From patchwork Tue Aug 29 02:02:20 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Tatashin X-Patchwork-Id: 9926703 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7748F6022E for ; Tue, 29 Aug 2017 02:10:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5FD3128853 for ; Tue, 29 Aug 2017 02:10:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 548A32885C; Tue, 29 Aug 2017 02:10:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, RCVD_IN_DNSWL_LOW, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D4EC928853 for ; Tue, 29 Aug 2017 02:10:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=svTL4sJAMBY1nYYH+w1ifwViA3KPezOWMz/0vQt8008=; b=YynF8P2hs/GXlh JmVQBVZZgb1X6UYIgDOo+zBgL2oPlLC8tjaNwRn5GVUyj91eKDva2speatw0vkxkI4wxjEvHw+Miq zDUgAPSCZtxbG9l13x3QFHrSuwnroIlyqrqQQSNLFifUW1paUzJu3hLH3NSi7MaktpY1LSnWmju8q 1vxINIgbQcdNwEB2s/kn7j5G+dVijlx/0irRFY3PuqnHAYZYeeSe4zjAE7ezcvHKUO8TuvKq9FyjZ Jy1ri+YPhCEa0Ddfj6xifNs/RUV8jYu3fQE4B4lDXAMCuhgqQSlu2tJc4dQoAXXwUPh7C6rlDvFZ+ nQLl+ZsIIMe0ZaRWecSA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dmVxw-0004du-5P; Tue, 29 Aug 2017 02:09:20 +0000 Received: from aserp1040.oracle.com ([141.146.126.69]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dmVsL-0000nF-78 for linux-arm-kernel@lists.infradead.org; Tue, 29 Aug 2017 02:03:38 +0000 Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id v7T22cQd011062 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 29 Aug 2017 02:02:38 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id v7T22cfi016104 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 29 Aug 2017 02:02:38 GMT Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id v7T22caG011415; Tue, 29 Aug 2017 02:02:38 GMT Received: from ca-ldom-ol-build-1.us.oracle.com (/10.129.68.23) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 28 Aug 2017 19:02:37 -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, ard.biesheuvel@linaro.org, will.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org, mgorman@techsingularity.net, Steven.Sistare@oracle.com, daniel.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] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170828_190333_437527_D7ED9254 X-CRM114-Status: GOOD ( 11.53 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 | 66 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 02c9d7553409..96fde5bf9597 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -84,6 +84,66 @@ static struct notifier_block kasan_die_notifier = { }; #endif +/* + * x86 variant of vmemmap_populate() uses either PMD_SIZE pages or base pages + * to map allocated memory. This routine determines the page size for the given + * address from vmemmap. + */ +static u64 get_vmemmap_pgsz(u64 addr) +{ + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + + pgd = pgd_offset_k(addr); + BUG_ON(pgd_none(*pgd) || pgd_large(*pgd)); + + p4d = p4d_offset(pgd, addr); + BUG_ON(p4d_none(*p4d) || p4d_large(*p4d)); + + pud = pud_offset(p4d, addr); + BUG_ON(pud_none(*pud) || pud_large(*pud)); + + pmd = pmd_offset(pud, addr); + BUG_ON(pmd_none(*pmd)); + + if (pmd_large(*pmd)) + return PMD_SIZE; + return PAGE_SIZE; +} + +/* + * Memory that was allocated by vmemmap_populate is not zeroed, so we must + * zero it here explicitly. + */ +static void +zero_vmemmap_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); + + /* Round to the start end of the mapped pages */ + start = rounddown(start, get_vmemmap_pgsz(start)); + end = roundup(end, get_vmemmap_pgsz(start)); + memset((void *)start, 0, end - start); + } + + start = (u64)kasan_mem_to_shadow(_stext); + end = (u64)kasan_mem_to_shadow(_end); + + /* Round to the start end of the mapped pages */ + start = rounddown(start, get_vmemmap_pgsz(start)); + end = roundup(end, get_vmemmap_pgsz(start)); + memset((void *)start, 0, end - start); +} + void __init kasan_early_init(void) { int i; @@ -146,6 +206,12 @@ void __init kasan_init(void) load_cr3(init_top_pgt); __flush_tlb_all(); + /* + * vmemmap_populate does not zero the memory, so we need to zero it + * explicitly + */ + zero_vmemmap_populated_memory(); + /* * kasan_zero_page has been used as early shadow memory, thus it may * contain some garbage. Now we can clear and write protect it, since