How to execute code before main entry point (using __mod_init_func)?

[localacct]

Hi

I am trying to execute some code before the main entry point in the binary. I tried to use __mod_init_func and I can see __DATA segment and the corresponding section (__mod_init_func) created in the modified binary but how do I confirm that code execution goes to the address stored there?

        app = lief.parse("binary")

        # some random data
	mod_init_data = (
					0xaa,0xaa,0xaa,0xaa,
			             )

	mod_init_func_section = lief.MachO.Section("__mod_init_func",mod_init_data)
	mod_init_func_section.alignment = 2

	data_segment = lief.MachO.SegmentCommand()
	data_segment.name = "__DATA"

	mod_init_func_section = data_segment.add_section(mod_init_func_section)

	app.add(data_segment)