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 23E5AEB64D8 for ; Wed, 21 Jun 2023 10:20:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229629AbjFUKUU (ORCPT ); Wed, 21 Jun 2023 06:20:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232447AbjFUKTe (ORCPT ); Wed, 21 Jun 2023 06:19:34 -0400 Received: from gnuweeb.org (gnuweeb.org [51.81.211.47]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A0151AC for ; Wed, 21 Jun 2023 03:19:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gnuweeb.org; s=default; t=1687342764; bh=mcCkvxVLHbiXhXVk27bzkzKsXfz5QT7GpKCLNfrraFQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=PD9F0mX3mffRkhLwojUETY94RLenUfuA3AJWV/XFS6b/6uPf9h7XxldzUjD0r/Agm xhYgqEM9p/KFL+T+BEKnkx7dOuaIx75rCIsZaR7tSOw5KqzNQiPXJT11BUAGEvZZXv 0DBNc1klm00xriHgKBYozFqJQcgPlVuD97Kn6aBZ36f7VbXjLPtfJD5AztQjHr1CaR ZTrU/OfwO/1jhYRiQb1rwIOvrGO2MF8LEmxagZ3rJXSDKFpoKbcr1CiSoG0UubQ3En KTfeOgDc8eElTw1wvCFXBmXQ/1HMRRToyy21/6957ypUVoQawO9HH+0mrQpp84jopl mTGL9Hscwb7BA== Received: from biznet-home.integral.gnuweeb.org (unknown [68.183.184.174]) by gnuweeb.org (Postfix) with ESMTPSA id 7B0B2249D30; Wed, 21 Jun 2023 17:19:22 +0700 (WIB) Date: Wed, 21 Jun 2023 17:19:18 +0700 From: Ammar Faizi To: Stefan Hajnoczi Cc: io-uring@vger.kernel.org, Ammar Faizi , Jens Axboe , Jeff Moyer , Alviro Iskandar Setiawan , Guillem Jover Subject: Re: False positives in nolibc check Message-ID: References: <20230620133152.GA2615339@fedora> <20230621100447.GD2667602@fedora> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230621100447.GD2667602@fedora> X-Bpl: hUx9VaHkTWcLO7S8CQCslj6OzqBx2hfLChRz45nPESx5VSB/xuJQVOKOB1zSXE3yc9ntP27bV1M1 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Wed, Jun 21, 2023 at 12:04:47PM +0200, Stefan Hajnoczi wrote: > I don't know which features require the toolchain and libc to cooperate. > I guess Thread Local Storage won't work and helper functions that > compilers emit (like the memset example that Alviro gave). Yeah, thread local storage won't work. But the point of my question is about liburing. So I expect the answer that's relevant to liburing. I mean, you can still use libc and TLS in your app even though the liburing.so and liburing.a are nolibc. > Disabling hardening because it requires work to support it in a nolibc > world seems dubious to me. I don't think it's a good idea for io_uring > to lower security because that hurts its image and reduces adoption. > Especially right now, when the security of io_uring is being scrutinized > (https://security.googleblog.com/2023/06/learnings-from-kctf-vrps-42-linux.html). > > While I'm sharing these opinions with you, I understand that some people > want nolibc and are fine with disabling the stack protector. The main > thing I would like is for liburing to compile or fail with a clear error > message instead of breaking somewhere during the build. Right, my mistake. I think it's fixed in upstream by commit: 319f4be8bd049055c333185928758d0fb445fc43 ("build: Disable stack protector unconditionally") Please give it a whirl. I apologize for breaking the Fedora build. Regards, -- Ammar Faizi