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;
void *entry[];
};
instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, 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]>
---
drivers/input/keyboard/tca6416-keypad.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/input/keyboard/tca6416-keypad.c
b/drivers/input/keyboard/tca6416-keypad.c
index dc983ab6c0ad..cdeef180aead 100644
--- a/drivers/input/keyboard/tca6416-keypad.c
+++ b/drivers/input/keyboard/tca6416-keypad.c
@@ -219,9 +219,7 @@ static int tca6416_keypad_probe(struct i2c_client *client,
return -EINVAL;
}
- chip = kzalloc(sizeof(struct tca6416_keypad_chip) +
- pdata->nbuttons * sizeof(struct tca6416_button),
- GFP_KERNEL);
+ chip = kzalloc(struct_size(chip, buttons, pdata->nbuttons), GFP_KERNEL);
input = input_allocate_device();
if (!chip || !input) {
error = -ENOMEM;
--
2.20.1
