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 (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
  84     if (!CheckDebugAgentHandler (&IdtDescriptor, SOFT_INT_VECTOR_NUM)) {
  85       //
  86       // Do not trigger INT3 if Debug Agent did not setup IDT entries.
  87       //
  88       return;
  89     }
  90   } else {
  91     if (!CheckDebugAgentHandler (&IdtDescriptor, IO_HW_BREAKPOINT_VECTOR_NUM)) {
  92       //
  93       // Save and update IDT entry for INT1
  94       //
  95       SaveAndUpdateIdtEntry1 (&IdtDescriptor, &OriginalIdtEntry);
  96       IdtEntryHooked = TRUE;
  97     }
  98   }
  99
 100   //
 101   // Save Debug Register State
 102   //
 103   Dr0 = AsmReadDr0 ();
 104   Dr1 = AsmReadDr1 ();
 105   Dr2 = AsmReadDr2 ();
 106   Dr3 = AsmReadDr3 ();
 107   Dr7 = AsmReadDr7 ();
 108   Cr4 = AsmReadCr4 ();
 109
 110   //
 111   // DR0 = Signature
 112   // DR1 = The address of the Null-terminated ASCII string for the PE/COFF image's PDB file name
 113   // DR2 = The pointer to the ImageContext structure
 114   // DR3 = IO_PORT_BREAKPOINT_ADDRESS
 115   // DR7 = Disables all HW breakpoints except for DR3 I/O port access of length 1 byte
 116   // CR4 = Make sure DE(BIT3) is set
 117   //
 118   AsmWriteDr7 (0);
 119   AsmWriteDr0 (Signature);
 120   AsmWriteDr1 ((UINTN) ImageContext->PdbPointer);
 121   AsmWriteDr2 ((UINTN) ImageContext);
 122   AsmWriteDr3 (IO_PORT_BREAKPOINT_ADDRESS);
 123
 124   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
 125     AsmWriteDr7 (0x20000480);
 126     AsmWriteCr4 (Cr4 | BIT3);
 127     //
 128     // Do an IN from IO_PORT_BREAKPOINT_ADDRESS to generate a HW breakpoint until the port
 129     // returns a read value other than DEBUG_AGENT_IMAGE_WAIT
 130     //
 131     do {
 132       DebugAgentStatus = IoRead8 (IO_PORT_BREAKPOINT_ADDRESS);
 133     } while (DebugAgentStatus == DEBUG_AGENT_IMAGE_WAIT);
 134
 135   } else if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
 136     //
 137     // Generate a software break point.
 138     //
 139     CpuBreakpoint ();
 140   }
 141
 142   //
 143   // Restore Debug Register State only when Host didn't change it inside exception handler.
 144   // E.g.: User halts the target and sets the HW breakpoint while target is
 145   //       in the above exception handler
 146   //
 147   NewDr7 = AsmReadDr7 ();
 148   if (!IsDrxEnabled (0, NewDr7) && (AsmReadDr0 () == 0 || AsmReadDr0 () == Signature)) {
 149     //
 150     // If user changed Dr3 (by setting HW bp in the above exception handler,
 151     // we will not set Dr0 to 0 in GO/STEP handler because the break cause is not IMAGE_LOAD/_UNLOAD.
 152     //
 153     AsmWriteDr0 (Dr0);
 154   }
 155   if (!IsDrxEnabled (1, NewDr7) && (AsmReadDr1 () == (UINTN) ImageContext->PdbPointer)) {
 156     AsmWriteDr1 (Dr1);
 157   }
 158   if (!IsDrxEnabled (2, NewDr7) && (AsmReadDr2 () == (UINTN) ImageContext)) {
 159     AsmWriteDr2 (Dr2);
 160   }
 161   if (!IsDrxEnabled (3, NewDr7) && (AsmReadDr3 () == IO_PORT_BREAKPOINT_ADDRESS)) {
 162     AsmWriteDr3 (Dr3);
 163   }
 164   if (AsmReadCr4 () == (Cr4 | BIT3)) {
 165     AsmWriteCr4 (Cr4);
 166   }
 167   if (NewDr7 == 0x20000480) {
 168     AsmWriteDr7 (Dr7);
 169   }
 170   //
 171   // Restore original IDT entry for INT1 if it was hooked.
 172   //
 173   if (IdtEntryHooked) {
 174     RestoreIdtEntry1 (&IdtDescriptor, &OriginalIdtEntry);
 175   }
 176   //
 177   // Restore the interrupt state
 178   //
 179   SetInterruptState (InterruptState);
 180 }
 181
 182 /**
 183   Performs additional actions after a PE/COFF image has been loaded and relocated.
 184
 185   @param  ImageContext  Pointer to the image context structure that describes the
 186                         PE/COFF image that has already been loaded and relocated.
 187
 188 **/
 189 VOID
 190 EFIAPI
 191 PeCoffLoaderRelocateImageExtraAction (
 192   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 193   )
 194 {
 195   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_LOAD_SIGNATURE);
 196 }
 197
 198 /**
 199   Performs additional actions just before a PE/COFF image is unloaded.  Any resources
 200   that were allocated by PeCoffLoaderRelocateImageExtraAction() must be freed.
 201
 202   @param  ImageContext  Pointer to the image context structure that describes the
 203                         PE/COFF image that is being unloaded.
 204
 205 **/
 206 VOID
 207 EFIAPI
 208 PeCoffLoaderUnloadImageExtraAction (
 209   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 210   )
 211 {
 212   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_UNLOAD_SIGNATURE);
 213 }