Commit e8cc3348 authored by Michal Sekletar's avatar Michal Sekletar Committed by Greg Kroah-Hartman
Browse files

selftests: tty: add selftest for tty timestamp updates 



Add new test case which checks that timestamp updates on actual terminal
character device (e.g. /dev/pts/0) happen even if the terminal is
accessed via magic /dev/tty file.

Signed-off-by: default avatarMichal Sekletar <msekleta@redhat.com>
Message-ID: <20230613172107.78138-2-msekleta@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 360c11e2

tools/testing/selftests/Makefile

+1 −0
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@@ -86,6 +86,7 @@ TARGETS += timers 
endif

TARGETS += tmpfs

TARGETS += tpm2

TARGETS += tty

TARGETS += user

TARGETS += vDSO

TARGETS += mm

tools/testing/selftests/tty/.gitignore

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# SPDX-License-Identifier: GPL-2.0-only

tty_tstamp_update

tools/testing/selftests/tty/Makefile

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# SPDX-License-Identifier: GPL-2.0

CFLAGS = -O2 -Wall

TEST_GEN_PROGS := tty_tstamp_update



include ../lib.mk

tools/testing/selftests/tty/tty_tstamp_update.c

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// SPDX-License-Identifier: GPL-2.0



#include <errno.h>

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/stat.h>

#include <unistd.h>

#include <linux/limits.h>



#include "../kselftest.h"



#define MIN_TTY_PATH_LEN 8



static bool tty_valid(char *tty)

{

	if (strlen(tty) < MIN_TTY_PATH_LEN)

		return false;



	if (strncmp(tty, "/dev/tty", MIN_TTY_PATH_LEN) == 0 ||

	    strncmp(tty, "/dev/pts", MIN_TTY_PATH_LEN) == 0)

		return true;



	return false;

}



static int write_dev_tty(void)

{

	FILE *f;

	int r = 0;



	f = fopen("/dev/tty", "r+");

	if (!f)

		return -errno;



	r = fprintf(f, "hello, world!\n");

	if (r != strlen("hello, world!\n"))

		r = -EIO;



	fclose(f);

	return r;

}



int main(int argc, char **argv)

{

	int r;

	char tty[PATH_MAX] = {};

	struct stat st1, st2;



	ksft_print_header();

	ksft_set_plan(1);



	r = readlink("/proc/self/fd/0", tty, PATH_MAX);

	if (r < 0)

		ksft_exit_fail_msg("readlink on /proc/self/fd/0 failed: %m\n");



	if (!tty_valid(tty))

		ksft_exit_skip("invalid tty path '%s'\n", tty);



	r = stat(tty, &st1);

	if (r < 0)

		ksft_exit_fail_msg("stat failed on tty path '%s': %m\n", tty);



	/* We need to wait at least 8 seconds in order to observe timestamp change */

	/* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fbf47635315ab308c9b58a1ea0906e711a9228de */

	sleep(10);



	r = write_dev_tty();

	if (r < 0)

		ksft_exit_fail_msg("failed to write to /dev/tty: %s\n",

				   strerror(-r));



	r = stat(tty, &st2);

	if (r < 0)

		ksft_exit_fail_msg("stat failed on tty path '%s': %m\n", tty);



	/* We wrote to the terminal so timestamps should have been updated */

	if (st1.st_atim.tv_sec == st2.st_atim.tv_sec &&

	    st1.st_mtim.tv_sec == st2.st_mtim.tv_sec) {

		ksft_test_result_fail("tty timestamps not updated\n");

		ksft_exit_fail();

	}



	ksft_test_result_pass(

		"timestamps of terminal '%s' updated after write to /dev/tty\n", tty);

	return EXIT_SUCCESS;

}