[PATCH v2 2/2] ARM: integrator: impd1: use struct_size() in devm_kzalloc()

From: Gustavo A. R. Silva
Date: Sat Jan 05 2019 - 00:55:34 EST

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;
void *entry[];

instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Changes in v2:
- Fix devm_kzalloc parameter reported by kbuild test robot.

arch/arm/mach-integrator/impd1.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-integrator/impd1.c b/arch/arm/mach-integrator/impd1.c
index eb0149561be2..a0a1e2acdb5e 100644
--- a/arch/arm/mach-integrator/impd1.c
+++ b/arch/arm/mach-integrator/impd1.c
@@ -390,7 +390,7 @@ static int __ref impd1_probe(struct lm_device *dev)
char *mmciname;

lookup = devm_kzalloc(&dev->dev,
- sizeof(*lookup) + 3 * sizeof(struct gpiod_lookup),
+ struct_size(lookup, table, 3),
if (!lookup)
return -ENOMEM;