1/* Test that --glibc-hwcaps-prepend works, using dlopen and /etc/ld.so.cache.
2 Copyright (C) 2020-2022 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#include <dlfcn.h>
20#include <stddef.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <support/check.h>
25#include <support/support.h>
26#include <support/xdlfcn.h>
27#include <support/xunistd.h>
28
29/* Invoke /sbin/ldconfig with some error checking. */
30static void
31run_ldconfig (void)
32{
33 char *command = xasprintf (format: "%s/ldconfig", support_install_rootsbindir);
34 TEST_COMPARE (system (command), 0);
35 free (ptr: command);
36}
37
38/* The library under test. */
39#define SONAME "libmarkermod1.so"
40
41static int
42do_test (void)
43{
44 if (dlopen (SONAME, RTLD_NOW) != NULL)
45 FAIL_EXIT1 (SONAME " is already on the search path");
46
47 /* Install the default implementation of libmarkermod1.so. */
48 xmkdirp ("/etc", 0777);
49 support_write_file_string (path: "/etc/ld.so.conf", contents: "/glibc-test/lib\n");
50 xmkdirp ("/glibc-test/lib/glibc-hwcaps/prepend2", 0777);
51 xmkdirp ("/glibc-test/lib/glibc-hwcaps/prepend3", 0777);
52 {
53 char *src = xasprintf (format: "%s/elf/libmarkermod1-1.so", support_objdir_root);
54 support_copy_file (from: src, to: "/glibc-test/lib/" SONAME);
55 free (ptr: src);
56 }
57 run_ldconfig ();
58 {
59 /* The default implementation can now be loaded. */
60 void *handle = xdlopen (SONAME, RTLD_NOW);
61 int (*marker1) (void) = xdlsym (handle, symbol: "marker1");
62 TEST_COMPARE (marker1 (), 1);
63 xdlclose (handle);
64 }
65
66 /* Add the first override to the directory that is searched last. */
67 {
68 char *src = xasprintf (format: "%s/elf/libmarkermod1-2.so", support_objdir_root);
69 support_copy_file (from: src, to: "/glibc-test/lib/glibc-hwcaps/prepend2/"
70 SONAME);
71 free (ptr: src);
72 }
73 {
74 /* This is still the first implementation. The cache has not been
75 updated. */
76 void *handle = xdlopen (SONAME, RTLD_NOW);
77 int (*marker1) (void) = xdlsym (handle, symbol: "marker1");
78 TEST_COMPARE (marker1 (), 1);
79 xdlclose (handle);
80 }
81 run_ldconfig ();
82 {
83 /* After running ldconfig, it is the second implementation. */
84 void *handle = xdlopen (SONAME, RTLD_NOW);
85 int (*marker1) (void) = xdlsym (handle, symbol: "marker1");
86 TEST_COMPARE (marker1 (), 2);
87 xdlclose (handle);
88 }
89
90 /* Add the second override to the directory that is searched first. */
91 {
92 char *src = xasprintf (format: "%s/elf/libmarkermod1-3.so", support_objdir_root);
93 support_copy_file (from: src, to: "/glibc-test/lib/glibc-hwcaps/prepend3/"
94 SONAME);
95 free (ptr: src);
96 }
97 {
98 /* This is still the second implementation. */
99 void *handle = xdlopen (SONAME, RTLD_NOW);
100 int (*marker1) (void) = xdlsym (handle, symbol: "marker1");
101 TEST_COMPARE (marker1 (), 2);
102 xdlclose (handle);
103 }
104 run_ldconfig ();
105 {
106 /* After running ldconfig, it is the third implementation. */
107 void *handle = xdlopen (SONAME, RTLD_NOW);
108 int (*marker1) (void) = xdlsym (handle, symbol: "marker1");
109 TEST_COMPARE (marker1 (), 3);
110 xdlclose (handle);
111 }
112
113 /* Remove the second override again, without running ldconfig.
114 Ideally, this would revert to implementation 2. However, in the
115 current implementation, the cache returns exactly one file name
116 which does not exist after unlinking, so the dlopen fails. */
117 xunlink (path: "/glibc-test/lib/glibc-hwcaps/prepend3/" SONAME);
118 TEST_VERIFY (dlopen (SONAME, RTLD_NOW) == NULL);
119 run_ldconfig ();
120 {
121 /* After running ldconfig, the second implementation is available
122 once more. */
123 void *handle = xdlopen (SONAME, RTLD_NOW);
124 int (*marker1) (void) = xdlsym (handle, symbol: "marker1");
125 TEST_COMPARE (marker1 (), 2);
126 xdlclose (handle);
127 }
128
129 return 0;
130}
131
132static void
133prepare (int argc, char **argv)
134{
135 const char *no_restart = "no-restart";
136 if (argc == 2 && strcmp (s1: argv[1], s2: no_restart) == 0)
137 return;
138 /* Re-execute the test with an explicit loader invocation. */
139 execl (path: support_objdir_elf_ldso,
140 arg: support_objdir_elf_ldso,
141 "--glibc-hwcaps-prepend", "prepend3:prepend2",
142 argv[0], no_restart,
143 NULL);
144 printf (format: "error: execv of %s failed: %m\n", argv[0]);
145 _exit (status: 1);
146}
147
148#define PREPARE prepare
149#include <support/test-driver.c>
150

source code of glibc/elf/tst-glibc-hwcaps-prepend-cache.c