The cgroup1_hierarchy test uses setup_classid_environment to setup
cgroupv1 environment. The problem is that the environment is set in
/sys/fs/cgroup and therefore, if not run under an own mount namespace,
effectively deletes all system cgroups:
$ ls /sys/fs/cgroup | wc -l
27
$ sudo ./test_progs -t cgroup1_hierarchy
#41/1 cgroup1_hierarchy/test_cgroup1_hierarchy:OK
#41/2 cgroup1_hierarchy/test_root_cgid:OK
#41/3 cgroup1_hierarchy/test_invalid_level:OK
#41/4 cgroup1_hierarchy/test_invalid_cgid:OK
#41/5 cgroup1_hierarchy/test_invalid_hid:OK
#41/6 cgroup1_hierarchy/test_invalid_cgrp_name:OK
#41/7 cgroup1_hierarchy/test_invalid_cgrp_name2:OK
#41/8 cgroup1_hierarchy/test_sleepable_prog:OK
#41 cgroup1_hierarchy:OK
Summary: 1/8 PASSED, 0 SKIPPED, 0 FAILED
$ ls /sys/fs/cgroup | wc -l
1
To avoid this, run setup_cgroup_environment first which will create an
own mount namespace. This only affects the cgroupv1_hierarchy test as
all other cgroup1 test progs already run setup_cgroup_environment prior
to running setup_classid_environment.
Also add a comment to the header of setup_classid_environment to warn
against this invalid usage in future.
Fixes: 360769233c ("selftests/bpf: Add selftests for cgroup1 hierarchy")
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240429112311.402497-1-vmalik@redhat.com
Add selftests for cgroup1 hierarchy.
The result as follows,
$ tools/testing/selftests/bpf/test_progs --name=cgroup1_hierarchy
#36/1 cgroup1_hierarchy/test_cgroup1_hierarchy:OK
#36/2 cgroup1_hierarchy/test_root_cgid:OK
#36/3 cgroup1_hierarchy/test_invalid_level:OK
#36/4 cgroup1_hierarchy/test_invalid_cgid:OK
#36/5 cgroup1_hierarchy/test_invalid_hid:OK
#36/6 cgroup1_hierarchy/test_invalid_cgrp_name:OK
#36/7 cgroup1_hierarchy/test_invalid_cgrp_name2:OK
#36/8 cgroup1_hierarchy/test_sleepable_prog:OK
#36 cgroup1_hierarchy:OK
Summary: 1/8 PASSED, 0 SKIPPED, 0 FAILED
Besides, I also did some stress test similar to the patch #2 in this
series, as follows (with CONFIG_PROVE_RCU_LIST enabled):
- Continuously mounting and unmounting named cgroups in some tasks,
for example:
cgrp_name=$1
while true
do
mount -t cgroup -o none,name=$cgrp_name none /$cgrp_name
umount /$cgrp_name
done
- Continuously run this selftest concurrently,
while true; do ./test_progs --name=cgroup1_hierarchy; done
They can ran successfully without any RCU warnings in dmesg.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231111090034.4248-7-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
