From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) (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 D452326A1A7 for ; Tue, 30 Jun 2026 02:14:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782785680; cv=none; b=llp+8e9DSuNIJO4gq0TVDjTxAM8PEMur4XSgGX2FjFELqNLFbPsfyCpH5LpUwC1RywIxWsOgPmMxAJsk09UPYLilxM/dtaYP1hJtTw/+pGHF/SPc/va166bj10unL6cY7w8UkOUA5pKdDYZbPB+Z9U2D6XXuHsUr7pdxwjPLyzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782785680; c=relaxed/simple; bh=FQzy4cAfERQWKiFWqRGsLShXKr3V3U1l/gdATRjlQfU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=PJ6U2o5rjfBt5R+M0RBkYeHe3ZtTzfDoW+RFcy9Yfo6BL60+gypohQqU7gBkOsmAsej9S6HE5NDaA2tCXq+/NW049+8W1YAT9lw76aKbbAb+LbD/ZVgq/Ujt3oHX/Rd9wbC7jc3+qzd06iWfesYBIG8ToDy78GT4eJQ2jARq32M= 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=KxvJ+REr; arc=none smtp.client-ip=91.218.175.179 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="KxvJ+REr" Message-ID: <1f10e056-744e-45bf-af93-6192668be79c@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1782785666; 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=mpOKK/yk1zJCi69ZRKcl4qzI64WcdOOVWQyvaUeEG5M=; b=KxvJ+RErUVdsIcTzHUauiPGpgFaJYeNeeljI4FYbDkJ5uyMper9cKs25ngrLuVHQ0N5sxD DRbkYqTsbMLLxUQYQWJ1uih8UO3xMqZL+aaEjtqMNM1afh0MhS6djvWkjlJuzrVk5JeWFj GU4C0N4xuR6VGNPH3jEH/aL0beJfRFM= Date: Tue, 30 Jun 2026 10:14:17 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [RFC PATCH bpf-next 00/12] bpf: Introduce static-defined tracing probe for BPF Content-Language: en-US To: Xu Kuohai , bpf@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Yonghong Song , Jiri Olsa , KP Singh , Anton Protopopov , Amery Hung , Eyal Birger , Rong Tao References: <855e44f3-d22c-47e5-8bd1-c5d9f7014a75@linux.dev> <55499fcf-d552-4366-9016-21ede7f687ac@huaweicloud.com> <4f30012f-778b-4c7d-b610-2e18cf01abdd@linux.dev> <678ec73d-06f1-4860-94be-be000ca462d4@huaweicloud.com> <8ea18b6a-932c-4eb0-a536-d52ce3e1f457@huaweicloud.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Leon Hwang In-Reply-To: <8ea18b6a-932c-4eb0-a536-d52ce3e1f457@huaweicloud.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 30/6/26 09:19, Xu Kuohai wrote: > On 6/29/2026 9:53 PM, Leon Hwang wrote: > > So it is more of a user-space workaround than a formal solution. And even > for this workaround, there is no need to add a new libbpf API to remove the > stub. You can simply build two versions of bpf prog, one with subprog and > one without. When you need to trace fentry, load the first one; otherwise, > load the second one. Yep. > > What SDT resolves is dynamic tracing after the prog is loaded, the hacking > before loading does not apply. > I think current implementation is too complicated to justify this kind of workaround. I'd be more comfortable with a simpler approach. Thanks, Leon