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_assert.h"
24 #include "gdb_proc_service.h"
25 #include "gdb_thread_db.h"
29 #include "exceptions.h"
31 #include "gdbthread.h"
38 #include "solib-svr4.h"
41 #include "linux-nat.h"
42 #include "linux-procfs.h"
43 #include "linux-osdata.h"
44 #include "auto-load.h"
45 #include "cli/cli-utils.h"
50 /* GNU/Linux libthread_db support.
52 libthread_db is a library, provided along with libpthread.so, which
53 exposes the internals of the thread library to a debugger. It
54 allows GDB to find existing threads, new threads as they are
55 created, thread IDs (usually, the result of pthread_self), and
56 thread-local variables.
58 The libthread_db interface originates on Solaris, where it is
59 both more powerful and more complicated. This implementation
60 only works for LinuxThreads and NPTL, the two glibc threading
61 libraries. It assumes that each thread is permanently assigned
62 to a single light-weight process (LWP).
64 libthread_db-specific information is stored in the "private" field
65 of struct thread_info. When the field is NULL we do not yet have
66 information about the new thread; this could be temporary (created,
67 but the thread library's data structures do not reflect it yet)
68 or permanent (created using clone instead of pthread_create).
70 Process IDs managed by linux-thread-db.c match those used by
71 linux-nat.c: a common PID for all processes, an LWP ID for each
72 thread, and no TID. We save the TID in private. Keeping it out
73 of the ptid_t prevents thread IDs changing when libpthread is
74 loaded or unloaded. */
76 static char *libthread_db_search_path
;
78 /* Set to non-zero if thread_db auto-loading is enabled
79 by the "set auto-load libthread-db" command. */
80 static int auto_load_thread_db
= 1;
82 /* "show" command for the auto_load_thread_db configuration variable. */
85 show_auto_load_thread_db (struct ui_file
*file
, int from_tty
,
86 struct cmd_list_element
*c
, const char *value
)
88 fprintf_filtered (file
, _("Auto-loading of inferior specific libthread_db "
94 set_libthread_db_search_path (char *ignored
, int from_tty
,
95 struct cmd_list_element
*c
)
97 if (*libthread_db_search_path
== '\0')
99 xfree (libthread_db_search_path
);
100 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
104 /* If non-zero, print details of libthread_db processing. */
106 static unsigned int libthread_db_debug
;
109 show_libthread_db_debug (struct ui_file
*file
, int from_tty
,
110 struct cmd_list_element
*c
, const char *value
)
112 fprintf_filtered (file
, _("libthread-db debugging is %s.\n"), value
);
115 /* If we're running on GNU/Linux, we must explicitly attach to any new
118 /* This module's target vector. */
119 static struct target_ops thread_db_ops
;
121 /* Non-zero if we have determined the signals used by the threads
123 static int thread_signals
;
124 static sigset_t thread_stop_set
;
125 static sigset_t thread_print_set
;
127 struct thread_db_info
129 struct thread_db_info
*next
;
131 /* Process id this object refers to. */
134 /* Handle from dlopen for libthread_db.so. */
137 /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
138 HANDLE. It may be NULL for system library. */
141 /* Structure that identifies the child process for the
142 <proc_service.h> interface. */
143 struct ps_prochandle proc_handle
;
145 /* Connection to the libthread_db library. */
146 td_thragent_t
*thread_agent
;
148 /* True if we need to apply the workaround for glibc/BZ5983. When
149 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
150 list, nptl_db returns the parent's threads in addition to the new
151 (single) child thread. If this flag is set, we do extra work to
152 be able to ignore such stale entries. */
153 int need_stale_parent_threads_check
;
155 /* Location of the thread creation event breakpoint. The code at
156 this location in the child process will be called by the pthread
157 library whenever a new thread is created. By setting a special
158 breakpoint at this location, GDB can detect when a new thread is
159 created. We obtain this location via the td_ta_event_addr
161 CORE_ADDR td_create_bp_addr
;
163 /* Location of the thread death event breakpoint. */
164 CORE_ADDR td_death_bp_addr
;
166 /* Pointers to the libthread_db functions. */
168 td_err_e (*td_init_p
) (void);
170 td_err_e (*td_ta_new_p
) (struct ps_prochandle
* ps
,
172 td_err_e (*td_ta_map_id2thr_p
) (const td_thragent_t
*ta
, thread_t pt
,
173 td_thrhandle_t
*__th
);
174 td_err_e (*td_ta_map_lwp2thr_p
) (const td_thragent_t
*ta
,
175 lwpid_t lwpid
, td_thrhandle_t
*th
);
176 td_err_e (*td_ta_thr_iter_p
) (const td_thragent_t
*ta
,
177 td_thr_iter_f
*callback
, void *cbdata_p
,
178 td_thr_state_e state
, int ti_pri
,
179 sigset_t
*ti_sigmask_p
,
180 unsigned int ti_user_flags
);
181 td_err_e (*td_ta_event_addr_p
) (const td_thragent_t
*ta
,
182 td_event_e event
, td_notify_t
*ptr
);
183 td_err_e (*td_ta_set_event_p
) (const td_thragent_t
*ta
,
184 td_thr_events_t
*event
);
185 td_err_e (*td_ta_clear_event_p
) (const td_thragent_t
*ta
,
186 td_thr_events_t
*event
);
187 td_err_e (*td_ta_event_getmsg_p
) (const td_thragent_t
*ta
,
188 td_event_msg_t
*msg
);
190 td_err_e (*td_thr_validate_p
) (const td_thrhandle_t
*th
);
191 td_err_e (*td_thr_get_info_p
) (const td_thrhandle_t
*th
,
192 td_thrinfo_t
*infop
);
193 td_err_e (*td_thr_event_enable_p
) (const td_thrhandle_t
*th
,
196 td_err_e (*td_thr_tls_get_addr_p
) (const td_thrhandle_t
*th
,
197 psaddr_t map_address
,
198 size_t offset
, psaddr_t
*address
);
199 td_err_e (*td_thr_tlsbase_p
) (const td_thrhandle_t
*th
,
200 unsigned long int modid
,
204 /* List of known processes using thread_db, and the required
206 struct thread_db_info
*thread_db_list
;
208 static void thread_db_find_new_threads_1 (ptid_t ptid
);
209 static void thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
);
211 /* Add the current inferior to the list of processes using libpthread.
212 Return a pointer to the newly allocated object that was added to
213 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
216 static struct thread_db_info
*
217 add_thread_db_info (void *handle
)
219 struct thread_db_info
*info
;
221 info
= xcalloc (1, sizeof (*info
));
222 info
->pid
= ptid_get_pid (inferior_ptid
);
223 info
->handle
= handle
;
225 /* The workaround works by reading from /proc/pid/status, so it is
226 disabled for core files. */
227 if (target_has_execution
)
228 info
->need_stale_parent_threads_check
= 1;
230 info
->next
= thread_db_list
;
231 thread_db_list
= info
;
236 /* Return the thread_db_info object representing the bookkeeping
237 related to process PID, if any; NULL otherwise. */
239 static struct thread_db_info
*
240 get_thread_db_info (int pid
)
242 struct thread_db_info
*info
;
244 for (info
= thread_db_list
; info
; info
= info
->next
)
245 if (pid
== info
->pid
)
251 /* When PID has exited or has been detached, we no longer want to keep
252 track of it as using libpthread. Call this function to discard
253 thread_db related info related to PID. Note that this closes
254 LIBTHREAD_DB_SO's dlopen'ed handle. */
257 delete_thread_db_info (int pid
)
259 struct thread_db_info
*info
, *info_prev
;
263 for (info
= thread_db_list
; info
; info_prev
= info
, info
= info
->next
)
264 if (pid
== info
->pid
)
270 if (info
->handle
!= NULL
)
271 dlclose (info
->handle
);
273 xfree (info
->filename
);
276 info_prev
->next
= info
->next
;
278 thread_db_list
= info
->next
;
283 /* Prototypes for local functions. */
284 static int attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
285 const td_thrinfo_t
*ti_p
);
286 static void detach_thread (ptid_t ptid
);
289 /* Use "struct private_thread_info" to cache thread state. This is
290 a substantial optimization. */
292 struct private_thread_info
294 /* Flag set when we see a TD_DEATH event for this thread. */
295 unsigned int dying
:1;
297 /* Cached thread state. */
304 thread_db_err_str (td_err_e err
)
311 return "generic 'call succeeded'";
313 return "generic error";
315 return "no thread to satisfy query";
317 return "no sync handle to satisfy query";
319 return "no LWP to satisfy query";
321 return "invalid process handle";
323 return "invalid thread handle";
325 return "invalid synchronization handle";
327 return "invalid thread agent";
329 return "invalid key";
331 return "no event message for getmsg";
333 return "FPU register set not available";
335 return "application not linked with libthread";
337 return "requested event is not supported";
339 return "capability not available";
341 return "debugger service failed";
343 return "operation not applicable to";
345 return "no thread-specific data for this thread";
347 return "malloc failed";
349 return "only part of register set was written/read";
351 return "X register set not available for this thread";
352 #ifdef THREAD_DB_HAS_TD_NOTALLOC
354 return "thread has not yet allocated TLS for given module";
356 #ifdef THREAD_DB_HAS_TD_VERSION
358 return "versions of libpthread and libthread_db do not match";
360 #ifdef THREAD_DB_HAS_TD_NOTLS
362 return "there is no TLS segment in the given module";
365 snprintf (buf
, sizeof (buf
), "unknown thread_db error '%d'", err
);
370 /* Return 1 if any threads have been registered. There may be none if
371 the threading library is not fully initialized yet. */
374 have_threads_callback (struct thread_info
*thread
, void *args
)
376 int pid
= * (int *) args
;
378 if (ptid_get_pid (thread
->ptid
) != pid
)
381 return thread
->private != NULL
;
385 have_threads (ptid_t ptid
)
387 int pid
= ptid_get_pid (ptid
);
389 return iterate_over_threads (have_threads_callback
, &pid
) != NULL
;
392 struct thread_get_info_inout
394 struct thread_info
*thread_info
;
395 struct thread_db_info
*thread_db_info
;
398 /* A callback function for td_ta_thr_iter, which we use to map all
401 THP is a handle to the current thread; if INFOP is not NULL, the
402 struct thread_info associated with this thread is returned in
405 If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
406 zero is returned to indicate success. */
409 thread_get_info_callback (const td_thrhandle_t
*thp
, void *argp
)
414 struct thread_get_info_inout
*inout
;
415 struct thread_db_info
*info
;
418 info
= inout
->thread_db_info
;
420 err
= info
->td_thr_get_info_p (thp
, &ti
);
422 error (_("thread_get_info_callback: cannot get thread info: %s"),
423 thread_db_err_str (err
));
425 /* Fill the cache. */
426 thread_ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
427 inout
->thread_info
= find_thread_ptid (thread_ptid
);
429 if (inout
->thread_info
== NULL
)
431 /* New thread. Attach to it now (why wait?). */
432 if (!have_threads (thread_ptid
))
433 thread_db_find_new_threads_1 (thread_ptid
);
435 attach_thread (thread_ptid
, thp
, &ti
);
436 inout
->thread_info
= find_thread_ptid (thread_ptid
);
437 gdb_assert (inout
->thread_info
!= NULL
);
443 /* Fetch the user-level thread id of PTID. */
446 thread_from_lwp (ptid_t ptid
)
450 struct thread_db_info
*info
;
451 struct thread_get_info_inout io
= {0};
453 /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
456 /* This ptid comes from linux-nat.c, which should always fill in the
458 gdb_assert (ptid_get_lwp (ptid
) != 0);
460 info
= get_thread_db_info (ptid_get_pid (ptid
));
462 /* Access an lwp we know is stopped. */
463 info
->proc_handle
.ptid
= ptid
;
464 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, ptid_get_lwp (ptid
),
467 error (_("Cannot find user-level thread for LWP %ld: %s"),
468 ptid_get_lwp (ptid
), thread_db_err_str (err
));
470 /* Long-winded way of fetching the thread info. */
471 io
.thread_db_info
= info
;
472 io
.thread_info
= NULL
;
473 thread_get_info_callback (&th
, &io
);
477 /* Attach to lwp PTID, doing whatever else is required to have this
478 LWP under the debugger's control --- e.g., enabling event
479 reporting. Returns true on success. */
481 thread_db_attach_lwp (ptid_t ptid
)
486 struct thread_db_info
*info
;
488 info
= get_thread_db_info (ptid_get_pid (ptid
));
493 /* This ptid comes from linux-nat.c, which should always fill in the
495 gdb_assert (ptid_get_lwp (ptid
) != 0);
497 /* Access an lwp we know is stopped. */
498 info
->proc_handle
.ptid
= ptid
;
500 /* If we have only looked at the first thread before libpthread was
501 initialized, we may not know its thread ID yet. Make sure we do
502 before we add another thread to the list. */
503 if (!have_threads (ptid
))
504 thread_db_find_new_threads_1 (ptid
);
506 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, ptid_get_lwp (ptid
),
509 /* Cannot find user-level thread. */
512 err
= info
->td_thr_get_info_p (&th
, &ti
);
515 warning (_("Cannot get thread info: %s"), thread_db_err_str (err
));
519 attach_thread (ptid
, &th
, &ti
);
524 verbose_dlsym (void *handle
, const char *name
)
526 void *sym
= dlsym (handle
, name
);
528 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
534 enable_thread_event (int event
, CORE_ADDR
*bp
)
538 struct thread_db_info
*info
;
540 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
542 /* Access an lwp we know is stopped. */
543 info
->proc_handle
.ptid
= inferior_ptid
;
545 /* Get the breakpoint address for thread EVENT. */
546 err
= info
->td_ta_event_addr_p (info
->thread_agent
, event
, ¬ify
);
550 /* Set up the breakpoint. */
551 gdb_assert (exec_bfd
);
552 (*bp
) = (gdbarch_convert_from_func_ptr_addr
554 /* Do proper sign extension for the target. */
555 (bfd_get_sign_extend_vma (exec_bfd
) > 0
556 ? (CORE_ADDR
) (intptr_t) notify
.u
.bptaddr
557 : (CORE_ADDR
) (uintptr_t) notify
.u
.bptaddr
),
559 create_thread_event_breakpoint (target_gdbarch (), *bp
);
564 /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
565 return 1 if this version is lower (and not equal) to
566 VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
569 inferior_has_bug (const char *ver_symbol
, int ver_major_min
, int ver_minor_min
)
571 struct bound_minimal_symbol version_msym
;
572 CORE_ADDR version_addr
;
574 int err
, got
, retval
= 0;
576 version_msym
= lookup_minimal_symbol (ver_symbol
, NULL
, NULL
);
577 if (version_msym
.minsym
== NULL
)
580 version_addr
= BMSYMBOL_VALUE_ADDRESS (version_msym
);
581 got
= target_read_string (version_addr
, &version
, 32, &err
);
582 if (err
== 0 && memchr (version
, 0, got
) == &version
[got
-1])
586 retval
= (sscanf (version
, "%d.%d", &major
, &minor
) == 2
587 && (major
< ver_major_min
588 || (major
== ver_major_min
&& minor
< ver_minor_min
)));
596 enable_thread_event_reporting (void)
598 td_thr_events_t events
;
600 struct thread_db_info
*info
;
602 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
604 /* We cannot use the thread event reporting facility if these
605 functions aren't available. */
606 if (info
->td_ta_event_addr_p
== NULL
607 || info
->td_ta_set_event_p
== NULL
608 || info
->td_ta_event_getmsg_p
== NULL
609 || info
->td_thr_event_enable_p
== NULL
)
612 /* Set the process wide mask saying which events we're interested in. */
613 td_event_emptyset (&events
);
614 td_event_addset (&events
, TD_CREATE
);
616 /* There is a bug fixed between linuxthreads 2.1.3 and 2.2 by
617 commit 2e4581e4fba917f1779cd0a010a45698586c190a
618 * manager.c (pthread_exited): Correctly report event as TD_REAP
619 instead of TD_DEATH. Fix comments.
620 where event reporting facility is broken for TD_DEATH events,
621 so don't enable it if we have glibc but a lower version. */
622 if (!inferior_has_bug ("__linuxthreads_version", 2, 2))
623 td_event_addset (&events
, TD_DEATH
);
625 err
= info
->td_ta_set_event_p (info
->thread_agent
, &events
);
628 warning (_("Unable to set global thread event mask: %s"),
629 thread_db_err_str (err
));
633 /* Delete previous thread event breakpoints, if any. */
634 remove_thread_event_breakpoints ();
635 info
->td_create_bp_addr
= 0;
636 info
->td_death_bp_addr
= 0;
638 /* Set up the thread creation event. */
639 err
= enable_thread_event (TD_CREATE
, &info
->td_create_bp_addr
);
642 warning (_("Unable to get location for thread creation breakpoint: %s"),
643 thread_db_err_str (err
));
647 /* Set up the thread death event. */
648 err
= enable_thread_event (TD_DEATH
, &info
->td_death_bp_addr
);
651 warning (_("Unable to get location for thread death breakpoint: %s"),
652 thread_db_err_str (err
));
657 /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
660 Return 1 if the caller should abort libthread_db initialization. Return 0
664 thread_db_find_new_threads_silently (ptid_t ptid
)
666 volatile struct gdb_exception except
;
668 TRY_CATCH (except
, RETURN_MASK_ERROR
)
670 thread_db_find_new_threads_2 (ptid
, 1);
673 if (except
.reason
< 0)
675 if (libthread_db_debug
)
676 exception_fprintf (gdb_stderr
, except
,
677 "Warning: thread_db_find_new_threads_silently: ");
679 /* There is a bug fixed between nptl 2.6.1 and 2.7 by
680 commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
681 where calls to td_thr_get_info fail with TD_ERR for statically linked
682 executables if td_thr_get_info is called before glibc has initialized
685 If the nptl bug is NOT present in the inferior and still thread_db
686 reports an error return 1. It means the inferior has corrupted thread
687 list and GDB should fall back only to LWPs.
689 If the nptl bug is present in the inferior return 0 to silently ignore
690 such errors, and let gdb enumerate threads again later. In such case
691 GDB cannot properly display LWPs if the inferior thread list is
692 corrupted. For core files it does not apply, no 'later enumeration'
695 if (!target_has_execution
|| !inferior_has_bug ("nptl_version", 2, 7))
697 exception_fprintf (gdb_stderr
, except
,
698 _("Warning: couldn't activate thread debugging "
699 "using libthread_db: "));
706 /* Lookup a library in which given symbol resides.
707 Note: this is looking in GDB process, not in the inferior.
708 Returns library name, or NULL. */
711 dladdr_to_soname (const void *addr
)
715 if (dladdr (addr
, &info
) != 0)
716 return info
.dli_fname
;
720 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
722 Failure could happen if libthread_db does not have symbols we expect,
723 or when it refuses to work with the current inferior (e.g. due to
724 version mismatch between libthread_db and libpthread). */
727 try_thread_db_load_1 (struct thread_db_info
*info
)
731 /* Initialize pointers to the dynamic library functions we will use.
732 Essential functions first. */
734 info
->td_init_p
= verbose_dlsym (info
->handle
, "td_init");
735 if (info
->td_init_p
== NULL
)
738 err
= info
->td_init_p ();
741 warning (_("Cannot initialize libthread_db: %s"),
742 thread_db_err_str (err
));
746 info
->td_ta_new_p
= verbose_dlsym (info
->handle
, "td_ta_new");
747 if (info
->td_ta_new_p
== NULL
)
750 /* Initialize the structure that identifies the child process. */
751 info
->proc_handle
.ptid
= inferior_ptid
;
753 /* Now attempt to open a connection to the thread library. */
754 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
757 if (libthread_db_debug
)
758 printf_unfiltered (_("td_ta_new failed: %s\n"),
759 thread_db_err_str (err
));
764 #ifdef THREAD_DB_HAS_TD_VERSION
767 /* The errors above are not unexpected and silently ignored:
768 they just mean we haven't found correct version of
772 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
777 info
->td_ta_map_id2thr_p
= verbose_dlsym (info
->handle
, "td_ta_map_id2thr");
778 if (info
->td_ta_map_id2thr_p
== NULL
)
781 info
->td_ta_map_lwp2thr_p
= verbose_dlsym (info
->handle
,
782 "td_ta_map_lwp2thr");
783 if (info
->td_ta_map_lwp2thr_p
== NULL
)
786 info
->td_ta_thr_iter_p
= verbose_dlsym (info
->handle
, "td_ta_thr_iter");
787 if (info
->td_ta_thr_iter_p
== NULL
)
790 info
->td_thr_validate_p
= verbose_dlsym (info
->handle
, "td_thr_validate");
791 if (info
->td_thr_validate_p
== NULL
)
794 info
->td_thr_get_info_p
= verbose_dlsym (info
->handle
, "td_thr_get_info");
795 if (info
->td_thr_get_info_p
== NULL
)
798 /* These are not essential. */
799 info
->td_ta_event_addr_p
= dlsym (info
->handle
, "td_ta_event_addr");
800 info
->td_ta_set_event_p
= dlsym (info
->handle
, "td_ta_set_event");
801 info
->td_ta_clear_event_p
= dlsym (info
->handle
, "td_ta_clear_event");
802 info
->td_ta_event_getmsg_p
= dlsym (info
->handle
, "td_ta_event_getmsg");
803 info
->td_thr_event_enable_p
= dlsym (info
->handle
, "td_thr_event_enable");
804 info
->td_thr_tls_get_addr_p
= dlsym (info
->handle
, "td_thr_tls_get_addr");
805 info
->td_thr_tlsbase_p
= dlsym (info
->handle
, "td_thr_tlsbase");
807 if (thread_db_find_new_threads_silently (inferior_ptid
) != 0)
809 /* Even if libthread_db initializes, if the thread list is
810 corrupted, we'd not manage to list any threads. Better reject this
811 thread_db, and fall back to at least listing LWPs. */
815 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
817 if (libthread_db_debug
|| *libthread_db_search_path
)
821 library
= dladdr_to_soname (*info
->td_ta_new_p
);
823 library
= LIBTHREAD_DB_SO
;
825 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
829 /* The thread library was detected. Activate the thread_db target
830 if this is the first process using it. */
831 if (thread_db_list
->next
== NULL
)
832 push_target (&thread_db_ops
);
834 /* Enable event reporting, but not when debugging a core file. */
835 if (target_has_execution
)
836 enable_thread_event_reporting ();
841 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
842 relative, or just LIBTHREAD_DB. */
845 try_thread_db_load (const char *library
, int check_auto_load_safe
)
848 struct thread_db_info
*info
;
850 if (libthread_db_debug
)
851 printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
854 if (check_auto_load_safe
)
856 if (access (library
, R_OK
) != 0)
858 /* Do not print warnings by file_is_auto_load_safe if the library does
859 not exist at this place. */
860 if (libthread_db_debug
)
861 printf_unfiltered (_("open failed: %s.\n"), safe_strerror (errno
));
865 if (!file_is_auto_load_safe (library
, _("auto-load: Loading libthread-db "
866 "library \"%s\" from explicit "
872 handle
= dlopen (library
, RTLD_NOW
);
875 if (libthread_db_debug
)
876 printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
880 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
884 td_init
= dlsym (handle
, "td_init");
887 const char *const libpath
= dladdr_to_soname (td_init
);
890 printf_unfiltered (_("Host %s resolved to: %s.\n"),
895 info
= add_thread_db_info (handle
);
897 /* Do not save system library name, that one is always trusted. */
898 if (strchr (library
, '/') != NULL
)
899 info
->filename
= gdb_realpath (library
);
901 if (try_thread_db_load_1 (info
))
904 /* This library "refused" to work on current inferior. */
905 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
909 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
910 Try loading libthread_db in directory(OBJ)/SUBDIR.
911 SUBDIR may be NULL. It may also be something like "../lib64".
912 The result is true for success. */
915 try_thread_db_load_from_pdir_1 (struct objfile
*obj
, const char *subdir
)
917 struct cleanup
*cleanup
;
920 const char *obj_name
= objfile_name (obj
);
922 if (obj_name
[0] != '/')
924 warning (_("Expected absolute pathname for libpthread in the"
925 " inferior, but got %s."), obj_name
);
929 path
= xmalloc (strlen (obj_name
) + (subdir
? strlen (subdir
) + 1 : 0)
930 + 1 + strlen (LIBTHREAD_DB_SO
) + 1);
931 cleanup
= make_cleanup (xfree
, path
);
933 strcpy (path
, obj_name
);
934 cp
= strrchr (path
, '/');
935 /* This should at minimum hit the first character. */
936 gdb_assert (cp
!= NULL
);
943 strcat (cp
, LIBTHREAD_DB_SO
);
945 result
= try_thread_db_load (path
, 1);
947 do_cleanups (cleanup
);
951 /* Handle $pdir in libthread-db-search-path.
952 Look for libthread_db in directory(libpthread)/SUBDIR.
953 SUBDIR may be NULL. It may also be something like "../lib64".
954 The result is true for success. */
957 try_thread_db_load_from_pdir (const char *subdir
)
961 if (!auto_load_thread_db
)
965 if (libpthread_name_p (objfile_name (obj
)))
967 if (try_thread_db_load_from_pdir_1 (obj
, subdir
))
970 /* We may have found the separate-debug-info version of
971 libpthread, and it may live in a directory without a matching
973 if (obj
->separate_debug_objfile_backlink
!= NULL
)
974 return try_thread_db_load_from_pdir_1 (obj
->separate_debug_objfile_backlink
,
983 /* Handle $sdir in libthread-db-search-path.
984 Look for libthread_db in the system dirs, or wherever a plain
985 dlopen(file_without_path) will look.
986 The result is true for success. */
989 try_thread_db_load_from_sdir (void)
991 return try_thread_db_load (LIBTHREAD_DB_SO
, 0);
994 /* Try to load libthread_db from directory DIR of length DIR_LEN.
995 The result is true for success. */
998 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
1000 struct cleanup
*cleanup
;
1004 if (!auto_load_thread_db
)
1007 path
= xmalloc (dir_len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1);
1008 cleanup
= make_cleanup (xfree
, path
);
1010 memcpy (path
, dir
, dir_len
);
1011 path
[dir_len
] = '/';
1012 strcpy (path
+ dir_len
+ 1, LIBTHREAD_DB_SO
);
1014 result
= try_thread_db_load (path
, 1);
1016 do_cleanups (cleanup
);
1020 /* Search libthread_db_search_path for libthread_db which "agrees"
1021 to work on current inferior.
1022 The result is true for success. */
1025 thread_db_load_search (void)
1027 VEC (char_ptr
) *dir_vec
;
1028 struct cleanup
*cleanups
;
1032 dir_vec
= dirnames_to_char_ptr_vec (libthread_db_search_path
);
1033 cleanups
= make_cleanup_free_char_ptr_vec (dir_vec
);
1035 for (i
= 0; VEC_iterate (char_ptr
, dir_vec
, i
, this_dir
); ++i
)
1037 const int pdir_len
= sizeof ("$pdir") - 1;
1038 size_t this_dir_len
;
1040 this_dir_len
= strlen (this_dir
);
1042 if (strncmp (this_dir
, "$pdir", pdir_len
) == 0
1043 && (this_dir
[pdir_len
] == '\0'
1044 || this_dir
[pdir_len
] == '/'))
1046 char *subdir
= NULL
;
1047 struct cleanup
*free_subdir_cleanup
1048 = make_cleanup (null_cleanup
, NULL
);
1050 if (this_dir
[pdir_len
] == '/')
1052 subdir
= xmalloc (strlen (this_dir
));
1053 make_cleanup (xfree
, subdir
);
1054 strcpy (subdir
, this_dir
+ pdir_len
+ 1);
1056 rc
= try_thread_db_load_from_pdir (subdir
);
1057 do_cleanups (free_subdir_cleanup
);
1061 else if (strcmp (this_dir
, "$sdir") == 0)
1063 if (try_thread_db_load_from_sdir ())
1071 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
1079 do_cleanups (cleanups
);
1080 if (libthread_db_debug
)
1081 printf_unfiltered (_("thread_db_load_search returning %d\n"), rc
);
1085 /* Return non-zero if the inferior has a libpthread. */
1088 has_libpthread (void)
1090 struct objfile
*obj
;
1093 if (libpthread_name_p (objfile_name (obj
)))
1099 /* Attempt to load and initialize libthread_db.
1100 Return 1 on success. */
1103 thread_db_load (void)
1105 struct thread_db_info
*info
;
1107 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1112 /* Don't attempt to use thread_db on executables not running
1114 if (!target_has_registers
)
1117 /* Don't attempt to use thread_db for remote targets. */
1118 if (!(target_can_run (¤t_target
) || core_bfd
))
1121 if (thread_db_load_search ())
1124 /* We couldn't find a libthread_db.
1125 If the inferior has a libpthread warn the user. */
1126 if (has_libpthread ())
1128 warning (_("Unable to find libthread_db matching inferior's thread"
1129 " library, thread debugging will not be available."));
1133 /* Either this executable isn't using libpthread at all, or it is
1134 statically linked. Since we can't easily distinguish these two cases,
1135 no warning is issued. */
1140 disable_thread_event_reporting (struct thread_db_info
*info
)
1142 if (info
->td_ta_clear_event_p
!= NULL
)
1144 td_thr_events_t events
;
1146 /* Set the process wide mask saying we aren't interested in any
1148 td_event_fillset (&events
);
1149 info
->td_ta_clear_event_p (info
->thread_agent
, &events
);
1152 info
->td_create_bp_addr
= 0;
1153 info
->td_death_bp_addr
= 0;
1157 check_thread_signals (void)
1159 if (!thread_signals
)
1164 lin_thread_get_thread_signals (&mask
);
1165 sigemptyset (&thread_stop_set
);
1166 sigemptyset (&thread_print_set
);
1168 for (i
= 1; i
< NSIG
; i
++)
1170 if (sigismember (&mask
, i
))
1172 if (signal_stop_update (gdb_signal_from_host (i
), 0))
1173 sigaddset (&thread_stop_set
, i
);
1174 if (signal_print_update (gdb_signal_from_host (i
), 0))
1175 sigaddset (&thread_print_set
, i
);
1182 /* Check whether thread_db is usable. This function is called when
1183 an inferior is created (or otherwise acquired, e.g. attached to)
1184 and when new shared libraries are loaded into a running process. */
1187 check_for_thread_db (void)
1189 /* Do nothing if we couldn't load libthread_db.so.1. */
1190 if (!thread_db_load ())
1194 /* This function is called via the new_objfile observer. */
1197 thread_db_new_objfile (struct objfile
*objfile
)
1199 /* This observer must always be called with inferior_ptid set
1203 /* libpthread with separate debug info has its debug info file already
1204 loaded (and notified without successful thread_db initialization)
1205 the time observer_notify_new_objfile is called for the library itself.
1206 Static executables have their separate debug info loaded already
1207 before the inferior has started. */
1208 && objfile
->separate_debug_objfile_backlink
== NULL
1209 /* Only check for thread_db if we loaded libpthread,
1210 or if this is the main symbol file.
1211 We need to check OBJF_MAINLINE to handle the case of debugging
1212 a statically linked executable AND the symbol file is specified AFTER
1213 the exec file is loaded (e.g., gdb -c core ; file foo).
1214 For dynamically linked executables, libpthread can be near the end
1215 of the list of shared libraries to load, and in an app of several
1216 thousand shared libraries, this can otherwise be painful. */
1217 && ((objfile
->flags
& OBJF_MAINLINE
) != 0
1218 || libpthread_name_p (objfile_name (objfile
))))
1219 check_for_thread_db ();
1222 /* This function is called via the inferior_created observer.
1223 This handles the case of debugging statically linked executables. */
1226 thread_db_inferior_created (struct target_ops
*target
, int from_tty
)
1228 check_for_thread_db ();
1231 /* Attach to a new thread. This function is called when we receive a
1232 TD_CREATE event or when we iterate over all threads and find one
1233 that wasn't already in our list. Returns true on success. */
1236 attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
1237 const td_thrinfo_t
*ti_p
)
1239 struct private_thread_info
*private;
1240 struct thread_info
*tp
;
1242 struct thread_db_info
*info
;
1244 /* If we're being called after a TD_CREATE event, we may already
1245 know about this thread. There are two ways this can happen. We
1246 may have iterated over all threads between the thread creation
1247 and the TD_CREATE event, for instance when the user has issued
1248 the `info threads' command before the SIGTRAP for hitting the
1249 thread creation breakpoint was reported. Alternatively, the
1250 thread may have exited and a new one been created with the same
1251 thread ID. In the first case we don't need to do anything; in
1252 the second case we should discard information about the dead
1253 thread and attach to the new one. */
1254 tp
= find_thread_ptid (ptid
);
1257 /* If tp->private is NULL, then GDB is already attached to this
1258 thread, but we do not know anything about it. We can learn
1259 about it here. This can only happen if we have some other
1260 way besides libthread_db to notice new threads (i.e.
1261 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
1262 exit, so this can not be a stale thread recreated with the
1264 if (tp
->private != NULL
)
1266 if (!tp
->private->dying
)
1269 delete_thread (ptid
);
1274 if (target_has_execution
)
1275 check_thread_signals ();
1277 /* Under GNU/Linux, we have to attach to each and every thread. */
1278 if (target_has_execution
1283 res
= lin_lwp_attach_lwp (ptid_build (ptid_get_pid (ptid
),
1287 /* Error, stop iterating. */
1292 /* Pretend this thread doesn't exist yet, and keep
1297 /* Otherwise, we sucessfully attached to the thread. */
1300 /* Construct the thread's private data. */
1301 private = xmalloc (sizeof (struct private_thread_info
));
1302 memset (private, 0, sizeof (struct private_thread_info
));
1304 /* A thread ID of zero may mean the thread library has not initialized
1305 yet. But we shouldn't even get here if that's the case. FIXME:
1306 if we change GDB to always have at least one thread in the thread
1307 list this will have to go somewhere else; maybe private == NULL
1308 until the thread_db target claims it. */
1309 gdb_assert (ti_p
->ti_tid
!= 0);
1310 private->th
= *th_p
;
1311 private->tid
= ti_p
->ti_tid
;
1312 if (ti_p
->ti_state
== TD_THR_UNKNOWN
|| ti_p
->ti_state
== TD_THR_ZOMBIE
)
1315 /* Add the thread to GDB's thread list. */
1317 add_thread_with_info (ptid
, private);
1319 tp
->private = private;
1321 info
= get_thread_db_info (ptid_get_pid (ptid
));
1323 /* Enable thread event reporting for this thread, except when
1324 debugging a core file. */
1325 if (target_has_execution
)
1327 err
= info
->td_thr_event_enable_p (th_p
, 1);
1329 error (_("Cannot enable thread event reporting for %s: %s"),
1330 target_pid_to_str (ptid
), thread_db_err_str (err
));
1337 detach_thread (ptid_t ptid
)
1339 struct thread_info
*thread_info
;
1341 /* Don't delete the thread now, because it still reports as active
1342 until it has executed a few instructions after the event
1343 breakpoint - if we deleted it now, "info threads" would cause us
1344 to re-attach to it. Just mark it as having had a TD_DEATH
1345 event. This means that we won't delete it from our thread list
1346 until we notice that it's dead (via prune_threads), or until
1347 something re-uses its thread ID. We'll report the thread exit
1348 when the underlying LWP dies. */
1349 thread_info
= find_thread_ptid (ptid
);
1350 gdb_assert (thread_info
!= NULL
&& thread_info
->private != NULL
);
1351 thread_info
->private->dying
= 1;
1355 thread_db_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1357 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1358 struct thread_db_info
*info
;
1360 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1364 if (target_has_execution
)
1366 disable_thread_event_reporting (info
);
1368 /* Delete the old thread event breakpoints. Note that
1369 unlike when mourning, we can remove them here because
1370 there's still a live inferior to poke at. In any case,
1371 GDB will not try to insert anything in the inferior when
1372 removing a breakpoint. */
1373 remove_thread_event_breakpoints ();
1376 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
1379 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
1381 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1383 /* If there are no more processes using libpthread, detach the
1384 thread_db target ops. */
1385 if (!thread_db_list
)
1386 unpush_target (&thread_db_ops
);
1389 /* Check if PID is currently stopped at the location of a thread event
1390 breakpoint location. If it is, read the event message and act upon
1394 check_event (ptid_t ptid
)
1396 struct regcache
*regcache
= get_thread_regcache (ptid
);
1397 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1403 struct thread_db_info
*info
;
1405 info
= get_thread_db_info (ptid_get_pid (ptid
));
1407 /* Bail out early if we're not at a thread event breakpoint. */
1408 stop_pc
= regcache_read_pc (regcache
)
1409 - target_decr_pc_after_break (gdbarch
);
1410 if (stop_pc
!= info
->td_create_bp_addr
1411 && stop_pc
!= info
->td_death_bp_addr
)
1414 /* Access an lwp we know is stopped. */
1415 info
->proc_handle
.ptid
= ptid
;
1417 /* If we have only looked at the first thread before libpthread was
1418 initialized, we may not know its thread ID yet. Make sure we do
1419 before we add another thread to the list. */
1420 if (!have_threads (ptid
))
1421 thread_db_find_new_threads_1 (ptid
);
1423 /* If we are at a create breakpoint, we do not know what new lwp
1424 was created and cannot specifically locate the event message for it.
1425 We have to call td_ta_event_getmsg() to get
1426 the latest message. Since we have no way of correlating whether
1427 the event message we get back corresponds to our breakpoint, we must
1428 loop and read all event messages, processing them appropriately.
1429 This guarantees we will process the correct message before continuing
1430 from the breakpoint.
1432 Currently, death events are not enabled. If they are enabled,
1433 the death event can use the td_thr_event_getmsg() interface to
1434 get the message specifically for that lwp and avoid looping
1441 err
= info
->td_ta_event_getmsg_p (info
->thread_agent
, &msg
);
1444 if (err
== TD_NOMSG
)
1447 error (_("Cannot get thread event message: %s"),
1448 thread_db_err_str (err
));
1451 err
= info
->td_thr_get_info_p (msg
.th_p
, &ti
);
1453 error (_("Cannot get thread info: %s"), thread_db_err_str (err
));
1455 ptid
= ptid_build (ptid_get_pid (ptid
), ti
.ti_lid
, 0);
1460 /* Call attach_thread whether or not we already know about a
1461 thread with this thread ID. */
1462 attach_thread (ptid
, msg
.th_p
, &ti
);
1468 if (!in_thread_list (ptid
))
1469 error (_("Spurious thread death event."));
1471 detach_thread (ptid
);
1476 error (_("Spurious thread event."));
1483 thread_db_wait (struct target_ops
*ops
,
1484 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1487 struct thread_db_info
*info
;
1488 struct target_ops
*beneath
= find_target_beneath (ops
);
1490 ptid
= beneath
->to_wait (beneath
, ptid
, ourstatus
, options
);
1492 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
1495 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
1496 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
1499 info
= get_thread_db_info (ptid_get_pid (ptid
));
1501 /* If this process isn't using thread_db, we're done. */
1505 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1507 /* New image, it may or may not end up using thread_db. Assume
1508 not unless we find otherwise. */
1509 delete_thread_db_info (ptid_get_pid (ptid
));
1510 if (!thread_db_list
)
1511 unpush_target (&thread_db_ops
);
1513 /* Thread event breakpoints are deleted by
1514 update_breakpoints_after_exec. */
1519 /* If we do not know about the main thread yet, this would be a good time to
1521 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
&& !have_threads (ptid
))
1522 thread_db_find_new_threads_1 (ptid
);
1524 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
1525 && ourstatus
->value
.sig
== GDB_SIGNAL_TRAP
)
1526 /* Check for a thread event. */
1529 if (have_threads (ptid
))
1531 /* Fill in the thread's user-level thread id. */
1532 thread_from_lwp (ptid
);
1539 thread_db_mourn_inferior (struct target_ops
*ops
)
1541 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1543 delete_thread_db_info (ptid_get_pid (inferior_ptid
));
1545 target_beneath
->to_mourn_inferior (target_beneath
);
1547 /* Delete the old thread event breakpoints. Do this after mourning
1548 the inferior, so that we don't try to uninsert them. */
1549 remove_thread_event_breakpoints ();
1551 /* Detach thread_db target ops. */
1552 if (!thread_db_list
)
1553 unpush_target (ops
);
1556 struct callback_data
1558 struct thread_db_info
*info
;
1563 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1568 struct thread_info
*tp
;
1569 struct callback_data
*cb_data
= data
;
1570 struct thread_db_info
*info
= cb_data
->info
;
1572 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1574 error (_("find_new_threads_callback: cannot get thread info: %s"),
1575 thread_db_err_str (err
));
1579 /* A thread ID of zero means that this is the main thread, but
1580 glibc has not yet initialized thread-local storage and the
1581 pthread library. We do not know what the thread's TID will
1582 be yet. Just enable event reporting and otherwise ignore
1585 /* In that case, we're not stopped in a fork syscall and don't
1586 need this glibc bug workaround. */
1587 info
->need_stale_parent_threads_check
= 0;
1589 if (target_has_execution
)
1591 err
= info
->td_thr_event_enable_p (th_p
, 1);
1593 error (_("Cannot enable thread event reporting for LWP %d: %s"),
1594 (int) ti
.ti_lid
, thread_db_err_str (err
));
1600 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1601 bit expensive, as it needs to open /proc/pid/status, so try to
1602 avoid doing the work if we know we don't have to. */
1603 if (info
->need_stale_parent_threads_check
)
1605 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1607 if (tgid
!= -1 && tgid
!= info
->pid
)
1611 ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
1612 tp
= find_thread_ptid (ptid
);
1613 if (tp
== NULL
|| tp
->private == NULL
)
1615 if (attach_thread (ptid
, th_p
, &ti
))
1616 cb_data
->new_threads
+= 1;
1618 /* Problem attaching this thread; perhaps it exited before we
1620 This could mean that the thread list inside glibc itself is in
1621 inconsistent state, and libthread_db could go on looping forever
1622 (observed with glibc-2.3.6). To prevent that, terminate
1623 iteration: thread_db_find_new_threads_2 will retry. */
1630 /* Helper for thread_db_find_new_threads_2.
1631 Returns number of new threads found. */
1634 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1637 volatile struct gdb_exception except
;
1638 struct callback_data data
;
1639 td_err_e err
= TD_ERR
;
1642 data
.new_threads
= 0;
1644 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1646 /* Iterate over all user-space threads to discover new threads. */
1647 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1648 find_new_threads_callback
,
1651 TD_THR_LOWEST_PRIORITY
,
1653 TD_THR_ANY_USER_FLAGS
);
1656 if (libthread_db_debug
)
1658 if (except
.reason
< 0)
1659 exception_fprintf (gdb_stderr
, except
,
1660 "Warning: find_new_threads_once: ");
1662 printf_filtered (_("Found %d new threads in iteration %d.\n"),
1663 data
.new_threads
, iteration
);
1669 return data
.new_threads
;
1672 /* Search for new threads, accessing memory through stopped thread
1673 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1674 searches in a row do not discover any new threads. */
1677 thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
)
1679 td_err_e err
= TD_OK
;
1680 struct thread_db_info
*info
;
1683 info
= get_thread_db_info (ptid_get_pid (ptid
));
1685 /* Access an lwp we know is stopped. */
1686 info
->proc_handle
.ptid
= ptid
;
1690 /* Require 4 successive iterations which do not find any new threads.
1691 The 4 is a heuristic: there is an inherent race here, and I have
1692 seen that 2 iterations in a row are not always sufficient to
1693 "capture" all threads. */
1694 for (i
= 0, loop
= 0; loop
< 4 && err
== TD_OK
; ++i
, ++loop
)
1695 if (find_new_threads_once (info
, i
, &err
) != 0)
1697 /* Found some new threads. Restart the loop from beginning. */
1702 find_new_threads_once (info
, 0, &err
);
1705 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1709 thread_db_find_new_threads_1 (ptid_t ptid
)
1711 thread_db_find_new_threads_2 (ptid
, 0);
1715 update_thread_core (struct lwp_info
*info
, void *closure
)
1717 info
->core
= linux_common_core_of_thread (info
->ptid
);
1722 thread_db_find_new_threads (struct target_ops
*ops
)
1724 struct thread_db_info
*info
;
1725 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 if (beneath
->to_pid_to_str (beneath
, ptid
))
1770 return beneath
->to_pid_to_str (beneath
, ptid
);
1772 return normal_pid_to_str (ptid
);
1775 /* Return a string describing the state of the thread specified by
1779 thread_db_extra_thread_info (struct target_ops
*self
,
1780 struct thread_info
*info
)
1782 if (info
->private == NULL
)
1785 if (info
->private->dying
)
1791 /* Get the address of the thread local variable in load module LM which
1792 is stored at OFFSET within the thread local storage for thread PTID. */
1795 thread_db_get_thread_local_address (struct target_ops
*ops
,
1800 struct thread_info
*thread_info
;
1801 struct target_ops
*beneath
;
1803 /* If we have not discovered any threads yet, check now. */
1804 if (!have_threads (ptid
))
1805 thread_db_find_new_threads_1 (ptid
);
1807 /* Find the matching thread. */
1808 thread_info
= find_thread_ptid (ptid
);
1810 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1814 struct thread_db_info
*info
;
1816 info
= get_thread_db_info (ptid_get_pid (ptid
));
1818 /* Finally, get the address of the variable. */
1821 /* glibc doesn't provide the needed interface. */
1822 if (!info
->td_thr_tls_get_addr_p
)
1823 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1824 _("No TLS library support"));
1826 /* Note the cast through uintptr_t: this interface only works if
1827 a target address fits in a psaddr_t, which is a host pointer.
1828 So a 32-bit debugger can not access 64-bit TLS through this. */
1829 err
= info
->td_thr_tls_get_addr_p (&thread_info
->private->th
,
1830 (psaddr_t
)(uintptr_t) lm
,
1835 /* If glibc doesn't provide the needed interface throw an error
1836 that LM is zero - normally cases it should not be. */
1837 if (!info
->td_thr_tlsbase_p
)
1838 throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR
,
1839 _("TLS load module not found"));
1841 /* This code path handles the case of -static -pthread executables:
1842 https://sourceware.org/ml/libc-help/2014-03/msg00024.html
1843 For older GNU libc r_debug.r_map is NULL. For GNU libc after
1844 PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
1845 The constant number 1 depends on GNU __libc_setup_tls
1846 initialization of l_tls_modid to 1. */
1847 err
= info
->td_thr_tlsbase_p (&thread_info
->private->th
,
1849 address
= (char *) address
+ offset
;
1852 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1853 /* The memory hasn't been allocated, yet. */
1854 if (err
== TD_NOTALLOC
)
1855 /* Now, if libthread_db provided the initialization image's
1856 address, we *could* try to build a non-lvalue value from
1857 the initialization image. */
1858 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1859 _("TLS not allocated yet"));
1862 /* Something else went wrong. */
1864 throw_error (TLS_GENERIC_ERROR
,
1865 (("%s")), thread_db_err_str (err
));
1867 /* Cast assuming host == target. Joy. */
1868 /* Do proper sign extension for the target. */
1869 gdb_assert (exec_bfd
);
1870 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1871 ? (CORE_ADDR
) (intptr_t) address
1872 : (CORE_ADDR
) (uintptr_t) address
);
1875 beneath
= find_target_beneath (ops
);
1876 if (beneath
->to_get_thread_local_address
)
1877 return beneath
->to_get_thread_local_address (beneath
, ptid
, lm
, offset
);
1879 throw_error (TLS_GENERIC_ERROR
,
1880 _("TLS not supported on this target"));
1883 /* Callback routine used to find a thread based on the TID part of
1887 thread_db_find_thread_from_tid (struct thread_info
*thread
, void *data
)
1889 long *tid
= (long *) data
;
1891 if (thread
->private->tid
== *tid
)
1897 /* Implement the to_get_ada_task_ptid target method for this target. */
1900 thread_db_get_ada_task_ptid (struct target_ops
*self
, long lwp
, long thread
)
1902 struct thread_info
*thread_info
;
1904 thread_db_find_new_threads_1 (inferior_ptid
);
1905 thread_info
= iterate_over_threads (thread_db_find_thread_from_tid
, &thread
);
1907 gdb_assert (thread_info
!= NULL
);
1909 return (thread_info
->ptid
);
1913 thread_db_resume (struct target_ops
*ops
,
1914 ptid_t ptid
, int step
, enum gdb_signal signo
)
1916 struct target_ops
*beneath
= find_target_beneath (ops
);
1917 struct thread_db_info
*info
;
1919 if (ptid_equal (ptid
, minus_one_ptid
))
1920 info
= get_thread_db_info (ptid_get_pid (inferior_ptid
));
1922 info
= get_thread_db_info (ptid_get_pid (ptid
));
1924 /* This workaround is only needed for child fork lwps stopped in a
1925 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1926 workaround can be disabled. */
1928 info
->need_stale_parent_threads_check
= 0;
1930 beneath
->to_resume (beneath
, ptid
, step
, signo
);
1933 /* qsort helper function for info_auto_load_libthread_db, sort the
1934 thread_db_info pointers primarily by their FILENAME and secondarily by their
1935 PID, both in ascending order. */
1938 info_auto_load_libthread_db_compare (const void *ap
, const void *bp
)
1940 struct thread_db_info
*a
= *(struct thread_db_info
**) ap
;
1941 struct thread_db_info
*b
= *(struct thread_db_info
**) bp
;
1944 retval
= strcmp (a
->filename
, b
->filename
);
1948 return (a
->pid
> b
->pid
) - (a
->pid
- b
->pid
);
1951 /* Implement 'info auto-load libthread-db'. */
1954 info_auto_load_libthread_db (char *args
, int from_tty
)
1956 struct ui_out
*uiout
= current_uiout
;
1957 const char *cs
= args
? args
: "";
1958 struct thread_db_info
*info
, **array
;
1959 unsigned info_count
, unique_filenames
;
1960 size_t max_filename_len
, max_pids_len
, pids_len
;
1961 struct cleanup
*back_to
;
1965 cs
= skip_spaces_const (cs
);
1967 error (_("'info auto-load libthread-db' does not accept any parameters"));
1970 for (info
= thread_db_list
; info
; info
= info
->next
)
1971 if (info
->filename
!= NULL
)
1974 array
= xmalloc (sizeof (*array
) * info_count
);
1975 back_to
= make_cleanup (xfree
, array
);
1978 for (info
= thread_db_list
; info
; info
= info
->next
)
1979 if (info
->filename
!= NULL
)
1980 array
[info_count
++] = info
;
1982 /* Sort ARRAY by filenames and PIDs. */
1984 qsort (array
, info_count
, sizeof (*array
),
1985 info_auto_load_libthread_db_compare
);
1987 /* Calculate the number of unique filenames (rows) and the maximum string
1988 length of PIDs list for the unique filenames (columns). */
1990 unique_filenames
= 0;
1991 max_filename_len
= 0;
1994 for (i
= 0; i
< info_count
; i
++)
1996 int pid
= array
[i
]->pid
;
1997 size_t this_pid_len
;
1999 for (this_pid_len
= 0; pid
!= 0; pid
/= 10)
2002 if (i
== 0 || strcmp (array
[i
- 1]->filename
, array
[i
]->filename
) != 0)
2005 max_filename_len
= max (max_filename_len
,
2006 strlen (array
[i
]->filename
));
2010 pids_len
-= strlen (", ");
2011 max_pids_len
= max (max_pids_len
, pids_len
);
2015 pids_len
+= this_pid_len
+ strlen (", ");
2019 pids_len
-= strlen (", ");
2020 max_pids_len
= max (max_pids_len
, pids_len
);
2023 /* Table header shifted right by preceding "libthread-db: " would not match
2025 if (info_count
> 0 && args
== auto_load_info_scripts_pattern_nl
)
2026 ui_out_text (uiout
, "\n");
2028 make_cleanup_ui_out_table_begin_end (uiout
, 2, unique_filenames
,
2029 "LinuxThreadDbTable");
2031 ui_out_table_header (uiout
, max_filename_len
, ui_left
, "filename",
2033 ui_out_table_header (uiout
, pids_len
, ui_left
, "PIDs", "Pids");
2034 ui_out_table_body (uiout
);
2036 pids
= xmalloc (max_pids_len
+ 1);
2037 make_cleanup (xfree
, pids
);
2039 /* Note I is incremented inside the cycle, not at its end. */
2040 for (i
= 0; i
< info_count
;)
2042 struct cleanup
*chain
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
2046 ui_out_field_string (uiout
, "filename", info
->filename
);
2049 while (i
< info_count
&& strcmp (info
->filename
, array
[i
]->filename
) == 0)
2051 if (pids_end
!= pids
)
2056 pids_end
+= xsnprintf (pids_end
, &pids
[max_pids_len
+ 1] - pids_end
,
2057 "%u", array
[i
]->pid
);
2058 gdb_assert (pids_end
< &pids
[max_pids_len
+ 1]);
2064 ui_out_field_string (uiout
, "pids", pids
);
2066 ui_out_text (uiout
, "\n");
2067 do_cleanups (chain
);
2070 do_cleanups (back_to
);
2072 if (info_count
== 0)
2073 ui_out_message (uiout
, 0, _("No auto-loaded libthread-db.\n"));
2077 init_thread_db_ops (void)
2079 thread_db_ops
.to_shortname
= "multi-thread";
2080 thread_db_ops
.to_longname
= "multi-threaded child process.";
2081 thread_db_ops
.to_doc
= "Threads and pthreads support.";
2082 thread_db_ops
.to_detach
= thread_db_detach
;
2083 thread_db_ops
.to_wait
= thread_db_wait
;
2084 thread_db_ops
.to_resume
= thread_db_resume
;
2085 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
2086 thread_db_ops
.to_find_new_threads
= thread_db_find_new_threads
;
2087 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
2088 thread_db_ops
.to_stratum
= thread_stratum
;
2089 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
2090 thread_db_ops
.to_get_thread_local_address
2091 = thread_db_get_thread_local_address
;
2092 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
2093 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
2094 thread_db_ops
.to_magic
= OPS_MAGIC
;
2096 complete_target_initialization (&thread_db_ops
);
2099 /* Provide a prototype to silence -Wmissing-prototypes. */
2100 extern initialize_file_ftype _initialize_thread_db
;
2103 _initialize_thread_db (void)
2105 init_thread_db_ops ();
2107 /* Defer loading of libthread_db.so until inferior is running.
2108 This allows gdb to load correct libthread_db for a given
2109 executable -- there could be mutiple versions of glibc,
2110 compiled with LinuxThreads or NPTL, and until there is
2111 a running inferior, we can't tell which libthread_db is
2112 the correct one to load. */
2114 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
2116 add_setshow_optional_filename_cmd ("libthread-db-search-path",
2118 &libthread_db_search_path
, _("\
2119 Set search path for libthread_db."), _("\
2120 Show the current search path or libthread_db."), _("\
2121 This path is used to search for libthread_db to be loaded into \
2123 Its value is a colon (':') separate list of directories to search.\n\
2124 Setting the search path to an empty list resets it to its default value."),
2125 set_libthread_db_search_path
,
2127 &setlist
, &showlist
);
2129 add_setshow_zuinteger_cmd ("libthread-db", class_maintenance
,
2130 &libthread_db_debug
, _("\
2131 Set libthread-db debugging."), _("\
2132 Show libthread-db debugging."), _("\
2133 When non-zero, libthread-db debugging is enabled."),
2135 show_libthread_db_debug
,
2136 &setdebuglist
, &showdebuglist
);
2138 add_setshow_boolean_cmd ("libthread-db", class_support
,
2139 &auto_load_thread_db
, _("\
2140 Enable or disable auto-loading of inferior specific libthread_db."), _("\
2141 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
2142 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
2143 locations to load libthread_db compatible with the inferior.\n\
2144 Standard system libthread_db still gets loaded even with this option off.\n\
2145 This options has security implications for untrusted inferiors."),
2146 NULL
, show_auto_load_thread_db
,
2147 auto_load_set_cmdlist_get (),
2148 auto_load_show_cmdlist_get ());
2150 add_cmd ("libthread-db", class_info
, info_auto_load_libthread_db
,
2151 _("Print the list of loaded inferior specific libthread_db.\n\
2152 Usage: info auto-load libthread-db"),
2153 auto_load_info_cmdlist_get ());
2155 /* Add ourselves to objfile event chain. */
2156 observer_attach_new_objfile (thread_db_new_objfile
);
2158 /* Add ourselves to inferior_created event chain.
2159 This is needed to handle debugging statically linked programs where
2160 the new_objfile observer won't get called for libpthread. */
2161 observer_attach_inferior_created (thread_db_inferior_created
);