syscall.s

来自「glibc 库, 不仅可以学习使用库函数,还可以学习函数的具体实现,是提高功力的」· S 代码 · 共 28 行

/* Copyright (C) 1993, 1997, 2005 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <sysdep.h>

ENTRY (syscall)
	popl %ecx		/* Pop return address into %ecx.  */
	popl %eax		/* Pop syscall number into %eax.  */
	pushl %ecx		/* Push back return address.  */
	.byte 0x9a, 0, 0, 0, 0, 7, 0 /* lcall $7, $0 -- gas bug */
	ret
END (syscall)