From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 7D37E21BBC421 for ; Sun, 25 Jun 2017 20:03:17 -0700 (PDT) Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jun 2017 20:04:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,393,1493708400"; d="scan'208";a="985149144" Received: from fmsmsx105.amr.corp.intel.com ([10.18.124.203]) by orsmga003.jf.intel.com with ESMTP; 25 Jun 2017 20:04:45 -0700 Received: from fmsmsx122.amr.corp.intel.com (10.18.125.37) by FMSMSX105.amr.corp.intel.com (10.18.124.203) with Microsoft SMTP Server (TLS) id 14.3.319.2; Sun, 25 Jun 2017 20:04:45 -0700 Received: from shsmsx101.ccr.corp.intel.com (10.239.4.153) by fmsmsx122.amr.corp.intel.com (10.18.125.37) with Microsoft SMTP Server (TLS) id 14.3.319.2; Sun, 25 Jun 2017 20:04:45 -0700 Received: from shsmsx102.ccr.corp.intel.com ([169.254.2.146]) by SHSMSX101.ccr.corp.intel.com ([169.254.1.197]) with mapi id 14.03.0319.002; Mon, 26 Jun 2017 11:04:43 +0800 From: "Zeng, Star" To: "Ni, Ruiyu" , "edk2-devel@lists.01.org" CC: "Gao, Liming" , "Zeng, Star" Thread-Topic: [PATCH V2 3/3] DuetPkg FsVariable: Update GetNextVariableName to follow UEFI 2.7 Thread-Index: AQHS6/fkhgduWBrMm0+q6tMuxOxLcqIxlQAAgACYeJCAAJHcgIADt4gA Date: Mon, 26 Jun 2017 03:04:42 +0000 Message-ID: <0C09AFA07DD0434D9E2A0C6AEB0483103B8ED350@shsmsx102.ccr.corp.intel.com> References: <1498205290-157888-1-git-send-email-star.zeng@intel.com> <1498205290-157888-4-git-send-email-star.zeng@intel.com> <734D49CCEBEEF84792F5B80ED585239D5B9A1821@SHSMSX104.ccr.corp.intel.com> <0C09AFA07DD0434D9E2A0C6AEB0483103B8ECCF8@shsmsx102.ccr.corp.intel.com> <734D49CCEBEEF84792F5B80ED585239D5B9A239D@SHSMSX104.ccr.corp.intel.com> In-Reply-To: <734D49CCEBEEF84792F5B80ED585239D5B9A239D@SHSMSX104.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 3/3] DuetPkg FsVariable: Update GetNextVariableName to follow UEFI 2.7 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: Mon, 26 Jun 2017 03:03:17 -0000 Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Ray, The code is like low hanging fruit from my practice for me, and I don't thi= nk it hurts readability although it may not bring performance improvement, = it depends on how many variables in variable region, how many times of call= ing GetNextVariableName, and how fast of GetNextVariableName. The code practice I did is on NT32 and my real platforms. Is there anyone c= an make sure he/she tested all the systems in the world for their code? Anyway, I can update the patch if you insist. Thanks, Star -----Original Message----- From: Ni, Ruiyu=20 Sent: Saturday, June 24, 2017 10:08 AM To: Zeng, Star ; edk2-devel@lists.01.org Cc: Gao, Liming Subject: RE: [PATCH V2 3/3] DuetPkg FsVariable: Update GetNextVariableName = to follow UEFI 2.7 Star, I don't recommend to add the additional check for performance consideration= . Because we have no idea what the input VariableName buffer is like. If the VariableName is like ['\0', '?', '?', '?'] with MaxLen equals to 4, = "VariableName[MaxLen-1] !=3D 0" check is redundant. The NT32 case you met cannot represent the all possible cases. You could use the possibility theory to decide what the most efficient way = is. Additionally I think code readability is more important than efficiency. In this case, we need the data about the performance improvement to decide = whether this check is necessary. Regards, Ray >-----Original Message----- >From: Zeng, Star >Sent: Friday, June 23, 2017 5:33 PM >To: Ni, Ruiyu ; edk2-devel@lists.01.org >Cc: Gao, Liming ; Zeng, Star=20 > >Subject: RE: [PATCH V2 3/3] DuetPkg FsVariable: Update=20 >GetNextVariableName to follow UEFI 2.7 > >Ray, > >It is to pass the check quickly and avoid scanning all the chars in=20 >VariableName by StrnLenS for normal boot without invalid cases. >I did experiments in the code of GetNextVariableName with below debug=20 >code for normal boot on NT32 and my real platforms, all the cases will go = into the branch "xxx 2". > if (((VariableName[MaxLen - 1] !=3D 0))) { > DEBUG ((DEBUG_INFO, "xxx 1\n")); > } else { > DEBUG ((DEBUG_INFO, "xxx 2\n")); > } > > >Thanks, >Star >-----Original Message----- >From: Ni, Ruiyu >Sent: Friday, June 23, 2017 4:20 PM >To: Zeng, Star ; edk2-devel@lists.01.org >Cc: Gao, Liming >Subject: RE: [PATCH V2 3/3] DuetPkg FsVariable: Update=20 >GetNextVariableName to follow UEFI 2.7 > >Star, >What's the benefit of this check "VariableName[MaxLen - 1] !=3D 0"? >I think this check "StrnLenS (VariableName, MaxLen) =3D=3D MaxLen" should = be enough. > >Thanks/Ray > >> -----Original Message----- >> From: Zeng, Star >> Sent: Friday, June 23, 2017 4:08 PM >> To: edk2-devel@lists.01.org >> Cc: Zeng, Star ; Gao, Liming=20 >> ; Ni, Ruiyu >> Subject: [PATCH V2 3/3] DuetPkg FsVariable: Update=20 >> GetNextVariableName to follow UEFI 2.7 >> >> "The size must be large enough to fit input string supplied in=20 >> VariableName buffer" is added in the description for VariableNameSize. >> And two cases of EFI_INVALID_PARAMETER are added. >> 1. The input values of VariableName and VendorGuid are not a name and >> GUID of an existing variable. >> 2. Null-terminator is not found in the first VariableNameSize bytes of >> the input VariableName buffer. >> >> This patch is to update code to follow them. >> >> Cc: Liming Gao >> Cc: Ruiyu Ni >> Contributed-under: TianoCore Contribution Agreement 1.0 >> Signed-off-by: Star Zeng >> --- >> DuetPkg/FSVariable/FSVariable.c | 21 ++++++++++++++++++++- >> 1 file changed, 20 insertions(+), 1 deletion(-) >> >> diff --git a/DuetPkg/FSVariable/FSVariable.c=20 >> b/DuetPkg/FSVariable/FSVariable.c index 34b79305c871..6069cfa8fb98=20 >> 100644 >> --- a/DuetPkg/FSVariable/FSVariable.c >> +++ b/DuetPkg/FSVariable/FSVariable.c >> @@ -6,7 +6,7 @@ disk. They can be changed by user. BIOS is not able=20 >> to protoect those. >> Duet trusts all meta data from disk. If variable code, variable=20 >> metadata and variable data is modified in inproper way, the behavior=20 >> is undefined. >> >> -Copyright (c) 2006 - 2016, Intel Corporation. All rights=20 >> reserved.
>> +Copyright (c) 2006 - 2017, Intel Corporation. All rights=20 >> +reserved.
>> This program and the accompanying materials are licensed and made=20 >> available under the terms and conditions of the BSD License which=20 >> accompanies this distribution. The full text of the license may be=20 >> found at @@ -1400,14 +1400,33 @@ Returns: >> VARIABLE_POINTER_TRACK Variable; >> UINTN VarNameSize; >> EFI_STATUS Status; >> + UINTN MaxLen; >> >> if (VariableNameSize =3D=3D NULL || VariableName =3D=3D NULL || Vendo= rGuid =3D=3D >> NULL) { >> return EFI_INVALID_PARAMETER; >> } >> >> + // >> + // Calculate the possible maximum length of name string, including th= e Null >> terminator. >> + // >> + MaxLen =3D *VariableNameSize / sizeof (CHAR16); >> + if ((MaxLen =3D=3D 0) || >> + ((VariableName[MaxLen - 1] !=3D 0) && (StrnLenS (VariableName, Ma= xLen) >> =3D=3D MaxLen))) { >> + // >> + // Null-terminator is not found in the first VariableNameSize bytes= of the >> input VariableName buffer. >> + // >> + return EFI_INVALID_PARAMETER; >> + } >> + >> Status =3D FindVariable (VariableName, VendorGuid, &Variable); >> >> if (Variable.CurrPtr =3D=3D NULL || EFI_ERROR (Status)) { >> + if (VariableName[0] !=3D 0) { >> + // >> + // The input values of VariableName and VendorGuid are not a name >> and GUID of an existing variable. >> + // >> + Status =3D EFI_INVALID_PARAMETER; >> + } >> return Status; >> } >> >> -- >> 2.7.0.windows.1