Re: [PATCH bpf-next v4 08/20] bpf: Walk the exception unwind in the verifier

["Alexei Starovoitov" <alexei.starovoitov@gmail.com>]

On Mon Sep 21, 2026 at 9:01 PM UTC, Yonghong Song wrote:
> --- /dev/null
> +++ b/include/linux/bpf_cleanup_abi.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */
> +#ifndef _LINUX_BPF_CLEANUP_ABI_H
> +#define _LINUX_BPF_CLEANUP_ABI_H
> +
> +/*
> + * Value arch_bpf_run_cleanup_pad() leaves in r0 on the way into a landing pad.
> + * It has to be a constant the verifier knows: LLVM names r0 as both the
> + * exception pointer and the exception selector register, so every pad reads it
> + * before anything else and is free to store what it read. It gets a header of
> + * its own because the two sides that have to agree on it are the verifier and
> + * the arch dispatchers, which are assembly.
> + */
> +#define BPF_PAD_ENTRY_R0	1
> +
> +#endif /* _LINUX_BPF_CLEANUP_ABI_H */

I'm not going to read the AI reasons in commit log that it came up with
to justify new .h.
I bet it doesn't need new .h. If it does, please spell it out with human voice.
And, in general, pls tell AI to be terse. and remember it forever.

I told my clanker to be like me. Terse and to the point.