X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Flinux-thread-db.c;h=659d99d9347a95467066c6f513ff0f2af3cd9aef;hb=112e8700a6fd2fed65ca70132c9cbed4132e8bd4;hp=eb7bb80720641c8b85e430847e8ad11f30ed6793;hpb=b798847d060c439bc350e5fbaf6e8d315b18c727;p=deliverable%2Fbinutils-gdb.git
diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c
index eb7bb80720..6072685d73 100644
--- a/gdb/linux-thread-db.c
+++ b/gdb/linux-thread-db.c
@@ -1,13 +1,12 @@
/* libthread_db assisted debugging support, generic parts.
- Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007
- Free Software Foundation, Inc.
+ Copyright (C) 1999-2016 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
@@ -16,39 +15,103 @@
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see . */
#include "defs.h"
-
-#include "gdb_assert.h"
#include
#include "gdb_proc_service.h"
-#include "gdb_thread_db.h"
-
+#include "nat/gdb_thread_db.h"
+#include "gdb_vecs.h"
#include "bfd.h"
-#include "exceptions.h"
+#include "command.h"
+#include "gdbcmd.h"
#include "gdbthread.h"
#include "inferior.h"
+#include "infrun.h"
#include "symfile.h"
#include "objfiles.h"
#include "target.h"
#include "regcache.h"
+#include "solib.h"
#include "solib-svr4.h"
#include "gdbcore.h"
#include "observer.h"
#include "linux-nat.h"
-
+#include "nat/linux-procfs.h"
+#include "nat/linux-ptrace.h"
+#include "nat/linux-osdata.h"
+#include "auto-load.h"
+#include "cli/cli-utils.h"
#include
+#include
+#include "nat/linux-namespaces.h"
+#include
-#ifdef HAVE_GNU_LIBC_VERSION_H
-#include
-#endif
+/* GNU/Linux libthread_db support.
-#ifndef LIBTHREAD_DB_SO
-#define LIBTHREAD_DB_SO "libthread_db.so.1"
-#endif
+ libthread_db is a library, provided along with libpthread.so, which
+ exposes the internals of the thread library to a debugger. It
+ allows GDB to find existing threads, new threads as they are
+ 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 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
+ information about the new thread; this could be temporary (created,
+ but the thread library's data structures do not reflect it yet)
+ or permanent (created using clone instead of pthread_create).
+
+ Process IDs managed by linux-thread-db.c match those used by
+ linux-nat.c: a common PID for all processes, an LWP ID for each
+ thread, and no TID. We save the TID in private. Keeping it out
+ of the ptid_t prevents thread IDs changing when libpthread is
+ loaded or unloaded. */
+
+static char *libthread_db_search_path;
+
+/* Set to non-zero if thread_db auto-loading is enabled
+ by the "set auto-load libthread-db" command. */
+static int auto_load_thread_db = 1;
+
+/* "show" command for the auto_load_thread_db configuration variable. */
+
+static void
+show_auto_load_thread_db (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Auto-loading of inferior specific libthread_db "
+ "is %s.\n"),
+ value);
+}
+
+static void
+set_libthread_db_search_path (char *ignored, int from_tty,
+ struct cmd_list_element *c)
+{
+ if (*libthread_db_search_path == '\0')
+ {
+ xfree (libthread_db_search_path);
+ libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
+ }
+}
+
+/* If non-zero, print details of libthread_db processing. */
+
+static unsigned int libthread_db_debug;
+
+static void
+show_libthread_db_debug (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("libthread-db debugging is %s.\n"), value);
+}
/* If we're running on GNU/Linux, we must explicitly attach to any new
threads. */
@@ -56,85 +119,134 @@
/* This module's target vector. */
static struct target_ops thread_db_ops;
-/* The target vector that we call for things this module can't handle. */
-static struct target_ops *target_beneath;
-
-/* Non-zero if we're using this module's target vector. */
-static int using_thread_db;
-
/* Non-zero if we have determined the signals used by the threads
library. */
static int thread_signals;
static sigset_t thread_stop_set;
static sigset_t thread_print_set;
-/* Structure that identifies the child process for the
- interface. */
-static struct ps_prochandle proc_handle;
-
-/* Connection to the libthread_db library. */
-static td_thragent_t *thread_agent;
-
-/* Pointers to the libthread_db functions. */
-
-static td_err_e (*td_init_p) (void);
-
-static td_err_e (*td_ta_new_p) (struct ps_prochandle * ps,
- td_thragent_t **ta);
-static td_err_e (*td_ta_map_id2thr_p) (const td_thragent_t *ta, thread_t pt,
- td_thrhandle_t *__th);
-static td_err_e (*td_ta_map_lwp2thr_p) (const td_thragent_t *ta,
- lwpid_t lwpid, td_thrhandle_t *th);
-static td_err_e (*td_ta_thr_iter_p) (const td_thragent_t *ta,
- td_thr_iter_f *callback, void *cbdata_p,
- td_thr_state_e state, int ti_pri,
- sigset_t *ti_sigmask_p,
- unsigned int ti_user_flags);
-static td_err_e (*td_ta_event_addr_p) (const td_thragent_t *ta,
- td_event_e event, td_notify_t *ptr);
-static td_err_e (*td_ta_set_event_p) (const td_thragent_t *ta,
- td_thr_events_t *event);
-static td_err_e (*td_ta_event_getmsg_p) (const td_thragent_t *ta,
- td_event_msg_t *msg);
-
-static td_err_e (*td_thr_validate_p) (const td_thrhandle_t *th);
-static td_err_e (*td_thr_get_info_p) (const td_thrhandle_t *th,
- td_thrinfo_t *infop);
-static td_err_e (*td_thr_event_enable_p) (const td_thrhandle_t *th,
- int event);
-
-static td_err_e (*td_thr_tls_get_addr_p) (const td_thrhandle_t *th,
- void *map_address,
- size_t offset, void **address);
-
-/* Location of the thread creation event breakpoint. The code at this
- location in the child process will be called by the pthread library
- whenever a new thread is created. By setting a special breakpoint
- at this location, GDB can detect when a new thread is created. We
- obtain this location via the td_ta_event_addr call. */
-static CORE_ADDR td_create_bp_addr;
-
-/* Location of the thread death event breakpoint. */
-static CORE_ADDR td_death_bp_addr;
-
-/* Prototypes for local functions. */
-static void thread_db_find_new_threads (void);
-static void attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
- const td_thrinfo_t *ti_p, int verbose);
-static void detach_thread (ptid_t ptid, int verbose);
-
+struct thread_db_info
+{
+ struct thread_db_info *next;
-/* Building process ids. */
+ /* Process id this object refers to. */
+ int pid;
-#define GET_PID(ptid) ptid_get_pid (ptid)
-#define GET_LWP(ptid) ptid_get_lwp (ptid)
-#define GET_THREAD(ptid) ptid_get_tid (ptid)
+ /* Handle from dlopen for libthread_db.so. */
+ void *handle;
-#define is_lwp(ptid) (GET_LWP (ptid) != 0)
-#define is_thread(ptid) (GET_THREAD (ptid) != 0)
+ /* 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
+ interface. */
+ struct ps_prochandle proc_handle;
+
+ /* Connection to the libthread_db library. */
+ td_thragent_t *thread_agent;
+
+ /* True if we need to apply the workaround for glibc/BZ5983. When
+ we catch a PTRACE_O_TRACEFORK, and go query the child's thread
+ list, nptl_db returns the parent's threads in addition to the new
+ (single) child thread. If this flag is set, we do extra work to
+ be able to ignore such stale entries. */
+ int need_stale_parent_threads_check;
+
+ /* Pointers to the libthread_db functions. */
+
+ 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;
+};
-#define BUILD_LWP(lwp, pid) ptid_build (pid, lwp, 0)
-
+/* List of known processes using thread_db, and the required
+ bookkeeping. */
+struct thread_db_info *thread_db_list;
+
+static void thread_db_find_new_threads_1 (ptid_t ptid);
+static void thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new);
+
+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
+ LIBTHREAD_DB_SO. */
+
+static struct thread_db_info *
+add_thread_db_info (void *handle)
+{
+ struct thread_db_info *info = XCNEW (struct thread_db_info);
+
+ info->pid = ptid_get_pid (inferior_ptid);
+ info->handle = handle;
+
+ /* The workaround works by reading from /proc/pid/status, so it is
+ disabled for core files. */
+ if (target_has_execution)
+ info->need_stale_parent_threads_check = 1;
+
+ info->next = thread_db_list;
+ thread_db_list = info;
+
+ return info;
+}
+
+/* Return the thread_db_info object representing the bookkeeping
+ related to process PID, if any; NULL otherwise. */
+
+static struct thread_db_info *
+get_thread_db_info (int pid)
+{
+ struct thread_db_info *info;
+
+ for (info = thread_db_list; info; info = info->next)
+ if (pid == info->pid)
+ return info;
+
+ return NULL;
+}
+
+/* When PID has exited or has been detached, we no longer want to keep
+ track of it as using libpthread. Call this function to discard
+ thread_db related info related to PID. Note that this closes
+ LIBTHREAD_DB_SO's dlopen'ed handle. */
+
+static void
+delete_thread_db_info (int pid)
+{
+ struct thread_db_info *info, *info_prev;
+
+ info_prev = NULL;
+
+ for (info = thread_db_list; info; info_prev = info, info = info->next)
+ if (pid == info->pid)
+ break;
+
+ if (info == NULL)
+ return;
+
+ if (info->handle != NULL)
+ dlclose (info->handle);
+
+ xfree (info->filename);
+
+ if (info_prev)
+ info_prev->next = info->next;
+ else
+ thread_db_list = info->next;
+
+ xfree (info);
+}
/* Use "struct private_thread_info" to cache thread state. This is
a substantial optimization. */
@@ -145,11 +257,8 @@ struct private_thread_info
unsigned int dying:1;
/* Cached thread state. */
- unsigned int th_valid:1;
- unsigned int ti_valid:1;
-
td_thrhandle_t th;
- td_thrinfo_t ti;
+ thread_t tid;
};
@@ -219,333 +328,626 @@ thread_db_err_str (td_err_e err)
return buf;
}
}
-
-/* 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. */
+/* Fetch the user-level thread id of PTID. */
-static int
-thread_get_info_callback (const td_thrhandle_t *thp, void *infop)
+static struct thread_info *
+thread_from_lwp (ptid_t ptid)
{
+ td_thrhandle_t th;
td_thrinfo_t ti;
td_err_e err;
- struct thread_info *thread_info;
- ptid_t thread_ptid;
+ struct thread_db_info *info;
+ 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 (ptid_get_lwp (ptid) != 0);
- err = td_thr_get_info_p (thp, &ti);
+ 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, ptid_get_lwp (ptid),
+ &th);
+ if (err != TD_OK)
+ error (_("Cannot find user-level thread for LWP %ld: %s"),
+ 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. */
- thread_ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, ti.ti_tid);
- thread_info = find_thread_pid (thread_ptid);
+ tp = find_thread_ptid (ptid);
+ return record_thread (info, tp, ptid, &th, &ti);
+}
+
+
+/* See linux-nat.h. */
+
+int
+thread_db_notice_clone (ptid_t parent, ptid_t child)
+{
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (ptid_get_pid (child));
- /* In the case of a zombie thread, don't continue. We don't want to
- attach to it thinking it is a new thread. */
- if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
+ if (info == NULL)
+ return 0;
+
+ thread_from_lwp (child);
+
+ /* 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 void *
+verbose_dlsym (void *handle, const char *name)
+{
+ void *sym = dlsym (handle, name);
+ if (sym == NULL)
+ warning (_("Symbol \"%s\" not found in libthread_db: %s"),
+ name, dlerror ());
+ return sym;
+}
+
+/* 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])
{
- if (infop != NULL)
- *(struct thread_info **) infop = thread_info;
- if (thread_info != NULL)
- {
- memcpy (&thread_info->private->th, thp, sizeof (*thp));
- thread_info->private->th_valid = 1;
- memcpy (&thread_info->private->ti, &ti, sizeof (ti));
- thread_info->private->ti_valid = 1;
- }
- return TD_THR_ZOMBIE;
+ 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;
+}
+
+/* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
+ if appropriate.
+
+ Return 1 if the caller should abort libthread_db initialization. Return 0
+ otherwise. */
- if (thread_info == NULL)
+static int
+thread_db_find_new_threads_silently (ptid_t ptid)
+{
+
+ TRY
{
- /* New thread. Attach to it now (why wait?). */
- attach_thread (thread_ptid, thp, &ti, 1);
- thread_info = find_thread_pid (thread_ptid);
- gdb_assert (thread_info != NULL);
+ thread_db_find_new_threads_2 (ptid, 1);
}
- memcpy (&thread_info->private->th, thp, sizeof (*thp));
- thread_info->private->th_valid = 1;
- memcpy (&thread_info->private->ti, &ti, sizeof (ti));
- thread_info->private->ti_valid = 1;
-
- if (infop != NULL)
- *(struct thread_info **) infop = thread_info;
+ CATCH (except, RETURN_MASK_ERROR)
+ {
+ 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;
}
-/* Accessor functions for the thread_db information, with caching. */
+/* Lookup a library in which given symbol resides.
+ Note: this is looking in GDB process, not in the inferior.
+ Returns library name, or NULL. */
-static void
-thread_db_map_id2thr (struct thread_info *thread_info, int fatal)
+static const char *
+dladdr_to_soname (const void *addr)
+{
+ Dl_info info;
+
+ if (dladdr (addr, &info) != 0)
+ return info.dli_fname;
+ return NULL;
+}
+
+/* Attempt to initialize dlopen()ed libthread_db, described by INFO.
+ Return 1 on success.
+ Failure could happen if libthread_db does not have symbols we expect,
+ or when it refuses to work with the current inferior (e.g. due to
+ version mismatch between libthread_db and libpthread). */
+
+static int
+try_thread_db_load_1 (struct thread_db_info *info)
{
td_err_e err;
- if (thread_info->private->th_valid)
- return;
+ /* Initialize pointers to the dynamic library functions we will use.
+ Essential functions first. */
+
+#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)
- err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (thread_info->ptid),
- &thread_info->private->th);
+ CHK (TDB_VERBOSE_DLSYM (info, td_init));
+
+ err = info->td_init_p ();
if (err != TD_OK)
{
- if (fatal)
- error (_("Cannot find thread %ld: %s"),
- (long) GET_THREAD (thread_info->ptid),
+ warning (_("Cannot initialize libthread_db: %s"),
thread_db_err_str (err));
+ return 0;
+ }
+
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_new));
+
+ /* Initialize the structure that identifies the child process. */
+ info->proc_handle.ptid = inferior_ptid;
+
+ /* Now attempt to open a connection to the thread library. */
+ err = info->td_ta_new_p (&info->proc_handle, &info->thread_agent);
+ if (err != TD_OK)
+ {
+ if (libthread_db_debug)
+ fprintf_unfiltered (gdb_stdlog, _("td_ta_new failed: %s\n"),
+ thread_db_err_str (err));
+ else
+ switch (err)
+ {
+ case TD_NOLIBTHREAD:
+#ifdef THREAD_DB_HAS_TD_VERSION
+ case TD_VERSION:
+#endif
+ /* The errors above are not unexpected and silently ignored:
+ they just mean we haven't found correct version of
+ libthread_db yet. */
+ break;
+ default:
+ warning (_("td_ta_new failed: %s"), thread_db_err_str (err));
+ }
+ return 0;
}
+
+ /* These are essential. */
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_map_lwp2thr));
+ CHK (TDB_VERBOSE_DLSYM (info, td_thr_get_info));
+
+ /* 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
- thread_info->private->th_valid = 1;
-}
-
-/* Convert between user-level thread ids and LWP ids. */
+ CHK (TDB_VERBOSE_DLSYM (info, td_ta_thr_iter));
-static ptid_t
-thread_from_lwp (ptid_t ptid)
-{
- td_thrhandle_t th;
- td_err_e err;
- struct thread_info *thread_info;
- ptid_t thread_ptid;
+#undef TDB_VERBOSE_DLSYM
+#undef TDB_DLSYM
+#undef CHK
- if (GET_LWP (ptid) == 0)
- ptid = BUILD_LWP (GET_PID (ptid), GET_PID (ptid));
+ if (info->td_ta_thr_iter_p == NULL)
+ {
+ struct lwp_info *lp;
+ int pid = ptid_get_pid (inferior_ptid);
- gdb_assert (is_lwp (ptid));
+ linux_stop_and_wait_all_lwps ();
- err = td_ta_map_lwp2thr_p (thread_agent, GET_LWP (ptid), &th);
- if (err != TD_OK)
- error (_("Cannot find user-level thread for LWP %ld: %s"),
- GET_LWP (ptid), thread_db_err_str (err));
-
- thread_info = NULL;
-
- /* Fetch the thread info. If we get back TD_THR_ZOMBIE, then the
- event thread has already died. If another gdb interface has called
- thread_alive() previously, the thread won't be found on the thread list
- 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. */
- if (thread_get_info_callback (&th, &thread_info) == TD_THR_ZOMBIE
- && thread_info == NULL)
- return pid_to_ptid (-1);
-
- gdb_assert (thread_info && thread_info->private->ti_valid);
-
- return ptid_build (GET_PID (ptid), GET_LWP (ptid),
- thread_info->private->ti.ti_tid);
-}
+ ALL_LWPS (lp)
+ if (ptid_get_pid (lp->ptid) == pid)
+ thread_from_lwp (lp->ptid);
-static ptid_t
-lwp_from_thread (ptid_t ptid)
-{
- return BUILD_LWP (GET_LWP (ptid), GET_PID (ptid));
-}
-
+ 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;
+ }
-void
-thread_db_init (struct target_ops *target)
-{
- target_beneath = target;
-}
+ printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
-static void *
-verbose_dlsym (void *handle, const char *name)
-{
- void *sym = dlsym (handle, name);
- if (sym == NULL)
- warning (_("Symbol \"%s\" not found in libthread_db: %s"), name, dlerror ());
- return sym;
+ if (*libthread_db_search_path || libthread_db_debug)
+ {
+ struct ui_file *file;
+ const char *library;
+
+ library = dladdr_to_soname ((const void *) *info->td_ta_new_p);
+ if (library == NULL)
+ library = LIBTHREAD_DB_SO;
+
+ /* 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 this is the first process using it. */
+ if (thread_db_list->next == NULL)
+ push_target (&thread_db_ops);
+
+ return 1;
}
+/* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
+ relative, or just LIBTHREAD_DB. */
+
static int
-thread_db_load (void)
+try_thread_db_load (const char *library, int check_auto_load_safe)
{
void *handle;
- td_err_e err;
+ struct thread_db_info *info;
+
+ if (libthread_db_debug)
+ 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 (LIBTHREAD_DB_SO, RTLD_NOW);
+ handle = dlopen (library, RTLD_NOW);
if (handle == NULL)
{
- fprintf_filtered (gdb_stderr, "\n\ndlopen failed on '%s' - %s\n",
- LIBTHREAD_DB_SO, dlerror ());
- fprintf_filtered (gdb_stderr,
- "GDB will not be able to debug pthreads.\n\n");
+ if (libthread_db_debug)
+ fprintf_unfiltered (gdb_stdlog, _("dlopen failed: %s.\n"), dlerror ());
return 0;
}
- /* Initialize pointers to the dynamic library functions we will use.
- Essential functions first. */
+ if (libthread_db_debug && strchr (library, '/') == NULL)
+ {
+ void *td_init;
- td_init_p = verbose_dlsym (handle, "td_init");
- if (td_init_p == NULL)
- return 0;
+ td_init = dlsym (handle, "td_init");
+ if (td_init != NULL)
+ {
+ const char *const libpath = dladdr_to_soname (td_init);
- td_ta_new_p = verbose_dlsym (handle, "td_ta_new");
- if (td_ta_new_p == NULL)
- return 0;
+ if (libpath != NULL)
+ fprintf_unfiltered (gdb_stdlog, _("Host %s resolved to: %s.\n"),
+ library, libpath);
+ }
+ }
- td_ta_map_id2thr_p = verbose_dlsym (handle, "td_ta_map_id2thr");
- if (td_ta_map_id2thr_p == NULL)
- return 0;
+ info = add_thread_db_info (handle);
- td_ta_map_lwp2thr_p = verbose_dlsym (handle, "td_ta_map_lwp2thr");
- if (td_ta_map_lwp2thr_p == NULL)
- return 0;
+ /* Do not save system library name, that one is always trusted. */
+ if (strchr (library, '/') != NULL)
+ info->filename = gdb_realpath (library);
- td_ta_thr_iter_p = verbose_dlsym (handle, "td_ta_thr_iter");
- if (td_ta_thr_iter_p == NULL)
- return 0;
+ if (try_thread_db_load_1 (info))
+ return 1;
- td_thr_validate_p = verbose_dlsym (handle, "td_thr_validate");
- if (td_thr_validate_p == NULL)
- return 0;
+ /* This library "refused" to work on current inferior. */
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
+ return 0;
+}
- td_thr_get_info_p = verbose_dlsym (handle, "td_thr_get_info");
- if (td_thr_get_info_p == NULL)
- return 0;
+/* Subroutine of try_thread_db_load_from_pdir to simplify it.
+ 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. */
- /* Initialize the library. */
- err = td_init_p ();
- if (err != TD_OK)
+static int
+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] != '/')
{
- warning (_("Cannot initialize libthread_db: %s"), thread_db_err_str (err));
+ warning (_("Expected absolute pathname for libpthread in the"
+ " inferior, but got %s."), obj_name);
return 0;
}
- /* These are not essential. */
- td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr");
- td_ta_set_event_p = dlsym (handle, "td_ta_set_event");
- td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg");
- td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable");
- td_thr_tls_get_addr_p = dlsym (handle, "td_thr_tls_get_addr");
+ 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)
+ {
+ strcat (cp, subdir);
+ strcat (cp, "/");
+ }
+ strcat (cp, LIBTHREAD_DB_SO);
- return 1;
+ result = try_thread_db_load (path, 1);
+
+ do_cleanups (cleanup);
+ return result;
}
-static td_err_e
-enable_thread_event (td_thragent_t *thread_agent, int event, CORE_ADDR *bp)
+/* Handle $pdir in libthread-db-search-path.
+ 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 (const char *subdir)
{
- td_notify_t notify;
- td_err_e err;
+ struct objfile *obj;
- /* Get the breakpoint address for thread EVENT. */
- err = td_ta_event_addr_p (thread_agent, event, ¬ify);
- if (err != TD_OK)
- return err;
-
- /* Set up the breakpoint. */
- gdb_assert (exec_bfd);
- (*bp) = (gdbarch_convert_from_func_ptr_addr
- (current_gdbarch,
- /* 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));
-
- return TD_OK;
+ if (!auto_load_thread_db)
+ return 0;
+
+ ALL_OBJFILES (obj)
+ if (libpthread_name_p (objfile_name (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,
+ subdir);
+
+ return 0;
+ }
+
+ return 0;
}
-static void
-enable_thread_event_reporting (void)
+/* Handle $sdir in libthread-db-search-path.
+ Look for libthread_db in the system dirs, or wherever a plain
+ dlopen(file_without_path) will look.
+ The result is true for success. */
+
+static int
+try_thread_db_load_from_sdir (void)
{
- td_thr_events_t events;
- td_notify_t notify;
- td_err_e err;
-#ifdef HAVE_GNU_LIBC_VERSION_H
- const char *libc_version;
- int libc_major, libc_minor;
-#endif
+ return try_thread_db_load (LIBTHREAD_DB_SO, 0);
+}
- /* We cannot use the thread event reporting facility if these
- functions aren't available. */
- if (td_ta_event_addr_p == NULL || td_ta_set_event_p == NULL
- || td_ta_event_getmsg_p == NULL || td_thr_event_enable_p == NULL)
- return;
+/* Try to load libthread_db from directory DIR of length DIR_LEN.
+ The result is true for success. */
- /* 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);
+static int
+try_thread_db_load_from_dir (const char *dir, size_t dir_len)
+{
+ struct cleanup *cleanup;
+ char *path;
+ int result;
- err = td_ta_set_event_p (thread_agent, &events);
- if (err != TD_OK)
+ 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, 1);
+
+ do_cleanups (cleanup);
+ return result;
+}
+
+/* Search libthread_db_search_path for libthread_db which "agrees"
+ to work on current inferior.
+ The result is true for success. */
+
+static int
+thread_db_load_search (void)
+{
+ 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);
+
+ for (i = 0; VEC_iterate (char_ptr, dir_vec, i, this_dir); ++i)
{
- warning (_("Unable to set global thread event mask: %s"),
- thread_db_err_str (err));
- return;
+ const int pdir_len = sizeof ("$pdir") - 1;
+ size_t this_dir_len;
+
+ this_dir_len = strlen (this_dir);
+
+ if (strncmp (this_dir, "$pdir", pdir_len) == 0
+ && (this_dir[pdir_len] == '\0'
+ || this_dir[pdir_len] == '/'))
+ {
+ char *subdir = NULL;
+ struct cleanup *free_subdir_cleanup
+ = make_cleanup (null_cleanup, NULL);
+
+ if (this_dir[pdir_len] == '/')
+ {
+ subdir = (char *) xmalloc (strlen (this_dir));
+ make_cleanup (xfree, subdir);
+ strcpy (subdir, this_dir + pdir_len + 1);
+ }
+ rc = try_thread_db_load_from_pdir (subdir);
+ do_cleanups (free_subdir_cleanup);
+ if (rc)
+ break;
+ }
+ else if (strcmp (this_dir, "$sdir") == 0)
+ {
+ if (try_thread_db_load_from_sdir ())
+ {
+ rc = 1;
+ break;
+ }
+ }
+ else
+ {
+ if (try_thread_db_load_from_dir (this_dir, this_dir_len))
+ {
+ rc = 1;
+ break;
+ }
+ }
}
- /* Delete previous thread event breakpoints, if any. */
- remove_thread_event_breakpoints ();
- td_create_bp_addr = 0;
- td_death_bp_addr = 0;
+ do_cleanups (cleanups);
+ if (libthread_db_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ _("thread_db_load_search returning %d\n"), rc);
+ return rc;
+}
+
+/* Return non-zero if the inferior has a libpthread. */
+
+static int
+has_libpthread (void)
+{
+ struct objfile *obj;
+
+ ALL_OBJFILES (obj)
+ if (libpthread_name_p (objfile_name (obj)))
+ return 1;
+
+ return 0;
+}
+
+/* Attempt to load and initialize libthread_db.
+ Return 1 on success. */
+
+static int
+thread_db_load (void)
+{
+ struct thread_db_info *info;
+
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
+
+ if (info != NULL)
+ return 1;
+
+ /* Don't attempt to use thread_db on executables not running
+ yet. */
+ if (!target_has_registers)
+ return 0;
+
+ /* Don't attempt to use thread_db for remote targets. */
+ if (!(target_can_run (¤t_target) || core_bfd))
+ return 0;
- /* Set up the thread creation event. */
- err = enable_thread_event (thread_agent, TD_CREATE, &td_create_bp_addr);
- if (err != TD_OK)
- {
- warning (_("Unable to get location for thread creation breakpoint: %s"),
- thread_db_err_str (err));
- return;
- }
+ if (thread_db_load_search ())
+ return 1;
- /* Set up the thread death event. */
- err = enable_thread_event (thread_agent, TD_DEATH, &td_death_bp_addr);
- if (err != TD_OK)
+ /* We couldn't find a libthread_db.
+ If the inferior has a libpthread warn the user. */
+ if (has_libpthread ())
{
- warning (_("Unable to get location for thread death breakpoint: %s"),
- thread_db_err_str (err));
- return;
+ warning (_("Unable to find libthread_db matching inferior's thread"
+ " library, thread debugging will not be available."));
+ return 0;
}
-}
-
-static void
-disable_thread_event_reporting (void)
-{
- td_thr_events_t events;
- /* Set the process wide mask saying we aren't interested in any
- events anymore. */
- td_event_emptyset (&events);
- td_ta_set_event_p (thread_agent, &events);
-
- /* Delete thread event breakpoints, if any. */
- remove_thread_event_breakpoints ();
- td_create_bp_addr = 0;
- td_death_bp_addr = 0;
+ /* Either this executable isn't using libpthread at all, or it is
+ statically linked. Since we can't easily distinguish these two cases,
+ no warning is issued. */
+ return 0;
}
static void
check_thread_signals (void)
{
-#ifdef GET_THREAD_SIGNALS
if (!thread_signals)
{
sigset_t mask;
int i;
- GET_THREAD_SIGNALS (&mask);
+ lin_thread_get_thread_signals (&mask);
sigemptyset (&thread_stop_set);
sigemptyset (&thread_print_set);
@@ -553,15 +955,14 @@ 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;
}
}
}
-#endif
}
/* Check whether thread_db is usable. This function is called when
@@ -571,470 +972,439 @@ check_thread_signals (void)
void
check_for_thread_db (void)
{
- td_err_e err;
- static int already_loaded;
-
/* Do nothing if we couldn't load libthread_db.so.1. */
- if (td_ta_new_p == NULL)
- return;
-
- /* First time through, report that libthread_db was successfuly
- loaded. Can't print this in in thread_db_load as, at that stage,
- the interpreter and it's console haven't started. */
-
- if (!already_loaded)
- {
- Dl_info info;
- const char *library = NULL;
- if (dladdr ((*td_ta_new_p), &info) != 0)
- library = info.dli_fname;
-
- /* Try dlinfo? */
-
- if (library == NULL)
- /* Paranoid - don't let a NULL path slip through. */
- library = LIBTHREAD_DB_SO;
-
- printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
- library);
- already_loaded = 1;
- }
-
- if (using_thread_db)
- /* Nothing to do. The thread library was already detected and the
- target vector was already activated. */
- return;
-
- /* Don't attempt to use thread_db on targets which can not run
- (executables not running yet, core files) for now. */
- if (!target_has_execution)
+ if (!thread_db_load ())
return;
-
- /* Don't attempt to use thread_db for remote targets. */
- if (!target_can_run (¤t_target))
- return;
-
- /* Initialize the structure that identifies the child process. */
- proc_handle.pid = GET_PID (inferior_ptid);
-
- /* Now attempt to open a connection to the thread library. */
- err = td_ta_new_p (&proc_handle, &thread_agent);
- switch (err)
- {
- case TD_NOLIBTHREAD:
- /* No thread library was detected. */
- break;
-
- case TD_OK:
- printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
-
- /* The thread library was detected. Activate the thread_db target. */
- push_target (&thread_db_ops);
- using_thread_db = 1;
-
- enable_thread_event_reporting ();
- thread_db_find_new_threads ();
- break;
-
- default:
- warning (_("Cannot initialize thread debugging library: %s"),
- thread_db_err_str (err));
- break;
- }
}
+/* This function is called via the new_objfile observer. */
+
static void
thread_db_new_objfile (struct objfile *objfile)
{
- if (objfile != NULL)
+ /* This observer must always be called with inferior_ptid set
+ correctly. */
+
+ if (objfile != NULL
+ /* 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. */
-
static void
-attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
- const td_thrinfo_t *ti_p, int verbose)
+check_pid_namespace_match (void)
{
- struct thread_info *tp;
- td_err_e err;
-
- /* 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_pid (ptid);
- gdb_assert (tp != 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))
+ {
+ warning (_ ("Target and debugger are in different PID "
+ "namespaces; thread lists and other data are "
+ "likely unreliable. "
+ "Connect to gdbserver inside the container."));
+ }
+ }
+}
- if (!tp->private->dying)
- return;
+/* This function is called via the inferior_created observer.
+ This handles the case of debugging statically linked executables. */
- delete_thread (ptid);
- }
+static void
+thread_db_inferior_created (struct target_ops *target, int from_tty)
+{
+ check_pid_namespace_match ();
+ check_for_thread_db ();
+}
- check_thread_signals ();
+/* Update the thread's state (what's displayed in "info threads"),
+ from libthread_db thread state information. */
- if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
- return; /* A zombie thread -- do not attach. */
+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);
+}
- /* Under GNU/Linux, we have to attach to each and every thread. */
- if (lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)), 0) < 0)
- return;
+/* 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. */
- /* Add the thread to GDB's thread list. */
- tp = add_thread (ptid);
- tp->private = xmalloc (sizeof (struct private_thread_info));
- memset (tp->private, 0, sizeof (struct private_thread_info));
+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;
+
+ /* 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. */
+ priv = XCNEW (struct private_thread_info);
+
+ 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 (verbose)
- printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid));
+ if (target_has_execution)
+ check_thread_signals ();
- /* Enable thread event reporting for this thread. */
- err = td_thr_event_enable_p (th_p, 1);
- if (err != TD_OK)
- error (_("Cannot enable thread event reporting for %s: %s"),
- target_pid_to_str (ptid), thread_db_err_str (err));
+ return tp;
}
static void
-thread_db_attach (char *args, int from_tty)
+thread_db_detach (struct target_ops *ops, const char *args, int from_tty)
{
- target_beneath->to_attach (args, from_tty);
+ struct target_ops *target_beneath = find_target_beneath (ops);
+ struct thread_db_info *info;
- /* Destroy thread info; it's no longer valid. */
- init_thread_list ();
+ info = get_thread_db_info (ptid_get_pid (inferior_ptid));
- /* The child process is now the actual multi-threaded
- program. Snatch its process ID... */
- proc_handle.pid = GET_PID (inferior_ptid);
+ if (info)
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
- /* ...and perform the remaining initialization steps. */
- enable_thread_event_reporting ();
- thread_db_find_new_threads ();
-}
+ target_beneath->to_detach (target_beneath, args, from_tty);
-static void
-detach_thread (ptid_t ptid, int verbose)
-{
- struct thread_info *thread_info;
+ /* NOTE: From this point on, inferior_ptid is null_ptid. */
- if (verbose)
- printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (ptid));
-
- /* 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. */
- thread_info = find_thread_pid (ptid);
- gdb_assert (thread_info != NULL);
- thread_info->private->dying = 1;
+ /* If there are no more processes using libpthread, detach the
+ thread_db target ops. */
+ if (!thread_db_list)
+ unpush_target (&thread_db_ops);
}
-static void
-thread_db_detach (char *args, int from_tty)
+static ptid_t
+thread_db_wait (struct target_ops *ops,
+ ptid_t ptid, struct target_waitstatus *ourstatus,
+ int options)
{
- disable_thread_event_reporting ();
+ struct thread_db_info *info;
+ struct target_ops *beneath = find_target_beneath (ops);
+
+ ptid = beneath->to_wait (beneath, ptid, ourstatus, options);
- /* There's no need to save & restore inferior_ptid here, since the
- inferior is supposed to be survive this function call. */
- inferior_ptid = lwp_from_thread (inferior_ptid);
+ switch (ourstatus->kind)
+ {
+ case TARGET_WAITKIND_IGNORE:
+ case TARGET_WAITKIND_EXITED:
+ case TARGET_WAITKIND_THREAD_EXITED:
+ case TARGET_WAITKIND_SIGNALLED:
+ return ptid;
+ }
- /* Forget about the child's process ID. We shouldn't need it
- anymore. */
- proc_handle.pid = 0;
+ info = get_thread_db_info (ptid_get_pid (ptid));
- target_beneath->to_detach (args, from_tty);
-}
+ /* If this process isn't using thread_db, we're done. */
+ if (info == NULL)
+ return ptid;
-static int
-clear_lwpid_callback (struct thread_info *thread, void *dummy)
-{
- /* If we know that our thread implementation is 1-to-1, we could save
- a certain amount of information; it's not clear how much, so we
- are always conservative. */
+ if (ourstatus->kind == TARGET_WAITKIND_EXECD)
+ {
+ /* New image, it may or may not end up using thread_db. Assume
+ not unless we find otherwise. */
+ delete_thread_db_info (ptid_get_pid (ptid));
+ if (!thread_db_list)
+ unpush_target (&thread_db_ops);
- thread->private->th_valid = 0;
- thread->private->ti_valid = 0;
+ return ptid;
+ }
- return 0;
+ /* Fill in the thread's user-level thread id and status. */
+ thread_from_lwp (ptid);
+
+ return ptid;
}
static void
-thread_db_resume (ptid_t ptid, int step, enum target_signal signo)
+thread_db_mourn_inferior (struct target_ops *ops)
{
- struct cleanup *old_chain = save_inferior_ptid ();
+ struct target_ops *target_beneath = find_target_beneath (ops);
- if (GET_PID (ptid) == -1)
- inferior_ptid = lwp_from_thread (inferior_ptid);
- else if (is_thread (ptid))
- ptid = lwp_from_thread (ptid);
+ delete_thread_db_info (ptid_get_pid (inferior_ptid));
- /* Clear cached data which may not be valid after the resume. */
- iterate_over_threads (clear_lwpid_callback, NULL);
+ target_beneath->to_mourn_inferior (target_beneath);
- target_beneath->to_resume (ptid, step, signo);
-
- do_cleanups (old_chain);
+ /* Detach thread_db target ops. */
+ if (!thread_db_list)
+ unpush_target (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. */
+struct callback_data
+{
+ struct thread_db_info *info;
+ int new_threads;
+};
-static void
-check_event (ptid_t ptid)
+static int
+find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
{
- td_event_msg_t msg;
td_thrinfo_t ti;
td_err_e err;
- CORE_ADDR stop_pc;
- int loop = 0;
-
- /* Bail out early if we're not at a thread event breakpoint. */
- stop_pc = read_pc_pid (ptid) - gdbarch_decr_pc_after_break (current_gdbarch);
- if (stop_pc != td_create_bp_addr && stop_pc != td_death_bp_addr)
- return;
-
- /* 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. */
+ ptid_t ptid;
+ struct thread_info *tp;
+ struct callback_data *cb_data = (struct callback_data *) data;
+ struct thread_db_info *info = cb_data->info;
- loop = 1;
+ err = info->td_thr_get_info_p (th_p, &ti);
+ if (err != TD_OK)
+ error (_("find_new_threads_callback: cannot get thread info: %s"),
+ thread_db_err_str (err));
- do
+ if (ti.ti_lid == -1)
{
- err = td_ta_event_getmsg_p (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 = 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, ti.ti_tid);
+ /* 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;
+ }
- 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, 1);
+ 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. */
- break;
+ /* 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;
- case TD_DEATH:
+ return 0;
+ }
- if (!in_thread_list (ptid))
- error (_("Spurious thread death event."));
+ /* Ignore stale parent threads, caused by glibc/BZ5983. This is a
+ bit expensive, as it needs to open /proc/pid/status, so try to
+ avoid doing the work if we know we don't have to. */
+ if (info->need_stale_parent_threads_check)
+ {
+ int tgid = linux_proc_get_tgid (ti.ti_lid);
- detach_thread (ptid, 1);
+ if (tgid != -1 && tgid != info->pid)
+ return 0;
+ }
- break;
+ ptid = ptid_build (info->pid, ti.ti_lid, 0);
+ tp = find_thread_ptid (ptid);
+ if (tp == NULL || tp->priv == NULL)
+ record_thread (info, tp, ptid, th_p, &ti);
- default:
- error (_("Spurious thread event."));
- }
- }
- while (loop);
+ return 0;
}
-static ptid_t
-thread_db_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
-{
- extern ptid_t trap_ptid;
-
- if (GET_PID (ptid) != -1 && is_thread (ptid))
- ptid = lwp_from_thread (ptid);
+/* Helper for thread_db_find_new_threads_2.
+ Returns number of new threads found. */
- ptid = target_beneath->to_wait (ptid, ourstatus);
+static int
+find_new_threads_once (struct thread_db_info *info, int iteration,
+ td_err_e *errp)
+{
+ struct callback_data data;
+ td_err_e err = TD_ERR;
- if (proc_handle.pid == 0)
- /* The current child process isn't the actual multi-threaded
- program yet, so don't try to do any special thread-specific
- post-processing and bail out early. */
- return ptid;
+ data.info = info;
+ data.new_threads = 0;
- if (ourstatus->kind == TARGET_WAITKIND_EXITED
- || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
- return pid_to_ptid (-1);
+ /* See comment in thread_db_update_thread_list. */
+ gdb_assert (info->td_ta_thr_iter_p != NULL);
- if (ourstatus->kind == TARGET_WAITKIND_EXECD)
+ TRY
+ {
+ /* 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);
+ }
+ CATCH (except, RETURN_MASK_ERROR)
{
- remove_thread_event_breakpoints ();
- unpush_target (&thread_db_ops);
- using_thread_db = 0;
+ if (libthread_db_debug)
+ {
+ exception_fprintf (gdb_stdlog, except,
+ "Warning: find_new_threads_once: ");
+ }
+ }
+ END_CATCH
- return pid_to_ptid (GET_PID (ptid));
+ if (libthread_db_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ _("Found %d new threads in iteration %d.\n"),
+ data.new_threads, iteration);
}
- if (ourstatus->kind == TARGET_WAITKIND_STOPPED
- && ourstatus->value.sig == TARGET_SIGNAL_TRAP)
- /* Check for a thread event. */
- check_event (ptid);
-
- if (!ptid_equal (trap_ptid, null_ptid))
- trap_ptid = thread_from_lwp (trap_ptid);
-
- /* Change the ptid 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;
-
- return ptid;
-}
+ if (errp != NULL)
+ *errp = err;
-static void
-thread_db_kill (void)
-{
- /* There's no need to save & restore inferior_ptid here, since the
- inferior isn't supposed to survive this function call. */
- inferior_ptid = lwp_from_thread (inferior_ptid);
- target_beneath->to_kill ();
+ return data.new_threads;
}
-static void
-thread_db_create_inferior (char *exec_file, char *allargs, char **env,
- int from_tty)
-{
- unpush_target (&thread_db_ops);
- using_thread_db = 0;
- target_beneath->to_create_inferior (exec_file, allargs, env, from_tty);
-}
+/* Search for new threads, accessing memory through stopped thread
+ PTID. If UNTIL_NO_NEW is true, repeat searching until several
+ searches in a row do not discover any new threads. */
static void
-thread_db_post_startup_inferior (ptid_t ptid)
+thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
{
- if (proc_handle.pid == 0)
- {
- /* The child process is now the actual multi-threaded
- program. Snatch its process ID... */
- proc_handle.pid = GET_PID (ptid);
-
- /* ...and perform the remaining initialization steps. */
- enable_thread_event_reporting ();
- thread_db_find_new_threads ();
- }
-}
+ td_err_e err = TD_OK;
+ struct thread_db_info *info;
+ int i, loop;
-static void
-thread_db_mourn_inferior (void)
-{
- /* Forget about the child's process ID. We shouldn't need it
- anymore. */
- proc_handle.pid = 0;
+ info = get_thread_db_info (ptid_get_pid (ptid));
- target_beneath->to_mourn_inferior ();
+ /* Access an lwp we know is stopped. */
+ info->proc_handle.ptid = ptid;
- /* 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 ();
+ 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 && 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);
- /* Detach thread_db target ops. */
- unpush_target (&thread_db_ops);
- using_thread_db = 0;
+ if (err != TD_OK)
+ error (_("Cannot find new threads: %s"), thread_db_err_str (err));
}
-static int
-find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
+static void
+thread_db_find_new_threads_1 (ptid_t ptid)
{
- td_thrinfo_t ti;
- td_err_e err;
- ptid_t ptid;
-
- err = td_thr_get_info_p (th_p, &ti);
- if (err != TD_OK)
- error (_("find_new_threads_callback: cannot get thread info: %s"),
- thread_db_err_str (err));
-
- if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
- return 0; /* A zombie -- ignore. */
-
- ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, ti.ti_tid);
-
- if (!in_thread_list (ptid))
- attach_thread (ptid, th_p, &ti, 1);
-
- return 0;
+ thread_db_find_new_threads_2 (ptid, 0);
}
+/* Implement the to_update_thread_list target method for this
+ target. */
+
static void
-thread_db_find_new_threads (void)
+thread_db_update_thread_list (struct target_ops *ops)
{
- td_err_e err;
+ struct thread_db_info *info;
+ struct inferior *inf;
- /* Iterate over all user-space threads to discover new threads. */
- err = td_ta_thr_iter_p (thread_agent, find_new_threads_callback, NULL,
- TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
- TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
- if (err != TD_OK)
- error (_("Cannot find new threads: %s"), thread_db_err_str (err));
+ prune_threads ();
+
+ 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);
+ }
+
+ /* Give the beneath target a chance to do extra processing. */
+ ops->beneath->to_update_thread_list (ops->beneath);
}
static char *
-thread_db_pid_to_str (ptid_t ptid)
+thread_db_pid_to_str (struct target_ops *ops, ptid_t ptid)
{
- if (is_thread (ptid))
+ struct thread_info *thread_info = find_thread_ptid (ptid);
+ struct target_ops *beneath;
+
+ if (thread_info != NULL && thread_info->priv != NULL)
{
static char buf[64];
- struct thread_info *thread_info;
+ thread_t tid;
- thread_info = find_thread_pid (ptid);
- if (thread_info == NULL)
- snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld) (Missing)",
- GET_THREAD (ptid), GET_LWP (ptid));
- else
- snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
- GET_THREAD (ptid), GET_LWP (ptid));
+ tid = thread_info->priv->tid;
+ snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
+ (unsigned long) tid, ptid_get_lwp (ptid));
return buf;
}
- if (target_beneath->to_pid_to_str (ptid))
- return target_beneath->to_pid_to_str (ptid);
-
- return normal_pid_to_str (ptid);
+ beneath = find_target_beneath (ops);
+ 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->dying)
+ if (info->priv == NULL)
+ return NULL;
+
+ if (info->priv->dying)
return "Exiting";
return NULL;
@@ -1044,32 +1414,62 @@ thread_db_extra_thread_info (struct thread_info *info)
is stored at OFFSET within the thread local storage for thread PTID. */
static CORE_ADDR
-thread_db_get_thread_local_address (ptid_t ptid,
+thread_db_get_thread_local_address (struct target_ops *ops,
+ ptid_t ptid,
CORE_ADDR lm,
CORE_ADDR offset)
{
- if (is_thread (ptid))
- {
- td_err_e err;
- void *address;
- struct thread_info *thread_info;
+ struct thread_info *thread_info;
+ struct target_ops *beneath;
- /* glibc doesn't provide the needed interface. */
- if (!td_thr_tls_get_addr_p)
- throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR,
- _("No TLS library support"));
+ /* Find the matching thread. */
+ thread_info = find_thread_ptid (ptid);
- /* Caller should have verified that lm != 0. */
- gdb_assert (lm != 0);
+ /* We may not have discovered the thread yet. */
+ if (thread_info != NULL && thread_info->priv == NULL)
+ thread_info = thread_from_lwp (ptid);
- /* Get info about the thread. */
- thread_info = find_thread_pid (ptid);
- thread_db_map_id2thr (thread_info, 1);
+ 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 (ptid_get_pid (ptid));
/* Finally, get the address of the variable. */
- err = td_thr_tls_get_addr_p (&thread_info->private->th,
- (void *)(size_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. */
@@ -1094,11 +1494,180 @@ thread_db_get_thread_local_address (ptid_t ptid,
: (CORE_ADDR) (uintptr_t) address);
}
- if (target_beneath->to_get_thread_local_address)
- return target_beneath->to_get_thread_local_address (ptid, lm, offset);
+ beneath = find_target_beneath (ops);
+ 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 (struct target_ops *self, long lwp, long thread)
+{
+ /* 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 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 (ptid_get_pid (inferior_ptid));
else
- throw_error (TLS_GENERIC_ERROR,
- _("TLS not supported on this target"));
+ 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
+ workaround can be disabled. */
+ if (info)
+ info->need_stale_parent_threads_check = 0;
+
+ beneath->to_resume (beneath, ptid, step, signo);
+}
+
+/* qsort helper function for info_auto_load_libthread_db, sort the
+ thread_db_info pointers primarily by their FILENAME and secondarily by their
+ PID, both in ascending order. */
+
+static int
+info_auto_load_libthread_db_compare (const void *ap, const void *bp)
+{
+ struct thread_db_info *a = *(struct thread_db_info **) ap;
+ struct thread_db_info *b = *(struct thread_db_info **) bp;
+ int retval;
+
+ retval = strcmp (a->filename, b->filename);
+ if (retval)
+ return retval;
+
+ return (a->pid > b->pid) - (a->pid - b->pid);
+}
+
+/* Implement 'info auto-load libthread-db'. */
+
+static void
+info_auto_load_libthread_db (char *args, int from_tty)
+{
+ struct ui_out *uiout = current_uiout;
+ const char *cs = args ? args : "";
+ struct thread_db_info *info, **array;
+ unsigned info_count, unique_filenames;
+ size_t max_filename_len, max_pids_len, pids_len;
+ struct cleanup *back_to;
+ char *pids;
+ int i;
+
+ 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");
+
+ make_cleanup_ui_out_table_begin_end (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;)
+ {
+ struct cleanup *chain = make_cleanup_ui_out_tuple_begin_end (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 (chain);
+ }
+
+ do_cleanups (back_to);
+
+ if (info_count == 0)
+ uiout->message (_("No auto-loaded libthread-db.\n"));
}
static void
@@ -1107,34 +1676,83 @@ init_thread_db_ops (void)
thread_db_ops.to_shortname = "multi-thread";
thread_db_ops.to_longname = "multi-threaded child process.";
thread_db_ops.to_doc = "Threads and pthreads support.";
- thread_db_ops.to_attach = thread_db_attach;
thread_db_ops.to_detach = thread_db_detach;
- thread_db_ops.to_resume = thread_db_resume;
thread_db_ops.to_wait = thread_db_wait;
- thread_db_ops.to_kill = thread_db_kill;
- thread_db_ops.to_create_inferior = thread_db_create_inferior;
- thread_db_ops.to_post_startup_inferior = thread_db_post_startup_inferior;
+ 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_get_thread_local_address
= thread_db_get_thread_local_address;
thread_db_ops.to_extra_thread_info = thread_db_extra_thread_info;
+ thread_db_ops.to_get_ada_task_ptid = thread_db_get_ada_task_ptid;
thread_db_ops.to_magic = OPS_MAGIC;
+
+ complete_target_initialization (&thread_db_ops);
}
+/* Provide a prototype to silence -Wmissing-prototypes. */
+extern initialize_file_ftype _initialize_thread_db;
+
void
_initialize_thread_db (void)
{
- /* Only initialize the module if we can load libthread_db. */
- if (thread_db_load ())
- {
- init_thread_db_ops ();
- add_target (&thread_db_ops);
-
- /* Add ourselves to objfile event chain. */
- observer_attach_new_objfile (thread_db_new_objfile);
- }
+ init_thread_db_ops ();
+
+ /* 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 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);
+
+ add_setshow_optional_filename_cmd ("libthread-db-search-path",
+ class_support,
+ &libthread_db_search_path, _("\
+Set search path for libthread_db."), _("\
+Show the current search path or libthread_db."), _("\
+This path is used to search for libthread_db to be loaded into \
+gdb itself.\n\
+Its value is a colon (':') separate list of directories to search.\n\
+Setting the search path to an empty list resets it to its default value."),
+ set_libthread_db_search_path,
+ NULL,
+ &setlist, &showlist);
+
+ add_setshow_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);
+
+ 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);
}