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> --- 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
