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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B4F0C433DF for ; Mon, 22 Jun 2020 07:58:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 271632083E for ; Mon, 22 Jun 2020 07:58:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IGGEgHv3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727964AbgFVH6s (ORCPT ); Mon, 22 Jun 2020 03:58:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726954AbgFVH6k (ORCPT ); Mon, 22 Jun 2020 03:58:40 -0400 Received: from mail-wm1-x342.google.com (mail-wm1-x342.google.com [IPv6:2a00:1450:4864:20::342]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 486F1C061794; Mon, 22 Jun 2020 00:58:40 -0700 (PDT) Received: by mail-wm1-x342.google.com with SMTP id g21so10291319wmg.0; Mon, 22 Jun 2020 00:58:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=mMMBH/im23ji4fEv1Kmx2CsCljHtX5RHIV2g8cbxlsI=; b=IGGEgHv3uSNDTYPQJ0KWiZkYDdsMf8Tt1uPKDhwyFavNMq1RCjG1qohBugu+bUGLuf 29FhdFTm5mG6F998JXZg7+bwxGtW9166GkrMmBmBCmRRttQSOERMJDT7Znx0qMmj42l2 9fPRHpKljOLFxFU4Pmvw0P03xuUUUcUO5U9uV2nFEUFQcye0TJRCDe89oFPNUS111+cL UvaY0Gc1UeaHUrfCtKRXRJco3NTiu457KXzdbxR5WByO5nfoHmIQu7pwepFOpx6gS0Te Ns9IMgLEye3pYx6wC4A1GT+ZHf2vYdM67JNQnORV8vOwV953iwcyi1pOXM77myQ2tKA8 IubA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=mMMBH/im23ji4fEv1Kmx2CsCljHtX5RHIV2g8cbxlsI=; b=K+7RPiS5xxCBdRy5wQ41A1lhUtifw362e81MCA93AWlDPJPAehjoDfpgWs/IDUiTQw xAkp+FcO2MghCOopCj1SnGjADbnxb4Yp0b+h8A/a5fZyMOfX7SjfLwr/n2ZekHTGk6y2 X+BV5ED7TBG/FUlDA9FVMkTEaolIHM3SLbzU1PSv36mPBPTJIDp952naThtobnHXHA53 0A8WbbGs4NfMb+jjTY+BWO93NDWZOuaTz74A5bNdMOX79rK0P+Zu+zSDCKjLKwK+bER+ 8RnGAp8+1opsOhooiQ/x8ZnC6Pymp1Hju5+DlHrv44jYMPti5MV2HJ/woxXhtJiBNjTV 4LeA== X-Gm-Message-State: AOAM533fDlslJ+VMwCQnyxQjjqy94ZjKcl8MAi5UFbK8Xjjqu4t98bgu RHjxQFEbndonfyai8c0MbH0= X-Google-Smtp-Source: ABdhPJzDatIBw65qbZ5xHtyEjDhL1ClxOVFqmJb4kWMFvawdCgy+PRswhDHVwQx5Mv0OCGrL4+RRBQ== X-Received: by 2002:a7b:cc8b:: with SMTP id p11mr6908746wma.180.1592812719000; Mon, 22 Jun 2020 00:58:39 -0700 (PDT) Received: from [172.22.36.87] (redhat-nat.vtp.fi.muni.cz. [78.128.215.6]) by smtp.gmail.com with ESMTPSA id b19sm22358112wmj.0.2020.06.22.00.58.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 22 Jun 2020 00:58:38 -0700 (PDT) Subject: Re: New mode DM-Verity error handling To: Mike Snitzer , Sami Tolvanen Cc: JeongHyeon Lee , dm-devel@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, agk@redhat.com, corbet@lwn.net References: <98eac3fc-c399-625d-5730-29853b3a0771@samsung.com> <20200618154444.GB18007@redhat.com> <20200618165006.GA103290@google.com> <20200618170952.GA18057@redhat.com> From: Milan Broz Message-ID: Date: Mon, 22 Jun 2020 09:58:37 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200618170952.GA18057@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/06/2020 19:09, Mike Snitzer wrote: > On Thu, Jun 18 2020 at 12:50pm -0400, > Sami Tolvanen wrote: > >> On Thu, Jun 18, 2020 at 11:44:45AM -0400, Mike Snitzer wrote: >>> I do not accept that panicing the system because of verity failure is >>> reasonable. >>> >>> In fact, even rebooting (via DM_VERITY_MODE_RESTART) looks very wrong. >>> >>> The device should be put in a failed state and left for admin recovery. >> >> That's exactly how the restart mode works on some Android devices. The >> bootloader sees the verification error and puts the device in recovery >> mode. Using the restart mode on systems without firmware support won't >> make sense, obviously. > > OK, so I need further justification from Samsung why they are asking for > this panic mode. I think when we have reboot already, panic is not much better :-) Just please note that dm-verity is used not only in Android world (with own tooling) but in normal Linux distributions, and I need to modify userspace (veritysetup) to support and recognize this flag. Please *always* increase minor dm-verity target version when adding a new feature - we can then provide some better hint if it is not supported. Thanks, Milan