Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753886AbdGSJpk (ORCPT ); Wed, 19 Jul 2017 05:45:40 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36752 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752808AbdGSJpg (ORCPT ); Wed, 19 Jul 2017 05:45:36 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Julian Calaby , Nitin Gupta , "David S. Miller" Subject: [PATCH 4.12 23/84] sparc64: Fix gup_huge_pmd Date: Wed, 19 Jul 2017 11:43:29 +0200 Message-Id: <20170719092323.280119308@linuxfoundation.org> X-Mailer: git-send-email 2.13.3 In-Reply-To: <20170719092322.362625377@linuxfoundation.org> References: <20170719092322.362625377@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1119 Lines: 37 4.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nitin Gupta [ Upstream commit dbd2667a4fb9ce4f547982b07cd69dda127c47ea ] The function assumes that each PMD points to head of a huge page. This is not correct as a PMD can point to start of any 8M region with a, say 256M, hugepage. The fix ensures that it points to the correct head of any PMD huge page. Cc: Julian Calaby Signed-off-by: Nitin Gupta Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- arch/sparc/mm/gup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/sparc/mm/gup.c +++ b/arch/sparc/mm/gup.c @@ -78,8 +78,8 @@ static int gup_huge_pmd(pmd_t *pmdp, pmd return 0; refs = 0; - head = pmd_page(pmd); - page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT); + page = pmd_page(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); + head = compound_head(page); do { VM_BUG_ON(compound_head(page) != head); pages[*nr] = page;