1#define LINUX_VERSION_CODE 331646
2#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + ((c) > 255 ? 255 : (c)))
3#define LINUX_VERSION_MAJOR 5
4#define LINUX_VERSION_PATCHLEVEL 15
5#define LINUX_VERSION_SUBLEVEL 126
6

source code of include/linux/version.h