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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 E66B1C433E3 for ; Thu, 20 Aug 2020 03:34:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFDEC20639 for ; Thu, 20 Aug 2020 03:34:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="HJ9D3ITY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726965AbgHTDeX (ORCPT ); Wed, 19 Aug 2020 23:34:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726435AbgHTDeW (ORCPT ); Wed, 19 Aug 2020 23:34:22 -0400 Received: from mail-qk1-x743.google.com (mail-qk1-x743.google.com [IPv6:2607:f8b0:4864:20::743]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63CA1C061757; Wed, 19 Aug 2020 20:34:22 -0700 (PDT) Received: by mail-qk1-x743.google.com with SMTP id 2so469783qkf.10; Wed, 19 Aug 2020 20:34:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=rR24exBfQVkWtacavopzrmH6PxpvBA+Nf0yqd/BMG9E=; b=HJ9D3ITYMCvLAArz8DK8SGV59PkSSo29GqCB9Z9SJ6XraYNdLynVE691bcdGgMSDDN hxxLdJyCMuzmbOtjTKDRoGlRqt5vH8x39y2B/Se5AyD93apZP7ce4Qyj85d70i/cEkPy 4IGmJneYPp0H3t+8UkWhwm6xBijIPn/+5zXLaIpW+DQ3qtlgGSwpjbSca8L5hWoVnI5y tl8EqNvSJjKx5W78/Sc1N9SDbg94vSZB0kJrpSH9onIdKswBLq5kEqaaptNxGhlvf0BB JuX1RPN/Uc7YH85ejg34Y6LPup/+D1xOGXN9TKU1uRuZDMq9wtYHZ/Z4M8ySdAvFaOIV oyEw== 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:references :mime-version:content-disposition:in-reply-to; bh=rR24exBfQVkWtacavopzrmH6PxpvBA+Nf0yqd/BMG9E=; b=EhjHwQ4WapOefVFIOO6YkLAFyzzoRtbIsoXrQYRAD/dh84BjkKigcnMByfC6h6vB6+ prIF8KQb9L0s85X+wStnrilq3iCxSBvT1lPvbp0Dj+d54gKdbzWZLajCcJD5xtmkzdji HseqP71Yt/buLgqlho/2rl97IegJSqXwVwyaDlRqoSdAiOtfxP2wwtLsDeN/OF89cSI1 fZFv7DpnyWOxVgf8J73u1+zQ3EoBfNqQHTrELOY3vX3yFfPxB+rw6M3pw6Sltk/MbC3P qFjmlg7/yd+aJg8FAZBTjgoYM4MwpG7CLKFI91ZSlezz9QrTka77uyOM8fy4DYQwjjNn O37A== X-Gm-Message-State: AOAM53039z9XcU8D/rwe4orq/ky/6/N0QY1ufdz6/5T31FZYsZAZ9MhM 86Zhx3Zw892zl4SA/X3kW0Q= X-Google-Smtp-Source: ABdhPJzic2ynnUlv8fsvPVT9UW/uNizR8J71CrvkvSNpOU+Ea0IlZKCor7tcjK61capu5RqbLNkjpw== X-Received: by 2002:a37:62cf:: with SMTP id w198mr1047965qkb.172.1597894461585; Wed, 19 Aug 2020 20:34:21 -0700 (PDT) Received: from ubuntu-n2-xlarge-x86 ([2604:1380:45d1:2600::1]) by smtp.gmail.com with ESMTPSA id o47sm1545390qtk.19.2020.08.19.20.34.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Aug 2020 20:34:20 -0700 (PDT) Date: Wed, 19 Aug 2020 20:34:19 -0700 From: Nathan Chancellor To: Nick Desaulniers Cc: Masahiro Yamada , Andrew Morton , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Michal Marek , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, Kees Cook , Tony Luck , Dmitry Vyukov , Michael Ellerman , Joe Perches , Joel Fernandes , Daniel Axtens , Arvind Sankar , Andy Shevchenko , Alexandru Ardelean , Yury Norov , x86@kernel.org, "H . Peter Anvin" , Ard Biesheuvel , "Paul E . McKenney" , Daniel Kiper , Bruce Ashfield , Marco Elver , Vamshi K Sthambamkadi , Andi Kleen , Linus Torvalds , =?iso-8859-1?Q?D=E1vid_Bolvansk=FD?= , Eli Friedman Subject: Re: [PATCH v2 3/5] Revert "lib/string.c: implement a basic bcmp" Message-ID: <20200820033419.GC2167124@ubuntu-n2-xlarge-x86> References: <20200819191654.1130563-1-ndesaulniers@google.com> <20200819191654.1130563-4-ndesaulniers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200819191654.1130563-4-ndesaulniers@google.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 19, 2020 at 12:16:52PM -0700, Nick Desaulniers wrote: > This reverts commit 5f074f3e192f10c9fade898b9b3b8812e3d83342. > > An earlier commit in the series prevents the compiler from emitting > calls to bcmp as part of "libcall optimization," and there are no > explicit callers, so we can now safely remove this interface. > > Suggested-by: Nathan Chancellor > Reviewed-by: Kees Cook > Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor > --- > include/linux/string.h | 3 --- > lib/string.c | 20 -------------------- > 2 files changed, 23 deletions(-) > > diff --git a/include/linux/string.h b/include/linux/string.h > index b1f3894a0a3e..f3bdb74bc230 100644 > --- a/include/linux/string.h > +++ b/include/linux/string.h > @@ -155,9 +155,6 @@ extern void * memscan(void *,int,__kernel_size_t); > #ifndef __HAVE_ARCH_MEMCMP > extern int memcmp(const void *,const void *,__kernel_size_t); > #endif > -#ifndef __HAVE_ARCH_BCMP > -extern int bcmp(const void *,const void *,__kernel_size_t); > -#endif > #ifndef __HAVE_ARCH_MEMCHR > extern void * memchr(const void *,int,__kernel_size_t); > #endif > diff --git a/lib/string.c b/lib/string.c > index 6012c385fb31..69328b8353e1 100644 > --- a/lib/string.c > +++ b/lib/string.c > @@ -922,26 +922,6 @@ __visible int memcmp(const void *cs, const void *ct, size_t count) > EXPORT_SYMBOL(memcmp); > #endif > > -#ifndef __HAVE_ARCH_BCMP > -/** > - * bcmp - returns 0 if and only if the buffers have identical contents. > - * @a: pointer to first buffer. > - * @b: pointer to second buffer. > - * @len: size of buffers. > - * > - * The sign or magnitude of a non-zero return value has no particular > - * meaning, and architectures may implement their own more efficient bcmp(). So > - * while this particular implementation is a simple (tail) call to memcmp, do > - * not rely on anything but whether the return value is zero or non-zero. > - */ > -#undef bcmp > -int bcmp(const void *a, const void *b, size_t len) > -{ > - return memcmp(a, b, len); > -} > -EXPORT_SYMBOL(bcmp); > -#endif > - > #ifndef __HAVE_ARCH_MEMSCAN > /** > * memscan - Find a character in an area of memory. > -- > 2.28.0.297.g1956fa8f8d-goog >