bpf: btf: Add struct bpf_btf_info

During BPF_OBJ_GET_INFO_BY_FD on a btf_fd, the current bpf_attr's
info.info is directly filled with the BTF binary data.  It is
not extensible.  In this case, we want to add BTF ID.

This patch adds "struct bpf_btf_info" which has the BTF ID as
one of its member.  The BTF binary data itself is exposed through
the "btf" and "btf_size" members.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Martin KaFai Lau 2018-05-04 14:49:52 -07:00 committed by Daniel Borkmann
parent 78958fca7e
commit 62dab84c81
3 changed files with 43 additions and 6 deletions

View file

@ -2021,6 +2021,21 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map,
return 0;
}
static int bpf_btf_get_info_by_fd(struct btf *btf,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
u32 info_len = attr->info.info_len;
int err;
err = check_uarg_tail_zero(uinfo, sizeof(*uinfo), info_len);
if (err)
return err;
return btf_get_info_by_fd(btf, attr, uattr);
}
#define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
@ -2044,7 +2059,7 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
err = bpf_map_get_info_by_fd(f.file->private_data, attr,
uattr);
else if (f.file->f_op == &btf_fops)
err = btf_get_info_by_fd(f.file->private_data, attr, uattr);
err = bpf_btf_get_info_by_fd(f.file->private_data, attr, uattr);
else
err = -EINVAL;