Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752506AbeADKDZ (ORCPT + 1 other); Thu, 4 Jan 2018 05:03:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38046 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751872AbeADKDX (ORCPT ); Thu, 4 Jan 2018 05:03:23 -0500 Date: Thu, 4 Jan 2018 18:03:08 +0800 From: Baoquan He To: Alexander Kuleshov Cc: Thomas Gleixner , Ingo Molnar , x86@kernel.org, Kees Cook , Dave Jiang , Naoya Horiguchi , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/KASLR: move aligning of minimal address to choose_random_location() Message-ID: <20180104100308.GB7235@x1> References: <20180104095421.10606-1-kuleshovmail@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180104095421.10606-1-kuleshovmail@gmail.com> User-Agent: Mutt/1.7.0 (2016-08-17) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 04 Jan 2018 10:03:23 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 01/04/18 at 03:54pm, Alexander Kuleshov wrote: > we align minimal possible address during randomization to CONFIG_PHYSICAL_ALIGN > two times: during getting of random physical address and virtual > address (only for x86_64). > > Let's move this to choose_random_location() to not duplicate code in > find_random_virt_addr() and find_random_phys_addr(). > > Signed-off-by: Alexander Kuleshov > --- > arch/x86/boot/compressed/kaslr.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c > index 8199a6187251..8c93e399fdfd 100644 > --- a/arch/x86/boot/compressed/kaslr.c > +++ b/arch/x86/boot/compressed/kaslr.c > @@ -673,9 +673,6 @@ static unsigned long find_random_phys_addr(unsigned long minimum, > return 0; > } > > - /* Make sure minimum is aligned. */ > - minimum = ALIGN(minimum, CONFIG_PHYSICAL_ALIGN); > - > if (process_efi_entries(minimum, image_size)) > return slots_fetch_random(); > > @@ -688,8 +685,6 @@ static unsigned long find_random_virt_addr(unsigned long minimum, > { > unsigned long slots, random_addr; > > - /* Make sure minimum is aligned. */ > - minimum = ALIGN(minimum, CONFIG_PHYSICAL_ALIGN); > /* Align image_size for easy slot calculations. */ > image_size = ALIGN(image_size, CONFIG_PHYSICAL_ALIGN); > > @@ -738,6 +733,9 @@ void choose_random_location(unsigned long input, > */ > min_addr = min(*output, 512UL << 20); > > + /* Make sure minimum is aligned. */ > + min_addr = ALIGN(min_addr, CONFIG_PHYSICAL_ALIGN); Hmm, the min_addr is passed to find_random_phys_addr(), but not to find_random_virt_addr(). > + > /* Walk available memory entries to find a random address. */ > random_addr = find_random_phys_addr(min_addr, output_size); > if (!random_addr) { > -- > 2.14.3 >