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path: root/drivers/tty/tty_io.c
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Diffstat (limited to 'drivers/tty/tty_io.c')
-rw-r--r--drivers/tty/tty_io.c24
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);