Commit f614f2c7 authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
Browse files

tools: Allow specifying base BTF file in resolve_btfids 



This commit allows specifying the base BTF for resolving btf id
lists/sets during link time in the resolve_btfids tool. The base BTF is
set to NULL if no path is passed. This allows resolving BTF ids for
module kernel objects.

Also, drop the --no-fail option, as it is only used in case .BTF_ids
section is not present, instead make no-fail the default mode. The long
option name is same as that of pahole.

Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-5-memxor@gmail.com
parent 14f267d9

tools/bpf/resolve_btfids/main.c

+19 −9
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ struct btf_id { 
struct object {

	const char *path;

	const char *btf;

	const char *base_btf_path;



	struct {

		int		 fd;
@@ -477,16 +478,27 @@ static int symbols_resolve(struct object *obj) 
	int nr_structs  = obj->nr_structs;

	int nr_unions   = obj->nr_unions;

	int nr_funcs    = obj->nr_funcs;

	struct btf *base_btf = NULL;

	int err, type_id;

	struct btf *btf;

	__u32 nr_types;



	btf = btf__parse(obj->btf ?: obj->path, NULL);

	if (obj->base_btf_path) {

		base_btf = btf__parse(obj->base_btf_path, NULL);

		err = libbpf_get_error(base_btf);

		if (err) {

			pr_err("FAILED: load base BTF from %s: %s\n",

			       obj->base_btf_path, strerror(-err));

			return -1;

		}

	}



	btf = btf__parse_split(obj->btf ?: obj->path, base_btf);

	err = libbpf_get_error(btf);

	if (err) {

		pr_err("FAILED: load BTF from %s: %s\n",

			obj->btf ?: obj->path, strerror(-err));

		return -1;

		goto out;

	}



	err = -1;
@@ -545,6 +557,7 @@ static int symbols_resolve(struct object *obj) 


	err = 0;

out:

	btf__free(base_btf);

	btf__free(btf);

	return err;

}
@@ -678,7 +691,6 @@ static const char * const resolve_btfids_usage[] = { 


int main(int argc, const char **argv)

{

	bool no_fail = false;

	struct object obj = {

		.efile = {

			.idlist_shndx  = -1,
@@ -695,8 +707,8 @@ int main(int argc, const char **argv) 
			 "be more verbose (show errors, etc)"),

		OPT_STRING(0, "btf", &obj.btf, "BTF data",

			   "BTF data"),

		OPT_BOOLEAN(0, "no-fail", &no_fail,

			   "do not fail if " BTF_IDS_SECTION " section is not found"),

		OPT_STRING('b', "btf_base", &obj.base_btf_path, "file",

			   "path of file providing base BTF"),

		OPT_END()

	};

	int err = -1;
@@ -717,10 +729,8 @@ int main(int argc, const char **argv) 
	 */

	if (obj.efile.idlist_shndx == -1 ||

	    obj.efile.symbols_shndx == -1) {

		if (no_fail)

		pr_debug("Cannot find .BTF_ids or symbols sections, nothing to do\n");

		return 0;

		pr_err("FAILED to find needed sections\n");

		return -1;

	}



	if (symbols_collect(&obj))

tools/testing/selftests/bpf/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -454,7 +454,7 @@ $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS) \ 
			     | $(TRUNNER_BINARY)-extras

	$$(call msg,BINARY,,$$@)

	$(Q)$$(CC) $$(CFLAGS) $$(filter %.a %.o,$$^) $$(LDLIBS) -o $$@

	$(Q)$(RESOLVE_BTFIDS) --no-fail --btf $(TRUNNER_OUTPUT)/btf_data.o $$@

	$(Q)$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.o $$@



endef