Re: [PATCH] nvme: target: use struct_size() in kmalloc()
From: Gustavo A. R. Silva
Date: Sat May 18 2019 - 12:40:24 EST
On 5/17/19 2:03 AM, xiaolinkui wrote:
> Use struct_size() to keep code sample.
What do you mean by that?
> 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;
> struct boo entry[];
> };
>
> instance = kmalloc(sizeof(struct foo) + count * sizeof(struct boo), 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);
>
How did you find this code?
If you used a tool like Coccinelle, mention it in the changelog text.
Did you compile it?
--
Gustavo
> Signed-off-by: xiaolinkui <xiaolinkui@xxxxxxxxxx>
> ---
> drivers/nvme/target/admin-cmd.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
> index 9f72d51..6f9f830 100644
> --- a/drivers/nvme/target/admin-cmd.c
> +++ b/drivers/nvme/target/admin-cmd.c
> @@ -248,8 +248,8 @@ static void nvmet_execute_get_log_page_ana(struct nvmet_req *req)
> u16 status;
>
> status = NVME_SC_INTERNAL;
> - desc = kmalloc(sizeof(struct nvme_ana_group_desc) +
> - NVMET_MAX_NAMESPACES * sizeof(__le32), GFP_KERNEL);
> + desc = kmalloc(struct_size(desc, nsids, NVMET_MAX_NAMESPACES),
> + GFP_KERNEL);
> if (!desc)
> goto out;
>
>