Re: [PATCH] x86: Don't randomize stack unless current->personality permits it

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sat, 2006-07-15 at 17:09 +0300, Al Boldi wrote:
> Arjan van de Ven wrote:
> > On Sat, 2006-07-15 at 14:29 +0300, Al Boldi wrote:
> > > Arjan van de Ven wrote:
> > > > > BTW, why does randomize_stack_top() mod against (8192*1024) instead
> > > > > of (8192) like arch_align_stack()?
> > > >
> > > >  because it wants to randomize for 8Mb, unlike arch_align_stack which
> > > > wants to randomize the last 8Kb within this 8Mb ;)
> > >
> > > Randomizing twice?
> >
> > a VMA can only be randomized in 4Kb (well page size) granularity, so the
> > 8Mb randomization can only work in that 4Kb unit, the "second"
> > randomization can work in 16 byte granularity.
> >
> > > There is even a case where a mere rename or running through an extra
> > > shell causes a slowdown.  And that's with randomization turned off.
> >
> > randomization off will slow stuff down yes... you get cache alias
> > contention that way.

a question.. do you have prelink installed/active on your system? that
may very well mess with timings...

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux