Re: [PATCH v3 2/3] mm/hmm: allow snapshot of the special zero page

[Jason Gunthorpe]

On Wed, Oct 23, 2019 at 12:55:14PM -0700, Ralph Campbell wrote:
> If a device driver like nouveau tries to use hmm_range_fault() to access
> the special shared zero page in system memory, hmm_range_fault() will
> return -EFAULT and kill the process.
> Allow hmm_range_fault() to return success (0) when the CPU pagetable
> entry points to the special shared zero page.
> page_to_pfn() and pfn_to_page() are defined on the zero page so just
> handle it like any other page.
> 
> Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: "JÃrÃme Glisse" <jglisse@xxxxxxxxxx>
> Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> ---
>  mm/hmm.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)

Applied to hmm.git

Thanks,
Jason