From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-2.mta1.migadu.com [95.215.58.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8CC833403E8 for ; Tue, 22 Sep 2026 05:25:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.2 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790054748; cv=none; b=sYOgLXL7col4s1Vd7SrVkkNXEUozGCV4xGRzRyojtCaYOMcL0oH9bmORnmmjIwcnkPpkoA43PUinR2P/YRHy/UO7WBLcOzift0p8SEektKUCtgIbYy3agTLixjGXBUfvZkBdw126a6T74hG4N4+97bgmtgnLJekfvyHOUyBWDVM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790054748; c=relaxed/simple; bh=oM0Z9qnK1z/kGJqxnex+d3x6p3Fh/VaA5BaQgsUYQmc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=SeePCPUoGoFhypEOINoKyFzpVLbUjj/yQpBw7w5wQfzbYpSgi5/s9EXZQXHPbkeDB6mH1XEp8xtV0Aulz8k2HNN4WGboi4uzlPea3xuxF6jAkv9xgi3g6B0a9Yw5/QbN7h24VSVTnmD7urmr6ydlJcNTTQlTEF/xpvblGbpjNpk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=BLU6wYC2; arc=none smtp.client-ip=95.215.58.2 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="BLU6wYC2" X-Envelope-To: bpf@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=oM0Z9qnK1z/kGJqxnex+d3x6p3Fh/VaA5BaQgsUYQmc=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790054741; v=1; x=1790659541; b=BLU6wYC2MXuN6qRlulEgYV6B0h2j2PNJmHPkuSwxjfcvnTolKx7OcAVOscvE8J9ar/pD5ySV 7O38Ekryou/8uQMgIctALMGKpB5USIfNtMNOi+Zko2f6f8W/7KkezKZwjpcXgc5gSmf4sspsfbY BwHya1CYcsot9DtIcl3DdHbE= X-Envelope-To: bpf@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id dcbe5487e574394c; Tue, 22 Sep 2026 05:25:41 +0000 X-Mizu-Trace-ID: dcbe5487e574394c X-Migadu-Flow: FLOW_OUT Message-ID: Date: Mon, 21 Sep 2026 22:25:38 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH bpf-next v4 08/20] bpf: Walk the exception unwind in the verifier Content-Language: en-GB To: Alexei Starovoitov , bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Eduard Zingerman , kernel-team@fb.com References: <20260921210033.1715000-1-yonghong.song@linux.dev> <20260921210114.1720196-1-yonghong.song@linux.dev> From: Yonghong Song In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 9/21/26 9:08 PM, Alexei Starovoitov wrote: > 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. Okay, I added this file to be shared in x86/net/bpf_cleanup_pad.S, arm64/net/bpf_cleanup_pad.S and verifier.c. Yes, we can remove it with single line comment in their respective files.