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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,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 4E968CA9EA0 for ; Tue, 22 Oct 2019 17:21:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1AFA220679 for ; Tue, 22 Oct 2019 17:21:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="f77MNkgR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730305AbfJVRVJ (ORCPT ); Tue, 22 Oct 2019 13:21:09 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:2388 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725837AbfJVRVJ (ORCPT ); Tue, 22 Oct 2019 13:21:09 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.42/8.16.0.42) with SMTP id x9MHJJdG029722 for ; Tue, 22 Oct 2019 10:21:08 -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-type; s=facebook; bh=m9qAyElN1GBDWp30dzZfSfuu5wxLxC4ELahqTfLSzyA=; b=f77MNkgRxgmE7sv6/luF5ZgbBeHSkXR7G1I6e8dSbK0QhWrtJvqY+iJjNvZY+rpPdGdA T8bWQ4tR853lpWaUl9Pkd1pyxeTag0AaHTTi8PdKQ/OIdY2U+ydGoQaRSf7t0cu/U59S 2FeGTvaO+6Xcs5BkxFcdJ8SiY90BL7J2L6M= Received: from maileast.thefacebook.com ([163.114.130.16]) by m0089730.ppops.net with ESMTP id 2vsvnbau8f-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 22 Oct 2019 10:21:08 -0700 Received: from 2401:db00:30:6012:face:0:17:0 (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::d) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Tue, 22 Oct 2019 10:21:07 -0700 Received: by dev101.prn2.facebook.com (Postfix, from userid 137359) id 96A37861A05; Tue, 22 Oct 2019 10:21:01 -0700 (PDT) Smtp-Origin-Hostprefix: dev From: Andrii Nakryiko Smtp-Origin-Hostname: dev101.prn2.facebook.com To: , , , CC: , , Andrii Nakryiko Smtp-Origin-Cluster: prn2c23 Subject: [PATCH v2 bpf-next] libbpf: make DECLARE_LIBBPF_OPTS macro strictly a variable declaration Date: Tue, 22 Oct 2019 10:21:00 -0700 Message-ID: <20191022172100.3281465-1-andriin@fb.com> X-Mailer: git-send-email 2.17.1 X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,1.0.8 definitions=2019-10-22_03:2019-10-22,2019-10-22 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 mlxlogscore=999 adultscore=0 lowpriorityscore=0 phishscore=0 impostorscore=0 spamscore=0 malwarescore=0 clxscore=1015 suspectscore=8 bulkscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1908290000 definitions=main-1910220143 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org LIBBPF_OPTS is implemented as a mix of field declaration and memset + assignment. This makes it neither variable declaration nor purely statements, which is a problem, because you can't mix it with either other variable declarations nor other function statements, because C90 compiler mode emits warning on mixing all that together. This patch changes LIBBPF_OPTS into a strictly declaration of variable and solves this problem, as can be seen in case of bpftool, which previously would emit compiler warning, if done this way (LIBBPF_OPTS as part of function variables declaration block). This patch also renames LIBBPF_OPTS into DECLARE_LIBBPF_OPTS to follow kernel convention for similar macros more closely. v1->v2: - rename LIBBPF_OPTS into DECLARE_LIBBPF_OPTS (Jakub Sitnicki). Signed-off-by: Andrii Nakryiko --- tools/bpf/bpftool/prog.c | 8 ++++---- tools/lib/bpf/libbpf.c | 4 ++-- tools/lib/bpf/libbpf.h | 19 ++++++++++++------- .../selftests/bpf/prog_tests/attach_probe.c | 2 +- .../selftests/bpf/prog_tests/core_reloc.c | 2 +- .../bpf/prog_tests/reference_tracking.c | 2 +- 6 files changed, 21 insertions(+), 16 deletions(-) diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 27da96a797ab..4535c863d2cd 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -1091,8 +1091,11 @@ static int do_run(int argc, char **argv) static int load_with_options(int argc, char **argv, bool first_prog_only) { - struct bpf_object_load_attr load_attr = { 0 }; enum bpf_prog_type common_prog_type = BPF_PROG_TYPE_UNSPEC; + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts, + .relaxed_maps = relaxed_maps, + ); + struct bpf_object_load_attr load_attr = { 0 }; enum bpf_attach_type expected_attach_type; struct map_replace *map_replace = NULL; struct bpf_program *prog = NULL, *pos; @@ -1106,9 +1109,6 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) const char *file; int idx, err; - LIBBPF_OPTS(bpf_object_open_opts, open_opts, - .relaxed_maps = relaxed_maps, - ); if (!REQ_ARGS(2)) return -1; diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 803219d6898c..8b4d765c422b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3678,7 +3678,7 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, static struct bpf_object * __bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags) { - LIBBPF_OPTS(bpf_object_open_opts, opts, + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, .relaxed_maps = flags & MAPS_RELAX_COMPAT, ); @@ -3730,7 +3730,7 @@ struct bpf_object * bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz, const char *name) { - LIBBPF_OPTS(bpf_object_open_opts, opts, + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, .object_name = name, /* wrong default, but backwards-compatible */ .relaxed_maps = true, diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 0fdf086beba7..c63e2ff84abc 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -75,14 +75,19 @@ struct bpf_object_open_attr { * have all the padding bytes initialized to zero. It's not guaranteed though, * when copying literal, that compiler won't copy garbage in literal's padding * bytes, but that's the best way I've found and it seems to work in practice. + * + * Macro declares opts struct of given type and name, zero-initializes, + * including any extra padding, it with memset() and then assigns initial + * values provided by users in struct initializer-syntax as varargs. */ -#define LIBBPF_OPTS(TYPE, NAME, ...) \ - struct TYPE NAME; \ - memset(&NAME, 0, sizeof(struct TYPE)); \ - NAME = (struct TYPE) { \ - .sz = sizeof(struct TYPE), \ - __VA_ARGS__ \ - } +#define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...) \ + struct TYPE NAME = ({ \ + memset(&NAME, 0, sizeof(struct TYPE)); \ + (struct TYPE) { \ + .sz = sizeof(struct TYPE), \ + __VA_ARGS__ \ + }; \ + }) struct bpf_object_open_opts { /* size of this struct, for forward/backward compatiblity */ diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index 0ee1ce100a4a..a83111a32d4a 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -50,7 +50,7 @@ void test_attach_probe(void) const int kprobe_idx = 0, kretprobe_idx = 1; const int uprobe_idx = 2, uretprobe_idx = 3; const char *obj_name = "attach_probe"; - LIBBPF_OPTS(bpf_object_open_opts, open_opts, + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts, .object_name = obj_name, .relaxed_maps = true, ); diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c index 523dca82dc82..09dfa75fe948 100644 --- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c +++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c @@ -377,7 +377,7 @@ void test_core_reloc(void) if (!test__start_subtest(test_case->case_name)) continue; - LIBBPF_OPTS(bpf_object_open_opts, opts, + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, .relaxed_core_relocs = test_case->relaxed_core_relocs, ); diff --git a/tools/testing/selftests/bpf/prog_tests/reference_tracking.c b/tools/testing/selftests/bpf/prog_tests/reference_tracking.c index 4493ba277bd7..fc0d7f4f02cf 100644 --- a/tools/testing/selftests/bpf/prog_tests/reference_tracking.c +++ b/tools/testing/selftests/bpf/prog_tests/reference_tracking.c @@ -5,7 +5,7 @@ void test_reference_tracking(void) { const char *file = "test_sk_lookup_kern.o"; const char *obj_name = "ref_track"; - LIBBPF_OPTS(bpf_object_open_opts, open_opts, + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts, .object_name = obj_name, .relaxed_maps = true, ); -- 2.17.1