The C bits of the kernel aren't even written closely to any C specification - they are written to, essentially, "what gcc does and is likely to keep doing". The

The C bits of the kernel aren't even written closely to any C specification - they are written to, essentially, "what gcc does and is likely to keep doing". They also use a number of gcc extensions which are underspecified compared to C itself. I'm not sure this is a real concern for the Linux kernel devs.