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 6BE68EB64D9 for ; Mon, 10 Jul 2023 17:43:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231537AbjGJRni (ORCPT ); Mon, 10 Jul 2023 13:43:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229823AbjGJRng (ORCPT ); Mon, 10 Jul 2023 13:43:36 -0400 Received: from 1wt.eu (ded1.1wt.eu [163.172.96.212]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id ABDB6DD for ; Mon, 10 Jul 2023 10:43:34 -0700 (PDT) Received: (from willy@localhost) by mail.home.local (8.17.1/8.17.1/Submit) id 36AHhRKI025103; Mon, 10 Jul 2023 19:43:27 +0200 Date: Mon, 10 Jul 2023 19:43:27 +0200 From: Willy Tarreau To: Thomas =?iso-8859-1?Q?Wei=DFschuh?= Cc: linux-kernel@vger.kernel.org, Zhangjin Wu Subject: Re: [PATCH] tools/nolibc: completely remove optional environ support Message-ID: References: <20230710-nolibc-environ-v1-1-173831573af6@weissschuh.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230710-nolibc-environ-v1-1-173831573af6@weissschuh.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, On Mon, Jul 10, 2023 at 07:22:53PM +0200, Thomas Weißschuh wrote: > In commit 52e423f5b93e ("tools/nolibc: export environ as a weak symbol on i386") > and friends the asm startup logic was extended to directly populate the > "environ" array. > > This makes it impossible for "environ" to be dropped by the linker. > Therefore also drop the other logic to handle non-present "environ". Hmmm OK but at least I'd like that we continue to reference it from nolibc-test to make sure it's still visible. Maybe we could just check that it's always equal to envp ? If we drop its reference from there, sooner or later someone will find it interesting to rename it and some programs referencing it will break. > Note: > > Given that nowadays both _auxv and environ are mandatory symbols imposed > by nolibc of pointer size does it make sense to keep the code to make > int-sized errno optional? While it indeed used to be related to having a data segment or not initially, it still has an impact on our ability to completely drop the errno setting code from all syscalls. Given the SET_ERRNO() macro now I guess it's very cheap to keep it, don't you think ? Thanks, Willy