Messages in this thread |  | | | Date | Fri, 20 Feb 2009 09:02:46 +0100 | | From | Ingo Molnar <> | | Subject | Re: [PATCH, v2] x86: use the right protections for split-up pagetables |
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* Ingo Molnar <mingo@elte.hu> wrote:
> [ Huang Ying also experienced problems in this area when writing > the EFI code, but the real bug in split_large_page() was not > realized back then. ]
> - * On Intel the NX bit of all levels must be cleared to make a > - * page executable. See section 4.13.2 of Intel 64 and IA-32 > - * Architectures Software Developer's Manual).
Hm, in hindsight, we should have noticed this bug sooner - when the NX comment above was added. There's never any good reason to play protection games with higher-level pagetable entries. We dont do it to user-space pagetables either - we just populate them to _PAGE_TABLE and that's it.
Ingo
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