libbpf: Improve error logging for mismatched BTF kind cases

Instead of printing out integer value of BTF kind, print out a string
representation of a kind.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200818223921.2911963-2-andriin@fb.com

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 775fa63..94d9276 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1886,6 +1886,29 @@ resolve_func_ptr(const struct btf *btf, __u32 id, __u32 *res_id)
        return btf_is_func_proto(t) ? t : NULL;
 }
 
+static const char *btf_kind_str(const struct btf_type *t)
+{
+       switch (btf_kind(t)) {
+       case BTF_KIND_UNKN: return "void";
+       case BTF_KIND_INT: return "int";
+       case BTF_KIND_PTR: return "ptr";
+       case BTF_KIND_ARRAY: return "array";
+       case BTF_KIND_STRUCT: return "struct";
+       case BTF_KIND_UNION: return "union";
+       case BTF_KIND_ENUM: return "enum";
+       case BTF_KIND_FWD: return "fwd";
+       case BTF_KIND_TYPEDEF: return "typedef";
+       case BTF_KIND_VOLATILE: return "volatile";
+       case BTF_KIND_CONST: return "const";
+       case BTF_KIND_RESTRICT: return "restrict";
+       case BTF_KIND_FUNC: return "func";
+       case BTF_KIND_FUNC_PROTO: return "func_proto";
+       case BTF_KIND_VAR: return "var";
+       case BTF_KIND_DATASEC: return "datasec";
+       default: return "unknown";
+       }
+}
+
 /*
  * Fetch integer attribute of BTF map definition. Such attributes are
  * represented using a pointer to an array, in which dimensionality of array
@@ -1902,8 +1925,8 @@ static bool get_map_field_int(const char *map_name, const struct btf *btf,
        const struct btf_type *arr_t;
 
        if (!btf_is_ptr(t)) {
-               pr_warn("map '%s': attr '%s': expected PTR, got %u.\n",
-                       map_name, name, btf_kind(t));
+               pr_warn("map '%s': attr '%s': expected PTR, got %s.\n",
+                       map_name, name, btf_kind_str(t));
                return false;
        }
 
@@ -1914,8 +1937,8 @@ static bool get_map_field_int(const char *map_name, const struct btf *btf,
                return false;
        }
        if (!btf_is_array(arr_t)) {
-               pr_warn("map '%s': attr '%s': expected ARRAY, got %u.\n",
-                       map_name, name, btf_kind(arr_t));
+               pr_warn("map '%s': attr '%s': expected ARRAY, got %s.\n",
+                       map_name, name, btf_kind_str(arr_t));
                return false;
        }
        arr_info = btf_array(arr_t);
@@ -2009,8 +2032,8 @@ static int parse_btf_map_def(struct bpf_object *obj,
                                return -EINVAL;
                        }
                        if (!btf_is_ptr(t)) {
-                               pr_warn("map '%s': key spec is not PTR: %u.\n",
-                                       map->name, btf_kind(t));
+                               pr_warn("map '%s': key spec is not PTR: %s.\n",
+                                       map->name, btf_kind_str(t));
                                return -EINVAL;
                        }
                        sz = btf__resolve_size(obj->btf, t->type);
@@ -2051,8 +2074,8 @@ static int parse_btf_map_def(struct bpf_object *obj,
                                return -EINVAL;
                        }
                        if (!btf_is_ptr(t)) {
-                               pr_warn("map '%s': value spec is not PTR: %u.\n",
-                                       map->name, btf_kind(t));
+                               pr_warn("map '%s': value spec is not PTR: %s.\n",
+                                       map->name, btf_kind_str(t));
                                return -EINVAL;
                        }
                        sz = btf__resolve_size(obj->btf, t->type);
@@ -2109,14 +2132,14 @@ static int parse_btf_map_def(struct bpf_object *obj,
                        t = skip_mods_and_typedefs(obj->btf, btf_array(t)->type,
                                                   NULL);
                        if (!btf_is_ptr(t)) {
-                               pr_warn("map '%s': map-in-map inner def is of unexpected kind %u.\n",
-                                       map->name, btf_kind(t));
+                               pr_warn("map '%s': map-in-map inner def is of unexpected kind %s.\n",
+                                       map->name, btf_kind_str(t));
                                return -EINVAL;
                        }
                        t = skip_mods_and_typedefs(obj->btf, t->type, NULL);
                        if (!btf_is_struct(t)) {
-                               pr_warn("map '%s': map-in-map inner def is of unexpected kind %u.\n",
-                                       map->name, btf_kind(t));
+                               pr_warn("map '%s': map-in-map inner def is of unexpected kind %s.\n",
+                                       map->name, btf_kind_str(t));
                                return -EINVAL;
                        }
 
@@ -2207,8 +2230,8 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj,
                return -EINVAL;
        }
        if (!btf_is_var(var)) {
-               pr_warn("map '%s': unexpected var kind %u.\n",
-                       map_name, btf_kind(var));
+               pr_warn("map '%s': unexpected var kind %s.\n",
+                       map_name, btf_kind_str(var));
                return -EINVAL;
        }
        if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED &&
@@ -2220,8 +2243,8 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj,
 
        def = skip_mods_and_typedefs(obj->btf, var->type, NULL);
        if (!btf_is_struct(def)) {
-               pr_warn("map '%s': unexpected def kind %u.\n",
-                       map_name, btf_kind(var));
+               pr_warn("map '%s': unexpected def kind %s.\n",
+                       map_name, btf_kind_str(var));
                return -EINVAL;
        }
        if (def->size > vi->size) {
@@ -4212,8 +4235,8 @@ static int bpf_core_spec_parse(const struct btf *btf,
                                return sz;
                        spec->bit_offset += access_idx * sz * 8;
                } else {
-                       pr_warn("relo for [%u] %s (at idx %d) captures type [%d] of unexpected kind %d\n",
-                               type_id, spec_str, i, id, btf_kind(t));
+                       pr_warn("relo for [%u] %s (at idx %d) captures type [%d] of unexpected kind %s\n",
+                               type_id, spec_str, i, id, btf_kind_str(t));
                        return -EINVAL;
                }
        }