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 B072A20945B95 for ; Wed, 20 Sep 2017 22:17:33 -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; 20 Sep 2017 22:20:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,423,1500966000"; d="scan'208";a="154308589" Received: from jwang36-mobl2.ccr.corp.intel.com ([10.239.192.31]) by fmsmga006.fm.intel.com with ESMTP; 20 Sep 2017 22:20:38 -0700 From: Jian J Wang To: edk2-devel@lists.01.org Cc: "Wang, Jian J" , Star Zeng , Eric Dong , Laszlo Ersek , Jiewen Yao , Michael Kinney , Jordan Justen , Ayellet Wolman Date: Thu, 21 Sep 2017 13:20:27 +0800 Message-Id: <20170921052032.13652-2-jian.j.wang@intel.com> X-Mailer: git-send-email 2.14.1.windows.1 In-Reply-To: <20170921052032.13652-1-jian.j.wang@intel.com> References: <20170921052032.13652-1-jian.j.wang@intel.com> Subject: [PATCH v2 1/6] MdeModulePkg/MdeModulePkg.dec: Add NULL pointer detection PCD 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, 21 Sep 2017 05:17:33 -0000 From: "Wang, Jian J" PCD PcdNullPointerDetectionPropertyMask is a bitmask used to control the NULL address detection functionality in code for different phases. If enabled, accessing NULL address in UEFI or SMM code can be caught as a page fault exception. BIT0 - Enable NULL pointer detection for UEFI. BIT1 - Enable NULL pointer detection for SMM. BIT2..6 - Reserved for future uses. BIT7 - Disable NULL pointer detection just after EndOfDxe. This is a workaround for those unsolvable NULL access issues in OptionROM, boot loader, etc. It can also help to avoid unnecessary exception caused by legacy memory (0-4095) access after EndOfDxe, such as Windows 7 boot on Qemu. Cc: Star Zeng Cc: Eric Dong Cc: Laszlo Ersek Cc: Jiewen Yao Cc: Michael Kinney Cc: Jordan Justen Cc: Ayellet Wolman Suggested-by: Ayellet Wolman Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jian J Wang --- MdeModulePkg/MdeModulePkg.dec | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec index 403a66a5ad..3f90b8d7e6 100644 --- a/MdeModulePkg/MdeModulePkg.dec +++ b/MdeModulePkg/MdeModulePkg.dec @@ -863,6 +863,19 @@ # @ValidList 0x80000006 | 0x03058002 gEfiMdeModulePkgTokenSpaceGuid.PcdErrorCodeSetVariable|0x03058002|UINT32|0x30001040 + ## Mask to control the NULL address detection in code for different phases. + # If enabled, accessing NULL address in UEFI or SMM code can be caught.

+ # BIT0 - Enable NULL pointer detection for UEFI.
+ # BIT1 - Enable NULL pointer detection for SMM.
+ # BIT2..6 - Reserved for future uses.
+ # BIT7 - Disable NULL pointer detection just after EndOfDxe.
+ # This is a workaround for those unsolvable NULL access issues in + # OptionROM, boot loader, etc. It can also help to avoid unnecessary + # exception caused by legacy memory (0-4095) access after EndOfDxe, + # such as Windows 7 boot on Qemu.
+ # @Prompt Enable NULL address detection. + gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask|0x0|UINT8|0x30001050 + [PcdsFixedAtBuild, PcdsPatchableInModule] ## Dynamic type PCD can be registered callback function for Pcd setting action. # PcdMaxPeiPcdCallBackNumberPerPcdEntry indicates the maximum number of callback function -- 2.14.1.windows.1