Re: [LTP] [PATCH] syscalls/fork01:Convert into new api

["xuyang2018.jy@fujitsu.com" <xuyang2018.jy@fujitsu.com>]

Hi Richard

Since Liao has did other work,  I will continue to do these cleanup works.

> Hello,
> 
> Liao Huangjie <liaohj.jy@fujitsu.com> writes:
> 
>> From: Huangjie Liao <liaohj.jy@fujitsu.com>
>>
>> Signed-off-by: Huangjie Liao <liaohj.jy@fujitsu.com>
>> ---
>>   testcases/kernel/syscalls/fork/fork01.c | 253 ++++++------------------
>>   1 file changed, 55 insertions(+), 198 deletions(-)
>>
>> diff --git a/testcases/kernel/syscalls/fork/fork01.c b/testcases/kernel/syscalls/fork/fork01.c
>> index 00d7c45c4..8ba712805 100644
>> --- a/testcases/kernel/syscalls/fork/fork01.c
>> +++ b/testcases/kernel/syscalls/fork/fork01.c
>> @@ -1,91 +1,17 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>>   /*
>>    * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
>> + * Author: Kathy Olmsted
>> + * Co-Pilot: Steve Shaw
>> + */
>> +
>> +/*\
>> + *[Description]
>>    *
>> - * This program is free software; you can redistribute it and/or modify it
>> - * under the terms of version 2 of the GNU General Public License as
>> - * published by the Free Software Foundation.
>> - *
>> - * This program is distributed in the hope that it would be useful, but
>> - * WITHOUT ANY WARRANTY; without even the implied warranty of
>> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>> - *
>> - * Further, this software is distributed without any warranty that it is
>> - * free of the rightful claim of any third person regarding infringement
>> - * or the like.  Any license provided herein, whether implied or
>> - * otherwise, applies only to this software file.  Patent licenses, if
>> - * any, provided herein do not apply to combinations of this program with
>> - * other software, or any other product whatsoever.
>> - *
>> - * You should have received a copy of the GNU General Public License along
>> - * with this program; if not, write the Free Software Foundation, Inc.,
>> - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
>> - *
>> - * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
>> - * Mountain View, CA  94043, or:
>> - *
>> - * http://www.sgi.com
>> - *
>> - * For further information regarding this notice, see:
>> - *
>> - * http://oss.sgi.com/projects/GenInfo/NoticeExplan/
>> - *
>> - *
>> - *    OS Test - Silicon Graphics, Inc.
>> - *    TEST IDENTIFIER	: fork01
>> - *    EXECUTED BY	: anyone
>> - *    TEST TITLE	: Basic test for fork(2)
>> - *    PARENT DOCUMENT	: frktds02
>> - *    TEST CASE TOTAL	: 2
>> - *    WALL CLOCK TIME	: 1
>> - *    CPU TYPES		: ALL
>> - *    AUTHOR		: Kathy Olmsted
>> - *    CO-PILOT		: Steve Shaw
>> - *    DATE STARTED	: 06/17/92
>> - *    INITIAL RELEASE	: UNICOS 7.0
>> - *    TEST CASES
>> - *	1.) fork returns without error
>> - *	2.) fork returns the pid of the child
>> - *    INPUT SPECIFICATIONS
>> - *	The standard options for system call tests are accepted.
>> - *	(See the parse_opts(3) man page).
>> - *    OUTPUT SPECIFICATIONS
>> - *    DURATION
>> - *	Terminates - with frequency and infinite modes.
>> - *    SIGNALS
>> - *	Uses SIGUSR1 to pause before test if option set.
>> - *	(See the parse_opts(3) man page).
>> - *    RESOURCES
>> - *	None
>> - *    ENVIRONMENTAL NEEDS
>> - *      No run-time environmental needs.
>> - *    SPECIAL PROCEDURAL REQUIREMENTS
>> - *	None
>> - *    INTERCASE DEPENDENCIES
>> - *	None
>> - *    DETAILED DESCRIPTION
>> - *	Setup:
>> - *	Setup signal handling.
>> - *	  Pause for SIGUSR1 if option specified.
>> - *	Test:
>> - *	 Loop if the proper options are given.
>> - *        fork()
>> - *	  Check return code, if system call failed (return=-1)
>> - *		Log the errno and Issue a FAIL message.
>> - *	  Otherwise, Issue a PASS message.
>> - *        CHILD:
>> - *           determine PID
>> - *           write to PID to a file and close the file
>> - *           exit
>> - *        PARENT:
>> - *           wait for child to exit
>> - *           read child PID from file
>> - *           compare child PID to fork() return code and report
>> - *           results
>> - *
>> - *	  Cleanup:
>> - *           Print errno log and/or timing stats if options given
>> + * This case tests fork()'s basic function.
> 
> The original descrption had more info than this. In particular:
> 
>> - *	1.) fork returns without error
>> - *	2.) fork returns the pid of the child

Ok, will keep it.
> 
> 
>>    */
>>   
>> +#define _GNU_SOURCE
>>   #include <errno.h>
>>   #include <string.h>
>>   #include <signal.h>
>> @@ -93,142 +19,73 @@
>>   #include <stdlib.h>
>>   #include <sys/types.h>
>>   #include <sys/wait.h>
>> -#include "test.h"
>> +#include <unistd.h>
>> +#include <stdio.h>
>> +#include "tst_test.h"
>>   
>>   #define	KIDEXIT	42
>> -static void setup();
>> -static void cleanup();
>> -
>>   #define LINE_SZ	20
>>   #define FILENAME "childpid"
>>   
>> -char *TCID = "fork01";
>> -int TST_TOTAL = 2;
>> +static char buf[LINE_SZ];
> 
> This doesn't need to be a global var. In fact we don't need it at all
> (see below).
> 
>>   
>> -/*
>> - * child_pid - the child side of the test
>> - *             determine the PID and write to a file
>> - */
>> -static void child_pid(void)
>> +static void do_child(void)
>>   {
>> +	int fd;
>>   
>> -	int fildes;
>> -	char tmp_line[LINE_SZ];
>> -
>> -	fildes = creat(FILENAME, 0700);
>> -	sprintf(tmp_line, "%d\n", getpid());
>> -	write(fildes, tmp_line, LINE_SZ);
>> -	close(fildes);
>> -
>> +	fd = creat(FILENAME, 0700);
>> +	sprintf(buf, "%d\n", getpid());
>> +	SAFE_WRITE(1, fd, buf, LINE_SZ);
>> +	SAFE_CLOSE(fd);
>>   }
> 
> This whole function can be replaced with SAFE_FILE_PRINTF i.e
> SAFE_FILE_PRINTF(FILENAME, "%d", getpid());
> 

Yes.

>>   
>> -/*
>> - * parent_pid - the parent side of the test
>> - *              read the value determined by the child
>> - *              compare and report results
>> - */
>> -static void parent_pid(void)
>> +static void check_child_pid(int pid)
>>   {
>> +	int fd;
>> +	pid_t child_pid;
>>   
>> -	int fildes;
>> -	char tmp_line[LINE_SZ];
>> -	pid_t child_id;
>> +	fd = SAFE_OPEN(FILENAME, O_RDWR);
>> +	SAFE_READ(1, fd, buf, LINE_SZ);
> 
> This can be replaced with SAFE_FILE_SCANF(FILENAME, "%d", &child_pid);

Yes.
> 
>>   
>> -	fildes = open(FILENAME, O_RDWR);
>> -	if (fildes == -1) {
>> -		tst_brkm(TBROK, cleanup,
>> -			 "parent open failed. errno: %d (%s)\n",
>> -			 errno, strerror(errno));
>> +	child_pid = atoi(buf);
>> +	if (child_pid != pid) {
>> +		tst_res(TFAIL, "child reported a pid of %d. parent received %d from fork()",
>> +				child_pid, pid);
> 
> This can be replaced with TST_EXP_EQ_LI(child_pid, pid).

Will do.
> 
>>   	} else {
>> -		if (read(fildes, tmp_line, LINE_SZ) == 0) {
>> -			tst_brkm(TBROK, cleanup,
>> -				 "fork(): parent failed to read PID from file errno: %d (%s)",
>> -				 errno, strerror(errno));
>> -		} else {
>> -			child_id = atoi(tmp_line);
>> -			if (TEST_RETURN != child_id) {
>> -				tst_resm(TFAIL,
>> -					 "child reported a pid of %d. parent received %ld from fork()",
>> -					 child_id, TEST_RETURN);
>> -			} else {
>> -				tst_resm(TPASS,
>> -					 "child pid and fork() return agree: %d",
>> -					 child_id);
>> -			}
>> -		}
>> -		close(fildes);
>> -	}
>> -}
>> -
>> -int main(int ac, char **av)
>> -{
>> -	int lc;
>> -	int fails;
>> -	int kid_status, wait_status;
>> -
>> -	tst_parse_opts(ac, av, NULL, NULL);
>> -
>> -	setup();
>> -
>> -	for (lc = 0; TEST_LOOPING(lc); lc++) {
>> -		tst_count = 0;
>> -		fails = 0;
>> -
>> -		TEST(fork());
>> -		if (TEST_RETURN == -1) {
>> -			tst_resm(TFAIL, "fork() Failed, errno=%d : %s",
>> -				 TEST_ERRNO, strerror(TEST_ERRNO));
>> -			tst_resm(TBROK, "unable to continue");
>> -		}
>> -		if (TEST_RETURN == 0) {
>> -			/* child */
>> -			child_pid();
>> -			exit(KIDEXIT);
>> -		} else {
>> -			/* parent */
>> -			tst_resm(TPASS, "fork() returned %ld",
>> -				 TEST_RETURN);
>> -			/* wait for the child to complete */
>> -			wait_status = waitpid(TEST_RETURN, &kid_status, 0);
>> -
>> -			if (wait_status == TEST_RETURN) {
>> -				if (kid_status != KIDEXIT << 8) {
>> -					tst_resm(TBROK,
>> -						 "incorrect child status returned on wait(): %d",
>> -						 kid_status);
>> -					fails++;
>> -				}
>> -			} else {
>> -				tst_resm(TBROK,
>> -					 "wait() for child status failed with %d errno: %d : %s",
>> -					 wait_status, errno,
>> -					 strerror(errno));
>> -				fails++;
>> -			}
>> -			if (fails == 0) {
>> -				/* verification tests */
>> -				parent_pid();
>> -			}
>> -		}		/* TEST_RETURN */
>> +		tst_res(TPASS, "child pid and fork() return agree: %d", pid);
>>   	}
>>   
>> -	cleanup();
>> -	tst_exit();
>> +	SAFE_CLOSE(fd);
>>   }
>>   
>> -static void setup(void)
>> +static void verify_fork(void)
>>   {
>> +	int kid_status, term_pid, pid;
>>   
>> -	tst_sig(FORK, DEF_HANDLER, cleanup);
>> -
>> -	TEST_PAUSE;
>> -
>> -	tst_tmpdir();
>> -}
>> +	pid = SAFE_FORK();
>> +	if (!pid) {
>> +		do_child();
>> +		exit(KIDEXIT);
>> +	}
>>   
>> -static void cleanup(void)
>> -{
>> +	term_pid = SAFE_WAITPID(pid, &kid_status, 0);
>> +	if (term_pid == pid) {
>> +		if (kid_status != KIDEXIT << 8)
>> +			tst_res(TFAIL, "incorrect child status returned %d", kid_status);
>> +		else
>> +			tst_res(TPASS, "correct child status returned
>> %d", kid_status);
> 
> The original test is not strictly correct. We should check if the child
> exited with WIFEXITED and use the WEXITSTATUS macro to get the exit
> status.

OK.
> 
>>   
>> -	tst_rmdir();
>> +		check_child_pid(pid);
>> +	} else {
>> +		tst_res(TFAIL, "waitpid() returns %d instead of  expected pid %d", term_pid, pid);
>> +	}
>>   
>> +	tst_reap_children();
>>   }
>> +
>> +static struct tst_test test = {
>> +	.needs_tmpdir = 1,
>> +	.needs_root = 1,
> 
> It doesn't need root.
Yes.

Best Regards
Yang Xu
> 
>> +	.forks_child = 1,
>> +	.test_all = verify_fork,
>> +};
>> -- 
>> 2.27.0
> 
> 

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