tty: cdev lock_kernel() pushdown

Parts of the serial code actually BUG() if we don't do this.

1 files changed, 25 insertions, 2 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index e94bee032314..fd182f2e4a6c 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2665,7 +2665,7 @@ static void release_dev(struct file *filp)
  *               ->siglock protects ->signal/->sighand
  */
 
-static int tty_open(struct inode *inode, struct file *filp)
+static int __tty_open(struct inode *inode, struct file *filp)
 {
         struct tty_struct *tty;
         int noctty, retval;
@@ -2779,6 +2779,19 @@ got_driver:
         return 0;
 }
 
+/* BKL pushdown: scary code avoidance wrapper */
+static int tty_open(struct inode *inode, struct file *filp)
+{
+        int ret;
+
+        lock_kernel();
+        ret = __tty_open(inode, filp);
+        unlock_kernel();
+        return ret;
+}
+
+
+
 #ifdef CONFIG_UNIX98_PTYS
 /**
  *      ptmx_open               -       open a unix 98 pty master
@@ -2792,7 +2805,7 @@ got_driver:
  *              allocated_ptys_lock handles the list of free pty numbers
  */
 
-static int ptmx_open(struct inode *inode, struct file *filp)
+static int __ptmx_open(struct inode *inode, struct file *filp)
 {
         struct tty_struct *tty;
         int retval;
@@ -2831,6 +2844,16 @@ out:
         devpts_kill_index(index);
         return retval;
 }
+
+static int ptmx_open(struct inode *inode, struct file *filp)
+{
+        int ret;
+
+        lock_kernel();
+        ret = __ptmx_open(inode, filp);
+        unlock_kernel();
+        return ret;
+}
 #endif
 
 /**