From: Hou Tao <houtao1@xxxxxxxxxx>
When there is bpf_dynptr field in the map key btf type or the map key
btf type is bpf_dyntr, set BPF_INT_F_DYNPTR_IN_KEY in map_flags.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
kernel/bpf/syscall.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 07c67ad1a6a07..46b96d062d2db 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1360,6 +1360,34 @@ static struct btf *get_map_btf(int btf_fd)
return btf;
}
+static int map_has_dynptr_in_key_type(struct btf *btf, u32 btf_key_id, u32 key_size)
+{
+ const struct btf_type *type;
+ struct btf_record *record;
+ u32 btf_key_size;
+
+ if (!btf_key_id)
+ return 0;
+
+ type = btf_type_id_size(btf, &btf_key_id, &btf_key_size);
+ if (!type || btf_key_size != key_size)
+ return -EINVAL;
+
+ /* For dynptr key, key BTF type must be struct */
+ if (!__btf_type_is_struct(type))
+ return 0;
+
+ if (btf_type_is_dynptr(btf, type))
+ return 1;
+
+ record = btf_parse_fields(btf, type, BPF_DYNPTR, key_size);
+ if (IS_ERR(record))
+ return PTR_ERR(record);
+
+ btf_record_free(record);
+ return !!record;
+}
+
#define BPF_MAP_CREATE_LAST_FIELD map_token_fd
/* called via syscall */
static int map_create(union bpf_attr *attr)
@@ -1398,6 +1426,14 @@ static int map_create(union bpf_attr *attr)
btf = get_map_btf(attr->btf_fd);
if (IS_ERR(btf))
return PTR_ERR(btf);
+
+ err = map_has_dynptr_in_key_type(btf, attr->btf_key_type_id, attr->key_size);
+ if (err < 0)
+ goto put_btf;
+ if (err > 0) {
+ attr->map_flags |= BPF_INT_F_DYNPTR_IN_KEY;
+ err = 0;
+ }
}
if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
--
2.29.2
