Sorry for top-posting. I'm replying from my phone. I've not looked at linux bpf before. I remember taking a quick look at bpf_jit_compile function but I didn't like emitting binary machine code with macro commands.
I spent few minutes today looking at linux code and I noticed few interesting things: - They use negative offsets to access auxiliary data. So, there is a clear distinction between local memory store and external data. I don't think it's a new addition, though. - They have a big enum of commands. Many of them translate to bpf commands but there are also special commands like load protocol number into A. There is a decoder from bpf but I have no clue how it works. - Those commands are adapted to work with skbuf data. Alex 20.12.13, 04:16, "David Laight" <[email protected]>": > > On Fri, Dec 20, 2013 at 01:28:12AM +0200, Mindaugas Rasiukevicius wrote: > > Alexander Nasonov <[email protected]> wrote: > > > > > > Well, if it wasn't needed for many year in bpf, why do we need it now? ;-) > > > > > > > Because it was decided to use BPF byte-code for more applications and that > > meant there is a need for improvements. It is called evolution. :) > > Has anyone here looked closely at the changes linux is making to bpf? > > David > > -- > David Laight: [email protected] -- Alex
