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 42925C77B7A for ; Tue, 6 Jun 2023 13:27:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237082AbjFFN1b (ORCPT ); Tue, 6 Jun 2023 09:27:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231431AbjFFN13 (ORCPT ); Tue, 6 Jun 2023 09:27:29 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3521118; Tue, 6 Jun 2023 06:27:27 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1686058046; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4GE9WjdAFKVw1j/LBC/tJ3tEETtCjZm6/3ok9EzRiww=; b=w5R70kFWsU64r33qYY+R3GNo4WBUNJSWY3CITWeMB8Ho1DaAglb56jHjjyHPUdrv0xPFtI 5mVQK8m+4uvVDtb0PQ04IOvf+Nxe7vbfrUesgfPsikP/YsWsH1P+FFdWBwyfUf64h/LZvF fFWNnm46QdtmJKPKnu3m2XwFtDTmwbhp7seekB0dxQ0yqEfBGFF+GFsXK/orl1Zzr2DUFn LhZDlI+aJNabFjlfG0h5Mt8G9qm4kNPmhx4HrfCLjDkr4/hDh3LJHMXkniebEdr9m9IiFf dQ6EmrUfZn0XPcSvFtp6RdIiC65U8/2DYMYqMqHFTELKgtQh4HlM7H7+2EIvVg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1686058046; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4GE9WjdAFKVw1j/LBC/tJ3tEETtCjZm6/3ok9EzRiww=; b=te48p/rqwl0Wh/jc2Vr4qpI19ykvDLPW9ambOLCElI800bdN5cVIUOd3midi7weyXM/aaQ uWeQsj/BVGfDvRBA== To: "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" , "hpa@zytor.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 In-Reply-To: References: <20230410081438.1750-1-xin3.li@intel.com> <20230410081438.1750-31-xin3.li@intel.com> <87wn0i578t.ffs@tglx> Date: Tue, 06 Jun 2023 15:27:25 +0200 Message-ID: <87fs74lo02.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. >> >> And thereby remove the useful comment and replace it with an undocumented >> macro mess. >> >> I'm simply refusing to review this. It's not my job to understand this >> undocumented hackery. >> > > I believe it's a nice idea to allow dynamic stack frame size, at least for > FRED. Believe belongs in the realm of religion. What we need here are proper facts, explanations and justifications. Nice ideas are not helpful when they are not having a value. > 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. > > 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. Making this FRED only is going to need even more justification. > and such corner cases are hard to test (self-tests needed?) There is a test. It's not that hard to find: # git grep -li ESPFIX tools/testing/selftests/ tools/testing/selftests/x86/sigreturn.c Thanks, tglx