On 31/05/19 21:24, Gustavo A. R. Silva wrote:
> 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;
>
>
Queued, thanks.
Paolo
