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=-14.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,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 20360C3A59B for ; Mon, 19 Aug 2019 04:37:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E6A752070B for ; Mon, 19 Aug 2019 04:37:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uYH4KbWl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726295AbfHSEhA (ORCPT ); Mon, 19 Aug 2019 00:37:00 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:35782 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725536AbfHSEhA (ORCPT ); Mon, 19 Aug 2019 00:37:00 -0400 Received: by mail-wr1-f68.google.com with SMTP id k2so7193008wrq.2; Sun, 18 Aug 2019 21:36:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ZUCw4jAs77fJWvJ1Lbk9AJyiu5YLLMkfP4oKtMz1NVw=; b=uYH4KbWl08ZgKEpjhyYlfwvt9PdrFvpKMSKrDB/bHWMyRU+XUtYSStUbBLT5ziwZGl t60r3tqUrSES+VTAuxKq3qBMi3tLrQQNaL0SIigL/02DNaxLMfCrVhVHJ211ZyUXZ2CQ auHG0As1cCwaTCqHlXIhGDIYQWlDA7UERd0CKQTsAQUNqEnPjlbwK2klFMq2mJshC6Qj EBIpU7+XyUzC5g/mNOtUuxvLD/JQM5MPi0R2nfcrpj8ak8j6MXSLzEMQqVf154qbaI3Q XtxeoHtsJPy7cv8bhx/BVrTiyu9jgeKD7IcKIy0KruGZZm/p3HQSrvz3cJG2aFSc+Umi 7Mfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ZUCw4jAs77fJWvJ1Lbk9AJyiu5YLLMkfP4oKtMz1NVw=; b=bWkDL8CL579GUqvVxFdcPOeEvD8g/9YTNR5FFATA0/4DgtD8zCZbux/xOwpzxHRMId P2N2fS7vZzMf6u614sHqfNvW53bWt7kEKglX+0yMw+c4DYFu7kr9WMHubG0tfvzUswN2 n+t1chn3iVHAbeaGEQqt7sNi2sjhdTAEf4ej0RUgZ3IBOvtjMjvh6IcBh1qvXlFLDcNi awFlUNvLkmJUTNZawGqDr8XmPM86eMhrneTv6qeYEq1AyuJ+eX/PuTScrqzH7qOMfu7g hG3c7UfKbHo2eO9HBRUsCGxLrIjXOhdBmoY37RXMzRIw+jvs3eAfoyxLv6u10+8u3bqd oXZQ== X-Gm-Message-State: APjAAAUBkgeTWcun9KOpTKvGWz1WFsG5mK6f/ohAFvRFOhUh3/4C9r72 Ej8sCDxpqIUZexBWrSqx/dY= X-Google-Smtp-Source: APXvYqyHKAGqzXXD27TODaxzJH2S8swRrcvJBmyoQQcxyqBVpHYwkStPF7Y+58W+JKHUm4F7neENzA== X-Received: by 2002:adf:de02:: with SMTP id b2mr24526170wrm.204.1566189417661; Sun, 18 Aug 2019 21:36:57 -0700 (PDT) Received: from localhost.localdomain ([2a01:4f8:222:2f1b::2]) by smtp.gmail.com with ESMTPSA id j10sm15218526wrd.26.2019.08.18.21.36.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 18 Aug 2019 21:36:56 -0700 (PDT) From: Nathan Chancellor To: Alexei Starovoitov , Daniel Borkmann Cc: Martin KaFai Lau , Song Liu , Yonghong Song , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Nathan Chancellor Subject: [PATCH] test_bpf: Fix a new clang warning about xor-ing two numbers Date: Sun, 18 Aug 2019 21:34:20 -0700 Message-Id: <20190819043419.68223-1-natechancellor@gmail.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 X-Patchwork-Bot: notify Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org r369217 in clang added a new warning about potential misuse of the xor operator as an exponentiation operator: ../lib/test_bpf.c:870:13: warning: result of '10 ^ 300' is 294; did you mean '1e300'? [-Wxor-used-as-pow] { { 4, 10 ^ 300 }, { 20, 10 ^ 300 } }, ~~~^~~~~ 1e300 ../lib/test_bpf.c:870:13: note: replace expression with '0xA ^ 300' to silence this warning ../lib/test_bpf.c:870:31: warning: result of '10 ^ 300' is 294; did you mean '1e300'? [-Wxor-used-as-pow] { { 4, 10 ^ 300 }, { 20, 10 ^ 300 } }, ~~~^~~~~ 1e300 ../lib/test_bpf.c:870:31: note: replace expression with '0xA ^ 300' to silence this warning The commit link for this new warning has some good logic behind wanting to add it but this instance appears to be a false positive. Adopt its suggestion to silence the warning but not change the code. According to the differential review link in the clang commit, GCC may eventually adopt this warning as well. Link: https://github.com/ClangBuiltLinux/linux/issues/643 Link: https://github.com/llvm/llvm-project/commit/920890e26812f808a74c60ebc14cc636dac661c1 Signed-off-by: Nathan Chancellor --- I highly doubt that 1e300 was intented but if it was (or something else was), please let me know. Commit history wasn't entirely clear on why this expression was used over just a raw number. lib/test_bpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/test_bpf.c b/lib/test_bpf.c index c41705835cba..5ef3eccee27c 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -867,7 +867,7 @@ static struct bpf_test tests[] = { }, CLASSIC, { }, - { { 4, 10 ^ 300 }, { 20, 10 ^ 300 } }, + { { 4, 0xA ^ 300 }, { 20, 0xA ^ 300 } }, }, { "SPILL_FILL", -- 2.23.0