ia64: Pin controlling tty for unaligned fault message

Prevent destruction of the controlling tty before tty_write_message()
can determine if the tty is safe to use.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/arch/ia64/kernel/unaligned.c b/arch/ia64/kernel/unaligned.c
index 622772b7fb6c..e7ae6088350a 100644
--- a/arch/ia64/kernel/unaligned.c
+++ b/arch/ia64/kernel/unaligned.c
@@ -1336,8 +1336,11 @@ ia64_handle_unaligned (unsigned long ifa, struct pt_regs *regs)
                          * Don't call tty_write_message() if we're in the kernel; we might
                          * be holding locks...
                          */
-                        if (user_mode(regs))
-                                tty_write_message(current->signal->tty, buf);
+                        if (user_mode(regs)) {
+                                struct tty_struct *tty = get_current_tty();
+                                tty_write_message(tty, buf);
+                                tty_kref_put(tty);
+                        }
                         buf[len-1] = '\0';      /* drop '\r' */
                         /* watch for command names containing %s */
                         printk(KERN_WARNING "%s", buf);