From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-171.mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) (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 25B073328E5 for ; Mon, 27 Oct 2025 23:22:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761607366; cv=none; b=FgXDy6turxuJaEw2CrvLE+EEa5dkab9D9+Y45wbnR4mzFR6FwQDvg+TVyrkWqZo9/WG7uwU0XDxT1YmcwprSqXmyFtCMQcWoEe3SH4O7oouznUPVOFTWBDDEPFSbAsE8PQsZX+Ak9ix0LmAWLf5KriOutl8vpgvXSYCKaab1584= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761607366; c=relaxed/simple; bh=xkUl2/NCrVjAluUScBtGf1qkHK3ETgy7/lVU2ik/bYY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uvmiekJRu3aUNdGDYAldWB5XHWJ1IN+KHAlioIZSGE+DStMSSZiU8f4AJLfVpNmijpq9CRN3s1phePq3wBk/DnTQ46D5mbbXocdjPx9yv5hUul0wJ8QbjWyKb+65py99jjjKt8BYQtVBa6jniPoooLh/gA4JC433Nr3ELL7yQek= 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=E2R/gY6d; arc=none smtp.client-ip=91.218.175.171 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="E2R/gY6d" 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=1761607362; 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=3AWwjc0UoLvD3R3stojTytlItHxwa9yZiXLoT7TlRbg=; b=E2R/gY6dpHc7tWdh2+SxrYb70jSrc+m4mTkzm8fiv+R208YyNOi5toAkZJW+XpSTdsRMWG CxfajUVb7/hMGhEZW+K68iAgYHlMVmvljO29+sOcgPtnnkNVwvK8Y5EVxdZ2tjl1QNwByj 5Ilr9Kh1kpumgiJSwtKp99IyxtK+EJI= From: Roman Gushchin To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Alexei Starovoitov , Suren Baghdasaryan , Michal Hocko , Shakeel Butt , Johannes Weiner , Andrii Nakryiko , JP Kobryn , linux-mm@kvack.org, cgroups@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Kumar Kartikeya Dwivedi , Tejun Heo , Roman Gushchin Subject: [PATCH v2 16/23] libbpf: introduce bpf_map__attach_struct_ops_opts() Date: Mon, 27 Oct 2025 16:21:59 -0700 Message-ID: <20251027232206.473085-6-roman.gushchin@linux.dev> In-Reply-To: <20251027232206.473085-1-roman.gushchin@linux.dev> References: <20251027232206.473085-1-roman.gushchin@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Introduce bpf_map__attach_struct_ops_opts(), an extended version of bpf_map__attach_struct_ops(), which takes additional struct bpf_struct_ops_opts argument. struct bpf_struct_ops_opts has the relative_fd member, which allows to pass an additional file descriptor argument. It can be used to attach struct ops maps to cgroups. Signed-off-by: Roman Gushchin --- tools/lib/bpf/bpf.c | 8 ++++++++ tools/lib/bpf/libbpf.c | 18 ++++++++++++++++-- tools/lib/bpf/libbpf.h | 14 ++++++++++++++ tools/lib/bpf/libbpf.map | 1 + 4 files changed, 39 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 339b19797237..4c8944f8d6ba 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -883,6 +883,14 @@ int bpf_link_create(int prog_fd, int target_fd, if (!OPTS_ZEROED(opts, cgroup)) return libbpf_err(-EINVAL); break; + case BPF_STRUCT_OPS: + relative_fd = OPTS_GET(opts, cgroup.relative_fd, 0); + attr.link_create.cgroup.relative_fd = relative_fd; + attr.link_create.cgroup.expected_revision = + OPTS_GET(opts, cgroup.expected_revision, 0); + if (!OPTS_ZEROED(opts, cgroup)) + return libbpf_err(-EINVAL); + break; default: if (!OPTS_ZEROED(opts, flags)) return libbpf_err(-EINVAL); diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index b90574f39d1c..be56a5dee505 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -13196,12 +13196,19 @@ static int bpf_link__detach_struct_ops(struct bpf_link *link) return close(link->fd); } -struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map) +struct bpf_link *bpf_map__attach_struct_ops_opts(const struct bpf_map *map, + const struct bpf_struct_ops_opts *opts) { + DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts); struct bpf_link_struct_ops *link; __u32 zero = 0; int err, fd; + if (!OPTS_VALID(opts, bpf_struct_ops_opts)) { + pr_warn("map '%s': invalid opts\n", map->name); + return libbpf_err_ptr(-EINVAL); + } + if (!bpf_map__is_struct_ops(map)) { pr_warn("map '%s': can't attach non-struct_ops map\n", map->name); return libbpf_err_ptr(-EINVAL); @@ -13237,7 +13244,9 @@ struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map) return &link->link; } - fd = bpf_link_create(map->fd, 0, BPF_STRUCT_OPS, NULL); + link_opts.cgroup.relative_fd = OPTS_GET(opts, relative_fd, 0); + + fd = bpf_link_create(map->fd, 0, BPF_STRUCT_OPS, &link_opts); if (fd < 0) { free(link); return libbpf_err_ptr(fd); @@ -13249,6 +13258,11 @@ struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map) return &link->link; } +struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map) +{ + return bpf_map__attach_struct_ops_opts(map, NULL); +} + /* * Swap the back struct_ops of a link with a new struct_ops map. */ diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 5118d0a90e24..dc84898715cf 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -922,6 +922,20 @@ bpf_program__attach_cgroup_opts(const struct bpf_program *prog, int cgroup_fd, struct bpf_map; LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map); + +struct bpf_struct_ops_opts { + /* size of this struct, for forward/backward compatibility */ + size_t sz; + __u32 flags; + __u32 relative_fd; + __u64 expected_revision; + size_t :0; +}; +#define bpf_struct_ops_opts__last_field expected_revision + +LIBBPF_API struct bpf_link * +bpf_map__attach_struct_ops_opts(const struct bpf_map *map, + const struct bpf_struct_ops_opts *opts); LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map); struct bpf_iter_attach_opts { diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 8ed8749907d4..bc00089343ce 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -451,4 +451,5 @@ LIBBPF_1.7.0 { global: bpf_map__set_exclusive_program; bpf_map__exclusive_program; + bpf_map__attach_struct_ops_opts; } LIBBPF_1.6.0; -- 2.51.0