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

   1 /* Copyright (C) 1995, 1996 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 /* Because the Linux version is in fact i386/ELF and the start.? file
  22    for this system (sysdeps/i386/elf/start.S) is also used by The Hurd
  23    and therefore this files must not contain the definition of the
  24    `errno' variable (I don't know why, ask Roland), we have to define
  25    it somewhere else.
  26
  27    ...and this place is here.  */
  28         .bss
  29         .globl errno
  30         .type errno,@object
  31         .size errno,4
  32 errno:  .zero 4
  33         .globl _errno
  34         .type _errno,@object
  35 _errno = errno  /* This name is expected by hj libc.so.5 startup code.  */
  36         .globl __errno
  37         .type __errno,@object
  38 __errno = errno /* This name is expected by the MT code.  */
  39         .text
  40
  41 /* The following code is only used in the shared library when we
  42    compile the reentrant version.  Otherwise each system call defines
  43    each own version.  */
  44
  45 #ifndef PIC
  46
  47 /* The syscall stubs jump here when they detect an error.
  48    The code for Linux is almost identical to the canonical Unix/i386
  49    code, except that the error number in %eax is negated.  */
  50
  51 ENTRY (__syscall_error)
  52         negl %eax
  53
  54 #define __syscall_error __syscall_error_1
  55 #include <sysdeps/unix/i386/sysdep.S>
  56
  57 #endif  /* !PIC */
  58
  59
  60 ENTRY (__errno_location)
  61 #ifdef PIC
  62         call .L2
  63 .L2:    popl %ecx
  64         addl $_GLOBAL_OFFSET_TABLE_+[.-.L2], %ecx
  65         movl errno@GOT(%ecx), %eax
  66 #else
  67         movl $errno, %eax
  68 #endif
  69         ret
  70 .Lfe1:
  71         .size   __errno_location, .Lfe1-__errno_location