US Patent 12008361 Coherence-based dynamic code rewriting, tracing and code coverage

A device tracks accesses to pages of code executed by processors and modifies a portion of the code without terminating the execution of the code. The device is connected to the processors via a coherence interconnect and a local memory of the device stores the code pages. As a result, any requests to access cache lines of the code pages made by the processors will be placed on the coherence interconnect, and the device is able to track any cache-line accesses of the code pages by monitoring the coherence interconnect. In response to a request to read a cache line having a particular address, a modified code portion is returned in place of the code portion stored in the code pages.