From: Hui Zhu <zhuhui@kylinos.cn>

While back-porting "mm: bpf kfuncs to access memcg data", I
encountered issues with test_cgroup_iter_memcg, specifically
in test_kmem.

The test_cgroup_iter_memcg test would falsely pass when
bpf_mem_cgroup_page_state() failed due to incompatible enum
values across kernel versions. Additionally, test_kmem would
fail on systems with cgroup.memory=nokmem enabled.

This series addresses these issues:
1. Add return value checks for bpf_mem_cgroup_page_state()
2. Return error when accessing kmem with nokmem enabled
3. Skip test_kmem when cgroup.memory=nokmem is set

Hui Zhu (3):
  selftests/bpf: Check bpf_mem_cgroup_page_state return value
  mm/memcontrol: Return error when accessing kmem with nokmem
  selftests/bpf: Skip test_kmem when cgroup.memory=nokmem

 mm/memcontrol.c                               |  3 +-
 .../bpf/prog_tests/cgroup_iter_memcg.c        | 40 +++++++++++++++++++
 2 files changed, 42 insertions(+), 1 deletion(-)

-- 
2.43.0