Merge changes Ie70d0155,I0692a91d,I8c5041a4

* changes:
  LockAgent: Add agent parameters to start_lock_agent script
  LockAgent: Add option to synthesize Java crash logging
  LockAgent: Add ability to generate a native crash

core/java/com/android/internal/os/RuntimeInit.java

@@ -64,6 +64,19 @@ public class RuntimeInit {
         return Log.printlns(Log.LOG_ID_CRASH, Log.ERROR, tag, msg, tr);
     }
 
+    public static void logUncaught(String threadName, String processName, int pid, Throwable e) {
+        StringBuilder message = new StringBuilder();
+        // The "FATAL EXCEPTION" string is still used on Android even though
+        // apps can set a custom UncaughtExceptionHandler that renders uncaught
+        // exceptions non-fatal.
+        message.append("FATAL EXCEPTION: ").append(threadName).append("\n");
+        if (processName != null) {
+            message.append("Process: ").append(processName).append(", ");
+        }
+        message.append("PID: ").append(pid);
+        Clog_e(TAG, message.toString(), e);
+    }
+
     /**
      * Logs a message when a thread encounters an uncaught exception. By
      * default, {@link KillApplicationHandler} will terminate this process later,
@@ -85,17 +98,7 @@ public class RuntimeInit {
             if (mApplicationObject == null && (Process.SYSTEM_UID == Process.myUid())) {
                 Clog_e(TAG, "*** FATAL EXCEPTION IN SYSTEM PROCESS: " + t.getName(), e);
             } else {
-                StringBuilder message = new StringBuilder();
+                logUncaught(t.getName(), ActivityThread.currentProcessName(), Process.myPid(), e);
-                // The "FATAL EXCEPTION" string is still used on Android even though
-                // apps can set a custom UncaughtExceptionHandler that renders uncaught
-                // exceptions non-fatal.
-                message.append("FATAL EXCEPTION: ").append(t.getName()).append("\n");
-                final String processName = ActivityThread.currentProcessName();
-                if (processName != null) {
-                    message.append("Process: ").append(processName).append(", ");
-                }
-                message.append("PID: ").append(Process.myPid());
-                Clog_e(TAG, message.toString(), e);
             }
         }
     }

tools/lock_agent/Android.bp

@@ -15,6 +15,8 @@ cc_library {
     include_dirs: [
         // NDK headers aren't available in platform NDK builds.
         "libnativehelper/include_jni",
+        // Use ScopedUtfChars.
+        "libnativehelper/header_only_include",
     ],
     header_libs: [
         "libopenjdkjvmti_headers",
@@ -33,6 +35,8 @@ cc_binary_host {
     include_dirs: [
         // NDK headers aren't available in platform NDK builds.
         "libnativehelper/include_jni",
+        // Use ScopedUtfChars.
+        "libnativehelper/header_only_include",
     ],
     header_libs: [
         "libopenjdkjvmti_headers",

tools/lock_agent/agent.cpp

@@ -19,6 +19,8 @@
 #include <memory>
 #include <sstream>
 
+#include <unistd.h>
+
 #include <jni.h>
 
 #include <jvmti.h>
@@ -26,10 +28,14 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/macros.h>
+#include <android-base/strings.h>
 #include <android-base/unique_fd.h>
 
 #include <fcntl.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
+
+#include <nativehelper/scoped_utf_chars.h>
 
 // We need dladdr.
 #if !defined(__APPLE__) && !defined(_WIN32)
@@ -61,6 +67,8 @@
 namespace {
 
 JavaVM* gJavaVM = nullptr;
+bool gForkCrash = false;
+bool gJavaCrash = false;
 
 // Converts a class name to a type descriptor
 // (ex. "java.lang.String" to "Ljava/lang/String;")
@@ -372,7 +380,7 @@ void prepareHook(jvmtiEnv* env) {
     }
 }
 
-jint attach(JavaVM* vm, char* options ATTRIBUTE_UNUSED, void* reserved ATTRIBUTE_UNUSED) {
+jint attach(JavaVM* vm, char* options, void* reserved ATTRIBUTE_UNUSED) {
     gJavaVM = vm;
 
     jvmtiEnv* env;
@@ -383,9 +391,66 @@ jint attach(JavaVM* vm, char* options ATTRIBUTE_UNUSED, void* reserved ATTRIBUTE
 
     prepareHook(env);
 
+    std::vector<std::string> config = android::base::Split(options, ",");
+    for (const std::string& c : config) {
+        if (c == "native_crash") {
+            gForkCrash = true;
+        } else if (c == "java_crash") {
+            gJavaCrash = true;
+        }
+    }
+
     return JVMTI_ERROR_NONE;
 }
 
+extern "C" JNIEXPORT
+jboolean JNICALL Java_com_android_lock_1checker_LockHook_getNativeHandlingConfig(JNIEnv*, jclass) {
+    return gForkCrash ? JNI_TRUE : JNI_FALSE;
+}
+
+extern "C" JNIEXPORT jboolean JNICALL
+Java_com_android_lock_1checker_LockHook_getSimulateCrashConfig(JNIEnv*, jclass) {
+    return gJavaCrash ? JNI_TRUE : JNI_FALSE;
+}
+
+extern "C" JNIEXPORT void JNICALL Java_com_android_lock_1checker_LockHook_nWtf(JNIEnv* env, jclass,
+        jstring msg) {
+    if (!gForkCrash || msg == nullptr) {
+        return;
+    }
+
+    // Create a native crash with the given message. Decouple from the current crash to create a
+    // tombstone but continue on.
+    //
+    // TODO: Once there are not so many reports, consider making this fatal for the calling process.
+    ScopedUtfChars utf(env, msg);
+    if (utf.c_str() == nullptr) {
+        return;
+    }
+    const char* args[] = {
+        "/system/bin/lockagent_crasher",
+        utf.c_str(),
+        nullptr
+    };
+    pid_t pid = fork();
+    if (pid < 0) {
+        return;
+    }
+    if (pid == 0) {
+        // Double fork so we return quickly. Leave init to deal with the zombie.
+        pid_t pid2 = fork();
+        if (pid2 == 0) {
+            execv(args[0], const_cast<char* const*>(args));
+            _exit(1);
+            __builtin_unreachable();
+        }
+        _exit(0);
+        __builtin_unreachable();
+    }
+    int status;
+    waitpid(pid, &status, 0);  // Ignore any results.
+}
+
 extern "C" JNIEXPORT jint JNICALL Agent_OnAttach(JavaVM* vm, char* options, void* reserved) {
     return attach(vm, options, reserved);
 }

tools/lock_agent/java/com/android/lock_checker/LockHook.java

@@ -16,6 +16,7 @@
 
 package com.android.lock_checker;
 
+import android.app.ActivityThread;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Looper;
@@ -24,6 +25,7 @@ import android.os.Process;
 import android.util.Log;
 import android.util.LogWriter;
 
+import com.android.internal.os.RuntimeInit;
 import com.android.internal.os.SomeArgs;
 import com.android.internal.util.StatLogger;
 
@@ -72,14 +74,23 @@ public class LockHook {
 
     private static final LockChecker[] sCheckers;
 
+    private static boolean sNativeHandling = false;
+    private static boolean sSimulateCrash = false;
+
     static {
         sHandlerThread = new HandlerThread("LockHook:wtf", Process.THREAD_PRIORITY_BACKGROUND);
         sHandlerThread.start();
         sHandler = new WtfHandler(sHandlerThread.getLooper());
 
         sCheckers = new LockChecker[] { new OnThreadLockChecker() };
+
+        sNativeHandling = getNativeHandlingConfig();
+        sSimulateCrash = getSimulateCrashConfig();
     }
 
+    private static native boolean getNativeHandlingConfig();
+    private static native boolean getSimulateCrashConfig();
+
     static <T> boolean shouldDumpStacktrace(StacktraceHasher hasher, Map<String, T> dumpedSet,
             T val, AnnotatedStackTraceElement[] st, int from, int to) {
         final String stacktraceHash = hasher.stacktraceHash(st, from, to);
@@ -175,7 +186,18 @@ public class LockHook {
     private static void handleViolation(Violation v) {
         String msg = v.toString();
         Log.wtf(TAG, msg);
+        if (sNativeHandling) {
+            nWtf(msg);  // Also send to native.
         }
+        if (sSimulateCrash) {
+            RuntimeInit.logUncaught("LockAgent",
+                    ActivityThread.isSystem() ? "system_server"
+                            : ActivityThread.currentProcessName(),
+                    Process.myPid(), v.getException());
+        }
+    }
+
+    private static native void nWtf(String msg);
 
     /**
      * Generates a hash for a given stacktrace of a {@link Throwable}.
@@ -297,5 +319,6 @@ public class LockHook {
     }
 
     interface Violation {
+        Throwable getException();
     }
 }

tools/lock_agent/java/com/android/lock_checker/OnThreadLockChecker.java

@@ -228,6 +228,8 @@ class OnThreadLockChecker implements LockHook.LockChecker {
         AnnotatedStackTraceElement[] mStack;
         OrderData mOppositeData;
 
+        private static final int STACK_OFFSET = 4;
+
         Violation(Thread self, Object alreadyHeld, Object lock,
                 AnnotatedStackTraceElement[] stack, OrderData oppositeData) {
             this.mSelfTid = (int) self.getId();
@@ -284,6 +286,26 @@ class OnThreadLockChecker implements LockHook.LockChecker {
                     lock.getClass().getName());
         }
 
+        // Synthesize an exception.
+        public Throwable getException() {
+            RuntimeException inner = new RuntimeException("Previously locked");
+            inner.setStackTrace(synthesizeStackTrace(mOppositeData.mStack));
+
+            RuntimeException outer = new RuntimeException(toString(), inner);
+            outer.setStackTrace(synthesizeStackTrace(mStack));
+
+            return outer;
+        }
+
+        private StackTraceElement[] synthesizeStackTrace(AnnotatedStackTraceElement[] stack) {
+
+            StackTraceElement[] out = new StackTraceElement[stack.length - STACK_OFFSET];
+            for (int i = 0; i < out.length; i++) {
+                out[i] = stack[i + STACK_OFFSET].getStackTraceElement();
+            }
+            return out;
+        }
+
         public String toString() {
             StringBuilder sb = new StringBuilder();
             sb.append("Lock inversion detected!\n");
@@ -294,7 +316,7 @@ class OnThreadLockChecker implements LockHook.LockChecker {
             sb.append(" on thread ").append(mOppositeData.mTid).append(" (")
                     .append(mOppositeData.mThreadName).append(")");
             sb.append(" at:\n");
-            sb.append(getAnnotatedStackString(mOppositeData.mStack, 4,
+            sb.append(getAnnotatedStackString(mOppositeData.mStack, STACK_OFFSET,
                     describeLocking(mAlreadyHeld, "will lock"), getTo(mOppositeData.mStack, mLock)
                     + 1, "    | "));
             sb.append("  Locking ");
@@ -303,7 +325,8 @@ class OnThreadLockChecker implements LockHook.LockChecker {
             sb.append(describeLock(mLock));
             sb.append(" on thread ").append(mSelfTid).append(" (").append(mSelfName).append(")");
             sb.append(" at:\n");
-            sb.append(getAnnotatedStackString(mStack, 4, describeLocking(mLock, "will lock"),
+            sb.append(getAnnotatedStackString(mStack, STACK_OFFSET,
+                    describeLocking(mLock, "will lock"),
                     getTo(mStack, mAlreadyHeld) + 1, "    | "));
 
             return sb.toString();

tools/lock_agent/start_with_lockagent.sh

@@ -1,5 +1,13 @@
 #!/system/bin/sh
+
+AGENT_OPTIONS=
+if [[ "$1" == --agent-options ]] ; then
+  shift
+  AGENT_OPTIONS="=$1"
+  shift
+fi
+
 APP=$1
 shift
-$APP -Xplugin:libopenjdkjvmti.so -agentpath:liblockagent.so $@
 
+$APP -Xplugin:libopenjdkjvmti.so "-agentpath:liblockagent.so$AGENT_OPTIONS" $@