Commit 3c5864ba authored by Chuyi Zhou's avatar Chuyi Zhou Committed by Martin KaFai Lau
Browse files

selftests/bpf: get trusted cgrp from bpf_iter__cgroup directly 



Commit f49843af (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: default avatarChuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231107132204.912120-3-zhouchuyi@bytedance.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent 0de4f50d

tools/testing/selftests/bpf/progs/iters_css_task.c

+4 −12
Original line number Diff line number Diff line
@@ -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;

}