Re: [PATCH v8 1/3] mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource()

[fan]

On Wed, Nov 01, 2023 at 04:51:51PM -0600, Vishal Verma wrote:
> A review of the memmap_on_memory modifications to add_memory_resource()
> revealed an instance of an open-coded kmemdup(). Replace it with
> kmemdup().
> 
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Oscar Salvador <osalvador@xxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Reported-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> Signed-off-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
> ---

Reviewed-by: Fan Ni <fan.ni@xxxxxxxxxxx>

>  mm/memory_hotplug.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index f8d3e7427e32..6be7de9efa55 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1439,11 +1439,11 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
>  	if (mhp_flags & MHP_MEMMAP_ON_MEMORY) {
>  		if (mhp_supports_memmap_on_memory(size)) {
>  			mhp_altmap.free = memory_block_memmap_on_memory_pages();
> -			params.altmap = kmalloc(sizeof(struct vmem_altmap), GFP_KERNEL);
> +			params.altmap = kmemdup(&mhp_altmap,
> +						sizeof(struct vmem_altmap),
> +						GFP_KERNEL);
>  			if (!params.altmap)
>  				goto error;
> -
> -			memcpy(params.altmap, &mhp_altmap, sizeof(mhp_altmap));
>  		}
>  		/* fallback to not using altmap  */
>  	}
> 
> -- 
> 2.41.0
>