[PATCH bpf-next v14 07/14] bpf: lookup struct_ops types from a given module BTF.

[thinker.li@xxxxxxxxx]

From: Kui-Feng Lee <thinker.li@xxxxxxxxx>

This is a preparation for searching for struct_ops types from a specified
module. BTF is always btf_vmlinux now. This patch passes a pointer of BTF
to bpf_struct_ops_find_value() and bpf_struct_ops_find(). Once the new
registration API of struct_ops types is used, other BTFs besides
btf_vmlinux can also be passed to them.

Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx>
---
 include/linux/bpf.h         |  4 ++--
 kernel/bpf/bpf_struct_ops.c | 11 ++++++-----
 kernel/bpf/verifier.c       |  2 +-
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 469d26d27e64..0163b46910b1 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1698,7 +1698,7 @@ struct bpf_struct_ops_desc {
 
 #if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL)
 #define BPF_MODULE_OWNER ((void *)((0xeB9FUL << 2) + POISON_POINTER_DELTA))
-const struct bpf_struct_ops_desc *bpf_struct_ops_find(u32 type_id);
+const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id);
 void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log);
 bool bpf_struct_ops_get(const void *kdata);
 void bpf_struct_ops_put(const void *kdata);
@@ -1742,7 +1742,7 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
 #endif
 void bpf_map_struct_ops_info_fill(struct bpf_map_info *info, struct bpf_map *map);
 #else
-static inline const struct bpf_struct_ops_desc *bpf_struct_ops_find(u32 type_id)
+static inline const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id)
 {
 	return NULL;
 }
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index 679bcdf763ef..bda31cc3bab0 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -221,11 +221,11 @@ void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
 extern struct btf *btf_vmlinux;
 
 static const struct bpf_struct_ops_desc *
-bpf_struct_ops_find_value(u32 value_id)
+bpf_struct_ops_find_value(struct btf *btf, u32 value_id)
 {
 	unsigned int i;
 
-	if (!value_id || !btf_vmlinux)
+	if (!value_id || !btf)
 		return NULL;
 
 	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
@@ -236,11 +236,12 @@ bpf_struct_ops_find_value(u32 value_id)
 	return NULL;
 }
 
-const struct bpf_struct_ops_desc *bpf_struct_ops_find(u32 type_id)
+const struct bpf_struct_ops_desc *
+bpf_struct_ops_find(struct btf *btf, u32 type_id)
 {
 	unsigned int i;
 
-	if (!type_id || !btf_vmlinux)
+	if (!type_id || !btf)
 		return NULL;
 
 	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
@@ -682,7 +683,7 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
 	struct bpf_map *map;
 	int ret;
 
-	st_ops_desc = bpf_struct_ops_find_value(attr->btf_vmlinux_value_type_id);
+	st_ops_desc = bpf_struct_ops_find_value(btf_vmlinux, attr->btf_vmlinux_value_type_id);
 	if (!st_ops_desc)
 		return ERR_PTR(-ENOTSUPP);
 
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index bd52d7b318a5..52c530b5733c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -20094,7 +20094,7 @@ static int check_struct_ops_btf_id(struct bpf_verifier_env *env)
 	}
 
 	btf_id = prog->aux->attach_btf_id;
-	st_ops_desc = bpf_struct_ops_find(btf_id);
+	st_ops_desc = bpf_struct_ops_find(btf_vmlinux, btf_id);
 	if (!st_ops_desc) {
 		verbose(env, "attach_btf_id %u is not a supported struct\n",
 			btf_id);
-- 
2.34.1