elf: Issue la_symbind for bind-now (BZ #23734)

The audit symbind callback is not called for binaries built with
-Wl,-z,now or when LD_BIND_NOW=1 is used, nor the PLT tracking callbacks
(plt_enter and plt_exit) since this would change the expected
program semantics (where no PLT is expected) and would have performance
implications (such as for BZ#15533).

LAV_CURRENT is also bumped to indicate the audit ABI change (where
la_symbind flags are set by the loader to indicate no possible PLT
trace).

To handle powerpc64 ELFv1 function descriptor, _dl_audit_symbind
requires to know whether bind-now is used so the symbol value is
updated to function text segment instead of the OPD (for lazy binding
this is done by PPC64_LOAD_FUNCPTR on _dl_runtime_resolve).

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
powerpc64-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/elf/tst-audit24d.c b/elf/tst-audit24d.c
new file mode 100644
index 0000000000..543f3b86a6
--- /dev/null
+++ b/elf/tst-audit24d.c
@@ -0,0 +1,36 @@
+/* LD_AUDIT test for la_symbind and bind-now.
+   Copyright (C) 2022 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 <support/check.h>
+#include <support/support.h>
+
+int tst_audit24dmod1_func1 (void);
+int tst_audit24dmod1_func2 (void);
+int tst_audit24dmod2_func1 (void);
+
+int
+do_test (void)
+{
+  TEST_COMPARE (tst_audit24dmod1_func1 (), 1);
+  TEST_COMPARE (tst_audit24dmod1_func2 (), 32);
+  TEST_COMPARE (tst_audit24dmod2_func1 (), 10);
+
+  return 0;
+}
+
+#include <support/test-driver.c>