glibc/elf/tst-dlopenfail.c
Florian Weimer f63b73814f Remove all loaded objects if dlopen fails, ignoring NODELETE [BZ #20839]
This introduces a “pending NODELETE” state in the link map, which is
flipped to the persistent NODELETE state late in dlopen, via
activate_nodelete.    During initial relocation, symbol binding
records pending NODELETE state only.  dlclose ignores pending NODELETE
state.  Taken together, this results that a partially completed dlopen
is rolled back completely because new NODELETE mappings are unloaded.

Tested on x86_64-linux-gnu and i386-linux-gnu.

Change-Id: Ib2a3d86af6f92d75baca65431d74783ee0dbc292
2019-11-27 20:55:35 +01:00

80 lines
2.9 KiB
C

/* Test dlopen rollback after failures involving NODELETE objects (bug 20839).
Copyright (C) 2019 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>