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@xxxxxxxxxxxxxx>
---
virt/kvm/irqchip.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index 79e59e4fa3dc..f8be6a3d1aa6 100644
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -196,9 +196,7 @@ int kvm_set_irq_routing(struct kvm *kvm,
nr_rt_entries += 1;
- new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head)),
- GFP_KERNEL_ACCOUNT);
-
+ new = kzalloc(struct_size(new, map, nr_rt_entries), GFP_KERNEL_ACCOUNT);
if (!new)
return -ENOMEM;
--
2.21.0
