From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932569Ab3JKU3Q (ORCPT ); Fri, 11 Oct 2013 16:29:16 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45806 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759015Ab3JKTkY (ORCPT ); Fri, 11 Oct 2013 15:40:24 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Gurudas Pai , "David S. Miller" , David Rientjes Subject: [ 075/110] mm: Fix generic hugetlb pte check return type. Date: Fri, 11 Oct 2013 12:38:55 -0700 Message-Id: <20131011193816.012772119@linuxfoundation.org> X-Mailer: git-send-email 1.8.4.3.gca3854a In-Reply-To: <20131011193807.584188672@linuxfoundation.org> References: <20131011193807.584188672@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Miller [ Upstream commit 26794942461f438a6bc725ec7294b08a6bd782c4 ] The include/asm-generic/hugetlb.h stubs that just vector huge_pte_*() calls to the pte_*() implementations won't work in certain situations. x86 and sparc, for example, return "unsigned long" from the bit checks, and just go "return pte_val(pte) & PTE_BIT_FOO;" But since huge_pte_*() returns 'int', if any high bits on 64-bit are relevant, they get chopped off. The net effect is that we can loop forever trying to COW a huge page, because the huge_pte_write() check signals false all the time. Reported-by: Gurudas Pai Tested-by: Gurudas Pai Signed-off-by: David S. Miller Acked-by: David Rientjes Signed-off-by: Greg Kroah-Hartman --- include/asm-generic/hugetlb.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/include/asm-generic/hugetlb.h +++ b/include/asm-generic/hugetlb.h @@ -6,12 +6,12 @@ static inline pte_t mk_huge_pte(struct p return mk_pte(page, pgprot); } -static inline int huge_pte_write(pte_t pte) +static inline unsigned long huge_pte_write(pte_t pte) { return pte_write(pte); } -static inline int huge_pte_dirty(pte_t pte) +static inline unsigned long huge_pte_dirty(pte_t pte) { return pte_dirty(pte); }