Kernel space is flagged in the page tables as exclusive to privileged code (ring 2 or lower), hence a page fault is triggered if user-mode programs try to touch it.

系统内核所使用的内存空间通过特权码（privileged code，2级或者更低）来标记，以防止用户模式的程序访问到内核空间而发生页面错误。

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Kernel space is flagged in the page tables as exclusive to privileged code (ring 2 or lower), hence a page fault is triggered if user-mode programs try to touch it.

系统内核所使用的内存空间通过特权码（privileged code，2级或者更低）来标记，以防止用户模式的程序访问到内核空间而发生页面错误。

youdao