Commit f49843afde (selftests/bpf: Add tests for css_task iter combining
with cgroup iter) added a test which demonstrates how css_task iter can be
combined with cgroup iter. That test used bpf_cgroup_from_id() to convert
bpf_iter__cgroup->cgroup to a trusted ptr which is pointless now, since
with the previous fix, we can get a trusted cgroup directly from
bpf_iter__cgroup.
Signed-off-by: Chuyi Zhou <zhouchuyi@xxxxxxxxxxxxx>
---
.../testing/selftests/bpf/progs/iters_css_task.c | 16 ++++------------
1 file changed, 4 insertions(+), 12 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/iters_css_task.c b/tools/testing/selftests/bpf/progs/iters_css_task.c
index e180aa1b1..9ac758649 100644
--- a/tools/testing/selftests/bpf/progs/iters_css_task.c
+++ b/tools/testing/selftests/bpf/progs/iters_css_task.c
@@ -56,12 +56,9 @@ SEC("?iter/cgroup")
int cgroup_id_printer(struct bpf_iter__cgroup *ctx)
{
struct seq_file *seq = ctx->meta->seq;
- struct cgroup *cgrp, *acquired;
+ struct cgroup *cgrp = ctx->cgroup;
struct cgroup_subsys_state *css;
struct task_struct *task;
- u64 cgrp_id;
-
- cgrp = ctx->cgroup;
/* epilogue */
if (cgrp == NULL) {
@@ -73,20 +70,15 @@ int cgroup_id_printer(struct bpf_iter__cgroup *ctx)
if (ctx->meta->seq_num == 0)
BPF_SEQ_PRINTF(seq, "prologue\n");
- cgrp_id = cgroup_id(cgrp);
-
- BPF_SEQ_PRINTF(seq, "%8llu\n", cgrp_id);
+ BPF_SEQ_PRINTF(seq, "%8llu\n", cgroup_id(cgrp));
- acquired = bpf_cgroup_from_id(cgrp_id);
- if (!acquired)
- return 0;
- css = &acquired->self;
+ css = &cgrp->self;
css_task_cnt = 0;
bpf_for_each(css_task, task, css, CSS_TASK_ITER_PROCS) {
if (task->pid == target_pid)
css_task_cnt++;
}
- bpf_cgroup_release(acquired);
+
return 0;
}
--
2.20.1
