glibc/elf/tst-dlopenfail.c

/* Test dlopen rollback after failures involving NODELETE objects (bug 20839).
   Copyright (C) 2019-2021 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <dlfcn.h>
#include <errno.h>
#include <gnu/lib-names.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <support/check.h>
#include <support/xdlfcn.h>

static int
do_test (void)
{
  /* This test uses libpthread as the canonical NODELETE module.  If
     libpthread is no longer NODELETE because it has been merged into
     libc, the test needs to be updated.  */
  TEST_VERIFY (dlsym (NULL, "pthread_create") == NULL);

  /* This is expected to fail because of the missing dependency.  */
  puts ("info: attempting to load tst-dlopenfailmod1.so");
  TEST_VERIFY (dlopen ("tst-dlopenfailmod1.so", RTLD_LAZY) == NULL);
  const char *message = dlerror ();
  TEST_COMPARE_STRING (message,
                       "tst-dlopenfail-missingmod.so:"
                       " cannot open shared object file:"
                       " No such file or directory");

  /* Do not probe for the presence of libpthread at this point because
     that might trigger relocation if bug 20839 is present, obscuring
     a subsequent crash.  */

  /* This is expected to succeed.  */
  puts ("info: loading tst-dlopenfailmod2.so");
  void *handle = xdlopen ("tst-dlopenfailmod2.so", RTLD_NOW);
  xdlclose (handle);

  /* libpthread should remain loaded.  */
  TEST_VERIFY (dlopen (LIBPTHREAD_SO, RTLD_LAZY | RTLD_NOLOAD) != NULL);
  TEST_VERIFY (dlsym (NULL, "pthread_create") == NULL);

  /* We can make libpthread global, and then the symbol should become
     available.  */
  TEST_VERIFY (dlopen (LIBPTHREAD_SO, RTLD_LAZY | RTLD_GLOBAL) != NULL);
  TEST_VERIFY (dlsym (NULL, "pthread_create") != NULL);

  /* sem_open is sufficiently complex to depend on relocations.  */
  void *(*sem_open_ptr) (const char *, int flag, ...)
    = dlsym (NULL, "sem_open");
  if (sem_open_ptr == NULL)
    /* Hurd does not implement sem_open.  */
    puts ("warning: sem_open not found, further testing not possible");
  else
    {
      errno = 0;
      TEST_VERIFY (sem_open_ptr ("/", 0) == NULL);
      TEST_COMPARE (errno, EINVAL);
    }

  return 0;
}

#include <support/test-driver.c>