SourceLevelDebugPkg/Library/PeCoffExtraActionLibDebug/PeCoffExtraActionLib.c

   1 /** @file
   2   PE/Coff Extra Action library instances.
   3
   4   Copyright (c) 2010 - 2018, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include <PeCoffExtraActionLib.h>
  10
  11 /**
  12   Check if the hardware breakpoint in Drx is enabled by checking the Lx and Gx bit in Dr7.
  13
  14   It assumes that DebugAgent will set both Lx and Gx bit when setting up the hardware breakpoint.
  15
  16
  17   @param  RegisterIndex  Index of Dr register. The value range is from 0 to 3.
  18   @param  Dr7            Value of Dr7 register.
  19
  20   @return TRUE   The hardware breakpoint specified in the Drx is enabled.
  21   @return FALSE  The hardware breakpoint specified in the Drx is disabled.
  22
  23 **/
  24 BOOLEAN
  25 IsDrxEnabled (
  26   IN  UINT8  RegisterIndex,
  27   IN  UINTN  Dr7
  28   )
  29 {
  30   return (BOOLEAN)(((Dr7 >> (RegisterIndex * 2)) & (BIT0 | BIT1)) == (BIT0 | BIT1));
  31 }
  32
  33 /**
  34   Common routine to report the PE/COFF image loading/relocating or unloading event.
  35
  36   If ImageContext is NULL, then ASSERT().
  37
  38   @param  ImageContext  Pointer to the image context structure that describes the
  39                         PE/COFF image.
  40   @param  Signature     IMAGE_LOAD_SIGNATURE or IMAGE_UNLOAD_SIGNATURE.
  41
  42 **/
  43 VOID
  44 PeCoffLoaderExtraActionCommon (
  45   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext,
  46   IN     UINTN                         Signature
  47   )
  48 {
  49   BOOLEAN                   InterruptState;
  50   UINTN                     Dr0;
  51   UINTN                     Dr1;
  52   UINTN                     Dr2;
  53   UINTN                     Dr3;
  54   UINTN                     Dr7;
  55   UINTN                     Cr4;
  56   UINTN                     NewDr7;
  57   UINT8                     LoadImageMethod;
  58   UINT8                     DebugAgentStatus;
  59   IA32_DESCRIPTOR           IdtDescriptor;
  60   IA32_IDT_GATE_DESCRIPTOR  OriginalIdtEntry;
  61   BOOLEAN                   IdtEntryHooked;
  62   UINT32                    RegEdx;
  63
  64   ASSERT (ImageContext != NULL);
  65
  66   if (ImageContext->PdbPointer != NULL) {
  67     DEBUG ((DEBUG_ERROR, "    PDB = %a\n", ImageContext->PdbPointer));
  68   }
  69
  70   //
  71   // Disable interrupts and save the current interrupt state
  72   //
  73   InterruptState = SaveAndDisableInterrupts ();
  74
  75   IdtEntryHooked  = FALSE;
  76   LoadImageMethod = PcdGet8 (PcdDebugLoadImageMethod);
  77   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
  78     //
  79     // If the CPU does not support Debug Extensions(CPUID:01 EDX:BIT2)
  80     // then force use of DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3
  81     //
  82     AsmCpuid (1, NULL, NULL, NULL, &RegEdx);
  83     if ((RegEdx & BIT2) == 0) {
  84       LoadImageMethod = DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3;
  85     }
  86   }
  87
  88   AsmReadIdtr (&IdtDescriptor);
  89   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
  90     if (!CheckDebugAgentHandler (&IdtDescriptor, SOFT_INT_VECTOR_NUM)) {
  91       //
  92       // Do not trigger INT3 if Debug Agent did not setup IDT entries.
  93       //
  94       return;
  95     }
  96   } else {
  97     if (!CheckDebugAgentHandler (&IdtDescriptor, IO_HW_BREAKPOINT_VECTOR_NUM)) {
  98       //
  99       // Save and update IDT entry for INT1
 100       //
 101       SaveAndUpdateIdtEntry1 (&IdtDescriptor, &OriginalIdtEntry);
 102       IdtEntryHooked = TRUE;
 103     }
 104   }
 105
 106   //
 107   // Save Debug Register State
 108   //
 109   Dr0 = AsmReadDr0 ();
 110   Dr1 = AsmReadDr1 ();
 111   Dr2 = AsmReadDr2 ();
 112   Dr3 = AsmReadDr3 ();
 113   Dr7 = AsmReadDr7 () | BIT10; // H/w sets bit 10, some simulators don't
 114   Cr4 = AsmReadCr4 ();
 115
 116   //
 117   // DR0 = Signature
 118   // DR1 = The address of the Null-terminated ASCII string for the PE/COFF image's PDB file name
 119   // DR2 = The pointer to the ImageContext structure
 120   // DR3 = IO_PORT_BREAKPOINT_ADDRESS
 121   // DR7 = Disables all HW breakpoints except for DR3 I/O port access of length 1 byte
 122   // CR4 = Make sure DE(BIT3) is set
 123   //
 124   AsmWriteDr7 (BIT10);
 125   AsmWriteDr0 (Signature);
 126   AsmWriteDr1 ((UINTN)ImageContext->PdbPointer);
 127   AsmWriteDr2 ((UINTN)ImageContext);
 128   AsmWriteDr3 (IO_PORT_BREAKPOINT_ADDRESS);
 129
 130   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
 131     AsmWriteDr7 (0x20000480);
 132     AsmWriteCr4 (Cr4 | BIT3);
 133     //
 134     // Do an IN from IO_PORT_BREAKPOINT_ADDRESS to generate a HW breakpoint until the port
 135     // returns a read value other than DEBUG_AGENT_IMAGE_WAIT
 136     //
 137     do {
 138       DebugAgentStatus = IoRead8 (IO_PORT_BREAKPOINT_ADDRESS);
 139     } while (DebugAgentStatus == DEBUG_AGENT_IMAGE_WAIT);
 140   } else if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
 141     //
 142     // Generate a software break point.
 143     //
 144     CpuBreakpoint ();
 145   }
 146
 147   //
 148   // Restore Debug Register State only when Host didn't change it inside exception handler.
 149   // E.g.: User halts the target and sets the HW breakpoint while target is
 150   //       in the above exception handler
 151   //
 152   NewDr7 = AsmReadDr7 () | BIT10; // H/w sets bit 10, some simulators don't
 153   if (!IsDrxEnabled (0, NewDr7) && ((AsmReadDr0 () == 0) || (AsmReadDr0 () == Signature))) {
 154     //
 155     // If user changed Dr3 (by setting HW bp in the above exception handler,
 156     // we will not set Dr0 to 0 in GO/STEP handler because the break cause is not IMAGE_LOAD/_UNLOAD.
 157     //
 158     AsmWriteDr0 (Dr0);
 159   }
 160
 161   if (!IsDrxEnabled (1, NewDr7) && (AsmReadDr1 () == (UINTN)ImageContext->PdbPointer)) {
 162     AsmWriteDr1 (Dr1);
 163   }
 164
 165   if (!IsDrxEnabled (2, NewDr7) && (AsmReadDr2 () == (UINTN)ImageContext)) {
 166     AsmWriteDr2 (Dr2);
 167   }
 168
 169   if (!IsDrxEnabled (3, NewDr7) && (AsmReadDr3 () == IO_PORT_BREAKPOINT_ADDRESS)) {
 170     AsmWriteDr3 (Dr3);
 171   }
 172
 173   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
 174     if (AsmReadCr4 () == (Cr4 | BIT3)) {
 175       AsmWriteCr4 (Cr4);
 176     }
 177
 178     if (NewDr7 == 0x20000480) {
 179       AsmWriteDr7 (Dr7);
 180     }
 181   } else if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
 182     if (NewDr7 == BIT10) {
 183       AsmWriteDr7 (Dr7);
 184     }
 185   }
 186
 187   //
 188   // Restore original IDT entry for INT1 if it was hooked.
 189   //
 190   if (IdtEntryHooked) {
 191     RestoreIdtEntry1 (&IdtDescriptor, &OriginalIdtEntry);
 192   }
 193
 194   //
 195   // Restore the interrupt state
 196   //
 197   SetInterruptState (InterruptState);
 198 }
 199
 200 /**
 201   Performs additional actions after a PE/COFF image has been loaded and relocated.
 202
 203   @param  ImageContext  Pointer to the image context structure that describes the
 204                         PE/COFF image that has already been loaded and relocated.
 205
 206 **/
 207 VOID
 208 EFIAPI
 209 PeCoffLoaderRelocateImageExtraAction (
 210   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 211   )
 212 {
 213   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_LOAD_SIGNATURE);
 214 }
 215
 216 /**
 217   Performs additional actions just before a PE/COFF image is unloaded.  Any resources
 218   that were allocated by PeCoffLoaderRelocateImageExtraAction() must be freed.
 219
 220   @param  ImageContext  Pointer to the image context structure that describes the
 221                         PE/COFF image that is being unloaded.
 222
 223 **/
 224 VOID
 225 EFIAPI
 226 PeCoffLoaderUnloadImageExtraAction (
 227   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 228   )
 229 {
 230   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_UNLOAD_SIGNATURE);
 231 }