sysdeps/unix/sysv/linux/s390/brk.c

   1 /*
   2    Copyright (C) 2000 Free Software Foundation, Inc.
   3    Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <unistd.h>
  23 #include <sysdep.h>
  24
  25 void *__curbrk = 0;
  26
  27 /* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
  28    to work around different old braindamage in the old Linux/x86 ELF
  29    dynamic linker.  Sigh.  */
  30 weak_alias (__curbrk, ___brk_addr)
  31
  32 int
  33 __brk (void *addr)
  34 {
  35   void *newbrk;
  36
  37   {
  38     register void *__addr asm("2") = addr;
  39
  40     asm ("svc  %b1\n\t"         /* call sys_brk */
  41          : "=d" (__addr)
  42          : "I" (SYS_ify(brk)), "r" (__addr)
  43          : "cc", "memory" );
  44     newbrk = __addr;
  45   }
  46   __curbrk = newbrk;
  47
  48   if (newbrk < addr)
  49     {
  50       __set_errno (ENOMEM);
  51       return -1;
  52     }
  53
  54   return 0;
  55 }
  56 weak_alias (__brk, brk)