From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264888AbTFQSr3 (ORCPT ); Tue, 17 Jun 2003 14:47:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264889AbTFQSr2 (ORCPT ); Tue, 17 Jun 2003 14:47:28 -0400 Received: from palrel13.hp.com ([156.153.255.238]:26346 "EHLO palrel13.hp.com") by vger.kernel.org with ESMTP id S264888AbTFQSr1 (ORCPT ); Tue, 17 Jun 2003 14:47:27 -0400 From: David Mosberger MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16111.25976.768140.306522@napali.hpl.hp.com> Date: Tue, 17 Jun 2003 12:01:12 -0700 To: "Aneesh Kumar K.V" Cc: "David S. Miller" , Russell King , davidm@hpl.hp.com, Linux Kernel List Subject: Re: force_successful_syscall_return() buggy? Newsgroups: fa.linux.kernel In-Reply-To: <3EEEBB1F.70609@digital.com> References: <3EEEBB1F.70609@digital.com> X-Mailer: VM 7.07 under Emacs 21.2.1 Reply-To: davidm@hpl.hp.com X-URL: http://www.hpl.hp.com/personal/David_Mosberger/ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>>>> On Tue, 17 Jun 2003 12:24:23 +0530, "Aneesh Kumar K.V" said: Aneesh> I was facing a simillar problem with ptrace on Alpha (ptrace Aneesh> on alpha expect the pt_regs at current + 2*PAGE_SIZE for Aneesh> 2.4. kernel ) w.r.t www.openssi.org project. What i found Aneesh> was that even after we return to user space subsequent Aneesh> syscalls are not putting pt_regs at that offset. I guess Aneesh> while entering the kernel kernel stack pointer always point Aneesh> to value stored in thread_struct.ksp ? If a platform doesn't start with an empty kernel stack on entry from user-space, that platform will be wasting (precious) stack space and ptrace() most likely won't work reliably. Personally, I'd consider such behavior a bug, but I suppose it is to some degree a platform-choice. --david