From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-184.mta0.migadu.com (out-184.mta0.migadu.com [91.218.175.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3F3B630DD3C for ; Mon, 13 Apr 2026 16:38:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.184 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776098286; cv=none; b=h6nREHxv/0Ond+K+9aTcFdbHYDqT9ox2Ux9KoWQ8fcoWr3IH2r+Pi3dGMXwpN+uZWeJpnpbr4b4Tvg29Kvphe+xCn2ytPukPkoKKgk/3c1HS6V+IwOYtYX80xw7N5LJCKZXi87dpXsLVsj0SWcQVzbzSR9Fk/x5G9IVJjplmr3M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776098286; c=relaxed/simple; bh=LsirsLNtt39wTKZPA+YTGKYfOI/MUdjDa3ENx9IOl/M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=JHCOcjiNDEJ8LshfJBDY0HzhEogCSajtXo71/wA81kQdRLr6LPS9gJMkwnJVUSF4dYIVRJt//N8zlke0KwwjP0s9kM6qE3dUfaWjtbCgyYXKuTU7Cm54RY9QAVnCgBujjzkdl24E++Jr62RT0YUoVoBlY75T6zTgS6DKUr3+9c8= 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=DA0Gv6nh; arc=none smtp.client-ip=91.218.175.184 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="DA0Gv6nh" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1776098283; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WWD2CmAX77KCX9SDFhxRCe+HNXaaKB/BBPC6P69rvJo=; b=DA0Gv6nhocj7o+h/3+4qNSYLo6g/GMxw4+hOV5jrKXg6j60eMD5k0VlZ+E0YrMH65y/pET glrP5bmLhdHJco3yJGxSWZw3IymN8j5QvFXWyTSfdNX/SggflP5spQ3+px8hSIDPoTWu8Z xarnkU5vq6GIbq1Jc4C4DeDfuLvlP8U= Date: Mon, 13 Apr 2026 09:37:42 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v4 12/18] bpf: Reject stack arguments if tail call reachable Content-Language: en-GB To: bot+bpf-ci@kernel.org, bpf@vger.kernel.org Cc: ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, jose.marchesi@oracle.com, kernel-team@fb.com, martin.lau@kernel.org, eddyz87@gmail.com, clm@meta.com, ihor.solodrai@linux.dev References: <20260412050010.266625-1-yonghong.song@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yonghong Song In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 4/11/26 10:43 PM, bot+bpf-ci@kernel.org wrote: >> Tailcalls are been deprecated. So reject stack arguments >> if tail call is in the way. > The commit message has a grammar issue ("are been" should probably > be "have been" or "are being"), but more importantly, is the claim > that tail calls are deprecated accurate? > > Looking at the mailing list discussion on the v1 series, Alexei's > guidance was "let's disallow mixing 6+ args and tailcalls" due to > stack frame layout incompatibility, not because tail calls are being > deprecated. > > Could the commit message more precisely describe the actual > reason for the restriction? Something along the lines of "tail > calls and stack arguments require incompatible stack frame > handling" would better explain to future readers why the > combination is rejected. Okay. Will update the commit message. > > > --- > AI reviewed your patch. Please fix the bug or email reply why it's not a bug. > See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md > > CI run summary: https://github.com/kernel-patches/bpf/actions/runs/24299298635