1 /* libthread_db assisted debugging support, generic parts.
3 Copyright (C) 1999-2001, 2003-2012 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "gdb_assert.h"
24 #include "gdb_proc_service.h"
25 #include "gdb_thread_db.h"
29 #include "exceptions.h"
31 #include "gdbthread.h"
38 #include "solib-svr4.h"
41 #include "linux-nat.h"
42 #include "linux-procfs.h"
43 #include "linux-osdata.h"
44 #include "auto-load.h"
49 /* GNU/Linux libthread_db support.
51 libthread_db is a library, provided along with libpthread.so, which
52 exposes the internals of the thread library to a debugger. It
53 allows GDB to find existing threads, new threads as they are
54 created, thread IDs (usually, the result of pthread_self), and
55 thread-local variables.
57 The libthread_db interface originates on Solaris, where it is
58 both more powerful and more complicated. This implementation
59 only works for LinuxThreads and NPTL, the two glibc threading
60 libraries. It assumes that each thread is permanently assigned
61 to a single light-weight process (LWP).
63 libthread_db-specific information is stored in the "private" field
64 of struct thread_info. When the field is NULL we do not yet have
65 information about the new thread; this could be temporary (created,
66 but the thread library's data structures do not reflect it yet)
67 or permanent (created using clone instead of pthread_create).
69 Process IDs managed by linux-thread-db.c match those used by
70 linux-nat.c: a common PID for all processes, an LWP ID for each
71 thread, and no TID. We save the TID in private. Keeping it out
72 of the ptid_t prevents thread IDs changing when libpthread is
73 loaded or unloaded. */
75 static char *libthread_db_search_path;
77 /* Set to non-zero if thread_db auto-loading is enabled
78 by the "set auto-load libthread-db" command. */
79 static int auto_load_thread_db = 1;
81 /* "show" command for the auto_load_thread_db configuration variable. */
84 show_auto_load_thread_db (struct ui_file *file, int from_tty,
85 struct cmd_list_element *c, const char *value)
87 fprintf_filtered (file, _("Auto-loading of inferior specific libthread_db "
93 set_libthread_db_search_path (char *ignored, int from_tty,
94 struct cmd_list_element *c)
96 if (*libthread_db_search_path == '\0')
98 xfree (libthread_db_search_path);
99 libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
103 /* If non-zero, print details of libthread_db processing. */
105 static unsigned int libthread_db_debug;
108 show_libthread_db_debug (struct ui_file *file, int from_tty,
109 struct cmd_list_element *c, const char *value)
111 fprintf_filtered (file, _("libthread-db debugging is %s.\n"), value);
114 /* If we're running on GNU/Linux, we must explicitly attach to any new
117 /* This module's target vector. */
118 static struct target_ops thread_db_ops;
120 /* Non-zero if we have determined the signals used by the threads
122 static int thread_signals;
123 static sigset_t thread_stop_set;
124 static sigset_t thread_print_set;
126 struct thread_db_info
128 struct thread_db_info *next;
130 /* Process id this object refers to. */
133 /* Handle from dlopen for libthread_db.so. */
136 /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
137 HANDLE. It may be NULL for system library. */
140 /* Structure that identifies the child process for the
141 <proc_service.h> interface. */
142 struct ps_prochandle proc_handle;
144 /* Connection to the libthread_db library. */
145 td_thragent_t *thread_agent;
147 /* True if we need to apply the workaround for glibc/BZ5983. When
148 we catch a PTRACE_O_TRACEFORK, and go query the child's thread
149 list, nptl_db returns the parent's threads in addition to the new
150 (single) child thread. If this flag is set, we do extra work to
151 be able to ignore such stale entries. */
152 int need_stale_parent_threads_check;
154 /* Location of the thread creation event breakpoint. The code at
155 this location in the child process will be called by the pthread
156 library whenever a new thread is created. By setting a special
157 breakpoint at this location, GDB can detect when a new thread is
158 created. We obtain this location via the td_ta_event_addr
160 CORE_ADDR td_create_bp_addr;
162 /* Location of the thread death event breakpoint. */
163 CORE_ADDR td_death_bp_addr;
165 /* Pointers to the libthread_db functions. */
167 td_err_e (*td_init_p) (void);
169 td_err_e (*td_ta_new_p) (struct ps_prochandle * ps,
171 td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt,
172 td_thrhandle_t *__th);
173 td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta,
174 lwpid_t lwpid, td_thrhandle_t *th);
175 td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
176 td_thr_iter_f *callback, void *cbdata_p,
177 td_thr_state_e state, int ti_pri,
178 sigset_t *ti_sigmask_p,
179 unsigned int ti_user_flags);
180 td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
181 td_event_e event, td_notify_t *ptr);
182 td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
183 td_thr_events_t *event);
184 td_err_e (*td_ta_clear_event_p) (const td_thragent_t *ta,
185 td_thr_events_t *event);
186 td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
187 td_event_msg_t *msg);
189 td_err_e (*td_thr_validate_p) (const td_thrhandle_t *th);
190 td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
191 td_thrinfo_t *infop);
192 td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th,
195 td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
196 psaddr_t map_address,
197 size_t offset, psaddr_t *address);
200 /* List of known processes using thread_db, and the required
202 struct thread_db_info *thread_db_list;
204 static void thread_db_find_new_threads_1 (ptid_t ptid);
205 static void thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new);
207 /* Add the current inferior to the list of processes using libpthread.
208 Return a pointer to the newly allocated object that was added to
209 THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
212 static struct thread_db_info *
213 add_thread_db_info (void *handle)
215 struct thread_db_info *info;
217 info = xcalloc (1, sizeof (*info));
218 info->pid = ptid_get_pid (inferior_ptid);
219 info->handle = handle;
221 /* The workaround works by reading from /proc/pid/status, so it is
222 disabled for core files. */
223 if (target_has_execution)
224 info->need_stale_parent_threads_check = 1;
226 info->next = thread_db_list;
227 thread_db_list = info;
232 /* Return the thread_db_info object representing the bookkeeping
233 related to process PID, if any; NULL otherwise. */
235 static struct thread_db_info *
236 get_thread_db_info (int pid)
238 struct thread_db_info *info;
240 for (info = thread_db_list; info; info = info->next)
241 if (pid == info->pid)
247 /* When PID has exited or has been detached, we no longer want to keep
248 track of it as using libpthread. Call this function to discard
249 thread_db related info related to PID. Note that this closes
250 LIBTHREAD_DB_SO's dlopen'ed handle. */
253 delete_thread_db_info (int pid)
255 struct thread_db_info *info, *info_prev;
259 for (info = thread_db_list; info; info_prev = info, info = info->next)
260 if (pid == info->pid)
266 if (info->handle != NULL)
267 dlclose (info->handle);
269 xfree (info->filename);
272 info_prev->next = info->next;
274 thread_db_list = info->next;
279 /* Prototypes for local functions. */
280 static int attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
281 const td_thrinfo_t *ti_p);
282 static void detach_thread (ptid_t ptid);
285 /* Use "struct private_thread_info" to cache thread state. This is
286 a substantial optimization. */
288 struct private_thread_info
290 /* Flag set when we see a TD_DEATH event for this thread. */
291 unsigned int dying:1;
293 /* Cached thread state. */
300 thread_db_err_str (td_err_e err)
307 return "generic 'call succeeded'";
309 return "generic error";
311 return "no thread to satisfy query";
313 return "no sync handle to satisfy query";
315 return "no LWP to satisfy query";
317 return "invalid process handle";
319 return "invalid thread handle";
321 return "invalid synchronization handle";
323 return "invalid thread agent";
325 return "invalid key";
327 return "no event message for getmsg";
329 return "FPU register set not available";
331 return "application not linked with libthread";
333 return "requested event is not supported";
335 return "capability not available";
337 return "debugger service failed";
339 return "operation not applicable to";
341 return "no thread-specific data for this thread";
343 return "malloc failed";
345 return "only part of register set was written/read";
347 return "X register set not available for this thread";
348 #ifdef THREAD_DB_HAS_TD_NOTALLOC
350 return "thread has not yet allocated TLS for given module";
352 #ifdef THREAD_DB_HAS_TD_VERSION
354 return "versions of libpthread and libthread_db do not match";
356 #ifdef THREAD_DB_HAS_TD_NOTLS
358 return "there is no TLS segment in the given module";
361 snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
366 /* Return 1 if any threads have been registered. There may be none if
367 the threading library is not fully initialized yet. */
370 have_threads_callback (struct thread_info *thread, void *args)
372 int pid = * (int *) args;
374 if (ptid_get_pid (thread->ptid) != pid)
377 return thread->private != NULL;
381 have_threads (ptid_t ptid)
383 int pid = ptid_get_pid (ptid);
385 return iterate_over_threads (have_threads_callback, &pid) != NULL;
388 struct thread_get_info_inout
390 struct thread_info *thread_info;
391 struct thread_db_info *thread_db_info;
394 /* A callback function for td_ta_thr_iter, which we use to map all
397 THP is a handle to the current thread; if INFOP is not NULL, the
398 struct thread_info associated with this thread is returned in
401 If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
402 zero is returned to indicate success. */
405 thread_get_info_callback (const td_thrhandle_t *thp, void *argp)
410 struct thread_get_info_inout *inout;
411 struct thread_db_info *info;
414 info = inout->thread_db_info;
416 err = info->td_thr_get_info_p (thp, &ti);
418 error (_("thread_get_info_callback: cannot get thread info: %s"),
419 thread_db_err_str (err));
421 /* Fill the cache. */
422 thread_ptid = ptid_build (info->pid, ti.ti_lid, 0);
423 inout->thread_info = find_thread_ptid (thread_ptid);
425 if (inout->thread_info == NULL)
427 /* New thread. Attach to it now (why wait?). */
428 if (!have_threads (thread_ptid))
429 thread_db_find_new_threads_1 (thread_ptid);
431 attach_thread (thread_ptid, thp, &ti);
432 inout->thread_info = find_thread_ptid (thread_ptid);
433 gdb_assert (inout->thread_info != NULL);
439 /* Fetch the user-level thread id of PTID. */
442 thread_from_lwp (ptid_t ptid)
446 struct thread_db_info *info;
447 struct thread_get_info_inout io = {0};
449 /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
452 /* This ptid comes from linux-nat.c, which should always fill in the
454 gdb_assert (GET_LWP (ptid) != 0);
456 info = get_thread_db_info (GET_PID (ptid));
458 /* Access an lwp we know is stopped. */
459 info->proc_handle.ptid = ptid;
460 err = info->td_ta_map_lwp2thr_p (info->thread_agent, GET_LWP (ptid), &th);
462 error (_("Cannot find user-level thread for LWP %ld: %s"),
463 GET_LWP (ptid), thread_db_err_str (err));
465 /* Long-winded way of fetching the thread info. */
466 io.thread_db_info = info;
467 io.thread_info = NULL;
468 thread_get_info_callback (&th, &io);
472 /* Attach to lwp PTID, doing whatever else is required to have this
473 LWP under the debugger's control --- e.g., enabling event
474 reporting. Returns true on success. */
476 thread_db_attach_lwp (ptid_t ptid)
481 struct thread_db_info *info;
483 info = get_thread_db_info (GET_PID (ptid));
488 /* This ptid comes from linux-nat.c, which should always fill in the
490 gdb_assert (GET_LWP (ptid) != 0);
492 /* Access an lwp we know is stopped. */
493 info->proc_handle.ptid = ptid;
495 /* If we have only looked at the first thread before libpthread was
496 initialized, we may not know its thread ID yet. Make sure we do
497 before we add another thread to the list. */
498 if (!have_threads (ptid))
499 thread_db_find_new_threads_1 (ptid);
501 err = info->td_ta_map_lwp2thr_p (info->thread_agent, GET_LWP (ptid), &th);
503 /* Cannot find user-level thread. */
506 err = info->td_thr_get_info_p (&th, &ti);
509 warning (_("Cannot get thread info: %s"), thread_db_err_str (err));
513 attach_thread (ptid, &th, &ti);
518 verbose_dlsym (void *handle, const char *name)
520 void *sym = dlsym (handle, name);
522 warning (_("Symbol \"%s\" not found in libthread_db: %s"),
528 enable_thread_event (int event, CORE_ADDR *bp)
532 struct thread_db_info *info;
534 info = get_thread_db_info (GET_PID (inferior_ptid));
536 /* Access an lwp we know is stopped. */
537 info->proc_handle.ptid = inferior_ptid;
539 /* Get the breakpoint address for thread EVENT. */
540 err = info->td_ta_event_addr_p (info->thread_agent, event, ¬ify);
544 /* Set up the breakpoint. */
545 gdb_assert (exec_bfd);
546 (*bp) = (gdbarch_convert_from_func_ptr_addr
548 /* Do proper sign extension for the target. */
549 (bfd_get_sign_extend_vma (exec_bfd) > 0
550 ? (CORE_ADDR) (intptr_t) notify.u.bptaddr
551 : (CORE_ADDR) (uintptr_t) notify.u.bptaddr),
553 create_thread_event_breakpoint (target_gdbarch, *bp);
558 /* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
559 return 1 if this version is lower (and not equal) to
560 VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
563 inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min)
565 struct minimal_symbol *version_msym;
566 CORE_ADDR version_addr;
568 int err, got, retval = 0;
570 version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL);
571 if (version_msym == NULL)
574 version_addr = SYMBOL_VALUE_ADDRESS (version_msym);
575 got = target_read_string (version_addr, &version, 32, &err);
576 if (err == 0 && memchr (version, 0, got) == &version[got -1])
580 retval = (sscanf (version, "%d.%d", &major, &minor) == 2
581 && (major < ver_major_min
582 || (major == ver_major_min && minor < ver_minor_min)));
590 enable_thread_event_reporting (void)
592 td_thr_events_t events;
594 struct thread_db_info *info;
596 info = get_thread_db_info (GET_PID (inferior_ptid));
598 /* We cannot use the thread event reporting facility if these
599 functions aren't available. */
600 if (info->td_ta_event_addr_p == NULL
601 || info->td_ta_set_event_p == NULL
602 || info->td_ta_event_getmsg_p == NULL
603 || info->td_thr_event_enable_p == NULL)
606 /* Set the process wide mask saying which events we're interested in. */
607 td_event_emptyset (&events);
608 td_event_addset (&events, TD_CREATE);
610 /* There is a bug fixed between linuxthreads 2.1.3 and 2.2 by
611 commit 2e4581e4fba917f1779cd0a010a45698586c190a
612 * manager.c (pthread_exited): Correctly report event as TD_REAP
613 instead of TD_DEATH. Fix comments.
614 where event reporting facility is broken for TD_DEATH events,
615 so don't enable it if we have glibc but a lower version. */
616 if (!inferior_has_bug ("__linuxthreads_version", 2, 2))
617 td_event_addset (&events, TD_DEATH);
619 err = info->td_ta_set_event_p (info->thread_agent, &events);
622 warning (_("Unable to set global thread event mask: %s"),
623 thread_db_err_str (err));
627 /* Delete previous thread event breakpoints, if any. */
628 remove_thread_event_breakpoints ();
629 info->td_create_bp_addr = 0;
630 info->td_death_bp_addr = 0;
632 /* Set up the thread creation event. */
633 err = enable_thread_event (TD_CREATE, &info->td_create_bp_addr);
636 warning (_("Unable to get location for thread creation breakpoint: %s"),
637 thread_db_err_str (err));
641 /* Set up the thread death event. */
642 err = enable_thread_event (TD_DEATH, &info->td_death_bp_addr);
645 warning (_("Unable to get location for thread death breakpoint: %s"),
646 thread_db_err_str (err));
651 /* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
654 Return 1 if the caller should abort libthread_db initialization. Return 0
658 thread_db_find_new_threads_silently (ptid_t ptid)
660 volatile struct gdb_exception except;
662 TRY_CATCH (except, RETURN_MASK_ERROR)
664 thread_db_find_new_threads_2 (ptid, 1);
667 if (except.reason < 0)
669 if (libthread_db_debug)
670 exception_fprintf (gdb_stderr, except,
671 "Warning: thread_db_find_new_threads_silently: ");
673 /* There is a bug fixed between nptl 2.6.1 and 2.7 by
674 commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
675 where calls to td_thr_get_info fail with TD_ERR for statically linked
676 executables if td_thr_get_info is called before glibc has initialized
679 If the nptl bug is NOT present in the inferior and still thread_db
680 reports an error return 1. It means the inferior has corrupted thread
681 list and GDB should fall back only to LWPs.
683 If the nptl bug is present in the inferior return 0 to silently ignore
684 such errors, and let gdb enumerate threads again later. In such case
685 GDB cannot properly display LWPs if the inferior thread list is
686 corrupted. For core files it does not apply, no 'later enumeration'
689 if (!target_has_execution || !inferior_has_bug ("nptl_version", 2, 7))
691 exception_fprintf (gdb_stderr, except,
692 _("Warning: couldn't activate thread debugging "
693 "using libthread_db: "));
700 /* Lookup a library in which given symbol resides.
701 Note: this is looking in GDB process, not in the inferior.
702 Returns library name, or NULL. */
705 dladdr_to_soname (const void *addr)
709 if (dladdr (addr, &info) != 0)
710 return info.dli_fname;
714 /* Attempt to initialize dlopen()ed libthread_db, described by INFO.
716 Failure could happen if libthread_db does not have symbols we expect,
717 or when it refuses to work with the current inferior (e.g. due to
718 version mismatch between libthread_db and libpthread). */
721 try_thread_db_load_1 (struct thread_db_info *info)
725 /* Initialize pointers to the dynamic library functions we will use.
726 Essential functions first. */
728 info->td_init_p = verbose_dlsym (info->handle, "td_init");
729 if (info->td_init_p == NULL)
732 err = info->td_init_p ();
735 warning (_("Cannot initialize libthread_db: %s"),
736 thread_db_err_str (err));
740 info->td_ta_new_p = verbose_dlsym (info->handle, "td_ta_new");
741 if (info->td_ta_new_p == NULL)
744 /* Initialize the structure that identifies the child process. */
745 info->proc_handle.ptid = inferior_ptid;
747 /* Now attempt to open a connection to the thread library. */
748 err = info->td_ta_new_p (&info->proc_handle, &info->thread_agent);
751 if (libthread_db_debug)
752 printf_unfiltered (_("td_ta_new failed: %s\n"),
753 thread_db_err_str (err));
758 #ifdef THREAD_DB_HAS_TD_VERSION
761 /* The errors above are not unexpected and silently ignored:
762 they just mean we haven't found correct version of
766 warning (_("td_ta_new failed: %s"), thread_db_err_str (err));
771 info->td_ta_map_id2thr_p = verbose_dlsym (info->handle, "td_ta_map_id2thr");
772 if (info->td_ta_map_id2thr_p == NULL)
775 info->td_ta_map_lwp2thr_p = verbose_dlsym (info->handle,
776 "td_ta_map_lwp2thr");
777 if (info->td_ta_map_lwp2thr_p == NULL)
780 info->td_ta_thr_iter_p = verbose_dlsym (info->handle, "td_ta_thr_iter");
781 if (info->td_ta_thr_iter_p == NULL)
784 info->td_thr_validate_p = verbose_dlsym (info->handle, "td_thr_validate");
785 if (info->td_thr_validate_p == NULL)
788 info->td_thr_get_info_p = verbose_dlsym (info->handle, "td_thr_get_info");
789 if (info->td_thr_get_info_p == NULL)
792 /* These are not essential. */
793 info->td_ta_event_addr_p = dlsym (info->handle, "td_ta_event_addr");
794 info->td_ta_set_event_p = dlsym (info->handle, "td_ta_set_event");
795 info->td_ta_clear_event_p = dlsym (info->handle, "td_ta_clear_event");
796 info->td_ta_event_getmsg_p = dlsym (info->handle, "td_ta_event_getmsg");
797 info->td_thr_event_enable_p = dlsym (info->handle, "td_thr_event_enable");
798 info->td_thr_tls_get_addr_p = dlsym (info->handle, "td_thr_tls_get_addr");
800 if (thread_db_find_new_threads_silently (inferior_ptid) != 0)
802 /* Even if libthread_db initializes, if the thread list is
803 corrupted, we'd not manage to list any threads. Better reject this
804 thread_db, and fall back to at least listing LWPs. */
808 printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
810 if (libthread_db_debug || *libthread_db_search_path)
814 library = dladdr_to_soname (*info->td_ta_new_p);
816 library = LIBTHREAD_DB_SO;
818 printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
822 /* The thread library was detected. Activate the thread_db target
823 if this is the first process using it. */
824 if (thread_db_list->next == NULL)
825 push_target (&thread_db_ops);
827 /* Enable event reporting, but not when debugging a core file. */
828 if (target_has_execution)
829 enable_thread_event_reporting ();
834 /* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
835 relative, or just LIBTHREAD_DB. */
838 try_thread_db_load (const char *library)
841 struct thread_db_info *info;
843 if (libthread_db_debug)
844 printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
846 handle = dlopen (library, RTLD_NOW);
849 if (libthread_db_debug)
850 printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
854 if (libthread_db_debug && strchr (library, '/') == NULL)
858 td_init = dlsym (handle, "td_init");
861 const char *const libpath = dladdr_to_soname (td_init);
864 printf_unfiltered (_("Host %s resolved to: %s.\n"),
869 info = add_thread_db_info (handle);
871 /* Do not save system library name, that one is always trusted. */
872 if (strchr (library, '/') != NULL)
873 info->filename = gdb_realpath (library);
875 if (try_thread_db_load_1 (info))
878 /* This library "refused" to work on current inferior. */
879 delete_thread_db_info (GET_PID (inferior_ptid));
883 /* Subroutine of try_thread_db_load_from_pdir to simplify it.
884 Try loading libthread_db from the same directory as OBJ.
885 The result is true for success. */
888 try_thread_db_load_from_pdir_1 (struct objfile *obj)
890 struct cleanup *cleanup;
894 if (obj->name[0] != '/')
896 warning (_("Expected absolute pathname for libpthread in the"
897 " inferior, but got %s."), obj->name);
901 path = xmalloc (strlen (obj->name) + 1 + strlen (LIBTHREAD_DB_SO) + 1);
902 cleanup = make_cleanup (xfree, path);
904 strcpy (path, obj->name);
905 cp = strrchr (path, '/');
906 /* This should at minimum hit the first character. */
907 gdb_assert (cp != NULL);
908 strcpy (cp + 1, LIBTHREAD_DB_SO);
910 if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db "
911 "library \"%s\" from $pdir.\n"),
915 result = try_thread_db_load (path);
917 do_cleanups (cleanup);
921 /* Handle $pdir in libthread-db-search-path.
922 Look for libthread_db in the directory of libpthread.
923 The result is true for success. */
926 try_thread_db_load_from_pdir (void)
930 if (!auto_load_thread_db)
934 if (libpthread_name_p (obj->name))
936 if (try_thread_db_load_from_pdir_1 (obj))
939 /* We may have found the separate-debug-info version of
940 libpthread, and it may live in a directory without a matching
942 if (obj->separate_debug_objfile_backlink != NULL)
943 return try_thread_db_load_from_pdir_1 (obj->separate_debug_objfile_backlink);
951 /* Handle $sdir in libthread-db-search-path.
952 Look for libthread_db in the system dirs, or wherever a plain
953 dlopen(file_without_path) will look.
954 The result is true for success. */
957 try_thread_db_load_from_sdir (void)
959 return try_thread_db_load (LIBTHREAD_DB_SO);
962 /* Try to load libthread_db from directory DIR of length DIR_LEN.
963 The result is true for success. */
966 try_thread_db_load_from_dir (const char *dir, size_t dir_len)
968 struct cleanup *cleanup;
972 if (!auto_load_thread_db)
975 path = xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
976 cleanup = make_cleanup (xfree, path);
978 memcpy (path, dir, dir_len);
980 strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
982 if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db "
983 "library \"%s\" from explicit "
988 result = try_thread_db_load (path);
990 do_cleanups (cleanup);
994 /* Search libthread_db_search_path for libthread_db which "agrees"
995 to work on current inferior.
996 The result is true for success. */
999 thread_db_load_search (void)
1001 const char *search_path = libthread_db_search_path;
1004 while (*search_path)
1006 const char *end = strchr (search_path, ':');
1007 const char *this_dir = search_path;
1008 size_t this_dir_len;
1012 this_dir_len = end - search_path;
1013 search_path += this_dir_len + 1;
1017 this_dir_len = strlen (this_dir);
1018 search_path += this_dir_len;
1021 if (this_dir_len == sizeof ("$pdir") - 1
1022 && strncmp (this_dir, "$pdir", this_dir_len) == 0)
1024 if (try_thread_db_load_from_pdir ())
1030 else if (this_dir_len == sizeof ("$sdir") - 1
1031 && strncmp (this_dir, "$sdir", this_dir_len) == 0)
1033 if (try_thread_db_load_from_sdir ())
1041 if (try_thread_db_load_from_dir (this_dir, this_dir_len))
1049 if (libthread_db_debug)
1050 printf_unfiltered (_("thread_db_load_search returning %d\n"), rc);
1054 /* Return non-zero if the inferior has a libpthread. */
1057 has_libpthread (void)
1059 struct objfile *obj;
1062 if (libpthread_name_p (obj->name))
1068 /* Attempt to load and initialize libthread_db.
1069 Return 1 on success. */
1072 thread_db_load (void)
1074 struct thread_db_info *info;
1076 info = get_thread_db_info (GET_PID (inferior_ptid));
1081 /* Don't attempt to use thread_db on executables not running
1083 if (!target_has_registers)
1086 /* Don't attempt to use thread_db for remote targets. */
1087 if (!(target_can_run (¤t_target) || core_bfd))
1090 if (thread_db_load_search ())
1093 /* We couldn't find a libthread_db.
1094 If the inferior has a libpthread warn the user. */
1095 if (has_libpthread ())
1097 warning (_("Unable to find libthread_db matching inferior's thread"
1098 " library, thread debugging will not be available."));
1102 /* Either this executable isn't using libpthread at all, or it is
1103 statically linked. Since we can't easily distinguish these two cases,
1104 no warning is issued. */
1109 disable_thread_event_reporting (struct thread_db_info *info)
1111 if (info->td_ta_clear_event_p != NULL)
1113 td_thr_events_t events;
1115 /* Set the process wide mask saying we aren't interested in any
1117 td_event_fillset (&events);
1118 info->td_ta_clear_event_p (info->thread_agent, &events);
1121 info->td_create_bp_addr = 0;
1122 info->td_death_bp_addr = 0;
1126 check_thread_signals (void)
1128 if (!thread_signals)
1133 lin_thread_get_thread_signals (&mask);
1134 sigemptyset (&thread_stop_set);
1135 sigemptyset (&thread_print_set);
1137 for (i = 1; i < NSIG; i++)
1139 if (sigismember (&mask, i))
1141 if (signal_stop_update (gdb_signal_from_host (i), 0))
1142 sigaddset (&thread_stop_set, i);
1143 if (signal_print_update (gdb_signal_from_host (i), 0))
1144 sigaddset (&thread_print_set, i);
1151 /* Check whether thread_db is usable. This function is called when
1152 an inferior is created (or otherwise acquired, e.g. attached to)
1153 and when new shared libraries are loaded into a running process. */
1156 check_for_thread_db (void)
1158 /* Do nothing if we couldn't load libthread_db.so.1. */
1159 if (!thread_db_load ())
1163 /* This function is called via the new_objfile observer. */
1166 thread_db_new_objfile (struct objfile *objfile)
1168 /* This observer must always be called with inferior_ptid set
1172 /* libpthread with separate debug info has its debug info file already
1173 loaded (and notified without successful thread_db initialization)
1174 the time observer_notify_new_objfile is called for the library itself.
1175 Static executables have their separate debug info loaded already
1176 before the inferior has started. */
1177 && objfile->separate_debug_objfile_backlink == NULL
1178 /* Only check for thread_db if we loaded libpthread,
1179 or if this is the main symbol file.
1180 We need to check OBJF_MAINLINE to handle the case of debugging
1181 a statically linked executable AND the symbol file is specified AFTER
1182 the exec file is loaded (e.g., gdb -c core ; file foo).
1183 For dynamically linked executables, libpthread can be near the end
1184 of the list of shared libraries to load, and in an app of several
1185 thousand shared libraries, this can otherwise be painful. */
1186 && ((objfile->flags & OBJF_MAINLINE) != 0
1187 || libpthread_name_p (objfile->name)))
1188 check_for_thread_db ();
1191 /* This function is called via the inferior_created observer.
1192 This handles the case of debugging statically linked executables. */
1195 thread_db_inferior_created (struct target_ops *target, int from_tty)
1197 check_for_thread_db ();
1200 /* Attach to a new thread. This function is called when we receive a
1201 TD_CREATE event or when we iterate over all threads and find one
1202 that wasn't already in our list. Returns true on success. */
1205 attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
1206 const td_thrinfo_t *ti_p)
1208 struct private_thread_info *private;
1209 struct thread_info *tp;
1211 struct thread_db_info *info;
1213 /* If we're being called after a TD_CREATE event, we may already
1214 know about this thread. There are two ways this can happen. We
1215 may have iterated over all threads between the thread creation
1216 and the TD_CREATE event, for instance when the user has issued
1217 the `info threads' command before the SIGTRAP for hitting the
1218 thread creation breakpoint was reported. Alternatively, the
1219 thread may have exited and a new one been created with the same
1220 thread ID. In the first case we don't need to do anything; in
1221 the second case we should discard information about the dead
1222 thread and attach to the new one. */
1223 tp = find_thread_ptid (ptid);
1226 /* If tp->private is NULL, then GDB is already attached to this
1227 thread, but we do not know anything about it. We can learn
1228 about it here. This can only happen if we have some other
1229 way besides libthread_db to notice new threads (i.e.
1230 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
1231 exit, so this can not be a stale thread recreated with the
1233 if (tp->private != NULL)
1235 if (!tp->private->dying)
1238 delete_thread (ptid);
1243 if (target_has_execution)
1244 check_thread_signals ();
1246 /* Under GNU/Linux, we have to attach to each and every thread. */
1247 if (target_has_execution
1252 res = lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)));
1255 /* Error, stop iterating. */
1260 /* Pretend this thread doesn't exist yet, and keep
1265 /* Otherwise, we sucessfully attached to the thread. */
1268 /* Construct the thread's private data. */
1269 private = xmalloc (sizeof (struct private_thread_info));
1270 memset (private, 0, sizeof (struct private_thread_info));
1272 /* A thread ID of zero may mean the thread library has not initialized
1273 yet. But we shouldn't even get here if that's the case. FIXME:
1274 if we change GDB to always have at least one thread in the thread
1275 list this will have to go somewhere else; maybe private == NULL
1276 until the thread_db target claims it. */
1277 gdb_assert (ti_p->ti_tid != 0);
1278 private->th = *th_p;
1279 private->tid = ti_p->ti_tid;
1280 if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
1283 /* Add the thread to GDB's thread list. */
1285 add_thread_with_info (ptid, private);
1287 tp->private = private;
1289 info = get_thread_db_info (GET_PID (ptid));
1291 /* Enable thread event reporting for this thread, except when
1292 debugging a core file. */
1293 if (target_has_execution)
1295 err = info->td_thr_event_enable_p (th_p, 1);
1297 error (_("Cannot enable thread event reporting for %s: %s"),
1298 target_pid_to_str (ptid), thread_db_err_str (err));
1305 detach_thread (ptid_t ptid)
1307 struct thread_info *thread_info;
1309 /* Don't delete the thread now, because it still reports as active
1310 until it has executed a few instructions after the event
1311 breakpoint - if we deleted it now, "info threads" would cause us
1312 to re-attach to it. Just mark it as having had a TD_DEATH
1313 event. This means that we won't delete it from our thread list
1314 until we notice that it's dead (via prune_threads), or until
1315 something re-uses its thread ID. We'll report the thread exit
1316 when the underlying LWP dies. */
1317 thread_info = find_thread_ptid (ptid);
1318 gdb_assert (thread_info != NULL && thread_info->private != NULL);
1319 thread_info->private->dying = 1;
1323 thread_db_detach (struct target_ops *ops, char *args, int from_tty)
1325 struct target_ops *target_beneath = find_target_beneath (ops);
1326 struct thread_db_info *info;
1328 info = get_thread_db_info (GET_PID (inferior_ptid));
1332 if (target_has_execution)
1334 disable_thread_event_reporting (info);
1336 /* Delete the old thread event breakpoints. Note that
1337 unlike when mourning, we can remove them here because
1338 there's still a live inferior to poke at. In any case,
1339 GDB will not try to insert anything in the inferior when
1340 removing a breakpoint. */
1341 remove_thread_event_breakpoints ();
1344 delete_thread_db_info (GET_PID (inferior_ptid));
1347 target_beneath->to_detach (target_beneath, args, from_tty);
1349 /* NOTE: From this point on, inferior_ptid is null_ptid. */
1351 /* If there are no more processes using libpthread, detach the
1352 thread_db target ops. */
1353 if (!thread_db_list)
1354 unpush_target (&thread_db_ops);
1357 /* Check if PID is currently stopped at the location of a thread event
1358 breakpoint location. If it is, read the event message and act upon
1362 check_event (ptid_t ptid)
1364 struct regcache *regcache = get_thread_regcache (ptid);
1365 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1371 struct thread_db_info *info;
1373 info = get_thread_db_info (GET_PID (ptid));
1375 /* Bail out early if we're not at a thread event breakpoint. */
1376 stop_pc = regcache_read_pc (regcache)
1377 - gdbarch_decr_pc_after_break (gdbarch);
1378 if (stop_pc != info->td_create_bp_addr
1379 && stop_pc != info->td_death_bp_addr)
1382 /* Access an lwp we know is stopped. */
1383 info->proc_handle.ptid = ptid;
1385 /* If we have only looked at the first thread before libpthread was
1386 initialized, we may not know its thread ID yet. Make sure we do
1387 before we add another thread to the list. */
1388 if (!have_threads (ptid))
1389 thread_db_find_new_threads_1 (ptid);
1391 /* If we are at a create breakpoint, we do not know what new lwp
1392 was created and cannot specifically locate the event message for it.
1393 We have to call td_ta_event_getmsg() to get
1394 the latest message. Since we have no way of correlating whether
1395 the event message we get back corresponds to our breakpoint, we must
1396 loop and read all event messages, processing them appropriately.
1397 This guarantees we will process the correct message before continuing
1398 from the breakpoint.
1400 Currently, death events are not enabled. If they are enabled,
1401 the death event can use the td_thr_event_getmsg() interface to
1402 get the message specifically for that lwp and avoid looping
1409 err = info->td_ta_event_getmsg_p (info->thread_agent, &msg);
1412 if (err == TD_NOMSG)
1415 error (_("Cannot get thread event message: %s"),
1416 thread_db_err_str (err));
1419 err = info->td_thr_get_info_p (msg.th_p, &ti);
1421 error (_("Cannot get thread info: %s"), thread_db_err_str (err));
1423 ptid = ptid_build (GET_PID (ptid), ti.ti_lid, 0);
1428 /* Call attach_thread whether or not we already know about a
1429 thread with this thread ID. */
1430 attach_thread (ptid, msg.th_p, &ti);
1436 if (!in_thread_list (ptid))
1437 error (_("Spurious thread death event."));
1439 detach_thread (ptid);
1444 error (_("Spurious thread event."));
1451 thread_db_wait (struct target_ops *ops,
1452 ptid_t ptid, struct target_waitstatus *ourstatus,
1455 struct thread_db_info *info;
1456 struct target_ops *beneath = find_target_beneath (ops);
1458 ptid = beneath->to_wait (beneath, ptid, ourstatus, options);
1460 if (ourstatus->kind == TARGET_WAITKIND_IGNORE)
1463 if (ourstatus->kind == TARGET_WAITKIND_EXITED
1464 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
1467 info = get_thread_db_info (GET_PID (ptid));
1469 /* If this process isn't using thread_db, we're done. */
1473 if (ourstatus->kind == TARGET_WAITKIND_EXECD)
1475 /* New image, it may or may not end up using thread_db. Assume
1476 not unless we find otherwise. */
1477 delete_thread_db_info (GET_PID (ptid));
1478 if (!thread_db_list)
1479 unpush_target (&thread_db_ops);
1481 /* Thread event breakpoints are deleted by
1482 update_breakpoints_after_exec. */
1487 /* If we do not know about the main thread yet, this would be a good time to
1489 if (ourstatus->kind == TARGET_WAITKIND_STOPPED && !have_threads (ptid))
1490 thread_db_find_new_threads_1 (ptid);
1492 if (ourstatus->kind == TARGET_WAITKIND_STOPPED
1493 && ourstatus->value.sig == GDB_SIGNAL_TRAP)
1494 /* Check for a thread event. */
1497 if (have_threads (ptid))
1499 /* Fill in the thread's user-level thread id. */
1500 thread_from_lwp (ptid);
1507 thread_db_mourn_inferior (struct target_ops *ops)
1509 struct target_ops *target_beneath = find_target_beneath (ops);
1511 delete_thread_db_info (GET_PID (inferior_ptid));
1513 target_beneath->to_mourn_inferior (target_beneath);
1515 /* Delete the old thread event breakpoints. Do this after mourning
1516 the inferior, so that we don't try to uninsert them. */
1517 remove_thread_event_breakpoints ();
1519 /* Detach thread_db target ops. */
1520 if (!thread_db_list)
1521 unpush_target (ops);
1524 struct callback_data
1526 struct thread_db_info *info;
1531 find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
1536 struct thread_info *tp;
1537 struct callback_data *cb_data = data;
1538 struct thread_db_info *info = cb_data->info;
1540 err = info->td_thr_get_info_p (th_p, &ti);
1542 error (_("find_new_threads_callback: cannot get thread info: %s"),
1543 thread_db_err_str (err));
1547 /* A thread ID of zero means that this is the main thread, but
1548 glibc has not yet initialized thread-local storage and the
1549 pthread library. We do not know what the thread's TID will
1550 be yet. Just enable event reporting and otherwise ignore
1553 /* In that case, we're not stopped in a fork syscall and don't
1554 need this glibc bug workaround. */
1555 info->need_stale_parent_threads_check = 0;
1557 if (target_has_execution)
1559 err = info->td_thr_event_enable_p (th_p, 1);
1561 error (_("Cannot enable thread event reporting for LWP %d: %s"),
1562 (int) ti.ti_lid, thread_db_err_str (err));
1568 /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
1569 bit expensive, as it needs to open /proc/pid/status, so try to
1570 avoid doing the work if we know we don't have to. */
1571 if (info->need_stale_parent_threads_check)
1573 int tgid = linux_proc_get_tgid (ti.ti_lid);
1575 if (tgid != -1 && tgid != info->pid)
1579 ptid = ptid_build (info->pid, ti.ti_lid, 0);
1580 tp = find_thread_ptid (ptid);
1581 if (tp == NULL || tp->private == NULL)
1583 if (attach_thread (ptid, th_p, &ti))
1584 cb_data->new_threads += 1;
1586 /* Problem attaching this thread; perhaps it exited before we
1588 This could mean that the thread list inside glibc itself is in
1589 inconsistent state, and libthread_db could go on looping forever
1590 (observed with glibc-2.3.6). To prevent that, terminate
1591 iteration: thread_db_find_new_threads_2 will retry. */
1598 /* Helper for thread_db_find_new_threads_2.
1599 Returns number of new threads found. */
1602 find_new_threads_once (struct thread_db_info *info, int iteration,
1605 volatile struct gdb_exception except;
1606 struct callback_data data;
1607 td_err_e err = TD_ERR;
1610 data.new_threads = 0;
1612 TRY_CATCH (except, RETURN_MASK_ERROR)
1614 /* Iterate over all user-space threads to discover new threads. */
1615 err = info->td_ta_thr_iter_p (info->thread_agent,
1616 find_new_threads_callback,
1619 TD_THR_LOWEST_PRIORITY,
1621 TD_THR_ANY_USER_FLAGS);
1624 if (libthread_db_debug)
1626 if (except.reason < 0)
1627 exception_fprintf (gdb_stderr, except,
1628 "Warning: find_new_threads_once: ");
1630 printf_filtered (_("Found %d new threads in iteration %d.\n"),
1631 data.new_threads, iteration);
1637 return data.new_threads;
1640 /* Search for new threads, accessing memory through stopped thread
1641 PTID. If UNTIL_NO_NEW is true, repeat searching until several
1642 searches in a row do not discover any new threads. */
1645 thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
1647 td_err_e err = TD_OK;
1648 struct thread_db_info *info;
1649 int pid = ptid_get_pid (ptid);
1652 info = get_thread_db_info (GET_PID (ptid));
1654 /* Access an lwp we know is stopped. */
1655 info->proc_handle.ptid = ptid;
1659 /* Require 4 successive iterations which do not find any new threads.
1660 The 4 is a heuristic: there is an inherent race here, and I have
1661 seen that 2 iterations in a row are not always sufficient to
1662 "capture" all threads. */
1663 for (i = 0, loop = 0; loop < 4 && err == TD_OK; ++i, ++loop)
1664 if (find_new_threads_once (info, i, &err) != 0)
1666 /* Found some new threads. Restart the loop from beginning. */
1671 find_new_threads_once (info, 0, &err);
1674 error (_("Cannot find new threads: %s"), thread_db_err_str (err));
1678 thread_db_find_new_threads_1 (ptid_t ptid)
1680 thread_db_find_new_threads_2 (ptid, 0);
1684 update_thread_core (struct lwp_info *info, void *closure)
1686 info->core = linux_common_core_of_thread (info->ptid);
1691 thread_db_find_new_threads (struct target_ops *ops)
1693 struct thread_db_info *info;
1694 struct inferior *inf;
1698 struct thread_info *thread;
1703 info = get_thread_db_info (inf->pid);
1707 thread = any_live_thread_of_process (inf->pid);
1708 if (thread == NULL || thread->executing)
1711 thread_db_find_new_threads_1 (thread->ptid);
1714 if (target_has_execution)
1715 iterate_over_lwps (minus_one_ptid /* iterate over all */,
1716 update_thread_core, NULL);
1720 thread_db_pid_to_str (struct target_ops *ops, ptid_t ptid)
1722 struct thread_info *thread_info = find_thread_ptid (ptid);
1723 struct target_ops *beneath;
1725 if (thread_info != NULL && thread_info->private != NULL)
1727 static char buf[64];
1730 tid = thread_info->private->tid;
1731 snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
1732 tid, GET_LWP (ptid));
1737 beneath = find_target_beneath (ops);
1738 if (beneath->to_pid_to_str (beneath, ptid))
1739 return beneath->to_pid_to_str (beneath, ptid);
1741 return normal_pid_to_str (ptid);
1744 /* Return a string describing the state of the thread specified by
1748 thread_db_extra_thread_info (struct thread_info *info)
1750 if (info->private == NULL)
1753 if (info->private->dying)
1759 /* Get the address of the thread local variable in load module LM which
1760 is stored at OFFSET within the thread local storage for thread PTID. */
1763 thread_db_get_thread_local_address (struct target_ops *ops,
1768 struct thread_info *thread_info;
1769 struct target_ops *beneath;
1771 /* If we have not discovered any threads yet, check now. */
1772 if (!have_threads (ptid))
1773 thread_db_find_new_threads_1 (ptid);
1775 /* Find the matching thread. */
1776 thread_info = find_thread_ptid (ptid);
1778 if (thread_info != NULL && thread_info->private != NULL)
1782 struct thread_db_info *info;
1784 info = get_thread_db_info (GET_PID (ptid));
1786 /* glibc doesn't provide the needed interface. */
1787 if (!info->td_thr_tls_get_addr_p)
1788 throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR,
1789 _("No TLS library support"));
1791 /* Caller should have verified that lm != 0. */
1792 gdb_assert (lm != 0);
1794 /* Finally, get the address of the variable. */
1795 /* Note the cast through uintptr_t: this interface only works if
1796 a target address fits in a psaddr_t, which is a host pointer.
1797 So a 32-bit debugger can not access 64-bit TLS through this. */
1798 err = info->td_thr_tls_get_addr_p (&thread_info->private->th,
1799 (psaddr_t)(uintptr_t) lm,
1802 #ifdef THREAD_DB_HAS_TD_NOTALLOC
1803 /* The memory hasn't been allocated, yet. */
1804 if (err == TD_NOTALLOC)
1805 /* Now, if libthread_db provided the initialization image's
1806 address, we *could* try to build a non-lvalue value from
1807 the initialization image. */
1808 throw_error (TLS_NOT_ALLOCATED_YET_ERROR,
1809 _("TLS not allocated yet"));
1812 /* Something else went wrong. */
1814 throw_error (TLS_GENERIC_ERROR,
1815 (("%s")), thread_db_err_str (err));
1817 /* Cast assuming host == target. Joy. */
1818 /* Do proper sign extension for the target. */
1819 gdb_assert (exec_bfd);
1820 return (bfd_get_sign_extend_vma (exec_bfd) > 0
1821 ? (CORE_ADDR) (intptr_t) address
1822 : (CORE_ADDR) (uintptr_t) address);
1825 beneath = find_target_beneath (ops);
1826 if (beneath->to_get_thread_local_address)
1827 return beneath->to_get_thread_local_address (beneath, ptid, lm, offset);
1829 throw_error (TLS_GENERIC_ERROR,
1830 _("TLS not supported on this target"));
1833 /* Callback routine used to find a thread based on the TID part of
1837 thread_db_find_thread_from_tid (struct thread_info *thread, void *data)
1839 long *tid = (long *) data;
1841 if (thread->private->tid == *tid)
1847 /* Implement the to_get_ada_task_ptid target method for this target. */
1850 thread_db_get_ada_task_ptid (long lwp, long thread)
1852 struct thread_info *thread_info;
1854 thread_db_find_new_threads_1 (inferior_ptid);
1855 thread_info = iterate_over_threads (thread_db_find_thread_from_tid, &thread);
1857 gdb_assert (thread_info != NULL);
1859 return (thread_info->ptid);
1863 thread_db_resume (struct target_ops *ops,
1864 ptid_t ptid, int step, enum gdb_signal signo)
1866 struct target_ops *beneath = find_target_beneath (ops);
1867 struct thread_db_info *info;
1869 if (ptid_equal (ptid, minus_one_ptid))
1870 info = get_thread_db_info (GET_PID (inferior_ptid));
1872 info = get_thread_db_info (GET_PID (ptid));
1874 /* This workaround is only needed for child fork lwps stopped in a
1875 PTRACE_O_TRACEFORK event. When the inferior is resumed, the
1876 workaround can be disabled. */
1878 info->need_stale_parent_threads_check = 0;
1880 beneath->to_resume (beneath, ptid, step, signo);
1883 /* qsort helper function for info_auto_load_libthread_db, sort the
1884 thread_db_info pointers primarily by their FILENAME and secondarily by their
1885 PID, both in ascending order. */
1888 info_auto_load_libthread_db_compare (const void *ap, const void *bp)
1890 struct thread_db_info *a = *(struct thread_db_info **) ap;
1891 struct thread_db_info *b = *(struct thread_db_info **) bp;
1894 retval = strcmp (a->filename, b->filename);
1898 return (a->pid > b->pid) - (a->pid - b->pid);
1901 /* Implement 'info auto-load libthread-db'. */
1904 info_auto_load_libthread_db (char *args, int from_tty)
1906 struct ui_out *uiout = current_uiout;
1907 const char *cs = args ? args : "";
1908 struct thread_db_info *info, **array;
1909 unsigned info_count, unique_filenames;
1910 size_t max_filename_len, max_pids_len, pids_len;
1911 struct cleanup *back_to;
1915 while (isspace (*cs))
1918 error (_("'info auto-load libthread-db' does not accept any parameters"));
1921 for (info = thread_db_list; info; info = info->next)
1922 if (info->filename != NULL)
1925 array = xmalloc (sizeof (*array) * info_count);
1926 back_to = make_cleanup (xfree, array);
1929 for (info = thread_db_list; info; info = info->next)
1930 if (info->filename != NULL)
1931 array[info_count++] = info;
1933 /* Sort ARRAY by filenames and PIDs. */
1935 qsort (array, info_count, sizeof (*array),
1936 info_auto_load_libthread_db_compare);
1938 /* Calculate the number of unique filenames (rows) and the maximum string
1939 length of PIDs list for the unique filenames (columns). */
1941 unique_filenames = 0;
1942 max_filename_len = 0;
1945 for (i = 0; i < info_count; i++)
1947 int pid = array[i]->pid;
1948 size_t this_pid_len;
1950 for (this_pid_len = 0; pid != 0; pid /= 10)
1953 if (i == 0 || strcmp (array[i - 1]->filename, array[i]->filename) != 0)
1956 max_filename_len = max (max_filename_len,
1957 strlen (array[i]->filename));
1961 pids_len -= strlen (", ");
1962 max_pids_len = max (max_pids_len, pids_len);
1966 pids_len += this_pid_len + strlen (", ");
1970 pids_len -= strlen (", ");
1971 max_pids_len = max (max_pids_len, pids_len);
1974 /* Table header shifted right by preceding "libthread-db: " would not match
1976 if (info_count > 0 && args == auto_load_info_scripts_pattern_nl)
1977 ui_out_text (uiout, "\n");
1979 make_cleanup_ui_out_table_begin_end (uiout, 2, unique_filenames,
1980 "LinuxThreadDbTable");
1982 ui_out_table_header (uiout, max_filename_len, ui_left, "filename",
1984 ui_out_table_header (uiout, pids_len, ui_left, "PIDs", "Pids");
1985 ui_out_table_body (uiout);
1987 pids = xmalloc (max_pids_len + 1);
1988 make_cleanup (xfree, pids);
1990 /* Note I is incremented inside the cycle, not at its end. */
1991 for (i = 0; i < info_count;)
1993 struct cleanup *chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
1997 ui_out_field_string (uiout, "filename", info->filename);
2000 while (i < info_count && strcmp (info->filename, array[i]->filename) == 0)
2002 if (pids_end != pids)
2007 pids_end += xsnprintf (pids_end, &pids[max_pids_len + 1] - pids_end,
2008 "%u", array[i]->pid);
2009 gdb_assert (pids_end < &pids[max_pids_len + 1]);
2015 ui_out_field_string (uiout, "pids", pids);
2017 ui_out_text (uiout, "\n");
2018 do_cleanups (chain);
2021 do_cleanups (back_to);
2023 if (info_count == 0)
2024 ui_out_message (uiout, 0, _("No auto-loaded libthread-db.\n"));
2028 init_thread_db_ops (void)
2030 thread_db_ops.to_shortname = "multi-thread";
2031 thread_db_ops.to_longname = "multi-threaded child process.";
2032 thread_db_ops.to_doc = "Threads and pthreads support.";
2033 thread_db_ops.to_detach = thread_db_detach;
2034 thread_db_ops.to_wait = thread_db_wait;
2035 thread_db_ops.to_resume = thread_db_resume;
2036 thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior;
2037 thread_db_ops.to_find_new_threads = thread_db_find_new_threads;
2038 thread_db_ops.to_pid_to_str = thread_db_pid_to_str;
2039 thread_db_ops.to_stratum = thread_stratum;
2040 thread_db_ops.to_has_thread_control = tc_schedlock;
2041 thread_db_ops.to_get_thread_local_address
2042 = thread_db_get_thread_local_address;
2043 thread_db_ops.to_extra_thread_info = thread_db_extra_thread_info;
2044 thread_db_ops.to_get_ada_task_ptid = thread_db_get_ada_task_ptid;
2045 thread_db_ops.to_magic = OPS_MAGIC;
2048 /* Provide a prototype to silence -Wmissing-prototypes. */
2049 extern initialize_file_ftype _initialize_thread_db;
2052 _initialize_thread_db (void)
2054 init_thread_db_ops ();
2055 add_target (&thread_db_ops);
2057 /* Defer loading of libthread_db.so until inferior is running.
2058 This allows gdb to load correct libthread_db for a given
2059 executable -- there could be mutiple versions of glibc,
2060 compiled with LinuxThreads or NPTL, and until there is
2061 a running inferior, we can't tell which libthread_db is
2062 the correct one to load. */
2064 libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
2066 add_setshow_optional_filename_cmd ("libthread-db-search-path",
2068 &libthread_db_search_path, _("\
2069 Set search path for libthread_db."), _("\
2070 Show the current search path or libthread_db."), _("\
2071 This path is used to search for libthread_db to be loaded into \
2073 Its value is a colon (':') separate list of directories to search.\n\
2074 Setting the search path to an empty list resets it to its default value."),
2075 set_libthread_db_search_path,
2077 &setlist, &showlist);
2079 add_setshow_zuinteger_cmd ("libthread-db", class_maintenance,
2080 &libthread_db_debug, _("\
2081 Set libthread-db debugging."), _("\
2082 Show libthread-db debugging."), _("\
2083 When non-zero, libthread-db debugging is enabled."),
2085 show_libthread_db_debug,
2086 &setdebuglist, &showdebuglist);
2088 add_setshow_boolean_cmd ("libthread-db", class_support,
2089 &auto_load_thread_db, _("\
2090 Enable or disable auto-loading of inferior specific libthread_db."), _("\
2091 Show whether auto-loading inferior specific libthread_db is enabled."), _("\
2092 If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
2093 locations to load libthread_db compatible with the inferior.\n\
2094 Standard system libthread_db still gets loaded even with this option off.\n\
2095 This options has security implications for untrusted inferiors."),
2096 NULL, show_auto_load_thread_db,
2097 auto_load_set_cmdlist_get (),
2098 auto_load_show_cmdlist_get ());
2100 add_cmd ("libthread-db", class_info, info_auto_load_libthread_db,
2101 _("Print the list of loaded inferior specific libthread_db.\n\
2102 Usage: info auto-load libthread-db"),
2103 auto_load_info_cmdlist_get ());
2105 /* Add ourselves to objfile event chain. */
2106 observer_attach_new_objfile (thread_db_new_objfile);
2108 /* Add ourselves to inferior_created event chain.
2109 This is needed to handle debugging statically linked programs where
2110 the new_objfile observer won't get called for libpthread. */
2111 observer_attach_inferior_created (thread_db_inferior_created);