The Linux kernel is written in C, but it also leverages extensions provided by GCC. In 2022, it moved from GCC/Clang -std=gnu89 to -std=gnu11. This article explores my notes on how these GNU extensions are utilized within the kernel. Statement expressions Statement expressions are commonly used in macros. Local labels Some macros use this extension to restart a for loop in a macro's replacement list. 123456789101112131415161718192021222324#define ___wait_event(wq_head, condition, state, exclusiv...