From 365624e2d2a342cdb693b4cc35d2312169959e28 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Fri, 13 Dec 2019 10:18:24 +0100 Subject: dlopen: Fix issues related to NODELETE handling and relocations The assumption behind the assert in activate_nodelete was wrong: Inconsistency detected by ld.so: dl-open.c: 459: activate_nodelete: Assertion `!imap->l_init_called || imap->l_type != lt_loaded' failed! (edit) It can happen that an already-loaded object that is in the local scope is promoted to NODELETE status, via binding to a unique symbol. Similarly, it is possible that such NODELETE promotion occurs to an already-loaded object from the global scope. This is why the loop in activate_nodelete has to cover all objects in the namespace of the new object. In do_lookup_unique, it could happen that the NODELETE status of an already-loaded object was overwritten with a pending NODELETE status. As a result, if dlopen fails, this could cause a loss of the NODELETE status of the affected object, eventually resulting in an incorrect unload. Fixes commit f63b73814f74032c0e5d0a83300e3d864ef905e5 ("Remove all loaded objects if dlopen fails, ignoring NODELETE [BZ #20839]"). --- elf/tst-dlopen-nodelete-reloc-mod9.cc | 42 +++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 elf/tst-dlopen-nodelete-reloc-mod9.cc (limited to 'elf/tst-dlopen-nodelete-reloc-mod9.cc') diff --git a/elf/tst-dlopen-nodelete-reloc-mod9.cc b/elf/tst-dlopen-nodelete-reloc-mod9.cc new file mode 100644 index 0000000000..06fb49cdf7 --- /dev/null +++ b/elf/tst-dlopen-nodelete-reloc-mod9.cc @@ -0,0 +1,42 @@ +/* First module defining a unique symbol (loaded indirectly). + 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 + . */ + +#include "tst-dlopen-nodelete-reloc.h" + +#include +#include +#include + +/* Just a flag here, not used for NODELETE processing. */ +bool may_finalize_mod9 = false; + +/* Explicit instantiation. This produces a unique symbol definition + which is not referenced by the library itself, so the library is + not marked NODELETE. */ +template struct unique_symbol<9>; + +static void __attribute__ ((destructor)) +fini (void) +{ + if (!may_finalize_mod9) + { + puts ("error: tst-dlopen-nodelete-reloc-mod9.so destructor" + " called too early"); + _exit (1); + } +} -- cgit v1.2.3