From patchwork Thu Nov 10 03:10:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhen Lei X-Patchwork-Id: 17935 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp700757wru; Wed, 9 Nov 2022 19:20:56 -0800 (PST) X-Google-Smtp-Source: AMsMyM6lq/YuKAyytSqKSnpnYT9aR/RhPIL5IPk87EXip2SwbwV3a+xRlOqrl4vcXfy1I+B1mD+t X-Received: by 2002:a05:6402:3641:b0:45c:4231:ddcc with SMTP id em1-20020a056402364100b0045c4231ddccmr62922367edb.224.1668050456596; Wed, 09 Nov 2022 19:20:56 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1668050456; cv=none; d=google.com; s=arc-20160816; b=rAHkT3EZ7RHLHjwVUypO6QquUTP67yOz6ea/+QGCFjAif+2RsemN5YYgQsJK/hL7se 13urnxmncJZRncV609X+oYcDMR2TiEYglAkLdwoxUu25HG6CFslT4A+m5OMd72OJZMLw Dt1EPT72Eov7jG9klpikheGF2GHO1lhaAiSNi3Pg0/sekb1klPBdp9T776VdHqQwSjPB f0o5fEcX/pwaJHckIUrbwZuYukR4WpflZP9q9z1CdmYPDlqRMSMaWhOhSGLgJ8sugE23 sh9o4SXxq5wZ6mkJLGtItGiJPfa23r/Sbw5xk6w0294nYCgG9qzvpO0qP4Q27ZFX8rvl /Yqg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from; bh=Nqfsd2jNg1p9iHMBLC1+3oRzE/9/EeLdQaeYabO3Hp0=; b=P3bG98AeKGa9yHSiE93Pra2jGzaOKr9sShG81VDVWMLsZWo/c4mD3BLYHmtcHJu8mH slB+3qXWzt5Ae+yEvTkWsJJSkXMisUINVru452rNeN/mQQDkxK38obgp9ETcpkGpxF36 xdDpC6scoTSVGv6Zd/JZ2lg9qUw2wt98UwrjE+WFSxhTLan3QgItOIYMCfGPFPWIFTsD A/+Q9N3g0frUzBbtLRhFk7ZJWm60XqfpRyv5alA+12g9oWCYbBN1mGAhFArnigIhzVpR cE5Y9FfXMkKrieN9YaUwlebtK41SlGxLmNTiP9GctagGKOTq2APGUniLtRxXvCIXo4Co aHDA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id a16-20020a1709066d5000b0078d288ddfc9si13636255ejt.143.2022.11.09.19.20.32; Wed, 09 Nov 2022 19:20:56 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232284AbiKJDLi (ORCPT + 99 others); Wed, 9 Nov 2022 22:11:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232167AbiKJDLf (ORCPT ); Wed, 9 Nov 2022 22:11:35 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E024F1D64D; Wed, 9 Nov 2022 19:11:33 -0800 (PST) Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4N76L25jtpzHvZ2; Thu, 10 Nov 2022 11:11:06 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 10 Nov 2022 11:11:32 +0800 Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 10 Nov 2022 11:11:31 +0800 From: Zhen Lei To: Alexander Viro , , CC: Zhen Lei Subject: [PATCH] fs: Clear a UBSAN shift-out-of-bounds warning Date: Thu, 10 Nov 2022 11:10:24 +0800 Message-ID: <20221110031024.204-1-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.37.3.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1749077675628713289?= X-GMAIL-MSGID: =?utf-8?q?1749077675628713289?= UBSAN: shift-out-of-bounds in fs/locks.c:2572:16 left shift of 1 by 63 places cannot be represented in type 'long long int' Switch the calculation method to ((quarter - 1) * 2 + 1) can help us eliminate this false positive. On the other hand, the old implementation has problems with char and short types, although not currently involved. printf("%d: %x\n", sizeof(char), INT_LIMIT(char)); printf("%d: %x\n", sizeof(short), INT_LIMIT(short)); 1: ffffff7f 2: ffff7fff Signed-off-by: Zhen Lei --- include/linux/fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index e654435f16512c1..88d42e2daed9f6c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1131,7 +1131,7 @@ struct file_lock_context { /* The following constant reflects the upper bound of the file/locking space */ #ifndef OFFSET_MAX -#define INT_LIMIT(x) (~((x)1 << (sizeof(x)*8 - 1))) +#define INT_LIMIT(x) ((((x)1 << (sizeof(x) * 8 - 2)) - 1) * 2 + 1) #define OFFSET_MAX INT_LIMIT(loff_t) #define OFFT_OFFSET_MAX INT_LIMIT(off_t) #endif