| /* Validate a thread handle. |
| Copyright (C) 1999-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@redhat.com>, 1999. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "thread_dbP.h" |
| #include <stdbool.h> |
| |
| static td_err_e |
| check_thread_list (const td_thrhandle_t *th, psaddr_t head, bool *uninit) |
| { |
| td_err_e err; |
| psaddr_t next, ofs; |
| |
| err = DB_GET_FIELD (next, th->th_ta_p, head, list_t, next, 0); |
| if (err == TD_OK) |
| { |
| if (next == 0) |
| { |
| *uninit = true; |
| return TD_NOTHR; |
| } |
| err = DB_GET_FIELD_ADDRESS (ofs, th->th_ta_p, 0, pthread, list, 0); |
| } |
| |
| while (err == TD_OK) |
| { |
| if (next == head) |
| return TD_NOTHR; |
| |
| if (next - (ofs - (psaddr_t) 0) == th->th_unique) |
| return TD_OK; |
| |
| err = DB_GET_FIELD (next, th->th_ta_p, next, list_t, next, 0); |
| } |
| |
| return err; |
| } |
| |
| |
| td_err_e |
| td_thr_validate (const td_thrhandle_t *th) |
| { |
| td_err_e err; |
| psaddr_t list; |
| |
| LOG ("td_thr_validate"); |
| |
| /* First check the list with threads using user allocated stacks. */ |
| bool uninit = false; |
| err = DB_GET_SYMBOL (list, th->th_ta_p, __stack_user); |
| if (err == TD_OK) |
| err = check_thread_list (th, list, &uninit); |
| |
| /* If our thread is not on this list search the list with stack |
| using implementation allocated stacks. */ |
| if (err == TD_NOTHR) |
| { |
| err = DB_GET_SYMBOL (list, th->th_ta_p, stack_used); |
| if (err == TD_OK) |
| err = check_thread_list (th, list, &uninit); |
| |
| if (err == TD_NOTHR && uninit && th->th_unique == 0) |
| /* __pthread_initialize_minimal has not run yet. |
| There is only the special case thread handle. */ |
| err = TD_OK; |
| } |
| |
| if (err == TD_OK) |
| { |
| /* Verify that this is not a stale element in a fork child. */ |
| pid_t match_pid = ps_getpid (th->th_ta_p->ph); |
| psaddr_t pid; |
| err = DB_GET_FIELD (pid, th->th_ta_p, th->th_unique, pthread, pid, 0); |
| if (err == TD_OK && (pid_t) (uintptr_t) pid < 0) |
| { |
| /* This was a thread that was about to fork, or it is the new sole |
| thread in a fork child. In the latter case, its tid was stored |
| via CLONE_CHILD_SETTID and so is already the proper child PID. */ |
| if (-(pid_t) (uintptr_t) pid == match_pid) |
| /* It is about to do a fork, but is really still the parent PID. */ |
| pid = (psaddr_t) (uintptr_t) match_pid; |
| else |
| /* It must be a fork child, whose new PID is in the tid field. */ |
| err = DB_GET_FIELD (pid, th->th_ta_p, th->th_unique, |
| pthread, tid, 0); |
| } |
| if (err == TD_OK && (pid_t) (uintptr_t) pid != match_pid) |
| err = TD_NOTHR; |
| } |
| |
| return err; |
| } |