On 08/25/2017 05:14 AM, Dan Carpenter wrote:
This code generates a Smatch warning:kernel/irq/irqdomain.c:1511 irq_domain_push_irq() warn: variable dereferenced before check 'root_irq_data' (see line 1508) irq_get_irq_data() does sometimes return NULL pointers so this seems like a real bug. Let's fix this bug by moving the check for NULL earlier. Signed-off-by: Dan Carpenter <[email protected]>
Thanks for identifying and fixing this. It looks plausible, so if it compiles without error you can add:
Acked-by: David Daney <[email protected]>
--- v2: Redo changelog. v3: Redo changelog again. Make it imperative. diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index b9c688944429..e84b7056bb08 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -1505,10 +1505,10 @@ int irq_domain_push_irq(struct irq_domain *domain, int virq, void *arg) if (WARN_ON(!irq_domain_is_hierarchy(domain))) return -EINVAL;- if (domain->parent != root_irq_data->domain)+ if (!root_irq_data) return -EINVAL;- if (!root_irq_data)+ if (domain->parent != root_irq_data->domain) return -EINVAL;child_irq_data = kzalloc_node(sizeof(*child_irq_data), GFP_KERNEL,
