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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D3D7FEB64DA for ; Wed, 5 Jul 2023 09:28:42 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=eoo0Bvrw; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4QwvVK3WP1z3bnp for ; Wed, 5 Jul 2023 19:28:41 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=eoo0Bvrw; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linuxfoundation.org (client-ip=139.178.84.217; helo=dfw.source.kernel.org; envelope-from=gregkh@linuxfoundation.org; receiver=lists.ozlabs.org) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4QwvTL6hDyz2y3Y for ; Wed, 5 Jul 2023 19:27:50 +1000 (AEST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B4ABA61380; Wed, 5 Jul 2023 09:27:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB110C433C7; Wed, 5 Jul 2023 09:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1688549268; bh=8Fx9fMjO8G9ugWAbuWMet+cg6+Joz5k8QhqzwC12qsY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eoo0Bvrw1UFedSuQIXZXLVU+9eSykKnlLCGNhX6WKDHSjWKzHs45W6Sc5+LEp8Yn2 /DNzBXf9tV7vuTj14UGRu+D/lPt07gtCii7fqIBtyh8Z2HAouCMzNmVKrvzTL3yT/s lpXJcXQKTCcazzOuTFZLURKsfcEGQZNtF3QMf8uc= Date: Wed, 5 Jul 2023 10:27:45 +0100 From: Greg KH To: Linux regressions mailing list Subject: Re: Fwd: Memory corruption in multithreaded user space program while calling fork Message-ID: <2023070544-porous-prenatal-406a@gregkh> References: <5c7455db-4ed8-b54f-e2d5-d2811908123d@leemhuis.info> <2023070359-evasive-regroup-f3b8@gregkh> <2023070453-plod-swipe-cfbf@gregkh> <20230704091808.aa2ed3c11a5351d9bf217ac9@linux-foundation.org> <2023070509-undertow-pulverize-5adc@gregkh> <7668c45a-70b1-dc2f-d0f5-c0e76ec17145@leemhuis.info> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7668c45a-70b1-dc2f-d0f5-c0e76ec17145@leemhuis.info> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jacob Young , Linux PowerPC , Linux Kernel Mailing List , Linux Memory Management , Bagas Sanjaya , Andrew Morton , Laurent Dufour , Suren Baghdasaryan , Linux ARM Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, Jul 05, 2023 at 10:51:57AM +0200, Linux regression tracking (Thorsten Leemhuis) wrote: > On 05.07.23 09:08, Greg KH wrote: > > On Tue, Jul 04, 2023 at 01:22:54PM -0700, Suren Baghdasaryan wrote: > >> On Tue, Jul 4, 2023 at 9:18 AM Andrew Morton wrote: > >>> On Tue, 4 Jul 2023 09:00:19 +0100 Greg KH wrote: > >>>>>>>> Thanks! I'll investigate this later today. After discussing with > >>>>>>>> Andrew, we would like to disable CONFIG_PER_VMA_LOCK by default until > >>>>>>>> the issue is fixed. I'll post a patch shortly. > >>>>>>> > >>>>>>> Posted at: https://lore.kernel.org/all/20230703182150.2193578-1-surenb@google.com/ > >>>>>> > >>>>>> As that change fixes something in 6.4, why not cc: stable on it as well? > >>>>> > >>>>> Sorry, I thought since per-VMA locks were introduced in 6.4 and this > >>>>> patch is fixing 6.4 I didn't need to send it to stable for older > >>>>> versions. Did I miss something? > >>>> > >>>> 6.4.y is a stable kernel tree right now, so yes, it needs to be included > >>>> there :) > >>> > >>> I'm in wait-a-few-days-mode on this. To see if we have a backportable > >>> fix rather than disabling the feature in -stable. > > Andrew, how long will you remain in "wait-a-few-days-mode"? Given what > Greg said below and that we already had three reports I know of I'd > prefer if we could fix this rather sooner than later in mainline -- > especially as Arch Linux and openSUSE Tumbleweed likely have switched to > 6.4.y already or will do so soon. Ick, yeah, and Fedora should be switching soon too, and I want to drop support for 6.3.y "any day now". Is there just a revert we can do now first to resolve the regression and then work on fixing this up "better" for 6.6-rc1? thanks, greg k-h