From: Feng Zhou zhoufeng.zf@bytedance.com
Add a kfunc that's similar to the bpf_current_task_under_cgroup. The difference is that it is a designated task.
When hook sched related functions, sometimes it is necessary to specify a task instead of the current task.
Signed-off-by: Feng Zhou zhoufeng.zf@bytedance.com --- kernel/bpf/helpers.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 00e5fb0682ac..88e3247b5c44 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2142,6 +2142,24 @@ __bpf_kfunc struct cgroup *bpf_cgroup_from_id(u64 cgid) return NULL; return cgrp; } + +/** + * bpf_task_under_cgroup - Check whether the task is a given subset of the + * cgroup2 hierarchy. The cgroup2 to test is assigned by cgrp. + * @cgrp: assigned cgrp. + * @task: assigned task. + */ +__bpf_kfunc int bpf_task_under_cgroup(struct cgroup *cgrp, + struct task_struct *task) +{ + if (unlikely(!cgrp)) + return -EAGAIN; + + if (unlikely(!task)) + return -ENOENT; + + return task_under_cgroup_hierarchy(task, cgrp); +} #endif /* CONFIG_CGROUPS */
/** @@ -2341,6 +2359,7 @@ BTF_ID_FLAGS(func, bpf_cgroup_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE) BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_RCU | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU) #endif BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL) BTF_SET8_END(generic_btf_ids)