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 E899CC433EF for ; Sat, 23 Oct 2021 13:44:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFC4960FE3 for ; Sat, 23 Oct 2021 13:44:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231186AbhJWNql (ORCPT ); Sat, 23 Oct 2021 09:46:41 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:44472 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229870AbhJWNqk (ORCPT ); Sat, 23 Oct 2021 09:46:40 -0400 Received: (from willy@localhost) by pcw.home.local (8.15.2/8.15.2/Submit) id 19NDhNMg005918; Sat, 23 Oct 2021 15:43:23 +0200 Date: Sat, 23 Oct 2021 15:43:23 +0200 From: Willy Tarreau To: Ammar Faizi Cc: Paul Walmsley , Palmer Dabbelt , Albert Ou , Linux Kernel Mailing List , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , David Laight , Peter Cordes , Bedirhan KURT , Louvian Lyndal Subject: Re: [PATCH 2/2] tools/nolibc: x86-64: Fix startup code bug Message-ID: <20211023134323.GA5881@1wt.eu> References: <20211023090246.GA4323@1wt.eu> <20211018045828.GA15329@1wt.eu> 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) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 23, 2021 at 08:27:15PM +0700, Ammar Faizi wrote: > Sorry for the delay, I got extra activities this week. Sorry for not > giving any update lately. No, really, don't be sorry, I'm myself quite busy, so I understnad, I was just inquiring to arrange my time, nothing more. > 1) I can send the %rsp alignment fix patch. I will send it today or > tomorrow (GMT+07 time). OK, no rush anyway. Even early next week is okay for me. > 2) I can't send the syscall change used for exit. Because I only > have x86 machine. So I can't apply the changes to other arch(s). I see. I can do it for the various archs then, as the ones that are supported are essentially the ones I can test. > For (2), basically sys_exit doesn't close the entire process. Instead > it only closes specific thread that calls that syscall. The libc uses > sys_exit_group to close the process and its threads. > > ^ It's not really an urgent thing, because the nolibc.h may not be > used for multithreaded app. Even so, I don't see something dangerous. Yep that's what I understood as well, so we may easily postpone this. > For (1), it's urgent, because the alignment violation causes segfault > if the compiler generates aligned move, often when we compile it > with -O3, usually that happens with SSE instructions, like `movdqa`, > `movaps`. Yes, that's what I saw from the other reports, I didn't notice it myself but I probably faced it and attributed it to anything else. > Preparing the patch... Great, thank you! Willy