[PATCH bpf-next v3 3/3] selftests/bpf: Add test for using css_task iter in sleepable progs

[Chuyi Zhou <zhouchuyi@xxxxxxxxxxxxx>]

This Patch add a test to prove css_task iter can be used in normal
sleepable progs.

Signed-off-by: Chuyi Zhou <zhouchuyi@xxxxxxxxxxxxx>
---
 .../selftests/bpf/progs/iters_task_failure.c  | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/iters_task_failure.c b/tools/testing/selftests/bpf/progs/iters_task_failure.c
index 6b1588d70652..fe0b19e545d0 100644
--- a/tools/testing/selftests/bpf/progs/iters_task_failure.c
+++ b/tools/testing/selftests/bpf/progs/iters_task_failure.c
@@ -103,3 +103,22 @@ int BPF_PROG(iter_css_task_for_each)
 	bpf_cgroup_release(cgrp);
 	return 0;
 }
+
+SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
+int BPF_PROG(iter_css_task_for_each_sleep)
+{
+	u64 cg_id = bpf_get_current_cgroup_id();
+	struct cgroup *cgrp = bpf_cgroup_from_id(cg_id);
+	struct cgroup_subsys_state *css;
+	struct task_struct *task;
+
+	if (cgrp == NULL)
+		return 0;
+	css = &cgrp->self;
+
+	bpf_for_each(css_task, task, css, CSS_TASK_ITER_PROCS) {
+
+	}
+	bpf_cgroup_release(cgrp);
+	return 0;
+}
-- 
2.20.1