Quelle  iters_task.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2023 Chuyi Zhou <zhouchuyi@bytedance.com> */

#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "bpf_misc.h"
#include "bpf_experimental.h"

char _license[] SEC("license") = "GPL";

pid_t target_pid;
int procs_cnt, threads_cnt, proc_threads_cnt, invalid_cnt;

void bpf_rcu_read_lock(void) __ksym;
void bpf_rcu_read_unlock(void) __ksym;

SEC("fentry.s/" SYS_PREFIX "sys_getpgid")
int iter_task_for_each_sleep(void *ctx)
{
 struct task_struct *cur_task = bpf_get_current_task_btf();
 struct task_struct *pos;

 if (cur_task->pid != target_pid)
  return 0;
 procs_cnt = threads_cnt = proc_threads_cnt = 0;

 bpf_rcu_read_lock();
 bpf_for_each(task, pos, NULL, ~0U) {
  /* Below instructions shouldn't be executed for invalid flags */
  invalid_cnt++;
 }

 bpf_for_each(task, pos, NULL, BPF_TASK_ITER_PROC_THREADS) {
  /* Below instructions shouldn't be executed for invalid task__nullable */
  invalid_cnt++;
 }

 bpf_for_each(task, pos, NULL, BPF_TASK_ITER_ALL_PROCS)
  if (pos->pid == target_pid)
   procs_cnt++;

 bpf_for_each(task, pos, cur_task, BPF_TASK_ITER_PROC_THREADS)
  proc_threads_cnt++;

 bpf_for_each(task, pos, NULL, BPF_TASK_ITER_ALL_THREADS)
  if (pos->tgid == target_pid)
   threads_cnt++;
 bpf_rcu_read_unlock();
 return 0;
}