[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>

1 files changed, 3 insertions, 1 deletions

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){