Merge tag 'iwlwifi-next-for-kalle-2015-08-04' of https://git.kernel.org/pub/scm/linux...

[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..57fc6ee12332e6932472ac1cc1796d607f114e4f 100644 (file)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -235,7 +235,6 @@ static void tty_del_file(struct file *file)
 /**
  *     tty_name        -       return tty naming
  *     @tty: tty structure
- *     @buf: buffer for output
  *
  *     Convert a tty structure into a name. The name reflects the kernel
  *     naming policy and if udev is in use may not reflect user space
@@ -243,13 +242,11 @@ static void tty_del_file(struct file *file)
  *     Locking: none
  */
 
-char *tty_name(struct tty_struct *tty, char *buf)
+const char *tty_name(const struct tty_struct *tty)
 {
        if (!tty) /* Hmm.  NULL pointer.  That's fun. */
-               strcpy(buf, "NULL tty");
-       else
-               strcpy(buf, tty->name);
-       return buf;
+               return "NULL tty";
+       return tty->name;
 }
 
 EXPORT_SYMBOL(tty_name);
@@ -770,8 +767,7 @@ static void do_tty_hangup(struct work_struct *work)
 void tty_hangup(struct tty_struct *tty)
 {
 #ifdef TTY_DEBUG_HANGUP
-       char    buf[64];
-       printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf));
+       printk(KERN_DEBUG "%s hangup...\n", tty_name(tty));
 #endif
        schedule_work(&tty->hangup_work);
 }
@@ -790,9 +786,7 @@ EXPORT_SYMBOL(tty_hangup);
 void tty_vhangup(struct tty_struct *tty)
 {
 #ifdef TTY_DEBUG_HANGUP
-       char    buf[64];
-
-       printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf));
+       printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty));
 #endif
        __tty_hangup(tty, 0);
 }
@@ -831,9 +825,7 @@ void tty_vhangup_self(void)
 static void tty_vhangup_session(struct tty_struct *tty)
 {
 #ifdef TTY_DEBUG_HANGUP
-       char    buf[64];
-
-       printk(KERN_DEBUG "%s vhangup session...\n", tty_name(tty, buf));
+       printk(KERN_DEBUG "%s vhangup session...\n", tty_name(tty));
 #endif
        __tty_hangup(tty, 1);
 }
@@ -1025,11 +1017,17 @@ 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;
 }
 
@@ -1763,7 +1761,6 @@ int tty_release(struct inode *inode, struct file *filp)
        struct tty_struct *o_tty = NULL;
        int     do_sleep, final;
        int     idx;
-       char    buf[64];
        long    timeout = 0;
        int     once = 1;
 
@@ -1787,7 +1784,7 @@ int tty_release(struct inode *inode, struct file *filp)
 
 #ifdef TTY_DEBUG_HANGUP
        printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__,
-                       tty_name(tty, buf), tty->count);
+                       tty_name(tty), tty->count);
 #endif
 
        if (tty->ops->close)
@@ -1838,7 +1835,7 @@ int tty_release(struct inode *inode, struct file *filp)
                if (once) {
                        once = 0;
                        printk(KERN_WARNING "%s: %s: read/write wait queue active!\n",
-                              __func__, tty_name(tty, buf));
+                              __func__, tty_name(tty));
                }
                schedule_timeout_killable(timeout);
                if (timeout < 120 * HZ)
@@ -1850,13 +1847,13 @@ int tty_release(struct inode *inode, struct file *filp)
        if (o_tty) {
                if (--o_tty->count < 0) {
                        printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n",
-                               __func__, o_tty->count, tty_name(o_tty, buf));
+                               __func__, o_tty->count, tty_name(o_tty));
                        o_tty->count = 0;
                }
        }
        if (--tty->count < 0) {
                printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n",
-                               __func__, tty->count, tty_name(tty, buf));
+                               __func__, tty->count, tty_name(tty));
                tty->count = 0;
        }
 
@@ -1899,7 +1896,7 @@ int tty_release(struct inode *inode, struct file *filp)
                return 0;
 
 #ifdef TTY_DEBUG_HANGUP
-       printk(KERN_DEBUG "%s: %s: final close\n", __func__, tty_name(tty, buf));
+       printk(KERN_DEBUG "%s: %s: final close\n", __func__, tty_name(tty));
 #endif
        /*
         * Ask the line discipline code to release its structures
@@ -1910,7 +1907,8 @@ int tty_release(struct inode *inode, struct file *filp)
        tty_flush_works(tty);
 
 #ifdef TTY_DEBUG_HANGUP
-       printk(KERN_DEBUG "%s: %s: freeing structure...\n", __func__, tty_name(tty, buf));
+       printk(KERN_DEBUG "%s: %s: freeing structure...\n", __func__,
+              tty_name(tty));
 #endif
        /*
         * The release_tty function takes care of the details of clearing
@@ -3593,6 +3591,13 @@ 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 +3622,11 @@ 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);