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/* Test dlopen of modules with initial-exec TLS after dlmopen.
Copyright (C) 2016-2024 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/>. */
/* This test tries to check that surplus static TLS is not used up for
dynamic TLS optimizations and 4*144 = 576 bytes of static TLS is
still available for dlopening modules with initial-exec TLS after 3
new dlmopen namespaces are created. It depends on rtld.nns=4 and
rtld.optional_static_tls=512 tunable settings. */
#include <errno.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static int do_test (void);
#include <support/xthread.h>
#include <support/xdlfcn.h>
#include <support/check.h>
#include <support/test-driver.c>
/* Have some big TLS in the main exe: should not use surplus TLS. */
__thread char maintls[1000];
static pthread_barrier_t barrier;
/* Forces multi-threaded behaviour. */
static void *
blocked_thread_func (void *closure)
{
xpthread_barrier_wait (&barrier);
/* TLS load and access tests run here in the main thread. */
xpthread_barrier_wait (&barrier);
return NULL;
}
static void *
load_and_access (Lmid_t lmid, const char *mod, const char *func)
{
/* Load module with TLS. */
void *p = xdlmopen (lmid, mod, RTLD_NOW);
/* Access the TLS variable to ensure it is allocated. */
void (*f) (void) = (void (*) (void))xdlsym (p, func);
f ();
return p;
}
static int
do_test (void)
{
void *mods[5];
{
int ret = pthread_barrier_init (&barrier, NULL, 2);
if (ret != 0)
{
errno = ret;
printf ("error: pthread_barrier_init: %m\n");
exit (1);
}
}
pthread_t blocked_thread = xpthread_create (NULL, blocked_thread_func, NULL);
xpthread_barrier_wait (&barrier);
printf ("maintls[%zu]:\t %p .. %p\n",
sizeof maintls, maintls, maintls + sizeof maintls);
memset (maintls, 1, sizeof maintls);
/* Load modules with dynamic TLS (use surplus static TLS for libc
in new namespaces and may be for TLS optimizations too). */
mods[0] = load_and_access (LM_ID_BASE, "tst-tls-ie-mod0.so", "access0");
mods[1] = load_and_access (LM_ID_NEWLM, "tst-tls-ie-mod1.so", "access1");
mods[2] = load_and_access (LM_ID_NEWLM, "tst-tls-ie-mod2.so", "access2");
mods[3] = load_and_access (LM_ID_NEWLM, "tst-tls-ie-mod3.so", "access3");
/* Load modules with initial-exec TLS (can only use surplus static TLS). */
mods[4] = load_and_access (LM_ID_BASE, "tst-tls-ie-mod6.so", "access6");
/* Here 576 bytes + 3 * libc use of surplus static TLS is in use so less
than 1024 bytes are available (exact number depends on TLS optimizations
and the libc TLS use). */
printf ("The next dlmopen should fail...\n");
void *p = dlmopen (LM_ID_BASE, "tst-tls-ie-mod4.so", RTLD_NOW);
if (p != NULL)
FAIL_EXIT1 ("error: expected dlmopen to fail because there is "
"not enough surplus static TLS.\n");
printf ("...OK failed with: %s.\n", dlerror ());
xpthread_barrier_wait (&barrier);
xpthread_join (blocked_thread);
/* Close the modules. */
for (int i = 0; i < 5; ++i)
xdlclose (mods[i]);
return 0;
}
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