From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) (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 A63D22095D20B for ; Sun, 25 Jun 2017 22:50:54 -0700 (PDT) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jun 2017 22:52:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,394,1493708400"; d="scan'208";a="1164611798" Received: from fmsmsx107.amr.corp.intel.com ([10.18.124.205]) by fmsmga001.fm.intel.com with ESMTP; 25 Jun 2017 22:52:23 -0700 Received: from shsmsx103.ccr.corp.intel.com (10.239.4.69) by fmsmsx107.amr.corp.intel.com (10.18.124.205) with Microsoft SMTP Server (TLS) id 14.3.319.2; Sun, 25 Jun 2017 22:52:23 -0700 Received: from shsmsx102.ccr.corp.intel.com ([169.254.2.146]) by SHSMSX103.ccr.corp.intel.com ([169.254.4.116]) with mapi id 14.03.0319.002; Mon, 26 Jun 2017 13:52:22 +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//fDSAgACGh9A= Date: Mon, 26 Jun 2017 05:52:21 +0000 Message-ID: <0C09AFA07DD0434D9E2A0C6AEB0483103B8ED461@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> In-Reply-To: <734D49CCEBEEF84792F5B80ED585239D5B9A462B@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 05:50:54 -0000 Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Before UEFI 2.6a and 2.7, the behavior is unpredictable, our *CODE* chose t= o return EFI_NOT_FOUND. "Passing in a VariableName parameter that is neither a Null-terminated stri= ng nor a value that was returned on the previous call to GetNextVariableName() may also produce unpredictable results." Thanks, Star -----Original Message----- From: Ni, Ruiyu=20 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 GetNextVariableName = to follow UEFI 2.7 Can you add more comments here to describe the purpose is to change the ret= urn status from Not Found to Invalid Parameter, and the reason of choosing = Invalid Parameter? Thanks/Ray > -----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 >=20 > It is to return EFI_INVALID_PARAMETER when the input VariableName and=20 > 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 case. > After the spec change, EFI_NOT_FOUND seemingly is reserved to indicate=20 > the ending of searching. >=20 >=20 > 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 >=20 > I understand your point. > But I do think it hurts readability. >=20 > 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; > } >=20 >=20 > Thanks/Ray >=20 > > -----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, and=20 > > 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 for=20 > > 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 equals=20 > > 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 efficiency= . > > In this case, we need the data about the performance improvement to=20 > > 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=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"=20 > > >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 VariableNameSiz= e. > > >> 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=20 > > >> 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, variable=20 > > >> metadata and variable data is modified in inproper way, the=20 > > >> 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 License =20 > > >> which accompanies this distribution. The full text of the=20 > > >> 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 =3D= =3D=20 > > >> + 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 not=20 > > >> + a name > > >> and GUID of an existing variable. > > >> + // > > >> + Status =3D EFI_INVALID_PARAMETER; > > >> + } > > >> return Status; > > >> } > > >> > > >> -- > > >> 2.7.0.windows.1