From 88e85a7daf8e21f2d6cb054374d480c540725cde Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Tue, 26 Jun 2018 12:55:35 +0900 Subject: [PATCH] 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 Acked-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- Makefile | 5 ----- net/Makefile | 4 ---- net/bpfilter/Kconfig | 2 +- scripts/cc-can-link.sh | 2 +- 4 files changed, 2 insertions(+), 11 deletions(-) diff --git a/Makefile b/Makefile index c9132594860b..e1bd4c3627bc 100644 --- a/Makefile +++ b/Makefile @@ -507,11 +507,6 @@ ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLA KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO endif -ifeq ($(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/$(SRCARCH)/Makefile. # CC_VERSION_TEXT is referenced from Kconfig (so it needs export), diff --git a/net/Makefile b/net/Makefile index 13ec0d5415c7..bdaf53925acd 100644 --- a/net/Makefile +++ b/net/Makefile @@ -20,11 +20,7 @@ obj-$(CONFIG_TLS) += tls/ 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 a948b072c28f..76deb6615883 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 @@ menuconfig BPFILTER 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 208eb2825dab..6efcead31989 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 int main(void) {