BPF::init() failed on Kernel 5.18.4 with /virtual/main.c:4:12: error: use of undeclared identifier 'TASK_COMM_LEN'

[yzhao1012]

A rather simple BPF::init() call with a trivial BPF program written in BCC format:

  std::string program = R"(                                                                     
int on_sched_process_exit(struct tracepoint__sched__sched_process_exit* args) {                      
    uint64_t id = bpf_get_current_pid_tgid();                                                        
    uint32_t tgid = id >> 32;                                                                        
    uint32_t pid = id;                                                                               
    bpf_trace_printk("process_exit: %d %d\n", tgid, pid);                                            
    return 0;                                                                                        
}                                                                                                    
  )";                                                                                                
  BPF bpf;                                                                                  
  bpf.init(program);
}

Failed with error message:

/virtual/main.c:4:12: error: use of undeclared identifier 'TASK_COMM_LEN'
        char comm[TASK_COMM_LEN];
                  ^
1 error generated.

I suppose this is part of BCC's rewriting added this?

[chenhengqi]

Just opened #4095 to fix this issue.