Golang C (.so) imports segmentation violation on call

Hello I'm going to work with thirdparty library (.so file) with golang in linux environment. So I tried to practice a bit with something trivial, like importing functions from linux native libs. And got stuck on importing and calling sqrt function. Here is my code:

package main
    	// #cgo LDFLAGS: -ldl
    	// #include <dlfcn.h>
    	// #include <stdio.h>
    	import "C"
    	import "fmt"
    
    	func main() {
    
    	
    		export_name := "sqrt"
    		lib_path := "/lib/libm.so.6"
    
    		//Loading .so
    		handle := C.dlopen(C.CString(lib_path), C.RTLD_LAZY)
    		if handle == nil {
    			fmt.Println(lib_path+":\tNOT FOUND")
    			return
    		} else {
    			fmt.Println(lib_path+":\tSUCCESS")
    			}
    
    		//looking for function address
    		func_pointer := C.dlsym(handle, C.CString(export_name ))
    		if func_pointer == nil {
    			fmt.Println(export_name+":\tNOT FOUND")
    			return
    		} else {
    			fmt.Println(export_name+":\t", func_pointer)
    			}
    
    		//negotiating datatypes
            //From c lib description: double sqrt(double x);
    		sqrt  := *(*(func(float64)float64))(func_pointer)

    		//Calling function
    		sqrt(4)
    
    	}

when I run it, I always get segmentation violation:

/lib/libm.so.6: SUCCESS
sqrt:    0x7f37117ea270
unexpected fault address 0x0
fatal error: fault
[signal SIGSEGV: segmentation violation code=0x80 addr=0x0 pc=0x4019fa]

goroutine 1 [running]:
runtime.throw(0x4a6643, 0x5)
        /usr/lib/go/src/runtime/panic.go:566 +0x95 fp=0xc42004be00 sp=0xc42004bde0
runtime.sigpanic()
        /usr/lib/go/src/runtime/sigpanic_unix.go:27 +0x288 fp=0xc42004be58 sp=0xc42004be00
main.main()
        /home/afx/goc/so.go:37 +0x2ba fp=0xc42004bf48 sp=0xc42004be58
runtime.main()
        /usr/lib/go/src/runtime/proc.go:183 +0x1f4 fp=0xc42004bfa0 sp=0xc42004bf48
runtime.goexit()
        /usr/lib/go/src/runtime/asm_amd64.s:2086 +0x1 fp=0xc42004bfa8 sp=0xc42004bfa0

goroutine 17 [syscall, locked to thread]:
runtime.goexit()
        /usr/lib/go/src/runtime/asm_amd64.s:2086 +0x1
exit status 2

What is the problem ?
Thank you in advance.

P.S.
When I'm redefining function pointers of native Go functions (like here https://stackoverflow.com/questions/22933169/go-convert-unsafe-pointer-to-function-pointer-and-vice-versa) everything works fine. But import fails.

Here is solution. I had to use bridge C function:

package main

// #cgo LDFLAGS: -ldl
// #include <dlfcn.h>
// #include <stdio.h>
//
// double
// my_sqrt_bridge(void *f, double x)
// {
//	//description: ((return_data_type (*)(input_data_type))bridge_input_function_pointer) (bridge_input_value)
//	return ((double (*)(double))f)(x);
// }
import "C"
import "fmt"

func main() {

	export_name := "sqrt"
	lib_path := "/lib/libm.so.6"

	//Loading .so
	handle := C.dlopen(C.CString(lib_path), C.RTLD_LAZY)
	if handle == nil {
		fmt.Println(lib_path + ":\tNOT FOUND")
		return
	} else {
		fmt.Println(lib_path + ":\tSUCCESS")
	}

	//looking for function address
	func_pointer := C.dlsym(handle, C.CString(export_name))
	if func_pointer == nil {
		fmt.Println(export_name + ":\tNOT FOUND")
		return
	} else {
		fmt.Println(export_name+":\t", func_pointer)
	}

	fmt.Printf("%f", C.my_sqrt_bridge(func_pointer, 2))

}

Would it be possible in your case to let cgo link the library for you? Eg:

package main

/*
#cgo LDFLAGS: -lm
#include <math.h>
*/
import "C"
import "fmt"

func main() {
	fmt.Printf("%g\n", C.sqrt(2))  //prints 1.4142135623730951
}

For a third party library /some/lib/dir/libxxx.so:

LDFLAGS: -L/some/lib/dir -lxxx