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@xxxxxxxxxxxxxx>
---
drivers/infiniband/hw/usnic/usnic_uiom.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c
index 49275a548751..ce01a59fccc4 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
@@ -157,9 +157,8 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
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;
--
2.20.1
