sysdeps/unix/sysv/linux/sparc/sparc32/brk.c

   1 /* brk system call for Linux/SPARC.
   2    Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Miguel de Icaza (miguel@nuclecu.unam.mx)
   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 /* This must be initialized data because commons can't have aliases.  */
  26 void *__curbrk = 0;
  27
  28 /* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
  29    to work around different old braindamage in the old Linux ELF dynamic
  30    linker.  */
  31 weak_alias (__curbrk, ___brk_addr)
  32
  33 int
  34 __brk (void *addr)
  35 {
  36   void *newbrk;
  37
  38   {
  39     register void *o0 __asm__("%o0") = addr;
  40     register int g1 __asm__("%g1") = __NR_brk;
  41     __asm ("t 0x10" : "=r"(o0) : "r"(g1), "0"(o0) : "cc");
  42     newbrk = o0;
  43   }
  44
  45   __curbrk = newbrk;
  46
  47   if (newbrk < addr)
  48     {
  49       __set_errno (ENOMEM);
  50       return -1;
  51     }
  52
  53   return 0;
  54 }
  55 weak_alias (__brk, brk)