Merge branch 'selftests-net-extract-bpf-building-logic-from-the-makefile'

Jakub Kicinski says:

====================
selftests: net: extract BPF building logic from the Makefile

This has been sitting in my tree for a while. I will soon add YNL/libynl
support for networking selftests. This prompted a small cleanup of
the selftest makefile for net/. We don't want to be piling logic
for each library in there. YNL will get its own .mk file which can
be included. Do the same for the BPF building section, already.

No funcional changes here, just a code move and small rename.
====================

Link: https://lore.kernel.org/r/20240423183542.3807234-1-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/Makefile

@@ -82,10 +82,6 @@ TEST_GEN_PROGS += so_incoming_cpu
 TEST_PROGS += sctp_vrf.sh
 TEST_GEN_FILES += sctp_hello
 TEST_GEN_FILES += csum
-TEST_GEN_FILES += nat6to4.o
-TEST_GEN_FILES += xdp_dummy.o
-TEST_GEN_FILES += sample_ret0.bpf.o
-TEST_GEN_FILES += sample_map_ret0.bpf.o
 TEST_GEN_FILES += ip_local_port_range
 TEST_GEN_FILES += bind_wildcard
 TEST_PROGS += test_vxlan_mdb.sh
@@ -100,6 +96,8 @@ TEST_PROGS += bpf_offload.py
 TEST_FILES := settings
 TEST_FILES += in_netns.sh lib.sh net_helper.sh setup_loopback.sh setup_veth.sh
 
+TEST_GEN_FILES += $(patsubst %.c,%.o,$(wildcard *.bpf.c))
+
 TEST_INCLUDES := forwarding/lib.sh
 
 include ../lib.mk
@@ -110,56 +108,4 @@ $(OUTPUT)/tcp_inq: LDLIBS += -lpthread
 $(OUTPUT)/bind_bhash: LDLIBS += -lpthread
 $(OUTPUT)/io_uring_zerocopy_tx: CFLAGS += -I../../../include/
 
-# Rules to generate bpf objs
-CLANG ?= clang
-SCRATCH_DIR := $(OUTPUT)/tools
-BUILD_DIR := $(SCRATCH_DIR)/build
-BPFDIR := $(abspath ../../../lib/bpf)
-APIDIR := $(abspath ../../../include/uapi)
-
-CCINCLUDE += -I../bpf
-CCINCLUDE += -I../../../../usr/include/
-CCINCLUDE += -I$(SCRATCH_DIR)/include
-
-BPFOBJ := $(BUILD_DIR)/libbpf/libbpf.a
-
-MAKE_DIRS := $(BUILD_DIR)/libbpf
-$(MAKE_DIRS):
-	$(call msg,MKDIR,,$@)
-	$(Q)mkdir -p $@
-
-# Get Clang's default includes on this system, as opposed to those seen by
-# '--target=bpf'. This fixes "missing" files on some architectures/distros,
-# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
-#
-# Use '-idirafter': Don't interfere with include mechanics except where the
-# build would have failed anyways.
-define get_sys_includes
-$(shell $(1) $(2) -v -E - </dev/null 2>&1 \
-	| sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
-$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
-endef
-
-ifneq ($(CROSS_COMPILE),)
-CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
-endif
-
-CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
-
-BPF_PROG_OBJS := $(OUTPUT)/nat6to4.o $(OUTPUT)/xdp_dummy.o \
-	$(OUTPUT)/sample_map_ret0.bpf.o $(OUTPUT)/sample_ret0.bpf.o
-
-$(BPF_PROG_OBJS): $(OUTPUT)/%.o : %.c $(BPFOBJ) | $(MAKE_DIRS)
-	$(call msg,BPF_PROG,,$@)
-	$(Q)$(CLANG) -O2 -g --target=bpf $(CCINCLUDE) $(CLANG_SYS_INCLUDES) \
-	-c $< -o $@
-
-$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile)		       \
-	   $(APIDIR)/linux/bpf.h					       \
-	   | $(BUILD_DIR)/libbpf
-	$(call msg,MAKE,,$@)
-	$(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(BUILD_DIR)/libbpf/ \
-		    EXTRA_CFLAGS='-g -O0'				       \
-		    DESTDIR=$(SCRATCH_DIR) prefix= all install_headers
-
-EXTRA_CLEAN := $(SCRATCH_DIR)
+include bpf.mk

tools/testing/selftests/net/bpf.mk

+# SPDX-License-Identifier: GPL-2.0
+# Rules to generate bpf objs
+CLANG ?= clang
+SCRATCH_DIR := $(OUTPUT)/tools
+BUILD_DIR := $(SCRATCH_DIR)/build
+BPFDIR := $(top_srcdir)/tools/lib/bpf
+APIDIR := $(top_srcdir)/tools/include/uapi
+
+CCINCLUDE += -I$(selfdir)/bpf
+CCINCLUDE += -I$(top_srcdir)/usr/include/
+CCINCLUDE += -I$(SCRATCH_DIR)/include
+
+BPFOBJ := $(BUILD_DIR)/libbpf/libbpf.a
+
+MAKE_DIRS := $(BUILD_DIR)/libbpf
+$(MAKE_DIRS):
+	$(call msg,MKDIR,,$@)
+	$(Q)mkdir -p $@
+
+# Get Clang's default includes on this system, as opposed to those seen by
+# '--target=bpf'. This fixes "missing" files on some architectures/distros,
+# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
+#
+# Use '-idirafter': Don't interfere with include mechanics except where the
+# build would have failed anyways.
+define get_sys_includes
+$(shell $(1) $(2) -v -E - </dev/null 2>&1 \
+	| sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
+$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
+endef
+
+ifneq ($(CROSS_COMPILE),)
+CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
+endif
+
+CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
+
+BPF_PROG_OBJS := $(patsubst %.c,$(OUTPUT)/%.o,$(wildcard *.bpf.c))
+
+$(BPF_PROG_OBJS): $(OUTPUT)/%.o : %.c $(BPFOBJ) | $(MAKE_DIRS)
+	$(call msg,BPF_PROG,,$@)
+	$(Q)$(CLANG) -O2 -g --target=bpf $(CCINCLUDE) $(CLANG_SYS_INCLUDES) \
+	-c $< -o $@
+
+$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile)		       \
+	   $(APIDIR)/linux/bpf.h					       \
+	   | $(BUILD_DIR)/libbpf
+	$(call msg,MAKE,,$@)
+	$(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(BUILD_DIR)/libbpf/ \
+		    EXTRA_CFLAGS='-g -O0'				       \
+		    DESTDIR=$(SCRATCH_DIR) prefix= all install_headers
+
+EXTRA_CLEAN += $(SCRATCH_DIR)

tools/testing/selftests/net/udpgro.sh

@@ -7,7 +7,7 @@ source net_helper.sh
 
 readonly PEER_NS="ns-peer-$(mktemp -u XXXXXX)"
 
-BPF_FILE="xdp_dummy.o"
+BPF_FILE="xdp_dummy.bpf.o"
 
 # set global exit status, but never reset nonzero one.
 check_err()

tools/testing/selftests/net/udpgro_bench.sh

@@ -7,7 +7,7 @@ source net_helper.sh
 
 readonly PEER_NS="ns-peer-$(mktemp -u XXXXXX)"
 
-BPF_FILE="xdp_dummy.o"
+BPF_FILE="xdp_dummy.bpf.o"
 
 cleanup() {
 	local -r jobs="$(jobs -p)"

tools/testing/selftests/net/udpgro_frglist.sh

@@ -7,7 +7,7 @@ source net_helper.sh
 
 readonly PEER_NS="ns-peer-$(mktemp -u XXXXXX)"
 
-BPF_FILE="xdp_dummy.o"
+BPF_FILE="xdp_dummy.bpf.o"
 
 cleanup() {
 	local -r jobs="$(jobs -p)"
@@ -42,8 +42,8 @@ run_one() {
 
 	ip -n "${PEER_NS}" link set veth1 xdp object ${BPF_FILE} section xdp
 	tc -n "${PEER_NS}" qdisc add dev veth1 clsact
-	tc -n "${PEER_NS}" filter add dev veth1 ingress prio 4 protocol ipv6 bpf object-file nat6to4.o section schedcls/ingress6/nat_6  direct-action
-	tc -n "${PEER_NS}" filter add dev veth1 egress prio 4 protocol ip bpf object-file nat6to4.o section schedcls/egress4/snat4 direct-action
+	tc -n "${PEER_NS}" filter add dev veth1 ingress prio 4 protocol ipv6 bpf object-file nat6to4.bpf.o section schedcls/ingress6/nat_6  direct-action
+	tc -n "${PEER_NS}" filter add dev veth1 egress prio 4 protocol ip bpf object-file nat6to4.bpf.o section schedcls/egress4/snat4 direct-action
         echo ${rx_args}
 	ip netns exec "${PEER_NS}" ./udpgso_bench_rx ${rx_args} -r &
 
@@ -89,7 +89,7 @@ if [ ! -f ${BPF_FILE} ]; then
 	exit -1
 fi
 
-if [ ! -f nat6to4.o ]; then
+if [ ! -f nat6to4.bpf.o ]; then
 	echo "Missing nat6to4 helper. Run 'make' first"
 	exit -1
 fi

tools/testing/selftests/net/udpgro_fwd.sh

@@ -3,7 +3,7 @@
 
 source net_helper.sh
 
-BPF_FILE="xdp_dummy.o"
+BPF_FILE="xdp_dummy.bpf.o"
 readonly BASE="ns-$(mktemp -u XXXXXX)"
 readonly SRC=2
 readonly DST=1

tools/testing/selftests/net/veth.sh

 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
 
-BPF_FILE="xdp_dummy.o"
+BPF_FILE="xdp_dummy.bpf.o"
 readonly STATS="$(mktemp -p /tmp ns-XXXXXX)"
 readonly BASE=`basename $STATS`
 readonly SRC=2