Relax locking for startActivityInPackage().

Both startActivityInPackage() and startActivitiesInPackage()
eventually call through to resolveActivity(), which might need to
acquire the AM lock.

The remainder of ActivityStarter.execute() already acquires the
WM lock when needed, so it should be safe to drop it from the overall
method.  Add additional guarding to ensure that this doesn't regress
in the future.

Bug: 115619667, 157863128
Test: atest WmTests:ActivityStarterTests
Test: atest FrameworksServicesTests:com.android.server.uri
Test: atest CtsAppSecurityHostTestCases:android.appsecurity.cts.AppSecurityTests#testPermissionDiffCert
Test: atest CtsWindowManagerDeviceTestCases:CrossAppDragAndDropTests
Test: atest CtsWindowManagerDeviceTestCases:ActivityStarterTests
Change-Id: Ia1693873a10d11ea61a8a7748e0558beffda8c5b
(cherry picked from commit 13a7cf7044a95f105a693d1c3943441de9c3c99a)

2 files changed, 16 insertions, 14 deletions

diff --git a/services/core/java/com/android/server/wm/ActivityStarter.java b/services/core/java/com/android/server/wm/ActivityStarter.java
index daa97b56ed66..30779973b204 100644
--- a/services/core/java/com/android/server/wm/ActivityStarter.java
+++ b/services/core/java/com/android/server/wm/ActivityStarter.java
@@ -639,8 +639,14 @@ class ActivityStarter {
                         mRequest.intent, caller);
             }
 
-            // Do not lock the resolving to avoid potential deadlock.
+            // If the caller hasn't already resolved the activity, we're willing
+            // to do so here, but because that may require acquiring the AM lock
+            // as part of calculating the NeededUriGrants, we must never hold
+            // the WM lock here to avoid deadlocking.
             if (mRequest.activityInfo == null) {
+                if (Thread.holdsLock(mService.mGlobalLock)) {
+                    Slog.wtf(TAG, new IllegalStateException("Caller must not hold WM lock"));
+                }
                 mRequest.resolveActivity(mSupervisor);
             }
 
diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index cf453c7feef8..205523b2a119 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -6174,12 +6174,10 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
                 boolean validateIncomingUser, PendingIntentRecord originatingPendingIntent,
                 boolean allowBackgroundActivityStart) {
             assertPackageMatchesCallingUid(callingPackage);
-            synchronized (mGlobalLock) {
-                return getActivityStartController().startActivitiesInPackage(uid, realCallingPid,
-                        realCallingUid, callingPackage, callingFeatureId, intents, resolvedTypes,
-                        resultTo, options, userId, validateIncomingUser, originatingPendingIntent,
-                        allowBackgroundActivityStart);
-            }
+            return getActivityStartController().startActivitiesInPackage(uid, realCallingPid,
+                    realCallingUid, callingPackage, callingFeatureId, intents, resolvedTypes,
+                    resultTo, options, userId, validateIncomingUser, originatingPendingIntent,
+                    allowBackgroundActivityStart);
         }
 
         @Override
@@ -6190,13 +6188,11 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
                 boolean validateIncomingUser, PendingIntentRecord originatingPendingIntent,
                 boolean allowBackgroundActivityStart) {
             assertPackageMatchesCallingUid(callingPackage);
-            synchronized (mGlobalLock) {
-                return getActivityStartController().startActivityInPackage(uid, realCallingPid,
-                        realCallingUid, callingPackage, callingFeatureId, intent, resolvedType,
-                        resultTo, resultWho, requestCode, startFlags, options, userId, inTask,
-                        reason, validateIncomingUser, originatingPendingIntent,
-                        allowBackgroundActivityStart);
-            }
+            return getActivityStartController().startActivityInPackage(uid, realCallingPid,
+                    realCallingUid, callingPackage, callingFeatureId, intent, resolvedType,
+                    resultTo, resultWho, requestCode, startFlags, options, userId, inTask,
+                    reason, validateIncomingUser, originatingPendingIntent,
+                    allowBackgroundActivityStart);
         }
 
         @Override