From patchwork Fri Jun 19 23:04:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 1313416 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=aYSIysx6; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49pZBQ5VsYz9sPF for ; Sat, 20 Jun 2020 09:04:30 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730238AbgFSXE1 (ORCPT ); Fri, 19 Jun 2020 19:04:27 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:43912 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729996AbgFSXE1 (ORCPT ); Fri, 19 Jun 2020 19:04:27 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 05JN01Ji030800 for ; Fri, 19 Jun 2020 16:04:26 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=6SMGNHMqEiT5yoSqQAHsmmbC2B1tn3KLG/YugBRYHdQ=; b=aYSIysx6fIY6cGLPfkhYBi29HifmSo7hcqGJdCdSdM0kBYnvHtnpRgNUV0YTfWnCMEUQ WbeUOtOajJwx0eKWAXPWo9gW1XxcuxZJa4p35vxmGCQHGRzhAvR1NWZY34/Zue1Ew34t OK90khNaLUzNL7OapJy/qEMphf1/Vn0EtLk= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 31s2rcs788-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 19 Jun 2020 16:04:26 -0700 Received: from intmgw003.08.frc2.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Fri, 19 Jun 2020 16:04:26 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id C22C02EC3619; Fri, 19 Jun 2020 16:04:23 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko , Yonghong Song Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf] libbpf: fix CO-RE relocs against .text section Date: Fri, 19 Jun 2020 16:04:22 -0700 Message-ID: <20200619230423.691274-1-andriin@fb.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216, 18.0.687 definitions=2020-06-19_22:2020-06-19,2020-06-19 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 suspectscore=0 bulkscore=0 malwarescore=0 mlxscore=0 lowpriorityscore=0 cotscore=-2147483648 priorityscore=1501 clxscore=1015 adultscore=0 spamscore=0 mlxlogscore=999 impostorscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006190161 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org bpf_object__find_program_by_title(), used by CO-RE relocation code, doesn't return .text "BPF program", if it is a function storage for sub-programs. Because of that, any CO-RE relocation in helper non-inlined functions will fail. Fix this by searching for .text-corresponding BPF program manually. Adjust one of bpf_iter selftest to exhibit this pattern. Reported-by: Yonghong Song Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm") Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Signed-off-by: Yonghong Song --- tools/lib/bpf/libbpf.c | 8 +++++++- tools/testing/selftests/bpf/progs/bpf_iter_netlink.c | 2 +- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 477c679ed945..f17151d866e6 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4818,7 +4818,13 @@ bpf_core_reloc_fields(struct bpf_object *obj, const char *targ_btf_path) err = -EINVAL; goto out; } - prog = bpf_object__find_program_by_title(obj, sec_name); + prog = NULL; + for (i = 0; i < obj->nr_programs; i++) { + if (!strcmp(obj->programs[i].section_name, sec_name)) { + prog = &obj->programs[i]; + break; + } + } if (!prog) { pr_warn("failed to find program '%s' for CO-RE offset relocation\n", sec_name); diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c b/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c index e7b8753eac0b..75ecf956a2df 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c @@ -25,7 +25,7 @@ struct bpf_iter__netlink { struct netlink_sock *sk; } __attribute__((preserve_access_index)); -static inline struct inode *SOCK_INODE(struct socket *socket) +static __attribute__((noinline)) struct inode *SOCK_INODE(struct socket *socket) { return &container_of(socket, struct socket_alloc, socket)->vfs_inode; }