From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-eopbgr690086.outbound.protection.outlook.com ([40.107.69.86]:64576 "EHLO NAM04-CO1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726850AbeJBNte (ORCPT ); Tue, 2 Oct 2018 09:49:34 -0400 Subject: Re: [PATCH 1/3] microblaze: Replace NR_syscalls macro from asm/unistd.h References: <1533792466-4227-1-git-send-email-firoz.khan@linaro.org> <1533792466-4227-2-git-send-email-firoz.khan@linaro.org> From: Michal Simek Message-ID: <89533601-366f-ebf4-dc31-996bc649bc51@xilinx.com> Date: Tue, 2 Oct 2018 09:07:25 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Firoz Khan , Michal Simek Cc: Greg Kroah-Hartman , Philippe Ombredanne , Thomas Gleixner , Kate Stewart , y2038@lists.linaro.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Arnd Bergmann , Deepa Dinamani , Marcin Juszkiewicz Message-ID: <20181002070725.J-wnYzlM9w4sldR-8hlc-UyU1ZoulVcLY9e9uukxLxk@z> On 18.9.2018 08:37, Firoz Khan wrote: > On 9 August 2018 at 12:18, Michal Simek wrote: >> On 9.8.2018 07:27, Firoz Khan wrote: >>> __NR_syscalls macro holds the number of system call exist in this >>> architecture. This macro is currently the part of asm/unistd.h file. >>> We have change the value of __NR_syscalls, if we add or delete a >>> system call. >>> >>> One of the patch in this patch series has a script which will >>> generate a uapi header based on syscall.tbl file. The syscall.tbl >>> file contains the number of system call information. So we have >>> two option to update __NR_syscalls value. >>> >>> 1. Update __NR_syscalls in asm/unistd.h manually by counting the >>> no.of system calls. No need to update __NR_syscalls untill >>> we either add a new system call or delete an existing system >>> call. >>> >>> 2. We can keep this feature it above mentioned script, that'll >>> count the number of syscalls and keep it in a generated file. >>> In this case we don't need to explicitly update __NR_syscalls >>> in asm/unistd.h file. >>> >>> The 2nd option will be the recommended one. For that, I moved the >>> NR_syscalls macro from asm/unistd.h to uapi/asm/unistd.h. The macro >>> name also changed form NR_syscalls to __NR_syscalls for making the >>> name convention same across all architecture. While __NR_syscalls >>> isn't strictly part of the uapi, having it as part of the generated >>> header to simplifies the implementation. >> >> This macro was in unistd.h in past but it was moved out because it was >> causing problem with strace. >> >> commit 40c2702a02b755e0183b702778331b351f3be20c >> Author: Michal Simek >> AuthorDate: Mon Jul 8 09:50:24 2013 +0200 >> Commit: Michal Simek >> CommitDate: Wed Jul 10 07:32:09 2013 +0200 >> >> microblaze: Move __NR_syscalls from uapi >> >> >> That's why I don't think this is the right thing to do. >> I have grepped strace and glibc and none is using this macro that's why >> I think it shouldn't be exported via uapi. > > > Thanks for you reply :) > Sorry for the delayed response :( > > I would like to keep __NR_syscalls macro to uapi header in order to simplify > the system call table generation script. Otherwise the __NR_syscalls > macro need to update manually. That become a problem. > > Please check the below implementation in uapi file make sense? > It is an easy workaround to leave __NR_syscalls macro in uapi/asm/unistd.h > and enclose it in #ifdef __KERNEL__ > > ... > ... > #define __NR_pkey_free 397 > #define __NR_statx 398 > > #ifdef __KERNEL__ > #define __NR_syscalls 399 > #endif > ... > ... This should be fine. M