/* 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) 1999-2017 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"
+#include <algorithm>
/* GNU/Linux libthread_db support.
created, thread IDs (usually, the result of pthread_self), and
thread-local variables.
- The libthread_db interface originates on Solaris, where it is
- both more powerful and more complicated. This implementation
- only works for LinuxThreads and NPTL, the two glibc threading
- libraries. It assumes that each thread is permanently assigned
- to a single light-weight process (LWP).
+ The libthread_db interface originates on Solaris, where it is both
+ more powerful and more complicated. This implementation only works
+ for NPTL, the glibc threading library. It assumes that each thread
+ is permanently assigned to a single light-weight process (LWP). At
+ some point it also supported the older LinuxThreads library, but it
+ no longer does.
libthread_db-specific information is stored in the "private" field
of struct thread_info. When the field is NULL we do not yet have
static char *libthread_db_search_path;
+/* Set to non-zero if thread_db auto-loading is enabled
+ by the "set auto-load libthread-db" command. */
+static int auto_load_thread_db = 1;
+
+/* "show" command for the auto_load_thread_db configuration variable. */
+
+static void
+show_auto_load_thread_db (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Auto-loading of inferior specific libthread_db "
+ "is %s.\n"),
+ value);
+}
+
static void
set_libthread_db_search_path (char *ignored, int from_tty,
struct cmd_list_element *c)
/* If 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;
be able to ignore such stale entries. */
int need_stale_parent_threads_check;
- /* Location of the thread creation event breakpoint. The code at
- this location in the child process will be called by the pthread
- library whenever a new thread is created. By setting a special
- breakpoint at this location, GDB can detect when a new thread is
- created. We obtain this location via the td_ta_event_addr
- call. */
- CORE_ADDR td_create_bp_addr;
-
- /* Location of the thread death event breakpoint. */
- CORE_ADDR td_death_bp_addr;
-
/* Pointers to the libthread_db functions. */
- td_err_e (*td_init_p) (void);
-
- td_err_e (*td_ta_new_p) (struct ps_prochandle * ps,
- td_thragent_t **ta);
- 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_thr_get_info_ftype *td_thr_get_info_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
xfree (info);
}
-/* Prototypes for local functions. */
-static int attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
- const td_thrinfo_t *ti_p);
-static void detach_thread (ptid_t ptid);
-\f
-
/* Use "struct private_thread_info" to cache thread state. This is
a substantial optimization. */
};
\f
-static char *
+static const char *
thread_db_err_str (td_err_e err)
{
static char buf[64];
return buf;
}
}
-\f
-/* Return 1 if any threads have been registered. There may be none if
- the threading library is not fully initialized yet. */
-
-static int
-have_threads_callback (struct thread_info *thread, void *args)
-{
- int pid = * (int *) args;
- if (ptid_get_pid (thread->ptid) != pid)
- return 0;
-
- return thread->private != NULL;
-}
-
-static int
-have_threads (ptid_t ptid)
-{
- int pid = ptid_get_pid (ptid);
-
- return iterate_over_threads (have_threads_callback, &pid) != NULL;
-}
-
-struct thread_get_info_inout
-{
- struct thread_info *thread_info;
- struct thread_db_info *thread_db_info;
-};
-
-/* A callback function for td_ta_thr_iter, which we use to map all
- threads to LWPs.
-
- 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));
+/* Fetch the user-level thread id of PTID. */
- /* 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. */
-
-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);
+ thread_from_lwp (child);
- /* 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);
-
- 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;
}
return sym;
}
-static td_err_e
-enable_thread_event (int event, CORE_ADDR *bp)
-{
- td_notify_t notify;
- td_err_e err;
- struct thread_db_info *info;
-
- info = get_thread_db_info (GET_PID (inferior_ptid));
-
- /* Access an lwp we know is stopped. */
- info->proc_handle.ptid = inferior_ptid;
-
- /* Get the breakpoint address for thread EVENT. */
- err = info->td_ta_event_addr_p (info->thread_agent, event, ¬ify);
- if (err != TD_OK)
- return err;
-
- /* Set up the breakpoint. */
- gdb_assert (exec_bfd);
- (*bp) = (gdbarch_convert_from_func_ptr_addr
- (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);
-
- 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 void
-enable_thread_event_reporting (void)
+static int
+inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min)
{
- 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));
-
- /* We cannot use the thread event reporting facility if these
- functions aren't available. */
- if (info->td_ta_event_addr_p == NULL
- || info->td_ta_set_event_p == NULL
- || info->td_ta_event_getmsg_p == NULL
- || info->td_thr_event_enable_p == NULL)
- return;
+ struct bound_minimal_symbol version_msym;
+ CORE_ADDR version_addr;
+ char *version;
+ int err, got, retval = 0;
- /* Set the process wide mask saying which events we're interested in. */
- td_event_emptyset (&events);
- td_event_addset (&events, TD_CREATE);
-
-#ifdef HAVE_GNU_LIBC_VERSION_H
- /* The event reporting facility is broken for TD_DEATH events in
- glibc 2.1.3, so don't enable it if we have glibc but a lower
- version. */
- libc_version = gnu_get_libc_version ();
- if (sscanf (libc_version, "%d.%d", &libc_major, &libc_minor) == 2
- && (libc_major > 2 || (libc_major == 2 && libc_minor > 1)))
-#endif
- td_event_addset (&events, TD_DEATH);
+ version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL);
+ if (version_msym.minsym == NULL)
+ return 0;
- err = info->td_ta_set_event_p (info->thread_agent, &events);
- if (err != TD_OK)
+ 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])
{
- warning (_("Unable to set global thread event mask: %s"),
- thread_db_err_str (err));
- return;
- }
-
- /* Delete previous thread event breakpoints, if any. */
- remove_thread_event_breakpoints ();
- info->td_create_bp_addr = 0;
- info->td_death_bp_addr = 0;
+ int major, minor;
- /* Set up the thread creation event. */
- err = enable_thread_event (TD_CREATE, &info->td_create_bp_addr);
- if (err != TD_OK)
- {
- warning (_("Unable to get location for thread creation breakpoint: %s"),
- thread_db_err_str (err));
- return;
+ retval = (sscanf (version, "%d.%d", &major, &minor) == 2
+ && (major < ver_major_min
+ || (major == ver_major_min && minor < ver_minor_min)));
}
+ xfree (version);
- /* Set up the thread death event. */
- err = enable_thread_event (TD_DEATH, &info->td_death_bp_addr);
- if (err != TD_OK)
- {
- warning (_("Unable to get location for thread death breakpoint: %s"),
- thread_db_err_str (err));
- return;
- }
+ return retval;
}
-/* 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;
+ /* These are essential. */
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_map_lwp2thr));
+ 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_thr_tls_get_addr);
+ TDB_DLSYM (info, td_thr_tlsbase);
+
+ /* 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)))
+ info->td_ta_thr_iter_p = NULL;
+ else
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_thr_iter));
+
+#undef TDB_VERBOSE_DLSYM
+#undef TDB_DLSYM
+#undef CHK
- info->td_ta_thr_iter_p = verbose_dlsym (info->handle, "td_ta_thr_iter");
if (info->td_ta_thr_iter_p == NULL)
- return 0;
+ {
+ 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
if (thread_db_list->next == NULL)
push_target (&thread_db_ops);
- /* Enable event reporting, but not when debugging a core file. */
- if (target_has_execution)
- enable_thread_event_reporting ();
-
- /* There appears to be a bug in glibc-2.3.6: calls to td_thr_get_info fail
- with TD_ERR for statically linked executables if td_thr_get_info is
- called before glibc has initialized itself. Silently ignore such
- errors, and let gdb enumerate threads again later. */
- thread_db_find_new_threads_silently (inferior_ptid);
-
return 1;
}
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).release ();
+
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)
{
- char path[PATH_MAX], *cp;
-
- gdb_assert (strlen (obj->name) < sizeof (path));
- strcpy (path, obj->name);
- cp = strrchr (path, '/');
+ struct cleanup *cleanup;
+ char *path, *cp;
+ int result;
+ const char *obj_name = objfile_name (obj);
+ int alloc_len;
- if (cp == NULL)
+ if (obj_name[0] != '/')
{
warning (_("Expected absolute pathname for libpthread in the"
- " inferior, but got %s."), path);
- return 0;
- }
- else if (cp + 1 + strlen (LIBTHREAD_DB_SO) + 1 > path + sizeof (path))
- {
- warning (_("Unexpected: path to libpthread in the inferior is"
- " too long: %s"), path);
+ " inferior, but got %s."), obj_name);
return 0;
}
- else
+
+ 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);
+ cp = strrchr (path, '/');
+ /* This should at minimum hit the first character. */
+ gdb_assert (cp != NULL);
+ cp[1] = '\0';
+ if (subdir != NULL)
{
- strcpy (cp + 1, LIBTHREAD_DB_SO);
- return try_thread_db_load (path);
+ 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.
static int
try_thread_db_load_from_dir (const char *dir, size_t dir_len)
{
- char path[PATH_MAX];
+ struct cleanup *cleanup;
+ char *path;
+ int result;
- if (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1 > sizeof (path))
- {
- char *cp = xmalloc (dir_len + 1);
+ if (!auto_load_thread_db)
+ return 0;
- memcpy (cp, dir, dir_len);
- cp[dir_len] = '\0';
- warning (_("libthread-db-search-path component too long,"
- " ignored: %s."), cp);
- xfree (cp);
- 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);
- return try_thread_db_load (path);
+
+ result = try_thread_db_load (path, 1);
+
+ do_cleanups (cleanup);
+ return result;
}
/* Search libthread_db_search_path for libthread_db which "agrees"
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;
+
+ dir_vec = dirnames_to_char_ptr_vec (libthread_db_search_path);
+ cleanups = make_cleanup_free_char_ptr_vec (dir_vec);
- while (*search_path)
+ 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;
return 0;
}
-static void
-disable_thread_event_reporting (struct thread_db_info *info)
-{
- if (info->td_ta_clear_event_p != NULL)
- {
- td_thr_events_t events;
-
- /* Set the process wide mask saying we aren't interested in any
- events anymore. */
- td_event_fillset (&events);
- info->td_ta_clear_event_p (info->thread_agent, &events);
- }
-
- info->td_create_bp_addr = 0;
- info->td_death_bp_addr = 0;
-}
-
static void
check_thread_signals (void)
{
{
if (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 ();
}
-/* 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. */
-
-static int
-attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
- const td_thrinfo_t *ti_p)
+static void
+check_pid_namespace_match (void)
{
- struct private_thread_info *private;
- struct thread_info *tp = NULL;
- td_err_e err;
- struct thread_db_info *info;
-
- /* If we're being called after a TD_CREATE event, we may already
- know about this thread. There are two ways this can happen. We
- may have iterated over all threads between the thread creation
- and the TD_CREATE event, for instance when the user has issued
- the `info threads' command before the SIGTRAP for hitting the
- thread creation breakpoint was reported. Alternatively, the
- thread may have exited and a new one been created with the same
- 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))
+ /* Check is only relevant for local targets targets. */
+ if (target_can_run (¤t_target))
{
- tp = find_thread_ptid (ptid);
- gdb_assert (tp != NULL);
-
- /* If tp->private is NULL, then GDB is already attached to this
- thread, but we do not know anything about it. We can learn
- about it here. This can only happen if we have some other
- 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 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))
{
- if (!tp->private->dying)
- return 0;
-
- delete_thread (ptid);
- tp = NULL;
+ warning (_ ("Target and debugger are in different PID "
+ "namespaces; thread lists and other data are "
+ "likely unreliable. "
+ "Connect to gdbserver inside the container."));
}
}
+}
- if (target_has_execution)
- check_thread_signals ();
+/* This function is called via the inferior_created observer.
+ This handles the case of debugging statically linked executables. */
- if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
- return 0; /* A zombie thread -- do not attach. */
+static void
+thread_db_inferior_created (struct target_ops *target, int from_tty)
+{
+ check_pid_namespace_match ();
+ check_for_thread_db ();
+}
- /* 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;
+/* Update the thread's state (what's displayed in "info threads"),
+ from libthread_db thread state information. */
- /* 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;
+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);
+}
- info = get_thread_db_info (GET_PID (ptid));
+/* 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. */
- /* Enable thread event reporting for this thread, except when
- debugging a core file. */
- if (target_has_execution)
- {
- err = info->td_thr_event_enable_p (th_p, 1);
- if (err != TD_OK)
- error (_("Cannot enable thread event reporting for %s: %s"),
- target_pid_to_str (ptid), thread_db_err_str (err));
- }
+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)
+{
+ struct private_thread_info *priv;
- return 1;
-}
+ /* 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;
-static void
-detach_thread (ptid_t ptid)
-{
- struct thread_info *thread_info;
+ /* Construct the thread's private data. */
+ priv = XCNEW (struct private_thread_info);
- /* Don't delete the thread now, because it still reports as active
- until it has executed a few instructions after the event
- breakpoint - if we deleted it now, "info threads" would cause us
- to re-attach to it. Just mark it as having had a TD_DEATH
- event. This means that we won't delete it from our thread list
- until we notice that it's dead (via prune_threads), or until
- something re-uses its thread ID. 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;
+ 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;
+
+ if (target_has_execution)
+ check_thread_signals ();
+
+ return tp;
}
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)
- {
- disable_thread_event_reporting (info);
-
- /* Delete the old thread event breakpoints. Note that
- unlike when mourning, we can remove them here because
- there's still a live inferior to poke at. In any case,
- GDB will not try to insert anything in the inferior when
- removing a breakpoint. */
- remove_thread_event_breakpoints ();
- }
-
- delete_thread_db_info (GET_PID (inferior_ptid));
- }
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
target_beneath->to_detach (target_beneath, args, from_tty);
unpush_target (&thread_db_ops);
}
-/* Check if PID is currently stopped at the location of a thread event
- breakpoint location. If it is, read the event message and act upon
- the event. */
-
-static void
-check_event (ptid_t ptid)
-{
- struct regcache *regcache = get_thread_regcache (ptid);
- struct gdbarch *gdbarch = get_regcache_arch (regcache);
- td_event_msg_t msg;
- td_thrinfo_t ti;
- td_err_e err;
- CORE_ADDR stop_pc;
- int loop = 0;
- struct thread_db_info *info;
-
- info = get_thread_db_info (GET_PID (ptid));
-
- /* Bail out early if we're not at a thread event breakpoint. */
- stop_pc = regcache_read_pc (regcache)
- - gdbarch_decr_pc_after_break (gdbarch);
- if (stop_pc != info->td_create_bp_addr
- && stop_pc != info->td_death_bp_addr)
- return;
-
- /* Access an lwp we know is stopped. */
- info->proc_handle.ptid = ptid;
-
- /* If we have only looked at the first thread before libpthread was
- initialized, we may not know its thread ID yet. Make sure we do
- before we add another thread to the list. */
- if (!have_threads (ptid))
- thread_db_find_new_threads_1 (ptid);
-
- /* If we are at a create breakpoint, we do not know what new lwp
- was created and cannot specifically locate the event message for it.
- We have to call td_ta_event_getmsg() to get
- the latest message. Since we have no way of correlating whether
- the event message we get back corresponds to our breakpoint, we must
- loop and read all event messages, processing them appropriately.
- This guarantees we will process the correct message before continuing
- from the breakpoint.
-
- Currently, death events are not enabled. If they are enabled,
- the death event can use the td_thr_event_getmsg() interface to
- get the message specifically for that lwp and avoid looping
- below. */
-
- loop = 1;
-
- do
- {
- err = info->td_ta_event_getmsg_p (info->thread_agent, &msg);
- if (err != TD_OK)
- {
- if (err == TD_NOMSG)
- return;
-
- error (_("Cannot get thread event message: %s"),
- thread_db_err_str (err));
- }
-
- err = info->td_thr_get_info_p (msg.th_p, &ti);
- if (err != TD_OK)
- error (_("Cannot get thread info: %s"), thread_db_err_str (err));
-
- ptid = ptid_build (GET_PID (ptid), ti.ti_lid, 0);
-
- switch (msg.event)
- {
- case TD_CREATE:
- /* Call attach_thread whether or not we already know about a
- thread with this thread ID. */
- attach_thread (ptid, msg.th_p, &ti);
-
- break;
-
- case TD_DEATH:
-
- if (!in_thread_list (ptid))
- error (_("Spurious thread death event."));
-
- detach_thread (ptid);
-
- break;
-
- default:
- error (_("Spurious thread event."));
- }
- }
- while (loop);
-}
-
static ptid_t
thread_db_wait (struct target_ops *ops,
ptid_t ptid, struct target_waitstatus *ourstatus,
ptid = beneath->to_wait (beneath, ptid, ourstatus, options);
- if (ourstatus->kind == TARGET_WAITKIND_IGNORE)
- return ptid;
-
- if (ourstatus->kind == TARGET_WAITKIND_EXITED
- || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
- return ptid;
+ switch (ourstatus->kind)
+ {
+ case TARGET_WAITKIND_IGNORE:
+ case TARGET_WAITKIND_EXITED:
+ case TARGET_WAITKIND_THREAD_EXITED:
+ case 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);
- /* Thread event breakpoints are deleted by
- update_breakpoints_after_exec. */
-
return ptid;
}
- /* If we do not know about the main thread yet, this would be a good time to
- find it. */
- if (ourstatus->kind == TARGET_WAITKIND_STOPPED && !have_threads (ptid))
- thread_db_find_new_threads_1 (ptid);
-
- if (ourstatus->kind == TARGET_WAITKIND_STOPPED
- && ourstatus->value.sig == TARGET_SIGNAL_TRAP)
- /* 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);
- /* Delete the old thread event breakpoints. Do this after mourning
- the inferior, so that we don't try to uninsert them. */
- remove_thread_event_breakpoints ();
-
/* Detach thread_db target ops. */
if (!thread_db_list)
unpush_target (ops);
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)
{
/* A thread ID of zero means that this is the main thread, but
glibc has not yet initialized thread-local storage and the
pthread library. We do not know what the thread's TID will
- be yet. Just enable event reporting and otherwise ignore
- it. */
+ be yet. */
/* In that case, we're not stopped in a fork syscall and don't
need this glibc bug workaround. */
info->need_stale_parent_threads_check = 0;
- if (target_has_execution)
- {
- err = info->td_thr_event_enable_p (th_p, 1);
- if (err != TD_OK)
- error (_("Cannot enable thread event reporting for LWP %d: %s"),
- (int) ti.ti_lid, thread_db_err_str (err));
- }
-
return 0;
}
ptid = ptid_build (info->pid, ti.ti_lid, 0);
tp = find_thread_ptid (ptid);
- if (tp == NULL || tp->private == NULL)
- {
- if (attach_thread (ptid, th_p, &ti))
- cb_data->new_threads += 1;
- else
- /* Problem attaching this thread; perhaps it exited before we
- could attach it?
- This could mean that the thread list inside glibc itself is in
- inconsistent state, and libthread_db could go on looping forever
- (observed with glibc-2.3.6). To prevent that, terminate
- iteration: thread_db_find_new_threads_2 will retry. */
- return 1;
- }
+ if (tp == NULL || tp->priv == NULL)
+ record_thread (info, tp, ptid, th_p, &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 (info->td_ta_thr_iter_p != NULL);
+
+ 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
thread_db_find_new_threads_2 (ptid, 0);
}
-static int
-update_thread_core (struct lwp_info *info, void *closure)
-{
- info->core = linux_nat_core_of_thread_1 (info->ptid);
- return 0;
-}
+/* Implement the to_update_thread_list target method for this
+ target. */
static void
-thread_db_find_new_threads (struct target_ops *ops)
+thread_db_update_thread_list (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;
-
- thread_db_find_new_threads_1 (inferior_ptid);
+ 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;
+
+ /* 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, we
+ instead 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_1 (thread->ptid))
+ continue;
+
+ thread_db_find_new_threads_1 (thread->ptid);
+ }
- if (target_has_execution)
- iterate_over_lwps (minus_one_ptid /* iterate over all */,
- update_thread_core, NULL);
+ /* Give the beneath target a chance to do extra processing. */
+ ops->beneath->to_update_thread_list (ops->beneath);
}
-static char *
+static const char *
thread_db_pid_to_str (struct target_ops *ops, ptid_t ptid)
{
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)
+static const char *
+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 = std::max (max_filename_len,
+ strlen (array[i]->filename));
+
+ if (i > 0)
+ {
+ pids_len -= strlen (", ");
+ max_pids_len = std::max (max_pids_len, pids_len);
+ }
+ pids_len = 0;
+ }
+ pids_len += this_pid_len + strlen (", ");
+ }
+ if (i)
+ {
+ pids_len -= strlen (", ");
+ max_pids_len = std::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)
+ uiout->text ("\n");
+
+ {
+ ui_out_emit_table table_emitter (uiout, 2, unique_filenames,
+ "LinuxThreadDbTable");
+
+ uiout->table_header (max_filename_len, ui_left, "filename", "Filename");
+ uiout->table_header (pids_len, ui_left, "PIDs", "Pids");
+ uiout->table_body ();
+
+ 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;)
+ {
+ ui_out_emit_tuple tuple_emitter (uiout, NULL);
+ char *pids_end;
+
+ info = array[i];
+ uiout->field_string ("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';
+
+ uiout->field_string ("pids", pids);
+
+ uiout->text ("\n");
+ }
+ }
+
+ do_cleanups (back_to);
+
+ if (info_count == 0)
+ uiout->message (_("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
- executable -- there could be mutiple versions of glibc,
- compiled with LinuxThreads or NPTL, and until there is
- a running inferior, we can't tell which libthread_db is
- the correct one to load. */
+ executable -- there could be multiple versions of glibc,
+ and until there is a running inferior, we can't tell which
+ libthread_db is the correct one to load. */
libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
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