From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4BF4ECAAD3 for ; Wed, 14 Sep 2022 16:19:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229925AbiINQTu (ORCPT ); Wed, 14 Sep 2022 12:19:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229947AbiINQTr (ORCPT ); Wed, 14 Sep 2022 12:19:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D03F6617D for ; Wed, 14 Sep 2022 09:19:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7941361983 for ; Wed, 14 Sep 2022 16:19:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B09F8C433D6; Wed, 14 Sep 2022 16:19:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663172384; bh=gzUz6nLHWQZhe8Dhgb2CKpo8EjdQxRqjM4YKtKzAeJs=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=iKoEajK9zwe1BZx5Y66B80lEUD5vPlEaNXGlRT9jY8eExIxAGQlN85nciFJyfiSj3 bLd+pTI0N2p5mpfoNgADS4vS7T3jgHJJ/yMsHXclQN01mES192C3k9utBFWAUyHyV4 Zcd6Svl60DO4mlIdBJ+Ri3KWSyPg5pW5JAxRFxTl5sslvlEoH+rljQUtFiFwSV+ldm /2q+9BEvFn4Vz3IYdGg0tN6cjrUMgKaMWvSVravhkGFAS1bdDkWHgxTNC17H8nMrr0 i6Sdmj+FMeGNcU02sPY/vFowkzOKAZH/tClx0BbucPC6X4szPGb/IJEUy2b0jPDTTD H+uR92Z8GG6Yw== Date: Wed, 14 Sep 2022 11:19:42 -0500 From: Bjorn Helgaas To: Daniel Gomez Cc: "Deucher, Alexander" , "linux-pci@vger.kernel.org" , Thomas Gleixner , "Koenig, Christian" Subject: Re: PCI/MSI: kernel NULL pointer dereference Message-ID: <20220914161942.GA686189@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, Sep 08, 2022 at 04:30:28PM +0200, Daniel Gomez wrote: > On Thu, 8 Sept 2022 at 15:44, Deucher, Alexander > wrote: > > > -----Original Message----- > > > From: Bjorn Helgaas > > > Sent: Thursday, September 8, 2022 8:13 AM > > > To: Daniel Gomez > > > Cc: linux-pci@vger.kernel.org; Thomas Gleixner ; > > > Deucher, Alexander ; Koenig, Christian > > > > > > Subject: Re: PCI/MSI: kernel NULL pointer dereference > > > > > > On Thu, Sep 08, 2022 at 12:41:00PM +0200, Daniel Gomez wrote: > > > > Hi, > > > > > > > > I have the following error whenever I remove the fglrx module from the > > > > latest 6.0-rc4. > > > > > > You bisected to 93296cd1325d; I don't see a commit with a "Fixes:" > > > that references that. If you can reproduce this with an in-tree driver, we can > > > certainly fix it, but it's harder for an out-of-tree driver. > I understand, thanks. I tried with radeon but rmmod it is not possible > once it's loaded. A brute-force way to debug this would be to add logging to entry points in msi.c so you can see what MSI-related interfaces fglrx uses and in what order. Then you may be able to make a trivial module that does something similar that we could use as a test case so we could duplicate the failure and verify a fix. Bjorn