From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) (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 EF4B434D4D7 for ; Wed, 17 Dec 2025 16:28:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765988883; cv=none; b=m+TILjribO+aAWGBuMi5QQEUPXKI61U1omwjL2Oz0FUVKvPn57aM5yVQgU2sJFBBE6M4rZAxG/BsgB+CF2P4c65Q1WktTLLMsDZQ9GKGn/LaCCRDWvXXUXNZXn884s2DNlpeBxJc3l1Vf2hoNUm2LF2Tmgp2KjioxWAFZFs+wzY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765988883; c=relaxed/simple; bh=0v6GiZwQmw10VgYg7XmvF5rjkeue5FWN8L2ipdtQVmk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=c0KQKCrEqLWmNUsMmjDhoWuY/EEKMuIOXHbGYdNtWYfboQnq98d8SQqjf92PE/IUaFnoNry/Ydj48u+95rhNeL8vajy299aLZHv6aDd/6e9v35qzIItbXlEB9g7P8R6XQn8FPZADydIzjWELWmYPGEs90hfIjn+lb9JrPE5dxgs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=UbGQDrg+; arc=none smtp.client-ip=209.85.128.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="UbGQDrg+" Received: by mail-wm1-f53.google.com with SMTP id 5b1f17b1804b1-47a8195e515so49384045e9.0 for ; Wed, 17 Dec 2025 08:28:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1765988879; x=1766593679; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=AUIBRQ1EfMgD4rZghNrrxsliWBknI9gTPJQu3bDLcJY=; b=UbGQDrg+UUeEvVqqTzNHHL2CAtmr0I9eivMDfiPs4dvksQdkDU/B3/wR9FEybrFdHr SgIjdbP6RwhsIXv5PHq85HSnQFzcXVHnTKEStgGDukUaTAYffZ4OOz6dtGN1coTVe9FO Nehe2UuFXP6JgfANpbTmZK4g+WlyNCbIMgGcsLes3wNE3khOOdj7mNbWAcWsu+5PjlkQ 9+URkf7nYwCCb5XIlw3QHFKkzA9OnvR6QP/5eil33+qX9EZRYOuR4wlL5GM+Ay/sqnGv Jr4mfbsJdqrdkWD6uyWFIOvjMcABh1LW7b5DWRBxnP5rg6R4V2AHdYMWnYBuIaRN+gLy 72sQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1765988879; x=1766593679; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=AUIBRQ1EfMgD4rZghNrrxsliWBknI9gTPJQu3bDLcJY=; b=ne5gomIst4xQRlElt9Apwy2G4V12eiuXai513aHmSXwo81mxx14wtq9Q8WpV1/TMxL WeZNZmfj9HUTsIKOQsx0dsSSOqD75k/t/mua9JoqQC1ZfhfB+JLSiWQhuro1zNGQBlvB gh9Et5e2+m6OQiRoeif7JwAaBwJ5cdL6j5GRUwR101rbqbTsryfcI/XL6uJImwK2X00e GWzbmxXGioRaoqitjD63dQbx8ZuDxYfv7UTfYjqS/IrgxHKzpAO9yOwY2/GLuWLXga00 TWMl3Y7EK7QhRlHvG817WjwfBjEt/i+nsgIUhCz2/Vb+AGQV8/hNxj7ResYsYS0ZCm1c iX6Q== X-Forwarded-Encrypted: i=1; AJvYcCXlMcqRBa3USRh6uNUtgpW+kylE6REvtvvkew6/swLhRQ1k0HHIMl66sra0rqDZV8OjGjpw23Arrcp6SRQQwFQ=@vger.kernel.org X-Gm-Message-State: AOJu0YxOxHa2YDkItJBHYQAW1tm8OKdz5bCaY/9HLUfcTfDAnuDREZRn 8fAKu5n3dRq31HM+MzhDfsN+sMPneGgltKyD3JKRfksU4vA5tUIIS2YobgByVhx4duU= X-Gm-Gg: AY/fxX4AmG1aWYzgOHzybtCsIgNKxxy4XiS++XJC4f6XZ6tdUVfpP9h5Y8mMDdODNI2 lS+5KayVUFZ2PyZxYuab1KHIvD1x8lf3oT6ZRaZGPrYGVuknwUhThht/IemQx8toCQp89smDiV7 ImRgOQfJNoU3kur4ElIQQseo36PfyxLLACMLonlL8z5eBe92FEenkr44w4cN36GLrm0kdxGOeP1 I3+xrVZtr3oszaZEsGN9cNDTXv1KrhPnrJ7MseKT4GPTp6Yah8SKZD5B2liQn5JW4S82q7KVd2+ ldX1agrq80kMRG/46BvdfJampuHjkXJ13891Nw8EysNhPu+ZmSpFSNt8NXLaWJQGFXD4sxyEixc oXPyOS0hKczkWO/PrJZVhicLAeRzt5Ufyzq2U2yI3zX/+dbgRqNlUZKO0LtLrFHzltE8x1tkwEI 1ozqFX6Bg4uNboF+9OzNAlngmXJlAW+mY= X-Google-Smtp-Source: AGHT+IHGmMOUEefQoO5S3en43Zsul1QO3grq/W53kRWnWoSN5JrVJ1XTvQBX4MbJYn1xXsNPaQdx7A== X-Received: by 2002:a05:600c:5298:b0:46e:1a5e:211 with SMTP id 5b1f17b1804b1-47bdf5f0e9dmr21345875e9.21.1765988879254; Wed, 17 Dec 2025 08:27:59 -0800 (PST) Received: from blackdock.suse.cz (nat2.prg.suse.com. [195.250.132.146]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4310adeee0esm5728364f8f.29.2025.12.17.08.27.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Dec 2025 08:27:58 -0800 (PST) From: =?UTF-8?q?Michal=20Koutn=C3=BD?= To: linux-block@vger.kernel.org, bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, coreteam@netfilter.org, linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Cc: =?UTF-8?q?Michal=20Koutn=C3=BD?= , Hao Luo , Mathieu Desnoyers , Alexei Starovoitov , Phil Sutter , Yonghong Song , Jens Axboe , Jozsef Kadlecsik , Steven Rostedt , Martin KaFai Lau , KP Singh , Eric Dumazet , Florian Westphal , Jiri Olsa , Stanislav Fomichev , Song Liu , "David S. Miller" , Simon Horman , John Fastabend , Johannes Weiner , Daniel Borkmann , Andrii Nakryiko , Tejun Heo , Josef Bacik , Paolo Abeni , "Gustavo A. R. Silva" , Pablo Neira Ayuso , Eduard Zingerman , Yu Kuai , Masami Hiramatsu , Kees Cook , Jakub Kicinski Subject: [PATCH 0/4] Use __counted_by for ancestor arrays Date: Wed, 17 Dec 2025 17:27:32 +0100 Message-ID: <20251217162744.352391-1-mkoutny@suse.com> X-Mailer: git-send-email 2.52.0 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The trick with utilizing space in cgroup_root for cgroup::ancetors flex array was an obstacle for kernel reworks for -Wflex-array-member-not-at-end. The first patch fixes that, then I wanted to utilize __counted_by for this flex array which required some more rework how cgroup level is evaluated. Similar flex array is also in struct ioc_gq where it was tempting to simply use __counted_by(level), however, this would be off-by-one as it has semantics like cgroup's level (0 == root). Proper adjustment for __counted_by() would either need similar level/ancestor helpers or abstracted macros for ancestors up/down iterations. I only made a simple comment fixup since I'm not sure about benefit of __counted_by for structs that aren't sized based on direct user input. Michal Koutný (4): cgroup: Eliminate cgrp_ancestor_storage in cgroup_root cgroup: Introduce cgroup_level() helper cgroup: Use __counted_by for cgroup::ancestors blk-iocost: Correct comment ioc_gq::level block/bfq-iosched.c | 2 +- block/blk-iocost.c | 6 ++--- include/linux/cgroup-defs.h | 43 +++++++++++++++++++---------------- include/linux/cgroup.h | 18 ++++++++++++--- include/trace/events/cgroup.h | 8 +++---- kernel/bpf/helpers.c | 2 +- kernel/cgroup/cgroup.c | 9 ++++---- net/netfilter/nft_socket.c | 2 +- 8 files changed, 53 insertions(+), 37 deletions(-) base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8 -- 2.52.0