diff --git a/src/os/linux/vm/os_linux.cpp b/src/os/linux/vm/os_linux.cpp
index 8635a3d411f2488c9aa095649022348cdad43811..e3e117eb5fbe1b096d06fbfd35de61311d30d119 100644
--- a/src/os/linux/vm/os_linux.cpp
+++ b/src/os/linux/vm/os_linux.cpp
@@ -2597,10 +2597,14 @@ get_stack_bounds(uintptr_t *bottom, uintptr_t *top)
 // where we're going to put our guard pages, truncate the mapping at
 // that point by munmap()ping it.  This ensures that when we later
 // munmap() the guard pages we don't leave a hole in the stack
-// mapping.
+// mapping. This only affects the main/initial thread, but guard
+// against future OS changes
 bool os::create_stack_guard_pages(char* addr, size_t size) {
   uintptr_t stack_extent, stack_base;
-  if (get_stack_bounds(&stack_extent, &stack_base)) {
+  bool chk_bounds = NOT_DEBUG(os::Linux::is_initial_thread()) DEBUG_ONLY(true);
+  if (chk_bounds && get_stack_bounds(&stack_extent, &stack_base)) {
+      assert(os::Linux::is_initial_thread(),
+           "growable stack in non-initial thread");
     if (stack_extent < (uintptr_t)addr)
       ::munmap((void*)stack_extent, (uintptr_t)addr - stack_extent);
   }
@@ -2609,10 +2613,15 @@ bool os::create_stack_guard_pages(char* addr, size_t size) {
 }
 
 // If this is a growable mapping, remove the guard pages entirely by
-// munmap()ping them.  If not, just call uncommit_memory().
+// munmap()ping them.  If not, just call uncommit_memory(). This only
+// affects the main/initial thread, but guard against future OS changes
 bool os::remove_stack_guard_pages(char* addr, size_t size) {
   uintptr_t stack_extent, stack_base;
-  if (get_stack_bounds(&stack_extent, &stack_base)) {
+  bool chk_bounds = NOT_DEBUG(os::Linux::is_initial_thread()) DEBUG_ONLY(true);
+  if (chk_bounds && get_stack_bounds(&stack_extent, &stack_base)) {
+      assert(os::Linux::is_initial_thread(),
+           "growable stack in non-initial thread");
+
     return ::munmap(addr, size) == 0;
   }
 
diff --git a/src/share/vm/oops/instanceKlass.cpp b/src/share/vm/oops/instanceKlass.cpp
index ff8077f1bcd178446e199507dd8d90535452cf27..bfdf1d19598cdeb2a3bbd0aa796f1108323e0058 100644
--- a/src/share/vm/oops/instanceKlass.cpp
+++ b/src/share/vm/oops/instanceKlass.cpp
@@ -382,7 +382,7 @@ void instanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
       const char* desc = "Could not initialize class ";
       const char* className = this_oop->external_name();
       size_t msglen = strlen(desc) + strlen(className) + 1;
-      char* message = NEW_C_HEAP_ARRAY(char, msglen);
+      char* message = NEW_RESOURCE_ARRAY(char, msglen);
       if (NULL == message) {
         // Out of memory: can't create detailed error message
         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);