1 | /* Test for exit/dlclose race (Bug 22180). |
2 | Copyright (C) 2017-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | /* This file must be run from within a directory called "stdlib". */ |
20 | |
21 | /* This test verifies that when dlopen in one thread races against exit |
22 | in another thread, we don't call registered destructor twice. |
23 | |
24 | Expected result: |
25 | second |
26 | first |
27 | ... clean termination |
28 | */ |
29 | |
30 | #include <stdio.h> |
31 | #include <stdlib.h> |
32 | #include <errno.h> |
33 | #include <semaphore.h> |
34 | #include <support/check.h> |
35 | #include <support/xdlfcn.h> |
36 | #include <support/xthread.h> |
37 | |
38 | /* Semaphore to ensure we have a happens-before between the first function |
39 | starting and exit being called. */ |
40 | sem_t order1; |
41 | |
42 | /* Semaphore to ensure we have a happens-before between the second function |
43 | starting and the first function returning. */ |
44 | sem_t order2; |
45 | |
46 | void * |
47 | exit_thread (void *arg) |
48 | { |
49 | /* Wait for the dlclose to start... */ |
50 | sem_wait (sem: &order1); |
51 | /* Then try to run the exit sequence which should call all |
52 | __cxa_atexit registered functions and in parallel with |
53 | the executing dlclose(). */ |
54 | exit (0); |
55 | } |
56 | |
57 | |
58 | void |
59 | last (void) |
60 | { |
61 | /* Let dlclose thread proceed. */ |
62 | sem_post (sem: &order2); |
63 | } |
64 | |
65 | int |
66 | main (void) |
67 | { |
68 | int value; |
69 | void *dso; |
70 | pthread_t thread; |
71 | |
72 | atexit (func: last); |
73 | |
74 | dso = xdlopen (filename: "$ORIGIN/test-dlclose-exit-race-helper.so" , |
75 | RTLD_NOW|RTLD_GLOBAL); |
76 | if ((value = pthread_create (newthread: &thread, NULL, start_routine: exit_thread, NULL)) != 0) |
77 | { |
78 | /* If pthread_create fails, then exit() is called in the main |
79 | thread instead of a second thread, so the semaphore post that |
80 | would have happened in 'last' gets blocked behind the call to |
81 | first() - which is waiting on the semaphore, and thus |
82 | hangs. */ |
83 | sem_post (sem: &order2); |
84 | errno = value; |
85 | FAIL_EXIT1 ("pthread_create: %m" ); |
86 | } |
87 | |
88 | xdlclose (handle: dso); |
89 | xpthread_join (thr: thread); |
90 | |
91 | FAIL_EXIT1 ("Did not terminate via exit(0) in exit_thread() as expected." ); |
92 | } |
93 | |