** wip ** New improvements

ntoskrnl/kdbg/kdb.c

@@ -1141,20 +1141,29 @@ KdbpAttachToProcess(
     return KdbpAttachToThread(Thread->Cid.UniqueThread);
 }
 
-/*!\brief Calls the main loop ...
- */
+/**
+ * @brief   Calls the main interactive debugger loop.
+ **/
 static VOID
 KdbpCallMainLoop(VOID)
 {
     KdbpCliMainLoop(KdbEnteredOnSingleStep);
 }
 
-/*!\brief Internal function to enter KDB.
+/**
+ * @brief
+ * Internal function to enter KDBG and run the specified procedure.
  *
  * Disables interrupts, releases display ownership, ...
- */
+ *
+ * @param[in]   Function
+ * The procedure to execute under the KDBG environment.
+ * Either execute the the main interactive debugger loop (KdbpCallMainLoop)
+ * or run the KDBinit file (KdbpCliInterpretInitFile).
+ **/
 static VOID
-KdbpInternalEnter(VOID)
+KdbpInternalEnter(
+    _In_ VOID (*Function)(VOID))
 {
     PETHREAD Thread;
     PVOID SavedInitialStack, SavedStackBase, SavedKernelStack;
@@ -1178,7 +1187,7 @@ KdbpInternalEnter(VOID)
 
     // KdbPrintf("Switching to KDB stack 0x%08x-0x%08x (Current Stack is 0x%08x)\n", Thread->Tcb.StackLimit, Thread->Tcb.StackBase, Esp);
 
-    KdbpStackSwitchAndCall(KdbStack + KDB_STACK_SIZE - KDB_STACK_RESERVE, KdbpCallMainLoop);
+    KdbpStackSwitchAndCall(KdbStack + KDB_STACK_SIZE - KDB_STACK_RESERVE, Function);
 
     Thread->Tcb.InitialStack = SavedInitialStack;
     Thread->Tcb.StackBase = SavedStackBase;
@@ -1275,6 +1284,7 @@ KdbEnterDebuggerException(
     ULONG OldEflags;
     KIRQL OldIrql;
     NTSTATUS ExceptionCode;
+    VOID (*EnterFunction)(VOID) = KdbpCallMainLoop;
 
     ExceptionCode = (ExceptionRecord ? ExceptionRecord->ExceptionCode : STATUS_BREAKPOINT);
 
@@ -1333,7 +1343,6 @@ KdbEnterDebuggerException(
         {
             Resume = TRUE; /* Set the resume flag when continuing execution */
         }
-
         /*
          * When a temporary breakpoint is hit we have to make sure that we are
          * in the same context in which it was set, otherwise it could happen
@@ -1360,7 +1369,6 @@ KdbEnterDebuggerException(
 
             KdbEnteredOnSingleStep = TRUE;
         }
-
         /*
          * If we hit a breakpoint set by the debugger we set the single step flag,
          * ignore the next single step and reenable the breakpoint.
@@ -1482,23 +1490,24 @@ KdbEnterDebuggerException(
     }
     else if (ExceptionCode == STATUS_BREAKPOINT)
     {
+        /* Do the condition check and banner display only if we are entering
+         * because of a true code breakpoint. Running the KDBinit file is also
+         * done via a breakpoint, but it is artificial, so we skip the check
+         * and the banner in this case. */
         if (KdbInitFileBuffer)
         {
-            // FIXME? Should we do that call at the same place
-            // where we currently call KdbpInternalEnter?
-            // InterlockedIncrement(&KdbEntryCount);
-            KdbpCliInterpretInitFile();
-            // InterlockedDecrement(&KdbEntryCount);
-            EnterConditionMet = FALSE;
-            goto continue_execution; /* return */
+            EnterFunction = KdbpCliInterpretInitFile;
+            goto EnterKdbg;
         }
+
         if (!EnterConditionMet)
         {
             return kdHandleException;
         }
 
         KdbPrintf("\nEntered debugger on embedded INT3 at 0x%04x:0x%p.\n",
                   Context->SegCs & 0xffff, KeGetContextPc(Context));
+EnterKdbg:;
     }
     else
     {
@@ -1549,8 +1558,8 @@ KdbEnterDebuggerException(
         return kdHandleException;
     }
 
-    /* Call the main loop */
-    KdbpInternalEnter();
+    /* Enter KDBG proper and either run the KDBinit file or call the main loop */
+    KdbpInternalEnter(EnterFunction);
 
     /* Check if we should single step */
     if (KdbNumSingleSteps > 0)

ntoskrnl/kdbg/kdb.h

@@ -61,7 +61,7 @@ typedef enum _KD_CONTINUE_TYPE
 
 /* GLOBALS *******************************************************************/
 
-extern PCHAR KdbInitFileBuffer;
+extern volatile PCHAR KdbInitFileBuffer;
 
 extern PEPROCESS KdbCurrentProcess;
 extern PETHREAD KdbCurrentThread;

ntoskrnl/kdbg/kdb_cli.c

@@ -134,7 +134,7 @@ static ULONG KdbNumberOfColsPrinted = 0;
 static BOOLEAN KdbOutputAborted = FALSE;
 static BOOLEAN KdbRepeatLastCommand = FALSE;
 
-PCHAR KdbInitFileBuffer = NULL; /* Buffer where KDBinit file is loaded into during initialization */
+volatile PCHAR KdbInitFileBuffer = NULL; /* Buffer where KDBinit file is loaded into during initialization */
 BOOLEAN KdbpBugCheckRequested = FALSE;
 
 /* Variables for Dmesg */
@@ -3339,7 +3339,7 @@ KdbpCliMainLoop(
 
 /**
  * @brief
- * Interprets the KDBinit file from the SystemRoot\System32\drivers\etc
+ * Interprets the KDBinit file from the \SystemRoot\System32\drivers\etc
  * directory, that has been loaded by KdbpCliInit().
  *
  * This function is used to interpret the init file in the debugger context
@@ -3352,21 +3352,19 @@ VOID
 KdbpCliInterpretInitFile(VOID)
 {
     PCHAR p1, p2;
-    INT_PTR i;
-    CHAR c;
 
-    if (!KdbInitFileBuffer)
+    p1 = InterlockedExchangePointer((PVOID*)&KdbInitFileBuffer, NULL);
+    if (!p1)
         return;
 
     /* Execute the commands in the init file */
-    KdpDprintf("KDB: Executing KDBinit file...\n");
-    p1 = KdbInitFileBuffer;
+    KdbPuts("KDB: Executing KDBinit file...\n");
     while (p1[0] != '\0')
     {
-        i = strcspn(p1, "\r\n");
+        INT_PTR i = strcspn(p1, "\r\n");
         if (i > 0)
         {
-            c = p1[i];
+            CHAR c = p1[i];
             p1[i] = '\0';
 
             /* Look for "break" command and comments */
@@ -3378,8 +3376,8 @@ KdbpCliInterpretInitFile(VOID)
             if (strncmp(p2, "break", sizeof("break")-1) == 0 &&
                 (p2[sizeof("break")-1] == '\0' || isspace(p2[sizeof("break")-1])))
             {
-                /* Break into the debugger */
-                KdbpCliMainLoop(FALSE); // KdbpInternalEnter();
+                /* Run the debugger loop (we have already broken into the debugger) */
+                KdbpCliMainLoop(FALSE);
             }
             else if (p2[0] != '#' && p2[0] != '\0') /* Ignore empty lines and comments */
             {
@@ -3393,15 +3391,14 @@ KdbpCliInterpretInitFile(VOID)
         while (p1[0] == '\r' || p1[0] == '\n')
             p1++;
     }
-    KdpDprintf("KDB: KDBinit executed\n");
-    KdbInitFileBuffer = NULL;
+    KdbPuts("KDB: KDBinit executed\n");
 }
 
 /**
  * @brief   Called when KDB is initialized.
  *
- * Reads the KDBinit file from the SystemRoot\System32\drivers\etc directory
- * and executes it, by calling back into the debugger.
+ * Loads the KDBinit file from the \SystemRoot\System32\drivers\etc
+ * directory and interprets it, by calling back into the debugger.
  **/
 NTSTATUS
 KdbpCliInit(VOID)
@@ -3412,7 +3409,7 @@ KdbpCliInit(VOID)
     IO_STATUS_BLOCK Iosb;
     FILE_STANDARD_INFORMATION FileStdInfo;
     HANDLE hFile = NULL;
-    INT FileSize;
+    ULONG FileSize;
     PCHAR FileBuffer;
 
     /* Don't load the KDBinit file if its buffer is already lying around */
@@ -3434,7 +3431,7 @@ KdbpCliInit(VOID)
                         FILE_NO_INTERMEDIATE_BUFFERING);
     if (!NT_SUCCESS(Status))
     {
-        DPRINT1("Could not open \\SystemRoot\\System32\\drivers\\etc\\KDBinit (Status 0x%lx)\n", Status);
+        DPRINT("Could not open \\SystemRoot\\System32\\drivers\\etc\\KDBinit (Status 0x%lx)\n", Status);
         return Status;
     }
 
@@ -3451,16 +3448,17 @@ KdbpCliInit(VOID)
     FileSize = FileStdInfo.EndOfFile.u.LowPart;
 
     /* Allocate memory for the file */
-    FileBuffer = ExAllocatePool(PagedPool, FileSize + 1); /* add 1 byte for terminating '\0' */
+    FileBuffer = ExAllocatePool(NonPagedPool, FileSize + 1); /* Add 1 byte for terminating NUL */
     if (!FileBuffer)
     {
         ZwClose(hFile);
-        DPRINT1("Could not allocate %d bytes for KDBinit file\n", FileSize);
+        DPRINT1("Could not allocate %lu bytes for KDBinit file\n", FileSize);
         return Status;
     }
 
     /* Load file into memory */
-    Status = ZwReadFile(hFile, NULL, NULL, NULL, &Iosb, FileBuffer, FileSize, NULL, NULL);
+    Status = ZwReadFile(hFile, NULL, NULL, NULL, &Iosb,
+                        FileBuffer, FileSize, NULL, NULL);
     ZwClose(hFile);
 
     if (!NT_SUCCESS(Status) && (Status != STATUS_END_OF_FILE))
@@ -3473,10 +3471,10 @@ KdbpCliInit(VOID)
     FileSize = min(FileSize, (INT)Iosb.Information);
     FileBuffer[FileSize] = '\0';
 
-    /* Interpret the init file by calling back into the debugger */
-    KdbInitFileBuffer = FileBuffer;
+    /* Interpret the KDBinit file by calling back into the debugger */
+    InterlockedExchangePointer((PVOID*)&KdbInitFileBuffer, FileBuffer);
     DbgBreakPointWithStatus(DBG_STATUS_CONTROL_C);
-    KdbInitFileBuffer = NULL;
+    InterlockedExchangePointer((PVOID*)&KdbInitFileBuffer, NULL);
 
     ExFreePool(FileBuffer);
 
@@ -3618,7 +3616,7 @@ KdbInitialize(
 
     if (BootPhase >= 2)
     {
-        /* I/O is now set up for disk access: Read KDB Data */
+        /* I/O is now set up for disk access: load the KDBinit file */
         NTSTATUS Status = KdbpCliInit();
 
         /* Schedule an I/O reinitialization if needed */