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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 1947EC3279B for ; Fri, 6 Jul 2018 14:39:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDB8423FD2 for ; Fri, 6 Jul 2018 14:39:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CDB8423FD2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754054AbeGFOjZ (ORCPT ); Fri, 6 Jul 2018 10:39:25 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51182 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753630AbeGFOjY (ORCPT ); Fri, 6 Jul 2018 10:39:24 -0400 Received: from localhost (unknown [37.170.89.196]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 0EEF1CF7; Fri, 6 Jul 2018 14:39:22 +0000 (UTC) Date: Fri, 6 Jul 2018 16:39:19 +0200 From: Greg Kroah-Hartman To: Tycho Andersen Cc: Jiri Slaby , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, "Serge E . Hallyn" Subject: Re: [PATCH v2] uart: fix race between uart_put_char() and uart_shutdown() Message-ID: <20180706143919.GA2344@kroah.com> References: <20180628120542.GA4065@kroah.com> <20180629102446.11189-1-tycho@tycho.ws> <20180629164330.GL27027@cisco.cisco.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180629164330.GL27027@cisco.cisco.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 29, 2018 at 10:43:30AM -0600, Tycho Andersen wrote: > On Fri, Jun 29, 2018 at 04:24:46AM -0600, Tycho Andersen wrote: > > v2: switch to locking uport->lock on allocation/deallocation instead of > > locking the per-port mutex in uart_put_char. Note that since > > uport->lock is a spin lock, we have to switch the allocation to > > GFP_ATOMIC. > > Serge pointed out off-list that we may want to do the allocation > before the lock so that it's more likely to be successful. I'm happy > to send that change to this if it's what we want to do, I don't have a > strong preference. That sounds like a much better thing to do. thanks, greg k-h