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[209.132.180.67]) by mx.google.com with ESMTP id l70si33516681pge.446.2019.07.31.18.20.47; Wed, 31 Jul 2019 18:21:01 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b="TJ/PCl/h"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727125AbfHAAAy (ORCPT + 99 others); Wed, 31 Jul 2019 20:00:54 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:46356 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726231AbfHAAAx (ORCPT ); Wed, 31 Jul 2019 20:00:53 -0400 Received: by mail-lf1-f65.google.com with SMTP id z15so44477134lfh.13 for ; Wed, 31 Jul 2019 17:00:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=UL3lL/rjWfes+fqBB30GeSXSR3w1JyhR+8U0f8P1eUw=; b=TJ/PCl/hQElX3wQElbIdv9BNHS1NuixG7oAZ1vxbVQI1gHIpQ2dLcHWzSabCbNsIck N+AN3yb/710sXZrzNBPNKg1cZUhxr5pbsDr2/6OsRwHQ/2eivwLtwI2Rgmn3HOgBStVO oKQjm9mfVNxXCLTtbojX+1ZRACMN3Yg9PuLJeck8OD3typdwUOjDXisb13Kf5W9kh0cl xOPr/c1T4x9zxRxb3ean0ZH331bALNvBdBTVvHNKCJtc6XCWtNkVdBsLvYNTFx0+1j8z vBuwJo9HBVVy22IUjspo9icTkIlv369ddxDzivDujEy37iDyO2ZzGZqHU8LtDHCKbjEN LTeg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=UL3lL/rjWfes+fqBB30GeSXSR3w1JyhR+8U0f8P1eUw=; b=ownrlZ7WI2QpanNUN3rdd2hM2d3zhrZ5+fuNG+4aM25jBYhQVYoq/ltX1ApzQdDGt5 E9r3u3XmtduY+LqLaTvIWbFX+MWqFjZkZyjeNakirDOKW+tATFTzdlEq1fMm0YmGysLX X4vIl3rUd0+EeGvgOhKgKg1FfMOkxyxNlT2wrfJ6ihVM8ynpnzhqQ/BKX2m1L/meqYT3 XLbICWIo3lQYcfxcUHFTM3vtE0RvpY1ROpnb2PHBQ73AngXtNpVmJ3h8YpzTJRGiSD4a lT8nnlBANRC9ZJJizz0GDwnFpJIo1b7JThmR+/F5tsMdjkn1w4c+dJv30g5iUXTLHjl+ Cytg== X-Gm-Message-State: APjAAAUyVuSIFsxsjB9BMvNSiEiKcOGK9FZMY3lfJKBmeUItm5LwHmkf RMQjMNHxvVnPW7z+QIH4BJPJKLyUgu7ZeoP1eeE= X-Received: by 2002:ac2:46d5:: with SMTP id p21mr26506546lfo.133.1564617651943; Wed, 31 Jul 2019 17:00:51 -0700 (PDT) MIME-Version: 1.0 References: <1d2830aadbe9d8151728a7df5b88528fc72a0095.1564549413.git.joe@perches.com> <20190731171429.GA24222@amd> <765E740C-4259-4835-A58D-432006628BAC@zytor.com> <20190731184832.GZ31381@hirez.programming.kicks-ass.net> <201907311301.EC1D84F@keescook> In-Reply-To: From: Miguel Ojeda Date: Thu, 1 Aug 2019 02:00:41 +0200 Message-ID: Subject: Re: [RFC PATCH] compiler_attributes.h: Add 'fallthrough' pseudo keyword for switch/case use To: Joe Perches Cc: Kees Cook , Peter Zijlstra , "H. Peter Anvin" , Pavel Machek , Linus Torvalds , Borislav Petkov , Thomas Gleixner , Ingo Molnar , "Gustavo A . R . Silva" , Arnaldo Carvalho de Melo , Kan Liang , Namhyung Kim , Jiri Olsa , Alexander Shishkin , Shawn Landden , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , linux-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 1, 2019 at 12:07 AM Joe Perches wrote: > > Note also that this doesn't actually _use_ fallthrough > it just reserves it. If we are reserving it, we should be giving a compile error instead. I don't see how users will understand they shouldn't use it just yet (it is the same as adding it, which actually looks more like encouragement!). Cheers, Miguel