[CRIU] Re: [PATCH 4/5] util-net: Fix strict aliasing problem on certain compilers

[Cyrill Gorcunov]

On Tue, Jul 31, 2012 at 02:10:47PM +0400, Pavel Emelyanov wrote:
> >  	cmsg				= CMSG_FIRSTHDR(&fdset->hdr);
> > -	cmsg->cmsg_len			= fdset->hdr.msg_controllen;
> > -	cmsg->cmsg_level		= SOL_SOCKET;
> > -	cmsg->cmsg_type			= SCM_RIGHTS;
> 
> Huh? How does the net/core/rtnetlink.c work then?! It uses such tricks all the way around!
> 
> > +	from.cmsg_len			= fdset->hdr.msg_controllen;
> > +	from.cmsg_level			= SOL_SOCKET;
> > +	from.cmsg_type			= SCM_RIGHTS;
> > +
> > +	builtin_memcpy(cmsg, &from, sizeof(from));

I believe it depends on compiler version. On my F16 machine there is no such
problem, but only on the compiler 4.4.5.

	Cyrill