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

From: Pavel Machek
Date: Mon Dec 14 2015 - 15:26:40 EST


Hi!

> > I know. But either someone cares, and it should be fixes, or noone
> > cares, and the check should be removed.
>
> Someone cares, and it should be scheduled to be fixed for 4.5. The EFI
> mapping changes that were required to avoid the warning were much too
> big and late to make 4.4.
>
> So for now, don't enable CONFIG_DEBUG_WX for now. Unless you want to
> actively debug the EFI mapping changes, that is. Which I heartily
> recommend people doing.

Ok, good, except... This is thinkpad X60. Good old BIOS. It should
have no EFI.

pavel@duo:~$ dmesg | grep EFI
pavel@duo:~$

>From the messages I got:

> [ 3.285993] x86/mm: Found insecure W+X mapping at address
> ffe69000/0xffe69000

---[ Persisent kmap() Area ]---
0xffc00000-0xffd28000 1184K pte
0xffd28000-0xffddd000 724K RW GLB NX pte
0xffddd000-0xffe69000 560K pte
0xffe69000-0xffe6e000 20K RW GLB x pte
0xffe6e000-0xffe6f000 4K pte
---[ Fixmap Area ]---

That is not EFI, right?

Thanks,
Pavel


--
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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