Re: Restricting rdtsc [was: kernel aslr]

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Tue, Mar 28, 2017 at 11:30:52AM -0500, David Young wrote:
> What do you mean by "legitimately" use rdtsc?  It seems to me that it
> is legitimate for a user to use a high-resolution timer to profile some
> code that's under development.  They may want to avoid running that code
> with root privileges under most circumstances.

In fact, one of the open project items is to make it possible to do
gettimeofday and friends without a system call at all on x86. As usual,
questionable gains in security complete defeat performance again...

Joerg