1 | /* Verify that DSO is unloaded only if its TLS objects are destroyed. |
2 | Copyright (C) 2013-2022 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 | /* For the default case, i.e. NO_DELETE not defined, the test dynamically loads |
20 | a DSO and spawns a thread that subsequently calls into the DSO to register a |
21 | destructor for an object in the DSO and then calls dlclose on the handle for |
22 | the DSO. When the thread exits, the DSO should not be unloaded or else the |
23 | destructor called during thread exit will crash. Further in the main |
24 | thread, the DSO is opened and closed again, at which point the DSO should be |
25 | unloaded. |
26 | |
27 | When NO_DELETE is defined, the DSO is loaded twice, once with just RTLD_LAZY |
28 | flag and the second time with the RTLD_NODELETE flag set. The thread is |
29 | spawned, destructor registered and then thread exits without closing the |
30 | DSO. In the main thread, the first handle is then closed, followed by the |
31 | second handle. In the end, the DSO should remain loaded due to the |
32 | RTLD_NODELETE flag being set in the second dlopen call. */ |
33 | |
34 | #include <pthread.h> |
35 | #include <stdio.h> |
36 | #include <unistd.h> |
37 | #include <string.h> |
38 | #include <errno.h> |
39 | #include <link.h> |
40 | #include <stdbool.h> |
41 | #include <support/xdlfcn.h> |
42 | |
43 | #ifndef NO_DELETE |
44 | # define LOADED_IS_GOOD false |
45 | #endif |
46 | |
47 | #ifndef H2_RTLD_FLAGS |
48 | # define H2_RTLD_FLAGS (RTLD_LAZY) |
49 | #endif |
50 | |
51 | #define DSO_NAME "$ORIGIN/tst-tls-atexit-lib.so" |
52 | |
53 | /* Walk through the map in the _r_debug structure to see if our lib is still |
54 | loaded. */ |
55 | static bool |
56 | is_loaded (void) |
57 | { |
58 | struct link_map *lm = (struct link_map *) _r_debug.r_map; |
59 | |
60 | for (; lm; lm = lm->l_next) |
61 | if (lm->l_type == lt_loaded && lm->l_name |
62 | && strcmp (basename (DSO_NAME), basename (lm->l_name)) == 0) |
63 | { |
64 | printf (format: "%s is still loaded\n" , lm->l_name); |
65 | return true; |
66 | } |
67 | return false; |
68 | } |
69 | |
70 | /* Accept a valid handle returned by DLOPEN, load the reg_dtor symbol to |
71 | register a destructor and then call dlclose on the handle. The dlclose |
72 | should not unload the DSO since the destructor has not been called yet. */ |
73 | static void * |
74 | reg_dtor_and_close (void *h) |
75 | { |
76 | void (*reg_dtor) (void) = (void (*) (void)) xdlsym (handle: h, symbol: "reg_dtor" ); |
77 | |
78 | reg_dtor (); |
79 | |
80 | #ifndef NO_DELETE |
81 | xdlclose (h); |
82 | #endif |
83 | |
84 | return NULL; |
85 | } |
86 | |
87 | static int |
88 | spawn_thread (void *h) |
89 | { |
90 | pthread_t t; |
91 | int ret; |
92 | void *thr_ret; |
93 | |
94 | if ((ret = pthread_create (newthread: &t, NULL, start_routine: reg_dtor_and_close, arg: h)) != 0) |
95 | { |
96 | printf (format: "pthread_create failed: %s\n" , strerror (errnum: ret)); |
97 | return 1; |
98 | } |
99 | |
100 | if ((ret = pthread_join (th: t, thread_return: &thr_ret)) != 0) |
101 | { |
102 | printf (format: "pthread_join failed: %s\n" , strerror (errnum: ret)); |
103 | return 1; |
104 | } |
105 | |
106 | if (thr_ret != NULL) |
107 | return 1; |
108 | |
109 | return 0; |
110 | } |
111 | |
112 | static int |
113 | do_test (void) |
114 | { |
115 | /* Load the DSO. */ |
116 | void *h1 = xdlopen (DSO_NAME, RTLD_LAZY); |
117 | |
118 | #ifndef NO_DELETE |
119 | if (spawn_thread (h1) != 0) |
120 | return 1; |
121 | #endif |
122 | |
123 | void *h2 = xdlopen (DSO_NAME, H2_RTLD_FLAGS); |
124 | |
125 | #ifdef NO_DELETE |
126 | if (spawn_thread (h: h1) != 0) |
127 | return 1; |
128 | |
129 | xdlclose (handle: h1); |
130 | #endif |
131 | xdlclose (handle: h2); |
132 | |
133 | /* Check link maps to ensure that the DSO has unloaded. In the normal case, |
134 | the DSO should be unloaded if there are no uses. However, if one of the |
135 | dlopen calls were with RTLD_NODELETE, the DSO should remain loaded. */ |
136 | return is_loaded () == LOADED_IS_GOOD ? 0 : 1; |
137 | } |
138 | |
139 | #define TEST_FUNCTION do_test () |
140 | #include "../test-skeleton.c" |
141 | |