From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC40AC2F3A0 for ; Mon, 21 Jan 2019 14:22:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72AC12063F for ; Mon, 21 Jan 2019 14:22:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548080541; bh=K0ULNVuRJXG9MUcw7fVAXfzIXtBrcYsheI1hZw4u/D0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XHWOJGXhkgIzlmqfyEv54RGJtCAgSH7kEwsZ0NcUVZet5GH5RqWGXJZvfjQNT8fl+ XotfrOuQrqURAoOcOZP7/et1SyW3L9Ju/SC8w/0bQfjNwyMHVu//yw9ceQhOoWD7MF e5wJ0ZLpOj0tsir82UBcxJo55mOdAZEsJglLAhpc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729123AbfAUNqW (ORCPT ); Mon, 21 Jan 2019 08:46:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:55126 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729113AbfAUNqU (ORCPT ); Mon, 21 Jan 2019 08:46:20 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2442E20879; Mon, 21 Jan 2019 13:46:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548078379; bh=K0ULNVuRJXG9MUcw7fVAXfzIXtBrcYsheI1hZw4u/D0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QhjUlTcFMma/h6vlDmJu0TIepxxZXAFJYEZhdNhUiL41U8P1JqUuwC2pzi4QJXFDB kbqnuNSkpIubztOWf5blO45n9c4d1rLchjTThFzld1mukShQRTvsEsp6hi68NCmD6W YxlSEFQ7plQmeLHhop4HISmSSqBINpWDcNeNRHh4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jiri Slaby , Jiri Slaby , Mark Rutland , Dmitry Safonov Subject: [PATCH 4.20 003/111] tty: Simplify tty->count math in tty_reopen() Date: Mon, 21 Jan 2019 14:41:57 +0100 Message-Id: <20190121122456.156487880@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190121122455.819406896@linuxfoundation.org> References: <20190121122455.819406896@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Safonov commit cf62a1a13749db0d32b5cdd800ea91a4087319de upstream. As notted by Jiri, tty_ldisc_reinit() shouldn't rely on tty counter. Simplify math by increasing the counter after reinit success. Cc: Jiri Slaby Link: lkml.kernel.org/r/<20180829022353.23568-2-dima@arista.com> Suggested-by: Jiri Slaby Reviewed-by: Jiri Slaby Tested-by: Mark Rutland Signed-off-by: Dmitry Safonov Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1272,16 +1272,13 @@ static int tty_reopen(struct tty_struct if (retval) return retval; - tty->count++; - if (tty->ldisc) - goto out_unlock; + if (!tty->ldisc) + retval = tty_ldisc_reinit(tty, tty->termios.c_line); + tty_ldisc_unlock(tty); - retval = tty_ldisc_reinit(tty, tty->termios.c_line); - if (retval) - tty->count--; + if (retval == 0) + tty->count++; -out_unlock: - tty_ldisc_unlock(tty); return retval; }