Subject: Re: [PATCH net-next 01/11] ipv6: skb_put_zero() used to optimize code

From: Stephen Hemminger <[email-masked]>
Date: Wed, 14 Jun 2017 12:14:16 -0700

On Wed, 14 Jun 2017 21:01:32 +0200
Johannes Berg <[email-masked]> wrote:

> On Wed, 2017-06-14 at 08:44 -0700, Stephen Hemminger wrote:
> >   
> > >  	memcpy(skb_put(skb, sizeof(ra)), ra, sizeof(ra));
> > >  
> > > -	hdr = (struct mld_msg *) skb_put(skb, sizeof(struct
> > > mld_msg));
> > > -	memset(hdr, 0, sizeof(struct mld_msg));
> > > +	hdr = (struct mld_msg *) skb_put_zero(skb, sizeof(struct
> > > mld_msg));  
> > 
> > Why does skb_put_zero return char * instead of void *?
> > If returned void * it would save having to add lots of casts.
> > 
> > One could even go farther by making skb_put_zero a macro and
> > use typeof().  
> 
> I just copied it from skb_put() - you could ask the same there? :)

My taste is to  have less casts. Never understood why so many skb_
functions returned char *, probably a leftover from older Unix style.