From patchwork Wed Aug 2 20:38:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Tatashin X-Patchwork-Id: 796797 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=sparclinux-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3xN4rQ5mp4z9s78 for ; Thu, 3 Aug 2017 06:42:46 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753113AbdHBUmB (ORCPT ); Wed, 2 Aug 2017 16:42:01 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:29280 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752116AbdHBUjg (ORCPT ); Wed, 2 Aug 2017 16:39:36 -0400 Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id v72KcbMZ024938 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 2 Aug 2017 20:38:38 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id v72Kcbpj025007 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 2 Aug 2017 20:38:37 GMT Received: from abhmp0001.oracle.com (abhmp0001.oracle.com [141.146.116.7]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id v72KcbRP021790; Wed, 2 Aug 2017 20:38:37 GMT Received: from ca-ldom-ol-build-1.us.oracle.com (/10.129.68.23) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 02 Aug 2017 13:38:37 -0700 From: Pavel Tatashin To: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, mhocko@kernel.org Subject: [v4 10/15] x86/kasan: explicitly zero kasan shadow memory Date: Wed, 2 Aug 2017 16:38:19 -0400 Message-Id: <1501706304-869240-11-git-send-email-pasha.tatashin@oracle.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1501706304-869240-1-git-send-email-pasha.tatashin@oracle.com> References: <1501706304-869240-1-git-send-email-pasha.tatashin@oracle.com> X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: sparclinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: sparclinux@vger.kernel.org To optimize the performance of struct page initialization, vmemmap_populate() will no longer zero memory. We must explicitly zero the memory that is allocated by vmemmap_populate() for kasan, as this memory does not go through struct page initialization path. Signed-off-by: Pavel Tatashin Reviewed-by: Steven Sistare Reviewed-by: Daniel Jordan Reviewed-by: Bob Picco --- arch/x86/mm/kasan_init_64.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 02c9d7553409..7d06cf0b0b6e 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -84,6 +84,28 @@ static struct notifier_block kasan_die_notifier = { }; #endif +/* + * Memory that was allocated by vmemmap_populate is not zeroed, so we must + * zero it here explicitly. + */ +static void +zero_vemmap_populated_memory(void) +{ + u64 i, start, end; + + for (i = 0; i < E820_MAX_ENTRIES && pfn_mapped[i].end; i++) { + void *kaddr_start = pfn_to_kaddr(pfn_mapped[i].start); + void *kaddr_end = pfn_to_kaddr(pfn_mapped[i].end); + + start = (u64)kasan_mem_to_shadow(kaddr_start); + end = (u64)kasan_mem_to_shadow(kaddr_end); + memset((void *)start, 0, end - start); + } + start = (u64)kasan_mem_to_shadow(_stext); + end = (u64)kasan_mem_to_shadow(_end); + memset((void *)start, 0, end - start); +} + void __init kasan_early_init(void) { int i; @@ -156,6 +178,13 @@ void __init kasan_init(void) pte_t pte = __pte(__pa(kasan_zero_page) | __PAGE_KERNEL_RO); set_pte(&kasan_zero_pte[i], pte); } + + /* + * vmemmap_populate does not zero the memory, so we need to zero it + * explicitly + */ + zero_vemmap_populated_memory(); + /* Flush TLBs again to be sure that write protection applied. */ __flush_tlb_all();