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   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   UINT32                     RegEdx;
  69
  70   ASSERT (ImageContext != NULL);
  71
  72   if (ImageContext->PdbPointer != NULL) {
  73     DEBUG((EFI_D_ERROR, "    PDB = %a\n", ImageContext->PdbPointer));
  74   }
  75
  76   //
  77   // Disable interrupts and save the current interrupt state
  78   //
  79   InterruptState = SaveAndDisableInterrupts ();
  80
  81   IdtEntryHooked  = FALSE;
  82   LoadImageMethod = PcdGet8 (PcdDebugLoadImageMethod);
  83   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
  84     //
  85     // If the CPU does not support Debug Extensions(CPUID:01 EDX:BIT2)
  86     // then force use of DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3
  87     //
  88     AsmCpuid (1, NULL, NULL, NULL, &RegEdx);
  89     if ((RegEdx & BIT2) == 0) {
  90       LoadImageMethod = DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3;
  91     }
  92   }
  93   AsmReadIdtr (&IdtDescriptor);
  94   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
  95     if (!CheckDebugAgentHandler (&IdtDescriptor, SOFT_INT_VECTOR_NUM)) {
  96       //
  97       // Do not trigger INT3 if Debug Agent did not setup IDT entries.
  98       //
  99       return;
 100     }
 101   } else {
 102     if (!CheckDebugAgentHandler (&IdtDescriptor, IO_HW_BREAKPOINT_VECTOR_NUM)) {
 103       //
 104       // Save and update IDT entry for INT1
 105       //
 106       SaveAndUpdateIdtEntry1 (&IdtDescriptor, &OriginalIdtEntry);
 107       IdtEntryHooked = TRUE;
 108     }
 109   }
 110
 111   //
 112   // Save Debug Register State
 113   //
 114   Dr0 = AsmReadDr0 ();
 115   Dr1 = AsmReadDr1 ();
 116   Dr2 = AsmReadDr2 ();
 117   Dr3 = AsmReadDr3 ();
 118   Dr7 = AsmReadDr7 () | BIT10; // H/w sets bit 10, some simulators don't
 119   Cr4 = AsmReadCr4 ();
 120
 121   //
 122   // DR0 = Signature
 123   // DR1 = The address of the Null-terminated ASCII string for the PE/COFF image's PDB file name
 124   // DR2 = The pointer to the ImageContext structure
 125   // DR3 = IO_PORT_BREAKPOINT_ADDRESS
 126   // DR7 = Disables all HW breakpoints except for DR3 I/O port access of length 1 byte
 127   // CR4 = Make sure DE(BIT3) is set
 128   //
 129   AsmWriteDr7 (BIT10);
 130   AsmWriteDr0 (Signature);
 131   AsmWriteDr1 ((UINTN) ImageContext->PdbPointer);
 132   AsmWriteDr2 ((UINTN) ImageContext);
 133   AsmWriteDr3 (IO_PORT_BREAKPOINT_ADDRESS);
 134
 135   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
 136     AsmWriteDr7 (0x20000480);
 137     AsmWriteCr4 (Cr4 | BIT3);
 138     //
 139     // Do an IN from IO_PORT_BREAKPOINT_ADDRESS to generate a HW breakpoint until the port
 140     // returns a read value other than DEBUG_AGENT_IMAGE_WAIT
 141     //
 142     do {
 143       DebugAgentStatus = IoRead8 (IO_PORT_BREAKPOINT_ADDRESS);
 144     } while (DebugAgentStatus == DEBUG_AGENT_IMAGE_WAIT);
 145
 146   } else if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
 147     //
 148     // Generate a software break point.
 149     //
 150     CpuBreakpoint ();
 151   }
 152
 153   //
 154   // Restore Debug Register State only when Host didn't change it inside exception handler.
 155   // E.g.: User halts the target and sets the HW breakpoint while target is
 156   //       in the above exception handler
 157   //
 158   NewDr7 = AsmReadDr7 () | BIT10; // H/w sets bit 10, some simulators don't
 159   if (!IsDrxEnabled (0, NewDr7) && (AsmReadDr0 () == 0 || AsmReadDr0 () == Signature)) {
 160     //
 161     // If user changed Dr3 (by setting HW bp in the above exception handler,
 162     // we will not set Dr0 to 0 in GO/STEP handler because the break cause is not IMAGE_LOAD/_UNLOAD.
 163     //
 164     AsmWriteDr0 (Dr0);
 165   }
 166   if (!IsDrxEnabled (1, NewDr7) && (AsmReadDr1 () == (UINTN) ImageContext->PdbPointer)) {
 167     AsmWriteDr1 (Dr1);
 168   }
 169   if (!IsDrxEnabled (2, NewDr7) && (AsmReadDr2 () == (UINTN) ImageContext)) {
 170     AsmWriteDr2 (Dr2);
 171   }
 172   if (!IsDrxEnabled (3, NewDr7) && (AsmReadDr3 () == IO_PORT_BREAKPOINT_ADDRESS)) {
 173     AsmWriteDr3 (Dr3);
 174   }
 175   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
 176     if (AsmReadCr4 () == (Cr4 | BIT3)) {
 177       AsmWriteCr4 (Cr4);
 178     }
 179     if (NewDr7 == 0x20000480) {
 180       AsmWriteDr7 (Dr7);
 181     }
 182   } else if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
 183     if (NewDr7 == BIT10) {
 184       AsmWriteDr7 (Dr7);
 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   // Restore the interrupt state
 195   //
 196   SetInterruptState (InterruptState);
 197 }
 198
 199 /**
 200   Performs additional actions after a PE/COFF image has been loaded and relocated.
 201
 202   @param  ImageContext  Pointer to the image context structure that describes the
 203                         PE/COFF image that has already been loaded and relocated.
 204
 205 **/
 206 VOID
 207 EFIAPI
 208 PeCoffLoaderRelocateImageExtraAction (
 209   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 210   )
 211 {
 212   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_LOAD_SIGNATURE);
 213 }
 214
 215 /**
 216   Performs additional actions just before a PE/COFF image is unloaded.  Any resources
 217   that were allocated by PeCoffLoaderRelocateImageExtraAction() must be freed.
 218
 219   @param  ImageContext  Pointer to the image context structure that describes the
 220                         PE/COFF image that is being unloaded.
 221
 222 **/
 223 VOID
 224 EFIAPI
 225 PeCoffLoaderUnloadImageExtraAction (
 226   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 227   )
 228 {
 229   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_UNLOAD_SIGNATURE);
 230 }