1 files changed, 112 insertions, 0 deletions
diff --git a/elf/tst-tls-ie-dlmopen.c b/elf/tst-tls-ie-dlmopen.c
new file mode 100644
index 0000000000..c7b5c688e3
--- /dev/null
+++ b/elf/tst-tls-ie-dlmopen.c
@@ -0,0 +1,112 @@
+/* Test dlopen of modules with initial-exec TLS after dlmopen.
+   Copyright (C) 2016-2020 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/>.  */
+
+/* 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;
+}