Xtonlsab bug

[Joakim Tjernlund]

Ondrej Zajicek <santiago at crfreenet.org> wrote on 2010/04/29 23:15:22:
>
> On Thu, Apr 29, 2010 at 11:03:32PM +0200, Joakim Tjernlund wrote:
> >
> > Ondrej, this looks buggy:
> >
> > +static inline void htonlsab(void *h, void *n, u16 len) { memcpy(n, h, len); };
> > +static inline void ntohlsab(void *n, void *h, u16 len) { memcpy(h, n, len); };
> >
> > memcpy is not defined to handle overlapping memory. Best to add:
> > if (n != h)
> >   memcpy(...)
>
> Yes, but all usages of htonlsab()/ntohlsab() are non-overlapping.
> (overlapping/on place usage was replaced with htonlsab1()/ntohlsab1()).

I see, but it would be safer to have that check in case you
used them in the wrong way?

>
> > Might as well do that for these too:
> > +static inline void htonlsah(struct ospf_lsa_header *h, struct
> ospf_lsa_header *n) { *n = *h; };
> > +static inline void ntohlsah(struct ospf_lsa_header *n, struct
> ospf_lsa_header *h) { *h = *n; };
>
> *n = *h should be OK even if n == h, AFAIK.

Hopyfully, but isn't gcc allowed to use memcpy to do that
assignment?
If you add that if (h!=n) test, doesn't the need for Xlasb1() go away as well?

 Jocke