1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999-2001, 2003-2012 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"
49 #ifdef HAVE_GNU_LIBC_VERSION_H
50 #include <gnu/libc-version.h>
53 /* GNU/Linux libthread_db support.
55 libthread_db is a library, provided along with libpthread.so, which
56 exposes the internals of the thread library to a debugger. It
57 allows GDB to find existing threads, new threads as they are
58 created, thread IDs (usually, the result of pthread_self), and
59 thread-local variables.
61 The libthread_db interface originates on Solaris, where it is
62 both more powerful and more complicated. This implementation
63 only works for LinuxThreads and NPTL, the two glibc threading
64 libraries. It assumes that each thread is permanently assigned
65 to a single light-weight process (LWP).
67 libthread_db-specific information is stored in the "private" field
68 of struct thread_info. When the field is NULL we do not yet have
69 information about the new thread; this could be temporary (created,
70 but the thread library's data structures do not reflect it yet)
71 or permanent (created using clone instead of pthread_create).
73 Process IDs managed by linux-thread-db.c match those used by
74 linux-nat.c: a common PID for all processes, an LWP ID for each
75 thread, and no TID. We save the TID in private. Keeping it out
76 of the ptid_t prevents thread IDs changing when libpthread is
77 loaded or unloaded. */
79 static char *libthread_db_search_path
;
81 /* Set to non-zero if thread_db auto-loading is enabled
82 by the "set auto-load libthread-db" command. */
83 static int auto_load_thread_db
= 1;
85 /* "show" command for the auto_load_thread_db configuration variable. */
88 show_auto_load_thread_db (struct ui_file
*file
, int from_tty
,
89 struct cmd_list_element
*c
, const char *value
)
91 fprintf_filtered (file
, _("Auto-loading of inferior specific libthread_db "
97 set_libthread_db_search_path (char *ignored
, int from_tty
,
98 struct cmd_list_element
*c
)
100 if (*libthread_db_search_path
== '\0')
102 xfree (libthread_db_search_path
);
103 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
107 /* If non-zero, print details of libthread_db processing. */
109 static int libthread_db_debug
;
112 show_libthread_db_debug (struct ui_file
*file
, int from_tty
,
113 struct cmd_list_element
*c
, const char *value
)
115 fprintf_filtered (file
, _("libthread-db debugging is %s.\n"), value
);
118 /* If we're running on GNU/Linux, we must explicitly attach to any new
121 /* This module's target vector. */
122 static struct target_ops thread_db_ops
;
124 /* Non-zero if we have determined the signals used by the threads
126 static int thread_signals
;
127 static sigset_t thread_stop_set
;
128 static sigset_t thread_print_set
;
130 struct thread_db_info
132 struct thread_db_info
*next
;
134 /* Process id this object refers to. */
137 /* Handle from dlopen for libthread_db.so. */
140 /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
141 HANDLE. It may be NULL for system library. */
144 /* Structure that identifies the child process for the
145 <proc_service.h> interface. */
146 struct ps_prochandle proc_handle
;
148 /* Connection to the libthread_db library. */
149 td_thragent_t
*thread_agent
;
151 /* True if we need to apply the workaround for glibc/BZ5983. When
152 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
153 list, nptl_db returns the parent's threads in addition to the new
154 (single) child thread. If this flag is set, we do extra work to
155 be able to ignore such stale entries. */
156 int need_stale_parent_threads_check
;
158 /* Location of the thread creation event breakpoint. The code at
159 this location in the child process will be called by the pthread
160 library whenever a new thread is created. By setting a special
161 breakpoint at this location, GDB can detect when a new thread is
162 created. We obtain this location via the td_ta_event_addr
164 CORE_ADDR td_create_bp_addr
;
166 /* Location of the thread death event breakpoint. */
167 CORE_ADDR td_death_bp_addr
;
169 /* Pointers to the libthread_db functions. */
171 td_err_e (*td_init_p
) (void);
173 td_err_e (*td_ta_new_p
) (struct ps_prochandle
* ps
,
175 td_err_e (*td_ta_map_id2thr_p
) (const td_thragent_t
*ta
, thread_t pt
,
176 td_thrhandle_t
*__th
);
177 td_err_e (*td_ta_map_lwp2thr_p
) (const td_thragent_t
*ta
,
178 lwpid_t lwpid
, td_thrhandle_t
*th
);
179 td_err_e (*td_ta_thr_iter_p
) (const td_thragent_t
*ta
,
180 td_thr_iter_f
*callback
, void *cbdata_p
,
181 td_thr_state_e state
, int ti_pri
,
182 sigset_t
*ti_sigmask_p
,
183 unsigned int ti_user_flags
);
184 td_err_e (*td_ta_event_addr_p
) (const td_thragent_t
*ta
,
185 td_event_e event
, td_notify_t
*ptr
);
186 td_err_e (*td_ta_set_event_p
) (const td_thragent_t
*ta
,
187 td_thr_events_t
*event
);
188 td_err_e (*td_ta_clear_event_p
) (const td_thragent_t
*ta
,
189 td_thr_events_t
*event
);
190 td_err_e (*td_ta_event_getmsg_p
) (const td_thragent_t
*ta
,
191 td_event_msg_t
*msg
);
193 td_err_e (*td_thr_validate_p
) (const td_thrhandle_t
*th
);
194 td_err_e (*td_thr_get_info_p
) (const td_thrhandle_t
*th
,
195 td_thrinfo_t
*infop
);
196 td_err_e (*td_thr_event_enable_p
) (const td_thrhandle_t
*th
,
199 td_err_e (*td_thr_tls_get_addr_p
) (const td_thrhandle_t
*th
,
200 psaddr_t map_address
,
201 size_t offset
, psaddr_t
*address
);
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 /* In the case of a zombie thread, don't continue. We don't want to
430 attach to it thinking it is a new thread. */
431 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
432 return TD_THR_ZOMBIE
;
434 if (inout
->thread_info
== NULL
)
436 /* New thread. Attach to it now (why wait?). */
437 if (!have_threads (thread_ptid
))
438 thread_db_find_new_threads_1 (thread_ptid
);
440 attach_thread (thread_ptid
, thp
, &ti
);
441 inout
->thread_info
= find_thread_ptid (thread_ptid
);
442 gdb_assert (inout
->thread_info
!= NULL
);
448 /* Convert between user-level thread ids and LWP ids. */
451 thread_from_lwp (ptid_t ptid
)
455 struct thread_db_info
*info
;
456 struct thread_get_info_inout io
= {0};
458 /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
461 /* This ptid comes from linux-nat.c, which should always fill in the
463 gdb_assert (GET_LWP (ptid
) != 0);
465 info
= get_thread_db_info (GET_PID (ptid
));
467 /* Access an lwp we know is stopped. */
468 info
->proc_handle
.ptid
= ptid
;
469 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
471 error (_("Cannot find user-level thread for LWP %ld: %s"),
472 GET_LWP (ptid
), thread_db_err_str (err
));
474 /* Fetch the thread info. If we get back TD_THR_ZOMBIE, then the
475 event thread has already died. If another gdb interface has called
476 thread_alive() previously, the thread won't be found on the thread list
477 anymore. In that case, we don't want to process this ptid anymore
478 to avoid the possibility of later treating it as a newly
479 discovered thread id that we should add to the list. Thus,
480 we return a -1 ptid which is also how the thread list marks a
482 io
.thread_db_info
= info
;
483 io
.thread_info
= NULL
;
484 if (thread_get_info_callback (&th
, &io
) == TD_THR_ZOMBIE
485 && io
.thread_info
== NULL
)
486 return minus_one_ptid
;
488 gdb_assert (ptid_get_tid (ptid
) == 0);
493 /* Attach to lwp PTID, doing whatever else is required to have this
494 LWP under the debugger's control --- e.g., enabling event
495 reporting. Returns true on success. */
497 thread_db_attach_lwp (ptid_t ptid
)
502 struct thread_db_info
*info
;
504 info
= get_thread_db_info (GET_PID (ptid
));
509 /* This ptid comes from linux-nat.c, which should always fill in the
511 gdb_assert (GET_LWP (ptid
) != 0);
513 /* Access an lwp we know is stopped. */
514 info
->proc_handle
.ptid
= ptid
;
516 /* If we have only looked at the first thread before libpthread was
517 initialized, we may not know its thread ID yet. Make sure we do
518 before we add another thread to the list. */
519 if (!have_threads (ptid
))
520 thread_db_find_new_threads_1 (ptid
);
522 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, GET_LWP (ptid
), &th
);
524 /* Cannot find user-level thread. */
527 err
= info
->td_thr_get_info_p (&th
, &ti
);
530 warning (_("Cannot get thread info: %s"), thread_db_err_str (err
));
534 attach_thread (ptid
, &th
, &ti
);
539 verbose_dlsym (void *handle
, const char *name
)
541 void *sym
= dlsym (handle
, name
);
543 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
549 enable_thread_event (int event
, CORE_ADDR
*bp
)
553 struct thread_db_info
*info
;
555 info
= get_thread_db_info (GET_PID (inferior_ptid
));
557 /* Access an lwp we know is stopped. */
558 info
->proc_handle
.ptid
= inferior_ptid
;
560 /* Get the breakpoint address for thread EVENT. */
561 err
= info
->td_ta_event_addr_p (info
->thread_agent
, event
, ¬ify
);
565 /* Set up the breakpoint. */
566 gdb_assert (exec_bfd
);
567 (*bp
) = (gdbarch_convert_from_func_ptr_addr
569 /* Do proper sign extension for the target. */
570 (bfd_get_sign_extend_vma (exec_bfd
) > 0
571 ? (CORE_ADDR
) (intptr_t) notify
.u
.bptaddr
572 : (CORE_ADDR
) (uintptr_t) notify
.u
.bptaddr
),
574 create_thread_event_breakpoint (target_gdbarch
, *bp
);
579 /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
580 return 1 if this version is lower (and not equal) to
581 VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
584 inferior_has_bug (const char *ver_symbol
, int ver_major_min
, int ver_minor_min
)
586 struct minimal_symbol
*version_msym
;
587 CORE_ADDR version_addr
;
589 int err
, got
, retval
= 0;
591 version_msym
= lookup_minimal_symbol (ver_symbol
, NULL
, NULL
);
592 if (version_msym
== NULL
)
595 version_addr
= SYMBOL_VALUE_ADDRESS (version_msym
);
596 got
= target_read_string (version_addr
, &version
, 32, &err
);
597 if (err
== 0 && memchr (version
, 0, got
) == &version
[got
-1])
601 retval
= (sscanf (version
, "%d.%d", &major
, &minor
) == 2
602 && (major
< ver_major_min
603 || (major
== ver_major_min
&& minor
< ver_minor_min
)));
611 enable_thread_event_reporting (void)
613 td_thr_events_t events
;
615 #ifdef HAVE_GNU_LIBC_VERSION_H
616 const char *libc_version
;
617 int libc_major
, libc_minor
;
619 struct thread_db_info
*info
;
621 info
= get_thread_db_info (GET_PID (inferior_ptid
));
623 /* We cannot use the thread event reporting facility if these
624 functions aren't available. */
625 if (info
->td_ta_event_addr_p
== NULL
626 || info
->td_ta_set_event_p
== NULL
627 || info
->td_ta_event_getmsg_p
== NULL
628 || info
->td_thr_event_enable_p
== NULL
)
631 /* Set the process wide mask saying which events we're interested in. */
632 td_event_emptyset (&events
);
633 td_event_addset (&events
, TD_CREATE
);
635 #ifdef HAVE_GNU_LIBC_VERSION_H
636 /* The event reporting facility is broken for TD_DEATH events in
637 glibc 2.1.3, so don't enable it if we have glibc but a lower
639 libc_version
= gnu_get_libc_version ();
640 if (sscanf (libc_version
, "%d.%d", &libc_major
, &libc_minor
) == 2
641 && (libc_major
> 2 || (libc_major
== 2 && libc_minor
> 1)))
643 td_event_addset (&events
, TD_DEATH
);
645 err
= info
->td_ta_set_event_p (info
->thread_agent
, &events
);
648 warning (_("Unable to set global thread event mask: %s"),
649 thread_db_err_str (err
));
653 /* Delete previous thread event breakpoints, if any. */
654 remove_thread_event_breakpoints ();
655 info
->td_create_bp_addr
= 0;
656 info
->td_death_bp_addr
= 0;
658 /* Set up the thread creation event. */
659 err
= enable_thread_event (TD_CREATE
, &info
->td_create_bp_addr
);
662 warning (_("Unable to get location for thread creation breakpoint: %s"),
663 thread_db_err_str (err
));
667 /* Set up the thread death event. */
668 err
= enable_thread_event (TD_DEATH
, &info
->td_death_bp_addr
);
671 warning (_("Unable to get location for thread death breakpoint: %s"),
672 thread_db_err_str (err
));
677 /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
680 Return 1 if the caller should abort libthread_db initialization. Return 0
684 thread_db_find_new_threads_silently (ptid_t ptid
)
686 volatile struct gdb_exception except
;
688 TRY_CATCH (except
, RETURN_MASK_ERROR
)
690 thread_db_find_new_threads_2 (ptid
, 1);
693 if (except
.reason
< 0)
695 if (libthread_db_debug
)
696 exception_fprintf (gdb_stderr
, except
,
697 "Warning: thread_db_find_new_threads_silently: ");
699 /* There is a bug fixed between nptl 2.6.1 and 2.7 by
700 commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
701 where calls to td_thr_get_info fail with TD_ERR for statically linked
702 executables if td_thr_get_info is called before glibc has initialized
705 If the nptl bug is NOT present in the inferior and still thread_db
706 reports an error return 1. It means the inferior has corrupted thread
707 list and GDB should fall back only to LWPs.
709 If the nptl bug is present in the inferior return 0 to silently ignore
710 such errors, and let gdb enumerate threads again later. In such case
711 GDB cannot properly display LWPs if the inferior thread list is
714 if (!inferior_has_bug ("nptl_version", 2, 7))
716 exception_fprintf (gdb_stderr
, except
,
717 _("Warning: couldn't activate thread debugging "
718 "using libthread_db: "));
725 /* Lookup a library in which given symbol resides.
726 Note: this is looking in GDB process, not in the inferior.
727 Returns library name, or NULL. */
730 dladdr_to_soname (const void *addr
)
734 if (dladdr (addr
, &info
) != 0)
735 return info
.dli_fname
;
739 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
741 Failure could happen if libthread_db does not have symbols we expect,
742 or when it refuses to work with the current inferior (e.g. due to
743 version mismatch between libthread_db and libpthread). */
746 try_thread_db_load_1 (struct thread_db_info
*info
)
750 /* Initialize pointers to the dynamic library functions we will use.
751 Essential functions first. */
753 info
->td_init_p
= verbose_dlsym (info
->handle
, "td_init");
754 if (info
->td_init_p
== NULL
)
757 err
= info
->td_init_p ();
760 warning (_("Cannot initialize libthread_db: %s"),
761 thread_db_err_str (err
));
765 info
->td_ta_new_p
= verbose_dlsym (info
->handle
, "td_ta_new");
766 if (info
->td_ta_new_p
== NULL
)
769 /* Initialize the structure that identifies the child process. */
770 info
->proc_handle
.ptid
= inferior_ptid
;
772 /* Now attempt to open a connection to the thread library. */
773 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
776 if (libthread_db_debug
)
777 printf_unfiltered (_("td_ta_new failed: %s\n"),
778 thread_db_err_str (err
));
783 #ifdef THREAD_DB_HAS_TD_VERSION
786 /* The errors above are not unexpected and silently ignored:
787 they just mean we haven't found correct version of
791 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
796 info
->td_ta_map_id2thr_p
= verbose_dlsym (info
->handle
, "td_ta_map_id2thr");
797 if (info
->td_ta_map_id2thr_p
== NULL
)
800 info
->td_ta_map_lwp2thr_p
= verbose_dlsym (info
->handle
,
801 "td_ta_map_lwp2thr");
802 if (info
->td_ta_map_lwp2thr_p
== NULL
)
805 info
->td_ta_thr_iter_p
= verbose_dlsym (info
->handle
, "td_ta_thr_iter");
806 if (info
->td_ta_thr_iter_p
== NULL
)
809 info
->td_thr_validate_p
= verbose_dlsym (info
->handle
, "td_thr_validate");
810 if (info
->td_thr_validate_p
== NULL
)
813 info
->td_thr_get_info_p
= verbose_dlsym (info
->handle
, "td_thr_get_info");
814 if (info
->td_thr_get_info_p
== NULL
)
817 /* These are not essential. */
818 info
->td_ta_event_addr_p
= dlsym (info
->handle
, "td_ta_event_addr");
819 info
->td_ta_set_event_p
= dlsym (info
->handle
, "td_ta_set_event");
820 info
->td_ta_clear_event_p
= dlsym (info
->handle
, "td_ta_clear_event");
821 info
->td_ta_event_getmsg_p
= dlsym (info
->handle
, "td_ta_event_getmsg");
822 info
->td_thr_event_enable_p
= dlsym (info
->handle
, "td_thr_event_enable");
823 info
->td_thr_tls_get_addr_p
= dlsym (info
->handle
, "td_thr_tls_get_addr");
825 if (thread_db_find_new_threads_silently (inferior_ptid
) != 0)
827 /* Even if libthread_db initializes, if the thread list is
828 corrupted, we'd not manage to list any threads. Better reject this
829 thread_db, and fall back to at least listing LWPs. */
833 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
835 if (libthread_db_debug
|| *libthread_db_search_path
)
839 library
= dladdr_to_soname (*info
->td_ta_new_p
);
841 library
= LIBTHREAD_DB_SO
;
843 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
847 /* The thread library was detected. Activate the thread_db target
848 if this is the first process using it. */
849 if (thread_db_list
->next
== NULL
)
850 push_target (&thread_db_ops
);
852 /* Enable event reporting, but not when debugging a core file. */
853 if (target_has_execution
)
854 enable_thread_event_reporting ();
859 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
860 relative, or just LIBTHREAD_DB. */
863 try_thread_db_load (const char *library
)
866 struct thread_db_info
*info
;
868 if (libthread_db_debug
)
869 printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
871 handle
= dlopen (library
, RTLD_NOW
);
874 if (libthread_db_debug
)
875 printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
879 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
883 td_init
= dlsym (handle
, "td_init");
886 const char *const libpath
= dladdr_to_soname (td_init
);
889 printf_unfiltered (_("Host %s resolved to: %s.\n"),
894 info
= add_thread_db_info (handle
);
896 /* Do not save system library name, that one is always trusted. */
897 if (strchr (library
, '/') != NULL
)
898 info
->filename
= gdb_realpath (library
);
900 if (try_thread_db_load_1 (info
))
903 /* This library "refused" to work on current inferior. */
904 delete_thread_db_info (GET_PID (inferior_ptid
));
908 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
909 Try loading libthread_db from the same directory as OBJ.
910 The result is true for success. */
913 try_thread_db_load_from_pdir_1 (struct objfile
*obj
)
915 struct cleanup
*cleanup
;
919 if (obj
->name
[0] != '/')
921 warning (_("Expected absolute pathname for libpthread in the"
922 " inferior, but got %s."), obj
->name
);
926 path
= xmalloc (strlen (obj
->name
) + 1 + strlen (LIBTHREAD_DB_SO
) + 1);
927 cleanup
= make_cleanup (xfree
, path
);
929 strcpy (path
, obj
->name
);
930 cp
= strrchr (path
, '/');
931 /* This should at minimum hit the first character. */
932 gdb_assert (cp
!= NULL
);
933 strcpy (cp
+ 1, LIBTHREAD_DB_SO
);
935 if (!file_is_auto_load_safe (path
, _("auto-load: Loading libthread-db "
936 "library \"%s\" from $pdir.\n"),
940 result
= try_thread_db_load (path
);
942 do_cleanups (cleanup
);
946 /* Handle $pdir in libthread-db-search-path.
947 Look for libthread_db in the directory of libpthread.
948 The result is true for success. */
951 try_thread_db_load_from_pdir (void)
955 if (!auto_load_thread_db
)
959 if (libpthread_name_p (obj
->name
))
961 if (try_thread_db_load_from_pdir_1 (obj
))
964 /* We may have found the separate-debug-info version of
965 libpthread, and it may live in a directory without a matching
967 if (obj
->separate_debug_objfile_backlink
!= NULL
)
968 return try_thread_db_load_from_pdir_1 (obj
->separate_debug_objfile_backlink
);
976 /* Handle $sdir in libthread-db-search-path.
977 Look for libthread_db in the system dirs, or wherever a plain
978 dlopen(file_without_path) will look.
979 The result is true for success. */
982 try_thread_db_load_from_sdir (void)
984 return try_thread_db_load (LIBTHREAD_DB_SO
);
987 /* Try to load libthread_db from directory DIR of length DIR_LEN.
988 The result is true for success. */
991 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
993 struct cleanup
*cleanup
;
997 if (!auto_load_thread_db
)
1000 path
= xmalloc (dir_len
+ 1 + strlen (LIBTHREAD_DB_SO
) + 1);
1001 cleanup
= make_cleanup (xfree
, path
);
1003 memcpy (path
, dir
, dir_len
);
1004 path
[dir_len
] = '/';
1005 strcpy (path
+ dir_len
+ 1, LIBTHREAD_DB_SO
);
1007 if (!file_is_auto_load_safe (path
, _("auto-load: Loading libthread-db "
1008 "library \"%s\" from explicit "
1013 result
= try_thread_db_load (path
);
1015 do_cleanups (cleanup
);
1019 /* Search libthread_db_search_path for libthread_db which "agrees"
1020 to work on current inferior.
1021 The result is true for success. */
1024 thread_db_load_search (void)
1026 const char *search_path
= libthread_db_search_path
;
1029 while (*search_path
)
1031 const char *end
= strchr (search_path
, ':');
1032 const char *this_dir
= search_path
;
1033 size_t this_dir_len
;
1037 this_dir_len
= end
- search_path
;
1038 search_path
+= this_dir_len
+ 1;
1042 this_dir_len
= strlen (this_dir
);
1043 search_path
+= this_dir_len
;
1046 if (this_dir_len
== sizeof ("$pdir") - 1
1047 && strncmp (this_dir
, "$pdir", this_dir_len
) == 0)
1049 if (try_thread_db_load_from_pdir ())
1055 else if (this_dir_len
== sizeof ("$sdir") - 1
1056 && strncmp (this_dir
, "$sdir", this_dir_len
) == 0)
1058 if (try_thread_db_load_from_sdir ())
1066 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
1074 if (libthread_db_debug
)
1075 printf_unfiltered (_("thread_db_load_search returning %d\n"), rc
);
1079 /* Return non-zero if the inferior has a libpthread. */
1082 has_libpthread (void)
1084 struct objfile
*obj
;
1087 if (libpthread_name_p (obj
->name
))
1093 /* Attempt to load and initialize libthread_db.
1094 Return 1 on success. */
1097 thread_db_load (void)
1099 struct thread_db_info
*info
;
1101 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1106 /* Don't attempt to use thread_db on executables not running
1108 if (!target_has_registers
)
1111 /* Don't attempt to use thread_db for remote targets. */
1112 if (!(target_can_run (¤t_target
) || core_bfd
))
1115 if (thread_db_load_search ())
1118 /* We couldn't find a libthread_db.
1119 If the inferior has a libpthread warn the user. */
1120 if (has_libpthread ())
1122 warning (_("Unable to find libthread_db matching inferior's thread"
1123 " library, thread debugging will not be available."));
1127 /* Either this executable isn't using libpthread at all, or it is
1128 statically linked. Since we can't easily distinguish these two cases,
1129 no warning is issued. */
1134 disable_thread_event_reporting (struct thread_db_info
*info
)
1136 if (info
->td_ta_clear_event_p
!= NULL
)
1138 td_thr_events_t events
;
1140 /* Set the process wide mask saying we aren't interested in any
1142 td_event_fillset (&events
);
1143 info
->td_ta_clear_event_p (info
->thread_agent
, &events
);
1146 info
->td_create_bp_addr
= 0;
1147 info
->td_death_bp_addr
= 0;
1151 check_thread_signals (void)
1153 if (!thread_signals
)
1158 lin_thread_get_thread_signals (&mask
);
1159 sigemptyset (&thread_stop_set
);
1160 sigemptyset (&thread_print_set
);
1162 for (i
= 1; i
< NSIG
; i
++)
1164 if (sigismember (&mask
, i
))
1166 if (signal_stop_update (gdb_signal_from_host (i
), 0))
1167 sigaddset (&thread_stop_set
, i
);
1168 if (signal_print_update (gdb_signal_from_host (i
), 0))
1169 sigaddset (&thread_print_set
, i
);
1176 /* Check whether thread_db is usable. This function is called when
1177 an inferior is created (or otherwise acquired, e.g. attached to)
1178 and when new shared libraries are loaded into a running process. */
1181 check_for_thread_db (void)
1183 /* Do nothing if we couldn't load libthread_db.so.1. */
1184 if (!thread_db_load ())
1188 /* This function is called via the new_objfile observer. */
1191 thread_db_new_objfile (struct objfile
*objfile
)
1193 /* This observer must always be called with inferior_ptid set
1197 /* libpthread with separate debug info has its debug info file already
1198 loaded (and notified without successfult thread_db initialization))
1199 the time observer_notify_new_objfile is called for the library itself.
1200 Static executables have their separate debug info loaded already
1201 before the inferior has started. */
1202 && objfile
->separate_debug_objfile_backlink
== NULL
1203 /* Only check for thread_db if we loaded libpthread,
1204 or if this is the main symbol file.
1205 We need to check OBJF_MAINLINE to handle the case of debugging
1206 a statically linked executable AND the symbol file is specified AFTER
1207 the exec file is loaded (e.g., gdb -c core ; file foo).
1208 For dynamically linked executables, libpthread can be near the end
1209 of the list of shared libraries to load, and in an app of several
1210 thousand shared libraries, this can otherwise be painful. */
1211 && ((objfile
->flags
& OBJF_MAINLINE
) != 0
1212 || libpthread_name_p (objfile
->name
)))
1213 check_for_thread_db ();
1216 /* This function is called via the inferior_created observer.
1217 This handles the case of debugging statically linked executables. */
1220 thread_db_inferior_created (struct target_ops
*target
, int from_tty
)
1222 check_for_thread_db ();
1225 /* Attach to a new thread. This function is called when we receive a
1226 TD_CREATE event or when we iterate over all threads and find one
1227 that wasn't already in our list. Returns true on success. */
1230 attach_thread (ptid_t ptid
, const td_thrhandle_t
*th_p
,
1231 const td_thrinfo_t
*ti_p
)
1233 struct private_thread_info
*private;
1234 struct thread_info
*tp
;
1236 struct thread_db_info
*info
;
1238 /* If we're being called after a TD_CREATE event, we may already
1239 know about this thread. There are two ways this can happen. We
1240 may have iterated over all threads between the thread creation
1241 and the TD_CREATE event, for instance when the user has issued
1242 the `info threads' command before the SIGTRAP for hitting the
1243 thread creation breakpoint was reported. Alternatively, the
1244 thread may have exited and a new one been created with the same
1245 thread ID. In the first case we don't need to do anything; in
1246 the second case we should discard information about the dead
1247 thread and attach to the new one. */
1248 tp
= find_thread_ptid (ptid
);
1251 /* If tp->private is NULL, then GDB is already attached to this
1252 thread, but we do not know anything about it. We can learn
1253 about it here. This can only happen if we have some other
1254 way besides libthread_db to notice new threads (i.e.
1255 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
1256 exit, so this can not be a stale thread recreated with the
1258 if (tp
->private != NULL
)
1260 if (!tp
->private->dying
)
1263 delete_thread (ptid
);
1268 if (target_has_execution
)
1269 check_thread_signals ();
1271 if (ti_p
->ti_state
== TD_THR_UNKNOWN
|| ti_p
->ti_state
== TD_THR_ZOMBIE
)
1272 return 0; /* A zombie thread -- do not attach. */
1274 /* Under GNU/Linux, we have to attach to each and every thread. */
1275 if (target_has_execution
1280 res
= lin_lwp_attach_lwp (BUILD_LWP (ti_p
->ti_lid
, GET_PID (ptid
)));
1283 /* Error, stop iterating. */
1288 /* Pretend this thread doesn't exist yet, and keep
1293 /* Otherwise, we sucessfully attached to the thread. */
1296 /* Construct the thread's private data. */
1297 private = xmalloc (sizeof (struct private_thread_info
));
1298 memset (private, 0, sizeof (struct private_thread_info
));
1300 /* A thread ID of zero may mean the thread library has not initialized
1301 yet. But we shouldn't even get here if that's the case. FIXME:
1302 if we change GDB to always have at least one thread in the thread
1303 list this will have to go somewhere else; maybe private == NULL
1304 until the thread_db target claims it. */
1305 gdb_assert (ti_p
->ti_tid
!= 0);
1306 private->th
= *th_p
;
1307 private->tid
= ti_p
->ti_tid
;
1309 /* Add the thread to GDB's thread list. */
1311 add_thread_with_info (ptid
, private);
1313 tp
->private = private;
1315 info
= get_thread_db_info (GET_PID (ptid
));
1317 /* Enable thread event reporting for this thread, except when
1318 debugging a core file. */
1319 if (target_has_execution
)
1321 err
= info
->td_thr_event_enable_p (th_p
, 1);
1323 error (_("Cannot enable thread event reporting for %s: %s"),
1324 target_pid_to_str (ptid
), thread_db_err_str (err
));
1331 detach_thread (ptid_t ptid
)
1333 struct thread_info
*thread_info
;
1335 /* Don't delete the thread now, because it still reports as active
1336 until it has executed a few instructions after the event
1337 breakpoint - if we deleted it now, "info threads" would cause us
1338 to re-attach to it. Just mark it as having had a TD_DEATH
1339 event. This means that we won't delete it from our thread list
1340 until we notice that it's dead (via prune_threads), or until
1341 something re-uses its thread ID. We'll report the thread exit
1342 when the underlying LWP dies. */
1343 thread_info
= find_thread_ptid (ptid
);
1344 gdb_assert (thread_info
!= NULL
&& thread_info
->private != NULL
);
1345 thread_info
->private->dying
= 1;
1349 thread_db_detach (struct target_ops
*ops
, char *args
, int from_tty
)
1351 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1352 struct thread_db_info
*info
;
1354 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1358 if (target_has_execution
)
1360 disable_thread_event_reporting (info
);
1362 /* Delete the old thread event breakpoints. Note that
1363 unlike when mourning, we can remove them here because
1364 there's still a live inferior to poke at. In any case,
1365 GDB will not try to insert anything in the inferior when
1366 removing a breakpoint. */
1367 remove_thread_event_breakpoints ();
1370 delete_thread_db_info (GET_PID (inferior_ptid
));
1373 target_beneath
->to_detach (target_beneath
, args
, from_tty
);
1375 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1377 /* If there are no more processes using libpthread, detach the
1378 thread_db target ops. */
1379 if (!thread_db_list
)
1380 unpush_target (&thread_db_ops
);
1383 /* Check if PID is currently stopped at the location of a thread event
1384 breakpoint location. If it is, read the event message and act upon
1388 check_event (ptid_t ptid
)
1390 struct regcache
*regcache
= get_thread_regcache (ptid
);
1391 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1397 struct thread_db_info
*info
;
1399 info
= get_thread_db_info (GET_PID (ptid
));
1401 /* Bail out early if we're not at a thread event breakpoint. */
1402 stop_pc
= regcache_read_pc (regcache
)
1403 - gdbarch_decr_pc_after_break (gdbarch
);
1404 if (stop_pc
!= info
->td_create_bp_addr
1405 && stop_pc
!= info
->td_death_bp_addr
)
1408 /* Access an lwp we know is stopped. */
1409 info
->proc_handle
.ptid
= ptid
;
1411 /* If we have only looked at the first thread before libpthread was
1412 initialized, we may not know its thread ID yet. Make sure we do
1413 before we add another thread to the list. */
1414 if (!have_threads (ptid
))
1415 thread_db_find_new_threads_1 (ptid
);
1417 /* If we are at a create breakpoint, we do not know what new lwp
1418 was created and cannot specifically locate the event message for it.
1419 We have to call td_ta_event_getmsg() to get
1420 the latest message. Since we have no way of correlating whether
1421 the event message we get back corresponds to our breakpoint, we must
1422 loop and read all event messages, processing them appropriately.
1423 This guarantees we will process the correct message before continuing
1424 from the breakpoint.
1426 Currently, death events are not enabled. If they are enabled,
1427 the death event can use the td_thr_event_getmsg() interface to
1428 get the message specifically for that lwp and avoid looping
1435 err
= info
->td_ta_event_getmsg_p (info
->thread_agent
, &msg
);
1438 if (err
== TD_NOMSG
)
1441 error (_("Cannot get thread event message: %s"),
1442 thread_db_err_str (err
));
1445 err
= info
->td_thr_get_info_p (msg
.th_p
, &ti
);
1447 error (_("Cannot get thread info: %s"), thread_db_err_str (err
));
1449 ptid
= ptid_build (GET_PID (ptid
), ti
.ti_lid
, 0);
1454 /* Call attach_thread whether or not we already know about a
1455 thread with this thread ID. */
1456 attach_thread (ptid
, msg
.th_p
, &ti
);
1462 if (!in_thread_list (ptid
))
1463 error (_("Spurious thread death event."));
1465 detach_thread (ptid
);
1470 error (_("Spurious thread event."));
1477 thread_db_wait (struct target_ops
*ops
,
1478 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1481 struct thread_db_info
*info
;
1482 struct target_ops
*beneath
= find_target_beneath (ops
);
1484 ptid
= beneath
->to_wait (beneath
, ptid
, ourstatus
, options
);
1486 if (ourstatus
->kind
== TARGET_WAITKIND_IGNORE
)
1489 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
1490 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
1493 info
= get_thread_db_info (GET_PID (ptid
));
1495 /* If this process isn't using thread_db, we're done. */
1499 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1501 /* New image, it may or may not end up using thread_db. Assume
1502 not unless we find otherwise. */
1503 delete_thread_db_info (GET_PID (ptid
));
1504 if (!thread_db_list
)
1505 unpush_target (&thread_db_ops
);
1507 /* Thread event breakpoints are deleted by
1508 update_breakpoints_after_exec. */
1513 /* If we do not know about the main thread yet, this would be a good time to
1515 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
&& !have_threads (ptid
))
1516 thread_db_find_new_threads_1 (ptid
);
1518 if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
1519 && ourstatus
->value
.sig
== GDB_SIGNAL_TRAP
)
1520 /* Check for a thread event. */
1523 if (have_threads (ptid
))
1525 /* Change ptids back into the higher level PID + TID format. If
1526 the thread is dead and no longer on the thread list, we will
1527 get back a dead ptid. This can occur if the thread death
1528 event gets postponed by other simultaneous events. In such a
1529 case, we want to just ignore the event and continue on. */
1531 ptid
= thread_from_lwp (ptid
);
1532 if (GET_PID (ptid
) == -1)
1533 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1540 thread_db_mourn_inferior (struct target_ops
*ops
)
1542 struct target_ops
*target_beneath
= find_target_beneath (ops
);
1544 delete_thread_db_info (GET_PID (inferior_ptid
));
1546 target_beneath
->to_mourn_inferior (target_beneath
);
1548 /* Delete the old thread event breakpoints. Do this after mourning
1549 the inferior, so that we don't try to uninsert them. */
1550 remove_thread_event_breakpoints ();
1552 /* Detach thread_db target ops. */
1553 if (!thread_db_list
)
1554 unpush_target (ops
);
1557 struct callback_data
1559 struct thread_db_info
*info
;
1564 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1569 struct thread_info
*tp
;
1570 struct callback_data
*cb_data
= data
;
1571 struct thread_db_info
*info
= cb_data
->info
;
1573 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1575 error (_("find_new_threads_callback: cannot get thread info: %s"),
1576 thread_db_err_str (err
));
1578 if (ti
.ti_state
== TD_THR_UNKNOWN
|| ti
.ti_state
== TD_THR_ZOMBIE
)
1579 return 0; /* A zombie -- ignore. */
1583 /* A thread ID of zero means that this is the main thread, but
1584 glibc has not yet initialized thread-local storage and the
1585 pthread library. We do not know what the thread's TID will
1586 be yet. Just enable event reporting and otherwise ignore
1589 /* In that case, we're not stopped in a fork syscall and don't
1590 need this glibc bug workaround. */
1591 info
->need_stale_parent_threads_check
= 0;
1593 if (target_has_execution
)
1595 err
= info
->td_thr_event_enable_p (th_p
, 1);
1597 error (_("Cannot enable thread event reporting for LWP %d: %s"),
1598 (int) ti
.ti_lid
, thread_db_err_str (err
));
1604 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1605 bit expensive, as it needs to open /proc/pid/status, so try to
1606 avoid doing the work if we know we don't have to. */
1607 if (info
->need_stale_parent_threads_check
)
1609 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1611 if (tgid
!= -1 && tgid
!= info
->pid
)
1615 ptid
= ptid_build (info
->pid
, ti
.ti_lid
, 0);
1616 tp
= find_thread_ptid (ptid
);
1617 if (tp
== NULL
|| tp
->private == NULL
)
1619 if (attach_thread (ptid
, th_p
, &ti
))
1620 cb_data
->new_threads
+= 1;
1622 /* Problem attaching this thread; perhaps it exited before we
1624 This could mean that the thread list inside glibc itself is in
1625 inconsistent state, and libthread_db could go on looping forever
1626 (observed with glibc-2.3.6). To prevent that, terminate
1627 iteration: thread_db_find_new_threads_2 will retry. */
1634 /* Helper for thread_db_find_new_threads_2.
1635 Returns number of new threads found. */
1638 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1641 volatile struct gdb_exception except
;
1642 struct callback_data data
;
1643 td_err_e err
= TD_ERR
;
1646 data
.new_threads
= 0;
1648 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1650 /* Iterate over all user-space threads to discover new threads. */
1651 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1652 find_new_threads_callback
,
1655 TD_THR_LOWEST_PRIORITY
,
1657 TD_THR_ANY_USER_FLAGS
);
1660 if (libthread_db_debug
)
1662 if (except
.reason
< 0)
1663 exception_fprintf (gdb_stderr
, except
,
1664 "Warning: find_new_threads_once: ");
1666 printf_filtered (_("Found %d new threads in iteration %d.\n"),
1667 data
.new_threads
, iteration
);
1673 return data
.new_threads
;
1676 /* Search for new threads, accessing memory through stopped thread
1677 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1678 searches in a row do not discover any new threads. */
1681 thread_db_find_new_threads_2 (ptid_t ptid
, int until_no_new
)
1683 td_err_e err
= TD_OK
;
1684 struct thread_db_info
*info
;
1685 int pid
= ptid_get_pid (ptid
);
1688 info
= get_thread_db_info (GET_PID (ptid
));
1690 /* Access an lwp we know is stopped. */
1691 info
->proc_handle
.ptid
= ptid
;
1695 /* Require 4 successive iterations which do not find any new threads.
1696 The 4 is a heuristic: there is an inherent race here, and I have
1697 seen that 2 iterations in a row are not always sufficient to
1698 "capture" all threads. */
1699 for (i
= 0, loop
= 0; loop
< 4 && err
== TD_OK
; ++i
, ++loop
)
1700 if (find_new_threads_once (info
, i
, &err
) != 0)
1702 /* Found some new threads. Restart the loop from beginning. */
1707 find_new_threads_once (info
, 0, &err
);
1710 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1714 thread_db_find_new_threads_1 (ptid_t ptid
)
1716 thread_db_find_new_threads_2 (ptid
, 0);
1720 update_thread_core (struct lwp_info
*info
, void *closure
)
1722 info
->core
= linux_common_core_of_thread (info
->ptid
);
1727 thread_db_find_new_threads (struct target_ops
*ops
)
1729 struct thread_db_info
*info
;
1730 struct inferior
*inf
;
1734 struct thread_info
*thread
;
1739 info
= get_thread_db_info (inf
->pid
);
1743 thread
= any_live_thread_of_process (inf
->pid
);
1744 if (thread
== NULL
|| thread
->executing
)
1747 thread_db_find_new_threads_1 (thread
->ptid
);
1750 if (target_has_execution
)
1751 iterate_over_lwps (minus_one_ptid
/* iterate over all */,
1752 update_thread_core
, NULL
);
1756 thread_db_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
1758 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1759 struct target_ops
*beneath
;
1761 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1763 static char buf
[64];
1766 tid
= thread_info
->private->tid
;
1767 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1768 tid
, GET_LWP (ptid
));
1773 beneath
= find_target_beneath (ops
);
1774 if (beneath
->to_pid_to_str (beneath
, ptid
))
1775 return beneath
->to_pid_to_str (beneath
, ptid
);
1777 return normal_pid_to_str (ptid
);
1780 /* Return a string describing the state of the thread specified by
1784 thread_db_extra_thread_info (struct thread_info
*info
)
1786 if (info
->private == NULL
)
1789 if (info
->private->dying
)
1795 /* Get the address of the thread local variable in load module LM which
1796 is stored at OFFSET within the thread local storage for thread PTID. */
1799 thread_db_get_thread_local_address (struct target_ops
*ops
,
1804 struct thread_info
*thread_info
;
1805 struct target_ops
*beneath
;
1807 /* If we have not discovered any threads yet, check now. */
1808 if (!have_threads (ptid
))
1809 thread_db_find_new_threads_1 (ptid
);
1811 /* Find the matching thread. */
1812 thread_info
= find_thread_ptid (ptid
);
1814 if (thread_info
!= NULL
&& thread_info
->private != NULL
)
1818 struct thread_db_info
*info
;
1820 info
= get_thread_db_info (GET_PID (ptid
));
1822 /* glibc doesn't provide the needed interface. */
1823 if (!info
->td_thr_tls_get_addr_p
)
1824 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1825 _("No TLS library support"));
1827 /* Caller should have verified that lm != 0. */
1828 gdb_assert (lm
!= 0);
1830 /* Finally, get the address of the variable. */
1831 /* Note the cast through uintptr_t: this interface only works if
1832 a target address fits in a psaddr_t, which is a host pointer.
1833 So a 32-bit debugger can not access 64-bit TLS through this. */
1834 err
= info
->td_thr_tls_get_addr_p (&thread_info
->private->th
,
1835 (psaddr_t
)(uintptr_t) lm
,
1838 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1839 /* The memory hasn't been allocated, yet. */
1840 if (err
== TD_NOTALLOC
)
1841 /* Now, if libthread_db provided the initialization image's
1842 address, we *could* try to build a non-lvalue value from
1843 the initialization image. */
1844 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1845 _("TLS not allocated yet"));
1848 /* Something else went wrong. */
1850 throw_error (TLS_GENERIC_ERROR
,
1851 (("%s")), thread_db_err_str (err
));
1853 /* Cast assuming host == target. Joy. */
1854 /* Do proper sign extension for the target. */
1855 gdb_assert (exec_bfd
);
1856 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1857 ? (CORE_ADDR
) (intptr_t) address
1858 : (CORE_ADDR
) (uintptr_t) address
);
1861 beneath
= find_target_beneath (ops
);
1862 if (beneath
->to_get_thread_local_address
)
1863 return beneath
->to_get_thread_local_address (beneath
, ptid
, lm
, offset
);
1865 throw_error (TLS_GENERIC_ERROR
,
1866 _("TLS not supported on this target"));
1869 /* Callback routine used to find a thread based on the TID part of
1873 thread_db_find_thread_from_tid (struct thread_info
*thread
, void *data
)
1875 long *tid
= (long *) data
;
1877 if (thread
->private->tid
== *tid
)
1883 /* Implement the to_get_ada_task_ptid target method for this target. */
1886 thread_db_get_ada_task_ptid (long lwp
, long thread
)
1888 struct thread_info
*thread_info
;
1890 thread_db_find_new_threads_1 (inferior_ptid
);
1891 thread_info
= iterate_over_threads (thread_db_find_thread_from_tid
, &thread
);
1893 gdb_assert (thread_info
!= NULL
);
1895 return (thread_info
->ptid
);
1899 thread_db_resume (struct target_ops
*ops
,
1900 ptid_t ptid
, int step
, enum gdb_signal signo
)
1902 struct target_ops
*beneath
= find_target_beneath (ops
);
1903 struct thread_db_info
*info
;
1905 if (ptid_equal (ptid
, minus_one_ptid
))
1906 info
= get_thread_db_info (GET_PID (inferior_ptid
));
1908 info
= get_thread_db_info (GET_PID (ptid
));
1910 /* This workaround is only needed for child fork lwps stopped in a
1911 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1912 workaround can be disabled. */
1914 info
->need_stale_parent_threads_check
= 0;
1916 beneath
->to_resume (beneath
, ptid
, step
, signo
);
1919 /* qsort helper function for info_auto_load_libthread_db, sort the
1920 thread_db_info pointers primarily by their FILENAME and secondarily by their
1921 PID, both in ascending order. */
1924 info_auto_load_libthread_db_compare (const void *ap
, const void *bp
)
1926 struct thread_db_info
*a
= *(struct thread_db_info
**) ap
;
1927 struct thread_db_info
*b
= *(struct thread_db_info
**) bp
;
1930 retval
= strcmp (a
->filename
, b
->filename
);
1934 return (a
->pid
> b
->pid
) - (a
->pid
- b
->pid
);
1937 /* Implement 'info auto-load libthread-db'. */
1940 info_auto_load_libthread_db (char *args
, int from_tty
)
1942 struct ui_out
*uiout
= current_uiout
;
1943 const char *cs
= args
? args
: "";
1944 struct thread_db_info
*info
, **array
;
1945 unsigned info_count
, unique_filenames
;
1946 size_t max_filename_len
, max_pids_len
, pids_len
;
1947 struct cleanup
*back_to
;
1951 while (isspace (*cs
))
1954 error (_("'info auto-load libthread-db' does not accept any parameters"));
1957 for (info
= thread_db_list
; info
; info
= info
->next
)
1958 if (info
->filename
!= NULL
)
1961 array
= xmalloc (sizeof (*array
) * info_count
);
1962 back_to
= make_cleanup (xfree
, array
);
1965 for (info
= thread_db_list
; info
; info
= info
->next
)
1966 if (info
->filename
!= NULL
)
1967 array
[info_count
++] = info
;
1969 /* Sort ARRAY by filenames and PIDs. */
1971 qsort (array
, info_count
, sizeof (*array
),
1972 info_auto_load_libthread_db_compare
);
1974 /* Calculate the number of unique filenames (rows) and the maximum string
1975 length of PIDs list for the unique filenames (columns). */
1977 unique_filenames
= 0;
1978 max_filename_len
= 0;
1981 for (i
= 0; i
< info_count
; i
++)
1983 int pid
= array
[i
]->pid
;
1984 size_t this_pid_len
;
1986 for (this_pid_len
= 0; pid
!= 0; pid
/= 10)
1989 if (i
== 0 || strcmp (array
[i
- 1]->filename
, array
[i
]->filename
) != 0)
1992 max_filename_len
= max (max_filename_len
,
1993 strlen (array
[i
]->filename
));
1997 pids_len
-= strlen (", ");
1998 max_pids_len
= max (max_pids_len
, pids_len
);
2002 pids_len
+= this_pid_len
+ strlen (", ");
2006 pids_len
-= strlen (", ");
2007 max_pids_len
= max (max_pids_len
, pids_len
);
2010 /* Table header shifted right by preceding "libthread-db: " would not match
2012 if (info_count
> 0 && args
== auto_load_info_scripts_pattern_nl
)
2013 ui_out_text (uiout
, "\n");
2015 make_cleanup_ui_out_table_begin_end (uiout
, 2, unique_filenames
,
2016 "LinuxThreadDbTable");
2018 ui_out_table_header (uiout
, max_filename_len
, ui_left
, "filename",
2020 ui_out_table_header (uiout
, pids_len
, ui_left
, "PIDs", "Pids");
2021 ui_out_table_body (uiout
);
2023 pids
= xmalloc (max_pids_len
+ 1);
2024 make_cleanup (xfree
, pids
);
2026 /* Note I is incremented inside the cycle, not at its end. */
2027 for (i
= 0; i
< info_count
;)
2029 struct cleanup
*chain
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
2033 ui_out_field_string (uiout
, "filename", info
->filename
);
2036 while (i
< info_count
&& strcmp (info
->filename
, array
[i
]->filename
) == 0)
2038 if (pids_end
!= pids
)
2043 pids_end
+= xsnprintf (pids_end
, &pids
[max_pids_len
+ 1] - pids_end
,
2044 "%u", array
[i
]->pid
);
2045 gdb_assert (pids_end
< &pids
[max_pids_len
+ 1]);
2051 ui_out_field_string (uiout
, "pids", pids
);
2053 ui_out_text (uiout
, "\n");
2054 do_cleanups (chain
);
2057 do_cleanups (back_to
);
2059 if (info_count
== 0)
2060 ui_out_message (uiout
, 0, _("No auto-loaded libthread-db.\n"));
2064 init_thread_db_ops (void)
2066 thread_db_ops
.to_shortname
= "multi-thread";
2067 thread_db_ops
.to_longname
= "multi-threaded child process.";
2068 thread_db_ops
.to_doc
= "Threads and pthreads support.";
2069 thread_db_ops
.to_detach
= thread_db_detach
;
2070 thread_db_ops
.to_wait
= thread_db_wait
;
2071 thread_db_ops
.to_resume
= thread_db_resume
;
2072 thread_db_ops
.to_mourn_inferior
= thread_db_mourn_inferior
;
2073 thread_db_ops
.to_find_new_threads
= thread_db_find_new_threads
;
2074 thread_db_ops
.to_pid_to_str
= thread_db_pid_to_str
;
2075 thread_db_ops
.to_stratum
= thread_stratum
;
2076 thread_db_ops
.to_has_thread_control
= tc_schedlock
;
2077 thread_db_ops
.to_get_thread_local_address
2078 = thread_db_get_thread_local_address
;
2079 thread_db_ops
.to_extra_thread_info
= thread_db_extra_thread_info
;
2080 thread_db_ops
.to_get_ada_task_ptid
= thread_db_get_ada_task_ptid
;
2081 thread_db_ops
.to_magic
= OPS_MAGIC
;
2084 /* Provide a prototype to silence -Wmissing-prototypes. */
2085 extern initialize_file_ftype _initialize_thread_db
;
2088 _initialize_thread_db (void)
2090 init_thread_db_ops ();
2091 add_target (&thread_db_ops
);
2093 /* Defer loading of libthread_db.so until inferior is running.
2094 This allows gdb to load correct libthread_db for a given
2095 executable -- there could be mutiple versions of glibc,
2096 compiled with LinuxThreads or NPTL, and until there is
2097 a running inferior, we can't tell which libthread_db is
2098 the correct one to load. */
2100 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
2102 add_setshow_optional_filename_cmd ("libthread-db-search-path",
2104 &libthread_db_search_path
, _("\
2105 Set search path for libthread_db."), _("\
2106 Show the current search path or libthread_db."), _("\
2107 This path is used to search for libthread_db to be loaded into \
2109 Its value is a colon (':') separate list of directories to search.\n\
2110 Setting the search path to an empty list resets it to its default value."),
2111 set_libthread_db_search_path
,
2113 &setlist
, &showlist
);
2115 add_setshow_zinteger_cmd ("libthread-db", class_maintenance
,
2116 &libthread_db_debug
, _("\
2117 Set libthread-db debugging."), _("\
2118 Show libthread-db debugging."), _("\
2119 When non-zero, libthread-db debugging is enabled."),
2121 show_libthread_db_debug
,
2122 &setdebuglist
, &showdebuglist
);
2124 add_setshow_boolean_cmd ("libthread-db", class_support
,
2125 &auto_load_thread_db
, _("\
2126 Enable or disable auto-loading of inferior specific libthread_db."), _("\
2127 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
2128 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
2129 locations to load libthread_db compatible with the inferior.\n\
2130 Standard system libthread_db still gets loaded even with this option off.\n\
2131 This options has security implications for untrusted inferiors."),
2132 NULL
, show_auto_load_thread_db
,
2133 auto_load_set_cmdlist_get (),
2134 auto_load_show_cmdlist_get ());
2136 add_cmd ("libthread-db", class_info
, info_auto_load_libthread_db
,
2137 _("Print the list of loaded inferior specific libthread_db.\n\
2138 Usage: info auto-load libthread-db"),
2139 auto_load_info_cmdlist_get ());
2141 /* Add ourselves to objfile event chain. */
2142 observer_attach_new_objfile (thread_db_new_objfile
);
2144 /* Add ourselves to inferior_created event chain.
2145 This is needed to handle debugging statically linked programs where
2146 the new_objfile observer won't get called for libpthread. */
2147 observer_attach_inferior_created (thread_db_inferior_created
);