Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751534AbbKIXrT (ORCPT ); Mon, 9 Nov 2015 18:47:19 -0500 Received: from g2t2352.austin.hp.com ([15.217.128.51]:53230 "EHLO g2t2352.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750850AbbKIXrS (ORCPT ); Mon, 9 Nov 2015 18:47:18 -0500 Message-ID: <1447112591.21443.35.camel@hpe.com> Subject: Re: [PATCH] x86/mm: fix regression with huge pages on PAE From: Toshi Kani To: "Kirill A. Shutemov" , hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org Cc: bp@alien8.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, jgross@suse.com, konrad.wilk@oracle.com, elliott@hpe.com, boris.ostrovsky@oracle.com Date: Mon, 09 Nov 2015 16:43:11 -0700 In-Reply-To: <1447111090-8526-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1447111090-8526-1-git-send-email-kirill.shutemov@linux.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 (3.16.5-3.fc22) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2490 Lines: 60 On Tue, 2015-11-10 at 01:18 +0200, Kirill A. Shutemov wrote: > Recent PAT patchset has caused issue on 32-bit PAE machines: : > The problem is in pmd_pfn_mask() and pmd_flags_mask(). These helpers use > PMD_PAGE_MASK to calculate resulting mask. PMD_PAGE_MASK is 'unsigned > long', not 'unsigned long long' as physaddr_t. As result upper bits of > resulting mask is truncated. > > The patch reworks code to use PMD_SHIFT as base of mask calculation > instead of PMD_PAGE_MASK. > > pud_pfn_mask() and pud_flags_mask() aren't problematic since we don't > have PUD page table level on 32-bit systems, but they reworked too to be > consistent with PMD counterpart. > > Signed-off-by: Kirill A. Shutemov > Reported-and-Tested-by: Boris Ostrovsky > Fixes: f70abb0fc3da ("x86/asm: Fix pud/pmd interfaces to handle large PAT > bit") > Cc: Toshi Kani > --- > arch/x86/include/asm/pgtable_types.h | 14 ++++---------- > 1 file changed, 4 insertions(+), 10 deletions(-) > > diff --git a/arch/x86/include/asm/pgtable_types.h > b/arch/x86/include/asm/pgtable_types.h > index dd5b0aa9dd2f..c1e797266ce9 100644 > --- a/arch/x86/include/asm/pgtable_types.h > +++ b/arch/x86/include/asm/pgtable_types.h > @@ -279,17 +279,14 @@ static inline pmdval_t native_pmd_val(pmd_t pmd) > static inline pudval_t pud_pfn_mask(pud_t pud) > { > if (native_pud_val(pud) & _PAGE_PSE) > - return PUD_PAGE_MASK & PHYSICAL_PAGE_MASK; > + return ~((1ULL << PUD_SHIFT) - 1) & PHYSICAL_PAGE_MASK; Thanks for the fix! Should we fix the PMD/PUD MASK/SIZE macros, so that we do not hit the same issue again when they are used? --- a/arch/x86/include/asm/page_types.h +++ b/arch/x86/include/asm/page_types.h @@ -17,10 +17,10 @@ (ie, 32-bit PAE). */ #define PHYSICAL_PAGE_MASK (((signed long)PAGE_MASK) & __PHYSICAL_MASK) -#define PMD_PAGE_SIZE (_AC(1, UL) << PMD_SHIFT) +#define PMD_PAGE_SIZE (_AC(1, ULL) << PMD_SHIFT) #define PMD_PAGE_MASK (~(PMD_PAGE_SIZE-1)) -#define PUD_PAGE_SIZE (_AC(1, UL) << PUD_SHIFT) +#define PUD_PAGE_SIZE (_AC(1, ULL) << PUD_SHIFT) #define PUD_PAGE_MASK (~(PUD_PAGE_SIZE-1)) Thanks, -Toshi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/