From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 50556 invoked by alias); 28 Nov 2018 19:15:05 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 50520 invoked by uid 89); 28 Nov 2018 19:15:03 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-1.2 required=5.0 tests=BAYES_00,SPF_HELO_PASS,SPF_SOFTFAIL autolearn=no version=3.3.2 spammy= X-HELO: mail.baldwin.cx Received: from bigwig.baldwin.cx (HELO mail.baldwin.cx) (96.47.65.170) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 28 Nov 2018 19:15:01 +0000 Received: from John-Baldwins-MacBook-Pro-2.local (ralph.baldwin.cx [66.234.199.215]) by mail.baldwin.cx (Postfix) with ESMTPSA id 1168510B429; Wed, 28 Nov 2018 14:14:58 -0500 (EST) Subject: Re: [PATCH v3 2/3] Add an optional "alias" attribute to syscall entries. To: Pedro Alves , Eli Zaretskii References: <20181109200432.84491-1-jhb@FreeBSD.org> <20181109200432.84491-3-jhb@FreeBSD.org> <83efbuattx.fsf@gnu.org> <650590ef-3036-57a8-6cd5-abaa5654add3@FreeBSD.org> <34fcc769-4533-31bf-d258-36c6110037e0@redhat.com> <766d8293-d021-ce40-219e-f5a832b46fa7@FreeBSD.org> <83r2f5drm4.fsf@gnu.org> <24c28a03-e548-daac-1ad9-47d0f31eb13e@FreeBSD.org> <6b48a787-dec3-6be7-9a3d-7bb0284bc11c@redhat.com> Cc: gdb-patches@sourceware.org From: John Baldwin Openpgp: preference=signencrypt Message-ID: Date: Wed, 28 Nov 2018 19:15:00 -0000 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <6b48a787-dec3-6be7-9a3d-7bb0284bc11c@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-IsSubscribed: yes X-SW-Source: 2018-11/txt/msg00523.txt.bz2 On 11/28/18 10:34 AM, Pedro Alves wrote: > On 11/28/2018 06:00 PM, John Baldwin wrote: >> On 11/28/18 9:44 AM, Eli Zaretskii wrote: >>>> Cc: gdb-patches@sourceware.org >>>> From: John Baldwin >>>> Date: Wed, 28 Nov 2018 09:22:22 -0800 >>>> >>>> Yes, I think this is better as well. Eli, I don't know if other OS's will >>>> make use of this feature. Given Pedro's new text above, do you think it >>>> should still be moved into a native section or should it stay in the the >>>> syscall section? >>> >>> I question the need to make this text more general than this feature >>> will ever become. But if Pedro thinks we will have similar aliases on >>> other OSes, then sure, do it as Pedro suggests. > > Don't other BSD kernels do something similar? Hmm, it is true that 4.4BSD itself included some compat system calls to handle some ABI changes which is why the BSD's follow that model. NetBSD at least follows FreeBSD's model of renaming old system calls and adding new numbers for new ABIs. OpenBSD kind of does, but it retires older ABIs more aggressively and seems to reuse old numbers unlike FreeBSD and NetBSD. > I think Linux always adds new syscalls under a new name, even if the > old replaced one is deprecated. > >> Oh, I was just referring to Pedro's version being shorter. I'm fine with >> moving it. This is a bit longer as it restores a bit of the FreeBSD-specific >> note about syscall ABIs but that seemed relevant when moving it: > I'm fine with it as well. It just felt like if the we could keep it short, it'd > avoid fragmenting the information. IMO, a user reading the "catch syscall" > bits in the manual isn't going to remember to look up the FreeBSD-specific info > in a different node. Unless we add some xrefs. Yes, that is why I started with it in the syscall section. -- John Baldwin                                                                            Â