[PATCH V2] ARM: mm: make UACCESS_WITH_MEMCPY huge page aware

[Russell King - ARM Linux]

On Fri, Oct 11, 2013 at 11:11:32AM +0100, Steve Capper wrote:
> On Fri, Oct 11, 2013 at 10:57:51AM +0100, Russell King - ARM Linux wrote:
> > On Wed, Sep 25, 2013 at 01:31:29PM +0100, Steve Capper wrote:
> > > The memory pinning code in uaccess_with_memcpy.c does not check
> > > for HugeTLB or THP pmds, and will enter an infinite loop should
> > > a __copy_to_user or __clear_user occur against a huge page.
> > 
> > This patch causes a build error with certain configuration options:
> > 
> > arch/arm/lib/uaccess_with_memcpy.c: In function 'pin_page_for_write':
> > arch/arm/lib/uaccess_with_memcpy.c:57:2: error: implicit declaration of function 'pmd_thp_or_huge'
> > arch/arm/lib/uaccess_with_memcpy.c:60:3: error: implicit declaration of function 'pmd_hugewillfault'
> > 
> > found via a randconfig build, configuration:
> > 
> > http://www.arm.linux.org.uk/developer/build/file.php?type=config&idx=6265
> > 
> > > ---
> > >  arch/arm/include/asm/pgtable-3level.h |  3 +++
> > >  arch/arm/lib/uaccess_with_memcpy.c    | 41 ++++++++++++++++++++++++++++++++---
> > >  2 files changed, 41 insertions(+), 3 deletions(-)
> > 
> > As the macros are in pgtable-3level.h, this won't work with any configuration
> > using the 2level header file.
> 
> Hi Russell,
> Apologies, that was careless rebasing on my part.
> 
> Would you like a fix for this, or should I send a new patch?

I'd prefer a new patch please.

Thanks.