| Message ID | 20200415140151.439943-1-toke@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [bpf] cpumap: Avoid warning when CONFIG_DEBUG_PER_CPU_MAPS is enabled | expand |
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index 70f71b154fa5..23902afb3bba 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -99,8 +99,8 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr) bpf_map_init_from_attr(&cmap->map, attr); - /* Pre-limit array size based on NR_CPUS, not final CPU check */ - if (cmap->map.max_entries > NR_CPUS) { + /* Pre-limit array size based on nr_cpumask_bits, not final CPU check */ + if (cmap->map.max_entries > nr_cpumask_bits) { err = -E2BIG; goto free_cmap; }
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 using the nr_cpumask_bits variable in the map creation code instead of the NR_CPUS constant. Fixes: 6710e1126934 ("bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP") Cc: Jesper Dangaard Brouer <brouer@redhat.com> Reported-by: Xiumei Mu <xmu@redhat.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> --- kernel/bpf/cpumap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)