Re: [PATCH v4] [x86] detect and report lack of NX protections

From: H. Peter Anvin
Date: Tue Nov 10 2009 - 12:16:51 EST


On 11/10/2009 08:57 AM, Kees Cook wrote:
>
> 64-bit does not set nx_enabled to "1" by default anywhere. And setting
> the default to 1 in check_efer() seemed out of place to me.
>

If it doesn't set nx_enabled anywhere, you'll end up with the message

+ printk(KERN_NOTICE "Notice: NX (Execute Disable) protection "
+ "missing in CPU or disabled in BIOS!\n");

which seems obviously wrong... no?

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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