| /* Thread management interface, for the remote server for GDB. |
| Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008 |
| Free Software Foundation, Inc. |
| |
| Contributed by MontaVista Software. |
| |
| 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 "server.h" |
| |
| #include "linux-low.h" |
| |
| extern int debug_threads; |
| |
| static int thread_db_use_events; |
| |
| #ifdef HAVE_THREAD_DB_H |
| #include <thread_db.h> |
| #endif |
| |
| #include "gdb_proc_service.h" |
| |
| #include <stdint.h> |
| |
| /* 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; |
| |
| static int find_one_thread (int); |
| static int find_new_threads_callback (const td_thrhandle_t *th_p, void *data); |
| |
| 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 HAVE_TD_VERSION |
| case TD_VERSION: |
| return "version mismatch between libthread_db and libpthread"; |
| #endif |
| default: |
| snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err); |
| return buf; |
| } |
| } |
| |
| #if 0 |
| static char * |
| thread_db_state_str (td_thr_state_e state) |
| { |
| static char buf[64]; |
| |
| switch (state) |
| { |
| case TD_THR_STOPPED: |
| return "stopped by debugger"; |
| case TD_THR_RUN: |
| return "runnable"; |
| case TD_THR_ACTIVE: |
| return "active"; |
| case TD_THR_ZOMBIE: |
| return "zombie"; |
| case TD_THR_SLEEP: |
| return "sleeping"; |
| case TD_THR_STOPPED_ASLEEP: |
| return "stopped by debugger AND blocked"; |
| default: |
| snprintf (buf, sizeof (buf), "unknown thread_db state %d", state); |
| return buf; |
| } |
| } |
| #endif |
| |
| static int |
| thread_db_create_event (CORE_ADDR where) |
| { |
| td_event_msg_t msg; |
| td_err_e err; |
| struct process_info *process; |
| |
| if (debug_threads) |
| fprintf (stderr, "Thread creation event.\n"); |
| |
| /* FIXME: This assumes we don't get another event. |
| In the LinuxThreads implementation, this is safe, |
| because all events come from the manager thread |
| (except for its own creation, of course). */ |
| err = td_ta_event_getmsg (thread_agent, &msg); |
| if (err != TD_OK) |
| fprintf (stderr, "thread getmsg err: %s\n", |
| thread_db_err_str (err)); |
| |
| /* If we do not know about the main thread yet, this would be a good time to |
| find it. We need to do this to pick up the main thread before any newly |
| created threads. */ |
| process = get_thread_process (current_inferior); |
| if (process->thread_known == 0) |
| find_one_thread (process->lwpid); |
| |
| /* msg.event == TD_EVENT_CREATE */ |
| |
| find_new_threads_callback (msg.th_p, NULL); |
| |
| return 0; |
| } |
| |
| #if 0 |
| static int |
| thread_db_death_event (CORE_ADDR where) |
| { |
| if (debug_threads) |
| fprintf (stderr, "Thread death event.\n"); |
| |
| return 0; |
| } |
| #endif |
| |
| static int |
| thread_db_enable_reporting () |
| { |
| td_thr_events_t events; |
| td_notify_t notify; |
| td_err_e err; |
| |
| /* Set the process wide mask saying which events we're interested in. */ |
| td_event_emptyset (&events); |
| td_event_addset (&events, TD_CREATE); |
| |
| #if 0 |
| /* This is reported to be broken in glibc 2.1.3. A different approach |
| will be necessary to support that. */ |
| td_event_addset (&events, TD_DEATH); |
| #endif |
| |
| err = td_ta_set_event (thread_agent, &events); |
| if (err != TD_OK) |
| { |
| warning ("Unable to set global thread event mask: %s", |
| thread_db_err_str (err)); |
| return 0; |
| } |
| |
| /* Get address for thread creation breakpoint. */ |
| err = td_ta_event_addr (thread_agent, TD_CREATE, ¬ify); |
| if (err != TD_OK) |
| { |
| warning ("Unable to get location for thread creation breakpoint: %s", |
| thread_db_err_str (err)); |
| return 0; |
| } |
| set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr, |
| thread_db_create_event); |
| |
| #if 0 |
| /* Don't concern ourselves with reported thread deaths, only |
| with actual thread deaths (via wait). */ |
| |
| /* Get address for thread death breakpoint. */ |
| err = td_ta_event_addr (thread_agent, TD_DEATH, ¬ify); |
| if (err != TD_OK) |
| { |
| warning ("Unable to get location for thread death breakpoint: %s", |
| thread_db_err_str (err)); |
| return; |
| } |
| set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr, |
| thread_db_death_event); |
| #endif |
| |
| return 1; |
| } |
| |
| static int |
| find_one_thread (int lwpid) |
| { |
| td_thrhandle_t th; |
| td_thrinfo_t ti; |
| td_err_e err; |
| struct thread_info *inferior; |
| struct process_info *process; |
| |
| inferior = (struct thread_info *) find_inferior_id (&all_threads, lwpid); |
| process = get_thread_process (inferior); |
| if (process->thread_known) |
| return 1; |
| |
| /* Get information about this thread. */ |
| err = td_ta_map_lwp2thr (thread_agent, process->lwpid, &th); |
| if (err != TD_OK) |
| error ("Cannot get thread handle for LWP %d: %s", |
| lwpid, thread_db_err_str (err)); |
| |
| err = td_thr_get_info (&th, &ti); |
| if (err != TD_OK) |
| error ("Cannot get thread info for LWP %d: %s", |
| lwpid, thread_db_err_str (err)); |
| |
| if (debug_threads) |
| fprintf (stderr, "Found thread %ld (LWP %d)\n", |
| ti.ti_tid, ti.ti_lid); |
| |
| if (process->lwpid != ti.ti_lid) |
| { |
| warning ("PID mismatch! Expected %ld, got %ld", |
| (long) process->lwpid, (long) ti.ti_lid); |
| return 0; |
| } |
| |
| if (thread_db_use_events) |
| { |
| err = td_thr_event_enable (&th, 1); |
| if (err != TD_OK) |
| error ("Cannot enable thread event reporting for %d: %s", |
| ti.ti_lid, thread_db_err_str (err)); |
| } |
| |
| /* If the new thread ID is zero, a final thread ID will be available |
| later. Do not enable thread debugging yet. */ |
| if (ti.ti_tid == 0) |
| return 0; |
| |
| process->thread_known = 1; |
| process->tid = ti.ti_tid; |
| process->th = th; |
| |
| return 1; |
| } |
| |
| static void |
| maybe_attach_thread (const td_thrhandle_t *th_p, td_thrinfo_t *ti_p) |
| { |
| td_err_e err; |
| struct thread_info *inferior; |
| struct process_info *process; |
| |
| inferior = (struct thread_info *) find_inferior_id (&all_threads, |
| ti_p->ti_lid); |
| if (inferior != NULL) |
| return; |
| |
| if (debug_threads) |
| fprintf (stderr, "Attaching to thread %ld (LWP %d)\n", |
| ti_p->ti_tid, ti_p->ti_lid); |
| linux_attach_lwp (ti_p->ti_lid); |
| inferior = (struct thread_info *) find_inferior_id (&all_threads, |
| ti_p->ti_lid); |
| if (inferior == NULL) |
| { |
| warning ("Could not attach to thread %ld (LWP %d)\n", |
| ti_p->ti_tid, ti_p->ti_lid); |
| return; |
| } |
| |
| process = inferior_target_data (inferior); |
| |
| process->tid = ti_p->ti_tid; |
| process->thread_known = 1; |
| process->th = *th_p; |
| |
| if (thread_db_use_events) |
| { |
| err = td_thr_event_enable (th_p, 1); |
| if (err != TD_OK) |
| error ("Cannot enable thread event reporting for %d: %s", |
| ti_p->ti_lid, thread_db_err_str (err)); |
| } |
| } |
| |
| static int |
| find_new_threads_callback (const td_thrhandle_t *th_p, void *data) |
| { |
| td_thrinfo_t ti; |
| td_err_e err; |
| |
| err = td_thr_get_info (th_p, &ti); |
| if (err != TD_OK) |
| error ("Cannot get thread info: %s", thread_db_err_str (err)); |
| |
| /* Check for zombies. */ |
| if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE) |
| return 0; |
| |
| maybe_attach_thread (th_p, &ti); |
| |
| return 0; |
| } |
| |
| static void |
| thread_db_find_new_threads (void) |
| { |
| td_err_e err; |
| |
| /* This function is only called when we first initialize thread_db. |
| First locate the initial thread. If it is not ready for |
| debugging yet, then stop. */ |
| if (find_one_thread (all_threads.head->id) == 0) |
| return; |
| |
| /* Iterate over all user-space threads to discover new threads. */ |
| err = td_ta_thr_iter (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)); |
| } |
| |
| /* Cache all future symbols that thread_db might request. We can not |
| request symbols at arbitrary states in the remote protocol, only |
| when the client tells us that new symbols are available. So when |
| we load the thread library, make sure to check the entire list. */ |
| |
| static void |
| thread_db_look_up_symbols (void) |
| { |
| const char **sym_list = td_symbol_list (); |
| CORE_ADDR unused; |
| |
| for (sym_list = td_symbol_list (); *sym_list; sym_list++) |
| look_up_one_symbol (*sym_list, &unused); |
| } |
| |
| int |
| thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset, |
| CORE_ADDR load_module, CORE_ADDR *address) |
| { |
| #if HAVE_TD_THR_TLS_GET_ADDR |
| psaddr_t addr; |
| td_err_e err; |
| struct process_info *process; |
| |
| process = get_thread_process (thread); |
| if (!process->thread_known) |
| find_one_thread (process->lwpid); |
| if (!process->thread_known) |
| return TD_NOTHR; |
| |
| /* 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 = td_thr_tls_get_addr (&process->th, (psaddr_t) (uintptr_t) load_module, |
| offset, &addr); |
| if (err == TD_OK) |
| { |
| *address = (CORE_ADDR) (uintptr_t) addr; |
| return 0; |
| } |
| else |
| return err; |
| #else |
| return -1; |
| #endif |
| } |
| |
| int |
| thread_db_init (int use_events) |
| { |
| int err; |
| |
| /* FIXME drow/2004-10-16: This is the "overall process ID", which |
| GNU/Linux calls tgid, "thread group ID". When we support |
| attaching to threads, the original thread may not be the correct |
| thread. We would have to get the process ID from /proc for NPTL. |
| For LinuxThreads we could do something similar: follow the chain |
| of parent processes until we find the highest one we're attached |
| to, and use its tgid. |
| |
| This isn't the only place in gdbserver that assumes that the first |
| process in the list is the thread group leader. */ |
| proc_handle.pid = ((struct inferior_list_entry *)current_inferior)->id; |
| |
| /* Allow new symbol lookups. */ |
| all_symbols_looked_up = 0; |
| |
| thread_db_use_events = use_events; |
| |
| err = td_ta_new (&proc_handle, &thread_agent); |
| switch (err) |
| { |
| case TD_NOLIBTHREAD: |
| /* No thread library was detected. */ |
| return 0; |
| |
| case TD_OK: |
| /* The thread library was detected. */ |
| |
| if (use_events && thread_db_enable_reporting () == 0) |
| return 0; |
| thread_db_find_new_threads (); |
| thread_db_look_up_symbols (); |
| all_symbols_looked_up = 1; |
| return 1; |
| |
| default: |
| warning ("error initializing thread_db library: %s", |
| thread_db_err_str (err)); |
| } |
| |
| return 0; |
| } |