sysdeps/unix/x86_64/sysdep.S

   1 /* Copyright (C) 2001-2015 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <sysdep.h>
  19 #define _ERRNO_H
  20 #include <bits/errno.h>
  21 #include <tls.h>
  22
  23 #if IS_IN (rtld)
  24 # include <dl-sysdep.h>         /* Defines RTLD_PRIVATE_ERRNO.  */
  25 #endif
  26
  27 .globl C_SYMBOL_NAME(errno)
  28 .globl syscall_error
  29
  30 __syscall_error:
  31 #if defined (EWOULDBLOCK_sys) && EWOULDBLOCK_sys != EAGAIN
  32         /* We translate the system's EWOULDBLOCK error into EAGAIN.
  33            The GNU C library always defines EWOULDBLOCK==EAGAIN.
  34            EWOULDBLOCK_sys is the original number.  */
  35         cmp $EWOULDBLOCK_sys, %RAX_LP /* Is it the old EWOULDBLOCK?  */
  36         jne notb                /* Branch if not.  */
  37         movl $EAGAIN, %eax      /* Yes; translate it to EAGAIN.  */
  38 notb:
  39 #endif
  40 #ifdef PIC
  41         movq C_SYMBOL_NAME(errno@GOTTPOFF)(%rip), %rcx
  42         movl %eax, %fs:0(%rcx)
  43 #else
  44         movl %eax, %fs:C_SYMBOL_NAME(errno@TPOFF)
  45 #endif
  46         or $-1, %RAX_LP
  47         ret
  48
  49 #undef  __syscall_error
  50 END (__syscall_error)