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 90FBDC77B73 for ; Thu, 27 Apr 2023 08:31:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243116AbjD0IbA (ORCPT ); Thu, 27 Apr 2023 04:31:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243044AbjD0Ia5 (ORCPT ); Thu, 27 Apr 2023 04:30:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1845635A6; Thu, 27 Apr 2023 01:30:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9FAB263B95; Thu, 27 Apr 2023 08:30:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B45CFC433D2; Thu, 27 Apr 2023 08:30:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1682584255; bh=IjxCeFXNKWQY8KVcSMtLu5/gGhTGtBIACEOnd4UUKAY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DnWrxOYe0uv6FWThGph9NFDloKu5HSdxqADr2R2ACQAoVF9AKj/K04MBdUrKI6NeA 1jvnvbsfsYNxW7wYtnLOOrza9gQK0Yt5O8XPasYy3PavJ9B9ubsXyXHdU/3kdVgmx7 UOeOMN9DxOSWld/wjXnWg4dPf9s1NYn/Pkh1I3yU= Date: Thu, 27 Apr 2023 10:30:52 +0200 From: Greg KH To: SeongJae Park Cc: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org, David Gow , Sergio =?iso-8859-1?Q?Gonz=E1lez?= Collado , Richard Weinberger , tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org Subject: Re: [PATCH AUTOSEL 6.1 04/13] rust: arch/um: Disable FP/SIMD instruction to match x86 Message-ID: <2023042745-unclasp-briar-5b2a@gregkh> References: <20230314124325.470931-4-sashal@kernel.org> <20230425000118.45838-1-sj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230425000118.45838-1-sj@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 25, 2023 at 12:01:18AM +0000, SeongJae Park wrote: > Hello Sasha and Greg, > > > On Tue, 14 Mar 2023 08:43:16 -0400 Sasha Levin wrote: > > > From: David Gow > > > > [ Upstream commit 8849818679478933dd1d9718741f4daa3f4e8b86 ] > > > > The kernel disables all SSE and similar FP/SIMD instructions on > > x86-based architectures (partly because we shouldn't be using floats in > > the kernel, and partly to avoid the need for stack alignment, see: > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 ) > > > > UML does not do the same thing, which isn't in itself a problem, but > > does add to the list of differences between UML and "normal" x86 builds. > > > > In addition, there was a crash bug with LLVM < 15 / rustc < 1.65 when > > building with SSE, so disabling it fixes rust builds with earlier > > compiler versions, see: > > https://github.com/Rust-for-Linux/linux/pull/881 > > > > Signed-off-by: David Gow > > Reviewed-by: Sergio González Collado > > Signed-off-by: Richard Weinberger > > Signed-off-by: Sasha Levin > > There is a followup fix of this patch that merged into the mainline by commit > a3046a618a28 ("um: Only disable SSE on clang to work around old GCC bugs"), but > it has not added to 6.1.y so far. Without it, compiling on some setup using an > old version of gcc fails, as the followup is also mentioning. I also confirmed > the issue can be reproduced on latest 6.1.y. > > Could you please add the followup fix to 6.1.y? I confirmed the commit can be > cleanly cherry-picked on latest 6.1.y, and fixes the issue as expected. Now queued up, thanks. greg k-h