revert r46667 and r46669 because they introduced SEGV on CentOS.

see [Bug #9454] [Bug #9945]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@46672 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

10 files changed, 137 insertions, 222 deletions

diff --git a/ChangeLog b/ChangeLog
index 3f2fddc914..3e8e56f6c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -20,41 +20,6 @@ Thu Jul  3 15:17:22 2014  Koichi Sasada  <ko1@atdot.net>
 	  move definition of rb_frame_pop() and deprecate it.
 	  It doesn't care about `return' events.
 
-Thu Jul  3 15:00:35 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
-
-	* encoding.c (enc_find): [DOC] never accepted a symbol.
-	  [ruby-dev:48308] [Bug #9966]
-
-Thu Jul  3 13:23:31 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
-
-	* thread_pthread.c (ruby_init_stack, ruby_stack_overflowed_p):
-	  place get_stack above others to get stack boundary information.
-	  [ruby-core:60113] [Bug #9454]
-
-Thu Jul  3 13:23:31 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
-
-	* thread_pthread.c (ruby_init_stack, ruby_stack_overflowed_p):
-	  place get_stack above others to get stack boundary information.
-	  [ruby-core:60113] [Bug #9454]
-
-Thu Jul  3 13:23:31 2014  NARUSE, Yui  <naruse@ruby-lang.org>
-
-	* thread_pthread.c: rlimit is only available on Linux.
-	  At least r44712 breaks FreeBSD.
-	  [ruby-core:60113] [Bug #9454]
-
-Thu Jul  3 13:23:31 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
-
-	* thread_pthread.c: get current main thread stack size, which may
-	  be expanded than allocated size at initialization, by rlimit().
-	  [ruby-core:60113] [Bug #9454]
-
-Thu Jul  3 13:23:31 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
-
-	* thread_pthread.c: get current main thread stack size, which may
-	  be expanded than allocated size at initialization, by rlimit().
-	  [ruby-core:60113] [Bug #9454]
-
 Fri Jun 27 17:57:16 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* string.c (rb_str_substr): need to reset code range for shared
diff --git a/cont.c b/cont.c
index 13876862f4..e1c5c8953e 100644
--- a/cont.c
+++ b/cont.c
@@ -97,18 +97,16 @@ typedef struct rb_context_struct {
     size_t vm_stack_slen;  /* length of stack (head of th->stack) */
     size_t vm_stack_clen;  /* length of control frames (tail of th->stack) */
 #endif
-    struct {
-	VALUE *stack;
-	VALUE *stack_src;
-	size_t stack_size;
+    VALUE *machine_stack;
+    VALUE *machine_stack_src;
 #ifdef __ia64
-	VALUE *register_stack;
-	VALUE *register_stack_src;
-	int register_stack_size;
+    VALUE *machine_register_stack;
+    VALUE *machine_register_stack_src;
+    int machine_register_stack_size;
 #endif
-    } machine;
     rb_thread_t saved_thread;
     rb_jmpbuf_t jmpbuf;
+    size_t machine_stack_size;
 } rb_context_t;
 
 enum fiber_status {
@@ -188,11 +186,11 @@ cont_mark(void *ptr)
 #endif
 	}
 
-	if (cont->machine.stack) {
+	if (cont->machine_stack) {
 	    if (cont->type == CONTINUATION_CONTEXT) {
 		/* cont */
-		rb_gc_mark_locations(cont->machine.stack,
-				     cont->machine.stack + cont->machine.stack_size);
+		rb_gc_mark_locations(cont->machine_stack,
+				     cont->machine_stack + cont->machine_stack_size);
             }
             else {
 		/* fiber */
@@ -200,15 +198,15 @@ cont_mark(void *ptr)
                 rb_fiber_t *fib = (rb_fiber_t*)cont;
 		GetThreadPtr(cont->saved_thread.self, th);
 		if ((th->fiber != cont->self) && fib->status == RUNNING) {
-		    rb_gc_mark_locations(cont->machine.stack,
-					 cont->machine.stack + cont->machine.stack_size);
+		    rb_gc_mark_locations(cont->machine_stack,
+					 cont->machine_stack + cont->machine_stack_size);
 		}
 	    }
 	}
 #ifdef __ia64
-	if (cont->machine.register_stack) {
-	    rb_gc_mark_locations(cont->machine.register_stack,
-				 cont->machine.register_stack + cont->machine.register_stack_size);
+	if (cont->machine_register_stack) {
+	    rb_gc_mark_locations(cont->machine_register_stack,
+				 cont->machine_register_stack + cont->machine_register_stack_size);
 	}
 #endif
     }
@@ -225,7 +223,7 @@ cont_free(void *ptr)
 #if FIBER_USE_NATIVE
 	if (cont->type == CONTINUATION_CONTEXT) {
 	    /* cont */
-	    RUBY_FREE_UNLESS_NULL(cont->machine.stack);
+	    RUBY_FREE_UNLESS_NULL(cont->machine_stack);
 	}
 	else {
 	    /* fiber */
@@ -255,10 +253,10 @@ cont_free(void *ptr)
 #endif
 	}
 #else /* not FIBER_USE_NATIVE */
-	RUBY_FREE_UNLESS_NULL(cont->machine.stack);
+	RUBY_FREE_UNLESS_NULL(cont->machine_stack);
 #endif
 #ifdef __ia64
-	RUBY_FREE_UNLESS_NULL(cont->machine.register_stack);
+	RUBY_FREE_UNLESS_NULL(cont->machine_register_stack);
 #endif
 	RUBY_FREE_UNLESS_NULL(cont->vm_stack);
 
@@ -284,12 +282,12 @@ cont_memsize(const void *ptr)
 	    size += n * sizeof(*cont->vm_stack);
 	}
 
-	if (cont->machine.stack) {
-	    size += cont->machine.stack_size * sizeof(*cont->machine.stack);
+	if (cont->machine_stack) {
+	    size += cont->machine_stack_size * sizeof(*cont->machine_stack);
 	}
 #ifdef __ia64
-	if (cont->machine.register_stack) {
-	    size += cont->machine.register_stack_size * sizeof(*cont->machine.register_stack);
+	if (cont->machine_register_stack) {
+	    size += cont->machine_register_stack_size * sizeof(*cont->machine_register_stack);
 	}
 #endif
     }
@@ -377,42 +375,42 @@ cont_save_machine_stack(rb_thread_t *th, rb_context_t *cont)
 {
     size_t size;
 
-    SET_MACHINE_STACK_END(&th->machine.stack_end);
+    SET_MACHINE_STACK_END(&th->machine_stack_end);
 #ifdef __ia64
-    th->machine.register_stack_end = rb_ia64_bsp();
+    th->machine_register_stack_end = rb_ia64_bsp();
 #endif
 
-    if (th->machine.stack_start > th->machine.stack_end) {
-	size = cont->machine.stack_size = th->machine.stack_start - th->machine.stack_end;
-	cont->machine.stack_src = th->machine.stack_end;
+    if (th->machine_stack_start > th->machine_stack_end) {
+	size = cont->machine_stack_size = th->machine_stack_start - th->machine_stack_end;
+	cont->machine_stack_src = th->machine_stack_end;
     }
     else {
-	size = cont->machine.stack_size = th->machine.stack_end - th->machine.stack_start;
-	cont->machine.stack_src = th->machine.stack_start;
+	size = cont->machine_stack_size = th->machine_stack_end - th->machine_stack_start;
+	cont->machine_stack_src = th->machine_stack_start;
     }
 
-    if (cont->machine.stack) {
-	REALLOC_N(cont->machine.stack, VALUE, size);
+    if (cont->machine_stack) {
+	REALLOC_N(cont->machine_stack, VALUE, size);
     }
     else {
-	cont->machine.stack = ALLOC_N(VALUE, size);
+	cont->machine_stack = ALLOC_N(VALUE, size);
     }
 
     FLUSH_REGISTER_WINDOWS;
-    MEMCPY(cont->machine.stack, cont->machine.stack_src, VALUE, size);
+    MEMCPY(cont->machine_stack, cont->machine_stack_src, VALUE, size);
 
 #ifdef __ia64
     rb_ia64_flushrs();
-    size = cont->machine.register_stack_size = th->machine.register_stack_end - th->machine.register_stack_start;
-    cont->machine.register_stack_src = th->machine.register_stack_start;
-    if (cont->machine.register_stack) {
-	REALLOC_N(cont->machine.register_stack, VALUE, size);
+    size = cont->machine_register_stack_size = th->machine_register_stack_end - th->machine_register_stack_start;
+    cont->machine_register_stack_src = th->machine_register_stack_start;
+    if (cont->machine_register_stack) {
+	REALLOC_N(cont->machine_register_stack, VALUE, size);
     }
     else {
-	cont->machine.register_stack = ALLOC_N(VALUE, size);
+	cont->machine_register_stack = ALLOC_N(VALUE, size);
     }
 
-    MEMCPY(cont->machine.register_stack, cont->machine.register_stack_src, VALUE, size);
+    MEMCPY(cont->machine_register_stack, cont->machine_register_stack_src, VALUE, size);
 #endif
 }
 
@@ -426,13 +424,13 @@ cont_save_thread(rb_context_t *cont, rb_thread_t *th)
 {
     /* save thread context */
     cont->saved_thread = *th;
-    /* saved_thread->machine.stack_(start|end) should be NULL */
+    /* saved_thread->machine_stack_(start|end) should be NULL */
     /* because it may happen GC afterward */
-    cont->saved_thread.machine.stack_start = 0;
-    cont->saved_thread.machine.stack_end = 0;
+    cont->saved_thread.machine_stack_start = 0;
+    cont->saved_thread.machine_stack_end = 0;
 #ifdef __ia64
-    cont->saved_thread.machine.register_stack_start = 0;
-    cont->saved_thread.machine.register_stack_end = 0;
+    cont->saved_thread.machine_register_stack_start = 0;
+    cont->saved_thread.machine_register_stack_end = 0;
 #endif
 }
 
@@ -557,7 +555,7 @@ fiber_set_stack_location(void)
     VALUE *ptr;
 
     SET_MACHINE_STACK_END(&ptr);
-    th->machine.stack_start = (void*)(((VALUE)ptr & RB_PAGE_MASK) + STACK_UPPER((void *)&ptr, 0, RB_PAGE_SIZE));
+    th->machine_stack_start = (void*)(((VALUE)ptr & RB_PAGE_MASK) + STACK_UPPER((void *)&ptr, 0, RB_PAGE_SIZE));
 }
 
 static VOID CALLBACK
@@ -631,7 +629,7 @@ fiber_initialize_machine_stack_context(rb_fiber_t *fib, size_t size)
 	    rb_raise(rb_eFiberError, "can't create fiber");
 	}
     }
-    sth->machine.stack_maxsize = size;
+    sth->machine_stack_maxsize = size;
 #else /* not WIN32 */
     ucontext_t *context = &fib->context;
     char *ptr;
@@ -643,11 +641,11 @@ fiber_initialize_machine_stack_context(rb_fiber_t *fib, size_t size)
     context->uc_stack.ss_sp = ptr;
     context->uc_stack.ss_size = size;
     makecontext(context, rb_fiber_start, 0);
-    sth->machine.stack_start = (VALUE*)(ptr + STACK_DIR_UPPER(0, size));
-    sth->machine.stack_maxsize = size - RB_PAGE_SIZE;
+    sth->machine_stack_start = (VALUE*)(ptr + STACK_DIR_UPPER(0, size));
+    sth->machine_stack_maxsize = size - RB_PAGE_SIZE;
 #endif
 #ifdef __ia64
-    sth->machine.register_stack_maxsize = sth->machine.stack_maxsize;
+    sth->machine_register_stack_maxsize = sth->machine_stack_maxsize;
 #endif
 }
 
@@ -664,29 +662,29 @@ fiber_setcontext(rb_fiber_t *newfib, rb_fiber_t *oldfib)
 
     /* restore thread context */
     cont_restore_thread(&newfib->cont);
-    th->machine.stack_maxsize = sth->machine.stack_maxsize;
-    if (sth->machine.stack_end && (newfib != oldfib)) {
-	rb_bug("fiber_setcontext: sth->machine.stack_end has non zero value");
+    th->machine_stack_maxsize = sth->machine_stack_maxsize;
+    if (sth->machine_stack_end && (newfib != oldfib)) {
+	rb_bug("fiber_setcontext: sth->machine_stack_end has non zero value");
     }
 
     /* save  oldfib's machine stack */
     if (oldfib->status != TERMINATED) {
 	STACK_GROW_DIR_DETECTION;
-	SET_MACHINE_STACK_END(&th->machine.stack_end);
+	SET_MACHINE_STACK_END(&th->machine_stack_end);
 	if (STACK_DIR_UPPER(0, 1)) {
-	    oldfib->cont.machine.stack_size = th->machine.stack_start - th->machine.stack_end;
-	    oldfib->cont.machine.stack = th->machine.stack_end;
+	    oldfib->cont.machine_stack_size = th->machine_stack_start - th->machine_stack_end;
+	    oldfib->cont.machine_stack = th->machine_stack_end;
 	}
 	else {
-	    oldfib->cont.machine.stack_size = th->machine.stack_end - th->machine.stack_start;
-	    oldfib->cont.machine.stack = th->machine.stack_start;
+	    oldfib->cont.machine_stack_size = th->machine_stack_end - th->machine_stack_start;
+	    oldfib->cont.machine_stack = th->machine_stack_start;
 	}
     }
     /* exchange machine_stack_start between oldfib and newfib */
-    oldfib->cont.saved_thread.machine.stack_start = th->machine.stack_start;
-    th->machine.stack_start = sth->machine.stack_start;
-    /* oldfib->machine.stack_end should be NULL */
-    oldfib->cont.saved_thread.machine.stack_end = 0;
+    oldfib->cont.saved_thread.machine_stack_start = th->machine_stack_start;
+    th->machine_stack_start = sth->machine_stack_start;
+    /* oldfib->machine_stack_end should be NULL */
+    oldfib->cont.saved_thread.machine_stack_end = 0;
 #ifndef _WIN32
     if (!newfib->context.uc_stack.ss_sp && th->root_fiber != newfib->cont.self) {
 	rb_bug("non_root_fiber->context.uc_stac.ss_sp should not be NULL");
@@ -719,16 +717,16 @@ cont_restore_1(rb_context_t *cont)
 	    ((_JUMP_BUFFER*)(&buf))->Frame;
     }
 #endif
-    if (cont->machine.stack_src) {
+    if (cont->machine_stack_src) {
 	FLUSH_REGISTER_WINDOWS;
-	MEMCPY(cont->machine.stack_src, cont->machine.stack,
-		VALUE, cont->machine.stack_size);
+	MEMCPY(cont->machine_stack_src, cont->machine_stack,
+		VALUE, cont->machine_stack_size);
     }
 
 #ifdef __ia64
-    if (cont->machine.register_stack_src) {
-	MEMCPY(cont->machine.register_stack_src, cont->machine.register_stack,
-	       VALUE, cont->machine.register_stack_size);
+    if (cont->machine_register_stack_src) {
+	MEMCPY(cont->machine_register_stack_src, cont->machine_register_stack,
+	       VALUE, cont->machine_register_stack_size);
     }
 #endif
 
@@ -763,7 +761,7 @@ register_stack_extend(rb_context_t *cont, VALUE *vp, VALUE *curr_bsp)
         E(k) = E(l) = E(m) = E(n) = E(o) =
         E(p) = E(q) = E(r) = E(s) = E(t) = 0;
     }
-    if (curr_bsp < cont->machine.register_stack_src+cont->machine.register_stack_size) {
+    if (curr_bsp < cont->machine_register_stack_src+cont->machine_register_stack_size) {
         register_stack_extend(cont, vp, (VALUE*)rb_ia64_bsp());
     }
     cont_restore_0(cont, vp);
@@ -775,7 +773,7 @@ register_stack_extend(rb_context_t *cont, VALUE *vp, VALUE *curr_bsp)
 static void
 cont_restore_0(rb_context_t *cont, VALUE *addr_in_prev_frame)
 {
-    if (cont->machine.stack_src) {
+    if (cont->machine_stack_src) {
 #ifdef HAVE_ALLOCA
 #define STACK_PAD_SIZE 1
 #else
@@ -788,7 +786,7 @@ cont_restore_0(rb_context_t *cont, VALUE *addr_in_prev_frame)
 	    /* Stack grows downward */
 #endif
 #if STACK_GROW_DIRECTION <= 0
-	    volatile VALUE *const end = cont->machine.stack_src;
+	    volatile VALUE *const end = cont->machine_stack_src;
 	    if (&space[0] > end) {
 # ifdef HAVE_ALLOCA
 		volatile VALUE *sp = ALLOCA_N(VALUE, &space[0] - end);
@@ -804,7 +802,7 @@ cont_restore_0(rb_context_t *cont, VALUE *addr_in_prev_frame)
 	    /* Stack grows upward */
 #endif
 #if STACK_GROW_DIRECTION >= 0
-	    volatile VALUE *const end = cont->machine.stack_src + cont->machine.stack_size;
+	    volatile VALUE *const end = cont->machine_stack_src + cont->machine_stack_size;
 	    if (&space[STACK_PAD_SIZE] < end) {
 # ifdef HAVE_ALLOCA
 		volatile VALUE *sp = ALLOCA_N(VALUE, end - &space[STACK_PAD_SIZE]);
@@ -1159,8 +1157,8 @@ rb_fiber_terminate(rb_fiber_t *fib)
     terminated_machine_stack.ptr = fib->context.uc_stack.ss_sp;
     terminated_machine_stack.size = fib->context.uc_stack.ss_size / sizeof(VALUE);
     fib->context.uc_stack.ss_sp = NULL;
-    fib->cont.machine.stack = NULL;
-    fib->cont.machine.stack_size = 0;
+    fib->cont.machine_stack = NULL;
+    fib->cont.machine_stack_size = 0;
 #endif
     rb_fiber_transfer(return_fiber(), 1, &value);
 }
@@ -1271,7 +1269,7 @@ fiber_store(rb_fiber_t *next_fib)
 		machine_stack_cache_index++;
 	    }
 	    else {
-		if (terminated_machine_stack.ptr != fib->cont.machine.stack) {
+		if (terminated_machine_stack.ptr != fib->cont.machine_stack) {
 		    munmap((void*)terminated_machine_stack.ptr, terminated_machine_stack.size * sizeof(VALUE));
 		}
 		else {
@@ -1561,7 +1559,7 @@ Init_Cont(void)
 #else /* not WIN32 */
     pagesize = sysconf(_SC_PAGESIZE);
 #endif
-    SET_MACHINE_STACK_END(&th->machine.stack_end);
+    SET_MACHINE_STACK_END(&th->machine_stack_end);
 #endif
 
     rb_cFiber = rb_define_class("Fiber", rb_cObject);
diff --git a/gc.c b/gc.c
index 4b6226a622..71fd2ced8f 100644
--- a/gc.c
+++ b/gc.c
@@ -2246,14 +2246,14 @@ init_mark_stack(mark_stack_t *stack)
 
 
 #ifdef __ia64
-#define SET_STACK_END (SET_MACHINE_STACK_END(&th->machine.stack_end), th->machine.register_stack_end = rb_ia64_bsp())
+#define SET_STACK_END (SET_MACHINE_STACK_END(&th->machine_stack_end), th->machine_register_stack_end = rb_ia64_bsp())
 #else
-#define SET_STACK_END SET_MACHINE_STACK_END(&th->machine.stack_end)
+#define SET_STACK_END SET_MACHINE_STACK_END(&th->machine_stack_end)
 #endif
 
-#define STACK_START (th->machine.stack_start)
-#define STACK_END (th->machine.stack_end)
-#define STACK_LEVEL_MAX (th->machine.stack_maxsize/sizeof(VALUE))
+#define STACK_START (th->machine_stack_start)
+#define STACK_END (th->machine_stack_end)
+#define STACK_LEVEL_MAX (th->machine_stack_maxsize/sizeof(VALUE))
 
 #if STACK_GROW_DIRECTION < 0
 # define STACK_LENGTH  (size_t)(STACK_START - STACK_END)
@@ -2295,8 +2295,8 @@ stack_check(int water_mark)
     ret = STACK_LENGTH > STACK_LEVEL_MAX - water_mark;
 #ifdef __ia64
     if (!ret) {
-        ret = (VALUE*)rb_ia64_bsp() - th->machine.register_stack_start >
-              th->machine.register_stack_maxsize/sizeof(VALUE) - water_mark;
+        ret = (VALUE*)rb_ia64_bsp() - th->machine_register_stack_start >
+              th->machine_register_stack_maxsize/sizeof(VALUE) - water_mark;
     }
 #endif
     return ret;
@@ -2518,7 +2518,7 @@ mark_current_machine_context(rb_objspace_t *objspace, rb_thread_t *th)
 
     rb_gc_mark_locations(stack_start, stack_end);
 #ifdef __ia64
-    rb_gc_mark_locations(th->machine.register_stack_start, th->machine.register_stack_end);
+    rb_gc_mark_locations(th->machine_register_stack_start, th->machine_register_stack_end);
 #endif
 #if defined(__mc68000__)
     mark_locations_array(objspace, (VALUE*)((char*)STACK_END + 2),
@@ -2535,7 +2535,7 @@ rb_gc_mark_machine_stack(rb_thread_t *th)
     GET_STACK_BOUNDS(stack_start, stack_end, 0);
     rb_gc_mark_locations(stack_start, stack_end);
 #ifdef __ia64
-    rb_gc_mark_locations(th->machine.register_stack_start, th->machine.register_stack_end);
+    rb_gc_mark_locations(th->machine_register_stack_start, th->machine_register_stack_end);
 #endif
 }
 
diff --git a/test/ruby/test_exception.rb b/test/ruby/test_exception.rb
index 4aacc4b512..ea733b3add 100644
--- a/test/ruby/test_exception.rb
+++ b/test/ruby/test_exception.rb
@@ -568,15 +568,4 @@ end.join
 
     assert_equal("Ruby", favorite_lang)
   end
-
-  def test_machine_stackoverflow_by_define_method
-    bug9454 = '[ruby-core:60113] [Bug #9454]'
-    assert_separately([], <<-SRC)
-    assert_raise(SystemStackError, #{bug9454.dump}) {
-      define_method(:foo) {self.foo}
-      self.foo
-    }
-    SRC
-  rescue SystemStackError
-  end
 end
diff --git a/thread.c b/thread.c
index d4413f9721..5be0855040 100644
--- a/thread.c
+++ b/thread.c
@@ -122,7 +122,7 @@ static inline void blocking_region_end(rb_thread_t *th, struct rb_blocking_regio
 
 #ifdef __ia64
 #define RB_GC_SAVE_MACHINE_REGISTER_STACK(th)          \
-    do{(th)->machine.register_stack_end = rb_ia64_bsp();}while(0)
+    do{(th)->machine_register_stack_end = rb_ia64_bsp();}while(0)
 #else
 #define RB_GC_SAVE_MACHINE_REGISTER_STACK(th)
 #endif
@@ -130,8 +130,8 @@ static inline void blocking_region_end(rb_thread_t *th, struct rb_blocking_regio
     do {							\
 	FLUSH_REGISTER_WINDOWS;					\
 	RB_GC_SAVE_MACHINE_REGISTER_STACK(th);			\
-	setjmp((th)->machine.regs);				\
-	SET_MACHINE_STACK_END(&(th)->machine.stack_end);	\
+	setjmp((th)->machine_regs);				\
+	SET_MACHINE_STACK_END(&(th)->machine_stack_end);	\
     } while (0)
 
 #define GVL_UNLOCK_BEGIN() do { \
@@ -444,9 +444,9 @@ thread_cleanup_func_before_exec(void *th_ptr)
 {
     rb_thread_t *th = th_ptr;
     th->status = THREAD_KILLED;
-    th->machine.stack_start = th->machine.stack_end = 0;
+    th->machine_stack_start = th->machine_stack_end = 0;
 #ifdef __ia64
-    th->machine.register_stack_start = th->machine.register_stack_end = 0;
+    th->machine_register_stack_start = th->machine_register_stack_end = 0;
 #endif
 }
 
@@ -498,9 +498,9 @@ thread_start_func_2(rb_thread_t *th, VALUE *stack_start, VALUE *register_stack_s
 
     ruby_thread_set_native(th);
 
-    th->machine.stack_start = stack_start;
+    th->machine_stack_start = stack_start;
 #ifdef __ia64
-    th->machine.register_stack_start = register_stack_start;
+    th->machine_register_stack_start = register_stack_start;
 #endif
     thread_debug("thread start: %p\n", (void *)th);
 
diff --git a/thread_pthread.c b/thread_pthread.c
index 840e6844ab..55e2856e43 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -520,9 +520,6 @@ size_t pthread_get_stacksize_np(pthread_t);
 #   define MAINSTACKADDR_AVAILABLE 0
 # endif
 #endif
-#if MAINSTACKADDR_AVAILABLE && !defined(get_main_stack)
-# define get_main_stack(addr, size) get_stack(addr, size)
-#endif
 
 #ifdef STACKADDR_AVAILABLE
 /*
@@ -636,18 +633,6 @@ ruby_init_stack(volatile VALUE *addr
     )
 {
     native_main_thread.id = pthread_self();
-#if MAINSTACKADDR_AVAILABLE
-    if (native_main_thread.stack_maxsize) return;
-    {
-	void* stackaddr;
-	size_t size;
-	if (get_main_stack(&stackaddr, &size) == 0) {
-	    native_main_thread.stack_maxsize = size;
-	    native_main_thread.stack_start = stackaddr;
-	    return;
-	}
-    }
-#endif
 #ifdef STACK_END_ADDRESS
     native_main_thread.stack_start = STACK_END_ADDRESS;
 #else
@@ -665,7 +650,6 @@ ruby_init_stack(volatile VALUE *addr
     }
 #endif
     {
-#if defined(HAVE_GETRLIMIT)
 #if defined(PTHREAD_STACK_DEFAULT)
 # if PTHREAD_STACK_DEFAULT < RUBY_STACK_SPACE*5
 #  error "PTHREAD_STACK_DEFAULT is too small"
@@ -674,7 +658,15 @@ ruby_init_stack(volatile VALUE *addr
 #else
 	size_t size = RUBY_VM_THREAD_VM_STACK_SIZE;
 #endif
-	size_t space;
+	size_t space = space_size(size);
+#if MAINSTACKADDR_AVAILABLE
+	void* stackaddr;
+	STACK_GROW_DIR_DETECTION;
+	if (get_stack(&stackaddr, &size) == 0) {
+            space = STACK_DIR_UPPER((char *)addr - (char *)stackaddr, (char *)stackaddr - (char *)addr);
+        }
+	native_main_thread.stack_maxsize = size - space;
+#elif defined(HAVE_GETRLIMIT)
 	int pagesize = getpagesize();
 	struct rlimit rlim;
         STACK_GROW_DIR_DETECTION;
@@ -724,8 +716,8 @@ native_thread_init_stack(rb_thread_t *th)
     rb_thread_id_t curr = pthread_self();
 
     if (pthread_equal(curr, native_main_thread.id)) {
-	th->machine.stack_start = native_main_thread.stack_start;
-	th->machine.stack_maxsize = native_main_thread.stack_maxsize;
+	th->machine_stack_start = native_main_thread.stack_start;
+	th->machine_stack_maxsize = native_main_thread.stack_maxsize;
     }
     else {
 #ifdef STACKADDR_AVAILABLE
@@ -733,22 +725,17 @@ native_thread_init_stack(rb_thread_t *th)
 	size_t size;
 
 	if (get_stack(&start, &size) == 0) {
-	    th->machine.stack_start = start;
-	    th->machine.stack_maxsize = size;
-	}
-#elif defined get_stack_of
-	if (!th->machine.stack_maxsize) {
-	    native_mutex_lock(&th->interrupt_lock);
-	    native_mutex_unlock(&th->interrupt_lock);
+	    th->machine_stack_start = start;
+	    th->machine_stack_maxsize = size;
 	}
 #else
 	rb_raise(rb_eNotImpError, "ruby engine can initialize only in the main thread");
 #endif
     }
 #ifdef __ia64
-    th->machine.register_stack_start = native_main_thread.register_stack_start;
-    th->machine.stack_maxsize /= 2;
-    th->machine.register_stack_maxsize = th->machine.stack_maxsize;
+    th->machine_register_stack_start = native_main_thread.register_stack_start;
+    th->machine_stack_maxsize /= 2;
+    th->machine_register_stack_maxsize = th->machine_stack_maxsize;
 #endif
     return 0;
 }
@@ -775,7 +762,7 @@ thread_start_func_1(void *th_ptr)
 	native_thread_init(th);
 	/* run */
 #if defined USE_NATIVE_THREAD_INIT
-	thread_start_func_2(th, th->machine.stack_start, rb_ia64_bsp());
+	thread_start_func_2(th, th->machine_stack_start, rb_ia64_bsp());
 #else
 	thread_start_func_2(th, &stack_start, rb_ia64_bsp());
 #endif
@@ -895,19 +882,14 @@ native_thread_create(rb_thread_t *th)
 	thread_debug("create (use cached thread): %p\n", (void *)th);
     }
     else {
-#ifdef HAVE_PTHREAD_ATTR_INIT
 	pthread_attr_t attr;
-	pthread_attr_t *const attrp = &attr;
-#else
-	pthread_attr_t *const attrp = NULL;
-#endif
 	const size_t stack_size = th->vm->default_params.thread_machine_stack_size;
 	const size_t space = space_size(stack_size);
 
-        th->machine.stack_maxsize = stack_size - space;
+        th->machine_stack_maxsize = stack_size - space;
 #ifdef __ia64
-        th->machine.stack_maxsize /= 2;
-        th->machine.register_stack_maxsize = th->machine.stack_maxsize;
+        th->machine_stack_maxsize /= 2;
+        th->machine_register_stack_maxsize = th->machine_stack_maxsize;
 #endif
 
 #ifdef HAVE_PTHREAD_ATTR_INIT
@@ -922,18 +904,10 @@ native_thread_create(rb_thread_t *th)
 	CHECK_ERR(pthread_attr_setinheritsched(&attr, PTHREAD_INHERIT_SCHED));
 # endif
 	CHECK_ERR(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED));
-#endif
-#ifdef get_stack_of
-	native_mutex_lock(&th->interrupt_lock);
-#endif
-	err = pthread_create(&th->thread_id, attrp, thread_start_func_1, th);
-#ifdef get_stack_of
-	if (!err) {
-	    get_stack_of(th->thread_id,
-			 &th->machine.stack_start,
-			 &th->machine.stack_maxsize);
-	}
-	native_mutex_unlock(&th->interrupt_lock);
+
+	err = pthread_create(&th->thread_id, &attr, thread_start_func_1, th);
+#else
+	err = pthread_create(&th->thread_id, NULL, thread_start_func_1, th);
 #endif
 	thread_debug("create: %p (%d)\n", (void *)th, err);
 #ifdef HAVE_PTHREAD_ATTR_INIT
@@ -1527,24 +1501,15 @@ ruby_stack_overflowed_p(const rb_thread_t *th, const void *addr)
     const size_t water_mark = 1024 * 1024;
     STACK_GROW_DIR_DETECTION;
 
+    if (th) {
+	size = th->machine_stack_maxsize;
+	base = (char *)th->machine_stack_start - STACK_DIR_UPPER(0, size);
+    }
 #ifdef STACKADDR_AVAILABLE
-    if (get_stack(&base, &size) == 0) {
-# ifdef __APPLE__
-	if (pthread_equal(th->thread_id, native_main_thread.id)) {
-	    struct rlimit rlim;
-	    if (getrlimit(RLIMIT_STACK, &rlim) == 0 && rlim.rlim_cur > size) {
-		size = (size_t)rlim.rlim_cur;
-	    }
-	}
-# endif
-	base = (char *)base + STACK_DIR_UPPER(+size, -size);
+    else if (get_stack(&base, &size) == 0) {
+	STACK_DIR_UPPER((void)(base = (char *)base + size), (void)0);
     }
-    else
 #endif
-    if (th) {
-	size = th->machine.stack_maxsize;
-	base = (char *)th->machine.stack_start - STACK_DIR_UPPER(0, size);
-    }
     else {
 	return 0;
     }
diff --git a/thread_win32.c b/thread_win32.c
index a8bd59baf7..2bb56d0646 100644
--- a/thread_win32.c
+++ b/thread_win32.c
@@ -589,8 +589,8 @@ native_thread_init_stack(rb_thread_t *th)
     size = end - base;
     space = size / 5;
     if (space > 1024*1024) space = 1024*1024;
-    th->machine.stack_start = (VALUE *)end - 1;
-    th->machine.stack_maxsize = size - space;
+    th->machine_stack_start = (VALUE *)end - 1;
+    th->machine_stack_maxsize = size - space;
 }
 
 #ifndef InterlockedExchangePointer
@@ -618,7 +618,7 @@ thread_start_func_1(void *th_ptr)
     thread_debug("thread created (th: %p, thid: %p, event: %p)\n", th,
 		 th->thread_id, th->native_thread_data.interrupt_event);
 
-    thread_start_func_2(th, th->machine.stack_start, rb_ia64_bsp());
+    thread_start_func_2(th, th->machine_stack_start, rb_ia64_bsp());
 
     w32_close_handle(thread_id);
     thread_debug("thread deleted (th: %p)\n", th);
diff --git a/version.h b/version.h
index 6cb357b596..9c75d15a3f 100644
--- a/version.h
+++ b/version.h
@@ -1,10 +1,10 @@
 #define RUBY_VERSION "2.0.0"
-#define RUBY_RELEASE_DATE "2014-07-03"
-#define RUBY_PATCHLEVEL 514
+#define RUBY_RELEASE_DATE "2014-07-04"
+#define RUBY_PATCHLEVEL 515
 
 #define RUBY_RELEASE_YEAR 2014
 #define RUBY_RELEASE_MONTH 7
-#define RUBY_RELEASE_DAY 3
+#define RUBY_RELEASE_DAY 4
 
 #include "ruby/version.h"
 
diff --git a/vm.c b/vm.c
index d6467dbf92..3e25533b67 100644
--- a/vm.c
+++ b/vm.c
@@ -1858,11 +1858,11 @@ rb_thread_mark(void *ptr)
 
 	rb_mark_tbl(th->local_storage);
 
-	if (GET_THREAD() != th && th->machine.stack_start && th->machine.stack_end) {
+	if (GET_THREAD() != th && th->machine_stack_start && th->machine_stack_end) {
 	    rb_gc_mark_machine_stack(th);
-	    rb_gc_mark_locations((VALUE *)&th->machine.regs,
-				 (VALUE *)(&th->machine.regs) +
-				 sizeof(th->machine.regs) / sizeof(VALUE));
+	    rb_gc_mark_locations((VALUE *)&th->machine_regs,
+				 (VALUE *)(&th->machine_regs) +
+				 sizeof(th->machine_regs) / sizeof(VALUE));
 	}
 
 	vm_trace_mark_event_hooks(&th->event_hooks);
diff --git a/vm_core.h b/vm_core.h
index eb02c66730..0bffdd3daa 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -585,17 +585,15 @@ typedef struct rb_thread_struct {
     VALUE (*first_func)(ANYARGS);
 
     /* for GC */
-    struct {
-	VALUE *stack_start;
-	VALUE *stack_end;
-	size_t stack_maxsize;
+    VALUE *machine_stack_start;
+    VALUE *machine_stack_end;
+    size_t machine_stack_maxsize;
 #ifdef __ia64
-	VALUE *register_stack_start;
-	VALUE *register_stack_end;
-	size_t register_stack_maxsize;
+    VALUE *machine_register_stack_start;
+    VALUE *machine_register_stack_end;
+    size_t machine_register_stack_maxsize;
 #endif
-	jmp_buf regs;
-    } machine;
+    jmp_buf machine_regs;
     int mark_stack_len;
 
     /* statistics data for profiler */