On Thu, Apr 16, 2020 at 1:33 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote:
>
> When the kernel is built with CONFIG_DEBUG_PER_CPU_MAPS, the cpumap code
> can trigger a spurious warning if CONFIG_CPUMASK_OFFSTACK is also set. This
> happens because in this configuration, NR_CPUS can be larger than
> nr_cpumask_bits, so the initial check in cpu_map_alloc() is not sufficient
> to guard against hitting the warning in cpumask_check().
>
> Fix this by explicitly checking the supplied key against the
> nr_cpumask_bits variable before calling cpu_possible().
>
> Fixes: 6710e1126934 ("bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP")
> Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
> Reported-by: Xiumei Mu <xmu@xxxxxxxxxx>
> Tested-by: Xiumei Mu <xmu@xxxxxxxxxx>
> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Applied. Thanks
