Re: [PATCH v2 4/4] net: mdio: Add RTL9300 MDIO driver

[Simon Horman <horms@kernel.org>]

+ Dan Carpenter

On Tue, Dec 17, 2024 at 10:47:10AM +1300, Chris Packham wrote:
> 
> On 17/12/2024 05:48, Simon Horman wrote:
> > On Mon, Dec 16, 2024 at 04:13:46PM +1300, Chris Packham wrote:
> > > Add a driver for the MDIO controller on the RTL9300 family of Ethernet
> > > switches with integrated SoC. There are 4 physical SMI interfaces on the
> > > RTL9300 but access is done using the switch ports so a single MDIO bus
> > > is presented to the rest of the system.
> > > 
> > > Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>

...

> > > +		if (smi_addr[0] > MAX_SMI_BUSSES)
> > Hi Chris,
> > 
> > Should this condition be
> > 
> > 		if (smi_addr[0] >= MAX_SMI_BUSSES)
> Yes. You are correct.
> > > +			return dev_err_probe(dev, -EINVAL, "illegal smi bus number %d\n",
> > > +					     smi_addr[0]);
> > > +
> > > +		if (smi_addr[1] > MAX_SMI_ADDR)
> > > +			return dev_err_probe(dev, -EINVAL, "illegal smi addr %d\n", smi_addr[1]);
> > > +
> > > +		if (fwnode_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
> > > +			priv->smi_bus_isc45[smi_addr[0]] = true;
> > Otherwise it seems that smi_bus_isc45 may overflow here.
> > 
> > Flagged by Smatch.
> 
> Sounds like something I should start looking at for myself. Have you got a
> link to share?

Hi Chris,

Smatch is here: https://github.com/error27/smatch
And my usage of it is informed by
https://blogs.oracle.com/linux/post/smatch-static-analysis-tool-overview-by-dan-carpenter

FWIIW, I run it usking kchecker on individual source files.

I've also CCed the author, Dan Carpenter, for good measure.

...