1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "gdb_proc_service.h"
23 #include "nat/gdb_thread_db.h"
28 #include "gdbthread.h"
36 #include "solib-svr4.h"
38 #include "observable.h"
39 #include "linux-nat.h"
40 #include "nat/linux-procfs.h"
41 #include "nat/linux-ptrace.h"
42 #include "nat/linux-osdata.h"
43 #include "auto-load.h"
44 #include "cli/cli-utils.h"
47 #include "nat/linux-namespaces.h"
49 #include "common/pathstuff.h"
52 /* GNU/Linux libthread_db support.
54 libthread_db is a library, provided along with libpthread.so, which
55 exposes the internals of the thread library to a debugger. It
56 allows GDB to find existing threads, new threads as they are
57 created, thread IDs (usually, the result of pthread_self), and
58 thread-local variables.
60 The libthread_db interface originates on Solaris, where it is both
61 more powerful and more complicated. This implementation only works
62 for NPTL, the glibc threading library. It assumes that each thread
63 is permanently assigned to a single light-weight process (LWP). At
64 some point it also supported the older LinuxThreads library, but it
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 const target_info thread_db_target_info
= {
81 N_("multi-threaded child process."),
82 N_("Threads and pthreads support.")
85 class thread_db_target final
: public target_ops
88 const target_info
&info () const override
89 { return thread_db_target_info
; }
91 strata
stratum () const override
{ return thread_stratum
; }
93 void detach (inferior
*, int) override
;
94 ptid_t
wait (ptid_t
, struct target_waitstatus
*, int) override
;
95 void resume (ptid_t
, int, enum gdb_signal
) override
;
96 void mourn_inferior () override
;
97 void update_thread_list () override
;
98 const char *pid_to_str (ptid_t
) override
;
99 CORE_ADDR
get_thread_local_address (ptid_t ptid
,
100 CORE_ADDR load_module_addr
,
101 CORE_ADDR offset
) override
;
102 const char *extra_thread_info (struct thread_info
*) override
;
103 ptid_t
get_ada_task_ptid (long lwp
, long thread
) override
;
105 thread_info
*thread_handle_to_thread_info (const gdb_byte
*thread_handle
,
107 inferior
*inf
) override
;
110 static char *libthread_db_search_path
;
112 /* Set to non-zero if thread_db auto-loading is enabled
113 by the "set auto-load libthread-db" command. */
114 static int auto_load_thread_db
= 1;
116 /* Set to non-zero if load-time libthread_db tests have been enabled
117 by the "maintenence set check-libthread-db" command. */
118 static int check_thread_db_on_load
= 0;
120 /* "show" command for the auto_load_thread_db configuration variable. */
123 show_auto_load_thread_db (struct ui_file
*file
, int from_tty
,
124 struct cmd_list_element
*c
, const char *value
)
126 fprintf_filtered (file
, _("Auto-loading of inferior specific libthread_db "
132 set_libthread_db_search_path (const char *ignored
, int from_tty
,
133 struct cmd_list_element
*c
)
135 if (*libthread_db_search_path
== '\0')
137 xfree (libthread_db_search_path
);
138 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
142 /* If non-zero, print details of libthread_db processing. */
144 static unsigned int libthread_db_debug
;
147 show_libthread_db_debug (struct ui_file
*file
, int from_tty
,
148 struct cmd_list_element
*c
, const char *value
)
150 fprintf_filtered (file
, _("libthread-db debugging is %s.\n"), value
);
153 /* If we're running on GNU/Linux, we must explicitly attach to any new
156 /* This module's target vector. */
157 static thread_db_target the_thread_db_target
;
159 /* Non-zero if we have determined the signals used by the threads
161 static int thread_signals
;
162 static sigset_t thread_stop_set
;
163 static sigset_t thread_print_set
;
165 struct thread_db_info
167 struct thread_db_info
*next
;
169 /* Process id this object refers to. */
172 /* Handle from dlopen for libthread_db.so. */
175 /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
176 HANDLE. It may be NULL for system library. */
179 /* Structure that identifies the child process for the
180 <proc_service.h> interface. */
181 struct ps_prochandle proc_handle
;
183 /* Connection to the libthread_db library. */
184 td_thragent_t
*thread_agent
;
186 /* True if we need to apply the workaround for glibc/BZ5983. When
187 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
188 list, nptl_db returns the parent's threads in addition to the new
189 (single) child thread. If this flag is set, we do extra work to
190 be able to ignore such stale entries. */
191 int need_stale_parent_threads_check
;
193 /* Pointers to the libthread_db functions. */
195 td_init_ftype
*td_init_p
;
196 td_ta_new_ftype
*td_ta_new_p
;
197 td_ta_delete_ftype
*td_ta_delete_p
;
198 td_ta_map_lwp2thr_ftype
*td_ta_map_lwp2thr_p
;
199 td_ta_thr_iter_ftype
*td_ta_thr_iter_p
;
200 td_thr_get_info_ftype
*td_thr_get_info_p
;
201 td_thr_tls_get_addr_ftype
*td_thr_tls_get_addr_p
;
202 td_thr_tlsbase_ftype
*td_thr_tlsbase_p
;
205 /* List of known processes using thread_db, and the required
207 struct thread_db_info
*thread_db_list
;
209 static void thread_db_find_new_threads_1 (thread_info
*stopped
);
210 static void thread_db_find_new_threads_2 (thread_info
*stopped
,
213 static void check_thread_signals (void);
215 static struct thread_info
*record_thread
216 (struct thread_db_info
*info
, struct thread_info
*tp
,
217 ptid_t ptid
, const td_thrhandle_t
*th_p
, const td_thrinfo_t
*ti_p
);
219 /* Add the current inferior to the list of processes using libpthread.
220 Return a pointer to the newly allocated object that was added to
221 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
224 static struct thread_db_info
*
225 add_thread_db_info (void *handle
)
227 struct thread_db_info
*info
= XCNEW (struct thread_db_info
);
229 info
->pid
= inferior_ptid
.pid ();
230 info
->handle
= handle
;
232 /* The workaround works by reading from /proc/pid/status, so it is
233 disabled for core files. */
234 if (target_has_execution
)
235 info
->need_stale_parent_threads_check
= 1;
237 info
->next
= thread_db_list
;
238 thread_db_list
= info
;
243 /* Return the thread_db_info object representing the bookkeeping
244 related to process PID, if any; NULL otherwise. */
246 static struct thread_db_info
*
247 get_thread_db_info (int pid
)
249 struct thread_db_info
*info
;
251 for (info
= thread_db_list
; info
; info
= info
->next
)
252 if (pid
== info
->pid
)
258 static const char *thread_db_err_str (td_err_e err
);
260 /* When PID has exited or has been detached, we no longer want to keep
261 track of it as using libpthread. Call this function to discard
262 thread_db related info related to PID. Note that this closes
263 LIBTHREAD_DB_SO's dlopen'ed handle. */
266 delete_thread_db_info (int pid
)
268 struct thread_db_info
*info
, *info_prev
;
272 for (info
= thread_db_list
; info
; info_prev
= info
, info
= info
->next
)
273 if (pid
== info
->pid
)
279 if (info
->thread_agent
!= NULL
&& info
->td_ta_delete_p
!= NULL
)
281 td_err_e err
= info
->td_ta_delete_p (info
->thread_agent
);
284 warning (_("Cannot deregister process %d from libthread_db: %s"),
285 pid
, thread_db_err_str (err
));
286 info
->thread_agent
= NULL
;
289 if (info
->handle
!= NULL
)
290 dlclose (info
->handle
);
292 xfree (info
->filename
);
295 info_prev
->next
= info
->next
;
297 thread_db_list
= info
->next
;
302 /* Use "struct private_thread_info" to cache thread state. This is
303 a substantial optimization. */
305 struct thread_db_thread_info
: public private_thread_info
307 /* Flag set when we see a TD_DEATH event for this thread. */
310 /* Cached thread state. */
311 td_thrhandle_t th
{};
315 static thread_db_thread_info
*
316 get_thread_db_thread_info (thread_info
*thread
)
318 return static_cast<thread_db_thread_info
*> (thread
->priv
.get ());
322 thread_db_err_str (td_err_e err
)
329 return "generic 'call succeeded'";
331 return "generic error";
333 return "no thread to satisfy query";
335 return "no sync handle to satisfy query";
337 return "no LWP to satisfy query";
339 return "invalid process handle";
341 return "invalid thread handle";
343 return "invalid synchronization handle";
345 return "invalid thread agent";
347 return "invalid key";
349 return "no event message for getmsg";
351 return "FPU register set not available";
353 return "application not linked with libthread";
355 return "requested event is not supported";
357 return "capability not available";
359 return "debugger service failed";
361 return "operation not applicable to";
363 return "no thread-specific data for this thread";
365 return "malloc failed";
367 return "only part of register set was written/read";
369 return "X register set not available for this thread";
370 #ifdef THREAD_DB_HAS_TD_NOTALLOC
372 return "thread has not yet allocated TLS for given module";
374 #ifdef THREAD_DB_HAS_TD_VERSION
376 return "versions of libpthread and libthread_db do not match";
378 #ifdef THREAD_DB_HAS_TD_NOTLS
380 return "there is no TLS segment in the given module";
383 snprintf (buf
, sizeof (buf
), "unknown thread_db error '%d'", err
);
388 /* Fetch the user-level thread id of PTID. STOPPED is a stopped
389 thread that we can use to access memory. */
391 static struct thread_info
*
392 thread_from_lwp (thread_info
*stopped
, ptid_t ptid
)
397 struct thread_db_info
*info
;
398 struct thread_info
*tp
;
400 /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
403 /* This ptid comes from linux-nat.c, which should always fill in the
405 gdb_assert (ptid
.lwp () != 0);
407 info
= get_thread_db_info (ptid
.pid ());
409 /* Access an lwp we know is stopped. */
410 info
->proc_handle
.thread
= stopped
;
411 err
= info
->td_ta_map_lwp2thr_p (info
->thread_agent
, ptid
.lwp (),
414 error (_("Cannot find user-level thread for LWP %ld: %s"),
415 ptid
.lwp (), thread_db_err_str (err
));
417 err
= info
->td_thr_get_info_p (&th
, &ti
);
419 error (_("thread_get_info_callback: cannot get thread info: %s"),
420 thread_db_err_str (err
));
422 /* Fill the cache. */
423 tp
= find_thread_ptid (ptid
);
424 return record_thread (info
, tp
, ptid
, &th
, &ti
);
428 /* See linux-nat.h. */
431 thread_db_notice_clone (ptid_t parent
, ptid_t child
)
433 struct thread_db_info
*info
;
435 info
= get_thread_db_info (child
.pid ());
440 thread_info
*stopped
= find_thread_ptid (parent
);
442 thread_from_lwp (stopped
, child
);
444 /* If we do not know about the main thread's pthread info yet, this
445 would be a good time to find it. */
446 thread_from_lwp (stopped
, parent
);
451 verbose_dlsym (void *handle
, const char *name
)
453 void *sym
= dlsym (handle
, name
);
455 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
460 /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
461 return 1 if this version is lower (and not equal) to
462 VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
465 inferior_has_bug (const char *ver_symbol
, int ver_major_min
, int ver_minor_min
)
467 struct bound_minimal_symbol version_msym
;
468 CORE_ADDR version_addr
;
469 gdb::unique_xmalloc_ptr
<char> version
;
470 int err
, got
, retval
= 0;
472 version_msym
= lookup_minimal_symbol (ver_symbol
, NULL
, NULL
);
473 if (version_msym
.minsym
== NULL
)
476 version_addr
= BMSYMBOL_VALUE_ADDRESS (version_msym
);
477 got
= target_read_string (version_addr
, &version
, 32, &err
);
478 if (err
== 0 && memchr (version
.get (), 0, got
) == version
.get () + got
- 1)
482 retval
= (sscanf (version
.get (), "%d.%d", &major
, &minor
) == 2
483 && (major
< ver_major_min
484 || (major
== ver_major_min
&& minor
< ver_minor_min
)));
490 /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
493 Return 1 if the caller should abort libthread_db initialization. Return 0
497 thread_db_find_new_threads_silently (thread_info
*stopped
)
502 thread_db_find_new_threads_2 (stopped
, true);
505 CATCH (except
, RETURN_MASK_ERROR
)
507 if (libthread_db_debug
)
508 exception_fprintf (gdb_stdlog
, except
,
509 "Warning: thread_db_find_new_threads_silently: ");
511 /* There is a bug fixed between nptl 2.6.1 and 2.7 by
512 commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
513 where calls to td_thr_get_info fail with TD_ERR for statically linked
514 executables if td_thr_get_info is called before glibc has initialized
517 If the nptl bug is NOT present in the inferior and still thread_db
518 reports an error return 1. It means the inferior has corrupted thread
519 list and GDB should fall back only to LWPs.
521 If the nptl bug is present in the inferior return 0 to silently ignore
522 such errors, and let gdb enumerate threads again later. In such case
523 GDB cannot properly display LWPs if the inferior thread list is
524 corrupted. For core files it does not apply, no 'later enumeration'
527 if (!target_has_execution
|| !inferior_has_bug ("nptl_version", 2, 7))
529 exception_fprintf (gdb_stderr
, except
,
530 _("Warning: couldn't activate thread debugging "
531 "using libthread_db: "));
540 /* Lookup a library in which given symbol resides.
541 Note: this is looking in GDB process, not in the inferior.
542 Returns library name, or NULL. */
545 dladdr_to_soname (const void *addr
)
549 if (dladdr (addr
, &info
) != 0)
550 return info
.dli_fname
;
554 /* State for check_thread_db_callback. */
556 struct check_thread_db_info
558 /* The libthread_db under test. */
559 struct thread_db_info
*info
;
561 /* True if progress should be logged. */
564 /* True if the callback was called. */
567 /* Name of last libthread_db function called. */
568 const char *last_call
;
570 /* Value returned by last libthread_db call. */
571 td_err_e last_result
;
574 static struct check_thread_db_info
*tdb_testinfo
;
576 /* Callback for check_thread_db. */
579 check_thread_db_callback (const td_thrhandle_t
*th
, void *arg
)
581 gdb_assert (tdb_testinfo
!= NULL
);
582 tdb_testinfo
->threads_seen
= true;
584 #define LOG(fmt, args...) \
587 if (tdb_testinfo->log_progress) \
589 debug_printf (fmt, ## args); \
590 gdb_flush (gdb_stdlog); \
595 #define CHECK_1(expr, args...) \
600 LOG (" ... FAIL!\n"); \
606 #define CHECK(expr) \
607 CHECK_1 (expr, "(%s) == false", #expr)
609 #define CALL_UNCHECKED(func, args...) \
612 tdb_testinfo->last_call = #func; \
613 tdb_testinfo->last_result \
614 = tdb_testinfo->info->func ## _p (args); \
618 #define CHECK_CALL() \
619 CHECK_1 (tdb_testinfo->last_result == TD_OK, \
620 _("%s failed: %s"), \
621 tdb_testinfo->last_call, \
622 thread_db_err_str (tdb_testinfo->last_result)) \
624 #define CALL(func, args...) \
627 CALL_UNCHECKED (func, args); \
634 /* Check td_ta_thr_iter passed consistent arguments. */
636 CHECK (arg
== (void *) tdb_testinfo
);
637 CHECK (th
->th_ta_p
== tdb_testinfo
->info
->thread_agent
);
639 LOG (" %s", core_addr_to_string_nz ((CORE_ADDR
) th
->th_unique
));
641 /* Check td_thr_get_info. */
643 CALL (td_thr_get_info
, th
, &ti
);
645 LOG (" => %d", ti
.ti_lid
);
647 CHECK (ti
.ti_ta_p
== th
->th_ta_p
);
648 CHECK (ti
.ti_tid
== (thread_t
) th
->th_unique
);
650 /* Check td_ta_map_lwp2thr. */
652 memset (&th2
, 23, sizeof (td_thrhandle_t
));
653 CALL_UNCHECKED (td_ta_map_lwp2thr
, th
->th_ta_p
, ti
.ti_lid
, &th2
);
655 if (tdb_testinfo
->last_result
== TD_ERR
&& !target_has_execution
)
657 /* Some platforms require execution for td_ta_map_lwp2thr. */
658 LOG (_("; can't map_lwp2thr"));
664 LOG (" => %s", core_addr_to_string_nz ((CORE_ADDR
) th2
.th_unique
));
666 CHECK (memcmp (th
, &th2
, sizeof (td_thrhandle_t
)) == 0);
669 /* Attempt TLS access. Assuming errno is TLS, this calls
670 thread_db_get_thread_local_address, which in turn calls
671 td_thr_tls_get_addr for live inferiors or td_thr_tlsbase
672 for core files. This test is skipped if the thread has
673 not been recorded; proceeding in that case would result
674 in the test having the side-effect of noticing threads
677 Note that in glibc's libthread_db td_thr_tls_get_addr is
678 a thin wrapper around td_thr_tlsbase; this check always
679 hits the bulk of the code.
681 Note also that we don't actually check any libthread_db
682 calls are made, we just assume they were; future changes
683 to how GDB accesses TLS could result in this passing
684 without exercising the calls it's supposed to. */
685 ptid_t ptid
= ptid_t (tdb_testinfo
->info
->pid
, ti
.ti_lid
, 0);
686 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
687 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
691 scoped_restore_current_thread restore_current_thread
;
692 switch_to_thread (ptid
);
694 expression_up expr
= parse_expression ("(int) errno");
695 struct value
*val
= evaluate_expression (expr
.get ());
697 if (tdb_testinfo
->log_progress
)
699 struct value_print_options opts
;
701 get_user_print_options (&opts
);
703 value_print (val
, gdb_stdlog
, &opts
);
712 #undef CALL_UNCHECKED
719 /* Run integrity checks on the dlopen()ed libthread_db described by
720 INFO. Returns true on success, displays a warning and returns
721 false on failure. Logs progress messages to gdb_stdlog during
722 the test if LOG_PROGRESS is true. */
725 check_thread_db (struct thread_db_info
*info
, bool log_progress
)
727 bool test_passed
= true;
730 debug_printf (_("Running libthread_db integrity checks:\n"));
732 /* GDB avoids using td_ta_thr_iter wherever possible (see comment
733 in try_thread_db_load_1 below) so in order to test it we may
734 have to locate it ourselves. */
735 td_ta_thr_iter_ftype
*td_ta_thr_iter_p
= info
->td_ta_thr_iter_p
;
736 if (td_ta_thr_iter_p
== NULL
)
738 void *thr_iter
= verbose_dlsym (info
->handle
, "td_ta_thr_iter");
739 if (thr_iter
== NULL
)
742 td_ta_thr_iter_p
= (td_ta_thr_iter_ftype
*) thr_iter
;
745 /* Set up the test state we share with the callback. */
746 gdb_assert (tdb_testinfo
== NULL
);
747 struct check_thread_db_info tdb_testinfo_buf
;
748 tdb_testinfo
= &tdb_testinfo_buf
;
750 memset (tdb_testinfo
, 0, sizeof (struct check_thread_db_info
));
751 tdb_testinfo
->info
= info
;
752 tdb_testinfo
->log_progress
= log_progress
;
754 /* td_ta_thr_iter shouldn't be used on running processes. Note that
755 it's possible the inferior will stop midway through modifying one
756 of its thread lists, in which case the check will spuriously
758 linux_stop_and_wait_all_lwps ();
762 td_err_e err
= td_ta_thr_iter_p (info
->thread_agent
,
763 check_thread_db_callback
,
766 TD_THR_LOWEST_PRIORITY
,
768 TD_THR_ANY_USER_FLAGS
);
771 error (_("td_ta_thr_iter failed: %s"), thread_db_err_str (err
));
773 if (!tdb_testinfo
->threads_seen
)
774 error (_("no threads seen"));
776 CATCH (except
, RETURN_MASK_ERROR
)
778 if (warning_pre_print
)
779 fputs_unfiltered (warning_pre_print
, gdb_stderr
);
781 exception_fprintf (gdb_stderr
, except
,
782 _("libthread_db integrity checks failed: "));
788 if (test_passed
&& log_progress
)
789 debug_printf (_("libthread_db integrity checks passed.\n"));
793 linux_unstop_all_lwps ();
798 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
800 Failure could happen if libthread_db does not have symbols we expect,
801 or when it refuses to work with the current inferior (e.g. due to
802 version mismatch between libthread_db and libpthread). */
805 try_thread_db_load_1 (struct thread_db_info
*info
)
809 /* Initialize pointers to the dynamic library functions we will use.
810 Essential functions first. */
812 #define TDB_VERBOSE_DLSYM(info, func) \
813 info->func ## _p = (func ## _ftype *) verbose_dlsym (info->handle, #func)
815 #define TDB_DLSYM(info, func) \
816 info->func ## _p = (func ## _ftype *) dlsym (info->handle, #func)
825 CHK (TDB_VERBOSE_DLSYM (info
, td_init
));
827 err
= info
->td_init_p ();
830 warning (_("Cannot initialize libthread_db: %s"),
831 thread_db_err_str (err
));
835 CHK (TDB_VERBOSE_DLSYM (info
, td_ta_new
));
837 /* Initialize the structure that identifies the child process. */
838 info
->proc_handle
.thread
= inferior_thread ();
840 /* Now attempt to open a connection to the thread library. */
841 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
844 if (libthread_db_debug
)
845 fprintf_unfiltered (gdb_stdlog
, _("td_ta_new failed: %s\n"),
846 thread_db_err_str (err
));
851 #ifdef THREAD_DB_HAS_TD_VERSION
854 /* The errors above are not unexpected and silently ignored:
855 they just mean we haven't found correct version of
859 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
864 /* These are essential. */
865 CHK (TDB_VERBOSE_DLSYM (info
, td_ta_map_lwp2thr
));
866 CHK (TDB_VERBOSE_DLSYM (info
, td_thr_get_info
));
868 /* These are not essential. */
869 TDB_DLSYM (info
, td_thr_tls_get_addr
);
870 TDB_DLSYM (info
, td_thr_tlsbase
);
871 TDB_DLSYM (info
, td_ta_delete
);
873 /* It's best to avoid td_ta_thr_iter if possible. That walks data
874 structures in the inferior's address space that may be corrupted,
875 or, if the target is running, may change while we walk them. If
876 there's execution (and /proc is mounted), then we're already
877 attached to all LWPs. Use thread_from_lwp, which uses
878 td_ta_map_lwp2thr instead, which does not walk the thread list.
880 td_ta_map_lwp2thr uses ps_get_thread_area, but we can't use that
881 currently on core targets, as it uses ptrace directly. */
882 if (target_has_execution
883 && linux_proc_task_list_dir_exists (inferior_ptid
.pid ()))
884 info
->td_ta_thr_iter_p
= NULL
;
886 CHK (TDB_VERBOSE_DLSYM (info
, td_ta_thr_iter
));
888 #undef TDB_VERBOSE_DLSYM
892 /* Run integrity checks if requested. */
893 if (check_thread_db_on_load
)
895 if (!check_thread_db (info
, libthread_db_debug
))
899 if (info
->td_ta_thr_iter_p
== NULL
)
902 int pid
= inferior_ptid
.pid ();
903 thread_info
*curr_thread
= inferior_thread ();
905 linux_stop_and_wait_all_lwps ();
908 if (lp
->ptid
.pid () == pid
)
909 thread_from_lwp (curr_thread
, lp
->ptid
);
911 linux_unstop_all_lwps ();
913 else if (thread_db_find_new_threads_silently (inferior_thread ()) != 0)
915 /* Even if libthread_db initializes, if the thread list is
916 corrupted, we'd not manage to list any threads. Better reject this
917 thread_db, and fall back to at least listing LWPs. */
921 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
923 if (*libthread_db_search_path
|| libthread_db_debug
)
925 struct ui_file
*file
;
928 library
= dladdr_to_soname ((const void *) *info
->td_ta_new_p
);
930 library
= LIBTHREAD_DB_SO
;
932 /* If we'd print this to gdb_stdout when debug output is
933 disabled, still print it to gdb_stdout if debug output is
934 enabled. User visible output should not depend on debug
936 file
= *libthread_db_search_path
!= '\0' ? gdb_stdout
: gdb_stdlog
;
937 fprintf_unfiltered (file
, _("Using host libthread_db library \"%s\".\n"),
941 /* The thread library was detected. Activate the thread_db target
942 if this is the first process using it. */
943 if (thread_db_list
->next
== NULL
)
944 push_target (&the_thread_db_target
);
949 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
950 relative, or just LIBTHREAD_DB. */
953 try_thread_db_load (const char *library
, int check_auto_load_safe
)
956 struct thread_db_info
*info
;
958 if (libthread_db_debug
)
959 fprintf_unfiltered (gdb_stdlog
,
960 _("Trying host libthread_db library: %s.\n"),
963 if (check_auto_load_safe
)
965 if (access (library
, R_OK
) != 0)
967 /* Do not print warnings by file_is_auto_load_safe if the library does
968 not exist at this place. */
969 if (libthread_db_debug
)
970 fprintf_unfiltered (gdb_stdlog
, _("open failed: %s.\n"),
971 safe_strerror (errno
));
975 if (!file_is_auto_load_safe (library
, _("auto-load: Loading libthread-db "
976 "library \"%s\" from explicit "
982 handle
= dlopen (library
, RTLD_NOW
);
985 if (libthread_db_debug
)
986 fprintf_unfiltered (gdb_stdlog
, _("dlopen failed: %s.\n"), dlerror ());
990 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
994 td_init
= dlsym (handle
, "td_init");
997 const char *const libpath
= dladdr_to_soname (td_init
);
1000 fprintf_unfiltered (gdb_stdlog
, _("Host %s resolved to: %s.\n"),
1005 info
= add_thread_db_info (handle
);
1007 /* Do not save system library name, that one is always trusted. */
1008 if (strchr (library
, '/') != NULL
)
1009 info
->filename
= gdb_realpath (library
).release ();
1011 if (try_thread_db_load_1 (info
))
1014 /* This library "refused" to work on current inferior. */
1015 delete_thread_db_info (inferior_ptid
.pid ());
1019 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
1020 Try loading libthread_db in directory(OBJ)/SUBDIR.
1021 SUBDIR may be NULL. It may also be something like "../lib64".
1022 The result is true for success. */
1025 try_thread_db_load_from_pdir_1 (struct objfile
*obj
, const char *subdir
)
1027 const char *obj_name
= objfile_name (obj
);
1029 if (obj_name
[0] != '/')
1031 warning (_("Expected absolute pathname for libpthread in the"
1032 " inferior, but got %s."), obj_name
);
1036 std::string path
= obj_name
;
1037 size_t cp
= path
.rfind ('/');
1038 /* This should at minimum hit the first character. */
1039 gdb_assert (cp
!= std::string::npos
);
1040 path
.resize (cp
+ 1);
1042 path
= path
+ subdir
+ "/";
1043 path
+= LIBTHREAD_DB_SO
;
1045 return try_thread_db_load (path
.c_str (), 1);
1048 /* Handle $pdir in libthread-db-search-path.
1049 Look for libthread_db in directory(libpthread)/SUBDIR.
1050 SUBDIR may be NULL. It may also be something like "../lib64".
1051 The result is true for success. */
1054 try_thread_db_load_from_pdir (const char *subdir
)
1056 if (!auto_load_thread_db
)
1059 for (objfile
*obj
: all_objfiles (current_program_space
))
1060 if (libpthread_name_p (objfile_name (obj
)))
1062 if (try_thread_db_load_from_pdir_1 (obj
, subdir
))
1065 /* We may have found the separate-debug-info version of
1066 libpthread, and it may live in a directory without a matching
1068 if (obj
->separate_debug_objfile_backlink
!= NULL
)
1069 return try_thread_db_load_from_pdir_1 (obj
->separate_debug_objfile_backlink
,
1078 /* Handle $sdir in libthread-db-search-path.
1079 Look for libthread_db in the system dirs, or wherever a plain
1080 dlopen(file_without_path) will look.
1081 The result is true for success. */
1084 try_thread_db_load_from_sdir (void)
1086 return try_thread_db_load (LIBTHREAD_DB_SO
, 0);
1089 /* Try to load libthread_db from directory DIR of length DIR_LEN.
1090 The result is true for success. */
1093 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
1095 if (!auto_load_thread_db
)
1098 std::string path
= std::string (dir
, dir_len
) + "/" + LIBTHREAD_DB_SO
;
1100 return try_thread_db_load (path
.c_str (), 1);
1103 /* Search libthread_db_search_path for libthread_db which "agrees"
1104 to work on current inferior.
1105 The result is true for success. */
1108 thread_db_load_search (void)
1112 std::vector
<gdb::unique_xmalloc_ptr
<char>> dir_vec
1113 = dirnames_to_char_ptr_vec (libthread_db_search_path
);
1115 for (const gdb::unique_xmalloc_ptr
<char> &this_dir_up
: dir_vec
)
1117 const char *this_dir
= this_dir_up
.get ();
1118 const int pdir_len
= sizeof ("$pdir") - 1;
1119 size_t this_dir_len
;
1121 this_dir_len
= strlen (this_dir
);
1123 if (strncmp (this_dir
, "$pdir", pdir_len
) == 0
1124 && (this_dir
[pdir_len
] == '\0'
1125 || this_dir
[pdir_len
] == '/'))
1127 const char *subdir
= NULL
;
1129 std::string subdir_holder
;
1130 if (this_dir
[pdir_len
] == '/')
1132 subdir_holder
= std::string (this_dir
+ pdir_len
+ 1);
1133 subdir
= subdir_holder
.c_str ();
1135 rc
= try_thread_db_load_from_pdir (subdir
);
1139 else if (strcmp (this_dir
, "$sdir") == 0)
1141 if (try_thread_db_load_from_sdir ())
1149 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
1157 if (libthread_db_debug
)
1158 fprintf_unfiltered (gdb_stdlog
,
1159 _("thread_db_load_search returning %d\n"), rc
);
1163 /* Return non-zero if the inferior has a libpthread. */
1166 has_libpthread (void)
1168 for (objfile
*obj
: all_objfiles (current_program_space
))
1169 if (libpthread_name_p (objfile_name (obj
)))
1175 /* Attempt to load and initialize libthread_db.
1176 Return 1 on success. */
1179 thread_db_load (void)
1181 struct thread_db_info
*info
;
1183 info
= get_thread_db_info (inferior_ptid
.pid ());
1188 /* Don't attempt to use thread_db on executables not running
1190 if (!target_has_registers
)
1193 /* Don't attempt to use thread_db for remote targets. */
1194 if (!(target_can_run () || core_bfd
))
1197 if (thread_db_load_search ())
1200 /* We couldn't find a libthread_db.
1201 If the inferior has a libpthread warn the user. */
1202 if (has_libpthread ())
1204 warning (_("Unable to find libthread_db matching inferior's thread"
1205 " library, thread debugging will not be available."));
1209 /* Either this executable isn't using libpthread at all, or it is
1210 statically linked. Since we can't easily distinguish these two cases,
1211 no warning is issued. */
1216 check_thread_signals (void)
1218 if (!thread_signals
)
1223 lin_thread_get_thread_signals (&mask
);
1224 sigemptyset (&thread_stop_set
);
1225 sigemptyset (&thread_print_set
);
1227 for (i
= 1; i
< NSIG
; i
++)
1229 if (sigismember (&mask
, i
))
1231 if (signal_stop_update (gdb_signal_from_host (i
), 0))
1232 sigaddset (&thread_stop_set
, i
);
1233 if (signal_print_update (gdb_signal_from_host (i
), 0))
1234 sigaddset (&thread_print_set
, i
);
1241 /* Check whether thread_db is usable. This function is called when
1242 an inferior is created (or otherwise acquired, e.g. attached to)
1243 and when new shared libraries are loaded into a running process. */
1246 check_for_thread_db (void)
1248 /* Do nothing if we couldn't load libthread_db.so.1. */
1249 if (!thread_db_load ())
1253 /* This function is called via the new_objfile observer. */
1256 thread_db_new_objfile (struct objfile
*objfile
)
1258 /* This observer must always be called with inferior_ptid set
1262 /* libpthread with separate debug info has its debug info file already
1263 loaded (and notified without successful thread_db initialization)
1264 the time gdb::observers::new_objfile.notify is called for the library itself.
1265 Static executables have their separate debug info loaded already
1266 before the inferior has started. */
1267 && objfile
->separate_debug_objfile_backlink
== NULL
1268 /* Only check for thread_db if we loaded libpthread,
1269 or if this is the main symbol file.
1270 We need to check OBJF_MAINLINE to handle the case of debugging
1271 a statically linked executable AND the symbol file is specified AFTER
1272 the exec file is loaded (e.g., gdb -c core ; file foo).
1273 For dynamically linked executables, libpthread can be near the end
1274 of the list of shared libraries to load, and in an app of several
1275 thousand shared libraries, this can otherwise be painful. */
1276 && ((objfile
->flags
& OBJF_MAINLINE
) != 0
1277 || libpthread_name_p (objfile_name (objfile
))))
1278 check_for_thread_db ();
1282 check_pid_namespace_match (void)
1284 /* Check is only relevant for local targets targets. */
1285 if (target_can_run ())
1287 /* If the child is in a different PID namespace, its idea of its
1288 PID will differ from our idea of its PID. When we scan the
1289 child's thread list, we'll mistakenly think it has no threads
1290 since the thread PID fields won't match the PID we give to
1292 if (!linux_ns_same (inferior_ptid
.pid (), LINUX_NS_PID
))
1294 warning (_ ("Target and debugger are in different PID "
1295 "namespaces; thread lists and other data are "
1296 "likely unreliable. "
1297 "Connect to gdbserver inside the container."));
1302 /* This function is called via the inferior_created observer.
1303 This handles the case of debugging statically linked executables. */
1306 thread_db_inferior_created (struct target_ops
*target
, int from_tty
)
1308 check_pid_namespace_match ();
1309 check_for_thread_db ();
1312 /* Update the thread's state (what's displayed in "info threads"),
1313 from libthread_db thread state information. */
1316 update_thread_state (thread_db_thread_info
*priv
,
1317 const td_thrinfo_t
*ti_p
)
1319 priv
->dying
= (ti_p
->ti_state
== TD_THR_UNKNOWN
1320 || ti_p
->ti_state
== TD_THR_ZOMBIE
);
1323 /* Record a new thread in GDB's thread list. Creates the thread's
1324 private info. If TP is NULL or TP is marked as having exited,
1325 creates a new thread. Otherwise, uses TP. */
1327 static struct thread_info
*
1328 record_thread (struct thread_db_info
*info
,
1329 struct thread_info
*tp
,
1330 ptid_t ptid
, const td_thrhandle_t
*th_p
,
1331 const td_thrinfo_t
*ti_p
)
1333 /* A thread ID of zero may mean the thread library has not
1334 initialized yet. Leave private == NULL until the thread library
1336 if (ti_p
->ti_tid
== 0)
1339 /* Construct the thread's private data. */
1340 thread_db_thread_info
*priv
= new thread_db_thread_info
;
1343 priv
->tid
= ti_p
->ti_tid
;
1344 update_thread_state (priv
, ti_p
);
1346 /* Add the thread to GDB's thread list. If we already know about a
1347 thread with this PTID, but it's marked exited, then the kernel
1348 reused the tid of an old thread. */
1349 if (tp
== NULL
|| tp
->state
== THREAD_EXITED
)
1350 tp
= add_thread_with_info (ptid
, priv
);
1352 tp
->priv
.reset (priv
);
1354 if (target_has_execution
)
1355 check_thread_signals ();
1361 thread_db_target::detach (inferior
*inf
, int from_tty
)
1363 delete_thread_db_info (inf
->pid
);
1365 beneath ()->detach (inf
, from_tty
);
1367 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1369 /* If there are no more processes using libpthread, detach the
1370 thread_db target ops. */
1371 if (!thread_db_list
)
1372 unpush_target (this);
1376 thread_db_target::wait (ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1379 struct thread_db_info
*info
;
1381 ptid
= beneath ()->wait (ptid
, ourstatus
, options
);
1383 switch (ourstatus
->kind
)
1385 case TARGET_WAITKIND_IGNORE
:
1386 case TARGET_WAITKIND_EXITED
:
1387 case TARGET_WAITKIND_THREAD_EXITED
:
1388 case TARGET_WAITKIND_SIGNALLED
:
1392 info
= get_thread_db_info (ptid
.pid ());
1394 /* If this process isn't using thread_db, we're done. */
1398 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1400 /* New image, it may or may not end up using thread_db. Assume
1401 not unless we find otherwise. */
1402 delete_thread_db_info (ptid
.pid ());
1403 if (!thread_db_list
)
1404 unpush_target (&the_thread_db_target
);
1409 /* Fill in the thread's user-level thread id and status. */
1410 thread_from_lwp (find_thread_ptid (ptid
), ptid
);
1416 thread_db_target::mourn_inferior ()
1418 delete_thread_db_info (inferior_ptid
.pid ());
1420 beneath ()->mourn_inferior ();
1422 /* Detach thread_db target ops. */
1423 if (!thread_db_list
)
1424 unpush_target (&the_thread_db_target
);
1427 struct callback_data
1429 struct thread_db_info
*info
;
1434 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1438 struct thread_info
*tp
;
1439 struct callback_data
*cb_data
= (struct callback_data
*) data
;
1440 struct thread_db_info
*info
= cb_data
->info
;
1442 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1444 error (_("find_new_threads_callback: cannot get thread info: %s"),
1445 thread_db_err_str (err
));
1447 if (ti
.ti_lid
== -1)
1449 /* A thread with kernel thread ID -1 is either a thread that
1450 exited and was joined, or a thread that is being created but
1451 hasn't started yet, and that is reusing the tcb/stack of a
1452 thread that previously exited and was joined. (glibc marks
1453 terminated and joined threads with kernel thread ID -1. See
1455 if (libthread_db_debug
)
1456 fprintf_unfiltered (gdb_stdlog
,
1457 "thread_db: skipping exited and "
1458 "joined thread (0x%lx)\n",
1459 (unsigned long) ti
.ti_tid
);
1465 /* A thread ID of zero means that this is the main thread, but
1466 glibc has not yet initialized thread-local storage and the
1467 pthread library. We do not know what the thread's TID will
1470 /* In that case, we're not stopped in a fork syscall and don't
1471 need this glibc bug workaround. */
1472 info
->need_stale_parent_threads_check
= 0;
1477 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1478 bit expensive, as it needs to open /proc/pid/status, so try to
1479 avoid doing the work if we know we don't have to. */
1480 if (info
->need_stale_parent_threads_check
)
1482 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1484 if (tgid
!= -1 && tgid
!= info
->pid
)
1488 ptid_t
ptid (info
->pid
, ti
.ti_lid
);
1489 tp
= find_thread_ptid (ptid
);
1490 if (tp
== NULL
|| tp
->priv
== NULL
)
1491 record_thread (info
, tp
, ptid
, th_p
, &ti
);
1496 /* Helper for thread_db_find_new_threads_2.
1497 Returns number of new threads found. */
1500 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1503 struct callback_data data
;
1504 td_err_e err
= TD_ERR
;
1507 data
.new_threads
= 0;
1509 /* See comment in thread_db_update_thread_list. */
1510 gdb_assert (info
->td_ta_thr_iter_p
!= NULL
);
1514 /* Iterate over all user-space threads to discover new threads. */
1515 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1516 find_new_threads_callback
,
1519 TD_THR_LOWEST_PRIORITY
,
1521 TD_THR_ANY_USER_FLAGS
);
1523 CATCH (except
, RETURN_MASK_ERROR
)
1525 if (libthread_db_debug
)
1527 exception_fprintf (gdb_stdlog
, except
,
1528 "Warning: find_new_threads_once: ");
1533 if (libthread_db_debug
)
1535 fprintf_unfiltered (gdb_stdlog
,
1536 _("Found %d new threads in iteration %d.\n"),
1537 data
.new_threads
, iteration
);
1543 return data
.new_threads
;
1546 /* Search for new threads, accessing memory through stopped thread
1547 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1548 searches in a row do not discover any new threads. */
1551 thread_db_find_new_threads_2 (thread_info
*stopped
, bool until_no_new
)
1553 td_err_e err
= TD_OK
;
1554 struct thread_db_info
*info
;
1557 info
= get_thread_db_info (stopped
->ptid
.pid ());
1559 /* Access an lwp we know is stopped. */
1560 info
->proc_handle
.thread
= stopped
;
1564 /* Require 4 successive iterations which do not find any new threads.
1565 The 4 is a heuristic: there is an inherent race here, and I have
1566 seen that 2 iterations in a row are not always sufficient to
1567 "capture" all threads. */
1568 for (i
= 0, loop
= 0; loop
< 4 && err
== TD_OK
; ++i
, ++loop
)
1569 if (find_new_threads_once (info
, i
, &err
) != 0)
1571 /* Found some new threads. Restart the loop from beginning. */
1576 find_new_threads_once (info
, 0, &err
);
1579 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1583 thread_db_find_new_threads_1 (thread_info
*stopped
)
1585 thread_db_find_new_threads_2 (stopped
, 0);
1588 /* Implement the to_update_thread_list target method for this
1592 thread_db_target::update_thread_list ()
1594 struct thread_db_info
*info
;
1598 for (inferior
*inf
: all_inferiors ())
1600 struct thread_info
*thread
;
1605 info
= get_thread_db_info (inf
->pid
);
1609 thread
= any_live_thread_of_inferior (inf
);
1610 if (thread
== NULL
|| thread
->executing
)
1613 /* It's best to avoid td_ta_thr_iter if possible. That walks
1614 data structures in the inferior's address space that may be
1615 corrupted, or, if the target is running, the list may change
1616 while we walk it. In the latter case, it's possible that a
1617 thread exits just at the exact time that causes GDB to get
1618 stuck in an infinite loop. To avoid pausing all threads
1619 whenever the core wants to refresh the thread list, we
1620 instead use thread_from_lwp immediately when we see an LWP
1621 stop. That uses thread_db entry points that do not walk
1622 libpthread's thread list, so should be safe, as well as more
1624 if (target_has_execution_1 (thread
->ptid
))
1627 thread_db_find_new_threads_1 (thread
);
1630 /* Give the beneath target a chance to do extra processing. */
1631 this->beneath ()->update_thread_list ();
1635 thread_db_target::pid_to_str (ptid_t ptid
)
1637 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1639 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
1641 static char buf
[64];
1642 thread_db_thread_info
*priv
= get_thread_db_thread_info (thread_info
);
1644 snprintf (buf
, sizeof (buf
), "Thread 0x%lx (LWP %ld)",
1645 (unsigned long) priv
->tid
, ptid
.lwp ());
1650 return beneath ()->pid_to_str (ptid
);
1653 /* Return a string describing the state of the thread specified by
1657 thread_db_target::extra_thread_info (thread_info
*info
)
1659 if (info
->priv
== NULL
)
1662 thread_db_thread_info
*priv
= get_thread_db_thread_info (info
);
1670 /* Return pointer to the thread_info struct which corresponds to
1671 THREAD_HANDLE (having length HANDLE_LEN). */
1674 thread_db_target::thread_handle_to_thread_info (const gdb_byte
*thread_handle
,
1678 thread_t handle_tid
;
1680 /* Thread handle sizes must match in order to proceed. We don't use an
1681 assert here because the resulting internal error will cause GDB to
1682 exit. This isn't necessarily an internal error due to the possibility
1683 of garbage being passed as the thread handle via the python interface. */
1684 if (handle_len
!= sizeof (handle_tid
))
1685 error (_("Thread handle size mismatch: %d vs %zu (from libthread_db)"),
1686 handle_len
, sizeof (handle_tid
));
1688 handle_tid
= * (const thread_t
*) thread_handle
;
1690 for (thread_info
*tp
: inf
->non_exited_threads ())
1692 thread_db_thread_info
*priv
= get_thread_db_thread_info (tp
);
1694 if (priv
!= NULL
&& handle_tid
== priv
->tid
)
1701 /* Get the address of the thread local variable in load module LM which
1702 is stored at OFFSET within the thread local storage for thread PTID. */
1705 thread_db_target::get_thread_local_address (ptid_t ptid
,
1709 struct thread_info
*thread_info
;
1711 /* Find the matching thread. */
1712 thread_info
= find_thread_ptid (ptid
);
1714 /* We may not have discovered the thread yet. */
1715 if (thread_info
!= NULL
&& thread_info
->priv
== NULL
)
1716 thread_info
= thread_from_lwp (thread_info
, ptid
);
1718 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
1722 thread_db_info
*info
= get_thread_db_info (ptid
.pid ());
1723 thread_db_thread_info
*priv
= get_thread_db_thread_info (thread_info
);
1725 /* Finally, get the address of the variable. */
1728 /* glibc doesn't provide the needed interface. */
1729 if (!info
->td_thr_tls_get_addr_p
)
1730 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1731 _("No TLS library support"));
1733 /* Note the cast through uintptr_t: this interface only works if
1734 a target address fits in a psaddr_t, which is a host pointer.
1735 So a 32-bit debugger can not access 64-bit TLS through this. */
1736 err
= info
->td_thr_tls_get_addr_p (&priv
->th
,
1737 (psaddr_t
)(uintptr_t) lm
,
1742 /* If glibc doesn't provide the needed interface throw an error
1743 that LM is zero - normally cases it should not be. */
1744 if (!info
->td_thr_tlsbase_p
)
1745 throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR
,
1746 _("TLS load module not found"));
1748 /* This code path handles the case of -static -pthread executables:
1749 https://sourceware.org/ml/libc-help/2014-03/msg00024.html
1750 For older GNU libc r_debug.r_map is NULL. For GNU libc after
1751 PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
1752 The constant number 1 depends on GNU __libc_setup_tls
1753 initialization of l_tls_modid to 1. */
1754 err
= info
->td_thr_tlsbase_p (&priv
->th
, 1, &address
);
1755 address
= (char *) address
+ offset
;
1758 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1759 /* The memory hasn't been allocated, yet. */
1760 if (err
== TD_NOTALLOC
)
1761 /* Now, if libthread_db provided the initialization image's
1762 address, we *could* try to build a non-lvalue value from
1763 the initialization image. */
1764 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1765 _("TLS not allocated yet"));
1768 /* Something else went wrong. */
1770 throw_error (TLS_GENERIC_ERROR
,
1771 (("%s")), thread_db_err_str (err
));
1773 /* Cast assuming host == target. Joy. */
1774 /* Do proper sign extension for the target. */
1775 gdb_assert (exec_bfd
);
1776 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1777 ? (CORE_ADDR
) (intptr_t) address
1778 : (CORE_ADDR
) (uintptr_t) address
);
1781 return beneath ()->get_thread_local_address (ptid
, lm
, offset
);
1784 /* Implement the to_get_ada_task_ptid target method for this target. */
1787 thread_db_target::get_ada_task_ptid (long lwp
, long thread
)
1789 /* NPTL uses a 1:1 model, so the LWP id suffices. */
1790 return ptid_t (inferior_ptid
.pid (), lwp
, 0);
1794 thread_db_target::resume (ptid_t ptid
, int step
, enum gdb_signal signo
)
1796 struct thread_db_info
*info
;
1798 if (ptid
== minus_one_ptid
)
1799 info
= get_thread_db_info (inferior_ptid
.pid ());
1801 info
= get_thread_db_info (ptid
.pid ());
1803 /* This workaround is only needed for child fork lwps stopped in a
1804 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1805 workaround can be disabled. */
1807 info
->need_stale_parent_threads_check
= 0;
1809 beneath ()->resume (ptid
, step
, signo
);
1812 /* std::sort helper function for info_auto_load_libthread_db, sort the
1813 thread_db_info pointers primarily by their FILENAME and secondarily by their
1814 PID, both in ascending order. */
1817 info_auto_load_libthread_db_compare (const struct thread_db_info
*a
,
1818 const struct thread_db_info
*b
)
1822 retval
= strcmp (a
->filename
, b
->filename
);
1826 return a
->pid
< b
->pid
;
1829 /* Implement 'info auto-load libthread-db'. */
1832 info_auto_load_libthread_db (const char *args
, int from_tty
)
1834 struct ui_out
*uiout
= current_uiout
;
1835 const char *cs
= args
? args
: "";
1836 struct thread_db_info
*info
;
1837 unsigned unique_filenames
;
1838 size_t max_filename_len
, pids_len
;
1841 cs
= skip_spaces (cs
);
1843 error (_("'info auto-load libthread-db' does not accept any parameters"));
1845 std::vector
<struct thread_db_info
*> array
;
1846 for (info
= thread_db_list
; info
; info
= info
->next
)
1847 if (info
->filename
!= NULL
)
1848 array
.push_back (info
);
1850 /* Sort ARRAY by filenames and PIDs. */
1851 std::sort (array
.begin (), array
.end (),
1852 info_auto_load_libthread_db_compare
);
1854 /* Calculate the number of unique filenames (rows) and the maximum string
1855 length of PIDs list for the unique filenames (columns). */
1857 unique_filenames
= 0;
1858 max_filename_len
= 0;
1860 for (i
= 0; i
< array
.size (); i
++)
1862 int pid
= array
[i
]->pid
;
1863 size_t this_pid_len
;
1865 for (this_pid_len
= 0; pid
!= 0; pid
/= 10)
1868 if (i
== 0 || strcmp (array
[i
- 1]->filename
, array
[i
]->filename
) != 0)
1871 max_filename_len
= std::max (max_filename_len
,
1872 strlen (array
[i
]->filename
));
1875 pids_len
-= strlen (", ");
1878 pids_len
+= this_pid_len
+ strlen (", ");
1881 pids_len
-= strlen (", ");
1883 /* Table header shifted right by preceding "libthread-db: " would not match
1885 if (array
.size () > 0 && args
== auto_load_info_scripts_pattern_nl
)
1889 ui_out_emit_table
table_emitter (uiout
, 2, unique_filenames
,
1890 "LinuxThreadDbTable");
1892 uiout
->table_header (max_filename_len
, ui_left
, "filename", "Filename");
1893 uiout
->table_header (pids_len
, ui_left
, "PIDs", "Pids");
1894 uiout
->table_body ();
1896 /* Note I is incremented inside the cycle, not at its end. */
1897 for (i
= 0; i
< array
.size ();)
1899 ui_out_emit_tuple
tuple_emitter (uiout
, NULL
);
1902 uiout
->field_string ("filename", info
->filename
);
1905 while (i
< array
.size () && strcmp (info
->filename
,
1906 array
[i
]->filename
) == 0)
1910 string_appendf (pids
, "%u", array
[i
]->pid
);
1914 uiout
->field_string ("pids", pids
.c_str ());
1921 uiout
->message (_("No auto-loaded libthread-db.\n"));
1924 /* Implement 'maintenance check libthread-db'. */
1927 maintenance_check_libthread_db (const char *args
, int from_tty
)
1929 int inferior_pid
= inferior_ptid
.pid ();
1930 struct thread_db_info
*info
;
1932 if (inferior_pid
== 0)
1933 error (_("No inferior running"));
1935 info
= get_thread_db_info (inferior_pid
);
1937 error (_("No libthread_db loaded"));
1939 check_thread_db (info
, true);
1943 _initialize_thread_db (void)
1945 /* Defer loading of libthread_db.so until inferior is running.
1946 This allows gdb to load correct libthread_db for a given
1947 executable -- there could be multiple versions of glibc,
1948 and until there is a running inferior, we can't tell which
1949 libthread_db is the correct one to load. */
1951 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
1953 add_setshow_optional_filename_cmd ("libthread-db-search-path",
1955 &libthread_db_search_path
, _("\
1956 Set search path for libthread_db."), _("\
1957 Show the current search path or libthread_db."), _("\
1958 This path is used to search for libthread_db to be loaded into \
1960 Its value is a colon (':') separate list of directories to search.\n\
1961 Setting the search path to an empty list resets it to its default value."),
1962 set_libthread_db_search_path
,
1964 &setlist
, &showlist
);
1966 add_setshow_zuinteger_cmd ("libthread-db", class_maintenance
,
1967 &libthread_db_debug
, _("\
1968 Set libthread-db debugging."), _("\
1969 Show libthread-db debugging."), _("\
1970 When non-zero, libthread-db debugging is enabled."),
1972 show_libthread_db_debug
,
1973 &setdebuglist
, &showdebuglist
);
1975 add_setshow_boolean_cmd ("libthread-db", class_support
,
1976 &auto_load_thread_db
, _("\
1977 Enable or disable auto-loading of inferior specific libthread_db."), _("\
1978 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
1979 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
1980 locations to load libthread_db compatible with the inferior.\n\
1981 Standard system libthread_db still gets loaded even with this option off.\n\
1982 This options has security implications for untrusted inferiors."),
1983 NULL
, show_auto_load_thread_db
,
1984 auto_load_set_cmdlist_get (),
1985 auto_load_show_cmdlist_get ());
1987 add_cmd ("libthread-db", class_info
, info_auto_load_libthread_db
,
1988 _("Print the list of loaded inferior specific libthread_db.\n\
1989 Usage: info auto-load libthread-db"),
1990 auto_load_info_cmdlist_get ());
1992 add_cmd ("libthread-db", class_maintenance
,
1993 maintenance_check_libthread_db
, _("\
1994 Run integrity checks on the current inferior's libthread_db."),
1995 &maintenancechecklist
);
1997 add_setshow_boolean_cmd ("check-libthread-db",
1999 &check_thread_db_on_load
, _("\
2000 Set whether to check libthread_db at load time."), _("\
2001 Show whether to check libthread_db at load time."), _("\
2002 If enabled GDB will run integrity checks on inferior specific libthread_db\n\
2003 as they are loaded."),
2006 &maintenance_set_cmdlist
,
2007 &maintenance_show_cmdlist
);
2009 /* Add ourselves to objfile event chain. */
2010 gdb::observers::new_objfile
.attach (thread_db_new_objfile
);
2012 /* Add ourselves to inferior_created event chain.
2013 This is needed to handle debugging statically linked programs where
2014 the new_objfile observer won't get called for libpthread. */
2015 gdb::observers::inferior_created
.attach (thread_db_inferior_created
);