From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <nsz@port70.net>
Received: from port70.net (port70.net [81.7.13.123])
 by sourceware.org (Postfix) with ESMTP id C35EC386F021
 for <libc-alpha@sourceware.org>; Mon, 20 Apr 2020 21:17:52 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org C35EC386F021
Authentication-Results: sourceware.org;
 dmarc=none (p=none dis=none) header.from=port70.net
Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=nsz@port70.net
Received: by port70.net (Postfix, from userid 1002)
 id CC62DABEC0BA; Mon, 20 Apr 2020 23:17:51 +0200 (CEST)
Date: Mon, 20 Apr 2020 23:17:51 +0200
From: Szabolcs Nagy <nsz@port70.net>
To: Nicholas Piggin <npiggin@gmail.com>
Cc: Rich Felker <dalias@libc.org>,
 Nicholas Piggin via Libc-alpha <libc-alpha@sourceware.org>,
 libc-dev@lists.llvm.org, linuxppc-dev@lists.ozlabs.org,
 musl@lists.openwall.com
Subject: Re: [musl] Powerpc Linux 'scv' system call ABI proposal take 2
Message-ID: <20200420211751.GF23945@port70.net>
Mail-Followup-To: Nicholas Piggin <npiggin@gmail.com>,
 Rich Felker <dalias@libc.org>,
 Nicholas Piggin via Libc-alpha <libc-alpha@sourceware.org>,
 libc-dev@lists.llvm.org, linuxppc-dev@lists.ozlabs.org,
 musl@lists.openwall.com
References: <1586931450.ub4c8cq8dj.astroid@bobo.none>
 <20200415225539.GL11469@brightrain.aerifal.cx>
 <1586994952.nnxigedbu2.astroid@bobo.none>
 <20200416095800.GC23945@port70.net>
 <1587341904.1r83vbudyf.astroid@bobo.none>
 <20200420012904.GY11469@brightrain.aerifal.cx>
 <1587348046.pwnfbo52iq.astroid@bobo.none>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1587348046.pwnfbo52iq.astroid@bobo.none>
User-Agent: Mutt/1.10.1 (2018-07-13)
X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS,
 KAM_NUMSUBJECT, SPF_HELO_PASS, SPF_PASS,
 TXREP autolearn=no autolearn_force=no version=3.4.2
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on
 server2.sourceware.org
X-BeenThere: libc-alpha@sourceware.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Libc-alpha mailing list <libc-alpha.sourceware.org>
List-Unsubscribe: <http://sourceware.org/mailman/options/libc-alpha>,
 <mailto:libc-alpha-request@sourceware.org?subject=unsubscribe>
List-Archive: <https://sourceware.org/pipermail/libc-alpha/>
List-Post: <mailto:libc-alpha@sourceware.org>
List-Help: <mailto:libc-alpha-request@sourceware.org?subject=help>
List-Subscribe: <http://sourceware.org/mailman/listinfo/libc-alpha>,
 <mailto:libc-alpha-request@sourceware.org?subject=subscribe>
X-List-Received-Date: Mon, 20 Apr 2020 21:17:54 -0000

* Nicholas Piggin <npiggin@gmail.com> [2020-04-20 12:08:36 +1000]:
> Excerpts from Rich Felker's message of April 20, 2020 11:29 am:
> > Also, allowing patching of executable pages is generally frowned upon
> > these days because W^X is a desirable hardening property.
> 
> Right, it would want be write-protected after being patched.

"frowned upon" means that users may have to update
their security policy setting in pax, selinux, apparmor,
seccomp bpf filters and who knows what else that may
monitor and flag W&X mprotect.

libc update can break systems if the new libc does W&X.