1 files changed, 120 insertions, 0 deletions
diff --git a/nptl/tst-atfork3.c b/nptl/tst-atfork3.c
new file mode 100644
index 0000000000..466a5933c1
--- /dev/null
+++ b/nptl/tst-atfork3.c
@@ -0,0 +1,120 @@
+/* Check if pthread_atfork handler can call dlclose (BZ#24595)
+   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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdio.h>
+#include <dlfcn.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include <support/check.h>
+#include <support/xthread.h>
+#include <support/capture_subprocess.h>
+
+/* Check if pthread_atfork handlers do not deadlock when calling a function
+   that might alter the internal fork handle list, such as dlclose.
+
+   The test registers a callback set with pthread_atfork(), dlopen() a shared
+   library (nptl/tst-atfork3mod.c), calls an exported symbol from the library
+   (which in turn also registers atfork handlers), and calls fork to trigger
+   the callbacks.  */
+
+static void *handler;
+static bool run_dlclose_prepare;
+static bool run_dlclose_parent;
+static bool run_dlclose_child;
+
+static void
+prepare (void)
+{
+  if (run_dlclose_prepare)
+    TEST_COMPARE (dlclose (handler), 0);
+}
+
+static void
+parent (void)
+{
+  if (run_dlclose_parent)
+    TEST_COMPARE (dlclose (handler), 0);
+}
+
+static void
+child (void)
+{
+  if (run_dlclose_child)
+    TEST_COMPARE (dlclose (handler), 0);
+}
+
+static void
+proc_func (void *closure)
+{
+}
+
+static void
+do_test_generic (bool dlclose_prepare, bool dlclose_parent, bool dlclose_child)
+{
+  run_dlclose_prepare = dlclose_prepare;
+  run_dlclose_parent = dlclose_parent;
+  run_dlclose_child = dlclose_child;
+
+  handler = dlopen ("tst-atfork3mod.so", RTLD_NOW);
+  TEST_VERIFY (handler != NULL);
+
+  int (*atfork3mod_func)(void);
+  atfork3mod_func = dlsym (handler, "atfork3mod_func");
+  TEST_VERIFY (atfork3mod_func != NULL);
+
+  atfork3mod_func ();
+
+  struct support_capture_subprocess proc
+    = support_capture_subprocess (proc_func, NULL);
+  support_capture_subprocess_check (&proc, "tst-atfork3", 0, sc_allow_none);
+
+  handler = atfork3mod_func = NULL;
+
+  support_capture_subprocess_free (&proc);
+}
+
+static void *
+thread_func (void *closure)
+{
+  return NULL;
+}
+
+static int
+do_test (void)
+{
+  {
+    /* Make the process acts as multithread.  */
+    pthread_attr_t attr;
+    xpthread_attr_init (&attr);
+    xpthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
+    xpthread_create (&attr, thread_func, NULL);
+  }
+
+  TEST_COMPARE (pthread_atfork (prepare, parent, child), 0);
+
+  do_test_generic (true  /* prepare */, false /* parent */, false /* child */);
+  do_test_generic (false /* prepare */, true  /* parent */, false /* child */);
+  do_test_generic (false /* prepare */, false /* parent */, true  /* child */);
+
+  return 0;
+}
+
+#include <support/test-driver.c>