From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:51817 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716AbcFDCxD (ORCPT ); Fri, 3 Jun 2016 22:53:03 -0400 Subject: Re: [added to the 4.1 stable tree] powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism To: "Guilherme G. Piccoli" References: <1464989831-16666-1-git-send-email-sasha.levin@oracle.com> <1464989831-16666-88-git-send-email-sasha.levin@oracle.com> <201606040233.u542T0jY033418@mx0a-001b2d01.pphosted.com> Cc: stable@vger.kernel.org, stable-commits@vger.kernel.org, Michael Ellerman , Gavin Shan From: Sasha Levin Message-ID: <57524280.2030606@oracle.com> Date: Fri, 3 Jun 2016 22:52:48 -0400 MIME-Version: 1.0 In-Reply-To: <201606040233.u542T0jY033418@mx0a-001b2d01.pphosted.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: On 06/03/2016 10:33 PM, Guilherme G. Piccoli wrote: > On 06/03/2016 06:36 PM, Sasha Levin wrote: >> From: "Guilherme G. Piccoli" >> >> This patch has been added to the 4.1 stable tree. If you have any >> objections, please let us know. >> >> =============== >> >> [ Upstream commit 8445a87f7092bc8336ea1305be9306f26b846d93 ] >> >> Commit 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn") >> changed the pci_dn struct by removing its EEH-related members. >> As part of this clean-up, DDW mechanism was modified to read the device >> configuration address from eeh_dev struct. >> >> As a consequence, now if we disable EEH mechanism on kernel command-line >> for example, the DDW mechanism will fail, generating a kernel oops by >> dereferencing a NULL pointer (which turns to be the eeh_dev pointer). >> >> This patch just changes the configuration address calculation on DDW >> functions to a manual calculation based on pci_dn members instead of >> using eeh_dev-based address. >> >> No functional changes were made. This was tested on pSeries, both >> in PHyp and qemu guest. >> >> Fixes: 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn") >> Cc: stable@vger.kernel.org # v3.4+ >> Reviewed-by: Gavin Shan >> Signed-off-by: Guilherme G. Piccoli >> Signed-off-by: Michael Ellerman >> Signed-off-by: Sasha Levin > > > Hi Sasha, thanks for letting me know. > > Unfortunately, this patch has an issue; the proposed fix is simple and was already sent to linuxppc-dev list by Gavin Shan. > > Link to the proposed fix (already tested): https://patchwork.ozlabs.org/patch/626492 > > Thanks, and sorry for the inconvenience. > Cheers, > > > Guilherme Hey Guilherme, Since the fix isn't in Linus's tree yet, I'll revert this commit from both 4.1 and 3.18 and re-add it into the next release. Thanks for the report. Thanks, Sasha