From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.3 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_PASS autolearn=ham autolearn_force=no version=3.4.2 Received: (qmail 12776 invoked from network); 16 Apr 2020 04:49:04 -0000 Received-SPF: pass (mother.openwall.net: domain of lists.openwall.com designates 195.42.179.200 as permitted sender) receiver=inbox.vuxu.org; client-ip=195.42.179.200 envelope-from= Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with UTF8ESMTPZ; 16 Apr 2020 04:49:04 -0000 Received: (qmail 19973 invoked by uid 550); 16 Apr 2020 04:49:02 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 19955 invoked from network); 16 Apr 2020 04:49:01 -0000 From: Florian Weimer To: Rich Felker Cc: Nicholas Piggin , libc-alpha@sourceware.org, musl@lists.openwall.com, linuxppc-dev@lists.ozlabs.org, libc-dev@lists.llvm.org References: <1586931450.ub4c8cq8dj.astroid@bobo.none> <20200415225539.GL11469@brightrain.aerifal.cx> Date: Thu, 16 Apr 2020 06:48:44 +0200 In-Reply-To: <20200415225539.GL11469@brightrain.aerifal.cx> (Rich Felker's message of "Wed, 15 Apr 2020 18:55:39 -0400") Message-ID: <87k12gf32r.fsf@mid.deneb.enyo.de> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [musl] Powerpc Linux 'scv' system call ABI proposal take 2 * Rich Felker: > My preference would be that it work just like the i386 AT_SYSINFO > where you just replace "int $128" with "call *%%gs:16" and the kernel > provides a stub in the vdso that performs either scv or the old > mechanism with the same calling convention. The i386 mechanism has received some criticism because it provides an effective means to redirect execution flow to anyone who can write to the TCB. I am not sure if it makes sense to copy it.