glibc/elf/tst-dlopenfail-2.c
Florian Weimer a332bd1518 elf: Add elf/tst-dlopenfail-2 [BZ #25396]
Without CET, a jump into a newly loaded object through an overwritten
link map often does not crash, it just executes some random code.
CET detects this in some cases because the function pointer does not
point to the start of a function in the replacement shared object,
so there is no ENDBR instruction.

The new test uses a small shared object and the existing dangling
link map to trigger the bug.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2020-01-16 16:53:58 +01:00

60 lines
2.2 KiB
C

/* Test unrelated dlopen after dlopen failure involving NODELETE.
Copyright (C) 2019-2020 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");
/* Open a small shared object. With a dangling GL (dl_initfirst)
pointer, this is likely to crash because there is no longer any
mapped text segment there (bug 25396). */
puts ("info: attempting to load tst-dlopenfailmod3.so");
xdlclose (xdlopen ("tst-dlopenfailmod3.so", RTLD_NOW));
return 0;
}
/* Do not perturb the dangling link map. With M_PERTURB, the link map
appears to have l_init_called set, so there are no constructor
calls and no crashes. */
#define TEST_NO_MALLOPT
#include <support/test-driver.c>