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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F8D8EC8740 for ; Thu, 7 Sep 2023 16:19:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240577AbjIGQTQ (ORCPT ); Thu, 7 Sep 2023 12:19:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243249AbjIGQSV (ORCPT ); Thu, 7 Sep 2023 12:18:21 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B60B37A89; Thu, 7 Sep 2023 08:54:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694102077; x=1725638077; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=6EsGUJGhX1zT+Uyl+vPXWvJ0hitAvo76hypLco20y4Y=; b=QAVH/3JsotwOgGZF9bAzPXDf12AHmfMFwMmPk+104kEl7ohFKdMdpjaF Zsw0D3ZSNVOscn9h6giEbwnbsztAAecKcrNWUrNwHovBt413ss0DUA9uy Ngwn7ztm1dO2W8UmY5peCg2BCfjCdNp+iEE7+aNk2OyjRnN9pYprAqsjh F0TMB+gK1sS82REhttldmKTHIFZJgr8IbFtR7mCBSv3MPcLzzM+8dlQSU w9XnFEtGssVVImkXVapKO/5HF2wsl4PsslwiDNAJH1E++s93vGqmSy6/y Z5ufdmP0JtX613TLqB1eTnd1plcdXGnewI/LOS9teGC+nFFjEeTFRp0li A==; X-IronPort-AV: E=McAfee;i="6600,9927,10826"; a="408388049" X-IronPort-AV: E=Sophos;i="6.02,235,1688454000"; d="scan'208";a="408388049" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Sep 2023 08:51:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10826"; a="915793424" X-IronPort-AV: E=Sophos;i="6.02,235,1688454000"; d="scan'208";a="915793424" Received: from ningle-mobl2.amr.corp.intel.com (HELO [10.209.13.77]) ([10.209.13.77]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Sep 2023 08:51:06 -0700 Message-ID: <5a188bb6-add4-0522-069f-18fbd34aff16@intel.com> Date: Thu, 7 Sep 2023 08:51:06 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.0 Subject: Re: [PATCH 1/3] proc/vmcore: Do not map unaccepted memory Content-Language: en-US To: Adrian Hunter , "Kirill A. Shutemov" , Borislav Petkov , Andrew Morton Cc: Vlastimil Babka , Mike Rapoport , Lorenzo Stoakes , Tom Lendacky , Baoquan He , Vivek Goyal , Dave Young , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, kexec@lists.infradead.org References: <20230906073902.4229-1-adrian.hunter@intel.com> <20230906073902.4229-2-adrian.hunter@intel.com> <21bf2e44-3316-2372-44cb-1488f88650f5@intel.com> <30d0cebb-13f9-572e-9baa-b7450fec9108@intel.com> From: Dave Hansen In-Reply-To: <30d0cebb-13f9-572e-9baa-b7450fec9108@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/7/23 08:44, Adrian Hunter wrote: > On 7/09/23 18:39, Dave Hansen wrote: >> On 9/6/23 00:39, Adrian Hunter wrote: >>> @@ -559,7 +567,8 @@ static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma, >>> * pages without a reason. >>> */ >>> idx = srcu_read_lock(&vmcore_cb_srcu); >>> - if (!list_empty(&vmcore_cb_list)) >>> + if (!list_empty(&vmcore_cb_list) || >>> + range_contains_unaccepted_memory(paddr, paddr + size)) >>> ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot); >>> else >>> ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot); >> The whole callback mechanism which fs/proc/vmcore.c::pfn_is_ram() >> implements seems to be in place to ensure that there aren't a billion >> different "ram" checks in here. >> >> Is there a reason you can't register_vmcore_cb() a callback to check for >> unaccepted memory? > Someone asked for the change to be in arch-independent code... 😉 That doesn't really answer my question. virtio_mem_init_kdump(), for instance, is in arch-independent code.