Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030584AbVKXCfP (ORCPT ); Wed, 23 Nov 2005 21:35:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030585AbVKXCfO (ORCPT ); Wed, 23 Nov 2005 21:35:14 -0500 Received: from ozlabs.org ([203.10.76.45]:4311 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S1030584AbVKXCfN (ORCPT ); Wed, 23 Nov 2005 21:35:13 -0500 Date: Thu, 24 Nov 2005 13:34:56 +1100 From: David Gibson To: Andrew Morton , Linus Torvalds Cc: linuxppc64-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: powerpc: More hugepage boundary case fixes Message-ID: <20051124023456.GA3024@localhost.localdomain> Mail-Followup-To: Andrew Morton , Linus Torvalds , linuxppc64-dev@ozlabs.org, linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4126 Lines: 86 Please apply, Blah. The patch [0] I recently sent fixing errors with in_hugepage_area() and prepare_hugepage_range() for powerpc itself has an off-by-one bug. Furthermore, the related functions touches_hugepage_*_range() and within_hugepage_*_range() are also buggy. Some of the bugs, like those addressed in [0] originated with commit 7d24f0b8a53261709938ffabe3e00f88f6498df9 where we tweaked the semantics of where hugepages are allowed. Other bugs have been there essentially forever, and are due to the undefined behaviour of '<<' with shift counts greater than the type width (LOW_ESID_MASK could return non-zero for high ranges with the right congruences). The good news is that I now have a testsuite which should pick up things like this if they creep in again. [0] "powerpc-fix-for-hugepage-areas-straddling-4gb-boundary" in -mm Signed-off-by: David Gibson Index: working-2.6/include/asm-powerpc/page_64.h =================================================================== --- working-2.6.orig/include/asm-powerpc/page_64.h 2005-11-24 11:15:38.000000000 +1100 +++ working-2.6/include/asm-powerpc/page_64.h 2005-11-24 13:09:28.000000000 +1100 @@ -103,8 +103,9 @@ extern unsigned int HPAGE_SHIFT; #define HTLB_AREA_SIZE (1UL << HTLB_AREA_SHIFT) #define GET_HTLB_AREA(x) ((x) >> HTLB_AREA_SHIFT) -#define LOW_ESID_MASK(addr, len) (((1U << (GET_ESID(addr+len-1)+1)) \ - - (1U << GET_ESID(addr))) & 0xffff) +#define LOW_ESID_MASK(addr, len) \ + (((1U << (GET_ESID(min((addr)+(len)-1, 0x100000000UL))+1)) \ + - (1U << GET_ESID(min((addr), 0x100000000UL)))) & 0xffff) #define HTLB_AREA_MASK(addr, len) (((1U << (GET_HTLB_AREA(addr+len-1)+1)) \ - (1U << GET_HTLB_AREA(addr))) & 0xffff) @@ -113,17 +114,21 @@ extern unsigned int HPAGE_SHIFT; #define ARCH_HAS_SETCLEAR_HUGE_PTE #define touches_hugepage_low_range(mm, addr, len) \ - (LOW_ESID_MASK((addr), (len)) & (mm)->context.low_htlb_areas) + (((addr) < 0x100000000UL) \ + && (LOW_ESID_MASK((addr), (len)) & (mm)->context.low_htlb_areas)) #define touches_hugepage_high_range(mm, addr, len) \ - (HTLB_AREA_MASK((addr), (len)) & (mm)->context.high_htlb_areas) + ((((addr) + (len)) > 0x100000000UL) \ + && (HTLB_AREA_MASK((addr), (len)) & (mm)->context.high_htlb_areas)) #define __within_hugepage_low_range(addr, len, segmask) \ - ((LOW_ESID_MASK((addr), (len)) | (segmask)) == (segmask)) + ( (((addr)+(len)) <= 0x100000000UL) \ + && ((LOW_ESID_MASK((addr), (len)) | (segmask)) == (segmask))) #define within_hugepage_low_range(addr, len) \ __within_hugepage_low_range((addr), (len), \ current->mm->context.low_htlb_areas) #define __within_hugepage_high_range(addr, len, zonemask) \ - ((HTLB_AREA_MASK((addr), (len)) | (zonemask)) == (zonemask)) + ( ((addr) >= 0x100000000UL) \ + && ((HTLB_AREA_MASK((addr), (len)) | (zonemask)) == (zonemask))) #define within_hugepage_high_range(addr, len) \ __within_hugepage_high_range((addr), (len), \ current->mm->context.high_htlb_areas) Index: working-2.6/arch/powerpc/mm/hugetlbpage.c =================================================================== --- working-2.6.orig/arch/powerpc/mm/hugetlbpage.c 2005-11-24 11:15:38.000000000 +1100 +++ working-2.6/arch/powerpc/mm/hugetlbpage.c 2005-11-24 13:18:41.000000000 +1100 @@ -295,7 +295,7 @@ int prepare_hugepage_range(unsigned long if (addr < 0x100000000UL) err = open_low_hpage_areas(current->mm, LOW_ESID_MASK(addr, len)); - if ((addr + len) >= 0x100000000UL) + if ((addr + len) > 0x100000000UL) err = open_high_hpage_areas(current->mm, HTLB_AREA_MASK(addr, len)); if (err) { -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson - 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/