[lkml]   [2005]   [May]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Hyper-Threading Vulnerability
On Fri, May 13, 2005 at 07:00:12PM -0400, Lee Revell wrote:
> On Fri, 2005-05-13 at 23:47 +0100, Alan Cox wrote:
> > On Gwe, 2005-05-13 at 22:59, Matt Mackall wrote:
> > > It might not be much of a problem though. If he's a bit off per guess
> > > (really impressive), he'll still be many bits off by the time there's
> > > enough entropy in the primary pool to reseed the secondary pool so he
> > > can check his guesswork.
> >
> > You can also disable the tsc to user space in the intel processors.
> > Thats something they anticipated as being neccessary in secure
> > environments long ago. This makes the attack much harder.
> And break the hundreds of apps that depend on rdtsc? Am I missing
> something?

If those apps depend on rdtsc being a) present, and b) working
without providing fallbacks, they're already broken.

There's a reason its displayed in /proc/cpuinfo's flags field,
and visible through cpuid. Apps should be testing for presence
before assuming features are present.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-05-14 01:37    [W:0.110 / U:8.908 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site