[LTP] [PATCH v3 2/3] Refactor pidns30 test using new LTP API

Andrea Cervesato andrea.cervesato@suse.com
Wed Feb 8 10:42:38 CET 2023


Hi,

On 11/1/22 13:01, 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/pidns30.c | 312 +++++---------------
>>   1 file changed, 66 insertions(+), 246 deletions(-)
>>
>> diff --git a/testcases/kernel/containers/pidns/pidns30.c b/testcases/kernel/containers/pidns/pidns30.c
>> index c8b0806c0..b01759a87 100644
>> --- a/testcases/kernel/containers/pidns/pidns30.c
>> +++ b/testcases/kernel/containers/pidns/pidns30.c
>> @@ -1,296 +1,116 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>>   /*
>> -* Copyright (c) Bull S.A.S. 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
>> -*
>> -***************************************************************************
>> -* File: pidns30.c
>> -*
>> -*   Description:
>> -*    This testcase checks if the si_pid is correctly set when a process
>> -*    that has registered for notification on a posix mqueue is in a
>> -*    descendant namespace wrt the process that sends a message to that posix
>> -*    mqueue.
>> -*
>> -*   Test Assertion & Strategy:
>> -*    Parent                                   Child
>> -*    --------------------------------------------------------------------------
>> -*    Create a POSIX mqueue.
>> -*    Create a PID namespace container.
>> -*                                             Open that mqueue for reading
>> -*                                             Register for notification when a
>> -*                                                message arrives in that mqueue
>> -*                                             Install a handler for SIGUSR1.
>> -*    Write something to the mqueue.
>> -*                                             Inside the handler, check that
>> -*                                                si_pid is set to 0
>> -*
>> -*   Usage: <for command-line>
>> -*    pidns30
>> -*
>> -*   History:
>> -*    DATE      NAME                             DESCRIPTION
>> -*    01/12/08  Nadia Derbey               Creation of this test.
>> -*              <Nadia.Derbey@bull.net>
>> -*
>> -******************************************************************************/
>> + * Copyright (c) Bull S.A.S. 2008
>> + *               01/12/08  Nadia Derbey <Nadia.Derbey@bull.net>
>> + * Copyright (C) 2022 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
>> + */
>> +
>> +/*\
>> + * [Description]
>> + *
>> + * Clone a process with CLONE_NEWPID flag, register notification on a posix
>> + * mqueue and send a mqueue message from the parent. Then check if signal
>> + * notification contains si_pid of the parent.
>> + */
>> +
>>   #define _GNU_SOURCE 1
>> -#include <sys/wait.h>
>> -#include <sys/types.h>
>>   #include <signal.h>
>> -#include <stdlib.h>
>> -#include <unistd.h>
>> -#include <stdio.h>
>>   #include <mqueue.h>
>> -#include "lapi/syscalls.h"
>> -#include "pidns_helper.h"
>> -#include "test.h"
>> -
>> -char *TCID = "pidns30";
>> -int TST_TOTAL = 1;
>> -
>> -char *mqname = "mq1";
>> -int result = TFAIL;
>> +#include "tst_test.h"
>> +#include "tst_safe_posix_ipc.h"
>> +#include "lapi/namespaces_constants.h"
>>   
>> -int father_to_child[2];
>> -int child_to_father[2];
>> +#define MQNAME "/LTP_PIDNS30_MQ"
>>   
>> -#define CHILD_PID       1
>> -#define PARENT_PID      0
>> -
>> -#define MSG      "HOW ARE YOU"
>> -#define MSG_PRIO 1
>> -
>> -#define NO_STEP	-1
>> -#define F_STEP_0 0x00
>> -#define F_STEP_1 0x01
>> -#define F_STEP_2 0x02
>> -#define F_STEP_3 0x03
>> -#define C_STEP_0 0x10
>> -#define C_STEP_1 0x11
>> -#define C_STEP_2 0x12
>> -
>> -mqd_t rc = -1;
>> -mqd_t mqd = -1;
>> -
>> -static void remove_pipe(int *fd)
>> -{
>> -	close(fd[0]);
>> -	close(fd[1]);
>> -}
>> +static mqd_t mqd = -1;
>> +static int received;
> This should be volatile because it is used in the sighandler.
>
>>   
>>   static void remove_mqueue(mqd_t mqd)
>>   {
>> -	mq_close(mqd);
>> -	tst_syscall(__NR_mq_unlink, mqname);
>> -}
>> -
>> -static void cleanup(void)
>> -{
>> -	if (mqd != -1) {
>> -		remove_mqueue(mqd);
>> -	}
>> -	if (rc != -1) {
>> -		remove_mqueue(rc);
>> -	}
>> -	remove_pipe(father_to_child);
>> -	remove_pipe(child_to_father);
>> -}
>> +	if (mqd != -1)
>> +		SAFE_MQ_CLOSE(mqd);
>>   
>> -static void cleanup_child(void)
>> -{
>> -	if (mqd != -1) {
>> -		tst_syscall(__NR_mq_notify, mqd, NULL);
>> -	}
>> -	cleanup();
>> +	mq_unlink(MQNAME);
> We don't know that mq_unlink ever succeeds as we never check the
> result. This seems like lazyness because it is used at the beginning of
> run where it is expected to fail.
>
>>   }
>>   
>> -/*
>> - * child_signal_handler() - to handle SIGUSR1
>> - *
>> - * XXX (garrcoop): add calls to cleanup_child() -- or should this be handled
>> - * from the libltp signal handler?
>> - */
>> -static void child_signal_handler(int sig, siginfo_t * si, void *unused)
>> +static void child_signal_handler(LTP_ATTRIBUTE_UNUSED int sig, siginfo_t *si, LTP_ATTRIBUTE_UNUSED void *unused)
>>   {
>> -	char buf[256];
>> -	struct mq_attr attr;
>> +	tst_res(TINFO, "Received signal %s from pid %d",
>> tst_strsig(si->si_signo), si->si_pid);
> Again we should avoid calling tst_res in the signal handler
>
>>   
>> -	if (si->si_signo != SIGUSR1) {
>> -		printf("received signal = %d unexpectedly\n", si->si_signo);
>> +	if (si->si_signo != SIGUSR1 || si->si_code != SI_MESGQ ||
>> si->si_pid != 0)
> If the wrong signal or details are sent then we won't get any debug
> information. Unlike with the old version.
>
>>   		return;
>> -	}
>> -
>> -	if (si->si_code != SI_MESGQ) {
>> -		printf("expected signal code SI_MESGQ; got %d instead\n",
>> -		       si->si_code);
>> -		return;
>> -	}
>> -
>> -	if (si->si_pid) {
>> -		printf("expected signal originator PID = 0; got %d instead\n",
>> -		       si->si_pid);
>> -		return;
>> -	} else {
>> -		printf("signal originator PID = 0\n");
>> -		result = TPASS;
>> -	}
>>   
>> -	/*
>> -	 * Now read the message - Be silent on errors since this is not the
>> -	 * test purpose.
>> -	 */
>> -	rc = mq_getattr(si->si_int, &attr);
>> -	if (rc != -1)
>> -		mq_receive(si->si_int, buf, attr.mq_msgsize, NULL);
>> +	received++;
>>   }
>>   
>> -/*
>> - * child_fn() - Inside container
>> - *
>> - * XXX (garrcoop): add more calls to cleanup_child()?
>> - */
>> -int child_fn(void *arg)
>> +static int child_func(LTP_ATTRIBUTE_UNUSED void *arg)
>>   {
>> -	pid_t pid, ppid;
>> +	pid_t cpid, ppid;
>>   	struct sigaction sa;
>>   	struct sigevent notif;
>> -	char buf[5];
>> +	mqd_t mqd_child;
>>   
>> -	/* Set process id and parent pid */
>> -	pid = getpid();
>> +	cpid = getpid();
>>   	ppid = getppid();
>>   
>> -	if (pid != CHILD_PID || ppid != PARENT_PID) {
>> -		printf("pidns was not created\n");
>> -		return 1;
>> +	if (cpid != 1 || ppid != 0) {
>> +		tst_res(TFAIL, "got unexpected result of cpid=%d ppid=%d", cpid, ppid);
>> +		return 0;
> Again TST_EXP_EQ*
>
>>   	}
>>   
>> -	/* Close the appropriate end of each pipe */
>> -	close(child_to_father[0]);
>> -	close(father_to_child[1]);
>> +	TST_CHECKPOINT_WAIT(0);
>>   
>> -	while (read(father_to_child[0], buf, 1) != 1)
>> -		sleep(1);
>> -
>> -	mqd = tst_syscall(__NR_mq_open, mqname, O_RDONLY, 0, NULL);
>> -	if (mqd == -1) {
>> -		perror("mq_open failed");
>> -		return 1;
>> -	} else
>> -		printf("mq_open succeeded\n");
>> -
>> -	/* Register for notification on message arrival */
>> +	mqd_child = SAFE_MQ_OPEN(MQNAME, O_RDONLY, 0, NULL);
>>   	notif.sigev_notify = SIGEV_SIGNAL;
>>   	notif.sigev_signo = SIGUSR1;
>> -	notif.sigev_value.sival_int = mqd;
>> -	if (tst_syscall(__NR_mq_notify, mqd, &notif) == -1) {
>> -		perror("mq_notify failed");
>> -		return 1;
>> -	} else
>> -		printf("successfully registered for notification\n");
>> +	notif.sigev_value.sival_int = mqd_child;
>> +
>> +	SAFE_MQ_NOTIFY(mqd_child, &notif);
>>   
>> -	/* Define handler for SIGUSR1 */
>>   	sa.sa_flags = SA_SIGINFO;
>> -	sigemptyset(&sa.sa_mask);
>> +	SAFE_SIGEMPTYSET(&sa.sa_mask);
>>   	sa.sa_sigaction = child_signal_handler;
>> -	if (sigaction(SIGUSR1, &sa, NULL) == -1) {
>> -		perror("sigaction failed");
>> -		return 1;
>> -	} else
>> -		printf("successfully registered handler for SIGUSR1\n");
>> +	SAFE_SIGACTION(SIGUSR1, &sa, NULL);
>>   
>> -	/* Ask parent to send a message to the mqueue */
>> -	if (write(child_to_father[1], "c:ok", 5) != 5) {
>> -		perror("write failed");
>> -		return 1;
>> -	}
>> -
>> -	sleep(3);
>> +	TST_CHECKPOINT_WAKE_AND_WAIT(0);
>>   
>> -	/* Has parent sent a message? */
>> -	read(father_to_child[0], buf, 5);
>> -	if (strcmp(buf, "f:ok") != 0) {
>> -		printf("parent did not send the message!\n");
>> -		return 1;
>> +	if (received != 1) {
>> +		tst_res(TFAIL, "Signal hasn't been received after mqueue
>> event");
> If we receive more than one signal then this will also be printed. In
> any case we can shorted this with TST_EXP_EQ_*.
I would keep this message because it's easier to read when test fails.
>> +		return 0;
>>   	}
>> -	printf("parent is done - cleaning up\n");
>>   
>> -	cleanup_child();
>> +	tst_res(TPASS, "Signal has been received after mqueue event");
>>   
>> -	exit(0);
>> +	return 0;
>>   }
>>   
>> -static void setup(void)
>> +static void cleanup(void)
>>   {
>> -	tst_require_root();
>> -	check_newpid();
>> +	remove_mqueue(mqd);
>>   }
>>   
>> -int main(void)
>> +static void run(void)
>>   {
>> -	int status;
>> -	char buf[5];
>> -	pid_t cpid;
>> -
>> -	setup();
>> -
>> -	if (pipe(child_to_father) == -1 || pipe(father_to_child) == -1) {
>> -		tst_brkm(TBROK | TERRNO, cleanup, "pipe failed");
>> -	}
>> +	int ret;
>>   
>> -	tst_syscall(__NR_mq_unlink, mqname);
>> +	remove_mqueue(mqd);
>>   
>> -	/* container creation on PID namespace */
>> -	cpid = ltp_clone_quick(CLONE_NEWPID | SIGCHLD, child_fn, NULL);
>> -	if (cpid == -1)
>> -		tst_brkm(TBROK | TERRNO, cleanup, "clone failed");
>> +	ret = ltp_clone_quick(CLONE_NEWPID | SIGCHLD, child_func, NULL);
>> +	if (ret < 0)
>> +		tst_brk(TBROK | TERRNO, "clone failed");
>>   
>> -	mqd =
>> -	    tst_syscall(__NR_mq_open, mqname, O_RDWR | O_CREAT | O_EXCL, 0777,
>> -		    NULL);
>> -	if (mqd == -1)
>> -		tst_brkm(TBROK | TERRNO, cleanup, "mq_open failed");
>> -	else
>> -		tst_resm(TINFO, "successfully created posix mqueue");
>> +	mqd = SAFE_MQ_OPEN(MQNAME, O_RDWR | O_CREAT | O_EXCL, 0777, 0);
>>   
>> -	if (write(father_to_child[1], buf, 1) != 1)
>> -		tst_brkm(TBROK | TERRNO, cleanup, "write failed");
>> +	TST_CHECKPOINT_WAKE_AND_WAIT(0);
>>   
>> -	/* Close the appropriate end of each pipe */
>> -	close(child_to_father[1]);
>> -	close(father_to_child[0]);
>> +	SAFE_MQ_SEND(mqd, "pippo", 5, 1);
>>   
>> -	/* Is container ready */
>> -	read(child_to_father[0], buf, 5);
>> -	if (strcmp(buf, "c:ok") != 0)
>> -		tst_brkm(TBROK, cleanup,
>> -			 "container did not respond as expected!");
>> -
>> -	rc = mq_send(mqd, MSG, strlen(MSG), MSG_PRIO);
>> -	if (rc == -1)
>> -		tst_brkm(TBROK | TERRNO, cleanup, "mq_send failed");
>> -	else
>> -		tst_resm(TINFO, "mq_send succeeded");
>> -
>> -	/* Tell the child the message has been sent */
>> -	if (write(father_to_child[1], "f:ok", 5) != 5)
>> -		tst_brkm(TBROK | TERRNO, cleanup, "write failed");
>> -
>> -	/* Wait for child to finish */
>> -	if (wait(&status) == -1)
>> -		tst_resm(TBROK | TERRNO, "wait failed");
>> -
>> -	cleanup();
>> -
>> -	tst_exit();
>> +	TST_CHECKPOINT_WAKE(0);
>>   }
>> +
>> +static struct tst_test test = {
>> +	.test_all = run,
>> +	.cleanup = cleanup,
>> +	.needs_root = 1,
>> +	.needs_checkpoints = 1,
>> +};
>> -- 
>> 2.35.3
>
Andrea



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