From: Julia Lawall <Julia.Lawall@lip6.fr>
Date: Sun, 30 Nov 2014 17:03:47 +0000 (+0100)
Subject: crypto: powerpc - replace memset by memzero_explicit
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d83480b061f95db90bd9df69a21c20d0fd5c9232;p=linux-beck.git

crypto: powerpc - replace memset by memzero_explicit

Memset on a local variable may be removed when it is called just before the
variable goes out of scope.  Using memzero_explicit defeats this
optimization.  A simplified version of the semantic patch that makes this
change is as follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
type T;
@@

{
... when any
T x[...];
... when any
    when exists
- memset
+ memzero_explicit
  (x,
-0,
  ...)
... when != x
    when strict
}
// </smpl>

This change was suggested by Daniel Borkmann <dborkman@redhat.com>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

diff --git a/arch/powerpc/crypto/sha1.c b/arch/powerpc/crypto/sha1.c
index 0f88c7b41119..d3feba5a275f 100644
--- a/arch/powerpc/crypto/sha1.c
+++ b/arch/powerpc/crypto/sha1.c
@@ -66,7 +66,7 @@ static int sha1_update(struct shash_desc *desc, const u8 *data,
 			src = data + done;
 		} while (done + 63 < len);
 
-		memset(temp, 0, sizeof(temp));
+		memzero_explicit(temp, sizeof(temp));
 		partial = 0;
 	}
 	memcpy(sctx->buffer + partial, src, len - done);