@@ -122,6 +122,29 @@ endif
ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE),y)
LINUX_DEPENDENCIES += host-pahole
+
+# To build host-pahole, we need to install host-libbpf.
+# Particularly, we need to use libbpf Makefile target install_uapi_headers to
+# install a particular header file.
+# But, this generates a conflict when building the kernel:
+# In file included from libbpf_internal.h:17:0, from strset.c:9:
+# relo_core.h:10:6: error: nested redefinition of 'enum bpf_core_relo_kind'
+# enum bpf_core_relo_kind {
+# ^~~~~~~~~~~~~~~~~~
+# relo_core.h:10:6: error: redeclaration of 'enum bpf_core_relo_kind'
+# In file included from libbpf_legacy.h:13:0,
+# from libbpf_internal.h:16,
+# from strset.c:9:
+# /home/francis/buildroot/output/host/include/linux/bpf.h:6497:6: note: originally defined here
+# enum bpf_core_relo_kind {
+# So, better to remove it now as we already built host-pahole.
+define LINUX_REMOVE_LIBBPF_HEADER
+ if [ -f $(HOST_DIR)/include/linux/bpf.h ]; then \
+ rm $(HOST_DIR)/include/linux/bpf.h; \
+ fi
+endef
+
+LINUX_PRE_BUILD_HOOKS += LINUX_REMOVE_LIBBPF_HEADER
else
define LINUX_FIXUP_CONFIG_PAHOLE_CHECK
if grep -q "^CONFIG_DEBUG_INFO_BTF=y" $(KCONFIG_DOT_CONFIG); then \
@@ -39,26 +39,13 @@ define LIBBPF_INSTALL_TARGET_CMDS
-C $(@D)/src install DESTDIR=$(TARGET_DIR)
endef
-# We need to install_uapi_headers so we have btf.h to compile
-# host-pahole.
-# Nonetheless, this target adds bpf.h which generates a conflict when
-# building the kernel:
-# In file included from libbpf_internal.h:17:0, from strset.c:9:
-# relo_core.h:10:6: error: nested redefinition of 'enum bpf_core_relo_kind'
-# enum bpf_core_relo_kind {
-# ^~~~~~~~~~~~~~~~~~
-# relo_core.h:10:6: error: redeclaration of 'enum bpf_core_relo_kind'
-# In file included from libbpf_legacy.h:13:0,
-# from libbpf_internal.h:16,
-# from strset.c:9:
-# /home/francis/buildroot/output/host/include/linux/bpf.h:6497:6: note: originally defined here
-# enum bpf_core_relo_kind {
-# So, better to remove remove it now since we do not need it to build
-# host-pahole, the only user of host-libbpf.
+# We need to install_uapi_headers so we have btf.h to compile host-pahole.
+# Nonetheless, this target adds bpf.h which generates a conflict when building
+# the kernel.
+# So, if this file is present, it will be removed by linux.mk.
define HOST_LIBBPF_INSTALL_CMDS
$(HOST_MAKE_ENV) $(HOST_CONFIGURE_OPTS) $(MAKE) \
-C $(@D)/src install install_uapi_headers DESTDIR=$(HOST_DIR)
- rm $(HOST_DIR)/include/linux/bpf.h
endef
$(eval $(generic-package))
Removing bpf.h in host-libbpf leads to problems when building host-pahole [1]. So, we keep this file to build host-pahole and remove it before building the kernel to avoid conflicts with kernel bpf.h. Signed-off-by: Francis Laniel <flaniel@linux.microsoft.com> [1] http://autobuild.buildroot.net/results/7b3f560a773791e00b8bb32f64c0d39749b809b1/build-end.log --- linux/linux.mk | 23 +++++++++++++++++++++++ package/libbpf/libbpf.mk | 21 ++++----------------- 2 files changed, 27 insertions(+), 17 deletions(-)