From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 123888 invoked by alias); 1 Nov 2016 17:28:11 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 123873 invoked by uid 89); 1 Nov 2016 17:28:10 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_SORBS_SPAM,RP_MATCHES_RCVD,SPF_PASS autolearn=ham version=3.3.2 spammy=HX-HELO:sk:mailbac, H*RU:166.84.1.89, Hx-spam-relays-external:166.84.1.89, H*RU:sk:mailbac X-HELO: mailbackend.panix.com X-Gm-Message-State: ABUngvcm1s9H8xDtyzVYRUFGELtfiwNJVwSdx3SlirTYFOHGaH/VudnYgbgoYWaJL9nmt/e9HEz8RAJ8OT8TCg== X-Received: by 10.194.115.168 with SMTP id jp8mr3243wjb.27.1478021277745; Tue, 01 Nov 2016 10:27:57 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <0b9aa220-370a-a196-8640-a65b46b3c344@linaro.org> References: <1478010323-13076-1-git-send-email-adhemerval.zanella@linaro.org> <1478010323-13076-8-git-send-email-adhemerval.zanella@linaro.org> <87bmxzw6wn.fsf@linux-m68k.org> <0b9aa220-370a-a196-8640-a65b46b3c344@linaro.org> From: Zack Weinberg Date: Tue, 01 Nov 2016 17:28:00 -0000 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 07/15] Use semget syscall for Linux implementation To: Adhemerval Zanella Cc: Joseph Myers , Andreas Schwab , GNU C Library Content-Type: text/plain; charset=UTF-8 X-SW-Source: 2016-11/txt/msg00041.txt.bz2 On Tue, Nov 1, 2016 at 1:16 PM, Adhemerval Zanella wrote: > On 01/11/2016 14:40, Joseph Myers wrote: >> On Tue, 1 Nov 2016, Andreas Schwab wrote: >> >>> On Nov 01 2016, Adhemerval Zanella wrote: >>> >>>> This patch add a direct call to semget syscall if it is defined by >>>> kernel headers. >>> >>> That does not mean that the running kernel provides it. >> >> Specifically, this sort of patch series needs to be accompanied by an >> analysis of when the relevant syscalls were added for each supported >> architecture (and subarchitecture for cases with multiple syscall tables >> for different ABNs). If present (in the syscall table as well as in >> asm/unistd.h) in the minimum kernel version, OK, otherwise you need >> appropriate __ASSUME_* conditionals (even if not present in the latest >> kernel, it might be added in future, so you should have those conditionals >> now to avoid breaking things when current glibc is compiled with future >> kernel headers). > > Indeed, I did not consider the case of latest kernel headers. Based > on current Linux approach and historical implementation for sysv IPC > I think we can assume that either the kernel only supports the old > 'ipc' syscall or all the sysvipc syscall wire-up. Do you know if we > do require an __ASSUME for each syscall? It wouldn't have made sense to add direct syscalls for some but not all of the APIs that were multiplexed, so I would think one __ASSUME is enough. zw