From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EB3521F8AC5; Fri, 20 Feb 2026 15:16:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771600575; cv=none; b=bNfA3lnGpkZ1MaFdgY5JWkbM5OZI9TuZfCH9gZOdkreytpYb73C1tKCvYTZS+7tn7cnEu4DvAOkQcCE9ly+Is3y4kw+PW2Ny70J9qBWziD4ALkn8PRdg578rkW14kvogCr4Un90l99/WYRBAW4OkNxOEegeA3+egbSPi4HhqP5o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771600575; c=relaxed/simple; bh=oJZ5mIZ3ij+o3W18OBkwZ5UnpiFkSZVFTsT01xsl0to=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dYkGS2xdlCfKKUO6KKLn4YKvoTsMSixQ3OV54s809H3QI3hHgzpimkOiwMKKm9T0V8VyBtW4wJvIKo/FkoZe/uSpjfVjfTi/H6zdBXygR6vMOiHvDfSdkDb8bnPOjstlgsgwfrr9OM9DoNQ8ZZSOgdfHzBBDoCeem+M8cXmtoZI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ngyze6Dx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ngyze6Dx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73915C116C6; Fri, 20 Feb 2026 15:16:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771600574; bh=oJZ5mIZ3ij+o3W18OBkwZ5UnpiFkSZVFTsT01xsl0to=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ngyze6Dxy3vg+Zm+5uszt9yY4cI2qmN5WCKD9pctPfF3+S4X9NW/CtMsr64KtJZvC zyuiWJeFZ8mz94+2BYnvUFNEklpAp1hmoM/4HVo2Q/LqwJCqQZBzTkrr1JvgEeH7M/ GqjFk0pGtIJNy0yXPFpwWXRSePQG12JwLIB3SktQFnui0cGxVc9eRkjKaEvTvI24SW nIcvmGS/X8d8295PxHBgzArP30Nry01Y/krJMKjDF3MDaBVByRw9mqdCUrpj4xUqtk XY8zBLfF1pHNZFJJTP1hEviYPhNB/RgMkPUIZmhr6zKIAxDJiS/sL2YLmzZ3H0M0G7 g9+SHAl6MDf5w== Date: Fri, 20 Feb 2026 05:16:13 -1000 From: Tejun Heo To: Christian Brauner Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , KP Singh , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Lennart Poettering Subject: Re: [PATCH 2/4] cgroup: add bpf hook for attach Message-ID: References: <20260220-work-bpf-namespace-v1-0-866207db7b83@kernel.org> <20260220-work-bpf-namespace-v1-2-866207db7b83@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260220-work-bpf-namespace-v1-2-866207db7b83@kernel.org> Hello, On Fri, Feb 20, 2026 at 01:38:30AM +0100, Christian Brauner wrote: > Add a hook to manage attaching tasks to cgroup. I'm in the process of > adding various "universal truth" bpf programs to systemd that will make > use of this. > > This has been a long-standing request (cf. [1] and [2]). It will allow us to > enforce cgroup migrations and ensure that services can never escape their > cgroups. This is just one of many use-cases. >From cgroup POV, this looks fine to me but I'm curious whether something dumber would also work. With CLONE_INTO_CGROUP, cgroup migration isn't necessary at all. Would something dumber like a mount option disabling cgroup migrations completely work too or would that be too restrictive? Thanks. -- tejun