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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1553C7EE37 for ; Tue, 6 Jun 2023 20:41:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238734AbjFFUlV (ORCPT ); Tue, 6 Jun 2023 16:41:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234109AbjFFUlT (ORCPT ); Tue, 6 Jun 2023 16:41:19 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D90CCE7E for ; Tue, 6 Jun 2023 13:40:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1686084032; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=P3iJUW3O9cWWP9HZBjdRT6iyvu3td7ivmZhPbatcmK0=; b=aY4LQeBvgYU72D9XDPq3wPj9cEz6TwL9wU26ww4YoACxB52MLNq9nS97xUVLXPa536Iqpp 4aQhFc6kChp85+KjvbNm/ky9DgYOezx3/E4T87xt199Qk/mWOCrkYQqJBG5T56PybdYSPj AIcZDYeN6lOrSP4mEDUC6D6rqRaOuTI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-447-LsOftGK6NhKr4A3Eit7AyA-1; Tue, 06 Jun 2023 16:40:28 -0400 X-MC-Unique: LsOftGK6NhKr4A3Eit7AyA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 98B318032FF; Tue, 6 Jun 2023 20:40:27 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.112]) by smtp.corp.redhat.com (Postfix) with SMTP id 6439FC1603B; Tue, 6 Jun 2023 20:40:22 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 6 Jun 2023 22:40:05 +0200 (CEST) Date: Tue, 6 Jun 2023 22:39:59 +0200 From: Oleg Nesterov To: Wander Lairson Costa Cc: "Russell King (Oracle)" , Brian Cain , Michael Ellerman , Stafford Horne , Kefeng Wang , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , "Matthew Wilcox (Oracle)" , "Eric W. Biederman" , Andrei Vagin , Peter Zijlstra , "Paul E. McKenney" , Daniel Bristot de Oliveira , Yu Zhao , Alexey Gladkov , Mike Kravetz , Yang Shi , open list , Hu Chunyu , Valentin Schneider , Sebastian Andrzej Siewior , Steven Rostedt , Luis Goncalves Subject: Re: [PATCH v9] kernel/fork: beware of __put_task_struct calling context Message-ID: <20230606203958.GC18866@redhat.com> References: <20230516191441.34377-1-wander@redhat.com> <20230517152632.GC1286@redhat.com> <20230529122256.GA588@redhat.com> <20230601181359.GA23852@redhat.com> <20230602173302.GA32644@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/05, Wander Lairson Costa wrote: > > Thanks. I found an unrelated earlier splat in the console code. That's > why I couldn't reproduce it in the stock kernel. As expected... So... Not sure what can I say ;) can you verify that this patch doesn't solve the issues with CONFIG_PROVE_RAW_LOCK_NESTING pointed out by Sebastian? Using stress-ng or anything else. This is not that bad, unless I am totally confused the current code (without your patch) has the same problem (otherwise we wouldn't need this fix). But perhaps you can make 2/2 which adds the DEFINE_WAIT_OVERRIDE_MAP() hack as Peter suggested? Oleg.