| /* libthread_db assisted debugging support, generic parts. |
| |
| Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008 |
| 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 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 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, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| |
| #include "gdb_assert.h" |
| #include <dlfcn.h> |
| #include "gdb_proc_service.h" |
| #include "gdb_thread_db.h" |
| |
| #include "bfd.h" |
| #include "exceptions.h" |
| #include "gdbthread.h" |
| #include "inferior.h" |
| #include "symfile.h" |
| #include "objfiles.h" |
| #include "target.h" |
| #include "regcache.h" |
| #include "solib-svr4.h" |
| #include "gdbcore.h" |
| #include "observer.h" |
| #include "linux-nat.h" |
| |
| #include <signal.h> |
| |
| #ifdef HAVE_GNU_LIBC_VERSION_H |
| #include <gnu/libc-version.h> |
| #endif |
| |
| #ifndef LIBTHREAD_DB_SO |
| #define LIBTHREAD_DB_SO "libthread_db.so.1" |
| #endif |
| |
| /* If we're running on GNU/Linux, we must explicitly attach to any new |
| threads. */ |
| |
| /* 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 |
| <proc_service.h> 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); |
| static void detach_thread (ptid_t ptid, int verbose); |
| |
| |
| /* Building process ids. */ |
| |
| #define GET_PID(ptid) ptid_get_pid (ptid) |
| #define GET_LWP(ptid) ptid_get_lwp (ptid) |
| #define GET_THREAD(ptid) ptid_get_tid (ptid) |
| |
| #define is_lwp(ptid) (GET_LWP (ptid) != 0) |
| #define is_thread(ptid) (GET_THREAD (ptid) != 0) |
| |
| #define BUILD_LWP(lwp, pid) ptid_build (pid, lwp, 0) |
| |
| |
| /* Use "struct private_thread_info" to cache thread state. This is |
| a substantial optimization. */ |
| |
| struct private_thread_info |
| { |
| /* Flag set when we see a TD_DEATH event for this thread. */ |
| 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; |
| }; |
| |
| |
| static char * |
| thread_db_err_str (td_err_e err) |
| { |
| static char buf[64]; |
| |
| switch (err) |
| { |
| case TD_OK: |
| return "generic 'call succeeded'"; |
| case TD_ERR: |
| return "generic error"; |
| case TD_NOTHR: |
| return "no thread to satisfy query"; |
| case TD_NOSV: |
| return "no sync handle to satisfy query"; |
| case TD_NOLWP: |
| return "no LWP to satisfy query"; |
| case TD_BADPH: |
| return "invalid process handle"; |
| case TD_BADTH: |
| return "invalid thread handle"; |
| case TD_BADSH: |
| return "invalid synchronization handle"; |
| case TD_BADTA: |
| return "invalid thread agent"; |
| case TD_BADKEY: |
| return "invalid key"; |
| case TD_NOMSG: |
| return "no event message for getmsg"; |
| case TD_NOFPREGS: |
| return "FPU register set not available"; |
| case TD_NOLIBTHREAD: |
| return "application not linked with libthread"; |
| case TD_NOEVENT: |
| return "requested event is not supported"; |
| case TD_NOCAPAB: |
| return "capability not available"; |
| case TD_DBERR: |
| return "debugger service failed"; |
| case TD_NOAPLIC: |
| return "operation not applicable to"; |
| case TD_NOTSD: |
| return "no thread-specific data for this thread"; |
| case TD_MALLOC: |
| return "malloc failed"; |
| case TD_PARTIALREG: |
| return "only part of register set was written/read"; |
| case TD_NOXREGS: |
| return "X register set not available for this thread"; |
| #ifdef THREAD_DB_HAS_TD_NOTALLOC |
| case TD_NOTALLOC: |
| return "thread has not yet allocated TLS for given module"; |
| #endif |
| #ifdef THREAD_DB_HAS_TD_VERSION |
| case TD_VERSION: |
| return "versions of libpthread and libthread_db do not match"; |
| #endif |
| #ifdef THREAD_DB_HAS_TD_NOTLS |
| case TD_NOTLS: |
| return "there is no TLS segment in the given module"; |
| #endif |
| default: |
| snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err); |
| return buf; |
| } |
| } |
| |
| /* Return 1 if any threads have been registered. There may be none if |
| the threading library is not fully initialized yet. */ |
| |
| static int |
| have_threads_callback (struct thread_info *thread, void *dummy) |
| { |
| return 1; |
| } |
| |
| static int |
| have_threads (void) |
| { |
| return iterate_over_threads (have_threads_callback, NULL) != NULL; |
| } |
| |
| /* A callback function for td_ta_thr_iter, which we use to map all |
| threads to LWPs. |
| |
| THP is a handle to the current thread; if INFOP is not NULL, the |
| struct thread_info associated with this thread is returned in |
| *INFOP. |
| |
| If the thread is a zombie, TD_THR_ZOMBIE is returned. Otherwise, |
| zero is returned to indicate success. */ |
| |
| static int |
| thread_get_info_callback (const td_thrhandle_t *thp, void *infop) |
| { |
| td_thrinfo_t ti; |
| td_err_e err; |
| struct thread_info *thread_info; |
| ptid_t thread_ptid; |
| |
| err = 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); |
| |
| /* 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) |
| { |
| /* New thread. Attach to it now (why wait?). */ |
| attach_thread (thread_ptid, thp, &ti); |
| thread_info = find_thread_pid (thread_ptid); |
| gdb_assert (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. */ |
| |
| 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; |
| |
| if (GET_LWP (ptid) == 0) |
| ptid = BUILD_LWP (GET_PID (ptid), GET_PID (ptid)); |
| |
| gdb_assert (is_lwp (ptid)); |
| |
| 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); |
| } |
| |
| static ptid_t |
| lwp_from_thread (ptid_t ptid) |
| { |
| return BUILD_LWP (GET_LWP (ptid), GET_PID (ptid)); |
| } |
| |
| |
| void |
| thread_db_init (struct target_ops *target) |
| { |
| 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_err_e err; |
| |
| 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; |
| |
| td_ta_map_id2thr_p = verbose_dlsym (handle, "td_ta_map_id2thr"); |
| if (td_ta_map_id2thr_p == NULL) |
| return 0; |
| |
| td_ta_map_lwp2thr_p = verbose_dlsym (handle, "td_ta_map_lwp2thr"); |
| if (td_ta_map_lwp2thr_p == NULL) |
| return 0; |
| |
| td_ta_thr_iter_p = verbose_dlsym (handle, "td_ta_thr_iter"); |
| if (td_ta_thr_iter_p == NULL) |
| return 0; |
| |
| td_thr_validate_p = verbose_dlsym (handle, "td_thr_validate"); |
| if (td_thr_validate_p == NULL) |
| return 0; |
| |
| td_thr_get_info_p = verbose_dlsym (handle, "td_thr_get_info"); |
| if (td_thr_get_info_p == NULL) |
| return 0; |
| |
| /* Initialize the library. */ |
| err = td_init_p (); |
| if (err != TD_OK) |
| { |
| warning (_("Cannot initialize libthread_db: %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"); |
| |
| return 1; |
| } |
| |
| static td_err_e |
| enable_thread_event (td_thragent_t *thread_agent, int event, CORE_ADDR *bp) |
| { |
| td_notify_t notify; |
| td_err_e err; |
| |
| /* 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; |
| } |
| |
| 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 |
| |
| /* 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; |
| |
| /* 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); |
| |
| err = td_ta_set_event_p (thread_agent, &events); |
| if (err != TD_OK) |
| { |
| warning (_("Unable to set global thread event mask: %s"), |
| thread_db_err_str (err)); |
| return; |
| } |
| |
| /* Delete previous thread event breakpoints, if any. */ |
| remove_thread_event_breakpoints (); |
| td_create_bp_addr = 0; |
| td_death_bp_addr = 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; |
| } |
| |
| /* Set up the thread death event. */ |
| err = enable_thread_event (thread_agent, TD_DEATH, &td_death_bp_addr); |
| if (err != TD_OK) |
| { |
| warning (_("Unable to get location for thread death breakpoint: %s"), |
| thread_db_err_str (err)); |
| return; |
| } |
| } |
| |
| 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; |
| } |
| |
| static void |
| check_thread_signals (void) |
| { |
| #ifdef GET_THREAD_SIGNALS |
| if (!thread_signals) |
| { |
| sigset_t mask; |
| int i; |
| |
| GET_THREAD_SIGNALS (&mask); |
| sigemptyset (&thread_stop_set); |
| sigemptyset (&thread_print_set); |
| |
| for (i = 1; i < NSIG; i++) |
| { |
| if (sigismember (&mask, i)) |
| { |
| if (signal_stop_update (target_signal_from_host (i), 0)) |
| sigaddset (&thread_stop_set, i); |
| if (signal_print_update (target_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 |
| an inferior is created (or otherwise acquired, e.g. attached to) |
| and when new shared libraries are loaded into a running process. */ |
| |
| 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; |
| |
| if (info_verbose) |
| 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)) |
| 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; |
| } |
| } |
| |
| static void |
| thread_db_new_objfile (struct objfile *objfile) |
| { |
| if (objfile != NULL) |
| 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) |
| { |
| 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)) |
| { |
| tp = find_thread_pid (ptid); |
| gdb_assert (tp != NULL); |
| |
| if (!tp->private->dying) |
| return; |
| |
| delete_thread (ptid); |
| } |
| |
| 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. */ |
| |
| /* 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) |
| return; |
| |
| /* 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)); |
| |
| /* 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)); |
| } |
| |
| static void |
| detach_thread (ptid_t ptid, int verbose) |
| { |
| 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); |
| 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) |
| { |
| /* 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. */ |
| |
| thread->private->th_valid = 0; |
| thread->private->ti_valid = 0; |
| |
| return 0; |
| } |
| |
| static void |
| thread_db_resume (ptid_t ptid, int step, enum target_signal signo) |
| { |
| struct cleanup *old_chain = save_inferior_ptid (); |
| |
| if (GET_PID (ptid) == -1) |
| inferior_ptid = lwp_from_thread (inferior_ptid); |
| else if (is_thread (ptid)) |
| ptid = lwp_from_thread (ptid); |
| |
| /* Clear cached data which may not be valid after the resume. */ |
| iterate_over_threads (clear_lwpid_callback, NULL); |
| |
| target_beneath->to_resume (ptid, step, signo); |
| |
| do_cleanups (old_chain); |
| } |
| |
| /* Check if PID is currently stopped at the location of a thread event |
| breakpoint location. If it is, read the event message and act upon |
| the event. */ |
| |
| static void |
| check_event (ptid_t ptid) |
| { |
| 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. */ |
| |
| loop = 1; |
| |
| do |
| { |
| 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); |
| |
| switch (msg.event) |
| { |
| case TD_CREATE: |
| /* Call attach_thread whether or not we already know about a |
| thread with this thread ID. */ |
| attach_thread (ptid, msg.th_p, &ti); |
| |
| break; |
| |
| case TD_DEATH: |
| |
| if (!in_thread_list (ptid)) |
| error (_("Spurious thread death event.")); |
| |
| detach_thread (ptid, print_thread_events); |
| |
| break; |
| |
| default: |
| error (_("Spurious thread event.")); |
| } |
| } |
| while (loop); |
| } |
| |
| 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); |
| |
| ptid = target_beneath->to_wait (ptid, ourstatus); |
| |
| if (ourstatus->kind == TARGET_WAITKIND_EXITED |
| || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) |
| return pid_to_ptid (-1); |
| |
| if (ourstatus->kind == TARGET_WAITKIND_EXECD) |
| { |
| remove_thread_event_breakpoints (); |
| unpush_target (&thread_db_ops); |
| using_thread_db = 0; |
| |
| return pid_to_ptid (GET_PID (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 |
| && ourstatus->value.sig == TARGET_SIGNAL_TRAP) |
| /* Check for a thread event. */ |
| check_event (ptid); |
| |
| if (have_threads ()) |
| { |
| /* 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; |
| } |
| |
| return ptid; |
| } |
| |
| 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 (); |
| } |
| |
| static void |
| thread_db_mourn_inferior (void) |
| { |
| /* Forget about the child's process ID. We shouldn't need it |
| anymore. */ |
| proc_handle.pid = 0; |
| |
| target_beneath->to_mourn_inferior (); |
| |
| /* 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; |
| } |
| |
| 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; |
| |
| 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 (ti.ti_tid == 0) |
| { |
| /* A thread ID of zero means that this is the main thread, but |
| glibc has not yet initialized thread-local storage and the |
| pthread library. We do not know what the thread's TID will |
| be yet. Just enable event reporting and otherwise ignore |
| it. */ |
| |
| 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 0; |
| } |
| |
| if (!in_thread_list (ptid)) |
| attach_thread (ptid, th_p, &ti); |
| |
| return 0; |
| } |
| |
| static void |
| thread_db_find_new_threads (void) |
| { |
| td_err_e 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 char * |
| thread_db_pid_to_str (ptid_t ptid) |
| { |
| if (is_thread (ptid)) |
| { |
| static char buf[64]; |
| struct thread_info *thread_info; |
| |
| 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)); |
| |
| return buf; |
| } |
| |
| if (target_beneath->to_pid_to_str (ptid)) |
| return target_beneath->to_pid_to_str (ptid); |
| |
| return normal_pid_to_str (ptid); |
| } |
| |
| /* Return a string describing the state of the thread specified by |
| INFO. */ |
| |
| static char * |
| thread_db_extra_thread_info (struct thread_info *info) |
| { |
| 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, |
| 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 (); |
| |
| /* 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; |
| |
| thread = iterate_over_threads (same_ptid_callback, &ptid); |
| if (thread != NULL) |
| ptid = thread->ptid; |
| } |
| |
| if (is_thread (ptid)) |
| { |
| td_err_e err; |
| void *address; |
| struct thread_info *thread_info; |
| |
| /* 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")); |
| |
| /* Caller should have verified that lm != 0. */ |
| gdb_assert (lm != 0); |
| |
| /* Get info about the thread. */ |
| thread_info = find_thread_pid (ptid); |
| gdb_assert (thread_info); |
| 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); |
| |
| #ifdef THREAD_DB_HAS_TD_NOTALLOC |
| /* The memory hasn't been allocated, yet. */ |
| if (err == TD_NOTALLOC) |
| /* Now, if libthread_db provided the initialization image's |
| address, we *could* try to build a non-lvalue value from |
| the initialization image. */ |
| throw_error (TLS_NOT_ALLOCATED_YET_ERROR, |
| _("TLS not allocated yet")); |
| #endif |
| |
| /* Something else went wrong. */ |
| if (err != TD_OK) |
| throw_error (TLS_GENERIC_ERROR, |
| (("%s")), thread_db_err_str (err)); |
| |
| /* Cast assuming host == target. Joy. */ |
| /* Do proper sign extension for the target. */ |
| gdb_assert (exec_bfd); |
| return (bfd_get_sign_extend_vma (exec_bfd) > 0 |
| ? (CORE_ADDR) (intptr_t) address |
| : (CORE_ADDR) (uintptr_t) address); |
| } |
| |
| if (target_beneath->to_get_thread_local_address) |
| return target_beneath->to_get_thread_local_address (ptid, lm, offset); |
| else |
| throw_error (TLS_GENERIC_ERROR, |
| _("TLS not supported on this target")); |
| } |
| |
| static void |
| 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_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_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; |
| 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_magic = OPS_MAGIC; |
| } |
| |
| 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); |
| } |
| } |