From nobody Mon Feb 9 09:16:19 2026 Received: from out-172.mta1.migadu.com (out-172.mta1.migadu.com [95.215.58.172]) (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 C4193324B1D for ; Fri, 23 Jan 2026 09:02:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769158964; cv=none; b=DISuTmkqXj8nTGP3lrzN6O7ERE0ARQtv+/mqMKqsMmMXN9LDC5vGobK27VyL/AvKbelDSKV6K5NGTpxyMvVqxuUUDw2v9bXYTFHi1O/ss7CFg1e3/0o9WauxA9FYTh24LQmjPLHkf71wOJDS2N6TvTNy1iNj0lYvQRpcmJnmRhk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769158964; c=relaxed/simple; bh=cHHyeHa84VKYKc+fClfF1pIYHBp7EHYVUi+qkwVe0cE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SI7jkSG0YgnpGTGnTEaLc585dwHe1jaJhSbs9+AwRqWooZ9ELsURsvFBGlFfCuT7iPoWDUA61SXuOst8MWu4wLxblCUKAYuDrdOYnN8gB1pYgpYku4sr64+ES5eyyTrEYk3CHDrop5iiwvEIxAfTNuvnfjyBDeOOQl+CZbVCBfE= 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=wJHq11Pr; arc=none smtp.client-ip=95.215.58.172 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="wJHq11Pr" 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=1769158950; 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=3iLrjiv0gburAFEhS5XqHyT8faYM4NGG2Wz0oK9Qdf4=; b=wJHq11Pr0GtVVpulWuS2H7wQCNNdItz0NY2nkgb6vSa3RZXwQxkbhqsUeYiPsYfKmvchNj 8rb/XPQ/7gZHndK/RYsb4oM88oS1AN7JHx/F/2CE0WDV3dM+lYhsd1TvOWQaVrrDDvXsqB KOmnqEtcE6XYQWOHeU9x//WaEErpY50= 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 v3 11/12] selftests/bpf: Add test for memcg_bpf_ops hierarchies Date: Fri, 23 Jan 2026 17:01:54 +0800 Message-ID: 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 | 69 +++++++++++++++++++ 1 file changed, 69 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 9a8d16296f2d..bab9f3094f59 100644 --- a/tools/testing/selftests/bpf/prog_tests/memcg_ops.c +++ b/tools/testing/selftests/bpf/prog_tests/memcg_ops.c @@ -535,3 +535,72 @@ 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; + 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; + link2 =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); + memcg_ops__detach(skel); + close(first); + close(second); + close(third); + cleanup_cgroup_environment(); +} --=20 2.43.0