Simplify test_cpuset_perms_subtree by removing unnecessary chown of cgroup.procs files. The test verifies implicit migration triggered by enabling/disabling the cpuset controller via cgroup.subtree_control.
Implicit migration is handled internally by the kernel through cgroup_update_dfl_csses() when subtree_control is modified, and does not require cgroup.procs write permission. Only cgroup.subtree_control permission is needed to trigger the controller state change. Remove the allocation and cleanup of parent_procs and child_procs variables that are no longer needed. Signed-off-by: Shaojie Sun <[email protected]> --- tools/testing/selftests/cgroup/test_cpuset.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/tools/testing/selftests/cgroup/test_cpuset.c b/tools/testing/selftests/cgroup/test_cpuset.c index c5cf8b56ceb8..b323addcc519 100644 --- a/tools/testing/selftests/cgroup/test_cpuset.c +++ b/tools/testing/selftests/cgroup/test_cpuset.c @@ -167,7 +167,7 @@ static int test_cpuset_perms_object_deny(const char *root) static int test_cpuset_perms_subtree(const char *root) { char *parent = NULL, *child = NULL; - char *parent_procs = NULL, *parent_subctl = NULL, *child_procs = NULL; + char *parent_subctl = NULL; const uid_t test_euid = TEST_UID; int object_pid = 0; int ret = KSFT_FAIL; @@ -175,9 +175,6 @@ static int test_cpuset_perms_subtree(const char *root) parent = cg_name(root, "cpuset_test_0"); if (!parent) goto cleanup; - parent_procs = cg_name(parent, "cgroup.procs"); - if (!parent_procs) - goto cleanup; parent_subctl = cg_name(parent, "cgroup.subtree_control"); if (!parent_subctl) goto cleanup; @@ -187,16 +184,11 @@ static int test_cpuset_perms_subtree(const char *root) child = cg_name(parent, "cpuset_test_1"); if (!child) goto cleanup; - child_procs = cg_name(child, "cgroup.procs"); - if (!child_procs) - goto cleanup; if (cg_create(child)) goto cleanup; - /* Enable permissions as in a delegated subtree */ - if (chown(parent_procs, test_euid, -1) || - chown(parent_subctl, test_euid, -1) || - chown(child_procs, test_euid, -1)) + /* Grant minimal subtree_control permission to trigger implicit migration */ + if (chown(parent_subctl, test_euid, -1)) goto cleanup; /* Put a privileged child in the subtree and modify controller state @@ -221,12 +213,10 @@ static int test_cpuset_perms_subtree(const char *root) } cg_destroy(child); - free(child_procs); free(child); cg_destroy(parent); free(parent_subctl); - free(parent_procs); free(parent); return ret; -- 2.50.1
