Re: [PATCH] VMCI: Use kmalloc_array() in qp_alloc_ppn_set()

From: Michal Hocko
Date: Mon Jan 09 2017 - 04:40:19 EST


On Sun 08-01-17 17:37:08, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> Date: Sun, 8 Jan 2017 14:04:10 +0100
>
> Multiplications for the size determination of memory allocations
> indicated that array data structures should be processed.
> Thus use the corresponding function "kmalloc_array".
>
> This issue was detected by using the Coccinelle software.

I am surprised that Coccinelle found a single instance of this pattern.
If there are more then I would suggest changing all of them at once
along with the coccinelle program which has been used.

> Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/misc/vmw_vmci/vmci_queue_pair.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
> index 498c0854305f..7b5c8a89cc54 100644
> --- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
> +++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
> @@ -486,13 +486,15 @@ static int qp_alloc_ppn_set(void *prod_q,
> if (ppn_set->initialized)
> return VMCI_ERROR_ALREADY_EXISTS;
>
> - produce_ppns =
> - kmalloc(num_produce_pages * sizeof(*produce_ppns), GFP_KERNEL);
> + produce_ppns = kmalloc_array(num_produce_pages,
> + sizeof(*produce_ppns),
> + GFP_KERNEL);
> if (!produce_ppns)
> return VMCI_ERROR_NO_MEM;
>
> - consume_ppns =
> - kmalloc(num_consume_pages * sizeof(*consume_ppns), GFP_KERNEL);
> + consume_ppns = kmalloc_array(num_consume_pages,
> + sizeof(*consume_ppns),
> + GFP_KERNEL);
> if (!consume_ppns) {
> kfree(produce_ppns);
> return VMCI_ERROR_NO_MEM;
> --
> 2.11.0
>

--
Michal Hocko
SUSE Labs