Re: [PATCH] (4/4) use system get_random_bytes in hdlcdrv

[Stephen Hemminger <shemminger@xxxxxxxx>]

On Fri, 19 Sep 2003 23:46:42 +0200
Andi Kleen <ak@xxxxxxx> wrote:

> >  void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
> >  {
> > +   u8 prand;
> > +
> >     if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || !s->skb) 
> >             return;
> >     if (s->ch_params.fulldup) {
> > @@ -459,7 +452,9 @@
> >     if ((--s->hdlctx.slotcnt) > 0)
> >             return;
> >     s->hdlctx.slotcnt = s->ch_params.slottime;
> > -   if ((random_num() % 256) > s->ch_params.ppersist)
> > +
> > +   get_random_bytes(&prand, sizeof(prand));
> > +   if (prand > s->ch_params.ppersist)
> 
> The "hard" random numbers generated by get_random_bytes
> are a precious scarce resource (many systems don't generate them very often).
> They should only be used as seed or when it is needed for security, otherwise
> users who really need them risk blocking on /dev/random.
> Especially if that function is called often it would be a bad idea.

Well go ahead an leave it out.  It gets called once, and isn't important.