/* libthread_db assisted debugging support, generic parts.
- Copyright (C) 1999-2013 Free Software Foundation, Inc.
+ Copyright (C) 1999-2015 Free Software Foundation, Inc.
This file is part of GDB.
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
-
-#include "gdb_assert.h"
#include <dlfcn.h>
#include "gdb_proc_service.h"
-#include "gdb_thread_db.h"
+#include "nat/gdb_thread_db.h"
#include "gdb_vecs.h"
#include "bfd.h"
#include "command.h"
-#include "exceptions.h"
#include "gdbcmd.h"
#include "gdbthread.h"
#include "inferior.h"
+#include "infrun.h"
#include "symfile.h"
#include "objfiles.h"
#include "target.h"
#include "gdbcore.h"
#include "observer.h"
#include "linux-nat.h"
-#include "linux-procfs.h"
-#include "linux-osdata.h"
+#include "nat/linux-procfs.h"
+#include "nat/linux-ptrace.h"
+#include "nat/linux-osdata.h"
#include "auto-load.h"
-
+#include "cli/cli-utils.h"
#include <signal.h>
#include <ctype.h>
+#include "nat/linux-namespaces.h"
/* GNU/Linux libthread_db support.
by the "set auto-load libthread-db" command. */
static int auto_load_thread_db = 1;
+/* Returns true if we need to use thread_db thread create/death event
+ breakpoints to learn about threads. */
+
+static int
+thread_db_use_events (void)
+{
+ /* Not necessary if the kernel supports clone events. */
+ return !linux_supports_traceclone ();
+}
+
/* "show" command for the auto_load_thread_db configuration variable. */
static void
/* 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);
- td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt,
- td_thrhandle_t *__th);
- td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta,
- lwpid_t lwpid, td_thrhandle_t *th);
- td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
- td_thr_iter_f *callback, void *cbdata_p,
- td_thr_state_e state, int ti_pri,
- sigset_t *ti_sigmask_p,
- unsigned int ti_user_flags);
- td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
- td_event_e event, td_notify_t *ptr);
- td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
- td_thr_events_t *event);
- td_err_e (*td_ta_clear_event_p) (const td_thragent_t *ta,
- td_thr_events_t *event);
- td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
- td_event_msg_t *msg);
-
- td_err_e (*td_thr_validate_p) (const td_thrhandle_t *th);
- td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
- td_thrinfo_t *infop);
- td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th,
- int event);
-
- td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
- psaddr_t map_address,
- size_t offset, psaddr_t *address);
+ td_init_ftype *td_init_p;
+ td_ta_new_ftype *td_ta_new_p;
+ td_ta_map_lwp2thr_ftype *td_ta_map_lwp2thr_p;
+ td_ta_thr_iter_ftype *td_ta_thr_iter_p;
+ td_ta_event_addr_ftype *td_ta_event_addr_p;
+ td_ta_set_event_ftype *td_ta_set_event_p;
+ td_ta_clear_event_ftype *td_ta_clear_event_p;
+ td_ta_event_getmsg_ftype * td_ta_event_getmsg_p;
+ td_thr_validate_ftype *td_thr_validate_p;
+ td_thr_get_info_ftype *td_thr_get_info_p;
+ td_thr_event_enable_ftype *td_thr_event_enable_p;
+ td_thr_tls_get_addr_ftype *td_thr_tls_get_addr_p;
+ td_thr_tlsbase_ftype *td_thr_tlsbase_p;
};
/* List of known processes using thread_db, and the required
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);
+static void check_thread_signals (void);
+
+static struct thread_info *record_thread
+ (struct thread_db_info *info, struct thread_info *tp,
+ ptid_t ptid, const td_thrhandle_t *th_p, const td_thrinfo_t *ti_p);
+
/* 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
static struct thread_db_info *
add_thread_db_info (void *handle)
{
- struct thread_db_info *info;
+ struct thread_db_info *info = XCNEW (struct thread_db_info);
- info = xcalloc (1, sizeof (*info));
info->pid = ptid_get_pid (inferior_ptid);
info->handle = handle;
if (ptid_get_pid (thread->ptid) != pid)
return 0;
- return thread->private != NULL;
+ return thread->priv != NULL;
}
static int
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.
-
- THP is a handle to the current thread; if INFOP is not NULL, the
- struct thread_info associated with this thread is returned in
- *INFOP.
-
- If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise,
- zero is returned to indicate success. */
-
-static int
-thread_get_info_callback (const td_thrhandle_t *thp, void *argp)
-{
- td_thrinfo_t ti;
- td_err_e err;
- ptid_t thread_ptid;
- struct thread_get_info_inout *inout;
- struct thread_db_info *info;
-
- 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 (info->pid, ti.ti_lid, 0);
- inout->thread_info = find_thread_ptid (thread_ptid);
-
- if (inout->thread_info == NULL)
- {
- /* New thread. Attach to it now (why wait?). */
- 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);
- }
-
- return 0;
-}
\f
/* Fetch the user-level thread id of PTID. */
-static void
+static struct thread_info *
thread_from_lwp (ptid_t ptid)
{
td_thrhandle_t th;
+ td_thrinfo_t ti;
td_err_e err;
struct thread_db_info *info;
- struct thread_get_info_inout io = {0};
+ struct thread_info *tp;
/* 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);
+ gdb_assert (ptid_get_lwp (ptid) != 0);
- info = get_thread_db_info (GET_PID (ptid));
+ info = get_thread_db_info (ptid_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);
+ err = info->td_ta_map_lwp2thr_p (info->thread_agent, ptid_get_lwp (ptid),
+ &th);
if (err != TD_OK)
error (_("Cannot find user-level thread for LWP %ld: %s"),
- GET_LWP (ptid), thread_db_err_str (err));
+ ptid_get_lwp (ptid), thread_db_err_str (err));
- /* Long-winded way of fetching the thread info. */
- io.thread_db_info = info;
- io.thread_info = NULL;
- thread_get_info_callback (&th, &io);
+ err = info->td_thr_get_info_p (&th, &ti);
+ if (err != TD_OK)
+ error (_("thread_get_info_callback: cannot get thread info: %s"),
+ thread_db_err_str (err));
+
+ /* Fill the cache. */
+ tp = find_thread_ptid (ptid);
+ return record_thread (info, tp, ptid, &th, &ti);
}
\f
-/* 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. */
+/* See linux-nat.h. */
+
int
-thread_db_attach_lwp (ptid_t ptid)
+thread_db_notice_clone (ptid_t parent, ptid_t child)
{
td_thrhandle_t th;
td_thrinfo_t ti;
td_err_e err;
struct thread_db_info *info;
- info = get_thread_db_info (GET_PID (ptid));
+ info = get_thread_db_info (ptid_get_pid (child));
if (info == NULL)
return 0;
- /* This ptid comes from linux-nat.c, which should always fill in the
- LWP. */
- gdb_assert (GET_LWP (ptid) != 0);
-
- /* 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);
+ thread_from_lwp (child);
- 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;
-
- err = info->td_thr_get_info_p (&th, &ti);
- if (err != TD_OK)
- {
- warning (_("Cannot get thread info: %s"), thread_db_err_str (err));
- return 0;
- }
-
- attach_thread (ptid, &th, &ti);
+ /* If we do not know about the main thread yet, this would be a good
+ time to find it. */
+ thread_from_lwp (parent);
return 1;
}
}
static td_err_e
-enable_thread_event (int event, CORE_ADDR *bp)
+enable_thread_event (td_event_e 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));
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
/* Access an lwp we know is stopped. */
info->proc_handle.ptid = inferior_ptid;
static int
inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min)
{
- struct minimal_symbol *version_msym;
+ struct bound_minimal_symbol version_msym;
CORE_ADDR version_addr;
char *version;
int err, got, retval = 0;
version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL);
- if (version_msym == NULL)
+ if (version_msym.minsym == NULL)
return 0;
- version_addr = SYMBOL_VALUE_ADDRESS (version_msym);
+ version_addr = BMSYMBOL_VALUE_ADDRESS (version_msym);
got = target_read_string (version_addr, &version, 32, &err);
if (err == 0 && memchr (version, 0, got) == &version[got -1])
{
td_err_e err;
struct thread_db_info *info;
- info = get_thread_db_info (GET_PID (inferior_ptid));
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
/* We cannot use the thread event reporting facility if these
functions aren't available. */
static int
thread_db_find_new_threads_silently (ptid_t ptid)
{
- volatile struct gdb_exception except;
- TRY_CATCH (except, RETURN_MASK_ERROR)
+ TRY
{
thread_db_find_new_threads_2 (ptid, 1);
}
- if (except.reason < 0)
+ CATCH (except, RETURN_MASK_ERROR)
{
if (libthread_db_debug)
- exception_fprintf (gdb_stderr, except,
+ exception_fprintf (gdb_stdlog, except,
"Warning: thread_db_find_new_threads_silently: ");
/* There is a bug fixed between nptl 2.6.1 and 2.7 by
return 1;
}
}
+ END_CATCH
+
return 0;
}
/* 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;
+#define TDB_VERBOSE_DLSYM(info, func) \
+ info->func ## _p = (func ## _ftype *) verbose_dlsym (info->handle, #func)
+
+#define TDB_DLSYM(info, func) \
+ info->func ## _p = (func ## _ftype *) dlsym (info->handle, #func)
+
+#define CHK(a) \
+ do \
+ { \
+ if ((a) == NULL) \
+ return 0; \
+ } while (0)
+
+ CHK (TDB_VERBOSE_DLSYM (info, td_init));
err = info->td_init_p ();
if (err != TD_OK)
return 0;
}
- info->td_ta_new_p = verbose_dlsym (info->handle, "td_ta_new");
- if (info->td_ta_new_p == NULL)
- return 0;
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_new));
/* Initialize the structure that identifies the child process. */
info->proc_handle.ptid = inferior_ptid;
if (err != TD_OK)
{
if (libthread_db_debug)
- printf_unfiltered (_("td_ta_new failed: %s\n"),
- thread_db_err_str (err));
+ fprintf_unfiltered (gdb_stdlog, _("td_ta_new failed: %s\n"),
+ thread_db_err_str (err));
else
switch (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;
+ /* These are essential. */
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_map_lwp2thr));
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_thr_iter));
+ CHK (TDB_VERBOSE_DLSYM (info, td_thr_validate));
+ CHK (TDB_VERBOSE_DLSYM (info, td_thr_get_info));
- info->td_ta_map_lwp2thr_p = verbose_dlsym (info->handle,
- "td_ta_map_lwp2thr");
- if (info->td_ta_map_lwp2thr_p == NULL)
- return 0;
+ /* These are not essential. */
+ TDB_DLSYM (info, td_ta_event_addr);
+ TDB_DLSYM (info, td_ta_set_event);
+ TDB_DLSYM (info, td_ta_clear_event);
+ TDB_DLSYM (info, td_ta_event_getmsg);
+ TDB_DLSYM (info, td_thr_event_enable);
+ TDB_DLSYM (info, td_thr_tls_get_addr);
+ TDB_DLSYM (info, td_thr_tlsbase);
+
+#undef TDB_VERBOSE_DLSYM
+#undef TDB_DLSYM
+#undef CHK
+
+ /* It's best to avoid td_ta_thr_iter if possible. That walks data
+ structures in the inferior's address space that may be corrupted,
+ or, if the target is running, may change while we walk them. If
+ there's execution (and /proc is mounted), then we're already
+ attached to all LWPs. Use thread_from_lwp, which uses
+ td_ta_map_lwp2thr instead, which does not walk the thread list.
+
+ td_ta_map_lwp2thr uses ps_get_thread_area, but we can't use that
+ currently on core targets, as it uses ptrace directly. */
+ if (target_has_execution
+ && linux_proc_task_list_dir_exists (ptid_get_pid (inferior_ptid)))
+ {
+ struct lwp_info *lp;
+ int pid = ptid_get_pid (inferior_ptid);
- info->td_ta_thr_iter_p = verbose_dlsym (info->handle, "td_ta_thr_iter");
- if (info->td_ta_thr_iter_p == NULL)
- return 0;
+ linux_stop_and_wait_all_lwps ();
- info->td_thr_validate_p = verbose_dlsym (info->handle, "td_thr_validate");
- if (info->td_thr_validate_p == NULL)
- return 0;
+ ALL_LWPS (lp)
+ if (ptid_get_pid (lp->ptid) == pid)
+ thread_from_lwp (lp->ptid);
- 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");
-
- if (thread_db_find_new_threads_silently (inferior_ptid) != 0)
+ linux_unstop_all_lwps ();
+ }
+ else if (thread_db_find_new_threads_silently (inferior_ptid) != 0)
{
/* Even if libthread_db initializes, if the thread list is
corrupted, we'd not manage to list any threads. Better reject this
printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
- if (libthread_db_debug || *libthread_db_search_path)
+ if (*libthread_db_search_path || libthread_db_debug)
{
+ struct ui_file *file;
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);
+ /* If we'd print this to gdb_stdout when debug output is
+ disabled, still print it to gdb_stdout if debug output is
+ enabled. User visible output should not depend on debug
+ settings. */
+ file = *libthread_db_search_path != '\0' ? gdb_stdout : gdb_stdlog;
+ fprintf_unfiltered (file, _("Using host libthread_db library \"%s\".\n"),
+ library);
}
/* The thread library was detected. Activate the thread_db target
push_target (&thread_db_ops);
/* Enable event reporting, but not when debugging a core file. */
- if (target_has_execution)
+ if (target_has_execution && thread_db_use_events ())
enable_thread_event_reporting ();
return 1;
relative, or just LIBTHREAD_DB. */
static int
-try_thread_db_load (const char *library)
+try_thread_db_load (const char *library, int check_auto_load_safe)
{
void *handle;
struct thread_db_info *info;
if (libthread_db_debug)
- printf_unfiltered (_("Trying host libthread_db library: %s.\n"),
- library);
+ fprintf_unfiltered (gdb_stdlog,
+ _("Trying host libthread_db library: %s.\n"),
+ library);
+
+ if (check_auto_load_safe)
+ {
+ if (access (library, R_OK) != 0)
+ {
+ /* Do not print warnings by file_is_auto_load_safe if the library does
+ not exist at this place. */
+ if (libthread_db_debug)
+ fprintf_unfiltered (gdb_stdlog, _("open failed: %s.\n"),
+ safe_strerror (errno));
+ return 0;
+ }
+
+ if (!file_is_auto_load_safe (library, _("auto-load: Loading libthread-db "
+ "library \"%s\" from explicit "
+ "directory.\n"),
+ library))
+ return 0;
+ }
+
handle = dlopen (library, RTLD_NOW);
if (handle == NULL)
{
if (libthread_db_debug)
- printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ());
+ fprintf_unfiltered (gdb_stdlog, _("dlopen failed: %s.\n"), dlerror ());
return 0;
}
const char *const libpath = dladdr_to_soname (td_init);
if (libpath != NULL)
- printf_unfiltered (_("Host %s resolved to: %s.\n"),
+ fprintf_unfiltered (gdb_stdlog, _("Host %s resolved to: %s.\n"),
library, libpath);
}
}
return 1;
/* This library "refused" to work on current inferior. */
- delete_thread_db_info (GET_PID (inferior_ptid));
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
return 0;
}
struct cleanup *cleanup;
char *path, *cp;
int result;
+ const char *obj_name = objfile_name (obj);
+ int alloc_len;
- if (obj->name[0] != '/')
+ if (obj_name[0] != '/')
{
warning (_("Expected absolute pathname for libpthread in the"
- " inferior, but got %s."), obj->name);
+ " inferior, but got %s."), obj_name);
return 0;
}
- path = xmalloc (strlen (obj->name) + (subdir ? strlen (subdir) + 1 : 0)
- + 1 + strlen (LIBTHREAD_DB_SO) + 1);
+ alloc_len = (strlen (obj_name)
+ + (subdir ? strlen (subdir) + 1 : 0)
+ + 1 + strlen (LIBTHREAD_DB_SO) + 1);
+ path = (char *) xmalloc (alloc_len);
cleanup = make_cleanup (xfree, path);
- strcpy (path, obj->name);
+ strcpy (path, obj_name);
cp = strrchr (path, '/');
/* This should at minimum hit the first character. */
gdb_assert (cp != NULL);
}
strcat (cp, 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);
+ result = try_thread_db_load (path, 1);
do_cleanups (cleanup);
return result;
return 0;
ALL_OBJFILES (obj)
- if (libpthread_name_p (obj->name))
+ if (libpthread_name_p (objfile_name (obj)))
{
if (try_thread_db_load_from_pdir_1 (obj, subdir))
return 1;
static int
try_thread_db_load_from_sdir (void)
{
- return try_thread_db_load (LIBTHREAD_DB_SO);
+ return try_thread_db_load (LIBTHREAD_DB_SO, 0);
}
/* Try to load libthread_db from directory DIR of length DIR_LEN.
if (!auto_load_thread_db)
return 0;
- path = xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
+ path = (char *) xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
cleanup = make_cleanup (xfree, path);
memcpy (path, dir, dir_len);
path[dir_len] = '/';
strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
- 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);
+ result = try_thread_db_load (path, 1);
do_cleanups (cleanup);
return result;
|| this_dir[pdir_len] == '/'))
{
char *subdir = NULL;
- struct cleanup *free_subdir_cleanup = NULL;
+ struct cleanup *free_subdir_cleanup
+ = make_cleanup (null_cleanup, NULL);
if (this_dir[pdir_len] == '/')
{
- subdir = xmalloc (strlen (this_dir));
- free_subdir_cleanup = make_cleanup (xfree, subdir);
+ subdir = (char *) xmalloc (strlen (this_dir));
+ make_cleanup (xfree, subdir);
strcpy (subdir, this_dir + pdir_len + 1);
}
rc = try_thread_db_load_from_pdir (subdir);
- if (free_subdir_cleanup != NULL)
- do_cleanups (free_subdir_cleanup);
+ do_cleanups (free_subdir_cleanup);
if (rc)
break;
}
do_cleanups (cleanups);
if (libthread_db_debug)
- printf_unfiltered (_("thread_db_load_search returning %d\n"), rc);
+ fprintf_unfiltered (gdb_stdlog,
+ _("thread_db_load_search returning %d\n"), rc);
return rc;
}
struct objfile *obj;
ALL_OBJFILES (obj)
- if (libpthread_name_p (obj->name))
+ if (libpthread_name_p (objfile_name (obj)))
return 1;
return 0;
{
struct thread_db_info *info;
- info = get_thread_db_info (GET_PID (inferior_ptid));
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
if (info != NULL)
return 1;
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)))
+ || libpthread_name_p (objfile_name (objfile))))
check_for_thread_db ();
}
+static void
+check_pid_namespace_match (void)
+{
+ /* Check is only relevant for local targets targets. */
+ if (target_can_run (¤t_target))
+ {
+ /* If the child is in a different PID namespace, its idea of its
+ PID will differ from our idea of its PID. When we scan the
+ child's thread list, we'll mistakenly think it has no threads
+ since the thread PID fields won't match the PID we give to
+ libthread_db. */
+ if (!linux_ns_same (ptid_get_pid (inferior_ptid), LINUX_NS_PID))
+ {
+ warning (_ ("Target and debugger are in different PID "
+ "namespaces; thread lists and other data are "
+ "likely unreliable"));
+ }
+ }
+}
+
/* This function is called via the inferior_created observer.
This handles the case of debugging statically linked executables. */
static void
thread_db_inferior_created (struct target_ops *target, int from_tty)
{
+ check_pid_namespace_match ();
check_for_thread_db ();
}
+/* Update the thread's state (what's displayed in "info threads"),
+ from libthread_db thread state information. */
+
+static void
+update_thread_state (struct private_thread_info *priv,
+ const td_thrinfo_t *ti_p)
+{
+ priv->dying = (ti_p->ti_state == TD_THR_UNKNOWN
+ || ti_p->ti_state == TD_THR_ZOMBIE);
+}
+
/* 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. Returns true on success. */
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;
- td_err_e err;
struct thread_db_info *info;
/* If we're being called after a TD_CREATE event, we may already
tp = find_thread_ptid (ptid);
if (tp != NULL)
{
- /* If tp->private is NULL, then GDB is already attached to this
+ /* If tp->priv 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->priv != NULL)
{
- if (!tp->private->dying)
+ if (!tp->priv->dying)
return 0;
delete_thread (ptid);
}
}
- if (target_has_execution)
- check_thread_signals ();
-
/* Under GNU/Linux, we have to attach to each and every thread. */
if (target_has_execution
&& tp == NULL)
{
int res;
- res = lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)));
+ res = lin_lwp_attach_lwp (ptid_build (ptid_get_pid (ptid),
+ ti_p->ti_lid, 0));
if (res < 0)
{
/* Error, stop iterating. */
/* Otherwise, we sucessfully attached to the thread. */
}
+ info = get_thread_db_info (ptid_get_pid (ptid));
+ record_thread (info, tp, ptid, th_p, ti_p);
+ return 1;
+}
+
+/* Record a new thread in GDB's thread list. Creates the thread's
+ private info. If TP is NULL or TP is marked as having exited,
+ creates a new thread. Otherwise, uses TP. */
+
+static struct thread_info *
+record_thread (struct thread_db_info *info,
+ struct thread_info *tp,
+ ptid_t ptid, const td_thrhandle_t *th_p,
+ const td_thrinfo_t *ti_p)
+{
+ td_err_e err;
+ struct private_thread_info *priv;
+ int new_thread = (tp == NULL);
+
+ /* A thread ID of zero may mean the thread library has not
+ initialized yet. Leave private == NULL until the thread library
+ has initialized. */
+ if (ti_p->ti_tid == 0)
+ return tp;
+
/* Construct the thread's private data. */
- private = xmalloc (sizeof (struct private_thread_info));
- memset (private, 0, sizeof (struct private_thread_info));
-
- /* A thread ID of zero may mean the thread library has not initialized
- yet. But we shouldn't even get here if that's the case. FIXME:
- if we change GDB to always have at least one thread in the thread
- list this will have to go somewhere else; maybe private == NULL
- until the thread_db target claims it. */
- gdb_assert (ti_p->ti_tid != 0);
- private->th = *th_p;
- private->tid = ti_p->ti_tid;
- if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
- private->dying = 1;
-
- /* Add the thread to GDB's thread list. */
- if (tp == NULL)
- add_thread_with_info (ptid, private);
- else
- tp->private = private;
+ priv = XCNEW (struct private_thread_info);
+
+ priv->th = *th_p;
+ priv->tid = ti_p->ti_tid;
+ update_thread_state (priv, ti_p);
- info = get_thread_db_info (GET_PID (ptid));
+ /* Add the thread to GDB's thread list. If we already know about a
+ thread with this PTID, but it's marked exited, then the kernel
+ reused the tid of an old thread. */
+ if (tp == NULL || tp->state == THREAD_EXITED)
+ tp = add_thread_with_info (ptid, priv);
+ else
+ tp->priv = priv;
/* Enable thread event reporting for this thread, except when
debugging a core file. */
- if (target_has_execution)
+ if (target_has_execution && thread_db_use_events () && new_thread)
{
err = info->td_thr_event_enable_p (th_p, 1);
if (err != TD_OK)
target_pid_to_str (ptid), thread_db_err_str (err));
}
- return 1;
+ if (target_has_execution)
+ check_thread_signals ();
+
+ return tp;
}
static void
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;
+ gdb_assert (thread_info != NULL && thread_info->priv != NULL);
+ thread_info->priv->dying = 1;
}
static void
-thread_db_detach (struct target_ops *ops, char *args, int from_tty)
+thread_db_detach (struct target_ops *ops, const char *args, int from_tty)
{
struct target_ops *target_beneath = find_target_beneath (ops);
struct thread_db_info *info;
- info = get_thread_db_info (GET_PID (inferior_ptid));
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
if (info)
{
- if (target_has_execution)
+ if (target_has_execution && thread_db_use_events ())
{
disable_thread_event_reporting (info);
remove_thread_event_breakpoints ();
}
- delete_thread_db_info (GET_PID (inferior_ptid));
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
}
target_beneath->to_detach (target_beneath, args, from_tty);
int loop = 0;
struct thread_db_info *info;
- info = get_thread_db_info (GET_PID (ptid));
+ info = get_thread_db_info (ptid_get_pid (ptid));
/* Bail out early if we're not at a thread event breakpoint. */
- stop_pc = regcache_read_pc (regcache)
- - gdbarch_decr_pc_after_break (gdbarch);
+ stop_pc = regcache_read_pc (regcache);
+ if (!target_supports_stopped_by_sw_breakpoint ())
+ stop_pc -= gdbarch_decr_pc_after_break (gdbarch);
+
if (stop_pc != info->td_create_bp_addr
&& stop_pc != info->td_death_bp_addr)
return;
if (err != TD_OK)
error (_("Cannot get thread info: %s"), thread_db_err_str (err));
- ptid = ptid_build (GET_PID (ptid), ti.ti_lid, 0);
+ ptid = ptid_build (ptid_get_pid (ptid), ti.ti_lid, 0);
switch (msg.event)
{
|| ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
return ptid;
- info = get_thread_db_info (GET_PID (ptid));
+ info = get_thread_db_info (ptid_get_pid (ptid));
/* If this process isn't using thread_db, we're done. */
if (info == NULL)
{
/* 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));
+ delete_thread_db_info (ptid_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 == GDB_SIGNAL_TRAP)
/* Check for a thread event. */
check_event (ptid);
- if (have_threads (ptid))
- {
- /* Fill in the thread's user-level thread id. */
- thread_from_lwp (ptid);
- }
+ /* Fill in the thread's user-level thread id and status. */
+ thread_from_lwp (ptid);
return ptid;
}
{
struct target_ops *target_beneath = find_target_beneath (ops);
- delete_thread_db_info (GET_PID (inferior_ptid));
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
target_beneath->to_mourn_inferior (target_beneath);
td_err_e err;
ptid_t ptid;
struct thread_info *tp;
- struct callback_data *cb_data = data;
+ struct callback_data *cb_data = (struct callback_data *) data;
struct thread_db_info *info = cb_data->info;
err = info->td_thr_get_info_p (th_p, &ti);
error (_("find_new_threads_callback: cannot get thread info: %s"),
thread_db_err_str (err));
+ if (ti.ti_lid == -1)
+ {
+ /* A thread with kernel thread ID -1 is either a thread that
+ exited and was joined, or a thread that is being created but
+ hasn't started yet, and that is reusing the tcb/stack of a
+ thread that previously exited and was joined. (glibc marks
+ terminated and joined threads with kernel thread ID -1. See
+ glibc PR17707. */
+ if (libthread_db_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "thread_db: skipping exited and "
+ "joined thread (0x%lx)\n",
+ (unsigned long) ti.ti_tid);
+ return 0;
+ }
+
if (ti.ti_tid == 0)
{
/* A thread ID of zero means that this is the main thread, but
need this glibc bug workaround. */
info->need_stale_parent_threads_check = 0;
- if (target_has_execution)
+ if (target_has_execution && thread_db_use_events ())
{
err = info->td_thr_event_enable_p (th_p, 1);
if (err != TD_OK)
ptid = ptid_build (info->pid, ti.ti_lid, 0);
tp = find_thread_ptid (ptid);
- if (tp == NULL || tp->private == NULL)
+ if (tp == NULL || tp->priv == NULL)
{
if (attach_thread (ptid, th_p, &ti))
cb_data->new_threads += 1;
iteration: thread_db_find_new_threads_2 will retry. */
return 1;
}
+ else if (target_has_execution && !thread_db_use_events ())
+ {
+ /* Need to update this if not using the libthread_db events
+ (particularly, the TD_DEATH event). */
+ update_thread_state (tp->priv, &ti);
+ }
return 0;
}
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)
+ /* See comment in thread_db_update_thread_list. */
+ gdb_assert (!target_has_execution || thread_db_use_events ());
+
+ TRY
{
/* Iterate over all user-space threads to discover new threads. */
err = info->td_ta_thr_iter_p (info->thread_agent,
TD_SIGNO_MASK,
TD_THR_ANY_USER_FLAGS);
}
+ CATCH (except, RETURN_MASK_ERROR)
+ {
+ if (libthread_db_debug)
+ {
+ exception_fprintf (gdb_stdlog, except,
+ "Warning: find_new_threads_once: ");
+ }
+ }
+ END_CATCH
if (libthread_db_debug)
{
- 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);
+ fprintf_unfiltered (gdb_stdlog,
+ _("Found %d new threads in iteration %d.\n"),
+ data.new_threads, iteration);
}
if (errp != NULL)
struct thread_db_info *info;
int i, loop;
- info = get_thread_db_info (GET_PID (ptid));
+ info = get_thread_db_info (ptid_get_pid (ptid));
/* Access an lwp we know is stopped. */
info->proc_handle.ptid = ptid;
return 0;
}
+/* Update the thread list using td_ta_thr_iter. */
+
static void
-thread_db_find_new_threads (struct target_ops *ops)
+thread_db_update_thread_list_td_ta_thr_iter (struct target_ops *ops)
{
struct thread_db_info *info;
struct inferior *inf;
+ prune_threads ();
+
ALL_INFERIORS (inf)
{
struct thread_info *thread;
thread_db_find_new_threads_1 (thread->ptid);
}
+}
+
+/* Implement the to_update_thread_list target method for this
+ target. */
+
+static void
+thread_db_update_thread_list (struct target_ops *ops)
+{
+ /* It's best to avoid td_ta_thr_iter if possible. That walks data
+ structures in the inferior's address space that may be corrupted,
+ or, if the target is running, the list may change while we walk
+ it. In the latter case, it's possible that a thread exits just
+ at the exact time that causes GDB to get stuck in an infinite
+ loop. To avoid pausing all threads whenever the core wants to
+ refresh the thread list, if the kernel supports clone events
+ (meaning we're always already attached to all LWPs), we use
+ thread_from_lwp immediately when we see an LWP stop. That uses
+ thread_db entry points that do not walk libpthread's thread list,
+ so should be safe, as well as more efficient. */
+ if (target_has_execution && !thread_db_use_events ())
+ ops->beneath->to_update_thread_list (ops->beneath);
+ else
+ thread_db_update_thread_list_td_ta_thr_iter (ops);
if (target_has_execution)
iterate_over_lwps (minus_one_ptid /* iterate over all */,
struct thread_info *thread_info = find_thread_ptid (ptid);
struct target_ops *beneath;
- if (thread_info != NULL && thread_info->private != NULL)
+ if (thread_info != NULL && thread_info->priv != NULL)
{
static char buf[64];
thread_t tid;
- tid = thread_info->private->tid;
+ tid = thread_info->priv->tid;
snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
- tid, GET_LWP (ptid));
+ (unsigned long) tid, ptid_get_lwp (ptid));
return buf;
}
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);
+ return beneath->to_pid_to_str (beneath, ptid);
}
/* Return a string describing the state of the thread specified by
INFO. */
static char *
-thread_db_extra_thread_info (struct thread_info *info)
+thread_db_extra_thread_info (struct target_ops *self,
+ struct thread_info *info)
{
- if (info->private == NULL)
+ if (info->priv == NULL)
return NULL;
- if (info->private->dying)
+ if (info->priv->dying)
return "Exiting";
return NULL;
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)
+ /* We may not have discovered the thread yet. */
+ if (thread_info != NULL && thread_info->priv == NULL)
+ thread_info = thread_from_lwp (ptid);
+
+ if (thread_info != NULL && thread_info->priv != NULL)
{
td_err_e err;
psaddr_t address;
struct thread_db_info *info;
- info = get_thread_db_info (GET_PID (ptid));
-
- /* glibc doesn't provide the needed interface. */
- if (!info->td_thr_tls_get_addr_p)
- throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR,
- _("No TLS library support"));
-
- /* Caller should have verified that lm != 0. */
- gdb_assert (lm != 0);
+ info = get_thread_db_info (ptid_get_pid (ptid));
/* Finally, get the address of the variable. */
- /* 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);
+ if (lm != 0)
+ {
+ /* glibc doesn't provide the needed interface. */
+ if (!info->td_thr_tls_get_addr_p)
+ throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR,
+ _("No TLS library support"));
+
+ /* Note the cast through uintptr_t: this interface only works if
+ a target address fits in a psaddr_t, which is a host pointer.
+ So a 32-bit debugger can not access 64-bit TLS through this. */
+ err = info->td_thr_tls_get_addr_p (&thread_info->priv->th,
+ (psaddr_t)(uintptr_t) lm,
+ offset, &address);
+ }
+ else
+ {
+ /* If glibc doesn't provide the needed interface throw an error
+ that LM is zero - normally cases it should not be. */
+ if (!info->td_thr_tlsbase_p)
+ throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR,
+ _("TLS load module not found"));
+
+ /* This code path handles the case of -static -pthread executables:
+ https://sourceware.org/ml/libc-help/2014-03/msg00024.html
+ For older GNU libc r_debug.r_map is NULL. For GNU libc after
+ PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
+ The constant number 1 depends on GNU __libc_setup_tls
+ initialization of l_tls_modid to 1. */
+ err = info->td_thr_tlsbase_p (&thread_info->priv->th,
+ 1, &address);
+ address = (char *) address + offset;
+ }
#ifdef THREAD_DB_HAS_TD_NOTALLOC
/* The memory hasn't been allocated, yet. */
}
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;
+ return beneath->to_get_thread_local_address (beneath, ptid, lm, offset);
}
/* Implement the to_get_ada_task_ptid target method for this target. */
static ptid_t
-thread_db_get_ada_task_ptid (long lwp, long thread)
+thread_db_get_ada_task_ptid (struct target_ops *self, long lwp, long thread)
{
- struct thread_info *thread_info;
-
- thread_db_find_new_threads_1 (inferior_ptid);
- thread_info = iterate_over_threads (thread_db_find_thread_from_tid, &thread);
-
- gdb_assert (thread_info != NULL);
-
- return (thread_info->ptid);
+ /* NPTL uses a 1:1 model, so the LWP id suffices. */
+ return ptid_build (ptid_get_pid (inferior_ptid), lwp, 0);
}
static void
struct thread_db_info *info;
if (ptid_equal (ptid, minus_one_ptid))
- info = get_thread_db_info (GET_PID (inferior_ptid));
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
else
- info = get_thread_db_info (GET_PID (ptid));
+ info = get_thread_db_info (ptid_get_pid (ptid));
/* This workaround is only needed for child fork lwps stopped in a
PTRACE_O_TRACEFORK event. When the inferior is resumed, the
char *pids;
int i;
- while (isspace (*cs))
- cs++;
+ cs = skip_spaces_const (cs);
if (*cs)
error (_("'info auto-load libthread-db' does not accept any parameters"));
if (info->filename != NULL)
info_count++;
- array = xmalloc (sizeof (*array) * info_count);
+ array = XNEWVEC (struct thread_db_info *, info_count);
back_to = make_cleanup (xfree, array);
info_count = 0;
ui_out_table_header (uiout, pids_len, ui_left, "PIDs", "Pids");
ui_out_table_body (uiout);
- pids = xmalloc (max_pids_len + 1);
+ pids = (char *) xmalloc (max_pids_len + 1);
make_cleanup (xfree, pids);
/* Note I is incremented inside the cycle, not at its end. */
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_update_thread_list = thread_db_update_thread_list;
thread_db_ops.to_pid_to_str = thread_db_pid_to_str;
thread_db_ops.to_stratum = thread_stratum;
thread_db_ops.to_has_thread_control = tc_schedlock;
thread_db_ops.to_extra_thread_info = thread_db_extra_thread_info;
thread_db_ops.to_get_ada_task_ptid = thread_db_get_ada_task_ptid;
thread_db_ops.to_magic = OPS_MAGIC;
+
+ complete_target_initialization (&thread_db_ops);
}
/* Provide a prototype to silence -Wmissing-prototypes. */
_initialize_thread_db (void)
{
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
projects / deliverable / binutils-gdb.git / blobdiff