From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932200AbcAJFAU (ORCPT ); Sun, 10 Jan 2016 00:00:20 -0500 Received: from mail-pf0-f178.google.com ([209.85.192.178]:34233 "EHLO mail-pf0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756842AbcAJE7S (ORCPT ); Sat, 9 Jan 2016 23:59:18 -0500 From: Peter Hurley To: Greg Kroah-Hartman Cc: Jiri Slaby , linux-audit@redhat.com, linux-kernel@vger.kernel.org, Peter Hurley Subject: [RESEND][PATCH 05/15] tty: audit: Take siglock directly Date: Sat, 9 Jan 2016 20:58:58 -0800 Message-Id: <1452401948-30790-6-git-send-email-peter@hurleysoftware.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1452401948-30790-1-git-send-email-peter@hurleysoftware.com> References: <1447207560-16410-1-git-send-email-peter@hurleysoftware.com> <1452401948-30790-1-git-send-email-peter@hurleysoftware.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/tty/tty_audit.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c index 9effa81..5f65653 100644 --- 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(¤t->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(¤t->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); -- 2.7.0