On Thu, Feb 08, 2024 at 06:37:49PM -0800, thinker.li@xxxxxxxxx wrote:
SNIP
> enum bpf_struct_ops_state {
> @@ -1790,6 +1806,7 @@ int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc,
> struct btf *btf,
> struct bpf_verifier_log *log);
> void bpf_map_struct_ops_info_fill(struct bpf_map_info *info, struct bpf_map *map);
> +void bpf_struct_ops_desc_release(struct bpf_struct_ops_desc *st_ops_desc);
> #else
> #define register_bpf_struct_ops(st_ops, type) ({ (void *)(st_ops); 0; })
> static inline bool bpf_try_module_get(const void *data, struct module *owner)
> @@ -1814,6 +1831,10 @@ static inline void bpf_map_struct_ops_info_fill(struct bpf_map_info *info, struc
> {
> }
>
> +static inline void bpf_struct_ops_desc_release(struct bpf_struct_ops_desc *st_ops_desc, int len)
> +{
> +}
extra len argument?
jirka
SNIP
> +/* Clean up the arg_info in a struct bpf_struct_ops_desc. */
> +void bpf_struct_ops_desc_release(struct bpf_struct_ops_desc *st_ops_desc)
> +{
> + struct bpf_struct_ops_arg_info *arg_info;
> + int i;
> +
> + arg_info = st_ops_desc->arg_info;
> + if (!arg_info)
> + return;
> +
> + for (i = 0; i < btf_type_vlen(st_ops_desc->type); i++)
> + kfree(arg_info[i].info);
> +
> + kfree(arg_info);
> +}
> +
> int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc,
> struct btf *btf,
> struct bpf_verifier_log *log)
> {
> struct bpf_struct_ops *st_ops = st_ops_desc->st_ops;
> + struct bpf_struct_ops_arg_info *arg_info;
> const struct btf_member *member;
> const struct btf_type *t;
> s32 type_id, value_id;
> char value_name[128];
> const char *mname;
> - int i;
> + int i, err;
>
> if (strlen(st_ops->name) + VALUE_PREFIX_LEN >=
> sizeof(value_name)) {
> @@ -160,6 +320,17 @@ int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc,
> if (!is_valid_value_type(btf, value_id, t, value_name))
> return -EINVAL;
>
> + arg_info = kcalloc(btf_type_vlen(t), sizeof(*arg_info),
> + GFP_KERNEL);
> + if (!arg_info)
> + return -ENOMEM;
> +
> + st_ops_desc->arg_info = arg_info;
> + st_ops_desc->type = t;
> + st_ops_desc->type_id = type_id;
> + st_ops_desc->value_id = value_id;
> + st_ops_desc->value_type = btf_type_by_id(btf, value_id);
> +
> for_each_member(i, t, member) {
> const struct btf_type *func_proto;
>
> @@ -167,40 +338,52 @@ int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc,
> if (!*mname) {
> pr_warn("anon member in struct %s is not supported\n",
> st_ops->name);
> - return -EOPNOTSUPP;
> + err = -EOPNOTSUPP;
> + goto errout;
> }
>
> if (__btf_member_bitfield_size(t, member)) {
> pr_warn("bit field member %s in struct %s is not supported\n",
> mname, st_ops->name);
> - return -EOPNOTSUPP;
> + err = -EOPNOTSUPP;
> + goto errout;
> }
>
> func_proto = btf_type_resolve_func_ptr(btf,
> member->type,
> NULL);
> - if (func_proto &&
> - btf_distill_func_proto(log, btf,
> + if (!func_proto)
> + continue;
> +
> + if (btf_distill_func_proto(log, btf,
> func_proto, mname,
> &st_ops->func_models[i])) {
> pr_warn("Error in parsing func ptr %s in struct %s\n",
> mname, st_ops->name);
> - return -EINVAL;
> + err = -EINVAL;
> + goto errout;
> }
> +
> + err = prepare_arg_info(btf, st_ops->name, mname,
> + func_proto,
> + arg_info + i);
> + if (err)
> + goto errout;
> }
>
> if (st_ops->init(btf)) {
> pr_warn("Error in init bpf_struct_ops %s\n",
> st_ops->name);
> - return -EINVAL;
> + err = -EINVAL;
> + goto errout;
> }
>
> - st_ops_desc->type_id = type_id;
> - st_ops_desc->type = t;
> - st_ops_desc->value_id = value_id;
> - st_ops_desc->value_type = btf_type_by_id(btf, value_id);
> -
> return 0;
> +
> +errout:
> + bpf_struct_ops_desc_release(st_ops_desc);
> +
> + return err;
> }
>
> static int bpf_struct_ops_map_get_next_key(struct bpf_map *map, void *key,
> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> index db53bb76387e..533f02b92c94 100644
> --- a/kernel/bpf/btf.c
> +++ b/kernel/bpf/btf.c
> @@ -1699,6 +1699,13 @@ static void btf_free_struct_meta_tab(struct btf *btf)
> static void btf_free_struct_ops_tab(struct btf *btf)
> {
> struct btf_struct_ops_tab *tab = btf->struct_ops_tab;
> + int i;
> +
> + if (!tab)
> + return;
> +
> + for (i = 0; i < tab->cnt; i++)
> + bpf_struct_ops_desc_release(&tab->ops[i]);
>
> kfree(tab);
> btf->struct_ops_tab = NULL;
> @@ -6130,6 +6137,26 @@ static bool prog_args_trusted(const struct bpf_prog *prog)
> }
> }
>
> +int btf_ctx_arg_offset(struct btf *btf, const struct btf_type *func_proto,
> + u32 arg_no)
> +{
> + const struct btf_param *args;
> + const struct btf_type *t;
> + int off = 0, i;
> + u32 sz;
> +
> + args = btf_params(func_proto);
> + for (i = 0; i < arg_no; i++) {
> + t = btf_type_by_id(btf, args[i].type);
> + t = btf_resolve_size(btf, t, &sz);
> + if (IS_ERR(t))
> + return PTR_ERR(t);
> + off += roundup(sz, 8);
> + }
> +
> + return off;
> +}
> +
> bool btf_ctx_access(int off, int size, enum bpf_access_type type,
> const struct bpf_prog *prog,
> struct bpf_insn_access_aux *info)
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index c92d6af7d975..72ca27f49616 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -20419,6 +20419,12 @@ static int check_struct_ops_btf_id(struct bpf_verifier_env *env)
> }
> }
>
> + /* btf_ctx_access() used this to provide argument type info */
> + prog->aux->ctx_arg_info =
> + st_ops_desc->arg_info[member_idx].info;
> + prog->aux->ctx_arg_info_size =
> + st_ops_desc->arg_info[member_idx].cnt;
> +
> prog->aux->attach_func_proto = func_proto;
> prog->aux->attach_func_name = mname;
> env->ops = st_ops->verifier_ops;
> --
> 2.34.1
>
>
