Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 745 insertions, 0 deletions

diff --git a/toolkit/xre/dllservices/mozglue/WindowsDllBlocklist.cpp b/toolkit/xre/dllservices/mozglue/WindowsDllBlocklist.cpp
new file mode 100644
index 0000000000..29745d5af6
--- /dev/null
+++ b/toolkit/xre/dllservices/mozglue/WindowsDllBlocklist.cpp
@@ -0,0 +1,745 @@
+/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <windows.h>
+#include <winternl.h>
+
+#pragma warning(push)
+#pragma warning(disable : 4275 4530)  // See msvc-stl-wrapper.template.h
+#include <map>
+#pragma warning(pop)
+
+#include "Authenticode.h"
+#include "BaseProfiler.h"
+#include "nsWindowsDllInterceptor.h"
+#include "mozilla/CmdLineAndEnvUtils.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/StackWalk_windows.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/Vector.h"
+#include "mozilla/WindowsProcessMitigations.h"
+#include "mozilla/WindowsVersion.h"
+#include "mozilla/WinHeaderOnlyUtils.h"
+#include "nsWindowsHelpers.h"
+#include "WindowsDllBlocklist.h"
+#include "mozilla/AutoProfilerLabel.h"
+#include "mozilla/glue/Debug.h"
+#include "mozilla/glue/WindowsDllServices.h"
+#include "mozilla/glue/WinUtils.h"
+
+// Start new implementation
+#include "LoaderObserver.h"
+#include "ModuleLoadFrame.h"
+#include "mozilla/glue/WindowsUnicode.h"
+
+namespace mozilla {
+
+glue::Win32SRWLock gDllServicesLock;
+glue::detail::DllServicesBase* gDllServices;
+
+}  // namespace mozilla
+
+using namespace mozilla;
+
+using CrashReporter::Annotation;
+using CrashReporter::AnnotationWriter;
+
+#define DLL_BLOCKLIST_ENTRY(name, ...) {name, __VA_ARGS__},
+#define DLL_BLOCKLIST_STRING_TYPE const char*
+#include "mozilla/WindowsDllBlocklistLegacyDefs.h"
+
+// define this for very verbose dll load debug spew
+#undef DEBUG_very_verbose
+
+static uint32_t sInitFlags;
+static bool sBlocklistInitAttempted;
+static bool sBlocklistInitFailed;
+static bool sUser32BeforeBlocklist;
+
+typedef MOZ_NORETURN_PTR void(__fastcall* BaseThreadInitThunk_func)(
+    BOOL aIsInitialThread, void* aStartAddress, void* aThreadParam);
+static WindowsDllInterceptor::FuncHookType<BaseThreadInitThunk_func>
+    stub_BaseThreadInitThunk;
+
+typedef NTSTATUS(NTAPI* LdrLoadDll_func)(PWCHAR filePath, PULONG flags,
+                                         PUNICODE_STRING moduleFileName,
+                                         PHANDLE handle);
+static WindowsDllInterceptor::FuncHookType<LdrLoadDll_func> stub_LdrLoadDll;
+
+template <class T>
+struct RVAMap {
+  RVAMap(HANDLE map, DWORD offset) {
+    SYSTEM_INFO info;
+    GetSystemInfo(&info);
+
+    DWORD alignedOffset =
+        (offset / info.dwAllocationGranularity) * info.dwAllocationGranularity;
+
+    MOZ_ASSERT(offset - alignedOffset < info.dwAllocationGranularity, "Wtf");
+
+    mRealView = ::MapViewOfFile(map, FILE_MAP_READ, 0, alignedOffset,
+                                sizeof(T) + (offset - alignedOffset));
+
+    mMappedView =
+        mRealView
+            ? reinterpret_cast<T*>((char*)mRealView + (offset - alignedOffset))
+            : nullptr;
+  }
+  ~RVAMap() {
+    if (mRealView) {
+      ::UnmapViewOfFile(mRealView);
+    }
+  }
+  operator const T*() const { return mMappedView; }
+  const T* operator->() const { return mMappedView; }
+
+ private:
+  const T* mMappedView;
+  void* mRealView;
+};
+
+static DWORD GetTimestamp(const wchar_t* path) {
+  DWORD timestamp = 0;
+
+  HANDLE file = ::CreateFileW(path, GENERIC_READ, FILE_SHARE_READ, nullptr,
+                              OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
+  if (file != INVALID_HANDLE_VALUE) {
+    HANDLE map =
+        ::CreateFileMappingW(file, nullptr, PAGE_READONLY, 0, 0, nullptr);
+    if (map) {
+      RVAMap<IMAGE_DOS_HEADER> peHeader(map, 0);
+      if (peHeader) {
+        RVAMap<IMAGE_NT_HEADERS> ntHeader(map, peHeader->e_lfanew);
+        if (ntHeader) {
+          timestamp = ntHeader->FileHeader.TimeDateStamp;
+        }
+      }
+      ::CloseHandle(map);
+    }
+    ::CloseHandle(file);
+  }
+
+  return timestamp;
+}
+
+// This lock protects both the reentrancy sentinel and the crash reporter
+// data structures.
+static CRITICAL_SECTION sLock;
+
+/**
+ * Some versions of Windows call LoadLibraryEx to get the version information
+ * for a DLL, which causes our patched LdrLoadDll implementation to re-enter
+ * itself and cause infinite recursion and a stack-exhaustion crash. We protect
+ * against reentrancy by allowing recursive loads of the same DLL.
+ *
+ * Note that we don't use __declspec(thread) because that doesn't work in DLLs
+ * loaded via LoadLibrary and there can be a limited number of TLS slots, so
+ * we roll our own.
+ */
+class ReentrancySentinel {
+ public:
+  explicit ReentrancySentinel(const char* dllName) {
+    DWORD currentThreadId = GetCurrentThreadId();
+    AutoCriticalSection lock(&sLock);
+    mPreviousDllName = (*sThreadMap)[currentThreadId];
+
+    // If there is a DLL currently being loaded and it has the same name
+    // as the current attempt, we're re-entering.
+    mReentered = mPreviousDllName && !stricmp(mPreviousDllName, dllName);
+    (*sThreadMap)[currentThreadId] = dllName;
+  }
+
+  ~ReentrancySentinel() {
+    DWORD currentThreadId = GetCurrentThreadId();
+    AutoCriticalSection lock(&sLock);
+    (*sThreadMap)[currentThreadId] = mPreviousDllName;
+  }
+
+  bool BailOut() const { return mReentered; };
+
+  static void InitializeStatics() {
+    InitializeCriticalSection(&sLock);
+    sThreadMap = new std::map<DWORD, const char*>;
+  }
+
+ private:
+  static std::map<DWORD, const char*>* sThreadMap;
+
+  const char* mPreviousDllName;
+  bool mReentered;
+};
+
+std::map<DWORD, const char*>* ReentrancySentinel::sThreadMap;
+
+using WritableBuffer = mozilla::glue::detail::WritableBuffer<1024>;
+
+/**
+ * This is a linked list of DLLs that have been blocked. It doesn't use
+ * mozilla::LinkedList because this is an append-only list and doesn't need
+ * to be doubly linked.
+ */
+class DllBlockSet {
+ public:
+  static void Add(const char* name, unsigned long long version);
+
+  // Write the list of blocked DLLs to a WritableBuffer object. This method is
+  // run after a crash occurs and must therefore not use the heap, etc.
+  static void Write(WritableBuffer& buffer);
+
+ private:
+  DllBlockSet(const char* name, unsigned long long version)
+      : mName(name), mVersion(version), mNext(nullptr) {}
+
+  const char* mName;  // points into the gWindowsDllBlocklist string
+  unsigned long long mVersion;
+  DllBlockSet* mNext;
+
+  static DllBlockSet* gFirst;
+};
+
+DllBlockSet* DllBlockSet::gFirst;
+
+void DllBlockSet::Add(const char* name, unsigned long long version) {
+  AutoCriticalSection lock(&sLock);
+  for (DllBlockSet* b = gFirst; b; b = b->mNext) {
+    if (0 == strcmp(b->mName, name) && b->mVersion == version) {
+      return;
+    }
+  }
+  // Not already present
+  DllBlockSet* n = new DllBlockSet(name, version);
+  n->mNext = gFirst;
+  gFirst = n;
+}
+
+void DllBlockSet::Write(WritableBuffer& buffer) {
+  // It would be nicer to use AutoCriticalSection here. However, its destructor
+  // might not run if an exception occurs, in which case we would never leave
+  // the critical section. (MSVC warns about this possibility.) So we
+  // enter and leave manually.
+  ::EnterCriticalSection(&sLock);
+
+  // Because this method is called after a crash occurs, and uses heap memory,
+  // protect this entire block with a structured exception handler.
+  MOZ_SEH_TRY {
+    for (DllBlockSet* b = gFirst; b; b = b->mNext) {
+      // write name[,v.v.v.v];
+      buffer.Write(b->mName, strlen(b->mName));
+      if (b->mVersion != DllBlockInfo::ALL_VERSIONS) {
+        buffer.Write(",", 1);
+        uint16_t parts[4];
+        parts[0] = b->mVersion >> 48;
+        parts[1] = (b->mVersion >> 32) & 0xFFFF;
+        parts[2] = (b->mVersion >> 16) & 0xFFFF;
+        parts[3] = b->mVersion & 0xFFFF;
+        for (int p = 0; p < 4; ++p) {
+          char buf[32];
+          _ltoa_s(parts[p], buf, sizeof(buf), 10);
+          buffer.Write(buf, strlen(buf));
+          if (p != 3) {
+            buffer.Write(".", 1);
+          }
+        }
+      }
+      buffer.Write(";", 1);
+    }
+  }
+  MOZ_SEH_EXCEPT(EXCEPTION_EXECUTE_HANDLER) {}
+
+  ::LeaveCriticalSection(&sLock);
+}
+
+static UniquePtr<wchar_t[]> getFullPath(PWCHAR filePath, wchar_t* fname) {
+  // In Windows 8, the first parameter seems to be used for more than just the
+  // path name.  For example, its numerical value can be 1.  Passing a non-valid
+  // pointer to SearchPathW will cause a crash, so we need to check to see if we
+  // are handed a valid pointer, and otherwise just pass nullptr to SearchPathW.
+  PWCHAR sanitizedFilePath = nullptr;
+  if ((uintptr_t(filePath) >= 65536) && ((uintptr_t(filePath) & 1) == 0)) {
+    sanitizedFilePath = filePath;
+  }
+
+  // figure out the length of the string that we need
+  DWORD pathlen =
+      SearchPathW(sanitizedFilePath, fname, L".dll", 0, nullptr, nullptr);
+  if (pathlen == 0) {
+    return nullptr;
+  }
+
+  auto full_fname = MakeUnique<wchar_t[]>(pathlen + 1);
+  if (!full_fname) {
+    // couldn't allocate memory?
+    return nullptr;
+  }
+
+  // now actually grab it
+  SearchPathW(sanitizedFilePath, fname, L".dll", pathlen + 1, full_fname.get(),
+              nullptr);
+  return full_fname;
+}
+
+// No builtin function to find the last character matching a set
+static wchar_t* lastslash(wchar_t* s, int len) {
+  for (wchar_t* c = s + len - 1; c >= s; --c) {
+    if (*c == L'\\' || *c == L'/') {
+      return c;
+    }
+  }
+  return nullptr;
+}
+
+static bool ShouldBlockBasedOnBlockInfo(const DllBlockInfo& info,
+                                        const char* dllName, PWCHAR filePath,
+                                        wchar_t* fname,
+                                        unsigned long long* fVersion) {
+#ifdef DEBUG_very_verbose
+  printf_stderr("LdrLoadDll: info->mName: '%s'\n", info->mName);
+#endif
+
+  if (info.mFlags & DllBlockInfoFlags::REDIRECT_TO_NOOP_ENTRYPOINT) {
+    printf_stderr(
+        "LdrLoadDll: "
+        "Ignoring the REDIRECT_TO_NOOP_ENTRYPOINT flag\n");
+  }
+
+  if ((info.mFlags & DllBlockInfoFlags::CHILD_PROCESSES_ONLY) &&
+      !(sInitFlags & eDllBlocklistInitFlagIsChildProcess)) {
+    return false;
+  }
+
+  if ((info.mFlags & DllBlockInfoFlags::UTILITY_PROCESSES_ONLY) &&
+      !(sInitFlags & eDllBlocklistInitFlagIsUtilityProcess)) {
+    return false;
+  }
+
+  if ((info.mFlags & DllBlockInfoFlags::SOCKET_PROCESSES_ONLY) &&
+      !(sInitFlags & eDllBlocklistInitFlagIsSocketProcess)) {
+    return false;
+  }
+
+  if ((info.mFlags & DllBlockInfoFlags::GPU_PROCESSES_ONLY) &&
+      !(sInitFlags & eDllBlocklistInitFlagIsGPUProcess)) {
+    return false;
+  }
+
+  if ((info.mFlags & DllBlockInfoFlags::BROWSER_PROCESS_ONLY) &&
+      (sInitFlags & eDllBlocklistInitFlagIsChildProcess)) {
+    return false;
+  }
+
+  if ((info.mFlags & DllBlockInfoFlags::GMPLUGIN_PROCESSES_ONLY) &&
+      !(sInitFlags & eDllBlocklistInitFlagIsGMPluginProcess)) {
+    return false;
+  }
+
+  *fVersion = DllBlockInfo::ALL_VERSIONS;
+
+  if (info.mMaxVersion != DllBlockInfo::ALL_VERSIONS) {
+    ReentrancySentinel sentinel(dllName);
+    if (sentinel.BailOut()) {
+      return false;
+    }
+
+    UniquePtr<wchar_t[]> full_fname = getFullPath(filePath, fname);
+    if (!full_fname) {
+      // uh, we couldn't find the DLL at all, so...
+      printf_stderr(
+          "LdrLoadDll: Blocking load of '%s' (SearchPathW didn't find "
+          "it?)\n",
+          dllName);
+      return true;
+    }
+
+    if (info.mFlags & DllBlockInfoFlags::USE_TIMESTAMP) {
+      *fVersion = GetTimestamp(full_fname.get());
+      if (*fVersion > info.mMaxVersion) {
+        return false;
+      }
+    } else {
+      LauncherResult<ModuleVersion> version =
+          GetModuleVersion(full_fname.get());
+      // If we failed to get the version information, we block.
+      if (version.isOk()) {
+        return info.IsVersionBlocked(version.unwrap());
+      }
+    }
+  }
+  // Falling through to here means we should block.
+  return true;
+}
+
+struct CaseSensitiveStringComparator {
+  explicit CaseSensitiveStringComparator(const char* aTarget)
+      : mTarget(aTarget) {}
+
+  int operator()(const DllBlockInfo& aVal) const {
+    return strcmp(mTarget, aVal.mName);
+  }
+
+  const char* mTarget;
+};
+
+static NTSTATUS NTAPI patched_LdrLoadDll(PWCHAR filePath, PULONG flags,
+                                         PUNICODE_STRING moduleFileName,
+                                         PHANDLE handle) {
+  // We have UCS2 (UTF16?), we want ASCII, but we also just want the filename
+  // portion
+#define DLLNAME_MAX 128
+  char dllName[DLLNAME_MAX + 1];
+  wchar_t* dll_part;
+  char* dot;
+
+  int len = moduleFileName->Length / 2;
+  wchar_t* fname = moduleFileName->Buffer;
+
+  // The filename isn't guaranteed to be null terminated, but in practice
+  // it always will be; ensure that this is so, and bail if not.
+  // This is done instead of the more robust approach because of bug 527122,
+  // where lots of weird things were happening when we tried to make a copy.
+  if (moduleFileName->MaximumLength < moduleFileName->Length + 2 ||
+      fname[len] != 0) {
+#ifdef DEBUG
+    printf_stderr("LdrLoadDll: non-null terminated string found!\n");
+#endif
+    goto continue_loading;
+  }
+
+  dll_part = lastslash(fname, len);
+  if (dll_part) {
+    dll_part = dll_part + 1;
+    len -= dll_part - fname;
+  } else {
+    dll_part = fname;
+  }
+
+#ifdef DEBUG_very_verbose
+  printf_stderr("LdrLoadDll: dll_part '%S' %d\n", dll_part, len);
+#endif
+
+  // if it's too long, then, we assume we won't want to block it,
+  // since DLLNAME_MAX should be at least long enough to hold the longest
+  // entry in our blocklist.
+  if (len > DLLNAME_MAX) {
+#ifdef DEBUG
+    printf_stderr("LdrLoadDll: len too long! %d\n", len);
+#endif
+    goto continue_loading;
+  }
+
+  // copy over to our char byte buffer, lowercasing ASCII as we go
+  for (int i = 0; i < len; i++) {
+    wchar_t c = dll_part[i];
+
+    if (c > 0x7f) {
+      // welp, it's not ascii; if we need to add non-ascii things to
+      // our blocklist, we'll have to remove this limitation.
+      goto continue_loading;
+    }
+
+    // ensure that dll name is all lowercase
+    if (c >= 'A' && c <= 'Z') c += 'a' - 'A';
+
+    dllName[i] = (char)c;
+  }
+
+  dllName[len] = 0;
+
+#ifdef DEBUG_very_verbose
+  printf_stderr("LdrLoadDll: dll name '%s'\n", dllName);
+#endif
+
+  if (!(sInitFlags & eDllBlocklistInitFlagWasBootstrapped)) {
+    // Block a suspicious binary that uses various 12-digit hex strings
+    // e.g. MovieMode.48CA2AEFA22D.dll (bug 973138)
+    dot = strchr(dllName, '.');
+    if (dot && (strchr(dot + 1, '.') == dot + 13)) {
+      char* end = nullptr;
+      _strtoui64(dot + 1, &end, 16);
+      if (end == dot + 13) {
+        return STATUS_DLL_NOT_FOUND;
+      }
+    }
+    // Block binaries where the filename is at least 16 hex digits
+    if (dot && ((dot - dllName) >= 16)) {
+      char* current = dllName;
+      while (current < dot && isxdigit(*current)) {
+        current++;
+      }
+      if (current == dot) {
+        return STATUS_DLL_NOT_FOUND;
+      }
+    }
+
+    // then compare to everything on the blocklist
+    DECLARE_POINTER_TO_FIRST_DLL_BLOCKLIST_ENTRY(info);
+    DECLARE_DLL_BLOCKLIST_NUM_ENTRIES(infoNumEntries);
+    CaseSensitiveStringComparator comp(dllName);
+    size_t match = LowerBound(info, 0, infoNumEntries, comp);
+    if (match != infoNumEntries) {
+      // There may be multiple entries on the list. Since LowerBound() returns
+      // the first entry that matches (if there are any matches),
+      // search forward from there.
+      while (match < infoNumEntries && (comp(info[match]) == 0)) {
+        unsigned long long fVersion;
+        if (ShouldBlockBasedOnBlockInfo(info[match], dllName, filePath, fname,
+                                        &fVersion)) {
+          printf_stderr(
+              "LdrLoadDll: Blocking load of '%s' -- see "
+              "http://www.mozilla.com/en-US/blocklist/\n",
+              dllName);
+          DllBlockSet::Add(info[match].mName, fVersion);
+          return STATUS_DLL_NOT_FOUND;
+        }
+        ++match;
+      }
+    }
+  }
+
+continue_loading:
+#ifdef DEBUG_very_verbose
+  printf_stderr("LdrLoadDll: continuing load... ('%S')\n",
+                moduleFileName->Buffer);
+#endif
+
+  glue::ModuleLoadFrame loadFrame(moduleFileName);
+
+  NTSTATUS ret;
+  HANDLE myHandle;
+
+  ret = stub_LdrLoadDll(filePath, flags, moduleFileName, &myHandle);
+
+  if (handle) {
+    *handle = myHandle;
+  }
+
+  loadFrame.SetLoadStatus(ret, myHandle);
+
+  return ret;
+}
+
+#if defined(BLOCK_LOADLIBRARY_INJECTION)
+// Map of specific thread proc addresses we should block. In particular,
+// LoadLibrary* APIs which indicate DLL injection
+static void* gStartAddressesToBlock[4];
+#endif  // defined(BLOCK_LOADLIBRARY_INJECTION)
+
+static bool ShouldBlockThread(void* aStartAddress) {
+  // Allows crashfirefox.exe to continue to work. Also if your threadproc is
+  // null, this crash is intentional.
+  if (aStartAddress == nullptr) {
+    return false;
+  }
+
+#if defined(BLOCK_LOADLIBRARY_INJECTION)
+  for (auto p : gStartAddressesToBlock) {
+    if (p == aStartAddress) {
+      return true;
+    }
+  }
+#endif
+
+  bool shouldBlock = false;
+  MEMORY_BASIC_INFORMATION startAddressInfo = {0};
+  if (VirtualQuery(aStartAddress, &startAddressInfo,
+                   sizeof(startAddressInfo))) {
+    shouldBlock |= startAddressInfo.State != MEM_COMMIT;
+    shouldBlock |= startAddressInfo.Protect != PAGE_EXECUTE_READ;
+  }
+
+  return shouldBlock;
+}
+
+// Allows blocked threads to still run normally through BaseThreadInitThunk, in
+// case there's any magic there that we shouldn't skip.
+static DWORD WINAPI NopThreadProc(void* /* aThreadParam */) { return 0; }
+
+static MOZ_NORETURN void __fastcall patched_BaseThreadInitThunk(
+    BOOL aIsInitialThread, void* aStartAddress, void* aThreadParam) {
+  if (ShouldBlockThread(aStartAddress)) {
+    aStartAddress = (void*)NopThreadProc;
+  }
+
+  stub_BaseThreadInitThunk(aIsInitialThread, aStartAddress, aThreadParam);
+}
+
+static WindowsDllInterceptor NtDllIntercept;
+static WindowsDllInterceptor Kernel32Intercept;
+
+static void GetNativeNtBlockSetWriter();
+
+static glue::LoaderObserver gMozglueLoaderObserver;
+static nt::WinLauncherServices gWinLauncher;
+
+MFBT_API void DllBlocklist_Initialize(uint32_t aInitFlags) {
+  if (sBlocklistInitAttempted) {
+    return;
+  }
+  sBlocklistInitAttempted = true;
+
+  sInitFlags = aInitFlags;
+
+  glue::ModuleLoadFrame::StaticInit(&gMozglueLoaderObserver, &gWinLauncher);
+
+  // Bug 1361410: WRusr.dll will overwrite our hook and cause a crash.
+  // Workaround: If we detect WRusr.dll, don't hook.
+  if (!GetModuleHandleW(L"WRusr.dll")) {
+    Kernel32Intercept.Init(L"kernel32.dll");
+    if (!stub_BaseThreadInitThunk.SetDetour(Kernel32Intercept,
+                                            "BaseThreadInitThunk",
+                                            &patched_BaseThreadInitThunk)) {
+#ifdef DEBUG
+      printf_stderr("BaseThreadInitThunk hook failed\n");
+#endif
+    }
+  }
+
+#if defined(BLOCK_LOADLIBRARY_INJECTION)
+  // Populate a list of thread start addresses to block.
+  HMODULE hKernel = GetModuleHandleW(L"kernel32.dll");
+  if (hKernel) {
+    void* pProc;
+
+    pProc = (void*)GetProcAddress(hKernel, "LoadLibraryA");
+    gStartAddressesToBlock[0] = pProc;
+
+    pProc = (void*)GetProcAddress(hKernel, "LoadLibraryW");
+    gStartAddressesToBlock[1] = pProc;
+
+    pProc = (void*)GetProcAddress(hKernel, "LoadLibraryExA");
+    gStartAddressesToBlock[2] = pProc;
+
+    pProc = (void*)GetProcAddress(hKernel, "LoadLibraryExW");
+    gStartAddressesToBlock[3] = pProc;
+  }
+#endif
+
+  if (aInitFlags & eDllBlocklistInitFlagWasBootstrapped) {
+    GetNativeNtBlockSetWriter();
+    return;
+  }
+
+  // There are a couple of exceptional cases where we skip user32.dll check.
+  // - If the the process was bootstrapped by the launcher process, AppInit
+  //   DLLs will be intercepted by the new DllBlockList.  No need to check
+  //   here.
+  // - The code to initialize the base profiler loads winmm.dll which
+  //   statically links user32.dll on an older Windows.  This means if the base
+  //   profiler is active before coming here, we cannot fully intercept AppInit
+  //   DLLs.  Given that the base profiler is used outside the typical use
+  //   cases, it's ok not to check user32.dll in this scenario.
+  const bool skipUser32Check =
+      (sInitFlags & eDllBlocklistInitFlagWasBootstrapped) ||
+      (!IsWin10AnniversaryUpdateOrLater() &&
+       baseprofiler::profiler_is_active());
+
+  // In order to be effective against AppInit DLLs, the blocklist must be
+  // initialized before user32.dll is loaded into the process (bug 932100).
+  if (!skipUser32Check && GetModuleHandleW(L"user32.dll")) {
+    sUser32BeforeBlocklist = true;
+#ifdef DEBUG
+    printf_stderr("DLL blocklist was unable to intercept AppInit DLLs.\n");
+#endif
+  }
+
+  NtDllIntercept.Init("ntdll.dll");
+
+  ReentrancySentinel::InitializeStatics();
+
+  // We specifically use a detour, because there are cases where external
+  // code also tries to hook LdrLoadDll, and doesn't know how to relocate our
+  // nop space patches. (Bug 951827)
+  bool ok = stub_LdrLoadDll.SetDetour(NtDllIntercept, "LdrLoadDll",
+                                      &patched_LdrLoadDll);
+
+  if (!ok) {
+    sBlocklistInitFailed = true;
+#ifdef DEBUG
+    printf_stderr("LdrLoadDll hook failed, no dll blocklisting active\n");
+#endif
+  }
+
+  // If someone injects a thread early that causes user32.dll to load off the
+  // main thread this causes issues, so load it as soon as we've initialized
+  // the block-list. (See bug 1400637)
+  if (!sUser32BeforeBlocklist && !IsWin32kLockedDown()) {
+    ::LoadLibraryW(L"user32.dll");
+  }
+}
+
+#ifdef DEBUG
+MFBT_API void DllBlocklist_Shutdown() {}
+#endif  // DEBUG
+
+static void InternalWriteNotes(AnnotationWriter& aWriter) {
+  WritableBuffer buffer;
+  DllBlockSet::Write(buffer);
+
+  aWriter.Write(Annotation::BlockedDllList, buffer.Data(), buffer.Length());
+
+  if (sBlocklistInitFailed) {
+    aWriter.Write(Annotation::BlocklistInitFailed, "1");
+  }
+
+  if (sUser32BeforeBlocklist) {
+    aWriter.Write(Annotation::User32BeforeBlocklist, "1");
+  }
+}
+
+using WriterFn = void (*)(AnnotationWriter&);
+static WriterFn gWriterFn = &InternalWriteNotes;
+
+static void GetNativeNtBlockSetWriter() {
+  auto nativeWriter = reinterpret_cast<WriterFn>(
+      ::GetProcAddress(::GetModuleHandleW(nullptr), "NativeNtBlockSet_Write"));
+  if (nativeWriter) {
+    gWriterFn = nativeWriter;
+  }
+}
+
+MFBT_API void DllBlocklist_WriteNotes(AnnotationWriter& aWriter) {
+  MOZ_ASSERT(gWriterFn);
+  gWriterFn(aWriter);
+}
+
+MFBT_API bool DllBlocklist_CheckStatus() {
+  if (sBlocklistInitFailed || sUser32BeforeBlocklist) return false;
+  return true;
+}
+
+// ============================================================================
+// This section is for DLL Services
+// ============================================================================
+
+namespace mozilla {
+Authenticode* GetAuthenticode();
+}  // namespace mozilla
+
+/**
+ * Please note that DllBlocklist_SetFullDllServices is called with
+ * aSvc = nullptr to de-initialize the resources even though they
+ * have been initialized via DllBlocklist_SetBasicDllServices.
+ */
+MFBT_API void DllBlocklist_SetFullDllServices(
+    mozilla::glue::detail::DllServicesBase* aSvc) {
+  glue::AutoExclusiveLock lock(gDllServicesLock);
+  if (aSvc) {
+    aSvc->SetAuthenticodeImpl(GetAuthenticode());
+    aSvc->SetWinLauncherServices(gWinLauncher);
+    gMozglueLoaderObserver.Forward(aSvc);
+  }
+
+  gDllServices = aSvc;
+}
+
+MFBT_API void DllBlocklist_SetBasicDllServices(
+    mozilla::glue::detail::DllServicesBase* aSvc) {
+  if (!aSvc) {
+    return;
+  }
+
+  aSvc->SetAuthenticodeImpl(GetAuthenticode());
+  gMozglueLoaderObserver.Disable();
+}