samples/seccomp/Makefile: do not build tests if cross-compiling for MIPS

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)

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Markos Chandras 2014-04-03 14:48:32 -07:00 committed by Linus Torvalds
parent a5ed3cee94
commit e9107f88c9
1 changed files with 10 additions and 4 deletions

View File

@ -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