Re: [PATCH] mm/hmm/test: fix an error code in hmm_dmirror_init()

[Ralph Campbell <rcampbell@nvidia.com>]

On 5/13/20 2:42 AM, Dan Carpenter wrote:
> If the allocation fails, then this should return -ENOMEM instead of
> success.
> 
> Fixes: a149d2eb654b ("mm/hmm/test: add selftest driver for HMM")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>   lib/test_hmm.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/test_hmm.c b/lib/test_hmm.c
> index 00bca6116f930..b4d9434e49e72 100644
> --- a/lib/test_hmm.c
> +++ b/lib/test_hmm.c
> @@ -1119,8 +1119,10 @@ static int __init hmm_dmirror_init(void)
>   	 * make the code here simpler (i.e., we need a struct page for it).
>   	 */
>   	dmirror_zero_page = alloc_page(GFP_HIGHUSER | __GFP_ZERO);
> -	if (!dmirror_zero_page)
> +	if (!dmirror_zero_page) {
> +		ret = -ENOMEM;
>   		goto err_chrdev;
> +	}
>   
>   	pr_info("HMM test module loaded. This is only for testing HMM.\n");
>   	return 0;
> 

Thanks for fixing this. It looks like Wei Yongjun beat you to it
and Jason Gunthorpe has applied it to the hmm tree.

https://lore.kernel.org/linux-mm/20200512195932.GB9154@ziepe.ca/