[PATCH bpf-next v2 07/20] bpf: Use map_extra to indicate the max data size of dynptrs in map key

[Hou Tao <houtao@xxxxxxxxxxxxxxx>]

From: Hou Tao <houtao1@xxxxxxxxxx>

For map with dynptr key support, it needs to use map_extra to specify
the maximum data length of these dynptrs. The implementation of the map
will check whether map_extra is smaller than the limitation imposed by
memory allocation during map creation. It may also use map_extra to
optimize the memory allocation for dynptr.

Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
 kernel/bpf/syscall.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 46b96d062d2db..79459b218109e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1438,6 +1438,7 @@ static int map_create(union bpf_attr *attr)
 
 	if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
 	    attr->map_type != BPF_MAP_TYPE_ARENA &&
+	    !(attr->map_flags & BPF_INT_F_DYNPTR_IN_KEY) &&
 	    attr->map_extra != 0) {
 		err = -EINVAL;
 		goto put_btf;
-- 
2.29.2