elf/tst-glibc-hwcaps-prepend-cache.c

   1 /* Test that --glibc-hwcaps-prepend works, using dlopen and /etc/ld.so.cache.
   2    Copyright (C) 2020-2024 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.  */
  30 static void
  31 run_ldconfig (void)
  32 {
  33   char *command = xasprintf ("%s/ldconfig", support_install_rootsbindir);
  34   TEST_COMPARE (system (command), 0);
  35   free (command);
  36 }
  37
  38 /* The library under test.  */
  39 #define SONAME "libmarkermod1.so"
  40
  41 static int
  42 do_test (void)
  43 {
  44   if (dlopen (SONAME, RTLD_NOW) != NULL)
  45     FAIL_EXIT1 (SONAME " is already on the search path");
  46
  47   {
  48     /* Install the default implementation of libmarkermod1.so.  */
  49     char *conf_path = xasprintf ("%s/ld.so.conf", support_sysconfdir_prefix);
  50     xmkdirp (support_sysconfdir_prefix, 0777);
  51     support_write_file_string (conf_path, "/glibc-test/lib\n");
  52     free (conf_path);
  53   }
  54   xmkdirp ("/glibc-test/lib/glibc-hwcaps/prepend2", 0777);
  55   xmkdirp ("/glibc-test/lib/glibc-hwcaps/prepend3", 0777);
  56   {
  57     char *src = xasprintf ("%s/elf/libmarkermod1-1.so", support_objdir_root);
  58     support_copy_file (src, "/glibc-test/lib/" SONAME);
  59     free (src);
  60   }
  61   run_ldconfig ();
  62   {
  63     /* The default implementation can now be loaded.  */
  64     void *handle = xdlopen (SONAME, RTLD_NOW);
  65     int (*marker1) (void) = xdlsym (handle, "marker1");
  66     TEST_COMPARE (marker1 (), 1);
  67     xdlclose (handle);
  68   }
  69
  70   /* Add the first override to the directory that is searched last.  */
  71   {
  72     char *src = xasprintf ("%s/elf/libmarkermod1-2.so", support_objdir_root);
  73     support_copy_file (src, "/glibc-test/lib/glibc-hwcaps/prepend2/"
  74                        SONAME);
  75     free (src);
  76   }
  77   {
  78     /* This is still the first implementation.  The cache has not been
  79        updated.  */
  80     void *handle = xdlopen (SONAME, RTLD_NOW);
  81     int (*marker1) (void) = xdlsym (handle, "marker1");
  82     TEST_COMPARE (marker1 (), 1);
  83     xdlclose (handle);
  84   }
  85   run_ldconfig ();
  86   {
  87     /* After running ldconfig, it is the second implementation.  */
  88     void *handle = xdlopen (SONAME, RTLD_NOW);
  89     int (*marker1) (void) = xdlsym (handle, "marker1");
  90     TEST_COMPARE (marker1 (), 2);
  91     xdlclose (handle);
  92   }
  93
  94   /* Add the second override to the directory that is searched first.  */
  95   {
  96     char *src = xasprintf ("%s/elf/libmarkermod1-3.so", support_objdir_root);
  97     support_copy_file (src, "/glibc-test/lib/glibc-hwcaps/prepend3/"
  98                        SONAME);
  99     free (src);
 100   }
 101   {
 102     /* This is still the second implementation.  */
 103     void *handle = xdlopen (SONAME, RTLD_NOW);
 104     int (*marker1) (void) = xdlsym (handle, "marker1");
 105     TEST_COMPARE (marker1 (), 2);
 106     xdlclose (handle);
 107   }
 108   run_ldconfig ();
 109   {
 110     /* After running ldconfig, it is the third implementation.  */
 111     void *handle = xdlopen (SONAME, RTLD_NOW);
 112     int (*marker1) (void) = xdlsym (handle, "marker1");
 113     TEST_COMPARE (marker1 (), 3);
 114     xdlclose (handle);
 115   }
 116
 117   /* Remove the second override again, without running ldconfig.
 118      Ideally, this would revert to implementation 2.  However, in the
 119      current implementation, the cache returns exactly one file name
 120      which does not exist after unlinking, so the dlopen fails.  */
 121   xunlink ("/glibc-test/lib/glibc-hwcaps/prepend3/" SONAME);
 122   TEST_VERIFY (dlopen (SONAME, RTLD_NOW) == NULL);
 123   run_ldconfig ();
 124   {
 125     /* After running ldconfig, the second implementation is available
 126        once more.  */
 127     void *handle = xdlopen (SONAME, RTLD_NOW);
 128     int (*marker1) (void) = xdlsym (handle, "marker1");
 129     TEST_COMPARE (marker1 (), 2);
 130     xdlclose (handle);
 131   }
 132
 133   return 0;
 134 }
 135
 136 static void
 137 prepare (int argc, char **argv)
 138 {
 139   const char *no_restart = "no-restart";
 140   if (argc == 2 && strcmp (argv[1], no_restart) == 0)
 141     return;
 142   /* Re-execute the test with an explicit loader invocation.  */
 143   execl (support_objdir_elf_ldso,
 144          support_objdir_elf_ldso,
 145          "--glibc-hwcaps-prepend", "prepend3:prepend2",
 146          argv[0], no_restart,
 147          NULL);
 148   printf ("error: execv of %s failed: %m\n", argv[0]);
 149   _exit (1);
 150 }
 151
 152 #define PREPARE prepare
 153 #include <support/test-driver.c>