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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 06A9EC43381 for ; Mon, 18 Mar 2019 17:16:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C08E420863 for ; Mon, 18 Mar 2019 17:16:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="re7e79YQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727622AbfCRRQO (ORCPT ); Mon, 18 Mar 2019 13:16:14 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:36650 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726765AbfCRRQO (ORCPT ); Mon, 18 Mar 2019 13:16:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=zd2PatB3kgJ3fmUKExcsxWAv3pQUnPPizAMl6bLC1eM=; b=re7e79YQYePtoWPqedXK6ezH6 7uXj7dawFXhCd2KS7YojxGWsNRsG4NuScRH2puIqpQAYP+Cxh8Q6qGRdxpfltf5XkDg5vWgoCT7kt 8VcpouNZ1eSH6wuWX2kDoc/R6ZhVsiZZFORVUynajfNvyw+3j7Ii7DQg37YTEAiR1hFKu5m97t73y 7pSf8GIseeg+nwHC5GmOFn3p2cpHl6OSHwI7mqbN5C8h+0V+iHiN+ed0+i0gGoiUCkzYx4I+86W5r oIWQAXxY0+/S0nFWmBFkwY+Fc7wmpX/Ie+JgjX1aehUOgDRIwm4Rh9o0tRqCA8xyphKGYaPvikE2O 2VbSmObZQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1h5vrq-0002NV-TJ; Mon, 18 Mar 2019 17:16:07 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 317F5238A0165; Mon, 18 Mar 2019 18:16:04 +0100 (CET) Date: Mon, 18 Mar 2019 18:16:04 +0100 From: Peter Zijlstra To: Nick Desaulniers Cc: Matthias Kaehlcke , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , x86@kernel.org, LKML , Manoj Gupta , Tiancong Wang , Stephen Hines , clang-built-linux@googlegroups.com, Masahiro Yamada Subject: Re: [PATCH] x86/vdso: include generic __lshrdi3 in 32-bit vDSO Message-ID: <20190318171604.GU6058@hirez.programming.kicks-ass.net> References: <20190315222906.GC112750@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 18, 2019 at 10:09:37AM -0700, Nick Desaulniers wrote: > On Fri, Mar 15, 2019 at 3:29 PM Matthias Kaehlcke wrote: > > On Fri, Mar 15, 2019 at 02:31:09PM -0700, 'Nick Desaulniers' via Clang Built Linux wrote: > > > Is there a config I can set to reproduce this, in order to help > > > test? > > > > I encountered it with a Chrome OS specific configuration, but a > > defconfig should do. > > defconfig selects CONFIG_OPTIMIZE_FOR_PERFORMANCE=y. I needed to > select CONFIG_CC_OPTIMIZE_FOR_SIZE=y to repro. My CI is simply > running defconfigs, which is why I didn't catch this. I suspect the right fix is to make clang use -Os and abolish that -Oz madness.