Patents by Inventor Christos SAKALIS

Christos SAKALIS has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20210365554
    Abstract: A system and method for mitigating micro-architectural replay attacks in a processing system by delaying speculative execution on the processing system of a set of processor instructions upon detection that the set of processor instructions are part of a micro-architectural replay attack by detecting repeating speculative execution of the set of processor instructions interleaved with misspeculation and squashing of the set of processor instructions.
    Type: Application
    Filed: May 25, 2021
    Publication date: November 25, 2021
    Inventors: Christos SAKALIS, Stefanos KAXIRAS, Magnus SJÄLANDER
  • Patent number: 11163576
    Abstract: A system and method for efficiently preventing visible side-effects in the memory hierarchy during speculative execution is disclosed. Hiding the side-effects of executed instructions in the whole memory hierarchy is both expensive, in terms of performance and energy, and complicated. A system and method is disclosed to hide the side-effects of speculative loads in the cache(s) until the earliest time these speculative loads become non-speculative. A refinement is disclosed where loads that hit in the L1 cache are allowed to proceed by keeping their side-effects on the L1 cache hidden until these loads become non-speculative, and all other speculative loads that miss in the cache(s) are prevented from executing until they become non-speculative. To limit the performance deterioration caused by these delayed loads, a system and method is disclosed that augments the cache(s) with a value predictor or a re-computation engine that supplies predicted or recomputed values to the loads that missed in the cache(s).
    Type: Grant
    Filed: March 20, 2020
    Date of Patent: November 2, 2021
    Assignee: ETA SCALE AB
    Inventors: Christos Sakalis, Stefanos Kaxiras, Alberto Ros, Alexandra Jimborean, Magnus Själander
  • Publication number: 20200301712
    Abstract: A system and method for efficiently preventing visible side-effects in the memory hierarchy during speculative execution is disclosed. Hiding the side-effects of executed instructions in the whole memory hierarchy is both expensive, in terms of performance and energy, and complicated. A system and method is disclosed to hide the side-effects of speculative loads in the cache(s) until the earliest time these speculative loads become non-speculative. A refinement is disclosed where loads that hit in the L1 cache are allowed to proceed by keeping their side-effects on the L1 cache hidden until these loads become non-speculative, and all other speculative loads that miss in the cache(s) are prevented from executing until they become non-speculative. To limit the performance deterioration caused by these delayed loads, a system and method is disclosed that augments the cache(s) with a value predictor or a re-computation engine that supplies predicted or recomputed values to the loads that missed in the cache(s).
    Type: Application
    Filed: March 20, 2020
    Publication date: September 24, 2020
    Inventors: Christos SAKALIS, Stefanos KAXIRAS, Alberto ROS, Alexandra JIMBOREAN, Magnus SJÄLANDER