How to determine an offset for a kernel method?

[YiYiZheng]

Is there a doc showing how to determine?

For example, iPhone X 14.4.2, open1 method

Not sure if the code snippet below will hook open1 method?
ret = syscall(SYS_xnuspy_ctl, XNUSPY_INSTALL_HOOK, 0xfffffff007d574f4, open1, &open1_orig);

Just do not understand the difference between sysctlbyname and syscall...

3. Could you help me to find offset of necp_send_network_denied_event method in iPhone X 14.4.2

[gr3atest]

Take a look at this: #3