Re: [PATCH v4 00/45] x86: Kernel IBT

[Peter Zijlstra]

On Tue, Mar 15, 2022 at 11:26:10AM -0700, Alexei Starovoitov wrote:
> The bpf trampoline can attach to both indirect and non-indirect
> functions. My understanding is that only indirect targets will have
> endbr first insn. So the fix totally makes sense.

Correct, the compiler is free to not emit endbr if it can determine the
function will never be called indirectly (or it is explicitly marked so
with a function attribute).