Re: [PATCH bpf-next v2] arm64,bpf: Support struct arguments in the BPF trampoline

[Xu Kuohai]

On 5/11/2023 10:05 PM, Florent Revest wrote:
> This extends the BPF trampoline JIT to support attachment to functions
> that take small structures (up to 128bit) as argument. This is trivially
> achieved by saving/restoring a number of "argument registers" rather
> than a number of arguments.
>
> The AAPCS64 section 6.8.2 describes the parameter passing ABI.
> "Composite types" (like C structs) below 16 bytes (as enforced by the
> BPF verifier) are provided as part of the 8 argument registers as
> explained in the section C.12.
>
> Signed-off-by: Florent Revest <revest@xxxxxxxxxxxx>
> Acked-by: Yonghong Song <yhs@xxxxxx>
> ---
>
> Diff since v1: The stack layout comment now says "arg reg" instead of "arg".

LGTM. Thanks for updating the description.