linux-kernel - Re: char-TPM: Adjustments for ten function implementations

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Message-ID: <20171018202745.383724bc@kitsune.suse.cz>
Date:   Wed, 18 Oct 2017 20:27:45 +0200
From:   Michal Suchánek <msuchanek@...e.de>
To:     Joe Perches <joe@...ches.com>
Cc:     SF Markus Elfring <elfring@...rs.sourceforge.net>,
        linux-integrity@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        kernel-janitors@...r.kernel.org,
        Stefan Berger <stefanb@...ux.vnet.ibm.com>,
        Nayna Jain <nayna@...ux.vnet.ibm.com>,
        Jerry Snitselaar <jsnitsel@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
        Jason Gunthorpe <jgunthorpe@...idianresearch.com>,
        Corentin Labbe <clabbe.montjoie@...il.com>,
        James Bottomley <James.Bottomley@...senPartnership.comg>,
        Paul Mackerras <paulus@...ba.org>,
        Peter Hüwe <PeterHuewe@....de>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Dan Carpenter <dan.carpenter@...cle.com>,
        Kenneth Goldman <kgold@...ux.vnet.ibm.com>
Subject: Re: char-TPM: Adjustments for ten function implementations

On Wed, 18 Oct 2017 02:18:46 -0700
Joe Perches <joe@...ches.com> wrote:

> On Wed, 2017-10-18 at 11:00 +0200, SF Markus Elfring wrote:
> > > The printk removals do change the objects.
> > > 
> > > The value of that type of change is only for resource limited
> > > systems.  
> > 
> > I imagine that such small code adjustments are also useful for
> > other systems.  
> 
> Your imagination and mine differ.
> Where do you _think_ it matters?
> 
> For instance, nothing about
> 
> 	sizeof(type)
> vs
> 	sizeof(*ptr)
> 
> makes it easier for a human to read the code.
> 

However, it makes it less error-prone to modify the code.

If you do ptr = malloc(sizeof(*ptr)) and later you change the type of
the pointer the code is still correct whereas ptr = malloc(sizeof(some
type) no longer is.

That is the reason the source analysis tool warns about this usage and
you do not really need any more explanation for *this* change.

The others are not so clear.

Thanks

Michal