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76a50749 | 1 | /* Validate a thread handle. |
b168057a | 2 | Copyright (C) 1999-2015 Free Software Foundation, Inc. |
76a50749 UD |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@redhat.com>, 1999. | |
5 | ||
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. | |
10 | ||
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. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ | |
76a50749 UD |
19 | |
20 | #include "thread_dbP.h" | |
090addb4 | 21 | #include <stdbool.h> |
76a50749 UD |
22 | |
23 | static td_err_e | |
090addb4 | 24 | check_thread_list (const td_thrhandle_t *th, psaddr_t head, bool *uninit) |
76a50749 | 25 | { |
7f08f55a RM |
26 | td_err_e err; |
27 | psaddr_t next, ofs; | |
28 | ||
29 | err = DB_GET_FIELD (next, th->th_ta_p, head, list_t, next, 0); | |
30 | if (err == TD_OK) | |
31 | { | |
32 | if (next == 0) | |
090addb4 RM |
33 | { |
34 | *uninit = true; | |
35 | return TD_NOTHR; | |
36 | } | |
7f08f55a RM |
37 | err = DB_GET_FIELD_ADDRESS (ofs, th->th_ta_p, 0, pthread, list, 0); |
38 | } | |
39 | ||
40 | while (err == TD_OK) | |
41 | { | |
42 | if (next == head) | |
43 | return TD_NOTHR; | |
44 | ||
45 | if (next - (ofs - (psaddr_t) 0) == th->th_unique) | |
46 | return TD_OK; | |
47 | ||
48 | err = DB_GET_FIELD (next, th->th_ta_p, next, list_t, next, 0); | |
49 | } | |
50 | ||
51 | return err; | |
76a50749 UD |
52 | } |
53 | ||
54 | ||
55 | td_err_e | |
56 | td_thr_validate (const td_thrhandle_t *th) | |
57 | { | |
7f08f55a RM |
58 | td_err_e err; |
59 | psaddr_t list; | |
60 | ||
76a50749 UD |
61 | LOG ("td_thr_validate"); |
62 | ||
63 | /* First check the list with threads using user allocated stacks. */ | |
090addb4 | 64 | bool uninit = false; |
7f08f55a RM |
65 | err = DB_GET_SYMBOL (list, th->th_ta_p, __stack_user); |
66 | if (err == TD_OK) | |
090addb4 | 67 | err = check_thread_list (th, list, &uninit); |
76a50749 UD |
68 | |
69 | /* If our thread is not on this list search the list with stack | |
70 | using implementation allocated stacks. */ | |
7f08f55a RM |
71 | if (err == TD_NOTHR) |
72 | { | |
73 | err = DB_GET_SYMBOL (list, th->th_ta_p, stack_used); | |
74 | if (err == TD_OK) | |
090addb4 RM |
75 | err = check_thread_list (th, list, &uninit); |
76 | ||
7d9d8bd1 RM |
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; | |
7f08f55a | 81 | } |
76a50749 | 82 | |
d11dc9ec RM |
83 | if (err == TD_OK) |
84 | { | |
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) | |
90 | { | |
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); | |
101 | } | |
102 | if (err == TD_OK && (pid_t) (uintptr_t) pid != match_pid) | |
103 | err = TD_NOTHR; | |
104 | } | |
105 | ||
7f08f55a | 106 | return err; |
76a50749 | 107 | } |