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

/*
   Copyright (C) 2000-2015 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 Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#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 void *__addr __asm__("2") = addr;

    __asm__ ("svc  %b1\n\t"		/* call sys_brk */
	     : "=d" (__addr)
	     : "I" (SYS_ify(brk)), "r" (__addr)
	     : "cc", "memory" );
    newbrk = __addr;
  }
  __curbrk = newbrk;

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

  return 0;
}
weak_alias (__brk, brk)