My kernel version is 6.8
and the ftrace callback function looks like:
(We set USE_FENTRY_OFFSET to zero, prevent ftrace recursive by checking the address)

static void notrace ftrace_callback_handler(unsigned long ip, unsigned long parent_ip,
        struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
    struct pt_regs *regs = ftrace_get_regs(fregs);
    struct ftrace_hook *hook = container_of(ops, struct ftrace_hook, ops);

#if USE_FENTRY_OFFSET
    regs->ip = (unsigned long)hook->function;
#else
    if (!within_module(parent_ip, THIS_MODULE)){
        LOG_DEBUG("not true within_module(parent_ip, THIS_MODULE)");
        regs->ip = (unsigned long)hook->function;
    } else {
        LOG_DEBUG("true within_module(parent_ip, THIS_MODULE)");
    }
        
#endif //USE_FENTRY_OFFSET
}

But a little bit weird thing is in kernel v6.6 and v6.8
when we enter the callback function within_module(parent_ip, THIS_MODULE) always return false

This make the infinity loop in ftrace, but the same code works on kernel v5.15

I found the related kernel commit is about module layout

I am not sure is this commit makes checking by address does not work anymore?

If somebody can give me another solution to avoid go into infinity loop?