From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7959DC47404 for ; Thu, 10 Oct 2019 02:52:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D87820B7C for ; Thu, 10 Oct 2019 02:52:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732546AbfJJCwk (ORCPT ); Wed, 9 Oct 2019 22:52:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39694 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731589AbfJJCwk (ORCPT ); Wed, 9 Oct 2019 22:52:40 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 401BE30860D6; Thu, 10 Oct 2019 02:52:39 +0000 (UTC) Received: from dhcp-128-65.nay.redhat.com (ovpn-12-56.pek2.redhat.com [10.72.12.56]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 54D1260923; Thu, 10 Oct 2019 02:52:33 +0000 (UTC) Date: Thu, 10 Oct 2019 10:52:29 +0800 From: Dave Young To: Arvind Sankar Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Hans de Goede , 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 , kexec@lists.infradead.org Subject: Re: [PATCH] lib/string: make memzero_explicit inline instead of external Message-ID: <20191010025229.GA3376@dhcp-128-65.nay.redhat.com> References: <1d17349e-98ab-b582-6981-b484b0e970b6@redhat.com> <20191007220000.GA408752@rani.riverdale.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191007220000.GA408752@rani.riverdale.lan> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Thu, 10 Oct 2019 02:52:40 +0000 (UTC) Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On 10/07/19 at 06:00pm, Arvind Sankar wrote: > 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 > --- > 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 > -- Thanks for the fix! Ccing kexec list since the problem is kexec/kdump related. People can try it when they see same issue. Dave From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iIOZG-0007XU-52 for kexec@lists.infradead.org; Thu, 10 Oct 2019 02:52:44 +0000 Date: Thu, 10 Oct 2019 10:52:29 +0800 From: Dave Young Subject: Re: [PATCH] lib/string: make memzero_explicit inline instead of external Message-ID: <20191010025229.GA3376@dhcp-128-65.nay.redhat.com> References: <1d17349e-98ab-b582-6981-b484b0e970b6@redhat.com> <20191007220000.GA408752@rani.riverdale.lan> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191007220000.GA408752@rani.riverdale.lan> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Arvind Sankar Cc: linux-s390@vger.kernel.org, Herbert Xu , Ard Biesheuvel , Stephan Mueller , x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Hans de Goede , Ingo Molnar , Borislav Petkov , linux-crypto@vger.kernel.org, "H . Peter Anvin" , Thomas Gleixner , Ingo Molnar On 10/07/19 at 06:00pm, Arvind Sankar wrote: > 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 > --- > 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 > -- Thanks for the fix! Ccing kexec list since the problem is kexec/kdump related. People can try it when they see same issue. Dave _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec