Hi Daniel, > > Not all of the helpers have 4 or less byte arguments only, there are a > few with 8 byte arguments, so making that general assumption wouldn't > work. I guess what could be done is that helpers have a flag in struct > bpf_func_proto which indicates for JITs that all args are 4 byte on 32bit > so you could probably use convention similar to case2 for them. Presumably > for that information to process, the JIT might need to be reworked to > extract that via bpf_analyzer() that does a verifier run to re-analyze > the program like in nfp JIT case.
Let me try a better solution which can be used to support both 4 byte and 8 byte arguments. I hope it would work out. Are you sure this patch can pass if it only supports 4 byte arguments though? Let me list out what I have to do, so that you can tell me if I am thinking in a wrong way :- * I will add a bit flag in bpf_func_proto to represent whether different arguments in a function call are 4 bytes or 8 bytes. If lsb of bit flag is set then first argument is 8 byte, otherwise its not. I think I can handle this flag properly in build_insn() in my code. Does this sound okay? I don't understand second part of your solution, i.e. > Presumably > for that information to process, the JIT might need to be reworked to > extract that via bpf_analyzer() that does a verifier run to re-analyze > the program like in nfp JIT case. Please explain what are you suggesting and how can I extract bit flag from bpf_func_proto(). Please reply asap, as I would like to finish it over the weekend. Please. -Shubham
