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 2BF6821F077A2 for ; Wed, 20 Sep 2017 22:17:43 -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 22:20:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,423,1500966000"; d="scan'208";a="154308625" Received: from jwang36-mobl2.ccr.corp.intel.com ([10.239.192.31]) by fmsmga006.fm.intel.com with ESMTP; 20 Sep 2017 22:20:48 -0700 From: Jian J Wang To: edk2-devel@lists.01.org Cc: Star Zeng , Eric Dong , Laszlo Ersek , Jiewen Yao , Michael Kinney , Jordan Justen , Ayellet Wolman Date: Thu, 21 Sep 2017 13:20:30 +0800 Message-Id: <20170921052032.13652-5-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 4/6] MdeModulePkg/Core/Dxe: Add EndOfDxe workaround for NULL pointer detection 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 05:17:43 -0000 One of issue caused by enabling NULL pointer detection is that some PCI device OptionROM, binary drivers and binary OS boot loaders may have NULL pointer access bugs, which will prevent BIOS from booting and is almost impossible to fix. BIT7 of PCD PcdNullPointerDetectionPropertyMask is used as a workaround to indicate BIOS to disable NULL pointer detection right after event gEfiEndOfDxeEventGroupGuid, and then let boot continue. 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/Core/Dxe/DxeMain.inf | 1 + MdeModulePkg/Core/Dxe/Mem/Page.c | 4 ++- MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c | 48 +++++++++++++++++++++++++++ 3 files changed, 52 insertions(+), 1 deletion(-) diff --git a/MdeModulePkg/Core/Dxe/DxeMain.inf b/MdeModulePkg/Core/Dxe/DxeMain.inf index 30d5984f7c..0a161ffd71 100644 --- a/MdeModulePkg/Core/Dxe/DxeMain.inf +++ b/MdeModulePkg/Core/Dxe/DxeMain.inf @@ -192,6 +192,7 @@ gEfiMdeModulePkgTokenSpaceGuid.PcdPropertiesTableEnable ## CONSUMES gEfiMdeModulePkgTokenSpaceGuid.PcdImageProtectionPolicy ## CONSUMES gEfiMdeModulePkgTokenSpaceGuid.PcdDxeNxMemoryProtectionPolicy ## CONSUMES + gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask ## CONSUMES # [Hob] # RESOURCE_DESCRIPTOR ## CONSUMES diff --git a/MdeModulePkg/Core/Dxe/Mem/Page.c b/MdeModulePkg/Core/Dxe/Mem/Page.c index a142c79ee2..0468df3171 100644 --- a/MdeModulePkg/Core/Dxe/Mem/Page.c +++ b/MdeModulePkg/Core/Dxe/Mem/Page.c @@ -188,7 +188,9 @@ CoreAddRange ( // used for other purposes. // if (Type == EfiConventionalMemory && Start == 0 && (End >= EFI_PAGE_SIZE - 1)) { - SetMem ((VOID *)(UINTN)Start, EFI_PAGE_SIZE, 0); + if ((PcdGet8 (PcdNullPointerDetectionPropertyMask) & BIT0) == 0) { + SetMem ((VOID *)(UINTN)Start, EFI_PAGE_SIZE, 0); + } } // diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c index a73c4ccd64..73e3b269f3 100644 --- a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c +++ b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c @@ -995,6 +995,36 @@ MemoryProtectionExitBootServicesCallback ( } } +/** + Disable NULL pointer detection after EndOfDxe. This is a workaround resort in + order to skip unfixable NULL pointer access issues detected in OptionROM or + boot loaders. + + @param[in] Event The Event this notify function registered to. + @param[in] Context Pointer to the context data registered to the Event. +**/ +VOID +EFIAPI +DisableNullDetectionAtTheEndOfDxe ( + EFI_EVENT Event, + VOID *Context + ) +{ + EFI_STATUS Status; + + DEBUG ((DEBUG_INFO, "DisableNullDetectionAtTheEndOfDxe(): start\r\n")); + // + // Disable NULL pointer detection by enabling first 4K page + // + Status = gCpu->SetMemoryAttributes (gCpu, 0, EFI_PAGE_SIZE, 0); + ASSERT_EFI_ERROR (Status); + + CoreCloseEvent (Event); + DEBUG ((DEBUG_INFO, "DisableNullDetectionAtTheEndOfDxe(): end\r\n")); + + return; +} + /** Initialize Memory Protection support. **/ @@ -1006,6 +1036,7 @@ CoreInitializeMemoryProtection ( { EFI_STATUS Status; EFI_EVENT Event; + EFI_EVENT EndOfDxeEvent; VOID *Registration; mImageProtectionPolicy = PcdGet32(PcdImageProtectionPolicy); @@ -1044,6 +1075,23 @@ CoreInitializeMemoryProtection ( ); ASSERT_EFI_ERROR(Status); } + + // + // Register a callback to disable NULL pointer detection at EndOfDxe + // + if ((PcdGet8 (PcdNullPointerDetectionPropertyMask) & (BIT0|BIT7)) + == (BIT0|BIT7)) { + Status = CoreCreateEventEx ( + EVT_NOTIFY_SIGNAL, + TPL_NOTIFY, + DisableNullDetectionAtTheEndOfDxe, + NULL, + &gEfiEndOfDxeEventGroupGuid, + &EndOfDxeEvent + ); + ASSERT_EFI_ERROR (Status); + } + return ; } -- 2.14.1.windows.1