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 8146BC7EE2F for ; Tue, 6 Jun 2023 23:09:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240187AbjFFXJT (ORCPT ); Tue, 6 Jun 2023 19:09:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240177AbjFFXJR (ORCPT ); Tue, 6 Jun 2023 19:09:17 -0400 Received: from mail.zytor.com (unknown [IPv6:2607:7c80:54:3::138]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6B91E40; Tue, 6 Jun 2023 16:09:16 -0700 (PDT) Received: from [127.0.0.1] ([73.231.166.163]) (authenticated bits=0) by mail.zytor.com (8.17.1/8.17.1) with ESMTPSA id 356N8bGP252105 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Tue, 6 Jun 2023 16:08:38 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 356N8bGP252105 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2023051001; t=1686092919; bh=3b9xHSYvK1ODTV6BLAv0xVWIguRKDFcGaSug0CbiWIs=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=lp8OgYN8Nx23gG0GBdp2+NF5VIeuZfk3Mo5Ojzsj+Y44jqyrVWIXOicehW2aKzVJp JqFVYxvpJSaQFciKtVPgROBTG6n5uMKrQ6XoszEuB3DWKLw+1FGssXStL/WYAbnSjM xR9oSt3qQchjTQTOHfpRuqCsHOlLmuaOY2ak401nGV7DVp1YPEoS2MNQWNvlvTvlfe Rt2E4Aw/ApX/GWC6zg+8n8f19g4//QqSuOvoc6idSr0BNyxoWM3XhyXGMqzAQs4jG6 fFhB4o7T7ttvr6C2S/EufWurDsgxwhVNLkJhqTWJeFA2AZaQpwTJC0tnaNCs3RR/vS WhCwJC/MmG/Pw== Date: Tue, 06 Jun 2023 16:08:34 -0700 From: "H. Peter Anvin" To: Thomas Gleixner , "Li, Xin3" , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "kvm@vger.kernel.org" CC: "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "peterz@infradead.org" , "andrew.cooper3@citrix.com" , "Christopherson,, Sean" , "pbonzini@redhat.com" , "Shankar, Ravi V" , "jiangshanlai@gmail.com" , "Kang, Shan" Subject: RE: [PATCH v8 30/33] x86/fred: allow dynamic stack frame size User-Agent: K-9 Mail for Android In-Reply-To: <87fs74lo02.ffs@tglx> References: <20230410081438.1750-1-xin3.li@intel.com> <20230410081438.1750-31-xin3.li@intel.com> <87wn0i578t.ffs@tglx> <87fs74lo02.ffs@tglx> Message-ID: <0CE0EA20-DCD8-43D0-8C66-562207CE0F97@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On June 6, 2023 6:27:25 AM PDT, Thomas Gleixner wrot= e: >On Tue, Jun 06 2023 at 06:18, Xin3 Li wrote: >>> > A FRED stack frame could contain different amount of information for >>> > This approach also works for IDT, thus we unify the code=2E >>>=20 >>> And thereby remove the useful comment and replace it with an undocumen= ted >>> macro mess=2E >>>=20 >>> I'm simply refusing to review this=2E It's not my job to understand th= is >>> undocumented hackery=2E >>>=20 >> >> I believe it's a nice idea to allow dynamic stack frame size, at least = for >> FRED=2E > >Believe belongs in the realm of religion=2E What we need here are proper >facts, explanations and justifications=2E Nice ideas are not helpful when >they are not having a value=2E > >> It's totally my bad that I didn't make it meet the minimum standards, >> I will rewrite the commit message and add better comments=2E >> >> After a second thought, I probably should only apply the change to FRED= for >> 2 reasons, the change seems problematic with ESPFIX (which FRED >> doesn't need), > >Indeed=2E Making this FRED only is going to need even more justification= =2E > >> and such corner cases are hard to test (self-tests needed?) > >There is a test=2E It's not that hard to find: > ># git grep -li ESPFIX tools/testing/selftests/ >tools/testing/selftests/x86/sigreturn=2Ec > >Thanks, > > tglx For what it is worth, I am working on a FRED forward compatibly document a= t the moment=2E