With the program type raw_tracepoint, no data is generated.error: loading objects: field TraceSchedWakeup: program trace_sched_wakeup: load program: permission denied: 5: (61) r1 = *(u32 *)(r7 +2784): R7 invalid mem access 'inv' (5 line(s) omitted

[linliaoy]

Describe the bug

I used the program type tracepoint, tracepoint /sched/sched_wakeup, and the function parameter tracepoint format。But I changed the raw_tracepoint type, it is not useful, error：loading objects: field TraceSchedWakeup: program trace_sched_wakeup: load program: permission denied: 5: (61) r1 = *(u32 *)(r7 +2784): R7 invalid mem access 'inv' (5 line(s) omitted。
I know that task_struct *p is empty, which causes this error, but I don't know why I try to empty it


# bpf file
SEC("raw_tracepoint/sched_wakeup") 
int trace_sched_wakeup(struct bpf_raw_tracepoint_args *ctx) {
    struct task_struct *p ;
    p=(struct task_struct *) ctx->args[0];
    u64 ntime = bpf_ktime_get_ns();
    struct data_t r_p_data={0};
    r_p_data.pid = p->pid;
    r_p_data.currtime=ntime;
    bpf_perf_event_output(ctx, &output_events, BPF_F_CURRENT_CPU, &r_p_data, sizeof(r_p_data));
    return 0;
}

#go file
### load program    
        if err := rlimit.RemoveMemlock(); err != nil {
                return err
        }

        opts := ebpf.CollectionOptions{}
    
        opts.Programs = ebpf.ProgramOptions{
                KernelTypes: bpfutil.LoadBTFSpecOrNil(),
        }

        
        if err := loadBpfObjects(&objs, &opts); err != nil {
                return fmt.Errorf("loading objects: %v", err)
        }
        progentry, err := link.AttachRawTracepoint(link.RawTracepointOptions{Name: "sched_wakeup",Program:objs.TraceSchedWakeup})
        if err != nil {
                return fmt.Errorf("link softirq_entry: %s", err.Error())
        }
        links = append(links, progentry)

### perf read        
        reader, err := perf.NewReader(objs.bpfMaps.OutputEvents, 10000 * int(unsafe.Sizeof(bpfSchedEventT{})))
        if err != nil {
                fmt.Println(err)
                return
        }
        for {
               record, err := reader.Read()
               ....
         }

How to reproduce

linux kernel:4.19.91-26.6.al7.x86_64
k8s :1.24.6
Container image environment：kubeskoop container image

Version information

github.com/cilium/ebpf v0.13.2

[lmb]

HI @linliaoy, I see that you opened a discussion for this problem here: #1395 Your issue is most likely a bug in your C code, not a problem with the library. I can't help you with that, sorry. See #886 for places you might find help.