From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=192.55.52.120; helo=mga04.intel.com; envelope-from=hao.a.wu@intel.com; receiver=edk2-devel@lists.01.org Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 7C3C721E1B773 for ; Wed, 27 Sep 2017 20:53:37 -0700 (PDT) Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Sep 2017 20:55:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,448,1500966000"; d="scan'208";a="156952172" Received: from fmsmsx106.amr.corp.intel.com ([10.18.124.204]) by fmsmga006.fm.intel.com with ESMTP; 27 Sep 2017 20:55:49 -0700 Received: from fmsmsx113.amr.corp.intel.com (10.18.116.7) by FMSMSX106.amr.corp.intel.com (10.18.124.204) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 27 Sep 2017 20:55:49 -0700 Received: from shsmsx151.ccr.corp.intel.com (10.239.6.50) by FMSMSX113.amr.corp.intel.com (10.18.116.7) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 27 Sep 2017 20:55:49 -0700 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.159]) by SHSMSX151.ccr.corp.intel.com ([169.254.3.98]) with mapi id 14.03.0319.002; Thu, 28 Sep 2017 11:55:47 +0800 From: "Wu, Hao A" To: "Gao, Liming" , "edk2-devel@lists.01.org" CC: Paolo Bonzini , "Dong, Eric" , "Zeng, Star" Thread-Topic: [edk2] [PATCH v2 5/6] MdeModulePkg/Crc32: Fix possible out of range left shift Thread-Index: AQHTMqVxnJtAsuASIUKNEguaaOxFyaLJL46AgACGWGA= Date: Thu, 28 Sep 2017 03:55:46 +0000 Message-ID: References: <20170921064617.2628-1-hao.a.wu@intel.com> <20170921064617.2628-6-hao.a.wu@intel.com> <4A89E2EF3DFEDB4C8BFDE51014F606A14E15EA8E@SHSMSX152.ccr.corp.intel.com> In-Reply-To: <4A89E2EF3DFEDB4C8BFDE51014F606A14E15EA8E@SHSMSX152.ccr.corp.intel.com> Accept-Language: zh-CN, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] MIME-Version: 1.0 Subject: Re: [PATCH v2 5/6] MdeModulePkg/Crc32: Fix possible out of range left shift X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Sep 2017 03:53:37 -0000 Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Got it. I will send a new series to drop this patch. Best Regards, Hao Wu > -----Original Message----- > From: Gao, Liming > Sent: Thursday, September 28, 2017 11:54 AM > To: Wu, Hao A; edk2-devel@lists.01.org > Cc: Wu, Hao A; Paolo Bonzini; Dong, Eric; Zeng, Star > Subject: RE: [edk2] [PATCH v2 5/6] MdeModulePkg/Crc32: Fix possible out o= f > range left shift >=20 > Hao: > I sent another patch to introduce CacluateCrc32() API in BaseLib. It wi= ll update > MdeModulePkg Crc32 to depend on BaseLib. And, BaseLib CacluateCrc32() has > no such logic. So, I think this patch is not necessary. >=20 > Thanks > Liming > >-----Original Message----- > >From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of H= ao > >Wu > >Sent: Thursday, September 21, 2017 2:46 PM > >To: edk2-devel@lists.01.org > >Cc: Wu, Hao A ; Paolo Bonzini ; > >Dong, Eric ; Zeng, Star > >Subject: [edk2] [PATCH v2 5/6] MdeModulePkg/Crc32: Fix possible out of > >range left shift > > > >REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3D697 > > > >Within function ReverseBits(), left shift operations of 1 in the > >following statements: > >"(1 << Index)" and "(1 << (31 - Index))" > > > >will incur possible out of range left shift when Index is either 0 or > >31, since "1 << 31" is possible to exceed the range of type 'int' > >(signed). > > > >According to the C11 spec, Section 6.5.7: > >> 4 The result of E1 << E2 is E1 left-shifted E2 bit positions; vacated > >> bits are filled with zeros. If E1 has an unsigned type, the value > >> of the result is E1 * 2^E2 , reduced modulo one more than the > >> maximum value representable in the result type. If E1 has a signed > >> type and nonnegative value, and E1 * 2^E2 is representable in the > >> result type, then that is the resulting value; otherwise, the > >> behavior is undefined. > > > >This commit uses '1U' instead of '1' to resolve this issue. > > > >Cc: Steven Shi > >Cc: Star Zeng > >Cc: Eric Dong > >Cc: Paolo Bonzini > >Contributed-under: TianoCore Contribution Agreement 1.1 > >Signed-off-by: Hao Wu > >--- > > MdeModulePkg/Core/RuntimeDxe/Crc32.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > >diff --git a/MdeModulePkg/Core/RuntimeDxe/Crc32.c > >b/MdeModulePkg/Core/RuntimeDxe/Crc32.c > >index a6fe77fa34..2cd234b562 100644 > >--- a/MdeModulePkg/Core/RuntimeDxe/Crc32.c > >+++ b/MdeModulePkg/Core/RuntimeDxe/Crc32.c > >@@ -7,7 +7,7 @@ > > EFI Runtime Services Table are converted from physical address to > > virtual addresses. This requires that the 32-bit CRC be recomputed. > > > >-Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.
> >+Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.
> > This program and the accompanying materials > > are licensed and made available under the terms and conditions of the B= SD > >License > > which accompanies this distribution. The full text of the license may = be found > >at > >@@ -79,8 +79,8 @@ ReverseBits ( > > > > NewValue =3D 0; > > for (Index =3D 0; Index < 32; Index++) { > >- if ((Value & (1 << Index)) !=3D 0) { > >- NewValue =3D NewValue | (1 << (31 - Index)); > >+ if ((Value & (1U << Index)) !=3D 0) { > >+ NewValue =3D NewValue | (1U << (31 - Index)); > > } > > } > > > >-- > >2.12.0.windows.1 > > > >_______________________________________________ > >edk2-devel mailing list > >edk2-devel@lists.01.org > >https://lists.01.org/mailman/listinfo/edk2-devel