6.8-stable review patch. If anyone has any objections, please let me know.
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From: Viktor Malik vmalik@redhat.com
[ Upstream commit 19468ed51488dae19254e8a67c75d583b05fa5e3 ]
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: 360769233cc9 ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/bpf/cgroup_helpers.c | 3 +++ tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c | 7 ++++++- 2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index 19be9c63d5e84..e812876d79c7e 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -508,6 +508,9 @@ int cgroup_setup_and_join(const char *path) { /** * setup_classid_environment() - Setup the cgroupv1 net_cls environment * + * This function should only be called in a custom mount namespace, e.g. + * created by running setup_cgroup_environment. + * * After calling this function, cleanup_classid_environment should be called * once testing is complete. * diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c b/tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c index 74d6d7546f40f..25332e596750f 100644 --- a/tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c +++ b/tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c @@ -87,9 +87,12 @@ void test_cgroup1_hierarchy(void) goto destroy;
/* Setup cgroup1 hierarchy */ + err = setup_cgroup_environment(); + if (!ASSERT_OK(err, "setup_cgroup_environment")) + goto destroy; err = setup_classid_environment(); if (!ASSERT_OK(err, "setup_classid_environment")) - goto destroy; + goto cleanup_cgroup;
err = join_classid(); if (!ASSERT_OK(err, "join_cgroup1")) @@ -153,6 +156,8 @@ void test_cgroup1_hierarchy(void)
cleanup: cleanup_classid_environment(); +cleanup_cgroup: + cleanup_cgroup_environment(); destroy: test_cgroup1_hierarchy__destroy(skel); }