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Commit e48baa5f authored by Martijn Coenen's avatar Martijn Coenen
Browse files

Don't hold sProxyLock while retrieving interface descriptors. 

Since we can't guarantee apps won't call back into us while calling
getInterfaceDescriptor() (even though that's a *really* bad idea),
don't hold any locks while doing so, to protect us from deadlocks.

Bug: 140603195
Test: adb shell am dump binder-proxies
Change-Id: I6289c799aa7027f80792cb751fe1dc437552ea58
parent 5a8283d7

core/java/android/os/BinderProxy.java

+30 −29
Original line number Diff line number Diff line
@@ -241,9 +241,16 @@ public final class BinderProxy implements IBinder { 
            }



            Map<String, Integer> counts = new HashMap<>();

            final ArrayList<WeakReference<BinderProxy>> proxiesToQuery =

                    new ArrayList<WeakReference<BinderProxy>>();

            synchronized (sProxyMap) {

                for (ArrayList<WeakReference<BinderProxy>> a : mMainIndexValues) {

                    if (a != null) {

                    for (WeakReference<BinderProxy> weakRef : a) {

                        proxiesToQuery.addAll(a);

                    }

                }

            }

            for (WeakReference<BinderProxy> weakRef : proxiesToQuery) {

                BinderProxy bp = weakRef.get();

                String key;

                if (bp == null) {
@@ -265,8 +272,6 @@ public final class BinderProxy implements IBinder { 
                    counts.put(key, i + 1);

                }

            }

                }

            }

            Map.Entry<String, Integer>[] sorted = counts.entrySet().toArray(

                    new Map.Entry[counts.size()]);
@@ -354,10 +359,8 @@ public final class BinderProxy implements IBinder { 
     * @hide

     */

    public static InterfaceCount[] getSortedInterfaceCounts(int num) {

        synchronized (sProxyMap) {

        return sProxyMap.getSortedInterfaceCounts(num);

    }

    }



    /**

     * Returns the number of binder proxies held in this process.
@@ -376,12 +379,10 @@ public final class BinderProxy implements IBinder { 
     */

    public static void dumpProxyDebugInfo() {

        if (Build.IS_DEBUGGABLE) {

            synchronized (sProxyMap) {

            sProxyMap.dumpProxyInterfaceCounts();

            sProxyMap.dumpPerUidProxyCounts();

        }

    }

    }



    /**

     * Return a BinderProxy for IBinder.