selftests/bpf: Store BPF object files with .bpf.o extension

BPF object files are, in a way, the final artifact produced as part of
the ahead-of-time compilation process. That makes them somewhat special
compared to "regular" object files, which are a intermediate build
artifacts that can typically be removed safely. As such, it can make
sense to name them differently to make it easier to spot this difference
at a glance.

Among others, libbpf-bootstrap [0] has established the extension .bpf.o
for BPF object files. It seems reasonable to follow this example and
establish the same denomination for selftest build artifacts. To that
end, this change adjusts the corresponding part of the build system and
the test programs loading BPF object files to work with .bpf.o files.

  [0] https://github.com/libbpf/libbpf-bootstrap

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220901222253.1199242-1-deso@posteo.net

tools/testing/selftests/bpf/Makefile

@@ -45,7 +45,7 @@ ifneq ($(BPF_GCC),)
 TEST_GEN_PROGS += test_progs-bpf_gcc
 endif
 
-TEST_GEN_FILES = test_lwt_ip_encap.o test_tc_edt.o
+TEST_GEN_FILES = test_lwt_ip_encap.bpf.o test_tc_edt.bpf.o
 TEST_FILES = xsk_prereqs.sh $(wildcard progs/btf_dump_test_case_*.c)
 
 # Order correspond to 'make run_tests' order
@@ -358,17 +358,17 @@ LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
 LSKELS_EXTRA := test_ksyms_module.c test_ksyms_weak.c kfunc_call_test_subprog.c
 SKEL_BLACKLIST += $$(LSKELS)
 
-test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o
-linked_funcs.skel.h-deps := linked_funcs1.o linked_funcs2.o
-linked_vars.skel.h-deps := linked_vars1.o linked_vars2.o
-linked_maps.skel.h-deps := linked_maps1.o linked_maps2.o
+test_static_linked.skel.h-deps := test_static_linked1.bpf.o test_static_linked2.bpf.o
+linked_funcs.skel.h-deps := linked_funcs1.bpf.o linked_funcs2.bpf.o
+linked_vars.skel.h-deps := linked_vars1.bpf.o linked_vars2.bpf.o
+linked_maps.skel.h-deps := linked_maps1.bpf.o linked_maps2.bpf.o
 # In the subskeleton case, we want the test_subskeleton_lib.subskel.h file
 # but that's created as a side-effect of the skel.h generation.
-test_subskeleton.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o test_subskeleton.o
-test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o
-test_usdt.skel.h-deps := test_usdt.o test_usdt_multispec.o
+test_subskeleton.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o test_subskeleton.bpf.o
+test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o
+test_usdt.skel.h-deps := test_usdt.bpf.o test_usdt_multispec.bpf.o
 
-LINKED_BPF_SRCS := $(patsubst %.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
+LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
 
 # Set up extra TRUNNER_XXX "temporary" variables in the environment (relies on
 # $eval()) and pass control to DEFINE_TEST_RUNNER_RULES.
@@ -386,7 +386,7 @@ TRUNNER_EXTRA_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.o,		\
 TRUNNER_EXTRA_HDRS := $$(filter %.h,$(TRUNNER_EXTRA_SOURCES))
 TRUNNER_TESTS_HDR := $(TRUNNER_TESTS_DIR)/tests.h
 TRUNNER_BPF_SRCS := $$(notdir $$(wildcard $(TRUNNER_BPF_PROGS_DIR)/*.c))
-TRUNNER_BPF_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.o, $$(TRUNNER_BPF_SRCS))
+TRUNNER_BPF_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.bpf.o, $$(TRUNNER_BPF_SRCS))
 TRUNNER_BPF_SKELS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.skel.h,	\
 				 $$(filter-out $(SKEL_BLACKLIST) $(LINKED_BPF_SRCS),\
 					       $$(TRUNNER_BPF_SRCS)))
@@ -416,7 +416,7 @@ endif
 # input/output directory combination
 ifeq ($($(TRUNNER_BPF_PROGS_DIR)$(if $2,-)$2-bpfobjs),)
 $(TRUNNER_BPF_PROGS_DIR)$(if $2,-)$2-bpfobjs := y
-$(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.o:				\
+$(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.bpf.o:				\
 		     $(TRUNNER_BPF_PROGS_DIR)/%.c			\
 		     $(TRUNNER_BPF_PROGS_DIR)/*.h			\
 		     $$(INCLUDE_DIR)/vmlinux.h				\
@@ -426,25 +426,25 @@ $(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.o:				\
 	$$(call $(TRUNNER_BPF_BUILD_RULE),$$<,$$@,			\
 					  $(TRUNNER_BPF_CFLAGS))
 
-$(TRUNNER_BPF_SKELS): %.skel.h: %.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
+$(TRUNNER_BPF_SKELS): %.skel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
 	$$(call msg,GEN-SKEL,$(TRUNNER_BINARY),$$@)
 	$(Q)$$(BPFTOOL) gen object $$(<:.o=.linked1.o) $$<
 	$(Q)$$(BPFTOOL) gen object $$(<:.o=.linked2.o) $$(<:.o=.linked1.o)
 	$(Q)$$(BPFTOOL) gen object $$(<:.o=.linked3.o) $$(<:.o=.linked2.o)
 	$(Q)diff $$(<:.o=.linked2.o) $$(<:.o=.linked3.o)
-	$(Q)$$(BPFTOOL) gen skeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.o=)) > $$@
-	$(Q)$$(BPFTOOL) gen subskeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.o=)) > $$(@:.skel.h=.subskel.h)
+	$(Q)$$(BPFTOOL) gen skeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.bpf.o=)) > $$@
+	$(Q)$$(BPFTOOL) gen subskeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.bpf.o=)) > $$(@:.skel.h=.subskel.h)
 
-$(TRUNNER_BPF_LSKELS): %.lskel.h: %.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
+$(TRUNNER_BPF_LSKELS): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
 	$$(call msg,GEN-SKEL,$(TRUNNER_BINARY),$$@)
 	$(Q)$$(BPFTOOL) gen object $$(<:.o=.llinked1.o) $$<
 	$(Q)$$(BPFTOOL) gen object $$(<:.o=.llinked2.o) $$(<:.o=.llinked1.o)
 	$(Q)$$(BPFTOOL) gen object $$(<:.o=.llinked3.o) $$(<:.o=.llinked2.o)
 	$(Q)diff $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o)
-	$(Q)$$(BPFTOOL) gen skeleton -L $$(<:.o=.llinked3.o) name $$(notdir $$(<:.o=_lskel)) > $$@
+	$(Q)$$(BPFTOOL) gen skeleton -L $$(<:.o=.llinked3.o) name $$(notdir $$(<:.bpf.o=_lskel)) > $$@
 
 $(TRUNNER_BPF_SKELS_LINKED): $(TRUNNER_BPF_OBJS) $(BPFTOOL) | $(TRUNNER_OUTPUT)
-	$$(call msg,LINK-BPF,$(TRUNNER_BINARY),$$(@:.skel.h=.o))
+	$$(call msg,LINK-BPF,$(TRUNNER_BINARY),$$(@:.skel.h=.bpf.o))
 	$(Q)$$(BPFTOOL) gen object $$(@:.skel.h=.linked1.o) $$(addprefix $(TRUNNER_OUTPUT)/,$$($$(@F)-deps))
 	$(Q)$$(BPFTOOL) gen object $$(@:.skel.h=.linked2.o) $$(@:.skel.h=.linked1.o)
 	$(Q)$$(BPFTOOL) gen object $$(@:.skel.h=.linked3.o) $$(@:.skel.h=.linked2.o)
@@ -500,7 +500,7 @@ $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS)			\
 			     | $(TRUNNER_BINARY)-extras
 	$$(call msg,BINARY,,$$@)
 	$(Q)$$(CC) $$(CFLAGS) $$(filter %.a %.o,$$^) $$(LDLIBS) -o $$@
-	$(Q)$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.o $$@
+	$(Q)$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.bpf.o $$@
 	$(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool $(if $2,$2/)bpftool
 
 endef

tools/testing/selftests/bpf/README.rst

@@ -126,11 +126,11 @@ available in 10.0.1. The patch is available in llvm 11.0.0 trunk.
 
 __  https://reviews.llvm.org/D78466
 
-bpf_verif_scale/loop6.o test failure with Clang 12
-==================================================
+bpf_verif_scale/loop6.bpf.o test failure with Clang 12
+======================================================
 
 With Clang 12, the following bpf_verif_scale test failed:
-  * ``bpf_verif_scale/loop6.o``
+  * ``bpf_verif_scale/loop6.bpf.o``
 
 The verifier output looks like
 
@@ -245,7 +245,7 @@ See `kernel llvm reloc`_ for more explanation and some examples.
 Using clang 13 to compile old libbpf which has static linker support,
 there will be a compilation failure::
 
-  libbpf: ELF relo #0 in section #6 has unexpected type 2 in .../bpf_tcp_nogpl.o
+  libbpf: ELF relo #0 in section #6 has unexpected type 2 in .../bpf_tcp_nogpl.bpf.o
 
 Here, ``type 2`` refers to new relocation type ``R_BPF_64_ABS64``.
 To fix this issue, user newer libbpf.

tools/testing/selftests/bpf/get_cgroup_id_user.c

@@ -48,7 +48,7 @@ static int bpf_find_map(const char *test, struct bpf_object *obj,
 int main(int argc, char **argv)
 {
 	const char *probe_name = "syscalls/sys_enter_nanosleep";
-	const char *file = "get_cgroup_id_kern.o";
+	const char *file = "get_cgroup_id_kern.bpf.o";
 	int err, bytes, efd, prog_fd, pmu_fd;
 	int cgroup_fd, cgidmap_fd, pidmap_fd;
 	struct perf_event_attr attr = {};

tools/testing/selftests/bpf/prog_tests/bpf_obj_id.c

@@ -7,7 +7,7 @@ void serial_test_bpf_obj_id(void)
 {
 	const __u64 array_magic_value = 0xfaceb00c;
 	const __u32 array_key = 0;
-	const char *file = "./test_obj_id.o";
+	const char *file = "./test_obj_id.bpf.o";
 	const char *expected_prog_name = "test_obj_id";
 	const char *expected_map_name = "test_map_id";
 	const __u64 nsec_per_sec = 1000000000;

tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c

@@ -75,45 +75,45 @@ static void scale_test(const char *file,
 
 void test_verif_scale1()
 {
-	scale_test("test_verif_scale1.o", BPF_PROG_TYPE_SCHED_CLS, false);
+	scale_test("test_verif_scale1.bpf.o", BPF_PROG_TYPE_SCHED_CLS, false);
 }
 
 void test_verif_scale2()
 {
-	scale_test("test_verif_scale2.o", BPF_PROG_TYPE_SCHED_CLS, false);
+	scale_test("test_verif_scale2.bpf.o", BPF_PROG_TYPE_SCHED_CLS, false);
 }
 
 void test_verif_scale3()
 {
-	scale_test("test_verif_scale3.o", BPF_PROG_TYPE_SCHED_CLS, false);
+	scale_test("test_verif_scale3.bpf.o", BPF_PROG_TYPE_SCHED_CLS, false);
 }
 
 void test_verif_scale_pyperf_global()
 {
-	scale_test("pyperf_global.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("pyperf_global.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_pyperf_subprogs()
 {
-	scale_test("pyperf_subprogs.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("pyperf_subprogs.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_pyperf50()
 {
 	/* full unroll by llvm */
-	scale_test("pyperf50.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("pyperf50.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_pyperf100()
 {
 	/* full unroll by llvm */
-	scale_test("pyperf100.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("pyperf100.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_pyperf180()
 {
 	/* full unroll by llvm */
-	scale_test("pyperf180.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("pyperf180.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_pyperf600()
@@ -124,13 +124,13 @@ void test_verif_scale_pyperf600()
 	 * 16k insns in loop body.
 	 * Total of 5 such loops. Total program size ~82k insns.
 	 */
-	scale_test("pyperf600.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("pyperf600.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_pyperf600_bpf_loop(void)
 {
 	/* use the bpf_loop helper*/
-	scale_test("pyperf600_bpf_loop.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("pyperf600_bpf_loop.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_pyperf600_nounroll()
@@ -141,37 +141,37 @@ void test_verif_scale_pyperf600_nounroll()
 	 * ~110 insns in loop body.
 	 * Total of 5 such loops. Total program size ~1500 insns.
 	 */
-	scale_test("pyperf600_nounroll.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("pyperf600_nounroll.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_loop1()
 {
-	scale_test("loop1.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("loop1.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_loop2()
 {
-	scale_test("loop2.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("loop2.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_loop3_fail()
 {
-	scale_test("loop3.o", BPF_PROG_TYPE_RAW_TRACEPOINT, true /* fails */);
+	scale_test("loop3.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, true /* fails */);
 }
 
 void test_verif_scale_loop4()
 {
-	scale_test("loop4.o", BPF_PROG_TYPE_SCHED_CLS, false);
+	scale_test("loop4.bpf.o", BPF_PROG_TYPE_SCHED_CLS, false);
 }
 
 void test_verif_scale_loop5()
 {
-	scale_test("loop5.o", BPF_PROG_TYPE_SCHED_CLS, false);
+	scale_test("loop5.bpf.o", BPF_PROG_TYPE_SCHED_CLS, false);
 }
 
 void test_verif_scale_loop6()
 {
-	scale_test("loop6.o", BPF_PROG_TYPE_KPROBE, false);
+	scale_test("loop6.bpf.o", BPF_PROG_TYPE_KPROBE, false);
 }
 
 void test_verif_scale_strobemeta()
@@ -180,54 +180,54 @@ void test_verif_scale_strobemeta()
 	 * Total program size 20.8k insn.
 	 * ~350k processed_insns
 	 */
-	scale_test("strobemeta.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("strobemeta.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_strobemeta_bpf_loop(void)
 {
 	/* use the bpf_loop helper*/
-	scale_test("strobemeta_bpf_loop.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("strobemeta_bpf_loop.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_strobemeta_nounroll1()
 {
 	/* no unroll, tiny loops */
-	scale_test("strobemeta_nounroll1.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("strobemeta_nounroll1.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_strobemeta_nounroll2()
 {
 	/* no unroll, tiny loops */
-	scale_test("strobemeta_nounroll2.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("strobemeta_nounroll2.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_strobemeta_subprogs()
 {
 	/* non-inlined subprogs */
-	scale_test("strobemeta_subprogs.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
+	scale_test("strobemeta_subprogs.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
 }
 
 void test_verif_scale_sysctl_loop1()
 {
-	scale_test("test_sysctl_loop1.o", BPF_PROG_TYPE_CGROUP_SYSCTL, false);
+	scale_test("test_sysctl_loop1.bpf.o", BPF_PROG_TYPE_CGROUP_SYSCTL, false);
 }
 
 void test_verif_scale_sysctl_loop2()
 {
-	scale_test("test_sysctl_loop2.o", BPF_PROG_TYPE_CGROUP_SYSCTL, false);
+	scale_test("test_sysctl_loop2.bpf.o", BPF_PROG_TYPE_CGROUP_SYSCTL, false);
 }
 
 void test_verif_scale_xdp_loop()
 {
-	scale_test("test_xdp_loop.o", BPF_PROG_TYPE_XDP, false);
+	scale_test("test_xdp_loop.bpf.o", BPF_PROG_TYPE_XDP, false);
 }
 
 void test_verif_scale_seg6_loop()
 {
-	scale_test("test_seg6_loop.o", BPF_PROG_TYPE_LWT_SEG6LOCAL, false);
+	scale_test("test_seg6_loop.bpf.o", BPF_PROG_TYPE_LWT_SEG6LOCAL, false);
 }
 
 void test_verif_twfw()
 {
-	scale_test("twfw.o", BPF_PROG_TYPE_CGROUP_SKB, false);
+	scale_test("twfw.bpf.o", BPF_PROG_TYPE_CGROUP_SKB, false);
 }

tools/testing/selftests/bpf/prog_tests/btf.c

@@ -4651,8 +4651,8 @@ struct btf_file_test {
 };
 
 static struct btf_file_test file_tests[] = {
-	{ .file = "test_btf_newkv.o", },
-	{ .file = "test_btf_nokv.o", .btf_kv_notfound = true, },
+	{ .file = "test_btf_newkv.bpf.o", },
+	{ .file = "test_btf_nokv.bpf.o", .btf_kv_notfound = true, },
 };
 
 static void do_test_file(unsigned int test_num)

tools/testing/selftests/bpf/prog_tests/btf_dump.c

@@ -52,7 +52,7 @@ static int test_btf_dump_case(int n, struct btf_dump_test_case *t)
 	int err = 0, fd = -1;
 	FILE *f = NULL;
 
-	snprintf(test_file, sizeof(test_file), "%s.o", t->file);
+	snprintf(test_file, sizeof(test_file), "%s.bpf.o", t->file);
 
 	btf = btf__parse_elf(test_file, NULL);
 	if (!ASSERT_OK_PTR(btf, "btf_parse_elf")) {
@@ -841,8 +841,8 @@ static void test_btf_dump_datasec_data(char *str)
 	char license[4] = "GPL";
 	struct btf_dump *d;
 
-	btf = btf__parse("xdping_kern.o", NULL);
-	if (!ASSERT_OK_PTR(btf, "xdping_kern.o BTF not found"))
+	btf = btf__parse("xdping_kern.bpf.o", NULL);
+	if (!ASSERT_OK_PTR(btf, "xdping_kern.bpf.o BTF not found"))
 		return;
 
 	d = btf_dump__new(btf, btf_dump_snprintf, str, NULL);

tools/testing/selftests/bpf/prog_tests/btf_endian.c

@@ -23,7 +23,7 @@ void test_btf_endian() {
 	int var_id;
 
 	/* Load BTF in native endianness */
-	btf = btf__parse_elf("btf_dump_test_case_syntax.o", NULL);
+	btf = btf__parse_elf("btf_dump_test_case_syntax.bpf.o", NULL);
 	if (!ASSERT_OK_PTR(btf, "parse_native_btf"))
 		goto err_out;
 

tools/testing/selftests/bpf/prog_tests/connect_force_port.c

@@ -53,7 +53,7 @@ static int run_test(int cgroup_fd, int server_fd, int family, int type)
 	__u16 expected_peer_port = 60000;
 	struct bpf_program *prog;
 	struct bpf_object *obj;
-	const char *obj_file = v4 ? "connect_force_port4.o" : "connect_force_port6.o";
+	const char *obj_file = v4 ? "connect_force_port4.bpf.o" : "connect_force_port6.bpf.o";
 	int fd, err;
 	__u32 duration = 0;