Commit fe977716 authored by Yafang Shao's avatar Yafang Shao Committed by Alexei Starovoitov
Browse files

bpf: Add a new kfunc for cgroup1 hierarchy 



A new kfunc is added to acquire cgroup1 of a task:

- bpf_task_get_cgroup1
  Acquires the associated cgroup of a task whithin a specific cgroup1
  hierarchy. The cgroup1 hierarchy is identified by its hierarchy ID.

This new kfunc enables the tracing of tasks within a designated
container or cgroup directory in BPF programs.

Suggested-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarYafang Shao <laoar.shao@gmail.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231111090034.4248-2-laoar.shao@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 727a92d6

kernel/bpf/helpers.c

+20 −0
Original line number Diff line number Diff line
@@ -2228,6 +2228,25 @@ __bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task, 
	rcu_read_unlock();

	return ret;

}



/**

 * bpf_task_get_cgroup1 - Acquires the associated cgroup of a task within a

 * specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its

 * hierarchy ID.

 * @task: The target task

 * @hierarchy_id: The ID of a cgroup1 hierarchy

 *

 * On success, the cgroup is returen. On failure, NULL is returned.

 */

__bpf_kfunc struct cgroup *

bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id)

{

	struct cgroup *cgrp = task_get_cgroup1(task, hierarchy_id);



	if (IS_ERR(cgrp))

		return NULL;

	return cgrp;

}

#endif /* CONFIG_CGROUPS */



/**
@@ -2534,6 +2553,7 @@ 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)

BTF_ID_FLAGS(func, bpf_task_get_cgroup1, KF_ACQUIRE | KF_RCU | KF_RET_NULL)

#endif

BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)

BTF_ID_FLAGS(func, bpf_throw)