Re: [PATCH 1/1] mcb: Do not add the mcb_bus_type to the mcb_bus itself

Greg Kroah-Hartman
2023-07-10T15:05:49Z

On Mon, Jul 10, 2023 at 04:57:52PM +0200, Johannes Thumshirn wrote:
> From: Rodríguez Barbarin, José Javier <JoseJavier.Rodriguez@duagon.com>

This does not match your signed-off-by line.

>
> When allocating a new mcb_bus the bus_type is added to the mcb_bus
> itself, causing an issue when calling mcb_bus_add_devices().
> This function is not only called for each mcb_device under the
> mcb_bus but for the bus itself.
>
> This causes a crash when freeing the ida resources as the bus numbering
> gets corrupted due to a wrong cast of structs mcb_bus and mcb_device.
>
> Make the release of the mcb devices and their mcb bus explicit.
>
> Co-developed-by: Jorge Sanjuan Garcia <jorge.sanjuangarcia@duagon.com>
> Signed-off-by: Jorge Sanjuan Garcia <jorge.sanjuangarcia@duagon.com>
> Signed-off-by: Javier Rodriguez <josejavier.rodriguez@duagon.com>
> Signed-off-by: Johannes Thumshirn <jth@kernel.org>
> ---

What commit id does this fix?

> drivers/mcb/mcb-core.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mcb/mcb-core.c b/drivers/mcb/mcb-core.c
> index 978fdfc19a06..d4535b8aea1d 100644
> --- a/drivers/mcb/mcb-core.c
> +++ b/drivers/mcb/mcb-core.c
> @@ -251,6 +251,12 @@ int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev)
> }
> EXPORT_SYMBOL_NS_GPL(mcb_device_register, MCB);
>
> +
> +static void mcb_bus_unregister(struct mcb_bus *bus)
> +{
> + device_unregister(&bus->dev);
> +}
> +
> static void mcb_free_bus(struct device *dev)
> {
> struct mcb_bus *bus = to_mcb_bus(dev);
> @@ -286,7 +292,6 @@ struct mcb_bus *mcb_alloc_bus(struct device *carrier)
>
> device_initialize(&bus->dev);
> bus->dev.parent = carrier;
> - bus->dev.bus = &mcb_bus_type;

So what bus type does this device now belong to?

> bus->dev.type = &mcb_carrier_device_type;
> bus->dev.release = &mcb_free_bus;
>
> @@ -322,6 +327,7 @@ static void mcb_devices_unregister(struct mcb_bus *bus)
> void mcb_release_bus(struct mcb_bus *bus)
> {
> mcb_devices_unregister(bus);
> + mcb_bus_unregister(bus);

thanks.

greg k-h