Tell GDB about the threads, allow switching between them when single stepping

GdbStub.cpp

@@ -331,16 +331,37 @@ void GdbStub::handleQuery() {
 	else if(strncmp(query, "Xfer:features:read:target.xml:",
 					   strlen("Xfer:features:read:target.xml:")) == 0)
 		sendReply(target_xml);
+	else if (strncmp(query, "fThreadInfo", strlen("fThreadInfo")) == 0) {
+		auto list = ctu->tm.thread_list();
+		char tmp[17] = {0};
+		string val = "m";
+		for (auto it = list.begin(); it != list.end(); it++) {
+			if (!(*it)->started)
+				continue;
+			memset(tmp, 0, sizeof(tmp));
+			sprintf(tmp, "%x", (*it)->id);
+			val += (char*)tmp;
+			val += ",";
+		}
+		val.pop_back();
+		sendReply(val.c_str());
+	} else if (strncmp(query, "sThreadInfo", strlen("sThreadInfo")) == 0)
+		sendReply("l");
 	else
 		sendReply("");
 }
 
 void GdbStub::handleSetThread() {
-	if(memcmp(commandBuffer, "Hg0", 3) == 0 || memcmp(commandBuffer, "Hc-1", 4) == 0 ||
-		memcmp(commandBuffer, "Hc0", 4) == 0 || memcmp(commandBuffer, "Hc1", 4) == 0)
-		return sendReply("OK");
-
-	sendReply("E01");
+	// TODO: allow actually changing threads now :|
+	if(memcmp(commandBuffer, "Hg", 2) == 0 || memcmp(commandBuffer, "Hc", 2) == 0) {
+		// Get thread id
+		if (commandBuffer[2] != '-') {
+			int threadid = (int)hexToInt(commandBuffer + 2, strlen((char*)commandBuffer + 2));
+			ctu->tm.setCurrent(threadid);
+		}
+		sendReply("OK");
+	} else
+		sendReply("E01");
 }
 
 auto stringFromFormat(const char* format, ...) {
@@ -364,7 +385,10 @@ void GdbStub::sendSignal(uint32_t signal) {
 	intToGdbHex(sp, reg(31));
 	intToGdbHex(pc, reg(32));
 
+	auto curthread = ctu->tm.current();
 	string buffer = stringFromFormat("T%02x%02x:%.16s;%02x:%.16s;", latestSignal, 32, pc, 31, sp);
+	if (curthread != nullptr)
+		buffer += stringFromFormat("thread:%x;", curthread->id);
 	LOG_DEBUG(GdbStub, "Response: %s", buffer.c_str());
 	sendReply(buffer.c_str());
 }
@@ -669,6 +693,18 @@ void GdbStub::removeBreakpoint() {
 	sendReply("OK");
 }
 
+void GdbStub::isThreadAlive() {
+	int threadid = (int)hexToInt(commandBuffer + 1, strlen((char*)commandBuffer + 1));
+	auto threads = ctu->tm.thread_list();
+	for (auto it = threads.begin(); it != threads.end(); it++) {
+		if ((*it)->id == threadid) {
+			sendReply("OK");
+			return;
+		}
+	}
+	sendReply("E01");
+}
+
 void GdbStub::handlePacket() {
 	if(!isDataAvailable())
 		return;
@@ -719,6 +755,9 @@ void GdbStub::handlePacket() {
 	case 'z':
 		removeBreakpoint();
 		break;
+	case 'T':
+		isThreadAlive();
+		break;
 	case 'Z':
 		addBreakpoint();
 		break;

GdbStub.h

@@ -52,6 +52,7 @@ private:
 	void writeRegisters();
 	void readMemory();
 	void writeMemory();
+	void isThreadAlive();
 	void step();
 	void _continue();
 	bool commitBreakpoint(BreakpointType type, gptr addr, uint32_t len);

ThreadManager.cpp

@@ -2,7 +2,7 @@
 
 #define INSN_PER_SLICE 1000000
 
-Thread::Thread(Ctu *_ctu, int _id) : ctu(_ctu), id(_id) {
+Thread::Thread(Ctu *_ctu, int _id) : ctu(_ctu), id(_id), started(false) {
 	active = false;
 	memset(&regs, 0, sizeof(ThreadRegisters));
 
@@ -42,6 +42,7 @@ void Thread::resume(function<void()> cb) {
 
 	if(cb != nullptr)
 		onWake(cb);
+	started = true;
 	active = true;
 	ctu->tm.enqueue(id);
 }
@@ -269,6 +270,26 @@ shared_ptr<Thread> ThreadManager::last() {
 	return _last;
 }
 
+bool ThreadManager::setCurrent(int id) {
+	auto thread = threads.find(id);
+	if (thread == threads.end())
+		return false;
+	if(_current != nullptr) {
+		_current->freeze();
+		_last = _current;
+	}
+	_current = thread->second;
+	_current->thaw();
+	return true;
+}
+
+
 bool ThreadManager::isNative(int id) {
 	return nativeThreads.find(id) != nativeThreads.end();
 }
+
+vector<shared_ptr<Thread>> ThreadManager::thread_list() {
+	vector<shared_ptr<Thread>> vals;
+	transform(threads.begin(), threads.end(), back_inserter(vals), [](auto val){return val.second;} );
+	return vals;
+}

ThreadManager.h

@@ -14,6 +14,7 @@ public:
 	void onWake(function<void()> cb);
 
 	int id;
+	bool started;
 	ghandle handle;
 	bool active;
 	ThreadRegisters regs;
@@ -54,9 +55,11 @@ public:
 	void terminate(int id);
 	shared_ptr<Thread> current();
 	shared_ptr<Thread> last();
-
+	bool setCurrent(int id);
 	bool switched;
 
+	vector<shared_ptr<Thread>> thread_list();
+
 private:
 	void tryRunNative();
 	bool isNative(int id);