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

/*
   Copyright (C) 2000 Free Software Foundation, Inc.
   Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <errno.h>
#include <unistd.h>
#include <sysdep.h>

void *__curbrk = 0;

/* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
   to work around different old braindamage in the old Linux/x86 ELF
   dynamic linker.  Sigh.  */
weak_alias (__curbrk, ___brk_addr)

int
__brk (void *addr)
{
  void *newbrk;

  {
    register long r0 asm ("2");
    register void *__addr asm("2") = addr;

    asm ("svc  %b1\n\t"		/* call sys_brk */
	 : "=d" (r0)
	 : "I" (SYS_ify(brk)), "r" (__addr)
	 : _svc_clobber );
    newbrk = (void *) r0;
  }
  __curbrk = newbrk;

  if (newbrk < addr)
    {
      __set_errno (ENOMEM);
      return -1;
    }

  return 0;
}
weak_alias (__brk, brk)