From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757321Ab3KYRpt (ORCPT ); Mon, 25 Nov 2013 12:45:49 -0500 Received: from mailout32.mail01.mtsvc.net ([216.70.64.70]:57001 "EHLO n23.mail01.mtsvc.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754007Ab3KYRpp (ORCPT ); Mon, 25 Nov 2013 12:45:45 -0500 Message-ID: <52938CC7.1000409@hurleysoftware.com> Date: Mon, 25 Nov 2013 12:45:43 -0500 From: Peter Hurley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.1 MIME-Version: 1.0 To: Greg Kroah-Hartman CC: Jiri Slaby , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: Re: [PATCH] n_tty: Protect minimum_to_wake reset for concurrent readers References: <1383850917-24416-1-git-send-email-peter@hurleysoftware.com> <20131125163602.GA19071@kroah.com> <52938514.60007@hurleysoftware.com> <20131125171646.GA24680@kroah.com> <20131125172408.GA1656@kroah.com> In-Reply-To: <20131125172408.GA1656@kroah.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-User: 990527 peter@hurleysoftware.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/25/2013 12:24 PM, Greg Kroah-Hartman wrote: > On Mon, Nov 25, 2013 at 09:16:46AM -0800, Greg Kroah-Hartman wrote: >> On Mon, Nov 25, 2013 at 12:12:52PM -0500, Peter Hurley wrote: >>> On 11/25/2013 11:36 AM, Greg Kroah-Hartman wrote: >>>> On Thu, Nov 07, 2013 at 02:01:57PM -0500, Peter Hurley wrote: >>>>> With multiple, concurrent readers (each waiting to acquire the >>>>> atomic_read_lock mutex), a departing reader may mistakenly reset >>>>> minimum_to_wake after a new reader has already set a new value. >>>>> >>>>> Protect the minimum_to_wake reset with the atomic_read_lock critical >>>>> section. >>>>> >>>>> Signed-off-by: Peter Hurley >>>>> --- >>>>> drivers/tty/n_tty.c | 4 ++-- >>>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>> >>>> This patch doesn't apply to Linus's tree anymore (and hence, mine.) Is >>>> it needed for 3.13-final? Or just 3.14-rc1? Either way, can you >>>> refresh it and resend? >>> >>> Hmmm, for me this applies cleanly to your tty-linus branch: >>> >>> peter@thor:~/src/kernels/tty$ git tree -10 >>> * c7df628 (HEAD, tty-linus) n_tty: Protect minimum_to_wake reset for concurrent readers >>> * 3dcf344 (origin/tty-linus) TTY: amiserial, add missing platform check >>> * dc1dc2f TTY: pmac_zilog, check existence of ports in pmz_console_init() >>> * c284ee2 n_gsm: race between ld close and gsmtty open >>> * f301412 tty/serial/8250: fix typo in help text >>> * c77569d n_tty: Fix 4096-byte canonical reads >>> * 6f22253 n_tty: Fix echo overrun tail computation >>> * 42458f4 n_tty: Ensure reader restarts worker for next reader >>> * 6ce4eac (tag: v3.13-rc1, origin/tty-next, origin/master, origin/HEAD) Linux 3.13-rc1 >>> >>> I'll just resend it. >> >> Oh nevermind, it has leading extra spaces, which something added, I'll >> go edit it by hand and fix it up, sorry for not noticing. > > And 'git am' handles this just fine, I was just testing it out first > using 'patch' which didn't like the extra spaces, my fault. > > sorry for the noise, Not a problem. In fact, the interruption was fortuitous because I was testing an unsubmitted patch which I'd hoped would fix the readline() paste bug & bugzilla #55991. When I tried to resend this patch with git send-email, the 'Password:' prompt looped until I killed it. Thanks for the test vector :) Regards, Peter Hurley