From patchwork Sun Nov 30 16:59:33 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julia Lawall X-Patchwork-Id: 5408831 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 621F09F1CD for ; Sun, 30 Nov 2014 17:07:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A44FB20204 for ; Sun, 30 Nov 2014 17:07:54 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C1D9920154 for ; Sun, 30 Nov 2014 17:07:53 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xv7wj-0000Pt-0I; Sun, 30 Nov 2014 17:06:05 +0000 Received: from mail3-relais-sop.national.inria.fr ([192.134.164.104]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xv7wX-0000GC-6L for linux-arm-kernel@lists.infradead.org; Sun, 30 Nov 2014 17:05:54 +0000 X-IronPort-AV: E=Sophos;i="5.07,488,1413237600"; d="scan'208";a="91114607" Received: from palace.rsr.lip6.fr (HELO localhost.localdomain) ([132.227.105.202]) by mail3-relais-sop.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-SHA; 30 Nov 2014 18:06:28 +0100 From: Julia Lawall To: Herbert Xu Subject: [PATCH 7/8] crypto: replace memset by memzero_explicit Date: Sun, 30 Nov 2014 17:59:33 +0100 Message-Id: <1417366774-32412-8-git-send-email-Julia.Lawall@lip6.fr> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1417366774-32412-1-git-send-email-Julia.Lawall@lip6.fr> References: <1417366774-32412-1-git-send-email-Julia.Lawall@lip6.fr> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141130_090553_655107_7BE15EE0 X-CRM114-Status: GOOD ( 11.21 ) X-Spam-Score: -4.4 (----) Cc: Russell King , herbert@gondor.apana.org.au, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, dborkman@redhat.com, Julia Lawall , linux-crypto@vger.kernel.org, "David S. Miller" , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Julia Lawall 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/) // @@ identifier x; type T; @@ { ... when any T x[...]; ... when any when exists - memset + memzero_explicit (x, -0, ...) ... when != x when strict } // This change was suggested by Daniel Borkmann Signed-off-by: Julia Lawall --- Daniel Borkmann suggested that these patches could go through Herbert Xu's cryptodev tree. I was not able to compile test this one. arch/arm/crypto/sha512_neon_glue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/crypto/sha512_neon_glue.c b/arch/arm/crypto/sha512_neon_glue.c index f3452c6..b124dce 100644 --- a/arch/arm/crypto/sha512_neon_glue.c +++ b/arch/arm/crypto/sha512_neon_glue.c @@ -241,7 +241,7 @@ static int sha384_neon_final(struct shash_desc *desc, u8 *hash) sha512_neon_final(desc, D); memcpy(hash, D, SHA384_DIGEST_SIZE); - memset(D, 0, SHA512_DIGEST_SIZE); + memzero_explicit(D, SHA512_DIGEST_SIZE); return 0; }