Debug stub: suspend/resume threads on Linux

src/trusted/debug_stub/posix/thread_impl.cc

Index: src/trusted/debug_stub/posix/thread_impl.cc
diff --git a/src/trusted/debug_stub/posix/thread_impl.cc b/src/trusted/debug_stub/posix/thread_impl.cc
index 45e68c4316cc9abaff3c718d90d5337b0982ad7c..d07e3fb928b70bb45b4dd0c9000fe675842c1898 100644
--- a/src/trusted/debug_stub/posix/thread_impl.cc
+++ b/src/trusted/debug_stub/posix/thread_impl.cc
@@ -12,7 +12,9 @@
 #include "native_client/src/trusted/port/mutex.h"
 #include "native_client/src/trusted/port/platform.h"
 #include "native_client/src/trusted/port/thread.h"
+#include "native_client/src/trusted/service_runtime/nacl_app_thread.h"  // only for NaClAppThread->nap
 #include "native_client/src/trusted/service_runtime/nacl_signal.h"
+#include "native_client/src/trusted/service_runtime/sel_ldr.h"
 
 /*
  * Define the OS specific portions of IThread interface.
@@ -39,6 +41,8 @@ static IThread::ThreadMap_t *ThreadGetMap() {
   return map_;
 }
 
+volatile int signaled_ = 0;
+
 class Thread : public IThread {
  public:
   Thread(uint32_t id, struct NaClAppThread *natp)
@@ -103,6 +107,9 @@ class Thread : public IThread {
     struct NaClSignalContext context;
     NaClSignalContextFromHandler(&context, ucontext);
     if (NaClSignalContextIsUntrusted(&context)) {
+      while (__sync_lock_test_and_set(&signaled_, 1)) {
+        usleep(100);
+      }
       uint32_t thread_id = IPlatform::GetCurrentThread();
       Thread* thread = static_cast<Thread*>(Acquire(thread_id));
       State old_state = thread->state_;
@@ -115,6 +122,7 @@ class Thread : public IThread {
       NaClSignalContextToHandler(ucontext, &thread->context_);
       thread->state_ = old_state;
       Release(thread);
+      __sync_lock_release(&signaled_);
       return NACL_SIGNAL_RETURN;
     } else {
       // Do not attempt to debug crashes in trusted code.
@@ -180,6 +188,24 @@ void IThread::SetExceptionCatch(IThread::CatchFunc_t func, void *cookie) {
   s_CatchCookie = cookie;
 }
 
+void IThread::SuspendAll(uint32_t signaled_id) {
+  if (signaled_id == 0) {
+    NaClLog(LOG_FATAL, "IThread::SuspendAll: not implemented\n");
+  } else {
+    Thread* thread = static_cast<Thread*>(Acquire(signaled_id));
+    NaClUntrustedThreadsSuspendAll2(thread->natp_->nap, thread->natp_);
+    Release(thread);
+  }
+}
 
-}  // End of port namespace
+void IThread::ResumeAll(uint32_t signaled_id) {
+  if (signaled_id == 0) {
+    NaClLog(LOG_FATAL, "IThread::ResumeAll: not implemented\n");
+  } else {
+    Thread* thread = static_cast<Thread*>(Acquire(signaled_id));
+    NaClUntrustedThreadsResumeAll2(thread->natp_->nap, thread->natp_);
+    Release(thread);
+  }
+}
 
+}  // namespace port