bpf: btf: Break up btf_type_is_void()

This patch breaks up btf_type_is_void() into
btf_type_is_void() and btf_type_is_fwd().

It also adds btf_type_nosize() to better describe it is
testing a type has nosize info.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index ee4c82667d659019022f42cfc3c4a13cf9fc9124..2a50d87de485bb7681c415e09aa625649bd4849b 100644 (file)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -306,15 +306,22 @@ static bool btf_type_is_modifier(const struct btf_type *t)
 
 static bool btf_type_is_void(const struct btf_type *t)
 {
-       /* void => no type and size info.
-        * Hence, FWD is also treated as void.
-        */
-       return t == &btf_void || BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
+       return t == &btf_void;
+}
+
+static bool btf_type_is_fwd(const struct btf_type *t)
+{
+       return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
+}
+
+static bool btf_type_nosize(const struct btf_type *t)
+{
+       return btf_type_is_void(t) || btf_type_is_fwd(t);
 }
 
-static bool btf_type_is_void_or_null(const struct btf_type *t)
+static bool btf_type_nosize_or_null(const struct btf_type *t)
 {
-       return !t || btf_type_is_void(t);
+       return !t || btf_type_nosize(t);
 }
 
 /* union is only a special case of struct:
@@ -826,7 +833,7 @@ const struct btf_type *btf_type_id_size(const struct btf *btf,
        u32 size = 0;
 
        size_type = btf_type_by_id(btf, size_type_id);
-       if (btf_type_is_void_or_null(size_type))
+       if (btf_type_nosize_or_null(size_type))
                return NULL;
 
        if (btf_type_has_size(size_type)) {
@@ -842,7 +849,7 @@ const struct btf_type *btf_type_id_size(const struct btf *btf,
                size = btf->resolved_sizes[size_type_id];
                size_type_id = btf->resolved_ids[size_type_id];
                size_type = btf_type_by_id(btf, size_type_id);
-               if (btf_type_is_void(size_type))
+               if (btf_type_nosize_or_null(size_type))
                        return NULL;
        }
 
@@ -1164,7 +1171,7 @@ static int btf_modifier_resolve(struct btf_verifier_env *env,
        }
 
        /* "typedef void new_void", "const void"...etc */
-       if (btf_type_is_void(next_type))
+       if (btf_type_is_void(next_type) || btf_type_is_fwd(next_type))
                goto resolved;
 
        if (!env_type_is_resolve_sink(env, next_type) &&
@@ -1178,7 +1185,7 @@ static int btf_modifier_resolve(struct btf_verifier_env *env,
         * pretty print).
         */
        if (!btf_type_id_size(btf, &next_type_id, &next_type_size) &&
-           !btf_type_is_void(btf_type_id_resolve(btf, &next_type_id))) {
+           !btf_type_nosize(btf_type_id_resolve(btf, &next_type_id))) {
                btf_verifier_log_type(env, v->t, "Invalid type_id");
                return -EINVAL;
        }
@@ -1205,7 +1212,7 @@ static int btf_ptr_resolve(struct btf_verifier_env *env,
        }
 
        /* "void *" */
-       if (btf_type_is_void(next_type))
+       if (btf_type_is_void(next_type) || btf_type_is_fwd(next_type))
                goto resolved;
 
        if (!env_type_is_resolve_sink(env, next_type) &&
@@ -1235,7 +1242,7 @@ static int btf_ptr_resolve(struct btf_verifier_env *env,
        }
 
        if (!btf_type_id_size(btf, &next_type_id, &next_type_size) &&
-           !btf_type_is_void(btf_type_id_resolve(btf, &next_type_id))) {
+           !btf_type_nosize(btf_type_id_resolve(btf, &next_type_id))) {
                btf_verifier_log_type(env, v->t, "Invalid type_id");
                return -EINVAL;
        }
@@ -1396,7 +1403,7 @@ static int btf_array_resolve(struct btf_verifier_env *env,
        /* Check array->index_type */
        index_type_id = array->index_type;
        index_type = btf_type_by_id(btf, index_type_id);
-       if (btf_type_is_void_or_null(index_type)) {
+       if (btf_type_nosize_or_null(index_type)) {
                btf_verifier_log_type(env, v->t, "Invalid index");
                return -EINVAL;
        }
@@ -1415,7 +1422,7 @@ static int btf_array_resolve(struct btf_verifier_env *env,
        /* Check array->type */
        elem_type_id = array->type;
        elem_type = btf_type_by_id(btf, elem_type_id);
-       if (btf_type_is_void_or_null(elem_type)) {
+       if (btf_type_nosize_or_null(elem_type)) {
                btf_verifier_log_type(env, v->t,
                                      "Invalid elem");
                return -EINVAL;
@@ -1615,7 +1622,7 @@ static int btf_struct_resolve(struct btf_verifier_env *env,
                const struct btf_type *member_type = btf_type_by_id(env->btf,
                                                                member_type_id);
 
-               if (btf_type_is_void_or_null(member_type)) {
+               if (btf_type_nosize_or_null(member_type)) {
                        btf_verifier_log_member(env, v->t, member,
                                                "Invalid member");
                        return -EINVAL;