ELF_NGREG 15 arch/x86/include/asm/elf.h #define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t)) ELF_NGREG 16 arch/x86/include/asm/elf.h typedef elf_greg_t elf_gregset_t[ELF_NGREG];