__DECLARE_FLEX_ARRAY is defined in include/uapi/linux/stddef.h but doesn't seem to be explicitly included from include/uapi/linux/in.h, which breaks BPF selftests builds (once we sync linux/stddef.h into tools/include directory in the next patch). Fix this by explicitly including linux/stddef.h. Given this affects BPF CI and bpf tree, targeting this for bpf tree. Cc: Jakub Kicinski <kuba@xxxxxxxxxx> Cc: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Fixes: 5854a09b4957 ("net/ipv4: Use __DECLARE_FLEX_ARRAY() helper") Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> --- include/uapi/linux/in.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h index f243ce665f74..07a4cb149305 100644 --- a/include/uapi/linux/in.h +++ b/include/uapi/linux/in.h @@ -20,6 +20,7 @@ #define _UAPI_LINUX_IN_H #include <linux/types.h> +#include <linux/stddef.h> #include <linux/libc-compat.h> #include <linux/socket.h> -- 2.30.2