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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5330DC433EF for ; Mon, 25 Oct 2021 14:56:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28F3160EDF for ; Mon, 25 Oct 2021 14:56:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233662AbhJYO7J (ORCPT ); Mon, 25 Oct 2021 10:59:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230268AbhJYO7H (ORCPT ); Mon, 25 Oct 2021 10:59:07 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A8C0C061745 for ; Mon, 25 Oct 2021 07:56:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=zmLK+AKV4g2Qg/lbEfGjPewbRorji9DedTnXtifc7bU=; b=HxM0ibGfAlXgx4A71JCfpTjSQ8 dCCSkxk6gablTyCZv2MUNysEgUWQhyqswsfsTEnZdQXPU4TklZUUQSmSX8NehDbXXM/bERq8vmPIv Yg+i9ggQi+s/hdpvk5VHlgtU0XoqKEKvldANEyqlqL9KFg7HrL4yHgR+BgKJcoREI7PULt5HTji2r WZ2AnGrziyVXc/iIjcuMA9xQ7qiHKrlVwwU4LYvfOld0Hz97S+2nYVYsMc9xTVeXS++fWKSI8SIoE RHPv9WXzokwxyLuVolT1mh+9P6T8g2Q1pWlmzORBpGxrpBY0AwH3oG5NrRvioWUEPq3M28CFg6HYx Te0/OLQw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mf1Ox-00CA5K-Sf; Mon, 25 Oct 2021 14:56:40 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id ED33D3003A9; Mon, 25 Oct 2021 16:56:37 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id D597329DEC068; Mon, 25 Oct 2021 16:56:37 +0200 (CEST) Date: Mon, 25 Oct 2021 16:56:37 +0200 From: Peter Zijlstra To: Josh Poimboeuf Cc: Rob Landley , Masahiro Yamada , "linux-kernel@vger.kernel.org" , Andrii Nakryiko Subject: Re: Commit 0d989ac2c90b broke my x86-64 build. Message-ID: References: <53f767cd-9160-1015-d1b8-0230b5566574@landley.net> <20211024192742.uo62mbqb6hmhafjs@treble> <66ed460c-ac48-2b5a-e8e4-07613cf69ab0@landley.net> <20211025144656.fqqneysf72wwxp3m@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211025144656.fqqneysf72wwxp3m@treble> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 25, 2021 at 07:46:56AM -0700, Josh Poimboeuf wrote: > On Mon, Oct 25, 2021 at 11:04:33AM +0200, Peter Zijlstra wrote: > > On Sun, Oct 24, 2021 at 09:51:45PM -0500, Rob Landley wrote: > > > > Unfortunately I think CONFIG_STACK_VALIDATION is no longer optional on > > > > x86-64 these days, because of static calls and retpolines. > > > > > > Does it need stack validation, or just a frame unwinder? > > > > static_calls rely on objtool to find all "call __SCT*" instructions and > > write their location in a .static_call_sites section. > > > > The having of static calls is not optional on x86_64, and I have zero > > interest in trying to work out what not having static_call() does, or to > > maintain that option. > > What I meant was, make STATIC_CALL_INLINE optional. Then it would use > out-of-line static calls which should just work, no? Yeah, I suppose so... I think we're then missing a STACK_VALIDATION dependency for KCOV. We rely on objtool to nop out those __sanitizer_cov_* calls. I had really hoped to just make objtool an unconditional part of x86_64.