On Fri, Nov 17, 2017 at 02:38:31PM +0100, Johan Hovold wrote:
> Fix child-node lookup during initialisation which was using the wrong
> OF-helper and ended up searching the whole device tree depth-first
> starting at the parent rather than just matching on its children.
>
> To make things worse, the parent pci node could end up being prematurely
> freed as of_find_node_by_name() drops a reference to its first argument.
> Any matching child interrupt-controller node was also leaked.
>
> Fixes: 0c4ffcfe1fbc ("PCI: keystone: Add TI Keystone PCIe driver")
> Cc: stable <stable@xxxxxxxxxxxxxxx> # 3.18
> Acked-by: Murali Karicheri <m-karicheri2@xxxxxx>
> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> ---
Applied to pci/keystone for v4.16.
Thanks,
Lorenzo
> v2
> - amend commit message and mention explicitly that of_find_node_by_name()
> drops a reference to the start node
> - add Murali's and Lorenzo's acks
>
>
> drivers/pci/dwc/pci-keystone.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/dwc/pci-keystone.c b/drivers/pci/dwc/pci-keystone.c
> index 5bee3af47588..39405598b22d 100644
> --- a/drivers/pci/dwc/pci-keystone.c
> +++ b/drivers/pci/dwc/pci-keystone.c
> @@ -178,7 +178,7 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
> }
>
> /* interrupt controller is in a child node */
> - *np_temp = of_find_node_by_name(np_pcie, controller);
> + *np_temp = of_get_child_by_name(np_pcie, controller);
> if (!(*np_temp)) {
> dev_err(dev, "Node for %s is absent\n", controller);
> return -EINVAL;
> @@ -187,6 +187,7 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
> temp = of_irq_count(*np_temp);
> if (!temp) {
> dev_err(dev, "No IRQ entries in %s\n", controller);
> + of_node_put(*np_temp);
> return -EINVAL;
> }
>
> @@ -204,6 +205,8 @@ static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
> break;
> }
>
> + of_node_put(*np_temp);
> +
> if (temp) {
> *num_irqs = temp;
> return 0;
> --
> 2.15.0
>