From patchwork Mon Oct 7 22:00:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arvind Sankar X-Patchwork-Id: 11178559 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9E4ED76 for ; Mon, 7 Oct 2019 22:00:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8699621479 for ; Mon, 7 Oct 2019 22:00:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729457AbfJGWAG (ORCPT ); Mon, 7 Oct 2019 18:00:06 -0400 Received: from mail-qk1-f193.google.com ([209.85.222.193]:43756 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728422AbfJGWAG (ORCPT ); Mon, 7 Oct 2019 18:00:06 -0400 Received: by mail-qk1-f193.google.com with SMTP id h126so14233221qke.10; Mon, 07 Oct 2019 15:00:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:in-reply-to:user-agent; bh=ZU2lhuzvcrgsM0rNDDAmLSl8Fi5wF3gmf9pM3Bgvdh4=; b=nEBqwgpOz0zwXSxFbDBXCbC4ESIEV+bDZlAUMMogxLx9Y+wGfJnjiDCo7S0utspGDV +v8cQTtGVPrcfbam54onodMqoRwb89ZfwgA8HiJB8V08ksytcxSXVpOvSkKAZRN9fO3N 0kF5pczUqDkiU9rin5y9X63ufSMpGDDklfpEVGvXTu5pEF5E4OU5bUk/eoOJyMdx+1hL ffu425VEWxO3yDoRSveE85lYrORDZciutBcakcZGuwBod0Gwn/sujwBBVLsaC9QVAJlD B0Bw4TbOVKUUSlpLQJgHNHC/OC+1jtP1Qcgvj9yo+Zochv9ZSlLJmRJGwieBomxIFkPK +osQ== X-Gm-Message-State: APjAAAWeMewj9c08lveKGoL70grvi4AHqm7KMtpvRWh2ZFGIT+Wi6EWv fSLYwJ9Ud1w3akD0Jl/s4Dhtq/gVF9OVLA== X-Google-Smtp-Source: APXvYqyxz7pCaCHojodDGLBP1EWQgIU9sNOuMJ+ftpmvqJk91fya1fLMitK2111hM63EVcgElwz42A== X-Received: by 2002:a05:620a:7ca:: with SMTP id 10mr26285144qkb.410.1570485604791; Mon, 07 Oct 2019 15:00:04 -0700 (PDT) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id q200sm7852142qke.114.2019.10.07.15.00.04 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Oct 2019 15:00:04 -0700 (PDT) Date: Mon, 7 Oct 2019 18:00:02 -0400 From: Arvind Sankar To: linux-kernel@vger.kernel.org, Ingo Molnar , Hans de Goede Cc: linux-crypto@vger.kernel.org, linux-s390@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Herbert Xu , Ard Biesheuvel , Stephan Mueller Subject: [PATCH] lib/string: make memzero_explicit inline instead of external Message-ID: <20191007220000.GA408752@rani.riverdale.lan> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1d17349e-98ab-b582-6981-b484b0e970b6@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org With the use of the barrier implied by barrier_data(), there is no need for memzero_explicit to be extern. Making it inline saves the overhead of a function call, and allows the code to be reused in arch/*/purgatory without having to duplicate the implementation. Fixes: 906a4bb97f5d ("crypto: sha256 - Use get/put_unaligned_be32 to get input, memzero_explicit") Reviewed-by: Hans de Goede Tested-by: Hans de Goede Signed-off-by: Arvind Sankar Tested-by: Dave Young --- include/linux/string.h | 21 ++++++++++++++++++++- lib/string.c | 21 --------------------- 2 files changed, 20 insertions(+), 22 deletions(-) diff --git a/include/linux/string.h b/include/linux/string.h index b2f9df7f0761..b6ccdc2c7f02 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -227,7 +227,26 @@ static inline bool strstarts(const char *str, const char *prefix) } size_t memweight(const void *ptr, size_t bytes); -void memzero_explicit(void *s, size_t count); + +/** + * memzero_explicit - Fill a region of memory (e.g. sensitive + * keying data) with 0s. + * @s: Pointer to the start of the area. + * @count: The size of the area. + * + * Note: usually using memset() is just fine (!), but in cases + * where clearing out _local_ data at the end of a scope is + * necessary, memzero_explicit() should be used instead in + * order to prevent the compiler from optimising away zeroing. + * + * memzero_explicit() doesn't need an arch-specific version as + * it just invokes the one of memset() implicitly. + */ +static inline void memzero_explicit(void *s, size_t count) +{ + memset(s, 0, count); + barrier_data(s); +} /** * kbasename - return the last part of a pathname. diff --git a/lib/string.c b/lib/string.c index cd7a10c19210..08ec58cc673b 100644 --- a/lib/string.c +++ b/lib/string.c @@ -748,27 +748,6 @@ void *memset(void *s, int c, size_t count) EXPORT_SYMBOL(memset); #endif -/** - * memzero_explicit - Fill a region of memory (e.g. sensitive - * keying data) with 0s. - * @s: Pointer to the start of the area. - * @count: The size of the area. - * - * Note: usually using memset() is just fine (!), but in cases - * where clearing out _local_ data at the end of a scope is - * necessary, memzero_explicit() should be used instead in - * order to prevent the compiler from optimising away zeroing. - * - * memzero_explicit() doesn't need an arch-specific version as - * it just invokes the one of memset() implicitly. - */ -void memzero_explicit(void *s, size_t count) -{ - memset(s, 0, count); - barrier_data(s); -} -EXPORT_SYMBOL(memzero_explicit); - #ifndef __HAVE_ARCH_MEMSET16 /** * memset16() - Fill a memory area with a uint16_t