Hi Ethan,
On 23/02/25 01:16, Ethan Carter Edwards wrote:
> We are trying to get rid of all multiplications from allocation
> functions to prevent integer overflows[1]. Here the multiplication is
> obviously safe, but using kcalloc() is more appropriate and improves
> readability. This patch has no effect on runtime behavior.
>
> Link: https://github.com/KSPP/linux/issues/162 [1]
> Link:
> https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
>
> Signed-off-by: Ethan Carter Edwards <et...@ethancedwards.com>
> ---
> kernel/sched/topology.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> index
> c49aea8c10254dec985bba47b18f61be954d23f6..b4539b29fb36f6b2f0c5ca310620ebda29755e5c
> 100644
> --- a/kernel/sched/topology.c
> +++ b/kernel/sched/topology.c
> @@ -1918,7 +1918,7 @@ void sched_init_numa(int offline_node)
> */
> sched_domains_numa_levels = 0;
>
> - masks = kzalloc(sizeof(void *) * nr_levels, GFP_KERNEL);
> + masks = kcalloc(nr_levels, sizeof(void *), GFP_KERNEL);
Even though an overflow is very unlikely here, using kcalloc() improves
readability and adds a safeguard since its built-in overflow check has
minimal overhead.
Reviewed-by: Madadi Vineeth Reddy <vinee...@linux.ibm.com>
Thanks,
Madadi Vineeth Reddy
> if (!masks)
> return;
>
> @@ -1927,7 +1927,7 @@ void sched_init_numa(int offline_node)
> * CPUs of nodes that are that many hops away from us.
> */
> for (i = 0; i < nr_levels; i++) {
> - masks[i] = kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL);
> + masks[i] = kcalloc(nr_node_ids, sizeof(void *), GFP_KERNEL);
> if (!masks[i])
> return;
>
>
> ---
> base-commit: 5cf80612d3f72c46ad53ef5042b4c609c393122f
> change-id: 20250222-sched-kcalloc-1d5acea7249b
>
> Best regards,
