Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754189Ab3CKMpH (ORCPT ); Mon, 11 Mar 2013 08:45:07 -0400 Received: from multi.imgtec.com ([194.200.65.239]:1848 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754060Ab3CKMpD (ORCPT ); Mon, 11 Mar 2013 08:45:03 -0400 Message-ID: <513DD1C6.4040401@imgtec.com> Date: Mon, 11 Mar 2013 12:44:54 +0000 From: James Hogan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Vineet Gupta CC: Arnd Bergmann , , , Markos Subject: Re: SYSV IPC broken for no-legacy syscall kernels (was Re: [RFC PATCH v1 26/31] ARC: Build system: Makefiles, Kconfig, Linker script) References: <1352281674-2186-1-git-send-email-vgupta@synopsys.com> <1352281674-2186-27-git-send-email-vgupta@synopsys.com> <201211071413.49178.arnd@arndb.de> <513DCE2D.6010800@synopsys.com> In-Reply-To: <513DCE2D.6010800@synopsys.com> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.154.65] X-SEF-Processed: 7_3_0_01181__2013_03_11_12_44_54 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2275 Lines: 56 Hi Vineet, On 11/03/13 12:29, Vineet Gupta wrote: > On Wednesday 07 November 2012 07:43 PM, Arnd Bergmann wrote: >> On Wednesday 07 November 2012, Vineet Gupta wrote: >> >>> + >>> +config ARC >>> + def_bool y >>> + select ARCH_WANT_IPC_PARSE_VERSION >>> + # ARC Busybox based initramfs absolutely relies on DEVTMPFS for /dev >>> + # DEVTMPS in turn needs HOTPLUG >>> + select DEVTMPFS if !INITRAMFS_SOURCE="" >>> + select GENERIC_ATOMIC64 >>> + select GENERIC_CLOCKEVENTS >>> + select GENERIC_FIND_FIRST_BIT >>> + # for now, we don't need GENERIC_IRQ_PROBE, CONFIG_GENERIC_IRQ_CHIP >>> + select GENERIC_IRQ_SHOW >>> + select GENERIC_PENDING_IRQ if SMP >>> + select GENERIC_SMP_IDLE_THREAD >>> + select HAVE_GENERIC_HARDIRQS >>> + select HOTPLUG if !INITRAMFS_SOURCE="" >>> + select MODULES_USE_ELF_RELA >> You should not need ARCH_WANT_IPC_PARSE_VERSION > > It seems, we have a small bug in sysV IPC. > A lot of LTP tests have started failing on ARC 3.9-rc1 kernel due to absence of > ARCH_WANT_IPC_PARSE_VERSION. > > I'm assuming that for newer arches, msgctl(2) and friends need to have need to > have @cmd of type 0x01nn where 0x0100 is IPC_64. > However for ! ARCH_WANT_IPC_PARSE_VERSION, ipc/util.h seems to be defining a dummy > version of ipc_parse_version(), which doesn't strip out the 0x0100 from @cmds, > causing the code to not enter the switch block in SYSCALL_DEFINE3(msgctl) making > it fail. > Adding the above item to arch/arc/Kconfig obviously fixes the breakage. > > It seems there is some bogosity in the way ipc_parse_version() is defined. Given > the way it is used, to strip out the 0x0100 bit, it seems we always need the > function variant - the IA-64 ish comment in there seems to be bit-rot. > > What do you think ? FYI, for metag we assumed this was intentional and that IPC_64 shouldn't be passed since it is the default behaviour for new arches. You may find the following uClibc commit relevant: http://git.uclibc.org/uClibc/commit/?id=6c2fa3451f35f8d78a31689044b2d19efa4eaca2 Cheers James -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/