On 23/03/2019 21:04, Aditya Pakki wrote:
In case __get_free_pages fail, the fix returns error upstream
to avoid NULL pointer dereference.
Where does msi_pages ever get dereferenced?
The logic here might actually still have a chance of working out OK with
NULL depending on how the memory maps line up, but even if it doesn't,
the problem is certainly not one of dereferencing.
Robin.
Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>
---
v1: Return error upstream as suggested by Steven
---
drivers/pci/controller/pcie-xilinx.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/pcie-xilinx.c b/drivers/pci/controller/pcie-xilinx.c
index 9bd1a35cd5d8..91d8945bfb0c 100644
--- a/drivers/pci/controller/pcie-xilinx.c
+++ b/drivers/pci/controller/pcie-xilinx.c
@@ -335,15 +335,19 @@ static const struct irq_domain_ops msi_domain_ops = {
/**
* xilinx_pcie_enable_msi - Enable MSI support
* @port: PCIe port information
+ * Return: 0 on success, negative error on failure
*/
-static void xilinx_pcie_enable_msi(struct xilinx_pcie_port *port)
+static int xilinx_pcie_enable_msi(struct xilinx_pcie_port *port)
{
phys_addr_t msg_addr;
port->msi_pages = __get_free_pages(GFP_KERNEL, 0);
+ if (!port->msi_pages)
+ return -ENOMEM;
msg_addr = virt_to_phys((void *)port->msi_pages);
pcie_write(port, 0x0, XILINX_PCIE_REG_MSIBASE1);
pcie_write(port, msg_addr, XILINX_PCIE_REG_MSIBASE2);
+ return 0;
}
/* INTx Functions */
@@ -498,6 +502,7 @@ static int xilinx_pcie_init_irq_domain(struct xilinx_pcie_port *port)
struct device *dev = port->dev;
struct device_node *node = dev->of_node;
struct device_node *pcie_intc_node;
+ int ret;
/* Setup INTx */
pcie_intc_node = of_get_next_child(node, NULL);
@@ -526,7 +531,9 @@ static int xilinx_pcie_init_irq_domain(struct xilinx_pcie_port *port)
return -ENODEV;
}
- xilinx_pcie_enable_msi(port);
+ ret = xilinx_pcie_enable_msi(port);
+ if (ret)
+ return ret;
}
return 0;
