bpfilter: check compiler capability in Kconfig
With the brand-new syntax extension of Kconfig, we can directly
check the compiler capability in the configuration phase.
If the cc-can-link.sh fails, the BPFILTER_UMH is automatically
hidden by the dependency.
I also deleted 'default n', which is no-op.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Makefile b/Makefile
index c913259..e1bd4c3 100644
--- a/Makefile
+++ b/Makefile
@@ -507,11 +507,6 @@
KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
endif
-ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/cc-can-link.sh $(CC)), y)
- CC_CAN_LINK := y
- export CC_CAN_LINK
-endif
-
# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
diff --git a/net/Makefile b/net/Makefile
index 13ec0d5..bdaf539 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -20,11 +20,7 @@
obj-$(CONFIG_XFRM) += xfrm/
obj-$(CONFIG_UNIX) += unix/
obj-$(CONFIG_NET) += ipv6/
-ifneq ($(CC_CAN_LINK),y)
-$(warning CC cannot link executables. Skipping bpfilter.)
-else
obj-$(CONFIG_BPFILTER) += bpfilter/
-endif
obj-$(CONFIG_PACKET) += packet/
obj-$(CONFIG_NET_KEY) += key/
obj-$(CONFIG_BRIDGE) += bridge/
diff --git a/net/bpfilter/Kconfig b/net/bpfilter/Kconfig
index a948b07..76deb66 100644
--- a/net/bpfilter/Kconfig
+++ b/net/bpfilter/Kconfig
@@ -1,6 +1,5 @@
menuconfig BPFILTER
bool "BPF based packet filtering framework (BPFILTER)"
- default n
depends on NET && BPF && INET
help
This builds experimental bpfilter framework that is aiming to
@@ -9,6 +8,7 @@
if BPFILTER
config BPFILTER_UMH
tristate "bpfilter kernel module with user mode helper"
+ depends on $(success,$(srctree)/scripts/cc-can-link.sh $(CC))
default m
help
This builds bpfilter kernel module with embedded user mode helper
diff --git a/scripts/cc-can-link.sh b/scripts/cc-can-link.sh
index 208eb28..6efcead 100755
--- a/scripts/cc-can-link.sh
+++ b/scripts/cc-can-link.sh
@@ -1,7 +1,7 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
-cat << "END" | $@ -x c - -o /dev/null >/dev/null 2>&1 && echo "y"
+cat << "END" | $@ -x c - -o /dev/null >/dev/null 2>&1
#include <stdio.h>
int main(void)
{
