samples: seccomp: build sample programs for target architecture

These userspace programs include UAPI headers exported to usr/include/.
'make headers' always works for the target architecture (i.e. the same
architecture as the kernel), so the sample programs should be built for
the target as well. Kbuild now supports 'userprogs' for that.

I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because
$(CC) may not provide libc.

The 'ifndef CROSS_COMPILE' is no longer needed.

BTW, the -m31 for s390 is left-over code. Commit 5a79859ae0 ("s390:
remove 31 bit support") killed it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
This commit is contained in:
Masahiro Yamada 2020-04-29 12:45:16 +09:00
parent 8a2cc0505c
commit f59e766877
2 changed files with 4 additions and 40 deletions

View file

@ -126,7 +126,7 @@ config SAMPLE_PIDFD
config SAMPLE_SECCOMP
bool "Build seccomp sample code"
depends on SECCOMP_FILTER && HEADERS_INSTALL
depends on SECCOMP_FILTER && CC_CAN_LINK && HEADERS_INSTALL
help
Build samples of seccomp filters using various methods of
BPF filter construction.

View file

@ -1,44 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
ifndef CROSS_COMPILE
hostprogs := bpf-fancy dropper bpf-direct user-trap
userprogs := bpf-fancy dropper bpf-direct user-trap
HOSTCFLAGS_bpf-fancy.o += -I$(objtree)/usr/include
HOSTCFLAGS_bpf-fancy.o += -idirafter $(objtree)/include
HOSTCFLAGS_bpf-helper.o += -I$(objtree)/usr/include
HOSTCFLAGS_bpf-helper.o += -idirafter $(objtree)/include
bpf-fancy-objs := bpf-fancy.o bpf-helper.o
HOSTCFLAGS_dropper.o += -I$(objtree)/usr/include
HOSTCFLAGS_dropper.o += -idirafter $(objtree)/include
dropper-objs := dropper.o
userccflags += -I usr/include
HOSTCFLAGS_bpf-direct.o += -I$(objtree)/usr/include
HOSTCFLAGS_bpf-direct.o += -idirafter $(objtree)/include
bpf-direct-objs := bpf-direct.o
HOSTCFLAGS_user-trap.o += -I$(objtree)/usr/include
HOSTCFLAGS_user-trap.o += -idirafter $(objtree)/include
user-trap-objs := user-trap.o
# Try to match the kernel target.
ifndef CONFIG_64BIT
# s390 has -m31 flag to build 31 bit binaries
ifndef CONFIG_S390
MFLAG = -m32
else
MFLAG = -m31
endif
HOSTCFLAGS_bpf-direct.o += $(MFLAG)
HOSTCFLAGS_dropper.o += $(MFLAG)
HOSTCFLAGS_bpf-helper.o += $(MFLAG)
HOSTCFLAGS_bpf-fancy.o += $(MFLAG)
HOSTCFLAGS_user-trap.o += $(MFLAG)
HOSTLDLIBS_bpf-direct += $(MFLAG)
HOSTLDLIBS_bpf-fancy += $(MFLAG)
HOSTLDLIBS_dropper += $(MFLAG)
HOSTLDLIBS_user-trap += $(MFLAG)
endif
always-y := $(hostprogs)
endif
always-y := $(userprogs)