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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 0EC53C433FE for ; Fri, 11 Dec 2020 22:55:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D657D206E5 for ; Fri, 11 Dec 2020 22:55:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405130AbgLKV7p convert rfc822-to-8bit (ORCPT ); Fri, 11 Dec 2020 16:59:45 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:43074 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405008AbgLKV7T (ORCPT ); Fri, 11 Dec 2020 16:59:19 -0500 Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 0BBLo5s8023302 for ; Fri, 11 Dec 2020 13:58:34 -0800 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 35ccq09pgk-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 11 Dec 2020 13:58:33 -0800 Received: from intmgw003.03.ash8.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:11d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Fri, 11 Dec 2020 13:58:32 -0800 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id AC04E2EC8ED7; Fri, 11 Dec 2020 13:58:29 -0800 (PST) From: Andrii Nakryiko To: , , , CC: , Subject: [PATCH bpf-next 1/2] libbpf: support modules in bpf_program__set_attach_target() API Date: Fri, 11 Dec 2020 13:58:24 -0800 Message-ID: <20201211215825.3646154-2-andrii@kernel.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201211215825.3646154-1-andrii@kernel.org> References: <20201211215825.3646154-1-andrii@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343,18.0.737 definitions=2020-12-11_09:2020-12-11,2020-12-11 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 malwarescore=0 suspectscore=8 bulkscore=0 spamscore=0 impostorscore=0 phishscore=0 mlxlogscore=999 lowpriorityscore=0 clxscore=1015 mlxscore=0 adultscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012110144 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Support finding kernel targets in kernel modules when using bpf_program__set_attach_target() API. This brings it up to par with what libbpf supports when doing declarative SEC()-based target determination. Some minor internal refactoring was needed to make sure vmlinux BTF can be loaded before bpf_object's load phase. Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 64 ++++++++++++++++++++++++++---------------- 1 file changed, 40 insertions(+), 24 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 9be88a90a4aa..6ae748f6ea11 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2518,7 +2518,7 @@ static int bpf_object__finalize_btf(struct bpf_object *obj) return 0; } -static inline bool libbpf_prog_needs_vmlinux_btf(struct bpf_program *prog) +static bool prog_needs_vmlinux_btf(struct bpf_program *prog) { if (prog->type == BPF_PROG_TYPE_STRUCT_OPS || prog->type == BPF_PROG_TYPE_LSM) @@ -2533,37 +2533,43 @@ static inline bool libbpf_prog_needs_vmlinux_btf(struct bpf_program *prog) return false; } -static int bpf_object__load_vmlinux_btf(struct bpf_object *obj) +static bool obj_needs_vmlinux_btf(const struct bpf_object *obj) { - bool need_vmlinux_btf = false; struct bpf_program *prog; - int i, err; + int i; /* CO-RE relocations need kernel BTF */ if (obj->btf_ext && obj->btf_ext->core_relo_info.len) - need_vmlinux_btf = true; + return true; /* Support for typed ksyms needs kernel BTF */ for (i = 0; i < obj->nr_extern; i++) { const struct extern_desc *ext; ext = &obj->externs[i]; - if (ext->type == EXT_KSYM && ext->ksym.type_id) { - need_vmlinux_btf = true; - break; - } + if (ext->type == EXT_KSYM && ext->ksym.type_id) + return true; } bpf_object__for_each_program(prog, obj) { if (!prog->load) continue; - if (libbpf_prog_needs_vmlinux_btf(prog)) { - need_vmlinux_btf = true; - break; - } + if (prog_needs_vmlinux_btf(prog)) + return true; } - if (!need_vmlinux_btf) + return false; +} + +static int bpf_object__load_vmlinux_btf(struct bpf_object *obj, bool force) +{ + int err; + + /* btf_vmlinux could be loaded earlier */ + if (obj->btf_vmlinux) + return 0; + + if (!force && !obj_needs_vmlinux_btf(obj)) return 0; obj->btf_vmlinux = libbpf_find_kernel_btf(); @@ -7475,7 +7481,7 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr) } err = bpf_object__probe_loading(obj); - err = err ? : bpf_object__load_vmlinux_btf(obj); + err = err ? : bpf_object__load_vmlinux_btf(obj, false); err = err ? : bpf_object__resolve_externs(obj, obj->kconfig); err = err ? : bpf_object__sanitize_and_load_btf(obj); err = err ? : bpf_object__sanitize_maps(obj); @@ -10870,23 +10876,33 @@ int bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, const char *attach_func_name) { - int btf_id; + int btf_obj_fd = 0, btf_id = 0, err; if (!prog || attach_prog_fd < 0 || !attach_func_name) return -EINVAL; - if (attach_prog_fd) + if (prog->obj->loaded) + return -EINVAL; + + if (attach_prog_fd) { btf_id = libbpf_find_prog_btf_id(attach_func_name, attach_prog_fd); - else - btf_id = libbpf_find_vmlinux_btf_id(attach_func_name, - prog->expected_attach_type); - - if (btf_id < 0) - return btf_id; + if (btf_id < 0) + return btf_id; + } else { + /* load btf_vmlinux, if not yet */ + err = bpf_object__load_vmlinux_btf(prog->obj, true); + if (err) + return err; + err = find_kernel_btf_id(prog->obj, attach_func_name, + prog->expected_attach_type, + &btf_obj_fd, &btf_id); + if (err) + return err; + } prog->attach_btf_id = btf_id; - prog->attach_btf_obj_fd = 0; + prog->attach_btf_obj_fd = btf_obj_fd; prog->attach_prog_fd = attach_prog_fd; return 0; } -- 2.24.1