Re: 4.4-rc5: ugly warn on: 5 W+X pages found

Arjan van de Ven
2015-12-15T13:30:31Z

On 12/14/2015 11:56 PM, Pavel Machek wrote:
> On Mon 2015-12-14 13:24:08, Arjan van de Ven wrote:
>>
>>> That's weird. The only API to do that seems to be manually setting
>>> kmap_prot to _PAGE_KERNEL_EXEC, and nothing does that. (Why is
>>> kmap_prot a variable on x86 at all? It has exactly one writer, and
>>> that's the code that initializes it in the first place. Shouldn't we
>>> #define kmap_prot _PAGE_KERNEL?
>>
>> iirc it changes based on runtime detection of NX capability
>
> Huh. Is it possible that core duo is so old that it has no NX?

really stupid question I guess, but is PAE on ?
(64 bit pagetables are required for NX)