From: Jean-Philippe Brucker <jean-philippe@linaro.org>
Date: Thu, 16 Dec 2021 16:38:41 +0000
Subject: bpftool: Enable cross-building with clang
Patch-mainline: v5.17-rc1
Git-commit: bdadbb44c90aedaa74d46f1b113bd845774efa39
References: jsc#PED-1377
Cross-building using clang requires passing the "-target" flag rather
than using the CROSS_COMPILE prefix. Makefile.include transforms
CROSS_COMPILE into CLANG_CROSS_FLAGS, and adds that to CFLAGS. Remove
the cross flags for the bootstrap bpftool, and erase the CROSS_COMPILE
flag for the bootstrap libbpf.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20211216163842.829836-5-jean-philippe@linaro.org
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/bpf/bpftool/Makefile | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -57,7 +57,7 @@ $(LIBBPF_INTERNAL_HDRS): $(LIBBPF_HDRS_D
$(LIBBPF_BOOTSTRAP): $(wildcard $(BPF_DIR)/*.[ch] $(BPF_DIR)/Makefile) | $(LIBBPF_BOOTSTRAP_OUTPUT)
$(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_BOOTSTRAP_OUTPUT) \
DESTDIR=$(LIBBPF_BOOTSTRAP_DESTDIR) prefix= \
- ARCH= CC=$(HOSTCC) LD=$(HOSTLD) $@ install_headers
+ ARCH= CROSS_COMPILE= CC=$(HOSTCC) LD=$(HOSTLD) $@ install_headers
$(LIBBPF_BOOTSTRAP_INTERNAL_HDRS): $(LIBBPF_BOOTSTRAP_HDRS_DIR)/%.h: $(BPF_DIR)/%.h | $(LIBBPF_BOOTSTRAP_HDRS_DIR)
$(call QUIET_INSTALL, $@)
@@ -152,6 +152,9 @@ CFLAGS += -DHAVE_LIBBFD_SUPPORT
SRCS += $(BFD_SRCS)
endif
+HOST_CFLAGS = $(subst -I$(LIBBPF_INCLUDE),-I$(LIBBPF_BOOTSTRAP_INCLUDE),\
+ $(subst $(CLANG_CROSS_FLAGS),,$(CFLAGS)))
+
BPFTOOL_BOOTSTRAP := $(BOOTSTRAP_OUTPUT)bpftool
BOOTSTRAP_OBJS = $(addprefix $(BOOTSTRAP_OUTPUT),main.o common.o json_writer.o gen.o btf.o xlated_dumper.o btf_dumper.o disasm.o)
@@ -202,7 +205,7 @@ endif
CFLAGS += $(if $(BUILD_BPF_SKELS),,-DBPFTOOL_WITHOUT_SKELETONS)
$(BOOTSTRAP_OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c
- $(QUIET_CC)$(HOSTCC) $(CFLAGS) -c -MMD $< -o $@
+ $(QUIET_CC)$(HOSTCC) $(HOST_CFLAGS) -c -MMD $< -o $@
$(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c
$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD $< -o $@
@@ -213,15 +216,13 @@ ifneq ($(feature-zlib), 1)
endif
$(BPFTOOL_BOOTSTRAP): $(BOOTSTRAP_OBJS) $(LIBBPF_BOOTSTRAP)
- $(QUIET_LINK)$(HOSTCC) $(CFLAGS) $(LDFLAGS) $(BOOTSTRAP_OBJS) $(LIBS_BOOTSTRAP) -o $@
+ $(QUIET_LINK)$(HOSTCC) $(HOST_CFLAGS) $(LDFLAGS) $(BOOTSTRAP_OBJS) $(LIBS_BOOTSTRAP) -o $@
$(OUTPUT)bpftool: $(OBJS) $(LIBBPF)
$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $(OBJS) $(LIBS) -o $@
$(BOOTSTRAP_OUTPUT)%.o: %.c $(LIBBPF_BOOTSTRAP_INTERNAL_HDRS) | $(BOOTSTRAP_OUTPUT)
- $(QUIET_CC)$(HOSTCC) \
- $(subst -I$(LIBBPF_INCLUDE),-I$(LIBBPF_BOOTSTRAP_INCLUDE),$(CFLAGS)) \
- -c -MMD $< -o $@
+ $(QUIET_CC)$(HOSTCC) $(HOST_CFLAGS) -c -MMD $< -o $@
$(OUTPUT)%.o: %.c
$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD $< -o $@