Explore the comprehensive analysis of shadow stack mechanisms for protecting against control-flow hijacking attacks in C/C++ programs. Delve into the performance, compatibility, and security aspects of various shadow stack designs presented at the 2019 IEEE Symposium on Security & Privacy. Learn about the proposed Shadesmar design, which leverages a dedicated register for improved performance and minimal memory overhead. Examine case studies demonstrating the feasibility of dedicating a general-purpose register to security monitoring on modern architectures. Gain insights into the potential of Intel x86 extensions for memory protection and page table control in enhancing intra-process memory isolation. Understand the design requirements for dedicated hardware mechanisms supporting precise software security mitigations and their implications for future cybersecurity efforts.