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Re: [PATCH 2/5] Add explicit_bzero()

Ok, I should have added this to the commit message. The current version is not link-time optimization safe. See discussions:

My conclusion was to wait for proper compiler support.

On 18/03/16 12:24, Corinna Vinschen wrote:
On Mar 18 11:49, Sebastian Huber wrote:
This function is used by LibreSSL and OpenSSH and is provided by the
OpenBSD libc.
+#include <string.h>
+ * explicit_bzero - don't let the compiler optimize away bzero
+ */
+explicit_bzero(void *p, size_t n)
+	bzero(p, n);
The OpenSSH version looks a bit different:

    * Indirect bzero through a volatile pointer to hopefully avoid
    * dead-store optimisation eliminating the call.
   static void (* volatile ssh_bzero)(void *, size_t) = bzero;

   explicit_bzero(void *p, size_t n)
	  ssh_bzero(p, n);

Is that something we should do, too, or is that paranoia at its
finest only?


Sebastian Huber, embedded brains GmbH

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