1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999-2014 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "gdb_assert.h"
24 #include "gdb_proc_service.h"
25 #include "gdb_thread_db.h"
29 #include "exceptions.h"
31 #include "gdbthread.h"
38 #include "solib-svr4.h"
41 #include "linux-nat.h"
42 #include "linux-procfs.h"
43 #include "linux-osdata.h"
44 #include "auto-load.h"
45 #include "cli/cli-utils.h"
50 /* GNU/Linux libthread_db support.
52 libthread_db is a library, provided along with libpthread.so, which
53 exposes the internals of the thread library to a debugger. It
54 allows GDB to find existing threads, new threads as they are
55 created, thread IDs (usually, the result of pthread_self), and
56 thread-local variables.
58 The libthread_db interface originates on Solaris, where it is
59 both more powerful and more complicated. This implementation
60 only works for LinuxThreads and NPTL, the two glibc threading
61 libraries. It assumes that each thread is permanently assigned
62 to a single light-weight process (LWP).
64 libthread_db-specific information is stored in the "private" field
65 of struct thread_info. When the field is NULL we do not yet have
66 information about the new thread; this could be temporary (created,
67 but the thread library's data structures do not reflect it yet)
68 or permanent (created using clone instead of pthread_create).
70 Process IDs managed by linux-thread-db.c match those used by
71 linux-nat.c: a common PID for all processes, an LWP ID for each
72 thread, and no TID. We save the TID in private. Keeping it out
73 of the ptid_t prevents thread IDs changing when libpthread is
74 loaded or unloaded. */
76 static char *libthread_db_search_path;
78 /* Set to non-zero if thread_db auto-loading is enabled
79 by the "set auto-load libthread-db" command. */
80 static int auto_load_thread_db = 1;
82 /* "show" command for the auto_load_thread_db configuration variable. */
85 show_auto_load_thread_db (struct ui_file *file, int from_tty,
86 struct cmd_list_element *c, const char *value)
88 fprintf_filtered (file, _("Auto-loading of inferior specific libthread_db "
94 set_libthread_db_search_path (char *ignored, int from_tty,
95 struct cmd_list_element *c)
97 if (*libthread_db_search_path == '\0')
99 xfree (libthread_db_search_path);
100 libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
104 /* If non-zero, print details of libthread_db processing. */
106 static unsigned int libthread_db_debug;
109 show_libthread_db_debug (struct ui_file *file, int from_tty,
110 struct cmd_list_element *c, const char *value)
112 fprintf_filtered (file, _("libthread-db debugging is %s.\n"), value);
115 /* If we're running on GNU/Linux, we must explicitly attach to any new
118 /* This module's target vector. */
119 static struct target_ops thread_db_ops;
121 /* Non-zero if we have determined the signals used by the threads
123 static int thread_signals;
124 static sigset_t thread_stop_set;
125 static sigset_t thread_print_set;
127 struct thread_db_info
129 struct thread_db_info *next;
131 /* Process id this object refers to. */
134 /* Handle from dlopen for libthread_db.so. */
137 /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
138 HANDLE. It may be NULL for system library. */
141 /* Structure that identifies the child process for the
142 <proc_service.h> interface. */
143 struct ps_prochandle proc_handle;
145 /* Connection to the libthread_db library. */
146 td_thragent_t *thread_agent;
148 /* True if we need to apply the workaround for glibc/BZ5983. When
149 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
150 list, nptl_db returns the parent's threads in addition to the new
151 (single) child thread. If this flag is set, we do extra work to
152 be able to ignore such stale entries. */
153 int need_stale_parent_threads_check;
155 /* Location of the thread creation event breakpoint. The code at
156 this location in the child process will be called by the pthread
157 library whenever a new thread is created. By setting a special
158 breakpoint at this location, GDB can detect when a new thread is
159 created. We obtain this location via the td_ta_event_addr
161 CORE_ADDR td_create_bp_addr;
163 /* Location of the thread death event breakpoint. */
164 CORE_ADDR td_death_bp_addr;
166 /* Pointers to the libthread_db functions. */
168 td_err_e (*td_init_p) (void);
170 td_err_e (*td_ta_new_p) (struct ps_prochandle * ps,
172 td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt,
173 td_thrhandle_t *__th);
174 td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta,
175 lwpid_t lwpid, td_thrhandle_t *th);
176 td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
177 td_thr_iter_f *callback, void *cbdata_p,
178 td_thr_state_e state, int ti_pri,
179 sigset_t *ti_sigmask_p,
180 unsigned int ti_user_flags);
181 td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
182 td_event_e event, td_notify_t *ptr);
183 td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
184 td_thr_events_t *event);
185 td_err_e (*td_ta_clear_event_p) (const td_thragent_t *ta,
186 td_thr_events_t *event);
187 td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
188 td_event_msg_t *msg);
190 td_err_e (*td_thr_validate_p) (const td_thrhandle_t *th);
191 td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
192 td_thrinfo_t *infop);
193 td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th,
196 td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
197 psaddr_t map_address,
198 size_t offset, psaddr_t *address);
201 /* List of known processes using thread_db, and the required
203 struct thread_db_info *thread_db_list;
205 static void thread_db_find_new_threads_1 (ptid_t ptid);
206 static void thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new);
208 /* Add the current inferior to the list of processes using libpthread.
209 Return a pointer to the newly allocated object that was added to
210 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
213 static struct thread_db_info *
214 add_thread_db_info (void *handle)
216 struct thread_db_info *info;
218 info = xcalloc (1, sizeof (*info));
219 info->pid = ptid_get_pid (inferior_ptid);
220 info->handle = handle;
222 /* The workaround works by reading from /proc/pid/status, so it is
223 disabled for core files. */
224 if (target_has_execution)
225 info->need_stale_parent_threads_check = 1;
227 info->next = thread_db_list;
228 thread_db_list = info;
233 /* Return the thread_db_info object representing the bookkeeping
234 related to process PID, if any; NULL otherwise. */
236 static struct thread_db_info *
237 get_thread_db_info (int pid)
239 struct thread_db_info *info;
241 for (info = thread_db_list; info; info = info->next)
242 if (pid == info->pid)
248 /* When PID has exited or has been detached, we no longer want to keep
249 track of it as using libpthread. Call this function to discard
250 thread_db related info related to PID. Note that this closes
251 LIBTHREAD_DB_SO's dlopen'ed handle. */
254 delete_thread_db_info (int pid)
256 struct thread_db_info *info, *info_prev;
260 for (info = thread_db_list; info; info_prev = info, info = info->next)
261 if (pid == info->pid)
267 if (info->handle != NULL)
268 dlclose (info->handle);
270 xfree (info->filename);
273 info_prev->next = info->next;
275 thread_db_list = info->next;
280 /* Prototypes for local functions. */
281 static int attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
282 const td_thrinfo_t *ti_p);
283 static void detach_thread (ptid_t ptid);
286 /* Use "struct private_thread_info" to cache thread state. This is
287 a substantial optimization. */
289 struct private_thread_info
291 /* Flag set when we see a TD_DEATH event for this thread. */
292 unsigned int dying:1;
294 /* Cached thread state. */
301 thread_db_err_str (td_err_e err)
308 return "generic 'call succeeded'";
310 return "generic error";
312 return "no thread to satisfy query";
314 return "no sync handle to satisfy query";
316 return "no LWP to satisfy query";
318 return "invalid process handle";
320 return "invalid thread handle";
322 return "invalid synchronization handle";
324 return "invalid thread agent";
326 return "invalid key";
328 return "no event message for getmsg";
330 return "FPU register set not available";
332 return "application not linked with libthread";
334 return "requested event is not supported";
336 return "capability not available";
338 return "debugger service failed";
340 return "operation not applicable to";
342 return "no thread-specific data for this thread";
344 return "malloc failed";
346 return "only part of register set was written/read";
348 return "X register set not available for this thread";
349 #ifdef THREAD_DB_HAS_TD_NOTALLOC
351 return "thread has not yet allocated TLS for given module";
353 #ifdef THREAD_DB_HAS_TD_VERSION
355 return "versions of libpthread and libthread_db do not match";
357 #ifdef THREAD_DB_HAS_TD_NOTLS
359 return "there is no TLS segment in the given module";
362 snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
367 /* Return 1 if any threads have been registered. There may be none if
368 the threading library is not fully initialized yet. */
371 have_threads_callback (struct thread_info *thread, void *args)
373 int pid = * (int *) args;
375 if (ptid_get_pid (thread->ptid) != pid)
378 return thread->private != NULL;
382 have_threads (ptid_t ptid)
384 int pid = ptid_get_pid (ptid);
386 return iterate_over_threads (have_threads_callback, &pid) != NULL;
389 struct thread_get_info_inout
391 struct thread_info *thread_info;
392 struct thread_db_info *thread_db_info;
395 /* A callback function for td_ta_thr_iter, which we use to map all
398 THP is a handle to the current thread; if INFOP is not NULL, the
399 struct thread_info associated with this thread is returned in
402 If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
403 zero is returned to indicate success. */
406 thread_get_info_callback (const td_thrhandle_t *thp, void *argp)
411 struct thread_get_info_inout *inout;
412 struct thread_db_info *info;
415 info = inout->thread_db_info;
417 err = info->td_thr_get_info_p (thp, &ti);
419 error (_("thread_get_info_callback: cannot get thread info: %s"),
420 thread_db_err_str (err));
422 /* Fill the cache. */
423 thread_ptid = ptid_build (info->pid, ti.ti_lid, 0);
424 inout->thread_info = find_thread_ptid (thread_ptid);
426 if (inout->thread_info == NULL)
428 /* New thread. Attach to it now (why wait?). */
429 if (!have_threads (thread_ptid))
430 thread_db_find_new_threads_1 (thread_ptid);
432 attach_thread (thread_ptid, thp, &ti);
433 inout->thread_info = find_thread_ptid (thread_ptid);
434 gdb_assert (inout->thread_info != NULL);
440 /* Fetch the user-level thread id of PTID. */
443 thread_from_lwp (ptid_t ptid)
447 struct thread_db_info *info;
448 struct thread_get_info_inout io = {0};
450 /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
453 /* This ptid comes from linux-nat.c, which should always fill in the
455 gdb_assert (ptid_get_lwp (ptid) != 0);
457 info = get_thread_db_info (ptid_get_pid (ptid));
459 /* Access an lwp we know is stopped. */
460 info->proc_handle.ptid = ptid;
461 err = info->td_ta_map_lwp2thr_p (info->thread_agent, ptid_get_lwp (ptid),
464 error (_("Cannot find user-level thread for LWP %ld: %s"),
465 ptid_get_lwp (ptid), thread_db_err_str (err));
467 /* Long-winded way of fetching the thread info. */
468 io.thread_db_info = info;
469 io.thread_info = NULL;
470 thread_get_info_callback (&th, &io);
474 /* Attach to lwp PTID, doing whatever else is required to have this
475 LWP under the debugger's control --- e.g., enabling event
476 reporting. Returns true on success. */
478 thread_db_attach_lwp (ptid_t ptid)
483 struct thread_db_info *info;
485 info = get_thread_db_info (ptid_get_pid (ptid));
490 /* This ptid comes from linux-nat.c, which should always fill in the
492 gdb_assert (ptid_get_lwp (ptid) != 0);
494 /* Access an lwp we know is stopped. */
495 info->proc_handle.ptid = ptid;
497 /* If we have only looked at the first thread before libpthread was
498 initialized, we may not know its thread ID yet. Make sure we do
499 before we add another thread to the list. */
500 if (!have_threads (ptid))
501 thread_db_find_new_threads_1 (ptid);
503 err = info->td_ta_map_lwp2thr_p (info->thread_agent, ptid_get_lwp (ptid),
506 /* Cannot find user-level thread. */
509 err = info->td_thr_get_info_p (&th, &ti);
512 warning (_("Cannot get thread info: %s"), thread_db_err_str (err));
516 attach_thread (ptid, &th, &ti);
521 verbose_dlsym (void *handle, const char *name)
523 void *sym = dlsym (handle, name);
525 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
531 enable_thread_event (int event, CORE_ADDR *bp)
535 struct thread_db_info *info;
537 info = get_thread_db_info (ptid_get_pid (inferior_ptid));
539 /* Access an lwp we know is stopped. */
540 info->proc_handle.ptid = inferior_ptid;
542 /* Get the breakpoint address for thread EVENT. */
543 err = info->td_ta_event_addr_p (info->thread_agent, event, ¬ify);
547 /* Set up the breakpoint. */
548 gdb_assert (exec_bfd);
549 (*bp) = (gdbarch_convert_from_func_ptr_addr
551 /* Do proper sign extension for the target. */
552 (bfd_get_sign_extend_vma (exec_bfd) > 0
553 ? (CORE_ADDR) (intptr_t) notify.u.bptaddr
554 : (CORE_ADDR) (uintptr_t) notify.u.bptaddr),
556 create_thread_event_breakpoint (target_gdbarch (), *bp);
561 /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
562 return 1 if this version is lower (and not equal) to
563 VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
566 inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min)
568 struct minimal_symbol *version_msym;
569 CORE_ADDR version_addr;
571 int err, got, retval = 0;
573 version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL);
574 if (version_msym == NULL)
577 version_addr = SYMBOL_VALUE_ADDRESS (version_msym);
578 got = target_read_string (version_addr, &version, 32, &err);
579 if (err == 0 && memchr (version, 0, got) == &version[got -1])
583 retval = (sscanf (version, "%d.%d", &major, &minor) == 2
584 && (major < ver_major_min
585 || (major == ver_major_min && minor < ver_minor_min)));
593 enable_thread_event_reporting (void)
595 td_thr_events_t events;
597 struct thread_db_info *info;
599 info = get_thread_db_info (ptid_get_pid (inferior_ptid));
601 /* We cannot use the thread event reporting facility if these
602 functions aren't available. */
603 if (info->td_ta_event_addr_p == NULL
604 || info->td_ta_set_event_p == NULL
605 || info->td_ta_event_getmsg_p == NULL
606 || info->td_thr_event_enable_p == NULL)
609 /* Set the process wide mask saying which events we're interested in. */
610 td_event_emptyset (&events);
611 td_event_addset (&events, TD_CREATE);
613 /* There is a bug fixed between linuxthreads 2.1.3 and 2.2 by
614 commit 2e4581e4fba917f1779cd0a010a45698586c190a
615 * manager.c (pthread_exited): Correctly report event as TD_REAP
616 instead of TD_DEATH. Fix comments.
617 where event reporting facility is broken for TD_DEATH events,
618 so don't enable it if we have glibc but a lower version. */
619 if (!inferior_has_bug ("__linuxthreads_version", 2, 2))
620 td_event_addset (&events, TD_DEATH);
622 err = info->td_ta_set_event_p (info->thread_agent, &events);
625 warning (_("Unable to set global thread event mask: %s"),
626 thread_db_err_str (err));
630 /* Delete previous thread event breakpoints, if any. */
631 remove_thread_event_breakpoints ();
632 info->td_create_bp_addr = 0;
633 info->td_death_bp_addr = 0;
635 /* Set up the thread creation event. */
636 err = enable_thread_event (TD_CREATE, &info->td_create_bp_addr);
639 warning (_("Unable to get location for thread creation breakpoint: %s"),
640 thread_db_err_str (err));
644 /* Set up the thread death event. */
645 err = enable_thread_event (TD_DEATH, &info->td_death_bp_addr);
648 warning (_("Unable to get location for thread death breakpoint: %s"),
649 thread_db_err_str (err));
654 /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
657 Return 1 if the caller should abort libthread_db initialization. Return 0
661 thread_db_find_new_threads_silently (ptid_t ptid)
663 volatile struct gdb_exception except;
665 TRY_CATCH (except, RETURN_MASK_ERROR)
667 thread_db_find_new_threads_2 (ptid, 1);
670 if (except.reason < 0)
672 if (libthread_db_debug)
673 exception_fprintf (gdb_stderr, except,
674 "Warning: thread_db_find_new_threads_silently: ");
676 /* There is a bug fixed between nptl 2.6.1 and 2.7 by
677 commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
678 where calls to td_thr_get_info fail with TD_ERR for statically linked
679 executables if td_thr_get_info is called before glibc has initialized
682 If the nptl bug is NOT present in the inferior and still thread_db
683 reports an error return 1. It means the inferior has corrupted thread
684 list and GDB should fall back only to LWPs.
686 If the nptl bug is present in the inferior return 0 to silently ignore
687 such errors, and let gdb enumerate threads again later. In such case
688 GDB cannot properly display LWPs if the inferior thread list is
689 corrupted. For core files it does not apply, no 'later enumeration'
692 if (!target_has_execution || !inferior_has_bug ("nptl_version", 2, 7))
694 exception_fprintf (gdb_stderr, except,
695 _("Warning: couldn't activate thread debugging "
696 "using libthread_db: "));
703 /* Lookup a library in which given symbol resides.
704 Note: this is looking in GDB process, not in the inferior.
705 Returns library name, or NULL. */
708 dladdr_to_soname (const void *addr)
712 if (dladdr (addr, &info) != 0)
713 return info.dli_fname;
717 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
719 Failure could happen if libthread_db does not have symbols we expect,
720 or when it refuses to work with the current inferior (e.g. due to
721 version mismatch between libthread_db and libpthread). */
724 try_thread_db_load_1 (struct thread_db_info *info)
728 /* Initialize pointers to the dynamic library functions we will use.
729 Essential functions first. */
731 info->td_init_p = verbose_dlsym (info->handle, "td_init");
732 if (info->td_init_p == NULL)
735 err = info->td_init_p ();
738 warning (_("Cannot initialize libthread_db: %s"),
739 thread_db_err_str (err));
743 info->td_ta_new_p = verbose_dlsym (info->handle, "td_ta_new");
744 if (info->td_ta_new_p == NULL)
747 /* Initialize the structure that identifies the child process. */
748 info->proc_handle.ptid = inferior_ptid;
750 /* Now attempt to open a connection to the thread library. */
751 err = info->td_ta_new_p (&info->proc_handle, &info->thread_agent);
754 if (libthread_db_debug)
755 printf_unfiltered (_("td_ta_new failed: %s\n"),
756 thread_db_err_str (err));
761 #ifdef THREAD_DB_HAS_TD_VERSION
764 /* The errors above are not unexpected and silently ignored:
765 they just mean we haven't found correct version of
769 warning (_("td_ta_new failed: %s"), thread_db_err_str (err));
774 info->td_ta_map_id2thr_p = verbose_dlsym (info->handle, "td_ta_map_id2thr");
775 if (info->td_ta_map_id2thr_p == NULL)
778 info->td_ta_map_lwp2thr_p = verbose_dlsym (info->handle,
779 "td_ta_map_lwp2thr");
780 if (info->td_ta_map_lwp2thr_p == NULL)
783 info->td_ta_thr_iter_p = verbose_dlsym (info->handle, "td_ta_thr_iter");
784 if (info->td_ta_thr_iter_p == NULL)
787 info->td_thr_validate_p = verbose_dlsym (info->handle, "td_thr_validate");
788 if (info->td_thr_validate_p == NULL)
791 info->td_thr_get_info_p = verbose_dlsym (info->handle, "td_thr_get_info");
792 if (info->td_thr_get_info_p == NULL)
795 /* These are not essential. */
796 info->td_ta_event_addr_p = dlsym (info->handle, "td_ta_event_addr");
797 info->td_ta_set_event_p = dlsym (info->handle, "td_ta_set_event");
798 info->td_ta_clear_event_p = dlsym (info->handle, "td_ta_clear_event");
799 info->td_ta_event_getmsg_p = dlsym (info->handle, "td_ta_event_getmsg");
800 info->td_thr_event_enable_p = dlsym (info->handle, "td_thr_event_enable");
801 info->td_thr_tls_get_addr_p = dlsym (info->handle, "td_thr_tls_get_addr");
803 if (thread_db_find_new_threads_silently (inferior_ptid) != 0)
805 /* Even if libthread_db initializes, if the thread list is
806 corrupted, we'd not manage to list any threads. Better reject this
807 thread_db, and fall back to at least listing LWPs. */
811 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
813 if (libthread_db_debug || *libthread_db_search_path)
817 library = dladdr_to_soname (*info->td_ta_new_p);
819 library = LIBTHREAD_DB_SO;
821 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
825 /* The thread library was detected. Activate the thread_db target
826 if this is the first process using it. */
827 if (thread_db_list->next == NULL)
828 push_target (&thread_db_ops);
830 /* Enable event reporting, but not when debugging a core file. */
831 if (target_has_execution)
832 enable_thread_event_reporting ();
837 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
838 relative, or just LIBTHREAD_DB. */
841 try_thread_db_load (const char *library)
844 struct thread_db_info *info;
846 if (libthread_db_debug)
847 printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
849 handle = dlopen (library, RTLD_NOW);
852 if (libthread_db_debug)
853 printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
857 if (libthread_db_debug && strchr (library, '/') == NULL)
861 td_init = dlsym (handle, "td_init");
864 const char *const libpath = dladdr_to_soname (td_init);
867 printf_unfiltered (_("Host %s resolved to: %s.\n"),
872 info = add_thread_db_info (handle);
874 /* Do not save system library name, that one is always trusted. */
875 if (strchr (library, '/') != NULL)
876 info->filename = gdb_realpath (library);
878 if (try_thread_db_load_1 (info))
881 /* This library "refused" to work on current inferior. */
882 delete_thread_db_info (ptid_get_pid (inferior_ptid));
886 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
887 Try loading libthread_db in directory(OBJ)/SUBDIR.
888 SUBDIR may be NULL. It may also be something like "../lib64".
889 The result is true for success. */
892 try_thread_db_load_from_pdir_1 (struct objfile *obj, const char *subdir)
894 struct cleanup *cleanup;
897 const char *obj_name = objfile_name (obj);
899 if (obj_name[0] != '/')
901 warning (_("Expected absolute pathname for libpthread in the"
902 " inferior, but got %s."), obj_name);
906 path = xmalloc (strlen (obj_name) + (subdir ? strlen (subdir) + 1 : 0)
907 + 1 + strlen (LIBTHREAD_DB_SO) + 1);
908 cleanup = make_cleanup (xfree, path);
910 strcpy (path, obj_name);
911 cp = strrchr (path, '/');
912 /* This should at minimum hit the first character. */
913 gdb_assert (cp != NULL);
920 strcat (cp, LIBTHREAD_DB_SO);
922 if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db "
923 "library \"%s\" from $pdir.\n"),
927 result = try_thread_db_load (path);
929 do_cleanups (cleanup);
933 /* Handle $pdir in libthread-db-search-path.
934 Look for libthread_db in directory(libpthread)/SUBDIR.
935 SUBDIR may be NULL. It may also be something like "../lib64".
936 The result is true for success. */
939 try_thread_db_load_from_pdir (const char *subdir)
943 if (!auto_load_thread_db)
947 if (libpthread_name_p (objfile_name (obj)))
949 if (try_thread_db_load_from_pdir_1 (obj, subdir))
952 /* We may have found the separate-debug-info version of
953 libpthread, and it may live in a directory without a matching
955 if (obj->separate_debug_objfile_backlink != NULL)
956 return try_thread_db_load_from_pdir_1 (obj->separate_debug_objfile_backlink,
965 /* Handle $sdir in libthread-db-search-path.
966 Look for libthread_db in the system dirs, or wherever a plain
967 dlopen(file_without_path) will look.
968 The result is true for success. */
971 try_thread_db_load_from_sdir (void)
973 return try_thread_db_load (LIBTHREAD_DB_SO);
976 /* Try to load libthread_db from directory DIR of length DIR_LEN.
977 The result is true for success. */
980 try_thread_db_load_from_dir (const char *dir, size_t dir_len)
982 struct cleanup *cleanup;
986 if (!auto_load_thread_db)
989 path = xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
990 cleanup = make_cleanup (xfree, path);
992 memcpy (path, dir, dir_len);
994 strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
996 if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db "
997 "library \"%s\" from explicit "
1002 result = try_thread_db_load (path);
1004 do_cleanups (cleanup);
1008 /* Search libthread_db_search_path for libthread_db which "agrees"
1009 to work on current inferior.
1010 The result is true for success. */
1013 thread_db_load_search (void)
1015 VEC (char_ptr) *dir_vec;
1016 struct cleanup *cleanups;
1020 dir_vec = dirnames_to_char_ptr_vec (libthread_db_search_path);
1021 cleanups = make_cleanup_free_char_ptr_vec (dir_vec);
1023 for (i = 0; VEC_iterate (char_ptr, dir_vec, i, this_dir); ++i)
1025 const int pdir_len = sizeof ("$pdir") - 1;
1026 size_t this_dir_len;
1028 this_dir_len = strlen (this_dir);
1030 if (strncmp (this_dir, "$pdir", pdir_len) == 0
1031 && (this_dir[pdir_len] == '\0'
1032 || this_dir[pdir_len] == '/'))
1034 char *subdir = NULL;
1035 struct cleanup *free_subdir_cleanup
1036 = make_cleanup (null_cleanup, NULL);
1038 if (this_dir[pdir_len] == '/')
1040 subdir = xmalloc (strlen (this_dir));
1041 make_cleanup (xfree, subdir);
1042 strcpy (subdir, this_dir + pdir_len + 1);
1044 rc = try_thread_db_load_from_pdir (subdir);
1045 do_cleanups (free_subdir_cleanup);
1049 else if (strcmp (this_dir, "$sdir") == 0)
1051 if (try_thread_db_load_from_sdir ())
1059 if (try_thread_db_load_from_dir (this_dir, this_dir_len))
1067 do_cleanups (cleanups);
1068 if (libthread_db_debug)
1069 printf_unfiltered (_("thread_db_load_search returning %d\n"), rc);
1073 /* Return non-zero if the inferior has a libpthread. */
1076 has_libpthread (void)
1078 struct objfile *obj;
1081 if (libpthread_name_p (objfile_name (obj)))
1087 /* Attempt to load and initialize libthread_db.
1088 Return 1 on success. */
1091 thread_db_load (void)
1093 struct thread_db_info *info;
1095 info = get_thread_db_info (ptid_get_pid (inferior_ptid));
1100 /* Don't attempt to use thread_db on executables not running
1102 if (!target_has_registers)
1105 /* Don't attempt to use thread_db for remote targets. */
1106 if (!(target_can_run (¤t_target) || core_bfd))
1109 if (thread_db_load_search ())
1112 /* We couldn't find a libthread_db.
1113 If the inferior has a libpthread warn the user. */
1114 if (has_libpthread ())
1116 warning (_("Unable to find libthread_db matching inferior's thread"
1117 " library, thread debugging will not be available."));
1121 /* Either this executable isn't using libpthread at all, or it is
1122 statically linked. Since we can't easily distinguish these two cases,
1123 no warning is issued. */
1128 disable_thread_event_reporting (struct thread_db_info *info)
1130 if (info->td_ta_clear_event_p != NULL)
1132 td_thr_events_t events;
1134 /* Set the process wide mask saying we aren't interested in any
1136 td_event_fillset (&events);
1137 info->td_ta_clear_event_p (info->thread_agent, &events);
1140 info->td_create_bp_addr = 0;
1141 info->td_death_bp_addr = 0;
1145 check_thread_signals (void)
1147 if (!thread_signals)
1152 lin_thread_get_thread_signals (&mask);
1153 sigemptyset (&thread_stop_set);
1154 sigemptyset (&thread_print_set);
1156 for (i = 1; i < NSIG; i++)
1158 if (sigismember (&mask, i))
1160 if (signal_stop_update (gdb_signal_from_host (i), 0))
1161 sigaddset (&thread_stop_set, i);
1162 if (signal_print_update (gdb_signal_from_host (i), 0))
1163 sigaddset (&thread_print_set, i);
1170 /* Check whether thread_db is usable. This function is called when
1171 an inferior is created (or otherwise acquired, e.g. attached to)
1172 and when new shared libraries are loaded into a running process. */
1175 check_for_thread_db (void)
1177 /* Do nothing if we couldn't load libthread_db.so.1. */
1178 if (!thread_db_load ())
1182 /* This function is called via the new_objfile observer. */
1185 thread_db_new_objfile (struct objfile *objfile)
1187 /* This observer must always be called with inferior_ptid set
1191 /* libpthread with separate debug info has its debug info file already
1192 loaded (and notified without successful thread_db initialization)
1193 the time observer_notify_new_objfile is called for the library itself.
1194 Static executables have their separate debug info loaded already
1195 before the inferior has started. */
1196 && objfile->separate_debug_objfile_backlink == NULL
1197 /* Only check for thread_db if we loaded libpthread,
1198 or if this is the main symbol file.
1199 We need to check OBJF_MAINLINE to handle the case of debugging
1200 a statically linked executable AND the symbol file is specified AFTER
1201 the exec file is loaded (e.g., gdb -c core ; file foo).
1202 For dynamically linked executables, libpthread can be near the end
1203 of the list of shared libraries to load, and in an app of several
1204 thousand shared libraries, this can otherwise be painful. */
1205 && ((objfile->flags & OBJF_MAINLINE) != 0
1206 || libpthread_name_p (objfile_name (objfile))))
1207 check_for_thread_db ();
1210 /* This function is called via the inferior_created observer.
1211 This handles the case of debugging statically linked executables. */
1214 thread_db_inferior_created (struct target_ops *target, int from_tty)
1216 check_for_thread_db ();
1219 /* Attach to a new thread. This function is called when we receive a
1220 TD_CREATE event or when we iterate over all threads and find one
1221 that wasn't already in our list. Returns true on success. */
1224 attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
1225 const td_thrinfo_t *ti_p)
1227 struct private_thread_info *private;
1228 struct thread_info *tp;
1230 struct thread_db_info *info;
1232 /* If we're being called after a TD_CREATE event, we may already
1233 know about this thread. There are two ways this can happen. We
1234 may have iterated over all threads between the thread creation
1235 and the TD_CREATE event, for instance when the user has issued
1236 the `info threads' command before the SIGTRAP for hitting the
1237 thread creation breakpoint was reported. Alternatively, the
1238 thread may have exited and a new one been created with the same
1239 thread ID. In the first case we don't need to do anything; in
1240 the second case we should discard information about the dead
1241 thread and attach to the new one. */
1242 tp = find_thread_ptid (ptid);
1245 /* If tp->private is NULL, then GDB is already attached to this
1246 thread, but we do not know anything about it. We can learn
1247 about it here. This can only happen if we have some other
1248 way besides libthread_db to notice new threads (i.e.
1249 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
1250 exit, so this can not be a stale thread recreated with the
1252 if (tp->private != NULL)
1254 if (!tp->private->dying)
1257 delete_thread (ptid);
1262 if (target_has_execution)
1263 check_thread_signals ();
1265 /* Under GNU/Linux, we have to attach to each and every thread. */
1266 if (target_has_execution
1271 res = lin_lwp_attach_lwp (ptid_build (ptid_get_pid (ptid),
1275 /* Error, stop iterating. */
1280 /* Pretend this thread doesn't exist yet, and keep
1285 /* Otherwise, we sucessfully attached to the thread. */
1288 /* Construct the thread's private data. */
1289 private = xmalloc (sizeof (struct private_thread_info));
1290 memset (private, 0, sizeof (struct private_thread_info));
1292 /* A thread ID of zero may mean the thread library has not initialized
1293 yet. But we shouldn't even get here if that's the case. FIXME:
1294 if we change GDB to always have at least one thread in the thread
1295 list this will have to go somewhere else; maybe private == NULL
1296 until the thread_db target claims it. */
1297 gdb_assert (ti_p->ti_tid != 0);
1298 private->th = *th_p;
1299 private->tid = ti_p->ti_tid;
1300 if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
1303 /* Add the thread to GDB's thread list. */
1305 add_thread_with_info (ptid, private);
1307 tp->private = private;
1309 info = get_thread_db_info (ptid_get_pid (ptid));
1311 /* Enable thread event reporting for this thread, except when
1312 debugging a core file. */
1313 if (target_has_execution)
1315 err = info->td_thr_event_enable_p (th_p, 1);
1317 error (_("Cannot enable thread event reporting for %s: %s"),
1318 target_pid_to_str (ptid), thread_db_err_str (err));
1325 detach_thread (ptid_t ptid)
1327 struct thread_info *thread_info;
1329 /* Don't delete the thread now, because it still reports as active
1330 until it has executed a few instructions after the event
1331 breakpoint - if we deleted it now, "info threads" would cause us
1332 to re-attach to it. Just mark it as having had a TD_DEATH
1333 event. This means that we won't delete it from our thread list
1334 until we notice that it's dead (via prune_threads), or until
1335 something re-uses its thread ID. We'll report the thread exit
1336 when the underlying LWP dies. */
1337 thread_info = find_thread_ptid (ptid);
1338 gdb_assert (thread_info != NULL && thread_info->private != NULL);
1339 thread_info->private->dying = 1;
1343 thread_db_detach (struct target_ops *ops, const char *args, int from_tty)
1345 struct target_ops *target_beneath = find_target_beneath (ops);
1346 struct thread_db_info *info;
1348 info = get_thread_db_info (ptid_get_pid (inferior_ptid));
1352 if (target_has_execution)
1354 disable_thread_event_reporting (info);
1356 /* Delete the old thread event breakpoints. Note that
1357 unlike when mourning, we can remove them here because
1358 there's still a live inferior to poke at. In any case,
1359 GDB will not try to insert anything in the inferior when
1360 removing a breakpoint. */
1361 remove_thread_event_breakpoints ();
1364 delete_thread_db_info (ptid_get_pid (inferior_ptid));
1367 target_beneath->to_detach (target_beneath, args, from_tty);
1369 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1371 /* If there are no more processes using libpthread, detach the
1372 thread_db target ops. */
1373 if (!thread_db_list)
1374 unpush_target (&thread_db_ops);
1377 /* Check if PID is currently stopped at the location of a thread event
1378 breakpoint location. If it is, read the event message and act upon
1382 check_event (ptid_t ptid)
1384 struct regcache *regcache = get_thread_regcache (ptid);
1385 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1391 struct thread_db_info *info;
1393 info = get_thread_db_info (ptid_get_pid (ptid));
1395 /* Bail out early if we're not at a thread event breakpoint. */
1396 stop_pc = regcache_read_pc (regcache)
1397 - gdbarch_decr_pc_after_break (gdbarch);
1398 if (stop_pc != info->td_create_bp_addr
1399 && stop_pc != info->td_death_bp_addr)
1402 /* Access an lwp we know is stopped. */
1403 info->proc_handle.ptid = ptid;
1405 /* If we have only looked at the first thread before libpthread was
1406 initialized, we may not know its thread ID yet. Make sure we do
1407 before we add another thread to the list. */
1408 if (!have_threads (ptid))
1409 thread_db_find_new_threads_1 (ptid);
1411 /* If we are at a create breakpoint, we do not know what new lwp
1412 was created and cannot specifically locate the event message for it.
1413 We have to call td_ta_event_getmsg() to get
1414 the latest message. Since we have no way of correlating whether
1415 the event message we get back corresponds to our breakpoint, we must
1416 loop and read all event messages, processing them appropriately.
1417 This guarantees we will process the correct message before continuing
1418 from the breakpoint.
1420 Currently, death events are not enabled. If they are enabled,
1421 the death event can use the td_thr_event_getmsg() interface to
1422 get the message specifically for that lwp and avoid looping
1429 err = info->td_ta_event_getmsg_p (info->thread_agent, &msg);
1432 if (err == TD_NOMSG)
1435 error (_("Cannot get thread event message: %s"),
1436 thread_db_err_str (err));
1439 err = info->td_thr_get_info_p (msg.th_p, &ti);
1441 error (_("Cannot get thread info: %s"), thread_db_err_str (err));
1443 ptid = ptid_build (ptid_get_pid (ptid), ti.ti_lid, 0);
1448 /* Call attach_thread whether or not we already know about a
1449 thread with this thread ID. */
1450 attach_thread (ptid, msg.th_p, &ti);
1456 if (!in_thread_list (ptid))
1457 error (_("Spurious thread death event."));
1459 detach_thread (ptid);
1464 error (_("Spurious thread event."));
1471 thread_db_wait (struct target_ops *ops,
1472 ptid_t ptid, struct target_waitstatus *ourstatus,
1475 struct thread_db_info *info;
1476 struct target_ops *beneath = find_target_beneath (ops);
1478 ptid = beneath->to_wait (beneath, ptid, ourstatus, options);
1480 if (ourstatus->kind == TARGET_WAITKIND_IGNORE)
1483 if (ourstatus->kind == TARGET_WAITKIND_EXITED
1484 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
1487 info = get_thread_db_info (ptid_get_pid (ptid));
1489 /* If this process isn't using thread_db, we're done. */
1493 if (ourstatus->kind == TARGET_WAITKIND_EXECD)
1495 /* New image, it may or may not end up using thread_db. Assume
1496 not unless we find otherwise. */
1497 delete_thread_db_info (ptid_get_pid (ptid));
1498 if (!thread_db_list)
1499 unpush_target (&thread_db_ops);
1501 /* Thread event breakpoints are deleted by
1502 update_breakpoints_after_exec. */
1507 /* If we do not know about the main thread yet, this would be a good time to
1509 if (ourstatus->kind == TARGET_WAITKIND_STOPPED && !have_threads (ptid))
1510 thread_db_find_new_threads_1 (ptid);
1512 if (ourstatus->kind == TARGET_WAITKIND_STOPPED
1513 && ourstatus->value.sig == GDB_SIGNAL_TRAP)
1514 /* Check for a thread event. */
1517 if (have_threads (ptid))
1519 /* Fill in the thread's user-level thread id. */
1520 thread_from_lwp (ptid);
1527 thread_db_mourn_inferior (struct target_ops *ops)
1529 struct target_ops *target_beneath = find_target_beneath (ops);
1531 delete_thread_db_info (ptid_get_pid (inferior_ptid));
1533 target_beneath->to_mourn_inferior (target_beneath);
1535 /* Delete the old thread event breakpoints. Do this after mourning
1536 the inferior, so that we don't try to uninsert them. */
1537 remove_thread_event_breakpoints ();
1539 /* Detach thread_db target ops. */
1540 if (!thread_db_list)
1541 unpush_target (ops);
1544 struct callback_data
1546 struct thread_db_info *info;
1551 find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
1556 struct thread_info *tp;
1557 struct callback_data *cb_data = data;
1558 struct thread_db_info *info = cb_data->info;
1560 err = info->td_thr_get_info_p (th_p, &ti);
1562 error (_("find_new_threads_callback: cannot get thread info: %s"),
1563 thread_db_err_str (err));
1567 /* A thread ID of zero means that this is the main thread, but
1568 glibc has not yet initialized thread-local storage and the
1569 pthread library. We do not know what the thread's TID will
1570 be yet. Just enable event reporting and otherwise ignore
1573 /* In that case, we're not stopped in a fork syscall and don't
1574 need this glibc bug workaround. */
1575 info->need_stale_parent_threads_check = 0;
1577 if (target_has_execution)
1579 err = info->td_thr_event_enable_p (th_p, 1);
1581 error (_("Cannot enable thread event reporting for LWP %d: %s"),
1582 (int) ti.ti_lid, thread_db_err_str (err));
1588 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1589 bit expensive, as it needs to open /proc/pid/status, so try to
1590 avoid doing the work if we know we don't have to. */
1591 if (info->need_stale_parent_threads_check)
1593 int tgid = linux_proc_get_tgid (ti.ti_lid);
1595 if (tgid != -1 && tgid != info->pid)
1599 ptid = ptid_build (info->pid, ti.ti_lid, 0);
1600 tp = find_thread_ptid (ptid);
1601 if (tp == NULL || tp->private == NULL)
1603 if (attach_thread (ptid, th_p, &ti))
1604 cb_data->new_threads += 1;
1606 /* Problem attaching this thread; perhaps it exited before we
1608 This could mean that the thread list inside glibc itself is in
1609 inconsistent state, and libthread_db could go on looping forever
1610 (observed with glibc-2.3.6). To prevent that, terminate
1611 iteration: thread_db_find_new_threads_2 will retry. */
1618 /* Helper for thread_db_find_new_threads_2.
1619 Returns number of new threads found. */
1622 find_new_threads_once (struct thread_db_info *info, int iteration,
1625 volatile struct gdb_exception except;
1626 struct callback_data data;
1627 td_err_e err = TD_ERR;
1630 data.new_threads = 0;
1632 TRY_CATCH (except, RETURN_MASK_ERROR)
1634 /* Iterate over all user-space threads to discover new threads. */
1635 err = info->td_ta_thr_iter_p (info->thread_agent,
1636 find_new_threads_callback,
1639 TD_THR_LOWEST_PRIORITY,
1641 TD_THR_ANY_USER_FLAGS);
1644 if (libthread_db_debug)
1646 if (except.reason < 0)
1647 exception_fprintf (gdb_stderr, except,
1648 "Warning: find_new_threads_once: ");
1650 printf_filtered (_("Found %d new threads in iteration %d.\n"),
1651 data.new_threads, iteration);
1657 return data.new_threads;
1660 /* Search for new threads, accessing memory through stopped thread
1661 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1662 searches in a row do not discover any new threads. */
1665 thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
1667 td_err_e err = TD_OK;
1668 struct thread_db_info *info;
1671 info = get_thread_db_info (ptid_get_pid (ptid));
1673 /* Access an lwp we know is stopped. */
1674 info->proc_handle.ptid = ptid;
1678 /* Require 4 successive iterations which do not find any new threads.
1679 The 4 is a heuristic: there is an inherent race here, and I have
1680 seen that 2 iterations in a row are not always sufficient to
1681 "capture" all threads. */
1682 for (i = 0, loop = 0; loop < 4 && err == TD_OK; ++i, ++loop)
1683 if (find_new_threads_once (info, i, &err) != 0)
1685 /* Found some new threads. Restart the loop from beginning. */
1690 find_new_threads_once (info, 0, &err);
1693 error (_("Cannot find new threads: %s"), thread_db_err_str (err));
1697 thread_db_find_new_threads_1 (ptid_t ptid)
1699 thread_db_find_new_threads_2 (ptid, 0);
1703 update_thread_core (struct lwp_info *info, void *closure)
1705 info->core = linux_common_core_of_thread (info->ptid);
1710 thread_db_find_new_threads (struct target_ops *ops)
1712 struct thread_db_info *info;
1713 struct inferior *inf;
1717 struct thread_info *thread;
1722 info = get_thread_db_info (inf->pid);
1726 thread = any_live_thread_of_process (inf->pid);
1727 if (thread == NULL || thread->executing)
1730 thread_db_find_new_threads_1 (thread->ptid);
1733 if (target_has_execution)
1734 iterate_over_lwps (minus_one_ptid /* iterate over all */,
1735 update_thread_core, NULL);
1739 thread_db_pid_to_str (struct target_ops *ops, ptid_t ptid)
1741 struct thread_info *thread_info = find_thread_ptid (ptid);
1742 struct target_ops *beneath;
1744 if (thread_info != NULL && thread_info->private != NULL)
1746 static char buf[64];
1749 tid = thread_info->private->tid;
1750 snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
1751 tid, ptid_get_lwp (ptid));
1756 beneath = find_target_beneath (ops);
1757 if (beneath->to_pid_to_str (beneath, ptid))
1758 return beneath->to_pid_to_str (beneath, ptid);
1760 return normal_pid_to_str (ptid);
1763 /* Return a string describing the state of the thread specified by
1767 thread_db_extra_thread_info (struct thread_info *info)
1769 if (info->private == NULL)
1772 if (info->private->dying)
1778 /* Get the address of the thread local variable in load module LM which
1779 is stored at OFFSET within the thread local storage for thread PTID. */
1782 thread_db_get_thread_local_address (struct target_ops *ops,
1787 struct thread_info *thread_info;
1788 struct target_ops *beneath;
1790 /* If we have not discovered any threads yet, check now. */
1791 if (!have_threads (ptid))
1792 thread_db_find_new_threads_1 (ptid);
1794 /* Find the matching thread. */
1795 thread_info = find_thread_ptid (ptid);
1797 if (thread_info != NULL && thread_info->private != NULL)
1801 struct thread_db_info *info;
1803 info = get_thread_db_info (ptid_get_pid (ptid));
1805 /* glibc doesn't provide the needed interface. */
1806 if (!info->td_thr_tls_get_addr_p)
1807 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR,
1808 _("No TLS library support"));
1810 /* Caller should have verified that lm != 0. */
1811 gdb_assert (lm != 0);
1813 /* Finally, get the address of the variable. */
1814 /* Note the cast through uintptr_t: this interface only works if
1815 a target address fits in a psaddr_t, which is a host pointer.
1816 So a 32-bit debugger can not access 64-bit TLS through this. */
1817 err = info->td_thr_tls_get_addr_p (&thread_info->private->th,
1818 (psaddr_t)(uintptr_t) lm,
1821 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1822 /* The memory hasn't been allocated, yet. */
1823 if (err == TD_NOTALLOC)
1824 /* Now, if libthread_db provided the initialization image's
1825 address, we *could* try to build a non-lvalue value from
1826 the initialization image. */
1827 throw_error (TLS_NOT_ALLOCATED_YET_ERROR,
1828 _("TLS not allocated yet"));
1831 /* Something else went wrong. */
1833 throw_error (TLS_GENERIC_ERROR,
1834 (("%s")), thread_db_err_str (err));
1836 /* Cast assuming host == target. Joy. */
1837 /* Do proper sign extension for the target. */
1838 gdb_assert (exec_bfd);
1839 return (bfd_get_sign_extend_vma (exec_bfd) > 0
1840 ? (CORE_ADDR) (intptr_t) address
1841 : (CORE_ADDR) (uintptr_t) address);
1844 beneath = find_target_beneath (ops);
1845 if (beneath->to_get_thread_local_address)
1846 return beneath->to_get_thread_local_address (beneath, ptid, lm, offset);
1848 throw_error (TLS_GENERIC_ERROR,
1849 _("TLS not supported on this target"));
1852 /* Callback routine used to find a thread based on the TID part of
1856 thread_db_find_thread_from_tid (struct thread_info *thread, void *data)
1858 long *tid = (long *) data;
1860 if (thread->private->tid == *tid)
1866 /* Implement the to_get_ada_task_ptid target method for this target. */
1869 thread_db_get_ada_task_ptid (long lwp, long thread)
1871 struct thread_info *thread_info;
1873 thread_db_find_new_threads_1 (inferior_ptid);
1874 thread_info = iterate_over_threads (thread_db_find_thread_from_tid, &thread);
1876 gdb_assert (thread_info != NULL);
1878 return (thread_info->ptid);
1882 thread_db_resume (struct target_ops *ops,
1883 ptid_t ptid, int step, enum gdb_signal signo)
1885 struct target_ops *beneath = find_target_beneath (ops);
1886 struct thread_db_info *info;
1888 if (ptid_equal (ptid, minus_one_ptid))
1889 info = get_thread_db_info (ptid_get_pid (inferior_ptid));
1891 info = get_thread_db_info (ptid_get_pid (ptid));
1893 /* This workaround is only needed for child fork lwps stopped in a
1894 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1895 workaround can be disabled. */
1897 info->need_stale_parent_threads_check = 0;
1899 beneath->to_resume (beneath, ptid, step, signo);
1902 /* qsort helper function for info_auto_load_libthread_db, sort the
1903 thread_db_info pointers primarily by their FILENAME and secondarily by their
1904 PID, both in ascending order. */
1907 info_auto_load_libthread_db_compare (const void *ap, const void *bp)
1909 struct thread_db_info *a = *(struct thread_db_info **) ap;
1910 struct thread_db_info *b = *(struct thread_db_info **) bp;
1913 retval = strcmp (a->filename, b->filename);
1917 return (a->pid > b->pid) - (a->pid - b->pid);
1920 /* Implement 'info auto-load libthread-db'. */
1923 info_auto_load_libthread_db (char *args, int from_tty)
1925 struct ui_out *uiout = current_uiout;
1926 const char *cs = args ? args : "";
1927 struct thread_db_info *info, **array;
1928 unsigned info_count, unique_filenames;
1929 size_t max_filename_len, max_pids_len, pids_len;
1930 struct cleanup *back_to;
1934 cs = skip_spaces_const (cs);
1936 error (_("'info auto-load libthread-db' does not accept any parameters"));
1939 for (info = thread_db_list; info; info = info->next)
1940 if (info->filename != NULL)
1943 array = xmalloc (sizeof (*array) * info_count);
1944 back_to = make_cleanup (xfree, array);
1947 for (info = thread_db_list; info; info = info->next)
1948 if (info->filename != NULL)
1949 array[info_count++] = info;
1951 /* Sort ARRAY by filenames and PIDs. */
1953 qsort (array, info_count, sizeof (*array),
1954 info_auto_load_libthread_db_compare);
1956 /* Calculate the number of unique filenames (rows) and the maximum string
1957 length of PIDs list for the unique filenames (columns). */
1959 unique_filenames = 0;
1960 max_filename_len = 0;
1963 for (i = 0; i < info_count; i++)
1965 int pid = array[i]->pid;
1966 size_t this_pid_len;
1968 for (this_pid_len = 0; pid != 0; pid /= 10)
1971 if (i == 0 || strcmp (array[i - 1]->filename, array[i]->filename) != 0)
1974 max_filename_len = max (max_filename_len,
1975 strlen (array[i]->filename));
1979 pids_len -= strlen (", ");
1980 max_pids_len = max (max_pids_len, pids_len);
1984 pids_len += this_pid_len + strlen (", ");
1988 pids_len -= strlen (", ");
1989 max_pids_len = max (max_pids_len, pids_len);
1992 /* Table header shifted right by preceding "libthread-db: " would not match
1994 if (info_count > 0 && args == auto_load_info_scripts_pattern_nl)
1995 ui_out_text (uiout, "\n");
1997 make_cleanup_ui_out_table_begin_end (uiout, 2, unique_filenames,
1998 "LinuxThreadDbTable");
2000 ui_out_table_header (uiout, max_filename_len, ui_left, "filename",
2002 ui_out_table_header (uiout, pids_len, ui_left, "PIDs", "Pids");
2003 ui_out_table_body (uiout);
2005 pids = xmalloc (max_pids_len + 1);
2006 make_cleanup (xfree, pids);
2008 /* Note I is incremented inside the cycle, not at its end. */
2009 for (i = 0; i < info_count;)
2011 struct cleanup *chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
2015 ui_out_field_string (uiout, "filename", info->filename);
2018 while (i < info_count && strcmp (info->filename, array[i]->filename) == 0)
2020 if (pids_end != pids)
2025 pids_end += xsnprintf (pids_end, &pids[max_pids_len + 1] - pids_end,
2026 "%u", array[i]->pid);
2027 gdb_assert (pids_end < &pids[max_pids_len + 1]);
2033 ui_out_field_string (uiout, "pids", pids);
2035 ui_out_text (uiout, "\n");
2036 do_cleanups (chain);
2039 do_cleanups (back_to);
2041 if (info_count == 0)
2042 ui_out_message (uiout, 0, _("No auto-loaded libthread-db.\n"));
2046 init_thread_db_ops (void)
2048 thread_db_ops.to_shortname = "multi-thread";
2049 thread_db_ops.to_longname = "multi-threaded child process.";
2050 thread_db_ops.to_doc = "Threads and pthreads support.";
2051 thread_db_ops.to_detach = thread_db_detach;
2052 thread_db_ops.to_wait = thread_db_wait;
2053 thread_db_ops.to_resume = thread_db_resume;
2054 thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior;
2055 thread_db_ops.to_find_new_threads = thread_db_find_new_threads;
2056 thread_db_ops.to_pid_to_str = thread_db_pid_to_str;
2057 thread_db_ops.to_stratum = thread_stratum;
2058 thread_db_ops.to_has_thread_control = tc_schedlock;
2059 thread_db_ops.to_get_thread_local_address
2060 = thread_db_get_thread_local_address;
2061 thread_db_ops.to_extra_thread_info = thread_db_extra_thread_info;
2062 thread_db_ops.to_get_ada_task_ptid = thread_db_get_ada_task_ptid;
2063 thread_db_ops.to_magic = OPS_MAGIC;
2065 complete_target_initialization (&thread_db_ops);
2068 /* Provide a prototype to silence -Wmissing-prototypes. */
2069 extern initialize_file_ftype _initialize_thread_db;
2072 _initialize_thread_db (void)
2074 init_thread_db_ops ();
2076 /* Defer loading of libthread_db.so until inferior is running.
2077 This allows gdb to load correct libthread_db for a given
2078 executable -- there could be mutiple versions of glibc,
2079 compiled with LinuxThreads or NPTL, and until there is
2080 a running inferior, we can't tell which libthread_db is
2081 the correct one to load. */
2083 libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
2085 add_setshow_optional_filename_cmd ("libthread-db-search-path",
2087 &libthread_db_search_path, _("\
2088 Set search path for libthread_db."), _("\
2089 Show the current search path or libthread_db."), _("\
2090 This path is used to search for libthread_db to be loaded into \
2092 Its value is a colon (':') separate list of directories to search.\n\
2093 Setting the search path to an empty list resets it to its default value."),
2094 set_libthread_db_search_path,
2096 &setlist, &showlist);
2098 add_setshow_zuinteger_cmd ("libthread-db", class_maintenance,
2099 &libthread_db_debug, _("\
2100 Set libthread-db debugging."), _("\
2101 Show libthread-db debugging."), _("\
2102 When non-zero, libthread-db debugging is enabled."),
2104 show_libthread_db_debug,
2105 &setdebuglist, &showdebuglist);
2107 add_setshow_boolean_cmd ("libthread-db", class_support,
2108 &auto_load_thread_db, _("\
2109 Enable or disable auto-loading of inferior specific libthread_db."), _("\
2110 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
2111 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
2112 locations to load libthread_db compatible with the inferior.\n\
2113 Standard system libthread_db still gets loaded even with this option off.\n\
2114 This options has security implications for untrusted inferiors."),
2115 NULL, show_auto_load_thread_db,
2116 auto_load_set_cmdlist_get (),
2117 auto_load_show_cmdlist_get ());
2119 add_cmd ("libthread-db", class_info, info_auto_load_libthread_db,
2120 _("Print the list of loaded inferior specific libthread_db.\n\
2121 Usage: info auto-load libthread-db"),
2122 auto_load_info_cmdlist_get ());
2124 /* Add ourselves to objfile event chain. */
2125 observer_attach_new_objfile (thread_db_new_objfile);
2127 /* Add ourselves to inferior_created event chain.
2128 This is needed to handle debugging statically linked programs where
2129 the new_objfile observer won't get called for libpthread. */
2130 observer_attach_inferior_created (thread_db_inferior_created);