Re: [PATCH] PCI: Clean up resource allocation in devm_of_pci_get_host_bridge_resources()

From: Andy Shevchenko
Date: Tue Jun 05 2018 - 12:27:04 EST


On Wed, May 16, 2018 at 3:31 PM, Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote:
> Instead of first allocating and then freeing memory for struct resource
> in case we cannot parse a PCI resource from the device tree, work
> against a local struct and kmemdup it when we decide to go with it.
>

Bjorn, any comments on this?

> Suggested-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> ---
> drivers/pci/of.c | 14 ++++++--------
> 1 file changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index b06585a1da75..fc0f906c5c25 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -266,7 +266,7 @@ int devm_of_pci_get_host_bridge_resources(struct device *dev,
> struct list_head *resources, resource_size_t *io_base)
> {
> struct device_node *dev_node = dev->of_node;
> - struct resource *res;
> + struct resource *res, tmp_res;
> struct resource *bus_range;
> struct of_pci_range range;
> struct of_pci_range_parser parser;
> @@ -320,18 +320,16 @@ int devm_of_pci_get_host_bridge_resources(struct device *dev,
> if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
> continue;
>
> - res = devm_kzalloc(dev, sizeof(struct resource), GFP_KERNEL);
> + err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
> + if (err)
> + continue;
> +
> + res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
> if (!res) {
> err = -ENOMEM;
> goto failed;
> }
>
> - err = of_pci_range_to_resource(&range, dev_node, res);
> - if (err) {
> - devm_kfree(dev, res);
> - continue;
> - }
> -
> if (resource_type(res) == IORESOURCE_IO) {
> if (!io_base) {
> dev_err(dev,
> --
> 2.13.6



--
With Best Regards,
Andy Shevchenko