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=-18.8 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, 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 00944C43460 for ; Sat, 10 Apr 2021 16:49:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C3086611C9 for ; Sat, 10 Apr 2021 16:49:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234757AbhDJQuK (ORCPT ); Sat, 10 Apr 2021 12:50:10 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:58472 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234768AbhDJQuK (ORCPT ); Sat, 10 Apr 2021 12:50:10 -0400 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 13AGmxRE002734 for ; Sat, 10 Apr 2021 09:49:55 -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=/kSIJ3ZY88Dy7C1EeOpAyzBKGHGgjijAo1i0vcp3GoI=; b=HDFAHlvs+hK4B7+w6LNs+e+RKDl045RObvDMLcoc/1J6SX+OS3tW+fO+FhX1nOFhEhaq YquXbDh1CQIvDge+8B45jnxqkyDyMOsLoccc1NY8Q5a4mnd4NFLeFg2/JcbH29s9pgne FHUAjkvEy4T3DPM9G8Rd9slgiUJJpxhJL9Y= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 37ubax90wr-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Sat, 10 Apr 2021 09:49:55 -0700 Received: from intmgw002.06.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Sat, 10 Apr 2021 09:49:53 -0700 Received: by devbig003.ftw2.facebook.com (Postfix, from userid 128203) id 6B23A145045B; Sat, 10 Apr 2021 09:49:51 -0700 (PDT) From: Yonghong Song To: CC: Andrii Nakryiko , Arnaldo Carvalho de Melo , , Nick Desaulniers , Sedat Dilek Subject: [PATCH bpf-next 5/5] bpftool: fix a clang compilation warning Date: Sat, 10 Apr 2021 09:49:51 -0700 Message-ID: <20210410164951.770920-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210410164925.768741-1-yhs@fb.com> References: <20210410164925.768741-1-yhs@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: -t4lnjB0oel7U9ohYkSuC9siqO1pBmyY X-Proofpoint-ORIG-GUID: -t4lnjB0oel7U9ohYkSuC9siqO1pBmyY X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-04-10_07:2021-04-09,2021-04-10 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 impostorscore=0 lowpriorityscore=0 phishscore=0 adultscore=0 priorityscore=1501 bulkscore=0 mlxlogscore=770 clxscore=1015 mlxscore=0 suspectscore=0 spamscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104100126 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With clang compiler: make -j60 LLVM=3D1 LLVM_IAS=3D1 <=3D=3D=3D compile kernel # build selftests/bpf or bpftool make -j60 -C tools/testing/selftests/bpf LLVM=3D1 LLVM_IAS=3D1 make -j60 -C tools/bpf/bpftool LLVM=3D1 LLVM_IAS=3D1 the following compilation warning showed up, net.c:160:37: warning: comparison of integers of different signs: '__u3= 2' (aka 'unsigned int') and 'int' [-Wsign-compare] for (nh =3D (struct nlmsghdr *)buf; NLMSG_OK(nh, len); ^~~~~~~~~~~~~~~~~ .../tools/include/uapi/linux/netlink.h:99:24: note: expanded from macro= 'NLMSG_OK' (nlh)->nlmsg_len <=3D (len)) ~~~~~~~~~~~~~~~~ ^ ~~~ In this particular case, "len" is defined as "int" and (nlh)->nlmsg_len i= s "unsigned int". The macro NLMSG_OK is defined as below in uapi/linux/netlink.h. #define NLMSG_OK(nlh,len) ((len) >=3D (int)sizeof(struct nlmsghdr) && \ (nlh)->nlmsg_len >=3D sizeof(struct nlmsghdr= ) && \ (nlh)->nlmsg_len <=3D (len)) The clang compiler complains the comparision "(nlh)->nlmsg_len <=3D (len)= )", but in bpftool/net.c, it is already ensured that "len > 0" must be true. So let us add an explicit type conversion (from "int" to "unsigned int") for "len" in NLMSG_OK to silence this warning. Signed-off-by: Yonghong Song --- tools/bpf/bpftool/net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/bpf/bpftool/net.c b/tools/bpf/bpftool/net.c index ff3aa0cf3997..f836d115d7d6 100644 --- a/tools/bpf/bpftool/net.c +++ b/tools/bpf/bpftool/net.c @@ -157,7 +157,7 @@ static int netlink_recv(int sock, __u32 nl_pid, __u32= seq, if (len =3D=3D 0) break; =20 - for (nh =3D (struct nlmsghdr *)buf; NLMSG_OK(nh, len); + for (nh =3D (struct nlmsghdr *)buf; NLMSG_OK(nh, (unsigned int)len); nh =3D NLMSG_NEXT(nh, len)) { if (nh->nlmsg_pid !=3D nl_pid) { ret =3D -LIBBPF_ERRNO__WRNGPID; --=20 2.30.2