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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 087D6C41604 for ; Tue, 6 Oct 2020 08:32:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C13F20789 for ; Tue, 6 Oct 2020 08:32:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="UBksAM3Q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726006AbgJFIcc (ORCPT ); Tue, 6 Oct 2020 04:32:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725891AbgJFIca (ORCPT ); Tue, 6 Oct 2020 04:32:30 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64CBEC061755 for ; Tue, 6 Oct 2020 01:32:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=F8+5gkGPVqKgbh4FUVYDJTT7CPoPeJTjUg9zFd6ApBc=; b=UBksAM3QzNyHx3FLo60CS9n/2H 7+PaJK0UVGHJWTBqKgx1ZpvScnqNTryXRdT8dQ0CIla0cmlAqqdG+JXMzDAvnJRiHpol5tPDGKPA/ V/LMi35z8P6AO4hXGrU8wZ5956xyDCN8ERBQI0VVsY1RDTqu5Ss+42DMqvjAmbo7VovQkbI2BHDVc iWNj5crABf0V+zr2SVLLeEUQdxvTiseN3HLYWtWJ7cokJPOEEv7vKCYncBpONEApGXZra5NpT1VjX uevrcQH62qbw1ocyIQPq4fX7n47BPGCKe4jtpMNqR4+ClzgYaIovWvKgwlRbqf92cHDxRP6et1cXR rAzQy3ig==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kPiOG-0008FX-P5; Tue, 06 Oct 2020 08:32:20 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id E1C533006D0; Tue, 6 Oct 2020 10:32:05 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id CA8B328B30F6D; Tue, 6 Oct 2020 10:32:05 +0200 (CEST) Date: Tue, 6 Oct 2020 10:32:05 +0200 From: Peter Zijlstra To: Brian Gerst Cc: Andy Lutomirski , the arch/x86 maintainers , LKML , "Christopherson, Sean J" Subject: Re: [PATCH 0/2] Clean up x86_32 stackprotector Message-ID: <20201006083205.GN2628@hirez.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 05, 2020 at 07:10:39PM -0400, Brian Gerst wrote: > On Mon, Oct 5, 2020 at 3:30 PM Andy Lutomirski wrote: > > > > x86_32 stackprotector is a maintenance nightmare. Clean it up. This > > disables stackprotector on x86_32 on GCC 8.1 and on all clang > > versions -- I'll file a bug for the latter. > > This should be doable on 64-bit too. All that would need to be done > is to remove the zero-base of the percpu segment (which would simplify > alot of other code). Like what? I don't think it'd be hard to do, but I really don't see it doing anything other than make things confusing as heck.