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[2620:137:e000::3:5]) by mx.google.com with ESMTPS id f124-20020a0dc382000000b005a7cc83c4c1si3209084ywd.425.2023.10.27.09.39.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Oct 2023 09:39:28 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:5 as permitted sender) client-ip=2620:137:e000::3:5; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel-dk.20230601.gappssmtp.com header.s=20230601 header.b=WpbP58SL; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:5 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by groat.vger.email (Postfix) with ESMTP id 96378826AC5B; Fri, 27 Oct 2023 09:39:26 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at groat.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232190AbjJ0QjT (ORCPT + 99 others); Fri, 27 Oct 2023 12:39:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231721AbjJ0QjS (ORCPT ); Fri, 27 Oct 2023 12:39:18 -0400 Received: from mail-io1-xd29.google.com (mail-io1-xd29.google.com [IPv6:2607:f8b0:4864:20::d29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B66910A for ; Fri, 27 Oct 2023 09:39:15 -0700 (PDT) Received: by mail-io1-xd29.google.com with SMTP id ca18e2360f4ac-7a680e6a921so24638439f.1 for ; Fri, 27 Oct 2023 09:39:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1698424755; x=1699029555; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=7kdmvgTdy/g1PBhSvm6d233+JuZBABCykzPO40F6Sb0=; b=WpbP58SL1YsZcQ28IaLr6XChr451hr3yIBwZY+cs0kNE+0PqIitjFDVUpKCSowo5eu 37zAdNnzeUJLb43Um1n5qJxbDq2MzX7XNl0CB8SvSPsub+dPqAq8RoEYhEQcVZPKXheB Hq3jWEe4JgRMxeW3ekmbSMx0YJXno50rm7OPznqVEYrDRBOzMQDOu9+iNCT7nTyc/TBp 512w3Cin1+WSapmi8TfJDhNYod8gB8nd/B7Gfep19FtZdotGxj9fHDAPd88KeC04ew+h 7hmOctf5G1O+bPaKCTkkDBlxFBRhsQ1t3h/dOSxWt84FWusg7IORs3GoEO6/ur/qr71W dqtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698424755; x=1699029555; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7kdmvgTdy/g1PBhSvm6d233+JuZBABCykzPO40F6Sb0=; b=uOpHAZj9/PoaPmxFoE0lh5mwsn1ucsniiTcDZKda2DEK8as1+6JiIGPD2naVdzaIQj fIZ6XI5UM+OvewfURHZj/BJBf1hUaRoOUFBF2Vajdfp35zn0q0P17NOfUoGOGzwnVg99 4ANukE0BRVGT89CVYTt8Aa/lnnM0qS+MIV9x5YIAYYRHAeBEXWSg8VwI7g67NqLB13Z8 O3wOJEt+uAGOPe+hszownM0nB/NrTt7V66OXGhYb6Bn0IHqgZhJML8HWwVxuLjKlBbyH ihtDrfD0YUVWUR84rcFOePgGH4k4SGodGUboj5GRjLcykKGpf/Q3n+1x4wNJDUPZ1ASq KKVQ== X-Gm-Message-State: AOJu0YwbyrGZg/bctoDETaBBNjwBuOfxNJH34sl3/XfAn0LWv/XTzw3H 8/+OifgEMQUMoYywtm7UFoJu6A== X-Received: by 2002:a6b:5c10:0:b0:790:958e:a667 with SMTP id z16-20020a6b5c10000000b00790958ea667mr3344208ioh.2.1698424754862; Fri, 27 Oct 2023 09:39:14 -0700 (PDT) Received: from [192.168.1.116] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id r8-20020a6b5d08000000b0077e3566a801sm592681iob.29.2023.10.27.09.39.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 27 Oct 2023 09:39:14 -0700 (PDT) Message-ID: <2d15edac-0227-415a-b12c-922c6873ae04@kernel.dk> Date: Fri, 27 Oct 2023 10:39:13 -0600 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: lockdep: holding locks across syscall boundaries Content-Language: en-US To: Peter Zijlstra Cc: Ingo Molnar , LKML References: <20231027155949.GA26550@noisy.programming.kicks-ass.net> <20231027161235.GB26550@noisy.programming.kicks-ass.net> From: Jens Axboe In-Reply-To: <20231027161235.GB26550@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on groat.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (groat.vger.email [0.0.0.0]); Fri, 27 Oct 2023 09:39:26 -0700 (PDT) On 10/27/23 10:12 AM, Peter Zijlstra wrote: > The difference is that in this case the full lock order is determined by > kernel code (under our full control), while in the earlier example, the > lock order is determined by syscall order -- out of our control. Ah yes, good point - this seems like the key concept here. I think we're better off doing this seperately and just return -EDEADLK or something like that if it's being violated, rather than spew complaints. Thanks! -- Jens Axboe