sysdeps/unix/sysv/i386/linux/socket.S

   1 /* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <sysdep.h>
  20
  21 .globl syscall_error
  22
  23 /* The socket-oriented system calls are handled unusally in Linux.
  24    They are all gated through the single `socketcall' system call number.
  25    `socketcall' takes two arguments: the first is the subcode, specifying
  26    which socket function is being called; and the second is a pointer to
  27    the arguments to specific function.
  28
  29    The .S files for the other calls just #define socket and #include this.  */
  30
  31 ENTRY (socket)
  32
  33         /* Save registers.  */
  34         pushl %ebx
  35         pushl %ecx
  36
  37         movl $__NR_socketcall, %eax     /* System call number in %eax.  */
  38
  39         /* Use ## so `socket' is a separate token that might be #define'd.  */
  40         movl $SYS_##socket, %ebx        /* Subcode is first arg to syscall.  */
  41         lea 12(%esp), %ecx              /* Address of args in 2nd arg.  */
  42
  43         /* Do the system call trap.  */
  44         int $0x80
  45
  46         /* Restore registers.  */
  47         popl %ecx
  48         popl %ebx
  49
  50         /* %eax is < 0 if there was an error.  */
  51         testl %eax, %eax
  52         jl syscall_error
  53
  54         /* Successful; return the syscall's value.  */
  55         ret