mirror of
https://sourceware.org/git/binutils-gdb.git
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708bf0a14b
currently gdb -p <pid from a container> will print: warning: Target and debugger are in different PID namespaces; thread lists and other data are likely unreliable It correctly states the problem but it does not say how to solve it. Originally I wanted to suggest also the Docker "-p 1234:1234" parameter but I see the containers are more general topic than just Docker (even LxC etc.). According to Gary future GDBs should be able to work even without gdbserver. But currently gdbserver is still required. gdb/ChangeLog 2016-03-17 Jan Kratochvil <jan.kratochvil@redhat.com> * linux-thread-db.c (check_pid_namespace_match): Extend the message.
1764 lines
50 KiB
C
1764 lines
50 KiB
C
/* libthread_db assisted debugging support, generic parts.
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Copyright (C) 1999-2016 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 3 of the License, or
|
||
(at your option) any later version.
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||
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This program is distributed in the hope that it will be useful,
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||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include <dlfcn.h>
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#include "gdb_proc_service.h"
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#include "nat/gdb_thread_db.h"
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#include "gdb_vecs.h"
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#include "bfd.h"
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#include "command.h"
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#include "gdbcmd.h"
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#include "gdbthread.h"
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#include "inferior.h"
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#include "infrun.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "target.h"
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#include "regcache.h"
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#include "solib.h"
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#include "solib-svr4.h"
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#include "gdbcore.h"
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#include "observer.h"
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#include "linux-nat.h"
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#include "nat/linux-procfs.h"
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#include "nat/linux-ptrace.h"
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#include "nat/linux-osdata.h"
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#include "auto-load.h"
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#include "cli/cli-utils.h"
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#include <signal.h>
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#include <ctype.h>
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#include "nat/linux-namespaces.h"
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/* GNU/Linux libthread_db support.
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libthread_db is a library, provided along with libpthread.so, which
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exposes the internals of the thread library to a debugger. It
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allows GDB to find existing threads, new threads as they are
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created, thread IDs (usually, the result of pthread_self), and
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||
thread-local variables.
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|
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The libthread_db interface originates on Solaris, where it is both
|
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more powerful and more complicated. This implementation only works
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for NPTL, the glibc threading library. It assumes that each thread
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is permanently assigned to a single light-weight process (LWP). At
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some point it also supported the older LinuxThreads library, but it
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no longer does.
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libthread_db-specific information is stored in the "private" field
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of struct thread_info. When the field is NULL we do not yet have
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information about the new thread; this could be temporary (created,
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but the thread library's data structures do not reflect it yet)
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or permanent (created using clone instead of pthread_create).
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Process IDs managed by linux-thread-db.c match those used by
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linux-nat.c: a common PID for all processes, an LWP ID for each
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thread, and no TID. We save the TID in private. Keeping it out
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of the ptid_t prevents thread IDs changing when libpthread is
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loaded or unloaded. */
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static char *libthread_db_search_path;
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/* Set to non-zero if thread_db auto-loading is enabled
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by the "set auto-load libthread-db" command. */
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static int auto_load_thread_db = 1;
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/* "show" command for the auto_load_thread_db configuration variable. */
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static void
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show_auto_load_thread_db (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("Auto-loading of inferior specific libthread_db "
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"is %s.\n"),
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value);
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}
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static void
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set_libthread_db_search_path (char *ignored, int from_tty,
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struct cmd_list_element *c)
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{
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if (*libthread_db_search_path == '\0')
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{
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xfree (libthread_db_search_path);
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libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
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}
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}
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/* If non-zero, print details of libthread_db processing. */
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static unsigned int libthread_db_debug;
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static void
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show_libthread_db_debug (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("libthread-db debugging is %s.\n"), value);
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}
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/* If we're running on GNU/Linux, we must explicitly attach to any new
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threads. */
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/* This module's target vector. */
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static struct target_ops thread_db_ops;
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/* Non-zero if we have determined the signals used by the threads
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library. */
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static int thread_signals;
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static sigset_t thread_stop_set;
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static sigset_t thread_print_set;
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struct thread_db_info
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{
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struct thread_db_info *next;
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/* Process id this object refers to. */
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int pid;
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/* Handle from dlopen for libthread_db.so. */
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void *handle;
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/* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
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HANDLE. It may be NULL for system library. */
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char *filename;
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/* Structure that identifies the child process for the
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<proc_service.h> interface. */
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struct ps_prochandle proc_handle;
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/* Connection to the libthread_db library. */
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td_thragent_t *thread_agent;
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/* True if we need to apply the workaround for glibc/BZ5983. When
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we catch a PTRACE_O_TRACEFORK, and go query the child's thread
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list, nptl_db returns the parent's threads in addition to the new
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(single) child thread. If this flag is set, we do extra work to
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be able to ignore such stale entries. */
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int need_stale_parent_threads_check;
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/* Pointers to the libthread_db functions. */
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td_init_ftype *td_init_p;
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td_ta_new_ftype *td_ta_new_p;
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td_ta_map_lwp2thr_ftype *td_ta_map_lwp2thr_p;
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td_ta_thr_iter_ftype *td_ta_thr_iter_p;
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td_thr_validate_ftype *td_thr_validate_p;
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td_thr_get_info_ftype *td_thr_get_info_p;
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td_thr_tls_get_addr_ftype *td_thr_tls_get_addr_p;
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td_thr_tlsbase_ftype *td_thr_tlsbase_p;
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};
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/* List of known processes using thread_db, and the required
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bookkeeping. */
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struct thread_db_info *thread_db_list;
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static void thread_db_find_new_threads_1 (ptid_t ptid);
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static void thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new);
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static void check_thread_signals (void);
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static struct thread_info *record_thread
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(struct thread_db_info *info, struct thread_info *tp,
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ptid_t ptid, const td_thrhandle_t *th_p, const td_thrinfo_t *ti_p);
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/* Add the current inferior to the list of processes using libpthread.
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Return a pointer to the newly allocated object that was added to
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THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
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LIBTHREAD_DB_SO. */
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static struct thread_db_info *
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add_thread_db_info (void *handle)
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{
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struct thread_db_info *info = XCNEW (struct thread_db_info);
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info->pid = ptid_get_pid (inferior_ptid);
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info->handle = handle;
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/* The workaround works by reading from /proc/pid/status, so it is
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disabled for core files. */
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if (target_has_execution)
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info->need_stale_parent_threads_check = 1;
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info->next = thread_db_list;
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thread_db_list = info;
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return info;
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}
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/* Return the thread_db_info object representing the bookkeeping
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related to process PID, if any; NULL otherwise. */
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static struct thread_db_info *
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get_thread_db_info (int pid)
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{
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struct thread_db_info *info;
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for (info = thread_db_list; info; info = info->next)
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if (pid == info->pid)
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return info;
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return NULL;
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}
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/* When PID has exited or has been detached, we no longer want to keep
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track of it as using libpthread. Call this function to discard
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thread_db related info related to PID. Note that this closes
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LIBTHREAD_DB_SO's dlopen'ed handle. */
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static void
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delete_thread_db_info (int pid)
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{
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struct thread_db_info *info, *info_prev;
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info_prev = NULL;
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for (info = thread_db_list; info; info_prev = info, info = info->next)
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if (pid == info->pid)
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break;
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if (info == NULL)
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return;
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if (info->handle != NULL)
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dlclose (info->handle);
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xfree (info->filename);
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if (info_prev)
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info_prev->next = info->next;
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else
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thread_db_list = info->next;
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xfree (info);
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}
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/* Use "struct private_thread_info" to cache thread state. This is
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a substantial optimization. */
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struct private_thread_info
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{
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/* Flag set when we see a TD_DEATH event for this thread. */
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unsigned int dying:1;
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/* Cached thread state. */
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td_thrhandle_t th;
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thread_t tid;
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};
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static char *
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thread_db_err_str (td_err_e err)
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{
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static char buf[64];
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switch (err)
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{
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case TD_OK:
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return "generic 'call succeeded'";
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case TD_ERR:
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return "generic error";
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case TD_NOTHR:
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return "no thread to satisfy query";
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case TD_NOSV:
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return "no sync handle to satisfy query";
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case TD_NOLWP:
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return "no LWP to satisfy query";
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case TD_BADPH:
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return "invalid process handle";
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case TD_BADTH:
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return "invalid thread handle";
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case TD_BADSH:
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return "invalid synchronization handle";
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case TD_BADTA:
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return "invalid thread agent";
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case TD_BADKEY:
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return "invalid key";
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case TD_NOMSG:
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return "no event message for getmsg";
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case TD_NOFPREGS:
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return "FPU register set not available";
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case TD_NOLIBTHREAD:
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return "application not linked with libthread";
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case TD_NOEVENT:
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return "requested event is not supported";
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case TD_NOCAPAB:
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return "capability not available";
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case TD_DBERR:
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return "debugger service failed";
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case TD_NOAPLIC:
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return "operation not applicable to";
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case TD_NOTSD:
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return "no thread-specific data for this thread";
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case TD_MALLOC:
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return "malloc failed";
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case TD_PARTIALREG:
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return "only part of register set was written/read";
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case TD_NOXREGS:
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return "X register set not available for this thread";
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#ifdef THREAD_DB_HAS_TD_NOTALLOC
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case TD_NOTALLOC:
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return "thread has not yet allocated TLS for given module";
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#endif
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#ifdef THREAD_DB_HAS_TD_VERSION
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case TD_VERSION:
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return "versions of libpthread and libthread_db do not match";
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#endif
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#ifdef THREAD_DB_HAS_TD_NOTLS
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case TD_NOTLS:
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return "there is no TLS segment in the given module";
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#endif
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default:
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snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
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return buf;
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}
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}
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/* Fetch the user-level thread id of PTID. */
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static struct thread_info *
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thread_from_lwp (ptid_t ptid)
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{
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td_thrhandle_t th;
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td_thrinfo_t ti;
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td_err_e err;
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struct thread_db_info *info;
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struct thread_info *tp;
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/* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
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th.th_unique = 0;
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/* This ptid comes from linux-nat.c, which should always fill in the
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LWP. */
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gdb_assert (ptid_get_lwp (ptid) != 0);
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info = get_thread_db_info (ptid_get_pid (ptid));
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/* Access an lwp we know is stopped. */
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info->proc_handle.ptid = ptid;
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err = info->td_ta_map_lwp2thr_p (info->thread_agent, ptid_get_lwp (ptid),
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&th);
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if (err != TD_OK)
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error (_("Cannot find user-level thread for LWP %ld: %s"),
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ptid_get_lwp (ptid), thread_db_err_str (err));
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err = info->td_thr_get_info_p (&th, &ti);
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if (err != TD_OK)
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error (_("thread_get_info_callback: cannot get thread info: %s"),
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thread_db_err_str (err));
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/* Fill the cache. */
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tp = find_thread_ptid (ptid);
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return record_thread (info, tp, ptid, &th, &ti);
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}
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/* See linux-nat.h. */
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int
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thread_db_notice_clone (ptid_t parent, ptid_t child)
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{
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td_thrhandle_t th;
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td_thrinfo_t ti;
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td_err_e err;
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struct thread_db_info *info;
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info = get_thread_db_info (ptid_get_pid (child));
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if (info == NULL)
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return 0;
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thread_from_lwp (child);
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/* If we do not know about the main thread yet, this would be a good
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time to find it. */
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thread_from_lwp (parent);
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return 1;
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}
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static void *
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verbose_dlsym (void *handle, const char *name)
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{
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void *sym = dlsym (handle, name);
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if (sym == NULL)
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warning (_("Symbol \"%s\" not found in libthread_db: %s"),
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name, dlerror ());
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return sym;
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}
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/* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
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return 1 if this version is lower (and not equal) to
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VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
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static int
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inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min)
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||
{
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||
struct bound_minimal_symbol version_msym;
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CORE_ADDR version_addr;
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||
char *version;
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int err, got, retval = 0;
|
||
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version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL);
|
||
if (version_msym.minsym == NULL)
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return 0;
|
||
|
||
version_addr = BMSYMBOL_VALUE_ADDRESS (version_msym);
|
||
got = target_read_string (version_addr, &version, 32, &err);
|
||
if (err == 0 && memchr (version, 0, got) == &version[got -1])
|
||
{
|
||
int major, minor;
|
||
|
||
retval = (sscanf (version, "%d.%d", &major, &minor) == 2
|
||
&& (major < ver_major_min
|
||
|| (major == ver_major_min && minor < ver_minor_min)));
|
||
}
|
||
xfree (version);
|
||
|
||
return retval;
|
||
}
|
||
|
||
/* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
|
||
if appropriate.
|
||
|
||
Return 1 if the caller should abort libthread_db initialization. Return 0
|
||
otherwise. */
|
||
|
||
static int
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||
thread_db_find_new_threads_silently (ptid_t ptid)
|
||
{
|
||
|
||
TRY
|
||
{
|
||
thread_db_find_new_threads_2 (ptid, 1);
|
||
}
|
||
|
||
CATCH (except, RETURN_MASK_ERROR)
|
||
{
|
||
if (libthread_db_debug)
|
||
exception_fprintf (gdb_stdlog, except,
|
||
"Warning: thread_db_find_new_threads_silently: ");
|
||
|
||
/* There is a bug fixed between nptl 2.6.1 and 2.7 by
|
||
commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
|
||
where calls to td_thr_get_info fail with TD_ERR for statically linked
|
||
executables if td_thr_get_info is called before glibc has initialized
|
||
itself.
|
||
|
||
If the nptl bug is NOT present in the inferior and still thread_db
|
||
reports an error return 1. It means the inferior has corrupted thread
|
||
list and GDB should fall back only to LWPs.
|
||
|
||
If the nptl bug is present in the inferior return 0 to silently ignore
|
||
such errors, and let gdb enumerate threads again later. In such case
|
||
GDB cannot properly display LWPs if the inferior thread list is
|
||
corrupted. For core files it does not apply, no 'later enumeration'
|
||
is possible. */
|
||
|
||
if (!target_has_execution || !inferior_has_bug ("nptl_version", 2, 7))
|
||
{
|
||
exception_fprintf (gdb_stderr, except,
|
||
_("Warning: couldn't activate thread debugging "
|
||
"using libthread_db: "));
|
||
return 1;
|
||
}
|
||
}
|
||
END_CATCH
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Lookup a library in which given symbol resides.
|
||
Note: this is looking in GDB process, not in the inferior.
|
||
Returns library name, or NULL. */
|
||
|
||
static const char *
|
||
dladdr_to_soname (const void *addr)
|
||
{
|
||
Dl_info info;
|
||
|
||
if (dladdr (addr, &info) != 0)
|
||
return info.dli_fname;
|
||
return NULL;
|
||
}
|
||
|
||
/* Attempt to initialize dlopen()ed libthread_db, described by INFO.
|
||
Return 1 on success.
|
||
Failure could happen if libthread_db does not have symbols we expect,
|
||
or when it refuses to work with the current inferior (e.g. due to
|
||
version mismatch between libthread_db and libpthread). */
|
||
|
||
static int
|
||
try_thread_db_load_1 (struct thread_db_info *info)
|
||
{
|
||
td_err_e err;
|
||
|
||
/* Initialize pointers to the dynamic library functions we will use.
|
||
Essential functions first. */
|
||
|
||
#define TDB_VERBOSE_DLSYM(info, func) \
|
||
info->func ## _p = (func ## _ftype *) verbose_dlsym (info->handle, #func)
|
||
|
||
#define TDB_DLSYM(info, func) \
|
||
info->func ## _p = (func ## _ftype *) dlsym (info->handle, #func)
|
||
|
||
#define CHK(a) \
|
||
do \
|
||
{ \
|
||
if ((a) == NULL) \
|
||
return 0; \
|
||
} while (0)
|
||
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_init));
|
||
|
||
err = info->td_init_p ();
|
||
if (err != TD_OK)
|
||
{
|
||
warning (_("Cannot initialize libthread_db: %s"),
|
||
thread_db_err_str (err));
|
||
return 0;
|
||
}
|
||
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_ta_new));
|
||
|
||
/* Initialize the structure that identifies the child process. */
|
||
info->proc_handle.ptid = inferior_ptid;
|
||
|
||
/* Now attempt to open a connection to the thread library. */
|
||
err = info->td_ta_new_p (&info->proc_handle, &info->thread_agent);
|
||
if (err != TD_OK)
|
||
{
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog, _("td_ta_new failed: %s\n"),
|
||
thread_db_err_str (err));
|
||
else
|
||
switch (err)
|
||
{
|
||
case TD_NOLIBTHREAD:
|
||
#ifdef THREAD_DB_HAS_TD_VERSION
|
||
case TD_VERSION:
|
||
#endif
|
||
/* The errors above are not unexpected and silently ignored:
|
||
they just mean we haven't found correct version of
|
||
libthread_db yet. */
|
||
break;
|
||
default:
|
||
warning (_("td_ta_new failed: %s"), thread_db_err_str (err));
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/* These are essential. */
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_ta_map_lwp2thr));
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_thr_validate));
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_thr_get_info));
|
||
|
||
/* These are not essential. */
|
||
TDB_DLSYM (info, td_thr_tls_get_addr);
|
||
TDB_DLSYM (info, td_thr_tlsbase);
|
||
|
||
/* It's best to avoid td_ta_thr_iter if possible. That walks data
|
||
structures in the inferior's address space that may be corrupted,
|
||
or, if the target is running, may change while we walk them. If
|
||
there's execution (and /proc is mounted), then we're already
|
||
attached to all LWPs. Use thread_from_lwp, which uses
|
||
td_ta_map_lwp2thr instead, which does not walk the thread list.
|
||
|
||
td_ta_map_lwp2thr uses ps_get_thread_area, but we can't use that
|
||
currently on core targets, as it uses ptrace directly. */
|
||
if (target_has_execution
|
||
&& linux_proc_task_list_dir_exists (ptid_get_pid (inferior_ptid)))
|
||
info->td_ta_thr_iter_p = NULL;
|
||
else
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_ta_thr_iter));
|
||
|
||
#undef TDB_VERBOSE_DLSYM
|
||
#undef TDB_DLSYM
|
||
#undef CHK
|
||
|
||
if (info->td_ta_thr_iter_p == NULL)
|
||
{
|
||
struct lwp_info *lp;
|
||
int pid = ptid_get_pid (inferior_ptid);
|
||
|
||
linux_stop_and_wait_all_lwps ();
|
||
|
||
ALL_LWPS (lp)
|
||
if (ptid_get_pid (lp->ptid) == pid)
|
||
thread_from_lwp (lp->ptid);
|
||
|
||
linux_unstop_all_lwps ();
|
||
}
|
||
else if (thread_db_find_new_threads_silently (inferior_ptid) != 0)
|
||
{
|
||
/* Even if libthread_db initializes, if the thread list is
|
||
corrupted, we'd not manage to list any threads. Better reject this
|
||
thread_db, and fall back to at least listing LWPs. */
|
||
return 0;
|
||
}
|
||
|
||
printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
|
||
|
||
if (*libthread_db_search_path || libthread_db_debug)
|
||
{
|
||
struct ui_file *file;
|
||
const char *library;
|
||
|
||
library = dladdr_to_soname ((const void *) *info->td_ta_new_p);
|
||
if (library == NULL)
|
||
library = LIBTHREAD_DB_SO;
|
||
|
||
/* If we'd print this to gdb_stdout when debug output is
|
||
disabled, still print it to gdb_stdout if debug output is
|
||
enabled. User visible output should not depend on debug
|
||
settings. */
|
||
file = *libthread_db_search_path != '\0' ? gdb_stdout : gdb_stdlog;
|
||
fprintf_unfiltered (file, _("Using host libthread_db library \"%s\".\n"),
|
||
library);
|
||
}
|
||
|
||
/* The thread library was detected. Activate the thread_db target
|
||
if this is the first process using it. */
|
||
if (thread_db_list->next == NULL)
|
||
push_target (&thread_db_ops);
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
|
||
relative, or just LIBTHREAD_DB. */
|
||
|
||
static int
|
||
try_thread_db_load (const char *library, int check_auto_load_safe)
|
||
{
|
||
void *handle;
|
||
struct thread_db_info *info;
|
||
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
_("Trying host libthread_db library: %s.\n"),
|
||
library);
|
||
|
||
if (check_auto_load_safe)
|
||
{
|
||
if (access (library, R_OK) != 0)
|
||
{
|
||
/* Do not print warnings by file_is_auto_load_safe if the library does
|
||
not exist at this place. */
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog, _("open failed: %s.\n"),
|
||
safe_strerror (errno));
|
||
return 0;
|
||
}
|
||
|
||
if (!file_is_auto_load_safe (library, _("auto-load: Loading libthread-db "
|
||
"library \"%s\" from explicit "
|
||
"directory.\n"),
|
||
library))
|
||
return 0;
|
||
}
|
||
|
||
handle = dlopen (library, RTLD_NOW);
|
||
if (handle == NULL)
|
||
{
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog, _("dlopen failed: %s.\n"), dlerror ());
|
||
return 0;
|
||
}
|
||
|
||
if (libthread_db_debug && strchr (library, '/') == NULL)
|
||
{
|
||
void *td_init;
|
||
|
||
td_init = dlsym (handle, "td_init");
|
||
if (td_init != NULL)
|
||
{
|
||
const char *const libpath = dladdr_to_soname (td_init);
|
||
|
||
if (libpath != NULL)
|
||
fprintf_unfiltered (gdb_stdlog, _("Host %s resolved to: %s.\n"),
|
||
library, libpath);
|
||
}
|
||
}
|
||
|
||
info = add_thread_db_info (handle);
|
||
|
||
/* Do not save system library name, that one is always trusted. */
|
||
if (strchr (library, '/') != NULL)
|
||
info->filename = gdb_realpath (library);
|
||
|
||
if (try_thread_db_load_1 (info))
|
||
return 1;
|
||
|
||
/* This library "refused" to work on current inferior. */
|
||
delete_thread_db_info (ptid_get_pid (inferior_ptid));
|
||
return 0;
|
||
}
|
||
|
||
/* Subroutine of try_thread_db_load_from_pdir to simplify it.
|
||
Try loading libthread_db in directory(OBJ)/SUBDIR.
|
||
SUBDIR may be NULL. It may also be something like "../lib64".
|
||
The result is true for success. */
|
||
|
||
static int
|
||
try_thread_db_load_from_pdir_1 (struct objfile *obj, const char *subdir)
|
||
{
|
||
struct cleanup *cleanup;
|
||
char *path, *cp;
|
||
int result;
|
||
const char *obj_name = objfile_name (obj);
|
||
int alloc_len;
|
||
|
||
if (obj_name[0] != '/')
|
||
{
|
||
warning (_("Expected absolute pathname for libpthread in the"
|
||
" inferior, but got %s."), obj_name);
|
||
return 0;
|
||
}
|
||
|
||
alloc_len = (strlen (obj_name)
|
||
+ (subdir ? strlen (subdir) + 1 : 0)
|
||
+ 1 + strlen (LIBTHREAD_DB_SO) + 1);
|
||
path = (char *) xmalloc (alloc_len);
|
||
cleanup = make_cleanup (xfree, path);
|
||
|
||
strcpy (path, obj_name);
|
||
cp = strrchr (path, '/');
|
||
/* This should at minimum hit the first character. */
|
||
gdb_assert (cp != NULL);
|
||
cp[1] = '\0';
|
||
if (subdir != NULL)
|
||
{
|
||
strcat (cp, subdir);
|
||
strcat (cp, "/");
|
||
}
|
||
strcat (cp, LIBTHREAD_DB_SO);
|
||
|
||
result = try_thread_db_load (path, 1);
|
||
|
||
do_cleanups (cleanup);
|
||
return result;
|
||
}
|
||
|
||
/* Handle $pdir in libthread-db-search-path.
|
||
Look for libthread_db in directory(libpthread)/SUBDIR.
|
||
SUBDIR may be NULL. It may also be something like "../lib64".
|
||
The result is true for success. */
|
||
|
||
static int
|
||
try_thread_db_load_from_pdir (const char *subdir)
|
||
{
|
||
struct objfile *obj;
|
||
|
||
if (!auto_load_thread_db)
|
||
return 0;
|
||
|
||
ALL_OBJFILES (obj)
|
||
if (libpthread_name_p (objfile_name (obj)))
|
||
{
|
||
if (try_thread_db_load_from_pdir_1 (obj, subdir))
|
||
return 1;
|
||
|
||
/* We may have found the separate-debug-info version of
|
||
libpthread, and it may live in a directory without a matching
|
||
libthread_db. */
|
||
if (obj->separate_debug_objfile_backlink != NULL)
|
||
return try_thread_db_load_from_pdir_1 (obj->separate_debug_objfile_backlink,
|
||
subdir);
|
||
|
||
return 0;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Handle $sdir in libthread-db-search-path.
|
||
Look for libthread_db in the system dirs, or wherever a plain
|
||
dlopen(file_without_path) will look.
|
||
The result is true for success. */
|
||
|
||
static int
|
||
try_thread_db_load_from_sdir (void)
|
||
{
|
||
return try_thread_db_load (LIBTHREAD_DB_SO, 0);
|
||
}
|
||
|
||
/* Try to load libthread_db from directory DIR of length DIR_LEN.
|
||
The result is true for success. */
|
||
|
||
static int
|
||
try_thread_db_load_from_dir (const char *dir, size_t dir_len)
|
||
{
|
||
struct cleanup *cleanup;
|
||
char *path;
|
||
int result;
|
||
|
||
if (!auto_load_thread_db)
|
||
return 0;
|
||
|
||
path = (char *) xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
|
||
cleanup = make_cleanup (xfree, path);
|
||
|
||
memcpy (path, dir, dir_len);
|
||
path[dir_len] = '/';
|
||
strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
|
||
|
||
result = try_thread_db_load (path, 1);
|
||
|
||
do_cleanups (cleanup);
|
||
return result;
|
||
}
|
||
|
||
/* Search libthread_db_search_path for libthread_db which "agrees"
|
||
to work on current inferior.
|
||
The result is true for success. */
|
||
|
||
static int
|
||
thread_db_load_search (void)
|
||
{
|
||
VEC (char_ptr) *dir_vec;
|
||
struct cleanup *cleanups;
|
||
char *this_dir;
|
||
int i, rc = 0;
|
||
|
||
dir_vec = dirnames_to_char_ptr_vec (libthread_db_search_path);
|
||
cleanups = make_cleanup_free_char_ptr_vec (dir_vec);
|
||
|
||
for (i = 0; VEC_iterate (char_ptr, dir_vec, i, this_dir); ++i)
|
||
{
|
||
const int pdir_len = sizeof ("$pdir") - 1;
|
||
size_t this_dir_len;
|
||
|
||
this_dir_len = strlen (this_dir);
|
||
|
||
if (strncmp (this_dir, "$pdir", pdir_len) == 0
|
||
&& (this_dir[pdir_len] == '\0'
|
||
|| this_dir[pdir_len] == '/'))
|
||
{
|
||
char *subdir = NULL;
|
||
struct cleanup *free_subdir_cleanup
|
||
= make_cleanup (null_cleanup, NULL);
|
||
|
||
if (this_dir[pdir_len] == '/')
|
||
{
|
||
subdir = (char *) xmalloc (strlen (this_dir));
|
||
make_cleanup (xfree, subdir);
|
||
strcpy (subdir, this_dir + pdir_len + 1);
|
||
}
|
||
rc = try_thread_db_load_from_pdir (subdir);
|
||
do_cleanups (free_subdir_cleanup);
|
||
if (rc)
|
||
break;
|
||
}
|
||
else if (strcmp (this_dir, "$sdir") == 0)
|
||
{
|
||
if (try_thread_db_load_from_sdir ())
|
||
{
|
||
rc = 1;
|
||
break;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (try_thread_db_load_from_dir (this_dir, this_dir_len))
|
||
{
|
||
rc = 1;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
do_cleanups (cleanups);
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
_("thread_db_load_search returning %d\n"), rc);
|
||
return rc;
|
||
}
|
||
|
||
/* Return non-zero if the inferior has a libpthread. */
|
||
|
||
static int
|
||
has_libpthread (void)
|
||
{
|
||
struct objfile *obj;
|
||
|
||
ALL_OBJFILES (obj)
|
||
if (libpthread_name_p (objfile_name (obj)))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Attempt to load and initialize libthread_db.
|
||
Return 1 on success. */
|
||
|
||
static int
|
||
thread_db_load (void)
|
||
{
|
||
struct thread_db_info *info;
|
||
|
||
info = get_thread_db_info (ptid_get_pid (inferior_ptid));
|
||
|
||
if (info != NULL)
|
||
return 1;
|
||
|
||
/* Don't attempt to use thread_db on executables not running
|
||
yet. */
|
||
if (!target_has_registers)
|
||
return 0;
|
||
|
||
/* Don't attempt to use thread_db for remote targets. */
|
||
if (!(target_can_run (¤t_target) || core_bfd))
|
||
return 0;
|
||
|
||
if (thread_db_load_search ())
|
||
return 1;
|
||
|
||
/* We couldn't find a libthread_db.
|
||
If the inferior has a libpthread warn the user. */
|
||
if (has_libpthread ())
|
||
{
|
||
warning (_("Unable to find libthread_db matching inferior's thread"
|
||
" library, thread debugging will not be available."));
|
||
return 0;
|
||
}
|
||
|
||
/* Either this executable isn't using libpthread at all, or it is
|
||
statically linked. Since we can't easily distinguish these two cases,
|
||
no warning is issued. */
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
check_thread_signals (void)
|
||
{
|
||
if (!thread_signals)
|
||
{
|
||
sigset_t mask;
|
||
int i;
|
||
|
||
lin_thread_get_thread_signals (&mask);
|
||
sigemptyset (&thread_stop_set);
|
||
sigemptyset (&thread_print_set);
|
||
|
||
for (i = 1; i < NSIG; i++)
|
||
{
|
||
if (sigismember (&mask, i))
|
||
{
|
||
if (signal_stop_update (gdb_signal_from_host (i), 0))
|
||
sigaddset (&thread_stop_set, i);
|
||
if (signal_print_update (gdb_signal_from_host (i), 0))
|
||
sigaddset (&thread_print_set, i);
|
||
thread_signals = 1;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Check whether thread_db is usable. This function is called when
|
||
an inferior is created (or otherwise acquired, e.g. attached to)
|
||
and when new shared libraries are loaded into a running process. */
|
||
|
||
void
|
||
check_for_thread_db (void)
|
||
{
|
||
/* Do nothing if we couldn't load libthread_db.so.1. */
|
||
if (!thread_db_load ())
|
||
return;
|
||
}
|
||
|
||
/* This function is called via the new_objfile observer. */
|
||
|
||
static void
|
||
thread_db_new_objfile (struct objfile *objfile)
|
||
{
|
||
/* This observer must always be called with inferior_ptid set
|
||
correctly. */
|
||
|
||
if (objfile != NULL
|
||
/* libpthread with separate debug info has its debug info file already
|
||
loaded (and notified without successful thread_db initialization)
|
||
the time observer_notify_new_objfile is called for the library itself.
|
||
Static executables have their separate debug info loaded already
|
||
before the inferior has started. */
|
||
&& objfile->separate_debug_objfile_backlink == NULL
|
||
/* Only check for thread_db if we loaded libpthread,
|
||
or if this is the main symbol file.
|
||
We need to check OBJF_MAINLINE to handle the case of debugging
|
||
a statically linked executable AND the symbol file is specified AFTER
|
||
the exec file is loaded (e.g., gdb -c core ; file foo).
|
||
For dynamically linked executables, libpthread can be near the end
|
||
of the list of shared libraries to load, and in an app of several
|
||
thousand shared libraries, this can otherwise be painful. */
|
||
&& ((objfile->flags & OBJF_MAINLINE) != 0
|
||
|| libpthread_name_p (objfile_name (objfile))))
|
||
check_for_thread_db ();
|
||
}
|
||
|
||
static void
|
||
check_pid_namespace_match (void)
|
||
{
|
||
/* Check is only relevant for local targets targets. */
|
||
if (target_can_run (¤t_target))
|
||
{
|
||
/* If the child is in a different PID namespace, its idea of its
|
||
PID will differ from our idea of its PID. When we scan the
|
||
child's thread list, we'll mistakenly think it has no threads
|
||
since the thread PID fields won't match the PID we give to
|
||
libthread_db. */
|
||
if (!linux_ns_same (ptid_get_pid (inferior_ptid), LINUX_NS_PID))
|
||
{
|
||
warning (_ ("Target and debugger are in different PID "
|
||
"namespaces; thread lists and other data are "
|
||
"likely unreliable. "
|
||
"Connect to gdbserver inside the container."));
|
||
}
|
||
}
|
||
}
|
||
|
||
/* This function is called via the inferior_created observer.
|
||
This handles the case of debugging statically linked executables. */
|
||
|
||
static void
|
||
thread_db_inferior_created (struct target_ops *target, int from_tty)
|
||
{
|
||
check_pid_namespace_match ();
|
||
check_for_thread_db ();
|
||
}
|
||
|
||
/* Update the thread's state (what's displayed in "info threads"),
|
||
from libthread_db thread state information. */
|
||
|
||
static void
|
||
update_thread_state (struct private_thread_info *priv,
|
||
const td_thrinfo_t *ti_p)
|
||
{
|
||
priv->dying = (ti_p->ti_state == TD_THR_UNKNOWN
|
||
|| ti_p->ti_state == TD_THR_ZOMBIE);
|
||
}
|
||
|
||
/* Record a new thread in GDB's thread list. Creates the thread's
|
||
private info. If TP is NULL or TP is marked as having exited,
|
||
creates a new thread. Otherwise, uses TP. */
|
||
|
||
static struct thread_info *
|
||
record_thread (struct thread_db_info *info,
|
||
struct thread_info *tp,
|
||
ptid_t ptid, const td_thrhandle_t *th_p,
|
||
const td_thrinfo_t *ti_p)
|
||
{
|
||
td_err_e err;
|
||
struct private_thread_info *priv;
|
||
int new_thread = (tp == NULL);
|
||
|
||
/* A thread ID of zero may mean the thread library has not
|
||
initialized yet. Leave private == NULL until the thread library
|
||
has initialized. */
|
||
if (ti_p->ti_tid == 0)
|
||
return tp;
|
||
|
||
/* Construct the thread's private data. */
|
||
priv = XCNEW (struct private_thread_info);
|
||
|
||
priv->th = *th_p;
|
||
priv->tid = ti_p->ti_tid;
|
||
update_thread_state (priv, ti_p);
|
||
|
||
/* Add the thread to GDB's thread list. If we already know about a
|
||
thread with this PTID, but it's marked exited, then the kernel
|
||
reused the tid of an old thread. */
|
||
if (tp == NULL || tp->state == THREAD_EXITED)
|
||
tp = add_thread_with_info (ptid, priv);
|
||
else
|
||
tp->priv = priv;
|
||
|
||
if (target_has_execution)
|
||
check_thread_signals ();
|
||
|
||
return tp;
|
||
}
|
||
|
||
static void
|
||
thread_db_detach (struct target_ops *ops, const char *args, int from_tty)
|
||
{
|
||
struct target_ops *target_beneath = find_target_beneath (ops);
|
||
struct thread_db_info *info;
|
||
|
||
info = get_thread_db_info (ptid_get_pid (inferior_ptid));
|
||
|
||
if (info)
|
||
delete_thread_db_info (ptid_get_pid (inferior_ptid));
|
||
|
||
target_beneath->to_detach (target_beneath, args, from_tty);
|
||
|
||
/* NOTE: From this point on, inferior_ptid is null_ptid. */
|
||
|
||
/* If there are no more processes using libpthread, detach the
|
||
thread_db target ops. */
|
||
if (!thread_db_list)
|
||
unpush_target (&thread_db_ops);
|
||
}
|
||
|
||
static ptid_t
|
||
thread_db_wait (struct target_ops *ops,
|
||
ptid_t ptid, struct target_waitstatus *ourstatus,
|
||
int options)
|
||
{
|
||
struct thread_db_info *info;
|
||
struct target_ops *beneath = find_target_beneath (ops);
|
||
|
||
ptid = beneath->to_wait (beneath, ptid, ourstatus, options);
|
||
|
||
if (ourstatus->kind == TARGET_WAITKIND_IGNORE)
|
||
return ptid;
|
||
|
||
if (ourstatus->kind == TARGET_WAITKIND_EXITED
|
||
|| ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
|
||
return ptid;
|
||
|
||
info = get_thread_db_info (ptid_get_pid (ptid));
|
||
|
||
/* If this process isn't using thread_db, we're done. */
|
||
if (info == NULL)
|
||
return ptid;
|
||
|
||
if (ourstatus->kind == TARGET_WAITKIND_EXECD)
|
||
{
|
||
/* New image, it may or may not end up using thread_db. Assume
|
||
not unless we find otherwise. */
|
||
delete_thread_db_info (ptid_get_pid (ptid));
|
||
if (!thread_db_list)
|
||
unpush_target (&thread_db_ops);
|
||
|
||
return ptid;
|
||
}
|
||
|
||
/* Fill in the thread's user-level thread id and status. */
|
||
thread_from_lwp (ptid);
|
||
|
||
return ptid;
|
||
}
|
||
|
||
static void
|
||
thread_db_mourn_inferior (struct target_ops *ops)
|
||
{
|
||
struct target_ops *target_beneath = find_target_beneath (ops);
|
||
|
||
delete_thread_db_info (ptid_get_pid (inferior_ptid));
|
||
|
||
target_beneath->to_mourn_inferior (target_beneath);
|
||
|
||
/* Detach thread_db target ops. */
|
||
if (!thread_db_list)
|
||
unpush_target (ops);
|
||
}
|
||
|
||
struct callback_data
|
||
{
|
||
struct thread_db_info *info;
|
||
int new_threads;
|
||
};
|
||
|
||
static int
|
||
find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
|
||
{
|
||
td_thrinfo_t ti;
|
||
td_err_e err;
|
||
ptid_t ptid;
|
||
struct thread_info *tp;
|
||
struct callback_data *cb_data = (struct callback_data *) data;
|
||
struct thread_db_info *info = cb_data->info;
|
||
|
||
err = info->td_thr_get_info_p (th_p, &ti);
|
||
if (err != TD_OK)
|
||
error (_("find_new_threads_callback: cannot get thread info: %s"),
|
||
thread_db_err_str (err));
|
||
|
||
if (ti.ti_lid == -1)
|
||
{
|
||
/* A thread with kernel thread ID -1 is either a thread that
|
||
exited and was joined, or a thread that is being created but
|
||
hasn't started yet, and that is reusing the tcb/stack of a
|
||
thread that previously exited and was joined. (glibc marks
|
||
terminated and joined threads with kernel thread ID -1. See
|
||
glibc PR17707. */
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"thread_db: skipping exited and "
|
||
"joined thread (0x%lx)\n",
|
||
(unsigned long) ti.ti_tid);
|
||
return 0;
|
||
}
|
||
|
||
if (ti.ti_tid == 0)
|
||
{
|
||
/* A thread ID of zero means that this is the main thread, but
|
||
glibc has not yet initialized thread-local storage and the
|
||
pthread library. We do not know what the thread's TID will
|
||
be yet. */
|
||
|
||
/* In that case, we're not stopped in a fork syscall and don't
|
||
need this glibc bug workaround. */
|
||
info->need_stale_parent_threads_check = 0;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Ignore stale parent threads, caused by glibc/BZ5983. This is a
|
||
bit expensive, as it needs to open /proc/pid/status, so try to
|
||
avoid doing the work if we know we don't have to. */
|
||
if (info->need_stale_parent_threads_check)
|
||
{
|
||
int tgid = linux_proc_get_tgid (ti.ti_lid);
|
||
|
||
if (tgid != -1 && tgid != info->pid)
|
||
return 0;
|
||
}
|
||
|
||
ptid = ptid_build (info->pid, ti.ti_lid, 0);
|
||
tp = find_thread_ptid (ptid);
|
||
if (tp == NULL || tp->priv == NULL)
|
||
record_thread (info, tp, ptid, th_p, &ti);
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Helper for thread_db_find_new_threads_2.
|
||
Returns number of new threads found. */
|
||
|
||
static int
|
||
find_new_threads_once (struct thread_db_info *info, int iteration,
|
||
td_err_e *errp)
|
||
{
|
||
struct callback_data data;
|
||
td_err_e err = TD_ERR;
|
||
|
||
data.info = info;
|
||
data.new_threads = 0;
|
||
|
||
/* See comment in thread_db_update_thread_list. */
|
||
gdb_assert (info->td_ta_thr_iter_p != NULL);
|
||
|
||
TRY
|
||
{
|
||
/* Iterate over all user-space threads to discover new threads. */
|
||
err = info->td_ta_thr_iter_p (info->thread_agent,
|
||
find_new_threads_callback,
|
||
&data,
|
||
TD_THR_ANY_STATE,
|
||
TD_THR_LOWEST_PRIORITY,
|
||
TD_SIGNO_MASK,
|
||
TD_THR_ANY_USER_FLAGS);
|
||
}
|
||
CATCH (except, RETURN_MASK_ERROR)
|
||
{
|
||
if (libthread_db_debug)
|
||
{
|
||
exception_fprintf (gdb_stdlog, except,
|
||
"Warning: find_new_threads_once: ");
|
||
}
|
||
}
|
||
END_CATCH
|
||
|
||
if (libthread_db_debug)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
_("Found %d new threads in iteration %d.\n"),
|
||
data.new_threads, iteration);
|
||
}
|
||
|
||
if (errp != NULL)
|
||
*errp = err;
|
||
|
||
return data.new_threads;
|
||
}
|
||
|
||
/* Search for new threads, accessing memory through stopped thread
|
||
PTID. If UNTIL_NO_NEW is true, repeat searching until several
|
||
searches in a row do not discover any new threads. */
|
||
|
||
static void
|
||
thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
|
||
{
|
||
td_err_e err = TD_OK;
|
||
struct thread_db_info *info;
|
||
int i, loop;
|
||
|
||
info = get_thread_db_info (ptid_get_pid (ptid));
|
||
|
||
/* Access an lwp we know is stopped. */
|
||
info->proc_handle.ptid = ptid;
|
||
|
||
if (until_no_new)
|
||
{
|
||
/* Require 4 successive iterations which do not find any new threads.
|
||
The 4 is a heuristic: there is an inherent race here, and I have
|
||
seen that 2 iterations in a row are not always sufficient to
|
||
"capture" all threads. */
|
||
for (i = 0, loop = 0; loop < 4 && err == TD_OK; ++i, ++loop)
|
||
if (find_new_threads_once (info, i, &err) != 0)
|
||
{
|
||
/* Found some new threads. Restart the loop from beginning. */
|
||
loop = -1;
|
||
}
|
||
}
|
||
else
|
||
find_new_threads_once (info, 0, &err);
|
||
|
||
if (err != TD_OK)
|
||
error (_("Cannot find new threads: %s"), thread_db_err_str (err));
|
||
}
|
||
|
||
static void
|
||
thread_db_find_new_threads_1 (ptid_t ptid)
|
||
{
|
||
thread_db_find_new_threads_2 (ptid, 0);
|
||
}
|
||
|
||
/* Implement the to_update_thread_list target method for this
|
||
target. */
|
||
|
||
static void
|
||
thread_db_update_thread_list (struct target_ops *ops)
|
||
{
|
||
struct thread_db_info *info;
|
||
struct inferior *inf;
|
||
|
||
prune_threads ();
|
||
|
||
ALL_INFERIORS (inf)
|
||
{
|
||
struct thread_info *thread;
|
||
|
||
if (inf->pid == 0)
|
||
continue;
|
||
|
||
info = get_thread_db_info (inf->pid);
|
||
if (info == NULL)
|
||
continue;
|
||
|
||
thread = any_live_thread_of_process (inf->pid);
|
||
if (thread == NULL || thread->executing)
|
||
continue;
|
||
|
||
/* It's best to avoid td_ta_thr_iter if possible. That walks
|
||
data structures in the inferior's address space that may be
|
||
corrupted, or, if the target is running, the list may change
|
||
while we walk it. In the latter case, it's possible that a
|
||
thread exits just at the exact time that causes GDB to get
|
||
stuck in an infinite loop. To avoid pausing all threads
|
||
whenever the core wants to refresh the thread list, we
|
||
instead use thread_from_lwp immediately when we see an LWP
|
||
stop. That uses thread_db entry points that do not walk
|
||
libpthread's thread list, so should be safe, as well as more
|
||
efficient. */
|
||
if (target_has_execution_1 (thread->ptid))
|
||
continue;
|
||
|
||
thread_db_find_new_threads_1 (thread->ptid);
|
||
}
|
||
|
||
/* Give the beneath target a chance to do extra processing. */
|
||
ops->beneath->to_update_thread_list (ops->beneath);
|
||
}
|
||
|
||
static char *
|
||
thread_db_pid_to_str (struct target_ops *ops, ptid_t ptid)
|
||
{
|
||
struct thread_info *thread_info = find_thread_ptid (ptid);
|
||
struct target_ops *beneath;
|
||
|
||
if (thread_info != NULL && thread_info->priv != NULL)
|
||
{
|
||
static char buf[64];
|
||
thread_t tid;
|
||
|
||
tid = thread_info->priv->tid;
|
||
snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
|
||
(unsigned long) tid, ptid_get_lwp (ptid));
|
||
|
||
return buf;
|
||
}
|
||
|
||
beneath = find_target_beneath (ops);
|
||
return beneath->to_pid_to_str (beneath, ptid);
|
||
}
|
||
|
||
/* Return a string describing the state of the thread specified by
|
||
INFO. */
|
||
|
||
static char *
|
||
thread_db_extra_thread_info (struct target_ops *self,
|
||
struct thread_info *info)
|
||
{
|
||
if (info->priv == NULL)
|
||
return NULL;
|
||
|
||
if (info->priv->dying)
|
||
return "Exiting";
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Get the address of the thread local variable in load module LM which
|
||
is stored at OFFSET within the thread local storage for thread PTID. */
|
||
|
||
static CORE_ADDR
|
||
thread_db_get_thread_local_address (struct target_ops *ops,
|
||
ptid_t ptid,
|
||
CORE_ADDR lm,
|
||
CORE_ADDR offset)
|
||
{
|
||
struct thread_info *thread_info;
|
||
struct target_ops *beneath;
|
||
|
||
/* Find the matching thread. */
|
||
thread_info = find_thread_ptid (ptid);
|
||
|
||
/* We may not have discovered the thread yet. */
|
||
if (thread_info != NULL && thread_info->priv == NULL)
|
||
thread_info = thread_from_lwp (ptid);
|
||
|
||
if (thread_info != NULL && thread_info->priv != NULL)
|
||
{
|
||
td_err_e err;
|
||
psaddr_t address;
|
||
struct thread_db_info *info;
|
||
|
||
info = get_thread_db_info (ptid_get_pid (ptid));
|
||
|
||
/* Finally, get the address of the variable. */
|
||
if (lm != 0)
|
||
{
|
||
/* glibc doesn't provide the needed interface. */
|
||
if (!info->td_thr_tls_get_addr_p)
|
||
throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR,
|
||
_("No TLS library support"));
|
||
|
||
/* Note the cast through uintptr_t: this interface only works if
|
||
a target address fits in a psaddr_t, which is a host pointer.
|
||
So a 32-bit debugger can not access 64-bit TLS through this. */
|
||
err = info->td_thr_tls_get_addr_p (&thread_info->priv->th,
|
||
(psaddr_t)(uintptr_t) lm,
|
||
offset, &address);
|
||
}
|
||
else
|
||
{
|
||
/* If glibc doesn't provide the needed interface throw an error
|
||
that LM is zero - normally cases it should not be. */
|
||
if (!info->td_thr_tlsbase_p)
|
||
throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR,
|
||
_("TLS load module not found"));
|
||
|
||
/* This code path handles the case of -static -pthread executables:
|
||
https://sourceware.org/ml/libc-help/2014-03/msg00024.html
|
||
For older GNU libc r_debug.r_map is NULL. For GNU libc after
|
||
PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
|
||
The constant number 1 depends on GNU __libc_setup_tls
|
||
initialization of l_tls_modid to 1. */
|
||
err = info->td_thr_tlsbase_p (&thread_info->priv->th,
|
||
1, &address);
|
||
address = (char *) address + offset;
|
||
}
|
||
|
||
#ifdef THREAD_DB_HAS_TD_NOTALLOC
|
||
/* The memory hasn't been allocated, yet. */
|
||
if (err == TD_NOTALLOC)
|
||
/* Now, if libthread_db provided the initialization image's
|
||
address, we *could* try to build a non-lvalue value from
|
||
the initialization image. */
|
||
throw_error (TLS_NOT_ALLOCATED_YET_ERROR,
|
||
_("TLS not allocated yet"));
|
||
#endif
|
||
|
||
/* Something else went wrong. */
|
||
if (err != TD_OK)
|
||
throw_error (TLS_GENERIC_ERROR,
|
||
(("%s")), thread_db_err_str (err));
|
||
|
||
/* Cast assuming host == target. Joy. */
|
||
/* Do proper sign extension for the target. */
|
||
gdb_assert (exec_bfd);
|
||
return (bfd_get_sign_extend_vma (exec_bfd) > 0
|
||
? (CORE_ADDR) (intptr_t) address
|
||
: (CORE_ADDR) (uintptr_t) address);
|
||
}
|
||
|
||
beneath = find_target_beneath (ops);
|
||
return beneath->to_get_thread_local_address (beneath, ptid, lm, offset);
|
||
}
|
||
|
||
/* Implement the to_get_ada_task_ptid target method for this target. */
|
||
|
||
static ptid_t
|
||
thread_db_get_ada_task_ptid (struct target_ops *self, long lwp, long thread)
|
||
{
|
||
/* NPTL uses a 1:1 model, so the LWP id suffices. */
|
||
return ptid_build (ptid_get_pid (inferior_ptid), lwp, 0);
|
||
}
|
||
|
||
static void
|
||
thread_db_resume (struct target_ops *ops,
|
||
ptid_t ptid, int step, enum gdb_signal signo)
|
||
{
|
||
struct target_ops *beneath = find_target_beneath (ops);
|
||
struct thread_db_info *info;
|
||
|
||
if (ptid_equal (ptid, minus_one_ptid))
|
||
info = get_thread_db_info (ptid_get_pid (inferior_ptid));
|
||
else
|
||
info = get_thread_db_info (ptid_get_pid (ptid));
|
||
|
||
/* This workaround is only needed for child fork lwps stopped in a
|
||
PTRACE_O_TRACEFORK event. When the inferior is resumed, the
|
||
workaround can be disabled. */
|
||
if (info)
|
||
info->need_stale_parent_threads_check = 0;
|
||
|
||
beneath->to_resume (beneath, ptid, step, signo);
|
||
}
|
||
|
||
/* qsort helper function for info_auto_load_libthread_db, sort the
|
||
thread_db_info pointers primarily by their FILENAME and secondarily by their
|
||
PID, both in ascending order. */
|
||
|
||
static int
|
||
info_auto_load_libthread_db_compare (const void *ap, const void *bp)
|
||
{
|
||
struct thread_db_info *a = *(struct thread_db_info **) ap;
|
||
struct thread_db_info *b = *(struct thread_db_info **) bp;
|
||
int retval;
|
||
|
||
retval = strcmp (a->filename, b->filename);
|
||
if (retval)
|
||
return retval;
|
||
|
||
return (a->pid > b->pid) - (a->pid - b->pid);
|
||
}
|
||
|
||
/* Implement 'info auto-load libthread-db'. */
|
||
|
||
static void
|
||
info_auto_load_libthread_db (char *args, int from_tty)
|
||
{
|
||
struct ui_out *uiout = current_uiout;
|
||
const char *cs = args ? args : "";
|
||
struct thread_db_info *info, **array;
|
||
unsigned info_count, unique_filenames;
|
||
size_t max_filename_len, max_pids_len, pids_len;
|
||
struct cleanup *back_to;
|
||
char *pids;
|
||
int i;
|
||
|
||
cs = skip_spaces_const (cs);
|
||
if (*cs)
|
||
error (_("'info auto-load libthread-db' does not accept any parameters"));
|
||
|
||
info_count = 0;
|
||
for (info = thread_db_list; info; info = info->next)
|
||
if (info->filename != NULL)
|
||
info_count++;
|
||
|
||
array = XNEWVEC (struct thread_db_info *, info_count);
|
||
back_to = make_cleanup (xfree, array);
|
||
|
||
info_count = 0;
|
||
for (info = thread_db_list; info; info = info->next)
|
||
if (info->filename != NULL)
|
||
array[info_count++] = info;
|
||
|
||
/* Sort ARRAY by filenames and PIDs. */
|
||
|
||
qsort (array, info_count, sizeof (*array),
|
||
info_auto_load_libthread_db_compare);
|
||
|
||
/* Calculate the number of unique filenames (rows) and the maximum string
|
||
length of PIDs list for the unique filenames (columns). */
|
||
|
||
unique_filenames = 0;
|
||
max_filename_len = 0;
|
||
max_pids_len = 0;
|
||
pids_len = 0;
|
||
for (i = 0; i < info_count; i++)
|
||
{
|
||
int pid = array[i]->pid;
|
||
size_t this_pid_len;
|
||
|
||
for (this_pid_len = 0; pid != 0; pid /= 10)
|
||
this_pid_len++;
|
||
|
||
if (i == 0 || strcmp (array[i - 1]->filename, array[i]->filename) != 0)
|
||
{
|
||
unique_filenames++;
|
||
max_filename_len = max (max_filename_len,
|
||
strlen (array[i]->filename));
|
||
|
||
if (i > 0)
|
||
{
|
||
pids_len -= strlen (", ");
|
||
max_pids_len = max (max_pids_len, pids_len);
|
||
}
|
||
pids_len = 0;
|
||
}
|
||
pids_len += this_pid_len + strlen (", ");
|
||
}
|
||
if (i)
|
||
{
|
||
pids_len -= strlen (", ");
|
||
max_pids_len = max (max_pids_len, pids_len);
|
||
}
|
||
|
||
/* Table header shifted right by preceding "libthread-db: " would not match
|
||
its columns. */
|
||
if (info_count > 0 && args == auto_load_info_scripts_pattern_nl)
|
||
ui_out_text (uiout, "\n");
|
||
|
||
make_cleanup_ui_out_table_begin_end (uiout, 2, unique_filenames,
|
||
"LinuxThreadDbTable");
|
||
|
||
ui_out_table_header (uiout, max_filename_len, ui_left, "filename",
|
||
"Filename");
|
||
ui_out_table_header (uiout, pids_len, ui_left, "PIDs", "Pids");
|
||
ui_out_table_body (uiout);
|
||
|
||
pids = (char *) xmalloc (max_pids_len + 1);
|
||
make_cleanup (xfree, pids);
|
||
|
||
/* Note I is incremented inside the cycle, not at its end. */
|
||
for (i = 0; i < info_count;)
|
||
{
|
||
struct cleanup *chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
|
||
char *pids_end;
|
||
|
||
info = array[i];
|
||
ui_out_field_string (uiout, "filename", info->filename);
|
||
pids_end = pids;
|
||
|
||
while (i < info_count && strcmp (info->filename, array[i]->filename) == 0)
|
||
{
|
||
if (pids_end != pids)
|
||
{
|
||
*pids_end++ = ',';
|
||
*pids_end++ = ' ';
|
||
}
|
||
pids_end += xsnprintf (pids_end, &pids[max_pids_len + 1] - pids_end,
|
||
"%u", array[i]->pid);
|
||
gdb_assert (pids_end < &pids[max_pids_len + 1]);
|
||
|
||
i++;
|
||
}
|
||
*pids_end = '\0';
|
||
|
||
ui_out_field_string (uiout, "pids", pids);
|
||
|
||
ui_out_text (uiout, "\n");
|
||
do_cleanups (chain);
|
||
}
|
||
|
||
do_cleanups (back_to);
|
||
|
||
if (info_count == 0)
|
||
ui_out_message (uiout, 0, _("No auto-loaded libthread-db.\n"));
|
||
}
|
||
|
||
static void
|
||
init_thread_db_ops (void)
|
||
{
|
||
thread_db_ops.to_shortname = "multi-thread";
|
||
thread_db_ops.to_longname = "multi-threaded child process.";
|
||
thread_db_ops.to_doc = "Threads and pthreads support.";
|
||
thread_db_ops.to_detach = thread_db_detach;
|
||
thread_db_ops.to_wait = thread_db_wait;
|
||
thread_db_ops.to_resume = thread_db_resume;
|
||
thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior;
|
||
thread_db_ops.to_update_thread_list = thread_db_update_thread_list;
|
||
thread_db_ops.to_pid_to_str = thread_db_pid_to_str;
|
||
thread_db_ops.to_stratum = thread_stratum;
|
||
thread_db_ops.to_has_thread_control = tc_schedlock;
|
||
thread_db_ops.to_get_thread_local_address
|
||
= thread_db_get_thread_local_address;
|
||
thread_db_ops.to_extra_thread_info = thread_db_extra_thread_info;
|
||
thread_db_ops.to_get_ada_task_ptid = thread_db_get_ada_task_ptid;
|
||
thread_db_ops.to_magic = OPS_MAGIC;
|
||
|
||
complete_target_initialization (&thread_db_ops);
|
||
}
|
||
|
||
/* Provide a prototype to silence -Wmissing-prototypes. */
|
||
extern initialize_file_ftype _initialize_thread_db;
|
||
|
||
void
|
||
_initialize_thread_db (void)
|
||
{
|
||
init_thread_db_ops ();
|
||
|
||
/* Defer loading of libthread_db.so until inferior is running.
|
||
This allows gdb to load correct libthread_db for a given
|
||
executable -- there could be multiple versions of glibc,
|
||
and until there is a running inferior, we can't tell which
|
||
libthread_db is the correct one to load. */
|
||
|
||
libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
|
||
|
||
add_setshow_optional_filename_cmd ("libthread-db-search-path",
|
||
class_support,
|
||
&libthread_db_search_path, _("\
|
||
Set search path for libthread_db."), _("\
|
||
Show the current search path or libthread_db."), _("\
|
||
This path is used to search for libthread_db to be loaded into \
|
||
gdb itself.\n\
|
||
Its value is a colon (':') separate list of directories to search.\n\
|
||
Setting the search path to an empty list resets it to its default value."),
|
||
set_libthread_db_search_path,
|
||
NULL,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_zuinteger_cmd ("libthread-db", class_maintenance,
|
||
&libthread_db_debug, _("\
|
||
Set libthread-db debugging."), _("\
|
||
Show libthread-db debugging."), _("\
|
||
When non-zero, libthread-db debugging is enabled."),
|
||
NULL,
|
||
show_libthread_db_debug,
|
||
&setdebuglist, &showdebuglist);
|
||
|
||
add_setshow_boolean_cmd ("libthread-db", class_support,
|
||
&auto_load_thread_db, _("\
|
||
Enable or disable auto-loading of inferior specific libthread_db."), _("\
|
||
Show whether auto-loading inferior specific libthread_db is enabled."), _("\
|
||
If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
|
||
locations to load libthread_db compatible with the inferior.\n\
|
||
Standard system libthread_db still gets loaded even with this option off.\n\
|
||
This options has security implications for untrusted inferiors."),
|
||
NULL, show_auto_load_thread_db,
|
||
auto_load_set_cmdlist_get (),
|
||
auto_load_show_cmdlist_get ());
|
||
|
||
add_cmd ("libthread-db", class_info, info_auto_load_libthread_db,
|
||
_("Print the list of loaded inferior specific libthread_db.\n\
|
||
Usage: info auto-load libthread-db"),
|
||
auto_load_info_cmdlist_get ());
|
||
|
||
/* Add ourselves to objfile event chain. */
|
||
observer_attach_new_objfile (thread_db_new_objfile);
|
||
|
||
/* Add ourselves to inferior_created event chain.
|
||
This is needed to handle debugging statically linked programs where
|
||
the new_objfile observer won't get called for libpthread. */
|
||
observer_attach_inferior_created (thread_db_inferior_created);
|
||
}
|