libbpf: Enforce 64-bitness of BTF for BPF object files

BPF object files are always targeting 64-bit BPF target architecture, so
enforce that at BTF level as well.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200813204945.1020225-7-andriin@fb.com

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 6accdda..5d20b2d 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2434,6 +2434,8 @@ static int bpf_object__init_btf(struct bpf_object *obj,
                                BTF_ELF_SEC, err);
                        goto out;
                }
+               /* enforce 8-byte pointers for BPF-targeted BTFs */
+               btf__set_pointer_size(obj->btf, 8);
                err = 0;
        }
        if (btf_ext_data) {
@@ -2542,6 +2544,8 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
                if (IS_ERR(kern_btf))
                        return PTR_ERR(kern_btf);
 
+               /* enforce 8-byte pointers for BPF-targeted BTFs */
+               btf__set_pointer_size(obj->btf, 8);
                bpf_object__sanitize_btf(obj, kern_btf);
        }