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Wow, gcc generates code that's incorrect unless memory protection is being enforced? I didn't even realize it would be possible to build a kernel that way.

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GCC's code isn't incorrect. As per the C standard, after you've dereferenced a NULL pointer then all behavior is undefined. If GCC emitted code that launched ICBMs after a NULL pointer dereference, that wouldn't violate the spec either.

The real WTF here is that people are still building "secure" software in a language where programmer mistakes cause undefined behavior...

So why isn't gcc throwing big warnings and errors about dead code paths?

My guess is that GCC's dead code warning is produced in a pass that runs before the optimizer and isn't smart enough to prove the code is dead.

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