[PATCH][next] nvdimm/region: Use struct_size() in kzalloc()

[Gustavo A. R. Silva]

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

This issue was found with the help of Coccinelle and, audited and fixed
manually.

Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---
 drivers/nvdimm/region_devs.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 4502f9c4708d..8365fb1a9114 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -1063,8 +1063,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 		struct nd_blk_region *ndbr;
 
 		ndbr_desc = to_blk_region_desc(ndr_desc);
-		ndbr = kzalloc(sizeof(*ndbr) + sizeof(struct nd_mapping)
-				* ndr_desc->num_mappings,
+		ndbr = kzalloc(struct_size(ndbr, nd_region.mapping, ndr_desc->num_mappings),
 				GFP_KERNEL);
 		if (ndbr) {
 			nd_region = &ndbr->nd_region;
-- 
2.27.0