Commit 0d1e0269 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'bpftool: improve split BTF support' 



Andrii Nakryiko says:

====================

Few follow up improvements to bpftool for split BTF support:
  - emit "name <anon>" for non-named BTFs in `bpftool btf show` command;
  - when dumping /sys/kernel/btf/<module> use /sys/kernel/btf/vmlinux as the
    base BTF, unless base BTF is explicitly specified with -B flag.

This patch set also adds btf__base_btf() getter to access base BTF of the
struct btf.
====================

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents 97306be4 fa452837

tools/bpf/bpftool/btf.c

+23 −4
Original line number Diff line number Diff line
@@ -357,11 +357,13 @@ static int dump_btf_raw(const struct btf *btf, 
			dump_btf_type(btf, root_type_ids[i], t);

		}

	} else {

		const struct btf *base;

		int cnt = btf__get_nr_types(btf);

		int start_id = 1;



		if (base_btf)

			start_id = btf__get_nr_types(base_btf) + 1;

		base = btf__base_btf(btf);

		if (base)

			start_id = btf__get_nr_types(base) + 1;



		for (i = start_id; i <= cnt; i++) {

			t = btf__type_by_id(btf, i);
@@ -428,7 +430,7 @@ static int dump_btf_c(const struct btf *btf, 


static int do_dump(int argc, char **argv)

{

	struct btf *btf = NULL;

	struct btf *btf = NULL, *base = NULL;

	__u32 root_type_ids[2];

	int root_type_cnt = 0;

	bool dump_c = false;
@@ -502,7 +504,21 @@ static int do_dump(int argc, char **argv) 
		}

		NEXT_ARG();

	} else if (is_prefix(src, "file")) {

		btf = btf__parse_split(*argv, base_btf);

		const char sysfs_prefix[] = "/sys/kernel/btf/";

		const char sysfs_vmlinux[] = "/sys/kernel/btf/vmlinux";



		if (!base_btf &&

		    strncmp(*argv, sysfs_prefix, sizeof(sysfs_prefix) - 1) == 0 &&

		    strcmp(*argv, sysfs_vmlinux) != 0) {

			base = btf__parse(sysfs_vmlinux, NULL);

			if (libbpf_get_error(base)) {

				p_err("failed to parse vmlinux BTF at '%s': %ld\n",

				      sysfs_vmlinux, libbpf_get_error(base));

				base = NULL;

			}

		}



		btf = btf__parse_split(*argv, base ?: base_btf);

		if (IS_ERR(btf)) {

			err = -PTR_ERR(btf);

			btf = NULL;
@@ -567,6 +583,7 @@ static int do_dump(int argc, char **argv) 
done:

	close(fd);

	btf__free(btf);

	btf__free(base);

	return err;

}
@@ -750,6 +767,8 @@ show_btf_plain(struct bpf_btf_info *info, int fd, 
		printf("name [%s]  ", name);

	else if (name && name[0])

		printf("name %s  ", name);

	else

		printf("name <anon>  ");

	printf("size %uB", info->btf_size);



	n = 0;

tools/lib/bpf/btf.c

+5 −0
Original line number Diff line number Diff line
@@ -432,6 +432,11 @@ __u32 btf__get_nr_types(const struct btf *btf) 
	return btf->start_id + btf->nr_types - 1;

}



const struct btf *btf__base_btf(const struct btf *btf)

{

	return btf->base_btf;

}



/* internal helper returning non-const pointer to a type */

static struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id)

{

tools/lib/bpf/btf.h

+1 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, 
LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,

					const char *type_name, __u32 kind);

LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);

LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf);

LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,

						  __u32 id);

LIBBPF_API size_t btf__pointer_size(const struct btf *btf);

tools/lib/bpf/libbpf.map

+1 −0
Original line number Diff line number Diff line
@@ -340,6 +340,7 @@ LIBBPF_0.2.0 { 


LIBBPF_0.3.0 {

	global:

		btf__base_btf;

		btf__parse_elf_split;

		btf__parse_raw_split;

		btf__parse_split;