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From: thinker.li@gmail.com
To: bpf@vger.kernel.org, ast@kernel.org, martin.lau@linux.dev,
	song@kernel.org, kernel-team@meta.com, andrii@kernel.org
Cc: sinquersw@gmail.com, kuifeng@meta.com,
	Kui-Feng Lee <thinker.li@gmail.com>
Subject: [RFC bpf-next v3 02/11] bpf: add struct_ops_tab to btf.
Date: Wed, 20 Sep 2023 08:59:14 -0700	[thread overview]
Message-ID: <20230920155923.151136-3-thinker.li@gmail.com> (raw)
In-Reply-To: <20230920155923.151136-1-thinker.li@gmail.com>

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)
+{
+	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);
+		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;
+}
-- 
2.34.1


  parent reply	other threads:[~2023-09-20 16:00 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 ` thinker.li [this message]
2023-09-25 21:10   ` [RFC bpf-next v3 02/11] bpf: add struct_ops_tab to btf Martin KaFai Lau
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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