Omit icons from bulk SessionInfo calls.

Calls that return List<SessionInfo> can end up returning hundreds of
sessions, each of which include a "Bitmap appIcon" object.  Since we
quickly smash the entire list through a ParceledListSlice, we risk
exhausting FDs for all the ashmem regions.

To mitigate this, we omit these icons from the bulk calls, and then
fetch individual icons on-demand when explicitly requested.

Test: create 2k sessions and verify system doesn't croak
Bug: 38021844
Change-Id: I932073defe5b9b34a636818a69009d49060215fb

core/java/android/content/pm/PackageInstaller.java

@@ -24,6 +24,7 @@ import android.annotation.SdkConstant;
 import android.annotation.SdkConstant.SdkConstantType;
 import android.annotation.SystemApi;
 import android.app.ActivityManager;
+import android.app.AppGlobals;
 import android.content.Intent;
 import android.content.IntentSender;
 import android.content.pm.PackageManager.InstallReason;
@@ -1355,6 +1356,16 @@ public class PackageInstaller {
          * if unavailable.
          */
         public @Nullable Bitmap getAppIcon() {
+            if (appIcon == null) {
+                // Icon may have been omitted for calls that return bulk session
+                // lists, so try fetching the specific icon.
+                try {
+                    appIcon = AppGlobals.getPackageManager().getPackageInstaller()
+                            .getSessionInfo(sessionId).appIcon;
+                } catch (RemoteException e) {
+                    throw e.rethrowFromSystemServer();
+                }
+            }
             return appIcon;
         }
 

services/core/java/com/android/server/pm/PackageInstallerService.java

@@ -848,7 +848,7 @@ public class PackageInstallerService extends IPackageInstaller.Stub {
             for (int i = 0; i < mSessions.size(); i++) {
                 final PackageInstallerSession session = mSessions.valueAt(i);
                 if (session.userId == userId) {
-                    result.add(session.generateInfo());
+                    result.add(session.generateInfo(false));
                 }
             }
         }
@@ -866,7 +866,7 @@ public class PackageInstallerService extends IPackageInstaller.Stub {
                 final PackageInstallerSession session = mSessions.valueAt(i);
                 if (Objects.equals(session.installerPackageName, installerPackageName)
                         && session.userId == userId) {
-                    result.add(session.generateInfo());
+                    result.add(session.generateInfo(false));
                 }
             }
         }

services/core/java/com/android/server/pm/PackageInstallerSession.java

@@ -288,6 +288,10 @@ public class PackageInstallerSession extends IPackageInstallerSession.Stub {
     }
 
     public SessionInfo generateInfo() {
+        return generateInfo(true);
+    }
+
+    public SessionInfo generateInfo(boolean includeIcon) {
         final SessionInfo info = new SessionInfo();
         synchronized (mLock) {
             info.sessionId = sessionId;
@@ -302,7 +306,9 @@ public class PackageInstallerSession extends IPackageInstallerSession.Stub {
             info.installReason = params.installReason;
             info.sizeBytes = params.sizeBytes;
             info.appPackageName = params.appPackageName;
-            info.appIcon = params.appIcon;
+            if (includeIcon) {
+                info.appIcon = params.appIcon;
+            }
             info.appLabel = params.appLabel;
         }
         return info;