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 D87EFC4332F for ; Wed, 19 Oct 2022 19:36:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230192AbiJSTg0 (ORCPT ); Wed, 19 Oct 2022 15:36:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33386 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230289AbiJSTgZ (ORCPT ); Wed, 19 Oct 2022 15:36:25 -0400 Received: from mail-qv1-xf33.google.com (mail-qv1-xf33.google.com [IPv6:2607:f8b0:4864:20::f33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A43D41ACAB5 for ; Wed, 19 Oct 2022 12:36:21 -0700 (PDT) Received: by mail-qv1-xf33.google.com with SMTP id i9so12118234qvo.0 for ; Wed, 19 Oct 2022 12:36:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=oJrk5u73GSSntjHDSFWZPm3W+d2NptLnsl4jnQ6aTBs=; b=dyDRWkQ5VqKw/n/QUOQkovOpnXZICQosgvfGHTMEB24PTjukMWkEQb6WiGZ3AaswEh VYAjmCHm81UDyKGwrRTK4pqVsKdfk4eywGlq59bCDPl2XFFHJiWrSIA1mEV0BH0Um7H8 GojY9blG/jEQqPFxqq14doFT4faiTGwkuzpcw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=oJrk5u73GSSntjHDSFWZPm3W+d2NptLnsl4jnQ6aTBs=; b=ujACc99DVIZsTZ746aE+9JfyHLvMPfd2x9Bcf96r5nVGhHnIA4njq/xyGHrybA+3xc MZBgR/ybaUES1Ptv4quTYIruIwUoKQl46CbW6VBxA5Z/JTvKeX47CVnJ8sZ7DgsDrjN6 NSMpKtRI3lWta0LRsVmirgQOhOF0fxR9KtYkYQn8WHheO+77mTiUHN3mL2pbQTe8bb5E Rn0EdLky1ARCLdlwakiaOV7W5t1hI3Kcpt1j2QhT6wTDAyzWZ3TWHath3YSyH5dwMKW9 ocQ/ZxgOr+/r9LtbMYCjAIRLAeByx9Z8FPrQZfKNiwMjmivGRL9tb9RZbdEFqOBz+OH2 jT0A== X-Gm-Message-State: ACrzQf3idWSuO1M1HlhHLNTM2/usiJCO32Gdr1ODn/RWh7m1SHCiCqAm lNdkdmzFjxYOyvbriZK+vReMc6KmBbrmdg== X-Google-Smtp-Source: AMsMyM43AaR543G8WRD71EPIvdObfb3lge6Pr43i+Q7DYgGYZv6scSTICn5BgahY0rlWNSrvGCm94A== X-Received: by 2002:ad4:5dc6:0:b0:4b3:5d60:f41c with SMTP id m6-20020ad45dc6000000b004b35d60f41cmr8217618qvh.100.1666208180402; Wed, 19 Oct 2022 12:36:20 -0700 (PDT) Received: from mail-yw1-f170.google.com (mail-yw1-f170.google.com. [209.85.128.170]) by smtp.gmail.com with ESMTPSA id bj3-20020a05620a190300b006eeca296c00sm5738706qkb.104.2022.10.19.12.36.17 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 19 Oct 2022 12:36:17 -0700 (PDT) Received: by mail-yw1-f170.google.com with SMTP id 00721157ae682-35ad0584879so178079457b3.7 for ; Wed, 19 Oct 2022 12:36:17 -0700 (PDT) X-Received: by 2002:a81:1007:0:b0:357:45e3:304c with SMTP id 7-20020a811007000000b0035745e3304cmr8223552ywq.340.1666208177358; Wed, 19 Oct 2022 12:36:17 -0700 (PDT) MIME-Version: 1.0 References: <20221019162648.3557490-1-Jason@zx2c4.com> <20221019165455.GL25951@gate.crashing.org> In-Reply-To: From: Linus Torvalds Date: Wed, 19 Oct 2022 12:36:01 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] kbuild: treat char as always signed To: Andy Shevchenko Cc: Nick Desaulniers , Segher Boessenkool , "Jason A. Donenfeld" , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, linux-toolchains@vger.kernel.org, Masahiro Yamada , Kees Cook , Andrew Morton , Greg Kroah-Hartman Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-toolchains@vger.kernel.org On Wed, Oct 19, 2022 at 12:23 PM Andy Shevchenko wrote: > > > We do have a couple of signed bitfields in the kernel, but they are > > unusual enough that it's actually a good thing that sparse just made > > people be explicit about it. > > At least drivers/media/usb/msi2500/msi2500.c:289 can be converted > to use sign_extend32() I believe. Heh. I didn't even look at that one - I did check that yeah, the MIPS ones made sense (I say "ones", because while my grep pattern only finds one, there are several others that have spacing that just made my grep miss them). You're right, that msi2500 use is a very odd use of bitfields for just sign extension. That's hilariously odd code, but not exactly wrong. And using "signed int x:14" does make it very explicit that the bitfield wants that sign. And that code does actually have a fair number of comments to explain each step, so I think it's all ok. Strange, but ok. Linus