From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f193.google.com ([209.85.220.193]:46585 "EHLO mail-qk0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751127AbeABSoc (ORCPT ); Tue, 2 Jan 2018 13:44:32 -0500 Received: by mail-qk0-f193.google.com with SMTP id b132so32466205qkc.13 for ; Tue, 02 Jan 2018 10:44:32 -0800 (PST) Subject: Re: Regression: NULL pointer dereference caused by iproc_pcie_map_dma_ranges To: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= Cc: Oza Oza , Bjorn Helgaas , Scott Branden , Linux PCI , bcm-kernel-feedback-list , Jon Mason , Hauke Mehrtens References: From: Ray Jui Message-ID: <6707e532-7a5e-261c-4d5b-950d0ccc8f66@broadcom.com> Date: Tue, 2 Jan 2018 10:44:27 -0800 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: Hi Rafal, Can you please give the following patch a try to see if that fixes the issue? Thanks. From f91de124bc8fb5645d7dbbfd68a9a68617955749 Mon Sep 17 00:00:00 2001 From: Ray Jui Date: Tue, 2 Jan 2018 10:36:03 -0800 Subject: [PATCH] PCI: iproc: Fix NULL pointer dereference for BCMA With the inbound DMA mapping supported added, the iProc PCIe driver parses DT property "dma-ranges" through call to "of_pci_dma_range_parser_init". In the case of BCMA, this results in a NULL pointer deference due to a missing of_node. Fix this by adding a guard in pcie-iproc-platform.c to only enable the inbound DMA mapping logic when DT property "dma-ranges" is present fixes: dd9d4e7498de3 ("PCI: iproc: Add inbound DMA mapping support") Signed-off-by: Ray Jui --- drivers/pci/host/pcie-iproc-platform.c | 3 +++ drivers/pci/host/pcie-iproc.c | 8 +++++--- drivers/pci/host/pcie-iproc.h | 2 ++ 3 files changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/pci/host/pcie-iproc-platform.c b/drivers/pci/host/pcie-iproc-platform.c index a5073a9..235c545 100644 --- a/drivers/pci/host/pcie-iproc-platform.c +++ b/drivers/pci/host/pcie-iproc-platform.c @@ -92,6 +92,9 @@ static int iproc_pcie_pltfm_probe(struct platform_device *pdev) pcie->need_ob_cfg = true; } + if (of_property_read_bool(np, "dma-ranges")) + pcie->need_ib_cfg = true; + /* PHY use is optional */ pcie->phy = devm_phy_get(dev, "pcie-phy"); if (IS_ERR(pcie->phy)) { diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c index 935909b..7583606 100644 --- a/drivers/pci/host/pcie-iproc.c +++ b/drivers/pci/host/pcie-iproc.c @@ -1378,9 +1378,11 @@ int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res) } } - ret = iproc_pcie_map_dma_ranges(pcie); - if (ret && ret != -ENOENT) - goto err_power_off_phy; + if (pcie->need_ib_cfg) { + ret = iproc_pcie_map_dma_ranges(pcie); + if (ret && ret != -ENOENT) + goto err_power_off_phy; + } #ifdef CONFIG_ARM pcie->sysdata.private_data = pcie; diff --git a/drivers/pci/host/pcie-iproc.h b/drivers/pci/host/pcie-iproc.h index a6b55ce..4ac6282 100644 --- a/drivers/pci/host/pcie-iproc.h +++ b/drivers/pci/host/pcie-iproc.h @@ -74,6 +74,7 @@ struct iproc_msi; * @ob: outbound mapping related parameters * @ob_map: outbound mapping related parameters specific to the controller * + * @need_ib_cfg: indicates SW needs to configure the inbound mapping window * @ib: inbound mapping related parameters * @ib_map: outbound mapping region related parameters * @@ -101,6 +102,7 @@ struct iproc_pcie { struct iproc_pcie_ob ob; const struct iproc_pcie_ob_map *ob_map; + bool need_ib_cfg; struct iproc_pcie_ib ib; const struct iproc_pcie_ib_map *ib_map; -- 2.1.4 On 12/29/2017 2:34 PM, Rafał Miłecki wrote: > Hi, I just updated from kernel 4.9 to 4.14 and found a NULL pointer > dereference caused by the iproc driver. > > 1) For bcma case pcie->dev->of_node can be NULL > 2) iproc_pcie_map_dma_ranges calls pci_dma_range_parser_init > 3) pci_dma_range_parser_init calls of_n_addr_cells(node) (node is NULL) > > This is caused by a commit dd9d4e7498de3 ("PCI: iproc: Add inbound DMA > mapping support"). > > I believe that new DMA mapping code should be optional. > > Would you find a moment to fix that, please? >