/* libthread_db assisted debugging support, generic parts.
- Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008
- Free Software Foundation, Inc.
+ Copyright (C) 1999-2001, 2003-2012 Free Software Foundation, Inc.
This file is part of GDB.
#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 "linux-procfs.h"
+#include "linux-osdata.h"
+#include "auto-load.h"
#include <signal.h>
+#include <ctype.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.
libthread_db is a library, provided along with libpthread.so, which
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 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;
-/* 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_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);
+};
+
+/* 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);
+static void thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new);
+
+/* 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)
+{
+ 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;
+}
+
+/* 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 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);
+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
the threading library is not fully initialized yet. */
static int
-have_threads_callback (struct thread_info *thread, void *dummy)
+have_threads_callback (struct thread_info *thread, void *args)
{
- return 1;
+ int pid = * (int *) args;
+
+ if (ptid_get_pid (thread->ptid) != pid)
+ return 0;
+
+ return thread->private != NULL;
}
static int
-have_threads (void)
+have_threads (ptid_t ptid)
{
- return iterate_over_threads (have_threads_callback, NULL) != NULL;
+ 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;
- err = td_thr_get_info_p (thp, &ti);
+ inout = argp;
+ info = inout->thread_db_info;
+
+ 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, 0);
- 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;
- 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);
- 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);
}
- if (infop != NULL)
- *(struct thread_info **) infop = thread_info;
-
return 0;
}
\f
{
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;
/* This ptid comes from linux-nat.c, which should always fill in the
LWP. */
gdb_assert (GET_LWP (ptid) != 0);
- err = td_ta_map_lwp2thr_p (thread_agent, GET_LWP (ptid), &th);
+ info = get_thread_db_info (GET_PID (ptid));
+
+ /* 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);
+ 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;
gdb_assert (ptid_get_tid (ptid) == 0);
return ptid;
}
\f
-void
-thread_db_init (struct target_ops *target)
+/* 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)
{
- 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)
-{
- 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;
-
- 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 (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, 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;
}
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 (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
- td_event_addset (&events, TD_DEATH);
+#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
+ td_event_addset (&events, TD_DEATH);
+
+ err = info->td_ta_set_event_p (info->thread_agent, &events);
+ if (err != TD_OK)
+ {
+ warning (_("Unable to set global thread event mask: %s"),
+ thread_db_err_str (err));
+ return;
+ }
+
+ /* Delete previous thread event breakpoints, if any. */
+ remove_thread_event_breakpoints ();
+ info->td_create_bp_addr = 0;
+ info->td_death_bp_addr = 0;
+
+ /* Set up the thread creation event. */
+ 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"),
+ thread_db_err_str (err));
+ return;
+ }
+
+ /* Set up the thread death event. */
+ 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"),
+ thread_db_err_str (err));
+ return;
+ }
+}
+
+/* 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_2 (ptid, 1);
+ }
+
+ if (except.reason < 0 && libthread_db_debug)
+ {
+ 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 INFO.
+ Return 1 on success.
+ Failure could happen if libthread_db does not have symbols we expect,
+ or when it refuses to work with the current inferior (e.g. due to
+ version mismatch between libthread_db and libpthread). */
+
+static int
+try_thread_db_load_1 (struct thread_db_info *info)
+{
+ td_err_e err;
+
+ /* Initialize pointers to the dynamic library functions we will use.
+ Essential functions first. */
+
+ 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 (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");
+
+ 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)
+ 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 event reporting, but not when debugging a core file. */
+ if (target_has_execution)
+ 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 (libthread_db_debug)
+ printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
+ library);
+ 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 (GET_PID (inferior_ptid));
+ return 0;
+}
+
+/* Subroutine of try_thread_db_load_from_pdir to simplify it.
+ Try loading libthread_db from the same directory as OBJ.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_pdir_1 (struct objfile *obj)
+{
+ struct cleanup *cleanup;
+ char *path, *cp;
+ int result;
+
+ 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) + 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);
+ strcpy (cp + 1, LIBTHREAD_DB_SO);
+
+ if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db "
+ "library \"%s\" from $pdir.\n"),
+ path))
+ result = 0;
+ else
+ result = try_thread_db_load (path);
+
+ do_cleanups (cleanup);
+ return result;
+}
+
+/* Handle $pdir in libthread-db-search-path.
+ Look for libthread_db in the directory of libpthread.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_pdir (void)
+{
+ struct objfile *obj;
+
+ if (!auto_load_thread_db)
+ return 0;
+
+ ALL_OBJFILES (obj)
+ if (libpthread_name_p (obj->name))
+ {
+ if (try_thread_db_load_from_pdir_1 (obj))
+ 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);
+
+ return 0;
+ }
+
+ return 0;
+}
+
+/* Handle $sdir in libthread-db-search-path.
+ Look for libthread_db in the system dirs, or wherever a plain
+ dlopen(file_without_path) will look.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_sdir (void)
+{
+ return try_thread_db_load (LIBTHREAD_DB_SO);
+}
+
+/* Try to load libthread_db from directory DIR of length DIR_LEN.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_dir (const char *dir, size_t dir_len)
+{
+ struct cleanup *cleanup;
+ char *path;
+ int result;
+
+ if (!auto_load_thread_db)
+ return 0;
+
+ path = xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
+ cleanup = make_cleanup (xfree, path);
+
+ memcpy (path, dir, dir_len);
+ path[dir_len] = '/';
+ strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
+
+ if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db "
+ "library \"%s\" from explicit "
+ "directory.\n"),
+ path))
+ result = 0;
+ else
+ result = try_thread_db_load (path);
+
+ do_cleanups (cleanup);
+ return result;
+}
+
+/* Search libthread_db_search_path for libthread_db which "agrees"
+ to work on current inferior.
+ The result is true for success. */
+
+static int
+thread_db_load_search (void)
+{
+ const char *search_path = libthread_db_search_path;
+ int rc = 0;
+
+ while (*search_path)
+ {
+ const char *end = strchr (search_path, ':');
+ const char *this_dir = search_path;
+ size_t this_dir_len;
+
+ if (end)
+ {
+ this_dir_len = end - search_path;
+ search_path += this_dir_len + 1;
+ }
+ else
+ {
+ this_dir_len = strlen (this_dir);
+ search_path += this_dir_len;
+ }
+
+ if (this_dir_len == sizeof ("$pdir") - 1
+ && strncmp (this_dir, "$pdir", this_dir_len) == 0)
+ {
+ if (try_thread_db_load_from_pdir ())
+ {
+ rc = 1;
+ break;
+ }
+ }
+ else if (this_dir_len == sizeof ("$sdir") - 1
+ && strncmp (this_dir, "$sdir", this_dir_len) == 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;
+ }
+ }
+ }
+
+ 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 (obj->name))
+ 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 (GET_PID (inferior_ptid));
- err = td_ta_set_event_p (thread_agent, &events);
- if (err != TD_OK)
- {
- warning (_("Unable to set global thread event mask: %s"),
- thread_db_err_str (err));
- return;
- }
+ if (info != NULL)
+ return 1;
- /* Delete previous thread event breakpoints, if any. */
- remove_thread_event_breakpoints ();
- td_create_bp_addr = 0;
- td_death_bp_addr = 0;
+ /* Don't attempt to use thread_db on executables not running
+ yet. */
+ if (!target_has_registers)
+ return 0;
- /* Set up the thread creation event. */
- err = enable_thread_event (thread_agent, TD_CREATE, &td_create_bp_addr);
- if (err != TD_OK)
- {
- warning (_("Unable to get location for thread creation breakpoint: %s"),
- thread_db_err_str (err));
- return;
- }
+ /* Don't attempt to use thread_db for remote targets. */
+ if (!(target_can_run (¤t_target) || core_bfd))
+ return 0;
- /* Set up the thread death event. */
- err = enable_thread_event (thread_agent, TD_DEATH, &td_death_bp_addr);
- if (err != TD_OK)
+ if (thread_db_load_search ())
+ return 1;
+
+ /* We couldn't find a libthread_db.
+ If the inferior has a libpthread warn the user. */
+ if (has_libpthread ())
{
- warning (_("Unable to get location for thread death breakpoint: %s"),
- thread_db_err_str (err));
- return;
+ 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)
+disable_thread_event_reporting (struct thread_db_info *info)
{
- td_thr_events_t events;
+ 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_emptyset (&events);
- td_ta_set_event_p (thread_agent, &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);
+ }
- /* 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_thread_signals (void)
{
-#ifdef GET_THREAD_SIGNALS
if (!thread_signals)
{
sigset_t mask;
int i;
- GET_THREAD_SIGNALS (&mask);
+ lin_thread_get_thread_signals (&mask);
sigemptyset (&thread_stop_set);
sigemptyset (&thread_print_set);
{
if (sigismember (&mask, i))
{
- if (signal_stop_update (target_signal_from_host (i), 0))
+ if (signal_stop_update (gdb_signal_from_host (i), 0))
sigaddset (&thread_stop_set, i);
- if (signal_print_update (target_signal_from_host (i), 0))
+ if (signal_print_update (gdb_signal_from_host (i), 0))
sigaddset (&thread_print_set, i);
thread_signals = 1;
}
}
}
-#endif
}
/* Check whether thread_db is usable. This function is called when
void
check_for_thread_db (void)
{
- 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;
-
- /* 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;
-
- if (info_verbose)
- 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;
-
- /* 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))
+ if (!thread_db_load ())
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;
- }
}
+/* 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
+ /* 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)))
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)
{
struct private_thread_info *private;
- struct thread_info *tp = NULL;
+ 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 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
if (tp->private != NULL)
{
if (!tp->private->dying)
- return;
+ return 0;
delete_thread (ptid);
tp = NULL;
}
}
- check_thread_signals ();
+ if (target_has_execution)
+ 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. */
+ return 0; /* A zombie thread -- do not attach. */
/* Under GNU/Linux, we have to attach to each and every thread. */
- if (tp == NULL
- && lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid))) < 0)
- return;
+ if (target_has_execution
+ && tp == NULL)
+ {
+ int res;
+
+ res = lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)));
+ if (res < 0)
+ {
+ /* Error, stop iterating. */
+ return 0;
+ }
+ else if (res > 0)
+ {
+ /* Pretend this thread doesn't exist yet, and keep
+ iterating. */
+ return 1;
+ }
+
+ /* Otherwise, we sucessfully attached to the thread. */
+ }
/* Construct the thread's private data. */
private = xmalloc (sizeof (struct private_thread_info));
/* Add the thread to GDB's thread list. */
if (tp == NULL)
- tp = add_thread_with_info (ptid, private);
+ add_thread_with_info (ptid, private);
else
tp->private = private;
- /* 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));
+ info = get_thread_db_info (GET_PID (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));
+ }
+
+ return 1;
}
static void
until we notice that it's dead (via prune_threads), or until
something re-uses its thread ID. We'll report the thread exit
when the underlying LWP dies. */
- thread_info = find_thread_pid (ptid);
+ 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, char *args, int from_tty)
{
- disable_thread_event_reporting ();
+ struct target_ops *target_beneath = find_target_beneath (ops);
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (GET_PID (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 ();
+ }
+
+ delete_thread_db_info (GET_PID (inferior_ptid));
+ }
+
+ target_beneath->to_detach (target_beneath, args, from_tty);
- target_beneath->to_detach (args, from_tty);
+ /* NOTE: From this point on, inferior_ptid is null_ptid. */
- /* Should this be done by detach_command? */
- target_mourn_inferior ();
+ /* 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) - 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)
+ - 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));
}
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;
+ struct thread_db_info *info;
+ struct target_ops *beneath = find_target_beneath (ops);
+
+ ptid = beneath->to_wait (beneath, ptid, ourstatus, options);
- ptid = target_beneath->to_wait (ptid, ourstatus);
+ 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)
{
- 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 (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 ())
- thread_db_find_new_threads ();
+ 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 (have_threads ())
+ if (have_threads (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
event gets postponed by other simultaneous events. In such a
case, we want to just ignore the event and continue on. */
- if (!ptid_equal (trap_ptid, null_ptid))
- trap_ptid = thread_from_lwp (trap_ptid);
-
ptid = thread_from_lwp (ptid);
if (GET_PID (ptid) == -1)
ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
}
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));
+
+ 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. */
- ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, 0);
-
if (ti.ti_tid == 0)
{
/* A thread ID of zero means that this is the main thread, but
be yet. Just enable event reporting and otherwise ignore
it. */
- 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));
+ /* 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;
}
- if (!in_thread_list (ptid))
- attach_thread (ptid, th_p, &ti);
+ /* 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)
+ {
+ 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;
+ struct thread_db_info *info;
+ int pid = ptid_get_pid (ptid);
+ int i, loop;
- /* 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));
+ info = get_thread_db_info (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; ++i, ++loop)
+ if (find_new_threads_once (info, i, NULL) != 0)
+ /* Found some new threads. Restart the loop from beginning. */
+ loop = -1;
+ }
+ else
+ {
+ find_new_threads_once (info, 0, &err);
+ if (err != TD_OK)
+ error (_("Cannot find new threads: %s"), thread_db_err_str (err));
+ }
+}
+
+static void
+thread_db_find_new_threads_1 (ptid_t ptid)
+{
+ thread_db_find_new_threads_2 (ptid, 0);
+}
+
+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)
{
- struct thread_info *thread_info = find_thread_pid (ptid);
+ struct thread_info *thread_info = find_thread_ptid (ptid);
+ struct target_ops *beneath;
if (thread_info != NULL && thread_info->private != NULL)
{
thread_t tid;
tid = thread_info->private->tid;
- thread_info = find_thread_pid (ptid);
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);
}
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)
{
struct thread_info *thread_info;
+ struct target_ops *beneath;
/* If we have not discovered any threads yet, check now. */
- if (!have_threads ())
- thread_db_find_new_threads ();
+ if (!have_threads (ptid))
+ thread_db_find_new_threads_1 (ptid);
/* Find the matching thread. */
- thread_info = find_thread_pid (ptid);
+ thread_info = find_thread_ptid (ptid);
if (thread_info != NULL && thread_info->private != NULL)
{
td_err_e err;
- void *address;
+ psaddr_t address;
+ 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"));
gdb_assert (lm != 0);
/* Finally, get the address of the variable. */
- err = td_thr_tls_get_addr_p (&thread_info->private->th,
- (void *)(size_t) lm,
- offset, &address);
+ /* 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);
#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 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 (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);
+}
+
+/* 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;
+
+ while (isspace (*cs))
+ 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
init_thread_db_ops (void)
{
thread_db_ops.to_doc = "Threads and pthreads support.";
thread_db_ops.to_detach = thread_db_detach;
thread_db_ops.to_wait = thread_db_wait;
+ thread_db_ops.to_resume = thread_db_resume;
thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior;
thread_db_ops.to_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. */
- observer_attach_new_objfile (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.\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_zinteger_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 / thirdparty / binutils-gdb.git / blobdiff