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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26FF5C5ACA0 for ; Thu, 17 Aug 2023 20:14:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353428AbjHQUNl (ORCPT ); Thu, 17 Aug 2023 16:13:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349599AbjHQUNJ (ORCPT ); Thu, 17 Aug 2023 16:13:09 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01AA02D64; Thu, 17 Aug 2023 13:13:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8C0B261AF3; Thu, 17 Aug 2023 20:13:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BC47C433C7; Thu, 17 Aug 2023 20:13:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692303186; bh=aziOaixc2lJtyRiMlmlj48+cS+C2YnQu5Q+Dc0tYZJU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IXbMwcYfJeZgNSioEpHIUAvaMjwt2lp0UpdvmvRaAVx3iXbtYLkGVIjJANaVNu4ri NEa+0Avfz2wJvexiO/a66rFmyFsFQmsQlKXMIn7YDDUfm85PeXKW7dZ+nPvBRD02Li GwivvrWc3I2tNnz94wSF6KU7ZFZeUHTUwOhSFogweNAqDu2kruTE6k60IN2dK1hCVM 2fvHeSAjdLfEH70UxanorntRlE41DpimfTxy/vwP51hIUA9oIjebc+CeMUBnOyoxdJ vSAkdNRyrDyjMhZVnbxb528+AD9k59jwYnAuVcwd7fI6HeqRIARUMZWw2XFuARhDKn 1ZSt1e7arKhBw== Date: Thu, 17 Aug 2023 13:13:04 -0700 From: Nathan Chancellor To: Kees Cook Cc: Miguel Ojeda , Nick Desaulniers , Tom Rix , "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org, llvm@lists.linux.dev, linux-hardening@vger.kernel.org Subject: Re: [PATCH] Compiler Attributes: counted_by: Adjust name and identifier expansion Message-ID: <20230817201304.GA2714089@dev-arch.thelio-3990X> References: <20230817200558.never.077-kees@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230817200558.never.077-kees@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 17, 2023 at 01:06:03PM -0700, Kees Cook wrote: > GCC and Clang's current RFCs name this attribute "counted_by", and have > moved away from using a string for the member name. Update the kernel's > macros to match. Additionally provide a UAPI no-op macro for UAPI structs > that will gain annotations. > > Cc: Miguel Ojeda > Cc: Nick Desaulniers > Fixes: dd06e72e68bc ("Compiler Attributes: Add __counted_by macro") > Signed-off-by: Kees Cook Reviewed-by: Nathan Chancellor One comment below. > --- > include/linux/compiler_attributes.h | 26 +++++++++++++------------- > include/uapi/linux/stddef.h | 4 ++++ > 2 files changed, 17 insertions(+), 13 deletions(-) > > diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h > index 00efa35c350f..74716a407aac 100644 > --- a/include/linux/compiler_attributes.h > +++ b/include/linux/compiler_attributes.h > @@ -94,6 +94,19 @@ > # define __copy(symbol) > #endif > > +/* > + * Optional: only supported since gcc >= 14 > + * Optional: only supported since clang >= 17 Since you are in the area, should the supported clang version be optimistically updated to '18'? 17.x has already branched and I suspect it would be too late in the release cycle to cherry-pick that change from main if it were landed today (which seems pretty unlikely, given there do not appear to be many reviews from high profile clang folks yet). > + * > + * gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896 > + * clang: https://reviews.llvm.org/D148381 > + */ > +#if __has_attribute(__counted_by__) > +# define __counted_by(member) __attribute__((__counted_by__(member))) > +#else > +# define __counted_by(member) > +#endif > + > /* > * Optional: not supported by gcc > * Optional: only supported since clang >= 14.0 > @@ -129,19 +142,6 @@ > # define __designated_init > #endif > > -/* > - * Optional: only supported since gcc >= 14 > - * Optional: only supported since clang >= 17 > - * > - * gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896 > - * clang: https://reviews.llvm.org/D148381 > - */ > -#if __has_attribute(__element_count__) > -# define __counted_by(member) __attribute__((__element_count__(#member))) > -#else > -# define __counted_by(member) > -#endif > - > /* > * Optional: only supported since clang >= 14.0 > * > diff --git a/include/uapi/linux/stddef.h b/include/uapi/linux/stddef.h > index 7837ba4fe728..7c3fc3980881 100644 > --- a/include/uapi/linux/stddef.h > +++ b/include/uapi/linux/stddef.h > @@ -45,3 +45,7 @@ > TYPE NAME[]; \ > } > #endif > + > +#ifndef __counted_by > +#define __counted_by(m) > +#endif > -- > 2.34.1 >