From 794a8604fe6e4a311373cde57a86ad4aab9d32b8 Mon Sep 17 00:00:00 2001
From: Niklas Cassel <niklas.cassel@axis.com>
Date: Mon, 3 Apr 2017 17:35:12 -0500
Subject: [PATCH] PCI: dwc: Fix dw_pcie_ops NULL pointer dereference
Fix a crash from dereferencing a NULL dw_pcie_ops pointer. For example,
on ARTPEC-6:
Unable to handle kernel NULL pointer dereference at virtual address 00000004
pgd = c0204000
[00000004] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.11.0-rc3-next-20170321 #1
Hardware name: Axis ARTPEC-6 Platform
task: db098000 task.stack: db096000
PC is at dw_pcie_writel_dbi+0x2c/0xd0
Prior to 442ec4c04d12 ("PCI: dwc: all: Split struct pcie_port into
host-only and core structures"), every driver had a struct pcie_host_ops
with function pointers, typically used as:
if (pp->ops->readl_rc)
return pp->ops->readl_rc(...);
442ec4c04d12 split struct pcie_host_ops into two pieces: struct
dw_pcie_host_ops and struct dw_pcie_ops, so the above became:
if (pci->ops->readl_dbi)
return pci->ops->readl_dbi(...);
But pcie-artpec6.c and pcie-designware-plat.c don't need the dw_pcie_ops
pointers and didn't supply a pci->ops struct, which leads to NULL pointer
dereferences.
Supply an empty struct dw_pcie_ops to avoid the NULL pointer dereferences.
[bhelgaas: changelog]
Fixes: 442ec4c04d12 ("PCI: dwc: all: Split struct pcie_port into host-only and core structures")
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Joao Pinto <jpinto@synopsys.com>
---
drivers/pci/dwc/pcie-artpec6.c | 4 ++++
drivers/pci/dwc/pcie-designware-plat.c | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/drivers/pci/dwc/pcie-artpec6.c b/drivers/pci/dwc/pcie-artpec6.c
index fcd3ef8458835..6d23683c0892f 100644
--- a/drivers/pci/dwc/pcie-artpec6.c
+++ b/drivers/pci/dwc/pcie-artpec6.c
@@ -234,6 +234,9 @@ static int artpec6_add_pcie_port(struct artpec6_pcie *artpec6_pcie,
return 0;
}
+static const struct dw_pcie_ops dw_pcie_ops = {
+};
+
static int artpec6_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -252,6 +255,7 @@ static int artpec6_pcie_probe(struct platform_device *pdev)
return -ENOMEM;
pci->dev = dev;
+ pci->ops = &dw_pcie_ops;
artpec6_pcie->pci = pci;
diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
index b6c832ba39dd6..f20d494922ab8 100644
--- a/drivers/pci/dwc/pcie-designware-plat.c
+++ b/drivers/pci/dwc/pcie-designware-plat.c
@@ -86,6 +86,9 @@ static int dw_plat_add_pcie_port(struct pcie_port *pp,
return 0;
}
+static const struct dw_pcie_ops dw_pcie_ops = {
+};
+
static int dw_plat_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -103,6 +106,7 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
return -ENOMEM;
pci->dev = dev;
+ pci->ops = &dw_pcie_ops;
dw_plat_pcie->pci = pci;
--
2.30.2