From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754167AbaCLLWh (ORCPT ); Wed, 12 Mar 2014 07:22:37 -0400 Received: from mailapp01.imgtec.com ([195.89.28.115]:36455 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753655AbaCLLWg (ORCPT ); Wed, 12 Mar 2014 07:22:36 -0400 Message-ID: <53204372.1000400@imgtec.com> Date: Wed, 12 Mar 2014 11:22:26 +0000 From: Markos Chandras User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: CC: , , Subject: Re: [PATCH v2] samples/seccomp/Makefile: Do not build tests if cross-compiling for MIPS References: <52FD0131.9040304@imgtec.com> <1392804917-29789-1-git-send-email-markos.chandras@imgtec.com> In-Reply-To: <1392804917-29789-1-git-send-email-markos.chandras@imgtec.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [192.168.154.136] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/19/2014 10:15 AM, Markos Chandras wrote: > The Makefile is designed to use the host toolchain so it may be > unsafe to build the tests if the kernel has been configured and built > for another architecture. This fixes a build problem when the kernel has > been configured and built for the MIPS architecture but the host is > not MIPS (cross-compiled). The MIPS syscalls are only defined > if one of the following is true: > > 1) _MIPS_SIM == _MIPS_SIM_ABI64 > 2) _MIPS_SIM == _MIPS_SIM_ABI32 > 3) _MIPS_SIM == _MIPS_SIM_NABI32 > > Of course, none of these make sense on a non-MIPS toolchain and the > following build problem occurs when building on a non-MIPS host. > > linux/usr/include/linux/kexec.h:50: > userspace cannot reference function or variable defined in the kernel > samples/seccomp/bpf-direct.c: In function ‘emulator’: > samples/seccomp/bpf-direct.c:76:17: error: > ‘__NR_write’ undeclared (first use in this function) > > Cc: linux-next@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Reported-by: Paul Gortmaker > Signed-off-by: Markos Chandras > --- > This build problem is only reproducible on the linux-next tree at the moment > > Changes since v1: > - Rework code so native builds are allowed on MIPS > --- > samples/seccomp/Makefile | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/samples/seccomp/Makefile b/samples/seccomp/Makefile > index 7203e66..855051b 100644 > --- a/samples/seccomp/Makefile > +++ b/samples/seccomp/Makefile > @@ -18,8 +18,8 @@ HOSTCFLAGS_bpf-direct.o += -idirafter $(objtree)/include > bpf-direct-objs := bpf-direct.o > > # Try to match the kernel target. > -ifndef CONFIG_64BIT > ifndef CROSS_COMPILE > +ifndef CONFIG_64BIT > > # s390 has -m31 flag to build 31 bit binaries > ifndef CONFIG_S390 > @@ -36,7 +36,13 @@ HOSTLOADLIBES_bpf-direct += $(MFLAG) > HOSTLOADLIBES_bpf-fancy += $(MFLAG) > HOSTLOADLIBES_dropper += $(MFLAG) > endif > -endif > - > -# Tell kbuild to always build the programs > always := $(hostprogs-y) > +else > +# MIPS system calls are defined based on the -mabi that is passed > +# to the toolchain which may or may not be a valid option > +# for the host toolchain. So disable tests if target architecture > +# is MIPS but the host isn't. > +ifndef CONFIG_MIPS > +always := $(hostprogs-y) > +endif > +endif > CC'ing Andrew Morton as well Ping? Is anyone willing to take this patch in his tree so we can restore the build for allyes/allmod configs for MIPS on linux-next? -- markos