[U-Boot] [PATCH v3 2/3] dfu: ram support

Afzal Mohammed afzal.mohd.ma at gmail.com
Fri Sep 13 19:11:31 CEST 2013


+ Gerhard

On Fri, Sep 13, 2013 at 10:35:45PM +0530, Afzal Mohammed wrote:
> Hi Gerhard, Marek,
> 
> On Fri, Sep 13, 2013 at 05:37:36PM +0200, Gerhard Sittig wrote:
> > On Fri, Sep 13, 2013 at 15:51 +0200, Marek Vasut wrote:
> 
> > > > +	dfu->data.ram.size = simple_strtoul(++s, &s, 16);
> > > 
> > > This ++s, &s is quite crazy ;-)
> 
> > Actually it's not just a neat trick, but instead it's not
> > guaranteed to work.  It's an inviation for problems that you
> > don't need.
> > 
> > The order in which arguments for the call get evaluated isn't
> > specified, so behaviour is uncertain here.  Read: the
> > construction happens to work by coincidence for individual
> > setups, but isn't correct and need not work elsewhere, and may
> > break in arbitrary ways at any occasion, and then is hard to
> > track down since things may "seem to work" often enough or the
> > bug won't show up when you are diagnosing the problem.
> > 
> > The code needs to get fixed before getting picked up.  Doing the
> > increment in a separate instruction is cheap and simple, the
> > terse form is wrong.
> 
> Yes wrong me, I realize that result is compiler dependent and not
> guaranteed to work always, v4 posted taking care of the above.
> 
> Regards
> Afzal


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