From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Dan Williams <dan.j.williams@intel.com>,
Ross Zwisler <zwisler@kernel.org>,
Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>
Cc: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] libnvdimm, region: use struct_size() in kzalloc()
Date: Thu, 21 Feb 2019 09:23:53 -0600 [thread overview]
Message-ID: <20190221152353.GA14585@embeddedor> (raw)
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 <gustavo@embeddedor.com>
---
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
next reply other threads:[~2019-02-21 15:24 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-21 15:23 Gustavo A. R. Silva [this message]
2019-06-10 21:06 [PATCH] libnvdimm, region: Use struct_size() in kzalloc() Gustavo A. R. Silva
2019-08-28 18:30 ` Gustavo A. R. Silva
2019-08-28 20:25 ` Kees Cook
2019-08-28 18:51 ` Verma, Vishal L
2019-08-28 19:36 ` Gustavo A. R. Silva
2019-08-28 20:24 ` Verma, Vishal L
2019-08-29 21:04 ` Dan Williams
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