Re: [PATCH] mm/huge_memory: Clean up typo when copying user highpage

Andrew Morton
2011-10-12T20:42:28Z

On Wed, 12 Oct 2011 19:51:48 +0200
Andrea Arcangeli <aarcange@redhat.com> wrote:

> On Wed, Oct 12, 2011 at 10:39:36PM +0800, Hillf Danton wrote:
> > Hi Andrea
> >
> > When copying user highpage, the PAGE_SHIFT in the third parameter is a typo,
> > I think, and is replaced with PAGE_SIZE.
>
> That looks correct. I wonder how it was not noticed yet. Because it
> can't go out of bound, it didn't risk to crash the kernel and it didn't
> not risk to expose random data to the cowing task. So it shouldn't
> have security implications as far as I can tell, but the app could
> malfunction and crash (userland corruption only).

Which architectures care about the copy_user_page() `vaddr' argument?
mips, perhaps? I suspect the intersection between those architectures
and archs-which-implement-hugepages is the empty set.