[v6,1/3] mm/memory_hotplug: replace an open-coded kmemdup() in add_memory_resource()

Message ID 20231016-vv-kmem_memmap-v6-1-078f0d3c0371@intel.com
State New
Headers
Series mm: use memmap_on_memory semantics for dax/kmem |

Commit Message

Verma, Vishal L Oct. 17, 2023, 5:44 a.m. UTC
  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@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 mm/memory_hotplug.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
  

Comments

David Hildenbrand Oct. 17, 2023, 2:39 p.m. UTC | #1
On 17.10.23 07:44, 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@linux-foundation.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Reported-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
> ---
>   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  */
>   	}
> 

Reviewed-by: David Hildenbrand <david@redhat.com>
  

Patch

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  */
 	}