hvc: Convert to using interrupts instead of opal events

[firefly-linux-kernel-4.4.55.git] / drivers / tty / tty_io.c

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 2bb4dfc028734079f29a89bfb779bfdc7e0079eb..e5695467598f9b68629738586c5ed9285d8384ae 100644 (file)
--- 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);