linux-kernel - Re: [PATCH 3/4] char/tpm: Improve a size determination in nine functions

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Date:   Fri, 20 Oct 2017 13:23:51 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To:     Alexander.Steffen@...ineon.com
Cc:     andriy.shevchenko@...ux.intel.com, elfring@...rs.sourceforge.net,
        linux-integrity@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        benh@...nel.crashing.org, clabbe.montjoie@...il.com,
        jgunthorpe@...idianresearch.com, jsnitsel@...hat.com,
        kgold@...ux.vnet.ibm.com, mpe@...erman.id.au,
        nayna@...ux.vnet.ibm.com, paulus@...ba.org, PeterHuewe@....de,
        stefanb@...ux.vnet.ibm.com, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org
Subject: Re: [PATCH 3/4] char/tpm: Improve a size determination in nine
 functions

On Fri, Oct 20, 2017 at 12:01:39PM +0300, Jarkko Sakkinen wrote:
> On Thu, Oct 19, 2017 at 04:58:23PM +0000, Alexander.Steffen@...ineon.com wrote:
> > > On Tue, Oct 17, 2017 at 11:50:05AM +0000, Alexander.Steffen@...ineon.com
> > > wrote:
> > > > > > Replace the specification of data structures by pointer dereferences
> > > > > > as the parameter for the operator "sizeof" to make the corresponding
> > > > > > size
> > > > > > determination a bit safer according to the Linux coding style
> > > > > > convention.
> > > > >
> > > > >
> > > > > This patch does one style in favor of the other.
> > > >
> > > > I actually prefer that style, so I'd welcome this change :)
> > > >
> > > > > At the end it's Jarkko's call, though I would NAK this as I think some
> > > > > one already told this to you for some other similar patch(es).
> > > > >
> > > > >
> > > > > I even would suggest to stop doing this noisy stuff, which keeps people
> > > > > busy for nothing.
> > > >
> > > > Cleaning up old code is also worth something, even if does not change
> > > > one bit in the assembly output in the end...
> > > >
> > > > Alexander
> > > 
> > > Quite insignificant clean up it is that does more harm that gives any
> > > benefit as any new change adds debt to backporting.
> > > 
> > > Anyway, this has been a useful patch set for me in the sense that I have
> > > clearer picture now on discarding/accepting commits.
> > 
> > Indeed. I have now a better understanding for why some code looks as
> > ugly as it does.
> > 
> > > One line minor
> > > clean up will be from now on automatic NAK unless it causes a compiler
> > > warning or some other visible side-effect.
> > 
> > Not a nice policy, but at least a policy. I have deleted the tasks
> > that I had still planned for other cleanup activities.
> > 
> > Alexander
> 
> 1/4 and 2/4 are sensible clean ups as long as the commit message is
> refined.
> 
> Moving more functions to use tpm_buf instead of nasty tpm_cmd_t are
> also welcome changes.
> 
> Documenting functions (exported mainly) is also welcome. Or refining
> documentation.
> 
> It's really case by case. The important thing in small clean ups is
> a clearly written commit message that explains rationale.
> 
> /Jarkko

It's easy to say in retroperpective that code is "ugly". I would use
strong consideration before using that adjective for mainline code.
Rarely when you do something new first the form will be polished.

I was too steep with the policy above. It's not exactly like that in the
strict sense. It's always case by case like for any commit. However, it
is good to remember that "ugliness" does not cause regressions.

/Jarkko