From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757557AbbIVOGb (ORCPT ); Tue, 22 Sep 2015 10:06:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48638 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751225AbbIVOG3 (ORCPT ); Tue, 22 Sep 2015 10:06:29 -0400 Date: Tue, 22 Sep 2015 16:06:25 +0200 From: Andrea Arcangeli To: Shuah Khan Cc: Andre Przywara , Andrew Morton , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Pavel Emelyanov Subject: Re: [PATCH 2/2] selftests/userfaultfd: improve syscall number definition Message-ID: <20150922140625.GH25412@redhat.com> References: <1442918756-17892-1-git-send-email-andre.przywara@arm.com> <1442918756-17892-3-git-send-email-andre.przywara@arm.com> <56015C59.5010300@osg.samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56015C59.5010300@osg.samsung.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 22, 2015 at 07:49:13AM -0600, Shuah Khan wrote: > On 09/22/2015 04:45 AM, Andre Przywara wrote: > > At the moment the userfaultfd test program only supports x86 and an > > architecture called "powewrpc" ;-) > > Fix that typo and add the syscall numbers for other architectures as > > well. > > Also as in an ideal world a syscall number should come from the system > > header file , include that header and guard the explicit > > syscall number section below to avoid redefinitions. > > > > Signed-off-by: Andre Przywara > > --- > > tools/testing/selftests/vm/userfaultfd.c | 13 ++++++++++++- > > 1 file changed, 12 insertions(+), 1 deletion(-) > > > > diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c > > index 2c7cca6..63be27f 100644 > > --- a/tools/testing/selftests/vm/userfaultfd.c > > +++ b/tools/testing/selftests/vm/userfaultfd.c > > @@ -65,16 +65,27 @@ > > #include > > #include > > #include "../../../../include/uapi/linux/userfaultfd.h" > > +#include > > > > +/* ideally the above user header provides that number, but ... */ > > +#ifndef __NR_userfaultfd > > #ifdef __x86_64__ > > #define __NR_userfaultfd 323 > > #elif defined(__i386__) > > #define __NR_userfaultfd 374 > > -#elif defined(__powewrpc__) > > +#elif defined(__powerpc__) > > #define __NR_userfaultfd 364 > > +#elif defined(__ia64__) > > +#define __NR_userfaultfd 1343 > > +#elif defined(__arm__) > > +#define __NR_userfaultfd 388 > > +#elif defined(__aarch64__) > > +/* this is from the generic syscall table, used also on other architectures */ > > +#define __NR_userfaultfd 283 > > #else > > #error "missing __NR_userfaultfd definition" > > #endif > > +#endif /* !__NR_userfaultfd */ > > > > static unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size; > > > > > > This is not okay. User-space shouldn't be (re)defining/duplicating > syscall numbers. I can't take this patch. -mm has already been updated to do exactly that. Syscall numbers end up hardcoded into userland binaries/libs somewhere, so it's not a bugfix but certainly it's a nice cleanup to remove the whole #ifdef block. Andre, could you see if linux-next (which includes -mm) works for you by just running "cd tools/testing/selftests/vm/ && make"? If there's any further change required could you diff it against linux-next? Thanks! Andrea