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 1F2A8C433F5 for ; Mon, 27 Aug 2018 07:10:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0CAC208B3 for ; Mon, 27 Aug 2018 07:10:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C0CAC208B3 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 S1727142AbeH0K4A (ORCPT ); Mon, 27 Aug 2018 06:56:00 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:38998 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727058AbeH0K4A (ORCPT ); Mon, 27 Aug 2018 06:56:00 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C955881663F5; Mon, 27 Aug 2018 07:10:36 +0000 (UTC) Received: from localhost (ovpn-8-24.pek2.redhat.com [10.72.8.24]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AFDDD94641; Mon, 27 Aug 2018 07:10:35 +0000 (UTC) Date: Mon, 27 Aug 2018 15:10:32 +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: <20180827071032.GE1748@MiWiFi-R3L-srv> References: <20180807065000.30958-1-fanc.fnst@cn.fujitsu.com> <20180807065000.30958-5-fanc.fnst@cn.fujitsu.com> <20180827055607.GB1748@MiWiFi-R3L-srv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180827055607.GB1748@MiWiFi-R3L-srv> User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 27 Aug 2018 07:10:36 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 27 Aug 2018 07:10:36 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.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 08/27/18 at 01:56pm, Baoquan He wrote: > 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) { Sorry, I meant if (!num_immovable_mem) { > 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 > > > > > >