[$] Kernel control-flow-integrity support comes to GCC

Control-flow integrity (CFI) is a set of techniques that make it more difficult forattackers to hijack indirect jumps to exploit a system. The Linux kernel hassupported forward-edge CFI (which protects indirect function calls)since 2020, with the most recent implementationof the feature introduced in 2022. Thatversion avoids the overhead introduced by the earlier approach by using acompiler flag (-fsanitize=kcfi) that is present in Clang but not inGCC. Now, Kees Cook hasa patch set adding that support to GCC that looks likely to land in GCC17.