[PATCH bpf-next v3 10/13] tools/bpf: do not use pahole if clang/llvm can generate BTF sections

[PATCH bpf-next v3 10/13] tools/bpf: do not use pahole if clang/llvm can generate BTF sections

[Yonghong Song]

Add additional checks in tools/testing/selftests/bpf and
samples/bpf such that if clang/llvm compiler can generate
BTF sections, do not use pahole.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 samples/bpf/Makefile                 | 8 ++++++++
 tools/testing/selftests/bpf/Makefile | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index be0a961450bc..870fe7ee2b69 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -208,12 +208,20 @@ endif
 BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
 BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
 BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')
+BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
+			  clang -target bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \
+			  readelf -S ./llvm_btf_verify.o | grep BTF; \
+			  /bin/rm -f ./llvm_btf_verify.o)
 
+ifneq ($(BTF_LLVM_PROBE),)
+	EXTRA_CFLAGS += -g
+else
 ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),)
 	EXTRA_CFLAGS += -g
 	LLC_FLAGS += -mattr=dwarfris
 	DWARF2BTF = y
 endif
+endif
 
 # Trick to allow make to be run from this directory
 all:
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index d99dd6fc3fbe..8d5612724db8 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -121,7 +121,14 @@ $(OUTPUT)/test_xdp_noinline.o: CLANG_FLAGS += -fno-inline
 BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
 BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
 BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')
+BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
+			  clang -target bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \
+			  readelf -S ./llvm_btf_verify.o | grep BTF; \
+			  /bin/rm -f ./llvm_btf_verify.o)
 
+ifneq ($(BTF_LLVM_PROBE),)
+	CLANG_FLAGS += -g
+else
 ifneq ($(BTF_LLC_PROBE),)
 ifneq ($(BTF_PAHOLE_PROBE),)
 ifneq ($(BTF_OBJCOPY_PROBE),)
@@ -131,6 +138,7 @@ ifneq ($(BTF_OBJCOPY_PROBE),)
 endif
 endif
 endif
+endif
 
 $(OUTPUT)/%.o: %.c
 	$(CLANG) $(CLANG_FLAGS) \
-- 
2.17.1

[PATCH bpf-next v3 11/13] tools/bpf: refactor to implement btf_get_from_id() in lib/bpf

[Yonghong Song]

The function get_btf() is implemented in tools/bpf/bpftool/map.c
to get a btf structure given a map_info. This patch
refactored this function to be function btf_get_from_id()
in tools/lib/bpf so that it can be used later.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/bpf/bpftool/map.c | 68 ++--------------------------------------
 tools/lib/bpf/btf.c     | 69 +++++++++++++++++++++++++++++++++++++++++
 tools/lib/bpf/btf.h     | 18 ++++++-----
 3 files changed, 81 insertions(+), 74 deletions(-)

diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index 7bf38f0e152e..1b8a75fa0471 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -215,70 +215,6 @@ static int do_dump_btf(const struct btf_dumper *d,
 	return ret;
 }
 
-static int get_btf(struct bpf_map_info *map_info, struct btf **btf)
-{
-	struct bpf_btf_info btf_info = { 0 };
-	__u32 len = sizeof(btf_info);
-	__u32 last_size;
-	int btf_fd;
-	void *ptr;
-	int err;
-
-	err = 0;
-	*btf = NULL;
-	btf_fd = bpf_btf_get_fd_by_id(map_info->btf_id);
-	if (btf_fd < 0)
-		return 0;
-
-	/* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so
-	 * let's start with a sane default - 4KiB here - and resize it only if
-	 * bpf_obj_get_info_by_fd() needs a bigger buffer.
-	 */
-	btf_info.btf_size = 4096;
-	last_size = btf_info.btf_size;
-	ptr = malloc(last_size);
-	if (!ptr) {
-		err = -ENOMEM;
-		goto exit_free;
-	}
-
-	bzero(ptr, last_size);
-	btf_info.btf = ptr_to_u64(ptr);
-	err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
-
-	if (!err && btf_info.btf_size > last_size) {
-		void *temp_ptr;
-
-		last_size = btf_info.btf_size;
-		temp_ptr = realloc(ptr, last_size);
-		if (!temp_ptr) {
-			err = -ENOMEM;
-			goto exit_free;
-		}
-		ptr = temp_ptr;
-		bzero(ptr, last_size);
-		btf_info.btf = ptr_to_u64(ptr);
-		err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
-	}
-
-	if (err || btf_info.btf_size > last_size) {
-		err = errno;
-		goto exit_free;
-	}
-
-	*btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL);
-	if (IS_ERR(*btf)) {
-		err = PTR_ERR(*btf);
-		*btf = NULL;
-	}
-
-exit_free:
-	close(btf_fd);
-	free(ptr);
-
-	return err;
-}
-
 static json_writer_t *get_btf_writer(void)
 {
 	json_writer_t *jw = jsonw_new(stdout);
@@ -765,7 +701,7 @@ static int do_dump(int argc, char **argv)
 
 	prev_key = NULL;
 
-	err = get_btf(&info, &btf);
+	err = btf_get_from_id(info.btf_id, &btf);
 	if (err) {
 		p_err("failed to get btf");
 		goto exit_free;
@@ -909,7 +845,7 @@ static int do_lookup(int argc, char **argv)
 	}
 
 	/* here means bpf_map_lookup_elem() succeeded */
-	err = get_btf(&info, &btf);
+	err = btf_get_from_id(info.btf_id, &btf);
 	if (err) {
 		p_err("failed to get btf");
 		goto exit_free;
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 4748e0bacd2b..ab654628e966 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -42,6 +42,11 @@ struct btf_ext {
 	__u32 func_info_len;
 };
 
+static inline __u64 ptr_to_u64(const void *ptr)
+{
+	return (__u64) (unsigned long) ptr;
+}
+
 static int btf_add_type(struct btf *btf, struct btf_type *t)
 {
 	if (btf->types_size - btf->nr_types < 2) {
@@ -403,6 +408,70 @@ const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
 		return NULL;
 }
 
+int btf_get_from_id(__u32 id, struct btf **btf)
+{
+	struct bpf_btf_info btf_info = { 0 };
+	__u32 len = sizeof(btf_info);
+	__u32 last_size;
+	int btf_fd;
+	void *ptr;
+	int err;
+
+	err = 0;
+	*btf = NULL;
+	btf_fd = bpf_btf_get_fd_by_id(id);
+	if (btf_fd < 0)
+		return 0;
+
+	/* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so
+	 * let's start with a sane default - 4KiB here - and resize it only if
+	 * bpf_obj_get_info_by_fd() needs a bigger buffer.
+	 */
+	btf_info.btf_size = 4096;
+	last_size = btf_info.btf_size;
+	ptr = malloc(last_size);
+	if (!ptr) {
+		err = -ENOMEM;
+		goto exit_free;
+	}
+
+	bzero(ptr, last_size);
+	btf_info.btf = ptr_to_u64(ptr);
+	err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
+
+	if (!err && btf_info.btf_size > last_size) {
+		void *temp_ptr;
+
+		last_size = btf_info.btf_size;
+		temp_ptr = realloc(ptr, last_size);
+		if (!temp_ptr) {
+			err = -ENOMEM;
+			goto exit_free;
+		}
+		ptr = temp_ptr;
+		bzero(ptr, last_size);
+		btf_info.btf = ptr_to_u64(ptr);
+		err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
+	}
+
+	if (err || btf_info.btf_size > last_size) {
+		err = errno;
+		goto exit_free;
+	}
+
+	*btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL);
+	if (IS_ERR(*btf)) {
+		err = PTR_ERR(*btf);
+		*btf = NULL;
+	}
+
+exit_free:
+	close(btf_fd);
+	free(ptr);
+
+	return err;
+}
+
 static int btf_ext_validate_func_info(const struct btf_sec_func_info *sinfo,
 				      __u32 size, btf_print_fn_t err_log)
 {
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 513e55c1a928..c555decd70f2 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -67,14 +67,16 @@ LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
 LIBBPF_API int btf__fd(const struct btf *btf);
 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
+LIBBPF_API int btf_get_from_id(__u32 id, struct btf **btf);
 
-struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log);
-void btf_ext__free(struct btf_ext *btf_ext);
-int btf_ext_reloc_init(struct btf *btf, struct btf_ext *btf_ext,
-		       const char *sec_name, __u32 *btf_fd,
-		       void **func_info, __u32 *func_info_len);
-int btf_ext_reloc(struct btf *btf, struct btf_ext *btf_ext,
-		  const char *sec_name, __u32 insns_cnt, void **func_info,
-		  __u32 *func_info_len);
+LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size,
+					btf_print_fn_t err_log);
+LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
+LIBBPF_API int btf_ext_reloc_init(struct btf *btf, struct btf_ext *btf_ext,
+				  const char *sec_name, __u32 *btf_fd,
+				  void **func_info, __u32 *func_info_len);
+LIBBPF_API int btf_ext_reloc(struct btf *btf, struct btf_ext *btf_ext,
+			     const char *sec_name, __u32 insns_cnt,
+			     void **func_info, __u32 *func_info_len);
 
 #endif /* __LIBBPF_BTF_H */
-- 
2.17.1

[PATCH bpf-next v3 12/13] tools/bpf: enhance test_btf file testing to test func info

[Yonghong Song]

Change the bpf programs test_btf_haskv.c and test_btf_nokv.c to
have two sections, and enhance test_btf.c test_file feature
to test btf func_info returned by the kernel.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/test_btf.c       | 87 ++++++++++++++++++--
 tools/testing/selftests/bpf/test_btf_haskv.c | 16 +++-
 tools/testing/selftests/bpf/test_btf_nokv.c  | 16 +++-
 3 files changed, 106 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c
index e03a8cea4bb7..38ca942eba28 100644
--- a/tools/testing/selftests/bpf/test_btf.c
+++ b/tools/testing/selftests/bpf/test_btf.c
@@ -2180,13 +2180,13 @@ static struct btf_file_test file_tests[] = {
 },
 };
 
-static int file_has_btf_elf(const char *fn)
+static int file_has_btf_elf(const char *fn, bool *has_btf_ext)
 {
 	Elf_Scn *scn = NULL;
 	GElf_Ehdr ehdr;
+	int ret = 0;
 	int elf_fd;
 	Elf *elf;
-	int ret;
 
 	if (CHECK(elf_version(EV_CURRENT) == EV_NONE,
 		  "elf_version(EV_CURRENT) == EV_NONE"))
@@ -2218,14 +2218,12 @@ static int file_has_btf_elf(const char *fn)
 		}
 
 		sh_name = elf_strptr(elf, ehdr.e_shstrndx, sh.sh_name);
-		if (!strcmp(sh_name, BTF_ELF_SEC)) {
+		if (!strcmp(sh_name, BTF_ELF_SEC))
 			ret = 1;
-			goto done;
-		}
+		if (!strcmp(sh_name, BTF_EXT_ELF_SEC))
+			*has_btf_ext = true;
 	}
 
-	ret = 0;
-
 done:
 	close(elf_fd);
 	elf_end(elf);
@@ -2235,15 +2233,22 @@ static int file_has_btf_elf(const char *fn)
 static int do_test_file(unsigned int test_num)
 {
 	const struct btf_file_test *test = &file_tests[test_num - 1];
+	const char *expected_fnames[] = {"_dummy_tracepoint",
+					 "test_long_fname_1",
+					 "test_long_fname_2"};
+	__u32 func_lens[10], func_types[10], info_len;
+	struct bpf_prog_info info = {};
 	struct bpf_object *obj = NULL;
 	struct bpf_program *prog;
+	bool has_btf_ext = false;
+	struct btf *btf = NULL;
 	struct bpf_map *map;
-	int err;
+	int i, err, prog_fd;
 
 	fprintf(stderr, "BTF libbpf test[%u] (%s): ", test_num,
 		test->file);
 
-	err = file_has_btf_elf(test->file);
+	err = file_has_btf_elf(test->file, &has_btf_ext);
 	if (err == -1)
 		return err;
 
@@ -2271,6 +2276,7 @@ static int do_test_file(unsigned int test_num)
 	err = bpf_object__load(obj);
 	if (CHECK(err < 0, "bpf_object__load: %d", err))
 		goto done;
+	prog_fd = bpf_program__fd(prog);
 
 	map = bpf_object__find_map_by_name(obj, "btf_map");
 	if (CHECK(!map, "btf_map not found")) {
@@ -2285,6 +2291,69 @@ static int do_test_file(unsigned int test_num)
 		  test->btf_kv_notfound))
 		goto done;
 
+	if (!jit_enabled || !has_btf_ext)
+		goto skip_jit;
+
+	info_len = sizeof(struct bpf_prog_info);
+	info.nr_jited_func_types = ARRAY_SIZE(func_types);
+	info.nr_jited_func_lens = ARRAY_SIZE(func_lens);
+	info.jited_func_types = ptr_to_u64(&func_types[0]);
+	info.jited_func_lens = ptr_to_u64(&func_lens[0]);
+
+	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+
+	if (CHECK(err == -1, "invalid get info errno:%d", errno)) {
+		fprintf(stderr, "%s\n", btf_log_buf);
+		err = -1;
+		goto done;
+	}
+	if (CHECK(info.nr_jited_func_lens != 3,
+		  "incorrect info.nr_jited_func_lens %d",
+		  info.nr_jited_func_lens)) {
+		err = -1;
+		goto done;
+	}
+	if (CHECK(info.nr_jited_func_types != 3,
+		  "incorrect info.nr_jited_func_types %d",
+		  info.nr_jited_func_types)) {
+		err = -1;
+		goto done;
+	}
+	if (CHECK(info.btf_id == 0, "incorrect btf_id = 0")) {
+		err = -1;
+		goto done;
+	}
+
+	err = btf_get_from_id(info.btf_id, &btf);
+	if (CHECK(err, "cannot get btf from kernel, err: %d", err))
+		goto done;
+
+	/* check three functions */
+	for (i = 0; i < 3; i++) {
+		const struct btf_type *t;
+		const char *fname;
+
+		t = btf__type_by_id(btf, func_types[i]);
+		if (CHECK(!t, "btf__type_by_id failure: id %u",
+			  func_types[i])) {
+			err = -1;
+			goto done;
+		}
+
+		fname = btf__name_by_offset(btf, t->name_off);
+		err = strcmp(fname, expected_fnames[i]);
+		/* for the second and third functions in .text section,
+		 * the compiler may order them either way.
+		 */
+		if (i && err)
+			err = strcmp(fname, expected_fnames[3 - i]);
+		if (CHECK(err, "incorrect fname %s", fname ? : "")) {
+			err = -1;
+			goto done;
+		}
+	}
+
+skip_jit:
 	fprintf(stderr, "OK");
 
 done:
diff --git a/tools/testing/selftests/bpf/test_btf_haskv.c b/tools/testing/selftests/bpf/test_btf_haskv.c
index b21b876f475d..e5c79fe0ffdb 100644
--- a/tools/testing/selftests/bpf/test_btf_haskv.c
+++ b/tools/testing/selftests/bpf/test_btf_haskv.c
@@ -24,8 +24,8 @@ struct dummy_tracepoint_args {
 	struct sock *sock;
 };
 
-SEC("dummy_tracepoint")
-int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
+__attribute__((noinline))
+static int test_long_fname_2(struct dummy_tracepoint_args *arg)
 {
 	struct ipv_counts *counts;
 	int key = 0;
@@ -42,4 +42,16 @@ int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
 	return 0;
 }
 
+__attribute__((noinline))
+static int test_long_fname_1(struct dummy_tracepoint_args *arg)
+{
+	return test_long_fname_2(arg);
+}
+
+SEC("dummy_tracepoint")
+int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
+{
+	return test_long_fname_1(arg);
+}
+
 char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_btf_nokv.c b/tools/testing/selftests/bpf/test_btf_nokv.c
index 0ed8e088eebf..434188c37774 100644
--- a/tools/testing/selftests/bpf/test_btf_nokv.c
+++ b/tools/testing/selftests/bpf/test_btf_nokv.c
@@ -22,8 +22,8 @@ struct dummy_tracepoint_args {
 	struct sock *sock;
 };
 
-SEC("dummy_tracepoint")
-int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
+__attribute__((noinline))
+static int test_long_fname_2(struct dummy_tracepoint_args *arg)
 {
 	struct ipv_counts *counts;
 	int key = 0;
@@ -40,4 +40,16 @@ int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
 	return 0;
 }
 
+__attribute__((noinline))
+static int test_long_fname_1(struct dummy_tracepoint_args *arg)
+{
+	return test_long_fname_2(arg);
+}
+
+SEC("dummy_tracepoint")
+int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
+{
+	return test_long_fname_1(arg);
+}
+
 char _license[] SEC("license") = "GPL";
-- 
2.17.1

[PATCH bpf-next v3 13/13] tools/bpf: bpftool: add support for jited func types

[Yonghong Song]

This patch added support to print function signature
if btf func_info is available. Note that ksym
now uses function name instead of prog_name as
prog_name has a limit of 16 bytes including
ending '\0'.

The following is a sample output for selftests
test_btf with file test_btf_haskv.o:

  $ bpftool prog dump jited id 1
  int _dummy_tracepoint(struct dummy_tracepoint_args * ):
  bpf_prog_b07ccb89267cf242__dummy_tracepoint:
     0:   push   %rbp
     1:   mov    %rsp,%rbp
    ......
    3c:   add    $0x28,%rbp
    40:   leaveq
    41:   retq

  int test_long_fname_1(struct dummy_tracepoint_args * ):
  bpf_prog_2dcecc18072623fc_test_long_fname_1:
     0:   push   %rbp
     1:   mov    %rsp,%rbp
    ......
    3a:   add    $0x28,%rbp
    3e:   leaveq
    3f:   retq

  int test_long_fname_2(struct dummy_tracepoint_args * ):
  bpf_prog_89d64e4abf0f0126_test_long_fname_2:
     0:   push   %rbp
     1:   mov    %rsp,%rbp
    ......
    80:   add    $0x28,%rbp
    84:   leaveq
    85:   retq

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/bpf/bpftool/btf_dumper.c | 90 ++++++++++++++++++++++++++++++++++
 tools/bpf/bpftool/main.h       |  2 +
 tools/bpf/bpftool/prog.c       | 54 ++++++++++++++++++++
 3 files changed, 146 insertions(+)

diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index 55bc512a1831..6122b735ddcc 100644
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c
@@ -249,3 +249,93 @@ int btf_dumper_type(const struct btf_dumper *d, __u32 type_id,
 {
 	return btf_dumper_do_type(d, type_id, 0, data);
 }
+
+#define BTF_PRINT_ARG(...)						\
+	do {								\
+		pos += snprintf(func_sig + pos, size - pos,		\
+				__VA_ARGS__);				\
+		if (pos >= size)					\
+			return -1;					\
+	} while (0)
+#define BTF_PRINT_TYPE(type)					\
+	do {								\
+		pos = __btf_dumper_type_only(btf, type, func_sig,	\
+					     pos, size);		\
+		if (pos == -1)						\
+			return -1;					\
+	} while (0)
+
+static int __btf_dumper_type_only(struct btf *btf, __u32 type_id,
+				  char *func_sig, int pos, int size)
+{
+	const struct btf_type *t = btf__type_by_id(btf, type_id);
+	const struct btf_array *array;
+	int i, vlen;
+
+	switch (BTF_INFO_KIND(t->info)) {
+	case BTF_KIND_INT:
+		BTF_PRINT_ARG("%s ", btf__name_by_offset(btf, t->name_off));
+		break;
+	case BTF_KIND_STRUCT:
+		BTF_PRINT_ARG("struct %s ",
+			      btf__name_by_offset(btf, t->name_off));
+		break;
+	case BTF_KIND_UNION:
+		BTF_PRINT_ARG("union %s ",
+			      btf__name_by_offset(btf, t->name_off));
+		break;
+	case BTF_KIND_ENUM:
+		BTF_PRINT_ARG("enum %s ",
+			      btf__name_by_offset(btf, t->name_off));
+		break;
+	case BTF_KIND_ARRAY:
+		array = (struct btf_array *)(t + 1);
+		BTF_PRINT_TYPE(array->type);
+		BTF_PRINT_ARG("[%d]", array->nelems);
+		break;
+	case BTF_KIND_PTR:
+		BTF_PRINT_TYPE(t->type);
+		BTF_PRINT_ARG("* ");
+		break;
+	case BTF_KIND_UNKN:
+	case BTF_KIND_FWD:
+	case BTF_KIND_TYPEDEF:
+		return -1;
+	case BTF_KIND_VOLATILE:
+		BTF_PRINT_ARG("volatile ");
+		BTF_PRINT_TYPE(t->type);
+		break;
+	case BTF_KIND_CONST:
+		BTF_PRINT_ARG("const ");
+		BTF_PRINT_TYPE(t->type);
+		break;
+	case BTF_KIND_RESTRICT:
+		BTF_PRINT_ARG("restrict ");
+		BTF_PRINT_TYPE(t->type);
+		break;
+	case BTF_KIND_FUNC:
+	case BTF_KIND_FUNC_PROTO:
+		BTF_PRINT_TYPE(t->type);
+		BTF_PRINT_ARG("%s(", btf__name_by_offset(btf, t->name_off));
+		vlen = BTF_INFO_VLEN(t->info);
+		for (i = 0; i < vlen; i++) {
+			__u32 arg_type = ((__u32 *)(t + 1))[i];
+
+			if (i)
+				BTF_PRINT_ARG(", ");
+			BTF_PRINT_TYPE(arg_type);
+		}
+		BTF_PRINT_ARG(")");
+		break;
+	default:
+		return -1;
+	}
+
+	return pos;
+}
+
+int btf_dumper_type_only(struct btf *btf, __u32 type_id, char *func_sig,
+			 int size)
+{
+	return __btf_dumper_type_only(btf, type_id, func_sig, 0, size);
+}
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 28ee769bd11b..f887564476dc 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -168,6 +168,8 @@ struct btf_dumper {
  */
 int btf_dumper_type(const struct btf_dumper *d, __u32 type_id,
 		    const void *data);
+int btf_dumper_type_only(struct btf *btf, __u32 func_type_id, char *func_only,
+			 int size);
 
 struct nlattr;
 struct ifinfomsg;
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 335028968dfb..e78632a30ea3 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -47,6 +47,7 @@
 #include <linux/err.h>
 
 #include <bpf.h>
+#include <btf.h>
 #include <libbpf.h>
 
 #include "cfg.h"
@@ -447,9 +448,11 @@ static int do_show(int argc, char **argv)
 static int do_dump(int argc, char **argv)
 {
 	unsigned long *func_ksyms = NULL;
+	unsigned int *func_types = NULL;
 	struct bpf_prog_info info = {};
 	unsigned int *func_lens = NULL;
 	unsigned int nr_func_ksyms;
+	unsigned int nr_func_types;
 	unsigned int nr_func_lens;
 	struct dump_data dd = {};
 	__u32 len = sizeof(info);
@@ -546,6 +549,16 @@ static int do_dump(int argc, char **argv)
 		}
 	}
 
+	nr_func_types = info.nr_jited_func_types;
+	if (nr_func_types) {
+		func_types = malloc(nr_func_types * sizeof(__u32));
+		if (!func_types) {
+			p_err("mem alloc failed");
+			close(fd);
+			goto err_free;
+		}
+	}
+
 	memset(&info, 0, sizeof(info));
 
 	*member_ptr = ptr_to_u64(buf);
@@ -554,6 +567,8 @@ static int do_dump(int argc, char **argv)
 	info.nr_jited_ksyms = nr_func_ksyms;
 	info.jited_func_lens = ptr_to_u64(func_lens);
 	info.nr_jited_func_lens = nr_func_lens;
+	info.jited_func_types = ptr_to_u64(func_types);
+	info.nr_jited_func_types = nr_func_types;
 
 	err = bpf_obj_get_info_by_fd(fd, &info, &len);
 	close(fd);
@@ -577,6 +592,11 @@ static int do_dump(int argc, char **argv)
 		goto err_free;
 	}
 
+	if (info.nr_jited_func_types > nr_func_types) {
+		p_err("too many types returned");
+		goto err_free;
+	}
+
 	if ((member_len == &info.jited_prog_len &&
 	     info.jited_prog_insns == 0) ||
 	    (member_len == &info.xlated_prog_len &&
@@ -585,6 +605,12 @@ static int do_dump(int argc, char **argv)
 		goto err_free;
 	}
 
+	if (info.btf_id &&
+	    info.nr_jited_func_lens != info.nr_jited_func_types) {
+		p_err("unequal jited func lens and types");
+		goto err_free;
+	}
+
 	if (filepath) {
 		fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 		if (fd < 0) {
@@ -618,7 +644,9 @@ static int do_dump(int argc, char **argv)
 			struct kernel_sym *sym = NULL;
 			char sym_name[SYM_MAX_NAME];
 			unsigned char *img = buf;
+			struct btf *btf = NULL;
 			__u64 *ksyms = NULL;
+			char func_sig[1024];
 			__u32 *lens;
 			__u32 i;
 
@@ -627,6 +655,14 @@ static int do_dump(int argc, char **argv)
 				ksyms = (__u64 *) info.jited_ksyms;
 			}
 
+			if (info.btf_id) {
+				err = btf_get_from_id(info.btf_id, &btf);
+				if (err) {
+					p_err("failed to get btf");
+					goto err_free;
+				}
+			}
+
 			if (json_output)
 				jsonw_start_array(json_wtr);
 
@@ -642,12 +678,28 @@ static int do_dump(int argc, char **argv)
 					strcpy(sym_name, "unknown");
 				}
 
+				func_sig[0] = '\0';
+				if (btf) {
+					err = btf_dumper_type_only(btf,
+								   func_types[i],
+								   func_sig,
+								   sizeof(func_sig));
+					if (err < 0)
+						func_sig[0] = '\0';
+				}
+
 				if (json_output) {
 					jsonw_start_object(json_wtr);
+					if (func_sig[0] != '\0') {
+						jsonw_name(json_wtr, "proto");
+						jsonw_string(json_wtr, func_sig);
+					}
 					jsonw_name(json_wtr, "name");
 					jsonw_string(json_wtr, sym_name);
 					jsonw_name(json_wtr, "insns");
 				} else {
+					if (func_sig[0] != '\0')
+						printf("%s:\n", func_sig);
 					printf("%s:\n", sym_name);
 				}
 
@@ -685,12 +737,14 @@ static int do_dump(int argc, char **argv)
 	free(buf);
 	free(func_ksyms);
 	free(func_lens);
+	free(func_types);
 	return 0;
 
 err_free:
 	free(buf);
 	free(func_ksyms);
 	free(func_lens);
+	free(func_types);
 	return -1;
 }
 
-- 
2.17.1