From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f177.google.com (mail-yw1-f177.google.com [209.85.128.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7A3175678ED for ; Wed, 9 Sep 2026 13:35:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788960918; cv=none; b=YR2qDjS2BvMlutsSqO5ZtjfBkzl3AB+1j81PNECXf9rtaVI5beYMXrWflnTJX+Rx/Pj/9HXy+CQoh4z0/XE5yEP8ZYwqMkNujdvOjUDYRD/pQ00V1NxCHTZP3E7sELK0u6T5nEKhDo8YK6xS6kA3K0Jbw0b9aIKbGXhSK59XXu0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788960918; c=relaxed/simple; bh=pYAXFeuFVimJwDLBUI4en4oiYVdoAA0vzKgHRiam0R4=; h=From:Date:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=I/ei6BeKG8j8AEKdPBQPRC1dUnATBzdhi2vTROxA6ANfUHoxyNaM4DxUXEmtQ1r8YeTaMN/HocU+PrJhaFbQiU5hwxtryNKKb7eLNeBOexhBx4/BuBH3JRuSf4bG/6Al4FeLfm8ZWURPhnSmfSEhRcoIgBOFi7GtTCrUkIe/d5U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=aXHo/mVH; arc=none smtp.client-ip=209.85.128.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="aXHo/mVH" Received: by mail-yw1-f177.google.com with SMTP id 00721157ae682-861f30636f9so88847947b3.0 for ; Wed, 09 Sep 2026 06:35:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788960916; x=1789565716; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:date:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=IF7gGSnNHvzeRxMeQJEXPfnNoiV1RgOi8xQaXNAluos=; b=aXHo/mVHlqCY04RXO/+yLgAoiVc8v+p/f7jRRx+a4qrfZE53PLwBi3PvDHKeSezwje 600DrGithzi+RJ1XmZ3EOoX8JmRETN6Zc4cHC4rqHpUuhND3jQ3DqYcqrmotoOza2GkB CJS77HQnLiP0bDDemhEPiU1zqaQVl1sdD/n8qQ3R48qKTlj+lROE+MsJGjjE28dCDpNW 4JTwZ+VtcLQwU2N0T0KT7EwhGda22E439GC2l/KMqEblQuLhKgJAK78mpc32BOpyUTgU Ez+wVzdJCEBcXgSyBpBA43HLwgM5ZfcA8IkhXh98NNLOMj0JBiKXTGMlpUXKQ875DVdT salg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788960916; x=1789565716; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:date:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=IF7gGSnNHvzeRxMeQJEXPfnNoiV1RgOi8xQaXNAluos=; b=l1uYptJJR19q9wWGIA1/M01Qf4zyxjrriKRLWhrxIWHQy1EomOnxt9U9rCFLhaD8CK j0mC/TDoic5i7ssothtvW1aruNESI0zVn9dal2I8uPnXNl7zw57DQgEblmzZbE50A6GE GOY5Xt6lRgneND6fYhPo4h1Gf4AI2scXR/kjf5pIBTpwtSPlqdQxzCS1lrHFensXjS3q a/usMWF+OH3Acisf0AmFBnSiuLBcXKYWntQLnosd31HOLzUxOMvd5OQ9XnUzIh4FYihN BxzKxO+63Xwh3M9DUWRQFos0hk0SEHf2RaiHIITEF93+qUI9hQdbq5sUhgx1GS95nAKd Wiow== X-Forwarded-Encrypted: i=1; AKwUvByZ5ae7fmJm29gRbR/tmUjcWNQQbX+zoZI/oUILWVf5DFlSHk2it6zoWc6f0n6VgvSWVD0njMniruPgrbk=@vger.kernel.org X-Gm-Message-State: AFuF++n5vIFb7bjzBi+TUZi95iwAp7gNM4SoskiL/tjcdrKZ5OKfG2pT jVtrGmzsa51u6RFs5PzqdWDWty3sWRoLA+r47ZtiRKSPbWDuH4rHzhzj7Vp9BSchyaZ6JElm X-Gm-Gg: AYBFou0kpkB+SjuEpCxEs980cErqNkeUhkZI4LHMWlHCDLzd3CeyRhliM8D9LhYd5le mJC8K5muHCrlPaAOFnebC9zTgc2dMtwOWyh7lrHNfM1DiQzWojK0nwrzPFD5MMZ2pDxmrZ4UapO oXyj9O/gukYQ/meI+ODcvMcMIlKb7iqSrAURTvb0nVb2t/svDhG6MVVd7BxOzk/4KfOh+5h0JY/ W4uEGwW6hBEvS47+DB5XKk85d3/HGZ2eQip92GfVB8euRZnabXsKLVPUQ76zECXY26y2Grauus9 XQukSPITJCMhpqKpy16GiAxdWLGXlwKCDNjn3Mdi1AK2xFgEa0ru40XOhxvPd0ZiX01RpvS7D/a Ygo+xxG4Q4aUnIk7N98pnDhJfWJJ12mS3KPcJA5dBKMD5lSIcsg6CSUC5QlgoJ9BffWqeNLc1uZ QueWMYgf1CPVpr1bMPj7Swgs72aYQt0kbm/tdyz80ttUp8lDXgUGpIK68FT3TIsk9bow== X-Received: by 2002:a05:690c:ed6:b0:816:b469:cd12 with SMTP id 00721157ae682-87122f5564bmr131074277b3.8.1788960916082; Wed, 09 Sep 2026 06:35:16 -0700 (PDT) Received: from localhost ([45.112.44.120]) by smtp.gmail.com with ESMTPSA id 00721157ae682-881575de059sm2427287b3.18.2026.09.09.06.35.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Sep 2026 06:35:15 -0700 (PDT) From: Coiby Xu X-Google-Original-From: Coiby Xu Date: Wed, 9 Sep 2026 21:33:02 +0800 To: Randy Dunlap Cc: kexec@lists.infradead.org, Andrew Morton , Sourabh Jain , Baoquan He , Dave Young , Pratyush Yadav , Will Deacon , linux-arm-kernel@lists.infradead.org, Jinjie Ruan , Mike Rapoport , Pasha Tatashin , Jonathan Corbet , Shuah Khan , "open list:DOCUMENTATION" , open list Subject: Re: [PATCH v5 8/9] crash_dump: Disallow configfs/crash_dm_crypt_key/reuse if crash hotplug supported Message-ID: References: <20260909003657.1570544-1-coiby.xu@gmail.com> <20260909003657.1570544-9-coiby.xu@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: On Tue, Sep 08, 2026 at 10:46:03PM -0700, Randy Dunlap wrote: > > >On 9/8/26 5:36 PM, Coiby Xu wrote: >> If crash hotplug is supported, dm-crypt keys saved to reserved memory >> will be taken care of automatically. Thus it doesn't make sense to use >> configfs/crash_dm_crypt_key/reuse. Not reserving >> image->dm_crypt_keys_addr makes it implicitly to disallow using this >> API. Currently x86_64 and ppc64le have implemented crash hotplug >> feature. >> >> Also update the doc accordingly. Note two doc issues are fixed as well. >> >> Fixes: 9ebfa8dcaea7 ("crash_dump: reuse saved dm crypt keys for CPU/memory hot-plugging") >> Reviewed-by: Sourabh Jain >> Signed-off-by: Coiby Xu >> --- >> Documentation/admin-guide/kdump/kdump.rst | 16 ++++++++++------ >> kernel/crash_dump_dm_crypt.c | 12 ++++++++---- >> 2 files changed, 18 insertions(+), 10 deletions(-) >> >> diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst >> index 7587caadbae1..0bf2eb100a05 100644 >> --- a/Documentation/admin-guide/kdump/kdump.rst >> +++ b/Documentation/admin-guide/kdump/kdump.rst >> @@ -577,9 +577,10 @@ with /sys/kernel/config/crash_dm_crypt_keys for setup, >> >> 1. Tell the first kernel what logon keys are needed to unlock the disk volumes, >> # Add key #1 >> - mkdir /sys/kernel/config/crash_dm_crypt_keys/7d26b7b4-e342-4d2d-b660-7426b0996720 >> + VOL1_UUID=7d26b7b4-e342-4d2d-b660-7426b0996720 >> + mkdir /sys/kernel/config/crash_dm_crypt_keys/$VOL1_UUID >> # Add key #1's description >> - echo cryptsetup:7d26b7b4-e342-4d2d-b660-7426b0996720 > /sys/kernel/config/crash_dm_crypt_keys/description >> + echo cryptsetup:$VOL1_UUID > /sys/kernel/config/crash_dm_crypt_keys/$VOL1_UUID/description >> >> # how many keys do we have now? >> cat /sys/kernel/config/crash_dm_crypt_keys/count >> @@ -591,15 +592,18 @@ with /sys/kernel/config/crash_dm_crypt_keys for setup, >> cat /sys/kernel/config/crash_dm_crypt_keys/count >> 2 >> >> - # To support CPU/memory hot-plugging, reuse keys already saved to reserved >> - # memory >> - echo true > /sys/kernel/config/crash_dm_crypt_key/reuse >> - >> 2. Load the dump-capture kernel >> >> 3. After the dump-capture kerne get booted, restore the keys to user keyring > > kernel is booted, Thanks for catching this typo! I'll apply your suggestion to next version! [...] -- Best regards, Coiby