linux-kernel - Re: [PATCH v2 2/2] x86_32: Remove user bit from identity map PDE

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Date:	Wed, 12 Mar 2014 11:52:28 -0700
From:	Andy Lutomirski <luto@...capital.net>
To:	Dave Jones <davej@...hat.com>,
	Andy Lutomirski <luto@...capital.net>,
	"H. Peter Anvin" <hpa@...ux.intel.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	X86 ML <x86@...nel.org>, Stefani Seibold <stefani@...bold.net>,
	Andreas Brief <Andreas.Brief@...de-schwarz.com>,
	Martin Runge <Martin.Runge@...de-schwarz.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Andi Kleen <andi@...stfloor.org>
Subject: Re: [PATCH v2 2/2] x86_32: Remove user bit from identity map PDE

On Wed, Mar 12, 2014 at 11:39 AM, Dave Jones <davej@...hat.com> wrote:
> On Wed, Mar 12, 2014 at 11:29:45AM -0700, Andy Lutomirski wrote:
>  > The only reason that the user bit was set was to support userspace
>  > access to the compat vDSO in the fixmap.  The compat vDSO is gone,
>  > so the user bit can be removed.
>  >
>  > -/*
>  > - * For PDE_IDENT_ATTR include USER bit. As the PDE and PTE protection
>  > - * bits are combined, this will alow user to access the high address mapped
>  > - * VDSO in the presence of CONFIG_COMPAT_VDSO
>  > - */
>  >  #define PTE_IDENT_ATTR       0x003          /* PRESENT+RW */
>  > -#define PDE_IDENT_ATTR       0x067          /* PRESENT+RW+USER+DIRTY+ACCESSED */
>  > +#define PDE_IDENT_ATTR       0x063          /* PRESENT+RW+USER+DIRTY+ACCESSED */
>  >  #define PGD_IDENT_ATTR       0x001          /* PRESENT (no other attributes) */
>
> update the comment too ?

Damnit.  I fixed this for the other patchset...

--Andy

>
>         Dave
>



-- 
Andy Lutomirski
AMA Capital Management, LLC
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