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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 B6BC5C433FF for ; Thu, 15 Aug 2019 10:56:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9833E21744 for ; Thu, 15 Aug 2019 10:56:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731194AbfHOK4L (ORCPT ); Thu, 15 Aug 2019 06:56:11 -0400 Received: from foss.arm.com ([217.140.110.172]:41894 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731176AbfHOK4L (ORCPT ); Thu, 15 Aug 2019 06:56:11 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4A9D328; Thu, 15 Aug 2019 03:56:10 -0700 (PDT) Received: from e121166-lin.cambridge.arm.com (unknown [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E9A053F694; Thu, 15 Aug 2019 03:56:08 -0700 (PDT) Date: Thu, 15 Aug 2019 11:56:04 +0100 From: Lorenzo Pieralisi To: Stefan Agner Cc: hongxing.zhu@nxp.com, l.stach@pengutronix.de, jingoohan1@gmail.com, gustavo.pimentel@synopsys.com, tpiepho@impinj.com, leonard.crestez@nxp.com, bhelgaas@google.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RESEND v8] PCI: imx6: limit DBI register length Message-ID: <20190815105604.GA11095@e121166-lin.cambridge.arm.com> References: <20190726144007.26605-1-stefan@agner.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190726144007.26605-1-stefan@agner.ch> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Jul 26, 2019 at 04:40:07PM +0200, Stefan Agner wrote: > Define the length of the DBI registers and limit config space to its > length. This makes sure that the kernel does not access registers > beyond that point, avoiding the following abort on a i.MX 6Quad: > # cat /sys/devices/soc0/soc/1ffc000.pcie/pci0000\:00/0000\:00\:00.0/config > [ 100.021433] Unhandled fault: imprecise external abort (0x1406) at 0xb6ea7000 > ... > [ 100.056423] PC is at dw_pcie_read+0x50/0x84 > [ 100.060790] LR is at dw_pcie_rd_own_conf+0x44/0x48 > ... > > Signed-off-by: Stefan Agner > --- > Changes in v3: > - Rebase on pci/dwc > Changes in v4: > - Rebase on pci/dwc > Changes in v5: > - Rebased ontop of pci/dwc > - Use DBI length of 0x200 > Changes in v6: > - Use pci_dev.cfg_size mechanism to limit config space (this made patch 1 > of previous versions of this patchset obsolete). > Changes in v7: > - Restrict fixup to Synopsys/0xabcd > - Apply cfg_size limitation only if dbi_length is specified > Changes in v8: > - Restrict fixup for Synopsys/0xabcd and class PCI bridge > - Check device driver to be pci-imx6 > > drivers/pci/controller/dwc/pci-imx6.c | 33 +++++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) Applied to pci/imx for v5.4. Thanks, Lorenzo > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 9b5cb5b70389..8b8efa3063f5 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -57,6 +57,7 @@ enum imx6_pcie_variants { > struct imx6_pcie_drvdata { > enum imx6_pcie_variants variant; > u32 flags; > + int dbi_length; > }; > > struct imx6_pcie { > @@ -1212,6 +1213,7 @@ static const struct imx6_pcie_drvdata drvdata[] = { > .variant = IMX6Q, > .flags = IMX6_PCIE_FLAG_IMX6_PHY | > IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE, > + .dbi_length = 0x200, > }, > [IMX6SX] = { > .variant = IMX6SX, > @@ -1254,6 +1256,37 @@ static struct platform_driver imx6_pcie_driver = { > .shutdown = imx6_pcie_shutdown, > }; > > +static void imx6_pcie_quirk(struct pci_dev *dev) > +{ > + struct pci_bus *bus = dev->bus; > + struct pcie_port *pp = bus->sysdata; > + > + /* Bus parent is the PCI bridge, its parent is this platform driver */ > + if (!bus->dev.parent || !bus->dev.parent->parent) > + return; > + > + /* Make sure we only quirk devices associated with this driver */ > + if (bus->dev.parent->parent->driver != &imx6_pcie_driver.driver) > + return; > + > + if (bus->number == pp->root_bus_nr) { > + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); > + struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci); > + > + /* > + * Limit config length to avoid the kernel reading beyond > + * the register set and causing an abort on i.MX 6Quad > + */ > + if (imx6_pcie->drvdata->dbi_length) { > + dev->cfg_size = imx6_pcie->drvdata->dbi_length; > + dev_info(&dev->dev, "Limiting cfg_size to %d\n", > + dev->cfg_size); > + } > + } > +} > +DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_SYNOPSYS, 0xabcd, > + PCI_CLASS_BRIDGE_PCI, 8, imx6_pcie_quirk); > + > static int __init imx6_pcie_init(void) > { > #ifdef CONFIG_ARM > -- > 2.22.0 >