From: Viktor Malik <vmalik@xxxxxxxxxx> [ Upstream commit edd75c802855271c8610f58a2fc9e54aefc49ce5 ] Building BPF selftests with custom HOSTCFLAGS yields an error: # make HOSTCFLAGS="-O2" [...] HOSTCC ./tools/testing/selftests/bpf/tools/build/resolve_btfids/main.o main.c:73:10: fatal error: linux/rbtree.h: No such file or directory 73 | #include <linux/rbtree.h> | ^~~~~~~~~~~~~~~~ The reason is that tools/bpf/resolve_btfids/Makefile passes header include paths by extending HOSTCFLAGS which is overridden by setting HOSTCFLAGS in the make command (because of Makefile rules [1]). This patch fixes the above problem by passing the include paths via `HOSTCFLAGS_resolve_btfids` which is used by tools/build/Build.include and can be combined with overridding HOSTCFLAGS. [1] https://www.gnu.org/software/make/manual/html_node/Overriding.html Fixes: 56a2df7615fa ("tools/resolve_btfids: Compile resolve_btfids as host program") Signed-off-by: Viktor Malik <vmalik@xxxxxxxxxx> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> Link: https://lore.kernel.org/bpf/20230530123352.1308488-1-vmalik@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/bpf/resolve_btfids/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile index ac548a7baa73e..4b8079f294f65 100644 --- a/tools/bpf/resolve_btfids/Makefile +++ b/tools/bpf/resolve_btfids/Makefile @@ -67,7 +67,7 @@ $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OU LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null) LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf) -HOSTCFLAGS += -g \ +HOSTCFLAGS_resolve_btfids += -g \ -I$(srctree)/tools/include \ -I$(srctree)/tools/include/uapi \ -I$(LIBBPF_INCLUDE) \ @@ -76,7 +76,7 @@ HOSTCFLAGS += -g \ LIBS = $(LIBELF_LIBS) -lz -export srctree OUTPUT HOSTCFLAGS Q HOSTCC HOSTLD HOSTAR +export srctree OUTPUT HOSTCFLAGS_resolve_btfids Q HOSTCC HOSTLD HOSTAR include $(srctree)/tools/build/Makefile.include $(BINARY_IN): fixdep FORCE prepare | $(OUTPUT) -- 2.39.2