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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF752C433F4 for ; Mon, 27 Aug 2018 05:56:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60883216FA for ; Mon, 27 Aug 2018 05:56:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 60883216FA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726887AbeH0JlV (ORCPT ); Mon, 27 Aug 2018 05:41:21 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:34290 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726785AbeH0JlV (ORCPT ); Mon, 27 Aug 2018 05:41:21 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 89F1072620; Mon, 27 Aug 2018 05:56:11 +0000 (UTC) Received: from localhost (ovpn-8-24.pek2.redhat.com [10.72.8.24]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 767BF2027EA0; Mon, 27 Aug 2018 05:56:10 +0000 (UTC) Date: Mon, 27 Aug 2018 13:56:07 +0800 From: Baoquan He To: Chao Fan Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org, keescook@chromium.org, n-horiguchi@ah.jp.nec.com, indou.takao@jp.fujitsu.com, caoj.fnst@cn.fujitsu.com, douly.fnst@cn.fujitsu.com Subject: Re: [PATCH v5 4/4] x86/boot/KASLR: Limit kaslr to choosing the immovable memory Message-ID: <20180827055607.GB1748@MiWiFi-R3L-srv> References: <20180807065000.30958-1-fanc.fnst@cn.fujitsu.com> <20180807065000.30958-5-fanc.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180807065000.30958-5-fanc.fnst@cn.fujitsu.com> User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 27 Aug 2018 05:56:11 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 27 Aug 2018 05:56:11 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'bhe@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/07/18 at 02:50pm, Chao Fan wrote: > If 'CONFIG_MEMORY_HOTREMOVE' specified and the account of immovable If CONFIG_MEMORY_HOTREMOVE is enabled, > memory regions is not zero. Calculate the intersection between memory > regions from e820/efi memory table and immovable memory regions. > Or go on the old code. > > Rename process_mem_region to slots_count to match slots_fetch_random, > and name new function as process_mem_region. > > Signed-off-by: Chao Fan > --- > arch/x86/boot/compressed/kaslr.c | 66 ++++++++++++++++++++++++++------ > 1 file changed, 55 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c > index 720878f967a3..9c6e24a23a2d 100644 > --- a/arch/x86/boot/compressed/kaslr.c > +++ b/arch/x86/boot/compressed/kaslr.c > @@ -635,9 +635,9 @@ static unsigned long slots_fetch_random(void) > return 0; > } > > -static void process_mem_region(struct mem_vector *entry, > - unsigned long minimum, > - unsigned long image_size) > +static void slots_count(struct mem_vector *entry, > + unsigned long minimum, > + unsigned long image_size) > { > struct mem_vector region, overlap; > struct slot_area slot_area; > @@ -714,6 +714,56 @@ static void process_mem_region(struct mem_vector *entry, > } > } > > +static bool process_mem_region(struct mem_vector *region, > + unsigned long long minimum, > + unsigned long long image_size) > +{ Is it possible to take num_immovable_mem definition out from #ifdef CONFIG_MEMORY_HOTREMOVE block and check it here like below? This way, one level of indentation can be reduced in the for loop, and code is more readable. static bool process_mem_region(struct mem_vector *region, unsigned long long minimum, unsigned long long image_size) { /* * If no immovable memory found, or MEMORY_HOTREMOVE disabled, * walk all the regions, so use region directely. */ if (num_immovable_mem > 0) { slots_count(region, minimum, image_size); if (slot_area_index == MAX_SLOT_AREA) { debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n"); return 1; } return 0; } #ifdef CONFIG_MEMORY_HOTREMOVE for (i = 0; i < num_immovable_mem; i++) { ... } #endif } > +#ifdef CONFIG_MEMORY_HOTREMOVE > + /* > + * If immovable memory found, filter the intersection between > + * immovable memory and region to slots_count. > + * Otherwise, go on old code. > + */ > + if (num_immovable_mem > 0) { > + int i; > + > + for (i = 0; i < num_immovable_mem; i++) { > + struct mem_vector entry; > + unsigned long long start, end, entry_end, region_end; > + > + start = immovable_mem[i].start; > + end = start + immovable_mem[i].size; > + region_end = region->start + region->size; > + > + entry.start = clamp(region->start, start, end); > + entry_end = clamp(region_end, start, end); > + > + if (entry.start + image_size < entry_end) { > + entry.size = entry_end - entry.start; > + slots_count(&entry, minimum, image_size); > + > + if (slot_area_index == MAX_SLOT_AREA) { > + debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n"); > + return 1; > + } > + } > + } > + return 0; > + } > +#endif > + /* > + * If no immovable memory found, or MEMORY_HOTREMOVE disabled, > + * walk all the regions, so use region directely. > + */ > + slots_count(region, minimum, image_size); > + > + if (slot_area_index == MAX_SLOT_AREA) { > + debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n"); > + return 1; > + } > + return 0; > +} > + > #ifdef CONFIG_EFI > /* > * Returns true if mirror region found (and must have been processed > @@ -779,11 +829,8 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) > > region.start = md->phys_addr; > region.size = md->num_pages << EFI_PAGE_SHIFT; > - process_mem_region(®ion, minimum, image_size); > - if (slot_area_index == MAX_SLOT_AREA) { > - debug_putstr("Aborted EFI scan (slot_areas full)!\n"); > + if (process_mem_region(®ion, minimum, image_size)) > break; > - } > } > return true; > } > @@ -810,11 +857,8 @@ static void process_e820_entries(unsigned long minimum, > continue; > region.start = entry->addr; > region.size = entry->size; > - process_mem_region(®ion, minimum, image_size); > - if (slot_area_index == MAX_SLOT_AREA) { > - debug_putstr("Aborted e820 scan (slot_areas full)!\n"); > + if (process_mem_region(®ion, minimum, image_size)) > break; > - } > } > } > > -- > 2.17.1 > > >