X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Flinux-thread-db.c;h=23c29c9dd1d2d274f26fe4f0828f4358fe055210;hb=a3ed37d8bcb97329ff3acebba63c754d153d3363;hp=460e044c26ee379685c132378646064c843a21df;hpb=4105de343e714e0096723905ada442f1524776a6;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c index 460e044c26..23c29c9dd1 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) 1999-2013 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, @@ -16,9 +15,7 @@ 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" @@ -26,29 +23,94 @@ #include #include "gdb_proc_service.h" #include "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 "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 "linux-procfs.h" +#include "linux-osdata.h" +#include "auto-load.h" +#include "cli/cli-utils.h" #include +#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 LinuxThreads and NPTL, the two glibc threading + libraries. It assumes that each thread is permanently assigned + to a single light-weight process (LWP). + + 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. */ @@ -56,84 +118,169 @@ /* 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; +struct thread_db_info +{ + struct thread_db_info *next; + + /* Process id this object refers to. */ + int pid; + + /* 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 + 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; + + /* 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; -/* Connection to the libthread_db library. */ -static td_thragent_t *thread_agent; + /* Location of the thread death event breakpoint. */ + CORE_ADDR td_death_bp_addr; -/* Pointers to the libthread_db functions. */ + /* Pointers to the libthread_db functions. */ -static td_err_e (*td_init_p) (void); + td_err_e (*td_init_p) (void); -static td_err_e (*td_ta_new_p) (struct ps_prochandle * ps, + 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; + 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); +}; -/* 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); - +/* 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); + +/* 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; + + info = xcalloc (1, sizeof (*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; -/* Building process ids. */ + info->next = thread_db_list; + thread_db_list = info; -#define GET_PID(ptid) ptid_get_pid (ptid) -#define GET_LWP(ptid) ptid_get_lwp (ptid) -#define GET_THREAD(ptid) ptid_get_tid (ptid) + return info; +} + +/* Return the thread_db_info object representing the bookkeeping + related to process PID, if any; NULL otherwise. */ -#define is_lwp(ptid) (GET_LWP (ptid) != 0) -#define is_thread(ptid) (GET_THREAD (ptid) != 0) +static struct thread_db_info * +get_thread_db_info (int pid) +{ + struct thread_db_info *info; -#define BUILD_LWP(lwp, pid) ptid_build (pid, lwp, 0) + 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); +} + +/* 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); /* Use "struct private_thread_info" to cache thread state. This is @@ -145,11 +292,8 @@ 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; }; @@ -224,17 +368,30 @@ thread_db_err_str (td_err_e err) the threading library is not fully initialized yet. */ static int -have_threads_callback (struct thread_info *thread, void *dummy) +have_threads_callback (struct thread_info *thread, void *args) { - return 1; + int pid = * (int *) args; + + if (ptid_get_pid (thread->ptid) != pid) + return 0; + + return thread->private != NULL; } static int -have_threads (void) +have_threads (ptid_t ptid) { - return iterate_over_threads (have_threads_callback, NULL) != NULL; + 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. @@ -246,264 +403,221 @@ have_threads (void) zero is returned to indicate success. */ static int -thread_get_info_callback (const td_thrhandle_t *thp, void *infop) +thread_get_info_callback (const td_thrhandle_t *thp, void *argp) { td_thrinfo_t ti; td_err_e err; - struct thread_info *thread_info; ptid_t thread_ptid; + struct thread_get_info_inout *inout; + struct thread_db_info *info; + + inout = argp; + info = inout->thread_db_info; - err = td_thr_get_info_p (thp, &ti); + err = info->td_thr_get_info_p (thp, &ti); if (err != TD_OK) error (_("thread_get_info_callback: cannot get thread info: %s"), thread_db_err_str (err)); /* Fill the cache. */ - thread_ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, ti.ti_tid); - thread_info = find_thread_pid (thread_ptid); + 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) - { - 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; - } - - if (thread_info == NULL) + if (inout->thread_info == NULL) { /* 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); + 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); } - 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; - return 0; } - -/* Accessor functions for the thread_db information, with caching. */ - -static void -thread_db_map_id2thr (struct thread_info *thread_info, int fatal) -{ - td_err_e err; - - if (thread_info->private->th_valid) - return; - - err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (thread_info->ptid), - &thread_info->private->th); - if (err != TD_OK) - { - if (fatal) - error (_("Cannot find thread %ld: %s"), - (long) GET_THREAD (thread_info->ptid), - thread_db_err_str (err)); - } - else - thread_info->private->th_valid = 1; -} -/* Convert between user-level thread ids and LWP ids. */ +/* Fetch the user-level thread id of PTID. */ -static ptid_t +static void thread_from_lwp (ptid_t ptid) { td_thrhandle_t th; td_err_e err; - struct thread_info *thread_info; - ptid_t thread_ptid; + struct thread_db_info *info; + struct thread_get_info_inout io = {0}; - if (GET_LWP (ptid) == 0) - ptid = BUILD_LWP (GET_PID (ptid), GET_PID (ptid)); + /* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */ + th.th_unique = 0; - gdb_assert (is_lwp (ptid)); + /* This ptid comes from linux-nat.c, which should always fill in the + LWP. */ + gdb_assert (GET_LWP (ptid) != 0); - err = td_ta_map_lwp2thr_p (thread_agent, GET_LWP (ptid), &th); + info = get_thread_db_info (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); 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); -} - -static ptid_t -lwp_from_thread (ptid_t ptid) -{ - return BUILD_LWP (GET_LWP (ptid), GET_PID (ptid)); + /* Long-winded way of fetching the thread info. */ + io.thread_db_info = info; + io.thread_info = NULL; + thread_get_info_callback (&th, &io); } -void -thread_db_init (struct target_ops *target) +/* 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. */ +int +thread_db_attach_lwp (ptid_t ptid) { - target_beneath = target; -} - -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; -} - -static int -thread_db_load (void) -{ - void *handle; + td_thrhandle_t th; + td_thrinfo_t ti; td_err_e err; + struct thread_db_info *info; - handle = dlopen (LIBTHREAD_DB_SO, 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"); - return 0; - } - - /* Initialize pointers to the dynamic library functions we will use. - Essential functions first. */ - - td_init_p = verbose_dlsym (handle, "td_init"); - if (td_init_p == NULL) - return 0; - - td_ta_new_p = verbose_dlsym (handle, "td_ta_new"); - if (td_ta_new_p == NULL) - return 0; + info = get_thread_db_info (GET_PID (ptid)); - td_ta_map_id2thr_p = verbose_dlsym (handle, "td_ta_map_id2thr"); - if (td_ta_map_id2thr_p == NULL) + if (info == NULL) return 0; - td_ta_map_lwp2thr_p = verbose_dlsym (handle, "td_ta_map_lwp2thr"); - if (td_ta_map_lwp2thr_p == NULL) - return 0; + /* This ptid comes from linux-nat.c, which should always fill in the + LWP. */ + gdb_assert (GET_LWP (ptid) != 0); - td_ta_thr_iter_p = verbose_dlsym (handle, "td_ta_thr_iter"); - if (td_ta_thr_iter_p == NULL) - return 0; + /* Access an lwp we know is stopped. */ + info->proc_handle.ptid = ptid; - td_thr_validate_p = verbose_dlsym (handle, "td_thr_validate"); - if (td_thr_validate_p == NULL) - return 0; + /* 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); - td_thr_get_info_p = verbose_dlsym (handle, "td_thr_get_info"); - if (td_thr_get_info_p == NULL) + 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; - /* Initialize the library. */ - err = td_init_p (); + err = info->td_thr_get_info_p (&th, &ti); if (err != TD_OK) { - warning (_("Cannot initialize libthread_db: %s"), thread_db_err_str (err)); + warning (_("Cannot get thread info: %s"), thread_db_err_str (err)); 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"); - + attach_thread (ptid, &th, &ti); 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; +} + static td_err_e -enable_thread_event (td_thragent_t *thread_agent, int event, CORE_ADDR *bp) +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 = td_ta_event_addr_p (thread_agent, event, ¬ify); + 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 - (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; } +/* 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 minimal_symbol *version_msym; + CORE_ADDR version_addr; + char *version; + int err, got, retval = 0; + + version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL); + if (version_msym == NULL) + return 0; + + version_addr = SYMBOL_VALUE_ADDRESS (version_msym); + got = target_read_string (version_addr, &version, 32, &err); + if (err == 0 && memchr (version, 0, got) == &version[got -1]) + { + int major, minor; + + retval = (sscanf (version, "%d.%d", &major, &minor) == 2 + && (major < ver_major_min + || (major == ver_major_min && minor < ver_minor_min))); + } + xfree (version); + + return retval; +} + static void enable_thread_event_reporting (void) { td_thr_events_t events; - td_notify_t notify; 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 (td_ta_event_addr_p == NULL || td_ta_set_event_p == NULL - || td_ta_event_getmsg_p == NULL || td_thr_event_enable_p == NULL) + 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; /* 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 + /* There is a bug fixed between linuxthreads 2.1.3 and 2.2 by + commit 2e4581e4fba917f1779cd0a010a45698586c190a + * manager.c (pthread_exited): Correctly report event as TD_REAP + instead of TD_DEATH. Fix comments. + where event reporting facility is broken for TD_DEATH events, + so don't enable it if we have glibc but a lower version. */ + if (!inferior_has_bug ("__linuxthreads_version", 2, 2)) td_event_addset (&events, TD_DEATH); - err = td_ta_set_event_p (thread_agent, &events); + err = info->td_ta_set_event_p (info->thread_agent, &events); if (err != TD_OK) { warning (_("Unable to set global thread event mask: %s"), @@ -513,11 +627,11 @@ enable_thread_event_reporting (void) /* Delete previous thread event breakpoints, if any. */ remove_thread_event_breakpoints (); - td_create_bp_addr = 0; - td_death_bp_addr = 0; + info->td_create_bp_addr = 0; + info->td_death_bp_addr = 0; /* Set up the thread creation event. */ - err = enable_thread_event (thread_agent, TD_CREATE, &td_create_bp_addr); + 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"), @@ -526,7 +640,7 @@ enable_thread_event_reporting (void) } /* Set up the thread death event. */ - err = enable_thread_event (thread_agent, TD_DEATH, &td_death_bp_addr); + 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"), @@ -535,32 +649,504 @@ enable_thread_event_reporting (void) } } +/* 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. */ + +static int +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) + { + if (libthread_db_debug) + exception_fprintf (gdb_stderr, 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; + } + } + return 0; +} + +/* 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 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; + + /* 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; + + err = info->td_init_p (); + if (err != TD_OK) + { + warning (_("Cannot initialize libthread_db: %s"), + thread_db_err_str (err)); + return 0; + } + + info->td_ta_new_p = verbose_dlsym (info->handle, "td_ta_new"); + if (info->td_ta_new_p == NULL) + return 0; + + /* 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) + printf_unfiltered (_("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; + } + + info->td_ta_map_id2thr_p = verbose_dlsym (info->handle, "td_ta_map_id2thr"); + if (info->td_ta_map_id2thr_p == NULL) + return 0; + + info->td_ta_map_lwp2thr_p = verbose_dlsym (info->handle, + "td_ta_map_lwp2thr"); + if (info->td_ta_map_lwp2thr_p == NULL) + return 0; + + info->td_ta_thr_iter_p = verbose_dlsym (info->handle, "td_ta_thr_iter"); + if (info->td_ta_thr_iter_p == NULL) + return 0; + + info->td_thr_validate_p = verbose_dlsym (info->handle, "td_thr_validate"); + if (info->td_thr_validate_p == NULL) + return 0; + + info->td_thr_get_info_p = verbose_dlsym (info->handle, "td_thr_get_info"); + if (info->td_thr_get_info_p == NULL) + return 0; + + /* These are not essential. */ + info->td_ta_event_addr_p = dlsym (info->handle, "td_ta_event_addr"); + info->td_ta_set_event_p = dlsym (info->handle, "td_ta_set_event"); + info->td_ta_clear_event_p = dlsym (info->handle, "td_ta_clear_event"); + info->td_ta_event_getmsg_p = dlsym (info->handle, "td_ta_event_getmsg"); + info->td_thr_event_enable_p = dlsym (info->handle, "td_thr_event_enable"); + info->td_thr_tls_get_addr_p = dlsym (info->handle, "td_thr_tls_get_addr"); + + if (thread_db_find_new_threads_silently (inferior_ptid) != 0) + { + /* 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) + { + const char *library; + + library = dladdr_to_soname (*info->td_ta_new_p); + if (library == NULL) + library = LIBTHREAD_DB_SO; + + printf_unfiltered (_("Using host libthread_db library \"%s\".\n"), + library); + } + + /* 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); + + /* Enable event reporting, but not when debugging a core file. */ + if (target_has_execution) + enable_thread_event_reporting (); + + return 1; +} + +/* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute, + relative, or just LIBTHREAD_DB. */ + +static int +try_thread_db_load (const char *library) +{ + void *handle; + struct thread_db_info *info; + + if (libthread_db_debug) + printf_unfiltered (_("Trying host libthread_db library: %s.\n"), + library); + handle = dlopen (library, RTLD_NOW); + if (handle == NULL) + { + if (libthread_db_debug) + printf_unfiltered (_("dlopen failed: %s.\n"), dlerror ()); + return 0; + } + + if (libthread_db_debug && strchr (library, '/') == NULL) + { + void *td_init; + + td_init = dlsym (handle, "td_init"); + if (td_init != NULL) + { + const char *const libpath = dladdr_to_soname (td_init); + + if (libpath != NULL) + printf_unfiltered (_("Host %s resolved to: %s.\n"), + library, libpath); + } + } + + info = add_thread_db_info (handle); + + /* Do not save system library name, that one is always trusted. */ + if (strchr (library, '/') != NULL) + info->filename = gdb_realpath (library); + + if (try_thread_db_load_1 (info)) + return 1; + + /* This library "refused" to work on current inferior. */ + delete_thread_db_info (GET_PID (inferior_ptid)); + 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. */ + +static int +try_thread_db_load_from_pdir_1 (struct objfile *obj, const char *subdir) +{ + struct cleanup *cleanup; + char *path, *cp; + int result; + + if (obj->name[0] != '/') + { + warning (_("Expected absolute pathname for libpthread in the" + " inferior, but got %s."), obj->name); + return 0; + } + + path = xmalloc (strlen (obj->name) + (subdir ? strlen (subdir) + 1 : 0) + + 1 + strlen (LIBTHREAD_DB_SO) + 1); + 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); + + if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db " + "library \"%s\" from $pdir.\n"), + path)) + result = 0; + else + result = try_thread_db_load (path); + + do_cleanups (cleanup); + return result; +} + +/* 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) +{ + struct objfile *obj; + + if (!auto_load_thread_db) + return 0; + + ALL_OBJFILES (obj) + if (libpthread_name_p (obj->name)) + { + 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; +} + +/* Handle $sdir in libthread-db-search-path. + Look for libthread_db in the system dirs, or wherever a plain + dlopen(file_without_path) will look. + The result is true for success. */ + +static int +try_thread_db_load_from_sdir (void) +{ + return try_thread_db_load (LIBTHREAD_DB_SO); +} + +/* Try to load libthread_db from directory DIR of length DIR_LEN. + The result is true for success. */ + +static int +try_thread_db_load_from_dir (const char *dir, size_t dir_len) +{ + struct cleanup *cleanup; + char *path; + int result; + + if (!auto_load_thread_db) + return 0; + + path = xmalloc (dir_len + 1 + strlen (LIBTHREAD_DB_SO) + 1); + cleanup = make_cleanup (xfree, path); + + memcpy (path, dir, dir_len); + path[dir_len] = '/'; + strcpy (path + dir_len + 1, LIBTHREAD_DB_SO); + + if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db " + "library \"%s\" from explicit " + "directory.\n"), + path)) + result = 0; + else + result = try_thread_db_load (path); + + do_cleanups (cleanup); + return result; +} + +/* Search libthread_db_search_path for libthread_db which "agrees" + to work on current inferior. + The result is true for success. */ + +static int +thread_db_load_search (void) +{ + VEC (char_ptr) *dir_vec; + struct cleanup *cleanups; + char *this_dir; + int i, rc = 0; + + dir_vec = dirnames_to_char_ptr_vec (libthread_db_search_path); + cleanups = make_cleanup_free_char_ptr_vec (dir_vec); + + for (i = 0; VEC_iterate (char_ptr, dir_vec, i, this_dir); ++i) + { + const int pdir_len = sizeof ("$pdir") - 1; + size_t this_dir_len; + + this_dir_len = strlen (this_dir); + + if (strncmp (this_dir, "$pdir", pdir_len) == 0 + && (this_dir[pdir_len] == '\0' + || this_dir[pdir_len] == '/')) + { + char *subdir = NULL; + struct cleanup *free_subdir_cleanup + = make_cleanup (null_cleanup, NULL); + + if (this_dir[pdir_len] == '/') + { + subdir = xmalloc (strlen (this_dir)); + make_cleanup (xfree, subdir); + strcpy (subdir, this_dir + pdir_len + 1); + } + rc = try_thread_db_load_from_pdir (subdir); + do_cleanups (free_subdir_cleanup); + if (rc) + break; + } + else if (strcmp (this_dir, "$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; + } + } + } + + do_cleanups (cleanups); + if (libthread_db_debug) + printf_unfiltered (_("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 (obj->name)) + 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 (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; + + if (thread_db_load_search ()) + return 1; + + /* We couldn't find a libthread_db. + If the inferior has a libpthread warn the user. */ + if (has_libpthread ()) + { + warning (_("Unable to find libthread_db matching inferior's thread" + " library, thread debugging will not be available.")); + return 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 -disable_thread_event_reporting (void) +disable_thread_event_reporting (struct thread_db_info *info) { - td_thr_events_t events; + 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); - td_ta_set_event_p (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 (); - td_create_bp_addr = 0; - td_death_bp_addr = 0; + info->td_create_bp_addr = 0; + info->td_death_bp_addr = 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); @@ -568,15 +1154,14 @@ 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 @@ -586,95 +1171,60 @@ 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) - return; - - /* Don't attempt to use thread_db for remote targets. */ - if (!target_can_run (¤t_target)) + if (!thread_db_load ()) 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))) check_for_thread_db (); } +/* This function is called via the inferior_created observer. + This handles the case of debugging statically linked executables. */ + +static void +thread_db_inferior_created (struct target_ops *target, int from_tty) +{ + check_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. */ + 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, int verbose) + const td_thrinfo_t *ti_p) { + struct private_thread_info *private; struct thread_info *tp; td_err_e err; + struct thread_db_info *info; /* If we're being called after a TD_CREATE event, we may already know about this thread. There are two ways this can happen. We @@ -686,105 +1236,138 @@ attach_thread (ptid_t ptid, const td_thrhandle_t *th_p, thread ID. In the first case we don't need to do anything; in the second case we should discard information about the dead thread and attach to the new one. */ - if (in_thread_list (ptid)) + tp = find_thread_ptid (ptid); + if (tp != NULL) { - tp = find_thread_pid (ptid); - gdb_assert (tp != NULL); - - if (!tp->private->dying) - return; + /* 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 (!tp->private->dying) + return 0; - delete_thread (ptid); + 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. */ + if (target_has_execution) + check_thread_signals (); /* 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; + if (target_has_execution + && tp == NULL) + { + int res; + + res = lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid))); + if (res < 0) + { + /* Error, stop iterating. */ + return 0; + } + else if (res > 0) + { + /* Pretend this thread doesn't exist yet, and keep + iterating. */ + return 1; + } + + /* Otherwise, we sucessfully attached to the thread. */ + } + + /* Construct the thread's private data. */ + private = xmalloc (sizeof (struct private_thread_info)); + memset (private, 0, sizeof (struct private_thread_info)); + + /* A thread ID of zero may mean the thread library has not initialized + yet. But we shouldn't even get here if that's the case. FIXME: + if we change GDB to always have at least one thread in the thread + list this will have to go somewhere else; maybe private == NULL + until the thread_db target claims it. */ + gdb_assert (ti_p->ti_tid != 0); + private->th = *th_p; + private->tid = ti_p->ti_tid; + if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE) + private->dying = 1; /* Add the thread to GDB's thread list. */ - tp = add_thread (ptid); - tp->private = xmalloc (sizeof (struct private_thread_info)); - memset (tp->private, 0, sizeof (struct private_thread_info)); + if (tp == NULL) + add_thread_with_info (ptid, private); + else + tp->private = private; - if (verbose) - printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid)); + info = get_thread_db_info (GET_PID (ptid)); - /* 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)); + /* 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)); + } + + return 1; } static void -detach_thread (ptid_t ptid, int verbose) +detach_thread (ptid_t ptid) { struct thread_info *thread_info; - 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); + 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; } static void -thread_db_detach (char *args, int from_tty) -{ - disable_thread_event_reporting (); - - /* There's no need to save & restore inferior_ptid here, since the - inferior is not supposed to survive this function call. */ - inferior_ptid = lwp_from_thread (inferior_ptid); - - target_beneath->to_detach (args, from_tty); - - /* Should this be done by detach_command? */ - target_mourn_inferior (); -} - -static int -clear_lwpid_callback (struct thread_info *thread, void *dummy) +thread_db_detach (struct target_ops *ops, char *args, int from_tty) { - /* 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. */ + struct target_ops *target_beneath = find_target_beneath (ops); + struct thread_db_info *info; - thread->private->th_valid = 0; - thread->private->ti_valid = 0; + info = get_thread_db_info (GET_PID (inferior_ptid)); - return 0; -} - -static void -thread_db_resume (ptid_t ptid, int step, enum target_signal signo) -{ - struct cleanup *old_chain = save_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 (); + } - 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 (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_detach (target_beneath, args, from_tty); - target_beneath->to_resume (ptid, step, signo); + /* NOTE: From this point on, inferior_ptid is null_ptid. */ - do_cleanups (old_chain); + /* If there are no more processes using libpthread, detach the + thread_db target ops. */ + if (!thread_db_list) + unpush_target (&thread_db_ops); } /* Check if PID is currently stopped at the location of a thread event @@ -794,17 +1377,33 @@ thread_db_resume (ptid_t ptid, int step, enum target_signal signo) 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 = read_pc_pid (ptid) - gdbarch_decr_pc_after_break (current_gdbarch); - if (stop_pc != td_create_bp_addr && stop_pc != td_death_bp_addr) + 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 @@ -823,7 +1422,7 @@ check_event (ptid_t ptid) do { - err = td_ta_event_getmsg_p (thread_agent, &msg); + err = info->td_ta_event_getmsg_p (info->thread_agent, &msg); if (err != TD_OK) { if (err == TD_NOMSG) @@ -833,18 +1432,18 @@ check_event (ptid_t ptid) thread_db_err_str (err)); } - err = td_thr_get_info_p (msg.th_p, &ti); + 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, ti.ti_tid); + 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, 1); + attach_thread (ptid, msg.th_p, &ti); break; @@ -853,7 +1452,7 @@ check_event (ptid_t ptid) if (!in_thread_list (ptid)) error (_("Spurious thread death event.")); - detach_thread (ptid, 1); + detach_thread (ptid); break; @@ -865,101 +1464,100 @@ check_event (ptid_t ptid) } static ptid_t -thread_db_wait (ptid_t ptid, struct target_waitstatus *ourstatus) +thread_db_wait (struct target_ops *ops, + ptid_t ptid, struct target_waitstatus *ourstatus, + int options) { - extern ptid_t trap_ptid; + struct thread_db_info *info; + struct target_ops *beneath = find_target_beneath (ops); - if (GET_PID (ptid) != -1 && is_thread (ptid)) - ptid = lwp_from_thread (ptid); + ptid = beneath->to_wait (beneath, ptid, ourstatus, options); - ptid = target_beneath->to_wait (ptid, ourstatus); + if (ourstatus->kind == TARGET_WAITKIND_IGNORE) + return ptid; if (ourstatus->kind == TARGET_WAITKIND_EXITED - || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) - return pid_to_ptid (-1); + || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) + return ptid; + + info = get_thread_db_info (GET_PID (ptid)); + + /* If this process isn't using thread_db, we're done. */ + if (info == NULL) + return ptid; if (ourstatus->kind == TARGET_WAITKIND_EXECD) { - remove_thread_event_breakpoints (); - unpush_target (&thread_db_ops); - using_thread_db = 0; + /* 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); - return pid_to_ptid (GET_PID (ptid)); + /* 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 ()) - thread_db_find_new_threads (); + if (ourstatus->kind == TARGET_WAITKIND_STOPPED && !have_threads (ptid)) + thread_db_find_new_threads_1 (ptid); if (ourstatus->kind == TARGET_WAITKIND_STOPPED - && ourstatus->value.sig == TARGET_SIGNAL_TRAP) + && ourstatus->value.sig == GDB_SIGNAL_TRAP) /* Check for a thread event. */ check_event (ptid); - if (have_threads ()) + 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. */ - - if (!ptid_equal (trap_ptid, null_ptid)) - trap_ptid = thread_from_lwp (trap_ptid); - - ptid = thread_from_lwp (ptid); - if (GET_PID (ptid) == -1) - ourstatus->kind = TARGET_WAITKIND_SPURIOUS; + /* Fill in the thread's user-level thread id. */ + thread_from_lwp (ptid); } return ptid; } static void -thread_db_kill (void) +thread_db_mourn_inferior (struct target_ops *ops) { - /* 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 (); -} + struct target_ops *target_beneath = find_target_beneath (ops); -static void -thread_db_mourn_inferior (void) -{ - /* Forget about the child's process ID. We shouldn't need it - anymore. */ - proc_handle.pid = 0; + delete_thread_db_info (GET_PID (inferior_ptid)); - target_beneath->to_mourn_inferior (); + 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. */ - unpush_target (&thread_db_ops); - using_thread_db = 0; + 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_thrinfo_t ti; td_err_e err; ptid_t ptid; + struct thread_info *tp; + struct callback_data *cb_data = data; + struct thread_db_info *info = cb_data->info; - err = td_thr_get_info_p (th_p, &ti); + 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)); - 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 (ti.ti_tid == 0) { /* A thread ID of zero means that this is the main thread, but @@ -968,54 +1566,192 @@ find_new_threads_callback (const td_thrhandle_t *th_p, void *data) be yet. Just enable event reporting and otherwise ignore it. */ - 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)); + /* 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; } - if (!in_thread_list (ptid)) - attach_thread (ptid, th_p, &ti, 1); + /* 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); + + if (tgid != -1 && tgid != info->pid) + 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; + } 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 (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); + } + + if (errp != NULL) + *errp = err; + + return data.new_threads; +} + +/* 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_find_new_threads (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 i, loop; + + info = get_thread_db_info (GET_PID (ptid)); + + /* Access an lwp we know is stopped. */ + info->proc_handle.ptid = ptid; + + 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); - /* 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)); } +static void +thread_db_find_new_threads_1 (ptid_t ptid) +{ + thread_db_find_new_threads_2 (ptid, 0); +} + +static int +update_thread_core (struct lwp_info *info, void *closure) +{ + info->core = linux_common_core_of_thread (info->ptid); + return 0; +} + +static void +thread_db_find_new_threads (struct target_ops *ops) +{ + struct thread_db_info *info; + struct inferior *inf; + + ALL_INFERIORS (inf) + { + struct thread_info *thread; + + if (inf->pid == 0) + continue; + + info = get_thread_db_info (inf->pid); + if (info == NULL) + continue; + + thread = any_live_thread_of_process (inf->pid); + if (thread == NULL || thread->executing) + continue; + + thread_db_find_new_threads_1 (thread->ptid); + } + + if (target_has_execution) + iterate_over_lwps (minus_one_ptid /* iterate over all */, + update_thread_core, NULL); +} + 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->private != 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->private->tid; + snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)", + tid, GET_LWP (ptid)); return buf; } - if (target_beneath->to_pid_to_str (ptid)) - return target_beneath->to_pid_to_str (ptid); + 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); } @@ -1026,67 +1762,57 @@ thread_db_pid_to_str (ptid_t ptid) static char * thread_db_extra_thread_info (struct thread_info *info) { + if (info->private == NULL) + return NULL; + if (info->private->dying) return "Exiting"; return NULL; } -/* Return 1 if this thread has the same LWP as the passed PTID. */ - -static int -same_ptid_callback (struct thread_info *thread, void *arg) -{ - ptid_t *ptid_p = arg; - - return GET_LWP (thread->ptid) == GET_LWP (*ptid_p); -} - /* Get the address of the thread local variable in load module LM which 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 we have not discovered any threads yet, check now. */ - if (!is_thread (ptid) && !have_threads ()) - thread_db_find_new_threads (); + struct thread_info *thread_info; + struct target_ops *beneath; - /* Try to find a matching thread if we still have the LWP ID instead - of the thread ID. */ - if (!is_thread (ptid)) - { - struct thread_info *thread; + /* If we have not discovered any threads yet, check now. */ + if (!have_threads (ptid)) + thread_db_find_new_threads_1 (ptid); - thread = iterate_over_threads (same_ptid_callback, &ptid); - if (thread != NULL) - ptid = thread->ptid; - } + /* Find the matching thread. */ + thread_info = find_thread_ptid (ptid); - if (is_thread (ptid)) + if (thread_info != NULL && thread_info->private != NULL) { td_err_e err; - void *address; - struct thread_info *thread_info; + psaddr_t address; + struct thread_db_info *info; + + info = get_thread_db_info (GET_PID (ptid)); /* glibc doesn't provide the needed interface. */ - if (!td_thr_tls_get_addr_p) + 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); - /* Get info about the thread. */ - thread_info = find_thread_pid (ptid); - thread_db_map_id2thr (thread_info, 1); - /* Finally, get the address of the variable. */ - err = td_thr_tls_get_addr_p (&thread_info->private->th, - (void *)(size_t) lm, - offset, &address); + /* 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); #ifdef THREAD_DB_HAS_TD_NOTALLOC /* The memory hasn't been allocated, yet. */ @@ -1111,13 +1837,207 @@ 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); + 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; +} + +/* 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) +{ + 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); +} + +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 (GET_PID (inferior_ptid)); + else + info = get_thread_db_info (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 = xmalloc (sizeof (*array) * info_count); + back_to = make_cleanup (xfree, array); + + info_count = 0; + for (info = thread_db_list; info; info = info->next) + if (info->filename != NULL) + array[info_count++] = info; + + /* Sort ARRAY by filenames and PIDs. */ + + qsort (array, info_count, sizeof (*array), + info_auto_load_libthread_db_compare); + + /* Calculate the number of unique filenames (rows) and the maximum string + length of PIDs list for the unique filenames (columns). */ + + unique_filenames = 0; + max_filename_len = 0; + max_pids_len = 0; + pids_len = 0; + for (i = 0; i < info_count; i++) + { + int pid = array[i]->pid; + size_t this_pid_len; + + for (this_pid_len = 0; pid != 0; pid /= 10) + this_pid_len++; + + if (i == 0 || strcmp (array[i - 1]->filename, array[i]->filename) != 0) + { + unique_filenames++; + max_filename_len = max (max_filename_len, + strlen (array[i]->filename)); + + if (i > 0) + { + pids_len -= strlen (", "); + max_pids_len = max (max_pids_len, pids_len); + } + pids_len = 0; + } + pids_len += this_pid_len + strlen (", "); + } + if (i) + { + pids_len -= strlen (", "); + max_pids_len = max (max_pids_len, pids_len); + } + + /* Table header shifted right by preceding "libthread-db: " would not match + its columns. */ + if (info_count > 0 && args == auto_load_info_scripts_pattern_nl) + ui_out_text (uiout, "\n"); + + make_cleanup_ui_out_table_begin_end (uiout, 2, unique_filenames, + "LinuxThreadDbTable"); + + ui_out_table_header (uiout, max_filename_len, ui_left, "filename", + "Filename"); + ui_out_table_header (uiout, pids_len, ui_left, "PIDs", "Pids"); + ui_out_table_body (uiout); + + pids = xmalloc (max_pids_len + 1); + make_cleanup (xfree, pids); + + /* Note I is incremented inside the cycle, not at its end. */ + for (i = 0; i < info_count;) + { + struct cleanup *chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL); + char *pids_end; + + info = array[i]; + ui_out_field_string (uiout, "filename", info->filename); + pids_end = pids; + + while (i < info_count && strcmp (info->filename, array[i]->filename) == 0) + { + if (pids_end != pids) + { + *pids_end++ = ','; + *pids_end++ = ' '; + } + pids_end += xsnprintf (pids_end, &pids[max_pids_len + 1] - pids_end, + "%u", array[i]->pid); + gdb_assert (pids_end < &pids[max_pids_len + 1]); + + i++; + } + *pids_end = '\0'; + + ui_out_field_string (uiout, "pids", pids); + + ui_out_text (uiout, "\n"); + do_cleanups (chain); + } + + do_cleanups (back_to); + + if (info_count == 0) + ui_out_message (uiout, 0, _("No auto-loaded libthread-db.\n")); +} + static void init_thread_db_ops (void) { @@ -1125,9 +2045,8 @@ init_thread_db_ops (void) thread_db_ops.to_longname = "multi-threaded child process."; thread_db_ops.to_doc = "Threads and pthreads support."; 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_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_pid_to_str = thread_db_pid_to_str; @@ -1136,19 +2055,72 @@ init_thread_db_ops (void) 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; } +/* 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 (); + 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. */ + + 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); }