tty: audit: Take siglock directly

lock_task_sighand() is for situations where the struct task_struct*
may disappear while trying to deref the sighand; this never applies
to 'current'.

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

diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c
index 9effa81acdfcc67b54986bc3ff12fb721b30e927..5f65653cee485683cf9ceda7081b3818b050787a 100644 (file)
--- a/drivers/tty/tty_audit.c
+++ b/drivers/tty/tty_audit.c
@@ -180,22 +180,19 @@ void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 int tty_audit_push_current(void)
 {
        struct tty_audit_buf *buf = ERR_PTR(-EPERM);
-       struct task_struct *tsk = current;
        unsigned long flags;
 
-       if (!lock_task_sighand(tsk, &flags))
-               return -ESRCH;
-
-       if (tsk->signal->audit_tty) {
-               buf = tsk->signal->tty_audit_buf;
+       spin_lock_irqsave(&current->sighand->siglock, flags);
+       if (current->signal->audit_tty) {
+               buf = current->signal->tty_audit_buf;
                if (buf)
                        atomic_inc(&buf->count);
        }
-       unlock_task_sighand(tsk, &flags);
+       spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
        /*
         * Return 0 when signal->audit_tty set
-        * but tsk->signal->tty_audit_buf == NULL.
+        * but current->signal->tty_audit_buf == NULL.
         */
        if (!buf || IS_ERR(buf))
                return PTR_ERR(buf);