IB/usnic: Use struct_size() in kmalloc()

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>
This commit is contained in:
Gustavo A. R. Silva 2019-01-07 11:39:54 -06:00 committed by Jason Gunthorpe
parent b5c61b968d
commit 02fc184841

View File

@ -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;