{"id":813995,"url":"http://patchwork.ozlabs.org/api/patches/813995/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20170914223517.8242-10-pasha.tatashin@oracle.com/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/","list_archive_url":"https://lore.kernel.org/linuxppc-dev/","list_archive_url_format":"https://lore.kernel.org/linuxppc-dev/{}/","commit_url_format":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}"},"msgid":"<20170914223517.8242-10-pasha.tatashin@oracle.com>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/20170914223517.8242-10-pasha.tatashin@oracle.com/","date":"2017-09-14T22:35:15","name":"[v8,09/11] 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/people/71010/?format=json","name":"Pavel Tatashin","email":"pasha.tatashin@oracle.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20170914223517.8242-10-pasha.tatashin@oracle.com/mbox/","series":[{"id":3173,"url":"http://patchwork.ozlabs.org/api/series/3173/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=3173","date":"2017-09-14T22:35:12","name":"complete deferred page initialization","version":8,"mbox":"http://patchwork.ozlabs.org/series/3173/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/813995/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/813995/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Received":["from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68])\n\t(using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xtYWt0vYCz9sCZ\n\tfor ;\n\tFri, 15 Sep 2017 08:45:14 +1000 (AEST)","from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 3xtYWt04LCzDrZJ\n\tfor ;\n\tFri, 15 Sep 2017 08:45:14 +1000 (AEST)","from aserp1040.oracle.com (aserp1040.oracle.com [141.146.126.69])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby lists.ozlabs.org (Postfix) with ESMTPS id 3xtYLD6GPSzDrWl\n\tfor ;\n\tFri, 15 Sep 2017 08:36:52 +1000 (AEST)","from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74])\n\tby aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with\n\tESMTP id v8EMZcA8029598\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256\n\tverify=OK); Thu, 14 Sep 2017 22:35:39 GMT","from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72])\n\tby userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id v8EMZcee028809\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256\n\tverify=OK); Thu, 14 Sep 2017 22:35:38 GMT","from ubhmp0003.oracle.com (ubhmp0003.oracle.com [156.151.24.56])\n\tby userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id v8EMZc7k009764; \n\tThu, 14 Sep 2017 22:35:38 GMT","from cmex.localdomain (/12.145.98.253)\n\tby default (Oracle Beehive Gateway v4.0)\n\twith ESMTP ; Thu, 14 Sep 2017 22:35:38 +0000"],"Authentication-Results":"ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=oracle.com\n\t(client-ip=141.146.126.69; helo=aserp1040.oracle.com;\n\tenvelope-from=pasha.tatashin@oracle.com; receiver=)","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, willy@infradead.org, \n\tmhocko@kernel.org, ard.biesheuvel@linaro.org, will.deacon@arm.com,\n\tcatalin.marinas@arm.com, sam@ravnborg.org, mgorman@techsingularity.net,\n\tSteven.Sistare@oracle.com, daniel.m.jordan@oracle.com,\n\tbob.picco@oracle.com","Subject":"[PATCH v8 09/11] x86/kasan: explicitly zero kasan shadow memory","Date":"Thu, 14 Sep 2017 18:35:15 -0400","Message-Id":"<20170914223517.8242-10-pasha.tatashin@oracle.com>","X-Mailer":"git-send-email 2.14.1","In-Reply-To":"<20170914223517.8242-1-pasha.tatashin@oracle.com>","References":"<20170914223517.8242-1-pasha.tatashin@oracle.com>","X-Source-IP":"userv0022.oracle.com [156.151.31.74]","X-BeenThere":"linuxppc-dev@lists.ozlabs.org","X-Mailman-Version":"2.1.24","Precedence":"list","List-Id":"Linux on PowerPC Developers Mail List\n\t","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org","Sender":"\"Linuxppc-dev\"\n\t"},"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 bc84b73684b7..cc0399032673 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":["v8","09/11"]}