Received-SPF: pass (google.com: domain of linux-kernel+bounces-61189-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Date: Mon, 12 Feb 2024 09:10:38 +0100
From: Horatiu Vultur <horatiu.vultur@microchip.com>
To: Jakub Kicinski <kuba@kernel.org>
CC: <davem@davemloft.net>, <edumazet@google.com>, <pabeni@redhat.com>,
	<UNGLinuxDriver@microchip.com>, <netdev@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, Michal Swiatkowski
	<michal.swiatkowski@linux.intel.com>
Subject: Re: [PATCH net v2] lan966x: Fix crash when adding interface under a
 lag
Message-ID: <20240212081038.cbsb2exfmcxxntzq@DEN-DL-M31836.microchip.com>
References: <20240206123054.3052966-1-horatiu.vultur@microchip.com>
 <20240209135220.42e670d4@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Disposition: inline
In-Reply-To: <20240209135220.42e670d4@kernel.org>

The 02/09/2024 13:52, Jakub Kicinski wrote:

Hi Jakub,

> 
> On Tue, 6 Feb 2024 13:30:54 +0100 Horatiu Vultur wrote:
> >       for (lag = 0; lag < lan966x->num_phys_ports; ++lag) {
> > -             struct net_device *bond = lan966x->ports[lag]->bond;
> > +             struct lan966x_port *port = lan966x->ports[lag];
> >               int num_active_ports = 0;
> > +             struct net_device *bond;
> >               unsigned long bond_mask;
> >               u8 aggr_idx[16];
> >
> > -             if (!bond || (visited & BIT(lag)))
> > +             if (!port || !port->bond || (visited & BIT(lag)))
> >                       continue;
> >
> > +             bond = port->bond;
> >               bond_mask = lan966x_lag_get_mask(lan966x, bond);
> >
> >               for_each_set_bit(p, &bond_mask, lan966x->num_phys_ports) {
> >                       struct lan966x_port *port = lan966x->ports[p];
> >
> > +                     if (!port)
> > +                             continue;
> 
> Why would lan966x_lag_get_mask() set a bit for a port that doesn't
> exist? Earlier check makes sense. This one seems too defensive.

You are right, the lan966x_lag_get_mask() will not set a bit for a port
that doesn't exist[1]. Therefore this check is not needed.

[1] https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/microchip/lan966x/lan966x_lag.c#L354

> --
> pw-bot: cr

-- 
/Horatiu