On Fri, Jan 27, 2023 at 01:47:06AM +0000, dthaler1968@xxxxxxxxxxxxxx wrote: > From: Dave Thaler <dthaler@xxxxxxxxxxxxx> > > Add explanation about use of "u64", "u32", etc. as > the type convention used in BPF documentation. > > Signed-off-by: Dave Thaler <dthaler@xxxxxxxxxxxxx> Acked-by: David Vernet <void@xxxxxxxxxxxxx> > --- > V2 -> V3: updated commit message to respond to David Vernet > > V1 -> V2: addressed comments from Alexei and Stanislav > by using u64 instead of uint64_t > --- > Documentation/bpf/instruction-set.rst | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst > index 2d3fe59bd26..77990c97b5e 100644 > --- a/Documentation/bpf/instruction-set.rst > +++ b/Documentation/bpf/instruction-set.rst > @@ -7,6 +7,11 @@ eBPF Instruction Set Specification, v1.0 > > This document specifies version 1.0 of the eBPF instruction set. > > +Documentation conventions > +========================= > + > +For brevity, this document uses the type notion "u64", "u32", etc. > +to mean an unsigned integer whose width is the specified number of bits. > > Registers and calling convention > ================================ > @@ -123,6 +128,8 @@ the destination register is unchanged whereas for ``BPF_ALU`` the upper > > dst_reg = (u32) dst_reg + (u32) src_reg; > > +where '(u32)' indicates that the upper 32 bits are zeroed. > + > ``BPF_ADD | BPF_X | BPF_ALU64`` means:: > > dst_reg = dst_reg + src_reg > -- > 2.33.4 >
