From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx155.postini.com [74.125.245.155]) by kanga.kvack.org (Postfix) with SMTP id 7D9636B0038 for ; Sun, 28 Apr 2013 15:37:50 -0400 (EDT) Received: from /spool/local by e28smtp06.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 29 Apr 2013 01:02:23 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 98F2B3940058 for ; Mon, 29 Apr 2013 01:07:45 +0530 (IST) Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r3SJbc809109916 for ; Mon, 29 Apr 2013 01:07:38 +0530 Received: from d28av03.in.ibm.com (loopback [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r3SJbihD003098 for ; Mon, 29 Apr 2013 05:37:45 +1000 From: "Aneesh Kumar K.V" Subject: [PATCH -V7 07/18] powerpc: Don't truncate pgd_index wrongly Date: Mon, 29 Apr 2013 01:07:28 +0530 Message-Id: <1367177859-7893-8-git-send-email-aneesh.kumar@linux.vnet.ibm.com> In-Reply-To: <1367177859-7893-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1367177859-7893-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: benh@kernel.crashing.org, paulus@samba.org, dwg@au1.ibm.com, linux-mm@kvack.org Cc: linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" From: "Aneesh Kumar K.V" With PGD_INDEX_SIZE set to 12 the existing macro doesn't work. Fix it to use PTRS_PER_PGD The idea originally was to have one more bit in the result of pgd_index() than PGD_INDEX_SIZE, so that if one had an address corresponding to the last PGD entry, and then incremented that address by PGD_SIZE, and took pgd_index() of that, you wouldn't end up with zero. The commit that introduced that dates back to 2002, and the code that was sensitive to that edge case has long since been refactored (several times), so there is no need for it these days. Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/include/asm/pgtable-ppc64.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h index 0182c20..e3d55f6f 100644 --- a/arch/powerpc/include/asm/pgtable-ppc64.h +++ b/arch/powerpc/include/asm/pgtable-ppc64.h @@ -167,8 +167,7 @@ * Find an entry in a page-table-directory. We combine the address region * (the high order N bits) and the pgd portion of the address. */ -/* to avoid overflow in free_pgtables we don't use PTRS_PER_PGD here */ -#define pgd_index(address) (((address) >> (PGDIR_SHIFT)) & 0x1ff) +#define pgd_index(address) (((address) >> (PGDIR_SHIFT)) & (PTRS_PER_PGD - 1)) #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address)) -- 1.8.1.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org