@@ -84,6 +84,12 @@
are no longer supported. For v8 only implementations with native CAS
instruction are still supported (such as LEON).
+* If a lazy binding failure happens during dlopen, during the execution of
+ an ELF constructor, the process is now terminated. Previously, the
+ dynamic loader would return NULL from dlopen, with the lazy binding error
+ captured in a dlerror message. In general, this is unsafe because
+ resetting the stack in an arbitrary function call is not possible.
+
Changes to build and runtime requirements:
[Add changes to build and runtime requirements here]
@@ -199,7 +199,7 @@
tst-debug1 tst-main1 tst-absolute-sym tst-absolute-zero tst-big-note \
tst-unwind-ctor tst-unwind-main tst-audit13 \
tst-sonamemove-link tst-sonamemove-dlopen tst-dlopen-tlsmodid \
- tst-dlopen-self tst-auditmany
+ tst-dlopen-self tst-auditmany tst-initfinilazyfail
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
@@ -290,7 +290,8 @@
tst-sonamemove-runmod1 tst-sonamemove-runmod2 \
tst-auditmanymod1 tst-auditmanymod2 tst-auditmanymod3 \
tst-auditmanymod4 tst-auditmanymod5 tst-auditmanymod6 \
- tst-auditmanymod7 tst-auditmanymod8 tst-auditmanymod9
+ tst-auditmanymod7 tst-auditmanymod8 tst-auditmanymod9 \
+ tst-initlazyfailmod tst-finilazyfailmod
# Most modules build with _ISOMAC defined, but those filtered out
# depend on internal headers.
modules-names-tests = $(filter-out ifuncmod% tst-libc_dlvsym-dso tst-tlsmod%,\
@@ -1586,3 +1587,13 @@
$(objpfx)tst-unwind-ctor: $(objpfx)tst-unwind-ctor-lib.so
CFLAGS-tst-unwind-main.c += -funwind-tables -DUSE_PTHREADS=0
+
+$(objpfx)tst-initfinilazyfail: $(libdl)
+$(objpfx)tst-initfinilazyfail.out: \
+ $(objpfx)tst-initlazyfailmod.so $(objpfx)tst-finilazyfailmod.so
+# Override -z defs, so that we can reference an undefined symbol.
+# Force lazy binding for the same reason.
+LDFLAGS-tst-initlazyfailmod.so = \
+ -Wl,-z,lazy -Wl,--unresolved-symbols=ignore-all
+LDFLAGS-tst-finilazyfailmod.so = \
+ -Wl,-z,lazy -Wl,--unresolved-symbols=ignore-all
@@ -106,6 +106,30 @@
return false;
}
+/* Invoke dstructors for CLOSURE (a struct link_map *). Called with
+ exception handling temporarily disabled, to make errors fatal. */
+static void
+call_destructors (void *closure)
+{
+ struct link_map *map = closure;
+
+ if (map->l_info[DT_FINI_ARRAY] != NULL)
+ {
+ ElfW(Addr) *array =
+ (ElfW(Addr) *) (map->l_addr
+ + map->l_info[DT_FINI_ARRAY]->d_un.d_ptr);
+ unsigned int sz = (map->l_info[DT_FINI_ARRAYSZ]->d_un.d_val
+ / sizeof (ElfW(Addr)));
+
+ while (sz-- > 0)
+ ((fini_t) array[sz]) ();
+ }
+
+ /* Next try the old-style destructor. */
+ if (map->l_info[DT_FINI] != NULL)
+ DL_CALL_DT_FINI (map, ((void *) map->l_addr
+ + map->l_info[DT_FINI]->d_un.d_ptr));
+}
void
_dl_close_worker (struct link_map *map, bool force)
@@ -267,7 +291,8 @@
&& (imap->l_flags_1 & DF_1_NODELETE) == 0);
/* Call its termination function. Do not do it for
- half-cooked objects. */
+ half-cooked objects. Temporarily disable exception
+ handling, so that errors are fatal. */
if (imap->l_init_called)
{
/* When debugging print a message first. */
@@ -276,22 +301,9 @@
_dl_debug_printf ("\ncalling fini: %s [%lu]\n\n",
imap->l_name, nsid);
- if (imap->l_info[DT_FINI_ARRAY] != NULL)
- {
- ElfW(Addr) *array =
- (ElfW(Addr) *) (imap->l_addr
- + imap->l_info[DT_FINI_ARRAY]->d_un.d_ptr);
- unsigned int sz = (imap->l_info[DT_FINI_ARRAYSZ]->d_un.d_val
- / sizeof (ElfW(Addr)));
-
- while (sz-- > 0)
- ((fini_t) array[sz]) ();
- }
-
- /* Next try the old-style destructor. */
- if (imap->l_info[DT_FINI] != NULL)
- DL_CALL_DT_FINI (imap, ((void *) imap->l_addr
- + imap->l_info[DT_FINI]->d_un.d_ptr));
+ if (imap->l_info[DT_FINI_ARRAY] != NULL
+ || imap->l_info[DT_FINI] != NULL)
+ _dl_catch_exception (NULL, call_destructors, imap);
}
#ifdef SHARED
@@ -177,6 +177,23 @@
}
rtld_hidden_def (_dl_find_dso_for_object);
+/* struct dl_init_args and call_dl_init are used to call _dl_init with
+ exception handling disabled. */
+struct dl_init_args
+{
+ struct link_map *new;
+ int argc;
+ char **argv;
+ char **env;
+};
+
+static void
+call_dl_init (void *closure)
+{
+ struct dl_init_args *args = closure;
+ _dl_init (args->new, args->argc, args->argv, args->env);
+}
+
static void
dl_open_worker (void *a)
{
@@ -509,8 +526,19 @@
DL_STATIC_INIT (new);
#endif
- /* Run the initializer functions of new objects. */
- _dl_init (new, args->argc, args->argv, args->env);
+ /* Run the initializer functions of new objects. Temporarily
+ disable the exception handler, so that lazy binding failures are
+ fatal. */
+ {
+ struct dl_init_args init_args =
+ {
+ .new = new,
+ .argc = args->argc,
+ .argv = args->argv,
+ .env = args->env
+ };
+ _dl_catch_exception (NULL, call_dl_init, &init_args);
+ }
/* Now we can make the new map available in the global scope. */
if (mode & RTLD_GLOBAL)
new file mode 100644
@@ -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 ();
+}
new file mode 100644
@@ -0,0 +1,84 @@
+/* Test that lazy binding failures in constructors and destructors are fatal.
+ 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/>. */
+
+#include <dlfcn.h>
+#include <string.h>
+#include <support/capture_subprocess.h>
+#include <support/check.h>
+#include <support/xdlfcn.h>
+
+static void
+test_constructor (void *closure)
+{
+ void *handle = dlopen ("tst-initlazyfailmod.so", RTLD_LAZY);
+ if (handle == NULL)
+ FAIL_EXIT (2, "dlopen did not terminate the process: %s", dlerror ());
+ else
+ FAIL_EXIT (2, "dlopen did not terminate the process (%p)", handle);
+}
+
+static void
+test_destructor (void *closure)
+{
+ void *handle = xdlopen ("tst-finilazyfailmod.so", RTLD_LAZY);
+ int ret = dlclose (handle);
+ const char *message = dlerror ();
+ if (message != NULL)
+ FAIL_EXIT (2, "dlclose did not terminate the process: %d, %s",
+ ret, message);
+ else
+ FAIL_EXIT (2, "dlopen did not terminate the process: %d", ret);
+}
+
+static int
+do_test (void)
+{
+ {
+ struct support_capture_subprocess proc
+ = support_capture_subprocess (test_constructor, NULL);
+ support_capture_subprocess_check (&proc, "constructor", 127,
+ sc_allow_stderr);
+ printf ("info: constructor failure output: [[%s]]\n", proc.err.buffer);
+ TEST_VERIFY (strstr (proc.err.buffer,
+ "tst-initfinilazyfail: symbol lookup error: ")
+ != NULL);
+ TEST_VERIFY (strstr (proc.err.buffer,
+ "tst-initlazyfailmod.so: undefined symbol:"
+ " undefined_function\n") != NULL);
+ support_capture_subprocess_free (&proc);
+ }
+
+ {
+ struct support_capture_subprocess proc
+ = support_capture_subprocess (test_destructor, NULL);
+ support_capture_subprocess_check (&proc, "destructor", 127,
+ sc_allow_stderr);
+ printf ("info: destructor failure output: [[%s]]\n", proc.err.buffer);
+ TEST_VERIFY (strstr (proc.err.buffer,
+ "tst-initfinilazyfail: symbol lookup error: ")
+ != NULL);
+ TEST_VERIFY (strstr (proc.err.buffer,
+ "tst-finilazyfailmod.so: undefined symbol:"
+ " undefined_function\n") != NULL);
+ support_capture_subprocess_free (&proc);
+ }
+
+ return 0;
+}
+
+#include <support/test-driver.c>
new file mode 100644
@@ -0,0 +1,27 @@
+/* Helper module for tst-initfinilazyfail: lazy binding failure in constructor.
+ 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__ ((constructor))
+init (void)
+{
+ undefined_function ();
+}