Allow debugging only for apps forked from zygoteHEADmaster

When starting the runtime from app_process, we only pass JDWP options
if starting zygote. It prevents from opening a JDWP connection in
non-zygote programs while Android apps (forked from zygote) remain
debuggable.

Bug: 23050463

(cherry picked from commit 7a09b8322cab26d6e3da1362d3c74964ae66b5d4)

Change-Id: Ib5b6d3bc4d45389993c3c54226df5a7b72479d19
Signed-off-by: Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de>

3 files changed, 29 insertions, 23 deletions

diff --git a/cmds/app_process/app_main.cpp b/cmds/app_process/app_main.cpp
index 6fe358c..324c1d2 100644
--- a/cmds/app_process/app_main.cpp
+++ b/cmds/app_process/app_main.cpp
@@ -187,14 +187,16 @@ int main(int argc, const char* const argv[])
 
     if (zygote) {
         runtime.start("com.android.internal.os.ZygoteInit",
-                startSystemServer ? "start-system-server" : "");
+                startSystemServer ? "start-system-server" : "",
+                zygote);
     } else if (className) {
         // Remainder of args get passed to startup class main()
         runtime.mClassName = className;
         runtime.mArgC = argc - i;
         runtime.mArgV = argv + i;
         runtime.start("com.android.internal.os.RuntimeInit",
-                application ? "application" : "tool");
+                application ? "application" : "tool",
+                zygote);
     } else {
         fprintf(stderr, "Error: no class name or --zygote supplied.\n");
         app_usage();
diff --git a/core/jni/AndroidRuntime.cpp b/core/jni/AndroidRuntime.cpp
index 01ad2f0..ec20e91 100644
--- a/core/jni/AndroidRuntime.cpp
+++ b/core/jni/AndroidRuntime.cpp
@@ -444,7 +444,7 @@ void AndroidRuntime::parseExtraOpts(char* extraOptsBuf)
  *
  * Returns 0 on success.
  */
-int AndroidRuntime::startVm(JavaVM** pJavaVM, JNIEnv** pEnv)
+int AndroidRuntime::startVm(JavaVM** pJavaVM, JNIEnv** pEnv, bool zygote)
 {
     int result = -1;
     JavaVMInitArgs initArgs;
@@ -634,25 +634,29 @@ int AndroidRuntime::startVm(JavaVM** pJavaVM, JNIEnv** pEnv)
         }
     }
 
-    /* enable debugging; set suspend=y to pause during VM init */
-    /* use android ADB transport */
-    opt.optionString =
-        "-agentlib:jdwp=transport=dt_android_adb,suspend=n,server=y";
-    mOptions.add(opt);
+    /*
+     * Enable debugging only for apps forked from zygote.
+     * Set suspend=y to pause during VM init and use android ADB transport.
+     */
+    if (zygote) {
+      opt.optionString =
+          "-agentlib:jdwp=transport=dt_android_adb,suspend=n,server=y";
+      mOptions.add(opt);
 
-    ALOGD("CheckJNI is %s\n", checkJni ? "ON" : "OFF");
-    if (checkJni) {
-        /* extended JNI checking */
-        opt.optionString = "-Xcheck:jni";
-        mOptions.add(opt);
+      ALOGD("CheckJNI is %s\n", checkJni ? "ON" : "OFF");
+      if (checkJni) {
+          /* extended JNI checking */
+          opt.optionString = "-Xcheck:jni";
+          mOptions.add(opt);
 
-        /* set a cap on JNI global references */
-        opt.optionString = "-Xjnigreflimit:2000";
-        mOptions.add(opt);
+          /* set a cap on JNI global references */
+          opt.optionString = "-Xjnigreflimit:2000";
+          mOptions.add(opt);
 
-        /* with -Xcheck:jni, this provides a JNI function call trace */
-        //opt.optionString = "-verbose:jni";
-        //mOptions.add(opt);
+          /* with -Xcheck:jni, this provides a JNI function call trace */
+          //opt.optionString = "-verbose:jni";
+          //mOptions.add(opt);
+      }
     }
 
     char lockProfThresholdBuf[sizeof("-Xlockprofthreshold:") + sizeof(propBuf)];
@@ -807,7 +811,7 @@ char* AndroidRuntime::toSlashClassName(const char* className)
  * Passes the main function two arguments, the class name and the specified
  * options string.
  */
-void AndroidRuntime::start(const char* className, const char* options)
+void AndroidRuntime::start(const char* className, const char* options, bool zygote)
 {
     ALOGD("\n>>>>>> AndroidRuntime START %s <<<<<<\n",
             className != NULL ? className : "(unknown)");
@@ -840,7 +844,7 @@ void AndroidRuntime::start(const char* className, const char* options)
 
     /* start the virtual machine */
     JNIEnv* env;
-    if (startVm(&mJavaVM, &env) != 0) {
+    if (startVm(&mJavaVM, &env, zygote) != 0) {
         return;
     }
     onVmCreated(env);
diff --git a/include/android_runtime/AndroidRuntime.h b/include/android_runtime/AndroidRuntime.h
index 0b3ce9a..e8e869d 100644
--- a/include/android_runtime/AndroidRuntime.h
+++ b/include/android_runtime/AndroidRuntime.h
@@ -64,7 +64,7 @@ public:
 
     int addVmArguments(int argc, const char* const argv[]);
 
-    void start(const char *classname, const char* options);
+    void start(const char *classname, const char* options, bool zygote);
 
     void exit(int code);
 
@@ -116,7 +116,7 @@ public:
 private:
     static int startReg(JNIEnv* env);
     void parseExtraOpts(char* extraOptsBuf);
-    int startVm(JavaVM** pJavaVM, JNIEnv** pEnv);
+    int startVm(JavaVM** pJavaVM, JNIEnv** pEnv, bool zygote);
 
     Vector<JavaVMOption> mOptions;
     bool mExitWithoutCleanup;