On Tue, Sep 27, 2022 at 06:59:55PM +0000, dthaler1968@xxxxxxxxxxxxxx wrote: > From: Dave Thaler <dthaler@xxxxxxxxxxxxx> > > Signed-off-by: Dave Thaler <dthaler@xxxxxxxxxxxxx> > --- > Documentation/bpf/linux-notes.rst | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/Documentation/bpf/linux-notes.rst b/Documentation/bpf/linux-notes.rst > index 522ebe27d..0581ba326 100644 > --- a/Documentation/bpf/linux-notes.rst > +++ b/Documentation/bpf/linux-notes.rst > @@ -7,6 +7,12 @@ Linux implementation notes > > This document provides more details specific to the Linux kernel implementation of the eBPF instruction set. > > +Registers and calling convention > +================================ > + > +All program types only use R1 which contains the "context", which is typically a structure containing all > +the inputs needed, and the exit value for eBPF programs is passed as a 32 bit value. There is a patch pending that makes return values 64-bit. Also bpf progs that replace other bpf progs have all 5 input args. I think this paragraph is unnecessary. > + > Arithmetic instructions > ======================= > > -- > 2.33.4 >
