[PATCH] proposal adding explicit_bzero

[David CARLIER <devnexen@gmail.com>]

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Hi dear lists,
this is my first message so forgive me if this idea had already been rejected.

Kind regards.

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From c0a16cf96b96b009097d6ed656a2a7b8969e8399 Mon Sep 17 00:00:00 2001
From: David Carlier <dcarlier@afilias.info>
Date: Fri, 15 Jun 2018 13:30:09 +0000
Subject: [PATCH] string: adding simple explicit_bzero implementation.

glibc implementing it and modern security based code starting
using it widely, here a simple implementation using memory barrier.
---
 include/string.h            | 1 +
 src/string/explicit_bzero.c | 8 ++++++++
 2 files changed, 9 insertions(+)
 create mode 100644 src/string/explicit_bzero.c

diff --git a/include/string.h b/include/string.h
index ce1dc300..795a2abc 100644
--- a/include/string.h
+++ b/include/string.h
@@ -82,6 +82,7 @@ void *memccpy (void *__restrict, const void *__restrict, int, size_t);
 char *strsep(char **, const char *);
 size_t strlcat (char *, const char *, size_t);
 size_t strlcpy (char *, const char *, size_t);
+void explicit_bzero (void *, size_t);
 #endif
 
 #ifdef _GNU_SOURCE
diff --git a/src/string/explicit_bzero.c b/src/string/explicit_bzero.c
new file mode 100644
index 00000000..47dba3c7
--- /dev/null
+++ b/src/string/explicit_bzero.c
@@ -0,0 +1,8 @@
+#define _BSD_SOURCE
+#include <string.h>
+
+void explicit_bzero(void *d, size_t n)
+{
+	memset(d, 0, n);
+	__asm__ volatile("": "r="(d) :: "memory");
+}
-- 
2.14.1