irqdomain: Use struct_size() helper when allocating irqdomain

Instead of open-coding the size computation of struct irqdomain,
use the struct_size() helper instead.

This is going to be handy as we change the type of the revmap
array.

Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index fa94c86e47d4a8f16a02090a2243cef51762d45e..cdcb1989cd20cc9a82ae8296c8fb2da5a986ce2a 100644 (file)
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -150,7 +150,7 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size,
                    (!IS_ENABLED(CONFIG_IRQ_DOMAIN_NOMAP) && direct_max)))
                return NULL;
 
-       domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
+       domain = kzalloc_node(struct_size(domain, revmap, size),
                              GFP_KERNEL, of_node_to_nid(to_of_node(fwnode)));
        if (!domain)
                return NULL;