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 = kmalloc(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 = kmalloc(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>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
off = 0;
while (ret) {
- chunk = kmalloc(sizeof(*chunk) +
- sizeof(struct scatterlist) *
- min_t(int, ret, USNIC_UIOM_PAGE_CHUNK),
+ chunk = kmalloc(struct_size(chunk, page_list,
+ min_t(int, ret, USNIC_UIOM_PAGE_CHUNK)),
GFP_KERNEL);
if (!chunk) {
ret = -ENOMEM;