sysdeps/unix/i386/sysdep.S

   1 /* Copyright (C) 1991-1997,2000,2002,2004,2005,2011,2012
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdep.h>
  20 #define _ERRNO_H
  21 #include <bits/errno.h>
  22 #include <bp-asm.h>
  23 #include <bp-sym.h>
  24
  25 #ifdef IS_IN_rtld
  26 # include <dl-sysdep.h>         /* Defines RTLD_PRIVATE_ERRNO.  */
  27 #endif
  28
  29 .globl C_SYMBOL_NAME(errno)
  30 .globl syscall_error
  31
  32 __syscall_error:
  33 #if defined (EWOULDBLOCK_sys) && EWOULDBLOCK_sys != EAGAIN
  34         /* We translate the system's EWOULDBLOCK error into EAGAIN.
  35            The GNU C library always defines EWOULDBLOCK==EAGAIN.
  36            EWOULDBLOCK_sys is the original number.  */
  37         cmpl $EWOULDBLOCK_sys, %eax /* Is it the old EWOULDBLOCK?  */
  38         jne notb                /* Branch if not.  */
  39         movl $EAGAIN, %eax      /* Yes; translate it to EAGAIN.  */
  40 notb:
  41 #endif
  42 #ifndef PIC
  43 # ifndef NO_TLS_DIRECT_SEG_REFS
  44         movl %eax, %gs:C_SYMBOL_NAME(errno@NTPOFF)
  45 # else
  46         movl %gs:0, %ecx
  47         movl %eax, C_SYMBOL_NAME(errno@NTPOFF)(%ecx)
  48 # endif
  49 #else
  50         /* The caller has pushed %ebx and then set it up to
  51            point to the GOT before calling us through the PLT.  */
  52         movl C_SYMBOL_NAME(errno@GOTNTPOFF)(%ebx), %ecx
  53
  54         /* Pop %ebx value saved before jumping here.  */
  55         popl %ebx
  56 # ifndef NO_TLS_DIRECT_SEG_REFS
  57         addl %gs:0, %ecx
  58         movl %eax, (%ecx)
  59 # else
  60         movl %eax, %gs:0(%ecx)
  61 # endif
  62 #endif
  63         movl $-1, %eax
  64         ret
  65
  66 #undef  __syscall_error
  67 END (__syscall_error)