1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
// 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;
}
|
