[PATCH hmm 4/8] mm/hmm: add missing pfns set to hmm_vma_walk_pmd()

[Ralph Campbell]

On 3/11/20 11:35 AM, Jason Gunthorpe wrote:
> From: Jason Gunthorpe <jgg at mellanox.com>
> 
> All success exit paths from the walker functions must set the pfns array.
> 
> A migration entry with no required fault is a HMM_PFN_NONE return, just
> like the pte case.
> 
> Fixes: d08faca018c4 ("mm/hmm: properly handle migration pmd")
> Signed-off-by: Jason Gunthorpe <jgg at mellanox.com>

Reviewed-by: Ralph Campbell <rcampbell at nvidia.com>

> ---
>   mm/hmm.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/hmm.c b/mm/hmm.c
> index 32dcbfd3908315..5f5ccf13dd1e85 100644
> --- a/mm/hmm.c
> +++ b/mm/hmm.c
> @@ -394,7 +394,7 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp,
>   			pmd_migration_entry_wait(walk->mm, pmdp);
>   			return -EBUSY;
>   		}
> -		return 0;
> +		return hmm_pfns_fill(start, end, range, HMM_PFN_NONE);
>   	} else if (!pmd_present(pmd))
>   		return hmm_pfns_fill(start, end, range, HMM_PFN_ERROR);
>   
>