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"
24 #include "common/gdb_vecs.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 std::string
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 (const gdb_exception_RETURN_MASK_ERROR
&except
)
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: "));
539 /* Lookup a library in which given symbol resides.
540 Note: this is looking in GDB process, not in the inferior.
541 Returns library name, or NULL. */
544 dladdr_to_soname (const void *addr
)
548 if (dladdr (addr
, &info
) != 0)
549 return info
.dli_fname
;
553 /* State for check_thread_db_callback. */
555 struct check_thread_db_info
557 /* The libthread_db under test. */
558 struct thread_db_info
*info
;
560 /* True if progress should be logged. */
563 /* True if the callback was called. */
566 /* Name of last libthread_db function called. */
567 const char *last_call
;
569 /* Value returned by last libthread_db call. */
570 td_err_e last_result
;
573 static struct check_thread_db_info
*tdb_testinfo
;
575 /* Callback for check_thread_db. */
578 check_thread_db_callback (const td_thrhandle_t
*th
, void *arg
)
580 gdb_assert (tdb_testinfo
!= NULL
);
581 tdb_testinfo
->threads_seen
= true;
583 #define LOG(fmt, args...) \
586 if (tdb_testinfo->log_progress) \
588 debug_printf (fmt, ## args); \
589 gdb_flush (gdb_stdlog); \
594 #define CHECK_1(expr, args...) \
599 LOG (" ... FAIL!\n"); \
605 #define CHECK(expr) \
606 CHECK_1 (expr, "(%s) == false", #expr)
608 #define CALL_UNCHECKED(func, args...) \
611 tdb_testinfo->last_call = #func; \
612 tdb_testinfo->last_result \
613 = tdb_testinfo->info->func ## _p (args); \
617 #define CHECK_CALL() \
618 CHECK_1 (tdb_testinfo->last_result == TD_OK, \
619 _("%s failed: %s"), \
620 tdb_testinfo->last_call, \
621 thread_db_err_str (tdb_testinfo->last_result)) \
623 #define CALL(func, args...) \
626 CALL_UNCHECKED (func, args); \
633 /* Check td_ta_thr_iter passed consistent arguments. */
635 CHECK (arg
== (void *) tdb_testinfo
);
636 CHECK (th
->th_ta_p
== tdb_testinfo
->info
->thread_agent
);
638 LOG (" %s", core_addr_to_string_nz ((CORE_ADDR
) th
->th_unique
));
640 /* Check td_thr_get_info. */
642 CALL (td_thr_get_info
, th
, &ti
);
644 LOG (" => %d", ti
.ti_lid
);
646 CHECK (ti
.ti_ta_p
== th
->th_ta_p
);
647 CHECK (ti
.ti_tid
== (thread_t
) th
->th_unique
);
649 /* Check td_ta_map_lwp2thr. */
651 memset (&th2
, 23, sizeof (td_thrhandle_t
));
652 CALL_UNCHECKED (td_ta_map_lwp2thr
, th
->th_ta_p
, ti
.ti_lid
, &th2
);
654 if (tdb_testinfo
->last_result
== TD_ERR
&& !target_has_execution
)
656 /* Some platforms require execution for td_ta_map_lwp2thr. */
657 LOG (_("; can't map_lwp2thr"));
663 LOG (" => %s", core_addr_to_string_nz ((CORE_ADDR
) th2
.th_unique
));
665 CHECK (memcmp (th
, &th2
, sizeof (td_thrhandle_t
)) == 0);
668 /* Attempt TLS access. Assuming errno is TLS, this calls
669 thread_db_get_thread_local_address, which in turn calls
670 td_thr_tls_get_addr for live inferiors or td_thr_tlsbase
671 for core files. This test is skipped if the thread has
672 not been recorded; proceeding in that case would result
673 in the test having the side-effect of noticing threads
676 Note that in glibc's libthread_db td_thr_tls_get_addr is
677 a thin wrapper around td_thr_tlsbase; this check always
678 hits the bulk of the code.
680 Note also that we don't actually check any libthread_db
681 calls are made, we just assume they were; future changes
682 to how GDB accesses TLS could result in this passing
683 without exercising the calls it's supposed to. */
684 ptid_t ptid
= ptid_t (tdb_testinfo
->info
->pid
, ti
.ti_lid
, 0);
685 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
686 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
690 scoped_restore_current_thread restore_current_thread
;
691 switch_to_thread (ptid
);
693 expression_up expr
= parse_expression ("(int) errno");
694 struct value
*val
= evaluate_expression (expr
.get ());
696 if (tdb_testinfo
->log_progress
)
698 struct value_print_options opts
;
700 get_user_print_options (&opts
);
702 value_print (val
, gdb_stdlog
, &opts
);
711 #undef CALL_UNCHECKED
718 /* Run integrity checks on the dlopen()ed libthread_db described by
719 INFO. Returns true on success, displays a warning and returns
720 false on failure. Logs progress messages to gdb_stdlog during
721 the test if LOG_PROGRESS is true. */
724 check_thread_db (struct thread_db_info
*info
, bool log_progress
)
726 bool test_passed
= true;
729 debug_printf (_("Running libthread_db integrity checks:\n"));
731 /* GDB avoids using td_ta_thr_iter wherever possible (see comment
732 in try_thread_db_load_1 below) so in order to test it we may
733 have to locate it ourselves. */
734 td_ta_thr_iter_ftype
*td_ta_thr_iter_p
= info
->td_ta_thr_iter_p
;
735 if (td_ta_thr_iter_p
== NULL
)
737 void *thr_iter
= verbose_dlsym (info
->handle
, "td_ta_thr_iter");
738 if (thr_iter
== NULL
)
741 td_ta_thr_iter_p
= (td_ta_thr_iter_ftype
*) thr_iter
;
744 /* Set up the test state we share with the callback. */
745 gdb_assert (tdb_testinfo
== NULL
);
746 struct check_thread_db_info tdb_testinfo_buf
;
747 tdb_testinfo
= &tdb_testinfo_buf
;
749 memset (tdb_testinfo
, 0, sizeof (struct check_thread_db_info
));
750 tdb_testinfo
->info
= info
;
751 tdb_testinfo
->log_progress
= log_progress
;
753 /* td_ta_thr_iter shouldn't be used on running processes. Note that
754 it's possible the inferior will stop midway through modifying one
755 of its thread lists, in which case the check will spuriously
757 linux_stop_and_wait_all_lwps ();
761 td_err_e err
= td_ta_thr_iter_p (info
->thread_agent
,
762 check_thread_db_callback
,
765 TD_THR_LOWEST_PRIORITY
,
767 TD_THR_ANY_USER_FLAGS
);
770 error (_("td_ta_thr_iter failed: %s"), thread_db_err_str (err
));
772 if (!tdb_testinfo
->threads_seen
)
773 error (_("no threads seen"));
775 catch (const gdb_exception_RETURN_MASK_ERROR
&except
)
777 if (warning_pre_print
)
778 fputs_unfiltered (warning_pre_print
, gdb_stderr
);
780 exception_fprintf (gdb_stderr
, except
,
781 _("libthread_db integrity checks failed: "));
786 if (test_passed
&& log_progress
)
787 debug_printf (_("libthread_db integrity checks passed.\n"));
791 linux_unstop_all_lwps ();
796 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
798 Failure could happen if libthread_db does not have symbols we expect,
799 or when it refuses to work with the current inferior (e.g. due to
800 version mismatch between libthread_db and libpthread). */
803 try_thread_db_load_1 (struct thread_db_info
*info
)
807 /* Initialize pointers to the dynamic library functions we will use.
808 Essential functions first. */
810 #define TDB_VERBOSE_DLSYM(info, func) \
811 info->func ## _p = (func ## _ftype *) verbose_dlsym (info->handle, #func)
813 #define TDB_DLSYM(info, func) \
814 info->func ## _p = (func ## _ftype *) dlsym (info->handle, #func)
823 CHK (TDB_VERBOSE_DLSYM (info
, td_init
));
825 err
= info
->td_init_p ();
828 warning (_("Cannot initialize libthread_db: %s"),
829 thread_db_err_str (err
));
833 CHK (TDB_VERBOSE_DLSYM (info
, td_ta_new
));
835 /* Initialize the structure that identifies the child process. */
836 info
->proc_handle
.thread
= inferior_thread ();
838 /* Now attempt to open a connection to the thread library. */
839 err
= info
->td_ta_new_p (&info
->proc_handle
, &info
->thread_agent
);
842 if (libthread_db_debug
)
843 fprintf_unfiltered (gdb_stdlog
, _("td_ta_new failed: %s\n"),
844 thread_db_err_str (err
));
849 #ifdef THREAD_DB_HAS_TD_VERSION
852 /* The errors above are not unexpected and silently ignored:
853 they just mean we haven't found correct version of
857 warning (_("td_ta_new failed: %s"), thread_db_err_str (err
));
862 /* These are essential. */
863 CHK (TDB_VERBOSE_DLSYM (info
, td_ta_map_lwp2thr
));
864 CHK (TDB_VERBOSE_DLSYM (info
, td_thr_get_info
));
866 /* These are not essential. */
867 TDB_DLSYM (info
, td_thr_tls_get_addr
);
868 TDB_DLSYM (info
, td_thr_tlsbase
);
869 TDB_DLSYM (info
, td_ta_delete
);
871 /* It's best to avoid td_ta_thr_iter if possible. That walks data
872 structures in the inferior's address space that may be corrupted,
873 or, if the target is running, may change while we walk them. If
874 there's execution (and /proc is mounted), then we're already
875 attached to all LWPs. Use thread_from_lwp, which uses
876 td_ta_map_lwp2thr instead, which does not walk the thread list.
878 td_ta_map_lwp2thr uses ps_get_thread_area, but we can't use that
879 currently on core targets, as it uses ptrace directly. */
880 if (target_has_execution
881 && linux_proc_task_list_dir_exists (inferior_ptid
.pid ()))
882 info
->td_ta_thr_iter_p
= NULL
;
884 CHK (TDB_VERBOSE_DLSYM (info
, td_ta_thr_iter
));
886 #undef TDB_VERBOSE_DLSYM
890 /* Run integrity checks if requested. */
891 if (check_thread_db_on_load
)
893 if (!check_thread_db (info
, libthread_db_debug
))
897 if (info
->td_ta_thr_iter_p
== NULL
)
900 int pid
= inferior_ptid
.pid ();
901 thread_info
*curr_thread
= inferior_thread ();
903 linux_stop_and_wait_all_lwps ();
906 if (lp
->ptid
.pid () == pid
)
907 thread_from_lwp (curr_thread
, lp
->ptid
);
909 linux_unstop_all_lwps ();
911 else if (thread_db_find_new_threads_silently (inferior_thread ()) != 0)
913 /* Even if libthread_db initializes, if the thread list is
914 corrupted, we'd not manage to list any threads. Better reject this
915 thread_db, and fall back to at least listing LWPs. */
919 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
921 if (*libthread_db_search_path
|| libthread_db_debug
)
923 struct ui_file
*file
;
926 library
= dladdr_to_soname ((const void *) *info
->td_ta_new_p
);
928 library
= LIBTHREAD_DB_SO
;
930 /* If we'd print this to gdb_stdout when debug output is
931 disabled, still print it to gdb_stdout if debug output is
932 enabled. User visible output should not depend on debug
934 file
= *libthread_db_search_path
!= '\0' ? gdb_stdout
: gdb_stdlog
;
935 fprintf_unfiltered (file
, _("Using host libthread_db library \"%s\".\n"),
939 /* The thread library was detected. Activate the thread_db target
940 if this is the first process using it. */
941 if (thread_db_list
->next
== NULL
)
942 push_target (&the_thread_db_target
);
947 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
948 relative, or just LIBTHREAD_DB. */
951 try_thread_db_load (const char *library
, int check_auto_load_safe
)
954 struct thread_db_info
*info
;
956 if (libthread_db_debug
)
957 fprintf_unfiltered (gdb_stdlog
,
958 _("Trying host libthread_db library: %s.\n"),
961 if (check_auto_load_safe
)
963 if (access (library
, R_OK
) != 0)
965 /* Do not print warnings by file_is_auto_load_safe if the library does
966 not exist at this place. */
967 if (libthread_db_debug
)
968 fprintf_unfiltered (gdb_stdlog
, _("open failed: %s.\n"),
969 safe_strerror (errno
));
973 if (!file_is_auto_load_safe (library
, _("auto-load: Loading libthread-db "
974 "library \"%s\" from explicit "
980 handle
= dlopen (library
, RTLD_NOW
);
983 if (libthread_db_debug
)
984 fprintf_unfiltered (gdb_stdlog
, _("dlopen failed: %s.\n"), dlerror ());
988 if (libthread_db_debug
&& strchr (library
, '/') == NULL
)
992 td_init
= dlsym (handle
, "td_init");
995 const char *const libpath
= dladdr_to_soname (td_init
);
998 fprintf_unfiltered (gdb_stdlog
, _("Host %s resolved to: %s.\n"),
1003 info
= add_thread_db_info (handle
);
1005 /* Do not save system library name, that one is always trusted. */
1006 if (strchr (library
, '/') != NULL
)
1007 info
->filename
= gdb_realpath (library
).release ();
1009 if (try_thread_db_load_1 (info
))
1012 /* This library "refused" to work on current inferior. */
1013 delete_thread_db_info (inferior_ptid
.pid ());
1017 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
1018 Try loading libthread_db in directory(OBJ)/SUBDIR.
1019 SUBDIR may be NULL. It may also be something like "../lib64".
1020 The result is true for success. */
1023 try_thread_db_load_from_pdir_1 (struct objfile
*obj
, const char *subdir
)
1025 const char *obj_name
= objfile_name (obj
);
1027 if (obj_name
[0] != '/')
1029 warning (_("Expected absolute pathname for libpthread in the"
1030 " inferior, but got %s."), obj_name
);
1034 std::string path
= obj_name
;
1035 size_t cp
= path
.rfind ('/');
1036 /* This should at minimum hit the first character. */
1037 gdb_assert (cp
!= std::string::npos
);
1038 path
.resize (cp
+ 1);
1040 path
= path
+ subdir
+ "/";
1041 path
+= LIBTHREAD_DB_SO
;
1043 return try_thread_db_load (path
.c_str (), 1);
1046 /* Handle $pdir in libthread-db-search-path.
1047 Look for libthread_db in directory(libpthread)/SUBDIR.
1048 SUBDIR may be NULL. It may also be something like "../lib64".
1049 The result is true for success. */
1052 try_thread_db_load_from_pdir (const char *subdir
)
1054 if (!auto_load_thread_db
)
1057 for (objfile
*obj
: current_program_space
->objfiles ())
1058 if (libpthread_name_p (objfile_name (obj
)))
1060 if (try_thread_db_load_from_pdir_1 (obj
, subdir
))
1063 /* We may have found the separate-debug-info version of
1064 libpthread, and it may live in a directory without a matching
1066 if (obj
->separate_debug_objfile_backlink
!= NULL
)
1067 return try_thread_db_load_from_pdir_1 (obj
->separate_debug_objfile_backlink
,
1076 /* Handle $sdir in libthread-db-search-path.
1077 Look for libthread_db in the system dirs, or wherever a plain
1078 dlopen(file_without_path) will look.
1079 The result is true for success. */
1082 try_thread_db_load_from_sdir (void)
1084 return try_thread_db_load (LIBTHREAD_DB_SO
, 0);
1087 /* Try to load libthread_db from directory DIR of length DIR_LEN.
1088 The result is true for success. */
1091 try_thread_db_load_from_dir (const char *dir
, size_t dir_len
)
1093 if (!auto_load_thread_db
)
1096 std::string path
= std::string (dir
, dir_len
) + "/" + LIBTHREAD_DB_SO
;
1098 return try_thread_db_load (path
.c_str (), 1);
1101 /* Search libthread_db_search_path for libthread_db which "agrees"
1102 to work on current inferior.
1103 The result is true for success. */
1106 thread_db_load_search (void)
1110 std::vector
<gdb::unique_xmalloc_ptr
<char>> dir_vec
1111 = dirnames_to_char_ptr_vec (libthread_db_search_path
);
1113 for (const gdb::unique_xmalloc_ptr
<char> &this_dir_up
: dir_vec
)
1115 const char *this_dir
= this_dir_up
.get ();
1116 const int pdir_len
= sizeof ("$pdir") - 1;
1117 size_t this_dir_len
;
1119 this_dir_len
= strlen (this_dir
);
1121 if (strncmp (this_dir
, "$pdir", pdir_len
) == 0
1122 && (this_dir
[pdir_len
] == '\0'
1123 || this_dir
[pdir_len
] == '/'))
1125 const char *subdir
= NULL
;
1127 std::string subdir_holder
;
1128 if (this_dir
[pdir_len
] == '/')
1130 subdir_holder
= std::string (this_dir
+ pdir_len
+ 1);
1131 subdir
= subdir_holder
.c_str ();
1133 rc
= try_thread_db_load_from_pdir (subdir
);
1137 else if (strcmp (this_dir
, "$sdir") == 0)
1139 if (try_thread_db_load_from_sdir ())
1147 if (try_thread_db_load_from_dir (this_dir
, this_dir_len
))
1155 if (libthread_db_debug
)
1156 fprintf_unfiltered (gdb_stdlog
,
1157 _("thread_db_load_search returning %d\n"), rc
);
1161 /* Return non-zero if the inferior has a libpthread. */
1164 has_libpthread (void)
1166 for (objfile
*obj
: current_program_space
->objfiles ())
1167 if (libpthread_name_p (objfile_name (obj
)))
1173 /* Attempt to load and initialize libthread_db.
1174 Return 1 on success. */
1177 thread_db_load (void)
1179 struct thread_db_info
*info
;
1181 info
= get_thread_db_info (inferior_ptid
.pid ());
1186 /* Don't attempt to use thread_db on executables not running
1188 if (!target_has_registers
)
1191 /* Don't attempt to use thread_db for remote targets. */
1192 if (!(target_can_run () || core_bfd
))
1195 if (thread_db_load_search ())
1198 /* We couldn't find a libthread_db.
1199 If the inferior has a libpthread warn the user. */
1200 if (has_libpthread ())
1202 warning (_("Unable to find libthread_db matching inferior's thread"
1203 " library, thread debugging will not be available."));
1207 /* Either this executable isn't using libpthread at all, or it is
1208 statically linked. Since we can't easily distinguish these two cases,
1209 no warning is issued. */
1214 check_thread_signals (void)
1216 if (!thread_signals
)
1221 lin_thread_get_thread_signals (&mask
);
1222 sigemptyset (&thread_stop_set
);
1223 sigemptyset (&thread_print_set
);
1225 for (i
= 1; i
< NSIG
; i
++)
1227 if (sigismember (&mask
, i
))
1229 if (signal_stop_update (gdb_signal_from_host (i
), 0))
1230 sigaddset (&thread_stop_set
, i
);
1231 if (signal_print_update (gdb_signal_from_host (i
), 0))
1232 sigaddset (&thread_print_set
, i
);
1239 /* Check whether thread_db is usable. This function is called when
1240 an inferior is created (or otherwise acquired, e.g. attached to)
1241 and when new shared libraries are loaded into a running process. */
1244 check_for_thread_db (void)
1246 /* Do nothing if we couldn't load libthread_db.so.1. */
1247 if (!thread_db_load ())
1251 /* This function is called via the new_objfile observer. */
1254 thread_db_new_objfile (struct objfile
*objfile
)
1256 /* This observer must always be called with inferior_ptid set
1260 /* libpthread with separate debug info has its debug info file already
1261 loaded (and notified without successful thread_db initialization)
1262 the time gdb::observers::new_objfile.notify is called for the library itself.
1263 Static executables have their separate debug info loaded already
1264 before the inferior has started. */
1265 && objfile
->separate_debug_objfile_backlink
== NULL
1266 /* Only check for thread_db if we loaded libpthread,
1267 or if this is the main symbol file.
1268 We need to check OBJF_MAINLINE to handle the case of debugging
1269 a statically linked executable AND the symbol file is specified AFTER
1270 the exec file is loaded (e.g., gdb -c core ; file foo).
1271 For dynamically linked executables, libpthread can be near the end
1272 of the list of shared libraries to load, and in an app of several
1273 thousand shared libraries, this can otherwise be painful. */
1274 && ((objfile
->flags
& OBJF_MAINLINE
) != 0
1275 || libpthread_name_p (objfile_name (objfile
))))
1276 check_for_thread_db ();
1280 check_pid_namespace_match (void)
1282 /* Check is only relevant for local targets targets. */
1283 if (target_can_run ())
1285 /* If the child is in a different PID namespace, its idea of its
1286 PID will differ from our idea of its PID. When we scan the
1287 child's thread list, we'll mistakenly think it has no threads
1288 since the thread PID fields won't match the PID we give to
1290 if (!linux_ns_same (inferior_ptid
.pid (), LINUX_NS_PID
))
1292 warning (_ ("Target and debugger are in different PID "
1293 "namespaces; thread lists and other data are "
1294 "likely unreliable. "
1295 "Connect to gdbserver inside the container."));
1300 /* This function is called via the inferior_created observer.
1301 This handles the case of debugging statically linked executables. */
1304 thread_db_inferior_created (struct target_ops
*target
, int from_tty
)
1306 check_pid_namespace_match ();
1307 check_for_thread_db ();
1310 /* Update the thread's state (what's displayed in "info threads"),
1311 from libthread_db thread state information. */
1314 update_thread_state (thread_db_thread_info
*priv
,
1315 const td_thrinfo_t
*ti_p
)
1317 priv
->dying
= (ti_p
->ti_state
== TD_THR_UNKNOWN
1318 || ti_p
->ti_state
== TD_THR_ZOMBIE
);
1321 /* Record a new thread in GDB's thread list. Creates the thread's
1322 private info. If TP is NULL or TP is marked as having exited,
1323 creates a new thread. Otherwise, uses TP. */
1325 static struct thread_info
*
1326 record_thread (struct thread_db_info
*info
,
1327 struct thread_info
*tp
,
1328 ptid_t ptid
, const td_thrhandle_t
*th_p
,
1329 const td_thrinfo_t
*ti_p
)
1331 /* A thread ID of zero may mean the thread library has not
1332 initialized yet. Leave private == NULL until the thread library
1334 if (ti_p
->ti_tid
== 0)
1337 /* Construct the thread's private data. */
1338 thread_db_thread_info
*priv
= new thread_db_thread_info
;
1341 priv
->tid
= ti_p
->ti_tid
;
1342 update_thread_state (priv
, ti_p
);
1344 /* Add the thread to GDB's thread list. If we already know about a
1345 thread with this PTID, but it's marked exited, then the kernel
1346 reused the tid of an old thread. */
1347 if (tp
== NULL
|| tp
->state
== THREAD_EXITED
)
1348 tp
= add_thread_with_info (ptid
, priv
);
1350 tp
->priv
.reset (priv
);
1352 if (target_has_execution
)
1353 check_thread_signals ();
1359 thread_db_target::detach (inferior
*inf
, int from_tty
)
1361 delete_thread_db_info (inf
->pid
);
1363 beneath ()->detach (inf
, from_tty
);
1365 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1367 /* If there are no more processes using libpthread, detach the
1368 thread_db target ops. */
1369 if (!thread_db_list
)
1370 unpush_target (this);
1374 thread_db_target::wait (ptid_t ptid
, struct target_waitstatus
*ourstatus
,
1377 struct thread_db_info
*info
;
1379 ptid
= beneath ()->wait (ptid
, ourstatus
, options
);
1381 switch (ourstatus
->kind
)
1383 case TARGET_WAITKIND_IGNORE
:
1384 case TARGET_WAITKIND_EXITED
:
1385 case TARGET_WAITKIND_THREAD_EXITED
:
1386 case TARGET_WAITKIND_SIGNALLED
:
1390 info
= get_thread_db_info (ptid
.pid ());
1392 /* If this process isn't using thread_db, we're done. */
1396 if (ourstatus
->kind
== TARGET_WAITKIND_EXECD
)
1398 /* New image, it may or may not end up using thread_db. Assume
1399 not unless we find otherwise. */
1400 delete_thread_db_info (ptid
.pid ());
1401 if (!thread_db_list
)
1402 unpush_target (&the_thread_db_target
);
1407 /* Fill in the thread's user-level thread id and status. */
1408 thread_from_lwp (find_thread_ptid (ptid
), ptid
);
1414 thread_db_target::mourn_inferior ()
1416 delete_thread_db_info (inferior_ptid
.pid ());
1418 beneath ()->mourn_inferior ();
1420 /* Detach thread_db target ops. */
1421 if (!thread_db_list
)
1422 unpush_target (&the_thread_db_target
);
1425 struct callback_data
1427 struct thread_db_info
*info
;
1432 find_new_threads_callback (const td_thrhandle_t
*th_p
, void *data
)
1436 struct thread_info
*tp
;
1437 struct callback_data
*cb_data
= (struct callback_data
*) data
;
1438 struct thread_db_info
*info
= cb_data
->info
;
1440 err
= info
->td_thr_get_info_p (th_p
, &ti
);
1442 error (_("find_new_threads_callback: cannot get thread info: %s"),
1443 thread_db_err_str (err
));
1445 if (ti
.ti_lid
== -1)
1447 /* A thread with kernel thread ID -1 is either a thread that
1448 exited and was joined, or a thread that is being created but
1449 hasn't started yet, and that is reusing the tcb/stack of a
1450 thread that previously exited and was joined. (glibc marks
1451 terminated and joined threads with kernel thread ID -1. See
1453 if (libthread_db_debug
)
1454 fprintf_unfiltered (gdb_stdlog
,
1455 "thread_db: skipping exited and "
1456 "joined thread (0x%lx)\n",
1457 (unsigned long) ti
.ti_tid
);
1463 /* A thread ID of zero means that this is the main thread, but
1464 glibc has not yet initialized thread-local storage and the
1465 pthread library. We do not know what the thread's TID will
1468 /* In that case, we're not stopped in a fork syscall and don't
1469 need this glibc bug workaround. */
1470 info
->need_stale_parent_threads_check
= 0;
1475 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1476 bit expensive, as it needs to open /proc/pid/status, so try to
1477 avoid doing the work if we know we don't have to. */
1478 if (info
->need_stale_parent_threads_check
)
1480 int tgid
= linux_proc_get_tgid (ti
.ti_lid
);
1482 if (tgid
!= -1 && tgid
!= info
->pid
)
1486 ptid_t
ptid (info
->pid
, ti
.ti_lid
);
1487 tp
= find_thread_ptid (ptid
);
1488 if (tp
== NULL
|| tp
->priv
== NULL
)
1489 record_thread (info
, tp
, ptid
, th_p
, &ti
);
1494 /* Helper for thread_db_find_new_threads_2.
1495 Returns number of new threads found. */
1498 find_new_threads_once (struct thread_db_info
*info
, int iteration
,
1501 struct callback_data data
;
1502 td_err_e err
= TD_ERR
;
1505 data
.new_threads
= 0;
1507 /* See comment in thread_db_update_thread_list. */
1508 gdb_assert (info
->td_ta_thr_iter_p
!= NULL
);
1512 /* Iterate over all user-space threads to discover new threads. */
1513 err
= info
->td_ta_thr_iter_p (info
->thread_agent
,
1514 find_new_threads_callback
,
1517 TD_THR_LOWEST_PRIORITY
,
1519 TD_THR_ANY_USER_FLAGS
);
1521 catch (const gdb_exception_RETURN_MASK_ERROR
&except
)
1523 if (libthread_db_debug
)
1525 exception_fprintf (gdb_stdlog
, except
,
1526 "Warning: find_new_threads_once: ");
1530 if (libthread_db_debug
)
1532 fprintf_unfiltered (gdb_stdlog
,
1533 _("Found %d new threads in iteration %d.\n"),
1534 data
.new_threads
, iteration
);
1540 return data
.new_threads
;
1543 /* Search for new threads, accessing memory through stopped thread
1544 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1545 searches in a row do not discover any new threads. */
1548 thread_db_find_new_threads_2 (thread_info
*stopped
, bool until_no_new
)
1550 td_err_e err
= TD_OK
;
1551 struct thread_db_info
*info
;
1554 info
= get_thread_db_info (stopped
->ptid
.pid ());
1556 /* Access an lwp we know is stopped. */
1557 info
->proc_handle
.thread
= stopped
;
1561 /* Require 4 successive iterations which do not find any new threads.
1562 The 4 is a heuristic: there is an inherent race here, and I have
1563 seen that 2 iterations in a row are not always sufficient to
1564 "capture" all threads. */
1565 for (i
= 0, loop
= 0; loop
< 4 && err
== TD_OK
; ++i
, ++loop
)
1566 if (find_new_threads_once (info
, i
, &err
) != 0)
1568 /* Found some new threads. Restart the loop from beginning. */
1573 find_new_threads_once (info
, 0, &err
);
1576 error (_("Cannot find new threads: %s"), thread_db_err_str (err
));
1580 thread_db_find_new_threads_1 (thread_info
*stopped
)
1582 thread_db_find_new_threads_2 (stopped
, 0);
1585 /* Implement the to_update_thread_list target method for this
1589 thread_db_target::update_thread_list ()
1591 struct thread_db_info
*info
;
1595 for (inferior
*inf
: all_inferiors ())
1597 struct thread_info
*thread
;
1602 info
= get_thread_db_info (inf
->pid
);
1606 thread
= any_live_thread_of_inferior (inf
);
1607 if (thread
== NULL
|| thread
->executing
)
1610 /* It's best to avoid td_ta_thr_iter if possible. That walks
1611 data structures in the inferior's address space that may be
1612 corrupted, or, if the target is running, the list may change
1613 while we walk it. In the latter case, it's possible that a
1614 thread exits just at the exact time that causes GDB to get
1615 stuck in an infinite loop. To avoid pausing all threads
1616 whenever the core wants to refresh the thread list, we
1617 instead use thread_from_lwp immediately when we see an LWP
1618 stop. That uses thread_db entry points that do not walk
1619 libpthread's thread list, so should be safe, as well as more
1621 if (target_has_execution_1 (thread
->ptid
))
1624 thread_db_find_new_threads_1 (thread
);
1627 /* Give the beneath target a chance to do extra processing. */
1628 this->beneath ()->update_thread_list ();
1632 thread_db_target::pid_to_str (ptid_t ptid
)
1634 struct thread_info
*thread_info
= find_thread_ptid (ptid
);
1636 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
1638 thread_db_thread_info
*priv
= get_thread_db_thread_info (thread_info
);
1640 return string_printf ("Thread 0x%lx (LWP %ld)",
1641 (unsigned long) priv
->tid
, ptid
.lwp ());
1644 return beneath ()->pid_to_str (ptid
);
1647 /* Return a string describing the state of the thread specified by
1651 thread_db_target::extra_thread_info (thread_info
*info
)
1653 if (info
->priv
== NULL
)
1656 thread_db_thread_info
*priv
= get_thread_db_thread_info (info
);
1664 /* Return pointer to the thread_info struct which corresponds to
1665 THREAD_HANDLE (having length HANDLE_LEN). */
1668 thread_db_target::thread_handle_to_thread_info (const gdb_byte
*thread_handle
,
1672 thread_t handle_tid
;
1674 /* Thread handle sizes must match in order to proceed. We don't use an
1675 assert here because the resulting internal error will cause GDB to
1676 exit. This isn't necessarily an internal error due to the possibility
1677 of garbage being passed as the thread handle via the python interface. */
1678 if (handle_len
!= sizeof (handle_tid
))
1679 error (_("Thread handle size mismatch: %d vs %zu (from libthread_db)"),
1680 handle_len
, sizeof (handle_tid
));
1682 handle_tid
= * (const thread_t
*) thread_handle
;
1684 for (thread_info
*tp
: inf
->non_exited_threads ())
1686 thread_db_thread_info
*priv
= get_thread_db_thread_info (tp
);
1688 if (priv
!= NULL
&& handle_tid
== priv
->tid
)
1695 /* Get the address of the thread local variable in load module LM which
1696 is stored at OFFSET within the thread local storage for thread PTID. */
1699 thread_db_target::get_thread_local_address (ptid_t ptid
,
1703 struct thread_info
*thread_info
;
1705 /* Find the matching thread. */
1706 thread_info
= find_thread_ptid (ptid
);
1708 /* We may not have discovered the thread yet. */
1709 if (thread_info
!= NULL
&& thread_info
->priv
== NULL
)
1710 thread_info
= thread_from_lwp (thread_info
, ptid
);
1712 if (thread_info
!= NULL
&& thread_info
->priv
!= NULL
)
1716 thread_db_info
*info
= get_thread_db_info (ptid
.pid ());
1717 thread_db_thread_info
*priv
= get_thread_db_thread_info (thread_info
);
1719 /* Finally, get the address of the variable. */
1722 /* glibc doesn't provide the needed interface. */
1723 if (!info
->td_thr_tls_get_addr_p
)
1724 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR
,
1725 _("No TLS library support"));
1727 /* Note the cast through uintptr_t: this interface only works if
1728 a target address fits in a psaddr_t, which is a host pointer.
1729 So a 32-bit debugger can not access 64-bit TLS through this. */
1730 err
= info
->td_thr_tls_get_addr_p (&priv
->th
,
1731 (psaddr_t
)(uintptr_t) lm
,
1736 /* If glibc doesn't provide the needed interface throw an error
1737 that LM is zero - normally cases it should not be. */
1738 if (!info
->td_thr_tlsbase_p
)
1739 throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR
,
1740 _("TLS load module not found"));
1742 /* This code path handles the case of -static -pthread executables:
1743 https://sourceware.org/ml/libc-help/2014-03/msg00024.html
1744 For older GNU libc r_debug.r_map is NULL. For GNU libc after
1745 PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
1746 The constant number 1 depends on GNU __libc_setup_tls
1747 initialization of l_tls_modid to 1. */
1748 err
= info
->td_thr_tlsbase_p (&priv
->th
, 1, &address
);
1749 address
= (char *) address
+ offset
;
1752 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1753 /* The memory hasn't been allocated, yet. */
1754 if (err
== TD_NOTALLOC
)
1755 /* Now, if libthread_db provided the initialization image's
1756 address, we *could* try to build a non-lvalue value from
1757 the initialization image. */
1758 throw_error (TLS_NOT_ALLOCATED_YET_ERROR
,
1759 _("TLS not allocated yet"));
1762 /* Something else went wrong. */
1764 throw_error (TLS_GENERIC_ERROR
,
1765 (("%s")), thread_db_err_str (err
));
1767 /* Cast assuming host == target. Joy. */
1768 /* Do proper sign extension for the target. */
1769 gdb_assert (exec_bfd
);
1770 return (bfd_get_sign_extend_vma (exec_bfd
) > 0
1771 ? (CORE_ADDR
) (intptr_t) address
1772 : (CORE_ADDR
) (uintptr_t) address
);
1775 return beneath ()->get_thread_local_address (ptid
, lm
, offset
);
1778 /* Implement the to_get_ada_task_ptid target method for this target. */
1781 thread_db_target::get_ada_task_ptid (long lwp
, long thread
)
1783 /* NPTL uses a 1:1 model, so the LWP id suffices. */
1784 return ptid_t (inferior_ptid
.pid (), lwp
, 0);
1788 thread_db_target::resume (ptid_t ptid
, int step
, enum gdb_signal signo
)
1790 struct thread_db_info
*info
;
1792 if (ptid
== minus_one_ptid
)
1793 info
= get_thread_db_info (inferior_ptid
.pid ());
1795 info
= get_thread_db_info (ptid
.pid ());
1797 /* This workaround is only needed for child fork lwps stopped in a
1798 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1799 workaround can be disabled. */
1801 info
->need_stale_parent_threads_check
= 0;
1803 beneath ()->resume (ptid
, step
, signo
);
1806 /* std::sort helper function for info_auto_load_libthread_db, sort the
1807 thread_db_info pointers primarily by their FILENAME and secondarily by their
1808 PID, both in ascending order. */
1811 info_auto_load_libthread_db_compare (const struct thread_db_info
*a
,
1812 const struct thread_db_info
*b
)
1816 retval
= strcmp (a
->filename
, b
->filename
);
1820 return a
->pid
< b
->pid
;
1823 /* Implement 'info auto-load libthread-db'. */
1826 info_auto_load_libthread_db (const char *args
, int from_tty
)
1828 struct ui_out
*uiout
= current_uiout
;
1829 const char *cs
= args
? args
: "";
1830 struct thread_db_info
*info
;
1831 unsigned unique_filenames
;
1832 size_t max_filename_len
, pids_len
;
1835 cs
= skip_spaces (cs
);
1837 error (_("'info auto-load libthread-db' does not accept any parameters"));
1839 std::vector
<struct thread_db_info
*> array
;
1840 for (info
= thread_db_list
; info
; info
= info
->next
)
1841 if (info
->filename
!= NULL
)
1842 array
.push_back (info
);
1844 /* Sort ARRAY by filenames and PIDs. */
1845 std::sort (array
.begin (), array
.end (),
1846 info_auto_load_libthread_db_compare
);
1848 /* Calculate the number of unique filenames (rows) and the maximum string
1849 length of PIDs list for the unique filenames (columns). */
1851 unique_filenames
= 0;
1852 max_filename_len
= 0;
1854 for (i
= 0; i
< array
.size (); i
++)
1856 int pid
= array
[i
]->pid
;
1857 size_t this_pid_len
;
1859 for (this_pid_len
= 0; pid
!= 0; pid
/= 10)
1862 if (i
== 0 || strcmp (array
[i
- 1]->filename
, array
[i
]->filename
) != 0)
1865 max_filename_len
= std::max (max_filename_len
,
1866 strlen (array
[i
]->filename
));
1869 pids_len
-= strlen (", ");
1872 pids_len
+= this_pid_len
+ strlen (", ");
1875 pids_len
-= strlen (", ");
1877 /* Table header shifted right by preceding "libthread-db: " would not match
1879 if (array
.size () > 0 && args
== auto_load_info_scripts_pattern_nl
)
1883 ui_out_emit_table
table_emitter (uiout
, 2, unique_filenames
,
1884 "LinuxThreadDbTable");
1886 uiout
->table_header (max_filename_len
, ui_left
, "filename", "Filename");
1887 uiout
->table_header (pids_len
, ui_left
, "PIDs", "Pids");
1888 uiout
->table_body ();
1890 /* Note I is incremented inside the cycle, not at its end. */
1891 for (i
= 0; i
< array
.size ();)
1893 ui_out_emit_tuple
tuple_emitter (uiout
, NULL
);
1896 uiout
->field_string ("filename", info
->filename
);
1899 while (i
< array
.size () && strcmp (info
->filename
,
1900 array
[i
]->filename
) == 0)
1904 string_appendf (pids
, "%u", array
[i
]->pid
);
1908 uiout
->field_string ("pids", pids
.c_str ());
1915 uiout
->message (_("No auto-loaded libthread-db.\n"));
1918 /* Implement 'maintenance check libthread-db'. */
1921 maintenance_check_libthread_db (const char *args
, int from_tty
)
1923 int inferior_pid
= inferior_ptid
.pid ();
1924 struct thread_db_info
*info
;
1926 if (inferior_pid
== 0)
1927 error (_("No inferior running"));
1929 info
= get_thread_db_info (inferior_pid
);
1931 error (_("No libthread_db loaded"));
1933 check_thread_db (info
, true);
1937 _initialize_thread_db (void)
1939 /* Defer loading of libthread_db.so until inferior is running.
1940 This allows gdb to load correct libthread_db for a given
1941 executable -- there could be multiple versions of glibc,
1942 and until there is a running inferior, we can't tell which
1943 libthread_db is the correct one to load. */
1945 libthread_db_search_path
= xstrdup (LIBTHREAD_DB_SEARCH_PATH
);
1947 add_setshow_optional_filename_cmd ("libthread-db-search-path",
1949 &libthread_db_search_path
, _("\
1950 Set search path for libthread_db."), _("\
1951 Show the current search path or libthread_db."), _("\
1952 This path is used to search for libthread_db to be loaded into \
1954 Its value is a colon (':') separate list of directories to search.\n\
1955 Setting the search path to an empty list resets it to its default value."),
1956 set_libthread_db_search_path
,
1958 &setlist
, &showlist
);
1960 add_setshow_zuinteger_cmd ("libthread-db", class_maintenance
,
1961 &libthread_db_debug
, _("\
1962 Set libthread-db debugging."), _("\
1963 Show libthread-db debugging."), _("\
1964 When non-zero, libthread-db debugging is enabled."),
1966 show_libthread_db_debug
,
1967 &setdebuglist
, &showdebuglist
);
1969 add_setshow_boolean_cmd ("libthread-db", class_support
,
1970 &auto_load_thread_db
, _("\
1971 Enable or disable auto-loading of inferior specific libthread_db."), _("\
1972 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
1973 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
1974 locations to load libthread_db compatible with the inferior.\n\
1975 Standard system libthread_db still gets loaded even with this option off.\n\
1976 This option has security implications for untrusted inferiors."),
1977 NULL
, show_auto_load_thread_db
,
1978 auto_load_set_cmdlist_get (),
1979 auto_load_show_cmdlist_get ());
1981 add_cmd ("libthread-db", class_info
, info_auto_load_libthread_db
,
1982 _("Print the list of loaded inferior specific libthread_db.\n\
1983 Usage: info auto-load libthread-db"),
1984 auto_load_info_cmdlist_get ());
1986 add_cmd ("libthread-db", class_maintenance
,
1987 maintenance_check_libthread_db
, _("\
1988 Run integrity checks on the current inferior's libthread_db."),
1989 &maintenancechecklist
);
1991 add_setshow_boolean_cmd ("check-libthread-db",
1993 &check_thread_db_on_load
, _("\
1994 Set whether to check libthread_db at load time."), _("\
1995 Show whether to check libthread_db at load time."), _("\
1996 If enabled GDB will run integrity checks on inferior specific libthread_db\n\
1997 as they are loaded."),
2000 &maintenance_set_cmdlist
,
2001 &maintenance_show_cmdlist
);
2003 /* Add ourselves to objfile event chain. */
2004 gdb::observers::new_objfile
.attach (thread_db_new_objfile
);
2006 /* Add ourselves to inferior_created event chain.
2007 This is needed to handle debugging statically linked programs where
2008 the new_objfile observer won't get called for libpthread. */
2009 gdb::observers::inferior_created
.attach (thread_db_inferior_created
);