/* libthread_db assisted debugging support, generic parts.
- Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007
- Free Software Foundation, Inc.
+ Copyright (C) 1999-2014 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "gdb_assert.h"
#include <dlfcn.h>
#include "gdb_proc_service.h"
-#include "gdb_thread_db.h"
-
+#include "nat/gdb_thread_db.h"
+#include "gdb_vecs.h"
#include "bfd.h"
+#include "command.h"
#include "exceptions.h"
+#include "gdbcmd.h"
#include "gdbthread.h"
#include "inferior.h"
+#include "infrun.h"
#include "symfile.h"
#include "objfiles.h"
#include "target.h"
#include "regcache.h"
+#include "solib.h"
#include "solib-svr4.h"
#include "gdbcore.h"
#include "observer.h"
#include "linux-nat.h"
+#include "nat/linux-procfs.h"
+#include "nat/linux-osdata.h"
+#include "auto-load.h"
+#include "cli/cli-utils.h"
#include <signal.h>
+#include <ctype.h>
-#ifdef HAVE_GNU_LIBC_VERSION_H
-#include <gnu/libc-version.h>
-#endif
+/* GNU/Linux libthread_db support.
-#ifndef LIBTHREAD_DB_SO
-#define LIBTHREAD_DB_SO "libthread_db.so.1"
-#endif
+ libthread_db is a library, provided along with libpthread.so, which
+ exposes the internals of the thread library to a debugger. It
+ allows GDB to find existing threads, new threads as they are
+ created, thread IDs (usually, the result of pthread_self), and
+ thread-local variables.
+
+ The libthread_db interface originates on Solaris, where it is
+ both more powerful and more complicated. This implementation
+ only works for LinuxThreads and NPTL, the two glibc threading
+ libraries. It assumes that each thread is permanently assigned
+ to a single light-weight process (LWP).
+
+ libthread_db-specific information is stored in the "private" field
+ of struct thread_info. When the field is NULL we do not yet have
+ information about the new thread; this could be temporary (created,
+ but the thread library's data structures do not reflect it yet)
+ or permanent (created using clone instead of pthread_create).
+
+ Process IDs managed by linux-thread-db.c match those used by
+ linux-nat.c: a common PID for all processes, an LWP ID for each
+ thread, and no TID. We save the TID in private. Keeping it out
+ of the ptid_t prevents thread IDs changing when libpthread is
+ loaded or unloaded. */
+
+static char *libthread_db_search_path;
+
+/* Set to non-zero if thread_db auto-loading is enabled
+ by the "set auto-load libthread-db" command. */
+static int auto_load_thread_db = 1;
+
+/* "show" command for the auto_load_thread_db configuration variable. */
+
+static void
+show_auto_load_thread_db (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Auto-loading of inferior specific libthread_db "
+ "is %s.\n"),
+ value);
+}
+
+static void
+set_libthread_db_search_path (char *ignored, int from_tty,
+ struct cmd_list_element *c)
+{
+ if (*libthread_db_search_path == '\0')
+ {
+ xfree (libthread_db_search_path);
+ libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
+ }
+}
+
+/* If non-zero, print details of libthread_db processing. */
+
+static unsigned int libthread_db_debug;
+
+static void
+show_libthread_db_debug (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("libthread-db debugging is %s.\n"), value);
+}
/* If we're running on GNU/Linux, we must explicitly attach to any new
threads. */
/* This module's target vector. */
static struct target_ops thread_db_ops;
-/* The target vector that we call for things this module can't handle. */
-static struct target_ops *target_beneath;
-
-/* Non-zero if we're using this module's target vector. */
-static int using_thread_db;
-
/* Non-zero if we have determined the signals used by the threads
library. */
static int thread_signals;
static sigset_t thread_stop_set;
static sigset_t thread_print_set;
-/* Structure that identifies the child process for the
- <proc_service.h> interface. */
-static struct ps_prochandle proc_handle;
+struct thread_db_info
+{
+ struct thread_db_info *next;
+
+ /* Process id this object refers to. */
+ int pid;
+
+ /* Handle from dlopen for libthread_db.so. */
+ void *handle;
+
+ /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
+ HANDLE. It may be NULL for system library. */
+ char *filename;
+
+ /* Structure that identifies the child process for the
+ <proc_service.h> interface. */
+ struct ps_prochandle proc_handle;
-/* Connection to the libthread_db library. */
-static td_thragent_t *thread_agent;
+ /* Connection to the libthread_db library. */
+ td_thragent_t *thread_agent;
-/* Pointers to the libthread_db functions. */
+ /* True if we need to apply the workaround for glibc/BZ5983. When
+ we catch a PTRACE_O_TRACEFORK, and go query the child's thread
+ list, nptl_db returns the parent's threads in addition to the new
+ (single) child thread. If this flag is set, we do extra work to
+ be able to ignore such stale entries. */
+ int need_stale_parent_threads_check;
-static td_err_e (*td_init_p) (void);
+ /* Location of the thread creation event breakpoint. The code at
+ this location in the child process will be called by the pthread
+ library whenever a new thread is created. By setting a special
+ breakpoint at this location, GDB can detect when a new thread is
+ created. We obtain this location via the td_ta_event_addr
+ call. */
+ CORE_ADDR td_create_bp_addr;
-static td_err_e (*td_ta_new_p) (struct ps_prochandle * ps,
+ /* Location of the thread death event breakpoint. */
+ CORE_ADDR td_death_bp_addr;
+
+ /* Pointers to the libthread_db functions. */
+
+ td_err_e (*td_init_p) (void);
+
+ td_err_e (*td_ta_new_p) (struct ps_prochandle * ps,
td_thragent_t **ta);
-static td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt,
- td_thrhandle_t *__th);
-static td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta,
- lwpid_t lwpid, td_thrhandle_t *th);
-static td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
- td_thr_iter_f *callback, void *cbdata_p,
- td_thr_state_e state, int ti_pri,
- sigset_t *ti_sigmask_p,
- unsigned int ti_user_flags);
-static td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
- td_event_e event, td_notify_t *ptr);
-static td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
- td_thr_events_t *event);
-static td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
- td_event_msg_t *msg);
-
-static td_err_e (*td_thr_validate_p) (const td_thrhandle_t *th);
-static td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
- td_thrinfo_t *infop);
-static td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th,
- int event);
-
-static td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
- void *map_address,
- size_t offset, void **address);
-
-/* Location of the thread creation event breakpoint. The code at this
- location in the child process will be called by the pthread library
- whenever a new thread is created. By setting a special breakpoint
- at this location, GDB can detect when a new thread is created. We
- obtain this location via the td_ta_event_addr call. */
-static CORE_ADDR td_create_bp_addr;
-
-/* Location of the thread death event breakpoint. */
-static CORE_ADDR td_death_bp_addr;
+ td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt,
+ td_thrhandle_t *__th);
+ td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta,
+ lwpid_t lwpid, td_thrhandle_t *th);
+ td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
+ td_thr_iter_f *callback, void *cbdata_p,
+ td_thr_state_e state, int ti_pri,
+ sigset_t *ti_sigmask_p,
+ unsigned int ti_user_flags);
+ td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
+ td_event_e event, td_notify_t *ptr);
+ td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
+ td_thr_events_t *event);
+ td_err_e (*td_ta_clear_event_p) (const td_thragent_t *ta,
+ td_thr_events_t *event);
+ td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
+ td_event_msg_t *msg);
+
+ td_err_e (*td_thr_validate_p) (const td_thrhandle_t *th);
+ td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
+ td_thrinfo_t *infop);
+ td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th,
+ int event);
+
+ td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
+ psaddr_t map_address,
+ size_t offset, psaddr_t *address);
+ td_err_e (*td_thr_tlsbase_p) (const td_thrhandle_t *th,
+ unsigned long int modid,
+ psaddr_t *base);
+};
-/* Prototypes for local functions. */
-static void thread_db_find_new_threads (void);
-static void attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
- const td_thrinfo_t *ti_p, int verbose);
-static void detach_thread (ptid_t ptid, int verbose);
-\f
+/* List of known processes using thread_db, and the required
+ bookkeeping. */
+struct thread_db_info *thread_db_list;
-/* Building process ids. */
+static void thread_db_find_new_threads_1 (ptid_t ptid);
+static void thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new);
-#define GET_PID(ptid) ptid_get_pid (ptid)
-#define GET_LWP(ptid) ptid_get_lwp (ptid)
-#define GET_THREAD(ptid) ptid_get_tid (ptid)
+/* Add the current inferior to the list of processes using libpthread.
+ Return a pointer to the newly allocated object that was added to
+ THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
+ LIBTHREAD_DB_SO. */
-#define is_lwp(ptid) (GET_LWP (ptid) != 0)
-#define is_thread(ptid) (GET_THREAD (ptid) != 0)
+static struct thread_db_info *
+add_thread_db_info (void *handle)
+{
+ struct thread_db_info *info;
+
+ info = xcalloc (1, sizeof (*info));
+ info->pid = ptid_get_pid (inferior_ptid);
+ info->handle = handle;
+
+ /* The workaround works by reading from /proc/pid/status, so it is
+ disabled for core files. */
+ if (target_has_execution)
+ info->need_stale_parent_threads_check = 1;
+
+ info->next = thread_db_list;
+ thread_db_list = info;
+
+ return info;
+}
-#define BUILD_LWP(lwp, pid) ptid_build (pid, lwp, 0)
+/* Return the thread_db_info object representing the bookkeeping
+ related to process PID, if any; NULL otherwise. */
+
+static struct thread_db_info *
+get_thread_db_info (int pid)
+{
+ struct thread_db_info *info;
+
+ for (info = thread_db_list; info; info = info->next)
+ if (pid == info->pid)
+ return info;
+
+ return NULL;
+}
+
+/* When PID has exited or has been detached, we no longer want to keep
+ track of it as using libpthread. Call this function to discard
+ thread_db related info related to PID. Note that this closes
+ LIBTHREAD_DB_SO's dlopen'ed handle. */
+
+static void
+delete_thread_db_info (int pid)
+{
+ struct thread_db_info *info, *info_prev;
+
+ info_prev = NULL;
+
+ for (info = thread_db_list; info; info_prev = info, info = info->next)
+ if (pid == info->pid)
+ break;
+
+ if (info == NULL)
+ return;
+
+ if (info->handle != NULL)
+ dlclose (info->handle);
+
+ xfree (info->filename);
+
+ if (info_prev)
+ info_prev->next = info->next;
+ else
+ thread_db_list = info->next;
+
+ xfree (info);
+}
+
+/* Prototypes for local functions. */
+static int attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
+ const td_thrinfo_t *ti_p);
+static void detach_thread (ptid_t ptid);
\f
/* Use "struct private_thread_info" to cache thread state. This is
unsigned int dying:1;
/* Cached thread state. */
- unsigned int th_valid:1;
- unsigned int ti_valid:1;
-
td_thrhandle_t th;
- td_thrinfo_t ti;
+ thread_t tid;
};
\f
}
}
\f
+/* Return 1 if any threads have been registered. There may be none if
+ the threading library is not fully initialized yet. */
+
+static int
+have_threads_callback (struct thread_info *thread, void *args)
+{
+ int pid = * (int *) args;
+
+ if (ptid_get_pid (thread->ptid) != pid)
+ return 0;
+
+ return thread->private != NULL;
+}
+
+static int
+have_threads (ptid_t ptid)
+{
+ int pid = ptid_get_pid (ptid);
+
+ return iterate_over_threads (have_threads_callback, &pid) != NULL;
+}
+
+struct thread_get_info_inout
+{
+ struct thread_info *thread_info;
+ struct thread_db_info *thread_db_info;
+};
+
/* A callback function for td_ta_thr_iter, which we use to map all
threads to LWPs.
zero is returned to indicate success. */
static int
-thread_get_info_callback (const td_thrhandle_t *thp, void *infop)
+thread_get_info_callback (const td_thrhandle_t *thp, void *argp)
{
td_thrinfo_t ti;
td_err_e err;
- struct thread_info *thread_info;
ptid_t thread_ptid;
+ struct thread_get_info_inout *inout;
+ struct thread_db_info *info;
+
+ inout = argp;
+ info = inout->thread_db_info;
- err = td_thr_get_info_p (thp, &ti);
+ err = info->td_thr_get_info_p (thp, &ti);
if (err != TD_OK)
error (_("thread_get_info_callback: cannot get thread info: %s"),
thread_db_err_str (err));
/* Fill the cache. */
- thread_ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, ti.ti_tid);
- thread_info = find_thread_pid (thread_ptid);
+ thread_ptid = ptid_build (info->pid, ti.ti_lid, 0);
+ inout->thread_info = find_thread_ptid (thread_ptid);
- /* In the case of a zombie thread, don't continue. We don't want to
- attach to it thinking it is a new thread. */
- if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
- {
- if (infop != NULL)
- *(struct thread_info **) infop = thread_info;
- if (thread_info != NULL)
- {
- memcpy (&thread_info->private->th, thp, sizeof (*thp));
- thread_info->private->th_valid = 1;
- memcpy (&thread_info->private->ti, &ti, sizeof (ti));
- thread_info->private->ti_valid = 1;
- }
- return TD_THR_ZOMBIE;
- }
-
- if (thread_info == NULL)
+ if (inout->thread_info == NULL)
{
/* New thread. Attach to it now (why wait?). */
- attach_thread (thread_ptid, thp, &ti, 1);
- thread_info = find_thread_pid (thread_ptid);
- gdb_assert (thread_info != NULL);
+ if (!have_threads (thread_ptid))
+ thread_db_find_new_threads_1 (thread_ptid);
+ else
+ attach_thread (thread_ptid, thp, &ti);
+ inout->thread_info = find_thread_ptid (thread_ptid);
+ gdb_assert (inout->thread_info != NULL);
}
- memcpy (&thread_info->private->th, thp, sizeof (*thp));
- thread_info->private->th_valid = 1;
- memcpy (&thread_info->private->ti, &ti, sizeof (ti));
- thread_info->private->ti_valid = 1;
-
- if (infop != NULL)
- *(struct thread_info **) infop = thread_info;
-
return 0;
}
-
-/* Accessor functions for the thread_db information, with caching. */
-
-static void
-thread_db_map_id2thr (struct thread_info *thread_info, int fatal)
-{
- td_err_e err;
-
- if (thread_info->private->th_valid)
- return;
-
- err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (thread_info->ptid),
- &thread_info->private->th);
- if (err != TD_OK)
- {
- if (fatal)
- error (_("Cannot find thread %ld: %s"),
- (long) GET_THREAD (thread_info->ptid),
- thread_db_err_str (err));
- }
- else
- thread_info->private->th_valid = 1;
-}
\f
-/* Convert between user-level thread ids and LWP ids. */
+/* Fetch the user-level thread id of PTID. */
-static ptid_t
+static void
thread_from_lwp (ptid_t ptid)
{
td_thrhandle_t th;
td_err_e err;
- struct thread_info *thread_info;
- ptid_t thread_ptid;
+ struct thread_db_info *info;
+ struct thread_get_info_inout io = {0};
+
+ /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
+ th.th_unique = 0;
- if (GET_LWP (ptid) == 0)
- ptid = BUILD_LWP (GET_PID (ptid), GET_PID (ptid));
+ /* This ptid comes from linux-nat.c, which should always fill in the
+ LWP. */
+ gdb_assert (ptid_get_lwp (ptid) != 0);
- gdb_assert (is_lwp (ptid));
+ info = get_thread_db_info (ptid_get_pid (ptid));
- err = td_ta_map_lwp2thr_p (thread_agent, GET_LWP (ptid), &th);
+ /* Access an lwp we know is stopped. */
+ info->proc_handle.ptid = ptid;
+ err = info->td_ta_map_lwp2thr_p (info->thread_agent, ptid_get_lwp (ptid),
+ &th);
if (err != TD_OK)
error (_("Cannot find user-level thread for LWP %ld: %s"),
- GET_LWP (ptid), thread_db_err_str (err));
-
- thread_info = NULL;
-
- /* Fetch the thread info. If we get back TD_THR_ZOMBIE, then the
- event thread has already died. If another gdb interface has called
- thread_alive() previously, the thread won't be found on the thread list
- anymore. In that case, we don't want to process this ptid anymore
- to avoid the possibility of later treating it as a newly
- discovered thread id that we should add to the list. Thus,
- we return a -1 ptid which is also how the thread list marks a
- dead thread. */
- if (thread_get_info_callback (&th, &thread_info) == TD_THR_ZOMBIE
- && thread_info == NULL)
- return pid_to_ptid (-1);
-
- gdb_assert (thread_info && thread_info->private->ti_valid);
-
- return ptid_build (GET_PID (ptid), GET_LWP (ptid),
- thread_info->private->ti.ti_tid);
-}
+ ptid_get_lwp (ptid), thread_db_err_str (err));
-static ptid_t
-lwp_from_thread (ptid_t ptid)
-{
- return BUILD_LWP (GET_LWP (ptid), GET_PID (ptid));
+ /* Long-winded way of fetching the thread info. */
+ io.thread_db_info = info;
+ io.thread_info = NULL;
+ thread_get_info_callback (&th, &io);
}
\f
-void
-thread_db_init (struct target_ops *target)
-{
- target_beneath = target;
-}
-
-static void *
-verbose_dlsym (void *handle, const char *name)
-{
- void *sym = dlsym (handle, name);
- if (sym == NULL)
- warning (_("Symbol \"%s\" not found in libthread_db: %s"), name, dlerror ());
- return sym;
-}
-
-static int
-thread_db_load (void)
+/* Attach to lwp PTID, doing whatever else is required to have this
+ LWP under the debugger's control --- e.g., enabling event
+ reporting. Returns true on success. */
+int
+thread_db_attach_lwp (ptid_t ptid)
{
- void *handle;
+ td_thrhandle_t th;
+ td_thrinfo_t ti;
td_err_e err;
+ struct thread_db_info *info;
- handle = dlopen (LIBTHREAD_DB_SO, RTLD_NOW);
- if (handle == NULL)
- {
- fprintf_filtered (gdb_stderr, "\n\ndlopen failed on '%s' - %s\n",
- LIBTHREAD_DB_SO, dlerror ());
- fprintf_filtered (gdb_stderr,
- "GDB will not be able to debug pthreads.\n\n");
- return 0;
- }
-
- /* Initialize pointers to the dynamic library functions we will use.
- Essential functions first. */
-
- td_init_p = verbose_dlsym (handle, "td_init");
- if (td_init_p == NULL)
- return 0;
+ info = get_thread_db_info (ptid_get_pid (ptid));
- td_ta_new_p = verbose_dlsym (handle, "td_ta_new");
- if (td_ta_new_p == NULL)
+ if (info == NULL)
return 0;
- td_ta_map_id2thr_p = verbose_dlsym (handle, "td_ta_map_id2thr");
- if (td_ta_map_id2thr_p == NULL)
- return 0;
-
- td_ta_map_lwp2thr_p = verbose_dlsym (handle, "td_ta_map_lwp2thr");
- if (td_ta_map_lwp2thr_p == NULL)
- return 0;
+ /* This ptid comes from linux-nat.c, which should always fill in the
+ LWP. */
+ gdb_assert (ptid_get_lwp (ptid) != 0);
- td_ta_thr_iter_p = verbose_dlsym (handle, "td_ta_thr_iter");
- if (td_ta_thr_iter_p == NULL)
- return 0;
+ /* Access an lwp we know is stopped. */
+ info->proc_handle.ptid = ptid;
- td_thr_validate_p = verbose_dlsym (handle, "td_thr_validate");
- if (td_thr_validate_p == NULL)
- return 0;
+ /* If we have only looked at the first thread before libpthread was
+ initialized, we may not know its thread ID yet. Make sure we do
+ before we add another thread to the list. */
+ if (!have_threads (ptid))
+ thread_db_find_new_threads_1 (ptid);
- td_thr_get_info_p = verbose_dlsym (handle, "td_thr_get_info");
- if (td_thr_get_info_p == NULL)
+ err = info->td_ta_map_lwp2thr_p (info->thread_agent, ptid_get_lwp (ptid),
+ &th);
+ if (err != TD_OK)
+ /* Cannot find user-level thread. */
return 0;
- /* Initialize the library. */
- err = td_init_p ();
+ err = info->td_thr_get_info_p (&th, &ti);
if (err != TD_OK)
{
- warning (_("Cannot initialize libthread_db: %s"), thread_db_err_str (err));
+ warning (_("Cannot get thread info: %s"), thread_db_err_str (err));
return 0;
}
- /* These are not essential. */
- td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr");
- td_ta_set_event_p = dlsym (handle, "td_ta_set_event");
- td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg");
- td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable");
- td_thr_tls_get_addr_p = dlsym (handle, "td_thr_tls_get_addr");
-
+ attach_thread (ptid, &th, &ti);
return 1;
}
+static void *
+verbose_dlsym (void *handle, const char *name)
+{
+ void *sym = dlsym (handle, name);
+ if (sym == NULL)
+ warning (_("Symbol \"%s\" not found in libthread_db: %s"),
+ name, dlerror ());
+ return sym;
+}
+
static td_err_e
-enable_thread_event (td_thragent_t *thread_agent, int event, CORE_ADDR *bp)
+enable_thread_event (int event, CORE_ADDR *bp)
{
td_notify_t notify;
td_err_e err;
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
+
+ /* Access an lwp we know is stopped. */
+ info->proc_handle.ptid = inferior_ptid;
/* Get the breakpoint address for thread EVENT. */
- err = td_ta_event_addr_p (thread_agent, event, ¬ify);
+ err = info->td_ta_event_addr_p (info->thread_agent, event, ¬ify);
if (err != TD_OK)
return err;
/* Set up the breakpoint. */
gdb_assert (exec_bfd);
(*bp) = (gdbarch_convert_from_func_ptr_addr
- (current_gdbarch,
+ (target_gdbarch (),
/* Do proper sign extension for the target. */
(bfd_get_sign_extend_vma (exec_bfd) > 0
? (CORE_ADDR) (intptr_t) notify.u.bptaddr
: (CORE_ADDR) (uintptr_t) notify.u.bptaddr),
¤t_target));
- create_thread_event_breakpoint ((*bp));
+ create_thread_event_breakpoint (target_gdbarch (), *bp);
return TD_OK;
}
+/* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
+ return 1 if this version is lower (and not equal) to
+ VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
+
+static int
+inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min)
+{
+ struct bound_minimal_symbol version_msym;
+ CORE_ADDR version_addr;
+ char *version;
+ int err, got, retval = 0;
+
+ version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL);
+ if (version_msym.minsym == NULL)
+ 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;
+}
+
static void
enable_thread_event_reporting (void)
{
td_thr_events_t events;
- td_notify_t notify;
td_err_e err;
-#ifdef HAVE_GNU_LIBC_VERSION_H
- const char *libc_version;
- int libc_major, libc_minor;
-#endif
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
/* We cannot use the thread event reporting facility if these
functions aren't available. */
- if (td_ta_event_addr_p == NULL || td_ta_set_event_p == NULL
- || td_ta_event_getmsg_p == NULL || td_thr_event_enable_p == NULL)
+ if (info->td_ta_event_addr_p == NULL
+ || info->td_ta_set_event_p == NULL
+ || info->td_ta_event_getmsg_p == NULL
+ || info->td_thr_event_enable_p == NULL)
return;
/* Set the process wide mask saying which events we're interested in. */
td_event_emptyset (&events);
td_event_addset (&events, TD_CREATE);
-#ifdef HAVE_GNU_LIBC_VERSION_H
- /* The event reporting facility is broken for TD_DEATH events in
- glibc 2.1.3, so don't enable it if we have glibc but a lower
- version. */
- libc_version = gnu_get_libc_version ();
- if (sscanf (libc_version, "%d.%d", &libc_major, &libc_minor) == 2
- && (libc_major > 2 || (libc_major == 2 && libc_minor > 1)))
-#endif
+ /* There is a bug fixed between linuxthreads 2.1.3 and 2.2 by
+ commit 2e4581e4fba917f1779cd0a010a45698586c190a
+ * manager.c (pthread_exited): Correctly report event as TD_REAP
+ instead of TD_DEATH. Fix comments.
+ where event reporting facility is broken for TD_DEATH events,
+ so don't enable it if we have glibc but a lower version. */
+ if (!inferior_has_bug ("__linuxthreads_version", 2, 2))
td_event_addset (&events, TD_DEATH);
- err = td_ta_set_event_p (thread_agent, &events);
+ err = info->td_ta_set_event_p (info->thread_agent, &events);
if (err != TD_OK)
{
warning (_("Unable to set global thread event mask: %s"),
/* Delete previous thread event breakpoints, if any. */
remove_thread_event_breakpoints ();
- td_create_bp_addr = 0;
- td_death_bp_addr = 0;
+ info->td_create_bp_addr = 0;
+ info->td_death_bp_addr = 0;
/* Set up the thread creation event. */
- err = enable_thread_event (thread_agent, TD_CREATE, &td_create_bp_addr);
+ err = enable_thread_event (TD_CREATE, &info->td_create_bp_addr);
if (err != TD_OK)
{
warning (_("Unable to get location for thread creation breakpoint: %s"),
}
/* Set up the thread death event. */
- err = enable_thread_event (thread_agent, TD_DEATH, &td_death_bp_addr);
+ err = enable_thread_event (TD_DEATH, &info->td_death_bp_addr);
if (err != TD_OK)
{
warning (_("Unable to get location for thread death breakpoint: %s"),
}
}
-static void
-disable_thread_event_reporting (void)
-{
- td_thr_events_t events;
+/* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
+ if appropriate.
- /* Set the process wide mask saying we aren't interested in any
- events anymore. */
- td_event_emptyset (&events);
- td_ta_set_event_p (thread_agent, &events);
+ Return 1 if the caller should abort libthread_db initialization. Return 0
+ otherwise. */
- /* Delete thread event breakpoints, if any. */
- remove_thread_event_breakpoints ();
- td_create_bp_addr = 0;
- td_death_bp_addr = 0;
-}
-
-static void
-check_thread_signals (void)
+static int
+thread_db_find_new_threads_silently (ptid_t ptid)
{
-#ifdef GET_THREAD_SIGNALS
- if (!thread_signals)
- {
- sigset_t mask;
- int i;
+ volatile struct gdb_exception except;
- GET_THREAD_SIGNALS (&mask);
- sigemptyset (&thread_stop_set);
- sigemptyset (&thread_print_set);
+ TRY_CATCH (except, RETURN_MASK_ERROR)
+ {
+ thread_db_find_new_threads_2 (ptid, 1);
+ }
- for (i = 1; i < NSIG; i++)
+ if (except.reason < 0)
+ {
+ if (libthread_db_debug)
+ exception_fprintf (gdb_stderr, 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))
{
- if (sigismember (&mask, i))
- {
- if (signal_stop_update (target_signal_from_host (i), 0))
- sigaddset (&thread_stop_set, i);
- if (signal_print_update (target_signal_from_host (i), 0))
- sigaddset (&thread_print_set, i);
- thread_signals = 1;
- }
+ exception_fprintf (gdb_stderr, except,
+ _("Warning: couldn't activate thread debugging "
+ "using libthread_db: "));
+ return 1;
}
}
-#endif
+ return 0;
}
-/* 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. */
+/* Lookup a library in which given symbol resides.
+ Note: this is looking in GDB process, not in the inferior.
+ Returns library name, or NULL. */
-void
-check_for_thread_db (void)
+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;
- static int already_loaded;
- /* Do nothing if we couldn't load libthread_db.so.1. */
- if (td_ta_new_p == NULL)
- return;
+ /* Initialize pointers to the dynamic library functions we will use.
+ Essential functions first. */
- /* First time through, report that libthread_db was successfuly
- loaded. Can't print this in in thread_db_load as, at that stage,
- the interpreter and it's console haven't started. */
+ info->td_init_p = verbose_dlsym (info->handle, "td_init");
+ if (info->td_init_p == NULL)
+ return 0;
- if (!already_loaded)
+ err = info->td_init_p ();
+ if (err != TD_OK)
{
- Dl_info info;
- const char *library = NULL;
- if (dladdr ((*td_ta_new_p), &info) != 0)
- library = info.dli_fname;
+ warning (_("Cannot initialize libthread_db: %s"),
+ thread_db_err_str (err));
+ return 0;
+ }
+
+ info->td_ta_new_p = verbose_dlsym (info->handle, "td_ta_new");
+ if (info->td_ta_new_p == NULL)
+ return 0;
- /* Try dlinfo? */
+ /* 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)
+ printf_unfiltered (_("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;
+ }
+ info->td_ta_map_id2thr_p = verbose_dlsym (info->handle, "td_ta_map_id2thr");
+ if (info->td_ta_map_id2thr_p == NULL)
+ return 0;
+
+ info->td_ta_map_lwp2thr_p = verbose_dlsym (info->handle,
+ "td_ta_map_lwp2thr");
+ if (info->td_ta_map_lwp2thr_p == NULL)
+ return 0;
+
+ info->td_ta_thr_iter_p = verbose_dlsym (info->handle, "td_ta_thr_iter");
+ if (info->td_ta_thr_iter_p == NULL)
+ return 0;
+
+ info->td_thr_validate_p = verbose_dlsym (info->handle, "td_thr_validate");
+ if (info->td_thr_validate_p == NULL)
+ return 0;
+
+ info->td_thr_get_info_p = verbose_dlsym (info->handle, "td_thr_get_info");
+ if (info->td_thr_get_info_p == NULL)
+ return 0;
+
+ /* These are not essential. */
+ info->td_ta_event_addr_p = dlsym (info->handle, "td_ta_event_addr");
+ info->td_ta_set_event_p = dlsym (info->handle, "td_ta_set_event");
+ info->td_ta_clear_event_p = dlsym (info->handle, "td_ta_clear_event");
+ info->td_ta_event_getmsg_p = dlsym (info->handle, "td_ta_event_getmsg");
+ info->td_thr_event_enable_p = dlsym (info->handle, "td_thr_event_enable");
+ info->td_thr_tls_get_addr_p = dlsym (info->handle, "td_thr_tls_get_addr");
+ info->td_thr_tlsbase_p = dlsym (info->handle, "td_thr_tlsbase");
+
+ 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_debug || *libthread_db_search_path)
+ {
+ const char *library;
+
+ library = dladdr_to_soname (*info->td_ta_new_p);
if (library == NULL)
- /* Paranoid - don't let a NULL path slip through. */
library = LIBTHREAD_DB_SO;
printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
library);
- already_loaded = 1;
}
- if (using_thread_db)
- /* Nothing to do. The thread library was already detected and the
- target vector was already activated. */
- return;
+ /* 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);
- /* Don't attempt to use thread_db on targets which can not run
- (executables not running yet, core files) for now. */
- if (!target_has_execution)
- return;
+ /* Enable event reporting, but not when debugging a core file. */
+ if (target_has_execution)
+ enable_thread_event_reporting ();
+
+ 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)
+ printf_unfiltered (_("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)
+ printf_unfiltered (_("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)
+ printf_unfiltered (_("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)
+ printf_unfiltered (_("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);
+
+ if (obj_name[0] != '/')
+ {
+ warning (_("Expected absolute pathname for libpthread in the"
+ " inferior, but got %s."), obj_name);
+ return 0;
+ }
+
+ path = xmalloc (strlen (obj_name) + (subdir ? strlen (subdir) + 1 : 0)
+ + 1 + strlen (LIBTHREAD_DB_SO) + 1);
+ 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 $sdir in libthread-db-search-path.
+ Look for libthread_db in the system dirs, or wherever a plain
+ dlopen(file_without_path) will look.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_sdir (void)
+{
+ return try_thread_db_load (LIBTHREAD_DB_SO, 0);
+}
+
+/* Try to load libthread_db from directory DIR of length DIR_LEN.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_dir (const char *dir, size_t dir_len)
+{
+ struct cleanup *cleanup;
+ char *path;
+ int result;
+
+ if (!auto_load_thread_db)
+ return 0;
+
+ path = xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
+ cleanup = make_cleanup (xfree, path);
+
+ memcpy (path, dir, dir_len);
+ path[dir_len] = '/';
+ strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
+
+ result = try_thread_db_load (path, 1);
+
+ do_cleanups (cleanup);
+ return result;
+}
+
+/* Search libthread_db_search_path for libthread_db which "agrees"
+ to work on current inferior.
+ The result is true for success. */
+
+static int
+thread_db_load_search (void)
+{
+ VEC (char_ptr) *dir_vec;
+ struct cleanup *cleanups;
+ char *this_dir;
+ int i, rc = 0;
+
+ dir_vec = dirnames_to_char_ptr_vec (libthread_db_search_path);
+ cleanups = make_cleanup_free_char_ptr_vec (dir_vec);
+
+ for (i = 0; VEC_iterate (char_ptr, dir_vec, i, this_dir); ++i)
+ {
+ const int pdir_len = sizeof ("$pdir") - 1;
+ size_t this_dir_len;
+
+ this_dir_len = strlen (this_dir);
+
+ if (strncmp (this_dir, "$pdir", pdir_len) == 0
+ && (this_dir[pdir_len] == '\0'
+ || this_dir[pdir_len] == '/'))
+ {
+ char *subdir = NULL;
+ struct cleanup *free_subdir_cleanup
+ = make_cleanup (null_cleanup, NULL);
+
+ if (this_dir[pdir_len] == '/')
+ {
+ subdir = xmalloc (strlen (this_dir));
+ make_cleanup (xfree, subdir);
+ strcpy (subdir, this_dir + pdir_len + 1);
+ }
+ rc = try_thread_db_load_from_pdir (subdir);
+ do_cleanups (free_subdir_cleanup);
+ if (rc)
+ break;
+ }
+ else if (strcmp (this_dir, "$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)
+ printf_unfiltered (_("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))
- return;
+ if (!(target_can_run (¤t_target) || core_bfd))
+ return 0;
- /* Initialize the structure that identifies the child process. */
- proc_handle.pid = GET_PID (inferior_ptid);
+ if (thread_db_load_search ())
+ return 1;
- /* Now attempt to open a connection to the thread library. */
- err = td_ta_new_p (&proc_handle, &thread_agent);
- switch (err)
+ /* We couldn't find a libthread_db.
+ If the inferior has a libpthread warn the user. */
+ if (has_libpthread ())
{
- case TD_NOLIBTHREAD:
- /* No thread library was detected. */
- break;
+ 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
+disable_thread_event_reporting (struct thread_db_info *info)
+{
+ if (info->td_ta_clear_event_p != NULL)
+ {
+ td_thr_events_t events;
+
+ /* Set the process wide mask saying we aren't interested in any
+ events anymore. */
+ td_event_fillset (&events);
+ info->td_ta_clear_event_p (info->thread_agent, &events);
+ }
+
+ info->td_create_bp_addr = 0;
+ info->td_death_bp_addr = 0;
+}
+
+static void
+check_thread_signals (void)
+{
+ if (!thread_signals)
+ {
+ sigset_t mask;
+ int i;
- case TD_OK:
- printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
+ lin_thread_get_thread_signals (&mask);
+ sigemptyset (&thread_stop_set);
+ sigemptyset (&thread_print_set);
- /* The thread library was detected. Activate the thread_db target. */
- push_target (&thread_db_ops);
- using_thread_db = 1;
+ 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;
+ }
+ }
+ }
+}
- enable_thread_event_reporting ();
- thread_db_find_new_threads ();
- break;
+/* 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. */
- default:
- warning (_("Cannot initialize thread debugging library: %s"),
- thread_db_err_str (err));
- break;
- }
+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)
{
- if (objfile != NULL)
+ /* 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 ();
}
+/* 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_for_thread_db ();
+}
+
/* Attach to a new thread. This function is called when we receive a
TD_CREATE event or when we iterate over all threads and find one
- that wasn't already in our list. */
+ that wasn't already in our list. Returns true on success. */
-static void
+static int
attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
- const td_thrinfo_t *ti_p, int verbose)
+ const td_thrinfo_t *ti_p)
{
+ struct private_thread_info *private;
struct thread_info *tp;
td_err_e err;
+ struct thread_db_info *info;
/* If we're being called after a TD_CREATE event, we may already
know about this thread. There are two ways this can happen. We
thread ID. In the first case we don't need to do anything; in
the second case we should discard information about the dead
thread and attach to the new one. */
- if (in_thread_list (ptid))
+ tp = find_thread_ptid (ptid);
+ if (tp != NULL)
{
- tp = find_thread_pid (ptid);
- gdb_assert (tp != NULL);
-
- if (!tp->private->dying)
- return;
+ /* If tp->private is NULL, then GDB is already attached to this
+ thread, but we do not know anything about it. We can learn
+ about it here. This can only happen if we have some other
+ way besides libthread_db to notice new threads (i.e.
+ PTRACE_EVENT_CLONE); assume the same mechanism notices thread
+ exit, so this can not be a stale thread recreated with the
+ same ID. */
+ if (tp->private != NULL)
+ {
+ if (!tp->private->dying)
+ return 0;
- delete_thread (ptid);
+ delete_thread (ptid);
+ tp = NULL;
+ }
}
- check_thread_signals ();
-
- if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
- return; /* A zombie thread -- do not attach. */
+ if (target_has_execution)
+ check_thread_signals ();
/* Under GNU/Linux, we have to attach to each and every thread. */
- if (lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)), 0) < 0)
- return;
+ if (target_has_execution
+ && tp == NULL)
+ {
+ int res;
- /* Add the thread to GDB's thread list. */
- tp = add_thread (ptid);
- tp->private = xmalloc (sizeof (struct private_thread_info));
- memset (tp->private, 0, sizeof (struct private_thread_info));
+ res = lin_lwp_attach_lwp (ptid_build (ptid_get_pid (ptid),
+ ti_p->ti_lid, 0));
+ if (res < 0)
+ {
+ /* Error, stop iterating. */
+ return 0;
+ }
+ else if (res > 0)
+ {
+ /* Pretend this thread doesn't exist yet, and keep
+ iterating. */
+ return 1;
+ }
- if (verbose)
- printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid));
+ /* Otherwise, we sucessfully attached to the thread. */
+ }
- /* Enable thread event reporting for this thread. */
- err = td_thr_event_enable_p (th_p, 1);
- if (err != TD_OK)
- error (_("Cannot enable thread event reporting for %s: %s"),
- target_pid_to_str (ptid), thread_db_err_str (err));
-}
+ /* Construct the thread's private data. */
+ private = xmalloc (sizeof (struct private_thread_info));
+ memset (private, 0, sizeof (struct private_thread_info));
+
+ /* A thread ID of zero may mean the thread library has not initialized
+ yet. But we shouldn't even get here if that's the case. FIXME:
+ if we change GDB to always have at least one thread in the thread
+ list this will have to go somewhere else; maybe private == NULL
+ until the thread_db target claims it. */
+ gdb_assert (ti_p->ti_tid != 0);
+ private->th = *th_p;
+ private->tid = ti_p->ti_tid;
+ if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
+ private->dying = 1;
-static void
-thread_db_attach (char *args, int from_tty)
-{
- target_beneath->to_attach (args, from_tty);
+ /* Add the thread to GDB's thread list. */
+ if (tp == NULL)
+ add_thread_with_info (ptid, private);
+ else
+ tp->private = private;
- /* Destroy thread info; it's no longer valid. */
- init_thread_list ();
+ info = get_thread_db_info (ptid_get_pid (ptid));
- /* The child process is now the actual multi-threaded
- program. Snatch its process ID... */
- proc_handle.pid = GET_PID (inferior_ptid);
+ /* Enable thread event reporting for this thread, except when
+ debugging a core file. */
+ if (target_has_execution)
+ {
+ err = info->td_thr_event_enable_p (th_p, 1);
+ if (err != TD_OK)
+ error (_("Cannot enable thread event reporting for %s: %s"),
+ target_pid_to_str (ptid), thread_db_err_str (err));
+ }
- /* ...and perform the remaining initialization steps. */
- enable_thread_event_reporting ();
- thread_db_find_new_threads ();
+ return 1;
}
static void
-detach_thread (ptid_t ptid, int verbose)
+detach_thread (ptid_t ptid)
{
struct thread_info *thread_info;
- if (verbose)
- printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (ptid));
-
/* Don't delete the thread now, because it still reports as active
until it has executed a few instructions after the event
breakpoint - if we deleted it now, "info threads" would cause us
to re-attach to it. Just mark it as having had a TD_DEATH
event. This means that we won't delete it from our thread list
until we notice that it's dead (via prune_threads), or until
- something re-uses its thread ID. */
- thread_info = find_thread_pid (ptid);
- gdb_assert (thread_info != NULL);
+ something re-uses its thread ID. We'll report the thread exit
+ when the underlying LWP dies. */
+ thread_info = find_thread_ptid (ptid);
+ gdb_assert (thread_info != NULL && thread_info->private != NULL);
thread_info->private->dying = 1;
}
static void
-thread_db_detach (char *args, int from_tty)
+thread_db_detach (struct target_ops *ops, const char *args, int from_tty)
{
- disable_thread_event_reporting ();
+ struct target_ops *target_beneath = find_target_beneath (ops);
+ struct thread_db_info *info;
- /* There's no need to save & restore inferior_ptid here, since the
- inferior is supposed to be survive this function call. */
- inferior_ptid = lwp_from_thread (inferior_ptid);
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
- /* Forget about the child's process ID. We shouldn't need it
- anymore. */
- proc_handle.pid = 0;
-
- target_beneath->to_detach (args, from_tty);
-}
-
-static int
-clear_lwpid_callback (struct thread_info *thread, void *dummy)
-{
- /* If we know that our thread implementation is 1-to-1, we could save
- a certain amount of information; it's not clear how much, so we
- are always conservative. */
-
- thread->private->th_valid = 0;
- thread->private->ti_valid = 0;
-
- return 0;
-}
-
-static void
-thread_db_resume (ptid_t ptid, int step, enum target_signal signo)
-{
- struct cleanup *old_chain = save_inferior_ptid ();
+ if (info)
+ {
+ if (target_has_execution)
+ {
+ disable_thread_event_reporting (info);
+
+ /* Delete the old thread event breakpoints. Note that
+ unlike when mourning, we can remove them here because
+ there's still a live inferior to poke at. In any case,
+ GDB will not try to insert anything in the inferior when
+ removing a breakpoint. */
+ remove_thread_event_breakpoints ();
+ }
- if (GET_PID (ptid) == -1)
- inferior_ptid = lwp_from_thread (inferior_ptid);
- else if (is_thread (ptid))
- ptid = lwp_from_thread (ptid);
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
+ }
- /* Clear cached data which may not be valid after the resume. */
- iterate_over_threads (clear_lwpid_callback, NULL);
+ target_beneath->to_detach (target_beneath, args, from_tty);
- target_beneath->to_resume (ptid, step, signo);
+ /* NOTE: From this point on, inferior_ptid is null_ptid. */
- do_cleanups (old_chain);
+ /* If there are no more processes using libpthread, detach the
+ thread_db target ops. */
+ if (!thread_db_list)
+ unpush_target (&thread_db_ops);
}
/* Check if PID is currently stopped at the location of a thread event
static void
check_event (ptid_t ptid)
{
+ struct regcache *regcache = get_thread_regcache (ptid);
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
td_event_msg_t msg;
td_thrinfo_t ti;
td_err_e err;
CORE_ADDR stop_pc;
int loop = 0;
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (ptid_get_pid (ptid));
/* Bail out early if we're not at a thread event breakpoint. */
- stop_pc = read_pc_pid (ptid) - gdbarch_decr_pc_after_break (current_gdbarch);
- if (stop_pc != td_create_bp_addr && stop_pc != td_death_bp_addr)
+ stop_pc = regcache_read_pc (regcache)
+ - target_decr_pc_after_break (gdbarch);
+ if (stop_pc != info->td_create_bp_addr
+ && stop_pc != info->td_death_bp_addr)
return;
+ /* Access an lwp we know is stopped. */
+ info->proc_handle.ptid = ptid;
+
+ /* If we have only looked at the first thread before libpthread was
+ initialized, we may not know its thread ID yet. Make sure we do
+ before we add another thread to the list. */
+ if (!have_threads (ptid))
+ thread_db_find_new_threads_1 (ptid);
+
/* If we are at a create breakpoint, we do not know what new lwp
was created and cannot specifically locate the event message for it.
We have to call td_ta_event_getmsg() to get
do
{
- err = td_ta_event_getmsg_p (thread_agent, &msg);
+ err = info->td_ta_event_getmsg_p (info->thread_agent, &msg);
if (err != TD_OK)
{
if (err == TD_NOMSG)
thread_db_err_str (err));
}
- err = td_thr_get_info_p (msg.th_p, &ti);
+ err = info->td_thr_get_info_p (msg.th_p, &ti);
if (err != TD_OK)
error (_("Cannot get thread info: %s"), thread_db_err_str (err));
- ptid = ptid_build (GET_PID (ptid), ti.ti_lid, ti.ti_tid);
+ ptid = ptid_build (ptid_get_pid (ptid), ti.ti_lid, 0);
switch (msg.event)
{
case TD_CREATE:
/* Call attach_thread whether or not we already know about a
thread with this thread ID. */
- attach_thread (ptid, msg.th_p, &ti, 1);
+ attach_thread (ptid, msg.th_p, &ti);
break;
if (!in_thread_list (ptid))
error (_("Spurious thread death event."));
- detach_thread (ptid, 1);
+ detach_thread (ptid);
break;
}
static ptid_t
-thread_db_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
+thread_db_wait (struct target_ops *ops,
+ ptid_t ptid, struct target_waitstatus *ourstatus,
+ int options)
{
- extern ptid_t trap_ptid;
-
- if (GET_PID (ptid) != -1 && is_thread (ptid))
- ptid = lwp_from_thread (ptid);
+ struct thread_db_info *info;
+ struct target_ops *beneath = find_target_beneath (ops);
- ptid = target_beneath->to_wait (ptid, ourstatus);
+ ptid = beneath->to_wait (beneath, ptid, ourstatus, options);
- if (proc_handle.pid == 0)
- /* The current child process isn't the actual multi-threaded
- program yet, so don't try to do any special thread-specific
- post-processing and bail out early. */
+ if (ourstatus->kind == TARGET_WAITKIND_IGNORE)
return ptid;
if (ourstatus->kind == TARGET_WAITKIND_EXITED
- || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
- return pid_to_ptid (-1);
+ || 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)
{
- remove_thread_event_breakpoints ();
- unpush_target (&thread_db_ops);
- using_thread_db = 0;
+ /* 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 pid_to_ptid (GET_PID (ptid));
+ /* Thread event breakpoints are deleted by
+ update_breakpoints_after_exec. */
+
+ return ptid;
}
+ /* If we do not know about the main thread yet, this would be a good time to
+ find it. */
+ if (ourstatus->kind == TARGET_WAITKIND_STOPPED && !have_threads (ptid))
+ thread_db_find_new_threads_1 (ptid);
+
if (ourstatus->kind == TARGET_WAITKIND_STOPPED
- && ourstatus->value.sig == TARGET_SIGNAL_TRAP)
+ && ourstatus->value.sig == GDB_SIGNAL_TRAP)
/* Check for a thread event. */
check_event (ptid);
- if (!ptid_equal (trap_ptid, null_ptid))
- trap_ptid = thread_from_lwp (trap_ptid);
-
- /* Change the ptid back into the higher level PID + TID format.
- If the thread is dead and no longer on the thread list, we will
- get back a dead ptid. This can occur if the thread death event
- gets postponed by other simultaneous events. In such a case,
- we want to just ignore the event and continue on. */
- ptid = thread_from_lwp (ptid);
- if (GET_PID (ptid) == -1)
- ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
-
- return ptid;
-}
-
-static void
-thread_db_kill (void)
-{
- /* There's no need to save & restore inferior_ptid here, since the
- inferior isn't supposed to survive this function call. */
- inferior_ptid = lwp_from_thread (inferior_ptid);
- target_beneath->to_kill ();
-}
-
-static void
-thread_db_create_inferior (char *exec_file, char *allargs, char **env,
- int from_tty)
-{
- unpush_target (&thread_db_ops);
- using_thread_db = 0;
- target_beneath->to_create_inferior (exec_file, allargs, env, from_tty);
-}
-
-static void
-thread_db_post_startup_inferior (ptid_t ptid)
-{
- if (proc_handle.pid == 0)
+ if (have_threads (ptid))
{
- /* The child process is now the actual multi-threaded
- program. Snatch its process ID... */
- proc_handle.pid = GET_PID (ptid);
-
- /* ...and perform the remaining initialization steps. */
- enable_thread_event_reporting ();
- thread_db_find_new_threads ();
+ /* Fill in the thread's user-level thread id. */
+ thread_from_lwp (ptid);
}
+
+ return ptid;
}
static void
-thread_db_mourn_inferior (void)
+thread_db_mourn_inferior (struct target_ops *ops)
{
- /* Forget about the child's process ID. We shouldn't need it
- anymore. */
- proc_handle.pid = 0;
+ struct target_ops *target_beneath = find_target_beneath (ops);
- target_beneath->to_mourn_inferior ();
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
+
+ target_beneath->to_mourn_inferior (target_beneath);
/* Delete the old thread event breakpoints. Do this after mourning
the inferior, so that we don't try to uninsert them. */
remove_thread_event_breakpoints ();
/* Detach thread_db target ops. */
- unpush_target (&thread_db_ops);
- using_thread_db = 0;
+ 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 = data;
+ struct thread_db_info *info = cb_data->info;
- err = td_thr_get_info_p (th_p, &ti);
+ 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_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
- return 0; /* A zombie -- ignore. */
+ 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. Just enable event reporting and otherwise ignore
+ it. */
+
+ /* 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;
+
+ if (target_has_execution)
+ {
+ err = info->td_thr_event_enable_p (th_p, 1);
+ if (err != TD_OK)
+ error (_("Cannot enable thread event reporting for LWP %d: %s"),
+ (int) ti.ti_lid, thread_db_err_str (err));
+ }
+
+ 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);
- ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, ti.ti_tid);
+ if (tgid != -1 && tgid != info->pid)
+ return 0;
+ }
- if (!in_thread_list (ptid))
- attach_thread (ptid, th_p, &ti, 1);
+ ptid = ptid_build (info->pid, ti.ti_lid, 0);
+ tp = find_thread_ptid (ptid);
+ if (tp == NULL || tp->private == NULL)
+ {
+ if (attach_thread (ptid, th_p, &ti))
+ cb_data->new_threads += 1;
+ else
+ /* Problem attaching this thread; perhaps it exited before we
+ could attach it?
+ This could mean that the thread list inside glibc itself is in
+ inconsistent state, and libthread_db could go on looping forever
+ (observed with glibc-2.3.6). To prevent that, terminate
+ iteration: thread_db_find_new_threads_2 will retry. */
+ return 1;
+ }
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)
+{
+ volatile struct gdb_exception except;
+ struct callback_data data;
+ td_err_e err = TD_ERR;
+
+ data.info = info;
+ data.new_threads = 0;
+
+ TRY_CATCH (except, RETURN_MASK_ERROR)
+ {
+ /* 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);
+ }
+
+ if (libthread_db_debug)
+ {
+ if (except.reason < 0)
+ exception_fprintf (gdb_stderr, except,
+ "Warning: find_new_threads_once: ");
+
+ printf_filtered (_("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 (void)
+thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
{
- td_err_e err;
+ 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);
- /* Iterate over all user-space threads to discover new threads. */
- err = td_ta_thr_iter_p (thread_agent, find_new_threads_callback, NULL,
- TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
- TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
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);
+}
+
+static int
+update_thread_core (struct lwp_info *info, void *closure)
+{
+ info->core = linux_common_core_of_thread (info->ptid);
+ return 0;
+}
+
+static void
+thread_db_find_new_threads (struct target_ops *ops)
+{
+ struct thread_db_info *info;
+ struct inferior *inf;
+
+ 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;
+
+ thread_db_find_new_threads_1 (thread->ptid);
+ }
+
+ if (target_has_execution)
+ iterate_over_lwps (minus_one_ptid /* iterate over all */,
+ update_thread_core, NULL);
+}
+
static char *
-thread_db_pid_to_str (ptid_t ptid)
+thread_db_pid_to_str (struct target_ops *ops, ptid_t ptid)
{
- if (is_thread (ptid))
+ struct thread_info *thread_info = find_thread_ptid (ptid);
+ struct target_ops *beneath;
+
+ if (thread_info != NULL && thread_info->private != NULL)
{
static char buf[64];
- struct thread_info *thread_info;
+ thread_t tid;
- thread_info = find_thread_pid (ptid);
- if (thread_info == NULL)
- snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld) (Missing)",
- GET_THREAD (ptid), GET_LWP (ptid));
- else
- snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
- GET_THREAD (ptid), GET_LWP (ptid));
+ tid = thread_info->private->tid;
+ snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
+ tid, ptid_get_lwp (ptid));
return buf;
}
- if (target_beneath->to_pid_to_str (ptid))
- return target_beneath->to_pid_to_str (ptid);
+ beneath = find_target_beneath (ops);
+ if (beneath->to_pid_to_str (beneath, ptid))
+ return beneath->to_pid_to_str (beneath, ptid);
return normal_pid_to_str (ptid);
}
INFO. */
static char *
-thread_db_extra_thread_info (struct thread_info *info)
+thread_db_extra_thread_info (struct target_ops *self,
+ struct thread_info *info)
{
+ if (info->private == NULL)
+ return NULL;
+
if (info->private->dying)
return "Exiting";
is stored at OFFSET within the thread local storage for thread PTID. */
static CORE_ADDR
-thread_db_get_thread_local_address (ptid_t ptid,
+thread_db_get_thread_local_address (struct target_ops *ops,
+ ptid_t ptid,
CORE_ADDR lm,
CORE_ADDR offset)
{
- if (is_thread (ptid))
- {
- td_err_e err;
- void *address;
- struct thread_info *thread_info;
+ struct thread_info *thread_info;
+ struct target_ops *beneath;
+
+ /* If we have not discovered any threads yet, check now. */
+ if (!have_threads (ptid))
+ thread_db_find_new_threads_1 (ptid);
- /* glibc doesn't provide the needed interface. */
- if (!td_thr_tls_get_addr_p)
- throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR,
- _("No TLS library support"));
+ /* Find the matching thread. */
+ thread_info = find_thread_ptid (ptid);
- /* Caller should have verified that lm != 0. */
- gdb_assert (lm != 0);
+ if (thread_info != NULL && thread_info->private != NULL)
+ {
+ td_err_e err;
+ psaddr_t address;
+ struct thread_db_info *info;
- /* Get info about the thread. */
- thread_info = find_thread_pid (ptid);
- thread_db_map_id2thr (thread_info, 1);
+ info = get_thread_db_info (ptid_get_pid (ptid));
/* Finally, get the address of the variable. */
- err = td_thr_tls_get_addr_p (&thread_info->private->th,
- (void *)(size_t) lm,
- offset, &address);
+ 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->private->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->private->th,
+ 1, &address);
+ address = (char *) address + offset;
+ }
#ifdef THREAD_DB_HAS_TD_NOTALLOC
/* The memory hasn't been allocated, yet. */
: (CORE_ADDR) (uintptr_t) address);
}
- if (target_beneath->to_get_thread_local_address)
- return target_beneath->to_get_thread_local_address (ptid, lm, offset);
+ beneath = find_target_beneath (ops);
+ return beneath->to_get_thread_local_address (beneath, ptid, lm, offset);
+}
+
+/* Callback routine used to find a thread based on the TID part of
+ its PTID. */
+
+static int
+thread_db_find_thread_from_tid (struct thread_info *thread, void *data)
+{
+ long *tid = (long *) data;
+
+ if (thread->private->tid == *tid)
+ return 1;
+
+ return 0;
+}
+
+/* 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)
+{
+ struct thread_info *thread_info;
+
+ thread_db_find_new_threads_1 (inferior_ptid);
+ thread_info = iterate_over_threads (thread_db_find_thread_from_tid, &thread);
+
+ gdb_assert (thread_info != NULL);
+
+ return (thread_info->ptid);
+}
+
+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
- throw_error (TLS_GENERIC_ERROR,
- _("TLS not supported on this target"));
+ 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 = xmalloc (sizeof (*array) * 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 = 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
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_attach = thread_db_attach;
thread_db_ops.to_detach = thread_db_detach;
- thread_db_ops.to_resume = thread_db_resume;
thread_db_ops.to_wait = thread_db_wait;
- thread_db_ops.to_kill = thread_db_kill;
- thread_db_ops.to_create_inferior = thread_db_create_inferior;
- thread_db_ops.to_post_startup_inferior = thread_db_post_startup_inferior;
+ thread_db_ops.to_resume = thread_db_resume;
thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior;
thread_db_ops.to_find_new_threads = thread_db_find_new_threads;
thread_db_ops.to_pid_to_str = thread_db_pid_to_str;
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)
{
- /* Only initialize the module if we can load libthread_db. */
- if (thread_db_load ())
- {
- init_thread_db_ops ();
- add_target (&thread_db_ops);
-
- /* Add ourselves to objfile event chain. */
- observer_attach_new_objfile (thread_db_new_objfile);
- }
+ 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 mutiple versions of glibc,
+ compiled with LinuxThreads or NPTL, 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);
}
projects / deliverable / binutils-gdb.git / blobdiff