glibc/elf/tst-dlopen-aout.c
Florian Weimer 23d2e5faf0 elf: Self-dlopen failure with explict loader invocation [BZ #24900]
In case of an explicit loader invocation, ld.so essentially performs
a dlopen call to load the main executable.  Since the pathname of
the executable is known at this point, it gets stored in the link
map.  In regular mode, the pathname is not known and "" is used
instead.

As a result, if a program calls dlopen on the pathname of the main
program, the dlopen call succeeds and returns a handle for the main
map.  This results in an unnecessary difference between glibc
testing (without --enable-hardcoded-path-in-tests) and production
usage.

This commit discards the names when building the link map in
_dl_new_object for the main executable, but it still determines
the origin at this point in case of an explict loader invocation.
The reason is that the specified pathname has to be used; the kernel
has a different notion of the main executable.
2019-08-15 18:53:32 +02:00

86 lines
2.4 KiB
C

/* Test case for BZ #16634 and BZ#24900.
Verify that incorrectly dlopen()ing an executable without
__RTLD_OPENEXEC does not cause assertion in ld.so, and that it
actually results in an error.
Copyright (C) 2014-2019 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
<http://www.gnu.org/licenses/>. */
#include <dlfcn.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <support/check.h>
#include <support/support.h>
#include <support/xthread.h>
__thread int x;
void *
fn (void *p)
{
return p;
}
/* Call dlopen on PATH and check that fails with an error message
indicating an attempt to open an ET_EXEC or PIE object. */
static void
check_dlopen_failure (const char *path)
{
void *handle = dlopen (path, RTLD_LAZY);
if (handle != NULL)
FAIL_EXIT1 ("dlopen succeeded unexpectedly: %s", path);
const char *message = dlerror ();
TEST_VERIFY_EXIT (message != NULL);
if ((strstr (message,
"cannot dynamically load position-independent executable")
== NULL)
&& strstr (message, "cannot dynamically load executable") == NULL)
FAIL_EXIT1 ("invalid dlopen error message: \"%s\"", message);
}
static int
do_test (int argc, char *argv[])
{
int j;
for (j = 0; j < 100; ++j)
{
pthread_t thr;
check_dlopen_failure (argv[0]);
/* We create threads to force TLS allocation, which triggers
the original bug i.e. running out of surplus slotinfo entries
for TLS. */
thr = xpthread_create (NULL, fn, NULL);
xpthread_join (thr);
}
/* The elf subdirectory (or $ORIGIN in the container case) is on the
library search path. */
check_dlopen_failure ("tst-dlopen-aout");
return 0;
}
#define TEST_FUNCTION_ARGV do_test
#include <support/test-driver.c>