Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757254AbZDEDtm (ORCPT ); Sat, 4 Apr 2009 23:49:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756940AbZDEDte (ORCPT ); Sat, 4 Apr 2009 23:49:34 -0400 Received: from mx2.redhat.com ([66.187.237.31]:59732 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750757AbZDEDtd (ORCPT ); Sat, 4 Apr 2009 23:49:33 -0400 Message-ID: <49D82A52.8050808@redhat.com> Date: Sat, 04 Apr 2009 23:49:38 -0400 From: Masami Hiramatsu User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Mathieu Desnoyers , Ingo Molnar CC: Ananth N Mavinakayanahalli , LKML , systemtap-ml Subject: Re: [BUG][-tip] kprobes on module functions hits kernel BUG in text_poke on x86-32 References: <49D76FFF.6020202@redhat.com> <20090404154230.GB2451@Krystal> <49D7A6DF.8080804@redhat.com> <49D7AF26.5030808@redhat.com> <49D82987.5090003@redhat.com> In-Reply-To: <49D82987.5090003@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1174 Lines: 38 Masami Hiramatsu wrote: > Hmm, ok. AFAICS, fixmap is only for lowmem, and pkmap is only for highmem. Oops, I mean kmap... > So, I think we have some options; > > A) Separate text_poke into __text_poke and __text_poke_highmem. And > use pkmap_atomic in __text_poke_highmem. This way doesn't require > any additional change except adding KM_TEXT_POKE0/1 in km_type. > > B) Add set_fixmap_page and use it in text_poke. This will require > changes in paravirt_ops and pgtable.c. We need to ensure there is > no side effects. > > C) Change pkmap_atomic_prot to map lowmem only if the page's pgprot > is different from user specified pgprot. And use it instead of > fixmap. This also requires KM_TEXT_POKE0/1, however we can > remove FIX_TEXT_POKE0/1. same, s/pkmap/kmap/g -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division e-mail: mhiramat@redhat.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/