
1910 struct thread_db_info
*info
;
1912 if (ptid_equal (ptid
, minus_one_ptid
))
1913 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1915 info
= get_thread_db_info (ptid_get_pid (ptid
));
1917 /* This workaround is only needed for child fork lwps stopped in a
1918 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1919 workaround can be disabled. */
1921 info
->need_stale_parent_threads_check
= 0;
1923 beneath
->to_resume (beneath
, ptid
, step
, signo
);
1926 /* qsort helper function for info_auto_load_libthread_db, sort the
1927 thread_db_info pointers primarily by their FILENAME and secondarily by their
1928 PID, both in ascending order. */
1931 info_auto_load_libthread_db_compare (const void *ap
, const void *bp
)
1933 struct thread_db_info
*a
= *(struct thread_db_info
**) ap
;
1934 struct thread_db_info
*b
= *(struct thread_db_info
**) bp
;
1937 retval
= strcmp (a
->filename
, b
->filename
);
1941 return (a
->pid
> b
->pid
) - (a
->pid
- b
->pid
);
1944 /* Implement 'info auto-load libthread-db'. */
1947 info_auto_load_libthread_db (char *args
, int from_tty
)
1949 struct ui_out
*uiout
= current_uiout
;
1950 const char *cs
= args
? args
: "";
1951 struct thread_db_info
*info
, **array
;
1952 unsigned info_count
, unique_filenames
;
1953 size_t max_filename_len
, max_pids_len
, pids_len
;
1954 struct cleanup
*back_to
;
1958 cs
= skip_spaces_const (cs
);
1960 error (_("'info auto-load libthread-db' does not accept any parameters"));
1963 for (info
= thread_db_list
; info
; info
= info
->next
)
1964 if (info
->filename
!= NULL
)
1967 array
= xmalloc (sizeof (*array
) * info_count
);
1968 back_to
= make_cleanup (xfree
, array
);
1971 for (info
= thread_db_list
; info
; info
= info
->next
)
1972 if (info
->filename
!= NULL
)
1973 array
[info_count
++] = info
;
1975 /* Sort ARRAY by filenames and PIDs. */
1977 qsort (array
, info_count
, sizeof (*array
),
1978 info_auto_load_libthread_db_compare
);
1980 /* Calculate the number of unique filenames (rows) and the maximum string
1981 length of PIDs list for the unique filenames (columns). */
1983 unique_filenames
= 0;
1984 max_filename_len
= 0;
1987 for (i
= 0; i
< info_count
; i
++)
1989 int pid
= array
[i
]->pid
;
1990 size_t this_pid_len
;
1992 for (this_pid_len
= 0; pid
!= 0; pid
/= 10)
1995 if (i
== 0 || strcmp (array
[i
- 1]->filename
, array
[i
]->filename
) != 0)
1998 max_filename_len
= max (max_filename_len
,
1999 strlen (array
[i
]->filename
));
2003 pids_len
-= strlen (", ");
2004 max_pids_len
= max (max_pids_len
, pids_len
);
2008 pids_len
+= this_pid_len
+ strlen (", ");
2012 pids_len
-= strlen (", ");
2013 max_pids_len
= max (max_pids_len
, pids_len
);
2016 /* Table header shifted right by preceding "libthread-db: " would not match
2018 if (info_count
> 0 && args
== auto_load_info_scripts_pattern_nl
)
2019 ui_out_text (uiout
, "\n");
2021 make_cleanup_ui_out_table_begin_end (uiout
, 2, unique_filenames
,
2022 "LinuxThreadDbTable");
2024 ui_out_table_header (uiout
, max_filename_len
, ui_left
, "filename",
2026 ui_out_table_header (uiout
, pids_len
, ui_left
, "PIDs", "Pids");
2027 ui_out_table_body (uiout
);
2029 pids
= xmalloc (max_pids_len
+ 1);
2030 make_cleanup (xfree
, pids
);
2032 /* Note I is incremented inside the cycle, not at its end. */
2033 for (i
= 0; i
< info_count
;)
2035 struct cleanup
*chain
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
2039 ui_out_field_string (uiout
, "filename", info
->filename
);
2042 while (i
< info_count
&& strcmp (info
->filename
, array
[i
]->filename
) == 0)
2044 if (pids_end
!= pids
)
2049 pids_end
+= xsnprintf (pids_end
, &pids
[max_pids_len
+ 1] - pids_end
,
2050 "%u", array
[i
]->pid
);
2051 gdb_assert (pids_end
< &pids
[max_pids_len
+ 1]);
2057 ui_out_field_string (uiout
, "pids", pids
);
2059 ui_out_text (uiout
, "\n");
2060 do_cleanups (chain
);
2063 do_cleanups (back_to
);
2065 if (info_count
== 0)
2066 ui_out_message (uiout
, 0, _("No auto-loaded libthread-db.\n"));
2070 init_thread_db_ops (void)
2072 thread_db_ops
.to_shortname
= "multi-thread";
2073 thread_db_ops
.to_longname
= "multi-threaded child process.";
2074 thread_db_ops
.to_doc
= "Threads and pthreads support.";
2075 thread_db_ops
.to_detach
= thread_db_detach
;
2076 thread_db_ops
.to_wait
= thread_db_wait
;
2077 thread_db_ops
.to_resume
= thread_db_resume
;
2078 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
2079 thread_db_ops
.to_update_thread_list
= thread_db_update_thread_list
;
2080 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
2081 thread_db_ops
.to_stratum
= thread_stratum
;
2082 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
2083 thread_db_ops
.to_get_thread_local_address
2084 = thread_db_get_thread_local_address
;
2085 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
2086 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
2087 thread_db_ops
.to_magic
= OPS_MAGIC
;
2089 complete_target_initialization (&thread_db_ops
);
2092 /* Provide a prototype to silence -Wmissing-prototypes. */
2093 extern initialize_file_ftype _initialize_thread_db
;
2096 _initialize_thread_db (void)
2098 init_thread_db_ops ();
2100 /* Defer loading of libthread_db.so until inferior is running.
2101 This allows gdb to load correct libthread_db for a given
2102 executable -- there could be mutiple versions of glibc,
2103 compiled with LinuxThreads or NPTL, and until there is
2104 a running inferior, we can't tell which libthread_db is
2105 the correct one to load. */
2107 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
2109 add_setshow_optional_filename_cmd ("libthread-db-search-path",
2111 &libthread_db_search_path
, _("\
2112 Set search path for libthread_db."), _("\
2113 Show the current search path or libthread_db."), _("\
2114 This path is used to search for libthread_db to be loaded into \
2116 Its value is a colon (':') separate list of directories to search.\n\
2117 Setting the search path to an empty list resets it to its default value."),
2118 set_libthread_db_search_path
,
2120 &setlist
, &showlist
);
2122 add_setshow_zuinteger_cmd ("libthread-db", class_maintenance
,
2123 &libthread_db_debug
, _("\
2124 Set libthread-db debugging."), _("\
2125 Show libthread-db debugging."), _("\
2126 When non-zero, libthread-db debugging is enabled."),
2128 show_libthread_db_debug
,
2129 &setdebuglist
, &showdebuglist
);
2131 add_setshow_boolean_cmd ("libthread-db", class_support
,
2132 &auto_load_thread_db
, _("\
2133 Enable or disable auto-loading of inferior specific libthread_db."), _("\
2134 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
2135 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
2136 locations to load libthread_db compatible with the inferior.\n\
2137 Standard system libthread_db still gets loaded even with this option off.\n\
2138 This options has security implications for untrusted inferiors."),
2139 NULL
, show_auto_load_thread_db
,
2140 auto_load_set_cmdlist_get (),
2141 auto_load_show_cmdlist_get ());
2143 add_cmd ("libthread-db", class_info
, info_auto_load_libthread_db
,
2144 _("Print the list of loaded inferior specific libthread_db.\n\
2145 Usage: info auto-load libthread-db"),
2146 auto_load_info_cmdlist_get ());
2148 /* Add ourselves to objfile event chain. */
2149 observer_attach_new_objfile (thread_db_new_objfile
);
2151 /* Add ourselves to inferior_created event chain.
2152 This is needed to handle debugging statically linked programs where
2153 the new_objfile observer won't get called for libpthread. */
2154 observer_attach_inferior_created (thread_db_inferior_created
);