Control-flow Enforcement Technology
Intel's and AMD's hardware support for checking returns (with a shadow stack) and indirect jumps (with landing-pad instructions).
Control-flow Enforcement Technology (CET) adds the shadow stack (SHSTK) and indirect branch tracking (IBT) to x86-64; compilers emit support with -fcf-protection=full (GCC/Clang) and /CETCOMPAT (MSVC linker), and the OS enables each feature per process.
See also