original_kernel/include/asm-x86/a.out.h

#ifndef _ASM_X86_A_OUT_H
#define _ASM_X86_A_OUT_H

struct exec
{
	unsigned int a_info;	/* Use macros N_MAGIC, etc for access */
	unsigned a_text;	/* length of text, in bytes */
	unsigned a_data;	/* length of data, in bytes */
	unsigned a_bss;		/* length of uninitialized data area for file, in bytes */
	unsigned a_syms;	/* length of symbol table data in file, in bytes */
	unsigned a_entry;	/* start address */
	unsigned a_trsize;	/* length of relocation info for text, in bytes */
	unsigned a_drsize;	/* length of relocation info for data, in bytes */
};

#define N_TRSIZE(a)	((a).a_trsize)
#define N_DRSIZE(a)	((a).a_drsize)
#define N_SYMSIZE(a)	((a).a_syms)

#ifdef __KERNEL__
# include <linux/thread_info.h>
# define STACK_TOP	TASK_SIZE
# ifdef CONFIG_X86_32
#  define STACK_TOP_MAX	STACK_TOP
# else
#  define STACK_TOP_MAX	TASK_SIZE64
# endif
#endif

#endif /* _ASM_X86_A_OUT_H */