/* libthread_db assisted debugging support, generic parts.
- Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006
+ Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009
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_thread_db.h"
#include "bfd.h"
+#include "command.h"
#include "exceptions.h"
+#include "gdbcmd.h"
#include "gdbthread.h"
#include "inferior.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 <signal.h>
+
#ifdef HAVE_GNU_LIBC_VERSION_H
#include <gnu/libc-version.h>
#endif
-#ifndef LIBTHREAD_DB_SO
-#define LIBTHREAD_DB_SO "libthread_db.so.1"
-#endif
+/* GNU/Linux libthread_db support.
-/* If we're running on GNU/Linux, we must explicitly attach to any new
- threads. */
+ 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.
-/* FIXME: There is certainly some room for improvements:
- - Cache LWP ids.
- - Bypass libthread_db when fetching or storing registers for
- threads bound to a LWP. */
+ 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).
-/* This module's target vector. */
-static struct target_ops thread_db_ops;
+ 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).
-/* The target vector that we call for things this module can't handle. */
-static struct target_ops *target_beneath;
+ 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. */
-/* Pointer to the next function on the objfile event chain. */
-static void (*target_new_objfile_chain) (struct objfile * objfile);
+static char *libthread_db_search_path;
-/* Non-zero if we're using this module's target vector. */
-static int using_thread_db;
+/* 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;
/* Non-zero if we have determined the signals used by the threads
library. */
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;
-/* Connection to the libthread_db library. */
-static td_thragent_t *thread_agent;
+ /* Structure that identifies the child process for the
+ <proc_service.h> interface. */
+ struct ps_prochandle proc_handle;
-/* Pointers to the libthread_db functions. */
+ /* Connection to the libthread_db library. */
+ td_thragent_t *thread_agent;
-static td_err_e (*td_init_p) (void);
+ /* 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_ta_new_p) (struct ps_prochandle * ps,
+ /* 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;
+
+ /* 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_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,
+ void *map_address,
+ size_t offset, void **address);
+};
-/* 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;
+
+static void thread_db_find_new_threads_1 (ptid_t 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. */
+
+static struct thread_db_info *
+add_thread_db_info (void *handle)
+{
+ int pid;
+ struct thread_db_info *info;
+
+ info = xcalloc (1, sizeof (*info));
+ info->pid = ptid_get_pid (inferior_ptid);
+ info->handle = handle;
+ info->need_stale_parent_threads_check = 1;
+
+ info->next = thread_db_list;
+ thread_db_list = info;
-/* Building process ids. */
+ return info;
+}
+
+/* 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;
+}
-#define GET_PID(ptid) ptid_get_pid (ptid)
-#define GET_LWP(ptid) ptid_get_lwp (ptid)
-#define GET_THREAD(ptid) ptid_get_tid (ptid)
+/* 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. */
-#define is_lwp(ptid) (GET_LWP (ptid) != 0)
-#define is_thread(ptid) (GET_THREAD (ptid) != 0)
+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;
-#define BUILD_LWP(lwp, pid) ptid_build (pid, lwp, 0)
+ if (info->handle != NULL)
+ dlclose (info->handle);
+
+ if (info_prev)
+ info_prev->next = info->next;
+ else
+ thread_db_list = info->next;
+
+ xfree (info);
+}
+
+/* Prototypes for local functions. */
+static void 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
return "only part of register set was written/read";
case TD_NOXREGS:
return "X register set not available for this thread";
+#ifdef THREAD_DB_HAS_TD_NOTALLOC
+ case TD_NOTALLOC:
+ return "thread has not yet allocated TLS for given module";
+#endif
+#ifdef THREAD_DB_HAS_TD_VERSION
+ case TD_VERSION:
+ return "versions of libpthread and libthread_db do not match";
+#endif
+#ifdef THREAD_DB_HAS_TD_NOTLS
+ case TD_NOTLS:
+ return "there is no TLS segment in the given module";
+#endif
default:
snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
return buf;
}
}
\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;
- }
+ 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. */
{
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};
- 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 (GET_LWP (ptid) != 0);
- gdb_assert (is_lwp (ptid));
+ info = get_thread_db_info (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, 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
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);
+ io.thread_db_info = info;
+ io.thread_info = NULL;
+ if (thread_get_info_callback (&th, &io) == TD_THR_ZOMBIE
+ && io.thread_info == NULL)
+ return minus_one_ptid;
- return ptid_build (GET_PID (ptid), GET_LWP (ptid),
- thread_info->private->ti.ti_tid);
-}
-
-static ptid_t
-lwp_from_thread (ptid_t ptid)
-{
- return BUILD_LWP (GET_LWP (ptid), GET_PID (ptid));
+ gdb_assert (ptid_get_tid (ptid) == 0);
+ return ptid;
}
\f
-void
-thread_db_init (struct target_ops *target)
-{
- target_beneath = target;
-}
-
-static void *
-verbose_dlsym (void *handle, const char *name)
+/* 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 *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)
-{
- 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;
- }
+ info = get_thread_db_info (GET_PID (ptid));
- /* 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)
+ if (info == NULL)
return 0;
- td_ta_new_p = verbose_dlsym (handle, "td_ta_new");
- if (td_ta_new_p == NULL)
- return 0;
+ /* This ptid comes from linux-nat.c, which should always fill in the
+ LWP. */
+ gdb_assert (GET_LWP (ptid) != 0);
- td_ta_map_id2thr_p = verbose_dlsym (handle, "td_ta_map_id2thr");
- if (td_ta_map_id2thr_p == NULL)
- return 0;
+ /* Access an lwp we know is stopped. */
+ info->proc_handle.ptid = ptid;
- td_ta_map_lwp2thr_p = verbose_dlsym (handle, "td_ta_map_lwp2thr");
- if (td_ta_map_lwp2thr_p == NULL)
- return 0;
-
- td_ta_thr_iter_p = verbose_dlsym (handle, "td_ta_thr_iter");
- if (td_ta_thr_iter_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_validate_p = verbose_dlsym (handle, "td_thr_validate");
- if (td_thr_validate_p == NULL)
- return 0;
-
- 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, 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 (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;
}
const char *libc_version;
int libc_major, libc_minor;
#endif
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (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_addset (&events, TD_CREATE);
#ifdef HAVE_GNU_LIBC_VERSION_H
- /* FIXME: kettenis/2000-04-23: The event reporting facility is
- broken for TD_DEATH events in glibc 2.1.3, so don't enable it for
- now. */
+ /* 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
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"),
}
}
+/* Same as thread_db_find_new_threads_1, but silently ignore errors. */
+
+static void
+thread_db_find_new_threads_silently (ptid_t ptid)
+{
+ volatile struct gdb_exception except;
+
+ TRY_CATCH (except, RETURN_MASK_ERROR)
+ {
+ thread_db_find_new_threads_1 (ptid);
+ }
+
+ if (except.reason < 0 && info_verbose)
+ {
+ exception_fprintf (gdb_stderr, except,
+ "Warning: thread_db_find_new_threads_silently: ");
+ }
+}
+
+/* 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 HANDLE.
+ 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. */
+
+ info->td_init_p = verbose_dlsym (info->handle, "td_init");
+ if (info->td_init_p == NULL)
+ return 0;
+
+ err = info->td_init_p ();
+ if (err != TD_OK)
+ {
+ 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;
+
+ /* 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 (info_verbose)
+ 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_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");
+
+ printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
+
+ if (info_verbose || *libthread_db_search_path)
+ {
+ const char *library;
+
+ library = dladdr_to_soname (*info->td_ta_new_p);
+ if (library == NULL)
+ library = LIBTHREAD_DB_SO;
+
+ printf_unfiltered (_("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);
+
+ enable_thread_event_reporting ();
+
+ /* There appears to be a bug in glibc-2.3.6: 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. Silently ignore such
+ errors, and let gdb enumerate threads again later. */
+ thread_db_find_new_threads_silently (inferior_ptid);
+
+ 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)
+{
+ void *handle;
+ struct thread_db_info *info;
+
+ if (info_verbose)
+ printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
+ library);
+ handle = dlopen (library, RTLD_NOW);
+ if (handle == NULL)
+ {
+ if (info_verbose)
+ printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
+ return 0;
+ }
+
+ if (info_verbose && 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);
+
+ if (try_thread_db_load_1 (info))
+ return 1;
+
+ /* This library "refused" to work on current inferior. */
+ delete_thread_db_info (GET_PID (inferior_ptid));
+ return 0;
+}
+
+
+/* Search libthread_db_search_path for libthread_db which "agrees"
+ to work on current inferior. */
+
+static int
+thread_db_load_search (void)
+{
+ char path[PATH_MAX];
+ const char *search_path = libthread_db_search_path;
+ int rc = 0;
+
+ while (*search_path)
+ {
+ const char *end = strchr (search_path, ':');
+ if (end)
+ {
+ size_t len = end - search_path;
+ if (len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path))
+ {
+ char *cp = xmalloc (len + 1);
+ memcpy (cp, search_path, len);
+ cp[len] = '\0';
+ warning (_("libthread_db_search_path component too long,"
+ " ignored: %s."), cp);
+ xfree (cp);
+ search_path += len + 1;
+ continue;
+ }
+ memcpy (path, search_path, len);
+ path[len] = '\0';
+ search_path += len + 1;
+ }
+ else
+ {
+ size_t len = strlen (search_path);
+
+ if (len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path))
+ {
+ warning (_("libthread_db_search_path component too long,"
+ " ignored: %s."), search_path);
+ break;
+ }
+ memcpy (path, search_path, len + 1);
+ search_path += len;
+ }
+ strcat (path, "/");
+ strcat (path, LIBTHREAD_DB_SO);
+ if (try_thread_db_load (path))
+ {
+ rc = 1;
+ break;
+ }
+ }
+ if (rc == 0)
+ rc = try_thread_db_load (LIBTHREAD_DB_SO);
+ return rc;
+}
+
+/* Attempt to load and initialize libthread_db.
+ Return 1 on success.
+ */
+
+static int
+thread_db_load (void)
+{
+ struct objfile *obj;
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (GET_PID (inferior_ptid));
+
+ if (info != NULL)
+ return 1;
+
+ /* 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 0;
+
+ /* Don't attempt to use thread_db for remote targets. */
+ if (!target_can_run (¤t_target))
+ return 0;
+
+ if (thread_db_load_search ())
+ return 1;
+
+ /* None of the libthread_db's on our search path, not the system default
+ ones worked. If the executable is dynamically linked against
+ libpthread, try loading libthread_db from the same directory. */
+
+ ALL_OBJFILES (obj)
+ if (libpthread_name_p (obj->name))
+ {
+ char path[PATH_MAX], *cp;
+
+ gdb_assert (strlen (obj->name) < sizeof (path));
+ strcpy (path, obj->name);
+ cp = strrchr (path, '/');
+
+ if (cp == NULL)
+ {
+ warning (_("Expected absolute pathname for libpthread in the"
+ " inferior, but got %s."), path);
+ }
+ else if (cp + 1 + strlen (LIBTHREAD_DB_SO) + 1 > path + sizeof (path))
+ {
+ warning (_("Unexpected: path to libpthread in the inferior is"
+ " too long: %s"), path);
+ }
+ else
+ {
+ strcpy (cp + 1, LIBTHREAD_DB_SO);
+ if (try_thread_db_load (path))
+ return 1;
+ }
+ 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 (void)
{
td_thr_events_t events;
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (GET_PID (inferior_ptid));
/* 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);
+ info->td_ta_set_event_p (info->thread_agent, &events);
/* Delete 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;
}
static void
check_for_thread_db (void)
{
td_err_e err;
- static int already_loaded;
-
- /* 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. */
-
- if (!already_loaded)
- {
- Dl_info info;
- const char *library = NULL;
- if (dladdr ((*td_ta_new_p), &info) != 0)
- library = info.dli_fname;
-
- /* Try dlinfo? */
-
- if (library == NULL)
- /* Paranoid - don't let a NULL path slip through. */
- library = LIBTHREAD_DB_SO;
+ static void *last_loaded;
- 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. */
+ /* Do nothing if we couldn't load libthread_db.so.1. */
+ if (!thread_db_load ())
return;
-
- /* 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;
-
- /* Don't attempt to use thread_db for remote targets. */
- if (!target_can_run (¤t_target))
- return;
-
- /* Initialize the structure that identifies the child process. */
- proc_handle.pid = GET_PID (inferior_ptid);
-
- /* Now attempt to open a connection to the thread library. */
- err = td_ta_new_p (&proc_handle, &thread_agent);
- switch (err)
- {
- case TD_NOLIBTHREAD:
- /* No thread library was detected. */
- break;
-
- case TD_OK:
- printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
-
- /* The thread library was detected. Activate the thread_db target. */
- push_target (&thread_db_ops);
- using_thread_db = 1;
-
- enable_thread_event_reporting ();
- thread_db_find_new_threads ();
- break;
-
- default:
- warning (_("Cannot initialize thread debugging library: %s"),
- thread_db_err_str (err));
- break;
- }
}
static void
thread_db_new_objfile (struct objfile *objfile)
{
+ /* This observer must always be called with inferior_ptid set
+ correctly. */
+
if (objfile != NULL)
check_for_thread_db ();
-
- if (target_new_objfile_chain)
- target_new_objfile_chain (objfile);
}
/* Attach to a new thread. This function is called when we receive a
static void
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 thread_info *tp;
+ struct private_thread_info *private;
+ struct thread_info *tp = NULL;
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 and attach to the new one. */
if (in_thread_list (ptid))
{
- tp = find_thread_pid (ptid);
+ tp = find_thread_ptid (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;
- delete_thread (ptid);
+ delete_thread (ptid);
+ tp = NULL;
+ }
}
check_thread_signals ();
- /* 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));
-
- if (verbose)
- printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid));
-
if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
return; /* A zombie thread -- do not attach. */
/* Under GNU/Linux, we have to attach to each and every thread. */
-#ifdef ATTACH_LWP
- ATTACH_LWP (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)), 0);
-#endif
+ if (tp == NULL
+ && lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid))) < 0)
+ return;
- /* 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));
-static void
-thread_db_attach (char *args, int from_tty)
-{
- target_beneath->to_attach (args, from_tty);
+ /* 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;
- /* Destroy thread info; it's no longer valid. */
- init_thread_list ();
+ /* Add the thread to GDB's thread list. */
+ if (tp == NULL)
+ tp = add_thread_with_info (ptid, private);
+ else
+ tp->private = private;
- /* The child process is now the actual multi-threaded
- program. Snatch its process ID... */
- proc_handle.pid = GET_PID (inferior_ptid);
+ info = get_thread_db_info (GET_PID (ptid));
- /* ...and perform the remaining initialization steps. */
- enable_thread_event_reporting ();
- thread_db_find_new_threads ();
+ /* Enable thread event reporting for this thread. */
+ 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));
}
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)
-{
- disable_thread_event_reporting ();
-
- /* 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);
-
- /* 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)
+thread_db_detach (struct target_ops *ops, char *args, int from_tty)
{
- /* 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. */
+ struct target_ops *target_beneath = find_target_beneath (ops);
+ struct thread_db_info *info;
- thread->private->th_valid = 0;
- thread->private->ti_valid = 0;
+ info = get_thread_db_info (GET_PID (inferior_ptid));
- return 0;
-}
+ if (info)
+ {
+ disable_thread_event_reporting ();
-static void
-thread_db_resume (ptid_t ptid, int step, enum target_signal signo)
-{
- struct cleanup *old_chain = save_inferior_ptid ();
+ /* 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 (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 (GET_PID (ptid));
/* Bail out early if we're not at a thread event breakpoint. */
- stop_pc = read_pc_pid (ptid) - DECR_PC_AFTER_BREAK;
- if (stop_pc != td_create_bp_addr && stop_pc != td_death_bp_addr)
+ stop_pc = regcache_read_pc (regcache)
+ - gdbarch_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 (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 (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)
{
+ /* Breakpoints have already been marked non-inserted by the
+ layer below. We're safe in knowing that removing them will
+ not write the shadows of the old image into the new
+ image. */
remove_thread_event_breakpoints ();
- unpush_target (&thread_db_ops);
- using_thread_db = 0;
- return pid_to_ptid (GET_PID (ptid));
+ /* New image, it may or may not end up using thread_db. Assume
+ not unless we find otherwise. */
+ delete_thread_db_info (GET_PID (ptid));
+ if (!thread_db_list)
+ unpush_target (&thread_db_ops);
+
+ 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)
/* 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 LONGEST
-thread_db_xfer_partial (struct target_ops *ops, enum target_object object,
- const char *annex, gdb_byte *readbuf,
- const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
-{
- struct cleanup *old_chain = save_inferior_ptid ();
- LONGEST xfer;
-
- if (is_thread (inferior_ptid))
+ if (have_threads (ptid))
{
- /* FIXME: This seems to be necessary to make sure breakpoints
- are removed. */
- if (!target_thread_alive (inferior_ptid))
- inferior_ptid = pid_to_ptid (GET_PID (inferior_ptid));
- else
- inferior_ptid = lwp_from_thread (inferior_ptid);
+ /* Change ptids 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;
}
- xfer = target_beneath->to_xfer_partial (ops, object, annex,
- readbuf, writebuf, offset, len);
-
- do_cleanups (old_chain);
- return xfer;
-}
-
-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)
- {
- /* 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 ();
- }
+ 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 (GET_PID (inferior_ptid));
- /* Delete the old thread event breakpoints. Do this after mourning
- the inferior, so that we don't try to uninsert them. */
+ /* Delete the old thread event breakpoints. Mark breakpoints out,
+ so that we don't try to un-insert them. */
+ mark_breakpoints_out ();
remove_thread_event_breakpoints ();
+ target_beneath->to_mourn_inferior (target_beneath);
+
/* Detach thread_db target ops. */
- unpush_target (&thread_db_ops);
- using_thread_db = 0;
+ if (!thread_db_list)
+ unpush_target (ops);
}
static int
td_thrinfo_t ti;
td_err_e err;
ptid_t ptid;
+ struct thread_info *tp;
+ struct thread_db_info *info = data;
- 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. */
- ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, ti.ti_tid);
+ 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 (!in_thread_list (ptid))
- attach_thread (ptid, th_p, &ti, 1);
+ 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);
+ 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->private == NULL)
+ attach_thread (ptid, th_p, &ti);
return 0;
}
+/* Search for new threads, accessing memory through stopped thread
+ PTID. */
+
static void
-thread_db_find_new_threads (void)
+thread_db_find_new_threads_1 (ptid_t ptid)
{
td_err_e err;
+ struct lwp_info *lp;
+ struct thread_db_info *info;
+ int pid = ptid_get_pid (ptid);
+
+ /* In linux, we can only read memory through a stopped lwp. */
+ ALL_LWPS (lp, ptid)
+ if (lp->stopped && ptid_get_pid (lp->ptid) == pid)
+ break;
+
+ if (!lp)
+ /* There is no stopped thread. Bail out. */
+ return;
+
+ info = get_thread_db_info (GET_PID (ptid));
+ /* Access an lwp we know is stopped. */
+ info->proc_handle.ptid = ptid;
/* 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);
+ err = info->td_ta_thr_iter_p (info->thread_agent, find_new_threads_callback,
+ info, 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 (struct target_ops *ops)
+{
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (GET_PID (inferior_ptid));
+
+ if (info == NULL)
+ return;
+
+ thread_db_find_new_threads_1 (inferior_ptid);
+}
+
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 %ld (LWP %ld) (Missing)",
- GET_THREAD (ptid), GET_LWP (ptid));
- else
- snprintf (buf, sizeof (buf), "Thread %ld (LWP %ld)",
- GET_THREAD (ptid), GET_LWP (ptid));
+ tid = thread_info->private->tid;
+ snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
+ tid, 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);
}
static char *
thread_db_extra_thread_info (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))
+ 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);
+
+ /* Find the matching thread. */
+ thread_info = find_thread_ptid (ptid);
+
+ if (thread_info != NULL && thread_info->private != NULL)
{
td_err_e err;
void *address;
- struct thread_info *thread_info;
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (GET_PID (ptid));
/* glibc doesn't provide the needed interface. */
- if (!td_thr_tls_get_addr_p)
+ if (!info->td_thr_tls_get_addr_p)
throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR,
_("No TLS library support"));
/* Caller should have verified that lm != 0. */
gdb_assert (lm != 0);
- /* Get info about the thread. */
- thread_info = find_thread_pid (ptid);
- thread_db_map_id2thr (thread_info, 1);
-
/* Finally, get the address of the variable. */
- err = td_thr_tls_get_addr_p (&thread_info->private->th,
- (void *)(size_t) lm,
- offset, &address);
+ err = info->td_thr_tls_get_addr_p (&thread_info->private->th,
+ (void *)(size_t) lm,
+ offset, &address);
#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);
+ if (beneath->to_get_thread_local_address)
+ return beneath->to_get_thread_local_address (beneath, ptid, lm, offset);
else
throw_error (TLS_GENERIC_ERROR,
_("TLS not supported on this target"));
}
+/* 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 (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 target_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 (GET_PID (inferior_ptid));
+ else
+ info = get_thread_db_info (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);
+}
+
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_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_xfer_partial = thread_db_xfer_partial;
- 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;
}
+/* 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. */
- target_new_objfile_chain = deprecated_target_new_objfile_hook;
- deprecated_target_new_objfile_hook = thread_db_new_objfile;
- }
+ init_thread_db_ops ();
+ add_target (&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."),
+ NULL,
+ NULL,
+ &setlist, &showlist);
+ /* Add ourselves to objfile event chain. */
+ observer_attach_new_objfile (thread_db_new_objfile);
}
projects / binutils.git / blobdiff