From nobody Mon Feb 9 06:34:06 2026 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 36C6439E171 for ; Wed, 4 Feb 2026 09:01:36 +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=1770195697; cv=none; b=qkDlZmEdZ4GWRktNxggo6zpmyNPf6/EFhgyruFuGVZbvn1Y2eLR9wBHXFj3JnaIQc2o0Udl1ue8cBO5qz3bN0P43ZP4kfNJLxyaZGlocDn01Sc7L4oueXHAmSlVQdYJ5ik3aD1tIEnzTaOY51UnPNTzsY2sRh35Ca837qJrnnM0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770195697; c=relaxed/simple; bh=Yd0LYViJzg36CWeJ+K605t2VuFT0Zc7y8Lli4qzW2Zk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AA8m/6wj4K7WoEkbAucuZgDhp89znib8Z1sz7tpYviQyVBx+HnjLPi64h7h4SfmrX4g4wYaM5grp+vIkF/prufTVBViXrsorIXNQXc5BC3JA91U7Dhg33haQAtreE2LK15fN1QZPTFMhlt/KsNYwJcP9MTT5OgFrgxfmZljXxkc= 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=qb4JFLb4; 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="qb4JFLb4" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1770195695; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JUgIlqpjjjKsmTkW8jalrAzVxUqTtIlI0a7hWgOUGus=; b=qb4JFLb4WR4PhEKpDXKKSeOEg3T9iUuMYWzao8DhB0Maow2Ot7VfRx1u1uCpQ2IoKxxSmE 8ok6gQSIbSaEcFpHYlhI/wKY4afiTMY0HP+IUpQ+Jg/IqvGVwTTLb+0q5mU/1z5KN7k4Sv ogKq87qv1LveACxZHC/zgqhyceeXIDU= From: Hui Zhu To: Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Shuah Khan , Peter Zijlstra , Miguel Ojeda , Nathan Chancellor , Kees Cook , Tejun Heo , Jeff Xu , mkoutny@suse.com, Jan Hendrik Farr , Christian Brauner , Randy Dunlap , Brian Gerst , Masahiro Yamada , davem@davemloft.net, Jakub Kicinski , Jesper Dangaard Brouer , JP Kobryn , Willem de Bruijn , Jason Xing , Paul Chaignon , Anton Protopopov , Amery Hung , Chen Ridong , Lance Yang , Jiayuan Chen , linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Hui Zhu , Geliang Tang Subject: [RFC PATCH bpf-next v6 11/12] selftests/bpf: Add test for memcg_bpf_ops hierarchies Date: Wed, 4 Feb 2026 17:00:07 +0800 Message-ID: <031afcd7c16e97f1f3c0d4a8a526a9eee2ad23fd.1770194182.git.zhuhui@kylinos.cn> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Hui Zhu Add a new selftest, `test_memcg_ops_hierarchies`, to validate the behavior of attaching `memcg_bpf_ops` in a nested cgroup hierarchy, specifically testing the `BPF_F_ALLOW_OVERRIDE` flag. The test case performs the following steps: 1. Creates a three-level deep cgroup hierarchy: `/cg`, `/cg/cg`, and `/cg/cg/cg`. 2. Attaches a BPF struct_ops to the top-level cgroup (`/cg`) with the `BPF_F_ALLOW_OVERRIDE` flag. 3. Successfully attaches a new struct_ops to the middle cgroup (`/cg/cg`) without the flag, overriding the inherited one. 4. Asserts that attaching another struct_ops to the deepest cgroup (`/cg/cg/cg`) fails with -EBUSY, because its parent did not specify `BPF_F_ALLOW_OVERRIDE`. This test ensures that the attachment logic correctly enforces the override rules across a cgroup subtree. Signed-off-by: Geliang Tang Signed-off-by: Hui Zhu --- .../selftests/bpf/prog_tests/memcg_ops.c | 71 +++++++++++++++++++ 1 file changed, 71 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/memcg_ops.c b/tools/tes= ting/selftests/bpf/prog_tests/memcg_ops.c index 8c787439f83c..378ee3b3bc01 100644 --- a/tools/testing/selftests/bpf/prog_tests/memcg_ops.c +++ b/tools/testing/selftests/bpf/prog_tests/memcg_ops.c @@ -553,3 +553,74 @@ void test_memcg_ops_below_min_over_high(void) close(low_cgroup_fd); cleanup_cgroup_environment(); } + +void test_memcg_ops_hierarchies(void) +{ + int ret, first =3D -1, second =3D -1, third =3D -1; + struct memcg_ops *skel =3D NULL; + struct bpf_map *map; + struct bpf_link *link1 =3D NULL, *link2 =3D NULL, *link3 =3D NULL; + DECLARE_LIBBPF_OPTS(bpf_struct_ops_opts, opts); + + ret =3D setup_cgroup_environment(); + if (!ASSERT_OK(ret, "setup_cgroup_environment")) + goto cleanup; + + first =3D create_and_get_cgroup("/cg"); + if (!ASSERT_GE(first, 0, "create_and_get_cgroup /cg")) + goto cleanup; + ret =3D enable_controllers("/cg", "memory"); + if (!ASSERT_OK(ret, "enable_controllers")) + goto cleanup; + + second =3D create_and_get_cgroup("/cg/cg"); + if (!ASSERT_GE(second, 0, "create_and_get_cgroup /cg/cg")) + goto cleanup; + ret =3D enable_controllers("/cg/cg", "memory"); + if (!ASSERT_OK(ret, "enable_controllers")) + goto cleanup; + + third =3D create_and_get_cgroup("/cg/cg/cg"); + if (!ASSERT_GE(third, 0, "create_and_get_cgroup /cg/cg/cg")) + goto cleanup; + ret =3D enable_controllers("/cg/cg/cg", "memory"); + if (!ASSERT_OK(ret, "enable_controllers")) + goto cleanup; + + skel =3D memcg_ops__open_and_load(); + if (!ASSERT_OK_PTR(skel, "memcg_ops__open_and_load")) + goto cleanup; + + map =3D bpf_object__find_map_by_name(skel->obj, "low_mcg_ops"); + if (!ASSERT_OK_PTR(map, "bpf_object__find_map_by_name low_mcg_ops")) + goto cleanup; + + opts.relative_fd =3D first; + opts.flags =3D BPF_F_ALLOW_OVERRIDE; + link1 =3D bpf_map__attach_struct_ops_opts(map, &opts); + if (!ASSERT_OK_PTR(link1, "bpf_map__attach_struct_ops_opts")) + goto cleanup; + + opts.relative_fd =3D second; + opts.flags =3D 0; + link2 =3D bpf_map__attach_struct_ops_opts(map, &opts); + if (!ASSERT_OK_PTR(link2, "bpf_map__attach_struct_ops_opts")) + goto cleanup; + + opts.relative_fd =3D third; + opts.flags =3D 0; + link3 =3D bpf_map__attach_struct_ops_opts(map, &opts); + if (!ASSERT_ERR_PTR(link3, "bpf_map__attach_struct_ops_opts")) + goto cleanup; + +cleanup: + bpf_link__destroy(link1); + bpf_link__destroy(link2); + bpf_link__destroy(link3); + memcg_ops__detach(skel); + memcg_ops__destroy(skel); + close(first); + close(second); + close(third); + cleanup_cgroup_environment(); +} --=20 2.43.0