win_util.cc

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// Copyright 2024 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "core/fxcrt/win/win_util.h"
 
#include <windows.h>
#include <processthreadsapi.h>
 
namespace pdfium {
 
bool IsUser32AndGdi32Available() {
  static auto is_user32_and_gdi32_available = []() {
    // If win32k syscalls aren't disabled, then user32 and gdi32 are available.
 
    typedef decltype(
        GetProcessMitigationPolicy)* GetProcessMitigationPolicyType;
    GetProcessMitigationPolicyType get_process_mitigation_policy_func =
        reinterpret_cast<GetProcessMitigationPolicyType>(GetProcAddress(
            GetModuleHandle(L"kernel32.dll"), "GetProcessMitigationPolicy"));
 
    if (!get_process_mitigation_policy_func)
      return true;
 
    PROCESS_MITIGATION_SYSTEM_CALL_DISABLE_POLICY policy = {};
    if (get_process_mitigation_policy_func(GetCurrentProcess(),
                                           ProcessSystemCallDisablePolicy,
                                           &policy, sizeof(policy))) {
      return policy.DisallowWin32kSystemCalls == 0;
    }
 
    return true;
  }();
  return is_user32_and_gdi32_available;
}
 
}  // namespace pdfium