On 01/05/18 06:57, Mark Rutland wrote: > Document the rationale and usage of the new nospec*() helpers. > > Signed-off-by: Mark Rutland <mark.rutl...@arm.com> > Signed-off-by: Will Deacon <will.dea...@arm.com> > Cc: Dan Williams <dan.j.willi...@intel.com> > Cc: Jonathan Corbet <cor...@lwn.net> > Cc: Peter Zijlstra <pet...@infradead.org> > --- > Documentation/speculation.txt | 166 > ++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 166 insertions(+) > create mode 100644 Documentation/speculation.txt > > diff --git a/Documentation/speculation.txt b/Documentation/speculation.txt > new file mode 100644 > index 000000000000..748fcd4dcda4 > --- /dev/null > +++ b/Documentation/speculation.txt > @@ -0,0 +1,166 @@ > + > +Typically speculative execution cannot be observed from architectural state, > +such as the contents of registers. However, in some cases it is possible to > +observe its impact on microarchitectural state, such as the presence or > +absence of data in caches. Such state may form side-channels which can be > +observed to extract secret information.
I'm curious about what it takes to observe this... or is that covered in the exploit papers? thanks, -- ~Randy
