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 <[email protected]>
---
net/core/flow_offload.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/core/flow_offload.c b/net/core/flow_offload.c
index 5ce7d47a960e..3d93e51b83e0 100644
--- a/net/core/flow_offload.c
+++ b/net/core/flow_offload.c
@@ -7,8 +7,7 @@ struct flow_rule *flow_rule_alloc(unsigned int num_actions)
{
struct flow_rule *rule;
- rule = kzalloc(sizeof(struct flow_rule) +
- sizeof(struct flow_action_entry) * num_actions,
+ rule = kzalloc(struct_size(rule, action.entries, num_actions),
GFP_KERNEL);
if (!rule)
return NULL;
--
2.21.0
