__CONCAT
__CONCAT(exec_,__elfN(imgact))(struct image_params *imgp)
#define __CONCAT(x,y) __CONCAT1(x,y)
#define __CONCAT(x,y) x/**/y
#define __ElfType(x) typedef __ElfN(x) __CONCAT(Elf_,x)
#define __CONCAT(x,y) x ## y