diff options
Diffstat (limited to 'drivers/tty/tty_io.c')
| -rw-r--r-- | drivers/tty/tty_io.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 2bb4dfc02873..e5695467598f 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1025,11 +1025,17 @@ void start_tty(struct tty_struct *tty) } EXPORT_SYMBOL(start_tty); -/* We limit tty time update visibility to every 8 seconds or so. */ static void tty_update_time(struct timespec *time) { unsigned long sec = get_seconds(); - if (abs(sec - time->tv_sec) & ~7) + + /* + * We only care if the two values differ in anything other than the + * lower three bits (i.e every 8 seconds). If so, then we can update + * the time of the tty device, otherwise it could be construded as a + * security leak to let userspace know the exact timing of the tty. + */ + if ((sec ^ time->tv_sec) & ~7) time->tv_sec = sec; } @@ -3593,6 +3599,13 @@ static ssize_t show_cons_active(struct device *dev, } static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); +static struct attribute *cons_dev_attrs[] = { + &dev_attr_active.attr, + NULL +}; + +ATTRIBUTE_GROUPS(cons_dev); + static struct device *consdev; void console_sysfs_notify(void) @@ -3617,12 +3630,11 @@ int __init tty_init(void) if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) panic("Couldn't register /dev/console driver\n"); - consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, - "console"); + consdev = device_create_with_groups(tty_class, NULL, + MKDEV(TTYAUX_MAJOR, 1), NULL, + cons_dev_groups, "console"); if (IS_ERR(consdev)) consdev = NULL; - else - WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); #ifdef CONFIG_VT vty_init(&console_fops); |