6.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Viktor Malik <vmalik@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20240429112311.402497-1-vmalik@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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);
}
--
2.43.0
