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 X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 340E6C282DD for ; Thu, 9 Jan 2020 14:22:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05D262082E for ; Thu, 9 Jan 2020 14:22:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="B/NJisdC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728406AbgAIOWV (ORCPT ); Thu, 9 Jan 2020 09:22:21 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:47798 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727854AbgAIOWV (ORCPT ); Thu, 9 Jan 2020 09:22:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=DxwGKPgO3D2IF3vBmmjgp81bFThWYwYhX5RdXbco5Vo=; b=B/NJisdCPQlvKBnTqKVFtn2Go NAg3mAMBmiN3dBFD8HAHKGw5ee+Ur9TD1HKyNvo+32i/1abY6CP2Ru/6fLY3gFHq209m04Xh3cBci jr+snZNNUC5MR+kYlsBiz5Ngw+VLANGRmFWYtq3EtsqFn5qW0eDDiEbjs60yj4kJ7m0O4pNs3v7Ie utaeWhVrty7kE6rbBn/yUyUiM1VnzaxNYRRGqLkyYvGe7XwQOT2pY6WFGk5flU9TqWIc2d5fFJYe8 xx/2P49Gsio08YULRWfK+RrcUVEVVrKoECNvRBcvCn6D7J7BS+1nm6Dsf119Q7sqpK77yOFgt9tio sKS2iXZew==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ipYhW-0005xu-97; Thu, 09 Jan 2020 14:22:18 +0000 Date: Thu, 9 Jan 2020 06:22:18 -0800 From: Christoph Hellwig To: Abdul Haleem Cc: linuxppc-dev , sachinp , linux-scsi , jcmvbkbc@gmail.com, linux-next , Oliver , "aneesh.kumar" , Brian King , manvanth , Christoph Hellwig Subject: Re: [linux-next/mainline][bisected 3acac06][ppc] Oops when unloading mpt3sas driver Message-ID: <20200109142218.GA16477@infradead.org> References: <1578489498.29952.11.camel@abdul> <1578560245.30409.0.camel@abdul.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1578560245.30409.0.camel@abdul.in.ibm.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-next-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On Thu, Jan 09, 2020 at 02:27:25PM +0530, Abdul Haleem wrote: > + CC Christoph Hellwig The only thing this commit changed for the dma coherent case (which ppc64 uses) is that we now look up the page to free by the DMA address instead of the virtual address passed in. Which suggests this call stack passes in a broken dma address. I suspect we somehow managed to disable the ppc iommu bypass mode after allocating memory, which would cause symptoms like this, and thus the commit is just exposing a pre-existing problem.