8189170: Add option to disable stack overflow checking in primordial thread...

8189170: Add option to disable stack overflow checking in primordial thread for use with JNI_CreateJavaJVM
Reviewed-by: dcubed

src/os/aix/vm/os_aix.cpp

 /*
- * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2012, 2014 SAP AG. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -410,7 +410,7 @@ void os::Aix::query_multipage_support() {
   // thread (because primordial thread's stack may have different page size than
   // pthread thread stacks). Running a VM on the primordial thread won't work for a
   // number of reasons so we may just as well guarantee it here
-  guarantee(!os::Aix::is_primordial_thread(), "Must not be called for primordial thread");
+  guarantee(!os::is_primordial_thread(), "Must not be called for primordial thread");
 
   // query stack page size
   {
@@ -3835,7 +3835,7 @@ void os::init(void) {
 
   ThreadCritical::initialize();
 
-  // Main_thread points to the aboriginal thread.
+  // _main_thread points to the thread that created/loaded the JVM.
   Aix::_main_thread = pthread_self();
 
   initial_time_count = os::elapsed_counter();
@@ -4511,7 +4511,7 @@ void os::pause() {
   }
 }
 
-bool os::Aix::is_primordial_thread() {
+bool os::is_primordial_thread(void) {
   if (pthread_self() == (pthread_t)1) {
     return true;
   } else {
@@ -4646,7 +4646,7 @@ static void query_stack_dimensions(address* p_stack_base, size_t* p_stack_size)
 
   // This only works when invoked on a pthread. As we agreed not to use
   // primordial threads anyway, I assert here
-  guarantee(!os::Aix::is_primordial_thread(), "not allowed on the primordial thread");
+  guarantee(!os::is_primordial_thread(), "not allowed on the primordial thread");
 
   // information about this api can be found (a) in the pthread.h header and
   // (b) in http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.basetechref/doc/basetrf1/pthread_getthrds_np.htm

src/os/aix/vm/os_aix.hpp

 /*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2013 SAP AG. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -170,12 +170,6 @@ class Aix {
   // Given an address, returns the size of the page backing that address
   static size_t query_pagesize(void* p);
 
-  // Return `true' if the calling thread is the primordial thread. The
-  // primordial thread is the thread which contains the main function,
-  // *not* necessarily the thread which initialized the VM by calling
-  // JNI_CreateJavaVM.
-  static bool is_primordial_thread(void);
-
   static int page_size(void) {
     assert(_page_size != -1, "not initialized");
     return _page_size;

src/os/bsd/vm/os_bsd.cpp

 /*
- * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -3611,7 +3611,7 @@ void os::init(void) {
 
   Bsd::initialize_system_info();
 
-  // main_thread points to the aboriginal thread
+  // _main_thread points to the thread that created/loaded the JVM.
   Bsd::_main_thread = pthread_self();
 
   Bsd::clock_init();

src/os/bsd/vm/os_bsd.hpp

 /*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -92,7 +92,6 @@ class Bsd {
 
   static void hotspot_sigmask(Thread* thread);
 
-  static bool is_initial_thread(void);
   static pid_t gettid();
 
   static int page_size(void)                                        { return _page_size; }

src/os/linux/vm/os_linux.cpp

 /*
- * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -946,8 +946,8 @@ bool os::create_attached_thread(JavaThread* thread) {
     }
   }
 
-  if (os::Linux::is_initial_thread()) {
-    // If current thread is initial thread, its stack is mapped on demand,
+  if (os::is_primordial_thread()) {
+    // If current thread is primordial thread, its stack is mapped on demand,
     // see notes about MAP_GROWSDOWN. Here we try to force kernel to map
     // the entire stack region to avoid SEGV in stack banging.
     // It is also useful to get around the heap-stack-gap problem on SuSE
@@ -1032,21 +1032,24 @@ extern "C" Thread* get_thread() {
 }
 
 //////////////////////////////////////////////////////////////////////////////
-// initial thread
+// primordial thread
 
-// Check if current thread is the initial thread, similar to Solaris thr_main.
-bool os::Linux::is_initial_thread(void) {
+// Check if current thread is the primordial thread, similar to Solaris thr_main.
+bool os::is_primordial_thread(void) {
   char dummy;
   // If called before init complete, thread stack bottom will be null.
   // Can be called if fatal error occurs before initialization.
-  if (initial_thread_stack_bottom() == NULL) return false;
-  assert(initial_thread_stack_bottom() != NULL &&
-         initial_thread_stack_size()   != 0,
-         "os::init did not locate initial thread's stack region");
-  if ((address)&dummy >= initial_thread_stack_bottom() &&
-      (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size())
+  if (os::Linux::initial_thread_stack_bottom() == NULL) return false;
+  assert(os::Linux::initial_thread_stack_bottom() != NULL &&
+         os::Linux::initial_thread_stack_size()   != 0,
+         "os::init did not locate primordial thread's stack region");
+  if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() &&
+      (address)&dummy < os::Linux::initial_thread_stack_bottom() +
+                        os::Linux::initial_thread_stack_size()) {
        return true;
-  else return false;
+  } else {
+       return false;
+  }
 }
 
 // Find the virtual memory area that contains addr
@@ -1073,7 +1076,7 @@ static bool find_vma(address addr, address* vma_low, address* vma_high) {
   return false;
 }
 
-// Locate initial thread stack. This special handling of initial thread stack
+// Locate primordial thread stack. This special handling of primordial thread stack
 // is needed because pthread_getattr_np() on most (all?) Linux distros returns
 // bogus value for the primordial process thread. While the launcher has created
 // the VM in a new thread since JDK 6, we still have to allow for the use of the
@@ -1097,7 +1100,10 @@ void os::Linux::capture_initial_stack(size_t max_size) {
   // 6308388: a bug in ld.so will relocate its own .data section to the
   //   lower end of primordial stack; reduce ulimit -s value a little bit
   //   so we won't install guard page on ld.so's data section.
+  //   But ensure we don't underflow the stack size - allow 1 page spare
+  if (stack_size >= (size_t)(3 * page_size())) {
     stack_size -= 2 * page_size();
+  }
 
   // Try to figure out where the stack base (top) is. This is harder.
   //
@@ -1218,16 +1224,16 @@ void os::Linux::capture_initial_stack(size_t max_size) {
 
       if (i != 28 - 2) {
          assert(false, "Bad conversion from /proc/self/stat");
-         // product mode - assume we are the initial thread, good luck in the
+         // product mode - assume we are the primordial thread, good luck in the
          // embedded case.
-         warning("Can't detect initial thread stack location - bad conversion");
+         warning("Can't detect primordial thread stack location - bad conversion");
          stack_start = (uintptr_t) &rlim;
       }
     } else {
       // For some reason we can't open /proc/self/stat (for example, running on
       // FreeBSD with a Linux emulator, or inside chroot), this should work for
       // most cases, so don't abort:
-      warning("Can't detect initial thread stack location - no /proc/self/stat");
+      warning("Can't detect primordial thread stack location - no /proc/self/stat");
       stack_start = (uintptr_t) &rlim;
     }
   }
@@ -1247,7 +1253,7 @@ void os::Linux::capture_initial_stack(size_t max_size) {
     stack_top = (uintptr_t)high;
   } else {
     // failed, likely because /proc/self/maps does not exist
-    warning("Can't detect initial thread stack location - find_vma failed");
+    warning("Can't detect primordial thread stack location - find_vma failed");
     // best effort: stack_start is normally within a few pages below the real
     // stack top, use it as stack top, and reduce stack size so we won't put
     // guard page outside stack.
@@ -3066,11 +3072,11 @@ address get_stack_commited_bottom(address bottom, size_t size) {
 // 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. This only affects the main/initial thread
+// mapping. This only affects the main/primordial thread
 
 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
 
-  if (os::Linux::is_initial_thread()) {
+  if (os::is_primordial_thread()) {
     // As we manually grow stack up to bottom inside create_attached_thread(),
     // it's likely that os::Linux::initial_thread_stack_bottom is mapped and
     // we don't need to do anything special.
@@ -3095,14 +3101,14 @@ bool os::pd_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(). This only
-// affects the main/initial thread, but guard against future OS changes
-// It's safe to always unmap guard pages for initial thread because we
-// always place it right after end of the mapped region
+// affects the main/primordial thread, but guard against future OS changes.
+// It's safe to always unmap guard pages for primordial thread because we
+// always place it right after end of the mapped region.
 
 bool os::remove_stack_guard_pages(char* addr, size_t size) {
   uintptr_t stack_extent, stack_base;
 
-  if (os::Linux::is_initial_thread()) {
+  if (os::is_primordial_thread()) {
     return ::munmap(addr, size) == 0;
   }
 
@@ -4877,10 +4883,9 @@ const char* os::exception_name(int exception_code, char* buf, size_t size) {
   }
 }
 
-// this is called _before_ the most of global arguments have been parsed
+// this is called _before_ most of the global arguments have been parsed
 void os::init(void) {
   char dummy;   /* used to get a guess on initial stack address */
-//  first_hrtime = gethrtime();
 
   // With LinuxThreads the JavaMain thread pid (primordial thread)
   // is different than the pid of the java launcher thread.
@@ -4907,7 +4912,7 @@ void os::init(void) {
 
   Linux::initialize_system_info();
 
-  // main_thread points to the aboriginal thread
+  // _main_thread points to the thread that created/loaded the JVM.
   Linux::_main_thread = pthread_self();
 
   Linux::clock_init();

src/os/linux/vm/os_linux.hpp

 /*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -137,7 +137,6 @@ class Linux {
 
   static address   initial_thread_stack_bottom(void)                { return _initial_thread_stack_bottom; }
   static uintptr_t initial_thread_stack_size(void)                  { return _initial_thread_stack_size; }
-  static bool is_initial_thread(void);
 
   static int page_size(void)                                        { return _page_size; }
   static void set_page_size(int val)                                { _page_size = val; }

src/os/solaris/vm/os_solaris.cpp

 /*
- * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -200,17 +200,21 @@ static inline stack_t get_stack_info() {
   return st;
 }
 
-address os::current_stack_base() {
+bool os::is_primordial_thread(void) {
   int r = thr_main() ;
   guarantee (r == 0 || r == 1, "CR6501650 or CR6493689") ;
-  bool is_primordial_thread = r;
+  return r == 1;
+}
+
+address os::current_stack_base() {
+  bool _is_primordial_thread = is_primordial_thread();
 
   // Workaround 4352906, avoid calls to thr_stksegment by
   // thr_main after the first one (it looks like we trash
   // some data, causing the value for ss_sp to be incorrect).
-  if (!is_primordial_thread || os::Solaris::_main_stack_base == NULL) {
+  if (!_is_primordial_thread || os::Solaris::_main_stack_base == NULL) {
     stack_t st = get_stack_info();
-    if (is_primordial_thread) {
+    if (_is_primordial_thread) {
       // cache initial value of stack base
       os::Solaris::_main_stack_base = (address)st.ss_sp;
     }
@@ -224,9 +228,7 @@ address os::current_stack_base() {
 size_t os::current_stack_size() {
   size_t size;
 
-  int r = thr_main() ;
-  guarantee (r == 0 || r == 1, "CR6501650 or CR6493689") ;
-  if(!r) {
+  if (!is_primordial_thread()) {
     size = get_stack_info().ss_size;
   } else {
     struct rlimit limits;
@@ -1277,9 +1279,7 @@ void _handle_uncaught_cxx_exception() {
 
 // First crack at OS-specific initialization, from inside the new thread.
 void os::initialize_thread(Thread* thr) {
-  int r = thr_main() ;
-  guarantee (r == 0 || r == 1, "CR6501650 or CR6493689") ;
-  if (r) {
+  if (is_primordial_thread()) {
     JavaThread* jt = (JavaThread *)thr;
     assert(jt != NULL,"Sanity check");
     size_t stack_size;
@@ -4904,6 +4904,7 @@ void os::init(void) {
   // (Solaris only) this switches to calls that actually do locking.
   ThreadCritical::initialize();
 
+  // main_thread points to the thread that created/loaded the JVM.
   main_thread = thr_self();
 
   // Constant minimum stack size allowed. It must be at least

src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp

 /*
- * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2012, 2015 SAP AG. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -510,8 +510,8 @@ size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
 //    pthread_attr_getstack()
 
 static void current_stack_region(address * bottom, size_t * size) {
-  if (os::Linux::is_initial_thread()) {
-     // initial thread needs special handling because pthread_getattr_np()
+  if (os::is_primordial_thread()) {
+     // primordial thread needs special handling because pthread_getattr_np()
      // may return bogus value.
     *bottom = os::Linux::initial_thread_stack_bottom();
     *size   = os::Linux::initial_thread_stack_size();

src/os_cpu/linux_sparc/vm/os_linux_sparc.cpp

 /*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -162,8 +162,8 @@ address os::current_stack_pointer() {
 }
 
 static void current_stack_region(address* bottom, size_t* size) {
-  if (os::Linux::is_initial_thread()) {
-    // initial thread needs special handling because pthread_getattr_np()
+  if (os::is_primordial_thread()) {
+    // primordial thread needs special handling because pthread_getattr_np()
     // may return bogus value.
     *bottom = os::Linux::initial_thread_stack_bottom();
     *size = os::Linux::initial_thread_stack_size();

src/os_cpu/linux_x86/vm/os_linux_x86.cpp

 /*
- * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -712,8 +712,8 @@ size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
 //    pthread_attr_getstack()
 
 static void current_stack_region(address * bottom, size_t * size) {
-  if (os::Linux::is_initial_thread()) {
-     // initial thread needs special handling because pthread_getattr_np()
+  if (os::is_primordial_thread()) {
+     // primordial thread needs special handling because pthread_getattr_np()
      // may return bogus value.
      *bottom = os::Linux::initial_thread_stack_bottom();
      *size   = os::Linux::initial_thread_stack_size();

src/os_cpu/linux_zero/vm/os_linux_zero.cpp

 /*
- * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2007, 2008, 2009, 2010 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -360,7 +360,7 @@ static void current_stack_region(address *bottom, size_t *size) {
   // The initial thread has a growable stack, and the size reported
   // by pthread_attr_getstack is the maximum size it could possibly
   // be given what currently mapped.  This can be huge, so we cap it.
-  if (os::Linux::is_initial_thread()) {
+  if (os::is_primordial_thread()) {
     stack_bytes = stack_top - stack_bottom;
 
     if (stack_bytes > JavaThread::stack_size_at_create())

src/share/vm/memory/threadLocalAllocBuffer.cpp

 /*
- * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -200,7 +200,7 @@ void ThreadLocalAllocBuffer::initialize() {
 
   set_desired_size(initial_desired_size());
 
-  // Following check is needed because at startup the main (primordial)
+  // Following check is needed because at startup the main
   // thread is initialized before the heap is.  The initialization for
   // this thread is redone in startup_initialization below.
   if (Universe::heap() != NULL) {
@@ -223,7 +223,7 @@ void ThreadLocalAllocBuffer::startup_initialization() {
 
   _global_stats = new GlobalTLABStats();
 
-  // During jvm startup, the main (primordial) thread is initialized
+  // During jvm startup, the main thread is initialized
   // before the heap is initialized.  So reinitialize it now.
   guarantee(Thread::current()->is_Java_thread(), "tlab initialization thread not Java thread");
   Thread::current()->tlab().initialize();

src/share/vm/runtime/globals.hpp

 /*
- * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1124,6 +1124,10 @@ class CommandLineFlags {
           "Use detached threads that are recycled upon termination "        \
           "(for Solaris only)")                                             \
                                                                             \
+  experimental(bool, DisablePrimordialThreadGuardPages, false,              \
+               "Disable the use of stack guard pages if the JVM is loaded " \
+               "on the primordial process thread")                          \
+                                                                            \
   product(bool, UseLWPSynchronization, true,                                \
           "Use LWP-based instead of libthread-based synchronization "       \
           "(SPARC only)")                                                   \

src/share/vm/runtime/os.hpp

 /*
- * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -449,7 +449,24 @@ class os: AllStatic {
   static bool create_thread(Thread* thread,
                             ThreadType thr_type,
                             size_t stack_size = 0);
+
+  // The "main thread", also known as "starting thread", is the thread
+  // that loads/creates the JVM via JNI_CreateJavaVM.
   static bool create_main_thread(JavaThread* thread);
+
+  // The primordial thread is the initial process thread. The java
+  // launcher never uses the primordial thread as the main thread, but
+  // applications that host the JVM directly may do so. Some platforms
+  // need special-case handling of the primordial thread if it attaches
+  // to the VM.
+  static bool is_primordial_thread(void)
+#if defined(_WINDOWS) || defined(BSD)
+    // No way to identify the primordial thread.
+    { return false; }
+#else
+  ;
+#endif
+
   static bool create_attached_thread(JavaThread* thread);
   static void pd_start_thread(Thread* thread);
   static void start_thread(Thread* thread);

src/share/vm/runtime/thread.cpp

 /*
- * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -2485,7 +2485,15 @@ void JavaThread::java_resume() {
 }
 
 void JavaThread::create_stack_guard_pages() {
-  if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
+  if (!os::uses_stack_guard_pages() ||
+      _stack_guard_state != stack_guard_unused ||
+      (DisablePrimordialThreadGuardPages && os::is_primordial_thread())) {
+      if (TraceThreadEvents) {
+        tty->print_cr("Stack guard page creation for thread "
+                      UINTX_FORMAT " disabled", os::current_thread_id());
+      }
+    return;
+  }
   address low_addr = stack_base() - stack_size();
   size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
 

src/share/vm/runtime/thread.hpp

 /*
- * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1801,7 +1801,8 @@ inline bool JavaThread::stack_yellow_zone_disabled() {
 
 inline bool JavaThread::stack_yellow_zone_enabled() {
 #ifdef ASSERT
-  if (os::uses_stack_guard_pages()) {
+  if (os::uses_stack_guard_pages() &&
+      !(DisablePrimordialThreadGuardPages && os::is_primordial_thread())) {
     assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use");
   }
 #endif