[LTP] [PATCH v2 2/3] syscalls: munmap02: Make it a variant of munmap01
Andrea Cervesato
andrea.cervesato@suse.com
Mon Jul 7 10:19:14 CEST 2025
Hi!
On 7/4/25 5:40 PM, Ricardo B. Marlière via ltp wrote:
> From: Ricardo B. Marlière <rbm@suse.com>
>
> Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
> ---
> runtest/syscalls | 1 -
> testcases/kernel/syscalls/munmap/.gitignore | 1 -
> testcases/kernel/syscalls/munmap/munmap01.c | 38 ++++-
> testcases/kernel/syscalls/munmap/munmap02.c | 252 ----------------------------
> 4 files changed, 30 insertions(+), 262 deletions(-)
>
> diff --git a/runtest/syscalls b/runtest/syscalls
> index 582422ac9ca8ccae598c626a11cf6ee7c30f0e3a..9c80bccb09114d8b9730fdee05e3e28f5cc44afc 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -949,7 +949,6 @@ munlock02 munlock02
> munlockall01 munlockall01
>
> munmap01 munmap01
> -munmap02 munmap02
> munmap03 munmap03
>
> nanosleep01 nanosleep01
> diff --git a/testcases/kernel/syscalls/munmap/.gitignore b/testcases/kernel/syscalls/munmap/.gitignore
> index 94d8c10a24cae47c6805546bff41a84a2a2e8173..aa6e14a670e85dd17f965b4a465997a021f8b4ac 100644
> --- a/testcases/kernel/syscalls/munmap/.gitignore
> +++ b/testcases/kernel/syscalls/munmap/.gitignore
> @@ -1,3 +1,2 @@
> /munmap01
> -/munmap02
> /munmap03
> diff --git a/testcases/kernel/syscalls/munmap/munmap01.c b/testcases/kernel/syscalls/munmap/munmap01.c
> index c4c81295277f4951b2ddec96ce4b7ef767c65fbf..a9ea98a03cf6e749e33233b4158bd55514cfa25f 100644
> --- a/testcases/kernel/syscalls/munmap/munmap01.c
> +++ b/testcases/kernel/syscalls/munmap/munmap01.c
> @@ -9,20 +9,27 @@
> * 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.
> + * longer accessible (even if partially unmapped).
> *
> - * 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).
> + * munmap call should succeed to unmap a part or all of the mapped region of
> + * a 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 "tst_test.h"
>
> +static size_t page_sz;
> static int fd;
We can set it to -1, so if fd != -1 we close the file.
> static int mapped;
mapped flag can be replaced by map_base, by checking if it's NULL or not.
> +static char *map_base;
> static char *map_addr;
> static unsigned int map_len;
> +static unsigned int map_len_full;
> +static const char *const variants[] = {
> + "unmapped region not accessible",
> + "partially unmapped region not accessible",
> +};
>
> static void run(void)
> {
> @@ -51,22 +58,36 @@ static void run(void)
>
> static void setup(void)
> {
> - size_t page_sz = SAFE_SYSCONF(_SC_PAGESIZE);
> + page_sz = SAFE_SYSCONF(_SC_PAGESIZE);
> +
> + tst_res(TINFO, "Testing variant: %s", variants[tst_variant]);
>
> - map_len = 3 * page_sz;
> + map_len_full = 3 * page_sz;
> + map_len = map_len_full;
>
> fd = SAFE_OPEN("mmapfile", O_RDWR | O_CREAT, 0666);
>
> SAFE_LSEEK(fd, map_len, SEEK_SET);
> SAFE_WRITE(SAFE_WRITE_ALL, fd, "a", 1);
>
> - map_addr = SAFE_MMAP(0, map_len, PROT_READ | PROT_WRITE,
> + map_base = SAFE_MMAP(0, map_len, PROT_READ | PROT_WRITE,
> MAP_FILE | MAP_SHARED, fd, 0);
> + map_addr = map_base;
> mapped = 1;
> +
> + if (tst_variant) {
> + /* Narrow the mapped area to test partial unmapping */
This comment is not really helpful, so we can remove it. It's clear by
the following lines that we are moving to a +page_sz memory location.
> + map_addr = map_addr + page_sz;
> + map_len = map_len - page_sz;
> + }
> }
>
> static void cleanup(void)
> {
> + if (tst_variant && !mapped) {
> + /* Unmap the partially mapped region left */
Comment not needed.
> + SAFE_MUNMAP(map_base, map_len_full - map_len);
> + }
We are only unmapping the first page_sz when tst_variant == 1, so the
whole cleanup can be summed up with:
static void cleanup(void)
{
long len;
if (map_base) {
len = tst_variant ? page_sz : map_len;
SAFE_MUNMAP(map_base, len);
}
if (fd != -1)
SAFE_CLOSE(fd);
}
> if (mapped)
> SAFE_MUNMAP(map_addr, map_len);
> if (fd)
> @@ -79,4 +100,5 @@ static struct tst_test test = {
> .cleanup = cleanup,
> .needs_tmpdir = 1,
> .forks_child = 1,
> + .test_variants = ARRAY_SIZE(variants),
> };
> diff --git a/testcases/kernel/syscalls/munmap/munmap02.c b/testcases/kernel/syscalls/munmap/munmap02.c
> deleted file mode 100644
> index 311c0ea14a2f1b7120c792095c6990a7d2aa16d8..0000000000000000000000000000000000000000
> --- a/testcases/kernel/syscalls/munmap/munmap02.c
> +++ /dev/null
> @@ -1,252 +0,0 @@
> -/*
> - *
> - * 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
> - */
> -
> -/*
> - * Test Name: munmap02
> - *
> - * 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
> - * if the region specified by the address and the length is part or all of
> - * the mapped region.
> - *
> - * Expected Result:
> - * munmap call should succeed to unmap a part or all of mapped region of a
> - * file or anonymous shared memory 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.
> - */
> -#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 = "munmap02";
> -int TST_TOTAL = 1;
> -
> -static size_t page_sz;
> -char *addr; /* addr of memory mapped region */
> -int fildes; /* file descriptor for tempfile */
> -unsigned int map_len; /* length of the region to be mapped */
> -
> -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)
> -{
> - 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 part of the mapped region of the
> - * temporary file from the address and length that is part of
> - * the mapped region.
> - */
> - 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;
> -
> - /* This message is printed if no SIGSEGV */
> - tst_resm(TFAIL, "process succeeds to refer unmapped "
> - "memory region");
> - cleanup();
> -
> - }
> - tst_exit();
> -}
> -
> -/*
> - * setup() - performs all ONE TIME setup for this test.
> - * Setup 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)
> -{
> -
> - 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;
> -
> - /* Get the system page size */
> - page_sz = getpagesize();
> -
> - /*
> - * Get the length of the open file to be mapped into process
> - * address space.
> - */
> - 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));
> - }
> -
> - /*
> - * move the file pointer to maplength position from the beginning
> - * of the file.
> - */
> - SAFE_LSEEK(cleanup, fildes, 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));
> - }
> -
> - /*
> - * map the open file 'TEMPFILE' 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));
> - }
> -
> - /*
> - * increment the start address of the region at which the file is
> - * mapped to a maplength of 3 times the system page size by the value
> - * of system page size and decrement the maplength value by the value
> - * of system page size.
> - */
> - addr = (char *)((long)addr + page_sz);
> - map_len = map_len - page_sz;
> -}
> -
> -/*
> - * void
> - * 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)
> -{
> - tst_resm(TPASS, "Functionality of munmap() successful");
> -
> - /* Invoke test cleanup function and exit */
> - cleanup();
> -
> - tst_exit();
> -}
> -
> -/*
> - * cleanup() - performs all ONE TIME cleanup for this test at
> - * completion or premature exit.
> - * Unmap the portion of the region of the file left unmapped.
> - * Close the temporary file.
> - * Remove the temporary directory.
> - */
> -void cleanup(void)
> -{
> -
> - /*
> - * get the start address and length of the portion of
> - * the mapped region of the file.
> - */
> - addr = (char *)((long)addr - page_sz);
> - map_len = map_len - page_sz;
> -
> - /* unmap the portion of the region of the file left unmapped */
> - SAFE_MUNMAP(NULL, addr, map_len);
> -
> - /* Close the temporary file */
> - SAFE_CLOSE(NULL, fildes);
> -
> - tst_rmdir();
> -}
>
- Andrea
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