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 <[email protected]>
---
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 a6d4872..f71ea52 100644
--- a/Makefile
+++ b/Makefile
@@ -520,11 +520,6 @@ 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/$(SRCARCH)/Makefile.
# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
diff --git a/net/Makefile b/net/Makefile
index 13ec0d5..bdaf539 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -20,11 +20,7 @@ obj-$(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 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 @@ 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 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)
{
--
2.7.4
On 06/26/2018 05:55 AM, Masahiro Yamada wrote:
> 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 <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
On Tue, Jun 26, 2018 at 12:55:35PM +0900, Masahiro Yamada wrote:
> 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 <[email protected]>
I haven't tested it yet, but looks good to me as well.
Thank you for the follow up.
Acked-by: Alexei Starovoitov <[email protected]>
From: Masahiro Yamada <[email protected]>
Date: Tue, 26 Jun 2018 12:55:35 +0900
> 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 <[email protected]>
Applied, thank you.