From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 07 Sep 2005 14:40:44 +0100 (BST) Received: from extgw-uk.mips.com ([IPv6:::ffff:62.254.210.129]:46087 "EHLO bacchus.net.dhis.org") by linux-mips.org with ESMTP id ; Wed, 7 Sep 2005 14:40:23 +0100 Received: from dea.linux-mips.net (localhost.localdomain [127.0.0.1]) by bacchus.net.dhis.org (8.13.4/8.13.1) with ESMTP id j87DlJ1O012197; Wed, 7 Sep 2005 14:47:19 +0100 Received: (from ralf@localhost) by dea.linux-mips.net (8.13.4/8.13.4/Submit) id j87DlHR7012196; Wed, 7 Sep 2005 14:47:17 +0100 Date: Wed, 7 Sep 2005 14:47:17 +0100 From: Ralf Baechle To: "Maciej W. Rozycki" Cc: Atsushi Nemoto , linux-mips@linux-mips.org Subject: Re: unkillable process due to setup_frame() failure Message-ID: <20050907134717.GA3493@linux-mips.org> References: <20050907.014234.108739386.anemo@mba.ocn.ne.jp> <20050906184118.GC3102@linux-mips.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 8886 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Wed, Sep 07, 2005 at 10:14:16AM +0100, Maciej W. Rozycki wrote: > > > So, the process can not be kill by SIGKILL. In 2.6.12, 'sigkill > > > priority fix' was applied to __dequeue_signal(), but it does not help > > > while the SIGTRAP is queued to tsk->pending but SIGKILL (by kill > > > command) is queued to tsk->signal->shared_pending. > > > > The behaviour of not advancing the EPC beyond the faulting instruction is > > part of the problem - but I believe that was the usual behaviour for > > MIPS UNIXoid operating systems. > > Well, SIGKILL should always work and frankly I can't see a reason to > return back to user space in the affected context in the first place. > What's left in EPC shouldn't matter. I said it's part of the problem - not that it should be changed. The behaviour as far as I can say is also standard for MIPS unixoid operating systems. That said, I definately prefer the approach of Atushi's suggested fix #2. The other question is why we try to continue if delivering a signal failed and we already know that repeated attempts would fail again. Ralf