Re: [hugepage] Check for brk() entering a hugepage region

[Bill Irwin <bill.irwin@oracle.com>]

On Tue, Nov 14, 2006 at 03:03:39PM +1100, 'David Gibson' wrote:
> Andrew, please apply.  I could have sworn I checked ages ago, and
> thought that sys_brk() eventually called do_mmap_pgoff() which would
> do the necessary checks.  Can't find any evidence of such a change
> though, so either I was just blind at the time, or it happened before
> the changeover to git.
> Unlike mmap(), the codepath for brk() creates a vma without first
> checking that it doesn't touch a region exclusively reserved for
> hugepages.  On powerpc, this can allow it to create a normal page vma
> in a hugepage region, causing oopses and other badness.
> This patch adds a test to prevent this.  With this patch, brk() will
> simply fail if it attempts to move the break into a hugepage reserved
> region.
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Acked-by: William Irwin <wli@holomorphy.com>


-- wli

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