From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta0.migadu.com (out-189.mta0.migadu.com [91.218.175.189]) (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 6D00C2D0638 for ; Tue, 4 Nov 2025 22:38:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762295892; cv=none; b=GKkaCzXAXsh+M5kFemAg35OBog8TKW/4GTbyFjpG5kxYJ8EkZDzXQyFpLhorpbShYv9cVRoZu0cQnXszhWaXGTxfM4GT6FdG/8exp8P/S8DFbShXT9nJ/pFPNfol+IOMmdcCq/se37YIb6lLA3pytqY/AkmTDLQrp3hb7j7UcWQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762295892; c=relaxed/simple; bh=7MF25Q3wGEEdGh4DIpFO74rrmUwNRw+dQhOkjPEMyv4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ZWKjL2L2erjqet0C7dcVBWdsQ51E0qvUAOCDVHCnZuw04nhtKy02FDT6QDsDxEp0vqB5WPqPBiWozcaMu17i0twkpKNwxUnuZT8uIudAIf+17g3INqKfE5FpJ5ViPK8Qe3Al97hKrexWV7+/nZri1mc8wtRswibC1EstKR0NPeE= 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=MVnkouY2; arc=none smtp.client-ip=91.218.175.189 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="MVnkouY2" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1762295886; 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=/QNbliKAyYhVskCt0RxnSd6MsBLzbaJ7Vz7N7Wd9qUk=; b=MVnkouY2EKqMrWBWXYOtKdS51DptXK1CWOZrbPw0jMycU1s0No4L0sohkltPPQv2S6QMp4 qQqUED3GgkpnphkfBsQBc6FVZdhPWtGWASLO1hhEqS/y1ap2ZxWSqHaMO5T9bV2ya9YKcK RuGpt5cuqooOuAhTzZyyNLHbTDXtMcE= Date: Tue, 4 Nov 2025 14:37:59 -0800 Precedence: bulk X-Mailing-List: dwarves@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH dwarves v1 0/3] btf_encoder: support for BPF magic kernel functions To: Eduard Zingerman , Alan Maguire , andrii@kernel.org, dwarves@vger.kernel.org, acme@kernel.org Cc: bpf@vger.kernel.org, ast@kernel.org, tj@kernel.org, kernel-team@meta.com References: <20251029190249.3323752-1-ihor.solodrai@linux.dev> <517837f0-127e-42bc-83f4-2c85203ef468@oracle.com> <0db4e51eed95f9d4616ff5936d335ae71ac2a016.camel@gmail.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Ihor Solodrai In-Reply-To: <0db4e51eed95f9d4616ff5936d335ae71ac2a016.camel@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 11/4/25 2:33 PM, Eduard Zingerman wrote: > On Tue, 2025-11-04 at 14:25 -0800, Ihor Solodrai wrote: >> On 11/4/25 12:59 PM, Alan Maguire wrote: >>> On 29/10/2025 19:02, Ihor Solodrai wrote: >>>> This series implements BTF encoding of BPF kernel functions marked >>>> with KF_MAGIC_ARGS flag in pahole. >>>> >>>> The kfunc flag indicates that the arguments of a kfunc with __magic >>>> suffix are implicitly set by the verifier, and so pahole must emit two >>>> functions to BTF: >>>> * kfunc_impl() with the arguments matching kernel declaration >>>> * kfunc() with __magic arguments omitted >>>> >>>> For more details see relevant patch series for BPF: >>>> "bpf: magic kernel functions" >>>> >>>> This series is built upon KF_IMPLICIT_PROG_AUX_ARG support [1], >>>> although the approach changed signifcantly to call it a v2. >>>> >>>> [1] https://lore.kernel.org/dwarves/20250924211512.1287298-1-ihor.solodrai@linux.dev/ >>>> >>>> Ihor Solodrai (3): >>>> btf_encoder: refactor btf_encoder__add_func_proto >>>> btf_encoder: factor out btf_encoder__add_bpf_kfunc() >>>> btf_encoder: support kfuncs with KF_MAGIC_ARGS flag >>>> >>>> btf_encoder.c | 292 ++++++++++++++++++++++++++++++++++++++------------ >>>> 1 file changed, 222 insertions(+), 70 deletions(-) >>>> >>> >>> seems like we could potentially pull in patches 1 and 2 as cleanups >>> prior to handling the KF_MAGIC/IMPLICIT change; would that be worthwhile? >>> >> >> Hi Alan. >> >> Feel free to merge in the refactoring patches if you think they are >> useful. No objections. > > Hi Alan, Ihor, > > If you thinking about merging patch #1, please consider my comment: > > > > +static int32_t btf_encoder__add_func_proto_for_state(struct btf_encoder *encoder, struct btf_encoder_func_state *state) > > > You can get rid of the `encoder` parameter here. > > See https://github.com/acmel/dwarves/commit/080d1f27ae71e30c269a1e26e85bb86c3683f195 . > > I sound a bit like a broken record, sorry. Oh, thanks for the ping, I missed this comment. Alan, let me re-spin the refactoring patches separately. > > [...]