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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 7549DC43219 for ; Sat, 27 Apr 2019 15:28:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FF48206A3 for ; Sat, 27 Apr 2019 15:28:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728571AbfD0P2s (ORCPT ); Sat, 27 Apr 2019 11:28:48 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33018 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727315AbfD0PPU (ORCPT ); Sat, 27 Apr 2019 11:15:20 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hKP2s-00014G-2B; Sat, 27 Apr 2019 16:15:18 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hKP2o-0004fS-DD; Sat, 27 Apr 2019 16:15:14 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Linus Torvalds" , "Greg Kroah-Hartman" , "Jann Horn" Date: Sat, 27 Apr 2019 16:13:09 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 202/202] tty: mark Siemens R3964 line discipline as BROKEN In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.66-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman commit c7084edc3f6d67750f50d4183134c4fb5712a5c8 upstream. The n_r3964 line discipline driver was written in a different time, when SMP machines were rare, and users were trusted to do the right thing. Since then, the world has moved on but not this code, it has stayed rooted in the past with its lovely hand-crafted list structures and loads of "interesting" race conditions all over the place. After attempting to clean up most of the issues, I just gave up and am now marking the driver as BROKEN so that hopefully someone who has this hardware will show up out of the woodwork (I know you are out there!) and will help with debugging a raft of changes that I had laying around for the code, but was too afraid to commit as odds are they would break things. Many thanks to Jann and Linus for pointing out the initial problems in this codebase, as well as many reviews of my attempts to fix the issues. It was a case of whack-a-mole, and as you can see, the mole won. Reported-by: Jann Horn Signed-off-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- drivers/char/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -380,7 +380,7 @@ config XILINX_HWICAP config R3964 tristate "Siemens R3964 line discipline" - depends on TTY + depends on TTY && BROKEN ---help--- This driver allows synchronous communication with devices using the Siemens R3964 packet protocol. Unless you are dealing with special