Commit 6d65f682 authored by yangsonghua's avatar yangsonghua Committed by Tejun Heo
Browse files

sched_ext: Improve cross-compilation support in Makefile 



Modify the tools/sched_ext/Makefile to better handle cross-compilation
environments by:

1. Fix host tools build directory structure by separating obj/ from output
   (HOST_BUILD_DIR now points to $(OBJ_DIR)/host/obj)
2. Properly propagate CROSS_COMPILE to libbpf sub-make invocation
3. Add missing $(HOST_BPFOBJ) build rule with proper host toolchain flags
   (ARCH=, CROSS_COMPILE=, explicit HOSTCC/HOSTLD)
4. Consistently quote $(HOSTCC) in bpftool build rule
5. Change LDFLAGS assignment to += to allow external extensions

The changes ensure proper cross-compilation behavior while maintaining
backward compatibility with native builds. Host tools are now correctly
built with the host toolchain while target binaries use the cross-toolchain.

Signed-off-by: default avataryangsonghua <yangsonghua@lixiang.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 0b304617

tools/sched_ext/Makefile

+17 −6
Original line number Diff line number Diff line
@@ -61,8 +61,8 @@ SCXOBJ_DIR := $(OBJ_DIR)/sched_ext 
BINDIR := $(OUTPUT_DIR)/bin

BPFOBJ := $(BPFOBJ_DIR)/libbpf.a

ifneq ($(CROSS_COMPILE),)

HOST_BUILD_DIR		:= $(OBJ_DIR)/host

HOST_OUTPUT_DIR	:= host-tools

HOST_BUILD_DIR		:= $(OBJ_DIR)/host/obj

HOST_OUTPUT_DIR	:= $(OBJ_DIR)/host

HOST_INCLUDE_DIR	:= $(HOST_OUTPUT_DIR)/include

else

HOST_BUILD_DIR		:= $(OBJ_DIR)
@@ -98,7 +98,7 @@ ifneq ($(LLVM),) 
CFLAGS += -Wno-unused-command-line-argument

endif



LDFLAGS = -lelf -lz -lpthread

LDFLAGS += -lelf -lz -lpthread



IS_LITTLE_ENDIAN = $(shell $(CC) -dM -E - </dev/null |				\

			grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__')
@@ -136,14 +136,25 @@ $(MAKE_DIRS): 
$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile)			\

	   $(APIDIR)/linux/bpf.h						\

	   | $(OBJ_DIR)/libbpf

	$(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(OBJ_DIR)/libbpf/	\

	$(Q)$(MAKE) $(submake_extras) CROSS_COMPILE=$(CROSS_COMPILE) 		\

		    -C $(BPFDIR) OUTPUT=$(OBJ_DIR)/libbpf/			\

		    EXTRA_CFLAGS='-g -O0 -fPIC'					\

		    LDFLAGS="$(LDFLAGS)"					\

		    DESTDIR=$(OUTPUT_DIR) prefix= all install_headers



$(HOST_BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile)		\

	   $(APIDIR)/linux/bpf.h						\

	   | $(HOST_BUILD_DIR)/libbpf

	$(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) 				\

		    OUTPUT=$(HOST_BUILD_DIR)/libbpf/				\

		    ARCH= CROSS_COMPILE= CC="$(HOSTCC)" LD=$(HOSTLD)		\

		    EXTRA_CFLAGS='-g -O0 -fPIC'					\

		    DESTDIR=$(HOST_OUTPUT_DIR) prefix= all install_headers



$(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile)	\

		    $(HOST_BPFOBJ) | $(HOST_BUILD_DIR)/bpftool

	$(Q)$(MAKE) $(submake_extras)  -C $(BPFTOOLDIR)				\

		    ARCH= CROSS_COMPILE= CC=$(HOSTCC) LD=$(HOSTLD)		\

		    ARCH= CROSS_COMPILE= CC="$(HOSTCC)" LD=$(HOSTLD)		\

		    EXTRA_CFLAGS='-g -O0'					\

		    OUTPUT=$(HOST_BUILD_DIR)/bpftool/				\

		    LIBBPF_OUTPUT=$(HOST_BUILD_DIR)/libbpf/			\
@@ -185,7 +196,7 @@ $(addprefix $(BINDIR)/,$(c-sched-targets)): \ 
		$(SCX_COMMON_DEPS)

	$(eval sched=$(notdir $@))

	$(CC) $(CFLAGS) -c $(sched).c -o $(SCXOBJ_DIR)/$(sched).o

	$(CC) -o $@ $(SCXOBJ_DIR)/$(sched).o $(HOST_BPFOBJ) $(LDFLAGS)

	$(CC) -o $@ $(SCXOBJ_DIR)/$(sched).o $(BPFOBJ) $(LDFLAGS)



$(c-sched-targets): %: $(BINDIR)/%