From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030515AbWKOOyJ (ORCPT ); Wed, 15 Nov 2006 09:54:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030525AbWKOOyI (ORCPT ); Wed, 15 Nov 2006 09:54:08 -0500 Received: from public.id2-vpn.continvity.gns.novell.com ([195.33.99.129]:12695 "EHLO emea1-mh.id2.novell.com") by vger.kernel.org with ESMTP id S1030515AbWKOOyG (ORCPT ); Wed, 15 Nov 2006 09:54:06 -0500 Message-Id: <455B3868.76E4.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 7.0.1 Date: Wed, 15 Nov 2006 14:55:20 +0000 From: "Jan Beulich" To: Subject: [PATCH] i386: clear_fixmap() should not use set_pte() Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org While not strictly required with the current code (as the upper half of page table entries generated by __set_fixmap() cannot be non-zero due to the second parameter of this function being 'unsigned long'), the use of set_pte() in __set_fixmap() in the context of clear_fixmap() is still improper with CONFIG_X86_PAE (see the respective comment in include/asm-i386/pgtable-3level.h) and would turn into a bug if that second parameter ever gets changed to a 64-bit type. Signed-off-by: Jan Beulich --- linux-2.6.19-rc5/arch/i386/mm/pgtable.c 2006-11-08 09:21:37.000000000 +0100 +++ 2.6.19-rc5-i386-clear_fixmap/arch/i386/mm/pgtable.c 2006-11-06 12:13:29.000000000 +0100 @@ -95,8 +95,11 @@ static void set_pte_pfn(unsigned long va return; } pte = pte_offset_kernel(pmd, vaddr); - /* stored as-is, to permit clearing entries */ - set_pte(pte, pfn_pte(pfn, flags)); + if (pgprot_val(flags)) + /* stored as-is, to permit clearing entries */ + set_pte(pte, pfn_pte(pfn, flags)); + else + pte_clear(&init_mm, vaddr, pte); /* * It's enough to flush this one mapping.