From patchwork Wed Apr 12 14:04:57 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Punit Agrawal X-Patchwork-Id: 9677545 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 905CD601C3 for ; Wed, 12 Apr 2017 14:05:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8296A2867F for ; Wed, 12 Apr 2017 14:05:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7608B28688; Wed, 12 Apr 2017 14:05:46 +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=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID 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 1DD202867F for ; Wed, 12 Apr 2017 14:05:46 +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:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=pUc9dxd/vkBol0EOzXTUTzs3CrfyZVK2SElXhZXMyxE=; b=LzB67NqkD1PPeP2JyWBro/OrMp 9LyXIWoOKEpLqcCP8UCqmJtP+yRftVlgjkMm2Y8w2jFdUjWMULl8LVpENsfVNAsbaiZwj/H9fCbur b592i1mMp1kVeeDUwEyzuCBoyzcEmAHfHbiJIEF6+mbDhZlGgMhQHP3uIPMnuWgwxBZvA3LQhssks 5Gx3N3q5C60NSJcgatIG2NPNiEDuOZq336BloDTGg56xqCYXXsRnogChWOfJ1FIDY3XJYus9Ibm1e Sk8ECjCnn5kYwT4J7VbWfqfJSAvSgIQcPiaorsqTDyfjDTXLlwIvl8HUnhkBlaFCpwTUMHNS9nH3i M+4PQl2A==; 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 1cyIu0-0000Og-Tf; Wed, 12 Apr 2017 14:05:44 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cyItp-0000CL-Ro for linux-arm-kernel@lists.infradead.org; Wed, 12 Apr 2017 14:05:36 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 628EE15A2; Wed, 12 Apr 2017 07:05:15 -0700 (PDT) Received: from localhost (e105922-lin.cambridge.arm.com [10.1.207.56]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 33CB83F52A; Wed, 12 Apr 2017 07:05:15 -0700 (PDT) From: Punit Agrawal To: catalin.marinas@arm.com, will.deacon@arm.com Subject: [PATCH 1/3] arm64: hugetlb: Fix huge_pte_offset to return poisoned page table entries Date: Wed, 12 Apr 2017 15:04:57 +0100 Message-Id: <20170412140459.21824-2-punit.agrawal@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170412140459.21824-1-punit.agrawal@arm.com> References: <20170412140459.21824-1-punit.agrawal@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170412_070533_909436_F516803C X-CRM114-Status: GOOD ( 11.77 ) 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: , Cc: David Woods , Punit Agrawal , steve.capper@arm.com, tbaicar@codeaurora.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org 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 When memory failure is enabled, a poisoned hugepage pte is marked as a swap entry. huge_pte_offset() does not return the poisoned page table entries when it encounters PUD/PMD hugepages. This behaviour of huge_pte_offset() leads to error such as below when munmap is called on poisoned hugepages. [ 344.165544] mm/pgtable-generic.c:33: bad pmd 000000083af00074. Fix huge_pte_offset() to return the poisoned pte which is then appropriately handled by the generic layer code. Signed-off-by: Punit Agrawal Cc: Catalin Marinas Cc: Steve Capper Cc: David Woods Tested-by: Tyler Baicar --- arch/arm64/mm/hugetlbpage.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 7514a000e361..5f1832165d69 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -143,15 +143,24 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) pr_debug("%s: addr:0x%lx pgd:%p\n", __func__, addr, pgd); if (!pgd_present(*pgd)) return NULL; - pud = pud_offset(pgd, addr); - if (!pud_present(*pud)) - return NULL; - if (pud_huge(*pud)) + pud = pud_offset(pgd, addr); + /* + * In case of HW Poisoning, a hugepage pud/pmd can contain + * poisoned entries. Poisoned entries are marked as swap + * entries. + * + * For puds/pmds that are not present, check to see if it + * could be a swap entry (!present and !none). + */ + if ((!pte_present(pud_pte(*pud)) && !pud_none(*pud)) || pud_huge(*pud)) return (pte_t *)pud; + pmd = pmd_offset(pud, addr); - if (!pmd_present(*pmd)) + if (pmd_none(*pmd)) return NULL; + if (!pmd_present(*pmd) && !pmd_none(*pmd)) + return (pte_t *)pmd; if (pte_cont(pmd_pte(*pmd))) { pmd = pmd_offset( @@ -160,6 +169,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) } if (pmd_huge(*pmd)) return (pte_t *)pmd; + pte = pte_offset_kernel(pmd, addr); if (pte_present(*pte) && pte_cont(*pte)) { pte = pte_offset_kernel(