[PATCH 1/5] net: Introduce DSA class for Ethernet switches

[Tom Rini]

On Tue, Jan 19, 2021 at 11:06:10AM -0700, Simon Glass wrote:
> Hi Claudiu,
> 
> On Fri, 15 Jan 2021 at 09:47, Claudiu Manoil <claudiu.manoil at nxp.com> wrote:
> >
> > >-----Original Message-----
> > >From: Simon Glass <sjg at chromium.org>
> > >Sent: Thursday, January 14, 2021 5:42 PM
> > >To: Claudiu Manoil <claudiu.manoil at nxp.com>
> > >Cc: Joe Hershberger <joe.hershberger at ni.com>; Bin Meng
> > ><bmeng.cn at gmail.com>; Michael Walle <michael at walle.cc>; U-Boot Mailing
> > >List <u-boot at lists.denx.de>; Vladimir Oltean <vladimir.oltean at nxp.com>;
> > >Alexandru Marginean <alexandru.marginean at nxp.com>
> > >Subject: Re: [PATCH 1/5] net: Introduce DSA class for Ethernet switches
> > >
> > [...]
> > >
> > >Reviewed-by: Simon Glass <sjg at chromium.org>
> > >
> > >I don't think it is necessary to have the 'if (!pdev)' checks around
> > >the place. We need a way in U-Boot to have checks like that to catch
> > >programming errors  but to be able to turn them off in production code
> > >to reduce size.
> > >
> > >I suppose a Kconfig would do it, with:
> > >
> > >if (CONFIG_IS_ENABLED(SAFETY) && !pdev)
> > >    return log_,msg_ref("safety", -ENODEV)
> > >
> > >Also note that -ENODEV is used by drive rmodel so it generally isn't
> > >safe to return it as a logic error. I think in this case because it
> > >never happens, it should be OK.
> > >
> >
> > Thanks for the review, Simon.
> > I thought about using assert(pdev) checks, but during development the
> > simple "if (!pdev)..." proved more friendly.  I like your idea about enabling
> > the checks at compile time and disabling them in production.
> > For now, since this SAFETY flag is not implemented, my understanding is
> > that you’re ok with leaving the pdev checks in the code as they are right now
> > and sometime in the future these will be converted to the "SAFETY" construct
> > you mention.
> >
> 
> Yes that's fine, you have my review tag.
> 
> +Tom Rini what do you think about CONFIG_SAFETY or similar to allow
> these bug checks to be disabled for code-size reasons?

I don't know.  Setting aside the name, my first concern is "so we
disable certain forms of sanity checks, now assuming a malicious entity
somewhere, what's now able to be exploited?"

-- 
Tom
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