| Message ID | 20190529162014.GA27389@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | Peter Rosin |
| Headers | show |
| Series | i2c: mux: Use struct_size() in devm_kzalloc() | expand |
On 2019-05-29 18:20, 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 = 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. Thanks, patch applied to i2c-mux/for-next Cheers, Peter
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;
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@embeddedor.com> --- drivers/i2c/i2c-mux.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)