thread_pthread.c: adjust stack size

* thread_pthread.c (ruby_init_stack): adjust stack size for offset of
  addr from the bottom.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36013 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Sun Jun 10 17:54:26 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* thread_pthread.c (ruby_init_stack): adjust stack size for offset of
+	  addr from the bottom.
+
 Sun Jun 10 15:49:47 2012  Tanaka Akira  <akr@fsij.org>
 
 	* process.c (retry_fork): call after_fork except in a child process.

thread_pthread.c

@@ -608,8 +608,9 @@ ruby_init_stack(volatile VALUE *addr
 	size_t size = 0;
 	size_t space = 0;
 #if defined(STACKADDR_AVAILABLE)
-	void* addr;
-	get_stack(&addr, &size);
+	void* stackaddr;
+	get_stack(&stackaddr, &size);
+	space = STACK_DIR_UPPER((char *)addr - (char *)stackaddr, (char *)stackaddr - (char *)addr);
 #elif defined(HAVE_GETRLIMIT)
 	struct rlimit rlim;
 	if (getrlimit(RLIMIT_STACK, &rlim) == 0) {