Don't create or check permissions on profiles during app startup
The impact is small but the IO work can be perform at different
moments. Profile creation is done during app install and
permission check postpone until the first profile write.
Bug: 28785119
Bug: 28625993
Change-Id: Ib364f21f07a78c78e03851fa12142319ea1f931b
diff --git a/core/java/android/app/LoadedApk.java b/core/java/android/app/LoadedApk.java
index 1f3dfa7..152f45e 100644
--- a/core/java/android/app/LoadedApk.java
+++ b/core/java/android/app/LoadedApk.java
@@ -543,12 +543,7 @@
// It is NOT ok to call this function from the system_server (for any of the packages it
// loads code from) so we explicitly disallow it there.
if (needToSetupJitProfiles && !ActivityThread.isSystem()) {
- // Temporarily disable logging of disk reads/writes on the Looper thread
- // as this is early and necessary. Write is only needed to create the
- // profile file if it's not already there.
- StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
setupJitProfileSupport();
- StrictMode.setThreadPolicy(oldPolicy);
}
}
@@ -572,6 +567,15 @@
if (!SystemProperties.getBoolean("dalvik.vm.usejitprofiles", false)) {
return;
}
+ // Only set up profile support if the loaded apk has the same uid as the
+ // current process.
+ // Currently, we do not support profiling across different apps.
+ // (e.g. application's uid might be different when the code is
+ // loaded by another app via createApplicationContext)
+ if (mApplicationInfo.uid != Process.myUid()) {
+ return;
+ }
+
final List<String> codePaths = new ArrayList<>();
if ((mApplicationInfo.flags & ApplicationInfo.FLAG_HAS_CODE) != 0) {
codePaths.add(mApplicationInfo.sourceDir);
@@ -587,55 +591,11 @@
}
final File profileFile = getPrimaryProfileFile(mPackageName);
- if (profileFile.exists()) {
- if (!profileFile.canRead() || !profileFile.canWrite()) {
- // The apk might be loaded in a context where we don't have permissions
- // to track the profile (e.g. when loaded by another app via
- // createApplicationContext)
- return;
- }
- } else {
- // Profile does not exist. Create it.
- FileDescriptor fd = null;
- try {
- final int permissions = 0600; // read-write for user.
- fd = Os.open(profileFile.getAbsolutePath(), OsConstants.O_CREAT, permissions);
- Os.fchmod(fd, permissions);
- Os.fchown(fd, mApplicationInfo.uid, mApplicationInfo.uid);
- } catch (ErrnoException e) {
- if (e.errno == OsConstants.EACCES) {
- // It can happen that the profile file does not exist but the apk is loaded in a
- // context where we don't have permissions (e.g. when loaded by another app via
- // createApplicationContext)
- return;
- }
- Log.v(TAG, "Unable to create jit profile file "
- + profileFile + ": " + e.getMessage());
- try {
- Os.unlink(profileFile.getAbsolutePath());
- } catch (ErrnoException unlinkErr) {
- if (unlinkErr.errno != OsConstants.ENOENT) {
- Log.v(TAG, "Unable to unlink jit profile file "
- + profileFile + ": " + unlinkErr.getMessage());
- }
- }
- return;
- } finally {
- IoUtils.closeQuietly(fd);
- }
- }
-
final File foreignDexProfilesFile =
Environment.getDataProfilesDeForeignDexDirectory(UserHandle.myUserId());
- String foreignDexProfilesPath = null;
- if (!foreignDexProfilesFile.exists()) {
- Log.v(TAG, "ForeignDexProfilesPath does not exists:" +
- foreignDexProfilesFile.getPath());
- } else {
- foreignDexProfilesPath = foreignDexProfilesFile.getAbsolutePath();
- }
- VMRuntime.registerAppInfo(profileFile.getAbsolutePath(), mApplicationInfo.dataDir,
- codePaths.toArray(new String[codePaths.size()]), foreignDexProfilesPath);
+
+ VMRuntime.registerAppInfo(profileFile.getPath(), mApplicationInfo.dataDir,
+ codePaths.toArray(new String[codePaths.size()]), foreignDexProfilesFile.getPath());
}
/**
