elf: Use _dl_catch_error from base namespace in dl-libc.c [BZ #27646]

dlerrror_run in elf/dl-libc.c needs to call GLRO (dl_catch_error)
from the base namespace, just like the exported dlerror
implementation.

Fixes commit b2964eb1d9a6b8ab1250e8a881cf406182da5875 ("dlfcn:
Failures after dlmopen should not terminate process [BZ #24772]").

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/elf/tst-dlmopen-gethostbyname-mod.c b/elf/tst-dlmopen-gethostbyname-mod.c
new file mode 100644
index 0000000000..9a68ea5050
--- /dev/null
+++ b/elf/tst-dlmopen-gethostbyname-mod.c
@@ -0,0 +1,29 @@
+/* Exercise dlerror_run in elf/dl-libc.c after dlmopen, via NSS.  Helper module.
+   Copyright (C) 2021 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 <netdb.h>
+#include <nss.h>
+
+void
+call_gethostbyname (void)
+{
+  __nss_configure_lookup ("hosts", "files");
+  /* This should not terminate the process due to a missing
+     _nss_files_getcanonname_r symbol.  */
+  gethostbyname ("localhost");
+}