Re: [LTP] [PATCH v1] Refactor pidns05 test using new LTP API

[Richard Palethorpe <rpalethorpe@suse.de>]

Hello,

Andrea Cervesato <andrea.cervesato@suse.com> writes:

> Hi!
>
> Can we merge this patch anyway? ltp_clone should be added after with a
> single patch.

I started work on an update to tst_clone so that it can replace most
intances of ltp_clone. However it appears that it can already replace
most instances of ltp_clone_quick.

AFAICT all you need to do is get rid of child_func and use tst_clone
like fork.

I don't remember if there is anything else in this patch that needs
reviewing, so there is no guarantee that when I look at this again it
will get merged.

So I don't see any advantage to deferring the change to tst_clone.

>
> Andrea
>
> On 10/11/22 11:56, Richard Palethorpe wrote:
>> Hello,
>>
>> Andrea Cervesato via ltp <ltp@lists.linux.it> writes:
>>
>>> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
>>> ---
>>>   testcases/kernel/containers/pidns/pidns05.c | 288 ++++++--------------
>>>   1 file changed, 78 insertions(+), 210 deletions(-)
>>>
>>> diff --git a/testcases/kernel/containers/pidns/pidns05.c b/testcases/kernel/containers/pidns/pidns05.c
>>> index 79e146e36..1c588991b 100644
>>> --- a/testcases/kernel/containers/pidns/pidns05.c
>>> +++ b/testcases/kernel/containers/pidns/pidns05.c
>>> @@ -1,256 +1,124 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>>   /*
>>> -* Copyright (c) International Business Machines Corp., 2007
>>> -* 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
>>> -*
>>> -***************************************************************************
>>> -*
>>> -* Assertion:
>>> -*   a) Create a  container.
>>> -*   b) Create many levels of child containers inside this container.
>>> -*   c) Now do kill -9 init , outside of the container.
>>> -*   d) This should kill all the child containers.
>>> -*      (containers created at the level below)
>>> -*
>>> -* Description:
>>> -* 1. Parent process clone a process with flag CLONE_NEWPID
>>> -* 2. The container will recursively loop and creates 4 more containers.
>>> -* 3. All the container init's  goes into sleep(), waiting to be terminated.
>>> -* 4. The parent process will kill child[3] by passing SIGKILL
>>> -* 5. Now parent process, verifies the child containers 4 & 5 are destroyed.
>>> -* 6. If they are killed then
>>> -*	Test passed
>>> -*  else Test failed.
>>> -*
>>> -* Test Name: pidns05
>>> -*
>>> -* History:
>>> -*
>>> -* FLAG DATE		NAME				DESCRIPTION
>>> -* 31/10/08  Veerendra C <vechandr@in.ibm.com>	Verifies killing of NestedCont's
>>> -*
>>> -*******************************************************************************/
>>> -#define _GNU_SOURCE 1
>>> + * Copyright (c) International Business Machines Corp., 2007
>>> + *		08/10/08 Veerendra C <vechandr@in.ibm.com>
>>> + * Copyright (C) 2022 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
>>> + */
>>> +
>>> +/*\
>>> + * [Description]
>>> + *
>>> + * Clone a process with CLONE_NEWPID flag and create many levels of child
>>> + * containers. Then kill container init process from parent and check if all
>>> + * containers have been killed.
>>> + */
>>> +
>>>   #include <sys/wait.h>
>>> -#include <assert.h>
>>> -#include <stdio.h>
>>> -#include <stdlib.h>
>>> -#include <unistd.h>
>>> -#include <string.h>
>>> -#include <errno.h>
>>> -#include "pidns_helper.h"
>>> -#include "test.h"
>>> -#include "safe_macros.h"
>>> +#include "tst_test.h"
>>> +#include "lapi/namespaces_constants.h"
>>>   -#define INIT_PID	1
>>> -#define CINIT_PID	1
>>> -#define PARENT_PID	0
>>>   #define MAX_DEPTH	5
>>>   -char *TCID = "pidns05";
>>> -int TST_TOTAL = 1;
>>> -int fd[2];
>>> +static pid_t pid_max;
>>>   -int max_pid(void)
>>> +static int child_func(void *arg)
>>>   {
>>> -	FILE *fp;
>>>   	int ret;
>>> +	int *level;
>>> +	pid_t cpid, ppid;
>>> +
>>> +	cpid = getpid();
>>> +	ppid = getppid();
>>>   -	fp = fopen("/proc/sys/kernel/pid_max", "r");
>>> -	if (fp != NULL) {
>>> -		fscanf(fp, "%d", &ret);
>>> -		fclose(fp);
>>> -	} else {
>>> -		tst_resm(TBROK, "Cannot open /proc/sys/kernel/pid_max");
>>> -		ret = -1;
>>> +	if (cpid != 1 || ppid != 0) {
>>> +		tst_res(TFAIL, "Got unexpected result of cpid=%d ppid=%d", cpid, ppid);
>>> +		return 1;
>>>   	}
>>> -	return ret;
>>> +
>>> +	level = (int *)arg;
>>> +
>>> +	if (*level >= MAX_DEPTH) {
>>> +		TST_CHECKPOINT_WAKE(0);
>>> +		return 0;
>>> +	}
>>> +
>>> +	(*level)++;
>>> +
>>> +	ret = ltp_clone_quick(CLONE_NEWPID | SIGCHLD, child_func,
>>> level);
>> Again, ltp_clone should be converted to tst_clone.
>>
>>> +	if (ret < 0)
>>> +		tst_brk(TBROK | TERRNO, "clone failed");
>>> +
>>> +	pause();
>>> +
>>> +	return 0;
>>>   }
>>>   -/* find_cinit_pids() iteratively finds the pid's having same
>>> PGID as its parent.
>>> - * Input parameter - Accepts pointer to pid_t : To copy the pid's matching.
>>> - * Returns - the number of pids matched.
>>> -*/
>>> -int find_cinit_pids(pid_t * pids)
>>> +static int find_cinit_pids(pid_t *pids)
>>>   {
>>> -	int next = 0, pid_max, i;
>>> +	int i;
>>> +	int next = 0;
>>>   	pid_t parentpid, pgid, pgid2;
>>>   -	pid_max = max_pid();
>>>   	parentpid = getpid();
>>>   	pgid = getpgid(parentpid);
>>>   -	/* The loop breaks, when the loop counter reaches the
>>> parentpid value */
>>> -	for (i = parentpid + 1; i != parentpid; i++) {
>>> -		if (i > pid_max)
>>> -			i = 2;
>>> -
>>> +	for (i = parentpid + 1; i < pid_max; i++) {
>>>   		pgid2 = getpgid(i);
>>> +
>>>   		if (pgid2 == pgid) {
>>>   			pids[next] = i;
>>>   			next++;
>>>   		}
>>>   	}
>>> +
>>>   	return next;
>>>   }
>>>   -/*
>>> -* create_nested_container() Recursively create MAX_DEPTH nested containers
>>> -*/
>>> -int create_nested_container(void *vtest)
>>> +static void setup(void)
>>>   {
>>> -	int exit_val;
>>> -	int ret, count, *level;
>>> -	pid_t cpid, ppid;
>>> -	cpid = getpid();
>>> -	ppid = getppid();
>>> -	char mesg[] = "Nested Containers are created";
>>> -
>>> -	level = (int *)vtest;
>>> -	count = *level;
>>> -
>>> -	/* Child process closes up read side of pipe */
>>> -	close(fd[0]);
>>> -
>>> -	/* Comparing the values to make sure pidns is created correctly */
>>> -	if (cpid != CINIT_PID || ppid != PARENT_PID) {
>>> -		printf("Got unexpected cpid and/or ppid (cpid=%d ppid=%d)\n",
>>> -		       cpid, ppid);
>>> -		exit_val = 1;
>>> -	}
>>> -	if (count > 1) {
>>> -		count--;
>>> -		ret = do_clone_unshare_test(T_CLONE, CLONE_NEWPID,
>>> -					    create_nested_container,
>>> -					    (void *)&count);
>>> -		if (ret == -1) {
>>> -			printf("clone failed; errno = %d : %s\n",
>>> -			       ret, strerror(ret));
>>> -			exit_val = 1;
>>> -		} else
>>> -			exit_val = 0;
>>> -	} else {
>>> -		/* Sending mesg, 'Nested containers created' through the pipe */
>>> -		write(fd[1], mesg, (strlen(mesg) + 1));
>>> -		exit_val = 0;
>>> -	}
>>> -
>>> -	close(fd[1]);
>>> -	pause();
>>> -
>>> -	return exit_val;
>>> +	SAFE_FILE_SCANF("/proc/sys/kernel/pid_max", "%d\n", &pid_max);
>>>   }
>>>   -void kill_nested_containers()
>>> +static void run(void)
>>>   {
>>> -	int orig_count, new_count, status = 0, i;
>>> +	int ret, i;
>>> +	int status;
>>> +	int children;
>>> +	int level = 0;
>>>   	pid_t pids[MAX_DEPTH];
>>>   	pid_t pids_new[MAX_DEPTH];
>>>   -	orig_count = find_cinit_pids(pids);
>>> -	kill(pids[MAX_DEPTH - 3], SIGKILL);
>>> -	sleep(1);
>>> -
>>> -	/* After killing child container, getting the New PID list */
>>> -	new_count = find_cinit_pids(pids_new);
>>> +	ret = ltp_clone_quick(CLONE_NEWPID | SIGCHLD, child_func, &level);
>>> +	if (ret < 0)
>>> +		tst_brk(TBROK | TERRNO, "clone failed");
>>>   -	/* Verifying that the child containers were destroyed when
>>> parent is killed */
>>> -	if (orig_count - 2 != new_count)
>>> -		status = -1;
>>> +	TST_CHECKPOINT_WAIT(0);
>>>   -	for (i = 0; i < new_count; i++) {
>>> -		if (pids[i] != pids_new[i])
>>> -			status = -1;
>>> -	}
>>> +	find_cinit_pids(pids);
>>>   -	if (status == 0)
>>> -		tst_resm(TPASS, "The number of containers killed are %d",
>>> -			 orig_count - new_count);
>>> -	else
>>> -		tst_resm(TFAIL, "Failed to kill the sub-containers of "
>>> -			 "the container %d", pids[MAX_DEPTH - 3]);
>>> -
>>> -	/* Loops through the containers created to exit from sleep() */
>>> -	for (i = 0; i < MAX_DEPTH; i++) {
>>> -		kill(pids[i], SIGKILL);
>>> -		waitpid(pids[i], &status, 0);
>>> -	}
>>> -}
>>> +	SAFE_KILL(pids[0], SIGKILL);
>>>   -static void setup(void)
>>> -{
>>> -	tst_require_root();
>>> -	check_newpid();
>>> -}
>>> +	TST_RETRY_FUNC(waitpid(0, &status, WNOHANG), TST_RETVAL_NOTNULL);
>>>   -int main(void)
>>> -{
>>> -	int ret, nbytes, status;
>>> -	char readbuffer[80];
>>> -	pid_t pid, pgid;
>>> -	int count = MAX_DEPTH;
>>> +	children = find_cinit_pids(pids_new);
>>>   -	setup();
>>> +	if (children > 0) {
>>> +		tst_res(TFAIL, "%d children left after sending SIGKILL", children);
>>>   -	/*
>>> -	 * XXX (garrcoop): why in the hell is this fork-wait written this way?
>>> -	 * This doesn't add up with the pattern used for the rest of the tests,
>>> -	 * so I'm pretty damn sure this test is written incorrectly.
>>> -	 */
>>> -	pid = fork();
>>> -	if (pid == -1) {
>>> -		tst_brkm(TBROK | TERRNO, NULL, "fork failed");
>>> -	} else if (pid != 0) {
>>> -		/*
>>> -		 * NOTE: use waitpid so that we know we're waiting for the
>>> -		 * _top-level_ child instead of a spawned subcontainer.
>>> -		 *
>>> -		 * XXX (garrcoop): Might want to mask SIGCHLD in the top-level
>>> -		 * child too, or not *shrugs*.
>>> -		 */
>>> -		if (waitpid(pid, &status, 0) == -1) {
>>> -			perror("wait failed");
>>> +		for (i = 0; i < MAX_DEPTH; i++) {
>>> +			kill(pids[i], SIGKILL);
>>> +			waitpid(pids[i], &status, 0);
>>>   		}
>>> -		if (WIFEXITED(status))
>>> -			exit(WEXITSTATUS(status));
>>> -		else
>>> -			exit(status);
>>> -	}
>>>   -	/* To make all the containers share the same PGID as its
>>> parent */
>>> -	setpgid(0, 0);
>>> -
>>> -	pid = getpid();
>>> -	pgid = getpgid(pid);
>>> -	SAFE_PIPE(NULL, fd);
>>> -
>>> -	TEST(do_clone_unshare_test(T_CLONE, CLONE_NEWPID,
>>> -				   create_nested_container, (void *)&count));
>>> -	if (TEST_RETURN == -1) {
>>> -		tst_brkm(TFAIL | TTERRNO, NULL, "clone failed");
>>> +		return;
>>>   	}
>>>   -	close(fd[1]);
>>> -	/* Waiting for the MAX_DEPTH number of containers to be created */
>>> -	nbytes = read(fd[0], readbuffer, sizeof(readbuffer));
>>> -	close(fd[0]);
>>> -	if (nbytes > 0)
>>> -		tst_resm(TINFO, " %d %s", MAX_DEPTH, readbuffer);
>>> -	else
>>> -		tst_brkm(TFAIL, NULL, "unable to create %d containers",
>>> -			 MAX_DEPTH);
>>> -
>>> -	/* Kill the container created */
>>> -	kill_nested_containers();
>>> -
>>> -	tst_exit();
>>> +	tst_res(TPASS, "No children left after sending SIGKILL to the first child");
>>>   }
>>> +
>>> +static struct tst_test test = {
>>> +	.test_all = run,
>>> +	.setup = setup,
>>> +	.needs_root = 1,
>>> +	.needs_checkpoints = 1,
>>> +};
>>> -- 2.35.3
>>


-- 
Thank you,
Richard.

-- 
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