From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93F88606A31C for ; Tue, 20 Oct 2026 08:21:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=aABz0kj0; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nOYYg7oC DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=BQJlLat4qxj8pgDrowtyIAkoQQPKp9J5TEk8suVVKjQ=; b=aABz0kj0k/bJHHHDBxSq53EleX e9Z9T0sh8yK9J+aXf6UwFKjcnwGeBGrPnJSToclOS4X9eFobFCmX0jePD9vrX/nOvhj2us8YMDuqn PTu8O4wG3+Wf7dDxN4ZiMm4ONt85snbab4ShXce9DHJosNflrkfDtJL6y8MVgPfXxAfsr5NeFU4nT sGbaMrj5GjNiUCqP7ffcA3aU+CpBsrcQVuFw5Wpliz/jwncnkQT3W6wJS3p14aaTpmcnik7bvgYAd 4L2u2VraPaAU8tkQL9O0E3yxdGeX5LLNUTxneAPvZ7j0tEpOy7CE4PP7Th4oJTU9x8UPer/qXxmLl CH2CCLoA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xJ56Q-000000099fC-3Pfp; Tue, 20 Oct 2026 08:21:46 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBGYo-00000001NnV-2K0o; Mon, 28 Sep 2026 18:58:46 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 037B941905; Mon, 28 Sep 2026 18:58:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE8331F000FF; Mon, 28 Sep 2026 18:58:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790621925; bh=BQJlLat4qxj8pgDrowtyIAkoQQPKp9J5TEk8suVVKjQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=nOYYg7oCN+CEi6+HSLYl5pLYDPIkgl9oIzaKeRsIwnLQLz8gmq2Wlu8L8C67dnJeG 8Jqjug8DQ2jWcrnxQaDVIw6DTaQKfwBEz5XUeHMtQu+4oXvZNYq/hQmhg9GTUYuIaX BDacpyX/6tMbFS4fZj3+80NIoy+Z1ibgbEcH6aPXMhaAGIYuRy/vAvhAZDbjQBVPe9 7bwsvipBELhLtcU85W+9CT0n5D9xfPhyUfHWMBbm0bGZocbd8ObHRV61EiYsQnAK5O OCs1pBsYyjVxK8UZ3AoZWY14OtJ41S0GCn9WpAN4rU+kY6M4c63VqlKaID+AO+oIJZ sntZfdjPV6lGA== Message-ID: <9d4517d0-0e78-4eee-970e-0cac9d0a856f@kernel.org> Date: Mon, 28 Sep 2026 20:58:22 +0200 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 00/12] CRASH_MEMACTION: describe pages to a kdump kernel (was: CRASH_WIPE_SECRETS) To: "Lorenzo Stoakes (ARM)" , =?UTF-8?Q?Jan_Sebastian_G=C3=B6tte?= Cc: Jonathan Corbet , Shuah Khan , Randy Dunlap , Rob Herring , Saravana Kannan , Andrew Morton , Baoquan He , Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Dave Young , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Muchun Song , Oscar Salvador , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , Catalin Marinas , Will Deacon , Mark Rutland , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Benjamin Marzinski , Herbert Xu , "David S. Miller" , Mimi Zohar , David Howells , Jarkko Sakkinen , Paul Moore , James Morris , "Serge E. Hallyn" , James Bottomley , "Liam R. Howlett" , Jann Horn , Pedro Falcato , Rik van Riel , Harry Yoo , Lance Yang , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Usama Arif , Kiryl Shutsemau , Matthew Brost , Joshua Hahn , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Peter Xu , Arnd Bergmann , Eric Biggers , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, kexec@lists.infradead.org, driver-core@lists.linux.dev, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, dm-devel@lists.linux.dev, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org References: <20260928-crash-memaction-upstream-20260921-v3-0-e511e9ee2329@jaseg.de> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Tue, 20 Oct 2026 01:21:11 -0700 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" X-Spam-Status: No, score=-7.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 9/28/26 19:49, Lorenzo Stoakes (ARM) wrote: > On Mon, Sep 28, 2026 at 07:17:48PM +0200, Jan Sebastian Götte wrote: >> I'm using linux on an embedded target in a Hardware Security Module-like >> application. One requirement is that I want the system to be able to >> quickly erase its memory when it detects physical tampering. I'm >> approaching that by using kdump to load into a small payload that >> instead of dumping RAM, erases RAM frmo start to end. However, writing >> all of RAM, especially on an embedded target, is rather slow. For this >> reason, I propose a new crash_memaction mechanism that lets the old >> kernel indicate marked memory areas to the kdump kernel at page >> granularity. > > Sorry this all seems really invasive for what seems to be a very specific > use case. > > In general, with big changes like this, you should send the series as an > RFC. > > Please send any future revisions of this as an RFC. > > The bar for a new VMA flag, a new madvise() flag, It's actually three new madvise modes. Way to invasive indeed. This won't fly. -- Cheers, David