Merge branch 'bpf-prog-build'

Jiong Wang says:

====================
This set improves bpf object file related rules in selftests Makefile.
  - tell git to ignore the build dir "alu32".
  - extend sub-register mode compilation to all bpf object files to give
    LLVM compiler bpf back-end more exercise.
  - auto-generate bpf kernel object file list.
  - relax sub-register mode compilation criteria.

v1 -> v2:
  - rename "kern_progs" to "progs". (Alexei)
  - spin a new patch to remove build server kernel requirement for
    sub-register mode compilation (Alexei)
  - rebase on top of KaFai’s latest "test_sock_fields" patch set.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/.gitignore

@@ -29,3 +29,4 @@ test_netcnt
 test_section_names
 test_tcpnotify_user
 test_libbpf
+alu32

tools/testing/selftests/bpf/Makefile

@@ -25,41 +25,17 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test
 	test_socket_cookie test_cgroup_storage test_select_reuseport test_section_names \
 	test_netcnt test_tcpnotify_user test_sock_fields
 
-BPF_OBJ_FILES = \
-	test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \
-	sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o \
-	test_tcpnotify_kern.o sample_map_ret0.o test_tcpbpf_kern.o \
-	sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o \
-	test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o \
-	test_tunnel_kern.o test_sockhash_kern.o test_lwt_seg6local.o \
-	sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o \
-	get_cgroup_id_kern.o socket_cookie_prog.o test_select_reuseport_kern.o \
-	test_skb_cgroup_id_kern.o bpf_flow.o netcnt_prog.o test_xdp_vlan.o \
-	xdp_dummy.o test_map_in_map.o test_spin_lock.o test_map_lock.o \
-	test_sock_fields_kern.o
-
-# Objects are built with default compilation flags and with sub-register
-# code-gen enabled.
-BPF_OBJ_FILES_DUAL_COMPILE = \
-	test_pkt_access.o test_pkt_access.o test_xdp.o test_adjust_tail.o \
-	test_l4lb.o test_l4lb_noinline.o test_xdp_noinline.o test_tcp_estats.o \
-	test_obj_id.o test_pkt_md_access.o test_tracepoint.o \
-	test_stacktrace_map.o test_stacktrace_map.o test_stacktrace_build_id.o \
-	test_stacktrace_build_id.o test_get_stack_rawtp.o \
-	test_get_stack_rawtp.o test_tracepoint.o test_sk_lookup_kern.o \
-	test_queue_map.o test_stack_map.o
-
-TEST_GEN_FILES = $(BPF_OBJ_FILES) $(BPF_OBJ_FILES_DUAL_COMPILE)
-
-# Also test sub-register code-gen if LLVM + kernel both has eBPF v3 processor
-# support which is the first version to contain both ALU32 and JMP32
-# instructions.
+BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c)))
+TEST_GEN_FILES = $(BPF_OBJ_FILES)
+
+# Also test sub-register code-gen if LLVM has eBPF v3 processor support which
+# contains both ALU32 and JMP32 instructions.
 SUBREG_CODEGEN := $(shell echo "int cal(int a) { return a > 0; }" | \
 			$(CLANG) -target bpf -O2 -emit-llvm -S -x c - -o - | \
-			$(LLC) -mattr=+alu32 -mcpu=probe 2>&1 | \
+			$(LLC) -mattr=+alu32 -mcpu=v3 2>&1 | \
 			grep 'if w')
 ifneq ($(SUBREG_CODEGEN),)
-TEST_GEN_FILES += $(patsubst %.o,alu32/%.o, $(BPF_OBJ_FILES_DUAL_COMPILE))
+TEST_GEN_FILES += $(patsubst %.o,alu32/%.o, $(BPF_OBJ_FILES))
 endif
 
 # Order correspond to 'make run_tests' order
@@ -190,7 +166,8 @@ $(ALU32_BUILD_DIR)/test_progs_32: test_progs.c $(ALU32_BUILD_DIR) \
 	$(CC) $(CFLAGS) -o $(ALU32_BUILD_DIR)/test_progs_32 $< \
 		trace_helpers.c $(OUTPUT)/libbpf.a $(LDLIBS)
 
-$(ALU32_BUILD_DIR)/%.o: %.c $(ALU32_BUILD_DIR) $(ALU32_BUILD_DIR)/test_progs_32
+$(ALU32_BUILD_DIR)/%.o: progs/%.c $(ALU32_BUILD_DIR) \
+					$(ALU32_BUILD_DIR)/test_progs_32
 	$(CLANG) $(CLANG_FLAGS) \
 		 -O2 -target bpf -emit-llvm -c $< -o - |      \
 	$(LLC) -march=bpf -mattr=+alu32 -mcpu=$(CPU) $(LLC_FLAGS) \
@@ -202,7 +179,7 @@ endif
 
 # Have one program compiled without "-target bpf" to test whether libbpf loads
 # it successfully
-$(OUTPUT)/test_xdp.o: test_xdp.c
+$(OUTPUT)/test_xdp.o: progs/test_xdp.c
 	$(CLANG) $(CLANG_FLAGS) \
 		-O2 -emit-llvm -c $< -o - | \
 	$(LLC) -march=bpf -mcpu=$(CPU) $(LLC_FLAGS) -filetype=obj -o $@
@@ -210,7 +187,7 @@ ifeq ($(DWARF2BTF),y)
 	$(BTF_PAHOLE) -J $@
 endif
 
-$(OUTPUT)/%.o: %.c
+$(OUTPUT)/%.o: progs/%.c
 	$(CLANG) $(CLANG_FLAGS) \
 		 -O2 -target bpf -emit-llvm -c $< -o - |      \
 	$(LLC) -march=bpf -mcpu=$(CPU) $(LLC_FLAGS) -filetype=obj -o $@