{"id":806909,"url":"http://patchwork.ozlabs.org/api/1.0/patches/806909/?format=json","project":{"id":10,"url":"http://patchwork.ozlabs.org/api/1.0/projects/10/?format=json","name":"Linux SPARC Development ","link_name":"sparclinux","list_id":"sparclinux.vger.kernel.org","list_email":"sparclinux@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"<1503972142-289376-10-git-send-email-pasha.tatashin@oracle.com>","date":"2017-08-29T02:02:20","name":"[v7,09/11] x86/kasan: explicitly zero kasan shadow memory","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"038ea14fe28c0bdc8658a002a4cb05528830d5d3","submitter":{"id":71010,"url":"http://patchwork.ozlabs.org/api/1.0/people/71010/?format=json","name":"Pavel Tatashin","email":"pasha.tatashin@oracle.com"},"delegate":{"id":34,"url":"http://patchwork.ozlabs.org/api/1.0/users/34/?format=json","username":"davem","first_name":"David","last_name":"Miller","email":"davem@davemloft.net"},"mbox":"http://patchwork.ozlabs.org/project/sparclinux/patch/1503972142-289376-10-git-send-email-pasha.tatashin@oracle.com/mbox/","series":[{"id":285,"url":"http://patchwork.ozlabs.org/api/1.0/series/285/?format=json","date":"2017-08-29T02:02:11","name":"complete deferred page initialization","version":7,"mbox":"http://patchwork.ozlabs.org/series/285/mbox/"}],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/806909/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"patchwork-incoming@ozlabs.org","Delivered-To":"patchwork-incoming@ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=sparclinux-owner@vger.kernel.org;\n\treceiver=)","Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xhBpC3MFTz9sRV\n\tfor ;\n\tTue, 29 Aug 2017 12:06:43 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1751282AbdH2CGP (ORCPT );\n\tMon, 28 Aug 2017 22:06:15 -0400","from aserp1040.oracle.com ([141.146.126.69]:25869 \"EHLO\n\taserp1040.oracle.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1751270AbdH2CDu (ORCPT\n\t); Mon, 28 Aug 2017 22:03:50 -0400","from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234])\n\tby aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2)\n\twith ESMTP id v7T22cQd011062\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256\n\tverify=OK); Tue, 29 Aug 2017 02:02:38 GMT","from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235])\n\tby aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id\n\tv7T22cfi016104\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256\n\tverify=OK); Tue, 29 Aug 2017 02:02:38 GMT","from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17])\n\tby aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id\n\tv7T22caG011415; Tue, 29 Aug 2017 02:02:38 GMT","from ca-ldom-ol-build-1.us.oracle.com (/10.129.68.23)\n\tby default (Oracle Beehive Gateway v4.0)\n\twith ESMTP ; Mon, 28 Aug 2017 19:02:37 -0700"],"From":"Pavel Tatashin ","To":"linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org,\n\tlinux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org,\n\tlinux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org,\n\tx86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com,\n\theiko.carstens@de.ibm.com, davem@davemloft.net,\n\twilly@infradead.org, mhocko@kernel.org, ard.biesheuvel@linaro.org,\n\twill.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org,\n\tmgorman@techsingularity.net, Steven.Sistare@oracle.com,\n\tdaniel.m.jordan@oracle.com, bob.picco@oracle.com","Subject":"[PATCH v7 09/11] x86/kasan: explicitly zero kasan shadow memory","Date":"Mon, 28 Aug 2017 22:02:20 -0400","Message-Id":"<1503972142-289376-10-git-send-email-pasha.tatashin@oracle.com>","X-Mailer":"git-send-email 1.7.1","In-Reply-To":"<1503972142-289376-1-git-send-email-pasha.tatashin@oracle.com>","References":"<1503972142-289376-1-git-send-email-pasha.tatashin@oracle.com>","X-Source-IP":"aserv0022.oracle.com [141.146.126.234]","Sender":"sparclinux-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"sparclinux@vger.kernel.org"},"content":"To optimize the performance of struct page initialization,\nvmemmap_populate() will no longer zero memory.\n\nWe must explicitly zero the memory that is allocated by vmemmap_populate()\nfor kasan, as this memory does not go through struct page initialization\npath.\n\nSigned-off-by: Pavel Tatashin \nReviewed-by: Steven Sistare \nReviewed-by: Daniel Jordan \nReviewed-by: Bob Picco \n---\n arch/x86/mm/kasan_init_64.c | 66 +++++++++++++++++++++++++++++++++++++++++++++\n 1 file changed, 66 insertions(+)","diff":"diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c\nindex 02c9d7553409..96fde5bf9597 100644\n--- a/arch/x86/mm/kasan_init_64.c\n+++ b/arch/x86/mm/kasan_init_64.c\n@@ -84,6 +84,66 @@ static struct notifier_block kasan_die_notifier = {\n };\n #endif\n \n+/*\n+ * x86 variant of vmemmap_populate() uses either PMD_SIZE pages or base pages\n+ * to map allocated memory. This routine determines the page size for the given\n+ * address from vmemmap.\n+ */\n+static u64 get_vmemmap_pgsz(u64 addr)\n+{\n+\tpgd_t *pgd;\n+\tp4d_t *p4d;\n+\tpud_t *pud;\n+\tpmd_t *pmd;\n+\n+\tpgd = pgd_offset_k(addr);\n+\tBUG_ON(pgd_none(*pgd) || pgd_large(*pgd));\n+\n+\tp4d = p4d_offset(pgd, addr);\n+\tBUG_ON(p4d_none(*p4d) || p4d_large(*p4d));\n+\n+\tpud = pud_offset(p4d, addr);\n+\tBUG_ON(pud_none(*pud) || pud_large(*pud));\n+\n+\tpmd = pmd_offset(pud, addr);\n+\tBUG_ON(pmd_none(*pmd));\n+\n+\tif (pmd_large(*pmd))\n+\t\treturn PMD_SIZE;\n+\treturn PAGE_SIZE;\n+}\n+\n+/*\n+ * Memory that was allocated by vmemmap_populate is not zeroed, so we must\n+ * zero it here explicitly.\n+ */\n+static void\n+zero_vmemmap_populated_memory(void)\n+{\n+\tu64 i, start, end;\n+\n+\tfor (i = 0; i < E820_MAX_ENTRIES && pfn_mapped[i].end; i++) {\n+\t\tvoid *kaddr_start = pfn_to_kaddr(pfn_mapped[i].start);\n+\t\tvoid *kaddr_end = pfn_to_kaddr(pfn_mapped[i].end);\n+\n+\t\tstart = (u64)kasan_mem_to_shadow(kaddr_start);\n+\t\tend = (u64)kasan_mem_to_shadow(kaddr_end);\n+\n+\t\t/* Round to the start end of the mapped pages */\n+\t\tstart = rounddown(start, get_vmemmap_pgsz(start));\n+\t\tend = roundup(end, get_vmemmap_pgsz(start));\n+\t\tmemset((void *)start, 0, end - start);\n+\t}\n+\n+\tstart = (u64)kasan_mem_to_shadow(_stext);\n+\tend = (u64)kasan_mem_to_shadow(_end);\n+\n+\t/* Round to the start end of the mapped pages */\n+\tstart = rounddown(start, get_vmemmap_pgsz(start));\n+\tend = roundup(end, get_vmemmap_pgsz(start));\n+\tmemset((void *)start, 0, end - start);\n+}\n+\n void __init kasan_early_init(void)\n {\n \tint i;\n@@ -146,6 +206,12 @@ void __init kasan_init(void)\n \tload_cr3(init_top_pgt);\n \t__flush_tlb_all();\n \n+\t/*\n+\t * vmemmap_populate does not zero the memory, so we need to zero it\n+\t * explicitly\n+\t */\n+\tzero_vmemmap_populated_memory();\n+\n \t/*\n \t * kasan_zero_page has been used as early shadow memory, thus it may\n \t * contain some garbage. Now we can clear and write protect it, since\n","prefixes":["v7","09/11"]}