[Backport #13150]

	this patch contains r54158, r57410, r57631 and r57954.

	Prevent GC by volatile [Bug #13150]

	test/ruby/test_marshal.rb test_context_switch (load) and test_gc (dump)
	are failed on FreeBSD 10.3 and gcc7 (FreeBSD Ports Collection) 7.0.0
	20170115 (experimental); RB_GC_GUARD looks not worked well.

	* include/ruby/ruby.h (RB_GC_GUARD): prevent guarded pointer from
	  optimization by using as an input to inline asm.

	* ruby.h: remove comment

	* include/ruby/ruby.h (RB_GC_GUARD): remove comment unsupported by
	  Solaris AS.

	Hidden objects (klass == 0) are not visible to Ruby code invoked
	from other threads or signal handlers, so they can never be
	accessed from other contexts.  This makes it safe to call
	rb_gc_force_recycle on the object slot after releasing malloc
	memory.

	* marshal.c (rb_marshal_dump_limited): hide dump_arg and recycle when
	  done (rb_marshal_load_with_proc): hide load_arg and recycle when done
	  [ruby-core:79518]

	* marshal.c (rb_marshal_dump_limited): do not free dump_arg, which
	  may be dereferenced in check_dump_arg due to continuation, and
	  get rid of dangling pointers.

	* marshal.c (rb_marshal_load_with_proc): ditto for load_arg.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@59539 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 8 insertions, 12 deletions

diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 60cfb1174e..dccfdc763a 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -551,27 +551,23 @@ static inline int rb_type(VALUE obj);
 	((type) == RUBY_T_FLOAT) ? RB_FLOAT_TYPE_P(obj) : \
 	(!RB_SPECIAL_CONST_P(obj) && RB_BUILTIN_TYPE(obj) == (type)))
 
-/* RB_GC_GUARD_PTR() is an intermediate macro, and has no effect by
- * itself.  don't use it directly */
 #ifdef __GNUC__
-#define RB_GC_GUARD_PTR(ptr) \
-    __extension__ ({volatile VALUE *rb_gc_guarded_ptr = (ptr); rb_gc_guarded_ptr;})
-#else
-#ifdef _MSC_VER
+#define RB_GC_GUARD(v) \
+    (*__extension__ ({ \
+	volatile VALUE *rb_gc_guarded_ptr = &(v); \
+	__asm__("" : : "m"(rb_gc_guarded_ptr)); \
+	rb_gc_guarded_ptr; \
+    }))
+#elif defined _MSC_VER
 #pragma optimize("", off)
 static inline volatile VALUE *rb_gc_guarded_ptr(volatile VALUE *ptr) {return ptr;}
 #pragma optimize("", on)
+#define RB_GC_GUARD(v) (*rb_gc_guarded_ptr(&(v)))
 #else
 volatile VALUE *rb_gc_guarded_ptr_val(volatile VALUE *ptr, VALUE val);
 #define HAVE_RB_GC_GUARDED_PTR_VAL 1
 #define RB_GC_GUARD(v) (*rb_gc_guarded_ptr_val(&(v),(v)))
 #endif
-#define RB_GC_GUARD_PTR(ptr) rb_gc_guarded_ptr(ptr)
-#endif
-
-#ifndef RB_GC_GUARD
-#define RB_GC_GUARD(v) (*RB_GC_GUARD_PTR(&(v)))
-#endif
 
 #ifdef __GNUC__
 #define RB_UNUSED_VAR(x) x __attribute__ ((unused))