Re: [PATCH] IB/cm: Use struct_size() in kmalloc()

From: Jason Gunthorpe
Date: Mon Jan 07 2019 - 13:48:51 EST


On Mon, Jan 07, 2019 at 11:26:16AM -0600, 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;
> 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/core/cm.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)

Applied to for-next thanks

Jason