In the documentation of the eBPF ISA it is unspecified how integers are represented. Specify that twos complement is used. Signed-off-by: Will Hawkins <hawkinsw@xxxxxx> --- Documentation/bpf/instruction-set.rst | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst index 751e657973f0..63dfcba5eb9a 100644 --- a/Documentation/bpf/instruction-set.rst +++ b/Documentation/bpf/instruction-set.rst @@ -173,6 +173,11 @@ BPF_ARSH 0xc0 sign extending dst >>= (src & mask) BPF_END 0xd0 byte swap operations (see `Byte swap instructions`_ below) ======== ===== ========================================================== +eBPF supports 32- and 64-bit signed and unsigned integers. It does +not support floating-point data types. All signed integers are represented in +twos-complement format where the sign bit is stored in the most-significant +bit. + Underflow and overflow are allowed during arithmetic operations, meaning the 64-bit or 32-bit value will wrap. If eBPF program execution would result in division by zero, the destination register is instead set to zero. -- 2.40.1
