gccgo和LD_PRELOAD

Question

package hello
import "fmt"

func Hello() {
    fmt.Println("hello, world!")
}

gccgo -c hello.go -o libhello.so -shared
nm libhello.so
...
0000000000000000 T go.hello.Hello
0000000000000000 R go.hello.Hello$descriptor



package main
import "./hello"

func main() {
    hello.Hello()
}

gccgo  -g main.go -L. -lhello -ldl -o main
./main
hello, world!

它工作正常。但是当我查看exec文件时，它没有动态链接到libhello.so为什么??

ldd main
linux-vdso.so.1 =>  (0x00007ffd7bb88000)
libgo.so.4 => /lib64/libgo.so.4 (0x00007f134bca3000)
libm.so.6 => /lib64/libm.so.6 (0x00007f134b9a0000)
libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f134b78a000)
libc.so.6 => /lib64/libc.so.6 (0x00007f134b3c8000)
/lib64/ld-linux-x86-64.so.2 (0x00007f134c9ce000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f134b1ab000)

如何编写LD_PRELOAD挂钩到hijack函数（这里是go.hello.Hello？），因为C中函数的名称不能包含点

#include <stdio.h>
#include <string.h>
#define __USE_GNU
#include <dlfcn.h>

static void (*hello) () = 0;

__attribute__ ((constructor))
     void hello_init (void)
{
  hello = dlsym (RTLD_NEXT, "go.hello.Hello");
}

void Hello()
{
  int fd;
  if (!hello)
    return;
  printf("pre hello\n");
  hello();
  printf("post hello\n");
}

LD_PRELOAD=./libxxx.so ./main
hello, world!