From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8E36C3BD659 for ; Fri, 21 Aug 2026 14:53:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787324022; cv=none; b=usY0AKWdpKQI1he0zowVYd2y35Bv0L55RgPBxK7YW3MNsGmtJGRaj86GtDxyR2gAZXi8qdfe0GUqCp8fhVLtDSAt7x1FGQKoX+iTtkbqxLPXLtzMAKG5B1jhIgGDDPzj1HfxGZyMakn1pwIJZUOPox/ZRwl4jtjjuEh36Fw8mhA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787324022; c=relaxed/simple; bh=yVLVN6tqPoF0TEFTQk1A+vRL9+BTOsYuzr2pqrId/q8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KczkbB30OCz6NlUp/q3yN83ZEyVJQAGVFDK77wu2EhE1tz+qmWApkLOKFVosWoXWbQHsjqoIIYtWmRgFST00fyLDYvW5234QPsMcE26iluSym9I1V2PaTvIhkkpuvJgQuOOLGOieALuSbuIcrjXCgvHP8LcuOkYyTTUso7EicMc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PEqLsZh8; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PEqLsZh8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF4501F000E9; Fri, 21 Aug 2026 14:53:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787324018; bh=gjevPVNDI3BMq67YKVjzwksfTaXW8pJVyyPC7ES6lEo=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=PEqLsZh8icemV6iCXLH8M1lwsuZIi3ppcJsoYkHbdgbhu48kCp/fzBVJmA+oO0f10 A3T8kuGkGfXWM3lFtPhlABSA/ZLi5QI1UlAez8YchNUOWf6MIbU+Sq4O/RMx+ddJzd zX6mfViDwm9H4ky1grMR/7zMfO1HJVHZDI3kQdGakxl87mqdNfF2T069ytU4DpBR1R uUfOlu07HhdXWSEZcB7TpoBFiRx5U3OuBGcOl/m1t38yanYpaMdnHgb6oRM9K+QoCP Eur4/KYp8ziJXcXNbn3YRLL+yg8AgCvW4WKrQs5/fx9CGAIg6Vr6CfnI0j0QFnUrbm 1CtXL9ud/p8iw== Received: from phl-compute-04.internal (phl-compute-04.internal [10.202.2.44]) by mailfauth.ams.internal (Postfix) with ESMTP id 686B8198003A; Fri, 21 Aug 2026 10:53:34 -0400 (EDT) Received: from phl-frontend-04 ([10.202.2.163]) by phl-compute-04.internal (MEProxy); Fri, 21 Aug 2026 10:53:36 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: dmFkZTEbg+VVSOlsbnGiy6K3W4JLvpYCkMXlScxQEGLLdOvOtuyrQIKV5vXx+5KSTZnied 1BL05bKU0wpXElyHPT96soPhyznOA9yhQkJWdpXI71jCNZvHn/c8VAuX2g4/alGQJvz1qd B6T1tx9pKoO/3Xnvauupxnqq2zICVzTk4UBlHScruUUmAP9mnk/qzNvZQc+jf4jpBBOpED xE+2fgXCydrOnnCVlfS603l+zfBqCrVei/CtHb7spiwvo3P4OCFzG/j5TiRRMOyLcK4pgg ZSlRN9jwxfCyD9ZxG09NOzC4Ou0Dq8l4ppVyOBSA9VAPYEjjLuSug642uKL0/SMdJGusT8 FyQeFVv5+gCq6v82m5C+dc3R+HvKciPH93C1bDuVeIW4IkUVggKfOTqwr4KKZy3emCTP+n DBukM1AbkGCTiOllFIoIrYoui9xfTNkWipsxWRgRoasgv7YwnRXH5aQZquW9snqERvi/Xs R0upe+kYPe/qNbREEIgpWHKovwhkbXElaYqKpMSBzNUq1tliCfVcEBRiTFlkTSmPwDqgrW ibYpBtd+fq2PrhOJ9Bklg/CSpV2hTOVcWUlpUl15BIC4Ze+TqxA907+2A7dBb9OARMk/T8 nYgNX66kQKWXnHcaCI9pVHv1DteFjCk363spGtTWHEjy145SOc0yJlhjjcWg X-ME-Proxy: Feedback-ID: i10464835:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 21 Aug 2026 10:53:33 -0400 (EDT) Date: Fri, 21 Aug 2026 15:53:32 +0100 From: Kiryl Shutsemau To: Breno Leitao Cc: Ard Biesheuvel , Ilias Apalodimas , Miaohe Lin , Naoya Horiguchi , Andrew Morton , linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rmikey@meta.com, riel@surriel.com, kexec@lists.infradead.org, kernel-team@meta.com Subject: Re: [PATCH v2 6/6] efi: respect the poisoned pages coming from previous kernel Message-ID: References: <20260821-hwpoison-kho-v2-0-5743791e48e6@debian.org> <20260821-hwpoison-kho-v2-6-5743791e48e6@debian.org> 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 Content-Disposition: inline In-Reply-To: On Fri, Aug 21, 2026 at 07:03:06AM -0700, Breno Leitao wrote: > On Fri, Aug 21, 2026 at 01:13:55PM +0100, Kiryl Shutsemau wrote: > > On Fri, Aug 21, 2026 at 03:06:06AM -0700, Breno Leitao wrote: > > > + /* Reserve the table itself so it survives a further kexec. */ > > > + memblock_reserve(PAGE_ALIGN_DOWN(ppm), > > > + PAGE_ALIGN(ppm + sizeof(*pm) + bitmap_size) - > > > + PAGE_ALIGN_DOWN(ppm)); > > > > Hm. I don't think it is enough. > > > > On x86, kernel doesn't keep memblock around after boot (see > > CONFIG_ARCH_KEEP_MEMBLOCK). Reserving in memblock exclude the memory > > from page allocator. But kexec can place the image there. > > You mean the third kexec? > > 1) Kernel A hits an ECC error and marks page X poisoned. > 2) Kernel A kexecs into kernel B, which won't use that page since > it's in EFI_POISONED_PAGE and memblock-reserved. > 3) Kernel B kexecs into kernel C, which doesn't respect > EFI_POISONED_PAGE. > > Is this the scenario you mean? No. I think nothing prevents kernel B from putting kernel C image into the reserved space in !CONFIG_ARCH_KEEP_MEMBLOCK case. Kernel B excludes poisoned memory from buddy allocator, but kexec doesn't care about this when look for placement for the next image. -- Kiryl Shutsemau / Kirill A. Shutemov