[v2] elf: Add tst-ldconfig-ld_so_conf-update test

From: Alexandra Hájková <ahajkova@redhat.com>

 Test ldconfig after /etc/ld.so.conf update and verify a running process
 observes changes to /etc/ld.so.cache.
 The test uses the test-in-container framework.
---
 elf/Makefile                                  |  11 +-
 elf/tst-ldconfig-ld-mod.c                     |   8 ++
 elf/tst-ldconfig-ld_so_conf-update.c          | 115 ++++++++++++++++++
 .../postclean.req                             |   0
 .../tst-ldconfig-ld_so_conf-update.script     |   1 +
 5 files changed, 132 insertions(+), 3 deletions(-)
 create mode 100644 elf/tst-ldconfig-ld-mod.c
 create mode 100644 elf/tst-ldconfig-ld_so_conf-update.c
 create mode 100644 elf/tst-ldconfig-ld_so_conf-update.root/postclean.req
 create mode 100644 elf/tst-ldconfig-ld_so_conf-update.root/tst-ldconfig-ld_so_conf-update.script

Hi Alexandra,

> diff --git a/elf/Makefile b/elf/Makefile
> index 72a5aa88b1..a89226f163 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -162,8 +162,9 @@ tests-static-internal := tst-tls1-static tst-tls2-static \
>  CRT-tst-tls1-static-non-pie := $(csu-objpfx)crt1.o
>  tst-tls1-static-non-pie-no-pie = yes
>  
> -tests-container = \
> -			  tst-ldconfig-bad-aux-cache
> +tests-container := \
> +			  tst-ldconfig-bad-aux-cache \
> +			  tst-ldconfig-ld_so_conf-update
>  
>  tests := tst-tls9 tst-leaks1 \
>  	tst-array1 tst-array2 tst-array3 tst-array4 tst-array5 \
> @@ -309,7 +310,8 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
>  		tst-auditmanymod4 tst-auditmanymod5 tst-auditmanymod6 \
>  		tst-auditmanymod7 tst-auditmanymod8 tst-auditmanymod9 \
>  		tst-initlazyfailmod tst-finilazyfailmod \
> -		tst-dlopenfailmod1 tst-dlopenfaillinkmod tst-dlopenfailmod2
> +		tst-dlopenfailmod1 tst-dlopenfaillinkmod tst-dlopenfailmod2 \
> +		tst-ldconfig-ld-mod
>  # 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%,\
> @@ -1689,3 +1691,6 @@ $(objpfx)tst-dlopen-nodelete-reloc-mod17.so: \
>    $(objpfx)tst-dlopen-nodelete-reloc-mod15.so \
>    $(objpfx)tst-dlopen-nodelete-reloc-mod16.so
>  LDFLAGS-tst-dlopen-nodelete-reloc-mod17.so = -Wl,--no-as-needed
> +
> +$(objpfx)tst-ldconfig-ld_so_conf-update.out: $(objpfx)tst-ldconfig-ld-mod.so
> +$(objpfx)tst-ldconfig-ld_so_conf-update: $(libdl)

Looks okay.

> diff --git a/elf/tst-ldconfig-ld-mod.c b/elf/tst-ldconfig-ld-mod.c
> new file mode 100644
> index 0000000000..f8f658d03b
> --- /dev/null
> +++ b/elf/tst-ldconfig-ld-mod.c
> @@ -0,0 +1,8 @@
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +void
> +bar (void)
> +{
> +  printf ("Called DSO.\n");
> +}

Looks okay. I recall v1 had a whitespace issue; it's gone.

> diff --git a/elf/tst-ldconfig-ld_so_conf-update.c b/elf/tst-ldconfig-ld_so_conf-update.c
> new file mode 100644
> index 0000000000..54fae5c829
> --- /dev/null
> +++ b/elf/tst-ldconfig-ld_so_conf-update.c
> @@ -0,0 +1,115 @@
> +/* Test ldconfig after /etc/ld.so.conf update and verify that a running process
> +   observes changes to /etc/ld.so.cache.

Looks okay.

> +   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; see the file COPYING.LIB.  If
> +   not, see <https://www.gnu.org/licenses/>.  */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <errno.h>
> +
> +#include <support/capture_subprocess.h>
> +#include <support/check.h>
> +#include <support/support.h>
> +#include <support/xdlfcn.h>
> +#include <support/xstdio.h>
> +#include <support/xunistd.h>
> +
> +
> +#define DSO "libldconfig-ld-mod.so"
> +#define DSO_DIR "/tmp/tst-ldconfig"
> +#define CONF "/etc/ld.so.conf"

Looks okay. No changes here.

> +static void
> +run_ldconfig (void *x __attribute__((unused)))
> +{
> +  char *prog = xasprintf ("%s/ldconfig", support_install_rootsbindir);
> +  char *args[] = { prog, NULL };
> +
> +  execv (args[0], args);
> +  FAIL_EXIT1 ("execv: %m");
> +}

Function renamed and skipped using arguments. Looks okay.

> +/* Create a new directory.
> +   Copy a test shared object there.
> +   Try to dlopen it by soname.  This should fail.
> +   (Directory is not searched.)
> +   Run ldconfig.
> +   Try to dlopen it again.  It should still fail.
> +   (Directory is still not searched.)
> +   Add the directory to /etc/ld.so.conf.
> +   Try to dlopen it again.  It should still fail.
> +   (The loader does not read /etc/ld.so.conf, only /etc/ld.so.cache.)
> +   Run ldconfig.
> +   Try to dlopen it again.  This should finally succeed.  */

Looks okay.

> +static int
> +do_test (void)
> +{
> +  struct support_capture_subprocess result;
> +
> +  /* Create the needed directories.  */
> +  xmkdirp ("/var/cache/ldconfig", 0777);
> +  xmkdirp (DSO_DIR, 0777);
> +
> +  /* Rename the DSO to start with "lib" because there's an undocumented
> +     filter in ldconfig where it ignores any file that doesn't start with
> +     "lib" (for regular shared libraries) or "ld-" (for ld-linux-*).  */
> +  if (rename ("/usr/lib64/tst-ldconfig-ld-mod.so",
> +              "/tmp/tst-ldconfig/libldconfig-ld-mod.so"))
> +    FAIL_EXIT1 ("Renaming/moving the DSO failed: %m");
> +
> +
> +  /* Open the DSO.  We expect this to fail - tst-ldconfig directory
> +     is not searched.  */
> +  TEST_VERIFY_EXIT (dlopen (DSO, RTLD_NOW | RTLD_GLOBAL) == NULL);

You dropped the open_dso function in favour of TEST_VERIFY_EXIT. Looks okay.

> +  FILE *fp = xfopen (CONF, "a+");
> +  if (!fp)
> +    FAIL_EXIT1 ("creating /etc/ld.so.conf failed: %m");
> +  xfclose (fp);
> +
> +  /* Run ldconfig.  */
> +  result = support_capture_subprocess (run_ldconfig, NULL);
> +  support_capture_subprocess_check (&result, "execv", 0, sc_allow_none);
> +
> +  /* Try to dlopen the same DSO again, we expect this to fail again.  */
> +  TEST_VERIFY_EXIT (dlopen (DSO, RTLD_NOW | RTLD_GLOBAL) == NULL);
> +
> +  /* Add tst-ldconfig directory to /etc/ld.so.conf.  */
> +  fp = xfopen (CONF, "w");
> +  if (!(fwrite (DSO_DIR, 1, sizeof (DSO_DIR), fp)))
> +    FAIL_EXIT1 ("updating /etc/ld.so.conf failed: %m");
> +  xfclose (fp);
> +
> +  /* Try to dlopen the same DSO again, we expect this to still fail.  */
> +  TEST_VERIFY_EXIT (dlopen (DSO, RTLD_NOW | RTLD_GLOBAL) == NULL);
> +
> +  /* Run ldconfig again.  */
> +  result = support_capture_subprocess (run_ldconfig, NULL);
> +  support_capture_subprocess_check (&result, "execv", 0, sc_allow_none);
> +  support_capture_subprocess_free (&result);
> +
> +  /* Finally, we expect dlopen to pass now.  */
> +  TEST_VERIFY_EXIT (dlopen (DSO, RTLD_NOW | RTLD_GLOBAL) != NULL);
> +
> +  return 0;
> +}

Changes since v1 correspond to renaming function to run_ldconfig, and dropping
open_dso. Looks okay.

> +#include <support/test-driver.c>
> diff --git a/elf/tst-ldconfig-ld_so_conf-update.root/postclean.req b/elf/tst-ldconfig-ld_so_conf-update.root/postclean.req
> new file mode 100644
> index 0000000000..e69de29bb2
> diff --git a/elf/tst-ldconfig-ld_so_conf-update.root/tst-ldconfig-ld_so_conf-update.script b/elf/tst-ldconfig-ld_so_conf-update.root/tst-ldconfig-ld_so_conf-update.script
> new file mode 100644
> index 0000000000..be562ba554
> --- /dev/null
> +++ b/elf/tst-ldconfig-ld_so_conf-update.root/tst-ldconfig-ld_so_conf-update.script
> @@ -0,0 +1 @@
> +cp $B/elf/tst-ldconfig-ld-mod.so $L/tst-ldconfig-ld-mod.so

I applied the patch and ran the test. It ran and passed.

This version looks good to me and I'd say it's good enough for master.

Cheers,
Arjun

On 06/01/2020 15:05, Arjun Shankar wrote:
> +   Copyright (C) 2019 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.

It needs to update the copyright year to 2020

> 
> This version looks good to me and I'd say it's good enough for master.

And to not add any confusion, only once 2.32 master open or if
release manager (Siddhesh) agrees.

On 06/01/20 11:39 pm, Adhemerval Zanella wrote:
> 
> 
> On 06/01/2020 15:05, Arjun Shankar wrote:
>> +   Copyright (C) 2019 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
> 
> It needs to update the copyright year to 2020
> 
>>
>> This version looks good to me and I'd say it's good enough for master.
> 
> And to not add any confusion, only once 2.32 master open or if
> release manager (Siddhesh) agrees. 
> 

This is OK for master.

Thanks,
Siddhesh

On 1/7/20 5:20 AM, Siddhesh Poyarekar wrote:
> On 06/01/20 11:39 pm, Adhemerval Zanella wrote:
>>
>>
>> On 06/01/2020 15:05, Arjun Shankar wrote:
>>> +   Copyright (C) 2019 Free Software Foundation, Inc.
>>> +   This file is part of the GNU C Library.
>>
>> It needs to update the copyright year to 2020
>>
>>>
>>> This version looks good to me and I'd say it's good enough for master.
>>
>> And to not add any confusion, only once 2.32 master open or if
>> release manager (Siddhesh) agrees.
>>
> 
> This is OK for master.
> 
> Thanks,
> Siddhesh
> 

Hi,

If run on 32bit, this test fails while renaming tst-ldconfig-ld-mod.so 
as there is no /usr/lib64 directory.

The attached patch is constructing the file name with help of 
support_libdir_prefix.

If the patch is okay, let me know if I can commit it on master.

Bye,
Stefan

On 10/01/20 8:15 pm, Stefan Liebler wrote:
> Hi,
> 
> If run on 32bit, this test fails while renaming tst-ldconfig-ld-mod.so
> as there is no /usr/lib64 directory.
> 
> The attached patch is constructing the file name with help of
> support_libdir_prefix.
> 
> If the patch is okay, let me know if I can commit it on master.

Nice catch, looks OK to me.

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

On 1/10/20 5:00 PM, Siddhesh Poyarekar wrote:
> On 10/01/20 8:15 pm, Stefan Liebler wrote:
>> Hi,
>>
>> If run on 32bit, this test fails while renaming tst-ldconfig-ld-mod.so
>> as there is no /usr/lib64 directory.
>>
>> The attached patch is constructing the file name with help of
>> support_libdir_prefix.
>>
>> If the patch is okay, let me know if I can commit it on master.
> 
> Nice catch, looks OK to me.
> 
> Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
> 
Committed.

Thanks,
Stefan