The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 21, 2021
Filed:
Oct. 02, 2018
Arm Limited, Cambridge, GB;
Alastair David Reid, Fulbourn, GB;
Dominic Phillip Mulligan, St Neots, GB;
Milosch Meriac, Cambridge, GB;
Matthias Lothar Boettcher, Cambridge, GB;
Nathan Yong Seng Chong, Cambridge, GB;
Ian Michael Caulfield, Cambridge, GB;
Peter Richard Greenhalgh, Cambridge, GB;
Frederic Claude Marie Piry, Cagnes-sur-Mer, FR;
Albin Pierrick Tonnerre, Nice, FR;
Thomas Christopher Grocutt, Cambridge, GB;
Yasuo Ishii, Austin, TX (US);
Arm Limited, Cambridge, GB;
Abstract
A data processing apparatus comprises branch prediction circuitry adapted to store at least one branch prediction state entry in relation to a stream of instructions, input circuitry to receive at least one input to generate a new branch prediction state entry, wherein the at least one input comprises a plurality of bits; and coding circuitry adapted to perform an encoding operation to encode at least some of the plurality of bits based on a value associated with a current execution environment in which the stream of instructions is being executed. This guards against potential attacks which exploit the ability for branch prediction entries trained by one execution environment to be used by another execution environment as a basis for branch predictions.