From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=66.187.233.73; helo=mx1.redhat.com; envelope-from=lersek@redhat.com; receiver=edk2-devel@lists.01.org Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) (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 DFD0921F6A6CF for ; Fri, 23 Feb 2018 11:08:06 -0800 (PST) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 21B8440FB64A; Fri, 23 Feb 2018 19:14:07 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-120-112.rdu2.redhat.com [10.10.120.112]) by smtp.corp.redhat.com (Postfix) with ESMTP id B769C213AEED; Fri, 23 Feb 2018 19:14:01 +0000 (UTC) To: marcandre.lureau@redhat.com, edk2-devel@lists.01.org Cc: pjones@redhat.com, jiewen.yao@intel.com, stefanb@linux.vnet.ibm.com, qemu-devel@nongnu.org, javierm@redhat.com References: <20180223132311.26555-1-marcandre.lureau@redhat.com> <20180223132311.26555-4-marcandre.lureau@redhat.com> From: Laszlo Ersek Message-ID: <53540b2d-e52e-af98-6008-cab3a1688388@redhat.com> Date: Fri, 23 Feb 2018 20:14:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180223132311.26555-4-marcandre.lureau@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 23 Feb 2018 19:14:07 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 23 Feb 2018 19:14:07 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'lersek@redhat.com' RCPT:'' Subject: Re: [PATCH 3/7] HACK: HobLib: workaround infinite loop X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Feb 2018 19:08:07 -0000 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit On 02/23/18 14:23, marcandre.lureau@redhat.com wrote: > From: Marc-André Lureau > > Without this hack, GetNextHob() loops infinitely with the next patch. > I don't understand the reason. > > The loop is triggered by the GetFirstGuidHob (&gTpmErrorHobGuid) call. > > CC: Laszlo Ersek > CC: Stefan Berger > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Marc-André Lureau > --- > MdePkg/Library/PeiHobLib/HobLib.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/MdePkg/Library/PeiHobLib/HobLib.c b/MdePkg/Library/PeiHobLib/HobLib.c > index 5c0eeb992f..ed3c5fbd6d 100644 > --- a/MdePkg/Library/PeiHobLib/HobLib.c > +++ b/MdePkg/Library/PeiHobLib/HobLib.c > @@ -89,6 +89,10 @@ GetNextHob ( > if (Hob.Header->HobType == Type) { > return Hob.Raw; > } > + if (GET_HOB_LENGTH (HobStart) == 0) { > + DEBUG ((DEBUG_INFO, "FIXME: GetNextHob length == 0")); > + return NULL; > + } > Hob.Raw = GET_NEXT_HOB (Hob); > } > return NULL; > Strange. The HobLength field is supposed to include the size of the HOB header, so it should never be zero. Furthermore, the PEI core initializes the HOB list; it should be terminated with an End-of-HOB-List HOB: PeiCore() [MdeModulePkg/Core/Pei/PeiMain/PeiMain.c] InitializeMemoryServices() [MdeModulePkg/Core/Pei/Memory/MemoryServices.c] PeiCoreBuildHobHandoffInfoTable() [MdeModulePkg/Core/Pei/Hob/Hob.c] I tried to reproduce this issue by: - applying patches 1, 2, and 4 - in function PeimEntryMA(), file "SecurityPkg/Tcg/Tcg2Pei/Tcg2Pei.c", moving the GetFirstGuidHob (&gTpmErrorHobGuid) call to the top of the function. It didn't hang for me. Laszlo