diff options
author | Thiago Macieira <thiago.macieira@intel.com> | 2016-12-09 16:53:30 -0800 |
---|---|---|
committer | Thiago Macieira <thiago.macieira@intel.com> | 2016-12-17 04:11:09 +0000 |
commit | 7ca66b1e66e73a0cb35705df04507ef9f3440cab (patch) | |
tree | 390c66fa09fc6a3ed0a57ece00f12d6cdabc8a53 /src/corelib/plugin/qfactoryloader.cpp | |
parent | 8325808dcf0cc9061f05ec89b6c3e3afb8c1ab8f (diff) |
Fix race condition in QFactoryLoader: lock the mutex we already have
The process of loading a plugin is examplified by the qLoadPlugin
function (though not all users of QFactoryLoader use this function, they
all do something similar):
const int index = loader->indexOf(key);
if (index != -1) {
QObject *factoryObject = loader->instance(index);
if (FactoryInterface *factory = qobject_cast<FactoryInterface *>(factoryObject))
if (PluginInterface *result = factory->create(key, std::forward<Args>(args)...))
return result;
}
QFactoryLoader::indexOf already locked the mutex, but not
QFactoryLoader::instance. This commit fixes that.
Note that calling the virtual create() in the plugin's factory is not
protected by the mutex. Each plugin's factory must be thread-safe and
also create an object that works on any thread too. It's also the
responsibility of the caller of qLoadPlugin to ensure that it's called
thread-safely.
Task-number: QTBUG-42855
Change-Id: I63e21df51c7448bc8b5ffffd148ebee33d4c47de
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Diffstat (limited to 'src/corelib/plugin/qfactoryloader.cpp')
-rw-r--r-- | src/corelib/plugin/qfactoryloader.cpp | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/corelib/plugin/qfactoryloader.cpp b/src/corelib/plugin/qfactoryloader.cpp index c09dc6c22b..b8e18cc9a8 100644 --- a/src/corelib/plugin/qfactoryloader.cpp +++ b/src/corelib/plugin/qfactoryloader.cpp @@ -282,6 +282,7 @@ QObject *QFactoryLoader::instance(int index) const return 0; #ifndef QT_NO_LIBRARY + QMutexLocker lock(&d->mutex); if (index < d->libraryList.size()) { QLibraryPrivate *library = d->libraryList.at(index); if (library->instance || library->loadPlugin()) { @@ -297,6 +298,7 @@ QObject *QFactoryLoader::instance(int index) const return 0; } index -= d->libraryList.size(); + lock.unlock(); #endif QVector<QStaticPlugin> staticPlugins = QPluginLoader::staticPlugins(); |