From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967553AbaFQWJj (ORCPT ); Tue, 17 Jun 2014 18:09:39 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54674 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966935AbaFQVvx (ORCPT ); Tue, 17 Jun 2014 17:51:53 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Anthony Iliopoulos , "H. Peter Anvin" , Kamal Mostafa Subject: [PATCH 3.13 116/212] x86, mm, hugetlb: Add missing TLB page invalidation for hugetlb_cow() Date: Tue, 17 Jun 2014 14:43:30 -0700 Message-Id: <1403041506-13646-117-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1403041506-13646-1-git-send-email-kamal@canonical.com> References: <1403041506-13646-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Anthony Iliopoulos commit 9844f5462392b53824e8b86726e7c33b5ecbb676 upstream. The invalidation is required in order to maintain proper semantics under CoW conditions. In scenarios where a process clones several threads, a thread operating on a core whose DTLB entry for a particular hugepage has not been invalidated, will be reading from the hugepage that belongs to the forked child process, even after hugetlb_cow(). The thread will not see the updated page as long as the stale DTLB entry remains cached, the thread attempts to write into the page, the child process exits, or the thread gets migrated to a different processor. Signed-off-by: Anthony Iliopoulos Link: http://lkml.kernel.org/r/20140514092948.GA17391@server-36.huawei.corp Suggested-by: Shay Goikhman Acked-by: Dave Hansen Signed-off-by: H. Peter Anvin Signed-off-by: Kamal Mostafa --- arch/x86/include/asm/hugetlb.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h index a809121..68c0539 100644 --- a/arch/x86/include/asm/hugetlb.h +++ b/arch/x86/include/asm/hugetlb.h @@ -52,6 +52,7 @@ static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm, static inline void huge_ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { + ptep_clear_flush(vma, addr, ptep); } static inline int huge_pte_none(pte_t pte) -- 1.9.1