On 9/25/23 14:10, Martin KaFai Lau wrote:
On 9/20/23 8:59 AM, thinker.li@xxxxxxxxx wrote:
From: Kui-Feng Lee <thinker.li@xxxxxxxxx>
struct_ops_tab will be used to restore registered struct_ops.
Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx>
---
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.
Got it!
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.
Sure
+{
+ 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]).
Got it!
+ 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;
+}
