No, you misunderstand: I believe most of the operations you need to perform a context switch are safe in the kernel's context. Sure, you'll need a bit of assemb

No, you misunderstand: I believe most of the operations you need to perform a context switch are safe in the kernel's context. Sure, you'll need a bit of assembly code to copy out and set registers and stuff, and you can't do that bit in C either. But other than that, safe pointers should work.