From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (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 0C6162095A6A1 for ; Sun, 25 Jun 2017 23:30:35 -0700 (PDT) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jun 2017 23:32:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,394,1493708400"; d="scan'208";a="1164621741" Received: from fmsmsx105.amr.corp.intel.com ([10.18.124.203]) by fmsmga001.fm.intel.com with ESMTP; 25 Jun 2017 23:32:03 -0700 Received: from fmsmsx157.amr.corp.intel.com (10.18.116.73) by FMSMSX105.amr.corp.intel.com (10.18.124.203) with Microsoft SMTP Server (TLS) id 14.3.319.2; Sun, 25 Jun 2017 23:32:03 -0700 Received: from shsmsx152.ccr.corp.intel.com (10.239.6.52) by FMSMSX157.amr.corp.intel.com (10.18.116.73) with Microsoft SMTP Server (TLS) id 14.3.319.2; Sun, 25 Jun 2017 23:32:03 -0700 Received: from shsmsx102.ccr.corp.intel.com ([169.254.2.146]) by SHSMSX152.ccr.corp.intel.com ([169.254.6.122]) with mapi id 14.03.0319.002; Mon, 26 Jun 2017 14:31:59 +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//+nhQCAAIaIUP//fDSAgACGh9D//4JUgAARFDYw Date: Mon, 26 Jun 2017 06:31:58 +0000 Message-ID: <0C09AFA07DD0434D9E2A0C6AEB0483103B8ED4CD@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> <0C09AFA07DD0434D9E2A0C6AEB0483103B8ED350@shsmsx102.ccr.corp.intel.com> <734D49CCEBEEF84792F5B80ED585239D5B9A458B@SHSMSX104.ccr.corp.intel.com> <0C09AFA07DD0434D9E2A0C6AEB0483103B8ED40B@shsmsx102.ccr.corp.intel.com> <734D49CCEBEEF84792F5B80ED585239D5B9A462B@SHSMSX104.ccr.corp.intel.com> <0C09AFA07DD0434D9E2A0C6AEB0483103B8ED461@shsmsx102.ccr.corp.intel.com> <734D49CCEBEEF84792F5B80ED585239D5B9A46BB@SHSMSX104.ccr.corp.intel.com> In-Reply-To: <734D49CCEBEEF84792F5B80ED585239D5B9A46BB@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 06:30:35 -0000 Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable I meant the behavior by the spec was unpredictable. "Passing in a VariableName parameter that is neither a Null-terminated=20 string nor a value that was returned on the previous call to GetNextVariableName() may also produce *unpredictable* results." The behavior by the code was to return EFI_NOT_FOUND, it was our code's imp= lementation choice. Do you mean which piece of comments to be put in code? :) Thanks, Star -----Original Message----- From: Ni, Ruiyu=20 Sent: Monday, June 26, 2017 2:18 PM 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 Thanks! Could you please put the comments in code? But why do you say it's unpredictable? The behavior is to return EFI_NOT_FO= UND. Thanks/Ray > -----Original Message----- > From: Zeng, Star > Sent: Monday, June 26, 2017 1:52 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 >=20 > Before UEFI 2.6a and 2.7, the behavior is unpredictable, our *CODE*=20 > chose to return EFI_NOT_FOUND. >=20 > "Passing in a VariableName parameter that is neither a Null-terminated=20 > string nor a value that was returned on the previous call to > GetNextVariableName() may also produce unpredictable results." >=20 >=20 >=20 > Thanks, > Star > -----Original Message----- > From: Ni, Ruiyu > Sent: Monday, June 26, 2017 1:47 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 >=20 > Can you add more comments here to describe the purpose is to change=20 > the return status from Not Found to Invalid Parameter, and the reason=20 > of choosing Invalid Parameter? >=20 > Thanks/Ray >=20 > > -----Original Message----- > > From: Zeng, Star > > Sent: Monday, June 26, 2017 1:41 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 > > > > It is to return EFI_INVALID_PARAMETER when the input VariableName=20 > > and VendorGuid are not a valid variable to search next variable. > > It is added from UEFI 2.7 spec. > > Before the spec change, the code is to return EFI_NOT_FOUND at that cas= e. > > After the spec change, EFI_NOT_FOUND seemingly is reserved to=20 > > indicate the ending of searching. > > > > > > Thanks, > > Star > > -----Original Message----- > > From: Ni, Ruiyu > > Sent: Monday, June 26, 2017 1:37 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 > > > > I understand your point. > > But I do think it hurts readability. > > > > BTW, what does the below change does? > > if (Variable.CurrPtr =3D=3D NULL || EFI_ERROR (Status)) { > > + if (VariableName[0] !=3D 0) { > > + // > > + // The input values of VariableName and VendorGuid are not a=20 > > + name > > and GUID of an existing variable. > > + // > > + Status =3D EFI_INVALID_PARAMETER; > > + } > > return Status; > > } > > > > > > Thanks/Ray > > > > > -----Original Message----- > > > From: Zeng, Star > > > Sent: Monday, June 26, 2017 11:05 AM > > > 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, > > > > > > The code is like low hanging fruit from my practice for me, and I=20 > > > don't think it hurts readability although it may not bring=20 > > > performance improvement, it depends on how many variables in=20 > > > variable region, how many times of calling GetNextVariableName,=20 > > > and how fast of > > GetNextVariableName. > > > > > > The code practice I did is on NT32 and my real platforms. Is there=20 > > > anyone can make sure he/she tested all the systems in the world=20 > > > for their > > code? > > > > > > > > > Anyway, I can update the patch if you insist. > > > > > > > > > Thanks, > > > Star > > > -----Original Message----- > > > From: Ni, Ruiyu > > > 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=20 > > > GetNextVariableName to follow UEFI 2.7 > > > > > > Star, > > > I don't recommend to add the additional check for performance=20 > > > consideration. > > > Because we have no idea what the input VariableName buffer is like. > > > If the VariableName is like ['\0', '?', '?', '?'] with MaxLen=20 > > > 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=20 > > > efficient way > > is. > > > > > > Additionally I think code readability is more important than efficien= cy. > > > In this case, we need the data about the performance improvement=20 > > > 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=20 > > > >in VariableName by StrnLenS for normal boot without invalid cases. > > > >I did experiments in the code of GetNextVariableName with below=20 > > > >debug code for normal boot on NT32 and my real platforms, all the=20 > > > >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=20 > > > >> name > > and > > > >> GUID of an existing variable. > > > >> 2. Null-terminator is not found in the first VariableNameSize byte= s 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 > > > >> 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=20 > > > >> able to protoect those. > > > >> Duet trusts all meta data from disk. If variable code,=20 > > > >> variable metadata and variable data is modified in inproper=20 > > > >> way, the behavior 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=20 > > > >> made available under the terms and conditions of the BSD=20 > > > >> License which accompanies this distribution. The full text of=20 > > > >> the license may be 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 ||= =20 > > > >> VendorGuid =3D=3D > > > >> NULL) { > > > >> return EFI_INVALID_PARAMETER; > > > >> } > > > >> > > > >> + // > > > >> + // Calculate the possible maximum length of name string,=20 > > > >> + including the Null > > > >> terminator. > > > >> + // > > > >> + MaxLen =3D *VariableNameSize / sizeof (CHAR16); if ((MaxLen=20 > > > >> + =3D=3D > > > >> + 0) > > > >> + || > > > >> + ((VariableName[MaxLen - 1] !=3D 0) && (StrnLenS=20 > > > >> + (VariableName, > > > >> + MaxLen) > > > >> =3D=3D MaxLen))) { > > > >> + // > > > >> + // Null-terminator is not found in the first=20 > > > >> + 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=20 > > > >> + not a name > > > >> and GUID of an existing variable. > > > >> + // > > > >> + Status =3D EFI_INVALID_PARAMETER; > > > >> + } > > > >> return Status; > > > >> } > > > >> > > > >> -- > > > >> 2.7.0.windows.1