The Tor Browser: xpcom/components/nsNativeComponentLoader.cpp@97036ab72558 (annotated)

xpcom/components/nsNativeComponentLoader.cpp@97036ab72558 (annotated)

xpcom/components/nsNativeComponentLoader.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* 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/.
  * This Original Code has been modified by IBM Corporation.
  * Modifications made by IBM described herein are
  * Copyright (c) International Business Machines
  * Corporation, 2000
  *
  * Modifications to Mozilla code or documentation
  * identified per MPL Section 3.3
  *
  * Date             Modified by     Description of modification
  * 04/20/2000       IBM Corp.      Added PR_CALLBACK for Optlink use in OS2
  */
 /* Allow logging in the release build */
 #ifdef MOZ_LOGGING
 #define FORCE_PR_LOG
 #endif
 #include "nsNativeComponentLoader.h"
 #include "prlog.h"
 #include "prinit.h"
 #include "prerror.h"
 #include "nsComponentManager.h"
 #include "ManifestParser.h" // for LogMessage
 #include "nsCRTGlue.h"
 #include "nsThreadUtils.h"
 #include "nsTraceRefcnt.h"
 #include "nsIFile.h"
 #include "mozilla/WindowsDllBlocklist.h"
 #ifdef XP_WIN
 #include <windows.h>
 #endif
 #ifdef XP_MACOSX
 #include <signal.h>
 #endif
 #ifdef VMS
 #include <lib$routines.h>
 #include <ssdef.h>
 #endif
 #ifdef DEBUG
 #define IMPLEMENT_BREAK_AFTER_LOAD
 #endif
 using namespace mozilla;
 static PRLogModuleInfo *
 GetNativeModuleLoaderLog()
 {
     static PRLogModuleInfo *sLog;
     if (!sLog)
         sLog = PR_NewLogModule("nsNativeModuleLoader");
     return sLog;
 }
 #define LOG(level, args) PR_LOG(GetNativeModuleLoaderLog(), level, args)
 NS_IMPL_QUERY_INTERFACE(nsNativeModuleLoader,
                         mozilla::ModuleLoader)
 NS_IMPL_ADDREF_USING_AGGREGATOR(nsNativeModuleLoader,
                                 nsComponentManagerImpl::gComponentManager)
 NS_IMPL_RELEASE_USING_AGGREGATOR(nsNativeModuleLoader,
                                  nsComponentManagerImpl::gComponentManager)
 nsresult
 nsNativeModuleLoader::Init()
 {
     MOZ_ASSERT(NS_IsMainThread(), "Startup not on main thread?");
     LOG(PR_LOG_DEBUG, ("nsNativeModuleLoader::Init()"));
     return NS_OK;
 }
 class LoadModuleMainThreadRunnable : public nsRunnable
 {
 public:
     LoadModuleMainThreadRunnable(nsNativeModuleLoader* loader,
                                  FileLocation &file)
         : mLoader(loader)
         , mFile(file)
         , mResult(nullptr)
     { }
     NS_IMETHOD Run()
     {
         mResult = mLoader->LoadModule(mFile);
         return NS_OK;
     }
     nsRefPtr<nsNativeModuleLoader> mLoader;
     FileLocation mFile;
     const mozilla::Module* mResult;
 };
 const mozilla::Module*
 nsNativeModuleLoader::LoadModule(FileLocation &aFile)
 {
     if (aFile.IsZip()) {
         NS_ERROR("Binary components cannot be loaded from JARs");
         return nullptr;
     }
     nsCOMPtr<nsIFile> file = aFile.GetBaseFile();
     nsresult rv;
     if (!NS_IsMainThread()) {
         // If this call is off the main thread, synchronously proxy it
         // to the main thread.
         nsRefPtr<LoadModuleMainThreadRunnable> r = new LoadModuleMainThreadRunnable(this, aFile);
         NS_DispatchToMainThread(r, NS_DISPATCH_SYNC);
         return r->mResult;
     }
     nsCOMPtr<nsIHashable> hashedFile(do_QueryInterface(file));
     if (!hashedFile) {
         NS_ERROR("nsIFile is not nsIHashable");
         return nullptr;
     }
     nsAutoCString filePath;
     file->GetNativePath(filePath);
     NativeLoadData data;
     if (mLibraries.Get(hashedFile, &data)) {
         NS_ASSERTION(data.module, "Corrupt mLibraries hash");
         LOG(PR_LOG_DEBUG,
             ("nsNativeModuleLoader::LoadModule(\"%s\") - found in cache",
              filePath.get()));
         return data.module;
     }
     // We haven't loaded this module before
     {
 #ifdef HAS_DLL_BLOCKLIST
       AutoSetXPCOMLoadOnMainThread guard;
 #endif
       rv = file->Load(&data.library);
     }
     if (NS_FAILED(rv)) {
         char errorMsg[1024] = "<unknown; can't get error from NSPR>";
         if (PR_GetErrorTextLength() < (int) sizeof(errorMsg))
             PR_GetErrorText(errorMsg);
         LogMessage("Failed to load native module at path '%s': (%lx) %s",
                    filePath.get(), rv, errorMsg);
         return nullptr;
     }
 #ifdef IMPLEMENT_BREAK_AFTER_LOAD
     nsAutoCString leafName;
     file->GetNativeLeafName(leafName);
     char *env = getenv("XPCOM_BREAK_ON_LOAD");
     char *blist;
     if (env && *env && (blist = strdup(env))) {
         char *nextTok = blist;
         while (char *token = NS_strtok(":", &nextTok)) {
             if (leafName.Find(token, true) != kNotFound) {
                 NS_BREAK();
             }
         }
         free(blist);
     }
 #endif
     void *module = PR_FindSymbol(data.library, "NSModule");
     if (!module) {
         LogMessage("Native module at path '%s' doesn't export symbol `NSModule`.",
                    filePath.get());
         PR_UnloadLibrary(data.library);
         return nullptr;
     }
     data.module = *(mozilla::Module const *const *) module;
     if (mozilla::Module::kVersion != data.module->mVersion) {
         LogMessage("Native module at path '%s' is incompatible with this version of Firefox, has version %i, expected %i.",
                    filePath.get(), data.module->mVersion,
                    mozilla::Module::kVersion);
         PR_UnloadLibrary(data.library);
         return nullptr;
     }
     mLibraries.Put(hashedFile, data); // infallible
     return data.module;
 }
 PLDHashOperator
 nsNativeModuleLoader::ReleaserFunc(nsIHashable* aHashedFile,
                                    NativeLoadData& aLoadData, void*)
 {
     aLoadData.module = nullptr;
     return PL_DHASH_NEXT;
 }
 PLDHashOperator
 nsNativeModuleLoader::UnloaderFunc(nsIHashable* aHashedFile,
                                    NativeLoadData& aLoadData, void*)
 {
     if (PR_LOG_TEST(GetNativeModuleLoaderLog(), PR_LOG_DEBUG)) {
         nsCOMPtr<nsIFile> file(do_QueryInterface(aHashedFile));
         nsAutoCString filePath;
         file->GetNativePath(filePath);
         LOG(PR_LOG_DEBUG,
             ("nsNativeModuleLoader::UnloaderFunc(\"%s\")", filePath.get()));
     }
 #ifdef NS_BUILD_REFCNT_LOGGING
     nsTraceRefcnt::SetActivityIsLegal(false);
 #endif
 #if 0
     // XXXbsmedberg: do this as soon as the static-destructor crash(es)
     // are fixed
     PRStatus ret = PR_UnloadLibrary(aLoadData.library);
     NS_ASSERTION(ret == PR_SUCCESS, "Failed to unload library");
 #endif
 #ifdef NS_BUILD_REFCNT_LOGGING
     nsTraceRefcnt::SetActivityIsLegal(true);
 #endif
     return PL_DHASH_REMOVE;
 }
 void
 nsNativeModuleLoader::UnloadLibraries()
 {
     MOZ_ASSERT(NS_IsMainThread(), "Shutdown not on main thread?");
     mLibraries.Enumerate(ReleaserFunc, nullptr);
     mLibraries.Enumerate(UnloaderFunc, nullptr);
 }

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xpcom/components/nsNativeComponentLoader.cpp@97036ab72558 (annotated)

xpcom/components/nsNativeComponentLoader.cpp