Re: 4.4-rc5: ugly warn on: 5 W+X pages found
From: Pavel Machek
Date: Tue Dec 15 2015 - 09:08:45 EST
On Tue 2015-12-15 05:26:00, Arjan van de Ven wrote:
> 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)
pavel@duo:/data/l/linux$ cat /proc/cpuinfo | grep pae
flags : fpu vme de pse tsc msr pae mce cx8 apic
sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe
nx constant_tsc arch_perfmon bts aperfmperf pni monitor vmx est tm2
xtpr pdcm dtherm
But it still says:
address sizes : 32 bits physical, 32 bits virtual
I thought pae would be 36bit virtual?
I'm attaching /proc/config.gz..
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html