iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge branch 'bpftool: improve split BTF support'

Browse Source 
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: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Alexei Starovoitov 2020-12-03 10:17:27 -08:00
commit 0d1e026959
4 changed files with 30 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
tools/bpf/bpftool/btf.c
View File

@ -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 @@ done:
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;

5
tools/lib/bpf/btf.c
View File

@ -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)
{

1
tools/lib/bpf/btf.h
View File

@ -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);

1
tools/lib/bpf/libbpf.map
View File

@ -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;