From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262883AbVF3HLn (ORCPT ); Thu, 30 Jun 2005 03:11:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262884AbVF3HLn (ORCPT ); Thu, 30 Jun 2005 03:11:43 -0400 Received: from mx2.elte.hu ([157.181.151.9]:10661 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S262883AbVF3HLi (ORCPT ); Thu, 30 Jun 2005 03:11:38 -0400 Date: Thu, 30 Jun 2005 09:11:01 +0200 From: Ingo Molnar To: eliad lubovsky Cc: linux-kernel@vger.kernel.org Subject: Re: Handle kernel page faults using task gate Message-ID: <20050630071101.GB26239@elte.hu> References: <1119997135.4074.106.camel@localhost.localdomain> <20050629130901.GA29776@elte.hu> <20050629192740.GA5940@elte.hu> <1120114635.3422.2.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1120114635.3422.2.camel@localhost.localdomain> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * eliad lubovsky wrote: > How do I clear the 'busy' bit? > I set my TSS descriptor with > __set_tss_desc(cpu, GDT_ENTRY_PAGE_FAULT_TSS, &pagefault_tss); i suspect you have to clear the busy bit in the pagefault handler itself. The CPU marks it as busy upon fault. I guess it would be OK to just do the above __set_tss_desc() for _every_ pagefault, that too will clear the busy bit, but you are probably better off just clearing that bit manually: cpu_gdt_table[cpu][GDT_ENTRY_TSS].b &= 0xfffffdff; Ingo