From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from conssluserg-04.nifty.com (conssluserg-04.nifty.com [210.131.2.83]) by sourceware.org (Postfix) with ESMTPS id 61A7B3858C53 for ; Wed, 13 Apr 2022 17:22:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 61A7B3858C53 Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=nifty.ne.jp Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=nifty.ne.jp Received: from Express5800-S70 (ak044095.dynamic.ppp.asahi-net.or.jp [119.150.44.95]) (authenticated) by conssluserg-04.nifty.com with ESMTP id 23DHLxW4012737; Thu, 14 Apr 2022 02:21:59 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-04.nifty.com 23DHLxW4012737 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.ne.jp; s=dec2015msa; t=1649870519; bh=SxUKYl9fThZrD3dpRtBixz0DWdRYYUQBCUpJPu4PVGY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=AnUFx27/JcBdxIhrj2Cl79+JKR8WCmP1SnzxELdpfpnfGVldXBk3SNJlQU6ylHA3H lSM35u7U9+3NOeByFJep01mTAlNIUAVlcc0qRHpAkwVp9BPmwMU3htDXdROg2+vaZP A1YwtX5LavEzvPAmLusZHiw4uqQu1KomiZk3G7ZgQPtfCMjvQM2MrlG8gfX694TKls 9oZx/Ck+CX0lUHjHoeViS1wD6DzNIRwNyzSm0Jn7xUTd0gRhwv134XsUaFPecaS8nG ykst1eZDO1iCLB9h6laHw6k2SmENmM8OK9z6NRNVoHMwQNqO41PTph+faM5N6Mr0J1 AnBtHQhD+qlfA== X-Nifty-SrcIP: [119.150.44.95] Date: Thu, 14 Apr 2022 02:22:06 +0900 From: Takashi Yano To: cygwin@cygwin.com Cc: Alexey Izbyshev Subject: Re: Deadlock of the process tree when running make Message-Id: <20220414022206.208a9fbba80e926042d77a7a@nifty.ne.jp> In-Reply-To: <1bdd5ac77277343fbff9b560fa98b15e@ispras.ru> References: <9388316255ada0e0fcb2d849cce5a894@ispras.ru> <20220409191743.6da2268a36e8c9b4ab22c722@nifty.ne.jp> <1ecd670b1cdff43e0b0d7e5ee4c9cfc5@ispras.ru> <20220409204619.dd0e53902d5e108ef462e510@nifty.ne.jp> <907ce1b4416a826cb07990dd601bd687@ispras.ru> <20220410015753.753e2a238513eaf2a3da81e9@nifty.ne.jp> <20220410025410.196aa0a04368147dbbb31d3e@nifty.ne.jp> <7204ed0aa2d6b3fcfb239010e6b67646@ispras.ru> <20220410163432.00dd7b9f81f8f322d97688f2@nifty.ne.jp> <0e1a53626639cb21369225ff9092ecfc@ispras.ru> <20220411173526.6243b9492e0fc3d4132a58a8@nifty.ne.jp> <1bdd5ac77277343fbff9b560fa98b15e@ispras.ru> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.30; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-5.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Apr 2022 17:23:02 -0000 On Wed, 13 Apr 2022 19:48:04 +0300 Alexey Izbyshev wrote: > On 2022-04-11 13:10, Alexey Izbyshev wrote: > > On 2022-04-11 11:35, Takashi Yano wrote: > >> On Sun, 10 Apr 2022 23:49:29 +0300 > >> A countermeasure version is available at the following location: > >> https://tyan0.yr32.net/cygwin/x86/test/cygwin1-20220411.dll.xz > >> https://tyan0.yr32.net/cygwin/x86_64/test/cygwin1-20220411.dll.xz > >> > >> Could you please test? To keep the hanging tree, please install > >> cygwin another directory, and replace cygwin1.dll with the > >> countermeasure version. > >> > > Thank you for providing the binaries! I've started testing in a > > separate cygwin installation on the same machine, as you suggested. > > The hang previously took many hours to reproduce, so I'll keep tests > > running for a while and then report back. > > > The good news is that the tests have been running for two days so far > without any cygwin-related issues, so the patched version doesn't seem > to introduce new issues. > > The bad news is my theory about the suspicious "Unnamed file: > \FileSystem\Npfs" in the hanging bash.exe being a leak seems to be > wrong. I've closed that handle, but conhost.exe hasn't unblocked. All of > its threads are doing the same things as before: > > 1. Tries to enter a critical section. (Task Manager claims it waits for > thread 4, so probably the latter owns it). > 2. ReadFile("pty1-from-master-nat" named pipe) > 3. Waits for an anonymous event. > 4. Waits on a handle for "\Device\ConDrv" (in DeviceIoControl()). > 5. Blocked in GetMessageW(). > > I've created a model situation with bash.exe stopped at a breakpoint in > ClosePseudoConsole() at another machine again, and it seems that the > last time I missed that bash.exe contains *two* handles for (different) > "Unnamed file: \FileSystem\Npfs" here too, so it seems to be normal. > > What's probably not normal is the behavior of the hanging conhost.exe. > I've compared the points where conhost.exe is blocked, and all but one > threads in the model case are doing the same things as in the hanging > case, but the remaining thread is blocked in > ReadFile("\Device\NamedPipe\") (i.e. the read end of "hWritePipe" of > pcon) instead of trying to enter a critical section like thread 1 above. > So now I'm starting to doubt that it's a cygwin bug and not some > conhost.exe bug. > > I'll try to poke around the hanging conhost.exe some more, and also may > be will try to create a faster reproducer. Thanks for testing. Question is: Is the issue reproduced using new cygwin1.dll? Or is it still running without the issue so far? -- Takashi Yano