Re: [PATCH] soc: qcom: pmic_glink_altmode: Fix printing of a fwnode with %pOFn

[Konrad Dybcio]

On 11/2/26 1:33 AM, Asdlerto Korry wrote:
> pmic_glink_altmode_probe() walks the child nodes with
> device_for_each_child_node(), which yields a struct fwnode_handle, but
> prints it with %pOFn, which expects a struct device_node. vsprintf then
> treats the fwnode_handle as a device_node and passes &dn->fwnode to
> fwnode_get_name(), i.e. a pointer into the middle of the handle, and
> calls through a garbage fwnode->ops. The error path ("missing reg
> property") therefore oopses instead of printing the message:
> 
>   lr : fwnode_get_name+0x34/0x50
>   ...
>   device_node_string
>   pointer
>   vsnprintf
>   ...
>   pmic_glink_altmode_probe
> 
> It was hit on a Samsung Galaxy M52 5G (SM7325) whose vendor device tree
> has an extra "qcom,pmic-glink" compatible node without a reg property.

FWIW Vendor DTs are not supposed to work with the upstream kernel
(because they diverge so much from the upstream dt-bindings)> 
> Use %pfwP, the specifier for the name of a fwnode.
> 
> Fixes: 080b4e24852b ("soc: qcom: pmic_glink: Introduce altmode support")
> Signed-off-by: Asdlerto Korry <korryasdlerto@xxxxxxxxx>
> ---

But the issue and fix are of course real and valid

Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>

Konrad

>  drivers/soc/qcom/pmic_glink_altmode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/qcom/pmic_glink_altmode.c b/drivers/soc/qcom/pmic_glink_altmode.c
> index 465e5d2316a0..6f3737b096cf 100644
> --- a/drivers/soc/qcom/pmic_glink_altmode.c
> +++ b/drivers/soc/qcom/pmic_glink_altmode.c
> @@ -596,7 +596,7 @@ static int pmic_glink_altmode_probe(struct auxiliary_device *adev,
>  	device_for_each_child_node(dev, fwnode) {
>  		ret = fwnode_property_read_u32(fwnode, "reg", &port);
>  		if (ret < 0) {
> -			dev_err(dev, "missing reg property of %pOFn\n", fwnode);
> +			dev_err(dev, "missing reg property of %pfwP\n", fwnode);
>  			fwnode_handle_put(fwnode);
>  			return ret;
>  		}