Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751340AbdCHI1T (ORCPT ); Wed, 8 Mar 2017 03:27:19 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54188 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750770AbdCHI1S (ORCPT ); Wed, 8 Mar 2017 03:27:18 -0500 Date: Wed, 8 Mar 2017 16:18:57 +0800 From: Dave Young To: Baoquan He Cc: linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, thgarnie@google.com, keescook@chromium.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, akpm@linux-foundation.org Subject: Re: [PATCH 2/2] x86/mm/KASLR: Correct the upper boundary of KALSR mm regions if adjacent to EFI Message-ID: <20170308081857.GB12600@dhcp-128-65.nay.redhat.com> References: <1488959258-4731-1-git-send-email-bhe@redhat.com> <1488959258-4731-2-git-send-email-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1488959258-4731-2-git-send-email-bhe@redhat.com> User-Agent: Mutt/1.7.1 (2016-10-04) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Wed, 08 Mar 2017 08:19:08 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1507 Lines: 43 On 03/08/17 at 03:47pm, Baoquan He wrote: > EFI allocates runtime services regions top-down, starting from EFI_VA_START > to EFI_VA_END. So EFI_VA_START is bigger than EFI_VA_END and is the end of > EFI region. The upper boundary of memory regions randomized by KASLR should > be EFI_VA_END if it's adjacent to EFI region, but not EFI_VA_START. > > Correct it in this patch. > > Signed-off-by: Baoquan He > --- > arch/x86/mm/kaslr.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c > index 887e571..aed2064 100644 > --- a/arch/x86/mm/kaslr.c > +++ b/arch/x86/mm/kaslr.c > @@ -48,7 +48,7 @@ static const unsigned long vaddr_start = __PAGE_OFFSET_BASE; > #if defined(CONFIG_X86_ESPFIX64) > static const unsigned long vaddr_end = ESPFIX_BASE_ADDR; > #elif defined(CONFIG_EFI) > -static const unsigned long vaddr_end = EFI_VA_START; > +static const unsigned long vaddr_end = EFI_VA_END; > #else > static const unsigned long vaddr_end = __START_KERNEL_map; > #endif > @@ -105,7 +105,7 @@ void __init kernel_randomize_memory(void) > */ > BUILD_BUG_ON(vaddr_start >= vaddr_end); > BUILD_BUG_ON(IS_ENABLED(CONFIG_X86_ESPFIX64) && > - vaddr_end >= EFI_VA_START); > + vaddr_end >= EFI_VA_END); > BUILD_BUG_ON((IS_ENABLED(CONFIG_X86_ESPFIX64) || > IS_ENABLED(CONFIG_EFI)) && > vaddr_end >= __START_KERNEL_map); > -- > 2.5.5 > Acked-by: Dave Young Thanks Dave