diff options
Diffstat (limited to 'tools/lib/bpf/linker.c')
| -rw-r--r-- | tools/lib/bpf/linker.c | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c index 5e0aa2f2c0ca..46b16cbdcda3 100644 --- a/tools/lib/bpf/linker.c +++ b/tools/lib/bpf/linker.c @@ -94,6 +94,7 @@ struct dst_sec { int sec_sym_idx; /* section's DATASEC variable info, emitted on BTF finalization */ + bool has_btf; int sec_var_cnt; struct btf_var_secinfo *sec_vars; @@ -1436,6 +1437,16 @@ static int linker_append_btf(struct bpf_linker *linker, struct src_obj *obj) continue; dst_sec = &linker->secs[src_sec->dst_id]; + /* Mark section as having BTF regardless of the presence of + * variables. In some cases compiler might generate empty BTF + * with no variables information. E.g., when promoting local + * array/structure variable initial values and BPF object + * file otherwise has no read-only static variables in + * .rodata. We need to preserve such empty BTF and just set + * correct section size. + */ + dst_sec->has_btf = true; + t = btf__type_by_id(obj->btf, src_sec->sec_type_id); src_var = btf_var_secinfos(t); n = btf_vlen(t); @@ -1717,7 +1728,7 @@ static int finalize_btf(struct bpf_linker *linker) for (i = 1; i < linker->sec_cnt; i++) { struct dst_sec *sec = &linker->secs[i]; - if (!sec->sec_var_cnt) + if (!sec->has_btf) continue; id = btf__add_datasec(btf, sec->sec_name, sec->sec_sz); @@ -1895,8 +1906,10 @@ static int finalize_btf_ext(struct bpf_linker *linker) struct dst_sec *sec = &linker->secs[i]; sz = emit_btf_ext_data(linker, cur, sec->sec_name, &sec->func_info); - if (sz < 0) - return sz; + if (sz < 0) { + err = sz; + goto out; + } cur += sz; } @@ -1910,8 +1923,10 @@ static int finalize_btf_ext(struct bpf_linker *linker) struct dst_sec *sec = &linker->secs[i]; sz = emit_btf_ext_data(linker, cur, sec->sec_name, &sec->line_info); - if (sz < 0) - return sz; + if (sz < 0) { + err = sz; + goto out; + } cur += sz; } @@ -1925,8 +1940,10 @@ static int finalize_btf_ext(struct bpf_linker *linker) struct dst_sec *sec = &linker->secs[i]; sz = emit_btf_ext_data(linker, cur, sec->sec_name, &sec->core_relo_info); - if (sz < 0) - return sz; + if (sz < 0) { + err = sz; + goto out; + } cur += sz; } @@ -1937,8 +1954,10 @@ static int finalize_btf_ext(struct bpf_linker *linker) if (err) { linker->btf_ext = NULL; pr_warn("failed to parse final .BTF.ext data: %d\n", err); - return err; + goto out; } - return 0; +out: + free(data); + return err; } |