merge revision(s) 49452: [Backport #10813]

	* thread_pthread.c (reserve_stack): fix intermittent SIGBUS on
	  Linux, by reserving the stack virtual address space at process
	  start up so that it will not clash with the heap space.
	  [Fix GH-822]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_2@49578 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 47 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index e42b124395..a009ac25a7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri Feb 13 03:13:05 2015  Scott Francis  <scott.francis@shopify.com>
+
+	* thread_pthread.c (reserve_stack): fix intermittent SIGBUS on
+	  Linux, by reserving the stack virtual address space at process
+	  start up so that it will not clash with the heap space.
+	  [Fix GH-822]
+
 Fri Feb  6 12:05:13 2015  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* thread.c: Improve documentation for Thread#value
diff --git a/thread_pthread.c b/thread_pthread.c
index 7e4d36c479..711e60baf1 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -653,6 +653,42 @@ space_size(size_t stack_size)
     }
 }
 
+#ifdef __linux__
+static __attribute__((noinline)) void
+reserve_stack(volatile char *limit, size_t size)
+{
+# ifdef C_ALLOCA
+#   error needs alloca()
+# endif
+    struct rlimit rl;
+    volatile char buf[0x100];
+    STACK_GROW_DIR_DETECTION;
+
+    if (!getrlimit(RLIMIT_STACK, &rl) && rl.rlim_cur == RLIM_INFINITY)
+	return;
+
+    size -= sizeof(buf); /* margin */
+    if (IS_STACK_DIR_UPPER()) {
+	const volatile char *end = buf + sizeof(buf);
+	limit += size;
+	if (limit > end) {
+	    size = limit - end;
+	    limit = alloca(size);
+	    limit[size-1] = 0;
+	}
+    }
+    else {
+	limit -= size;
+	if (buf > limit) {
+	    limit = alloca(buf - limit);
+	    limit[0] = 0;
+	}
+    }
+}
+#else
+# define reserve_stack(limit, size) ((void)(limit), (void)(size))
+#endif
+
 #undef ruby_init_stack
 /* Set stack bottom of Ruby implementation.
  *
@@ -674,6 +710,7 @@ ruby_init_stack(volatile VALUE *addr
 	if (get_main_stack(&stackaddr, &size) == 0) {
 	    native_main_thread.stack_maxsize = size;
 	    native_main_thread.stack_start = stackaddr;
+	    reserve_stack(stackaddr, size);
 	    return;
 	}
     }
diff --git a/version.h b/version.h
index a89fb7c2fd..b11a37b359 100644
--- a/version.h
+++ b/version.h
@@ -1,10 +1,10 @@
 #define RUBY_VERSION "2.2.0"
-#define RUBY_RELEASE_DATE "2015-02-06"
-#define RUBY_PATCHLEVEL 43
+#define RUBY_RELEASE_DATE "2015-02-13"
+#define RUBY_PATCHLEVEL 44
 
 #define RUBY_RELEASE_YEAR 2015
 #define RUBY_RELEASE_MONTH 2
-#define RUBY_RELEASE_DAY 6
+#define RUBY_RELEASE_DAY 13
 
 #include "ruby/version.h"