fix r52806

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52821 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 29 insertions, 3 deletions

diff --git a/missing/explicit_bzero.c b/missing/explicit_bzero.c
index cb11bd6da1..f140acb374 100644
--- a/missing/explicit_bzero.c
+++ b/missing/explicit_bzero.c
@@ -1,8 +1,34 @@
+#include "ruby/missing.h"
 #include <string.h>
 
-/* prevent the compiler from optimizing away memset or bzero */
+/*
+ *BSD have explicit_bzero().
+ Windows, OS-X have memset_s().
+ Linux has none. *Sigh*
+*/
+
+#ifndef HAVE_EXPLICIT_BZERO
+/* Similar to bzero(), but have a guarantee not to be eliminated from compiler
+   optimization. */
 void
-explicit_bzero(void *p, size_t n)
+explicit_bzero(void *b, size_t len)
 {
-    memset(p, 0, n);
+#ifdef HAVE_MEMSET_S
+    memset_s(b, len, 0, len);
+#else
+    {
+	/*
+	 * TODO: volatile is not enough if compiler have a LTO (link time
+	 * optimization)
+	 */
+	volatile char* p = (volatile char*)b;
+
+	while(len) {
+	    *p = 0;
+	    p++;
+	    len--;
+	}
+    }
+#endif
 }
+#endif