[dpdk-dev] [PATCH v1 2/3] net/hyperv: implement core functionality

[Adrien Mazarguil]

On Tue, Dec 19, 2017 at 09:53:27AM +0000, Bruce Richardson wrote:
> On Mon, Dec 18, 2017 at 09:23:41PM +0100, Adrien Mazarguil wrote:
> > On Mon, Dec 18, 2017 at 10:34:12AM -0800, Stephen Hemminger wrote:
> > > On Mon, 18 Dec 2017 17:46:23 +0100
> > > Adrien Mazarguil <adrien.mazarguil at 6wind.com> wrote:
> > > 
> <snip>
> > > > +static int
> > > > +hyperv_iface_is_netvsc(const struct if_nameindex *iface)
> > > > +{
> > > > +	static const char temp[] = "/sys/class/net/%s/device/class_id";
> > > > +	char path[snprintf(NULL, 0, temp, iface->if_name) + 1];
> > > 
> > > Doing this snprintf is gross. Either use PATH_MAX or asprintf
> > 
> > I don't think allocating more stack space than necessary or on the heap with
> > a possible allocation failure to deal with is any better, sorry.
> > 
> > Prove this snprintf() call can fail and you'll have a point.
> > 
> While I get your point, I'd tend to go with Stephen's view on this that
> it's looking a bit "gross". What's the problem with allocating a bit
> more stack space for it?

Well, apart from making a stand, none really. Too "unusual" perhaps, but I
don't think "gross" is a valid argument to reject a perfectly valid piece of
code that doesn't rely on obscure knowledge nor weird side effects.

I'll update this in v2 to make it look more acceptable in any case.

-- 
Adrien Mazarguil
6WIND