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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 725BEC3A5A3 for ; Thu, 29 Aug 2019 18:34:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F96F205C9 for ; Thu, 29 Aug 2019 18:34:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567103668; bh=hkBnbXIj4Ow5ukHzAWFpSqN0IRB8d7dNXP7A+zZpRBQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i0n5MXskySxfr/YjEarkILi40W+Kzc8iGb9YKJVljAAtQtdv1ijh7K8Z3KwLonr4j 2NB5tFp5p4F75Jo5GiTzM7f6cmB7IRcPUcRGwnkSBTamApAISUbWFr1tJIO+RIRY1T f6WSr+JpeZg3Hv0053vaTwh1hqKdf7+SWHnXOzPI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728161AbfH2SNV (ORCPT ); Thu, 29 Aug 2019 14:13:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:55070 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727087AbfH2SNR (ORCPT ); Thu, 29 Aug 2019 14:13:17 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 67AC12189D; Thu, 29 Aug 2019 18:13:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567102396; bh=hkBnbXIj4Ow5ukHzAWFpSqN0IRB8d7dNXP7A+zZpRBQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qtxi24umdUcuSRIwdfk7cQXF9cWXQuDwXySud/jP4Yb1VydCYv1vxcTVEmOFlYLix DnOO0zrNtbjc7N5iw5smu2WgFVdqBeRRrn/pCf0RADLso02pyRUR40r5wgBvH7oqLr NhoRCbGxY4kMc8AcjRPeclf+lUt1g1TI+QBbHrY8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Andrii Nakryiko , Andrey Ignatov , Alexei Starovoitov , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 03/76] libbpf: set BTF FD for prog only when there is supported .BTF.ext data Date: Thu, 29 Aug 2019 14:11:58 -0400 Message-Id: <20190829181311.7562-3-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190829181311.7562-1-sashal@kernel.org> References: <20190829181311.7562-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrii Nakryiko [ Upstream commit 3415ec643e7bd644b03026efbe2f2b36cbe9b34b ] 5d01ab7bac46 ("libbpf: fix erroneous multi-closing of BTF FD") introduced backwards-compatibility issue, manifesting itself as -E2BIG error returned on program load due to unknown non-zero btf_fd attribute value for BPF_PROG_LOAD sys_bpf() sub-command. This patch fixes bug by ensuring that we only ever associate BTF FD with program if there is a BTF.ext data that was successfully loaded into kernel, which automatically means kernel supports func_info/line_info and associated BTF FD for progs (checked and ensured also by BTF sanitization code). Fixes: 5d01ab7bac46 ("libbpf: fix erroneous multi-closing of BTF FD") Reported-by: Andrey Ignatov Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- tools/lib/bpf/libbpf.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e308fcf16cdd0..ce579e3654d60 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2066,7 +2066,11 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.license = license; load_attr.kern_version = kern_version; load_attr.prog_ifindex = prog->prog_ifindex; - btf_fd = bpf_object__btf_fd(prog->obj); + /* if .BTF.ext was loaded, kernel supports associated BTF for prog */ + if (prog->obj->btf_ext) + btf_fd = bpf_object__btf_fd(prog->obj); + else + btf_fd = -1; load_attr.prog_btf_fd = btf_fd >= 0 ? btf_fd : 0; load_attr.func_info = prog->func_info; load_attr.func_info_rec_size = prog->func_info_rec_size; -- 2.20.1