/* libthread_db assisted debugging support, generic parts.
- Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
- 2010, 2011 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 "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>
-
-#ifdef HAVE_GNU_LIBC_VERSION_H
-#include <gnu/libc-version.h>
-#endif
+#include <ctype.h>
+#include "nat/linux-namespaces.h"
/* GNU/Linux libthread_db support.
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;
+
+/* 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
+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 non-zero, print details of libthread_db processing. */
-static int libthread_db_debug;
+static unsigned int libthread_db_debug;
static void
show_libthread_db_debug (struct ui_file *file, int from_tty,
/* Handle from dlopen for libthread_db.so. */
void *handle;
+ /* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
+ HANDLE. It may be NULL for system library. */
+ char *filename;
+
/* Structure that identifies the child process for the
<proc_service.h> interface. */
struct ps_prochandle proc_handle;
/* 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 (info->handle != NULL)
dlclose (info->handle);
+ xfree (info->filename);
+
if (info_prev)
info_prev->next = info->next;
else
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);
-
- /* 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)
- return TD_THR_ZOMBIE;
-
- 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
-/* Convert between user-level thread ids and LWP ids. */
+/* Fetch the user-level thread id of PTID. */
-static ptid_t
+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));
-
- /* Fetch the thread info. If we get back TD_THR_ZOMBIE, then the
- event thread has already died. If another gdb interface has called
- thread_alive() previously, the thread won't be found on the thread list
- anymore. In that case, we don't want to process this ptid anymore
- to avoid the possibility of later treating it as a newly
- discovered thread id that we should add to the list. Thus,
- we return a -1 ptid which is also how the thread list marks a
- dead thread. */
- 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;
+ ptid_get_lwp (ptid), thread_db_err_str (err));
+
+ 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;
/* Set up the breakpoint. */
gdb_assert (exec_bfd);
(*bp) = (gdbarch_convert_from_func_ptr_addr
- (target_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 (target_gdbarch, *bp);
+ create_thread_event_breakpoint (target_gdbarch (), *bp);
return TD_OK;
}
+/* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
+ return 1 if this version is lower (and not equal) to
+ VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
+
+static int
+inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min)
+{
+ struct bound_minimal_symbol version_msym;
+ CORE_ADDR version_addr;
+ char *version;
+ int err, got, retval = 0;
+
+ version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL);
+ if (version_msym.minsym == NULL)
+ return 0;
+
+ version_addr = BMSYMBOL_VALUE_ADDRESS (version_msym);
+ got = target_read_string (version_addr, &version, 32, &err);
+ if (err == 0 && memchr (version, 0, got) == &version[got -1])
+ {
+ int major, minor;
+
+ retval = (sscanf (version, "%d.%d", &major, &minor) == 2
+ && (major < ver_major_min
+ || (major == ver_major_min && minor < ver_minor_min)));
+ }
+ xfree (version);
+
+ return retval;
+}
+
static void
enable_thread_event_reporting (void)
{
td_thr_events_t events;
td_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));
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
/* We cannot use the thread event reporting facility if these
functions aren't available. */
td_event_emptyset (&events);
td_event_addset (&events, TD_CREATE);
-#ifdef HAVE_GNU_LIBC_VERSION_H
- /* The event reporting facility is broken for TD_DEATH events in
- glibc 2.1.3, so don't enable it if we have glibc but a lower
- version. */
- libc_version = gnu_get_libc_version ();
- if (sscanf (libc_version, "%d.%d", &libc_major, &libc_minor) == 2
- && (libc_major > 2 || (libc_major == 2 && libc_minor > 1)))
-#endif
+ /* There is a bug fixed between linuxthreads 2.1.3 and 2.2 by
+ commit 2e4581e4fba917f1779cd0a010a45698586c190a
+ * manager.c (pthread_exited): Correctly report event as TD_REAP
+ instead of TD_DEATH. Fix comments.
+ where event reporting facility is broken for TD_DEATH events,
+ so don't enable it if we have glibc but a lower version. */
+ if (!inferior_has_bug ("__linuxthreads_version", 2, 2))
td_event_addset (&events, TD_DEATH);
err = info->td_ta_set_event_p (info->thread_agent, &events);
}
}
-/* Same as thread_db_find_new_threads_1, but silently ignore errors. */
+/* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
+ if appropriate.
-static void
+ Return 1 if the caller should abort libthread_db initialization. Return 0
+ otherwise. */
+
+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 && libthread_db_debug)
+ CATCH (except, RETURN_MASK_ERROR)
{
- exception_fprintf (gdb_stderr, except,
- "Warning: thread_db_find_new_threads_silently: ");
+ if (libthread_db_debug)
+ exception_fprintf (gdb_stdlog, except,
+ "Warning: thread_db_find_new_threads_silently: ");
+
+ /* There is a bug fixed between nptl 2.6.1 and 2.7 by
+ commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
+ where calls to td_thr_get_info fail with TD_ERR for statically linked
+ executables if td_thr_get_info is called before glibc has initialized
+ itself.
+
+ If the nptl bug is NOT present in the inferior and still thread_db
+ reports an error return 1. It means the inferior has corrupted thread
+ list and GDB should fall back only to LWPs.
+
+ If the nptl bug is present in the inferior return 0 to silently ignore
+ such errors, and let gdb enumerate threads again later. In such case
+ GDB cannot properly display LWPs if the inferior thread list is
+ corrupted. For core files it does not apply, no 'later enumeration'
+ is possible. */
+
+ if (!target_has_execution || !inferior_has_bug ("nptl_version", 2, 7))
+ {
+ exception_fprintf (gdb_stderr, except,
+ _("Warning: couldn't activate thread debugging "
+ "using libthread_db: "));
+ return 1;
+ }
}
+ END_CATCH
+
+ return 0;
}
/* Lookup a library in which given symbol resides.
/* 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;
-
- 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 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_thr_iter_p = verbose_dlsym (info->handle, "td_ta_thr_iter");
- if (info->td_ta_thr_iter_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_thr_validate_p = verbose_dlsym (info->handle, "td_thr_validate");
- if (info->td_thr_validate_p == NULL)
- return 0;
+ linux_stop_and_wait_all_lwps ();
- info->td_thr_get_info_p = verbose_dlsym (info->handle, "td_thr_get_info");
- if (info->td_thr_get_info_p == NULL)
- return 0;
+ ALL_LWPS (lp)
+ if (ptid_get_pid (lp->ptid) == pid)
+ thread_from_lwp (lp->ptid);
- /* 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");
+ linux_unstop_all_lwps ();
+ }
+ else if (thread_db_find_new_threads_silently (inferior_ptid) != 0)
+ {
+ /* Even if libthread_db initializes, if the thread list is
+ corrupted, we'd not manage to list any threads. Better reject this
+ thread_db, and fall back to at least listing LWPs. */
+ return 0;
+ }
printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
- if (libthread_db_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);
+ library = dladdr_to_soname ((const void *) *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 ();
- /* 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;
}
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);
}
}
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));
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
return 0;
}
/* Subroutine of try_thread_db_load_from_pdir to simplify it.
- Try loading libthread_db from the same directory as OBJ.
+ Try loading libthread_db in directory(OBJ)/SUBDIR.
+ SUBDIR may be NULL. It may also be something like "../lib64".
The result is true for success. */
static int
-try_thread_db_load_from_pdir_1 (struct objfile *obj)
+try_thread_db_load_from_pdir_1 (struct objfile *obj, const char *subdir)
{
struct cleanup *cleanup;
char *path, *cp;
int result;
+ const char *obj_name = objfile_name (obj);
+ int alloc_len;
- if (obj->name[0] != '/')
+ 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) + 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);
- strcpy (cp + 1, LIBTHREAD_DB_SO);
- result = try_thread_db_load (path);
+ cp[1] = '\0';
+ if (subdir != NULL)
+ {
+ strcat (cp, subdir);
+ strcat (cp, "/");
+ }
+ strcat (cp, LIBTHREAD_DB_SO);
+
+ result = try_thread_db_load (path, 1);
do_cleanups (cleanup);
return result;
}
/* Handle $pdir in libthread-db-search-path.
- Look for libthread_db in the directory of libpthread.
+ Look for libthread_db in directory(libpthread)/SUBDIR.
+ SUBDIR may be NULL. It may also be something like "../lib64".
The result is true for success. */
static int
-try_thread_db_load_from_pdir (void)
+try_thread_db_load_from_pdir (const char *subdir)
{
struct objfile *obj;
+ if (!auto_load_thread_db)
+ return 0;
+
ALL_OBJFILES (obj)
- if (libpthread_name_p (obj->name))
+ if (libpthread_name_p (objfile_name (obj)))
{
- if (try_thread_db_load_from_pdir_1 (obj))
+ if (try_thread_db_load_from_pdir_1 (obj, subdir))
return 1;
/* We may have found the separate-debug-info version of
libpthread, and it may live in a directory without a matching
libthread_db. */
if (obj->separate_debug_objfile_backlink != NULL)
- return try_thread_db_load_from_pdir_1 (obj->separate_debug_objfile_backlink);
+ return try_thread_db_load_from_pdir_1 (obj->separate_debug_objfile_backlink,
+ subdir);
return 0;
}
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.
char *path;
int result;
- path = xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
+ if (!auto_load_thread_db)
+ return 0;
+
+ path = (char *) xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1);
cleanup = make_cleanup (xfree, path);
memcpy (path, dir, dir_len);
path[dir_len] = '/';
strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
- result = try_thread_db_load (path);
+
+ result = try_thread_db_load (path, 1);
do_cleanups (cleanup);
return result;
static int
thread_db_load_search (void)
{
- const char *search_path = libthread_db_search_path;
- int rc = 0;
+ VEC (char_ptr) *dir_vec;
+ struct cleanup *cleanups;
+ char *this_dir;
+ int i, rc = 0;
- while (*search_path)
+ dir_vec = dirnames_to_char_ptr_vec (libthread_db_search_path);
+ cleanups = make_cleanup_free_char_ptr_vec (dir_vec);
+
+ for (i = 0; VEC_iterate (char_ptr, dir_vec, i, this_dir); ++i)
{
- const char *end = strchr (search_path, ':');
- const char *this_dir = search_path;
+ const int pdir_len = sizeof ("$pdir") - 1;
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;
- }
+ this_dir_len = strlen (this_dir);
- if (this_dir_len == sizeof ("$pdir") - 1
- && strncmp (this_dir, "$pdir", this_dir_len) == 0)
+ if (strncmp (this_dir, "$pdir", pdir_len) == 0
+ && (this_dir[pdir_len] == '\0'
+ || this_dir[pdir_len] == '/'))
{
- if (try_thread_db_load_from_pdir ())
+ char *subdir = NULL;
+ struct cleanup *free_subdir_cleanup
+ = make_cleanup (null_cleanup, NULL);
+
+ if (this_dir[pdir_len] == '/')
{
- rc = 1;
- break;
+ subdir = (char *) xmalloc (strlen (this_dir));
+ make_cleanup (xfree, subdir);
+ strcpy (subdir, this_dir + pdir_len + 1);
}
+ rc = try_thread_db_load_from_pdir (subdir);
+ do_cleanups (free_subdir_cleanup);
+ if (rc)
+ break;
}
- else if (this_dir_len == sizeof ("$sdir") - 1
- && strncmp (this_dir, "$sdir", this_dir_len) == 0)
+ else if (strcmp (this_dir, "$sdir") == 0)
{
if (try_thread_db_load_from_sdir ())
{
}
}
+ 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;
{
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;
}
return;
}
+/* This function is called via the new_objfile observer. */
+
static void
thread_db_new_objfile (struct objfile *objfile)
{
/* This observer must always be called with inferior_ptid set
correctly. */
- if (objfile != NULL)
+ if (objfile != NULL
+ /* libpthread with separate debug info has its debug info file already
+ loaded (and notified without successful thread_db initialization)
+ the time observer_notify_new_objfile is called for the library itself.
+ Static executables have their separate debug info loaded already
+ before the inferior has started. */
+ && objfile->separate_debug_objfile_backlink == NULL
+ /* Only check for thread_db if we loaded libpthread,
+ or if this is the main symbol file.
+ We need to check OBJF_MAINLINE to handle the case of debugging
+ a statically linked executable AND the symbol file is specified AFTER
+ the exec file is loaded (e.g., gdb -c core ; file foo).
+ For dynamically linked executables, libpthread can be near the end
+ of the list of shared libraries to load, and in an app of several
+ thousand shared libraries, this can otherwise be painful. */
+ && ((objfile->flags & OBJF_MAINLINE) != 0
+ || libpthread_name_p (objfile_name (objfile))))
check_for_thread_db ();
}
+static void
+check_pid_namespace_match (void)
+{
+ /* Check is only relevant for local targets targets. */
+ if (target_can_run (¤t_target))
+ {
+ /* If the child is in a different PID namespace, its idea of its
+ PID will differ from our idea of its PID. When we scan the
+ child's thread list, we'll mistakenly think it has no threads
+ since the thread PID fields won't match the PID we give to
+ libthread_db. */
+ if (!linux_ns_same (ptid_get_pid (inferior_ptid), LINUX_NS_PID))
+ {
+ warning (_ ("Target and debugger are in different PID "
+ "namespaces; thread lists and other data are "
+ "likely unreliable"));
+ }
+ }
+}
+
+/* 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 = NULL;
- td_err_e err;
+ struct thread_info *tp;
struct thread_db_info *info;
/* If we're being called after a TD_CREATE event, we may already
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_ptid (ptid);
- gdb_assert (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 ();
-
- if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
- return 0; /* A zombie thread -- do not attach. */
-
/* Under GNU/Linux, we have to attach to each and every thread. */
if (target_has_execution
- && tp == NULL
- && lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid))) < 0)
- return 0;
+ && tp == NULL)
+ {
+ int res;
+
+ res = lin_lwp_attach_lwp (ptid_build (ptid_get_pid (ptid),
+ ti_p->ti_lid, 0));
+ if (res < 0)
+ {
+ /* Error, stop iterating. */
+ return 0;
+ }
+ else if (res > 0)
+ {
+ /* Pretend this thread doesn't exist yet, and keep
+ iterating. */
+ return 1;
+ }
+
+ /* 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;
-
- /* 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);
- info = get_thread_db_info (GET_PID (ptid));
+ priv->th = *th_p;
+ priv->tid = ti_p->ti_tid;
+ update_thread_state (priv, ti_p);
+
+ /* Add the thread to GDB's thread list. If we already know about a
+ thread with this PTID, but it's marked exited, then the kernel
+ reused the tid of an old thread. */
+ if (tp == NULL || tp->state == THREAD_EXITED)
+ tp = add_thread_with_info (ptid, priv);
+ else
+ tp->priv = priv;
/* 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 == TARGET_SIGNAL_TRAP)
+ && ourstatus->value.sig == GDB_SIGNAL_TRAP)
/* Check for a thread event. */
check_event (ptid);
- 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
- get back a dead ptid. This can occur if the thread death
- event gets postponed by other simultaneous events. In such a
- case, we want to just ignore the event and continue on. */
-
- ptid = thread_from_lwp (ptid);
- if (GET_PID (ptid) == -1)
- ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
- }
+ /* 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_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
- return 0; /* A zombie -- ignore. */
+ 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)
{
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)
static void
thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
{
- td_err_e err;
+ td_err_e err = TD_OK;
struct thread_db_info *info;
- int pid = ptid_get_pid (ptid);
int i, loop;
- if (target_has_execution)
- {
- struct lwp_info *lp;
-
- /* In linux, we can only read memory through a stopped lwp. */
- ALL_LWPS (lp, ptid)
- if (lp->stopped && ptid_get_pid (lp->ptid) == pid)
- break;
-
- if (!lp)
- /* There is no stopped thread. Bail out. */
- return;
- }
-
- info = get_thread_db_info (GET_PID (ptid));
+ info = get_thread_db_info (ptid_get_pid (ptid));
/* Access an lwp we know is stopped. */
info->proc_handle.ptid = ptid;
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;
+ for (i = 0, loop = 0; loop < 4 && err == TD_OK; ++i, ++loop)
+ if (find_new_threads_once (info, i, &err) != 0)
+ {
+ /* Found some new threads. Restart the loop from beginning. */
+ loop = -1;
+ }
}
else
- {
- find_new_threads_once (info, 0, &err);
- if (err != TD_OK)
- error (_("Cannot find new threads: %s"), thread_db_err_str (err));
- }
+ find_new_threads_once (info, 0, &err);
+
+ if (err != TD_OK)
+ error (_("Cannot find new threads: %s"), thread_db_err_str (err));
}
static void
static int
update_thread_core (struct lwp_info *info, void *closure)
{
- info->core = linux_nat_core_of_thread_1 (info->ptid);
+ info->core = linux_common_core_of_thread (info->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;
- info = get_thread_db_info (GET_PID (inferior_ptid));
+ prune_threads ();
- if (info == NULL)
- return;
+ 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);
+ }
+}
+
+/* Implement the to_update_thread_list target method for this
+ target. */
- thread_db_find_new_threads_1 (inferior_ptid);
+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
thread_db_resume (struct target_ops *ops,
- ptid_t ptid, int step, enum target_signal signo)
+ 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));
+ 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
beneath->to_resume (beneath, ptid, step, signo);
}
+/* qsort helper function for info_auto_load_libthread_db, sort the
+ thread_db_info pointers primarily by their FILENAME and secondarily by their
+ PID, both in ascending order. */
+
+static int
+info_auto_load_libthread_db_compare (const void *ap, const void *bp)
+{
+ struct thread_db_info *a = *(struct thread_db_info **) ap;
+ struct thread_db_info *b = *(struct thread_db_info **) bp;
+ int retval;
+
+ retval = strcmp (a->filename, b->filename);
+ if (retval)
+ return retval;
+
+ return (a->pid > b->pid) - (a->pid - b->pid);
+}
+
+/* Implement 'info auto-load libthread-db'. */
+
+static void
+info_auto_load_libthread_db (char *args, int from_tty)
+{
+ struct ui_out *uiout = current_uiout;
+ const char *cs = args ? args : "";
+ struct thread_db_info *info, **array;
+ unsigned info_count, unique_filenames;
+ size_t max_filename_len, max_pids_len, pids_len;
+ struct cleanup *back_to;
+ char *pids;
+ int i;
+
+ cs = skip_spaces_const (cs);
+ if (*cs)
+ error (_("'info auto-load libthread-db' does not accept any parameters"));
+
+ info_count = 0;
+ for (info = thread_db_list; info; info = info->next)
+ if (info->filename != NULL)
+ info_count++;
+
+ array = XNEWVEC (struct thread_db_info *, info_count);
+ back_to = make_cleanup (xfree, array);
+
+ info_count = 0;
+ for (info = thread_db_list; info; info = info->next)
+ if (info->filename != NULL)
+ array[info_count++] = info;
+
+ /* Sort ARRAY by filenames and PIDs. */
+
+ qsort (array, info_count, sizeof (*array),
+ info_auto_load_libthread_db_compare);
+
+ /* Calculate the number of unique filenames (rows) and the maximum string
+ length of PIDs list for the unique filenames (columns). */
+
+ unique_filenames = 0;
+ max_filename_len = 0;
+ max_pids_len = 0;
+ pids_len = 0;
+ for (i = 0; i < info_count; i++)
+ {
+ int pid = array[i]->pid;
+ size_t this_pid_len;
+
+ for (this_pid_len = 0; pid != 0; pid /= 10)
+ this_pid_len++;
+
+ if (i == 0 || strcmp (array[i - 1]->filename, array[i]->filename) != 0)
+ {
+ unique_filenames++;
+ max_filename_len = max (max_filename_len,
+ strlen (array[i]->filename));
+
+ if (i > 0)
+ {
+ pids_len -= strlen (", ");
+ max_pids_len = max (max_pids_len, pids_len);
+ }
+ pids_len = 0;
+ }
+ pids_len += this_pid_len + strlen (", ");
+ }
+ if (i)
+ {
+ pids_len -= strlen (", ");
+ max_pids_len = max (max_pids_len, pids_len);
+ }
+
+ /* Table header shifted right by preceding "libthread-db: " would not match
+ its columns. */
+ if (info_count > 0 && args == auto_load_info_scripts_pattern_nl)
+ ui_out_text (uiout, "\n");
+
+ make_cleanup_ui_out_table_begin_end (uiout, 2, unique_filenames,
+ "LinuxThreadDbTable");
+
+ ui_out_table_header (uiout, max_filename_len, ui_left, "filename",
+ "Filename");
+ ui_out_table_header (uiout, pids_len, ui_left, "PIDs", "Pids");
+ ui_out_table_body (uiout);
+
+ pids = (char *) xmalloc (max_pids_len + 1);
+ make_cleanup (xfree, pids);
+
+ /* Note I is incremented inside the cycle, not at its end. */
+ for (i = 0; i < info_count;)
+ {
+ struct cleanup *chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
+ char *pids_end;
+
+ info = array[i];
+ ui_out_field_string (uiout, "filename", info->filename);
+ pids_end = pids;
+
+ while (i < info_count && strcmp (info->filename, array[i]->filename) == 0)
+ {
+ if (pids_end != pids)
+ {
+ *pids_end++ = ',';
+ *pids_end++ = ' ';
+ }
+ pids_end += xsnprintf (pids_end, &pids[max_pids_len + 1] - pids_end,
+ "%u", array[i]->pid);
+ gdb_assert (pids_end < &pids[max_pids_len + 1]);
+
+ i++;
+ }
+ *pids_end = '\0';
+
+ ui_out_field_string (uiout, "pids", pids);
+
+ ui_out_text (uiout, "\n");
+ do_cleanups (chain);
+ }
+
+ do_cleanups (back_to);
+
+ if (info_count == 0)
+ ui_out_message (uiout, 0, _("No auto-loaded libthread-db.\n"));
+}
+
static void
init_thread_db_ops (void)
{
thread_db_ops.to_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
NULL,
&setlist, &showlist);
- add_setshow_zinteger_cmd ("libthread-db", class_maintenance,
- &libthread_db_debug, _("\
+ add_setshow_zuinteger_cmd ("libthread-db", class_maintenance,
+ &libthread_db_debug, _("\
Set libthread-db debugging."), _("\
Show libthread-db debugging."), _("\
When non-zero, libthread-db debugging is enabled."),
- NULL,
- show_libthread_db_debug,
- &setdebuglist, &showdebuglist);
+ NULL,
+ show_libthread_db_debug,
+ &setdebuglist, &showdebuglist);
+
+ add_setshow_boolean_cmd ("libthread-db", class_support,
+ &auto_load_thread_db, _("\
+Enable or disable auto-loading of inferior specific libthread_db."), _("\
+Show whether auto-loading inferior specific libthread_db is enabled."), _("\
+If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
+locations to load libthread_db compatible with the inferior.\n\
+Standard system libthread_db still gets loaded even with this option off.\n\
+This options has security implications for untrusted inferiors."),
+ NULL, show_auto_load_thread_db,
+ auto_load_set_cmdlist_get (),
+ auto_load_show_cmdlist_get ());
+
+ add_cmd ("libthread-db", class_info, info_auto_load_libthread_db,
+ _("Print the list of loaded inferior specific libthread_db.\n\
+Usage: info auto-load libthread-db"),
+ auto_load_info_cmdlist_get ());
/* Add ourselves to objfile event chain. */
observer_attach_new_objfile (thread_db_new_objfile);
+
+ /* Add ourselves to inferior_created event chain.
+ This is needed to handle debugging statically linked programs where
+ the new_objfile observer won't get called for libpthread. */
+ observer_attach_inferior_created (thread_db_inferior_created);
}
projects / deliverable / binutils-gdb.git / blobdiff