[LTP] [PATCH 1/3] syscalls: munmap01: Convert to new API

Andrea Cervesato andrea.cervesato@suse.com
Fri Jul 4 14:03:26 CEST 2025


Hi!

The conversion of the old API test is still bringing things which we 
want to get rid in the new test.
Read below.

On 7/3/25 8:39 PM, Ricardo B. Marlière via ltp wrote:
> From: Ricardo B. Marlière <rbm@suse.com>
>
> Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
> ---
>   testcases/kernel/syscalls/munmap/munmap01.c | 244 ++++++----------------------
>   1 file changed, 52 insertions(+), 192 deletions(-)
>
> diff --git a/testcases/kernel/syscalls/munmap/munmap01.c b/testcases/kernel/syscalls/munmap/munmap01.c
> index dfd81fa2b32de2354a8053c4b7ebf1d518b8bb67..b602c3094d7b351a69afe84b0c9c03d72078e64d 100644
> --- a/testcases/kernel/syscalls/munmap/munmap01.c
> +++ b/testcases/kernel/syscalls/munmap/munmap01.c
> @@ -1,157 +1,55 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
>   /*
> - *
> - *   Copyright (c) International Business Machines  Corp., 2001
> - *
> - *   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
> + * Copyright (c) International Business Machines  Corp., 2001
> + *	07/2001 Ported by Wayne Boyer
> + * Copyright (c) 2025 SUSE LLC Ricardo B. Marlière <rbm@suse.com>
>    */
>   
> -/*
> - * Test Name: munmap01
> +/*\
> + * Verify that, munmap call will succeed to unmap a mapped file or
> + * anonymous shared memory region from the calling process's address space
> + * and after successful completion of munmap, the unmapped region is no
> + * longer accessible.
>    *
> - * Test Description:
> - *  Verify that, munmap call will succeed to unmap a mapped file or
> - *  anonymous shared memory region from the calling process's address space
> - *  and after successful completion of munmap, the unmapped region is no
> - *  longer accessible.
> - *
> - * Expected Result:
> - *  munmap call should succeed to unmap a mapped file or anonymous shared
> - *  memory region from the process's address space and it returns with a
> - *  value 0, further reference to the unmapped region should result in a
> - *  segmentation fault (SIGSEGV).
> - *
> - * Algorithm:
> - *  Setup:
> - *   Setup signal handling.
> - *   Create temporary directory.
> - *   Pause for SIGUSR1 if option specified.
> - *
> - *  Test:
> - *   Loop if the proper options are given.
> - *   Execute system call
> - *   Check return code, if system call failed (return=-1)
> - *   	Log the errno and Issue a FAIL message.
> - *   Otherwise,
> - *   	Verify the Functionality of system call
> - *      if successful,
> - *      	Issue Functionality-Pass message.
> - *      Otherwise,
> - *		Issue Functionality-Fail message.
> - *  Cleanup:
> - *   Print errno log and/or timing stats if options given
> - *   Delete the temporary directory created.
> - *
> - * Usage:  <for command-line>
> - *  munmap01 [-c n] [-f] [-i n] [-I x] [-P x] [-t]
> - *     where,  -c n : Run n copies concurrently.
> - *             -f   : Turn off functionality Testing.
> - *	       -i n : Execute test n times.
> - *	       -I x : Execute test for x seconds.
> - *	       -P x : Pause for x seconds between iterations.
> - *	       -t   : Turn on syscall timing.
> - *
> - * HISTORY
> - *	07/2001 Ported by Wayne Boyer
> - *
> - * RESTRICTIONS:
> - *  None.$
> + * munmap call should succeed to unmap a mapped file or anonymous shared
> + * memory region from the process's address space and it returns with a
> + * value 0, further reference to the unmapped region should result in a
> + * segmentation fault (SIGSEGV).
>    */
> -#include <errno.h>
> -#include <unistd.h>
> -#include <fcntl.h>
> -#include <sys/stat.h>
> -#include <sys/mman.h>
> -
> -#include "test.h"
> -#include "safe_macros.h"
> -
> -#define TEMPFILE	"mmapfile"
>   
> -char *TCID = "munmap01";
> -int TST_TOTAL = 1;
> +#include "tst_test.h"
>   
> -char *addr;			/* addr of memory mapped region */
> -int fildes;			/* file descriptor for tempfile */
> -unsigned int map_len;		/* length of the region to be mapped */
> +static int fd;
> +static char *map_addr;
> +static unsigned int map_len;
>   
> -void setup();			/* Main setup function of test */
> -void cleanup();			/* cleanup function for the test */
> -void sig_handler();		/* signal catching function */
> -
> -int main(int ac, char **av)
> +static void run(void)
>   {
> -	int lc;
> -
> -	tst_parse_opts(ac, av, NULL, NULL);
> -
> -	for (lc = 0; TEST_LOOPING(lc); lc++) {
> -
> -		tst_count = 0;
> -
> -		setup();
> -
> -		/*
> -		 * Call munmap to unmap the mapped region of the
> -		 * temporary file from the calling process's address space.
> -		 */
> -		TEST(munmap(addr, map_len));
> -
> -		/* Check for the return value of munmap() */
> -		if (TEST_RETURN == -1) {
> -			tst_resm(TFAIL, "munmap() fails, errno=%d : %s",
> -				 TEST_ERRNO, strerror(TEST_ERRNO));
> -			continue;
> -		}
> -
> -		/*
> -		 * Check whether further reference is possible
> -		 * to the unmapped memory region by writing
> -		 * to the first byte of region with
> -		 * some arbitrary number.
> -		 */
> -		*addr = 50;
> +	SAFE_MUNMAP(map_addr, map_len);
>   
> -		/* This message is printed if no SIGSEGV */
> -		tst_resm(TFAIL, "process succeeds to refer unmapped memory region");
> +	/*
> +	 * Check whether further reference is possible to the unmapped memory
> +	 * region by writing to the first byte of region with some arbitrary
> +	 * number.
> +	 */
> +	*map_addr = 50;
>   
> -		cleanup();
> +	/* This message is printed if no SIGSEGV */
> +	tst_res(TFAIL, "process succeeds to refer unmapped memory region");
> +}
>   
> -	}
> -	tst_exit();
> +static void sig_handler(LTP_ATTRIBUTE_UNUSED int i)
> +{
> +	tst_res(TPASS, "Functionality of munmap() successful");
> +	_exit(0);
>   }
Signals must be used carefully and in specific situations due to their 
asynchronous nature. In this case, we can just SAFE_FORK() a child and 
to verify that child has been signaled after accessing a un-mapped memory.
>   
> -/*
> - * setup() - performs all ONE TIME setup for this test.
> - *
> - * Set up signal handler to catch SIGSEGV.
> - * Get system page size, create a temporary file for reading/writing,
> - * write one byte data into it, map the open file for the specified
> - * map length.
> - */
> -void setup(void)
> +static void setup(void)
>   {
>   	size_t page_sz;
>   
> -	tst_sig(NOFORK, DEF_HANDLER, cleanup);
> -
> -	/* call signal function to trap the signal generated */
> -	if (signal(SIGSEGV, sig_handler) == SIG_ERR) {
> -		tst_brkm(TBROK, cleanup, "signal fails to catch signal");
> -	}
> -
> -	TEST_PAUSE;
> +	/* Call signal function to trap the signal generated */
> +	SAFE_SIGNAL(SIGSEGV, sig_handler);
>   
>   	/* Get the system page size */
>   	page_sz = getpagesize();
> @@ -162,74 +60,36 @@ void setup(void)
>   	 */
>   	map_len = 3 * page_sz;
>   
> -	tst_tmpdir();
> -
> -	/* Creat a temporary file used for mapping */
> -	if ((fildes = open(TEMPFILE, O_RDWR | O_CREAT, 0666)) < 0) {
> -		tst_brkm(TBROK, cleanup, "open() on %s Failed, errno=%d : %s",
> -			 TEMPFILE, errno, strerror(errno));
> -	}
> +	/* Create a temporary file used for mapping */
> +	fd = SAFE_OPEN("mmapfile", O_RDWR | O_CREAT, 0666);
>   
>   	/*
> -	 * move the file pointer to maplength position from the beginning
> +	 * Move the file pointer to maplength position from the beginning
>   	 * of the file.
>   	 */
> -	SAFE_LSEEK(cleanup, fildes, map_len, SEEK_SET);
> +	SAFE_LSEEK(fd, map_len, SEEK_SET);
>   
>   	/* Write one byte into temporary file */
> -	if (write(fildes, "a", 1) != 1) {
> -		tst_brkm(TBROK, cleanup, "write() on %s Failed, errno=%d : %s",
> -			 TEMPFILE, errno, strerror(errno));
> -	}
> +	SAFE_WRITE(SAFE_WRITE_ALL, fd, "a", 1);
>   
>   	/*
> -	 * map the open file 'TEMPFILE' from its beginning up to the maplength
> +	 * Map the open file 'mmapfile' from its beginning up to the maplength
>   	 * into the calling process's address space at the system choosen
>   	 * with read/write permissions to the mapped region.
>   	 */
> -	addr = mmap(0, map_len, PROT_READ | PROT_WRITE,
> -		    MAP_FILE | MAP_SHARED, fildes, 0);
> -
> -	/* check for the return value of mmap system call */
> -	if (addr == (char *)MAP_FAILED) {
> -		tst_brkm(TBROK, cleanup, "mmap() Failed on %s, errno=%d : %s",
> -			 TEMPFILE, errno, strerror(errno));
> -	}
> -
> +	map_addr = SAFE_MMAP(0, map_len, PROT_READ | PROT_WRITE,
> +			     MAP_FILE | MAP_SHARED, fd, 0);
>   }
>   
> -/*
> - * sig_handler() - signal catching function.
> - *   This function is used to trap the signal generated when tried to read or
> - *   write to the memory mapped region which is already detached from the
> - *   calling process address space.
> - *   this function is invoked when SIGSEGV generated and it calls test
> - *   cleanup function and exit the program.
> - */
> -void sig_handler(void)
> +static void cleanup(void)
>   {
> -	tst_resm(TPASS, "Functionality of munmap() successful");
> -
> -	/* Invoke test cleanup function and exit */
> -	cleanup();
> -
> -	tst_exit();
> +	if (fd)
> +		SAFE_CLOSE(fd);
>   }
>   
> -/*
> - * cleanup() - performs all ONE TIME cleanup for this test at
> - *             completion or premature exit.
> - *  	       Close the temporary file.
> - *  	       Remove the temporary directory.
> - */
> -void cleanup(void)
> -{
> -
> -	/* Close the temporary file */
> -	if (close(fildes) < 0) {
> -		tst_brkm(TFAIL, NULL, "close() on %s Failed, errno=%d : %s",
> -			 TEMPFILE, errno, strerror(errno));
> -	}
> -
> -	tst_rmdir();
> -}
> +static struct tst_test test = {
> +	.test_all = run,
> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.needs_tmpdir = 1,
> +};

Also, please remove comments if not strictly needed, because they are 
kind of obvious when we read the test code.

- Andrea



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