Added $(objpfx)tst-dlmopen-gethostbyname: $(libdl) in elf/Makefile since

we still have $(libdl) in RHEL8.

commit c2059edce20c124d1a99f1a94cc52e83b77a917a

Author: Florian Weimer <fweimer@redhat.com>

Date:   Thu Jun 17 15:06:43 2021 +0200

    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>

Conflicts:

	elf/Makefile

diff --git a/elf/Makefile b/elf/Makefile

index e0919486a14cab1a..30417c3ce15abcb4 100644

--- a/elf/Makefile

+++ b/elf/Makefile

@@ -217,6 +217,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \

 	 tst-tls20 tst-tls21 \

 	 tst-rtld-run-static \

 	 tst-dlmopen-dlerror \

+	 tst-dlmopen-gethostbyname \

 #	 reldep9

 tests-internal += loadtest unload unload2 circleload1 \

 	 neededtest neededtest2 neededtest3 neededtest4 \

@@ -351,6 +352,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \

 		libmarkermod5-1 libmarkermod5-2 libmarkermod5-3 libmarkermod5-4 \

 		libmarkermod5-5 tst-tls20mod-bad tst-tls21mod \

 		tst-dlmopen-dlerror-mod \

+		tst-dlmopen-gethostbyname-mod \

 # Most modules build with _ISOMAC defined, but those filtered out

 # depend on internal headers.

@@ -1935,3 +1937,5 @@ $(objpfx)tst-tls21.out: $(objpfx)tst-tls21mod.so

 $(objpfx)tst-tls21mod.so: $(tst-tls-many-dynamic-modules:%=$(objpfx)%.so)

 $(objpfx)tst-rtld-run-static.out: $(objpfx)/ldconfig

+$(objpfx)tst-dlmopen-gethostbyname: $(libdl)

+$(objpfx)tst-dlmopen-gethostbyname.out: $(objpfx)tst-dlmopen-gethostbyname-mod.so

diff --git a/elf/dl-libc.c b/elf/dl-libc.c

index fc01f5514d4f656c..3a242d219756dac6 100644

--- a/elf/dl-libc.c

+++ b/elf/dl-libc.c

@@ -43,8 +43,8 @@ dlerror_run (void (*operate) (void *), void *args)

   const char *last_errstring = NULL;

   bool malloced;

-  int result = (_dl_catch_error (&objname, &last_errstring, &malloced,

-				operate, args)

+  int result = (GLRO (dl_catch_error) (&objname, &last_errstring, &malloced,

+				       operate, args)

 		?: last_errstring != NULL);

   if (result && malloced)

diff --git a/elf/tst-dlmopen-gethostbyname-mod.c b/elf/tst-dlmopen-gethostbyname-mod.c

new file mode 100644

index 0000000000000000..9a68ea5050c3060b

--- /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");

+}

diff --git a/elf/tst-dlmopen-gethostbyname.c b/elf/tst-dlmopen-gethostbyname.c

new file mode 100644

index 0000000000000000..12deb29900731c20

--- /dev/null

+++ b/elf/tst-dlmopen-gethostbyname.c

@@ -0,0 +1,31 @@

+/* Exercise dlerror_run in elf/dl-libc.c after dlmopen, via NSS (bug 27646).

+   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 <support/xdlfcn.h>

+

+static int

+do_test (void)

+{

+  void *handle = xdlmopen (LM_ID_NEWLM, "tst-dlmopen-gethostbyname-mod.so",

+                           RTLD_NOW);

+  void (*call_gethostbyname) (void) = xdlsym (handle, "call_gethostbyname");

+  call_gethostbyname ();

+  return 0;

+}

+

+#include <support/test-driver.c>