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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 8DD59C4361B for ; Mon, 14 Dec 2020 15:28:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44C6C22B2C for ; Mon, 14 Dec 2020 15:28:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731528AbgLNP2H (ORCPT ); Mon, 14 Dec 2020 10:28:07 -0500 Received: from elvis.franken.de ([193.175.24.41]:40266 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406208AbgLNP2G (ORCPT ); Mon, 14 Dec 2020 10:28:06 -0500 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1kopkv-0006Cf-02; Mon, 14 Dec 2020 16:27:21 +0100 Received: by alpha.franken.de (Postfix, from userid 1000) id 60377C037B; Mon, 14 Dec 2020 16:24:47 +0100 (CET) Date: Mon, 14 Dec 2020 16:24:47 +0100 From: Thomas Bogendoerfer To: Anders Roxell Cc: natechancellor@gmail.com, ndesaulniers@google.com, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH v2] mips: lib: uncached: fix non-standard usage of variable 'sp' Message-ID: <20201214152447.GC9149@alpha.franken.de> References: <20201211102437.3929348-1-anders.roxell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201211102437.3929348-1-anders.roxell@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Fri, Dec 11, 2020 at 11:24:37AM +0100, Anders Roxell wrote: > When building mips tinyconfig with clang the following warning show up: > > arch/mips/lib/uncached.c:45:6: warning: variable 'sp' is uninitialized when used here [-Wuninitialized] > if (sp >= (long)CKSEG0 && sp < (long)CKSEG2) > ^~ > arch/mips/lib/uncached.c:40:18: note: initialize the variable 'sp' to silence this warning > register long sp __asm__("$sp"); > ^ > = 0 > 1 warning generated. > > Rework to make an explicit inline move, instead of the non-standard use > of specifying registers for local variables. This is what's written > from the gcc-10 manual [1] about specifying registers for local > variables: > > "6.47.5.2 Specifying Registers for Local Variables > ................................................. > [...] > > "The only supported use for this feature is to specify registers for > input and output operands when calling Extended 'asm' (*note Extended > Asm::). [...]". > > [1] https://docs.w3cub.com/gcc~10/local-register-variables > Signed-off-by: Anders Roxell > --- > arch/mips/lib/uncached.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) applied to mips-next. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]