[LTP] [PATCH v1] Refactor pidns06 test using new LTP API

[Richard Palethorpe]

Hello,

I said I would merge these, but on closer inspection there are more
opportunities to use existing macros which will make the test more
concise and increase debugging info.

Andrea Cervesato via ltp <ltp@lists.linux.it> writes:

> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
> ---
>  testcases/kernel/containers/pidns/pidns06.c | 152 +++++---------------
>  1 file changed, 38 insertions(+), 114 deletions(-)
>
> diff --git a/testcases/kernel/containers/pidns/pidns06.c b/testcases/kernel/containers/pidns/pidns06.c
> index d6623941a..b561c055f 100644
> --- a/testcases/kernel/containers/pidns/pidns06.c
> +++ b/testcases/kernel/containers/pidns/pidns06.c
> @@ -1,133 +1,57 @@
> +// SPDX-License-Identifier: GPL-2.0
>  /*
> -* Copyright (c) International Business Machines Corp., 2008
> -* This program is free software; you can redistribute it and/or modify
> -* it under the terms of the GNU General Public License as published by
> -* the Free Software Foundation; either version 2 of the License, or
> -* (at your option) any later version.
> -* This program 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 General Public License for more details.
> -* You should have received a copy of the GNU General Public License
> -* along with this program; if not, write to the Free Software
> -* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> -
> -*************************************************************************
> -* Description:
> -*  Testcase tries killing of the parent namespace pid by the container-init.
> -*  It also tries killing of non-existent PID, by the container-init.
> -*  Returns Success if Unable to kill, and proper error number is set.
> -*  else Returns Failure
> -*
> -* Steps:
> -* 1. Parent process clone a process with flag CLONE_NEWPID
> -* 2. The pid of the parent namespace is passed to the container.
> -* 3. Container receieves the PID and passes SIGKILL to this PID.
> -* 4. If kill() is unsuccessful and the errno is set to 'No Such process'
> -*	then sets PASS
> -*    else,
> -*	sets FAIL
> -* 5. It also verifies by passing SIGKILL to FAKE_PID
> -* 6. If kill() is unsuccessful and the errno is set to 'No Such process'
> -*	then sets PASS
> -*    else,
> -*	sets FAIL
> -*
> -*******************************************************************************/
> -#define _GNU_SOURCE 1
> -#include <stdio.h>
> -#include <stdlib.h>
> -#include <sys/wait.h>
> -#include <assert.h>
> -#include <unistd.h>
> -#include <errno.h>
> -#include <signal.h>
> -#include "pidns_helper.h"
> -#include "test.h"
> + * Copyright (C) International Business Machines Corp., 2008
> + * Copyright (C) 2022 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
> + */
>  
> -#define CINIT_PID       1
> -#define PARENT_PID      0
> -#define FAKE_PID	-1
> +/*\
> + * [Description]
> + *
> + * Clone a process with CLONE_NEWPID flag and check that parent process can't
> + * be killed from child namespace.
> + */
>  
> -char *TCID = "pidns06";
> -int TST_TOTAL = 1;
> +#include "tst_test.h"
> +#include "lapi/namespaces_constants.h"
>  
> -/*
> - * kill_pid_in_childfun()
> - *      Cont-init tries to kill the parent-process using parent's global Pid.
> - *	Also checks passing SIGKILL to non existent PID in the container.
> - */
> -static int kill_pid_in_childfun(void *vtest)
> +static int child_func(LTP_ATTRIBUTE_UNUSED void *arg)

arg is not unused.

>  {
> -	int cpid, ppid, *par_pid;
> -	int ret = 0;
> +	pid_t cpid, ppid;
> +	int ret;
> +
>  	cpid = getpid();
>  	ppid = getppid();
> -	par_pid = (int *)vtest;
>  
> -	/* Checking the values to make sure pidns is created correctly */
> -	if (cpid != CINIT_PID || ppid != PARENT_PID) {
> -		printf("Unexpected result for Container: init "
> -		       "pid=%d ppid=%d\n", cpid, ppid);
> -		exit(1);
> +	if (cpid != 1 || ppid != 0) {
> +		tst_res(TFAIL, "Got unexpected result of cpid=%d ppid=%d", cpid, ppid);
> +		return 1;
>  	}

The TST_EXP* macros can be used to simplify this.

>  
> -	/*
> -	 * While trying kill() of the pid of the parent namespace..
> -	 * Check to see if the errno was set to the expected, value of 3 : ESRCH
> -	 */
> -	ret = kill(*par_pid, SIGKILL);
> -	if (ret == -1 && errno == ESRCH) {
> -		printf("Container: killing parent pid=%d failed as expected "
> -		       "with ESRCH\n", *par_pid);
> -	} else {
> -		printf("Container: killing parent pid=%d, didn't fail as "
> -		       "expected with ESRCH (%d) and a return value of -1. Got "
> -		       "%d (\"%s\") and a return value of %d instead.\n",
> -		       *par_pid, ESRCH, errno, strerror(errno), ret);
> -		exit(1);
> -	}
> -	/*
> -	 * While killing non-existent pid in the container,
> -	 * Check to see if the errno was set to the expected, value of 3 : ESRCH
> -	 */
> -	ret = kill(FAKE_PID, SIGKILL);
> -	if (ret == -1 && errno == ESRCH) {
> -		printf("Container: killing non-existent pid failed as expected "
> -		       "with ESRCH\n");
> -	} else {
> -		printf("Container: killing non-existent pid, didn't fail as "
> -		       "expected with ESRCH (%d) and a return value of -1. Got "
> -		       "%d (\"%s\") and a return value of %d instead.\n",
> -		       ESRCH, errno, strerror(errno), ret);
> -		exit(1);
> +	ret = kill(*(int *)arg, SIGKILL);

We have the TEST macro as well. Or TST_EXP_FAIL.

> +
> +	if (ret != -1 || errno != ESRCH) {

errno could be set to some stale value if ret != -1 (the TEST macro sets
it)

> +		tst_res(TFAIL, "kill() didn't fail with ESRCH");

TTERRNO can be used here with the TEST  macro. Otherwise we don't know
what errno was set.

> +		return 1;
>  	}
>  
> -	exit(0);
> -}
> +	tst_res(TPASS, "Can't kill parent process from child namespace");
>  
> -static void setup(void)
> -{
> -	tst_require_root();
> -	check_newpid();
> +	return 0;
>  }
>  
> -int main(void)
> +static void run(void)
>  {
> -	int status;
> -
> -	setup();
> +	int ret;
> +	pid_t pid;
>  
> -	pid_t pid = getpid();

I don't think you need to change this.

> +	pid = getpid();
>  
> -	tst_resm(TINFO, "Parent: Passing the pid of the process %d", pid);
> -	TEST(do_clone_unshare_test(T_CLONE, CLONE_NEWPID, kill_pid_in_childfun,
> -				   (void *)&pid));
> -	if (TEST_RETURN == -1) {
> -		tst_brkm(TFAIL | TTERRNO, NULL, "clone failed");
> -	} else if (wait(&status) == -1) {
> -		tst_brkm(TFAIL | TERRNO, NULL, "wait failed");
> -	}
> -
> -	tst_exit();
> +	ret = ltp_clone_quick(CLONE_NEWPID | SIGCHLD, child_func, &pid);

I want this to be replaced with tst_clone, but as agreed, it can be
defered to a later patch set.

> +	if (ret < 0)
> +		tst_brk(TBROK | TERRNO, "clone failed");
>  }
> +
> +static struct tst_test test = {
> +	.test_all = run,
> +	.needs_root = 1,
> +};
> -- 
> 2.35.3


-- 
Thank you,
Richard.