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.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

9 files changed, 64 insertions, 65 deletions

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 7e7f243d0ab2a3..5befca249452a9 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/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
diff --git a/tools/testing/selftests/net/bpf.mk b/tools/testing/selftests/net/bpf.mk
new file mode 100644
index 00000000000000..a4f6755dd89413
--- /dev/null
+++ b/tools/testing/selftests/net/bpf.mk
@@ -0,0 +1,53 @@
+# 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)
diff --git a/tools/testing/selftests/net/nat6to4.c b/tools/testing/selftests/net/nat6to4.bpf.c
index ac54c36b25fc81..ac54c36b25fc81 100644
--- a/tools/testing/selftests/net/nat6to4.c
+++ b/tools/testing/selftests/net/nat6to4.bpf.c
diff --git a/tools/testing/selftests/net/udpgro.sh b/tools/testing/selftests/net/udpgro.sh
index 8802604148dda1..11a1ebda564fd5 100755
--- a/tools/testing/selftests/net/udpgro.sh
+++ b/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()
diff --git a/tools/testing/selftests/net/udpgro_bench.sh b/tools/testing/selftests/net/udpgro_bench.sh
index 7080eae5312b2f..c51ea90a1395f3 100755
--- a/tools/testing/selftests/net/udpgro_bench.sh
+++ b/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)"
diff --git a/tools/testing/selftests/net/udpgro_frglist.sh b/tools/testing/selftests/net/udpgro_frglist.sh
index e1ff645bd3d1c7..17404f49cdb688 100755
--- a/tools/testing/selftests/net/udpgro_frglist.sh
+++ b/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
diff --git a/tools/testing/selftests/net/udpgro_fwd.sh b/tools/testing/selftests/net/udpgro_fwd.sh
index 83ed987cff340e..550d8eb3e224cd 100755
--- a/tools/testing/selftests/net/udpgro_fwd.sh
+++ b/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
diff --git a/tools/testing/selftests/net/veth.sh b/tools/testing/selftests/net/veth.sh
index 3a394b43e274bd..4f1edbafb94687 100755
--- a/tools/testing/selftests/net/veth.sh
+++ b/tools/testing/selftests/net/veth.sh
@@ -1,7 +1,7 @@
 #!/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
diff --git a/tools/testing/selftests/net/xdp_dummy.c b/tools/testing/selftests/net/xdp_dummy.bpf.c
index d988b2e0cee840..d988b2e0cee840 100644
--- a/tools/testing/selftests/net/xdp_dummy.c
+++ b/tools/testing/selftests/net/xdp_dummy.bpf.c