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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2ADC1C43387 for ; Mon, 14 Jan 2019 04:01:26 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5F37720657 for ; Mon, 14 Jan 2019 04:01:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F37720657 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 43dKXM3PrVzDqRc for ; Mon, 14 Jan 2019 15:01:23 +1100 (AEDT) Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 43dKVT15w1zDqRL for ; Mon, 14 Jan 2019 14:59:45 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 43dKVQ4Bklz9s9G; Mon, 14 Jan 2019 14:59:42 +1100 (AEDT) From: Michael Ellerman To: Arnd Bergmann , y2038@lists.linaro.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 14/15] arch: add split IPC system calls where needed In-Reply-To: <20190110162435.309262-15-arnd@arndb.de> References: <20190110162435.309262-1-arnd@arndb.de> <20190110162435.309262-15-arnd@arndb.de> Date: Mon, 14 Jan 2019 14:59:41 +1100 Message-ID: <87pnsz28k2.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dalias@libc.org, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, linux@dominikbrodowski.net, jcmvbkbc@gmail.com, deepa.kernel@gmail.com, hpa@zytor.com, sparclinux@vger.kernel.org, linux-s390@vger.kernel.org, dave@stgolabs.net, deller@gmx.de, x86@kernel.org, linux@armlinux.org.uk, mingo@redhat.com, geert@linux-m68k.org, firoz.khan@linaro.org, mattst88@gmail.com, fenghua.yu@intel.com, Arnd Bergmann , heiko.carstens@de.ibm.com, linux-m68k@lists.linux-m68k.org, ink@jurassic.park.msu.ru, luto@kernel.org, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, monstr@monstr.eu, tony.luck@intel.com, linux-parisc@vger.kernel.org, linux-mips@vger.kernel.org, paul.burton@mips.com, ebiederm@xmission.com, linux-alpha@vger.kernel.org, schwidefsky@de.ibm.com, akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org, davem@davemloft.net Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi Arnd, Arnd Bergmann writes: > The IPC system call handling is highly inconsistent across architectures, > some use sys_ipc, some use separate calls, and some use both. We also > have some architectures that require passing IPC_64 in the flags, and > others that set it implicitly. > > For the additon of a y2083 safe semtimedop() system call, I chose to only > support the separate entry points, but that requires first supporting > the regular ones with their own syscall numbers. > > The IPC_64 is now implied by the new semctl/shmctl/msgctl system > calls even on the architectures that require passing it with the ipc() > multiplexer. > > I'm not adding the new semtimedop() or semop() on 32-bit architectures, > those will get implemented using the new semtimedop_time64() version > that gets added along with the other time64 calls. > Three 64-bit architectures (powerpc, s390 and sparc) get semtimedop(). > > Signed-off-by: Arnd Bergmann > --- > One aspect here that might be a bit controversial is the use of > the same system call numbers across all architectures, synchronizing > all of them with the x86-32 numbers. With the new syscall.tbl > files, I hope we can just keep doing that in the future, and no > longer require the architecture maintainers to assign a number. > > This is mainly useful for implementers of the C libraries: if > we can add future system calls everywhere at the same time, using > a particular version of the kernel headers also guarantees that > the system call number macro is visible. > --- > arch/m68k/kernel/syscalls/syscall.tbl | 11 +++++++++++ > arch/mips/kernel/syscalls/syscall_o32.tbl | 11 +++++++++++ > arch/powerpc/kernel/syscalls/syscall.tbl | 12 ++++++++++++ I have some changes I'd like to make to our syscall table that will clash with this. I'll try and send them today. > diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl > index db3bbb8744af..1bffab54ff35 100644 > --- a/arch/powerpc/kernel/syscalls/syscall.tbl > +++ b/arch/powerpc/kernel/syscalls/syscall.tbl > @@ -425,3 +425,15 @@ > 386 nospu pkey_mprotect sys_pkey_mprotect > 387 nospu rseq sys_rseq > 388 nospu io_pgetevents sys_io_pgetevents compat_sys_io_pgetevents > +# room for arch specific syscalls > +392 64 semtimedop sys_semtimedop > +393 common semget sys_semget > +394 common semctl sys_semctl compat_sys_semctl > +395 common shmget sys_shmget > +396 common shmctl sys_shmctl compat_sys_shmctl > +397 common shmat sys_shmat compat_sys_shmat > +398 common shmdt sys_shmdt > +399 common msgget sys_msgget > +400 common msgsnd sys_msgsnd compat_sys_msgsnd > +401 common msgrcv sys_msgrcv compat_sys_msgrcv > +402 common msgctl sys_msgctl compat_sys_msgctl We already have a gap at 366-377 from when we tried to add the split IPC calls a few years back. I guess I don't mind leaving that gap and using the common numbers as you've done here. But it would be good to add a comment pointing out that we have room at 366 for more arch specific syscalls as well. cheers