On Wed, Mar 29, 2023 at 12:56 AM Andrii Nakryiko <andrii@xxxxxxxxxx> wrote: > > This basically prevents any forward compatibility. And we either way > just return -EINVAL, which would otherwise be returned from bpf() > syscall anyways. In your cover letter you make the argument that applications can opt out of the behaviour, but I think shows that this isn't entirely true. Apps linking old libbpf won't be able to fix their breakage without updating libbpf. This is especially annoying when you have to support multiple old versions where doing this isn't straightforward. Take this as another plea to make this opt in and instead work together to make this a default on the lib side. :)
