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=-6.0 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=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 2FFD3C10F11 for ; Wed, 24 Apr 2019 17:18:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 006FB21909 for ; Wed, 24 Apr 2019 17:18:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126337; bh=2m8CRpxJweqTXkQzcLzqntm09TU5xdmKmwBwmKQ32hY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vW8AMqKLSCuHLhO6+ot/yZ6vrvOeBHzqbmAQr6B3UVJ+xxASN9vFQ93FX8f07FSe5 lv/wSwpmmX2+DyUIeuA3Qsl4f50Mdx8qm1foXKGscRHbcuZx0AM4t090gx7rI+Csqx Qb3lJvqmxQIIFghy1asa9P+Bq6pRPFufx7KCO2z8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388916AbfDXRSz (ORCPT ); Wed, 24 Apr 2019 13:18:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:44028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388906AbfDXRSw (ORCPT ); Wed, 24 Apr 2019 13:18:52 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (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 30B8A21909; Wed, 24 Apr 2019 17:18:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126331; bh=2m8CRpxJweqTXkQzcLzqntm09TU5xdmKmwBwmKQ32hY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u6Knj6bIODGJB3hH+ppgf7IS18SQrzFUxYlOdAFNckbBVXwC6ktS9AL5evOjjW6NA 24z0itT3fXUbO8ouHMNdBR/bQuSLUbTPL3YXwKhAK2g2im/0Oo4NO94S+JmbDQ78c7 WFBZFnMjMx2jV+RTUsl1t8HAHTJz0gANtBJksud4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jann Horn , Linus Torvalds Subject: [PATCH 4.4 075/168] tty: mark Siemens R3964 line discipline as BROKEN Date: Wed, 24 Apr 2019 19:08:39 +0200 Message-Id: <20190424170928.315996897@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170923.452349382@linuxfoundation.org> References: <20190424170923.452349382@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/char/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -389,7 +389,7 @@ 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