Lazy binding failures during dlopen/dlclose must be fatal [BZ #24304]

If a lazy binding failure happens during the execution of an ELF
constructor or destructor, the dynamic loader catches the error
and reports it using the dlerror mechanism.  This is undesirable
because there could be other constructors and destructors that
need processing (which are skipped), and the process is in an
inconsistent state at this point.  Therefore, we have to issue
a fatal dynamic loader error error and terminate the process.

Note that the _dl_catch_exception in _dl_open is just an inner catch,
to roll back some state locally.  If called from dlopen, there is
still an outer catch, which is why calling _dl_init via call_dl_init
and a no-exception is required and cannot be avoiding by moving the
_dl_init call directly into _dl_open.

_dl_fini does not need changes because it does not install an error
handler, so errors are already fatal there.

Change-Id: I6b1addfe2e30f50a1781595f046f44173db9491a

1 files changed, 27 insertions, 0 deletions

diff --git a/elf/tst-finilazyfailmod.c b/elf/tst-finilazyfailmod.c
new file mode 100644
index 0000000000..2670bd1a94
--- /dev/null
+++ b/elf/tst-finilazyfailmod.c
@@ -0,0 +1,27 @@
+/* Helper module for tst-initfinilazyfail: lazy binding failure in destructor.
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+/* An undefined function.  Calling it will cause a lazy binding
+   failure.  */
+void undefined_function (void);
+
+static void __attribute__ ((destructor))
+fini (void)
+{
+  undefined_function ();
+}