ActivityThread: Attempt to attach agent with app's classloader

Try to use the app's (main) classloader when an attach-agent request
is handled. If that fails, retry without a classloader.

Add bind-application-time flag to ProfilerInfo. Use the flag to have
a second attach-agent point on app startup. Add --attach-agent-bind
to cmd activity start to expose the difference between pre-bind and
bind-time attaching.

Bug: 70901841
Test: m
Test: cts-tradefed run commandAndExit cts-dev -m CtsJvmtiAttachingHostTestCases
Change-Id: I21698ec3be43a6d095d577100b2adfb22daca7d5

4 files changed, 73 insertions, 15 deletions

diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index 7bda37e09f41..2ecd3120345d 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -1832,9 +1832,11 @@ public final class ActivityThread {
                     handleLocalVoiceInteractionStarted((IBinder) ((SomeArgs) msg.obj).arg1,
                             (IVoiceInteractor) ((SomeArgs) msg.obj).arg2);
                     break;
-                case ATTACH_AGENT:
-                    handleAttachAgent((String) msg.obj);
+                case ATTACH_AGENT: {
+                    Application app = getApplication();
+                    handleAttachAgent((String) msg.obj, app != null ? app.mLoadedApk : null);
                     break;
+                }
                 case APPLICATION_INFO_CHANGED:
                     mUpdatingSystemConfig = true;
                     try {
@@ -3119,11 +3121,23 @@ public final class ActivityThread {
         }
     }
 
-    static final void handleAttachAgent(String agent) {
+    private static boolean attemptAttachAgent(String agent, ClassLoader classLoader) {
         try {
-            VMDebug.attachAgent(agent);
+            VMDebug.attachAgent(agent, classLoader);
+            return true;
         } catch (IOException e) {
-            Slog.e(TAG, "Attaching agent failed: " + agent);
+            Slog.e(TAG, "Attaching agent with " + classLoader + " failed: " + agent);
+            return false;
+        }
+    }
+
+    static void handleAttachAgent(String agent, LoadedApk loadedApk) {
+        ClassLoader classLoader = loadedApk != null ? loadedApk.getClassLoader() : null;
+        if (attemptAttachAgent(agent, classLoader)) {
+            return;
+        }
+        if (classLoader != null) {
+            attemptAttachAgent(agent, null);
         }
     }
 
@@ -5441,12 +5455,16 @@ public final class ActivityThread {
         mCompatConfiguration = new Configuration(data.config);
 
         mProfiler = new Profiler();
+        String agent = null;
         if (data.initProfilerInfo != null) {
             mProfiler.profileFile = data.initProfilerInfo.profileFile;
             mProfiler.profileFd = data.initProfilerInfo.profileFd;
             mProfiler.samplingInterval = data.initProfilerInfo.samplingInterval;
             mProfiler.autoStopProfiler = data.initProfilerInfo.autoStopProfiler;
             mProfiler.streamingOutput = data.initProfilerInfo.streamingOutput;
+            if (data.initProfilerInfo.attachAgentDuringBind) {
+                agent = data.initProfilerInfo.agent;
+            }
         }
 
         // send up app name; do this *before* waiting for debugger
@@ -5496,6 +5514,10 @@ public final class ActivityThread {
 
         data.loadedApk = getLoadedApkNoCheck(data.appInfo, data.compatInfo);
 
+        if (agent != null) {
+            handleAttachAgent(agent, data.loadedApk);
+        }
+
         /**
          * Switch this process to density compatibility mode if needed.
          */
diff --git a/core/java/android/app/ProfilerInfo.java b/core/java/android/app/ProfilerInfo.java
index fad4798e3a3e..044b78003bd7 100644
--- a/core/java/android/app/ProfilerInfo.java
+++ b/core/java/android/app/ProfilerInfo.java
@@ -54,14 +54,24 @@ public class ProfilerInfo implements Parcelable {
      */
     public final String agent;
 
+    /**
+     * Whether the {@link agent} should be attached early (before bind-application) or during
+     * bind-application. Agents attached prior to binding cannot be loaded from the app's APK
+     * directly and must be given as an absolute path (or available in the default LD_LIBRARY_PATH).
+     * Agents attached during bind-application will miss early setup (e.g., resource initialization
+     * and classloader generation), but are searched in the app's library search path.
+     */
+    public final boolean attachAgentDuringBind;
+
     public ProfilerInfo(String filename, ParcelFileDescriptor fd, int interval, boolean autoStop,
-            boolean streaming, String agent) {
+            boolean streaming, String agent, boolean attachAgentDuringBind) {
         profileFile = filename;
         profileFd = fd;
         samplingInterval = interval;
         autoStopProfiler = autoStop;
         streamingOutput = streaming;
         this.agent = agent;
+        this.attachAgentDuringBind = attachAgentDuringBind;
     }
 
     public ProfilerInfo(ProfilerInfo in) {
@@ -71,6 +81,7 @@ public class ProfilerInfo implements Parcelable {
         autoStopProfiler = in.autoStopProfiler;
         streamingOutput = in.streamingOutput;
         agent = in.agent;
+        attachAgentDuringBind = in.attachAgentDuringBind;
     }
 
     /**
@@ -109,6 +120,7 @@ public class ProfilerInfo implements Parcelable {
         out.writeInt(autoStopProfiler ? 1 : 0);
         out.writeInt(streamingOutput ? 1 : 0);
         out.writeString(agent);
+        out.writeBoolean(attachAgentDuringBind);
     }
 
     public static final Parcelable.Creator<ProfilerInfo> CREATOR =
@@ -131,5 +143,6 @@ public class ProfilerInfo implements Parcelable {
         autoStopProfiler = in.readInt() != 0;
         streamingOutput = in.readInt() != 0;
         agent = in.readString();
+        attachAgentDuringBind = in.readBoolean();
     }
 }
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 6cdf0712c7c1..002381a5a3f0 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -7012,15 +7012,22 @@ public class ActivityManagerService extends IActivityManager.Stub
             }
 
             ProfilerInfo profilerInfo = null;
-            String agent = null;
+            String preBindAgent = null;
             if (mProfileApp != null && mProfileApp.equals(processName)) {
                 mProfileProc = app;
-                profilerInfo = (mProfilerInfo != null && mProfilerInfo.profileFile != null) ?
-                        new ProfilerInfo(mProfilerInfo) : null;
-                agent = mProfilerInfo != null ? mProfilerInfo.agent : null;
+                if (mProfilerInfo != null) {
+                    // Send a profiler info object to the app if either a file is given, or
+                    // an agent should be loaded at bind-time.
+                    boolean needsInfo = mProfilerInfo.profileFile != null
+                            || mProfilerInfo.attachAgentDuringBind;
+                    profilerInfo = needsInfo ? new ProfilerInfo(mProfilerInfo) : null;
+                    if (!mProfilerInfo.attachAgentDuringBind) {
+                        preBindAgent = mProfilerInfo.agent;
+                    }
+                }
             } else if (app.instr != null && app.instr.mProfileFile != null) {
                 profilerInfo = new ProfilerInfo(app.instr.mProfileFile, null, 0, false, false,
-                        null);
+                        null, false);
             }
 
             boolean enableTrackAllocation = false;
@@ -7087,8 +7094,8 @@ public class ActivityManagerService extends IActivityManager.Stub
 
             // If we were asked to attach an agent on startup, do so now, before we're binding
             // application code.
-            if (agent != null) {
-                thread.attachAgent(agent);
+            if (preBindAgent != null) {
+                thread.attachAgent(preBindAgent);
             }
 
             checkTime(startTime, "attachApplicationLocked: immediately before bindApplication");
diff --git a/services/core/java/com/android/server/am/ActivityManagerShellCommand.java b/services/core/java/com/android/server/am/ActivityManagerShellCommand.java
index 8488e526eba9..a7ace21607b5 100644
--- a/services/core/java/com/android/server/am/ActivityManagerShellCommand.java
+++ b/services/core/java/com/android/server/am/ActivityManagerShellCommand.java
@@ -114,6 +114,7 @@ final class ActivityManagerShellCommand extends ShellCommand {
     private boolean mAutoStop;
     private boolean mStreaming;   // Streaming the profiling output to a file.
     private String mAgent;  // Agent to attach on startup.
+    private boolean mAttachAgentDuringBind;  // Whether agent should be attached late.
     private int mDisplayId;
     private int mStackId;
     private int mTaskId;
@@ -295,7 +296,21 @@ final class ActivityManagerShellCommand extends ShellCommand {
                 } else if (opt.equals("--streaming")) {
                     mStreaming = true;
                 } else if (opt.equals("--attach-agent")) {
+                    if (mAgent != null) {
+                        cmd.getErrPrintWriter().println(
+                                "Multiple --attach-agent(-bind) not supported");
+                        return false;
+                    }
+                    mAgent = getNextArgRequired();
+                    mAttachAgentDuringBind = false;
+                } else if (opt.equals("--attach-agent-bind")) {
+                    if (mAgent != null) {
+                        cmd.getErrPrintWriter().println(
+                                "Multiple --attach-agent(-bind) not supported");
+                        return false;
+                    }
                     mAgent = getNextArgRequired();
+                    mAttachAgentDuringBind = true;
                 } else if (opt.equals("-R")) {
                     mRepeat = Integer.parseInt(getNextArgRequired());
                 } else if (opt.equals("-S")) {
@@ -381,7 +396,7 @@ final class ActivityManagerShellCommand extends ShellCommand {
                     }
                 }
                 profilerInfo = new ProfilerInfo(mProfileFile, fd, mSamplingInterval, mAutoStop,
-                        mStreaming, mAgent);
+                        mStreaming, mAgent, mAttachAgentDuringBind);
             }
 
             pw.println("Starting: " + intent);
@@ -755,7 +770,7 @@ final class ActivityManagerShellCommand extends ShellCommand {
                 return -1;
             }
             profilerInfo = new ProfilerInfo(profileFile, fd, mSamplingInterval, false, mStreaming,
-                    null);
+                    null, false);
         }
 
         try {
@@ -2679,6 +2694,7 @@ final class ActivityManagerShellCommand extends ShellCommand {
             pw.println("          (use with --start-profiler)");
             pw.println("      -P <FILE>: like above, but profiling stops when app goes idle");
             pw.println("      --attach-agent <agent>: attach the given agent before binding");
+            pw.println("      --attach-agent-bind <agent>: attach the given agent during binding");
             pw.println("      -R: repeat the activity launch <COUNT> times.  Prior to each repeat,");
             pw.println("          the top activity will be finished.");
             pw.println("      -S: force stop the target app before starting the activity");