SourceLevelDebugPkg/Library/PeCoffExtraActionLibDebug/PeCoffExtraActionLib.c

   1 /** @file
   2   PE/Coff Extra Action library instances.
   3
   4   Copyright (c) 2010 - 2013, Intel Corporation. All rights reserved.<BR>
   5   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php.
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include <PeCoffExtraActionLib.h>
  16
  17 /**
  18   Check if the hardware breakpoint in Drx is enabled by checking the Lx and Gx bit in Dr7.
  19
  20   It assumes that DebugAgent will set both Lx and Gx bit when setting up the hardware breakpoint.
  21
  22
  23   @param  RegisterIndex  Index of Dr register. The value range is from 0 to 3.
  24   @param  Dr7            Value of Dr7 register.
  25
  26   @return TRUE   The hardware breakpoint specified in the Drx is enabled.
  27   @return FALSE  The hardware breakpoint specified in the Drx is disabled.
  28
  29 **/
  30 BOOLEAN
  31 IsDrxEnabled (
  32   IN  UINT8  RegisterIndex,
  33   IN  UINTN  Dr7
  34   )
  35 {
  36   return (BOOLEAN) (((Dr7 >> (RegisterIndex * 2)) & (BIT0 | BIT1)) == (BIT0 | BIT1));
  37 }
  38
  39 /**
  40   Common routine to report the PE/COFF image loading/relocating or unloading event.
  41
  42   If ImageContext is NULL, then ASSERT().
  43
  44   @param  ImageContext  Pointer to the image context structure that describes the
  45                         PE/COFF image.
  46   @param  Signature     IMAGE_LOAD_SIGNATURE or IMAGE_UNLOAD_SIGNATURE.
  47
  48 **/
  49 VOID
  50 PeCoffLoaderExtraActionCommon (
  51   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext,
  52   IN     UINTN                         Signature
  53   )
  54 {
  55   BOOLEAN                    InterruptState;
  56   UINTN                      Dr0;
  57   UINTN                      Dr1;
  58   UINTN                      Dr2;
  59   UINTN                      Dr3;
  60   UINTN                      Dr7;
  61   UINTN                      Cr4;
  62   UINTN                      NewDr7;
  63   UINT8                      LoadImageMethod;
  64   UINT8                      DebugAgentStatus;
  65   IA32_DESCRIPTOR            IdtDescriptor;
  66   IA32_IDT_GATE_DESCRIPTOR   OriginalIdtEntry;
  67   BOOLEAN                    IdtEntryHooked;
  68
  69   ASSERT (ImageContext != NULL);
  70
  71   if (ImageContext->PdbPointer != NULL) {
  72     DEBUG((EFI_D_ERROR, "    PDB = %a\n", ImageContext->PdbPointer));
  73   }
  74
  75   //
  76   // Disable interrupts and save the current interrupt state
  77   //
  78   InterruptState = SaveAndDisableInterrupts ();
  79
  80   IdtEntryHooked  = FALSE;
  81   LoadImageMethod = PcdGet8 (PcdDebugLoadImageMethod);
  82   AsmReadIdtr (&IdtDescriptor);
  83   if (!CheckDebugAgentHandler (&IdtDescriptor)) {
  84     if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
  85       //
  86       // Do not trigger INT3 if Debug Agent did not setup IDT entries.
  87       //
  88       return;
  89     }
  90     //
  91     // Save and update IDT entry for INT1
  92     //
  93     SaveAndUpdateIdtEntry1 (&IdtDescriptor, &OriginalIdtEntry);
  94     IdtEntryHooked = TRUE;
  95   }
  96
  97   //
  98   // Save Debug Register State
  99   //
 100   Dr0 = AsmReadDr0 ();
 101   Dr1 = AsmReadDr1 ();
 102   Dr2 = AsmReadDr2 ();
 103   Dr3 = AsmReadDr3 ();
 104   Dr7 = AsmReadDr7 ();
 105   Cr4 = AsmReadCr4 ();
 106
 107   //
 108   // DR0 = Signature
 109   // DR1 = The address of the Null-terminated ASCII string for the PE/COFF image's PDB file name
 110   // DR2 = The pointer to the ImageContext structure
 111   // DR3 = IO_PORT_BREAKPOINT_ADDRESS
 112   // DR7 = Disables all HW breakpoints except for DR3 I/O port access of length 1 byte
 113   // CR4 = Make sure DE(BIT3) is set
 114   //
 115   AsmWriteDr7 (0);
 116   AsmWriteDr0 (Signature);
 117   AsmWriteDr1 ((UINTN) ImageContext->PdbPointer);
 118   AsmWriteDr2 ((UINTN) ImageContext);
 119   AsmWriteDr3 (IO_PORT_BREAKPOINT_ADDRESS);
 120
 121   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
 122     AsmWriteDr7 (0x20000480);
 123     AsmWriteCr4 (Cr4 | BIT3);
 124     //
 125     // Do an IN from IO_PORT_BREAKPOINT_ADDRESS to generate a HW breakpoint until the port
 126     // returns a read value other than DEBUG_AGENT_IMAGE_WAIT
 127     //
 128     do {
 129       DebugAgentStatus = IoRead8 (IO_PORT_BREAKPOINT_ADDRESS);
 130     } while (DebugAgentStatus == DEBUG_AGENT_IMAGE_WAIT);
 131
 132   } else if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
 133     //
 134     // Generate a software break point.
 135     //
 136     CpuBreakpoint ();
 137   }
 138
 139   //
 140   // Restore Debug Register State only when Host didn't change it inside exception handler.
 141   // E.g.: User halts the target and sets the HW breakpoint while target is
 142   //       in the above exception handler
 143   //
 144   NewDr7 = AsmReadDr7 ();
 145   if (!IsDrxEnabled (0, NewDr7) && (AsmReadDr0 () == 0 || AsmReadDr0 () == Signature)) {
 146     //
 147     // If user changed Dr3 (by setting HW bp in the above exception handler,
 148     // we will not set Dr0 to 0 in GO/STEP handler because the break cause is not IMAGE_LOAD/_UNLOAD.
 149     //
 150     AsmWriteDr0 (Dr0);
 151   }
 152   if (!IsDrxEnabled (1, NewDr7) && (AsmReadDr1 () == (UINTN) ImageContext->PdbPointer)) {
 153     AsmWriteDr1 (Dr1);
 154   }
 155   if (!IsDrxEnabled (2, NewDr7) && (AsmReadDr2 () == (UINTN) ImageContext)) {
 156     AsmWriteDr2 (Dr2);
 157   }
 158   if (!IsDrxEnabled (3, NewDr7) && (AsmReadDr3 () == IO_PORT_BREAKPOINT_ADDRESS)) {
 159     AsmWriteDr3 (Dr3);
 160   }
 161   if (AsmReadCr4 () == (Cr4 | BIT3)) {
 162     AsmWriteCr4 (Cr4);
 163   }
 164   if (NewDr7 == 0x20000480) {
 165     AsmWriteDr7 (Dr7);
 166   }
 167   //
 168   // Restore original IDT entry for INT1 if it was hooked.
 169   //
 170   if (IdtEntryHooked) {
 171     RestoreIdtEntry1 (&IdtDescriptor, &OriginalIdtEntry);
 172   }
 173   //
 174   // Restore the interrupt state
 175   //
 176   SetInterruptState (InterruptState);
 177 }
 178
 179 /**
 180   Performs additional actions after a PE/COFF image has been loaded and relocated.
 181
 182   @param  ImageContext  Pointer to the image context structure that describes the
 183                         PE/COFF image that has already been loaded and relocated.
 184
 185 **/
 186 VOID
 187 EFIAPI
 188 PeCoffLoaderRelocateImageExtraAction (
 189   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 190   )
 191 {
 192   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_LOAD_SIGNATURE);
 193 }
 194
 195 /**
 196   Performs additional actions just before a PE/COFF image is unloaded.  Any resources
 197   that were allocated by PeCoffLoaderRelocateImageExtraAction() must be freed.
 198
 199   @param  ImageContext  Pointer to the image context structure that describes the
 200                         PE/COFF image that is being unloaded.
 201
 202 **/
 203 VOID
 204 EFIAPI
 205 PeCoffLoaderUnloadImageExtraAction (
 206   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 207   )
 208 {
 209   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_UNLOAD_SIGNATURE);
 210 }