README: Add missing kernel option

[EricccTaiwan]

Close #2911

[arighi]

Is it really true? I just recompiled a kernel with CONFIG_SECURITY=y and CONFIG_BPF_LSM not set and I don't get any permission error. However, I tested it inside virtme-ng, so maybe other components are involved to trigger the issue (likely systemd).

So, I'm ok to recommend this option, but it'd be nice to understand exactly what is happening.

[etsal]

Is it really true? I just recompiled a kernel with CONFIG_SECURITY=y and CONFIG_BPF_LSM not set and I don't get any permission error. However, I tested it inside virtme-ng, so maybe other components are involved to trigger the issue (likely systemd).

So, I'm ok to recommend this option, but it'd be nice to understand exactly what is happening.

Second that, looking at the logs in the original issue (Frogging-Family/linux-tkg#1156) The problem seems lavd-specific and related to ftrace support.

Should we wait till the problem gets triaged a bit better before merging? The original problem (lavd not finding some pretty basic kfuncs) is not that obviously related to CONFIG_BPF_LSM.

[multics69]

Let me reproduce the original issue (Frogging-Family/linux-tkg#1156) with your changes.