From: Dave Thaler <dthaler@xxxxxxxxxxxxx> Improve clarity by adding an example of a signed comparison instruction Signed-off-by: Dave Thaler <dthaler@xxxxxxxxxxxxx> --- Documentation/bpf/instruction-set.rst | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst index 5e43e14abe8..b4464058905 100644 --- a/Documentation/bpf/instruction-set.rst +++ b/Documentation/bpf/instruction-set.rst @@ -11,7 +11,8 @@ 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. +to mean an unsigned integer whose width is the specified number of bits, +and "s32", etc. to mean a signed integer of the specified number of bits. Registers and calling convention ================================ @@ -264,6 +265,14 @@ BPF_JSLE 0xd0 PC += off if dst <= src signed The eBPF program needs to store the return value into register R0 before doing a BPF_EXIT. +Example: + +``BPF_JSGE | BPF_X | BPF_JMP32`` (0x7e) means:: + + if (s32)dst s>= (s32)src goto +offset + +where 's>=' indicates a signed '>=' comparison. + Helper functions ~~~~~~~~~~~~~~~~ -- 2.33.4
