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 = devm_kzalloc(dev, 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 = devm_kzalloc(dev, 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>
---
drivers/i2c/i2c-mux.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index 603252fa1284..8d5e4c6fdd8e 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -243,8 +243,7 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
{
struct i2c_mux_core *muxc;
- muxc = devm_kzalloc(dev, sizeof(*muxc)
- + max_adapters * sizeof(muxc->adapter[0])
+ muxc = devm_kzalloc(dev, struct_size(muxc, adapter, max_adapters)
+ sizeof_priv, GFP_KERNEL);
if (!muxc)
return NULL;
--
2.21.0
