diff --git a/Documentation/bpf/standardization/instruction-set.rst b/Documentation/bpf/standardization/instruction-set.rst index b44bdacd01957..997560abadabe 100644 --- a/Documentation/bpf/standardization/instruction-set.rst +++ b/Documentation/bpf/standardization/instruction-set.rst @@ -469,6 +469,12 @@ JSLT 0xc any PC += offset if dst < src signed JSLE 0xd any PC += offset if dst <= src signed ======== ===== ======= ================================= =================================================== +where 'PC' denotes the program counter, and the offset to increment by +is in units of 64-bit instructions relative to the instruction following +the jump instruction. Thus 'PC += 1' skips execution of the next +instruction if it's a basic instruction or results in undefined behavior +if the next instruction is a 128-bit wide instruction. + The BPF program needs to store the return value into register R0 before doing an ``EXIT``.