loc2c-runtime deref()

[Roland McGrath]

> The $target and $target->field extraction logic in the translator
> emits code that calls the macro deref() in src/runtime/loc2c-runtime.h
> to follow pointers.  This macro appears to be tuned for accessing
> user-space (refers to uaccess.h's __get_user_asm).  Is there good
> reason to believe it will continue to work even on kernel space
> pointers?  Do those lower level macros provide sufficient detection of
> null and other invalid pointer dereferencing?

You are misunderstanding the code.  Ignore the names in the implementation
details.  The runtime macros are tailored specifically for kernel-mode
access, and their sole purpose is to catch invalid pointer references.