From: Kui-Feng Lee <sinquersw@gmail.com>
To: Jiri Olsa <olsajiri@gmail.com>, thinker.li@gmail.com
Cc: bpf@vger.kernel.org, ast@kernel.org, martin.lau@linux.dev,
song@kernel.org, kernel-team@meta.com, andrii@kernel.org,
davemarchevsky@meta.com, dvernet@meta.com, kuifeng@meta.com
Subject: Re: [PATCH bpf-next v8 3/4] bpf: Create argument information for nullable arguments.
Date: Mon, 12 Feb 2024 09:50:21 -0800 [thread overview]
Message-ID: <ecded04a-6917-49ee-ae83-e1bfa43bd725@gmail.com> (raw)
In-Reply-To: <ZcoEzyRzxLUWWhw4@krava>
On 2/12/24 03:45, Jiri Olsa wrote:
> On Thu, Feb 08, 2024 at 06:37:49PM -0800, thinker.li@gmail.com 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?
Yes, this one should be removed.
>
> 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
>>
>>
next prev parent reply other threads:[~2024-02-12 17:50 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-09 2:37 [PATCH bpf-next v8 0/4] Support PTR_MAYBE_NULL for struct_ops arguments thinker.li
2024-02-09 2:37 ` [PATCH bpf-next v8 1/4] bpf: add btf pointer to struct bpf_ctx_arg_aux thinker.li
2024-02-11 18:59 ` Martin KaFai Lau
2024-02-09 2:37 ` [PATCH bpf-next v8 2/4] bpf: Move __kfunc_param_match_suffix() to btf.c thinker.li
2024-02-09 2:37 ` [PATCH bpf-next v8 3/4] bpf: Create argument information for nullable arguments thinker.li
2024-02-11 19:49 ` Martin KaFai Lau
2024-02-12 17:09 ` Kui-Feng Lee
2024-02-12 11:45 ` Jiri Olsa
2024-02-12 17:50 ` Kui-Feng Lee [this message]
2024-02-13 23:27 ` Martin KaFai Lau
2024-02-09 2:37 ` [PATCH bpf-next v8 4/4] selftests/bpf: Test PTR_MAYBE_NULL arguments of struct_ops operators thinker.li
2024-02-13 23:30 ` [PATCH bpf-next v8 0/4] Support PTR_MAYBE_NULL for struct_ops arguments patchwork-bot+netdevbpf
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