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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 11:13:18 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 11:13:18 +0000
commit9e7e4ab6617fef1d1681fc2d3e02554264ccc954 (patch)
tree336445493163aa0370cb7830d97ebd8819b2e2c5 /openbsd-compat/explicit_bzero.c
parentInitial commit. (diff)
downloadopenssh-9e7e4ab6617fef1d1681fc2d3e02554264ccc954.tar.xz
openssh-9e7e4ab6617fef1d1681fc2d3e02554264ccc954.zip
Adding upstream version 1:8.4p1.upstream/1%8.4p1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'openbsd-compat/explicit_bzero.c')
-rw-r--r--openbsd-compat/explicit_bzero.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/openbsd-compat/explicit_bzero.c b/openbsd-compat/explicit_bzero.c
new file mode 100644
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--- /dev/null
+++ b/openbsd-compat/explicit_bzero.c
@@ -0,0 +1,57 @@
+/* OPENBSD ORIGINAL: lib/libc/string/explicit_bzero.c */
+/* $OpenBSD: explicit_bzero.c,v 1.1 2014/01/22 21:06:45 tedu Exp $ */
+/*
+ * Public domain.
+ * Written by Ted Unangst
+ */
+
+#include "includes.h"
+
+#include <string.h>
+
+/*
+ * explicit_bzero - don't let the compiler optimize away bzero
+ */
+
+#ifndef HAVE_EXPLICIT_BZERO
+
+#ifdef HAVE_MEMSET_S
+
+void
+explicit_bzero(void *p, size_t n)
+{
+ if (n == 0)
+ return;
+ (void)memset_s(p, n, 0, n);
+}
+
+#else /* HAVE_MEMSET_S */
+
+/*
+ * Indirect bzero through a volatile pointer to hopefully avoid
+ * dead-store optimisation eliminating the call.
+ */
+static void (* volatile ssh_bzero)(void *, size_t) = bzero;
+
+void
+explicit_bzero(void *p, size_t n)
+{
+ if (n == 0)
+ return;
+ /*
+ * clang -fsanitize=memory needs to intercept memset-like functions
+ * to correctly detect memory initialisation. Make sure one is called
+ * directly since our indirection trick above successfully confuses it.
+ */
+#if defined(__has_feature)
+# if __has_feature(memory_sanitizer)
+ memset(p, 0, n);
+# endif
+#endif
+
+ ssh_bzero(p, n);
+}
+
+#endif /* HAVE_MEMSET_S */
+
+#endif /* HAVE_EXPLICIT_BZERO */