In ProfilerSignalHandler ensure that thread we are trying to sample locked the isolate.

src/platform-linux.cc

Index: src/platform-linux.cc
diff --git a/src/platform-linux.cc b/src/platform-linux.cc
index e2ab9d81b40c78064733a7ae7fe6a5f9c24ada87..1ecd8fc81b08b05a7dad8f2495255ec37db95091 100644
--- a/src/platform-linux.cc
+++ b/src/platform-linux.cc
@@ -853,6 +853,11 @@ static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
     // We require a fully initialized and entered isolate.
     return;
   }
+  if (v8::Locker::IsActive() &&
+      !isolate->thread_manager()->IsLockedByCurrentThread()) {
+    return;
+  }
+
   Sampler* sampler = isolate->logger()->sampler();
   if (sampler == NULL || !sampler->IsActive()) return;