From 2b90cb223320a93b1be6c2616efe6f9ff14d8b28 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 10 Jun 2019 16:06:13 -0500 Subject: [PATCH] libnvdimm, region: Use struct_size() in kzalloc() One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct nd_region { ... struct nd_mapping mapping[0]; }; instance = kzalloc(sizeof(struct nd_region) + sizeof(struct nd_mapping) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kzalloc(struct_size(instance, mapping, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Reviewed-by: Vishal Verma Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20190610210613.GA21989@embeddedor Signed-off-by: Dan Williams --- drivers/nvdimm/region_devs.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index af30cbe7a8ea..b477a8dc0020 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -1025,10 +1025,9 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus, } region_buf = ndbr; } else { - nd_region = kzalloc(sizeof(struct nd_region) - + sizeof(struct nd_mapping) - * ndr_desc->num_mappings, - GFP_KERNEL); + nd_region = kzalloc(struct_size(nd_region, mapping, + ndr_desc->num_mappings), + GFP_KERNEL); region_buf = nd_region; }