[tor-bugs] #13893 [Tor Browser]: Torbrowser 4.X.Y crashes on start when using MS EMET 5.x

[Tor Bug Tracker & Wiki]

#13893: Torbrowser 4.X.Y crashes on start when using MS EMET 5.x
-------------------------------------------------+-------------------------
 Reporter:  Diapolo                              |          Owner:  gk
     Type:  defect                               |         Status:
 Priority:  High                                 |  needs_review
Component:  Tor Browser                          |      Milestone:
 Severity:  Normal                               |        Version:
 Keywords:  tbb-usability-stoppoint-app,         |     Resolution:
  TorBrowserTeam201512, GeorgKoppen201512        |  Actual Points:
Parent ID:                                       |         Points:
  Sponsor:  SponsorU                             |
-------------------------------------------------+-------------------------
Changes (by cypherpunks_backup):

 * status:  assigned => needs_review


Comment:

 {{{
 --- nsWindowsDllInterceptor.h.orig
 +++ nsWindowsDllInterceptor.h
 @@ -82,7 +82,7 @@
      , mPatchedFnsLen(0)
    {}

 -  ~WindowsDllNopSpacePatcher()
 +  MOZ_NEVER_INLINE ~WindowsDllNopSpacePatcher()
    {
      // Restore the mov edi, edi to the beginning of each function we
 patched.

 @@ -119,7 +119,7 @@
    }

  #if defined(_M_IX86)
 -  bool AddHook(const char* aName, intptr_t aHookDest, void** aOrigFunc)
 +  MOZ_NEVER_INLINE bool AddHook(const char* aName, intptr_t aHookDest,
 void** aOrigFunc)
    {
      if (!mModule) {
        return false;
 @@ -161,7 +161,7 @@
      return rv;
    }

 -  bool WriteHook(byteptr_t aFn, intptr_t aHookDest, void** aOrigFunc)
 +  MOZ_NEVER_INLINE bool WriteHook(byteptr_t aFn, intptr_t aHookDest,
 void** aOrigFunc)
    {
      // Check that the 5 bytes before aFn are NOP's or INT 3's,
      // and that the 2 bytes after aFn are mov(edi, edi).
 @@ -234,7 +234,7 @@
    {
    }

 -  ~WindowsDllDetourPatcher()
 +  MOZ_NEVER_INLINE ~WindowsDllDetourPatcher()
    {
      int i;
      byteptr_t p;
 @@ -270,7 +270,7 @@
      }
    }

 -  void Init(const char* aModuleName, int aNumHooks = 0)
 +  MOZ_NEVER_INLINE void Init(const char* aModuleName, int aNumHooks = 0)
    {
      if (mModule) {
        return;
 @@ -301,7 +301,7 @@

    bool Initialized() { return !!mModule; }

 -  void LockHooks()
 +  MOZ_NEVER_INLINE void LockHooks()
    {
      if (!mModule) {
        return;
 @@ -314,7 +314,7 @@
      mModule = 0;
    }

 -  bool AddHook(const char* aName, intptr_t aHookDest, void** aOrigFunc)
 +  MOZ_NEVER_INLINE bool AddHook(const char* aName, intptr_t aHookDest,
 void** aOrigFunc)
    {
      if (!mModule) {
        return false;
 @@ -346,7 +346,7 @@
    int mMaxHooks;
    int mCurHooks;

 -  void CreateTrampoline(void* aOrigFunction, intptr_t aDest, void**
 aOutTramp)
 +  MOZ_NEVER_INLINE void CreateTrampoline(void* aOrigFunction, intptr_t
 aDest, void** aOutTramp)
    {
      *aOutTramp = nullptr;

 @@ -727,7 +727,7 @@
      }
    }

 -  bool AddHook(const char* aName, intptr_t aHookDest, void** aOrigFunc)
 +  MOZ_NEVER_INLINE bool AddHook(const char* aName, intptr_t aHookDest,
 void** aOrigFunc)
    {
      // Use a nop space patch if possible, otherwise fall back to a
 detour.
      // This should be the preferred method for adding hooks.
 @@ -743,7 +743,7 @@
      return AddDetour(aName, aHookDest, aOrigFunc);
    }

 -  bool AddDetour(const char* aName, intptr_t aHookDest, void** aOrigFunc)
 +  MOZ_NEVER_INLINE bool AddDetour(const char* aName, intptr_t aHookDest,
 void** aOrigFunc)
    {
      // Generally, code should not call this method directly. Use AddHook
 unless
      // there is a specific need to avoid nop space patches.
 }}}

 This fix prevents GCC to inline methods and destructors, to keep code
 small enough to never do jumps too far.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/13893#comment:20>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online