libbinder: stability check moved to trans time
Before: stability check done when binder is read from a parcel
After: stability check done when binder is transacted on
Why this change is being made/benefits:
- vendor binders can be used as tokens in system context
- pingBinder/interfaceChain/etc.. can be done on vendor binders in a
system context, so code can generically operate on binders. This is
particularly useful for service manager and dumpstate, which previously
I was going to special-case
- policy on which binders go where is entirely reliant on SELinux
whereas before there were additional runtime restrictions
Cons to this change:
- allowed binders must be determined by context. BpBinder now checks
stability based on kLocalStability. More work would need to be done to
get this working with APEX.
Bug: 136027762
Test: binderStabilityTest
Change-Id: Iff026e81a130dbb8885ca82ec24e69a5768847eb
Merged-In: Iff026e81a130dbb8885ca82ec24e69a5768847eb
diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index 1e1bc3a..07db50f 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -21,6 +21,7 @@
#include <binder/BpBinder.h>
#include <binder/IPCThreadState.h>
#include <binder/IServiceManager.h>
+#include <binder/Stability.h>
#include <cutils/atomic.h>
#include <utils/Log.h>
#include <utils/String8.h>
@@ -109,7 +110,13 @@
sp<IBinder> ProcessState::getContextObject(const sp<IBinder>& /*caller*/)
{
- return getStrongProxyForHandle(0);
+ sp<IBinder> context = getStrongProxyForHandle(0);
+
+ // The root object is special since we get it directly from the driver, it is never
+ // written by Parcell::writeStrongBinder.
+ internal::Stability::tryMarkCompilationUnit(context.get());
+
+ return context;
}
void ProcessState::startThreadPool()