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* [PATCH 3/4] IntelFrameworkModulePkg/Csm: Update CSM code to temporarily bypass NULL pointer detection if enabled.
@ 2017-09-13  8:07 Wang, Jian J
  0 siblings, 0 replies; 37+ messages in thread
From: Wang, Jian J @ 2017-09-13  8:07 UTC (permalink / raw)
  To: edk2-devel

CSM code has to access memory below 4096 (BDA, int vector, etc.). If NULL pointer detection is enabled, the page 0 must be enabled temporarily before accessing it and disabled again afterwards. Otherwise page fault will be triggered.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Justen, Jordan L <jordan.l.justen@intel.com>
Cc: Kinney, Michael D <michael.d.kinney@intel.com>
Cc: Wolman, Ayellet <ayellet.wolman@intel.com>
Suggested-by: Wolman, Ayellet <ayellet.wolman@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Wang, Jian J <jian.j.wang@intel.com>
---
 .../Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c       | 10 +++-
 .../Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h       | 18 +++++++
 .../Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf      |  2 +
 .../Csm/LegacyBiosDxe/LegacyBda.c                  |  4 ++
 .../Csm/LegacyBiosDxe/LegacyBios.c                 | 55 ++++++++++++++++++----
 .../Csm/LegacyBiosDxe/LegacyBiosDxe.inf            |  2 +
 .../Csm/LegacyBiosDxe/LegacyBiosInterface.h        | 23 +++++++++
 .../Csm/LegacyBiosDxe/LegacyBootSupport.c          | 33 ++++++++++---
 .../Csm/LegacyBiosDxe/LegacyPci.c                  | 17 ++++++-
 IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c  | 41 ++++++++++------
 10 files changed, 173 insertions(+), 32 deletions(-)

diff --git a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
index 7308523ad8..96148ae367 100644
--- a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
+++ b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
@@ -248,7 +248,7 @@ BiosKeyboardDriverBindingStart (
   //
   // Allocate the private device structure
   //
-    BiosKeyboardPrivate = (BIOS_KEYBOARD_DEV *) AllocateZeroPool (sizeof (BIOS_KEYBOARD_DEV));
+  BiosKeyboardPrivate = (BIOS_KEYBOARD_DEV *) AllocateZeroPool (sizeof (BIOS_KEYBOARD_DEV));
   if (NULL == BiosKeyboardPrivate) {
     Status = EFI_OUT_OF_RESOURCES;
     goto Done;
@@ -281,6 +281,9 @@ BiosKeyboardDriverBindingStart (
   BiosKeyboardPrivate->SimpleTextInputEx.UnregisterKeyNotify = BiosKeyboardUnregisterKeyNotify;    
   InitializeListHead (&BiosKeyboardPrivate->NotifyList);
 
+  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **) &BiosKeyboardPrivate->Cpu);
+  ASSERT_EFI_ERROR(Status);
+
   //
   // Report that the keyboard is being enabled
   //
@@ -1842,7 +1845,9 @@ BiosKeyboardTimerHandler (
   //
   // Clear the CTRL and ALT BDA flag
   //
-  KbFlag1 = *((UINT8 *) (UINTN) 0x417);  // read the STATUS FLAGS 1
+  DISABLE_NULL_DETECTION(BiosKeyboardPrivate);
+
+  KbFlag1 = *((UINT8 *) (UINTN) 0x417); // read the STATUS FLAGS 1
   KbFlag2 = *((UINT8 *) (UINTN) 0x418); // read STATUS FLAGS 2
 
   DEBUG_CODE (
@@ -1916,6 +1921,7 @@ BiosKeyboardTimerHandler (
   KbFlag1 &= ~0x0C;                      
   *((UINT8 *) (UINTN) 0x417) = KbFlag1; 
 
+  ENABLE_NULL_DETECTION(BiosKeyboardPrivate);
   
   //
   // Output EFI input key and shift/toggle state
diff --git a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h
index 0bf28ea140..b717ef676b 100644
--- a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h
+++ b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h
@@ -26,6 +26,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include <Protocol/IsaIo.h>
 #include <Protocol/DevicePath.h>
 #include <Protocol/Ps2Policy.h>
+#include <Protocol/Cpu.h>
 
 #include <Library/DebugLib.h>
 #include <Library/UefiLib.h>
@@ -212,6 +213,7 @@ typedef struct {
   EFI_HANDLE                                  Handle;
   EFI_LEGACY_BIOS_PROTOCOL                    *LegacyBios;
   EFI_ISA_IO_PROTOCOL                         *IsaIo;
+  EFI_CPU_ARCH_PROTOCOL                       *Cpu;
   EFI_SIMPLE_TEXT_INPUT_PROTOCOL              SimpleTextIn;
   EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL           SimpleTextInputEx;
   UINT16                                      DataRegisterAddress;
@@ -242,6 +244,22 @@ typedef struct {
       BIOS_KEYBOARD_DEV_SIGNATURE \
       )
 
+//
+// CSM needs to access memory between 0-4095, which will cause page fault exception 
+// if NULL pointer detection mechanism is enabled. Following macros can be used
+// to disable/enable NULL pointer detection before/after accessing those memory.
+//
+#define NULL_POINTER_DETECTION_ENABLED  ((PcdGet8(PcdNullPointerDetectionPropertyMask) & BIT0) != 0)
+#define DISABLE_NULL_DETECTION(Instance)                                        \
+  if (NULL_POINTER_DETECTION_ENABLED && (Instance)->Cpu != NULL) {              \
+    (Instance)->Cpu->SetMemoryAttributes((Instance)->Cpu, 0, EFI_PAGE_SIZE, 0); \
+  }
+  
+#define ENABLE_NULL_DETECTION(Instance)                                                     \
+  if (NULL_POINTER_DETECTION_ENABLED && (Instance)->Cpu != NULL) {                          \
+    (Instance)->Cpu->SetMemoryAttributes((Instance)->Cpu, 0, EFI_PAGE_SIZE, EFI_MEMORY_RP); \
+  }
+
 //
 // Global Variables
 //
diff --git a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf
index 4d4536466c..4291a10123 100644
--- a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf
+++ b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf
@@ -67,12 +67,14 @@
   gEfiSimpleTextInputExProtocolGuid             ## BY_START
   gEfiLegacyBiosProtocolGuid                    ## CONSUMES
   gEfiPs2PolicyProtocolGuid                     ## SOMETIMES_CONSUMES
+  gEfiCpuArchProtocolGuid                       ## SOMETIMES_CONSUMES
 
 [FeaturePcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdPs2KbdExtendedVerification|FALSE  ## CONSUMES
 
 [Pcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdFastPS2Detection                  ## SOMETIMES_CONSUMES
+  gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask  ## CONSUMES
 
 [UserExtensions.TianoCore."ExtraFiles"]
   KeyboardDxeExtra.uni
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c
index c45d5d4c3e..e7cee4b8a3 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c
@@ -34,6 +34,8 @@ LegacyBiosInitBda (
   BDA_STRUC *Bda;
   UINT8     *Ebda;
 
+  DISABLE_NULL_DETECTION(Private);
+
   Bda   = (BDA_STRUC *) ((UINTN) 0x400);
   Ebda  = (UINT8 *) ((UINTN) 0x9fc00);
 
@@ -62,5 +64,7 @@ LegacyBiosInitBda (
 
   *Ebda               = 0x01;
 
+  ENABLE_NULL_DETECTION(Private);
+
   return EFI_SUCCESS;
 }
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBios.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBios.c
index 3ead2d9828..c3ef542ea3 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBios.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBios.c
@@ -40,6 +40,7 @@ VOID                  *mRuntimeSmbiosEntryPoint = NULL;
 EFI_PHYSICAL_ADDRESS  mReserveSmbiosEntryPoint = 0;
 EFI_PHYSICAL_ADDRESS  mStructureTableAddress   = 0;
 UINTN                 mStructureTablePages     = 0;
+BOOLEAN               mEndOfDxe                = FALSE;
 
 /**
   Do an AllocatePages () of type AllocateMaxAddress for EfiBootServicesCode
@@ -765,6 +766,26 @@ InstallSmbiosEventCallback (
   }
 }
 
+/**
+  Callback function to toggle EndOfDxe status. NULL pointer detection needs this 
+  status to decide if it's necessary to change attributes of page 0. 
+
+  @param  Event                 Event whose notification function is being invoked.
+  @param  Context               The pointer to the notification function's context,
+                                which is implementation-dependent.
+
+**/
+VOID
+EFIAPI
+ToggleEndOfDxeStatus (
+  IN EFI_EVENT                Event,
+  IN VOID                     *Context
+  )
+{
+  mEndOfDxe = TRUE;
+  return;
+}
+
 /**
   Install Driver to produce Legacy BIOS protocol.
 
@@ -802,6 +823,7 @@ LegacyBiosInstall (
   UINT64                             Length;
   UINT8                              *SecureBoot;
   EFI_EVENT                          InstallSmbiosEvent;
+  EFI_EVENT                          EndOfDxeEvent;
 
   //
   // Load this driver's image to memory
@@ -964,8 +986,10 @@ LegacyBiosInstall (
   // Initialize region from 0x0000 to 4k. This initializes interrupt vector
   // range.
   //
-  gBS->SetMem ((VOID *) ClearPtr, 0x400, INITIAL_VALUE_BELOW_1K);
-  ZeroMem ((VOID *) ((UINTN)ClearPtr + 0x400), 0xC00);
+  DISABLE_NULL_DETECTION(Private);
+    gBS->SetMem ((VOID *) ClearPtr, 0x400, INITIAL_VALUE_BELOW_1K);
+    ZeroMem ((VOID *) ((UINTN)ClearPtr + 0x400), 0xC00);
+  ENABLE_NULL_DETECTION(Private);
 
   //
   // Allocate pages for OPROM usage
@@ -1104,12 +1128,14 @@ LegacyBiosInstall (
   //
   // Save Unexpected interrupt vector so can restore it just prior to boot
   //
-  BaseVectorMaster = (UINT32 *) (sizeof (UINT32) * PROTECTED_MODE_BASE_VECTOR_MASTER);
-  Private->BiosUnexpectedInt = BaseVectorMaster[0];
-  IntRedirCode = (UINT32) (UINTN) Private->IntThunk->InterruptRedirectionCode;
-  for (Index = 0; Index < 8; Index++) {
-    BaseVectorMaster[Index] = (EFI_SEGMENT (IntRedirCode + Index * 4) << 16) | EFI_OFFSET (IntRedirCode + Index * 4);
-  }
+  DISABLE_NULL_DETECTION(Private);
+    BaseVectorMaster = (UINT32 *) (sizeof (UINT32) * PROTECTED_MODE_BASE_VECTOR_MASTER);
+    Private->BiosUnexpectedInt = BaseVectorMaster[0];
+    IntRedirCode = (UINT32) (UINTN) Private->IntThunk->InterruptRedirectionCode;
+    for (Index = 0; Index < 8; Index++) {
+      BaseVectorMaster[Index] = (EFI_SEGMENT (IntRedirCode + Index * 4) << 16) | EFI_OFFSET (IntRedirCode + Index * 4);
+    }
+  ENABLE_NULL_DETECTION(Private);
   //
   // Save EFI value
   //
@@ -1133,6 +1159,19 @@ LegacyBiosInstall (
                   );
   ASSERT_EFI_ERROR (Status);  
 
+  //
+  // Create callback to update status of EndOfDxe, which is needed by NULL pointer detection
+  //
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_NOTIFY,
+                  ToggleEndOfDxeStatus,
+                  NULL,
+                  &gEfiEndOfDxeEventGroupGuid,
+                  &EndOfDxeEvent
+                  );
+  ASSERT_EFI_ERROR (Status);
+
   //
   // Make a new handle and install the protocol
   //
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
index 48473a0713..10dc392800 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
@@ -108,6 +108,7 @@
   gEfiDiskInfoIdeInterfaceGuid                  ## SOMETIMES_CONSUMES ##GUID #Used in LegacyBiosBuildIdeData() to assure device is a disk
   gEfiSmbiosTableGuid                           ## SOMETIMES_CONSUMES ##SystemTable
   gEfiLegacyBiosGuid                            ## SOMETIMES_CONSUMES ##GUID #Used in LegacyBiosInstallVgaRom() to locate handle buffer
+  gEfiEndOfDxeEventGroupGuid
 
 [Guids.IA32]
   gEfiAcpi20TableGuid                           ## SOMETIMES_CONSUMES ##SystemTable
@@ -147,6 +148,7 @@
   gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdHighPmmMemorySize            ## CONSUMES
   gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdOpromReservedMemoryBase      ## CONSUMES
   gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdOpromReservedMemorySize      ## CONSUMES
+  gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask        ## CONSUMES
 
 [Depex]
   gEfiLegacyRegion2ProtocolGuid AND gEfiLegacyInterruptProtocolGuid AND gEfiLegacyBiosPlatformProtocolGuid AND gEfiLegacy8259ProtocolGuid AND gEfiGenericMemTestProtocolGuid AND gEfiCpuArchProtocolGuid AND gEfiTimerArchProtocolGuid AND gEfiVariableWriteArchProtocolGuid
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosInterface.h b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosInterface.h
index fe9dd7463a..9d479309a4 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosInterface.h
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosInterface.h
@@ -108,6 +108,27 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #define NORMALIZE_EFI_SEGMENT(_Adr)      (UINT16) (((UINTN) (_Adr)) >> 4)
 #define NORMALIZE_EFI_OFFSET(_Adr)       (UINT16) (((UINT16) ((UINTN) (_Adr))) & 0xf)
 
+//
+// CSM needs to access memory between 0-4095, which will cause page fault exception 
+// if NULL pointer detection mechanism is enabled. Following macros can be used
+// to disable/enable NULL pointer detection before/after accessing those memory.
+//
+#define NULL_DETECTION_ENABLED                                                                        \
+  (  ((mEndOfDxe == FALSE) && ((PcdGet8(PcdNullPointerDetectionPropertyMask) & BIT0) == BIT0))        \
+  || ((mEndOfDxe == TRUE)  && ((PcdGet8(PcdNullPointerDetectionPropertyMask) & (BIT0|BIT7)) == BIT0)) \
+  )
+#define DISABLE_NULL_DETECTION(Instance)                                        \
+  if (NULL_DETECTION_ENABLED) {                                                 \
+    DEBUG((DEBUG_INFO, "%a(): disable NULL detection\r\n",  __func__));         \
+    (Instance)->Cpu->SetMemoryAttributes((Instance)->Cpu, 0, EFI_PAGE_SIZE, 0); \
+  }
+  
+#define ENABLE_NULL_DETECTION(Instance)                                                     \
+  if (NULL_DETECTION_ENABLED) {                                                             \
+    (Instance)->Cpu->SetMemoryAttributes((Instance)->Cpu, 0, EFI_PAGE_SIZE, EFI_MEMORY_RP); \
+    DEBUG((DEBUG_INFO, "%a(): enable NULL detection\r\n",  __func__));                      \
+  }
+
 //
 // Trace defines
 //
@@ -509,6 +530,8 @@ extern BBS_TABLE           *mBbsTable;
 
 extern EFI_GENERIC_MEMORY_TEST_PROTOCOL *gGenMemoryTest;
 
+extern BOOLEAN mEndOfDxe;
+
 #define PORT_70 0x70
 #define PORT_71 0x71
 
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
index 1e098b3726..d381c2f735 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
@@ -1073,8 +1073,10 @@ GenericLegacyBoot (
   // Use 182/10 to avoid floating point math.
   //
   LocalTime = (LocalTime * 182) / 10;
-  BdaPtr    = (UINT32 *) (UINTN)0x46C;
-  *BdaPtr   = LocalTime;
+  DISABLE_NULL_DETECTION(Private);
+    BdaPtr    = (UINT32 *) (UINTN)0x46C;
+    *BdaPtr   = LocalTime;
+  ENABLE_NULL_DETECTION(Private);
 
   //
   // Shadow PCI ROMs. We must do this near the end since this will kick
@@ -1320,6 +1322,7 @@ GenericLegacyBoot (
     //          set of TIANO vectors) or takes it over.
     //
     //
+    DISABLE_NULL_DETECTION(Private);
     BaseVectorMaster = (UINT32 *) (sizeof (UINT32) * PROTECTED_MODE_BASE_VECTOR_MASTER);
     for (Index = 0; Index < 8; Index++) {
       Private->ThunkSavedInt[Index] = BaseVectorMaster[Index];
@@ -1327,6 +1330,7 @@ GenericLegacyBoot (
         BaseVectorMaster[Index] = (UINT32) (Private->BiosUnexpectedInt);
       }
     }
+    ENABLE_NULL_DETECTION(Private);
 
     ZeroMem (&Regs, sizeof (EFI_IA32_REGISTER_SET));
     Regs.X.AX = Legacy16Boot;
@@ -1340,10 +1344,12 @@ GenericLegacyBoot (
       0
       );
 
+    DISABLE_NULL_DETECTION(Private);
     BaseVectorMaster = (UINT32 *) (sizeof (UINT32) * PROTECTED_MODE_BASE_VECTOR_MASTER);
     for (Index = 0; Index < 8; Index++) {
       BaseVectorMaster[Index] = Private->ThunkSavedInt[Index];
     }
+    ENABLE_NULL_DETECTION(Private);
   }
   Private->LegacyBootEntered = TRUE;
   if ((mBootMode == BOOT_LEGACY_OS) || (mBootMode == BOOT_UNCONVENTIONAL_DEVICE)) {
@@ -1731,9 +1737,11 @@ LegacyBiosBuildE820 (
   //
   // First entry is 0 to (640k - EBDA)
   //
-  E820Table[0].BaseAddr  = 0;
-  E820Table[0].Length    = (UINT64) ((*(UINT16 *) (UINTN)0x40E) << 4);
-  E820Table[0].Type      = EfiAcpiAddressRangeMemory;
+  DISABLE_NULL_DETECTION(Private);
+    E820Table[0].BaseAddr  = 0;
+    E820Table[0].Length    = (UINT64) ((*(UINT16 *) (UINTN)0x40E) << 4);
+    E820Table[0].Type      = EfiAcpiAddressRangeMemory;
+  ENABLE_NULL_DETECTION(Private);
 
   //
   // Second entry is (640k - EBDA) to 640k
@@ -1967,6 +1975,8 @@ LegacyBiosCompleteBdaBeforeBoot (
   UINT16                      MachineConfig;
   DEVICE_PRODUCER_DATA_HEADER *SioPtr;
 
+  DISABLE_NULL_DETECTION(Private);
+
   Bda           = (BDA_STRUC *) ((UINTN) 0x400);
   MachineConfig = 0;
 
@@ -2025,6 +2035,8 @@ LegacyBiosCompleteBdaBeforeBoot (
   MachineConfig       = (UINT16) (MachineConfig + 0x00 + 0x02 + (SioPtr->MousePresent * 0x04));
   Bda->MachineConfig  = MachineConfig;
 
+  ENABLE_NULL_DETECTION(Private);
+
   return EFI_SUCCESS;
 }
 
@@ -2049,15 +2061,20 @@ LegacyBiosUpdateKeyboardLedStatus (
   UINT8                 LocalLeds;
   EFI_IA32_REGISTER_SET Regs;
 
-  Bda                 = (BDA_STRUC *) ((UINTN) 0x400);
-
   Private             = LEGACY_BIOS_INSTANCE_FROM_THIS (This);
+
+  DISABLE_NULL_DETECTION(Private);
+
+  Bda                 = (BDA_STRUC *) ((UINTN) 0x400);
   LocalLeds           = Leds;
   Bda->LedStatus      = (UINT8) ((Bda->LedStatus &~0x07) | LocalLeds);
   LocalLeds           = (UINT8) (LocalLeds << 4);
   Bda->ShiftStatus    = (UINT8) ((Bda->ShiftStatus &~0x70) | LocalLeds);
   LocalLeds           = (UINT8) (Leds & 0x20);
   Bda->KeyboardStatus = (UINT8) ((Bda->KeyboardStatus &~0x20) | LocalLeds);
+
+  ENABLE_NULL_DETECTION(Private);
+
   //
   // Call into Legacy16 code to allow it to do any processing
   //
@@ -2102,7 +2119,9 @@ LegacyBiosCompleteStandardCmosBeforeBoot (
   //            to large capacity drives
   // CMOS 14 = BDA 40:10 plus bit 3(display enabled)
   //
+  DISABLE_NULL_DETECTION(Private);
   Bda = (UINT8)(*((UINT8 *)((UINTN)0x410)) | BIT3);
+  ENABLE_NULL_DETECTION(Private);
 
   //
   // Force display enabled
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
index 8ffdf0c1ff..2ca5dddf00 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
@@ -2279,6 +2279,7 @@ LegacyBiosInstallRom (
   UINTN                 Function;
   EFI_IA32_REGISTER_SET Regs;
   UINT8                 VideoMode;
+  UINT8                 OldVideoMode;
   EFI_TIME              BootTime;
   UINT32                *BdaPtr;
   UINT32                LocalTime;
@@ -2299,6 +2300,7 @@ LegacyBiosInstallRom (
   Device          = 0;
   Function        = 0;
   VideoMode       = 0;
+  OldVideoMode    = 0;
   PhysicalAddress = 0;
   MaxRomAddr      = PcdGet32 (PcdEndOpromShadowAddress);
 
@@ -2401,6 +2403,8 @@ LegacyBiosInstallRom (
   // 2. BBS compliants drives will not change 40:75 until boot time.
   // 3. Onboard IDE controllers will change 40:75
   //
+  DISABLE_NULL_DETECTION(Private);
+
   LocalDiskStart = (UINT8) ((*(UINT8 *) ((UINTN) 0x475)) + 0x80);
   if ((Private->Disk4075 + 0x80) < LocalDiskStart) {
     //
@@ -2426,6 +2430,9 @@ LegacyBiosInstallRom (
     //
     VideoMode = *(UINT8 *) ((UINTN) (0x400 + BDA_VIDEO_MODE));
   }
+
+  ENABLE_NULL_DETECTION(Private);
+
   //
   // Notify the platform that we are about to scan the ROM
   //
@@ -2466,9 +2473,11 @@ LegacyBiosInstallRom (
   // Multiply result by 18.2 for number of ticks since midnight.
   // Use 182/10 to avoid floating point math.
   //
+  DISABLE_NULL_DETECTION(Private);
   LocalTime = (LocalTime * 182) / 10;
   BdaPtr    = (UINT32 *) ((UINTN) 0x46C);
   *BdaPtr   = LocalTime;
+  ENABLE_NULL_DETECTION(Private);
   
   //
   // Pass in handoff data
@@ -2564,7 +2573,11 @@ LegacyBiosInstallRom (
     //
     // Set mode settings since PrepareToScanRom may change mode
     //
-    if (VideoMode != *(UINT8 *) ((UINTN) (0x400 + BDA_VIDEO_MODE))) {
+    DISABLE_NULL_DETECTION(Private);
+    OldVideoMode = *(UINT8 *) ((UINTN) (0x400 + BDA_VIDEO_MODE));
+    ENABLE_NULL_DETECTION(Private);
+
+    if (VideoMode != OldVideoMode) {
       //
       // The active video mode is changed, restore it to original mode.
       //
@@ -2604,7 +2617,9 @@ LegacyBiosInstallRom (
     }
   }
 
+  DISABLE_NULL_DETECTION(Private);
   LocalDiskEnd = (UINT8) ((*(UINT8 *) ((UINTN) 0x475)) + 0x80);
+  ENABLE_NULL_DETECTION(Private);
   
   //
   // Allow platform to perform any required actions after the
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
index 3d9a8b9649..50f6247a99 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
@@ -57,7 +57,11 @@ LegacyBiosInt86 (
   IN  EFI_IA32_REGISTER_SET         *Regs
   )
 {
-  UINT32  *VectorBase;
+  UINT16                Segment;
+  UINT16                Offset;
+  LEGACY_BIOS_INSTANCE  *Private;
+
+  Private = LEGACY_BIOS_INSTANCE_FROM_THIS (This);
 
   Regs->X.Flags.Reserved1 = 1;
   Regs->X.Flags.Reserved2 = 0;
@@ -72,12 +76,15 @@ LegacyBiosInt86 (
   // The base address of legacy interrupt vector table is 0.
   // We use this base address to get the legacy interrupt handler.
   //
-  VectorBase              = 0;
+  DISABLE_NULL_DETECTION(Private);
+    Segment               = (UINT16)(((UINT32 *)0)[BiosInt] >> 16);
+    Offset                = (UINT16)((UINT32 *)0)[BiosInt];
+  ENABLE_NULL_DETECTION(Private);
   
   return InternalLegacyBiosFarCall (
            This,
-           (UINT16) ((VectorBase)[BiosInt] >> 16),
-           (UINT16) (VectorBase)[BiosInt],
+           Segment,
+           Offset,
            Regs,
            &Regs->X.Flags,
            sizeof (Regs->X.Flags)
@@ -288,16 +295,22 @@ InternalLegacyBiosFarCall (
   // EBDA base address, if the current EBDA base address is smaller, it indicates
   // PcdEbdaReservedMemorySize should be adjusted to larger for more OPROMs.
   //
-  DEBUG_CODE (
-    {
-      UINTN                 EbdaBaseAddress;
-      UINTN                 ReservedEbdaBaseAddress;
-
-      EbdaBaseAddress = (*(UINT16 *) (UINTN) 0x40E) << 4;
-      ReservedEbdaBaseAddress = CONVENTIONAL_MEMORY_TOP - PcdGet32 (PcdEbdaReservedMemorySize);
-      ASSERT (ReservedEbdaBaseAddress <= EbdaBaseAddress);
-    }
-  );
+  if (!NULL_DETECTION_ENABLED) {
+    // 
+    // Only do following if NULL pointer detection is not enabled, because it cannot 
+    // be disabled at this time due to current TPL(=TPL_HIGH_LEVEL).
+    //
+    DEBUG_CODE (
+      {
+        UINTN                 EbdaBaseAddress;
+        UINTN                 ReservedEbdaBaseAddress;
+
+        EbdaBaseAddress = (*(UINT16 *) (UINTN) 0x40E) << 4;
+        ReservedEbdaBaseAddress = CONVENTIONAL_MEMORY_TOP - PcdGet32 (PcdEbdaReservedMemorySize);
+        ASSERT (ReservedEbdaBaseAddress <= EbdaBaseAddress);
+      }
+    );
+  }
 
   if (Stack != NULL && StackSize != 0) {
     //
-- 
2.14.1.windows.1




^ permalink raw reply related	[flat|nested] 37+ messages in thread
end of thread, other threads:[~2017-09-15  6:26 UTC | newest]

Thread overview: 37+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <Implement NULL pointer detection feature>
2017-09-13  9:25 ` [PATCH 0/4] Implement NULL pointer detection feature for special pool Wang, Jian J
2017-09-13  9:25   ` [PATCH 1/4] MdeModulePkg/Core: Implement NULL pointer detection in EDK-II Core Wang, Jian J
2017-09-13 16:33     ` Johnson, Brian (EXL - Eagan)
2017-09-14  1:37       ` Wang, Jian J
2017-09-13 17:28     ` Jordan Justen
2017-09-14  1:25       ` Wang, Jian J
2017-09-14  6:33         ` Jordan Justen
2017-09-14  6:51           ` Wang, Jian J
2017-09-14  8:22             ` Laszlo Ersek
2017-09-13  9:25   ` [PATCH 2/4] UefiCpuPkg/PiSmmCpuDxeSmm: Implement NULL pointer detection for SMM mode code Wang, Jian J
2017-09-13 16:33     ` Johnson, Brian (EXL - Eagan)
2017-09-14  1:31       ` Wang, Jian J
2017-09-13 17:31     ` Jordan Justen
2017-09-14  1:20       ` Wang, Jian J
2017-09-13  9:25   ` [PATCH 3/4] IntelFrameworkModulePkg/Csm: Update CSM code to temporarily bypass NULL pointer detection if enabled Wang, Jian J
2017-09-13 16:33     ` Johnson, Brian (EXL - Eagan)
2017-09-13  9:25   ` [PATCH 4/4] OvmfPkg/QemuVideoDxe: Update QemuVideoDxe driver to " Wang, Jian J
2017-09-13 16:33     ` Johnson, Brian (EXL - Eagan)
2017-09-13 23:34     ` Laszlo Ersek
2017-09-14  1:17       ` Wang, Jian J
2017-09-14  3:17         ` Wang, Jian J
2017-09-14  8:30           ` Laszlo Ersek
2017-09-14  8:38             ` Yao, Jiewen
2017-09-14  8:46               ` Wang, Jian J
2017-09-14  8:48                 ` Yao, Jiewen
2017-09-14  8:54                 ` Laszlo Ersek
2017-09-14  9:39                   ` Zeng, Star
2017-09-14  9:55                     ` Laszlo Ersek
2017-09-14 10:16                       ` Zeng, Star
2017-09-15  0:15                         ` Wang, Jian J
2017-09-15  6:05                           ` Wang, Jian J
2017-09-15  6:28                             ` Zeng, Star
2017-09-14  8:52               ` Laszlo Ersek
2017-09-14  5:50         ` Jordan Justen
2017-09-14  6:52           ` Wang, Jian J
2017-09-14  8:26         ` Laszlo Ersek
2017-09-13  8:07 [PATCH 3/4] IntelFrameworkModulePkg/Csm: Update CSM code to temporarily " Wang, Jian J

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