From patchwork Tue Mar 16 01:14:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 12140915 X-Patchwork-Delegate: bpf@iogearbox.net 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 A3C04C433E6 for ; Tue, 16 Mar 2021 01:15:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 552B264F71 for ; Tue, 16 Mar 2021 01:15:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234126AbhCPBO5 (ORCPT ); Mon, 15 Mar 2021 21:14:57 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:14936 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234204AbhCPBOa (ORCPT ); Mon, 15 Mar 2021 21:14:30 -0400 Received: from pps.filterd (m0148460.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 12G19ljr021520 for ; Mon, 15 Mar 2021 18:14:29 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=8zi1kIY50TKylIjIldVt+Yth2w8NYFrDNaaQtaBBFH0=; b=VUqTXHY1otH68I+aUUq/fM8ej7UvmrfeyObBL9J8T1V8SYv79ATlz1031z8yOWmjZoG+ NTSZOAxZDHShydXRRxg5GyVZaUBeYX/l6cLAePTt+Hu/awtPQNCkvjELLhxtQwTmsxor fSmBvs1OMUlEEEsHSr7p2kMs2qLExT6luE4= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 378usu3r84-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 15 Mar 2021 18:14:29 -0700 Received: from intmgw001.05.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 15 Mar 2021 18:14:29 -0700 Received: by devbig005.ftw2.facebook.com (Postfix, from userid 6611) id 59BE32942B57; Mon, 15 Mar 2021 18:14:26 -0700 (PDT) From: Martin KaFai Lau To: CC: Alexei Starovoitov , Daniel Borkmann , , Subject: [PATCH bpf-next 08/15] libbpf: Refactor bpf_object__resolve_ksyms_btf_id Date: Mon, 15 Mar 2021 18:14:26 -0700 Message-ID: <20210316011426.4178537-1-kafai@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210316011336.4173585-1-kafai@fb.com> References: <20210316011336.4173585-1-kafai@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-03-15_15:2021-03-15,2021-03-15 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 lowpriorityscore=0 mlxlogscore=999 mlxscore=0 spamscore=0 clxscore=1015 priorityscore=1501 adultscore=0 malwarescore=0 phishscore=0 bulkscore=0 impostorscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103160005 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This patch refactors most of the logic from bpf_object__resolve_ksyms_btf_id() into a new function bpf_object__resolve_ksym_var_btf_id(). It is to get ready for a later patch adding bpf_object__resolve_ksym_func_btf_id() which resolves a kernel function to the running kernel btf_id. Signed-off-by: Martin KaFai Lau Acked-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 125 ++++++++++++++++++++++------------------- 1 file changed, 68 insertions(+), 57 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2f351d3ad3e7..7d5f9b7877bc 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -7403,75 +7403,86 @@ static int bpf_object__read_kallsyms_file(struct bpf_object *obj) return err; } -static int bpf_object__resolve_ksyms_btf_id(struct bpf_object *obj) +static int bpf_object__resolve_ksym_var_btf_id(struct bpf_object *obj, + struct extern_desc *ext) { - struct extern_desc *ext; + const struct btf_type *targ_var, *targ_type; + __u32 targ_type_id, local_type_id; + const char *targ_var_name; + int i, id, btf_fd, err; struct btf *btf; - int i, j, id, btf_fd, err; - for (i = 0; i < obj->nr_extern; i++) { - const struct btf_type *targ_var, *targ_type; - __u32 targ_type_id, local_type_id; - const char *targ_var_name; - int ret; + btf = obj->btf_vmlinux; + btf_fd = 0; + id = btf__find_by_name_kind(btf, ext->name, BTF_KIND_VAR); + if (id == -ENOENT) { + err = load_module_btfs(obj); + if (err) + return err; - ext = &obj->externs[i]; - if (ext->type != EXT_KSYM || !ext->ksym.type_id) - continue; + for (i = 0; i < obj->btf_module_cnt; i++) { + btf = obj->btf_modules[i].btf; + /* we assume module BTF FD is always >0 */ + btf_fd = obj->btf_modules[i].fd; + id = btf__find_by_name_kind(btf, ext->name, BTF_KIND_VAR); + if (id != -ENOENT) + break; + } + } + if (id <= 0) { + pr_warn("extern (var ksym) '%s': failed to find BTF ID in kernel BTF(s).\n", + ext->name); + return -ESRCH; + } - btf = obj->btf_vmlinux; - btf_fd = 0; - id = btf__find_by_name_kind(btf, ext->name, BTF_KIND_VAR); - if (id == -ENOENT) { - err = load_module_btfs(obj); - if (err) - return err; + /* find local type_id */ + local_type_id = ext->ksym.type_id; - for (j = 0; j < obj->btf_module_cnt; j++) { - btf = obj->btf_modules[j].btf; - /* we assume module BTF FD is always >0 */ - btf_fd = obj->btf_modules[j].fd; - id = btf__find_by_name_kind(btf, ext->name, BTF_KIND_VAR); - if (id != -ENOENT) - break; - } - } - if (id <= 0) { - pr_warn("extern (ksym) '%s': failed to find BTF ID in kernel BTF(s).\n", - ext->name); - return -ESRCH; - } + /* find target type_id */ + targ_var = btf__type_by_id(btf, id); + targ_var_name = btf__name_by_offset(btf, targ_var->name_off); + targ_type = skip_mods_and_typedefs(btf, targ_var->type, &targ_type_id); - /* find local type_id */ - local_type_id = ext->ksym.type_id; + err = bpf_core_types_are_compat(obj->btf, local_type_id, + btf, targ_type_id); + if (err <= 0) { + const struct btf_type *local_type; + const char *targ_name, *local_name; - /* find target type_id */ - targ_var = btf__type_by_id(btf, id); - targ_var_name = btf__name_by_offset(btf, targ_var->name_off); - targ_type = skip_mods_and_typedefs(btf, targ_var->type, &targ_type_id); + local_type = btf__type_by_id(obj->btf, local_type_id); + local_name = btf__name_by_offset(obj->btf, local_type->name_off); + targ_name = btf__name_by_offset(btf, targ_type->name_off); - ret = bpf_core_types_are_compat(obj->btf, local_type_id, - btf, targ_type_id); - if (ret <= 0) { - const struct btf_type *local_type; - const char *targ_name, *local_name; + pr_warn("extern (var ksym) '%s': incompatible types, expected [%d] %s %s, but kernel has [%d] %s %s\n", + ext->name, local_type_id, + btf_kind_str(local_type), local_name, targ_type_id, + btf_kind_str(targ_type), targ_name); + return -EINVAL; + } - local_type = btf__type_by_id(obj->btf, local_type_id); - local_name = btf__name_by_offset(obj->btf, local_type->name_off); - targ_name = btf__name_by_offset(btf, targ_type->name_off); + ext->is_set = true; + ext->ksym.kernel_btf_obj_fd = btf_fd; + ext->ksym.kernel_btf_id = id; + pr_debug("extern (var ksym) '%s': resolved to [%d] %s %s\n", + ext->name, id, btf_kind_str(targ_var), targ_var_name); - pr_warn("extern (ksym) '%s': incompatible types, expected [%d] %s %s, but kernel has [%d] %s %s\n", - ext->name, local_type_id, - btf_kind_str(local_type), local_name, targ_type_id, - btf_kind_str(targ_type), targ_name); - return -EINVAL; - } + return 0; +} + +static int bpf_object__resolve_ksyms_btf_id(struct bpf_object *obj) +{ + struct extern_desc *ext; + int i, err; + + for (i = 0; i < obj->nr_extern; i++) { + ext = &obj->externs[i]; + if (ext->type != EXT_KSYM || !ext->ksym.type_id) + continue; + + err = bpf_object__resolve_ksym_var_btf_id(obj, ext); - ext->is_set = true; - ext->ksym.kernel_btf_obj_fd = btf_fd; - ext->ksym.kernel_btf_id = id; - pr_debug("extern (ksym) '%s': resolved to [%d] %s %s\n", - ext->name, id, btf_kind_str(targ_var), targ_var_name); + if (err) + return err; } return 0; }