Fix -Wundef warnings in regex_internal.h
[glibc.git] / nptl_db / td_thr_validate.c
blob8e6a21bc74a614f4f0a02aac765d19c717b4f47c
1 /* Validate a thread handle.
2 Copyright (C) 1999-2014 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@redhat.com>, 1999.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
20 #include "thread_dbP.h"
21 #include <stdbool.h>
23 static td_err_e
24 check_thread_list (const td_thrhandle_t *th, psaddr_t head, bool *uninit)
26 td_err_e err;
27 psaddr_t next, ofs;
29 err = DB_GET_FIELD (next, th->th_ta_p, head, list_t, next, 0);
30 if (err == TD_OK)
32 if (next == 0)
34 *uninit = true;
35 return TD_NOTHR;
37 err = DB_GET_FIELD_ADDRESS (ofs, th->th_ta_p, 0, pthread, list, 0);
40 while (err == TD_OK)
42 if (next == head)
43 return TD_NOTHR;
45 if (next - (ofs - (psaddr_t) 0) == th->th_unique)
46 return TD_OK;
48 err = DB_GET_FIELD (next, th->th_ta_p, next, list_t, next, 0);
51 return err;
55 td_err_e
56 td_thr_validate (const td_thrhandle_t *th)
58 td_err_e err;
59 psaddr_t list;
61 LOG ("td_thr_validate");
63 /* First check the list with threads using user allocated stacks. */
64 bool uninit = false;
65 err = DB_GET_SYMBOL (list, th->th_ta_p, __stack_user);
66 if (err == TD_OK)
67 err = check_thread_list (th, list, &uninit);
69 /* If our thread is not on this list search the list with stack
70 using implementation allocated stacks. */
71 if (err == TD_NOTHR)
73 err = DB_GET_SYMBOL (list, th->th_ta_p, stack_used);
74 if (err == TD_OK)
75 err = check_thread_list (th, list, &uninit);
77 if (err == TD_NOTHR && uninit && th->th_unique == 0)
78 /* __pthread_initialize_minimal has not run yet.
79 There is only the special case thread handle. */
80 err = TD_OK;
83 if (err == TD_OK)
85 /* Verify that this is not a stale element in a fork child. */
86 pid_t match_pid = ps_getpid (th->th_ta_p->ph);
87 psaddr_t pid;
88 err = DB_GET_FIELD (pid, th->th_ta_p, th->th_unique, pthread, pid, 0);
89 if (err == TD_OK && (pid_t) (uintptr_t) pid < 0)
91 /* This was a thread that was about to fork, or it is the new sole
92 thread in a fork child. In the latter case, its tid was stored
93 via CLONE_CHILD_SETTID and so is already the proper child PID. */
94 if (-(pid_t) (uintptr_t) pid == match_pid)
95 /* It is about to do a fork, but is really still the parent PID. */
96 pid = (psaddr_t) (uintptr_t) match_pid;
97 else
98 /* It must be a fork child, whose new PID is in the tid field. */
99 err = DB_GET_FIELD (pid, th->th_ta_p, th->th_unique,
100 pthread, tid, 0);
102 if (err == TD_OK && (pid_t) (uintptr_t) pid != match_pid)
103 err = TD_NOTHR;
106 return err;