Re: [PATCH] hugetlb: ensure we do not reference a surplus pageafter handing it to buddy

From: Adam Litke
Date: Wed Feb 20 2008 - 09:53:17 EST



On Tue, 2008-02-19 at 15:30 -0800, Andrew Morton wrote:
> On Tue, 19 Feb 2008 12:41:51 -0600 Adam Litke <agl@xxxxxxxxxx> wrote:
>
> > Indeed. I'll take credit for this thinko...
> >
> > On Tue, 2008-02-19 at 18:28 +0000, Andy Whitcroft wrote:
> > > When we free a page via free_huge_page and we detect that we are in
> > > surplus the page will be returned to the buddy. After this we no longer
> > > own the page. However at the end free_huge_page we clear out our mapping
> > > pointer from page private. Even where the page is not a surplus we
> > > free the page to the hugepage pool, drop the pool locks and then clear
> > > page private. In either case the page may have been reallocated. BAD.
> > >
> > > Make sure we clear out page private before we free the page.
> > >
> > > Signed-off-by: Andy Whitcroft <apw@xxxxxxxxxxxx>
> >
> > Acked-by: Adam Litke <agl@xxxxxxxxxx>
>
> Was I right to assume that this is also needed in 2.6.24.x?

Yep. Thanks Andrew.

--
Adam Litke - (agl at us.ibm.com)
IBM Linux Technology Center

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/