From: Martin KaFai Lau <martin.lau@linux.dev>
To: thinker.li@gmail.com
Cc: sinquersw@gmail.com, kuifeng@meta.com, bpf@vger.kernel.org,
ast@kernel.org, song@kernel.org, kernel-team@meta.com,
andrii@kernel.org
Subject: Re: [RFC bpf-next v3 02/11] bpf: add struct_ops_tab to btf.
Date: Mon, 25 Sep 2023 14:10:12 -0700 [thread overview]
Message-ID: <c77c5a5d-7174-4770-4ffb-ee297a28f025@linux.dev> (raw)
In-Reply-To: <20230920155923.151136-3-thinker.li@gmail.com>
On 9/20/23 8:59 AM, thinker.li@gmail.com wrote:
> From: Kui-Feng Lee <thinker.li@gmail.com>
>
> struct_ops_tab will be used to restore registered struct_ops.
>
> Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
> ---
> include/linux/btf.h | 9 +++++
> kernel/bpf/btf.c | 84 +++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 93 insertions(+)
>
> diff --git a/include/linux/btf.h b/include/linux/btf.h
> index 928113a80a95..5fabe23aedd2 100644
> --- a/include/linux/btf.h
> +++ b/include/linux/btf.h
> @@ -571,4 +571,13 @@ static inline bool btf_type_is_struct_ptr(struct btf *btf, const struct btf_type
> return btf_type_is_struct(t);
> }
>
> +struct bpf_struct_ops;
> +
> +int btf_add_struct_ops_btf(struct bpf_struct_ops *st_ops,
> + struct btf *btf);
> +int btf_add_struct_ops(struct bpf_struct_ops *st_ops,
> + struct module *owner);
> +const struct bpf_struct_ops **
> +btf_get_struct_ops(struct btf *btf, u32 *ret_cnt);
> +
> #endif
> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> index f93e835d90af..3fb9964f8672 100644
> --- a/kernel/bpf/btf.c
> +++ b/kernel/bpf/btf.c
> @@ -241,6 +241,12 @@ struct btf_id_dtor_kfunc_tab {
> struct btf_id_dtor_kfunc dtors[];
> };
>
> +struct btf_struct_ops_tab {
> + u32 cnt;
> + u32 capacity;
> + struct bpf_struct_ops *ops[];
> +};
> +
> struct btf {
> void *data;
> struct btf_type **types;
> @@ -258,6 +264,7 @@ struct btf {
> struct btf_kfunc_set_tab *kfunc_set_tab;
> struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab;
> struct btf_struct_metas *struct_meta_tab;
> + struct btf_struct_ops_tab *struct_ops_tab;
>
> /* split BTF support */
> struct btf *base_btf;
> @@ -1688,11 +1695,20 @@ static void btf_free_struct_meta_tab(struct btf *btf)
> btf->struct_meta_tab = NULL;
> }
>
> +static void btf_free_struct_ops_tab(struct btf *btf)
> +{
> + struct btf_struct_ops_tab *tab = btf->struct_ops_tab;
> +
> + kfree(tab);
> + btf->struct_ops_tab = NULL;
> +}
> +
> static void btf_free(struct btf *btf)
> {
> btf_free_struct_meta_tab(btf);
> btf_free_dtor_kfunc_tab(btf);
> btf_free_kfunc_set_tab(btf);
> + btf_free_struct_ops_tab(btf);
> kvfree(btf->types);
> kvfree(btf->resolved_sizes);
> kvfree(btf->resolved_ids);
> @@ -8601,3 +8617,71 @@ bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log,
>
> return !strncmp(reg_name, arg_name, cmp_len);
> }
> +
> +int btf_add_struct_ops_btf(struct bpf_struct_ops *st_ops, struct btf *btf)
A few nits.
'struct btf *btf' as the first argument, to be consistent with other similar btf
functions.
This new function is not used outside of this file, so at least static. I would
just fold this into btf_add_struct_ops() below which currently is mostly empty
other than a btf_get/put.
> +{
> + struct btf_struct_ops_tab *tab;
> + int i;
> +
> + /* Assume this function is called for a module when the module is
> + * loading.
> + */
> +
> + tab = btf->struct_ops_tab;
> + if (!tab) {
> + tab = kzalloc(sizeof(*tab) +
> + sizeof(struct bpf_struct_ops *) * 4,
> + GFP_KERNEL);
nit. offsetof(struct bpf_struct_ops_tab, ops[4]).
> + if (!tab)
> + return -ENOMEM;
> + tab->capacity = 4;
> + btf->struct_ops_tab = tab;
> + }
> +
> + for (i = 0; i < tab->cnt; i++)
> + if (tab->ops[i] == st_ops)
> + return -EEXIST;
> +
> + if (tab->cnt == tab->capacity) {
> + struct btf_struct_ops_tab *new_tab;
> +
> + new_tab = krealloc(tab, sizeof(*tab) +
> + sizeof(struct bpf_struct_ops *) *
> + tab->capacity * 2, GFP_KERNEL);
> + if (!new_tab)
> + return -ENOMEM;
> + tab = new_tab;
> + tab->capacity *= 2;
> + btf->struct_ops_tab = tab;
> + }
> +
> + btf->struct_ops_tab->ops[btf->struct_ops_tab->cnt++] = st_ops;
> +
> + return 0;
> +}
> +
> +int btf_add_struct_ops(struct bpf_struct_ops *st_ops, struct module *owner)
> +{
> + struct btf *btf = btf_get_module_btf(owner);
> + int ret;
> +
> + if (!btf)
> + return -ENOENT;
> +
> + ret = btf_add_struct_ops_btf(st_ops, btf);
> +
> + btf_put(btf);
> +
> + return ret;
> +}
> +
> +const struct bpf_struct_ops **btf_get_struct_ops(struct btf *btf, u32 *ret_cnt)
> +{
> + if (!btf)
> + return NULL;
> + if (!btf->struct_ops_tab)
> + return NULL;
> +
> + *ret_cnt = btf->struct_ops_tab->cnt;
> + return (const struct bpf_struct_ops **)btf->struct_ops_tab->ops;
> +}
next prev parent reply other threads:[~2023-09-25 21:10 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-20 15:59 [RFC bpf-next v3 00/11] Registrating struct_ops types from modules thinker.li
2023-09-20 15:59 ` [RFC bpf-next v3 01/11] bpf: refactory struct_ops type initialization to a function thinker.li
2023-09-20 15:59 ` [RFC bpf-next v3 02/11] bpf: add struct_ops_tab to btf thinker.li
2023-09-25 21:10 ` Martin KaFai Lau [this message]
2023-09-25 21:45 ` Kui-Feng Lee
2023-09-20 15:59 ` [RFC bpf-next v3 03/11] bpf: add register and unregister functions for struct_ops thinker.li
2023-09-25 23:07 ` Martin KaFai Lau
2023-09-25 23:13 ` Kui-Feng Lee
2023-09-25 23:31 ` Martin KaFai Lau
2023-09-26 0:19 ` Kui-Feng Lee
2023-09-20 15:59 ` [RFC bpf-next v3 04/11] bpf: attach a module BTF to a bpf_struct_ops thinker.li
2023-09-25 22:57 ` Martin KaFai Lau
2023-09-25 23:25 ` Kui-Feng Lee
2023-09-20 15:59 ` [RFC bpf-next v3 05/11] bpf: hold module for bpf_struct_ops_map thinker.li
2023-09-25 23:23 ` Martin KaFai Lau
2023-09-25 23:42 ` Kui-Feng Lee
2023-09-20 15:59 ` [RFC bpf-next v3 06/11] bpf: validate value_type thinker.li
2023-09-26 1:03 ` Martin KaFai Lau
2023-09-27 20:27 ` Kui-Feng Lee
2023-09-20 15:59 ` [RFC bpf-next v3 07/11] bpf, net: switch to storing struct_ops in btf thinker.li
2023-09-26 0:02 ` Martin KaFai Lau
2023-09-26 0:18 ` Kui-Feng Lee
2023-09-20 15:59 ` [RFC bpf-next v3 08/11] bpf: pass attached BTF to find correct type info of struct_ops progs thinker.li
2023-09-25 22:58 ` Andrii Nakryiko
2023-09-25 23:50 ` Kui-Feng Lee
2023-09-26 0:24 ` Martin KaFai Lau
2023-09-26 0:58 ` Kui-Feng Lee
2023-09-20 15:59 ` [RFC bpf-next v3 09/11] libbpf: Find correct module BTFs for struct_ops maps and progs thinker.li
2023-09-25 23:09 ` Andrii Nakryiko
2023-09-26 0:12 ` Kui-Feng Lee
2023-09-20 15:59 ` [RFC bpf-next v3 10/11] bpf: export btf_ctx_access to modules thinker.li
2023-09-20 15:59 ` [RFC bpf-next v3 11/11] selftests/bpf: test case for register_bpf_struct_ops() thinker.li
2023-09-26 1:19 ` Martin KaFai Lau
2023-09-26 1:33 ` [RFC bpf-next v3 00/11] Registrating struct_ops types from modules Martin KaFai Lau
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