From owner-freebsd-bugs@FreeBSD.ORG Sun Jul 29 02:56:28 2012 Return-Path: Delivered-To: freebsd-bugs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id E2890106564A; Sun, 29 Jul 2012 02:56:28 +0000 (UTC) (envelope-from listlog2011@gmail.com) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id CA4F78FC0C; Sun, 29 Jul 2012 02:56:28 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.5/8.14.5) with ESMTP id q6T2uAbZ063439; Sun, 29 Jul 2012 02:56:22 GMT (envelope-from listlog2011@gmail.com) Message-ID: <5014A64A.3010106@gmail.com> Date: Sun, 29 Jul 2012 10:56:10 +0800 From: David Xu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:14.0) Gecko/20120713 Thunderbird/14.0 MIME-Version: 1.0 To: davidxu@freebsd.org References: <201207272150.q6RLo9ew012879@freefall.freebsd.org> <501482CD.6050708@gmail.com> <50148F42.20105@gmail.com> In-Reply-To: <50148F42.20105@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Garrett Cooper , freebsd-bugs@freebsd.org Subject: Re: kern/170203: [kern] piped dd' s don' t behave sanely when dealing with a fifo X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: davidxu@freebsd.org List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 29 Jul 2012 02:56:29 -0000 On 2012/7/29 9:17, David Xu wrote: > On 2012/7/29 9:02, Garrett Cooper wrote: >> On Sat, Jul 28, 2012 at 5:24 PM, David Xu wrote: >>> On 2012/7/28 5:50, Garrett Cooper wrote: >>>> The following reply was made to PR kern/170203; it has been noted by >>>> GNATS. >>>> >>>> From: Garrett Cooper >>>> To: bug-followup@FreeBSD.org, yanegomi@gmail.com >>>> Cc: >>>> Subject: Re: kern/170203: [kern] piped dd's don't behave >>>> sanely >>>> when >>>> dealing with a fifo >>>> Date: Fri, 27 Jul 2012 14:47:47 -0700 >>>> >>>> Hi David! >>>> I'll give the patches you provided a shot this weekend. >>> FIFO pipe is quite broken! Beside the bug you have reported, there is >>> another bug, >>> when a writer closed the pipe, select() on reader side will never >>> return ! >>> I am curious that so long time, nobody found the bugs, does it >>> because FIFO >>> is seldom used by people ? >> Hmmm.. that's unfortunate. If you have a test program you can >> provide then I can test on a 7.x variant of FreeBSD as well as FreeBSD >> 8.3 (I'm curious as to whether or not it's fallout from recent >> refactoring related to pipe(2), which I don't believe made it back to >> 8.x). >> Thanks! >> -Garrett > > I have just written two quick-and-dirty test cases: > > http://people.freebsd.org/~davidxu/patch/fifopipe/fifo_selectread.c > http://people.freebsd.org/~davidxu/patch/fifopipe/fifo_selectwrite.c > > without patch for kernel code, a child process will print out "timeout". > > I have updated patch, the patch fixed lost-notification bug for select(): http://people.freebsd.org/~davidxu/patch/fifopipe/kernel_pipe2.diff