svn commit: r219672 - in head: share/man/man9 sys/i386/include

[Jung-uk Kim]

On Tuesday 15 March 2011 03:55 pm, Jung-uk Kim wrote:
> On Tuesday 15 March 2011 03:33 pm, Maxim Dounin wrote:
> > Hello!
> >
> > On Tue, Mar 15, 2011 at 05:14:26PM +0000, Jung-uk Kim wrote:
> > > Author: jkim
> > > Date: Tue Mar 15 17:14:26 2011
> > > New Revision: 219672
> > > URL: http://svn.freebsd.org/changeset/base/219672
> > >
> > > Log:
> > >   Unconditionally use binuptime(9) for get_cyclecount(9) on
> > > i386. Since this function is almost exclusively used for random
> > > harvesting, there is no need for micro-optimization.  Adjust
> > > the manual page accordingly.
> >
> > Note that on early boot only dummy timecounter available, and
> > binuptime() has no entropy.
> >
> > As a result of this change random(9) won't have entropy on early
> > boot on i386, and arc4random(9) as well.  While there are no
> > known major security problems associated with it - it at least
> > makes stack protector easily bypasseable as it now (again after
> > r198295) uses well-known stack guard instead of random one.  And
> > there may be other issues as well.
> >
> > Hope you thought well before moving i386 to a set of platforms
> > which have no early boot randomness at all.  And you have good
> > reason for doing it.
>
> Hmm...  Is bintime(9) good enough for you then?

I guess it won't work cause boottimebin is set pretty late.  Arg...  
If I can't come up with something sensible, I'll revert this commit.

Jung-uk Kim