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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13180C433EF for ; Tue, 10 May 2022 18:52:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235877AbiEJSwO convert rfc822-to-8bit (ORCPT ); Tue, 10 May 2022 14:52:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245507AbiEJSwN (ORCPT ); Tue, 10 May 2022 14:52:13 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A98350E20 for ; Tue, 10 May 2022 11:52:13 -0700 (PDT) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 24AFLirT007221 for ; Tue, 10 May 2022 11:52:13 -0700 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3fxywsugu1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 10 May 2022 11:52:12 -0700 Received: from twshared18213.14.prn3.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 10 May 2022 11:52:10 -0700 Received: by devbig019.vll3.facebook.com (Postfix, from userid 137359) id 73F0C19BA92A1; Tue, 10 May 2022 11:52:02 -0700 (PDT) From: Andrii Nakryiko To: , , CC: , , Nathan Chancellor Subject: [PATCH bpf-next] libbpf: clean up ringbuf size adjustment implementation Date: Tue, 10 May 2022 11:51:59 -0700 Message-ID: <20220510185159.754299-1-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: 1LGwyxW7b1RkDcqNNunxVJwvAve82Fse X-Proofpoint-ORIG-GUID: 1LGwyxW7b1RkDcqNNunxVJwvAve82Fse X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-10_05,2022-05-10_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Drop unused iteration variable, move overflow prevention check into the for loop. Fixes: 0087a681fa8c ("libbpf: Automatically fix up BPF_MAP_TYPE_RINGBUF size, if necessary") Reported-by: Nathan Chancellor Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 15117b9a4d1e..eb4565a89eab 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4951,7 +4951,7 @@ static bool is_pow_of_2(size_t x) static size_t adjust_ringbuf_sz(size_t sz) { __u32 page_sz = sysconf(_SC_PAGE_SIZE); - __u32 i, mul; + __u32 mul; /* if user forgot to set any size, make sure they see error */ if (sz == 0) @@ -4967,9 +4967,7 @@ static size_t adjust_ringbuf_sz(size_t sz) * user-set size to satisfy both user size request and kernel * requirements and substitute correct max_entries for map creation. */ - for (i = 0, mul = 1; ; i++, mul <<= 1) { - if (mul > UINT_MAX / page_sz) /* prevent __u32 overflow */ - break; + for (mul = 1; mul <= UINT_MAX / page_sz; mul <<= 1) { if (mul * page_sz > sz) return mul * page_sz; } -- 2.30.2