go run -race err: checkptr: pointer arithmetic computed bad pointer value

[xiaonuoz]

hi!
Can you help me to see where my example is going wrong, it's easy.

package main

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"strings"

	bpf "github.com/iovisor/gobpf/bcc"
)

const (
	file_read_c = `
	#include <asm/ptrace.h>
	#include <linux/fs.h>
	#include <linux/sched.h>

	struct readfile_event_t {
		u32 pid;
		char file_name[256];
	};

	BPF_PERF_OUTPUT(watch_readfile_events);

	int trace_vfs_read(struct pt_regs *ctx, struct file *file, char __user *buf, size_t count, loff_t *pos)
	{
		u32 pid = bpf_get_current_pid_tgid() >>32;

		struct readfile_event_t event = {};
		event.pid = pid;

		bpf_probe_read_kernel_str(&event.file_name, sizeof(event.file_name), (void *)file->f_path.dentry->d_name.name);
		watch_readfile_events.perf_submit(ctx, &event, sizeof(event));
		return 0;
	}
	`
)

func main() {
	BpfModule := bpf.NewModule(file_read_c, []string{})

	traceVfsRead, err := BpfModule.LoadKprobe("trace_vfs_read")
	if err != nil {
		fmt.Println("traceVfsWrite err:", err)
		return
	}

	err = BpfModule.AttachKprobe("vfs_read", traceVfsRead, -1)
	if err != nil {
		fmt.Println("AttachKprobe err:", err)
		return
	}
	table := bpf.NewTable(BpfModule.TableId("watch_readfile_events"), BpfModule)

	channel := make(chan []byte, 2048)

	perfMap, err := bpf.InitPerfMap(table, channel, nil)
	if err != nil {
		fmt.Println("InitPerfMap err:", err)
		return
	}

	perfMap.Start()
	defer perfMap.Stop()

	for data := range channel {
		getWriteEvent(data)
	}
}

type WatchFileEventsC struct {
	Pid      uint32
	FileName [256]byte
}

func getWriteEvent(data []byte) {
	var watchEvent WatchFileEventsC
	err := binary.Read(bytes.NewBuffer(data), binary.LittleEndian, &watchEvent)
	if err != nil {
		return
	}

	file_name := string(watchEvent.FileName[:bytes.IndexByte(watchEvent.FileName[:], 0)])
	if len(file_name) == 0 {
		return
	}

	if !strings.Contains(file_name, ".txt") {
		return
	}
	fmt.Printf("file_name:%v\n", file_name)
}

error: