Re: [PATCH 1/4] bpf, docs: Add note about type convention

[sdf@google.com]

On 10/27, dthaler1968@googlemail.com wrote:
> From: Dave Thaler <dthaler@microsoft.com>

> Add note about type convention

> Signed-off-by: Dave Thaler <dthaler@microsoft.com>

For the series:
Acked-by: Stanislav Fomichev <sdf@google.com>

Carry-on from my shift last week.

> ---
>   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 5d798437d..bed6d33fc 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
>   ================================
> @@ -116,6 +121,8 @@ BPF_END   0xd0   byte swap operations (see `Byte swap  
> instructions`_ below)

>     dst_reg = (u32) dst_reg + (u32) src_reg;

> +where '(u32)' indicates truncation to 32 bits.
> +
>   ``BPF_ADD | BPF_X | BPF_ALU64`` means::

>     dst_reg = dst_reg + src_reg
> --
> 2.33.4