/* libthread_db assisted debugging support, generic parts.
- Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009
- Free Software Foundation, Inc.
+ Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+ 2010 Free Software Foundation, Inc.
This file is part of GDB.
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);
int event);
td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
- void *map_address,
- size_t offset, void **address);
+ psaddr_t map_address,
+ size_t offset, psaddr_t *address);
};
/* List of known processes using thread_db, and the required
struct thread_db_info *thread_db_list;
static void thread_db_find_new_threads_1 (ptid_t ptid);
+static void thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new);
/* Add the current inferior to the list of processes using libpthread.
Return a pointer to the newly allocated object that was added to
}
/* Prototypes for local functions. */
-static void attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
- const td_thrinfo_t *ti_p);
+static int attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
+ const td_thrinfo_t *ti_p);
static void detach_thread (ptid_t ptid);
\f
/* Fill the cache. */
thread_ptid = ptid_build (info->pid, ti.ti_lid, 0);
- inout->thread_info = find_thread_pid (thread_ptid);
+ 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. */
thread_db_find_new_threads_1 (thread_ptid);
else
attach_thread (thread_ptid, thp, &ti);
- inout->thread_info = find_thread_pid (thread_ptid);
+ inout->thread_info = find_thread_ptid (thread_ptid);
gdb_assert (inout->thread_info != NULL);
}
/* Set up the breakpoint. */
gdb_assert (exec_bfd);
(*bp) = (gdbarch_convert_from_func_ptr_addr
- (current_gdbarch,
+ (target_gdbarch,
/* Do proper sign extension for the target. */
(bfd_get_sign_extend_vma (exec_bfd) > 0
? (CORE_ADDR) (intptr_t) notify.u.bptaddr
: (CORE_ADDR) (uintptr_t) notify.u.bptaddr),
¤t_target));
- create_thread_event_breakpoint ((*bp));
+ create_thread_event_breakpoint (target_gdbarch, *bp);
return TD_OK;
}
}
}
+/* Same as thread_db_find_new_threads_1, but silently ignore errors. */
+
+static void
+thread_db_find_new_threads_silently (ptid_t ptid)
+{
+ volatile struct gdb_exception except;
+
+ TRY_CATCH (except, RETURN_MASK_ERROR)
+ {
+ thread_db_find_new_threads_2 (ptid, 1);
+ }
+
+ if (except.reason < 0 && info_verbose)
+ {
+ exception_fprintf (gdb_stderr, except,
+ "Warning: thread_db_find_new_threads_silently: ");
+ }
+}
+
/* Lookup a library in which given symbol resides.
Note: this is looking in GDB process, not in the inferior.
Returns library name, or NULL. */
/* 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");
push_target (&thread_db_ops);
enable_thread_event_reporting ();
- thread_db_find_new_threads_1 (inferior_ptid);
+
+ /* 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;
}
}
static void
-disable_thread_event_reporting (void)
+disable_thread_event_reporting (struct thread_db_info *info)
{
- td_thr_events_t events;
- struct thread_db_info *info;
-
- info = get_thread_db_info (GET_PID (inferior_ptid));
+ if (info->td_ta_clear_event_p != NULL)
+ {
+ td_thr_events_t events;
- /* Set the process wide mask saying we aren't interested in any
- events anymore. */
- td_event_emptyset (&events);
- info->td_ta_set_event_p (info->thread_agent, &events);
+ /* Set the process wide mask saying we aren't interested in any
+ events anymore. */
+ td_event_fillset (&events);
+ info->td_ta_clear_event_p (info->thread_agent, &events);
+ }
- /* Delete thread event breakpoints, if any. */
- remove_thread_event_breakpoints ();
info->td_create_bp_addr = 0;
info->td_death_bp_addr = 0;
}
/* Attach to a new thread. This function is called when we receive a
TD_CREATE event or when we iterate over all threads and find one
- that wasn't already in our list. */
+ that wasn't already in our list. Returns true on success. */
-static void
+static int
attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
const td_thrinfo_t *ti_p)
{
thread and attach to the new one. */
if (in_thread_list (ptid))
{
- tp = find_thread_pid (ptid);
+ tp = find_thread_ptid (ptid);
gdb_assert (tp != NULL);
/* If tp->private is NULL, then GDB is already attached to this
if (tp->private != NULL)
{
if (!tp->private->dying)
- return;
+ return 0;
delete_thread (ptid);
tp = NULL;
check_thread_signals ();
if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
- return; /* A zombie thread -- do not attach. */
+ return 0; /* A zombie thread -- do not attach. */
/* Under GNU/Linux, we have to attach to each and every thread. */
if (tp == NULL
&& lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid))) < 0)
- return;
+ return 0;
/* Construct the thread's private data. */
private = xmalloc (sizeof (struct private_thread_info));
if (err != TD_OK)
error (_("Cannot enable thread event reporting for %s: %s"),
target_pid_to_str (ptid), thread_db_err_str (err));
+ return 1;
}
static void
until we notice that it's dead (via prune_threads), or until
something re-uses its thread ID. We'll report the thread exit
when the underlying LWP dies. */
- thread_info = find_thread_pid (ptid);
+ thread_info = find_thread_ptid (ptid);
gdb_assert (thread_info != NULL && thread_info->private != NULL);
thread_info->private->dying = 1;
}
if (info)
{
- disable_thread_event_reporting ();
+ 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
if (ourstatus->kind == TARGET_WAITKIND_EXECD)
{
- /* Breakpoints have already been marked non-inserted by the
- layer below. We're safe in knowing that removing them will
- not write the shadows of the old image into the new
- image. */
- remove_thread_event_breakpoints ();
-
/* New image, it may or may not end up using thread_db. Assume
not unless we find otherwise. */
delete_thread_db_info (GET_PID (ptid));
if (!thread_db_list)
unpush_target (&thread_db_ops);
+ /* Thread event breakpoints are deleted by
+ update_breakpoints_after_exec. */
+
return ptid;
}
delete_thread_db_info (GET_PID (inferior_ptid));
- /* Delete the old thread event breakpoints. Mark breakpoints out,
- so that we don't try to un-insert them. */
- mark_breakpoints_out ();
- remove_thread_event_breakpoints ();
-
target_beneath->to_mourn_inferior (target_beneath);
+ /* 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);
}
+struct callback_data
+{
+ struct thread_db_info *info;
+ int new_threads;
+};
+
static int
find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
{
td_err_e err;
ptid_t ptid;
struct thread_info *tp;
- struct thread_db_info *info = data;
+ struct callback_data *cb_data = data;
+ struct thread_db_info *info = cb_data->info;
err = info->td_thr_get_info_p (th_p, &ti);
if (err != TD_OK)
}
ptid = ptid_build (info->pid, ti.ti_lid, 0);
- tp = find_thread_pid (ptid);
+ tp = find_thread_ptid (ptid);
if (tp == NULL || tp->private == NULL)
- attach_thread (ptid, th_p, &ti);
+ {
+ if (attach_thread (ptid, th_p, &ti))
+ cb_data->new_threads += 1;
+ else
+ /* Problem attaching this thread; perhaps it exited before we
+ could attach it?
+ This could mean that the thread list inside glibc itself is in
+ inconsistent state, and libthread_db could go on looping forever
+ (observed with glibc-2.3.6). To prevent that, terminate
+ iteration: thread_db_find_new_threads_2 will retry. */
+ return 1;
+ }
return 0;
}
+/* Helper for thread_db_find_new_threads_2.
+ Returns number of new threads found. */
+
+static int
+find_new_threads_once (struct thread_db_info *info, int iteration,
+ td_err_e *errp)
+{
+ volatile struct gdb_exception except;
+ struct callback_data data;
+ td_err_e err = TD_ERR;
+
+ data.info = info;
+ data.new_threads = 0;
+
+ TRY_CATCH (except, RETURN_MASK_ERROR)
+ {
+ /* Iterate over all user-space threads to discover new threads. */
+ err = info->td_ta_thr_iter_p (info->thread_agent,
+ find_new_threads_callback,
+ &data,
+ TD_THR_ANY_STATE,
+ TD_THR_LOWEST_PRIORITY,
+ TD_SIGNO_MASK,
+ TD_THR_ANY_USER_FLAGS);
+ }
+
+ if (info_verbose)
+ {
+ if (except.reason < 0)
+ exception_fprintf (gdb_stderr, except,
+ "Warning: find_new_threads_once: ");
+
+ printf_filtered (_("Found %d new threads in iteration %d.\n"),
+ data.new_threads, iteration);
+ }
+
+ if (errp != NULL)
+ *errp = err;
+
+ return data.new_threads;
+}
+
/* Search for new threads, accessing memory through stopped thread
- PTID. */
+ PTID. If UNTIL_NO_NEW is true, repeat searching until several
+ searches in a row do not discover any new threads. */
static void
-thread_db_find_new_threads_1 (ptid_t ptid)
+thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
{
td_err_e err;
struct lwp_info *lp;
struct thread_db_info *info;
int pid = ptid_get_pid (ptid);
+ int i, loop;
/* In linux, we can only read memory through a stopped lwp. */
ALL_LWPS (lp, ptid)
/* Access an lwp we know is stopped. */
info->proc_handle.ptid = ptid;
- /* Iterate over all user-space threads to discover new threads. */
- err = info->td_ta_thr_iter_p (info->thread_agent, find_new_threads_callback,
- info, TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
- TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
- if (err != TD_OK)
- error (_("Cannot find new threads: %s"), thread_db_err_str (err));
+
+ if (until_no_new)
+ {
+ /* Require 4 successive iterations which do not find any new threads.
+ The 4 is a heuristic: there is an inherent race here, and I have
+ seen that 2 iterations in a row are not always sufficient to
+ "capture" all threads. */
+ for (i = 0, loop = 0; loop < 4; ++i, ++loop)
+ if (find_new_threads_once (info, i, NULL) != 0)
+ /* Found some new threads. Restart the loop from beginning. */
+ loop = -1;
+ }
+ else
+ {
+ td_err_e 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_1 (ptid_t ptid)
+{
+ thread_db_find_new_threads_2 (ptid, 0);
+}
+
+
static void
thread_db_find_new_threads (struct target_ops *ops)
{
static char *
thread_db_pid_to_str (struct target_ops *ops, ptid_t ptid)
{
- struct thread_info *thread_info = find_thread_pid (ptid);
+ struct thread_info *thread_info = find_thread_ptid (ptid);
struct target_ops *beneath;
if (thread_info != NULL && thread_info->private != NULL)
thread_db_find_new_threads_1 (ptid);
/* Find the matching thread. */
- thread_info = find_thread_pid (ptid);
+ thread_info = find_thread_ptid (ptid);
if (thread_info != NULL && thread_info->private != NULL)
{
td_err_e err;
- void *address;
+ psaddr_t address;
struct thread_db_info *info;
info = get_thread_db_info (GET_PID (ptid));
gdb_assert (lm != 0);
/* 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,
- (void *)(size_t) lm,
+ (psaddr_t)(uintptr_t) lm,
offset, &address);
#ifdef THREAD_DB_HAS_TD_NOTALLOC
projects / deliverable / binutils-gdb.git / blobdiff