linux-kernel - Re: [PATCH net-next v5 2/6] net: usb: lan78xx: Convert to PHYlink for improved PHY and MAC management

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Z-L1ap2HNc7apxHd@shell.armlinux.org.uk>
Date: Tue, 25 Mar 2025 18:26:50 +0000
From: "Russell King (Oracle)" <linux@...linux.org.uk>
To: Rengarajan.S@...rochip.com
Cc: andrew+netdev@...n.ch, davem@...emloft.net, Thangaraj.S@...rochip.com,
	Woojung.Huh@...rochip.com, pabeni@...hat.com,
	o.rempel@...gutronix.de, edumazet@...gle.com, kuba@...nel.org,
	phil@...pberrypi.org, kernel@...gutronix.de, horms@...nel.org,
	linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
	UNGLinuxDriver@...rochip.com, maxime.chevallier@...tlin.com
Subject: Re: [PATCH net-next v5 2/6] net: usb: lan78xx: Convert to PHYlink
 for improved PHY and MAC management

On Tue, Mar 25, 2025 at 05:37:53PM +0000, Rengarajan.S@...rochip.com wrote:
> Hi Oleksji,
> 
> On Wed, 2025-03-19 at 09:49 +0100, Oleksij Rempel wrote:
> >         udev = interface_to_usbdev(intf);
> >         net = dev->net;
> > 
> > +       rtnl_lock();
> > +       phylink_stop(dev->phylink);
> > +       phylink_disconnect_phy(dev->phylink);
> > +       rtnl_unlock();
> > +
> > +       netif_napi_del(&dev->napi);
> > +
> >         unregister_netdev(net);
> > 
> >         timer_shutdown_sync(&dev->stat_monitor);
> >         set_bit(EVENT_DEV_DISCONNECT, &dev->flags);
> >         cancel_delayed_work_sync(&dev->wq);
> > 
> > -       phydev = net->phydev;
> > -
> > -       phy_disconnect(net->phydev);
> > -
> > -       if (phy_is_pseudo_fixed_link(phydev)) {
> > -               fixed_phy_unregister(phydev);
> > -               phy_device_free(phydev);
> > -       }
> > +       phylink_destroy(dev->phylink);
> 
> Before destroying phylink here is it possible to add a check to make
> sure dev->phylink is allocated properly.

Not necessary.

How would dev->phylink not be "allocated properly" ?

If it isn't "allocated properly" then lan78xx_phylink_setup() will
return an error, which will cause lan78xx_probe() to fail. If the
probe function fails, then the driver won't be bound.

Having additional nonsense checks for things that shouldn't ever
happen is annying and detracts from code readability.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!