From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 21 Feb 2019 09:23:53 -0600 From: "Gustavo A. R. Silva" Subject: [PATCH] libnvdimm, region: use struct_size() in kzalloc() Message-ID: <20190221152353.GA14585@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Dan Williams , Ross Zwisler , Vishal Verma , Dave Jiang Cc: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-ID: 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 foo { int stuff; struct boo entry[]; }; instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), 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, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- 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 e2818f94f292..d36cb5df9683 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -1020,10 +1020,9 @@ 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; } -- 2.20.1