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 4ACEDEC8726 for ; Thu, 7 Sep 2023 18:02:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245697AbjIGSCF (ORCPT ); Thu, 7 Sep 2023 14:02:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245675AbjIGSB6 (ORCPT ); Thu, 7 Sep 2023 14:01:58 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4A16170C; Thu, 7 Sep 2023 11:01:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694109700; x=1725645700; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=fFdJWlOfOQFNWE/wQ1sARfEDpEEqtJd3bE+CeaqxZ+s=; b=i67LFL18l3seX2OcweH4aewbX8SBcqeifMMiMOmveyMaA+lfEtrO0Cr7 Y8ksE4t5DmkPaEIbemG1w95Kx1zOZl32L8oZJ2X73Miw0aMgnh7icdhv5 XpmubasZvnDAZcAXyzeVlv7ijAJK5tcx3f0vMdr5i8GXzOGmNlu2XqyOJ uZ7QvIDPgJ1STBEY2wwuwdHNceJHqMlFy/2IeXKaQ0mNHn9xW9RtkBGq1 OgzI58x3MjqOA/vQx48wvoeLYw53p5u1wCFyt+3rI5NaLztuzLj0V3IVm nvMrJgM771gQih1C1SHu5jYv1Zjpe3Xk8J+dMQM/2znYdX17n9VsK84/E A==; X-IronPort-AV: E=McAfee;i="6600,9927,10826"; a="443807581" X-IronPort-AV: E=Sophos;i="6.02,235,1688454000"; d="scan'208";a="443807581" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Sep 2023 08:44:16 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10826"; a="988818775" X-IronPort-AV: E=Sophos;i="6.02,235,1688454000"; d="scan'208";a="988818775" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO [10.0.2.15]) ([10.252.34.181]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Sep 2023 08:44:11 -0700 Message-ID: <30d0cebb-13f9-572e-9baa-b7450fec9108@intel.com> Date: Thu, 7 Sep 2023 18:44:05 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.15.0 Subject: Re: [PATCH 1/3] proc/vmcore: Do not map unaccepted memory To: Dave Hansen , "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> Content-Language: en-US From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki In-Reply-To: <21bf2e44-3316-2372-44cb-1488f88650f5@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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... ;-)