On Tue, 30 Aug 2016 21:07:50 +0200, Daniel Borkmann wrote:
quoted
Having two modes seems more straight forward and I think we would only
need to pay attention in the LD_IMM64 case, I don't think I've seen
LLVM generating XORs, it's just the cBPF -> eBPF conversion.
Okay, though, I think that the cBPF to eBPF migration wouldn't even
pass through the bpf_parse() handling, since verifier is not aware on
some of their aspects such as emitting calls directly (w/o *proto) or
arg mappings. Probably make sense to reject these (bpf_prog_was_classic())
if they cannot be handled anyway?
TBH again I only use cBPF for testing. It's a convenient way of
generating certain instruction sequences. I can probably just drop
it completely but the XOR patch is just 3 lines of code so not a huge
cost either... I'll keep patch 6 in my tree for now.
Alternatively - is there any eBPF assembler out there? Something
converting verifier output back into ELF would be quite cool.