From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4C05C2D0C6 for ; Fri, 27 Dec 2019 12:22:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B634F20CC7 for ; Fri, 27 Dec 2019 12:22:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727060AbfL0MV6 (ORCPT ); Fri, 27 Dec 2019 07:21:58 -0500 Received: from mx2.suse.de ([195.135.220.15]:38838 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726379AbfL0MVu (ORCPT ); Fri, 27 Dec 2019 07:21:50 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 62D25B277; Fri, 27 Dec 2019 12:21:48 +0000 (UTC) From: Michal Rostecki To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Michal Rostecki Subject: [PATCH bpf-next 1/2] libbpf: Add probe for large INSN limit Date: Fri, 27 Dec 2019 12:06:04 +0100 Message-Id: <20191227110605.1757-2-mrostecki@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20191227110605.1757-1-mrostecki@suse.de> References: <20191227110605.1757-1-mrostecki@suse.de> Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Introduce a new probe which checks whether kernel has large maximum program size (1M) which was increased in commit c04c0d2b968a ("bpf: increase complexity limit and maximum program size"). Based on the similar check in Cilium[0], authored by Daniel Borkmann. [0] https://github.com/cilium/cilium/commit/657d0f585afd26232cfa5d4e70b6f64d2ea91596 Co-authored-by: Daniel Borkmann Signed-off-by: Michal Rostecki --- tools/lib/bpf/libbpf.h | 1 + tools/lib/bpf/libbpf.map | 1 + tools/lib/bpf/libbpf_probes.c | 23 +++++++++++++++++++++++ 3 files changed, 25 insertions(+) diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index fe592ef48f1b..26bf539f1b3c 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -521,6 +521,7 @@ LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type, LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex); LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id, enum bpf_prog_type prog_type, __u32 ifindex); +LIBBPF_API bool bpf_probe_large_insn_limit(__u32 ifindex); /* * Get bpf_prog_info in continuous memory diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index e9713a574243..b300d74c921a 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -219,6 +219,7 @@ LIBBPF_0.0.7 { bpf_object__detach_skeleton; bpf_object__load_skeleton; bpf_object__open_skeleton; + bpf_probe_large_insn_limit; bpf_prog_attach_xattr; bpf_program__attach; bpf_program__name; diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index a9eb8b322671..925f95106a52 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -17,6 +17,8 @@ #include "libbpf.h" #include "libbpf_internal.h" +#define INSN_REPEAT 4128 + static bool grep(const char *buffer, const char *pattern) { return !!strstr(buffer, pattern); @@ -321,3 +323,24 @@ bool bpf_probe_helper(enum bpf_func_id id, enum bpf_prog_type prog_type, return res; } + +/* + * Probe for availability of kernel commit (5.3): + * + * c04c0d2b968a ("bpf: increase complexity limit and maximum program size") + */ +bool bpf_probe_large_insn_limit(__u32 ifindex) +{ + struct bpf_insn insns[INSN_REPEAT + 1]; + int i; + + for (i = 0; i < INSN_REPEAT; i++) + insns[i] = BPF_MOV64_IMM(BPF_REG_0, 1); + insns[INSN_REPEAT] = BPF_EXIT_INSN(); + + errno = 0; + probe_load(BPF_PROG_TYPE_SCHED_CLS, insns, ARRAY_SIZE(insns), NULL, 0, + ifindex); + + return errno != E2BIG && errno != EINVAL; +} -- 2.16.4