Re: [PATCH v5 1/9] lib/group_cpus: let group_cpu_evenly return number initialized masks

[Hannes Reinecke]

On 1/10/25 17:26, Daniel Wagner wrote:
> group_cpu_evenly might allocated less groups then the requested:
>
> group_cpu_evenly
>    __group_cpus_evenly
>      alloc_nodes_groups
>        # allocated total groups may be less than numgrps when
>        # active total CPU number is less then numgrps
>
> In this case, the caller will do an out of bound access because the
> caller assumes the masks returned has numgrps.
>
> Return the number of groups created so the caller can limit the access
> range accordingly.
>
> Signed-off-by: Daniel Wagner <wagi@xxxxxxxxxx>
> ---
>   block/blk-mq-cpumap.c        |  6 +++---
>   drivers/virtio/virtio_vdpa.c |  9 +++++----
>   fs/fuse/virtio_fs.c          |  6 +++---
>   include/linux/group_cpus.h   |  3 ++-
>   kernel/irq/affinity.c        |  9 +++++----
>   lib/group_cpus.c             | 12 +++++++++---
>   6 files changed, 27 insertions(+), 18 deletions(-)
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@xxxxxxx                                +49 911 74053 688
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