From b1fc0b1f21c4082d24d1f456a846b4fa7d16a70b Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Date: Mon, 25 Sep 2006 23:33:08 -0700
Subject: [PATCH] [PATCH] UML: tty locking

Ensure current->signal->tty doesn't get freed during log_exec().

Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 arch/um/kernel/exec.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index fc38a6d5906d..0561c43b4685 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -41,9 +41,11 @@ static long execve1(char *file, char __user * __user *argv,
         long error;
 
 #ifdef CONFIG_TTY_LOG
-	task_lock(current);
+	mutex_lock(&tty_mutex);
+	task_lock(current);	/* FIXME:  is this needed ? */
 	log_exec(argv, current->signal->tty);
 	task_unlock(current);
+	mutex_unlock(&tty_mutex);
 #endif
         error = do_execve(file, argv, env, &current->thread.regs);
         if (error == 0){
-- 
2.39.2