---
tools/bpf/bpftool/btf.c  |  9 ++++++---
tools/bpf/bpftool/main.c | 15 ++++++++++++++-
tools/bpf/bpftool/main.h |  1 +
3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index 8ab142ff5eac..c96b56e8e3a4 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c

@@ -358,8 +358,12 @@ static int dump_btf_raw(const struct btf *btf,

		}
	} else {
		int cnt = btf__get_nr_types(btf);
+		int start_id = 1;

-		for (i = 1; i <= cnt; i++) {
+		if (base_btf)
+			start_id = btf__get_nr_types(base_btf) + 1;
+
+		for (i = start_id; i <= cnt; i++) {
			t = btf__type_by_id(btf, i);
			dump_btf_type(btf, i, t);
		}

@@ -438,7 +442,6 @@ static int do_dump(int argc, char **argv)

		return -1;
	}
	src = GET_ARG();
-
	if (is_prefix(src, "map")) {
		struct bpf_map_info info = {};
		__u32 len = sizeof(info);

@@ -499,7 +502,7 @@ static int do_dump(int argc, char **argv)

		}
		NEXT_ARG();
	} else if (is_prefix(src, "file")) {
-		btf = btf__parse(*argv, NULL);
+		btf = btf__parse_split(*argv, base_btf);
		if (IS_ERR(btf)) {
			err = -PTR_ERR(btf);
			btf = NULL;

diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index 682daaa49e6a..b86f450e6fce 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c

@@ -11,6 +11,7 @@

#include <bpf/bpf.h>
#include <bpf/libbpf.h>
+#include <bpf/btf.h>

#include "main.h"

@@ -28,6 +29,7 @@ bool show_pinned;

bool block_mount;
bool verifier_logs;
bool relaxed_maps;
+struct btf *base_btf;
struct pinned_obj_table prog_table;
struct pinned_obj_table map_table;
struct pinned_obj_table link_table;

@@ -391,6 +393,7 @@ int main(int argc, char **argv)

		{ "mapcompat",	no_argument,	NULL,	'm' },
		{ "nomount",	no_argument,	NULL,	'n' },
		{ "debug",	no_argument,	NULL,	'd' },
+		{ "base-btf",	required_argument, NULL, 'B' },
		{ 0 }
	};
	int opt, ret;

@@ -407,7 +410,7 @@ int main(int argc, char **argv)

	hash_init(link_table.table);

	opterr = 0;
-	while ((opt = getopt_long(argc, argv, "Vhpjfmnd",
+	while ((opt = getopt_long(argc, argv, "VhpjfmndB:",
				  options, NULL)) >= 0) {
		switch (opt) {
		case 'V':

@@ -441,6 +444,15 @@ int main(int argc, char **argv)

			libbpf_set_print(print_all_levels);
			verifier_logs = true;
			break;
+		case 'B':
+			base_btf = btf__parse(optarg, NULL);
+			if (libbpf_get_error(base_btf)) {
+				p_err("failed to parse base BTF at '%s': %ld\n",
+				      optarg, libbpf_get_error(base_btf));
+				base_btf = NULL;
+				return -1;
+			}
+			break;
		default:
			p_err("unrecognized option '%s'", argv[optind - 1]);
			if (json_output)

@@ -465,6 +477,7 @@ int main(int argc, char **argv)

		delete_pinned_obj_table(&map_table);
		delete_pinned_obj_table(&link_table);
	}
+	btf__free(base_btf);

	return ret;
}

diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index c46e52137b87..76e91641262b 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h

@@ -90,6 +90,7 @@ extern bool show_pids;

extern bool block_mount;
extern bool verifier_logs;
extern bool relaxed_maps;
+extern struct btf *base_btf;
extern struct pinned_obj_table prog_table;
extern struct pinned_obj_table map_table;
extern struct pinned_obj_table link_table;
-- 
2.24.1