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 <gust...@embeddedor.com> --- 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), GFP_KERNEL); if (!lookup) return -ENOMEM; -- 2.20.1